Do current retinopathy of prematurity screening guidelines miss the early development of pre-threshold type 1 ROP in small for gestational age neonates?

PURPOSE

To investigate whether current UK retinopathy of prematurity (ROP) screening guidelines miss the early development of pre-threshold type 1 ROP in some neonates born small for gestational age (SGA) and consider if the guidelines should be changed.

METHODS

Data were collected on neonates of < or =31 completed weeks gestation and/or birth weight (BW) < or =1500 g born over a 37-month period. Babies who did not complete the screening programme in Cambridge and those with other ocular abnormalities were excluded. We compared the time course of ROP progression and the development of the early treatment for ROP pre-threshold ROP in relation to the gestational age and the BW of the babies.

RESULTS

A total of 105 neonates were included, 11 (10.5%) were born SGA (less than 9th centile of predicted BW). Of these 11, 2 (18.2%) had pre-threshold ROP at their first screen (median post-natal age (PNA) 6.5 weeks, median postmenstrual age (PMA) 33.5 weeks). No other neonate in this group developed pre-threshold ROP.Of the 94 other neonates, none had pre-threshold ROP at first screen (median PNA 7.1 weeks). Pre-threshold ROP developed in 12 (12.8%) of these babies between 8 and 12 (median 11.5) post-natal weeks, at a PMA of 33-38 (median 35.5) weeks.

CONCLUSION

Current UK ROP screening guidelines recommend first screening at 6-7 post-natal weeks. Our study suggests that pre-threshold type 1 ROP can develop before this especially in SGA babies. We suggest that screening should either start at 4 post-natal weeks in such babies, or be based on PMA rather than PNA, to allow timely laser therapy.