# Early Treatment for Retinopathy of Prematurity (ETROP) trial Study · id `maternal:etrop-trial` · Maternal & Newborn Atlas · release `fc5a600ec7387e71` (public) > General information from published sources, not medical advice, and not reviewed by clinicians. Check the cited source before relying on anything here. The atlas's own text and curation may be reused under Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0, https://creativecommons.org/licenses/by-nc/4.0/): credit the atlas, and do not use it commercially. See the atlas About page. Text quoted from a source stays under that source's own terms, given as the source's reuse\_basis. The atlas's reuse terms do not cover it. The downloads list each quotation with its source in third\_party\_quotations. Browse, life stage: Newborn; Infant follow-up Browse, care area: Preterm and sick newborns ## In plain language A US trial from the National Eye Institute that asked whether treating retinopathy of prematurity earlier gives better visual and structural results than conventional treatment. In babies with both eyes affected, one eye was treated early and the other managed conventionally. Early treatment lowered the share of unfavourable outcomes at 9 months, and the further analysis led the authors to modify the recommendations for treating eyes with ROP. ## Technical summary Registry NCT00027222 (phases 2 and 3, status UNKNOWN, last update posted 2005-06-24, lead sponsor the National Eye Institute) and the 2003 report (PubMed abstract only). The registry gives no enrolment count, no completion dates and no results. The abstract gives 317 infants with bilateral disease and 84 asymmetric cases; no total is stated and none is computed here. The registry lists eligibility as infants under 1251 g birth weight born at participating centres and/or examined by 42 days of life, and a maximum age of 42 days. ## Key facts - Design: Randomised trial in infants with high-risk prethreshold ROP. Bilateral cases: one eye randomised to early treatment (ablation of the avascular retina) and the fellow eye managed conventionally. Asymmetric cases: the one eye with high-risk prethreshold ROP randomised to early treatment or conventional management. - Phase: Phase 2/3 - Enrolled: 317 infants with bilateral high-risk prethreshold ROP (one eye randomised) (randomized count; Revised indications for the treatment of retinopathy of prematurity: results of the early treatment for retinopathy of prematurity randomized trial, snapshot `maternal:pubmed-14662586-2026-10-15`, retrieved 2026-10-15); 84 cases of asymmetric ROP (the one eye with high-risk prethreshold ROP randomised) (randomized count; Revised indications for the treatment of retinopathy of prematurity: results of the early treatment for retinopathy of prematurity randomized trial, snapshot `maternal:pubmed-14662586-2026-10-15`, retrieved 2026-10-15) - Started: 2001-10 (The Early Treatment for Retinopathy of Prematurity Study (ETROP), snapshot `maternal:ctgov-nct00027222-2026-10-15`, retrieved 2026-10-15) - Primary completion: Not reported - Completion: Not reported - Countries: United States (The Early Treatment for Retinopathy of Prematurity Study (ETROP), snapshot `maternal:ctgov-nct00027222-2026-10-15`, retrieved 2026-10-15) - Care setting: Not reported - Registry status: "UNKNOWN" (U.S. National Library of Medicine (ClinicalTrials.gov), snapshot `maternal:ctgov-nct00027222-2026-10-15`, retrieved 2026-10-15) ## Claims, with the population each applies to ## Context: Infants with high-risk prethreshold retinopathy of prematurity (ETROP trial) Recipient: Newborn; Population: Infants with bilateral high-risk prethreshold ROP (317) had one eye randomised to early treatment and the other eye managed conventionally; in asymmetric cases (84) the one eye with high-risk prethreshold ROP was randomised to early treatment or conventional management. High risk was decided with a model built on the natural history cohort of an earlier cryotherapy trial. The outcomes are counted per eye. Under the registry, infants of birth weight under 1251 g, born at participating centres and/or examined by 42 days of life, were eligible, and the early treatment trial required prethreshold ROP.; Care setting: Not stated in the abstract; Geography: United States (ClinicalTrials.gov locations); Life stage: Infants with high-risk prethreshold retinopathy of prematurity, followed to a corrected age of 9 months; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Visual acuity was assessed at a corrected age of 9 months by masked testers using Teller acuity cards; eyes were examined for structural outcome at corrected ages of 6 and 9 months. ### In ETROP, early treatment of high-risk prethreshold retinopathy of prematurity (ablation of the avascular retina) was compared with conventional management. In infants with both eyes affected, one eye was randomised to early treatment and the fellow eye was managed conventionally; in asymmetric cases the one eye with high-risk prethreshold ROP was randomised to early treatment or to conventional management. With earlier treatment, unfavourable grating visual acuity at a corrected age of 9 months fell from 19.5% to 14.5% (P=.01) and unfavourable structural outcomes at 9 months fell from 15.6% to 9.1% (P<.001). Further analysis supported retinal ablation for type 1 ROP (zone I, any stage with plus disease; zone I, stage 3 without plus disease; or zone II, stage 2 or 3 with plus disease) and a wait-and-watch approach for type 2 ROP (zone I, stage 1 or 2 without plus disease; or zone II, stage 3 without plus disease), which should be considered for treatment only if it progresses to type 1 or threshold ROP. The authors say early treatment significantly reduced unfavourable outcomes to a clinically important degree. - Category: Effect - Evidence stage: Interventional - Certainty: Certainty not assessed - Applies to: Recipient: Newborn; Population: Infants with bilateral high-risk prethreshold ROP (317) had one eye randomised to early treatment and the other eye managed conventionally; in asymmetric cases (84) the one eye with high-risk prethreshold ROP was randomised to early treatment or conventional management. High risk was decided with a model built on the natural history cohort of an earlier cryotherapy trial. The outcomes are counted per eye. Under the registry, infants of birth weight under 1251 g, born at participating centres and/or examined by 42 days of life, were eligible, and the early treatment trial required prethreshold ROP.; Care setting: Not stated in the abstract; Geography: United States (ClinicalTrials.gov locations); Life stage: Infants with high-risk prethreshold retinopathy of prematurity, followed to a corrected age of 9 months; Gestational age: Not reported; Postnatal age: Not reported; Follow-up: Visual acuity was assessed at a corrected age of 9 months by masked testers using Teller acuity cards; eyes were examined for structural outcome at corrected ages of 6 and 9 months. - Limitations: Only the abstract was read. The analysis combines bilateral and asymmetric cases and counts eyes, not infants. Follow-up in this paper ends at a corrected age of 9 months; the authors say long-term follow-up was being conducted. The grouping into type 1 and type 2 ROP comes from further analysis that led to modified treatment recommendations; it is not a separate trial. The abstract does not give how many eyes were in each group. - Last checked: 2026-10-15 - Sources: 1. Supports: Revised indications for the treatment of retinopathy of prematurity: results of the early treatment for retinopathy of prematurity randomized trial (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, RESULTS sentences 1 to 5 and CONCLUSIONS sentence 1. Retrieved 2026-10-15T13:49:23Z. Source state: Current. Snapshot hash: 3a686b6dbcc138d824b4b8b24d3c68588e1ddb859742bee2667f7a5038c7e31c. How it applies: Visual acuity, structural outcome and the type 1 and type 2 findings. 2. Background: Revised indications for the treatment of retinopathy of prematurity: results of the early treatment for retinopathy of prematurity randomized trial (Publication, edition PubMed record (abstract and bibliographic data) from NCBI E-utilities. The full text and the version of record were not fetched.) Locator: Abstract, OBJECTIVE, METHODS and CONCLUSIONS sentence 3. Retrieved 2026-10-15T13:49:23Z. Source state: Current. Snapshot hash: 3a686b6dbcc138d824b4b8b24d3c68588e1ddb859742bee2667f7a5038c7e31c. How it applies: Design, groups, outcome assessment and follow-up. ## Connected pages - Tests earlier treatment of ROP: Retinopathy of prematurity (`maternal:retinopathy-of-prematurity`) ## Provenance Content hash: 181227d1af01716c888bb1def9dc1cfb525bc0a93e3bca0ed8971c2f4119293f Last substantive edit: 2026-10-15 Evidence last checked: 2026-10-15