Photopigment optical density of the human foveola and a paradoxical senescent increase outside the fovea.
Photopigment optical density (OD) of middle-(M) and long-(L) wavelength-sensitive cones was determined to evaluate the hypothesis that reductions in the amount of photopigment are responsible for age-dependent sensitivity losses of the human cone pathways. Flicker thresholds were measured at the peak and tail of the photoreceptor's absorption spectrum as a function of the intensity of a bleaching background. Photopigment OD was measured at 0 (fovea), 2, 4, and 8 deg in the temporal retina by use of a 0.3-deg-diameter test spot. Seventy-two genetically characterized dichromats were studied so that the L- and M-cones could be analyzed separately. Subjects included 28 protanopes with M- but no L-cones and 44 deuteranopes with L- but no M-cones (all male, age range 12-29 and 55-83 years). Previous methods have not provided estimates of photopigment OD for separate cone classes in the foveola. In this study, it was found that foveolar cones are remarkably efficient, absorbing 78% of the available photons (OD = 0.65). Photopigment OD decreased exponentially with retinal eccentricity independently of age and cone type. Paradoxically, the OD of perifoveal cones increased significantly with age. Over the 70-year age range of our participants, the perifoveal M- and L-cones showed a 14% increase in capacity to absorb photons despite a 30% decrease in visual sensitivity over the same period.
Renner
Agnes B
AB
Department of Ophthalmology and Section of Neurobiology, Physiology and Behavior, University of California, Davis, Sacramento, CA 95817, USA.
Knau
Holger
H
Neitz
Maureen
M
Neitz
Jay
J
Werner
John S
JS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D002648:Child; D003117:Color Vision Defects / Q000235:genetics / Q000378:metabolism*; D005584:Fovea Centralis / Q000378:metabolism*; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D017949:Retinal Cone Photoreceptor Cells / Q000378:metabolism*; D012168:Retinal Pigments / Q000378:metabolism*
D012168:Retinal Pigments
J Opt Soc Am A. 1988 Dec;5(12):2106-12
3230479
Science. 1991 May 17;252(5008):971-4
1903559
Vis Neurosci. 1992 Jan;8(1):27-39
1739675
J Opt Soc Am A. 1992 Mar;9(3):355-63
1548554
Exp Eye Res. 1992 Sep;55(3):393-9
1426073
J Opt Soc Am A. 1993 Jan;10(1):52-8
8478745
J Opt Soc Am A. 1993 Feb;10(2):221-30
8478748
Photochem Photobiol. 1993 Nov;58(5):706-10
8284327
Neuron. 1994 May;12(5):1131-8
8185948
Vision Res. 1994 Jun;34(12):1605-8
7941368
J Opt Soc Am A Opt Image Sci Vis. 1995 Jun;12(6):1233-41
7769509
Optom Vis Sci. 1995 Mar;72(3):177-85
7609940
J Physiol. 1996 Apr 1;492 ( Pt 1):307-14
8730604
Vision Res. 1996 Jul;36(14):2079-85
8776474
Invest Ophthalmol Vis Sci. 1997 May;38(6):1271-4
9152246
Vision Res. 1997 Jul;37(14):1909-15
9274776
Invest Ophthalmol Vis Sci. 1998 Nov;39(12):2394-404
9804148
J Opt Soc Am A Opt Image Sci Vis. 1999 Jun;16(6):1229-37
10376352
Nat Neurosci. 1999 Oct;2(10):884-8
10491608
Vis Neurosci. 2004 May-Jun;21(3):205-16
15518190
Optom Wkly. 1961 Oct;8(52):329-58
13890336
J Physiol. 1963 Sep;168:360-73
14062682
Vision Res. 2001 Jan;41(1):23-36
11163613
J Opt Soc Am A Opt Image Sci Vis. 2000 Nov;17(11):1918-32
11059586
Proc Natl Acad Sci U S A. 2004 Jun 1;101(22):8461-6
15148406
Vision Res. 1966 Dec;6(12):669-82
6003389
J Physiol. 1972 May;223(1):89-107
4537944
Vision Res. 1973 Jun;13(6):1199-202
4713928
J Physiol. 1973 May;230(3):535-49
4541511
J Physiol. 1973 May;230(3):551-60
4541512
Vision Res. 1976;16(10):1095-8
969220
J Physiol. 1979 Mar;288:85-105
313984
J Physiol. 1980 Jan;298:501-11
7359434
Invest Ophthalmol Vis Sci. 1986 May;27(5):708-15
3009350
Vision Res. 1986;26(2):321-5
3716224
Vision Res. 1987;27(2):257-68
3554735
Invest Ophthalmol Vis Sci. 1987 Jun;28(6):985-91
3583637
Invest Ophthalmol Vis Sci. 1987 Nov;28(11):1824-31
3667153
J Physiol. 1963 Sep;168:374-88
14062683
J Physiol. 1965 Jan;176:38-45
14281405
J Opt Soc Am. 1960 Aug;50:780-4
13842659
Graefes Arch Clin Exp Ophthalmol. 2002 Mar;240(3):202-8
11935277
Vision Res. 2000;40(13):1711-37
10814758