Phacoemulsification cataract surgery in a large cohort of diabetes patients: Visual acuity outcomes and prognostic factors

PURPOSE: To assess visual acuity outcomes after phacoemulsification cataract surgery in a large population of diabetic patients with all degrees of diabetic retinopathy. SETTING: Diabetology and ophthalmology unit, Copenhagen, Denmark. DESIGN: Cohort study. METHODS: This review of prospectively collected data comprised patients who had small-incision phacoemulsification cataract surgery between 1999 and 2008 (10 years) according to the Danish National Patient Registry. RESULTS: Data of 7323 diabetic patients were reviewed. Of these patients, 285 had cataract surgery. The corrected distance visual acuity (CDVA) increased significantly after cataract surgery (P<.001; P<.05 in all diabetic retinopathy categories). The postoperative CDVA outcome was positively correlated with preoperative CDVA and negatively correlated with the degree of diabetic retinopathy and age (P<.001). Patients with a history of focal laser treatment for clinically significant macular edema had a higher risk for not gaining from cataract surgery (P=.04; relative risk, 1.6). In post hoc analysis, the proportion of patients in the cohort without diabetic retinopathy appeared to increase the year before cataract surgery (P=.03) and decrease the year after cataract surgery (P<.001). CONCLUSIONS: The CDVA increased significantly after phacoemulsification cataract surgery in diabetic patients regardless of the degree of diabetic retinopathy. The apparent progression in diabetic retinopathy after modern cataract surgery seems to reflect the masking of low grades of diabetic retinopathy by preoperative lens opacities.