Foveal sensitivity in eyes with diabetic macular edema with and without temporal perifoveal thickening

Background: Visual improvement after photocoagulation in focal diabetic macular edema is more frequent when temporal perifoveal area is not affected . functional status before treatment could be worse in eyes with perifoveal temporal thickening. The correlation between visual acuity and foveal sensitivity (usually significant), would allow to compare macular function. Objective: To compare the correlation between retinal sensitivity and visual acuity in eyes with diabetic macular edema, with and without temporal perifoveal thickening. Method: Non-experimental, retrospective, comparative, cross-sectional study in type 2 diabetics with macular edema. The correlation between foveal sensitivity and visual acuity was compared in eyes without temporal perifoveal thickening (group 1) and eyes with it (group 2). Multiple regression analysis was used to identify the contribution of foveal sensitivity to the changes of visual acuity, other variables were: center point thickness, center field thickness, temporal perifoveal thickness and macular volume. Results: 60 eyes in group 1, 29 eyes in group 2. Mean sensitivity did no differ between groups (30.0 +/- 0.59 vs. 28.4 +/- 1.05 dB; p = 0.2), but the correlation between sensitivity and visual acuity did it (group 1, rho: -0.41; group 2, rho: -0.25). In group 1, foveal sensitivity was the only explaining variable of the regression model (beta: -0.52), in group 2 no one explaining variable was included and temporal perifoveal thickness had a negative correlation with foveal sensitivity (rho: -0.60). Conclusions: Temporal penfoveal thickening reduces the correlation between foveal sensitivity and visual acuity in eyes with diabetic macular edema.