Outcomes of vitrectomy, membranectomy and internal limiting membrane peeling in patients with refractory diabetic macular edema and non-tractional epiretinal membrane

PURPOSE To evaluate the efficacy of vitrectomy, membranectomy, and internal limiting membrane (ILM) peeling on macular thickness and best corrected visual acuity (BCVA) in patients with refractory diffuse diabetic macular edema (DME) and non-tractional epiretinal membrane (NT-ERM). METHODS This prospective interventional case series included eyes with refractory DME (central subfield macular thickness [CSMT] > 300 μm) after at least two intravitreal injections of bevacizumab (IVB) and one intravitreal injection of triamcinolone (IVT), and accompanying NT-ERM. Complete ophthalmic examination, baseline spectral domain optical coherence tomography (SD-OCT), and fluorescein angiography (FA) were performed prior to 23 gauge pars plana vitrectomy with membranectomy and internal limiting membrane (ILM) peeling. Postoperative evaluation was done with clinical examination and SD-OCT. Linear mix model analysis was used to study postoperative results. RESULTS Twelve eyes from 11 patients (5 males) with a mean age of 60.33 ± 9.01 (range 46-73 years) were included. The mean follow-up time was 13.5 ± 4.48 months (range 4-20 months). A significant reduction in CSMT was found (from 559 ± 89 μm to 354 ± 76 μm; P = 0.001), with a non-significant BCVA change (from 0.84 ± 0.32 logMAR to 0.72 ± 0.2 logMAR; P = 0.967). There was no significant correlation between CSMT and BCVA (partial correlation = -0.115, P = 0.445) and also between estimated mean CSMT change per month and estimated mean BCVA change per month (r = 0.337, P = 0.283). CONCLUSION In this series, our results did not show that vitrectomy, membranectomy, and ILM peeling result in significant improvement of BCVA in eyes with refractory DME and non-tractional ERM in spite of central macular thickness reduction.