Amblyopia.

Amblyopia, a decrease in visual acuity, is a major public health problem with a prevalence of 1 to 4 percent in the United States. It is thought to develop early in life during the critical period of visual development. Early recognition of amblyogenic risk factors such as strabismus, refractive errors, and anatomic obstructions can facilitate early treatment and increase the chance for recovery of visual acuity. Multiple medical organizations endorse screening for visual abnormalities in children and young adults, yet only 20 percent of school-age children have routine vision screening examinations. Any child with a visual acuity in either eye of 20/40 or worse at age three to five years or 20/30 or worse at age six years or older, or a two-line difference in acuity between eyes, should be referred to an ophthalmologist for further evaluation and definitive therapy. Treatment is started at the time of diagnosis and depends on the etiology. Treatment options for children with strabismus include patching and atropine drops. Children with refractive errors should be prescribed corrective lenses. Corneal lesions, cataracts, and ptosis require surgery. The success of therapy is highly dependent on treatment compliance. Patients and their parents should be educated about the need for regular follow-up and the risk of permanent vision loss.