VITRECTOMY COMBINED WITH INVERTED INTERNAL LIMITING MEMBRANE FLAP INSERTION OR SINGLE-LAYERED FLAP COVERING TECHNIQUE FOR HIGHLY MYOPIC MACULAR HOLES WITH MACULAR RETINOSCHISIS

Purpose: To investigate the anatomical and visual outcomes of inverted internal limiting membrane flap insertion versus single-layered i-internal limiting membrane flap covering in highly myopic macular holes associated with macular retinoschisis. Methods: A retrospective study compared 23 G vitrectomy with inverted-internal limiting membrane flap insertion (30 eyes) or covering (31 eyes) in highly myopic macular holes patients. Pre- and postoperative optical coherence tomography images and best-corrected visual acuity (BCVA) were evaluated. Macular hole schisis was classified into three types based on the extent of outer layer schisis. Regression analysis identified predictors of closure rate and postoperative BCVA. Results: The baseline data of the two groups were matched, including BCVA, axial length, and minimum linear diameter, except for a higher hole height in insertion group (P = 0.038). After a mean follow-up of 11.7 months, type I closure rates were 83.3% (25/30) in the insertion group and 90.3% (28/31) in the covering group (P = 0.335), respectively. The intact external limiting membrane in the covering group (7/28) was higher compared with the insertion group (1/28) finally (P = 0.026). Final BCVA improved significantly in both groups (P < 0.001); the BCVA was better in closed highly myopic macular holes in the covering group (P = 0.011). Multivariate linear regression analysis revealed that preoperative BCVA (beta = 0.386, P = 0.001) and Macular hole schisis stage (beta = 0.309, P = 0.004) were independent predictive factors for the final BCVA. Conclusion: The single-layered inverted-internal limiting membrane flap covering favored foveal structure recovery and provided a better visual prognosis in closed highly myopic macular holes compared with insertion. The preoperative BCVA and macular hole schisis stage were independent predictors of visual outcomes in patients with highly myopic macular holes.