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.