Treatment for retinopathy of prematurity in Sweden 2008–2021: Reduced gestational age of treated infants and remaining differences in treatment type and recurrence rates between hospitals

Purpose

This study aimed to investigate various aspects of treatment for retinopathy of prematurity (ROP) in Sweden over the past 14 years, nationally and at a hospital level.

Methods

Data on screening and treatment for ROP in infants born in Sweden from 2008 to 2021 were extracted from the national ROP register, SWEDROP. During this period, Swedish screening guidelines were reduced from gestational age (GA) < 32 weeks to <31 weeks in 2012 and to <30 weeks in 2020.

Results

Altogether, 10 959 infants were screened and 600 infants treated for ROP during the study period. Parallel to changed guidelines, the number of screened infants decreased (p < 0.000) and the incidence of ROP and frequency of treatment increased (p < 0.001), while both remained similar in infants with a GA below 30 weeks. Among treated infants, GA and BW were reduced over the years (p < 0.001). Laser treatment (85.2% of primary treatments) became less common and anti-VEGF injections (13.6%) became more common over time (p < 0.001). Altogether 16 eyes were treated with the encircling band and 13 with vitrectomy. The total frequency of retreatment (32.7% of treated eyes) remained similar over time but was more common after primary anti-VEGF injection (67.7%) than laser treatment (27.2%). There were differences between the seven university hospitals regarding type of treatment and number of retreatments (p < 0.001).

Conclusion

The frequency of treatment and retreatment for ROP remained similar over time, but the type of treatment changed and anti-VEGF injections became more common. Differences between treating hospitals emphasize the importance of centralizing the most severe cases.