A 4-year-old girl is found to have best-corrected visual acuity of 6/6 in the right eye and 6/36 in the left eye. Cycloplegic refraction reveals +5.0 D in the right and +1.0 D in the left eye. There is no strabismus. The type of amblyopia is:

• A Strabismic amblyopia
• B Anisometropic amblyopia ✓
• C Ametropic amblyopia
• D Deprivation amblyopia

Explanation

Anisometropic amblyopia results from a significant difference in refractive error between the two eyes — the brain suppresses the more defocused image from the eye with higher refractive error. Here, the right eye has +5.0 D (high hyperopia) versus +1.0 D in the left, and the amblyopia (6/36) is in the right eye despite it having the higher refractive error — though in unilateral amblyopia, amblyopia typically affects the eye that has been chronically defocused. More precisely, with anisometropia >1.5 D, the more ametropic eye (here +5D right) becomes amblyopic. Strabismic amblyopia requires ocular misalignment. Ametropic amblyopia affects both eyes with bilateral high refractive error. Deprivation amblyopia is from media opacity.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.