Evaluation of a chromatometer: a new method for blue-yellow or green-red visual comparisons, and anomaly screening techniques.
Jean Gaudart, Jean-Pierre Pétrakian
Med Sci Monit 2005; 11(8): MT39-52
Background: Malbrel's chromatometer is a new apparatus which allows colorvision to be monitored. The aim of this study was to assess the accuracy of this new examination method.Material/Methods: The color vision of a patient was analyzed using a chromatometer for direct heterochromaticvisual comparisons. The patient's task was to adjust, using one eye only, the brightness of a yellow(or red) window to the one of a fixed blue (or green) window. Overall, 158 patients, aged 20 to 28, tookpart in the experiment. First, parametric means were used to study the response distributions and theluminous effects on the responses. Second, using non-parametric means, we considered that a patient hadan anomalous color vision according to the chromatometer if the response was higher than the 95(th) percentileor lower than 5(th) percentile. Third, anomalous responses were compared with the Ishihara plates andFarnsworth 28-hue responses. Results: The effect of a luminous stimulus on the response was significant(adjusted to the patient effect). Thus, the chromatometer appears to be a good method to analyze colorvision. This apparatus was easy to use and constituted a sensitive and specific test with high negativepredictive value. Conclusions: The chromatometer can be used as a first-line screening test to detectcolor vision anomalies during ophthalmology consultations. The chromatometer can be useful in identifyingearly ocular disease, monitoring disease development, or checking possible iatrogenic effects of a specifictreatment.
Keywords: Color Perception Tests - methods, Color Vision Defects - diagnosis, Adult, Color Perception - physiology, Color Perception Tests - methods, Color Vision Defects - diagnosis, Female, Humans, Male, Sensitivity and Specificity