Effect of vitreomacular separation on macular thickness determined by spectral-domain optical coherence tomography.

To determine the effects of vitreomacular separation on macular thickness. This was a retrospective, observational, cross-sectional study. Average foveal and central minimum thicknesses were measured by spectral-domain optical coherence tomography (SD-OCT) in 308 eyes of 308 healthy subjects (healthy group) and 298 normal fellow eyes of 298 patients with a unilateral macular hole (MH group). Multiple regression analyses were performed to determine the effects of various factors on the macular thickness. The mean age of the healthy group was 67.3 ± 9.6 years (range 40–88 years) and that of the MH group was 67.8 ± 7.0 years (range 43–91). SD-OCT images showed that 149 eyes (48.4 %) in the healthy group and 174 eyes (58.4 %) in the MH group had a vitreomacular separation. In the healthy group, the central minimum thickness of eyes with a vitreomacular separation (196 µm) was significantly thinner than those without a vitreomacular separation (205 µm; P < 0.001). In the MH group, the average foveal thickness (234 µm) and the central minimum thickness (177 µm) in eyes with a vitreomacular separation were thinner than those without it (247 and 199 µm, respectively; both P < 0.001). Multiple regression analyses showed that a vitreomacular separation was significantly correlated with thinner central minimum thicknesses in both groups (P < 0.001) and also with the average foveal thickness in the MH group (P < 0.001). A vitreomacular separation caused thinning of the central fovea in both the healthy eyes and the normal fellow eyes of unilateral MH patients; the extent of foveal thinning is greater in the MH group.