Treating Retinopathy of Prematurity with Dexamethasone Eye Drops : A Difference-in-Differences Study in Sweden Using Register Data

Summary, in English

PURPOSE: To estimate the effect of dexamethasone eye drops on the risk of progression from type 2 retinopathy of prematurity (ROP) to ROP requiring traditional treatments.

DESIGN: Register-based cohort study.

PARTICIPANTS: Preterm infants born before 30 weeks' gestation from 2015-2018 (control years) and from 2020-2021 (intervention years) registered in the Swedish Quality Register for ROP at 4 Swedish sites were included. In 1 of these sites, the intervention site, topical dexamethasone was introduced during the later period when type 2 ROP was diagnosed.

METHODS: The frequency of traditional ROP treatments (laser ablation or intravitreal injection of anti-VEGF) was compared between the 2 periods at sites that had and had not introduced topical dexamethasone during the later period. Analyses were conducted both on infants with severe ROP and on all included infants. The difference-in-differences statistical method was used.

MAIN OUTCOME MEASURES: The proportion of infants that required traditional ROP treatment in each group and the interaction odds ratio, adjusted for potential confounding factors.

RESULTS: At the intervention site, the incidence of traditional ROP treatment fell from 23/32 (72%) to 4/32 infants (13%; P < 0.001) with severe ROP and from 23/409 (5.6%) to 4/217 screened infants (1.8%; P = 0.03). For the 3 control sites, the equivalent numbers were from 82/175 (47%) to 32/57 infants (56%; P = 0.22) and from 82/950 (8.6%) to 32/441 infants (7.3%; P = 0.38). The difference-in-differences analyses resulted in an adjusted interaction odds ratio of 0.05 (95% confidence interval, 0.01-0.22; P < 0.001) for infants with severe ROP, suggesting a markedly larger decline in occurrence of traditional ROP treatments at the intervention site.

CONCLUSIONS: In this population of infants with severe ROP, the introduction of dexamethasone eye drops was associated with a significant reduction in the proportion of infants requiring traditional ROP treatments. A timely administration of low-dose dexamethasone eye drops may serve as a simple, cost-effective, and noninvasive intervention to reduce one of the leading causes of severe visual impairment worldwide. Further studies are needed to confirm our findings.

FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

• Author: Lotta A K C Gränse; Hanna Maria V Öhnell; Gerd Holmström; Johanna C Sundgren; Kristina Teär Fahnehjelm; Agneta Wallin; Eva Larsson; Despoina Tsamadou; Lars J Björklund; Ann Hellström; Jenny Wallander; Karin Sandgren Hochhard; Sten O L Andreasson; Elisabeth R Olhager; Jonas Björk
• Department/s: Retinopathy of Prematurity; Clinical research in families with inherited retinal degeneration; Ophthalmology, Lund; Department of Clinical Sciences, Lund; Ophthalmology (Malmö); Paediatrics (Lund); LU Profile Area: Proactive Ageing; Infect@LU; Epidemiology and population studies (EPI@Lund); LU Profile Area: Nature-based future solutions; eSSENCE: The e-Science Collaboration; Centre for Economic Demography; Division of Occupational and Environmental Medicine, Lund University; EpiHealth: Epidemiology for Health
• Publishing year: 2026-02
• Language: English
• Pages: 248-256
• Publication/Series: Ophthalmology
• Volume: 133
• Issue: 2
• Links: http://dx.doi.org/10.1016/j.ophtha.2025.09.020
• Document type: Journal article
• Publisher: Elsevier
• Topic: Ophthalmology; Pediatrics; Epidemiology
• Keywords: Female; Humans; Infant, Newborn; Male; Angiogenesis Inhibitors/therapeutic use; Dexamethasone/administration & dosage; Disease Progression; Gestational Age; Glucocorticoids/administration & dosage; Incidence; Infant, Premature; Intravitreal Injections; Laser Coagulation; Ophthalmic Solutions/administration & dosage; Registries; Retinopathy of Prematurity/drug therapy; Sweden/epidemiology; Vascular Endothelial Growth Factor A/antagonists & inhibitors
• Status: Published
• Research group: Retinopathy of Prematurity; Clinical research in families with inherited retinal degeneration; Ophthalmology (Malmö); Epidemiology and population studies (EPI@Lund)
• ISBN/ISSN/Other: ISSN: 1549-4713