New modifications of Swedish ROP guidelines based on 10-year data from the SWEDROP register.

Background/aims: During the last decade, improved neonatal care has resulted in increased survival of the most immature infants and improved health of more mature infants. We hypothesise that this has affected incidence and treatment of retinopathy of prematurity (ROP), enabling guidelines for screening to be modified.

Methods: In Sweden, all infants with gestational age (GA) at birth ≤30 weeks are screened for ROP. Results are registered in a web-based register, Swedish National ROP Register, with a coverage rate of 97%. Incidence of ROP and frequency of treatment, aspects on natural course of ROP and number of examinations, are calculated in relation to GA at birth in infants born during 2008-2017.

Results: Of 7249 infants, 31.9% (2310) had ROP and 6.1% (440) were treated. No infant with GA 30 weeks was treated. Incidence of ROP remained similar, but frequency of treatment increased (p=0.023). Over time, GA and birth weight were reduced in infants with ROP and with treated ROP. In the most immature infants, postmenstrual age was lower and postnatal age was higher when any ROP and stage 3 ROP were first detected (p<0.001). At treatment, postmenstrual but not postnatal age of the infant was associated with GA (p<0.001). During the 10-year period, 46 038 examinations were performed.

Conclusion: Modification of Swedish guidelines is proposed, including only infants with a GA of <30 weeks and postponing the first examination with 1 week in infants with GA 26-29 weeks. This would spare many infants from stressful examinations and reduce eye examinations with at least 20%.