RESTORATION PROCESS OF THE OUTER RETINAL LAYERS AFTER SURGICAL MACULAR HOLE CLOSURE

Purpose: To investigate the interrelationship among the outer retinal layers after macular hole surgery and elucidate the restoration process. Methods: This retrospective observational study included 50 eyes of 47 consecutive patients with closed macular holes in the first vitrectomy. Optical coherence tomography was obtained before surgery; at 1, 3, and 6 months postsurgery; and at the last visit. The complete continuous layer rate and mean defect length were evaluated for the outer nuclear layer (ONL), external limiting membrane (ELM), and ellipsoid zone (EZ). Results: At all postoperative visits, the complete continuous layer rate was in the descending order of ELM, ONL, and EZ and the mean defect length was in the ascending order of ELM, ONL, and EZ. External limiting membrane was necessary for ONL restoration. External limiting membrane and ONL were necessary for EZ restoration. Hyperreflective protrusions were observed from the area lacking ELM into the subretinal space after surgery. Ellipsoid zone was not formed in coexistence with the hyperreflective protrusions. Intermediate reflective protrusions appeared under the ONL plus ELM after surgery and were eventually replaced by EZ. Conclusion: Restoration of the outer retinal layers after surgical macular hole closure occurs in the order of ELM, ONL, and EZ.