Mid-term clinical results of CO₂ laser-assisted Sclerectomy Surgery (CLASS) for open-angle glaucoma treatment

Purpose: To evaluate the efficacy and safety of CO₂ Laser-assisted Sclerectomy Surgery (CLASS) in primary and pseudoexfoliative open-angle glaucoma. Materials and Methods: Single-arm, open-label study included data from 9 medical centers located in 7 countries. Subjects underwent nonpenetrating CLASS procedure with a CO₂ laser system (IOPtiMate). Intraocular pressure (IOP) and number of medications were measured at baseline, 1, 2, 4, and 6 weeks, and 3, 6, 12, 24, and 36 months. Complete success was defined as 5rIOPr18mm Hg and at least 20% IOP reduction with no medications, and qualified success as the same with or without medications at 12, 24, and 36 months. Results: A total of 111 consecutive eyes were enrolled in the study, 14 were excluded from the study due to protocol deviation or operator error. The mean age was 69.3±12.8 and 73.9% were whites. Percent change in IOP from baseline at 1, 2, and 3 years was, respectively, 45.1%, 46.8%, and 42.5% (P<0.001). Complete success rates after 12, 24, and 36 months were 60.2%, 57.9%, and 47.8%, respectively. Qualified success rates after 12, 24, and 36 months were 79.6%, 91.2%, and 84.8%, respectively. Number of medications dropped from 2.39±1.24 to 0.47±0.84, 0.53±0.75, and 0.71±0.89 at 12, 24, and 36 months, respectively (P<0.001). Conclusions: The CLASS procedure may be a simple and effective treatment for open-angle glaucoma providing extended relief of elevated IOP.