Novel findings from a 20-year-long longitudinal cohort study in Taiwan, published in Nature in 2025, found that a reciprocal relationship existed between age-related macular degeneration (AMD) and atrial fibrillation (AF), ie, the diagnosis of one condition increased the risk of the other.
There is still a lot of unknown information in the association between AMD and AF; however, they do both share the same biological process involving chronic inflammation, oxidative stress, and vascular endothelial growth factor.
Hou-Ren Tsai and colleagues wanted to investigate whether this shared commonality between the two conditions meant that by having one condition, the risk of the other one increased.
Data on adults aged 50 years and over during the study period, 2003 to 2018, was extracted from the National Health Insurance Research Database of Taiwan; this is a representative database covering 99.6% of the entire population. To investigate the bidirectional relationship of the two conditions, a retrospective cohort study design was adopted. The exposed group of the AF cohort was made up of individuals newly diagnosed with AF, and they were compared to the unexposed group, which comprised individuals without an AF diagnosis and matched to their exposed counterparts based on index date. Similarly, the exposed AMD group were individuals newly diagnosed with AMD and their matched controls in the unexposed group were those without a diagnosis of AMD.
The findings from the AMD cohort showed that those who were newly diagnosed with AMD had an 8% higher risk of developing AF compared to the unexposed group; the exposed group also showed a shorter mean follow-up period of 6.40 years compared to 6.46 years in the unexposed group. The incidence rate of developing AF was 9.85 per 1,000 person-years in the exposed group and 8.95 per 1,000 person-years in the unexposed group. Subgroup analysis showed that dry AMD, a subtype of the condition, was associated with an increased risk of developing AF, but that association was not found for wet AMD. When AF exposure was assessed by AMD subtype, it was found that AF was associated with increased risk of developing dry AMD but not wet AMD.
Those who were newly diagnosed with AF had a 10% higher risk of developing AMD compared with those in the unexposed group and a shorter mean follow-up length of 6.40 years compared to 6.46 years in the unexposed group. The incidence rate of developing AMD in the exposed group was 11.98 per 1,000 person-years compared to 10.88 per 1,000 person-years in the unexposed group.
GlobalData epidemiologists predict that by the end of 2025 there will be over 99,000,000 diagnosed prevalent cases of men and women aged 50 years and older with AMD in the 16 major markets (16MM: the US, France, Germany, Italy, Spain, the UK, Japan, Australia, Brazil, Canada, China, India, Mexico, Russia, South Africa, and South Korea), and that number is estimated to increase to just over 115,000,000 cases by the end of 2031. For AF, the predicted diagnosed prevalent cases in men and women aged 40 years and older by the end of 2025 in the 16MM is just over 24,000,000 cases, and that number is projected to increase to over 29,000,000 cases by the end of 2032 in the 16MM.
Prior to this research study, only a single cross-sectional study was conducted to investigate the correlation between AMD and AF; thus, the findings from this research contributed new knowledge that has highlighted a potential gap in healthcare and public health policy.