Vision Screening of Four‐year‐old Children

Summary Included in a general health control of an un‐selected population of 2 447 four‐year‐old children, a vision screening was performed, using a visual acuity test (Marquez‐Bostrom's hooks), cover test and Wirt Fly Stereo test. The screening could be carried out in 98% of the children. 364 children (15.2%) were referred because of newly detected visual defects, and 358 children (15.0%) were professionally examined. Of these, 40.8% had a visual acuity of ≤0.6 and 5.9% of ≤0.1. Functional amblyopia was found in 12.3% and manifest strabismus in 10.3%, The main error of refraction was hyperopia (≥ 2.5 D), diagnosed in 28.5%, while myopia was infrequent, 3.9%. The children examined by the ophthalmologist were also classified into four groups, according to their need of professional care, where group 0 means overreferral and groups 2–3 represent “significant eye disorders”, in need of ophthalmological treatment and/or observation. Overreferral was found in 16.5% and significant eye disorders in 43%. With the visual acuity test, 97% of the children with eye disorders were detected. Retesting children, who failed the tests, reduced the over‐referral from 39.5% to 12.5% ( p <0.001). By lowering the passing standards of the visual acuity test, still fewer children would have been overreferred, but, at the same time, 1/5 of children needing treatment would then have remained undiscovered. Including children already under professional care, the prevalence of strabismus in this unselected material of 4‐year‐old children was just below 4%, and the need for corrective glasses around 8%. Children reported to have family eye disorders, partus complications or present eye complaints were in the risk zone for suffering significant eye disorders, but this information from the parents was not sufficiently selective to be of practical value as a screening method. A small control group of 73 children and a follow‐up of 479 children at school 3 years later, revealed that no children with functional amblyopia were missed at the screening test.