The Collaborative Initial Glaucoma Treatment Study - Study design, methods, and baseline characteristics of enrolled patients

Objective: The Collaborative Initial Glaucoma Treatment Study (CIGTS) is a randomized, controlled clinical trial designed to determine whether patient s with newly diagnosed open-angle glaucoma (primary, pigmentary, or pseudoe xfoliative) are better treated by initial treatment with medications or by immediate filtration surgery. Design: Randomized, controlled clinical trial. Participants: A total of 607 patients with open-angle glaucoma were enrolle d. Intervention: Patients randomized to initial medications (n=307) received a stepped regimen of medications to lower intraocular pressure. Those random ized to initial surgery (n=300) underwent trabeculectomy to lower intraocul ar pressure. Main Outcome Measures: Progression in visual field loss constitutes the stu dy's primary outcome variable. Secondary outcomes include health-related qu ality of life, visual acuity, and intraocular pressure. Results: Randomized assignment resulted in a balanced distribution between treatment groups for most demographic and clinical measures assessed at enr ollment. More males than females were enrolled (55% were males), and a subs tantial percentage (38.1 %) of enrollees were blacks. Most enrollees (90.6% ) were diagnosed with primary open-angle glaucoma; the remainder had either pseudoexfoliative (4.8%) or pigmentary (4.6%) forms of open-angle glaucoma . Conclusions: Follow-up of this well-characterized group of patients should provide well-rounded guidance, based on both traditional ophthalmic measure s and patients' perspectives on their health-related quality of life, on ho w best to initially treat open-angle glaucoma.