Abnormalities of Cone Photopigments in Genetic Carriers of Protanomaly

Yasuma, T; H, Tokuda; Ichikawa, Hiroshi

doi:10.1001/archopht.1984.01040030717027

Cited by 7 publications

(2 citation statements)

References 16 publications

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“…The reduced red-light luminous sensitivity of protan carriers is called Schmidt's sign and has been confirmed by a number of other investigators [12][13][14][15][16] and there is supporting evidence from ERG studies. 17,18 This offers some promise for clinical diagnosis, although no practitioner would wish to measure the V λ function or order an ERG to diagnose heterozygosity for a protan colour vision deficiency.…”

Section: Carriers Of Deutan Colour Vision Deficiencymentioning

confidence: 65%

Diagnosing protan heterozygosity using the Medmont C‐100 colour vision test

Harris

Cole

2005

Clinical and Experimental Optometry

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Section: Carriers Of Deutan Colour Vision Deficiencymentioning

confidence: 65%

Diagnosing protan heterozygosity using the Medmont C‐100 colour vision test

Harris

Cole

2005

Clinical and Experimental Optometry

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“…Heterozygous carriers of color vision deficiencies have variable color vision (Cohn et al, 1989;Crone, 1959;Hood, Mollon, Purves, & Jordan, 2006;Jordan & Mollon, 1993;Krill & Schneiderman, 1964;Pickford, 1949;Verriest, 1972); carriers of deutan deficiency usually perform worse than carriers of protan deficiency, and normal trichromats (Hood et al, 2006;Verriest, 1972) and carriers of protan deficiency show reduced sensitivity to long-wavelength lights (Yasuma, Tokuda, & Ichikawa, 1984). Given the very dissimilar underlying cone mosaics between the carriers of the various deficiencies, the processing of color signals in these females remains of great interest.…”

Section: Introductionmentioning

confidence: 99%

Processing of color signals in female carriers of color vision deficiency

2012

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The aim of this study was to assess the chromatic sensitivity of carriers of color deficiency, specifically in relation to dependence on retinal illuminance, and to reference these findings to the corresponding red-green (RG) thresholds measured in normal trichromatic males. Thirty-six carriers of congenital RG color deficiency and 26 normal trichromatic males participated in the study. The retinal illuminance was estimated by measuring the pupil diameter and the optical density of the lens and the macular pigment. Each subject's color vision was examined using the Color Assessment and Diagnosis (CAD) test, the Ishihara and American Optical pseudoisochromatic plates, and the Nagel anomaloscope. Carriers of deuteranopia (D) and deuteranomaly (DA) had higher RG thresholds than male trichromats (p < 0.05). When referenced to male trichromats, carriers of protanomaly (PA) needed 28% less color signal strength; carriers of D required ∼60% higher thresholds at mesopic light levels. Variation in the L:M ratio and hence the absolute M-cone density may be the principal factor underlying the poorer chromatic sensitivity of D carriers in the low photopic range. The increased sensitivity of PA carriers at lower light levels is consistent with the pooling of signals from the hybrid M' and the M cones and the subsequent stronger inhibition of the rods. The findings suggest that signals from hybrid photopigments may pool preferentially with the spectrally closest "normal" pigments.

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Heterochromatic modulation photometry in heterozygous carriers of congenital color defects

Swanson

1991

Documenta Ophthalmologica Proceedings Series

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Abnormalities of Cone Photopigments in Genetic Carriers of Protanomaly

Cited by 7 publications

References 16 publications

Diagnosing protan heterozygosity using the Medmont C‐100 colour vision test

Diagnosing protan heterozygosity using the Medmont C‐100 colour vision test

Processing of color signals in female carriers of color vision deficiency

Heterochromatic modulation photometry in heterozygous carriers of congenital color defects

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