Effect of inverted internal limiting membrane flap technique on small-medium size macular holes

Inverted internal limiting membrane (ILM) flap technique was developed to achieve macular hole (MH) closure in large MH and refractory cases. In this study, we evaluate the effect of the technique for small-medium size MH. We recruited patients who underwent vitrectomy for small-medium size (< 400 μm) MH with either inverted ILM flap technique (flap group) or with conventional ILM peeling (peeling group). Using propensity score, 21 eyes of 21 patients in the peeling group were matched against 21 eyes of 21 patients in the flap group. We compared MH closure rate, postoperative visual acuity, and recovery of the external limiting membrane (ELM) and ellipsoid zone (EZ). The MH closure rate was not different between the two groups (flap vs peeling: 90% vs 100%, P = 0.49). Whereas there was no significant difference in visual acuity improvement between the two groups, the flap group showed more disruption of the ELM 3 months after surgery and of the EZ at 3 and 6 months after surgery (P = 0.02, P = 0.03, and P = 0.04, respectively). The result suggested that inverted ILM flap technique does not have additional benefits for small-medium size MHs and may delay recovery of retinal integrity.