Comparison Of The Effectiveness Of Vitrectomy With And Without Internal Limiting Membrane Peeling For Idiopathic Epiretinal Membrane:A Meta-Analysis

Objective:To evaluate the effect of vitrectomy with and without internal limiting membrane(ILM)on the prognosis of idiopathic macular epiretinal membrane(IERM)by meta-analysis.Methods:The clinical outcomes of the treatment that vitrectomy combined with and without internal limiting membrane for idiopathic epiretinal membrane were systematically searched by computer in databases such as PubMed,Embase,Cochrane,and CNKI.The published time for retrieved literature range from the establishment of the database to September 1,2018.The literature was screened according to the inclusion and exclusion criteria and data were extracted for statistical analysis.The primary outcome measures are best corrected visual acuity(BCVA),central macular thickness(CMT)and ERM recurrence and reoperation rates in patients with and without ILM peeling.Data processing was performed using RevMan5.3 statistical software provided by the Cochrane Collaboration.The mean differences(MD),odds ratio(OR)and 95% confidence interval(CI)of the results of each indicator were combined and analyzed for meta-analysis.Results:Twenty-one articles(16 retrospective cohort studies,1 prospective cohort study,and 4 randomized controlled trials(RCTs))involving 1735 eyes were identified.Through comprehensive analysis of data from all studies,no difference was observed between the postoperative best corrected visual acuity(BCVA)in the ILM peelling group and the non-ILM peelling group at 6 months,12 months,and at the final follow-up.The increase in visual acuity greater than 2 Snellen lines was not statistically different between the two groups.However,in total studies,the non-ILM group showed a better postoperative BCVA than the ILM peelling group at 3 months(MD=0.04,95% CI [0.01,0.07],P=0.006).But there was no significant BCVA difference in either the non-randomized studies or the RCTs at 3 months after operation(P = 0.05).It is worth noting that the overall visual acuity statistics at the time of more than 18 months after operation were contrary to those at 3 months after operation: BCVA was better in the ILM peeling group than that in the non-ILM peeling group.(MD =-0.14,95% CI [-0.24,-0.04],P = 0.007).The central macular thickness(CMT)at 3 months,12 months,and more than 18 months after surgery showed no statistically significant difference between the ILM peeling group and the non-ILM peeling group.However,total studies data showed at 6 months and final follow-up after operation,ILM peeling group had thicker CMT than the non-ILM peeling group(MD=13.54,95% CI [2.01,25.07],P=0.02)(MD=10.41,95% CI [0.80,20.03],P = 0.03).RCTs had the same result as the overall studies but there was no significant difference in CMT between the two groups at 6 months postoperatively and at the final follow-up in the non-randomized study.From the comparison of the average reduction of CMT at the final follow-up,the mean reduction of CMT was smaller in the ILM peeling group than in the non-ILM peeling group,and the total difference was statistically significant(MD=-33.54,95%CI ? [-58.35,-8.73],P=0.008).The results of the non-randomized studies were the same as the total studies but the results of RCTs showed that the mean reduction of CMT in the ILM peeling group was smaller,but the difference between the two groups was not statistically significant.There was a significant difference between the two groups in terms of postoperative ERM recurrence rate and reoperation rate: a lower ERM recurrence rate was observed in the ILM peeling group(OR=0.15,95%CI ?[0.09,0.26],P<0.00001)and lower reoperation rate at the final follow-up(OR=0.08,95% CI [0.02,0.32],P = 0.0004).Conclusion:(1)Compared with epiretinal membrane(ERM)peeling only,combined with internal limiting membrane peeling(ILM)may result in poorer early postoperative vision in patients with IERM,and better long-term visual acuity.(2)Non-randomized studies showed central macular thickness(CMT)was similar with or without ILM removal.Randomized controlled trials(RCTs)showed ILM peeling may bring about thicker CMT at various follow-up times.(3)Extra ILM peeling of Idiopathic epiretinal membrane(IERM)during vitrectomy can result in a significant reduction in ERM recurrence rates and reoperation rates.