Detection, prevention, and rehabilitation of amblyopia

Abstract

The necessity of visual preschool screening for reducing the prevalence of amblyopia is widely accepted. The beneficial results of large-scale screening programs conducted in Scandinavia are reported. Screening monocular visual acuity at 3.5 to 4 years of age appears to be an excellent basis for detecting and treating amblyopia and an acceptable compromise between the pitfalls encountered in screening younger children and the cost-to-benefit ratio. In this respect, several preschoolers' visual acuity charts have been evaluated. New recently developed small-target random stereotests and binocular suppression tests have also been developed with the aim of correcting the many false negatives (anisometropic amblyopia or bilateral high ametropia) induced by the usual stereotests. Longitudinal studies demonstrate that correction of high refractive errors decreases the risk of amblyopia and does not impede emmetropization. The validity of various photoscreening and videoscreening procedures for detecting refractive errors in infants prior to the onset of strabismus or amblyopia, as well as alternatives to conventional occlusion therapy, is discussed.