The study was done to perform a 12-month comparison between the different extents and locations of Schlemm’s canal incisions during suture trabeculotomy ab interno for open-angle glaucoma (OAG).

99 eyes of 99 patients were randomly assigned to one of three groups: the 360° incision group with 34 subjects, the upper-180° incision group having 34 people and the lower-180° incision group having 31 people.

The mean IOP (±SD) in all eyes was reduced from 18.6 (5.9) mmHg with 3.1 (1.1) medications to 13.7 (3.4) mmHg 20.8% reduction with 1.4 (1.3) medications at postoperative 12-month. Each group produced comparable mean reductions in both IOP and the number of medications throughout 12 months of follow-up. Kaplan-Meier cumulative survival analyses showed no significance among these three groups for criterion A and criterion B. Postoperative hyphema with niveau formation occurred significantly more in the 360° group than in the lower-180° group (p=0.031).

The study concluded that the different extents and locations of Schlemm’s canal incisions during suture trabeculotomy ab interno for OAG, including the 360° incision, the upper-180° incision and the lower-180° incision, do not affect both the IOP reduction and the medications throughout 12 months of follow-up.

Reference: https://bjo.bmj.com/content/early/2020/08/22/bjophthalmol-2020-316624