Amblyopia
At a glance
Reduced best-corrected vision from abnormal visual development, after excluding structural disease. Earlier detection improves the opportunity for treatment.
CAVE
- Leukocoria, abnormal red reflex, ptosis obstructing the pupil or an unexplained afferent defect requires another diagnosis.
Clinical presentation
- Interocular acuity difference, strabismus, significant anisometropia or bilateral high refractive error.
Diagnosis & investigations
- Measure monocular acuity with age-appropriate crowded optotypes and consistent testing, checking that the fellow eye is fully occluded. Perform cycloplegic refraction, ocular alignment/motility assessment, stereopsis when feasible and a dilated ocular examination.
- Identify strabismic, anisometropic, bilateral refractive or deprivation mechanisms. An unexplained RAPD, abnormal fundus, progressive loss or a poor response despite reliable treatment requires reassessment for organic disease. A fixation preference alone is not an adequate substitute for measurable acuity when the child can cooperate.
Differential diagnosis
- Retinal or optic nerve disease, media opacity and unreliable acuity measurement.
Treatment
- Correct refractive error and remove significant deprivation promptly; congenital cataract or visual-axis obstruction is not managed by patching alone. Allow optical improvement while reviewing progress.
- Add occlusion or atropine when indicated, using a regimen matched to age and severity. Explain skin care for patches and atropine toxicity precautions, including safe storage and seeking help for systemic anticholinergic symptoms. Older children can still benefit; do not deny a trial solely because a birthday threshold has passed.
| Finding | Action | Timing / detail |
|---|---|---|
| Refractive amblyopia improving with spectacles | Continue full-time optical correction and document the trajectory before adding treatment | Optical improvement can continue over several months; do not defer necessary deprivation treatment |
| Moderate amblyopia, approximately 20/40–20/80 in the studied young-child population | Often start 2 hours/day patching of the better eye or atropine 1% on 2 days/week as an alternative | Choose with family, age, contraindications and ability to monitor; atropine is not only a last resort |
| Severe amblyopia or plateau despite reliable 2-hour patching | Recheck refraction, adherence and diagnosis; consider increasing patching to 6 hours/day under paediatric supervision | Do not extrapolate one age-group trial into a rigid universal dose |
| Stable improvement and treatment reduction | Taper higher-dose patching, continue refractive correction and monitor for recurrence | Check acuity in both eyes; reverse amblyopia or atropine adverse effects require reassessment |
Follow-up
- Recheck both-eye acuity, refraction when needed, adherence and alignment, commonly in 6–12 weeks; younger children or more intensive treatment need earlier review. If improvement plateaus, verify actual patching time and optical correction before increasing intensity. After stopping, continue surveillance for recurrence, especially during the first year.
Risk factors & context
- Identify strabismus, anisometropia, high bilateral refractive error or visual deprivation.
- The cause determines both urgency and treatment.
Complications
- Persistent reduced vision and impaired binocular function.
- Excessive penalisation can reduce fellow-eye acuity; recurrence can occur after treatment ends.
When to refer
- Urgent paediatric ophthalmic assessment for deprivation, leukocoria or suspected structural disease.
References 2
- AAO · Amblyopia Preferred Practice Pattern ↗2023 · published online December 2022 · Diagnosis; refractive correction; occlusion; follow-up
- NEI / PEDIG · Increasing patching for persistent amblyopia ↗2013 · randomised trial · Persistent amblyopia after 2-hour patching; 6-hour regimen
Adapt to the patient, local pathways and authorised product information.