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  "id": "maternal:etrop-trial",
  "owner": "maternal",
  "kind": "study",
  "slug": "etrop-trial",
  "name": "Early Treatment for Retinopathy of Prematurity (ETROP) trial",
  "aliases": [],
  "atlases": [
    "maternal"
  ],
  "summary_plain": "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.",
  "summary_technical": "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.",
  "editorial_state": "draft",
  "last_substantive_edit": "2026-10-15",
  "last_evidence_check": "2026-10-15",
  "next_review_due": null,
  "identifiers": [],
  "navigation": {
    "maternal": {
      "life-stage": [
        "newborn",
        "infant-follow-up"
      ],
      "care-area": [
        "preterm-and-sick-newborn"
      ]
    }
  },
  "payload": {
    "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.",
    "drug_phase": "2/3",
    "registry_statuses": [
      {
        "status": "UNKNOWN",
        "snapshot": "maternal:ctgov-nct00027222-2026-10-15"
      }
    ],
    "start_date": {
      "date": "2001-10",
      "type": null,
      "snapshot": "maternal:ctgov-nct00027222-2026-10-15"
    },
    "primary_completion_date": null,
    "completion_date": null,
    "results_first_posted": null,
    "countries": [
      {
        "code": "US",
        "snapshot": "maternal:ctgov-nct00027222-2026-10-15"
      }
    ],
    "care_setting": null,
    "stopped_early": null,
    "enrollment": [
      {
        "count": 317,
        "basis": "randomized",
        "unit": "infants with bilateral high-risk prethreshold ROP (one eye randomised)",
        "snapshot": "maternal:pubmed-14662586-2026-10-15"
      },
      {
        "count": 84,
        "basis": "randomized",
        "unit": "cases of asymmetric ROP (the one eye with high-risk prethreshold ROP randomised)",
        "snapshot": "maternal:pubmed-14662586-2026-10-15"
      }
    ],
    "arms": [
      {
        "id": "maternal:etrop-trial-arm-early-treatment",
        "label": "Early treatment",
        "intervention": null,
        "description": "Eye randomised to early treatment by ablation of the avascular retina in high-risk prethreshold ROP."
      },
      {
        "id": "maternal:etrop-trial-arm-conventional",
        "label": "Conventional management",
        "intervention": null,
        "description": "Control eye: the fellow eye managed conventionally (bilateral cases), or the eye randomised to conventional management (asymmetric cases)."
      }
    ],
    "findings": []
  },
  "content_digest": "181227d1af01716c888bb1def9dc1cfb525bc0a93e3bca0ed8971c2f4119293f",
  "review": {
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      "owner": "maternal",
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      "category": "effect",
      "statement": "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.",
      "context": {
        "id": "maternal:ctx-etrop-high-risk-prethreshold-rop",
        "label": "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_note": "Infants with high-risk prethreshold retinopathy of prematurity, followed to a corrected age of 9 months",
        "life_stage_terms": {
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        "gestational_age_min_days": null,
        "gestational_age_max_days": null,
        "gestational_age_basis": null,
        "postnatal_age_min_days": null,
        "postnatal_age_max_days": null,
        "gestational_age_status": null,
        "postnatal_age_status": null,
        "followup_description": "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.",
        "eligibility": {
          "inclusion": [
            "Infants with bilateral high-risk prethreshold ROP, or asymmetric ROP in which one eye had high-risk prethreshold ROP",
            "Birth weight under 1251 g, born at participating centres and/or examined by 42 days of life (registry)"
          ],
          "exclusion": []
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      "evidence_stage": "interventional",
      "certainty": "not_assessed",
      "certainty_method": null,
      "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.",
      "editorial_state": "draft",
      "checked_at": "2026-10-15",
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