Review of experience with retinopathy of prematurity from the Pavia registry (1990-1993).

In this retrospective study we analysed the prevalence of retino-pathy of prematurity (ROP) and its sequelae in a sample of premature infants with birth weight less than 1500 grams. From 1 January 1990 to 31 October 1993, we studied 160 surviving premature infants with very low birth weight (< 1.500 g) referred to the Neonatal Intensive Care Unit of the I.R.C.C.S. Policlinico San Matteo, Pavia, Italy. Thirty percent of these infants suffered from ROP, and 13.7\%, with severe ROP, underwent cryotherapy. These latter had very-very low birth weight (< 1.000 g) and low gestational age (< 28 weeks). Follow-up of 69 infants at 12 months for retinal sequelae, refraction defects, bin-ocular vision and ocular motility impairments gave the following results: 1) strabismus 20.3\%; 2) > 3D hyperopia 3\%; 3) myopia 30.4\%; 4) > 5D myopia 3.7\%. The incidence of refraction and ocular motility anomalies in patients with acute ROP with spontaneous remission was similar to that of unaffected premature infants. Conversely, in the patients treated with cryotherapy the incidence of strabismus and > 5D myopia was greater than for untreated infants: 30\% vs 15.4\% (n.s.) and 14.7\% vs 0\% (p = 0.05), respectively. Cryotherapy was successful in 91.9\% of cases and in 37.8\% of cases the cicatricial sequelae were limited to peripheral chorioretinal scars.