Purchase this article with an account.
J. C. Rabin, J. Gooch, R. Rubin, S. Linnemeyer, M. Foxworth; Cone Specific Diagnosis of Normal and Abnormal Color Vision. Invest. Ophthalmol. Vis. Sci. 2010;51(13):6301.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Accurate color discrimination is essential for object recognition and obstacle avoidance. Pseudo-isochromatic plates (PIPs) detect the presence of color deficiency but do not reveal type or severity. Our purpose is to describe sensitivity, specificity and application of an automated test of cone contrast sensitivity (cone contrast test; CCT) which quantifies color vision in color deficient (CD) and color normal (CN) populations.
The computer-based CCT presents single red, green and violet letters centered on a grey background. Letters are visible only to L, M or S cones based on conversion of luminance and CIE chromaticity to cone contrast. Each L, M and S series of random sequence letters are presented in decreasing log steps of cone contrast to determine the cone-specific letter recognition threshold (L & M: 20/330 Snellen size; S: 20/440) . CCT sensitivity and specificity were determined by comparing scores to Rayleigh anomaloscope values in a pilot applicant population (n=947) and by assessment in patients undergoing evaluation for progression of ocular, systemic and/or neurological disease.
CCT sensitivity was 100% for detection and classification of hereditary CD in pilot applicants presumed to be CN based on preliminary screening at external sites (4% or 38 of 947 CD on CCT and anomlaoscope). In comparison to CCT, comprehensive PIP testing (Dvorine, SPP2, F2) in the same population showed lower sensitivity for CD detection (81%) due in part to prior experience with PIP tests. CCT specificity (percent CN confirmed normal) was 100% for L and M cone CCT and 99.8% for S cone in the CN population (n=909). The CCT detected acquired CD in various conditions and diseases spanning levels of the visual system.
The CCT quantifies type and severity of hereditary and acquired CD and grades color performance in the CN population. CCT randomization of letter sequence precludes rehearsal/learning effects. Acquired CD in various conditions is readily detected with threshold cone-specific CCT. The CCT is a clinically expedient index of color performance linkable to real-world color demands.
This PDF is available to Subscribers Only