Retinopathy of prematurity: are we screening too many babies?

PURPOSE: With advancement in neonatal care units, early detection of retinopathy of prematurity (ROP) in premature and very-low-birth-weight infants is important. Numerous studies have reported an increased risk of ROP in prematurely born infants, but only few have been long-term and strictly population-based. The aim of the present study was to find out whether birthweight <1251 grams and gestational age <30 weeks could provide a safe and efficient means of detecting treatable ROP. We have retrospectively tried to ascertain the incidence and associated risk factors that may contribute to the management of babies with ROP.
METHODS: Infants either with a birth weight below 1500 g or a gestational age of less than 32 weeks were screened for ROP during an 8-year period by a single examiner. Results An incidence of 64/205 (31.2%) ROP was noted. The mean age at detection was 5.5 +/- 2 weeks of life. The maximum stage reached was stage 1 in 27 (13.2%), stage 2 in 24 (11.7%) and stage 3 in 10 (4.8%) babies. Threshold ROP was present in three (1.5%) babies. Significantly fewer (150/205 = 73%) babies would have been examined had a birth weight of <1251 grams and a gestational age <30 weeks been applied. there were five (8%) babies with birth weight >1250 grams and eight (12%) babies with gestational age >30 weeks amongst babies with ROP but all were stage 1 or stage 2. All the stage 3 ROP and the threshold ROP cases were babies with birth weight <1000 grams and gestational age below 28 weeks.
CONCLUSION: Ophthalmic examination may be safely and efficiently concentrated in babies with birth weight <1251 grams and gestational age below 30 weeks. Birth weight (P < 0.005) and gestational age (P < 0.01) were the only significant risk factors. During this 8-year period there was no significant decrease in the number of babies screened for ROP and the overall incidence of all stages of the disease has remained constant. In the present series a lower incidence of severe ROP was noted compared to most previous studies. Our experience from this study suggests the need for further refinement of screening guidelines in order to focus screening on the vision-threatening stages of ROP.