Efficacy of cryotherapy for retinopathy of prematurity

This is a retrospective study of the benefit of transconjunctival cryotherapy for retinopathy of prematurity (ROP) in 43 eyes of 22 infants (birth weight 716-1675 g) from July 1985 to January 1988. Nine eyes were treated at ROP stage 4A (early), 14 eyes at stage 3 plus disease, and 20 eyes at stage 3. Cryotherapy was applied to the retinal avascular zone. In 13 eyes the ridge of extraretinal fibrovascular proliferation was also treated. Two eyes with peripheral exudative retinal detachment in two quadrants had additional treatment of the area of elevated retina. Reexamination was performed at the age of 26 to 52 months (average 38 months). Regression of the ROP was found in all eyes. Seven eyes showed a lateral traction of the temporal vascular arcades, six of these eyes had a slight macular ectopia. None of the eyes progressed to stage 4B or 5. Visual acuity was 6/60 or better. Twelve children (60%) achieved 6/18 or better and 5 (25%) 6/9 or more. Our data indicate that cryotherapy for ROP grade 3 and early stage 4A prevents the progression to advanced stages. The results also imply a functional benefit of cryotreatment in infants with progressive severe ROP.