Category: 3. Business

In today’s fast-paced digital economy, every sector increasingly adopting digital transformation to stay competitive and improve operational efficiency [39]. Many countries have rapidly progressed in infrastructures, support mechanisms, and aligning Information and Communication Technologies (ICT) policy with healthcare vision [37, 78]. These technological advantages have sparked the attention of many countries to digitize healthcare and the increasing penetration of mobile devices have influenced their use in medical education and healthcare delivery [56]. Innovative technologies like mobile devices offer methods to enhance healthcare data access in Low and Middle-Income Countries (LMICs). Mobile devices are thought to help hospital staff work more efficiently, leading to better patient care. Since the Covid-19 pandemic, the use of remote and virtual healthcare services like telehealth and remote monitoring has increased significantly. Bring Your Own Device (BYOD) supports this by allowing healthcare providers to move around easily and coordinate patient care more effectively [109].

Bring-your-own-device (BYOD) is generally conceptualized as employees’ use of personal mobile devices to complete work-related tasks [55]. Driven by rapid advances in ICT and a recent increase in consumer ICTs in the workplace, BYOD is considered a form of Information Technology (IT) consumerization [109]. BYOD is already a working fashion, as the use of portable electronic devices has progressively risen in past years. BYOD applies to workers bringing their devices to the office [23].

Furthermore, previous studies find out that the acceptance of BYOD depends on the combination of related variables that must be synchronously taken into account and it depends on the individual qualities that need to be discussed [25, 81, 91]. The importance of variables that affects the acceptance of individuals may not be the same when studied within developed and emerging nations as the beliefs, morals and traditions of these countries are also unique, and this may influence their attitudes towards technology acceptance [1, 6, 8, 13, 17].

Despite the growing adoption of BYOD in healthcare, and extensive research exists on various perspectives of BYOD adoption, there remains a significant gap in research exploring doctors’ perspectives, particularly their willingness to adopt BYOD, the concerns they face, and their firsthand experiences. Most of the studies concentrated on organisational risks such as virus attacks, employees’ improper use of assets and information [114] and growing concerns for organisation information security management [89, 108]. Unauthorised employees’ access to organisation information, download risky mobile applications and stolen; lost device [22] neglect safety issues about possible breaches of sensitive or secret details [108].

While numerous studies have explored BYOD in healthcare, the majority have focused on socio-technical aspects and its impact on clinical and administrative work [109], investigation of the role of BYOD devices in fostering cybersecurity awareness and its correlation with the productivity of healthcare professionals [67] and investigate security risk perception and safeguard adoption of mobile devices among medical practitioners and IT administrators [9]. Also, BYOD challenges and risks while managing and controlling corporate data and networks [12] and BYOD challenges when employees fail to comply with security policies [76]. Despite the acknowledged benefits of BYOD and its initiatives in recent literature, its adoption remains insignificant among doctors of developing countries, including Pakistan [58].

However, they neglect the perspective of the primary user—the doctors—who is expected to voluntarily use their personal devices for professional purposes. Without addressing the willingness of doctors to adopt BYOD, the effort to create a seamless BYOD environment becomes futile, as the success of this model hinges on their active and voluntary participation [22, 108, 110, 116]. This gap highlights the need to investigate doctors’ intention to ensure BYOD implementation aligns with their needs and preferences, ultimately enhancing its effectiveness in clinical practice.

Doctors’ intention to adopt BYOD is critical because they are the ones bringing their own devices into the professional setting [42]. Their concerns, motivations, and preferences are pivotal to the model’s success, yet remain underexplored in the literature. Key questions arise about their privacy concerns when blending personal and professional data on a single device [64, 70]. This lack of clarity on privacy-related apprehensions, especially when the device is owned and controlled by the doctor, creates a significant barrier to understanding their willingness to adopt BYOD [22].

Privacy and security are primary concerns in healthcare communication technologies. These problems emerge as mobile phones handle sensitive data and highly confidential data. The confidentiality vulnerability from practitioners is an issue that needs to be considered so that only permitted people can access sensitive information. However, some studies have investigated information security-related empirical research. The increase of different devices has led to an increased risk of exposure to viruses, malware, and a host of other security issues and the potential leaking of sensitive material and data [14]. The challenge in adopting BYOD is ensuring the safety and security of the doctors’ data and devices. Furthermore, using their own devices may instill greater confidence among doctors compared to using company-provided devices, which often require additional training or adjustment. Doctors may find personal devices more convenient, familiar, and efficient for professional use. Additionally, the cost of the device falls on the doctor, further emphasizing the need to understand their willingness and readiness to embrace BYOD.

The limitations of BYOD adoption are linked to several variables, representing the individual’s characteristics and features of the technology itself. The importance of variables that affect individuals’ acceptance may not be the same when studied within developed and emerging nations, as these countries’ beliefs, morals, and traditions are unique. Pakistan’s doctors represent the primary users of BYOD, and their acceptance of it can significantly influence its adoption. The study manifests a need for empirical evidence to identify and evaluate the determinant factors underlying how doctors in emerging nations might see and intend to adopt BYOD.

By addressing these gaps, this study seeks to contribute to a deeper understanding of doctors’ intentions and motivations, which are crucial for the effective implementation of BYOD in healthcare settings specifically doctors’ intention to accept health technologies to allow effective healthcare administration in Pakistan. Hence, a specific model is required to examine BYOD’s intention among the doctors in Pakistan.

Research model

Venkatesh [101] presented Unified Theory of Acceptance and Use of Technology (UTAUT) in 2003 after reviewing eight models and theories, this model is suitable for defining employees’ technology acceptance and use. UTAUT posits several factors that shape an individual’s inclination to adopt a technology [2]. The model presented three variables: performance expectancy, effort expectancy, and social influence that directly affect behavioural intention. Facilitating conditions and behavioural intention direct affect technology use. Those relationships moderated by age, gender, experience and voluntariness [101], as displayed in Fig. 1.

Nevertheless, in a healthcare context, the UTAUT model does not seem to have a similar effect as in any other settings in order to describe doctors’ attitudes, and the variance described in previous studies seems to be noticeably smaller than the variance defined in the UTAUT model, reflecting a limitation in the healthcare system [1, 15, 19, 52, 103]. These research results supported this study to integrate the UTAUT model with other factors to measure its significance in the Pakistani doctors’ context.

While UTAUT2 provides a comprehensive framework for understanding users’ behavioural intentions and technology usage, it has several limitations [2]. Cognitive perspectives are widely used to explain behavioural patterns and variables that may influence a protective or preventive action. These theories examine cognitive behaviour change and share the presumption that attitudes, beliefs, expectations of future events and outcomes are important factors for health-related behavior [72]. Protection Motivation Theory (PMT) is a social-cognitive model that identifies behavior [69]. PMT was presented by Rogers [84] as a theory for explaining the influence of fear appeals. It is commonly used in the health domain, but it has increasingly gained popularity in the information security domain [16, 99]. PMT examine the motivational reasons for adopting protective measures and breaks them into threat and coping appraisal. In the context of BYOD, the threat appraisal refers to the perceived vulnerability as a possibility of a security incident and the perceived severity as the impact of outcomes resulting from a security incident [27]. The coping appraisal refers to the individual’s evaluation of how well he/she can manage in the given situation. The coping appraisal process consists of response costs and self-efficacy, as shown in Fig. 2.

This research’s proposed hybrid model is presented in Fig. 3. The UTAUT model forms the backbone for the theoretical framework for this study. Additional factors were added to the base model to improve its performance regarding explaining the consumer’s behaviour. Perceived vulnerability and perceived severity represented the threat appraisal and; response cost and self-efficacy represented coping appraisal. In this study, all additional hypotheses have a negative affect on behavioural intention except self-efficacy.

The present study makes slight modifications to the model. In this research, the focus is on behavioural intention. Since the dependent variable is behavioural intention, and the adoption is pre-implementation, there is no sense to measure the use of technology. Age and gender will moderate all relationships of UTAUT due to the novelty of BYOD and the pre-implementation research, experience and voluntariness of use as a moderator had dropped.

Research objectives

The main research objective was to propose a hybrid model of intention to adopt BYOD amongst Pakistani doctors. Therefore, to accomplish the main objective, the following specific objectives were also formed:

• To identify the determinant factors for intention to adopt BYOD among Pakistani doctors

• To identify the moderating effect of age and gender on the intention to adopt BYOD

• To develop the hybrid model of behavioural intention to adopt BYOD among Pakistani doctors

• To validate the proposed model of intention to adopt BYOD through practitioners

Hypothesis development

In this study, the hybrid model was proposed as the theoretical framework. The hypotheses are divided into two categories; main (direct) relationships and moderating relationships. In this study, Intention to Adopt BYOD (IAB) is the dependent variable. Behavioural intention is the strength of a user’s intention to achieve a specific behaviour; it indicated a human’s desire to adopt a technology [30, 101].

Performance Expectancy (PE) is a key predictor of behavioral intention in technology adoption across various fields, including healthcare, education, and commerce. It reflects the perceived benefits of technology in enhancing efficiency and outcomes. Research by [11] and [31] shows that PE significantly influences the adoption of Business Intelligence (BI) systems and blockchain in healthcare, emphasizing improved decision-making and operational efficiency. Studies by [90] further highlight how PE drives Bring Your Own Device (BYOD) and mobile device adoption by promoting mobility and convenience. In education, [50] underline PE’s role in providing resource access and bridging knowledge gaps. Studies have shown that PE significantly influenced behavioural intention to adopt technology in healthcare [3, 32, 81, 105]. In BYOD, PE is defined as how adopting the technology will influence users to perform activities [101, 102]. It shows the practical value for users adopting the technology, identified in different technology acceptance models, such as perceived usefulness in the TAM, extrinsic motivation in the Motivational Model (MM), and relative advantage in the Innovation Diffusion Theory (IDT).

Overall, these studies illustrate PE’s importance in technology adoption, particularly where clear benefits exist, such as faster decision-making and enhanced collaboration. In healthcare, PE encapsulates advantages like real-time patient data access and workflow integration, making it a crucial element of frameworks like the Unified Theory of Acceptance and Use of Technology (UTAUT). PE influences technology adoption by enhancing user acceptance, facilitating collaboration, and empowering staff through the use of preferred devices. Positive experiences with personal devices lead to faster decision-making and better integration into workflows, making users more likely to embrace BYOD policies. In this study, PE is a doctors’ perception of the degree to which the doctors’ believe that using a BYOD will help him/her to attain gains in job performance. When doctors believe that using BYOD can empower them to improve healthcare capabilities, doctors’ are likely to adopt the technology. Thus, PE was measured with five questions that focused on the intention to adopt BYOD. Therefore, the researcher hypothesized that:

Effort Expectancy (EE) is a crucial predictor of behavioral intention in technology adoption, particularly in professional environments, acknowledged as the extent of ease linked to a consumers’ technology utilization [5]. Research by [11] and [31] shows that healthcare professionals are more likely to adopt technologies like Business Intelligence (BI) systems and blockchain when they find them intuitive and easy to use. EE has a significant role in predicting behavioural intention in healthcare settings [32, 60, 86] significance of PEOU is a related factor to EE, as a predictor of behavioural intention, confirmed by other studies [7]. Another study [59] identified that healthcare professionals’ behavioural intention for Electronic Health Record (EHR) system affected perceived ease of use rather than perceived usefulness. Furthermore, studies by [90] indicate that EE is vital in the adoption of BYOD policies and mobile technologies. Users prefer systems that integrate smoothly into their workflows without extensive training. It is also essential to recognize that the significance of EE can vary across different contexts and user demographics. A study by [50] found that, contrary to expectations, EE did not significantly affect medical students’ decisions regarding Wi-Fi adoption. This outcome might be attributed to their prior familiarity with the technology and its functionalities, indicating that users’ existing knowledge can influence their perceptions of new systems.

In the specific context of BYOD adoption within healthcare environments, the relevance of EE becomes even more pronounced. Healthcare professionals often operate under intense pressure, managing critical tasks that require efficiency and quick decision-making. Therefore, any perceived complexity associated with new technologies or a steep learning curve can significantly hinder their adoption. This reality highlights the necessity of developing BYOD systems that prioritize user-friendliness and can be easily incorporated into daily routines. Thus, it is essential to develop user-friendly BYOD systems that fit seamlessly into daily routines, promoting smoother adoption and enhancing efficiency in healthcare settings. The EE was measured with four questions that focused on the intention to adopt BYOD. Thus, the hypothesis of this research on the impact of the EE on behavioural intention among Pakistani doctors is:

Social influence (SI) refers to how significant others’ opinions can influence the individual’s behaviour regarding new technology [101]. Recent studies emphasize that SI, shaped by peer influence, organizational culture, and societal norms, significantly impacts behavioral intention to adopt new technologies. SI is described as the extent to which a users’ decision is affected by others’ perceptions [93]. The construct of SI in the UTAUT model adopted from the TRA, TAM2, TPB/DTPB, and C-TAM-TPB; social factors (MPCU); and image (IDT) [62]. Previous research has shown [33] revealed that SI significantly influenced health professionals’ acceptance of mobile-based clinical guideline applications in resource-limited settings, highlighting the importance of colleagues and organizational culture in driving adoption. Similarly, studies by [11], and [31] explored the adoption of BI systems, blockchain, AI-driven healthcare services, and EHR systems, demonstrating that SI is a critical enabler for fostering acceptance, especially in environments requiring collaboration and teamwork. Additional research by [2] and [50] further reinforces that SI significantly drives adoption through peer recommendations and shared expectations. While studies like [90] suggest that SI may have limited impact in more autonomous professions, such as healthcare and military settings, they acknowledge that SI can complement other factors such as performance expectancy and facilitating conditions in promoting adoption. A study by [81] found that SI significantly influenced emergency information systems. However, several findings have concluded that because of context, respondents traits, and the technologies investigated, SI did not affect behavioural intention in the healthcare context [92]. The disagreement in the literature about the effect of SI on behavioural intention in healthcare helps this research investigate its significance among Pakistani doctors. These findings collectively justify the inclusion of SI as a predictor in BYOD adoption research, as it captures the influence of peer dynamics, leadership endorsement, and organizational culture in encouraging the acceptance and integration of personal devices in healthcare workflows.

The SI was measured with three questions that focused on the intention to adopt BYOD. The hypothesis is as follows:

Facilitating Conditions (FC) are consistently identified as a significant predictor of behavioral intention and technology adoption in UTAUT-based studies. FC refers to the availability of organizational and technical resources, including IT support, infrastructure, and policies, that enable users to adopt and effectively use a technology [101]. Studies such as [11] and [31] highlight the importance of FC in healthcare, demonstrating that robust IT systems and accessible resources significantly enhance the adoption of BI systems and blockchain technology. Similarly, [50] found that FC strongly influences both behavioral intention and actual use of Wi-Fi systems among medical students, indicating the critical role of a supportive environment in fostering technology use.

In resource-constrained settings, [75] showed that FC is essential for the adoption of EHR systems by healthcare professionals, emphasizing that technical support and infrastructure are pivotal in overcoming barriers. Studies like [110] also affirm that FC plays a vital role in BYOD adoption. Facilitating Conditions (FC) are crucial for predicting behavioral intention and technology adoption, particularly in healthcare. Research on the hospital’s technical support and training substantially impacted HIS’s adoption [18, 38]. Research indicates that strong FC enhances the adoption of technologies like business intelligence systems, blockchain, electronic health records (EHR), and Bring Your Own Device (BYOD) practices. Studies show that supportive environments significantly influence technology use among medical professionals and students, helping them overcome barriers and effectively integrate personal devices into their workflows. These findings collectively underscore that facilitating conditions are critical for the successful adoption of BYOD in healthcare, where robust IT support, clear policies, and training programs can help professionals overcome technical challenges and ensure efficient use of personal devices in their workflows. The FC measured with three questions that focused on the intention to adopt BYOD. Hypothesis for FC is:

The Perceived Vulnerability (PV) is the user’s opinion about the probability that the threat will appear [65]. PV plays a significant role in influencing compliance behaviors within BYOD practices, largely through the process of threat appraisal. Research conducted by [97] explores BYOD security compliance through the lens of Protection Motivation Theory (PMT), identifying threat and coping appraisals as key predictors of compliance intentions. The study also highlights additional factors, such as mixed device usage and the visibility of company surveillance. Similarly, [4] investigate how perceived vulnerability, response efficacy, and subjective norms affect protective behaviors in BYOD environments. They suggest targeted interventions aimed at strengthening security practices among employees. Both studies emphasize that awareness of potential risks is a strong predictor of compliance intentions and protective behaviors, underscoring the necessity of enhancing risk awareness to promote secure practice. Additionally, [76] connect perceived vulnerability to security awareness and risk perception within their threat appraisal framework. Their study focuses on BYOD compliance in the public sector, establishing relationships between security behaviors and essential factors like policy clarity, self-efficacy, and psychological ownership, while emphasizing the critical role of training and support.

Individuals who believe their information system resources are vulnerable to an information system attack are more likely to take preventive measures [48]. Employees are vigilant about whether their data is secure, mainly using their own devices for work tasks. Hence, personal privacy and data confidentiality for using their mobile device is the most critical concerns [21]. In this context, it is possible to disclose employees’ private details to an unapproved entity. If employees think his/her data security is not assured, it will stop them from accepting BYOD. The PV measured with three questions; the researcher proposed the following hypothesis:

Perceived Severity (PS) refers to the degree of threat from unhealthy behaviours [84]. PS is observed as the degree to which a consumer thinks that risk impacts on his/her device would be dangerous [95]. However, there are different outcomes in the personal computing domain context [74]. If an employee uses his/her device instead of the company computer, the user’s security risk can be a significant problem.

Perceived severity is a significant component of threat appraisal that influences compliance behaviors in Bring Your Own Device (BYOD) practices by highlighting the potential consequences of security breaches. Tu et al. [97] incorporated perceived severity into their Protection Motivation Theory (PMT) framework, demonstrating its influence on compliance intentions alongside other relevant factors. Similarly, [4] identified it as a crucial determinant of behavioral intentions in BYOD environments. In general, users considering adopting BYOD may act differently based on their PS [113], the PV measured with three questions. Consequently, the researcher proposed the following hypothesis.

Response Cost (RC) which refers to the perceived effort, inconvenience, individuals’ costs when required to introduce a security policy safeguard measure, or time required to engage in protective behaviors, is vital for compliance with BYOD [115, 117]. It covers the costs of taking adaptive coping measures, like resources, time, commitment, inconvenience, complexity, comprehension, or other negative impacts on adopting the BYOD security plan [24]. If the expenses surpass the benefits, it is unlikely that the consumer will attempt any coping action [98]. RC applies to the costs affiliated with practising defensive behaviour. It has demonstrated a crucial part in personal computing, such that changes in perceived RC adversely affect intentions to implement security behaviours [95].

Moreover, [97] recognized response cost as a barrier to compliance intentions within the coping appraisal framework of Protection Motivation Theory (PMT). Al-Harthy and Ali [4] further supported this notion by showing that employees are less inclined to adopt protective behaviors when they perceive the effort as high, advocating for security measures that are user-friendly to foster compliance. When RC is high, individuals will be less likely to engage in a given protective behavior [96]. RC was found to negatively affect adopting anti-plagiarism software [65], BYOD practices [29] and online security behaviours [96]. Posey, Roberts & Lowry explained RC as perceived drawbacks such as expenses, disruptions, difficulties and likely adverse effects that users could incur [80].

Contrary to previous studies’ findings, if a person agrees that the proposed preventive behaviour is appropriate, the cost of responding is justified [106]. A study by showed that the RC to mobile device users has no substantial impact on defending their device from data violations [44]. The study by [76] suggests that when organizational policies are clear and well-supported, the perceived effort or difficulty associated with compliance—conceptualized as response cost—is likely reduced. By streamlining processes and minimizing complexity, organizations can foster an environment where employees are more inclined to adhere to BYOD security measures, thereby enhancing overall compliance and security outcomes. If consumers of devices are assured in their self-efficacy against security attacks, RC would not significantly impact their defensive behaviour. Thus, the RC was measured with three questions; the researcher proposed that:

Self-Efficacy (SE) is an individual’s confidence in their capability to present behaviour [24]. It originated from the social cognitive theory, which alluded to an individual’s belief in responding. However, according to social cognitive theory, people with stronger self-confidence in their skills can begin challenging behaviours. An individual’s belief in his or her skills to complete a behaviour has positively influenced the mobile health system [117]. Alhelaly et al. [10] underscored the significance of self-efficacy as a vital factor in protection motivation, illustrating its role in mitigating privacy concerns and promoting compliance with BYOD policies. Similarly, [97] incorporated self-efficacy into their PMT framework, demonstrating that heightened self-efficacy enhances employees’ coping abilities and strengthens their commitment to security measures. Al-Harthy and Ali [4] highlighted self-efficacy as a key determinant of behavioral intentions and protective behaviors in BYOD contexts, emphasizing the necessity of confidence-building strategies. These studies illustrate the critical importance of self-efficacy in BYOD security practices, urging organizations to prioritize the development of employee confidence through comprehensive training, robust support, and clear policies. Crossler, Long, Loraas, & Trinkle examined the factors determining whether employees follow BYOD policies through the PMT lens. They found that SE of BYOD is the salient factor for adopting BYOD policy [28].

Besides, the results obtained from several studies of PMT showed that SE might be the powerful predictor of intention to adopt preventative measures [112]. SE signifies an individual’s ability to perform protection behavior [52]. By contrast, another study suggested the insignificant effects of SE [34]. Therefore, further empirical evidence is required for an improved understanding of this issue. In this research, SE refers to an individual’s ability to implement security measures specified by a security policy to reduce the risk posed by BYOD adoption. Also, it can influence one’s desire to accept BYOD, such as belief and desire to improve the adoption of mhealth, thus enhancing the overall attitude towards BYOD. Therefore, the SE was measured with four questions that focused on the intention to adopt BYOD. We propose the following hypothesis:

Generally, different people have different perceptions about a particular aspect, or they understand and associate it uniquely based on their distinctive attributes, such as age, gender, preferences and experiences [47]. A moderator variable is a third variable affecting the relationship between the dependent and independent variables [85]. Within the study’s contemporary context, two moderators were examined, age and gender.

Age moderated the relationship between performance expectancy, effort expectancy, social influence, facilitating conditions and behavioural intention. Elderly consumers tend to have more problems understanding new or complicated information, affecting their learning of new technologies [102]. In previous technology adopted research, age was assumed as a moderator. However, the influence depended on context, and results were not consistent across different settings. Research revealed that elderly individuals are less willing to adopt e-health technologies [32]. However, research in a healthcare setting, age did not significantly influence healthcare professionals’ willingness to accept Health Information System (HIS). Research revealed that elderly individuals are less willing to adopt e-health technologies [32]. However, research in a healthcare setting, age did not significantly influence healthcare professionals’ willingness to accept HIS. The effect of age on technology adoption has been well examined in a commercial context, but a lack of studies apply to healthcare settings [73]. The current study hypothesized the effect of age as the following:

• H9: Age will moderate the relationship between performance expectancy, effort expectancy, social influence and facilitating conditions on the intention to adopt BYOD

Gender is vital while examining performance expectancy, effort expectancy, social influence, facilitating conditions on BI [102]. Studies examining the role of gender indicate how personality characteristics and gender variation are essential to understanding and using emerging technologies. The role of gender cannot be ignored in the evaluation of the acceptance of technology. The original UTAUT model investigated gender as a moderator and found its significant impact on the relationship between facilitating conditions to intention to adopt [101]. Another study also found that females are less interested and likely to adopt e-health technology [32]. To evaluate the impact of gender as a moderator on the relationship between facilitating conditions and intention to adopt the hypothesis is:

• H10: Gender will moderate the relationship between performance expectancy, effort expectancy, social influence and facilitating conditions on the intention to adopt BYOD. The 08 main research hypotheses and 02 moderator hypotheses are summarized in Table 1 in a tabular format; the hybrid research model is also presented in Fig. 4.

Amsterdam,

ING announced today that, as part of our €2.0 billion share buyback programme announced on 2 May 2025, in total 4,239,000 shares were repurchased during the week of 6 October 2025 up to and including 10 October 2025.

The shares were repurchased at an average price of €21.32 for a total amount of €90,367,787.70. For detailed information on the daily repurchased shares, individual share purchase transactions and weekly reports, see share buy back programme.

In line with the purpose of the programme to reduce the share capital of ING, the total number of shares repurchased under this programme to date is 92,123,891 at an average price of €19.67 for a total consideration of €1,811,927,494.72. To date approximately 90.60% of the maximum total value of the share buyback programme has been completed.

Note for editors

More on investor information, go to the investor relations section on this site.

For news updates, go to the newsroom on this site or via X (@ING_news feed).

For ING photos such as board members, buildings, go to Flickr.

ING PROFILE

ING is a global financial institution with a strong European base, offering banking services through its operating company ING Bank. The purpose of ING Bank is: empowering people to stay a step ahead in life and in business. ING Bank’s more than 60,000 employees offer retail and wholesale banking services to customers in over 100 countries.

ING Group shares are listed on the exchanges of Amsterdam (INGA NA, INGA.AS), Brussels and on the New York Stock Exchange (ADRs: ING US, ING.N).

ING aims to put sustainability at the heart of what we do. Our policies and actions are assessed by independent research and ratings providers, which give updates on them annually. ING’s ESG rating by MSCI was reconfirmed by MSCI as ‘AA’ in August 2024 for the fifth year. As of December 2023, in Sustainalytics’ view, ING’s management of ESG material risk is ‘Strong’. Our current ESG Risk Rating, is 17.2 (Low Risk). ING Group shares are also included in major sustainability and ESG index products of leading providers. Here are some examples: Euronext, STOXX, Morningstar and FTSE Russell. Society is transitioning to a low-carbon economy. So are our clients, and so is ING. We finance a lot of sustainable activities, but we still finance more that’s not. Follow our progress on ing.com/climate.

Important legal information

Elements of this press release contain or may contain information about ING Groep N.V. and/ or ING Bank N.V. within the meaning of Article 7(1) to (4) of EU Regulation No 596/2014 (‘Market Abuse Regulation’).

ING Group’s annual accounts are prepared in accordance with International Financial Reporting Standards as adopted by the European Union (‘IFRS- EU’). In preparing the financial information in this document, except as described otherwise, the same accounting principles are applied as in the 2024 ING Group consolidated annual accounts. All figures in this document are unaudited. Small differences are possible in the tables due to rounding.

Certain of the statements contained herein are not historical facts, including, without limitation, certain statements made of future expectations and other forward-looking statements that are based on management’s current views and assumptions and involve known and unknown risks and uncertainties that could cause actual results, performance or events to differ materially from those expressed or implied in such statements. Actual results, performance or events may differ materially from those in such statements due to a number of factors, including, without limitation: (1) changes in general economic conditions and customer behaviour, in particular economic conditions in ING’s core markets, including changes affecting currency exchange rates and the regional and global economic impact of the invasion of Russia into Ukraine and related international response measures (2) changes affecting interest rate levels (3) any default of a major market participant and related market disruption (4) changes in performance of financial markets, including in Europe and developing markets (5) fiscal uncertainty in Europe and the United States (6) discontinuation of or changes in ‘benchmark’ indices (7) inflation and deflation in our principal markets (8) changes in conditions in the credit and capital markets generally, including changes in borrower and counterparty creditworthiness (9) failures of banks falling under the scope of state compensation schemes (10) non- compliance with or changes in laws and regulations, including those concerning financial services, financial economic crimes and tax laws, and the interpretation and application thereof (11) geopolitical risks, political instabilities and policies and actions of governmental and regulatory authorities, including in connection with the invasion of Russia into Ukraine and the related international response measures (12) legal and regulatory risks in certain countries with less developed legal and regulatory frameworks (13) prudential supervision and regulations, including in relation to stress tests and regulatory restrictions on dividends and distributions (also among members of the group) (14) ING’s ability to meet minimum capital and other prudential regulatory requirements (15) changes in regulation of US commodities and derivatives businesses of ING and its customers (16) application of bank recovery and resolution regimes, including write down and conversion powers in relation to our securities (17) outcome of current and future litigation, enforcement proceedings, investigations or other regulatory actions, including claims by customers or stakeholders who feel misled or treated unfairly, and other conduct issues (18) changes in tax laws and regulations and risks of non-compliance or investigation in connection with tax laws, including FATCA (19) operational and IT risks, such as system disruptions or failures, breaches of security, cyber-attacks, human error, changes in operational practices or inadequate controls including in respect of third parties with which we do business and including any risks as a result of incomplete, inaccurate, or otherwise flawed outputs from the algorithms and data sets utilized in artificial intelligence (20) risks and challenges related to cybercrime including the effects of cyberattacks and changes in legislation and regulation related to cybersecurity and data privacy, including such risks and challenges as a consequence of the use of emerging technologies, such as advanced forms of artificial intelligence and quantum computing (21) changes in general competitive factors, including ability to increase or maintain market share (22) inability to protect our intellectual property and infringement claims by third parties (23) inability of counterparties to meet financial obligations or ability to enforce rights against such counterparties (24) changes in credit ratings (25) business, operational, regulatory, reputation, transition and other risks and challenges in connection with climate change, diversity, equity and inclusion and other ESG-related matters, including data gathering and reporting and also including managing the conflicting laws and requirements of governments, regulators and authorities with respect to these topics (26) inability to attract and retain key personnel (27) future liabilities under defined benefit retirement plans (28) failure to manage business risks, including in connection with use of models, use of derivatives, or maintaining appropriate policies and guidelines (29) changes in capital and credit markets, including interbank funding, as well as customer deposits, which provide the liquidity and capital required to fund our operations, and (30) the other risks and uncertainties detailed in the most recent annual report of ING Groep N.V. (including the Risk Factors contained therein) and ING’s more recent disclosures, including press releases, which are available on www.ING.com.

This document may contain ESG-related material that has been prepared by ING on the basis of publicly available information, internally developed data and other third-party sources believed to be reliable. ING has not sought to independently verify information obtained from public and third-party sources and makes no representations or warranties as to accuracy, completeness, reasonableness or reliability of such information.
Materiality, as used in the context of ESG, is distinct from, and should not be confused with, such term as defined in the Market Abuse Regulation or as defined for Securities and Exchange Commission (‘SEC’) reporting purposes. Any issues identified as material for purposes of ESG in this document are therefore not necessarily material as defined in the Market Abuse Regulation or for SEC reporting purposes. In addition, there is currently no single, globally recognized set of accepted definitions in assessing whether activities are “green” or “sustainable.” Without limiting any of the statements contained herein, we make no representation or warranty as to whether any of our securities constitutes a green or sustainable security or conforms to present or future investor expectations or objectives for green or sustainable investing. For information on characteristics of a security, use of proceeds, a description of applicable project(s) and/or any other relevant information, please reference the offering documents for such security.

This document may contain inactive textual addresses to internet websites operated by us and third parties. Reference to such websites is made for information purposes only, and information found at such websites is not incorporated by reference into this document. ING does not make any representation or warranty with respect to the accuracy or completeness of, or take any responsibility for, any information found at any websites operated by third parties. ING specifically disclaims any liability with respect to any information found at websites operated by third parties. ING cannot guarantee that websites operated by third parties remain available following the publication of this document, or that any information found at such websites will not change following the filing of this document. Many of those factors are beyond ING’s control.

Any forward-looking statements made by or on behalf of ING speak only as of the date they are made, and ING assumes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information or for any other reason.

This document does not constitute an offer to sell, or a solicitation of an offer to purchase, any securities in the United States or any other jurisdiction.

Glossary

 

Capital expenditure is total cash capital expenditure as stated in the condensed group cash flow statement. Capital expenditure for the operating segments, gas & low carbon energy businesses and customers & products businesses is presented on the same basis.

 

Replacement cost (RC) profit or loss reflects the replacement cost of inventories sold in the period and is calculated as profit or loss attributable to bp shareholders, adjusting for inventory holding gains and losses (net of tax). RC profit or loss for the group is a non-IFRS measure. The nearest equivalent measure on an IFRS basis is profit or loss attributable to bp shareholders.

 

Refining indicator margin (RIM) is a simple indicator of the weighted average of bp’s crude slate and product yield as deemed representative for each refinery. Actual margins realized by bp may vary due to a variety of factors, including the actual mix of a crude and product for a given quarter.

 

Technical service contract (TSC) – Technical service contract is an arrangement through which an oil and gas company bears the risks and costs of exploration, development and production. In return, the oil and gas company receives entitlement to variable physical volumes of hydrocarbons, representing recovery of the costs incurred and a profit margin which reflects incremental production added to the oilfield.

 

Underlying production – 2025 underlying production, when compared with 2024, is production after adjusting for acquisitions and divestments, curtailments, and entitlement impacts in our production-sharing agreements/contracts and technical service contract*.

 

Underlying RC profit or loss before interest and tax for the operating segments or customers & products businesses is a non-IFRS measure and is calculated as RC profit or loss including profit or loss attributable to non-controlling interests before interest and tax for the operating segments and excluding net adjusting items for the respective operating segment or business. The nearest equivalent measure on an IFRS basis for segments and businesses is RC profit or loss before interest and taxation.

 

Underlying effective tax rate (ETR) is a non-IFRS measure. The underlying ETR is calculated by dividing taxation on an underlying replacement cost (RC) basis by underlying RC profit or loss before tax. Taxation on an underlying RC basis for the group is calculated as taxation as stated on the group income statement adjusted for taxation on inventory holding gains and losses and total taxation on adjusting items. Information on underlying RC profit or loss is provided below. Taxation on an underlying RC basis presented for the operating segments is calculated through an allocation of taxation on an underlying RC basis to each segment. bp believes it is helpful to disclose the underlying ETR because this measure may help investors to understand and evaluate, in the same manner as management, the underlying trends in bp’s operational performance on a comparable basis, period on period. Taxation on an underlying RC basis and underlying ETR are non-IFRS measures. The nearest equivalent measure on an IFRS basis is the ETR on profit or loss for the period.

Our MG5 electric car became dangerously out of control, but MG won’t do anything about it.

The car suffered a power system malfunction after we had used a charger at a motorway service station.

It wouldn’t respond to any controls, including the off button, so we called the AA. The patrolman managed to get it started, then decided to give it a test drive. My family was onboard as it was pouring.

When he put the car into reverse, it shot forward and failed to stop when he applied the brake. It rammed into the AA van and its wheels began spinning and smoking as it tried to accelerate.

We all managed to exit the car, and the patrolman eventually succeeded in turning it off from the outside. We were told it was not safe to drive.

The AA arranged a transporter to take it to a dealership and paid for the repairs, which cost £2,500. The patrol van was also damaged.

The dealer has investigated the fault, for which we are to be charged £500, but has found nothing. MG has closed the case, and insists we request a further investigation at our own expense.

Six weeks on, the car is still with the dealership. We don’t want to drive it until we know it is safe, but can’t afford to keep paying for investigations.

AB, East Lothian

You are not the only MG owner whose car has seemingly gone rogue. One man was forced to drive his car into a police van after his brakes failed.

I asked the AA to send me its technician report, which confirms that the car “surged forward” when put into reverse.

It’s unsurprising that you are reluctant to get behind the wheel until you know what’s wrong and, since the car is still under warranty you are reluctant to throw your own money at the problem.

MG Motor UK seems remarkably unperturbed given the harm that could be caused by an out-of-control EV. Although the dealership had recommended that MG’s technical department review the case and issue guidance, MG, instead, closed it.

MG, when you complained, merely apologised for the “inconvenience”.

It ignored my questions about whether the review requested by the dealer was conducted before the case was closed, and how many incidents involving power surges or loss it is aware of.

However, it speedily commissioned another, more detailed, investigation of the vehicle and conducted a 25-mile test drive after using a range of public charging points. You were not charged for this test and will not now be billed for the previous one.

It says: “MG treats all issues where a malfunction may have potentially occurred as a priority. No malfunctions with any of the relevant in-vehicle equipment, or the ability to charge the vehicle using various systems, were detected on the car.

“MG, and the authorised dealership, having carefully examined the vehicle, have concluded that an error occurred not related to the car. We will continue to support the customer with information and advice.”

This leaves you in a difficult position. Your car has been given a clean bill of health, but you have lost confidence in it. You have therefore decided that your best option is to sell.

We welcome letters but cannot answer individually. Email us at consumer.champions@theguardian.com or write to Consumer Champions, Money, the Guardian, 90 York Way, London N1 9GU. Please include a daytime phone number. Submission and publication of all letters is subject to our terms and conditions.

Introduction

Presbyopia – the reduced ability of the natural lens to accommodate – affects almost all individuals by the age of 50, leaving them with decreased near visual acuity (VA). In 2011 alone, it is estimated that from a total of 244 million cases of uncorrected or under-corrected presbyopia in people aged less than 50 years, there was an approximate worldwide $11.023 billion loss in potential productivity.¹ One novel way to manage presbyopia is by the implantation of phakic intraocular lenses (IOLs) – IOLs that are placed over the natural lens rather than replacing it. These lenses refract light either via distinct regions with various radii of curvature, or diffractively by inducing add powers through Fresnel zones, which refract the light differently than their lens-base.² Phakic IOLs allow for patients to maintain their residual ability to accommodate, receive a refractive intraocular lens if needed, and avoid an increased risk of retinal detachment during this procedure if they are highly myopic.^3–6 Previous studies have extensively reported positive outcomes on various phakic IOLs in refractive surgery,^3,7–9 however few studies have explored their outcomes in presbyopia management.^10–13

In 2020, Schmid and Luedtke established promising results for the use of phakic IOLs in correcting presbyopia, where 8 patients undergoing presbyopia correction with a diffractive posterior chamber phakic IOL reached a median uncorrected distance VA of at least 0.1logMAR with no need for reading glasses at one-month post-operation.¹⁴ Four prospective studies by Stodulka et al, Takahashi et al, Bianchi et al, and Güel et al have found patients undergoing presbyopic phakic IOL correction to have significantly improved VA at follow-ups.^15–18 While such studies have reported positive outcomes for phakic IOL use in presbyopia management, they are limited in numbers and no previous study has yet directly compared a refractive and a diffractive phakic IOL for presbyopia management.

In this study, we evaluated and compared the optical quality of a diffractive phakic IOL – the IPCL with +2.5 diopters (D) add power (Care Group) – and a recently introduced refractive phakic model designed for presbyopia correction – the Artiplus (Ophtec). By measuring their optical-quality metrics and simulating postoperative VA at various aperture sizes and near, intermediate, and far distances, we aimed to provide comprehensive information on the optical properties of both approaches in the same study, allowing for better direct comparison of the models and a more personalized selection of phakic IOL based on patients’ needs.

Methods

Phakic IOLs

The Artiplus Model 470 (Artiplus) is a polysiloxane iris-fixated refractive phakic IOL (Ophtec, Groningen, the Netherlands),¹⁹ which has recently obtained a CE-marking. Its multi-segmented optic using the continuous transitional focus technology allows for improved VA at near, intermediate, and far distances (Figure 1). Its refractive index is 1.43, with dioptric powers ranging from +2.0 to −15.0D in 0.5D increments. Artiplus has an overall diameter of 8.5mm with a 6.0mm convex-concave body. We used an Artiplus IOL with a power of −3D.

Figure 1 Artiplus phakic intraocular lens (photo courtesy with permission from Ophtec, the Netherlands).19

The IPCL V2.0 is a hybrid hydrophilic acrylic phakic IOL with a refractive index of 1.465. It features a central hole to allow aqueous flow and six haptic pads to ensure its stability in the ciliary sulcus (Care Group, Gujarat, India).²⁰ It has an optic diameter of 6.60mm that can be customized up to 7.25mm with sizes ranging from 11.00 to 14.00mm (0.25mm step).²¹ The IPCL is available in the broad power range of −30.0D to +15.0D in 0.5D increments. The added power can also be customized by offering +1.5D, 2D, 2.5D, 3D, and 3.5D secondary foci. In the current study, we used an IPCL with a power of −3D and an add power of +2.5D, aligning with the range of the Artiplus model.

In our experiments, the optical power of the natural lens was modeled with a 23D Precizon Monofocal (Ophtec, Groningen, the Netherlands), with no spherical aberration. When assembling the 23D monofocal and phakic IOL with one another, the overall corneal aberration (0.27 µm) was similar to the mean of 0.280 µm (±0.086 µm) reported in the literature.²²

Optical Setup

The 23D monofocal and phakic IOLs were assembled into a custom-made and 3D-printed insert with the 23D monofocal placed posterior to the phakic IOL to simulate the in-vivo condition of the natural lens being posterior to a phakic IOL (Supplemental Figure 1). An estimated distance between the two lenses was 0.5mm, determined based on the IOL geometry and a dedicated spacer incorporated into the 3D-printed holder, which had a designed gap of 1.2 mm. The printing accuracy was approximately ±0.1mm. This resulting distance was comparable to the separation found between phakic IOLs and the crystalline lens (0.609±0.165mm) in the literature.²³

The optical quality of the phakic IOLs was evaluated with the Laboratory’s OptiSpheric IOL PRO2 (Trioptics GmbH, Wedel, Germany), with its design adhering to ISO 11979-2.^24,25 Two samples of each phakic IOL were tested for all experiments after placing them in a balanced salt solution (BSS, Bausch+Lomb, United States). Two samples sufficed for the experiments given the OptiSpheric’s accuracy against a reference lens (2% for MTF testing)²⁶ and the lab’s previous studies indicating high reproducibility^27,28 and repeatability²⁹ of the optical quality of IOLs, regardless of type or refractive power, using the laboratory’s OptiSpheric. Measurements were conducted with a photopic filter, and 3.0- and 4.5-mm apertures. A corneal model with 0.27µm of spherical aberration at 5.15mm was used representing the average value reported in the normal population,^22,28–31 and simulations were performed in polychromatic light to more closely mimic natural viewing conditions.

Image Quality Metrics

Variables measured with the setup included modulation transfer function (MTF). In addition to comparing the phakic IOLs’ MTF curves, the area under the curve of the MTFs (MTFa) up to 50 lp/mm with the simulated VA conversion was calculated using the methods outlined elsewhere.³² The through-focus MTF (TF MTF) was compared at 25, 50, and 100 lp/mm. Lastly, the 1951 USAF resolution test images were recorded. The results were graphed and analyzed with custom-made software (MATLAB, MathWorks, USA).

Results

Figure 2 shows the MTF levels of the IPCL and Artiplus phakic IOLs for a 3mm pupil measured at far, intermediate, and near focus. At this aperture, the lenses showed close MTF values at all distances.

Supplemental Figure 2 shows the TF MTF of the tested phakic IOLs for a 3mm pupil at 25, 50, and 100 lp/mm at a defocus range of 1 to −3D at the spectacle plane. At all tested frequencies, both the IPCL and Artiplus IOLs had a primary peak at 0D. At approximately −1.9D, IPCL had a higher secondary peak compared to Artiplus, but at the expense of a lower contrast at the intermediate range with a steep decline from the primary to the secondary focus. Given IPCL being a diffractive phakic IOL, such a bimodal shape of the TF MTF curve is expected.

Figure 2 Modulation transfer function curves of the tested lenses at three foci for a 3mm aperture. The tested foci included best far, intermediate, and near focus. The dotted lines show the values of each lens separately; the solid lines refer to the average of two lenses. Abbreviation: MTF, modulation transfer function.

Figure 3 presents the MTFa and simulated VA (logMAR) for the two lenses at a 3mm aperture. The two lenses had a similar primary peak at 0D, but IPCL had a second primary peak at approximately −1.9D. At an intermediate defocus of −1D, Artiplus showed a higher MTFa (0.32 versus 0.25) and better simulated VA (0.05 versus 0.13logMAR) than the IPCL.

Figure 3 The area under MTF curve and simulated VA of the tested lenses at 3mm aperture. The MTFa and simVA are graphed as a function of spectacle defocus. The dotted lines show the values of each lens separately; the solid lines refer to the average of two lenses. Abbreviations: MTFa, area under the modulation transfer function; simVA, simulated visual acuity.

At a 4.5mm aperture as shown in Figure 4, the MTF level of lenses at far, intermediate, and near focuses showed decreased values compared to the 3.0mm aperture, due to the presence of corneal spherical aberration. Notably at the near focus, IPCL had a lower MTF at all spatial frequencies compared to the Artiplus lens with the 4.5mm aperture, indicating a deficiency in near performance at higher apertures.

With the 4.5mm aperture, TF MTF values of the lenses at 25, 50, and 100 lp/mm decreased for all lenses compared to the 3.0mm aperture (Supplemental Figure 3). Still, both models preserved their multifocal properties extending the depth of focus at 4.5mm.

Figure 4 Modulation transfer function curves of the lenses at three foci for a 4.5mm aperture. The tested foci included best far, intermediate, and near focus. The dotted lines show the values of each lens separately; the solid lines refer to the average of two IOLs. Abbreviaton: MTF, modulation transfer function.

Nevertheless, the IPCL’s tolerance to hyperopic and negative defocus appeared further reduced at the extreme ends of the MTFa and simulated VA presented in Figure 5, demonstrating a steeper decline in its optical quality. Artiplus demonstrated a bimodal simulated VA with peaks of 0.05logMAR at −0.5D and 0.13logMAR at −2.4D. In contrast to the Artiplus, IPCL demonstrated a narrower simulated VA curve with a primary peak of 0.05logMAR at −0.25D. Testing with larger apertures also revealed that the optical performance of both the IPCL and the Artiplus was comparable in the intermediate range, with the two curves overlapping at −1.0D, which contrasts with the lens IPCL performance measured at 3mm.

Figure 5 The area under MTF curve and simulated VA of the tested lenses at 4.5mm aperture. The MTFa and simVA are graphed as a function of spectacle defocus. The dotted lines show the values of each lens separately; the solid lines refer to the average of two lenses. Abbreviations: MTFa, area under the modulation transfer function; simVA, simulated visual acuity.

The USAF resolution target images presented in Figure 6 confirmed the MTFa results. At −1.0D, Artiplus has better image resolution than IPCL with the 3.0mm aperture, while its resolution became more similar to IPCL at the 4.5mm aperture. At −2.0D with the 3.0mm aperture, IPCL had a better image resolution than the Artiplus, but at the same defocus value with the 4.5mm aperture, IPCL had a worse contrast than the Artiplus. Overall, at both pupil sizes, especially the 4.5mm size, Artiplus had an improved image quality at the ends of the defocus range, compared to the IPCL.

Figure 6 The United States Air Force target images for tested lenses across defocus range. The defocus range included +1.0D to −3.0D, at 0.5D increments at 3-mm and 4.5-mm apertures.

Discussion

Given phakic IOL’s recent introduction to presbyopia treatment, the literature on laboratory studies evaluating such lenses is still limited. Our study tested and compared the optical performance of refractive versus diffractive phakic IOLs – IPCL (+2.5D add) and Artiplus – at 3.0 and 4.5mm apertures for surgical management of presbyopia. We demonstrated good optical quality of the two models across the studied focus range, with the Artiplus providing a flatter simulated defocus curve. While expected differences in VA between the two approaches were minimal, they may become more pronounced in patients with larger pupils.

Our study’s MTF values of the IPCL with +2.5D added power at the 3.0mm aperture decreased with spatial frequency, and the curves decreased to lower MTF values with an increased aperture size of 4.5mm. The IPCL phakic IOL for presbyopia has been studied in a laboratory by Yu et al with additional powers of 2D and 4D at a 3.0mm aperture.³³ Yu et al found the MTF values at 100 cycles/mm to be 27% and 24% with the 2D and 4D add powers respectively, compared to our study with MTF values closer to 11% at 100 cycles/mm. The reason for this discrepancy and the lower MTF value reported in our study results from differences in the optical setups applied in both studies. The primary factor limiting the IOL performance using our approach is the presence of corneal spherical aberration. In contrast, the corneal lens used by Yu et al was designed to minimize spherical aberration, as inferred from its resemblance to the corneal model outlined in the ISO standard. Another contributing factor is the use of polychromatic light in our evaluation of IOL performance. By contrast, the optical bench used by Yu et al employed a 546 nm light source, which is free of chromatic aberration effects and may therefore yield higher objective quality metrics.²⁸ However, in agreement with our study, they found that the IPCL MTF levels gradually worsen with increasing apertures. This change was also seen in a prospective cohort study by Stodulka et al where highly myopic patients undergoing presbyopic treatment with IPCL had difficulty seeing under dim light conditions.¹⁷ They found the mean uncorrected distance visual acuity (UDVA) to be 0.11logMAR, with uncorrected near visual acuity (UNVA) improving to J1 for 15 of 17 eyes as the other 2 eyes were J1 at baseline. Schmid and Luedtke retrospectively studied the use of IPCL for presbyopia treatment in 16 eyes of 8 patients and found 9 out of 16 to be emmetropic with UDVA of at least 0.1logMAR with no need for reading glasses at one-month post-operation.¹⁴ Similarly, in our study, with apertures of 3.0 and 4.5mm, we respectively found the simulated VA to be −0.01logMAR and 0.07logMAR at distance. At the near focus, ie, at −2D, we found simulated VA to be 0.03 and 0.16logMAR for the two apertures respectively, which may show a lack of need for reading glasses. Overall, based on our and other studies, we can conclude that IPCL for the treatment of presbyopia can result in significantly improved near and far distances, but the len’s design appears to be susceptible to pupil-size changes.

The Artiplus lens studied is currently being clinically investigated by Güel et al as part of a prospective non-controlled multicenter clinical trial.¹⁸ The one-year clinical trial has shown that at 6 months post-operation, mean monocular UDVA, uncorrected intermediate VA (UIVA) at 80cm, and UNVA at 40cm were 0.01±0.08, 0.03±0.08, and 0.07±0.09logMAR respectively, with binocular UDVA, UIVA, and UNVA being −0.06±0.08, −0.01±0.07, and 0.02±0.08logMAR respectively.³⁴ The results of this study appear to agree with ours for far and intermediate, but not fully for near distance. With the 3mm aperture, we found the simulated VA to be approximately −0.02, 0.06, and 0.12 logMAR at far, intermediate, and near focuses (respectively 0, −1.25, and −2.5 defocus values). It is important to note; however, that our results simulate the scenario of complete accommodation loss, which can differ from real-world clinical cases. In practice, the loss of accommodation is a gradual process, and patients receiving such lenses often retain some ability to accommodate.³⁵ Laboratory studies thus can predict the maximum lens-related depth-of-focus improvement that patients may experience at various distances, with possibly better outcomes for those whose lenses may still have residual accommodation.

Lastly, our work did not study the EVO Visian Implantable Collamer Lens by STAAR Surgical (Monrovia, California, USA). This lens is a collagen and poly-hydroxyethyl methacrylate iris-fixated refractive phakic IOL with dioptric powers ranging from −0.5 to –18.0D.³⁶ It has a plate-haptic design with a central convex/concave optical zone ranging from 4.9 to 5.8mm diameter and a 0.36mm diameter central port allowing aqueous flow.^36,37 The STAAR phakic IOL for the treatment of presbyopia has been studied prospectively by Rateb et al showing uncorrected VA improving from 1.3±0.06logMAR to 0.76±0.2logMAR post-operatively.³⁸ Alfonso et al studied the STAAR lens to correct moderate to high myopia and presbyopia and found postoperative UDVA and corrected DVA (CDVA) values of 0.09 ± 0.19 and 0.02 ± 0.03logMAR, following bilateral implantation in 40 patients.³⁹ To be able to offer a comprehensive review of phakic IOL options available for patients with presbyopia, future studies comparing the STAAR phakic IOL to the Artiplus and IPCL phakic IOLs can be significantly beneficial.

In addition to the range of vision, which typically distinguishes presbyopia-correcting IOL solutions, another key differentiating factor is the occurrence and severity of photic phenomena. These unwanted light effects involve the perception of glare, halos, or starbursts when looking at light sources, such as streetlights or headlights of cars at night.⁴⁰ In studying presbyopia-correcting IOLs, literature has found photic phenomena to greatly vary between lens types, and to be one of the most common complaints of patients undergoing IOL procedures – as high in 32.9% of eyes found by de Vries et al.^40,41 Generally, a lower incidence of photic phenomena has been associated with the refractive rather than the diffractive principle in the context of multifocal IOLs implanted into the capsular bag.⁴² It is of interest to confirm whether this can also be observed in the context of phakic multifocal IOLs. Therefore, by studying photic phenomena rates with phakic IOLs and their comparison to other methods of presbyopia treatment, we can gather more information on the rate of side effects associated with phakic IOLs, which warrants further clinical and laboratory investigations. Additionally, due to the limitation of the OptiSpheric setup, this study did not evaluate the effects of IOL decentration or tilt on the IOL performance– factors that have been shown to impact visual outcomes resulting in symptoms such as glare or visual halos.^43,44 Future studies on the impact of tilt and decentration on phakic IOL outcomes may add insights into the side effects of such IOLs.

Conclusion

Our study evaluated and contrasted the optical quality of diffractive versus refractive phakic IOL models – IPCL with added power of 2.5D and Artiplus – for the management of presbyopia at near, intermediate, and far distances simulating various pupil sizes. We found that both IPCL and Artiplus can effectively expand the range of vision, potentially alleviating visual symptoms in presbyopic patients and restoring vision at intermediate and near distances. Although the optical quality of both models was comparable at a 3mm pupil size, an increase to 4.5mm led to reduced defocus tolerance, with the IPCL model appearing more affected. While our study aids in directly comparing the two models and choosing a phakic IOL more appropriate based on patients’ individualized needs, it still needs to be considered that lens performance may differ under in vivo conditions due to the interaction between the IOL optics and the eye’s intrinsic aberrations and residual accommodation. Future studies evaluating the impact of these aspects and the perception of photic phenomena in presbyopic patients undergoing phakic IOL implantation can provide physicians and patients with a more comprehensive understanding of their treatment options.

Abbreviations

BSS, balanced salt solution; CDVA, corrected distance visual acuity; D, diopters; IPCL, implantable phakic contact lens; IOL, intraocular lens; MTF, modulation transfer function; MTFa, area under the modulation transfer function; TF MTF, through-focus modulation transfer function; UDVA, uncorrected distance visual acuity; UIVA, uncorrected intermediate visual acuity; UNVA, uncorrected near visual acuity; VA, visual acuity.

Data Sharing Statement

The datasets generated during and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising, or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Funding

Supported by a research grant from OPHTEC BV, Groningen, The Netherlands. The David J Apple Laboratory receives support from the Klaus Tschira Foundation, Heidelberg, Germany.

Disclosure

GU Auffarth reports grants, personal fees, non-financial support and consulting fees from Afidera, Johnson&Johnson and Alcon, grants, personal fees, and non-financial support from Carl Zeiss Meditec, Hoya, Kowa, Oculentis/Teleon, Rayner, Santen, Sifi, Ursapharm, grants, and personal fees from Biotech, Oculus, EyeYon grants from Acufocus, Anew, Contamac, Glaukos, Physiol, Rheacell, outside the submitted work. The University of Heidelberg holds a patent application (No. WO2024/023230) entitled “Lens with extended depth of focus by inducing an excess of longitudinal chromatic aberration,” with GU Auffarth and G Łabuz as inventors. G Łabuz reports non-financial support from Contamac outside the submitted work. R Khoramnia reports grants, personal fees, and non-financial support from Alcon, Johnson&Johnson, Hoya, Physiol, Rayner, personal fees, and non-financial support from Kowa, Ophtec, Oculentis/Teleon, Santen, Staar, 1stQ, BVI, Zeiss, SIFI, and Acufocus, outside the submitted work. The remaining authors have nothing to disclose.

References

1. Frick KD, Joy SM, Wilson DA, Naidoo KS, Holden BA. The global burden of potential productivity loss from uncorrected presbyopia. Ophthalmology. 2015;122(8):1706–1710. doi:10.1016/j.ophtha.2015.04.014

2. Schwiegerling J. Refractive and diffractive principles in presbyopia-correcting IOLs – an optical lesson. Available from: https://us.alconscience.com/sites/g/files/rbvwei1736/files/pdf/Refractive-and-Diffractive-Principles-in-Presbyopia-Correcting-IOLs-An-Optical-Lesson-US-REF-1900001.pdf. Accessed August 14, 2025.

3. Namdev V, Kaur M, Sharma VK, Mulay A, Raj R, Titiyal JS. Current paradigms in refractive surgery. Med J Armed Forces India. 2024;80(5):497–504. doi:10.1016/j.mjafi.2024.08.003

4. Kumar K, Kohli P, Babu N, Khare G, Ramasamy K. Incidence and management of rhegmatogenous retinal detachment after pars plana vitrectomy and sutureless scleral-fixated intraocular lens. Indian J Ophthalmol. 2020;68(7):1432–1435. doi:10.4103/ijo.IJO_1974_19

5. Jafarinasab M, Kalantarion M, Hooshmandi S, et al. Indications and outcomes of intraocular lens exchange among pseudophakic eyes in a Tertiary Referral Center. BMC Ophthalmol. 2023;23(1):127. doi:10.1186/s12886-023-02871-y

6. Rodríguez-calvo-de-mora M, Rocha-de-lossada C, Rodríguez-Vallejo M, Zamora-de-la-cruz D, Fernández J. Retinal detachment after refractive lens exchange: a narrative review. Archivos de la Sociedad Española de Oftalmología. 2023;98(9):507–520. doi:10.1016/j.oftale.2023.06.013

7. Vasavada V, Srivastava S, Vasavada SA, Sudhalkar A, Vasavada AR, Vasavada VA. Safety and efficacy of a new phakic posterior chamber IOL for correction of myopia: 3 years of follow-up. J Refract Surg. 2018;34(12):817–823. doi:10.3928/1081597X-20181105-01

8. Kamiya K, Shimizu K, Igarashi A, et al. Posterior chamber phakic intraocular lens implantation: comparative, multicentre study in 351 eyes with low-to-moderate or high myopia. Br J Ophthalmol. 2018;102(2):177–181. doi:10.1136/bjophthalmol-2017-310164

9. Sachdev GS, Singh S, Ramamurthy S, Rajpal N, Dandapani R. Comparative analysis of clinical outcomes between two types of posterior chamber phakic intraocular lenses for correction of myopia and myopic astigmatism. Indian J Ophthalmol. 2019;67(7):1061–1065. doi:10.4103/ijo.IJO_1501_18

10. Pérez-Vives C, Ferrer-Blasco T, Cerviño-Expósito A, Madrid-Costa D, Montés-Micó R. Simulated prototype of posterior chamber phakic intraocular lens for presbyopia correction. J Cataract Refract Surg. 2015;41(10):2266–2273. doi:10.1016/j.jcrs.2015.10.050

11. Ferraz CA, Allemann N, Chamon W. Phakic intraocular lens for presbyopia correction. Arq Bras Oftalmol. 2007;70(4):603–608. doi:10.1590/s0004-27492007000400009

12. Alió JL, Mulet ME. Presbyopia correction with an anterior chamber phakic multifocal intraocular lens. Ophthalmology. 2005;112(8):1368–1374. doi:10.1016/j.ophtha.2005.02.029

13. Baïkoff G, Matach G, Fontaine A, Ferraz C, Spera C. Correction of presbyopia with refractive multifocal phakic intraocular lenses. J Cataract Refract Surg. 2004;30(7):1454–1460. doi:10.1016/j.jcrs.2003.12.051

14. Schmid R, Luedtke H. A novel concept of correcting presbyopia: first clinical results with a phakic diffractive intraocular lens. Clin Ophthalmol. 2020;14:2011–2019. doi:10.2147/OPTH.S255613

15. Bianchi GR, Paredes A, Puccio B, Parra-Hernández A. Implantable phakic contact lens: vault evaluation 5 years postoperatively. J Cataract Refract Surg. 2024;50(10):1000–1005. doi:10.1097/j.jcrs.0000000000001496

16. Takahashi M, Kamiya K, Shoji N, Kato S, Igarashi A, Shimizu K. Intentional undercorrection by implantation of posterior chamber phakic intraocular lens with a central hole (Hole ICL) for early presbyopia. Biomed Res Int. 2018;2018:6158520. doi:10.1155/2018/6158520

17. Stodulka P, Slovak M, Sramka M, Polisensky J, Liska K. Posterior chamber phakic intraocular lens for the correction of presbyopia in highly myopic patients. J Cataract Refract Surg. 2020;46(1):40–44. doi:10.1097/j.jcrs.0000000000000033

18. Truong D. Ophtec’s artiplus shows promising one-year clinical results. CAKE. 2024. Available from: https://cakemagazine.org/ophtecs-artiplus-shows-promising-one-year-clinical-results/. Accessed November 1, 2024.

19. Artiplus. Available from: https://www.ophtec.com/product-overview/artiplus. Accessed November 2, 2024.

20. Care Group. Available from: https://caregroupiol.com/products/phakic-lenses/ipcl/. Accessed November 2, 2024.

21. Spectrum Ophthalmics. IPCL – the customised refractive solution. Available from: https://www.spectrumophthalmics.uk/app/uploads/2022/08/IPCL-Presbyopic-Surgeons-Brochure.pdf. Accessed August 14, 2025.

22. Wang L, Dai E, Koch DD, Nathoo A. Optical aberrations of the human anterior cornea. J Cataract Refract Surg. 2003;29(8):1514–1521. doi:10.1016/s0886-3350(03)00467-x

23. Du C, Wang J, Wang X, Dong Y, Gu Y, Shen Y. Ultrasound biomicroscopy of anterior segment accommodative changes with posterior chamber phakic intraocular lens in high myopia. Ophthalmology. 2012;119(1):99–105. doi:10.1016/j.ophtha.2011.07.001

24. Łabuz G, Yan W, Baur ID, Khoramnia R, Auffarth GU. Chromatic aberration and spectral dependency of extended-range-of-vision intraocular lens technology. Sci Rep. 2023;13(1):14781. doi:10.1038/s41598-023-41634-z

25. ISO 11979-2:2014. ISO. Available from: https://www.iso.org/standard/55682.html. Accessed October 10, 2024.

26. TRIOPTICS GmbH. Technische Daten OptiSpheric^® AF 500. INV; 2019. Available from: www.trioptics.com. Accessed August 14, 2025.

27. Son HS, Tandogan T, Liebing S, et al. In vitro optical quality measurements of three intraocular lens models having identical platform. BMC Ophthalmol. 2017;17:108. doi:10.1186/s12886-017-0460-0

28. Lee Y, Łabuz G, Son HS, Yildirim TM, Khoramnia R, Auffarth GU. Assessment of the image quality of extended depth-of-focus intraocular lens models in polychromatic light. J Cataract Refract Surg. 2020;46(1):108–115. doi:10.1097/j.jcrs.0000000000000037

29. Łabuz G, Papadatou E, Khoramnia R, Auffarth GU. Longitudinal chromatic aberration and polychromatic image quality metrics of intraocular lenses. J Refract Surg. 2018;34(12):832–838. doi:10.3928/1081597X-20181108-01

30. Łabuz G, Auffarth GU, Knorz MC, Son HS, Yildirim TM, Khoramnia R. Trifocality achieved through polypseudophakia: optical quality and light loss compared with a single trifocal intraocular lens. J Refract Surg. 2020;36(9):570–577. doi:10.3928/1081597X-20200715-01

31. Łabuz G, Son HS, Naujokaitis T, Yildirim TM, Khoramnia R, Auffarth GU. Laboratory Investigation of Preclinical Visual-Quality Metrics and Halo-Size in Enhanced Monofocal Intraocular Lenses. Ophthalmol Ther. 2021;10(4):1093–1104. doi:10.1007/s40123-021-00411-9

32. Alarcon A, Canovas C, Rosen R, et al. Preclinical metrics to predict through-focus visual acuity for pseudophakic patients. Biomed Opt Express. 2016;7(5):1877–1888. doi:10.1364/BOE.7.001877

33. Yu C, Kamiya K, Kawamorita T. Modulation transfer function of implantable phakic intraocular contact lens (IPCL) for myopia and presbyopia. Graefes Arch Clin Exp Ophthalmol. 2024;262(10):3201–3206. doi:10.1007/s00417-024-06539-1

34. Ophtec. Artiplus Model 470. Available from: https://www.ophtec.com/product-overview/artiplus. Accessed October 30, 2024.

35. Pérez-Prados R, Piñero DP, Pérez-Cambrodí RJ, Madrid-Costa D. Soft multifocal simultaneous image contact lenses: a review. Clin Exp Optometry. 2017;100(2):107–127. doi:10.1111/cxo.12488

36. STAAR Surgical. EVO Visian Implantable Collamer Lens; 2021. Available from: https://edfu.staar.com/edfu/5c784538fd5dd20001d67c89/ICL%20eDFU’s/eDFU-0016_Rev_01_EVO%20Visian%20ICL.pdf. Accessed August 14, 2025.

37. Packer M. Evaluation of the EVO/EVO+ sphere and toric visian ICL: six month results from the United States Food and Drug Administration Clinical Trial. Clin Ophthalmol. 2022;16:1541–1553. doi:10.2147/OPTH.S369467

38. Rateb M, Gad AAM, Tohamy D, Elmohamady MN. A prospective comparative study between implantable phakic intraocular contact lens and implantable Collamer lens in treatment of myopia in adults. J Ophthalmol. 2022;2022:9212253. doi:10.1155/2022/9212253

39. Alfonso JF, Fernández-Vega-Cueto L, Lisa C, Alfonso-Bartolozzi B, Palacios A, Madrid-Costa D. Clinical and aberrometric outcomes of a new implantable Collamer lens for myopia and presbyopia correction in phakic patients. J Refract Surg. 2023;39(9):589–596. doi:10.3928/1081597X-20230726-02

40. Ukai Y, Okemoto H, Seki Y, et al. Quantitative assessment of photic phenomena in the presbyopia-correcting intraocular lens. PLoS One. 2021;16(12):e0260406. doi:10.1371/journal.pone.0260406

41. de Vries NE, Webers CAB, Touwslager WRH, et al. Dissatisfaction after implantation of multifocal intraocular lenses. J Cataract Refract Surg. 2011;37(5):859–865. doi:10.1016/j.jcrs.2010.11.032

42. Łabuz G, Khoramnia R, Naujokaitis T, Auffarth GU. Optical benchtop evaluation of special intraocular lens optics. Ophthalmologie. 2024;121(9):698–705. doi:10.1007/s00347-024-02064-y

43. Ashena Z, Maqsood S, Ahmed SN, Nanavaty MA. Effect of intraocular lens tilt and decentration on visual acuity, dysphotopsia and wavefront aberrations. Vision. 2020;4(3):41. doi:10.3390/vision4030041

44. Chen XY, Wang YC, Zhao TY, et al. Tilt and decentration with various intraocular lenses: a narrative review. World J Clin Cases. 2022;10(12):3639–3646. doi:10.12998/wjcc.v10.i12.3639

Leon Neal/Getty Images

‘Support they need’

Total Knee Arthroplasty (TKA) is an orthopedic surgical procedure that replaces a damaged human joint with a prosthesis made of artificial materials. TKA aims to alleviate joint pain, instability, deformities, and severe functional impairment caused by various types of arthritis, traumatic arthritis, and non-pyogenic arthritis, thereby reconstructing a joint with near-normal functionality and enhancing joint performance. Recognized as the safest and most effective treatment for alleviating pain and improving limb function in patients with knee arthritis, the utilization of TKA has been on a steady rise, increasing annually by 5% to 17%.¹ However, systematic reviews indicate that only 3 randomized controlled trials (RCTs) with a total sample size of less than 100 participants have evaluated the efficacy of MET in post-TKA rehabilitation. These studies suggest limited evidence regarding the efficacy of MET post-TKA, warranting further investigation into its impact on functional recovery. Despite undergoing TKA, many patients still experience suboptimal functional recovery, which is primarily characterized by persistent postoperative pain, joint stiffness, and limited ability to perform daily activities.^2–4 Conventional rehabilitation methods have not significantly improved postoperative knee joint mobility, possibly due to early postoperative symptoms like pain and swelling.⁴ Hence, with the increasing number of patients undergoing TKA (growing annually by 5–17%), implementing effective early rehabilitation training is crucial for enhancing postoperative knee joint function and improving the quality of life for TKA patients.

Muscle Energy Technique (MET) is a manipulative treatment targeting disorders of the soft tissues, muscles, and skeletal system. It involves precise therapist-controlled direction and force application, coupled with active patient participation, utilizing isometric muscle contractions to mitigate pain, stretch tight muscles and fascia, reduce muscle rigidity, improve local blood circulation, strengthen weak muscles, and increase mobility in stiff joints. Common MET techniques include Reciprocal Inhibition (RI), Contract Relax (CR), Contract Relax Antagonistic Contraction (CRAC), and Annulare Muscle Energy Technique (A-MET), each serving distinct purposes. For instance, RI primarily relaxes agonist muscles through the active contraction of antagonist muscles, thereby increasing joint Range of Motion (ROM) and reducing adhesions in joints, ligaments, and fascia. CR involves isometric contraction of the agonist muscle, causing tendon tissues to stretch, passively elongating and alleviating abnormal collagen tissue adhesions, thereby releasing collagen in tendons and facilitating more freedom in muscle fiber contraction and extension, along with enhanced mobility in the connected fibrous tissue.⁵

MET has gained widespread recognition in global fields of rehabilitation medicine, rehabilitative therapy, and sports rehabilitation. Its primary treatment targets include individuals with sports injuries, post-traumatic injuries from traffic accidents, chronic injury-related pain complications, and patients with limb joint functional impairments. As China’s aging population grows, the incidence of knee arthritis is also increasing and is expected to continue to rise significantly. However, the effectiveness of existing post-TKA rehabilitation methods in China is inadequate for achieving rehabilitation goals. This study challenges traditional rehabilitation approaches by incorporating novel rehabilitation techniques. By comparing the effects of conventional rehabilitation methods (Routine Rehabilitation Treatment, RRT) and Muscle Energy Technique (MET) on knee joint functional rehabilitation in post-TKA patients, the study explores the impact of MET on functional recovery and long-term prognosis in these patients. The findings not only optimize the rehabilitation treatment pathway, providing more effective rehabilitation methods for TKA patients, but also align with the current objectives of “Healthy China 2030”, playing a significant role in improving postoperative functional recovery and the quality of life for patients.

Clinical Data and Methodology

Baseline Data Patient Records

The study selected 80 patients who underwent Total Knee Arthroplasty (TKA) between January 2021 and December 2021 at the Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University. All procedures were performed by the same team of doctors, utilizing prostheses of the same material provided by the same company, and followed a uniform postoperative treatment protocol.

Sample Size Calculation

Based on ROM data (α=0.05, β=0.2), A sample size of 36 patients per group was required to achieve adequate statistical power, with 40 patients enrolled per group to account for potential dropout. The actual study included 36 patients in the MET group and 42 patients in the RRT group, which was slightly different from the planned 36/group.

Inclusion Criteria

a. Patients diagnosed with osteoarthritis undergoing unilateral Total Knee Arthroplasty; b. Patients undergoing Total Knee Arthroplasty for the first time; c. Patients aged between 50 and 80 years; d. Patients with good compliance, capable of participating in functional exercises; e. Patients willing to participate in the study, agree to follow-up appointments, and provide signed informed consent.

Exclusion Criteria

a. Patients with a history of knee surgery or rheumatoid arthritis; b. Patients with concurrent lower limb acute infection or other joint functional impairments; c. Patients with preoperative coagulation disorders or lower limb Deep Vein Thrombosis (DVT); d. Patients with consciousness, cognitive impairments, or severe mental illness. Elimination Criteria: a. Patients who need to discontinue the treatment plan for personal reasons; b. Patients who experience severe adverse reactions and are unable to adhere to the set treatment plan; c. Patients who withdraw from the clinical study midway; d. Patients who fail to attend scheduled clinic follow-ups, resulting in incomplete follow-up or assessment data.

Research Methodology

Prospective data collection was performed from January 2021 to December 2021, involving 80 patients who met the inclusion and exclusion criteria and underwent TKA at our facility. Block randomization (size=4) via opaque envelopes was employed to allocate patients into two groups. A computerized random number sequence was generated, and the allocation sequence was concealed in opaque, sequentially numbered envelopes. The assessors, who were blinded to group allocation, opened the envelopes according to the patient’s hospital admission order, ensuring a randomized and blinded assignment. The patients, in accordance with their hospital admission order, opened these envelopes and were subsequently randomly assigned to either the Muscle Energy Technique (MET) rehabilitation group or the conventional rehabilitation group.

The conventional rehabilitation treatment methods for the control group are as follows: Preoperative rehabilitation assessment, including the evaluation of muscle strength, Range of Motion (ROM), and circumference of different parts of the operative limb. Development of a rehabilitation plan based on the assessment results, which includes ankle pump dorsiflexion and plantarflexion exercises, muscle strength training, joint ROM exercises, gait training, and Activities of Daily Living (ADL) training. Muscle strength training, encompassing quadriceps muscle strength training, hamstring muscle strength training, and straight leg raise exercises. Each exercise is held for 10 seconds, with 20 repetitions per set and two sets conducted daily. Joint ROM exercises, involving both active and passive knee flexion exercises. Each exercise is held for 5 seconds, with 20 repetitions per set and two sets conducted daily. Gait training, which includes guidance on how to perform body position transitions, stand up from the ground, and walk correctly using a walker, all within the first 24 hours post-surgery. Rehabilitation evaluation, assessing the patient’s muscle strength, joint ROM, gait, walking distance, and ADL status after undergoing the rehabilitation training. The Muscle Energy Technique (MET) intervention rehabilitation treatment methods specifically implemented in the experimental group include:

The MET intervention comprised 2 sessions per day for 6 consecutive days during inpatient rehabilitation, followed by 3 sessions per week for 8 weeks during outpatient rehabilitation. Specifically, the intervention included Post-Isometric Relaxation (PIR) and Post-Facilitation Stretch (PFS) techniques to target the quadriceps muscle. These techniques aim to enhance neuromuscular activation by engaging Type II muscle fibers and improving the extensibility of antagonist muscles, ultimately leading to enhanced knee extension function. The specific implementation is as follows: The patient lies supine with the knee passively flexed to 15 degrees. The patient is instructed to perform isometric contractions of the quadriceps against resistance, followed by relaxation, then the therapist rapidly stretches to the next resistance point. Each quadriceps isometric contraction lasts 10 seconds, performed 10 times per set, with one stretch after completing a set and two sets per day. After each stretch, the knee extension angle is remeasured to maximize the improvement of knee extension limitations. Once the patient’s knee joint can fully extend, they are guided through regular muscle strength training, including isometric contractions of the quadriceps, assessing the strength of medial muscle contractions, ensuring proper contraction and relaxation of key muscles, straight leg raise exercises, active knee flexion exercises, and bedside passive knee flexion exercises. The training starts on the second day post-TKA and continues for six consecutive days until discharge, aiming to achieve full knee extension and mastery of the isometric contraction technique of the quadriceps. Eccentric contraction of the quadriceps combined with conventional straight leg raise training, which further strengthens the muscle strength of the knee extensors, activates the power of the quadriceps, particularly the strength of the vastus medialis muscle. This approach ensures more coordinated contraction within the different muscles of the quadriceps, laying the foundation for the completion of straight leg raise exercises. The specific implementation is as follows: The patient is guided to sit at the edge of the bed, actively extending the knee, then, under the therapist’s control, passively flexing the knee to 60 degrees. The patient exerts force toward the resistance point in the direction of stretch, and the therapist provides single-handed equal resistance (isometric contraction) or uses a sequential progressive resistance. The patient is instructed to extend the knee (isotonic contraction), activating the quadriceps muscle. The therapist rapidly stretches to the next resistance point, the patient extends the knee again, and the therapist observes the contraction response, especially in the position of the vastus medialis muscle, to ensure the quadriceps are in an activated state. Each resistance contraction lasts 5 seconds, followed by one stretch, repeated 10 times per set, with two sets per day. The training begins on the second day post-TKA and continues for six consecutive days until discharge. The goal is to correctly master the force application method of the adductor muscles of the thigh, activate the quadriceps early, and complete the straight leg raise training regimen.

Conventional Range of Motion (ROM) training followed by Reciprocal Inhibition (RI) technique (knee flexor muscle training) effectively stimulates the electrical response rate of knee flexor muscles and induces neuromuscular activation. This method also alleviates pain through reciprocal inhibition and stimulation of mechanoreceptors. The specific implementation is as follows: Before starting the therapy, the patient is seated at the edge of the bed with the thigh snug against the bed edge and the leg dangling. The therapist, facing the patient, stabilizes the operative thigh with one hand and places the other hand under the distal end of the affected calf. The patient is instructed to take deep breaths; if the thigh muscles of the operative limb are tense, they are gently tapped to induce relaxation. The patient is then guided to actively flex the knee for 5 seconds. Simultaneously, the therapist, while seated, places a hand on the patient’s posterior ankle, providing equal resistance against the patient’s hamstring muscle contraction. After maintaining the knee flexion resistance for 5 seconds, the therapist relaxes the pressure. When the patient’s muscles are balanced and coordinated, the therapist continually advances the joint’s range of motion until the highest resistance point of knee flexion is reached. Each resistance contraction lasts 5 seconds, with the joint’s range of motion advanced once. This is performed 10 times per set, with two sets per day. The training begins on the second day post-TKA and continues for six consecutive days until discharge. The objective is to correctly master the hamstring muscle’s force application method, activate the hamstring muscle early, and successfully complete the active knee flexion training regimen.

Observation Indicators

Knee Joint Active Range of Motion

The goniometer is used to measure the active range of motion of the patient’s knee joint, including the flexion angle in the supine and sitting positions, and the extension angle in the sitting position. Each movement is measured twice, and the best value is taken. Measurements are taken at 3 days, 7 days, 1 month, and 3 months, with a planned follow-up at 6 months.

Time Up and Go Test (TUG)

Initially, the patient sits on a chair 45 cm high. Timing starts when the patient stands up, walks 3 meters, turns, returns to the chair, and sits down again. The total time taken for this process is recorded. This scale is simple, easy to operate, and has high reliability and validity, making it suitable for evaluating short-term and long-term rehabilitation effects post-knee arthroplasty.¹ The TUG test is performed and recorded 7 days and 1 month postoperatively.

Hospital for Special Surgery (HSS) Knee Score

The HSS knee scoring system, proposed by the Hospital for Special Surgery in the USA, includes six dimensions: pain, function, range of motion, muscle strength, knee flexion deformity, and knee instability. Each question has five multiple-choice options, with the scores converted to a 100-point scale, where 0 points indicate the most severe symptoms, and 100 points indicate the least severe. The HSS knee scores are recorded 1 month and 3 months postoperatively.

Visual Analogue Scale for Pain (VAS)

A 10 cm ruler is used, divided into ten equal parts, with the ends labeled “0” and “10”, representing no pain and unbearable extreme pain, respectively. The middle part of the scale corresponds to the respective pain levels. Subjects assess their pain level based on their sensation and mark it on the appropriate scale. VAS scoring criteria: 0–2 points are considered “excellent”, 3–5 points “good”, 6–8 points “fair”, and 8–10 points “poor”. VAS pain scores are recorded at 3 days, 7 days, 1 month, and 3 months postoperatively.

Statistical Methods

All clinical research data are recorded in a standardized observation chart created with Microsoft Excel and are managed by a dedicated person responsible for clinical data. Analysis is conducted using SPSS software version 22.0. For comparing quantitative data between two groups, repeated-measures ANOVA was employed to account for time-related effects and group differences. Paired-sample t-tests were utilized to compare pre- and post-treatment outcomes within each group, with a significance level set at P < 0.05. All measurement data should fit a normal or approximately normal distribution and are presented as mean ± standard deviation. The independent samples t-test is used for analyzing the aforementioned indicators, with P < 0.05 considered statistically significant.

Results

MET Significantly Enhances Patients’ Knee Joint ROM

The range of motion (ROM) of the knee joint can reach 135 degrees during flexion and 0 degrees during extension, with internal and external rotation angles being approximately 10 degrees each. Limited joint mobility may be a result of knee injuries or degeneration. When the quadriceps muscles are weak, complete extension of the knee joint is not possible. This study compared the intergroup effects, time effects, and interaction effects on the ROM of the knee joint post-TKA between the two patient groups. As indicated in Table 1, the experimental results were statistically significant (P < 0.001). The results of the repeated-measures ANOVA demonstrated that, over time, the active ROM of the knee joint in the experimental group was significantly superior to that in the control group (P < 0.001). Notably, on the third day post-surgery, the knee joint activity degree of the patients in the experimental group was 19.3% higher than that in the control group. These results suggest that, compared to conventional rehabilitation methods, the rehabilitation treatment utilizing MET can significantly improve the ROM of the knee joint in patients post-TKA (Figure 1).

Table 1 Comparison of Active Range of Motion Scores of the Knee Joint Between Two Groups of Patients (, Degrees)

Figure 1 Comparison results of ROM (Range of Motion) between the two groups of patients.

MET Does Not Improve Patients’ TUG Scores

This study compared the Time Up and Go (TUG) test scores post-TKA between the two patient groups, and the experimental results are presented in Table 2. The data reveal that there was no significant difference in the TUG scores between the two groups one month post-surgery (P > 0.05), indicating no statistical significance. However, the TUG scores three months post-surgery were statistically significant (P < 0.001), with the scores of the Routine Rehabilitation Treatment (RRT) group being higher than those of the MET group. These results suggest that, compared to conventional rehabilitation methods, the MET rehabilitation approach does not enhance patients’ TUG scores.

Table 2 Comparison of Time Taken for the Timed Up and Go (TUG) Test After Intervention Between Two Groups of Patients () Unit: seconds

MET Significantly Improves Patients’ HSS Scores

This study compared the differences in the Hospital for Special Surgery (HSS) scores between the two patient groups, focusing on intergroup effects, time effects, and interaction effects. The scoring results, as shown in Table 3, were statistically significant (P < 0.001). The data indicate that before the commencement of the rehabilitation treatment, the scores of both groups were similar. However, as time progressed, one month post-intervention, the HSS scores of patients in the MET group were 22.2% higher than those in the RRT group; and three months post-intervention, the HSS scores in the MET group still surpassed those in the RRT group by 14.2%. These results demonstrate that, compared to conventional treatment methods, the MET rehabilitation approach can significantly enhance patients’ postoperative HSS scores, and this improvement is sustained over time.

Table 3 Comparison of HSS Scores Before and After Intervention Between Two Groups of Patients () Unit: Points

MET Significantly Reduces Postoperative VAS in Patients

Postoperative pain management is one of the critical factors affecting early mobility in patients undergoing Total Knee Arthroplasty (TKA), and effective postoperative analgesia can reduce hospital stay duration and medical expenses. This study compared the postoperative pain conditions between the two patient groups. The differences in pain scores between the groups, considering intergroup effects, time effects, and interaction effects, were statistically significant (P < 0.001), indicating different therapeutic effects from the two intervention measures. Over time, the condition of knee joint pain in patients in the MET group was better than that in the control group. The differences in pain levels at 3 days, 7 days, one month, and three months post-surgery for both groups are presented in Table 4. The data clearly indicate that patients who underwent rehabilitation with the MET method experienced a significant reduction in knee joint pain perception. On the third day post-surgery, the pain scores in the conventional group were 1.34 times higher than those in the MET group; three months post-surgery, the pain scores in the conventional group were 3.67 times higher than those in the MET group. The results of this study indicate that using the MET method for patient rehabilitation can significantly suppress postoperative pain in patients. Moreover, this suppressive effect becomes more pronounced as the recovery time increases.

Table 4 Comparison of Knee Joint Pain Scores Between Two Groups of Patients () Unit: Points

Discussion

Currently, domestic rehabilitation techniques for Total Knee Arthroplasty (TKA) primarily include isometric muscle contraction, isometric resistance contraction, active and passive Range of Motion (ROM) training, Continuous Passive Motion (CPM) device training for sustained passive activity, gait training, and more.⁶ Singular isometric contraction training, however, may not sufficiently activate muscle strength and lacks coordination during contraction and relaxation. ROM training without resistance can lead to inadequate active knee flexion strength, failing to aid in patient recovery effectively. Additionally, post-TKA patients may exhibit exercise-induced muscle force errors due to kinesiophobia, leading to compensatory movements, making it challenging to control the direction of force application, rendering the exercise ineffective and failing to achieve the true purpose of the exercise. The hallmark of the Muscle Energy Technique (MET) is its active, gentle, and non-impactful nature. During the alternating active contraction and relaxation of muscles, the soft tissues surrounding the joint form a spiraling and unwinding effect. The therapeutic characteristic of this technique necessitates the active participation of the patient, continuous cooperation during treatment, and muscle contractions of specific degrees and directions as set by the operator. Various muscle contraction methods, including isometric, concentric, and eccentric contractions, are often combined in application. This training can improve tissue fluid metabolism, accelerate the synthesis of new cells, promote tissue fiber repair and strengthening, improve joint angles, relax tense muscles and fascia, alleviate pain, balance the muscle strength around the joint, and restore the normal biomechanics of the joint and surrounding tissues.^5,7

TKA is regarded as one of the surgeries with significant effects on severe knee joint diseases, capable of reconstructing knee joint function and alleviating knee pain. However, the incidence of severe postoperative pain after TKA can be as high as 60%, lasting 48–72 hours, and may even develop into chronic pain.⁸ Some patients experience pain, knee joint dysfunction, and muscle weakness after TKA, severely affecting their ability to walk. Postoperative pain can severely impede the recovery of knee joint function and even affect patients’ daily lives. Studies suggest that MET can alleviate patients’ pain through mechanisms such as stimulating mechanoreceptors or reciprocal inhibition, and strength training of the quadriceps can improve the motor function of the knee joint.⁹ This conclusion aligns with the experimental group’s knee joint pain score results, and our experimental findings indicate that MET significantly alleviates patients’ pain with a sustained effect (remaining significant after three months). Starting from the third day post-surgery, each test result showed that the pain scores of patients in the experimental group were significantly lower than those in the control group. Currently, MET is widely used domestically and internationally for soft tissue pain treatment, such as for muscle strains, lateral epicondylitis of the humerus,⁷ periarthritis of the shoulder¹⁰, piriformis syndrome¹¹, and elbow joint stiffness¹². Recently, MET has also been applied for functional rehabilitation training post-ACL reconstruction¹³, post-meniscus repair surgery¹⁴, and more, though the literature is sparse and further exploration in knee joint applications is needed.

This experiment has direct evidence indicating that MET can enhance active knee joint mobility, accelerate knee joint recovery, and alleviate pain. Therefore, compared to conventional rehabilitation treatments, MET is considered to have better therapeutic effects, shorter recovery periods, and higher patient satisfaction. Thus, MET can be regarded as a rehabilitation treatment method for TKA patients worthy of widespread promotion and application.

Data Sharing Statement

The experimental data used to support the findings of this study are available from the corresponding author upon request.

Ethical Approval

Approved by the Ethics Committee of The First Affiliated Hospital of Nanjing Medical University (Approval number: 2022-SR-666), informed consent obtained.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Funding

The work was not funded by any funding.

Disclosure

The authors declared that they have no conflicts of interest regarding this work.

References

1. Mistry JB, Elmallah RDK, Bhave A, et al. Rehabilitative guidelines after total knee arthroplasty: a review. J Knee Surg. 2016;201(03):201–217. doi:10.1055/s-0036-1579670

2. Zuin M, Gentili V, Cervellati C, et al. Viral load difference between symptomatic and asymptomatic COVID-19 patients: systematic review and meta-analysis. Infect Dis Rep. 2021;13(3):645–653. doi:10.3390/idr13030061

3. Thomas E, Cavallaro AR, Mani D, et al. The efficacy of muscle energy techniques in symptomatic and asymptomatic subjects: a systematic review. Chiropr Man Therap. 2019;27(1):1–18. doi:10.1186/s12998-019-0258-7

4. Mascarenhas VV, Rego P, Dantas P, et al. Imaging prevalence of femoroacetabular impingement in symptomatic patients, athletes, and asymptomatic individuals: a systematic review. Eur J Radiol. 2016;85(1):73–95. doi:10.1016/j.ejrad.2015.10.016

5. Sbardella S, La Russa C, Bernetti A, et al. Muscle energy technique in the rehabilitative treatment for acute and chronic non-specific neck pain: a systematic review. Healthcare. 2021;9(6):746. doi:10.3390/healthcare9060746

6. Wang T, Gu H, Gao H. Research on the best evidence application of postoperative rehabilitation exercises for knee arthroplasty patients based on the concept of accelerated recovery. Chin J Mod Nurs. 2020;26(5):595–599.

7. Li J, Zhang J, Hei G, et al. Therapeutic effect observation of muscle intramuscular effect patch combined with muscle energy technique in treating lateral epicondylitis of humerus. Chin J Phys Med Rehabil. 2018;40(3):208–210.

8. Luo G, Wang W, Han X. Current research on postoperative analgesia after total knee arthroplasty. Gansu Med. 2017;36(11):921–923.

9. Wang L, Lv L, Zhang H, et al. Effectiveness of deep hyperthermia combined with dynamic traction in the treatment of knee osteoarthritis. J Clin Rehabil. 2021;35(3):367–377. doi:10.1177/0269215520966702

10. Yu H, Shang J, Yan Z. Clinical efficacy analysis of muscle energy technique combined with muscle intramuscular effect patch in the treatment of periarthritis of shoulder. Liaoning Sports Sci Technol. 2021;43(3):59–62.

11. Zhou Y, Gao H, Qiu J, et al. Observation on the therapeutic effect of needle knife combined with muscle energy technique on piriformis syndrome. Chin Rehabil. 2018;33(3):237–239.

12. Wang X, Xu L. Application of static progressive stretching technique combined with muscle energy technique in the rehabilitation treatment of post-traumatic elbow joint stiffness. Chin Rehabil. 2020;35(8):409–412.

13. Li J, Zhang W, Guan S, et al. Application of muscle energy technique in rehabilitation training of patients after anterior cruciate ligament reconstruction. Nurs Res Mid-Month Ed. 2017;31(8):2925–2927.

14. Ye Z, Li S. The impact of rehabilitation training nursing based on muscle energy technique on functional rehabilitation after meniscus injury surgery. China Med Herald. 2020;17(29):171–174.

PARIS–(BUSINESS WIRE)–
The Estée Lauder Companies Inc. (NYSE:EL), under the High Patronage of Mr. Emmanuel Macron, President of the French Republic,today announced the opening of its Fragrance Atelier within its new La Maison des Parfums on Rue Volney in Paris. This newly established global innovation hub is fully dedicated to world-class fragrance expertise, advanced technologies and cutting-edge capabilities, and will accelerate the company’s strategic ambitions in luxury and prestige fragrances. Rooted in the legacy of Mrs. Estée Lauder’s pioneering vision and her lifelong passion for fragrance, the Atelier’s opening marks a significant milestone in the company’s longstanding commitment to fragrance excellence and craftsmanship.

This press release features multimedia. View the full release here: https://www.businesswire.com/news/home/20251013447078/en/

The Exterior of La Maison des Parfums

“It is with great pride and excitement that we open our Fragrance Atelier in Paris,” said Stéphane de La Faverie, President and Chief Executive Officer, The Estée Lauder Companies. “Building on our incredible heritage of creativity and innovation, the Atelier will propel our future growth in this dynamic category — uniting world-class expertise, cutting-edge technology, and the artistry of fragrance to accelerate innovation across our portfolio. Located in the cradle of perfumery, our teams will blend state-of-the-art technology, data-driven intelligence, and olfactive expertise to craft the next generation of extraordinary scents for our consumers worldwide.”

“The Fragrance Atelier is an exciting new model for creation — a space that harnesses creativity and science to shape the future of fragrance,” said René Lammers, The Estée Lauder Companies’ Chief Research & Innovation Officer. “This hub brings together experts from across our fragrance brands and partners in an environment purpose-built for experimentation. Together, they will accelerate the journey from inspiration to formulation and ultimately to the final consumer experience.”

A Bold Addition to The Estée Lauder Companies’ Innovation Network

The Atelier further enhances The Estée Lauder Companies’ global research and innovation network across the United States (New York and Minnesota), China (Shanghai), Europe (Belgium), and Canada (Toronto). Together, these sites seamlessly integrate category- and region-specific strengths to drive breakthrough discovery across the full spectrum of beauty. The Atelier introduces an AI-enabled, end-to-end creation process that combines olfactive and neuroscience modeling with real-time monitoring of patents, research, and regulations. These resources will accelerate discovery, develop new technologies, fuel experimentation, and enable faster response to evolving consumer trends, reducing fragrance development lead times by up to 30–50% in the coming years.

A Transformative Space Custom Built for Fragrance Innovation

Inside the Atelier, specialized co-creation and innovation spaces bring artistry and science to life. In the Music Room, perfumers from leading fragrance houses and brand teams collaborate to compose signature accords and explore new olfactive territories. In the adjoining laboratories, experts use CO₂ supercritical extraction, GCMS molecule analysis, and AI-driven sillage measurement to understand fragrance structure and longevity at the molecular level. Proprietary neuroscience-based consumer modeling transforms sensory data into insight, helping creators design fragrances that stir emotion and inspire desire.

Serving as a shared innovation engine for all fragrance brands within the company’s portfolio, the Atelier accelerates collaboration and discovery across Jo Malone London, TOM FORD, Le Labo, KILIAN PARIS, and Editions de Parfums Frédéric Malle, as well as across Estée Lauder, Clinique, AERIN Beauty, Aramis, and BALMAIN Beauty fragrances. Each brand retains its distinctive voice while drawing on shared access to next-generation technology, proprietary ingredients, and scientific expertise.

Located in the heart of Paris, La Maison des Parfums unites the company’s fragrance, creative, and innovation teams within a five-story, 2,000-square-meter space that blends French craftsmanship with modern design. Its architecture evokes the composition of a fragrance — travertine as the base, artisanal details as the heart, and light-infused finishes as the top note — creating an immersive environment where heritage and innovation coexist in harmony.

Deepening The Estée Lauder Companies’ Commitment to France

The Atelier’s opening underscores The Estée Lauder Companies’ enduring commitment to France, a country whose strong culture of innovation and investment continues to make it a vital strategic market and creative hub for the company. The company’s presence in France spans nearly six decades, beginning with its first French office in 1966. Today, Paris serves as the location for the company’s EUKEM regional headquarters, a newly created geographic cluster encompassing Europe, the United Kingdom and Ireland, and emerging markets in Asia, Africa and the Middle East, as well as the headquarters of the company’s French sales affiliate.

The Estée Lauder Companies employs more than 1,200 people in France and proudly operates the global headquarters of several of its brands there, including KILIAN PARIS, Editions de Parfums Frédéric Malle, Darphin Paris, and Lab Series. The establishment of La Maison des Parfums and the Fragrance Atelier builds on this foundation, further connecting the company to France’s world-renowned ecosystem of perfumers, suppliers, and creative talent.

“We are extremely proud that The Estée Lauder Companies has chosen France as the location for its new Fragrance Atelier — an innovative project announced at the most recent Choose France summit,” said Pascal Cagni, French Ambassador for International Investments and Chairman of the Board of Business France. “Their choice demonstrates the confidence that international leaders have in French excellence, which is driven by a unique ecosystem of creative talent, innovation, and globally recognized expertise. The French perfume and cosmetics industry, with more than €30 billion in revenue, is a key driver of growth and attractiveness. The Estée Lauder Companies’ Fragrance Atelier is a perfect demonstration of France’s ability to offer companies an environment conducive to the development of their most ambitious projects. I commend the remarkable work of the Business France teams which enables France to remain at the forefront of the global perfume industry.”

Cautionary Note Regarding Forward-Looking Statements

Statements in this press release may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include those in the various quotations. Although the Company believes that its expectations are based on reasonable assumptions within the bounds of its knowledge of its business and operations, actual results may differ materially from the Company’s expectations. Factors that could cause actual results to differ from expectations include the ability to successfully implement the Company’s strategy, including Beauty Reimagined and the profit recovery and growth plan; successfully transition its leadership; and those other factors described in the Company’s filings with the Securities and Exchange Commission, including its most recent filings with the Securities and Exchange Commission. The Company assumes no responsibility to update forward-looking statements made herein or otherwise.

About The Estée Lauder Companies

The Estée Lauder Companies Inc. is one of the world’s leading manufacturers, marketers, and sellers of quality skin care, makeup, fragrance, and hair care products, and is a steward of luxury and prestige brands globally. The company’s products are sold in approximately 150 countries and territories under brand names including: Estée Lauder, Aramis, Clinique, Lab Series, Origins, M·A·C, La Mer, Bobbi Brown Cosmetics, Aveda, Jo Malone London, Bumble and bumble, Darphin Paris, TOM FORD, Smashbox, AERIN Beauty, Le Labo, Editions de Parfums Frédéric Malle, GLAMGLOW, KILIAN PARIS, Too Faced, Dr.Jart+, the DECIEM family of brands, including The Ordinary and NIOD, and BALMAIN Beauty.

View source version on businesswire.com: https://www.businesswire.com/news/home/20251013447078/en/

Media Relations:

Lauren Pratapas

[email protected]

Investor Relations:

Rainey Mancini

[email protected]

Source: The Estée Lauder Companies Inc.