ROP Screening Protocol
All infants born at less than 32 weeks gestational age or with birth weight less than 1500g should undergo their first retinopathy of prematurity (ROP) screening examination at 31 weeks postmenstrual age (or 4 weeks chronological age, whichever is later), performed by an ophthalmologist experienced in ROP evaluation. 1
Initial Screening Criteria
Who Needs Screening
- Mandatory screening: All infants <32 weeks gestational age at birth, regardless of clinical course 1
- Selective screening: Infants 29-37 weeks gestation who had an unstable medical course (supplemental oxygen requirement) or chronic lung disease of infancy (CLDI) 1
- No screening needed: Infants >37 weeks gestational age 1
The conservative approach of screening all infants <32 weeks is preferred over relying on "medically stable" criteria, as this reduces the risk of missing cases 1.
Timing of First Examination
- Standard timing: 31-33 weeks postmenstrual age OR 4 weeks chronological age, whichever comes later 1
- The examination must be conducted by an ophthalmologist skilled in evaluating the premature infant retina 2, 1
Examination Technique
Preferred Method
- Binocular indirect ophthalmoscopy remains the reference standard for ROP diagnosis 3
- Use +20 or +28 diopter lens with indirect ophthalmoscope 4
- Mydriasis achieved with tropicamide 1% and phenylephrine 2.5% 4
Alternative Screening Modalities
- Retinal photography (RetCam) can be used as an adjunct but should not replace indirect ophthalmoscopy due to insufficient sensitivity (68%) for detecting peripheral disease 5, 3
- Digital imaging has excellent specificity (99%) but misses mild peripheral ROP in zone III 3
- Telemedicine approaches are acceptable when coupled with timely referral pathways for abnormal findings 2
Follow-Up Examination Schedule
Based on Initial Findings
If no ROP detected and incomplete vascularization:
- Repeat examination every 2 weeks until vessels reach ora serrata 4
- Then extend to every 3-4 weeks until complete vascularization 4
If any stage of ROP present:
- Zone I or Zone II disease: Weekly or every 1-2 weeks depending on severity 1, 6
- Zone III with regression: Every 2 weeks until vessels pass into Zone III on two sequential exams 1, 7
If prethreshold or threshold disease:
- Weekly examinations until treatment or regression 6
Discontinuation Criteria
Screening can be safely discontinued when:
- Complete retinal vascularization documented 1, 6
- ROP regressing with vessels passed into Zone III on at least two sequential examinations 1, 7
Continue screening if:
- Vessels or ROP remain in Zone I or Zone II (highest risk for progression) 1, 6
- History of CLDI even with Zone III disease 1
Critical Pitfalls to Avoid
Missed Follow-Up Appointments
- Greatest risk: Infants with unresolved ROP in Zone I or II discharged home who miss appointments 1, 6
- This represents the most common cause of preventable vision loss from ROP 1
- Careful coordination of outpatient ophthalmology appointments is essential before discharge 1
Premature Discontinuation
- Do not stop screening based solely on postmenstrual age 1
- Incomplete vascularization at 32 weeks leaves retina vulnerable to injury 1
- Continue until anatomic criteria for discontinuation are met 1, 7
Special Population Considerations
Infants with CLDI:
- Require screening even if 29-37 weeks gestation 1
- Need more frequent follow-up due to higher risk 1, 6
- Oxygen management becomes critical—target saturation ≥95% once past acute ROP risk period 6