Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP):211 Manual of Procedures, Volume 3, Phase 3 Follow-Up Study (Revised September 1996)

摘要

The purpose of the study is to examine the long-term structural and functional211u001eeffects of cryotherapy as a treatment for severe retinopathy of prematurity 211u001e(ROP). In the initial phase of the study, eyes with 5 contiguous or 8 total clock 211u001ehours of stage 3+ ROP, in 291 infants with birth weights less than 1251 g, were 211u001erandomized to receive cryotherapy or no cryotherapy. Follow-up to age 12 months 211u001eindicated that cryotherapy reduced the incidence of unfavorable structural 211u001eoutcome by 45.8% and the incidence of unfavorable visual acuity outcome by 37.8%. 211u001eFollow-up to age 5 1/2 years during Phase II of the study indicated that 211u001ecryotherapy reduced the incidence of unfavorable structural outcome by 41%. For 211u001evision, cryotherapy reduced the incidence of unfavorable acuity outcome by 24% 211u001ewhen based on measurement of Snellen recognition acuity. The present study will 211u001efollow all patients in the multicenter randomized cohort (n=256) as well as those 211u001enatural history patients (n=104) at one center (Philadelphia) who did not develop 211u001eROP as infants.