Purpose:To analyze the anatomical and visual outcomes after internal limiting membrane (ILM) peeling or ILM flap insertion in highly myopic macular holes (HMMHs), and try to compare these two surgical techniques in large HMMHs.Methods:This is a retrospective, consecutive series study of patients with HMMH undergone vitrectomy from September 2016 to January 2021. We observed the outcomes of the HMMHs with ILM peeling and ILM flap insertion, respectively. Binary logistic regression and receiver operating characteristic (ROC) curve were used to analyze the relationship between the minimum linear diameter (MLD) of macular hole and the initial closure rate in ILM peeling group. Finally, we compared the surgical outcomes between these two surgical techniques in large HMMHs.Results: There were 69 HMMHs using ILM peeling with a mean MLD of 423.55 +/- 190.99 mu m and 33 HMMHs using ILM flap insertion with a mean MLD of 600.79 +/- 187.85 mu m. The initial type I closure rate was 86.9% (60/69) and 81.8% (27/33), respectively. MLD had a good correlation with the initial closure rate in HMMHs with ILM peeling (P=0.046). The large HMMH (MLD>461.5 mu m obtained by ROC curve) were present in 26 eyes with each surgical technique and there was no significant difference of baseline characteristics between them. In large HMMHs, the initial closure rate of ILM peeling was 73.0% and that of ILM flap insertion was 84.6% (P=0.499). Postoperative best-corrected visual acuity (BCVA) improved significantly in both groups (P<0.001), and the BCVA at last follow-up was better in closed large HMMHs with ILM peeling(P=0.034).Conclusion: In HMMHs with ILM peeling, the initial closure rate was decreased when MLD >461.5 mu m. ILM peeling may obtain better functional prognosis in eyes with closed large macular holes compared with ILM flap insertion.