Comparative efficacy evaluation of inverted internal limiting membrane flap technique and internal limiting membrane peeling in large macular holes: a systematic review and meta-analysis

Abstract

Background: The purpose of this study was to compare the anatomical and visual outcomes of inverted internal limiting membrane (ILM) flap technique and internal limiting membrane peeling in large macular holes (MH).

Methods: Related studies were reviewed by searching electronic databases of Pubmed, Embase, Cochrane Library. We searched for articles that compared inverted ILM flap technique with ILM peeling for large MH (> 400 μm). Double-arm meta-analysis was performed for the primary end point that was the rate of MH closure, and the secondary end point was postoperative visual acuity (VA). Heterogeneity, publication bias, sensitivity analysis and subgroup analysis were conducted to guarantee the statistical power.

Results: This review included eight studies involving 593 eyes, 4 randomized control trials and 4 retrospective studies. After sensitivity analysis for eliminating the heterogeneity of primary outcome, the pooled data showed the rate of MH closure with inverted ILM flap technique group was statistically significantly higher than ILM peeling group (odds ratio (OR) = 3.95, 95% confidence interval (CI) = 1.89 to 8.27; P = 0.0003). At the follow-up duration of 3 months, postoperative VA was significantly better in the group of inverted ILM flap than ILM peeling (mean difference (MD) = - 0.16, 95% CI = - 0.23 to 0.09; P < 0.00001). However, there was no difference in visual outcomes between the two groups of different surgical treatments at relatively long-term follow-up over 6 months (MD = 0.01, 95% CI = - 0.12 to 0.15; P = 0.86).

Conclusion: Vitrectomy with inverted ILM flap technique had a better anatomical outcome than ILM peeling. Flap technique also had a signifcant visual gain in the short term, but the limitations in visual recovery at a longer follow-up was found.

Keywords: Internal limiting membrane peeling; Inverted internal limiting membrane flap technique; Large macular hole; Meta-analysis.

Fig. 1

Flow diagram of the study selection process

Fig. 2

Forest plots of MH closure rate between inverted ILM flap and ILM peeling group

Fig. 3

Forest plots of MH closure rate between inverted ILM flap and ILM peeling group after removing Iwasaki’s study

Fig. 4

Forest plots of preoperative VA between inverted ILM flap and ILM peeling group. Michalewska’s study was not included in the analysis of preoperative VA due to the SD of preoperative VA was not given

Fig. 5

Forest plots of postoperative VA between inverted ILM flap and ILM peeling group. Michalewska’s study was not included in the analysis of postoperative VA due to the SD of postoperative VA was not given

Fig. 6

Forest plots of postoperative VA based on follow-up duration in the subgroup analysis. The subgroup analysis based on follow-up duration that divided the included studies into follow-up duration at 3 months and follow-up duration ≥ 6 months. Michalewska’s study was not included

Fig. 7

Funnel plot analysis of MH closure rate. SE standard error, OR odds ratio

Fig. 8

Funnel plot analysis of preoperative VA