Erectile dysfunction and the risk of glaucoma in men: a prospective nested case-control study using large-scale UK primary care data.

BACKGROUND/AIMS: Primary open-angle glaucoma (POAG) is a leading cause of irreversible sight loss worldwide. A vascular mechanism has been proposed in POAG pathogenesis but supporting evidence remains limited. This study examined whether treatment for erectile dysfunction (ED), a condition with known vascular associations, is linked to POAG risk in men. METHODS: A prospective nested case-control study used nationally representative UK primary care data from Clinical Practice Research Datalink (CPRD) Gold and CPRD Aurum. Cases diagnosed with POAG (n=218 056) were matched 4:1 by age and primary care practice to controls without glaucoma diagnosis or treatment (n=876 872). Conditional logistic regression estimated odds ratios (ORs) and 95% CIs for the association between ED medication use and POAG risk, adjusted for age, ethnicity and deprivation. RESULTS: Mean age was 69 years in cases and 68 years in controls. ED medications were prescribed in 20% of cases versus 17% of controls. ED medication use was associated with significantly higher POAG risk (OR 1.29, 95% CI 1.25 to 1.32 in CPRD Gold; OR 1.17, 95% CI 1.15 to 1.18 in CPRD Aurum). Older age and Black or Asian ethnicity were consistently associated with increased risk. Hypertension, diabetes, asthma, migraine and sickle cell disease were additional risk factors, while myocardial infarction and angina were associated with lower risk. CONCLUSION: ED medication use was prospectively associated with higher POAG risk. The on-demand nature of ED medication use suggests a vascular rather than direct pharmacological mechanism. Experimental studies examining vasoactive medications and POAG outcomes are needed to confirm these findings.