Vitrectomy with internal limiting membrane (ILM) peeling versus vitrectomy with no peeling for idiopathic...

Several observational studies have suggested the potential benefit of internal limiting membrane (ILM) peeling to treat idiopathic full-thickness macular hole (FTMH). However, no strong evidence is available on the potential benefit(s) of this surgical manoeuvre and uncertainty remains among vitreoretinal surgeons about the indication for peeling the ILM, whether to use it in all cases or in long-standing and/or larger holes.

To determine whether ILM peeling improves anatomical and functional outcomes of macular hole surgery compared with the no-peeling technique and to investigate the impact of different parameters such as presenting vision, stage/size of the hole and duration of symptoms in the success of the surgery.

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) which contains the Cochrane Eyes and Vision Group Trials Register (The Cochrane Library 2013, Issue 2), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, (January 1950 to February 2013), EMBASE (January 1980 to February 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to February 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We searched the reference lists of included studies for any additional studies not identified by the electronic searches. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 28 February 2013.We searched reference lists of the studies included in the review for information about other studies on ILM peeling in macular hole surgery. We searched Proceedings for the following conferences up to February 2013: American Academy of Ophthalmology (AAO), Annual Meeting of the American Society of Retina Specialists (ASRS), Annual Meeting of the Retina Society, Congress of the Asia-Pacific Academy of Ophthalmology (APAO), European Association for Vision and Eye Research (EVER) Annual Congress, European Vitreoretinal Society (EVRS) Annual Meeting, Association for Research in Vision and Ophthalmology (ARVO) Meeting, International Vitreoretinal Meeting, and World Ophthalmology Congress.

Only randomised controlled trials (RCTs) comparing ILM peeling with the no-peeling counterpart were included.

Two review authors (KSC and NL) independently assessed the titles and abstracts of all RCTs identified by electronic and manual searches.We obtained Individual patient data (IPD) from three of the four identified eligible trials. The fourth identified RCT had only been published in abstract form and no IPD were available; we included data from this published abstract for one outcome (macular hole closure).The primary outcome was distance visual acuity at six months. Secondary outcomes included distance and near  visual acuity at three and 12 months postoperatively, near visual acuity at six months postoperatively, primary (after a single surgery) and final (following more than one surgery) macular hole closure, need for additional surgical interventions, vision-related quality of life and intraoperative and postoperative complications.We performed meta-analysis using standard techniques (the Mantel-Haenszel odds ratio (OR) for binary outcomes, mean difference (MD) for continuous outcomes) using a fixed-effect model. For two outcomes we also used the IPD to perform adjusted analyses using regression methods.

We identified and included four RCTs; these were conducted in Denmark, France, Hong Kong and the United Kingdom/Republic of Ireland and randomised 47, 80, 49 and 141 participants respectively.There was no evidence of a difference in the primary outcome (distance visual acuity at six months), nor in distance visual acuity at 12 months between randomised groups. However, there was evidence of improved best corrected distance visual acuity in the ILM peeling group at three months (WMD -0.09, 95% CI -0.17 to -0.02). We found no evidence for a difference in near vision between groups at any of the time points investigated.Overall, more participants in the ILM peeling group than in the no-peeling group had primary macular hole closure (OR 9.27, 95% CI 4.98 to 17.24); this held true when results were stratified by the stage of the macular hole. There was also evidence that those in the ILM peeling group were more likely to have final macular hole closure (OR 3.99, 95% CI 1.63 to 9.75). Fewer participants required further surgery in the ILM peeling group than in the no-peeling group (OR 0.11, 95% CI: 0.05 to 0.23).Rates of intraoperative and postoperative complications were similar in both groups.Based on the results of one study, there was no evidence that total VFQ-25 or EQ-5D scores differed between the groups at six months.  Based on this same study, ILM peeling is highly likely to be cost-effective.

Although we found no evidence of a benefit of ILM peeling in terms of the primary outcome (visual acuity at six months), ILM peeling appears to be superior to its no-peeling counterpart as it offers more favourable cost effectiveness by increasing the likelihood of primary anatomical closure and subsequently decreasing the likelihood of further surgery, with no differences in unwanted side-effects compared with no peeling.