The Three-Year Outcomes of Microhook ab Interno Trabeculotomy Combined with Phacoemulsification in Japanese Patients with Cataract and Open-Angle Glaucoma

Background and Objectives: This study aimed to report the efficacy of microhook ab interno trabeculotomy with phacoemulsification three years after the operation. Materials and Methods: This retrospective observational study over 3 years included 16 glaucoma patients (27 eyes) who underwent microhook ab interno trabeculotomy with phacoemulsification at St. Marianna University Hospital from April 2020 to March 2021. Preoperative and postoperative best-corrected visual acuity (BCVA), intraocular pressure (IOP), antiglaucoma medication scores, and mean deviation (MD) slope were analyzed. Results: The preoperative mean IOP was 16.2 ± 4.4 mmHg, and this IOP decreased significantly to 12.6 ± 1.8, 13.0 ± 2.1, 12.0 ± 1.8, 12.4 ± 2.0, 12.6 ± 1.9 and 12.3 ± 1.3 mmHg at 6, 12, 18, 24, 30 and 36 months after the operation, respectively. The preoperative mean BCVA (LogMAR) was 0.1 ± 0.2 and this was improved significantly to 0.012 ± 0.20, 0.0078 ± 0.20, 0.0013 ± 0.16, −0.001 ± 0.14, 0.007 ± 0.17, and 0.010 ± 0.20 at 6, 12, 18, 24, 30 and 36 months after the operation. The preoperative antiglaucoma medication score was 3.11 ± 1.26, and this score decreased significantly to 0.22 ± 0.62, 0.44 ± 0.79, 0.48 ± 0.79, 0.63 ± 0.87, 0.63 ± 0.87 and 0.85 ± 0.93 at 6, 12, 18, 24, 30 and 36 months after the operation, respectively. The postoperative MD slope was significantly more positive than the preoperative slope (estimated difference, 0.330 dB/year; SE, 0.116; p = 0.0084). Conclusions: These findings suggest that microhook ab interno trabeculotomy with phacoemulsification can reduce IOP and medication burden and improved visual acuity through 3 years. Although there is potential beneficial effect, further study will be needed to prove its effect on visual field progression.