Objective: To report the ocular structure and visual acuity outcomes at age 15 years, and the incidence of retinal detachment between 10 and 15 years of age, for patients in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP). Methods: Subjects were 254 survivors from 291 preterm children with birth weights less than 1251 g and severe (threshold) retinopathy of prematurity (ROP) in one or both eyes, who participated in the CRYO-ROP trial. At age 15 years, unfavorable ocular structure was posterior retinal fold or worse judged by study-certified ophthalmologists. Unfavorable distance visual acuity was 20/200 or worse measured by studycertified testers using Early Treatment of Diabetic Retinopathy Study recognition acuity charts. Results: Thirty percent of treated eyes and 51.9% of control eyes (P < .001) had unfavorable structural outcomes. Between 10 and 15 years of age, new retinal folds, detachments, or obscuring of the view of the posterior pole occurred in 4.5% of treated and 7.7% of control eyes. Unfavorable visual acuity outcomeswere found in 44.7% of treated and 64.3% of control eyes (P < .001). Conclusion: The benefit of cryotherapy for treatment of threshold ROP, for both structure and visual function, was maintained across 15 years of follow-up. New retinal detachments, even in eyes with relatively good structural findings at age 10 years, suggest value in long-term, regular follow-up of eyes that experience threshold ROP. Objective: To report the ocular structure and visual acuity outcomes at age 15 years, and the incidence of retinal detachment between 10 and 15 years of age, for patients in the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP). Methods: Subjects were 254 survivors from 291 preterm children with birth weights less than 1251 g and severe (threshold) retinopathy of prematurity (ROP) in one or both eyes, who participated in the CRYO-ROP trial. At age 15 years, unfavorable ocular structure was Unfavorable distance visual acuity was 20/200 or worse measured by study certified testers using Early Treatment of Diabetic Retinopathy Study recognition acuity charts. Results: Thirty percent of treated eyes and 51.9% of control eyes (P <.001) had unfavorable structural outcomes. Between 10 and 15 years of age, new retinal folds, detachments, or obscuring of the view of the posterior pole occurred i Unfavorable visual acuity outcomes found in 44.7% of treated and 64.3% of control eyes (P <.001). Conclusion: The benefit of cryotherapy for treatment of threshold ROP, for both structure and visual function, was maintained across 15 years of follow-up. New retinal detachments, even in eyes with relatively good structural findings at age 10 years, suggest value in long-term, regular follow-up of eyes that experience threshold ROP.