The SKILL Card test in optic neuritis: Experience of the Optic Neuritis Treatment Trial

Objectives: To assess the value of the Smith-Kettlewell Institute Low Luminance (SKILL) Card test. designed to measure vision at reduced contrast and luminance. among patients with previous optic neuritis. Materials and Methods: The SKILL Card test was administered to 295 patients participating in the Optic Neuritis Treatment Trial (ONTT) follow-up study, concurrent with measurement of visual acuity, visual field, contrast sensitivity, and color vision. Health-related quality of life (HRQL) was also assessed in a subset of patients using the National Eye Institute Visual Function Questionnaire and an ONTT-developed questionnaire. Results: The SKILL Card difference score (high-contrast acuity score minus low-contrast acuity score) was only Weakly associated with the other measures of vision function (r(s) absolute range, 0.05-0.31) and with the HRQL measures ( r(s) absolute range. 0.02-0.15). In contrast. the light and dark component scores of the SKILL Card test had higher associations with the other vision measures (r(s) absolute range. 0.27-0.54) and with the HRQL measures (r(s) absolute range, 0.10-0.40). Conclusions: The SKILL Card difference score is not a meaningful measure for patients with optic neuritis however, the test appears to have clinical usefulness as a method to measure high-contrast and low-contrast acuity.