Collaborative initial glaucoma treatment study comparing initial treatmentrandomized to medications or surgery

Purpose: To report interim outcome data, using all available follow-up thro ugh 5 years after treatment initiation, in the Collaborative Initial Glauco ma Treatment Study (CIGTS). Design: Randomized clinical trial. Participants. Six hundred seven newly diagnosed glaucoma patients. Methods: In a randomized clinical trial, 607 patients with newly diagnosed open-angle glaucoma were initially treated with either medication or trabec ulectomy (with or without 5-fluorouracil). After treatment onset and early follow-up, patients were evaluated clinically at 6-month intervals. In addi tion, quality of life telephone interviews were conducted at similar freque ncy to the clinical visits. Patients in both arms of CIGTS were treated agg ressively in an effort to reduce intraocular pressure (IOP) to a level at o r below a predetermined target pressure specific for each individual eye. V isual field (VF) scores were analyzed by time-specific comparisons and by r epeated measures models. Main Outcome Measures: VF loss was the primary outcome variable in CIGTS. S econdary outcomes of visual acuity (VA), IOP, and cataract were also studie d. Results: On the basis of completed follow-up through 4 years and partially completed through 5 years, VF loss did not differ significantly by initial treatment. Over the entire period of follow-up, surgical patients had a gre ater risk of substantial VA loss compared with medical patients. However, b y 4 years after treatment, the average VA in the two groups was about equal . Over the course of follow-up, IOP in the medicine group has averaged 17 t o 18 mmHg, whereas that in the surgery group averaged 14 to 15 mmHg. The ra te of cataract requiring removal was greater in the surgically treated grou p. Conclusions: Both initial medical or initial surgical therapy result in abo ut the same VF outcome after up to 5 years of follow-up. VA loss was greate r in the surgery group, but the differences between groups seem to be conve rging as follow-up continues. When aggressive treatment aimed at substantia l reduction in IOP from baseline is used, loss of VF can be seen to be mini mal in general. Because 4 to 5 years of follow-up in a chronic disease is n ot adequate to draw treatment conclusions, these interim CIGTS outcomes do not support altering current treatment approaches to open-angle glaucoma. O phthalmology 2001;108:1943-1953 (C) 2001 by the American Academy of Ophthal mology.