title: Incidence and early course of retinopathy of prematurity. The Cryotherapy for Retinopathy of Prematurity Cooperative Group.
abstract: In the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (ROP), 4099 infants weighing less than 1251 g at birth underwent sequential ophthalmic examinations, beginning at age 4 to 6 weeks, to monitor the incidence and course of ROP. Overall, 65.8% of the infants developed ROP to some degree; 81.6% for infants of less than 1000 g birth weight. As expected, ROP incidence and severity were higher in lower birth weight and gestational age categories. Black infants appeared less susceptible to ROP, of all severity categories, than nonblack infants. The timing of retinal vascular events correlated more closely with postconceptional age than with postnatal age, implicating the level of maturity more than postnatal environmental influences in governing the timing of these vascular events. These results include the current incidence of various severity stages of ROP found in the United States and provide new insight into the development of ROP.
authors.affiliation: Department of Ophthalmology, Oregon Health Sciences University, Portland.
authors.forename: E A
authors.initials: EA
authors.lastname: Palmer
authors.forename: J T
authors.initials: JT
authors.lastname: Flynn
authors.forename: R J
authors.initials: RJ
authors.lastname: Hardy
authors.forename: D L
authors.initials: DL
authors.lastname: Phelps
authors.forename: C L
authors.initials: CL
authors.lastname: Phillips
authors.forename: D B
authors.initials: DB
authors.lastname: Schaffer
authors.forename: B
authors.initials: B
authors.lastname: Tung
mesh_terms: D003452:Cryosurgery; D005260:Female; D005654:Fundus Oculi; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D007223:Infant; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008297:Male; D012171:Retinal Vessels / Q000254:growth & development*; D012178:Retinopathy of Prematurity / Q000453:epidemiology / Q000503:physiopathology*; D014481:United States / Q000453:epidemiology