Impact of long-term statin therapy on age-related macular degeneration: A nationwide population-based study.

Objective: Age-related macular degeneration (AMD) is a leading cause of vision loss worldwide among older adults. Although some studies propose that statins could reduce AMD risk and progression, others report conflicting findings. This study aimed to evaluate the impact of statin use on the incidence of AMD.

Methods: This study used Taiwan's National Health Insurance Research Database (2000-2021) with the LGTD2000 cohort. Participants were categorized into statin users (≥6 months, 2001-2020) and nonusers. AMD incidence was analysed using Cox regression and Kaplan-Meier methods, with propensity score matching applied to report adjusted hazard ratios (AHRs) and confidence intervals (CIs).

Results: After adjusting for confounding factors, statin use for over 2 years was associated with a significantly lower risk of AMD compared to nonstatin users (AHR = 0.79, 95% CI: 0.69-0.91). Subgroup analyses demonstrated that long-term statin use (≥730 days) showed protective associations across most sex and age groups. Specifically, risk reduction was observed for both non-neovascular AMD (AHR = 0.84, 95% CI: 0.70-1.02) and neovascular AMD (AHR = 0.72, 95% CI: 0.59-0.88). Furthermore, dose-response analysis revealed that higher cumulative statin exposure was associated with a decreased AMD risk, while lower cumulative exposure was associated with an increased risk.

Conclusions: This study indicated that prolonged statin use exceeding 2 years was associated with a significantly decreased risk of developing both non-neovascular and neovascular AMD.