Strabismus and Amblyopia
Pediatric Ophthalmology High-Yield Essentials
1. The Relationship
Strabismus (misalignment of the eyes) is one of the most common causes of amblyopia (a developmental reduction in vision). When eyes are misaligned, the brain ignores the image from the deviating eye to avoid diplopia (double vision), leading to “lazy eye” or amblyopia.
2. Amblyopia Classification
| Type | Etiology |
|---|---|
| Strabismic | Constant unilateral strabismus. |
| Refractive | Anisometropia (large difference in refractive error) or high bilateral refractive error. |
| Deprivation | Obstruction of the visual axis (e.g., congenital cataract, ptosis). Most severe form. |
3. Management & Treatment
- Treat the Cause: Correct the strabismus or refractive error first (e.g., glasses, surgery).
- Occlusion Therapy (Patching): The gold standard. Patching the better eye forces the amblyopic eye to develop.
- Penalization: Using atropine drops in the better eye to blur its vision, encouraging use of the amblyopic eye.
- Critical Period: Treatment is highly effective if initiated during the “critical period” of visual development (usually up to age 7-8).
4. NEET PG High-Yield Pearls
- Anisometropia: The most common cause of refractive amblyopia.
- Strabismus: Alternating strabismus rarely leads to severe amblyopia because the brain uses both eyes intermittently. Constant unilateral strabismus is the primary risk factor.
- Screening: Early screening is vital; amblyopia is reversible in childhood but becomes permanent if untreated after the critical period.