Correlation between outer retinal thickening and retinal function impairment in patients with idiopathic epiretinal membranes

Purpose: To examine the relationship between retinal layer thickness, retinal sensitivity, and visual function in patients with idiopathic epiretinal membrane using spectral domain optical coherence tomography automated segmentation algorithm. Methods: Twenty-four eyes with epiretinal membrane and 12 control eyes were enrolled. Ophthalmic evaluations included best-corrected visual acuity, mean retinal sensitivity (MRS) of radial 10° and 4° areas tested with microperimetry, and measurements of 4 retinal layer thicknesses by means spectral domain optical coherence tomography. Relations between retinal layer thickness, MRS, and best-corrected visual acuity values were explored. Results: Compared with controls, MRS (P < 0.001) and best-corrected visual acuity (P < 0.001) values were reduced. In the epiretinal membrane group, MRS of the central 4° values was associated with thickening of the outer nuclear layer (P < 0.05). Furthermore, a correlation was found between the inner nuclear layer thickening and the MRS of the central 4° limited to the inferior quadrant (P < 0.05). The decreased best-corrected visual acuity values were correlated with the thickening of three of four quadrant of the inner nuclear layer, inferior and temporal quadrants of the outer plexiform layer, and finally outer nuclear layer nasal quadrant. Conclusion: We found a meaningful correlation between MRS impairment of the central 4° and outer nuclear layer thickness and showed which intraretinal layers mainly contributes to visual acuity loss.