Endoscopic Cyclophotocoagulation (ECP) for Glaucoma: Clinical Evidence, Unresolved Challenges, and Future Directions in Minimally Invasive Therapy: A Systematic Review
Background: Glaucoma is the leading cause of irreversible blindness globally, and reducing intraocular pressure (IOP) is the only evidence-based therapeutic strategy. Minimally invasive glaucoma surgery (MIGS) is a promising alternative to traditional filtering surgeries, with endoscopic cyclophotocoagulation (ECP) as a core modality that reduces aqueous humor production via direct ciliary process photocoagulation. However, uncertainties regarding its standardization and long-term efficacy remain. Methods: A systematic search was conducted in PubMed, Web of Science, and Embase for studies published between January 2010 and May 2025, focusing on ECP’s efficacy, safety, technical parameters, and clinical applications in glaucoma. After screening, 7 eligible studies (2 retrospective, 5 prospective) involving primary open-angle glaucoma (POAG), primary angle-closure glaucoma (PACG), and refractory glaucoma were analyzed. Results: ECP achieved stable IOP reduction across subgroups: standalone ECP yielded 30.8% IOP reduction in refractory glaucoma, phaco-ECP achieved 20% - 27.3% IOP reduction, and phaco-ECP-iStent showed 30.8% IOP reduction, with 82% - 88% of patients reaching target IOP or surgical success. Medication use decreased by 40% - 71.5% across groups. Combined phaco-ECP had a 3% 2-year reoperation rate, compared with 15% for standalone ECP. ECP had a lower severe complication rate (<1.4%) than traditional procedures (trabeculectomy, transscleral cyclophotocoagulation), with mild, transient adverse events. Key uncertainties included unstandardized energy parameters, experience-dependent laser distance regulation, and controversial “pop sound” utility. Conclusion: ECP is a safe and effective minimally invasive intervention for glaucoma, especially in refractory cases and combined cataract-glaucoma surgery. Future advancements should focus on intelligent parameter optimization, equipment refinement, and long-term data accumulation to promote its transformation from empiricism to precision medicine.
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