Incidence of severe retinopathy of prematurity
- Neonatal Unit
- The Princess Anne Hospital
- Coxford Road, Southampton
- Hants, UK
- Department of Ophthalmology
- Westmead Hospital
- Sydney, NSW, Australia
- Neonatal Unit
- The Princess Anne Hospital
- Coxford Road, Southampton
- Hants, UK
- Department of Ophthalmology
- Westmead Hospital
- Sydney, NSW, Australia
Editor—We were interested to read the article of Vyas et al 1 on the incidence of severe retinopathy of prematurity (ROP) in 11 neonatal units in five cities in England in 1994. We have published similar data from eight neonatal units in New South Wales (NSW) Australia in 1993 and 1994.2 These data were prospectively collected in the NSW Neonatal Intensive Care Unit's data collection and is stored and maintained in the NSW Centre for Perinatal Health Services Research, University of Sydney, NSW.
For infants of < 29 weeks gestation, there was no significant difference in severe ROP (≥ stage 3) between the five cities in England and NSW (table 1).
Incidence of severe retinopathy of prematurity (ROP) in five cities in England and in New South Wales (NSW), Australia
Unlike Vyas et al,1 we could not find an association between improved survival and the development of severe ROP. In six of the neonatal units in our study (two have been excluded from this analysis as they are children's hospitals and have very few small premature infants), survival in infants of < 27 weeks gestation ranged from 51.3% to 68.8%. The percentage with severe ROP for the two units with the lowest and highest survival was 15 (3/20) and 24 (5/21) respectively, while the range of severe ROP in the six neonatal units was 15% (3/20) to 36% (9/25). In infants of 27–28 weeks gestation, survival ranged from 85.1% to 96.7% and the percentage with severe ROP for the two units with the lowest and highest survival was 7 (4/56) and 3 (2/58) respectively, while the range of severe ROP in this group of infants was 2% (1/50) to 7% (4/56) (unpublished observations). We have also shown that, despite an increase in survival of preterm infants following the introduction of surfactant, there was no significant impact on the incidence or severity of ROP.3
In infants of 29–31 weeks gestation, six of 443 infants (1.4%) developed severe ROP and one required Cryo/Laser treatment.2 This infant was 30 weeks gestation with a birth weight of 1305 g. We therefore agree with Vyaset al 1 that there should be no reduction in the upper limit of gestation or birth weight for screening for ROP.
