Inverted internal limiting membrane flap technique for retinal detachment due to macular holes in high myopia with axial length ≥ 30 mm.

To compare the efficacy of internal limiting membrane (ILM) flap covering to that of ILM flap insertion for the treatment of macular hole retinal detachment (MHRD) in highly myopic eyes with axial length (AL) ≥ 30 mm. We retrospectively analysed the medical records of 48 MHRD patients with high myopia (AL ≥ 30 mm). According to different surgical methods, the patients were divided into a covering group (23 eyes) and an insertion group (25 eyes). The rate of retinal reattachment and MH closure were compared between the two groups, and the related factors affecting the initial anatomical results were analysed. After primary vitrectomy and single silicone oil removal, there were 18 eyes (78.3%) in the covering group, and 20 eyes (80.0%) in the insertion group had retinal reattachment (P = 1.000). Moreover, 16 eyes (69.6%) in the covering group and 17 eyes (68.0%) in the insertion group had their MHs sealed (P = 0.907). The best-corrected visual acuity (BCVA) at 12 months and the improvement in BCVA postoperatively in the two groups were not statistically significant (P = 0.543, 0.955). Logistic regression analysis showed that elongated AL (OR = 1.844, 95% CI 1.037-3.280, P = 0.037) and higher choroidal atrophy (OR = 2.986, 95% CI 1.011-8.821, P = 0.048) were risk factors affecting initial anatomical success. For extremely high-myopia MHRD with AL ≥ 30 mm, ILM flap covering and insertion can both effectively seal the MH and promote retinal reattachment, but the visual function improvement may still be limited. The longer the AL and the higher the choroidal atrophy, the greater is the risk of initial anatomical failure.