Supplementary Material for: Anatomical, functional, and prognostic results of vitrectomy in epiretinal membranes secondary to retinal vein occlusions

Introduction: We investigated the anatomical and functional results of vitrectomy associated with the peeling of secondary epiretinal membranes (ERM) in patients with retinal vein occlusion (RVO) and determined the prognostic factors of surgical outcomes.
Methods: This retrospective, multicenter, observational study included 50 patients with RVO who underwent vitrectomy with ERM removal between July 2012 and February 2021. Visual acuity (VA) and central macular thickness (CMT) were investigated up to three years. Univariate analysis identified the predictive factors associated with functional and anatomical outcomes.
Results: Fifty eyes from 50 patients (62% with central RVO) were included. The mean VA of 0.9 ± 0.7 logMAR preoperatively improved to 0.5 ± 0.5 logMAR after 24 months (p=0.01). Anatomically, the mean preoperative CMT was 501 ± 168 μm, decreasing to 348 ± 108 μm at month 24 (p=0.008). By 36 months, VA had improved or stabilized in 90% of the eyes, whereas CMT had reduced by at least 20% from baseline in 80% of the eyes. A lower number of intravitreal injections (IVI) was required after vitrectomy. Worse preoperative VA, absence of preoperative pan-retinal photocoagulation, and postoperative use of adjunctive IVI were associated with VA recovery. Higher baseline CMT and the use of preoperative dexamethasone injections were associated with an improvement in CMT.
Conclusion: Vitrectomy for ERM secondary to RVO was effective in improving VA and recovering CMT for up to 3 years and reduced the number of IVIs.