Cryotherapy for Stage 3+ Retinopathy of Prematurity

To the Editor. —We read with interest the article by Greven and Tasman 1 that appeared in the July 1989 issue of theArchives. The authors hypothesize as to the cause for retinal breaks and rhegmatogenous retinal detachments that developed in three eyes 12 to 44 months following cryotherapy for stage 3+ retinopathy of prematurity (ROP). They suggest that the firm chorioretinal adhesion created by the cryoapplications prevents this area from stretching as the eye grows and that the retinal tears resulted. Although they could not substantiate it, they did not rule out the possibility of vitreous traction as the cause for the retinal breaks, which seems to be a more likely mechanism. Severe retinal freezing due to excessively cold temperatures at the cryoprobe tip can cause retinal necrosis with vitreous condensation and subsequent tear formation. The type of tears described by Greven and Tasman, at the junction of treated