Purpose: We describe a modified canaloplasty technique and report the short-term efficacy for primary open-angle glaucoma (POAG) patients with disruption of Schlemm canal (SC) wall resulting from prior glaucoma surgery.
Patients and methods: This was a single-surgeon prospective cohort study. POAG patients scheduled for canaloplasty were included and divided into 2 groups: group1 included POAG patients without a history of glaucoma surgery and group 2 included POAG patients with failed glaucoma surgery and disrupted SC. The status of SC was determined by gonioscopy and ultrasound biomicroscopy. Standard canaloplasty procedures were performed in group 1. A modified canaloplasty technique was used in group 2. Primary outcome measures included the intraocular pressure and glaucoma medication use at various follow-up points.
Results: Seventeen patients were enrolled in group 1 and 9 patients were enrolled in group 2. At the 12-month follow-up, there was no significant difference between groups 1 and 2 (17.8±2.7 vs. 16.7±2.4 mm Hg, respectively; P=0.362) and in the mean number of medications (0.9±1.2 vs. 0.3±0.5, respectively; P=0.061). In both groups, at all follow-up points, the intraocular pressure and the mean glaucoma medication usage had decreased significantly compared with measurements at baseline (P<0.001). The rate for successful circumferential catheterization was not significant between the 2 groups (88.2% vs. 77.8%, P=0.063).
Conclusion: Modified canaloplasty is a feasible, safe, and potentially effective option for patients with POAG and regions of SC disruption resulting from previous glaucoma-filtering surgery.