Possible effects of internal limiting membrane peeling in vitrectomy for macular vein occlusion

Purpose To evaluate the effect of pars plana vitrectomy (PPV) either with or without internal limiting membrane (ILM) peeling for macular edema associated with macular vein occlusion (MVO). Methods In this retrospective, interventional, comparative case series study, 41 patients (41 eyes) underwent PPV either with or without ILM peeling for macular edema due to MVO. Twenty-eight eyes without ILM peeling (PPV alone) were compared with 13 eyes with ILM peeling (ILM-off). The main outcome measures were best-corrected visual acuity (BCVA) and foveal thickness, evaluated by optical coherence tomography. Results Baseline demographic characteristics of the two groups were similar. Postoperative follow-up period ranged from 12 to 53 months (mean, 27.9 months). The postoperative mean BCVA improved and foveal thickness decreased significantly in both groups. The difference in BCVA between the two groups was not significant at any time point. The mean foveal thickness in the ILM-off group was thicker than that in the PPV alone group during the follow-up period. No patient had severe intraoperative or postoperative complications. Conclusion PPV either with or without ILM peeling may improve the anatomical and functional outcomes of macular edema secondary to MVO. Removal of the ILM does not appear to affect visual outcome; however, it may not reduce the foveal thickness as much as PPV alone.