Early manifest glaucoma trial - Design and baseline data

Objectives: The Early Manifest Glaucoma Trial (EMGT) will evaluate the effe ctiveness of reducing intraocular pressure (IOP) in early, previously untre ated open-angle glaucoma. Its secondary aims are to explore factors related to glaucoma progression and to study the natural history of the disease. T his article describes the EMGT design and presents baseline data. Design: Randomized, clinical trial. Participants: Newly diagnosed patients 50 to 80 years of age with early gla ucomatous visual field defects were mainly identified from a population-bas ed screening of more than 44,000 residents of Malmo and Helsingborg, Sweden . Exclusion criteria were advanced visual field loss; mean IOP greater than 30 mmHg or any IOP greater than 35 mmHg; visual acuity less than 0.5; and inability to complete follow-up protocols. Interventions: After informed consent, patients were randomized to treatmen t or no initial treatment with close follow-up. Treated patients had laser trabeculoplasty and started receiving topical betaxolol twice daily in elig ible eyes. Follow-up visits include computerized perimetry and tonometry ev ery 3 months and fundus photography every 6 months. Decisions to change or begin treatment are made jointly with the patient when EMGT progression occ urs and also later if clinically needed. Main Outcome Measures: The EMGT progression is defined by sustained increas es of visual field loss in three consecutive C30-2 Humphrey tests, as deter mined from computer-based analyses, or by optic disc changes, as determined from flicker chronoscopy and side-by-side comparisons of fundus photograph s performed by masked, independent graders. Results: A total of 255 patients were randomized between 1993 and 1997 and will be followed for at least 4 years. All had generally good health status ; mean age was 68.1 years, and 66% were women. At baseline, mean IOP was 20 .6 mmHg and 80% of eyes had IOP less than 25 mmHg, Conclusions: The Early Manifest Glaucoma Trial is the first large randomize d, clinical trial to evaluate the role of immediate pressure reduction, as compared to no initial reduction, in patients with early glaucoma and norma l or moderately elevated IOP, Its results will have implications for: (1) t he clinical management of glaucoma; (2) understanding the role of IOP and t he natural history of glaucoma; and (3) evaluating the rationale for glauco ma screening.