Strabismus (ocular misalignment) can lead to amblyopia and permanent vision loss. Amblyopia-poor vision in an otherwise normal eye-is best addressed in the preschool years; if this condition is left untreated, irreversible visual loss may ensue. Strabismus is sometimes indicative of or associated with a more serious condition (Table 1).

Table 1

 Parents commonly discover strabismus. In one study, strabismus or leukocoria as the presenting symptom of retinoblastoma was discovered by a family member in 75% of cases.¹ But not all ocular disease is recognized at home. Screening for ocular disease at each well-child visit ensures that prompt referral to an ophthalmologist, preferably a pediatric ophthalmologist, can be made. Early detection and diagnosis of ocular defects can prevent vision loss, facilitate the treatment of associated life-threatening conditions, and ameliorate any adverse emotional effects.

Children do not "outgrow" strabismus, and its psychological impact must not be overlooked. Strabismus can have an adverse effect on the psychological well-being of children.² In addition, adults with strabismus experience more general anxiety, social anxiety, and social avoidance than those in the general population.³ Psychosocial adjustment improves after surgical correction.

The 3 screening methods needed to detect strabismus are:

• Gross inspection.
• Light reflex tests, including the Bruckner test (inspection for a red reflex).
• Cover tests.

In the general pediatric clinic, ophthalmoscopy and measurement of visual acuity are also crucial.

In this article, we review the basics of the eye examination and provide an overview of the strabismus evaluation in the primary care setting.

EPIDEMIOLOGY

Amblyopia is the most common cause of visual impairment in children, ⁴ and strabismus is one of the major causes of amblyopia. In a multiethnic study of pediatric eye disease, the prevalence of strabismus ranged from 1.2% to 5.6%.⁵ In another study, Ip and colleagues⁶ examined 6-year-old children with and without eye-strain symptoms (double or blurred vision, sore eyes, headaches associated with work requiring near-vision); strabismus was found in 7.3% and 1.8%, respectively. Typically, children with strabismus and/or amblyopia have no symptoms.