Outcomes and risk factors for ab interno trabeculotomy with a Kahook Dual Blade.

PURPOSE: To verify the surgical results and risk factors for ab interno trabeculotomy using a Kahook Dual Blade (KDB-LOT) in patients with various glaucoma types.

METHODS: This study was a retrospective case series of 205 eyes that underwent KDB-LOT. For Kaplan-Meier survival analysis, criterion A was defined as a ≤ 20% reduction in intraocular pressure (IOP) from baseline. Criteria B, C, and D were IOPs of ≤ 21, 18, and 15 mmHg, respectively. The Cox proportional hazard (CPH) model investigated prognostic factors.

RESULTS: The mean (SD) IOP decreased from 24.7 (7.98) to 17.6 (4.80) mmHg in all cases, from 21.3 (6.88) to 17.8 (3.52) mmHg in primary open-angle glaucoma (POAG), from 25.4 (7.32) to 17.1 (4.65) mmHg in exfoliation glaucoma, from 30.6 (8.88) to 17.8 (8.29) mmHg in uveitic glaucoma, and from 30.8 (7.29) to 17.3 (0.83) mmHg in steroid-induced glaucoma at 1 year after KDB-LOT. The Kaplan-Meier survival analysis showed that patients with POAG had the best prognosis under criteria B and C, and the 1-year survival rate in patients under criterion D was less than 35% for any disease type. CPH analysis revealed that age and KDB-LOT with phacoemulsification were good prognostic factors. Risk factors for surgical failure were previous cataract surgery, selective laser trabeculoplasty, and postoperative peripheral anterior synechiae.

CONCLUSION: KDB-LOT was effective in treating patients with several glaucoma types but showed difficulty in pushing IOP below 15 mmHg. Prognostic factors should be considered when making decisions regarding surgical indications.