The glaucoma intensive treatment study: interim results from an ongoing longitudinal randomized clinical trial

Purpose The aim of the study was to determine the perimetric rate of glaucoma progression in the ongoing Glaucoma Intensive Treatment Study (GITS) after 3 years of follow-up. Design This is a randomized, two-centre, prospective open-labelled treatment trial for open-angle glaucoma (OAG). Participants The participants of this study were treatment-naive patients with newly diagnosed OAG, aged 46-78 years, with early to moderate glaucomatous visual field loss scheduled to be followed for 5 years within the study. Methods Patients were randomized to initial treatment with either topical monotherapy or with an intensive approach using drugs from three different classes, plus 360 degrees laser trabeculoplasty. Changes in treatment were allowed. Standard automated perimetry and tonometry were performed and side-effects documented. All results are presented using intention-to-treat analysis. Results A total of 242 patients were randomized. After 3 years of follow-up, eight patients were lost to follow-up, six of whom were deceased. The median untreated baseline intraocular pressure (IOP) was 24 mmHg in both arms. The median IOP was almost constant over the 3 years of follow-up: approximate to 17 mmHg in the mono-arm and approximate to 14 mmHg in the multi-treatment arm. Treatment was intensified in 42% of the mono-treated patients and in 7% of the multi-treated patients. Treatment was reduced in 13% of the multi-treated patients. The median perimetric rate of progression was -0.5%/year in the mono-treated group and -0.1%/year in the multi-treated group (p = 0.03). Conclusion The rate of disease progression was significantly slower in the multi-treated patients than in the mono-treated patients. Further follow-up will show whether this difference is sustained over time.