Randomized comparison of diode laser photocoagulation versus cryotherapy for threshold retinopathy of prematurity: Three year outcome

Purpose: To report the structural and functional outcomes at 3 years postmenstrual age for the treatment of threshold retinopathy of prematurity. Methods: Nineteen patients were entered into a prospective randomized treatment protocol, in which one eye received cryotherapy and one eye received diode laser photocoagulation. Asymmetric eyes were randomly assigned. Two patients have died and and 3 patients are no longer available for 3 year outcome exams. Results: Eight males and 5 females participated with a mean birthweight of 655 grams and a mean gestational age of 24.8 weeks. Four patients had asymmetrical disease, 3 receiving laser photocoagulation and one cryotherapy. Thirteen patients were able to have acuity determined. Seven patients (50%) have developed strabismus. There were 2 discordant outcomes, with the laser eye having the favorable outcome. Laser photocoagulation Cryotherapy P value Number of eyes treated 13 11 Geometric Mean Visual Acuity 20/46 20/72 0.05 Mean refractive error -5.97 D -7.06 D NS Favorable structural outcome 13/13 9/11 NS. Conclusions: Laser photocoagulation appears to have an outcome comparable to cryotherapy when the patients are examined three years following therapy. These data are suggestive that laser photocoagulation may have a minimal advantage.