Purpose: To identify results from the Ocular Hypertension Study that can aid patients and clinicians to make evidence-based decisions about the management of ocular hypertension. Design: Perspective. Results: At 60 months, the cumulative frequency of developing primary open-angle glaucoma (POAG) was 4.4% in the medication group and 9.5% in the observation group (hazard ratio for medication, 0.40; 95% confidence interval [CI], 0.27–0.59; P <.0001). At 13 years the cumulative proportion of participants who developed POAG was 0.22 (95% CI 0.19–0.25) in the original observation group and 0.16 (95% CI 0.13–0.19) in the original medication group (complementary log-log x 2 P =.009). A 5-factor model (older age, higher IOP, thinner central corneal thickness, larger cup-to-disc ratio, and higher visual field pattern standard deviation) separated participants at high and low risk of developing POAG. Conclusions: Clinicians and patients can make evidence-based decisions about the management of ocular hypertension using the risk model and considering patient age, medical status, life expectancy, and personal preference.