Artifact of Worth Four Dot Test in Strabismic Patients

ABSTRACT

It is the purpose of this study to evaluate fusional status of 49 strabismic patients who showed orthophoria less than 10 prism diopters (PD) after surgery under alternate prism and cover test. We undertook the Worth 4-dot(W4D) test twice, reversing the position of the red/green glasses between the eyes for the second trial. Bagolini test was also performed in 31 of 49 cases. Nineteen of 49 case(18.4%) showed different results on the W4D test with red/green glasses after reversal at near or distance, either changing fusional status or changing laterality of suppression. Four of 31 cases (18.0%) showed different status of fusion or suppression between W4D and Bagolini tests. We think that it repeating test twice, with the red/green glass reversed between trials, and with combination of Bagolini test, provides better reliability of W4D test.