Vision screening in infants, children and youth.

A Cochrane review of literature from 1966 to 2004 on screening for correctable visual acuity defects in school-aged children and adolescents found “no robust trials available that allow the benefits of school vision screening to be measured. The disadvantage of attending school with a visual acuity deficit also needs to be quantified. The impact of a screening program will depend on the geographical, and the socioeconomic setting in which it is conducted” [2]. However, major refractive errors can occur in 5% to 7% of preschoolers [3][4]; individual randomized, longitudinal studies report that early screening has been associated with a decrease in the prevalence of amblyopia and improved acuity by 60% [5]. Screening before three years of age is associated with a 70% lower prevalence of amblyopia after treatment [4][6]. The single and most effective test for amblyopia is the determination of visual acuity by noninvasive testing. A Cochrane review on screening specifically for amblyopia (1966 to 2005) concluded that “the lack of data from randomized controlled trials makes it difficult to analyze the impact of screening programs on the prevalence of amblyopia. The absence of such evidence cannot be taken to mean that vision screening is not beneficial; simply that this intervention has not yet been tested in robust studies” [7]. Adverse effects on educational and social development, as well as limitations to career choice are obvious consequences of poor visual acuity. Uncorrected amblyopia is a significant risk factor for total blindness, in the case of injury or disease, in the better functioning eye. The American Academy of Ophthalmology and the American Academy of Pediatrics [6] recommend visual assessment from birth and at all routine health supervisory visits. The child’s anatomy and function should be checked at regular infant and well-child visits, and visual acuity should be assessed at the preschool stage as well as when there is a complaint. Infants with a known risk (retinopathy of prematurity, Down’s syndrome, etc) or significant family history (congenital glaucoma, strabismus) should be referred for further evaluation [6].