360° inverted internal limiting membrane flap technique for idiopathic macular holes ≤ 250 µm, > 250 and ≤ 400 µm, and > 400 µm.

Purpose: To study the functional and morphological results of the inverted internal limiting membrane (ILM) flap technique for the treatment of idiopathic macular holes (MHs) sized ≤ 250 µm, > 250 and ≤ 400 µm, and > 400 µm.

Methods: Retrospective, nonrandomized interventional study of 65 eyes with primary idiopathic MHs who underwent pars plana vitrectomy (PPV) with the inverted ILM flap technique. Closure rate, best-corrected visual acuity (BCVA), and integrity of external limiting membrane (ELM) and ellipsoid zone (EZ) were analyzed by optical coherence tomography (OCT).

Results: Total closure rate was 96.9% with 100% in the ≤ 250 µm group, 100% in the > 250 and ≤ 400 µm group, and 91.7% in the > 400 µm group. Mean BCVA significantly improved after treatment: from 0.7 to 0.3 LogMAR in the ≤ 250 µm group (n = 15, p < 0.001), from 0.9 to 0.4 LogMAR in the > 250 and ≤ 400 µm group (n = 26, p < 0.001), and from 1.0 to 0.5 LogMAR in the > 400 µm group (n = 24, p < 0.001). A total of 16 patients had follow-up over 14 months: BCVA increased from 0.9 LogMAR preoperatively to 0.4 after 1 month (p < 0.00001) and to 0.3 LogMAR after 14 months (p = 0.03). A recovered ELM could be observed in 56.3% after 1 month and in 87.5% after 14 months. A recovered EZ could be observed in 18.8% after 1 month and in 68.8% after 14 months.

Conclusion: The study demonstrates a high closure rate with corresponding restitution of outer retinal layers. In addition to its importance for the treatment of MHs > 400 µm, the inverted ILM flap technique also appears to be effective and safe for the treatment of MHs < 400 µm.

Trial registration: WHO: DRKS00021241.