Worth 4-dot test
Binocular vision assessment using colored filters and lights to evaluate suppression, fusion, and diplopia in children.
Full Definition
The Worth 4-dot test is a clinical assessment of binocular vision that uses red-green dissociating filters and four illuminated targets (one red, two green, one white) to evaluate sensory fusion, suppression, and diplopia. The patient wears glasses with a red filter over one eye and green filter over the other, creating different visual inputs to each eye. Normal binocular vision results in seeing four lights, while suppression causes fewer lights to be seen, and diplopia results in more than four lights. The test can be performed at distance and near to assess different aspects of binocular function. In pediatric patients, this test helps identify amblyopia, strabismus, and the presence of abnormal retinal correspondence.
Usage
Usage note: Named after Claude Worth; capitalize 'Worth' but use lowercase for 'dot' - 'Worth 4-dot test'.
In Context
- "The Worth 4-dot test revealed suppression of the left eye, consistent with the child's history of amblyopia." — binocular vision assessment
- "At near fixation, the Worth 4-dot test showed diplopia, indicating disrupted fusion despite good distance stereopsis." — clinical examination findings