Comparison of Trabeculectomy and Argon Laser Trabeculoplasty Sequences in Advanced Glaucoma Management

The Advanced Glaucoma Intervention Study (AGIS) focuses on managing advanced glaucoma, a condition where medication alone can't lower eye pressure adequately, causing vision loss. Before 1980, a surgical procedure called trabeculectomy was commonly used. However, laser trabeculoplasty has gained popularity since then. The study aims to understand which sequence of these interventions yields the best long-term results, as success varies and some patients may need multiple procedures over time. The study involves individuals with advanced glaucoma, comparing two intervention sequences to manage the disease. Participants are randomly assigned to one of two sequences: either starting with trabeculectomy, followed by argon laser trabeculoplasty (ALT) if the first procedure fails, then a second trabeculectomy if ALT fails; or starting with ALT, followed by trabeculectomy if ALT fails, then another trabeculectomy if the first one fails. These interventions are supplemented with medication as needed. The study follows all patients for at least 5 years, scheduling regular examinations to evaluate visual function loss, intervention failure rates, complication rates, and the need for additional therapy. The primary outcome is the percentage of eyes with decreased vision, while secondary outcomes include sustained vision loss, intervention failures, number of prescribed glaucoma medications, and eye pressure levels.