Microstructural morphology and visual acuity outcome in eyes with epiretinal membrane before, during, and after membrane peeling in intraoperative optical coherence tomography assisted macular surgery

AIM: To measure the difference of intraoperative central macular thickness (CMT) before, during, and after membrane peeling and investigate the influence of intraoperative macular stretching on postoperative best corrected visual acuity (BCVA) outcome and postoperative CMT development. METHODS: A total of 59 eyes of 59 patients who underwent vitreoretinal surgery for epiretinal membrane was analyzed. Videos with intraoperative optical coherence tomography (OCT) were recorded. Difference of intraoperative CMT before, during, and after peeling was measured. Pre- and postoperatively obtained BCVA and spectral-domain OCT images were analyzed. RESULTS: Mean age of the patients was 70±8.13y (range 46-86y). Mean baseline BCVA was 0.49±0.27 logMAR (range 0.1-1.3). Three and six months postoperatively the mean BCVA was 0.36±0.25 (P=0.01 vs baseline) and 0.38±0.35 (P=0.08 vs baseline) logMAR respectively. Mean stretch of the macula during surgery was 29% from baseline (range 2%-159%). Intraoperative findings of macular stretching did not correlate with visual acuity outcome within 6mo after surgery (r=-0.06, P=0.72). However, extent of macular stretching during surgery significantly correlated with less reduction of CMT at the fovea centralis (r=-0.43, P<0.01) and 1 mm nasal and temporal from the fovea (r=-0.37, P=0.02 and r=-0.50, P<0.01 respectively) 3mo postoperatively. CONCLUSION: The extent of retinal stretching during membrane peeling may predict the development of postoperative central retinal thickness, though there is no correlation with visual acuity development within the first 6mo postoperatively