Advances in laser technology assist in treatment for retinopathy of prematurity

Cryotherapy is the accepted method to treat retinopathy of prematurity (ROP). The Cryotherapy for Retinopathy of Prematurity Cooperative Group conducted a prospective randomized study which established the beneficial effectiveness of cryopexy as a treatment modality for threshold ROP. Despite demonstrating the overall beneficial effects of cryotherapy, a small subgroup of infants in the study with zone-I threshold ROP showed either no beneficial effects or at most a minimal reduction in unfavorable events in eyes treated with cryotherapy. The failure rate was reduced from 91.77% to 75% when comparing control to treated eyes although only twelve eyes were treated. Based on these poor treatment results and significant advances in laser technology a renewed interest has developed in the use of laser photocoagulation to treat eyes with zone I threshold ROP. Delivery of thermal laser spots to the retinal periphery has been simplified following development of an indirect laser delivery system. Additional interest has been stimulated by the recent commercial availability of the compact solid state diode lasers. This laser, unlike older gas ion lasers has a lower cost, does not require any ancillary cooling, operates on standard voltage requirements and in some instances is capable of being driven by batteries. A diode laser as a result can easily transported to, and operated in, the neonatal intensive care unit. The authors present the results of a prospective study evaluating diode laser photocoagulation in the management of 23 consecutive premature infant eyes with zone I threshold ROP. The mean follow-up was 53.6 weeks. A favorable outcome was achieved in 22 of the 23 eyes. Various features of the diode laser which appeared to significantly contribute to these improved treatment results are discussed.