The natural history of macular edema after cataract surgery in diabetes

Objective: a rational basis for laser therapy. To determine the natural his tory of macular edema after cataract surgery in diabetes to provide Design: Prospective clinical and angiographic trial. Participants: Thirty-two patients with diabetes undergoing cataract surgery . Intervention: Phacoemulsification surgery with intraoperative fluorescein a ngiography, and postoperative clinical and angiographic assessment without macular laser therapy for 1 year after surgery. Main Outcome Measures: Clinically significant macular edema, postoperative macular and optic disc hyperfluorescence relative to the intraoperative ang iogram, and logarithm of the minimum angle of resolution (LogMAR) visual ac uity. Results: In the first postoperative year, macular fluorescence remained at its intraoperative level in 2 (6%) of 32 eyes and increased in 30 (94%) of 32 eyes, returning to its intraoperative level within 1 year of surgery in 13 (43%) of 30 eyes. Optic disc fluorescence remained at its intraoperative level in 2 (6%) of 32 eyes, was not graded in 3 (9%) of 32 eyes, and incre ased in 27 (84%) of 32 eyes, returning to its intraoperative level within 1 year of surgery in 19 (70%) of 27 eyes. Clinically significant macular ede ma was identified in the first postoperative year in 18 (56%) of 32 eyes, b eing present at the time of surgery in 5 eyes and arising de novo within 1 year of surgery in 13 eyes. It resolved spontaneously within 1 year of surg ery in 0 of 5 eyes in which it had been present at the time of surgery and in 9 (69%) of 13 eyes in which it arose in the first 6 months after surgery (P = 0.05). Angiographic and clinical resolutions of macular edema were le ss likely in eyes with more severe retinopathy at the time of surgery (P = 0.03, 0.005). One-year LogMAR acuity of 0.3 or less (greater than or equal to 20/40) was achieved in 27 (84%) of 32 eyes. Clinically significant macul ar edema at the time of surgery was associated with poorer 1-year visual ac uity in multivariate analysis (P = 0.005, r(2) = 0.5), Conclusions: Clinically significant macular edema present in diabetic eyes at the time of cataract surgery is unlikely to resolve spontaneously, but c linically significant macular edema arising after surgery commonly resolves , particularly if retinopathy is mild, These findings have implications for the timing of cataract surgery in diabetes and postoperative macular laser therapy.