Pars plana vitrectomy and internal limiting membrane peeling for macular edema secondary to retinal vein occlusion

Nader Baharivand, Amirhossein Hariri, Alireza Javadzadeh, Ebadollah Heidari, Karim SadegiNikookari Eye Hospital, Tabriz University of Medical Sciences, Tabriz, IranPurpose: To evaluate the effects of vitrectomy and internal limiting membrane peeling for treatment of macular edema secondary to retinal vein occlusion (RVO).Methods: Nine cases of visual loss due to macular edema caused by central retinal vein occlusion or branch retinal vein occlusion underwent pars plana vitrectomy with removal of the preretinal hyaloid, peeling of the internal limiting membrane stained with indocyanine green dye, air–fluid exchange, and postoperative prone positioning. Best-corrected visual acuity (BCVA) and central foveal thickness by optical coherence tomography were measured pre- and postoperatively then compared to assess the outcome of surgery.Results: In all cases intraretinal blood and retinal thickening diminished within 2 months of surgery. Visual acuity improved in all of the central retinal vein occlusion cases and 3/6 branch retinal vein occlusion cases. The decrease in macular thickness was statistically significant (mean postoperative macular thickness 361 ± 61.1 versus mean preoperative macular thickness 563.9 ± 90.0, P = 0.001, t-test). The improvement in BCVA was not statistically significant (mean preoperative BCVA in LogMAR 1.23 ± 0.29 versus mean postoperative BCVA in LogMAR 1.06 ± 0.49, P = 0.09, t-test).Conclusion: In eyes with macular edema secondary to RVO, pars plana vitrectomy with internal limiting membrane peeling can resolve macular edema, but the improvement in BCVA was not statistically significant in this study.Keywords: air–fluid exchange, retinal thickening, retinal hypoxia, concomitant retinal ischemia