Natural History of Open-Angle Glaucoma.

OBJECTIVE: This article, based on the Early Manifest Glaucoma Trial (EMGT), provides prospective natural history data on progression of glaucomatous field defects in 3 of the most common glaucoma types. DESIGN: Cohort of EMGT patients randomized to the untreated control group and followed up to the time of progression, when treatment could be initiated. PARTICIPANTS: We evaluated 118 control patients: 46 with high-tension glaucoma (HTG), 57 with normal-tension glaucoma (NTG), and 15 with pseudoexfoliation glaucoma (PEXG). METHODS: Visual fields were tested every 3 months with the Humphrey 30-2 Full Threshold test program. MAIN OUTCOME MEASURES: Linear regression analyses of the perimetric mean deviation (MD) values were performed, and the rate of progression was defined as the regression coefficient in decibels per year. Percentages of progressed eyes and time to progression were determined using EMGT event-based predetermined progression criteria derived from Glaucoma Change Probability Maps. RESULTS: The median and interquartile rates of visual function loss were -0.40 (1.05) dB/year overall and -0.46 (1.61) in HTG, -0.22 (0.65) in NTG, and -1.13 (6.13) in PEXG. Thus, interpatient variability was large. Mean rates were considerably higher than medians: -1.08 dB/year overall, -1.31 in HTG, -0.36 in NTG, and -3.13 in PEXG. Differences in median visual function progression rates among groups were statistically significant (NTG vs. HTG, P = 0.003; PEXG vs. non-PEXG, P<0.001). Progression was considerably and significantly faster in older than in younger patients (P = 0.002). By 6 years, 68% of patients had progressed overall, 74% of those with HTG, 56% of those with NTG, and 93% of those with PEXG (P = 0.012). Median time to progression also differed considerably among groups: 19.5 months in PEXG, 44.8 months in HTG, and particularly 61.1 months in NTG (P