Retinal microaneurysmal closure following focal laser photocoagulation in diabetic macular edema.

OBJECTIVE To determine the temporal relationship of microaneurysmal dosure following focal laser photocoagulation in diabetic macular edema. PATIENTS AND METHODS This prospective study included 25 eyes of 23 diabetic patients with clinically significant macular edema. Ten to 20 well-defined microaneurysms were preselected and marked on an enlarged photograph of the prelaser fundus fluorescein angiogram. These preselected microaneurysms were focally lasered and followed up angiographically at 48 hours, 1 week, 3 weeks, 6 weeks, and 12 weeks after photocoagulation. Thereafter, the average time span between photocoagulation and the closure of the microaneurysms was determined. RESULTS The mean number of preselected microaneurysms at baseline was 18.24 +/- 3.51, which remained the same at 48 hours. However, the mean microaneurysmal count decreased to 11.76 +/- 2.65 (35% reduction) at 1 week, 9.12 +/- 2.53 (50% reduction), 7.12 +/- 2.26 (61% reduction), and 4.56 +/- 1.32 (75% reduction) at 3, 6, and 12 weeks, respectively. The majority of the microaneurysms (35%) closed between 48 hours and 1 week. CONCLUSIONS The microaneurysmal closure following focal laser photocoagulation is a delayed process. None of the preselected microaneurysms showed closure within 48 hours, and 75% of the preselected microaneurysms closed at the end of 12 weeks.