Retinopathy of prematurity (ROP) is an abnormal retinal vascular development disease of premature infants that may progress to retinal bleeding, retinal detachment, and blindness if severe disease is missed or untreated.
| Infant Group | Screen? | Practical Note |
|---|---|---|
| Birth weight <1500 g | Yes | Major Baylor screening criterion |
| Gestational age ≤30+6 weeks | Yes | Baylor: 30+6 qualifies; 31+0 does not |
| BW 1500–2000 g with unstable clinical course | Yes, if significant risk | Oxygen exposure, hypotension, sepsis, cardiorespiratory instability, or severe illness |
| >30 weeks and stable | Usually no | Screen only if clinical course warrants |
A 30+6 infant qualifies; a 31+0 infant does not — unless clinical instability creates additional risk. When in doubt, screen.
The first ROP exam must occur at at least 31 weeks PMA AND at least 4 weeks postnatal age. Use whichever criterion results in the later date. Eligible infants must be actively tracked so the exam is never missed.
| GA at Birth | First ROP Exam |
|---|---|
| 22 weeks | 31 weeks PMA or 9 weeks chronological age |
| 23 weeks | 31 weeks PMA or 8 weeks chronological age |
| 24 weeks | 31 weeks PMA or 7 weeks chronological age |
| 25 weeks | 31 weeks PMA or 6 weeks chronological age |
| 26 weeks | 31 weeks PMA or 5 weeks chronological age |
| 27 weeks | 31 weeks PMA or 4 weeks chronological age |
| 28 weeks | 32 weeks PMA or 4 weeks chronological age |
| 29 weeks | 33 weeks PMA or 4 weeks chronological age |
| 30 weeks | 34 weeks PMA or 4 weeks chronological age |
| Older GA but high-risk course | ~4 weeks chronological age |
Timing follows AAP screening schedule for premature infants at risk for ROP.
Every ROP documentation must describe zone, stage, and presence or absence of plus disease.
| Zone | Meaning |
|---|---|
| Zone I | Most posterior retina around optic nerve and macula — highest risk |
| Zone II | Extends from Zone I edge toward nasal ora serrata |
| Zone III | Temporal crescent of peripheral retina — usually lower risk |
| Stage | Meaning |
|---|---|
| Stage 0 | Immature avascular retina — no ROP yet |
| Stage 1 | Demarcation line between vascular and avascular retina |
| Stage 2 | Elevated ridge |
| Stage 3 | Extraretinal fibrovascular proliferation / neovascularization |
| Stage 4a | Partial retinal detachment — extrafoveal |
| Stage 4b | Partial retinal detachment — foveal involvement |
| Stage 5 | Total retinal detachment |
Zone I Stage 1 with plus disease is more dangerous than Zone III Stage 3 without plus. Never interpret stage in isolation.
Follow-up interval depends on zone, stage, plus disease, and the ophthalmologist's judgment.
| Eye Finding | Suggested Follow-Up |
|---|---|
| Very low-risk findings | Every 2–3 weeks (if ophthalmology agrees) |
| Typical immature retina or mild ROP | Every 1–2 weeks |
| Posterior disease, Zone I, suspected aggressive ROP, or worsening stage | Weekly or more frequent |
| Very high-risk disease | Twice weekly |
Infants treated with anti-VEGF cannot stop screening at 45 weeks PMA. Late reactivation can occur weeks to months after injection. Ophthalmology must define a specific end point for each infant.
The most important prevention strategy is careful oxygen use with close saturation titration.
For premature infants on supplemental oxygen who remain at risk for ROP, Baylor recommends a saturation target of 90–95%.
Lower oxygen targets reduce ROP incidence but may increase mortality. Aggressive desaturation targeting is not justified for ROP prevention alone. Use a balanced range.
Treatment is indicated for Type 1 ROP. Treatment must be performed within 72 hours of Type 1 ROP being confirmed.
| Type 1 ROP Pattern | Treat? |
|---|---|
| Zone I, any Stage with plus disease | Yes — within 72 h |
| Zone I, Stage 3 (any stage) | Yes — within 72 h |
| Zone II, Stage 2 or 3 with plus disease | Yes — within 72 h |
| Type 2 ROP (Zone I Stage 1–2 no plus; Zone II Stage 3 no plus) | Observe closely, do not treat yet |
Once Type 1 ROP is confirmed, treatment delay increases the risk of retinal detachment. Coordinate with ophthalmology and anesthesia immediately.
Ablates avascular retina to reduce the angiogenic drive for abnormal neovascularization.
Off-label use of bevacizumab (anti-VEGF monoclonal antibody) injected intravitreally. Used increasingly for Zone I or posterior Zone II disease.
Anti-VEGF changes the natural history of ROP. Particularly close follow-up is required around 45–55 weeks PMA — this is when late reactivation most commonly occurs. Ophthalmology must define when screening can end for each treated infant.
Anti-VEGF agents reach the systemic circulation and can affect the pulmonary vasculature. Baylor requires a limited echocardiogram within 3 days before the injection and again 1–2 weeks afterwards, specifically to look for pulmonary hypertension. An infant who already has pulmonary hypertension or significant chronic lung disease needs that discussed with ophthalmology and cardiology before anti-VEGF is chosen over laser.
The SUPPORT and BOOST-II trials compared lower (85–89%) with higher (91–95%) saturation targets in extremely preterm infants. The lower target reduced severe ROP but was associated with higher mortality — which is why the balanced 90–95% range (alarms 88–96%) is used instead of driving saturations down for the eyes alone.
Outpatient appointment delays after discharge are a leading cause of missed treatment-level ROP. The appointment must be confirmed, not just recommended, before the infant leaves the NICU.
| Mistake | Why It Is Dangerous | Better Action |
|---|---|---|
| Forgetting to screen a 30-week infant | Severe ROP can be missed before the treatment window closes | Use automatic ROP eligibility tracking for all admitted preterm infants |
| Waiting until discharge to arrange ROP follow-up | Outpatient delays can cause missed treatment-level disease | Schedule the outpatient ophthalmology appointment before discharge |
| Thinking Stage 1 or Stage 2 always means safe | Zone I Stage 1 with plus disease requires urgent treatment | Always interpret stage alongside zone and plus disease |
| Using very low SpO₂ targets to prevent ROP | Sub-90% targets may reduce ROP but increase mortality | Use 90–95% in at-risk preterm infants on oxygen |
| Treating anti-VEGF as "finished" after one injection | Reactivation can occur at 45–55 weeks PMA and beyond | Maintain prolonged ophthalmology surveillance; document end-of-screening plan |
"Your baby needs eye screening because very premature babies can have delayed or abnormal blood vessel growth in the retina — the layer at the back of the eye that senses light."
"Most mild ROP gets better on its own as the blood vessels finish growing. But some babies develop severe disease that needs treatment to prevent the retina from detaching, which could cause serious vision loss or blindness."
"The eye exam schedule is very important. The exams may feel uncomfortable for your baby, but they are quick and done by a specialist. If your baby goes home before the eyes are fully mature, you must already have an outpatient eye appointment arranged — missing that appointment is not safe."
"If your baby needs treatment, the most common options are a laser procedure or an injection into the eye. Both can protect vision, and the doctor will explain which is best for your baby's specific situation."