title: The influence of L-opsin gene polymorphisms and neural ageing on spatio-chromatic contrast sensitivity in 20-71 year olds.
abstract: Chromatic contrast sensitivity may be a more sensitive measure of an individual's visual function than achromatic contrast sensitivity. Here, the first aim was to quantify individual- and age-related variations in chromatic contrast sensitivity to a range of spatial frequencies for stimuli along two complementary directions in color space. The second aim was to examine whether polymorphisms at specific amino acid residues of the L- and M-opsin genes (OPN1LW and OPN1MW) known to affect spectral tuning of the photoreceptors could influence spatio-chromatic contrast sensitivity. Chromatic contrast sensitivity functions were measured in 50 healthy individuals (20-71 years) employing a novel pseudo-isochromatic grating stimulus. The spatio-chromatic contrast sensitivity functions were found to be low pass for all subjects, independent of age and color vision. The results revealed a senescent decline in spatio-chromatic contrast sensitivity. There were considerable between-individual differences in sensitivity within each age decade for individuals 49 years old or younger, and age did not predict sensitivity for these age decades alone. Forty-six subjects (including a color deficient male and eight female carriers) were genotyped for L- and M-opsin genes. The Ser180Ala polymorphisms on the L-opsin gene were found to influence the subject's color discrimination and their sensitivity to spatio-chromatic patterns. The results expose the significant role of neural and genetic factors in the deterioration of visual function with increasing age.
authors.affiliation: Department of Optometry and Visual Science, Buskerud and Vestfold University College, Kongsberg, Norway; Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Ås, Norway.
authors.forename: Elise W
authors.initials: EW
authors.lastname: Dees
authors.affiliation: Department of Optometry and Visual Science, Buskerud and Vestfold University College, Kongsberg, Norway.
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Gilson
authors.affiliation: Department of Ophthalmology, Eye Institute, University of Washington, Seattle, WA, United States.
authors.forename: Maureen
authors.initials: M
authors.lastname: Neitz
authors.affiliation: Department of Optometry and Visual Science, Buskerud and Vestfold University College, Kongsberg, Norway. Electronic address: rigmor.baraas@hbv.no.
authors.forename: Rigmor C
authors.initials: RC
authors.lastname: Baraas
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000235:genetics*; D003118:Color Perception / Q000235:genetics* / Q000502:physiology; D055253:Color Vision / Q000235:genetics*; D015350:Contrast Sensitivity / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055355:Opsins / Q000235:genetics*; D010775:Photic Stimulation / Q000379:methods; D020641:Polymorphism, Single Nucleotide; D055815:Young Adult
chemical_list: D055355:Opsins
keywords: Color vision; Heterozygotes for color deficiency; Opsin genes; Polymorphisms; Senescence; Spatio-chromatic sensitivity