Results after lens extraction in patients with diabetic retinopathy - Early treatment diabetic retinopathy study report number 25

Objective: To assess the visual results after surgical lens removal in pati ents with diabetic retinopathy. Design: A multicenter randomized clinical trial designed to assess the effe ct of photocoagulation and aspirin ill patients with mild to severe nonprol iferative or early proliferative diabetic retinopathy and/or macular edema. Participants: Of the 3711 patients enrolled in the Early Treatment Diabetic Retinopathy Study, lens surgery was performed on 205 patients (270 eyes) d uring follow-up that ranged from 4 to 9 years. Outcome Measurements: Visual acuity, macular edema status, and degree of di abetic retinopathy. In addition, risk factors associated with lens extracti on and with poor postoperative visual acuity (worse than 20/100) were asses sed. Results: The risk of lens extraction increased with increasing age, female sex, and baseline proteinuria. Ocular variables associated with increased r isk of lens surgery included poor baseline visual acuity and vitrectomy per formed during the course of the study. At 1 year after lens surgery, visual acuity improvement of 2 or more lines from preoperative levels occurred in 64.3% of the operated-on eyes assigned to early photocoagulation and 59.3% of eyes assigned to deferral of photocoagulation. In eyes assigned to earl y photocoagulation, 46% of eyes achieved visual acuity better than 20/40; 7 3%, better than 20/100; and 8%, 5/200 or worse at 1 year after surgery. Vis ual acuity results for eyes assigned to deferral of laser photocoagulation at I year were not as favorable; 36% achieved visual acuity better than 20/ 40; 55%, better than 20/100; and 17%, 5/200 or worse at 1 year after surger y. Evaluation of 1-year postoperative visual acuities for all eyes with mil d to moderate nonproliferative diabetic retinopathy at the annual visit bef ore lens surgery showed that 53% were better than 20/40; 90%, better than 2 0/100; and 1%, 5/200 or worse. However, for eyes with severe nonproliferati ve or worse retinopathy at the annual visit before lens surgery, only 25% w ere better than 20/40; 42%, better than 20/100; and 22%, 5/200 or worse at 1 year after lens surgery. There was little change in visual acuity between 1 and 2 years postoperatively. Increased severity of retinopathy and poor visual acuity before surgery were associated with visual acuity of worse th an 20/100 at 1 year after surgery. Lens surgery was associated with a borde rline statistically significant increased risk of progression of diabetic r etinopathy in the adjusted analyses (P = .03). No statistically significant long-term increased risk of macular edema was documented after lens surger y. Conclusions: Visual acuity results after lens surgery in patients in the Ea rly Treatment Diabetic Retinopathy Study were better than published results for similar patients. This map be because of more intensive photocoagulati on for lesions of diabetic retinopathy in the Early Treatment Diabetic Reti nopathy Study than in previously reported studies. Although patients with s evere nonproliferative retinopathy or worse before lens surgery had poorer visual results, visual improvement was seen in 55% of these patients at 1-y ear follow-up. The main causes of poor visual results in eyes after lens su rgery were complications of proliferative retinopathy and/or macular edema.