Assessment of postoperative foveal displacement after vitrectomy and epiretinal membrane peeling using ImageJ software.

PURPOSE: To analyze foveal displacement after macular surgery for idiopathic epiretinal membrane (iERM) using ImageJ software from spectral domain optical tomography (SD-OCT) infrared fundus photographs. METHODS: This retrospective study included total of 75 eyes of 74 patients from the Kocaeli University School of Medicine. The iERM was divided into four stages according to the OCT-based ectopic inner retinal layers (EIFL) staging scheme. SD-OCT infrared fundus photographs were acquired with a Spectralis OCT instrument. The preoperative and postoperative positions of the fovea and the four choroidal landmarks outside the fovea were manually marked from these infrared fundus photographs and entered into ImageJ software, and the displacement of the fovea in the horizontal, vertical, and total planes was measured. RESULTS: A predominant nasal shift was noted in the majority of foveal positions. When examining the EIFL staging of iERM through structural SD-OCT, the magnitude of foveal displacement is most pronounced in Stage 4 (530 ± 440 μm), succeeded by Stage 3 (310 ± 210 μm), and subsequently Stage 2 (230 ± 140 μm) during the final postoperative visit. At the last visit, 80% of eyes had a visual gain of at least 10-letters, and foveal displacement along the y-axis was found to be significantly higher in these patients compared to those with a visual gain of less than 10-letters (p = 0.034). CONCLUSION: In patients with higher visual gain after iERM peeling, the fovea tends to shift more along the Y-axis, suggesting that the amount of vertical foveal displacement is a more predictive factor for postoperative visual gain than the horizontal axis.