Cryotherapy for retinopathy of prematurity: a histopathologic comparison of a treated and untreated eye.

A female infant born at 28 weeks gestational age, weighing 570 g, developed retinopathy of prematurity (ROP) which progressed to threshold disease in one eye. Transscleral cryotherapy of the avascular peripheral retina resulted in complete clinical regression of the active ROP in that eye. The fellow eye continued to manifest subthreshold ROP. Histopathologic findings included a striking reduction of the cryotreated retina to a thin glial scar, with associated retinal pigment epithelium atrophy, denudation of Bruch's membrane, and extensive atrophy of the underlying choroidal vasculature, predominantly the choriocapillaris.