Abstract
Abstract: :
Purpose:Recent work by our team and other eye/vision screening programs reveals that despite better awareness, many preschool children possess significant undiagnosed eye disease and visual dysfunction which place them at risk for permanent vision loss, notably amblyopia. Undiagnosed ocular and visual pathology during the preschool years is particularly costly, as treatment during this brief window of eye and CNS plasticity often results in substantial vision recovery. Despite some successful pilot programs, there is still debate over whether screening is effective. To address this issue, we evaluate a regional screening program which incorporates the most comprehensive battery of vision tests attempted to date. Methods: Over 600 2–to–5–year–old children enrolled in day care facilities completed tests of orthoptics (Hirshberg reflex, cover–uncover test, fixation and tracking, convergence), refractive error (Welch Allyn SureSight non–cycloplegic autorefractor), monocular near and distance visual acuity (Landolt C, LEA symbols, or Teller cards), stereopsis (Randot E or Randot StereoSmile cards), monocular contrast sensitivity (Adams sine–wave cards) and color vision (modified Pease–Allen color plates). If a child failed any single measure (based on standard pediatric norms), s/he was retested. If the child again failed that or any other measure on the 2nd test, s/he was referred for a full eye exam to a pediatric optometrist or ophthalmologist. Results: Most preschool children completed all tests in the battery. 13 % of preschoolers were referred on the basis of at least one abnormal screening result. For 83% of these children, the eye care specialist diagnosed a optical, ocular or neuro–ophthalmic condition significant enough to require immediate treatment (spectacle correction, patching, or surgery). 17% of referred children were false positives. Although all screening measures were effective, positive predictive values for visual acuity, SureSight autorefraction and stereopsis all exceeded 85%. Conclusions: Our extensive test battery was a success, both in terms of patient compliance and accuracy. Nonetheless, among preschool children, the incidence of significant undetected eye and visual disorders is high, thus early screening is clearly warranted. As expected, tests of visual acuity were strong predictors of visual pathology but surprisingly, so were measures of refractive error and stereopsis. This is an interesting result as stereopsis is a test often omitted in screening regimens.
Keywords: screening for ambylopia and strabismus • clinical (human) or epidemiologic studies: prevalence/incidence • visual development: infancy and childhood