Effect of cataract surgery on the progression of diabetic retinopathy

Purpose: To study the effect of cataract surgery and other factors on the progression of diabetic retinopathy using the nonoperated contralateral eye as a control. Setting: Department of Ophthalmology, Catholic University Medical College, Uijongbu St: Mary's Hospital, Seoul, Korea. Methods: Monocular cataract surgery was performed in 75 patients who had the same degree of retinopathy or no retinopathy in both eyes preoperatively. Patients were assigned to 1 of 2 groups as follows: Group A, progression of retinopathy in the operated eye caused by cataract surgery; Group B, no progression of retinopathy bilaterally, comparable level of progression in both eyes, or more progression of retinopathy in the nonoperated eye than in the operated eye. The differences between the 2 groups in age, duration of and treatment methods for diabetes, renal function, and presence of preoperative macular edema were compared. The 1-year follow-up included evaluation of the progression of retinopathy. Results: Surgery caused the retinopathy to progress in 23 patients (30.6%, Group A); 52 patients (69.4%, Group B) had no progression of retinopathy or a comparable level of retinopathy postoperatively. The operated eye had more progression of retinopathy than the nonoperated contralateral eye (P <.05). There was no significant difference between the 2 groups in age, diabetes duration, surgical method, or hypertension. Preoperative macular edema and poor renal function significantly affected the progression of diabetic retinopathy after cataract surgery (P <.05). Conclusions: Diabetic retinopathy progressed after cataract surgery. The presence of preoperative macular edema and poor renal function increased the progression of retinopathy postoperatively.