Comparisons of foveal thickness and slope after macular hole surgery with and without internal limiting membrane peeling

BACKGROUND: We have shown that the foveal contour was asymmetrical after idiopathic macular hole (MH) closure by pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling. The purpose of this study was to determine whether these morphological changes differ in eyes after PPV without ILM peeling. METHODS: Ten eyes of 10 patients that underwent PPV without ILM peeling and 12 eyes of 11 patients with ILM peeling were studied. The MH in all eyes was <400 µm in diameter. Six months after the PPV, the macular thickness and foveal slope around the closed MH were determined by spectral-domain optical coherence tomography. The thickness of the ganglion cell complex was measured by another spectral-domain optical coherence tomography instrument >6 months after the surgery. RESULTS: The mean parafoveal retinal thickness in the non-peeled group was 367.1 µm in the nasal (N), 353.0 µm in the temporal (T), 366.9 µm in the superior (S), and 357.3 µm in the inferior (I) sectors. The T, S, and I sectors were significantly thicker than the corresponding sectors in the ILM peeled group (p=0.0008, 0.003, and 0.03, respectively). The mean ganglion cell complex was thicker not only in the N sector but also in the T sector in the non-peeled group. The mean retinal slopes in the non-peeled group (N, 40.2°; T, 37.6°; S, 41.2°; I, 39.5°) were flatter than those in the peeled group (N, 52.3°; T, 43.6°; S, 50.8°; I, 51.9°; p=0.009, 0.09, 0.008, and 0.017, respectively). CONCLUSION: The symmetrical fovea after MH surgery in the non-ILM peeled eyes indicates that the asymmetrical fovea after ILM peeling was probably due to the ILM peeling.