Corneal Diseases in Children: Amblyopia Management

Abstract

Amblyopia is an additional challenge to the visual rehabilitation of a child with a corneal opacity. Although amblyopia is defined as impaired vision, usually in one eye, that is structurally normal, amblyopia often coexists in a child with a corneal disorder. Key concepts include critical period of visual development, assessment of vision in children, identification of amblyopia risk factors, definition of amblyopia, and treatment options for amblyopia. The critical period of visual development spans birth to about age 10, a time in which proper visual input from each eye is paramount in order to “teach” the visual cortex the characteristics of excellent vision. There are a variety of methods to assess visual acuity; often a decision about visual impairment needs to be made over several office visits to obtain reproducible and accurate information. Amblyogenic risk factors include asymmetric refractive error (anisometropia), high refractive error in both eyes (ametropia), misaligned visual axes (strabismus), and media opacity. In the preverbal child, a decision to treat amblyopia is made on the basis of an identified amblyogenic risk factor or demonstration of asymmetric visual acuity. There may be a difference between the eyes on preferential looking testing or consistent objection to patching one eye versus the other. In the verbal child, amblyopia is confirmed when a two-line or greater difference in vision is identified, despite correction of any refractive error. Familiarity with treatment options, such as glasses, patching, pharmacologic, and optical penalization is crucial to improve vision.