Outcomes of standalone ab interno trabeculotomy in the treatment of open-angle glaucoma in eyes with high myopia

BACKGROUND: We retrospectively evaluate the long-term efficacy and safety of trabeculotomy glaucoma surgery in treating open-angle glaucoma (OAG) in eyes with high myopia (HM). METHODS: This study included 20 eyes with HM (axial length ≥ 26.5 mm) and OAG; age, preoperative IOP (intraocular pressure), and sex-matched 20 non-HM eyes (axial length < 26.5 mm) served as controls. Each eye underwent standalone ab interno trabeculotomy using a Kahook dual blade. A follow-up examination was performed 36 months after surgery. The main outcome measure was the operative success rate (i.e., a ≥ 20% pre- to post-operative reduction in IOP with or without IOP-lowering medication). Kaplan–Meier analysis was employed as a measure of surgical success. The secondary outcome measures were postoperative IOP, the number of glaucoma medications, and postoperative complications. RESULTS: IOP and the number of glaucoma medications were statistically significantly reduced at all postoperative follow-up examinations. The Kaplan–Meier analysis demonstrated that the probability of postoperative success at 36 months was 45% and 65% for HM and non-HM eyes, respectively. In the HM group, the presence of pathological myopia was statistically significant risk factor for surgical failure. No critical postoperative complications were detected. CONCLUSIONS: In our study, the long-term efficacy of ab interno trabeculotomy in HM eyes with OAG was inferior to that in non-HM eyes with OAG. Our findings suggest that surgical indications for trabeculotomy in HM should be determined based on the presence of pathological myopia.