In Reply We thank Dr Anderson for his interest in our recent publication1 reporting clinical outcomes of patients with ocular hypertension after 20 years of follow-up or within 2 years of death. He asked key questions about how the findings of the Ocular Hypertension Treatment Study (OHTS)1 inform the treatment of patients with ocular hypertension (OHT). Dr Anderson proposed that most patients with OHT might be observed without treatment until they manifest early signs of glaucomatous damage. He asked how a prediction model for developing primary open-angle glaucoma (POAG) would modify this overall approach.