Abstract
Purpose: :
Data from population–based studies have suggested that cataract surgery may result in an increased risk of developing advanced age–related macular degeneration (AMD). We investigate this potential relationship with the neovascular form of advanced AMD in data from the Age–Related Eye Disease Study (AREDS). AREDS has many more cases of advanced AMD and cataract surgery than the published population–based studies.
Methods: :
Neovascular AMD (NV AMD) was assessed annually from centrally graded stereoscopic fundus photographs. Risk of NV AMD associated with cataract surgery was assessed using four complementary analytic methods: ordinary logistic regression, repeated measures logistic regression, cases (cataract surgery) vs matched controls, and Cox proportional hazard with time–dependent covariates. Four methods were used because no single method is clearly more informative than the others, and each approach has both strengths and weaknesses compared with the other approaches. Analyses were for RE and LE separately, and combined utilizing generalized estimating equations where possible. Covariate adjustments included age, smoking, gender, race, AREDS treatment, and AMD status on a 9–point severity scale.
Results: :
There were 1704 cataract surgeries and 543 NV AMD events after baseline among 8152 eyes with median follow–up 9 years. Cataract surgery was not significantly associated with NV AMD in any of the following analyses: Ordinary logistic regression analysis of incidence at 5 years (odds ratio [OR] 1.10, 95%CI 0.64–1.88), Repeated measures logistic regression (RE, OR=1.14, 95%CI 0.91–1.43; LE, OR=0.99, 95%CI 0.80–1.22), Case control approach (ratio of the number of eyes with cataract surgery [cases] with subsequent NV AMD before their matched controls to the number of eyes without cataract surgery [controls] with NV AMD before their matched cases = 0.85, 95%CI 0.56–1.27), and Cox proportional hazards (RE hazard ratio =1.38, 95%CI 0.97–1.96; LE hazard ratio =1.15, 95%CI 0.78–1.70).
Conclusions: :
In this large clinic–based longitudinal cohort study these analyses show no clear evidence of an association between cataract surgery and neovascular AMD. Patients undergoing cataract surgery can probably be reassured that the surgery will not markedly increase their risk for progression to neovascular AMD.
Keywords: age-related macular degeneration • cataract • choroid: neovascularization