Presented at the Neonatal Society 2006 Spring Meeting.
Heckford E, Curley A (introduced by A Ogilvy-Stuart)
Rosie NICU, Box 226, Addenbrooke’s Hospital, Cambridge CB2 2QQ, UK
Background: Retinopathy of prematurity (ROP) is a vasoproliferative disorder of the eye that affects premature neonates and can result in blindness. The Royal College of Ophthalmology guidelines recommend that all infants <31 weeks gestation and/or <1500g are screened for ROP from 6-7 weeks postnatal age (1). On our unit a 29 week gestation infant with birth weight (BW) < 0.4th centile was noted to have stage 3 plus ROP bilaterally requiring laser therapy at first ROP screen at 6 weeks.
Objectives: To determine whether neonates born small for gestational age (SGA) are at increased risk of developing early ROP and therefore should be screened at an earlier stage.
Methods: Data were collected on all infants born January 2003 – September 2005 of gestation ≤31 weeks gestation and/or BW ≤1500g (n=162). We looked at the characteristics of the 87 babies who completed their ROP screening in Cambridge. We excluded those who did not complete their screening in Cambridge (n=39), those who died before screening (n=35) and those whose retinopathy was not related to prematurity (n=1). For each of the 87 babies we calculated birth centile and compared ROP stage, presence of plus disease at first screen, worst ROP stage and whether ROP treatment was required. Ethical approval was not sought for this departmental audit.
Results: Of the 87 babies, 11 had BW < 9th centile and 76 had BW > 9th centile. Of the infants with BW < 9th centile (11) 2 had stage 3 and/or plus disease at first screen (mean age 6.1 weeks). By comparison, none of the infants with BW > 9th centile (76) had stage 3 ROP or plus disease at the time of first screen (mean age 7.1 weeks). We showed that the mean PNA at laser treatment in the < 9th centile group was 6.5 weeks as compared with 10.9 weeks in the infants with BW > 9th centile.
Conclusion: Previous studies have suggested that intrauterine growth restriction is an independent risk factor for ROP (2,3) and that this may be mediated through growth factors such as insulin-like growth factor (IGF-1) and vascular endothelial growth factor (VEGF) (4). Our study demonstrates that SGA (< 9th centile) infants are at risk of developing severe ROP earlier than their counterparts. We therefore recommend first ROP screen at 4 weeks postnatal age for those infants with BW < 9th centile.
References
1. The Royal College of Opthalmologists, British Association of Perinatal Medicine. Early Hum Dev 1996;46:239-58.
2 Darlow BA et al. Pediatrics 2005;116:516.
3 Regev RH et al. J Pediatr 2003;143:186-91.
4 Smith LE. Biol Neonate 2005;88:237-44.