Effect of inverted internal limiting membrane flap technique on small-medium size macular holes (original) (raw)

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. A macular hole is characterized by a full thickness central foveal hole and causes metamorphopsia and vision loss. Since Kelly et al. 1 reported pars-plana vitrectomy (PPV) for treating macular holes (MHs) in 1991, it has become a standard treatment for MHs 2-6 . While the MH closure rate was improved with internal limiting membrane (ILM) peeling 7 , it was still suboptimal in large MHs 8 . In 2010, Michalewska et al. 9 reported the inverted ILM flap technique for large idiopathic MHs. The technique consists of partial peeling of the ILM and placing the flap over the MH. The authors reported that the technique increased the rate of complete MH closure to 98% for large idiopathic MHs (> 400 μm) compared with 88% with conventional PPV and ILM peeling. Although the inverted ILM flap technique was originally developed for large MHs, myopic MHs, and MH retinal detachment , the technique is sometimes used for small-medium size MHs . The risks and benefits of this approach have yet to be determined. In this study, the MH closure rate, postoperative best-corrected visual acuity (BCVA), and recovery of the external limiting membrane (ELM) and ellipsoid zone (EZ), which are closely associated with postoperative BCVA , were compared in the inverted ILM flap technique and conventional ILM peeling in small-medium size MHs. This was a retrospective, nonrandomized, comparative study. The study was approved by the Nagasaki University Hospital Clinical Research Ethics Committee and complied with the Declaration of Helsinki. Information about this study was made public, and patients were given the opportunity to refuse to participate in this study. The ethics committee waived the need for written informed consent. Patients who underwent vitrectomy for MH at Nagasaki University Hospital between July 2014 and October 2017 were recruited. Among the participants, patients whose minimum MH diameter was < 400 μm, full-thickness MH were included. Exclusion criteria were recurrent and secondary MHs, high myopia (axial length ≥ 27 mm), and MH with retinal detachment. Standard 3-port 25-gauge pars plana vitrectomy was performed with Constellation Vision System (Alcon Surgical, Ft. Worth, TX, USA). Triamcinolone acetonide was used to visualize the vitreous. Selection of inverted ILM