Impact of inverted internal limiting membrane-flap technique on functional outcome and structural restoration of small and medium size macular holes

PURPOSE: To evaluate the impact of the inverted internal limiting membrane (ILM)-flap technique on the visual outcome and anatomical recovery for small (<250 μ), medium (<400 μ), and large (>400 μ) macular holes (MHs). METHODS: Retrospective study included consecutive idiopathic MH cases operated on using the inverted ILM-flap technique. Clinical data were retrieved from electronic medical records (EMRs), surgical videos, and optical coherence tomography (OCT) machines. Eyes with axial length >25 mm, coexisting macular diseases, and follow-up <6 weeks were excluded. Data included the presence or absence of ILM flap and restoration of External Limiting Membrane (ELM), Ellipsoid Zone (EZ) lines. Mean visual improvement and structural recovery were compared between eyes showing ILM flap and those showing no flap in three MH size groups. RESULTS: Forty eyes of 38 patients with a mean age of 62.7 ± 10.1 years and a mean MH diameter of 348 ± 152 μm were included. The mean follow-up was 527 ± 478 days with anatomical closure observed in all eyes. Mean best-corrected visual acuity (BCVA) improved significantly from 0.87 ± 0.38 to 0.35 ± 0.26. ILM flap was visible in 29 (72.5%) all MHs, 7 (53.8%) small MHs (n = 13), 8 (61.5%) medium MHs (n = 13), and 14 (100%) large MHs (n = 14). The mean BCVA change was 0.47 ± 0.34, 0.53 ± 0.48, and 0.56 ± 0.20 in large, medium, and small MHs, respectively, and the difference between eyes showing ILM flap versus no flap in each MH size group was not statistically significant (P > 0.05). However, for medium MHs, it was higher in the ILM flap (0.66 ± 0.52) group compared to the no flap (0.32 ± 0.37) group. One eye with small MH developed significant gliosis resulting in reduced BCVA. ELM was restored in all eyes with small and medium MHs. CONCLUSION: We observed that the ILM flap did not adversely affect anatomical and visual outcomes for MHs <400 μm. Restoration of ELM suggests minimal interference in structural recovery by an ILM flap.