Role of Vitrectomy in Nontractional Refractory Diabetic Macular Edema

Background: Currently, the gold standard of diabetic macular edema (DME) treatment is anti-vascular endothelial growth factor (VEGF) injections, although a percentage of patients do not respond optimally. Vitrectomy with or without internal limiting membrane (ILM) peeling is a well-established treatment for DME cases with a tractional component while its role for nontractional cases is unclear.The aim of this study is to evaluate the role of vitrectomy with or without ILM peeling in nontractional refractory DME.Methods: We performed a retrospective review of twenty-eight eyes with nontractional refractory DME treated with vitrectomy at San Giuseppe Hospital, Milan, between 2016 and 2018. All surgeries were performed by a single experienced vitreoretinal surgeon. In 43.4% of cases, the ILM was peeled. Best corrected visual acuity and optical coherence tomography (OCT) scans were assessed preoperatively and at 6, 12, and 24 months post-vitrectomy. Results: The mean central macular thickness improved from 413.1 ± 84.4 to 291.3 ± 57.6 μm at two years (p < 0.0001). The mean logarithm of the minimum angle of resolution logMAR best-corrected visual acuity (BCVA) improved after two years, from 0.6 ± 0.2 to 0.2 ± 0.1 (p < 0.0001). We found no difference between ILM peeling vs. no ILM peeling group in terms of anatomical (p = 0.8) and visual outcome (p = 0.3). Eyes with DME and subfoveal serous retinal detachment (SRD) at baseline had better visual outcomes at the final visit (p = 0.001). Conclusions:We demonstrated anatomical and visual improvement of patients who underwent vitrectomy for nontractional refractory DME with and without ILM peeling. Improvement was greater in patients presenting subretinal fluid preoperatively.