Reduction of severe macular edema in eyes with poor vision after panretinal photocoagulation for proliferative diabetic retinopathy.

Currently available data from multicenter randomized trials on laser treatment of diabetic macular edema refer only to eyes with pretreatment visual acuities of 20/160 or better. After observing reduction of more severe macular edema and visual improvement following panretinal photocoagulation (PRP) alone in some patients, we reviewed our experience with this problem. In 18 eyes of 14 patients with proliferative diabetic retinopathy and visual acuity of 20/200 or worse, secondary to severe macular edema were identified. At 6 months after PRP without focal macular laser treatment, macular edema was reduced in 13 eyes, 8 of which improved by greater than or equal to 2 lines of vision. Among the latter 8 eyes, the visual acuity of 4 recovered to 20/80 or better; the remaining 10 eyes, which had chronic retinal pigment epithelial atrophy or extensive macular ischemia, did not improve. Based on these observations, we suggest that peripheral PRP performed in multiple sessions over several months may have a beneficial effect on severe macular edema in some eyes with adequate macular perfusion.