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). At ARVO 2005 we reported on finding no clear evidence of increased risk of neovascular AMD with cataract surgery in the Age-Related Eye Disease Study (AREDS). We now investigate this potential relationship with the geographic atrophy form of advanced AMD.
Methods::
Geographic atrophy (GA) was assessed annually from centrally graded fundus photographs. Risk of GA and of GA involving the center point (CGA) associated with cataract surgery was assessed using three complementary analytic methods: ordinary logistic regression, cases (cataract surgery) vs matched controls, and Cox proportional hazard with time-dependent covariates. Three 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, AREDS treatment, and AMD status on a 6-point severity scale.
Results::
There were 1739 cataract surgeries and 526 CGA events after baseline among 7806 eyes with median follow-up 9 years. There was no evidence of an association of cataract surgery with increased risk of CGA in any of the following analyses: Ordinary logistic regression analysis of incidence (odds ratio [OR] 0.43, 95%CI 0.28-0.66), Case control approach (ratio of the number of eyes with cataract surgery [cases] with subsequent CGA before their matched controls to the number of eyes without cataract surgery [controls] with CGA before their matched cases = 0.64, 95%CI 0.50-0.78), and Cox proportional hazards (RE hazard ratio =0.83, 95%CI 0.56-1.23; LE hazard ratio =0.72, 95%CI 0.47-1.10). Ratios <1 suggest reduced risk. Results were similar for GA.
Conclusions::
In this large clinic-based longitudinal cohort study these analyses show no clear evidence of an association between cataract surgery and CGA or GA. Patients undergoing cataract surgery can probably be reassured that the surgery is unlikely to increase their risk for progression to CGA or GA.
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: risk factor assessment • cataract