Beyond screening for risk factors: objective detection of strabismus and amblyopia.

IMPORTANCE Commercially available automated vision screening devices assess refractive risk factors, not amblyopia or strabismus, underreferring affected children and overreferring healthy children. Nearly half of affected children are not identified until after age 5 years, when treatment is less effective. OBJECTIVES To determine the diagnostic accuracy of the Pediatric Vision Scanner (PVS), a binocular retinal birefringence scanner, to objectively identify strabismus and amblyopia, and to compare retinal birefringence screening with a widely used automated pediatric screening device. DESIGN, SETTING, AND PARTICIPANTS Three hundred consecutive preschool children (aged 2-6 years) were screened using the PVS and the SureSight Autorefractor at 2 pediatric ophthalmology private practices. A masked comprehensive pediatric ophthalmic examination provided the gold standard for determining sensitivity and specificity for each screening device. MAIN OUTCOMES AND MEASURES The primary outcome was sensitivity and specificity of the PVS for detecting the targeted conditions, strabismus and amblyopia, in children aged 2 to 6 years. Secondary outcomes included the positive and negative likelihood ratios of the PVS for identifying the targeted conditions. In addition, sensitivity, specificity, and positive and negative likelihood ratios of the SureSight Autorefractor for the targeted conditions were assessed in the same cohort of children. RESULTS Of the 300 patients, 188 had strabismus only, amblyopia only, or both, and 112 had no strabismus or amblyopia. The sensitivity of the PVS to detect strabismus and amblyopia (0.97; 95% CI, 0.94-1.00) was significantly higher than that of the SureSight Autorefractor (0.74; 95% CI, 0.66-0.83). Specificity of the PVS for strabismus and amblyopia (0.87; 95% CI, 0.80-0.95) was significantly higher than that of the SureSight Autorefractor (0.62; 95% CI, 0.50-0.73). CONCLUSIONS AND RELEVANCE The PVS identified children with strabismus and/or amblyopia with high sensitivity, outperforming the SureSight Autorefractor. Accurate, early detection of these conditions could improve long-term vision outcomes of affected preschool children.