Association between anticholinergic burden and geographic atrophy secondary to age-related macular degeneration: a case-control study

Age-related macular degeneration (AMD) is a leading cause of visual impairment in older adults. Given the high prevalence of polypharmacy in this population, cumulative medication effects, particularly anticholinergic burden, may represent a clinically relevant factor requiring further investigation. This study aimed to investigate the association between anticholinergic burden, overall drug burden, and geographic atrophy secondary age-related macular degeneration (GA secondary to AMD).

In this case-control study, 102 participants aged 55-90 years were included. Anticholinergic burden was assessed using the Anticholinergic Cognitive Burden (ACB) scale. Medications regularly used by patients for chronic conditions and continued for a minimum duration of three months were included. Drug burden was defined as polypharmacy (≥ 5 medications). Multivariate logistic regression analyses were performed adjusting for age, gender, and multimorbidity.

Patients with GA secondary to AMD had a higher number of medications and a greater prevalence of both drug burden and anticholinergic burden compared to controls (p = 0.010, p = 0.039, and p = 0.046, respectively). In multivariate analysis, anticholinergic burden (OR: 2.55, 95% CI: 1.11-5.84, p = 0.026) and drug burden (OR: 3.41, 95% CI: 1.21-9.58, p = 0.017) were independently associated with GA secondary to AMD.

Increased anticholinergic and overall drug burden were independently associated with GA secondary to AMD in older adults. These findings suggest a potential relationship between cumulative medication exposure and AMD. Further prospective studies are needed to determine whether this association has clinical or causal significance.