Prevalence of severe retinopathy of prematurity in a geographically defined population in Croatia.

The aim of this study was to evaluate the prevalence of stage III of retinopathy of prematurity (ROP) among newborns of birth weight < 1500 g and gestational age (GA) < or = 32 weeks, and to compare these prevalences during two time periods (1998-2002 and 2003-2007). The investigation was conducted at the Department of Gynecology and Obstetrics, University Hospital in Rijeka, Croatia. The screening for ROP was performed by an ophthalmologist using a binocular indirect ophthalmoscope. Over a period of 10 years, there were 28,627 liveborn newborns, with 136 (0.48%) premature newborns with a birth weights < 1500 g and 226 (0.79%) newborns with GA at birth < or = 32 weeks. The proportions of survivors among newborns with birth weights < 1500 g (51.1% vs. 70.5%) and among newborns with GA at birth < or = 32 weeks (67.9% vs. 77.0%) were significantly higher in the later period. During the period 2003-2007, the proportion examined for ROP was higher among newborns with birth weight < 1500 g (52.9% vs. 97.1%) and among newborns with GA at birth < or = 32 weeks (46.5% vs. 96.9%). The prevalence of stage III ROP was significantly lower in 2003-2007 compared to that in 1998-2002 among newborns with birth weight < 1500 g (30.6% vs. 14.0%) and newborns with GA at birth < or = 32 weeks (22.4% vs. 8.8%). The prevalence of total ROP among newborns was significantly lower in 2003-2007 compared with 1998-2002. This decrease in prevalence may be explained by advances in neonatal intensive care unit, increased survival of very low birth weight infants and carefully timed retinal examinations.