RESUMO
BACKGROUND: Visual improvement after focal photocoagulation in diabetic macular edema is more common in eyes without temporal perifoveal thickening. This feature is related to a lower macular volume before treatment; the higher proportion of visual improvement could be associated with a shorter need of volume reduction. OBJECTIVE: To compare macular volume before and after focal photocoagulation in eyes with diabetic macular edema, with and without temporal perifoveal thickening. METHODS: Non-experimental, retrospective, longitudinal, comparative study in diabetics with macular edema treated with focal photocoagulation. Macular volume measured with optical coherence tomography, and best corrected visual acuity were compared between eyes with (group 1) and without temporal perifoveal thickening (group 2, independent samples Student's t test). The comparison was also performed after stratifying the groups by baseline visual acuity. RESULTS: One hundred and twenty eyes, 65 eyes from group 1 (54.2%) and 55 from group 2 (45.8%). Mean volume before and after treatment and mean absolute and percentage changes were lower in group 2 (p < 0.001) regardless of visual acuity. Macular volume decreased significantly in eyes of group 1; only eyes in group 2 with visual acuity < 0.5 before treatment increased their visual function (p < 0.001). CONCLUSIONS: Eyes without temporal perifoveal thickening had visual improvement, although their volume did not change statistically. The significant volume reduction in eyes with temporal perifoveal thickening was not associated to visual improvement. The anatomical change was not enough to explain the functional improvement.
