Modified inverted internal limiting membrane flap technique for lamellar macular hole

Background Lamellar macular hole (LMH) is a partial-thickness macular defect thought to be caused by vitreofoveal traction, anteroposterior and tangential forces exerting traction on the fovea. Methods This is a retrospective study involving 19 eyes. 25-gauge pars plana vitrectomy (PPV), fovea sparing internal limiting membrane (ILM) peeling combined with modified inverted ILM flap under air for treatment of LMH was used. Results The study comprised 14 females and 5 males, involving 13 right and 6 left eyes, with a mean age of 69.52 ± 8.13 years. Symptom duration averaged 498.94 ± 646.96 days. The preoperative residual foveal thickness, which initially averaged 62.26 ± 46.21µm, increased to a post-operative central foveal thickness of 85.05 ± 48.11 µm after 6 months. Foveal configuration was improved in 15 of 19 eyes (78.94%), one patient had persistent macular edema, and 3 eyes had irregular foveal contour. Among 19 eyes examined, 13 eyes (68.42%) showed intact external limiting membrane (ELM) and ellipsoid zone (EZ) lines both before and after the surgery, resulting in a smooth restoration of the foveal contour. Conversely, in 6 eyes (31.57%) assessed before the operation, the ELM and EZ lines were disrupted. Of these, 3 eyes (15.78%) exhibited improvement, while in the remaining 3 eyes (15.78%), the ELM and EZ lines remained disrupted even after 6 months of follow-up. The mean pre-operative best corrected visual acuity (BCVA) in LogMAR was 0.66 ± 0.43 and the mean post-operative BCVA in LogMAR at 1 months was 0.55 ± 0.24, at 3 months was 0.53 ± 0.25 and at 6 months was 0.51 ± 0.24, indicating an overall improvement in BCVA compared to pre-operative levels. Mean BCVA improved from 0.66 ± 0.43 logMAR pre-operative to 0.51 ± 0.24 logMAR at 6 months post-operatively (p = 0.058). There were no instances of full thickness macular hole and no foveal detachment. Conclusion PPV with fovea sparing ILM peeling combined with modified inverted ILM flap under air results in good morphological and functional outcomes. Trial registration: The study project registration number (Tongji Hospital affiliated with Tongji University School of Medicine (Number: K-W-2024-001)).