Results of cryotherapy at different locations for retinopathy of prematurity.

Fifty eyes with stage 3 plus retinopathy of prematurity (ROP) were treated with cryotherapy. The avascular retina (AR) only was treated in 15 eyes with a mean extent of 8.3 hours of stage 3 ROP; the ridge extraretinal fibrovascular proliferation complex (REFP) was treated in 17 eyes with a mean extent of 7.5 hours; and both locations (BL) were treated in 18 eyes with a mean extent of 7.7 hours. Ninety-three percent to 94% of eyes in each group had less than grade III retrolental fibroplasia (RLF-Reese). However, 87% of the AR treated eyes, 59% of the REFP treated eyes, and 44% of the BL treated eyes had less than grade II RLF. Whether more than or less than 8 hours of stage 3 ROP was treated, significantly better results occurred in the AR group than the BL group (.02 < P < .05) and a statistical trend suggests that treating the AR is more effective than treating the REFP (.1 < P < .2).