By reporting the natural outcome of preterm infants with birth weights less than 1251 g, the Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) Cooperative Group has made yet another important contribution.1 They rightly point out that there is a paucity of valid data on retinopathy of prematurity (ROP) outcome. This, they state, is because of two factors: first, the inadequacy of many ophthalmic examination protocols and, second, the lack of data from comparable infants in whom ROP did not develop. A third factor should be added: the dearth of geographically based rather than hospital-based studies.
The causes of the ophthalmic sequelae of premature birth are poorly understood but certainly not all can be attributed to ROP, because even in infants without any detectable ocular or neurological abnormality, the incidence of strabismus is higher than in infants born at full term.2,3 However, apart from ROP, the single most important etiological
Fielder AR. The Natural Ocular Outcome of Premature Birth and Retinopathy: Status at 1 Year. Arch Ophthalmol. 1995;113(7):850-851. doi:10.1001/archopht.1995.01100070020008