Aging of the human lens

Pokorny, Joel; Smith, Vivianne C.; Lutze, Margaret

doi:10.1364/ao.26.001437

Cited by 448 publications

(349 citation statements)

References 20 publications

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“…Average spectral lens density calculations for each individual were done in accordance with the Pokorny et al (1987) two-factor non-linear lens density spectrum model. In this model, the optical density of the total lens transmission (T L ) is separated into two components which are light-wavelength dependent, (i) portion of the lens affected by ageing after the age of 20 (T L1 ) and (ii) stable portion after the age of 20 (T L2 ).…”

Section: Discussionmentioning

confidence: 99%

“…Ideally, knowledge of the lens density of each study subject would be useful so that the data could be individually corrected. Using the two-factor non-linear lens density spectrum formula (Pokorny et al, 1987) the average lens density was calculated for each subject. Lens density was negatively correlated with melatonin suppression following short wavelength treatments.…”

Section: Discussionmentioning

confidence: 99%

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Light-induced melatonin suppression: age-related reduction in response to short wavelength light

Herljevic

Middleton

Thapan

et al. 2005

Experimental Gerontology

143

103

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Light-induced melatonin suppression: age-related reduction in response to short wavelength light

Herljevic

Middleton

Thapan

et al. 2005

Experimental Gerontology

143

103

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“…The decline in macular pigment levels with age correlates well with some, 19,33 but not all, 18,22 recent psychophysical reports of macular pigment levels in normal populations. Some of this drop of Raman signal with age may be the result of increasing yellowing of the lens as subjects age, [34][35][36] but this effect could account for only half of the more than 75% drop in average Raman signal seen between ages 20 and 60 years (see Ref. 27 for a detailed discussion of this issue).…”

Section: Discussionmentioning

confidence: 99%

Resonance Raman measurement of macular carotenoids in normal subjects and in age-related macular degeneration patients

et al. 2002

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Purpose-Dietary carotenoids lutein and zeaxanthin may play a protective role against visual loss from age-related macular degeneration (AMD) through antioxidant and light screening mechanisms. We used a novel noninvasive objective method to quantify lutein and zeaxanthin in the human macula using resonance Raman spectroscopy and compared macular pigment levels in AMD and normal subjects. Design-Observational study of an ophthalmology clinic-based population.Participants and Controls-Ninety-three AMD eyes from 63 patients and 220 normal eyes from 138 subjects.Methods-Macular carotenoid levels were quantified by illuminating the macula with a lowpower argon laser spot and measuring Raman backscattered light using a spectrograph. This technique is sensitive, specific, and repeatable even in subjects with significant macular pathologic features.Main Outcome Measure-Raman signal intensity at 1525 cm −1 generated by the carboncarbon double-bond vibrations of lutein and zeaxanthin.Results-Carotenoid Raman signal intensity declined with age in normal eyes (P < 0.001). Average levels of lutein and zeaxanthin were 32% lower in AMD eyes versus normal elderly control eyes as long as the subjects were not consuming high-dose lutein supplements (P = 0.001). Patients who had begun to consume supplements containing high doses of lutein (≥4 mg/day) regularly after their initial diagnosis of AMD had average macular pigment levels that were in the normal range (P = 0.829) and that were significantly higher than in AMD patients not consuming these supplements (P = 0.038).Conclusions-These findings are consistent with the hypothesis that low levels of lutein and zeaxanthin in the human macula may represent a pathogenic risk factor for the development of Correspondence and reprint requests to Paul S. Bernstein, MD, PhD, Moran Eye Center, University of Utah School of Medicine, 50 North Medical Drive, Salt Lake City, UT 84132. paul.bernstein@hsc.utah.edu. Three authors (PSB, RWM, and WG) and the University of Utah hold patent rights to the ocular Raman technology described in this article, and these authors and the university own significant equity interests in Spectrotek, LC, a company that has licensed the technology.Presented in part as a poster at the annual meeting of the American Academy of Ophthalmology, New Orleans, Louisiana, November 2001. A major epidemiologic study found that high dietary intakes and blood levels of these xanthophyll carotenoids are correlated with a significantly lower risk of AMD, 12,13 but another study did not reach the same conclusion. 14 These inconsistent findings derive in part from the fact that blood levels and dietary intakes of lutein and zeaxanthin are relatively poor markers of the actual amounts present in the macula. 15 Clearly, it is of utmost importance to know the levels of lutein and zeaxanthin at their relevant site of action, the human macula. Recently, an autopsy study has reported that eyes from donors with a history of AMD had lower levels of macular carotenoids than eyes wi...

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“…An electronically tunable filter (Varispec; Cambridge Research & Instrumentation, Boston, MA) was used to control the wavelength of the test light. Final spectral sensitivity values were corrected for lens absorption with an agedependent lens correction (Pokorny et al, 1987). To obtain an estimate of L:M cone ratio, a subjects' spectral sensitivity data are best fit to a weighted sum of an L-and an M-photopigment template (Jacobs and Neitz, 1993;Carroll et al, 2000).…”

Section: Methodsmentioning

confidence: 99%

Organization of the Human Trichromatic Cone Mosaic

Hofer¹,

Carroll²,

Neitz³

et al. 2005

J. Neurosci.

389

311

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Using high-resolution adaptive-optics imaging combined with retinal densitometry, we characterized the arrangement of short-(S), middle-(M), and long-(L) wavelength-sensitive cones in eight human foveal mosaics. As suggested by previous studies, we found males with normal color vision that varied in the ratio of L to M cones (from 1.1:1 to 16.5:1). We also found a protan carrier with an even more extreme L:M ratio (0.37:1). All subjects had nearly identical S-cone densities, indicating independence of the developmental mechanism that governs the relative numerosity of L/M and S cones. L:M cone ratio estimates were correlated highly with those obtained in the same eyes using the flicker photometric electroretinogram (ERG), although the comparison indicates that the signal from each M cone makes a larger contribution to the ERG than each L cone. Although all subjects had highly disordered arrangements of L and M cones, three subjects showed evidence for departures from a strictly random rule for assigning the L and M cone photopigments. In two retinas, these departures corresponded to local clumping of cones of like type. In a third retina, the L:M cone ratio differed significantly at two retinal locations on opposite sides of the fovea. These results suggest that the assignment of L and M pigment, although highly irregular, is not a completely random process. Surprisingly, in the protan carrier, in which X-chromosome inactivation would favor L-or M-cone clumping, there was no evidence of clumping, perhaps as a result of cone migration during foveal development.

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Aging of the human lens

Cited by 448 publications

References 20 publications

Light-induced melatonin suppression: age-related reduction in response to short wavelength light

Light-induced melatonin suppression: age-related reduction in response to short wavelength light

Resonance Raman measurement of macular carotenoids in normal subjects and in age-related macular degeneration patients

Organization of the Human Trichromatic Cone Mosaic

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