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° 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: ≈17 mmHg in the mono-arm and ≈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.