Efficacy of Canaloplasty for the Management of Primary Open-Angle Glaucoma: Protocol for a Systematic Review.

Glaucoma forms the leading cause of irreversible blindness worldwide, with a disproportionately rising prevalence in Asian and African countries. Primary open-angle glaucoma (POAG) accounts for the majority of cases. Medical therapies for POAG are not without side effects, and surgical treatments carry high complication rates. Ab interno canaloplasty promises a safer, minimally invasive, yet effective treatment option for mild-to-moderate POAG, as well as a cost-effective technique for low-resource countries. However, no systematic review currently exists to verify this procedure's efficacy. The aim of this study was to develop a protocol for a systematic review aimed at evaluating the efficacy of canaloplasty against all other forms of POAG treatment. This systematic review and meta-analysis will include randomized controlled trials evaluating the short-term, medium-term, and long-term efficacy and safety of ab interno canaloplasty in treating POAG in comparison to all other treatments. Mean changes in intraocular pressure will form the primary outcome measure. Secondary outcome measures include proportion of participants who are medication-free after treatment and mean changes in the health-related quality of life. MEDLINE, Embase, Cochrane Library, and ClinicalTrials.gov databases will be searched for relevant randomized controlled trials. All studies will be subject to prespecified inclusion and exclusion criteria. The quality of the eligible randomized controlled trials will be assessed using the Cochrane risk of bias tool. Data will be extracted with a focus on raw data where possible, and analysis will be performed using RevMan 5.4 software to compare the mean changes in intraocular pressure (mm Hg) between ab interno canaloplasty and other comparator therapies. A funnel plot will be used to assess the risk of publication bias if 10 or more trials are included in the review. I2 statistics will be used to assess heterogeneity. Sensitivity analysis will be conducted to exclude studies with a high risk of bias and, where possible, on the primary outcome. The GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach will be used to summarize the main findings. The results of this systematic review are not yet available as it is still at the protocol stage. This protocol was registered on the PROSPERO database for systematic reviews (CRD42024558671) on June 27, 2024. Data collection for this review began on July 14, 2024, with the anticipated completion date being early 2026. The findings will be important to patients, clinicians, and policymakers worldwide in addressing the growing burden and health inequality of glaucoma. PROSPERO CRD42024558671; https://www.crd.york.ac.uk/PROSPERO/view/CRD42024558671. PRR1-10.2196/69527.