Evaluation of the iScreen digital screening system for amblyogenic factors

Background: A digital photoscreener, the iScreen screening system, is now a vailable to detect amblyogenic factors. We carried out a prospective study to evaluate the accuracy of the device in detecting anisometropia, signific ant refractive error, strabismus and opacities of the ocular media. Methods: A total of 449 consecutive patients (median age 7 years) from a pr ivate pediatric ophthalmology practice underwent screening with the iScreen photoscreener operated by a minimally trained technician. The results were compared to the masked clinical examination of a pediatric ophthalmologist . Results: The iScreen device had a sensitivity of 92.4%, specificity of 89.1 %, positive predictive value of 94.1% and false-negative rate of 13.8%. Of the 21 patients with a false-negative result, 12 had myopia of less than -1 .50 dioptres. High hyperopia was missed in two patients, high astigmatism i n one, unequal cylindrical error in one and strabismus in five. Interpretation: The iScreen digital photoscreener produced accurate and tim ely screening for potentially amblyogenic defects in the study population.