Efficacy of Penetrating Canaloplasty versus Trabeculectomy in Patients with Bilateral Primary Glaucoma: A Self-Control Study.

Abstract

Introduction: Schlemm's canal-based minimally invasive glaucoma surgeries (MIGSs) are gaining increasing recognition and acceptance, but majority of these MIGSs are recommended in eyes with open angle. Bleb-independent penetrating canaloplasty (PCP) restores physiological aqueous outflow in eyes with both open and closed angles. We aimed to compare the efficacy, safety, and postoperative management of PCP versus trabeculectomy (TRAB) in patients with bilateral primary glaucoma.

Methods: This study is prospective self-control case series in a tertiary hospital in China. A total of 54 eyes from 27 patients with bilateral primary open angle glaucoma (n = 18) or primary angle-closure glaucoma (n = 9) were included. TRAB with mitomycin C was performed in one eye, while PCP was performed in the contralateral fellow eye. Intraocular pressure (IOP), number of glaucoma medications, surgery-related complications, and postoperative interventions were compared between groups. Complete (without medication) and qualified success (with/without medication) were defined as IOP ≤21 mm Hg and ≥20% IOP reduction.

Results: Mean IOP decreased from 32.5 ± 8.87 mm Hg on 2.3 ± 1.43 medications at baseline to 15.5 ± 5.02 mm Hg on 0.12 ± 0.33 medications at 24 months in TRAB group (both p < 0.0001) and from 30.0 ± 9.61 mm Hg on 2.7 ± 1.10 medications to 15.5 ± 4.36 mm Hg on 0.40 ± 0.82 medications in PCP group (both p < 0.0001). Equal complete success (12 months: 84.0%, p > 0.999; 24 months: 72.0%, p > 0.999) was achieved at both 12 and 24 months in two groups. Although not statistically significant, higher qualified success was observed in PCP (88.0%) than in TRAB group (80.0%, p = 0.702) at 24 months. However, 63.0% eyes (n = 17) in TRAB group needed bleb managements to maintain a lower IOP. Transient IOP spike (>25 mm Hg, 22.2%) and microhyphema (22.2%) were the most common complications for PCP, while hypotony (14.8%) and wound leakage (11.1%) were frequently seen after TRAB.

Conclusion: PCP demonstrates comparable IOP-lowering effect with TRAB in eyes with primary glaucoma, but with less postoperative complications and interventions.