Diagnosis of Normal and Abnormal Color Vision with Cone-Specific VEPs

Jeff C Rabin, Andrew C Kryder, Dan Lam, Jeff C Rabin, Andrew C Kryder, Dan Lam

Abstract

Purpose: Normal color vision depends on normal long wavelength (L), middle wavelength (M), and short wavelength sensitive (S) cones. Hereditary "red-green" color vision deficiency (CVD) is due to a shift in peak sensitivity or lack of L or M cones. Hereditary S cone CVD is rare but can be acquired as an early sign of disease. Current tests detect CVD but few diagnose type or severity, critical for linking performance to real-world demands. The anomaloscope and newer subjective tests quantify CVD but are not applicable to infants or cognitively impaired patients. Our purpose was to develop an objective test of CVD with sensitivity and specificity comparable to current tests.

Methods: A calibrated visual-evoked potential (VEP) display and Food and Drug Administration-approved system was used to record L, M, and S cone-specific pattern-onset VEPs from 18 color vision normals (CVNs) and 13 hereditary CVDs. VEP amplitudes and latencies were compared between groups to establish VEP sensitivity and specificity.

Results: Cone VEPs show 100% sensitivity for diagnosis of CVD and 94% specificity for confirming CVN. L cone (protan) CVDs showed a significant increase in L cone latency (53.1 msec, P < 0.003) and decreased amplitude (10.8 uV, P < 0.0000005) but normal M and S cone VEPs (P > 0.31). M cone (deutan) CVDs showed a significant increase in M cone latency (31.0 msec, P < 0.000004) and decreased amplitude (8.4 uV, P < 0.006) but normal L and S cone VEPs (P > 0.29).

Conclusions: Cone-specific VEPs offer a rapid, objective test to diagnose hereditary CVD and show potential for detecting acquired CVD in various diseases.

Translational relevance: This paper describes the efficacy of cone-specific color VEPs for quantification of normal and abnormal color vision. The rapid, objective nature of this approach makes it suitable for detecting color sensitivity loss in infants and the cognitively impaired.

Keywords: VEPs; color vision; electrophysiology.

Figures

Figure 1
Figure 1
L, M, and S cone-specific checkerboard patterns used for pattern-onset VEPs. The cone-specific colored checks appeared as increments to the gray background, which appears different on each display due to color induction effects and photographic differences. The Weber contrast values are color coded for each cone type, while the white text represents contrast to nontargeted cone types, which is near or below threshold for detection.
Figure 2
Figure 2
Normal cone-specific pattern-onset VEP showing VEP latency and amplitude.
Figure 3
Figure 3
VEP waveforms from a normal subject (left), protan (L cone deficient, middle), and deutan (M cone deficient, right). VEP amplitude is shown on the y-axis (μV) and latency on the x-axis (msec). The L cone deficient (protan) shows decreased VEP amplitude and increased latency on the L cone VEP, and the M cone deficient (deutan) shows decreased amplitude and increased latency on the M cone VEP.
Figure 4
Figure 4
Mean VEP amplitudes (±2 standard errors) are shown for CVN, protan, and deutan groups. Compared to CVNs, two-tailed t-tests showed a significant decrease in VEP amplitude for protans on the L cone VEP (P < 0.0000005; “*”) and for deutans on the M cone VEP (P < 0.007; “*”). There was no difference between groups on the S cone VEP (P > 0.37).
Figure 5
Figure 5
Mean VEP latencies (±2 standard errors) are shown for CVN and protan, deutan, and CVD groups. Compared to CVNs, two-tailed t-tests showed a significant increase in VEP latency for protans on the L cone VEP (P < 0.003; “*”) and for deutans on the M cone VEP (P < 0.000004; “*”). There was no difference between groups on the S cone VEP (P > 0.58).
Figure 6
Figure 6
S cone VEPs are shown for a CVN subject at field sizes ranging from the standard 30-degree field down to 5 degrees. Please see text for further details.

References

    1. De Valois RL,, De Valois KK. A multi-stage color model. Vision Res. 1993; 33: 1053–1065.
    1. Jacobs GH. Evolution of colour vision in mammals. Philos Trans R Soc Lond B Biol Sci. 2009; 364: 2957 –29.
    1. Krill AE:, Krill AR,, Archer DB, Krill's Hereditary Retinal and Choroidal Diseases. Vol II: Clinical Characteristics; New York: Harper and Row; 1977: 335 –3 90.
    1. Pokorny J,, Smith VC,, Verriest G, eds Congenital and Acquired Color Defects. New York: Grune and Stratton ; 1979.
    1. Cole BL,, Maddocks JD. Color vision testing by Farnsworth lantern and ability to identify approach-path signal colors. Aviat Space Environ Med. 2008; 79: 585–590.
    1. Barbur J,, Rodriguez-Carmona M,, Evans S,, Milburn N. Minimum color vision requirements for professional flight crew, part III: Recommendations for new color vision standards. DOT/FAA/AM-09/11, June 2009, Final Report, Office of Aerospace Medicine, Washington, DC, 20591. Available at: .
    1. Spaulding JAB,, Cole BL,, Mir FA. Advice for medical students and practitioners with colour vision deficiency: a website resource. Clinical Exp Optom. 2010; 93: 40–41.
    1. Dain SJ,, Casolin A,, Long J,, Hilmi MR. Color vision and the railways: part 1. The Railway LED Lantern Test. Optom Vis Sci. 2015; 92:38 – 46.
    1. Adams AJ. Chromatic and luminosity processing in retinal disease. Am Optom Physiol Opt. 1982; 59: 954–960.
    1. Adams AJ,, Rodic R,, Husted R,, Stamper R. Spectral sensitivity and color discrimination changes in glaucoma and glaucoma-suspect patients. Invest Ophthalmol Vis Sci. 1982; 23: 516–524.
    1. Greenstein VC,, Hood DC,, Ritch R,, Steinberger D,, Carr RE. S, (blue) cone pathway vulnerability in retinitis pigmentosa diabetes and glaucoma. Invest Ophthalmol Vis Sci. 1989; 30: 1732–1737.
    1. Rabin J. Quantification of color vision with cone contrast sensitivity. Vis Neuroscience. 2004; 21: 483–485.
    1. O'Neill-Biba M,, Sivaprasad S,, Rodriguez-Carmona M,, Wolf JE,, Barbur JL. Loss of chromatic sensitivity in AMD and diabetes: a comparative study. Ophthalmic Physiol Opt. 2010; 30: 705–716.
    1. Niwa Y,, Muraki S,, Naito F,, Minamikawa T,, Ohji M. Evaluation of acquired color vision deficiency in glaucoma using the Rabin cone contrast test. Invest Ophthalmol Vis Sci. 2014; 55: 6686–6690.
    1. Mollon JD,, Reffin JP. A computer-controlled colour vision test that combines the principles of Chibret and Stilling. J Physiol. 1989; 414: 5P.
    1. Regan BC,, Reffin JP,, Mollon JD. Luminance noise and the rapid determination of discrimination ellipses in colour deficiency. Vision Res. 1994; 34: 1279–1299.
    1. Jennings BJ,, Barbur JL. Colour detection thresholds as a function of chromatic adaptation and light level. Ophthalmic Physiol Opt. 2010; 30: 560–567.
    1. Rodriguez-Carmona M,, O'Neill-Biba M,, Barbur JL. Assessing the severity of color vision loss with implications for aviation and other occupational environments. Aviat Space Environ Med. 2012; 83: 19–29.
    1. Rabin J. Cone specific measures of human color vision. Invest Ophthalmol Vis Sci. 1996; 37: 2771 –27.
    1. Rabin J,, Gooch J,, Ivan D. Rapid quantification of color vision: the cone contrast test. Invest Ophthalmol Vis Sci. 2011; 52: 816 –8.
    1. Kulikowski J,, Murray N,, Parry I. Electrophysiological correlates of chromatic-opponent and chromatic stimulation in man. Colour Vision Deficiencies IX. 1989; 52:145 – 153.
    1. Rabin J,, Adams A. Cortical potentials evoked by short wavelength patterned light. Optom Vis Sci. 1992; 69: 522 –5.
    1. Rabin J,, Switkes E,, Crognale M,, Schneck ME,, Adams AJ. Visual evoked potentials in three-dimensional color space: correlates of spatio-chromatic processing. Vision Res. 1994; 34: 2657 –26.
    1. Tobimatsu S,, Tomoda H,, Kato M. Parvocellular and magnocellular contributions to visual evoked potentials in humans: stimulation with chromatic and achromatic gratings and apparent motion. J Neurol Sci. 1995; 134: 73–82.
    1. Gerth C,, Delahunt PB,, Crognale MA,, Werner JS. Topography of the chromatic pattern-onset VEP. J Vis. 2003; 3: 171 –1.
    1. Smith VC,, Pokorny J. Spectral sensitivity of the foveal cone pigments between 400 and 500 nm. Vision Res. 1975; 15: 161–171.
    1. Wyszecki G,, Stiles WS. Color Science: Concepts and Methods, Quantitative Data and Formulae. New York: Wiley-Interscience; 1982.
    1. Cole GR,, Hine T. Computation of cone contrasts for color vision research. Behav Res Methods Instruments Comput. 1992; 24: 22–27.
    1. Alpern M,, Pugh EN. The density and photosensitivity of human rhodopsin in the living retina. J Physiol. 1974; 237: 341–370.
    1. Parry N,, Robson A. Optimization of large field tritan stimuli using concentric isoluminant annuli. J Vis. 2012; 12: 11.
    1. Skiba R,, Duncan C,, Crognale M. The effects of luminance contribution from large fields to chromatic visual evoked potentials. Vision Res. 2014; 95: 68–74.
    1. Vanston JE,, Crognale M. Chromatic visual evoked potentials using customized color space. J Vis. 2015; 15: 255.

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