Cyclodialysis Surgery for Enhanced Uveoscleral Outflow and Intra-Ocular Pressure Lowering in Glaucoma: A Systematic Review and Meta-Analysis of 100 Years of Clinical Evidence

ObjectiveTo perform a systematic review and meta-analysis of the clinical evidence of the treatment effect of surgical cyclodialysis in the management of intraocular (IOP) in patients with glaucoma. MethodsA comprehensive literature review was conducted of peer-reviewed interventional studies from the PubMed, Cochrane, Web of Science and EMBASE databases of surgical cyclodialysis treatment for the lowering of intraocular pressure in patients with glaucoma. Key outcome measures of treatment success were long-term IOP control, as well as IOP-lowering medication burden and the incidence of intraoperative and postoperative adverse events. The meta-analysis was registered with Prospero ID CRD42025632759 ResultsA total of 40 studies spanning a publication period of more than 100 years of surgical cyclodialysis treatment encompassing data from over 4,082 eyes were included in the analysis. Clinical evidence comprised observational, non-randomized studies, 75% of which involved an ab-externo approach and 25% comprised an ab-interno cyclodialysis intervention. Given the natural evolution of the clinical paradigm over the years, changes in surgical technique, instrumentation and addressable population, the overall analysis was constructed to account for the significant variability in outcomes reporting. Across the final evaluable dataset, the clinical performance of cyclodialysis surgery was characterized by overall qualified success rates of 72.3% on average (range 33%-97%) over a postoperative follow-up period ranging from 6 to 132 months. Depending on surgical technique and disease severity, reported success rates indicate slightly increased efficacy and lower rate of complications with ab-interno intervention. Durability of the cyclodialysis procedure varied significantly, with higher rates of failure in patients with advanced and refractory glaucoma. Specific complications such as persistent hyphema, hypotony and vision loss were reported infrequently. All outcomes, including IOP reduction, ocular safety, and durability, showed significant improvement with the newer interventional ab-interno surgical techniques. ConclusionCyclodialysis remains an enduring surgical intervention and one of the few available surgical options for uveoscleral outflow enhancement in glaucoma patients. The IOP lowering effect of the procedure can be significant, albeit variable, with better clinical performance in mild and moderate glaucoma and with advanced interventional ab-interno surgical approaches. SynopsisResults of a meta-analysis comprising more than 4,000 glaucoma cases of cyclodialysis surgery for the lowering of intraocular pressure demonstrate significant and sustained efficacy of one of the few surgical interventions for uveoscleral outflow enhancement.