The efficacy of focal laser therapy in radiation-induced macular edema

Objective: The purpose of the study was to determine whether focal laser therapy improves or prevents deterioration of visual acuity in radiation- induced macular edema. Design: Retrospective review. Participants: The chart review of 19 patients. Intervention: Comparison of 19 patients with radiation-induced macular edema secondary to radioactive scleral plaque application for choroidal melanoma managed by focal laser therapy with a matched group of 23 similar patients followed by observation. Results: Doubling of the visual angle occurred in 68% of all cases with 2 years of follow-up. At 6 months, 8 of 19 (42%) treated but no observed cases experienced ≥ 1 Shellen line improvement in visual acuity (P = 0.005, Fischer's exact test), and the visual angle was halved in 3 of 19 (1.6%) treated but no observed cases at 6 months (P = 0.069). Resolution of macular edema occurred at 6 months in 5 of 19 (26%) treated and 1 of 23 (4%) observed cases (P = 0.21). No significant difference in visual acuity between the two groups was present after 2 years. Conclusions: Progressive visual loss secondary to radiation-induced macular edema is rapid and severe. Focal laser therapy may modestly improve visual acuity and promote resolution of macular edema at 6 months, but benefit from single treatment is not sustained at 2 years.