Long-term effects of vitrectomy and internal limiting membrane peeling for macular edema secondary to central retinal vein occlusion and hemiretinal vein occlusion

Purpose: The purpose of this study was to evaluate the long-term effects of vitrectomy and internal limiting membrane peeling for macular edema secondary to central retinal vein occlusion (CRVO) and hemiretinal vein occlusion (HRVO). Methods: Best-corrected visual acuity, central foveal thickness by optical coherence tomography, and fluorescein angiography were evaluated retrospectively in 20 patients (20 eyes). The mean follow-up time was 61.2 months. Pars plana vitrectomy and internal limiting membrane peeling using indocyanine green staining were performed in all patients. Results: Preoperative mean central foveal thickness of all 20 eyes decreased significantly by 6 months, and this reduction was maintained until 60 months. The mean central foveal thickness of the group with perfused type CRVO, ischemic type CRVO, and HRVO at 6 months significantly decreased from the preoperative value, and the significant reduction was maintained until 60 months. Best-corrected visual acuity of the perfused CRVO and HRVO groups tended to improve in contrast to the ischemic CRVO group postoperatively. Best-corrected visual acuity of the perfused CRVO group at 24 months or later was significantly improved from preoperative best-corrected visual acuity. Conclusion: Pars plana vitrectomy with internal limiting membrane peeling in eyes with macular edema secondary to CRVO and HRVO produces an anatomical improvement, which persists up to 5 years, and a best-corrected visual acuity improvement, at least in perfused CRVO and HRVO.