Citation

Rabin J, Gooch J, Ivan D. Invest. Ophthalmol. Vis. Sci. 2011; 52(2): 816-820.

Affiliation

Aerospace Ophthalmology, USAF School Aerospace Medicine, San Antonio, TX, United States.

Copyright

(Copyright © 2011, Association for Research in Vision and Ophthalmology)

DOI

10.1167/iovs.10-6283

PMID

21051721

Abstract

Purpose: To describe the design, specificity, and sensitivity of the cone contrast test (CCT), a computer-based cone specific (L, M, S) contrast sensitivity test for diagnosing type and severity of color vision deficiency (CVD). Methods: The CCT presents a randomized series of colored letters visible only to L, M or S cones in decreasing steps of cone contrast to determine L, M and S letter recognition thresholds. Sensitivity and specificity were determined by retrospective comparison of CCT scores to anomaloscope and pseudo-isochromatic plate (PIP) results in 1,446 applicants for pilot training. Results: CVD was detected in 49 of 1,446 applicants (3.4%) with hereditary red-green (protan or deutan) CVD detected in 47 of 1,359 males (3.5%) and blue-yellow (tritan) in 2 of 1,446. In agreement with the anomaloscope the CCT showed 100% sensitivity for detection and categorization of CVD (40 deutan, 7 protan, 2 tritan). PIP testing showed lower sensitivity (80% detected; 20% missed) due in part to applicant prior experience and/or pre-test preparation. CCT specificity for confirming normal color vision was 100% for L and M tests and 99.8% for S cone. Conclusions: The CCT has sensitivity and specificity comparable to anomaloscope testing and exceeds PIP sensitivity in practiced observers. The CCT provides a rapid (6 min), clinically expedient, measure of color vision for quantifying normal color performance, diagnosing type and severity of hereditary deficiency, and for detection of acquired sensitivity loss due to ocular, neurologic and/or systemic disease, as well as injury and physiological stressors such as altitude and fatigue.

Language: en