Efficacy and safety of vitrectomy with internal limiting membrane peeling for diabetic macular edema: a Meta-analysis

AIM: To evaluate the efficacy and safety of vitrectomy with internal limiting membrane (ILM) peeling for diabetic macular edema (DME).METHODS: The PubMed, Embase, Web of Science, Cochrane, SionMed, ClinicalTrials.gov, CNKI databases and Wanfang databases, published until Oct. 2017, were searched to identify studies comparing the clinical outcomes following vitrectomy with and without ILM peeling, for treating DME. Pooled results were expressed as odds ratios (ORs) with corresponding 95% confidence intervals (CI) for vitrectomy with and without ILM peeling with regard to best corrected visual acuity (BCVA), central macular thickness (CMT), and complication incidents.RESULTS: A total of 14 studies involving 857 eyes were included of which three studies were Chinese and the rests were English literatures. Meta-analysis indicated that compared with vitrectomy alone, vitrectomy with ILM peeling could improve BCVA more obviously (OR=1.66, 95%CI: 1.12-2.46, P=0.01) and had higher rate of CMT reduction (OR=3.89, 95%CI: 1.37-11.11, P=0.01). There were significant statistical differences between the two surgical methods for both BCVA and CMT (P<0.05). For the incidence of intraoperative and postoperative complications, the incidence of epiretinal membrane (ERM) was slightly lower in the ILM peeling group than the group without ILM peeling (OR=0.38, 95%CI: 0.07-2.00, P=0.25), although insigni?cant statistically. Other incidences of overall complications, iatrogenic peripheral retinal break and increased intraocular pressure indicated no significant difference between two groups (OR=1.19, 95%CI: 0.82-1.73, P=0.36; OR=1.21, 95%CI: 0.66-2.21, P=0.53; OR=1.34, 95%CI: 0.75-2.40, P=0.32).CONCLUSION: Vitrectomy is effective for DME and the effect can be improved by additional ILM peeling, especially for anatomical efficacy, without increasing the incidence of intraoperative and postoperative complications. However, it is imperative to gain more evaluation in the future due to the paucity of prospective randomized study.