Results suggest patients with age-related macular degeneration who have visual disability should be targets for risk factor management and disease prevention for cardiovascular disease.
A nationwide cohort study of nearly 4 million adults in Korea found that age-related macular degeneration (AMD) was not strongly associated with an increased risk of cardiovascular disease (CVD).1
However, the investigative team, led by Dong Hui Lim, MD, PhD, Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, indicated the risk was increased (17%) when patients with AMD had visual disability, suggesting the need to target these patients for CVD risk factor management and disease prevention.
“Therefore, individuals with both AMD and visual disability should be monitored for CVD risk,” wrote the investigative team.1 “The underlying pathophysiology between advanced AMD and CVD needs to be elucidated in future studies.”
The population of people with AMD is expected to rise to 288 million in the next 2 decades, signifying the importance of addressing comorbid conditions in people with AMD. There are conflicting results, however, on the association between AMD and the risk of CVD. Previous studies from the US have reported a 19% higher risk of incident myocardial infarction and a 20% higher risk of ischemic stroke in patients with AMD, as well as a 42% decrease in the risk of hospitalized MI or a 44% decrease in the risk of cerebrovascular accident.2
Other studies have investigated the association of AMD with CVD by stage and have shown no association between late AMD and the risk of CVD. But investigators noted these studies were often limited by suboptimal adjustment of potential confounders and a short follow-up period. In addition, though visual disability is associated with cardiometabolic conditions, the presence of visual disability was not considered in previous studies on CVD risk in patients with AMD.
For this investigation, Lim and colleagues analyzed the association between AMD, visual disability, and the risk of CVD using data from the Korean National Health Insurance System (NHIS) database (2009 - 2019). Among 4,470,729 participants aged ≥50 years who underwent general health screenings in 2009, exclusions based on missing data and history of MI and ischemic stroke left 3,789,963 participants for the analysis.
The study defined visual disability as best-corrected visual acuity (BCVA) of ≤20/100 and validated documentation from a specialist physician. Endpoints for the study - identified using the ICD-10 codes - were incidence MI and ischemic stroke, with investigators defining CVD as a composite of MI and ischemic stroke. Participants were followed up with from the data of health examination in 2009 to the date of incident MI, incident stroke, death, censored data, or end of the study period in December 2019.
Of the total population enrolled in the analysis, 43,753 participants (1.13%) had AMD at the baseline, of which 3123 subjects (7.1% of the AMD group) had a visual disability. At baseline, the group with AMD and visual disability was older, with a higher proportion of men and current smokers, and had a lower prevalence of hypertension and dyslipidemia than the AMD without visual disability group (all P <.001).
With a mean follow-up of 9.77 years, the analysis found there were 254,670 overall CVD events (6.72%), 112,174 cases of MI, and 156,675 cases of ischemic stroke. Data showed AMD was not associated with the risk of overall CVD (aHR, 1.02; 95% CI, 1.00 - 1.05; P = .101), but a 17% increased risk for CVD in AMD with visual disability (aHR, 1.17; 95% CI, 1.06 - 1.29).
Moreover, Lim and colleagues found AMD was associated with a 5% increased risk of MI (aHR, 1.05; 95% CI, 1.01 - 1.10), and AMD with visual disability had an 18% increased risk for MI (aHR, 1.18; 95% CI, 1.01 - 1.37). Additionally, AMD was not associated with the risk of ischemic stroke (aHR, 1.02; 95% CI, 0.98 - 1.06), but the association was significant in patients with AMD and visual disability (aHR, 1.20; 95% CI, 1.06 - 1.35).
When stratified by age and sex, investigators found no significant interaction according to age groups, but the relationship between AMD and CVD was more evident in women, with a significant interaction between AMD and sex (P-interaction = .0006). Moreover, the trends in the risk of CVD were higher with AMD and visual disability in patients who had cardiometabolic comorbidities, according to the analysis.
Lim and colleagues reiterated the need for a prospective study that specifies a chronological order in AMD and visual disability to enhance the understanding between AMD with visual disability and CVD.
“In summary, AMD with visual disability, but not all AMD, was associated with an increased risk of CVD,” they wrote. "Patients with AMD who have visual disability should be targeted for risk factor management and disease prevention for CVD."