Novel snapshot imaging of photoreceptor bleaching in macaque and human retinas

Kazato, Yoko; Shibata, Naohisa; Hanazono, Gen; Suzuki, Wataru; Tanifuji, Manabu; Tsunoda, Kazushige

doi:10.1007/s10384-010-0826-9

Cited by 3 publications

(3 citation statements)

References 35 publications

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“…Kazato et al[ 42 ] showed that the retinal reflectance at the fovea was higher than that at the parafovea which is consistent with our results. They suggested that the retinal reflectance depended on the cone density as we have.…”

Section: Discussionsupporting

confidence: 93%

Slow Cone Reflectance Changes during Bleaching Determined by Adaptive Optics Scanning Laser Ophthalmoscope in Living Human Eyes

et al. 2015

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To investigate the changes in the reflectance of human cone photoreceptors by an adaptive optics scanning laser ophthalmoscope (AO-SLO) during photobleaching. A custom-built AO-SLO with an observation light of 840-nm was used to measure the cone densities and the reflectance changes during bleaching by 630 nm red light emitting diodes. Measurements were made at 1° and 3° temporal to the fovea within an area of 1° × 1° in 8 eyes of 8 normal subjects. After dark-adaptation, images of the cone mosaics were recorded continuously for 5-min before, 5-min during, and after 5-min of light stimulation with a sampling rate of 5-Hz. The first positive peak (P1) was observed at 72.2 ± 15.0-s and a second positive peak (P2) at 257.5 ± 34.5-s at 1°. The increase of the reflectance of P1 was significantly larger at 1° (34.4 ± 13.9%) than at 3° (26.0 ± 10.5%; P = 0.03, Wilcoxon’s signed rank test). The average cone density at 1° (51123.13 ± 1401.23 cells/mm2) was significantly larger than that at 3° (30876.13 ± 1459.28 cells/mm2; P <0.001, Wilcoxon’s signed rank test). The changes in the reflectance of the cones during bleaching by red light had two peaks. The two peaks may be caused by regeneration of cone photopigment during bleaching.

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Section: Discussionsupporting

confidence: 93%

Slow Cone Reflectance Changes during Bleaching Determined by Adaptive Optics Scanning Laser Ophthalmoscope in Living Human Eyes

et al. 2015

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“…Reflectometry may suffer from media opacities and macular pathology that will complicate image acquisition and that may invalidate the assumptions in the underlying mathematical model. Only a few reflectometry studies have been carried out with commercial instrumentation in Europe and Japan (Kazato et al, 2010; van de Kraats et al, 2008), and it is concerning that results do not correlate well when tested head-to-head against AFI or HFP in the same patients (Dennison et al, 2013). Resonance Raman imaging can also be implemented in a chemically specific imaging mode, but required light levels approach ANSI limits, so only a few normal volunteers have been imaged (Sharifzadeh et al, 2008).…”

Section: Carotenoids and Eye Disease And Function Throughout The Lmentioning

confidence: 99%

Lutein, zeaxanthin, and meso-zeaxanthin: The basic and clinical science underlying carotenoid-based nutritional interventions against ocular disease

Bernstein

Vachali

et al. 2016

Progress in Retinal and Eye Research

440

419

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The human macula uniquely concentrates three carotenoids: lutein, zeaxanthin, and meso-zeaxanthin. Lutein and zeaxanthin must be obtained from dietary sources such as green leafy vegetables and orange and yellow fruits and vegetables, while meso-zeaxanthin is rarely found in diet and is believed to be formed at the macula by metabolic transformations of ingested carotenoids. Epidemiological studies and large-scale clinical trials such as AREDS2 have brought attention to the potential ocular health and functional benefits of these three xanthophyll carotenoids consumed through the diet or supplements, but the basic science and clinical research underlying recommendations for nutritional interventions against age-related macular degeneration and other eye diseases are underappreciated by clinicians and vision researchers alike. In this review article, we first examine the chemistry, biophysics, and physiology of these yellow pigments that are specifically concentrated in the macula lutea through the means of high-affinity binding proteins and specialized transport and metabolic proteins where they play important roles as short-wavelength (blue) light-absorbers and localized, efficient antioxidants in a region at high risk for light-induced oxidative stress. Next, we turn to clinical evidence supporting functional benefits of these carotenoids in normal eyes and for their potential protective actions against ocular disease from infancy to old age.

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“…The spatial distribution of the reflectance changes was determined later by examining images obtained by either a fundus camera or a scanning laser ophthalmoscope (SLO), that is, imaging fundus reflectometry. [23][24][25][26][27][28][29][30][31][32][33] With these techniques, the distribution of photoreceptors was mapped objectively and non-invasively as bleach-derived light reflectance changes in normal and diseased eyes. However, the responses of the different types of photoreceptors, especially rods and S-cones, could not be segregated accurately because the response time courses were not monitored accurately.…”

mentioning

confidence: 99%

Functional Topography of Rod and Cone Photoreceptors in Macaque Retina Determined by Retinal Densitometry

Hanazono

Tsunoda

Kazato

et al. 2012

Invest. Ophthalmol. Vis. Sci.

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PURPOSE. The purpose of this study is to determine the topography of bleaching in rods, middle/long-wavelength (M/ L) and short-wavelength (S) cones in the macaque retina by using a modified retinal densitometry technique. METHODS.A modified commercial digital fundus camera system was used to measure continuously the intensity of the light reflectance during bleaching with band pass lights in the ocular fundus of three adult Rhesus monkeys (Macaca mulatta) under general anesthesia. The topography of bleaching in rods, M/L-, and S-cones was obtained separately by considering the characteristic time course of the reflectance changes, depending on the wavelengths of light and retinal locations. RESULTS.The distribution of M/L-cones response had a steep peak at the foveal center and was elongated horizontally. The distribution of rod responses was minimum at the foveal center and maximum along a circular region at the eccentricity of the optic disc. The distribution of S-cone responses was highest at the fovea and was excavated centrally. There was a circular region with the maximal responses at 0.38 to 1.0 degrees from the foveal center. T he human visual system is a duplex system, consisting of a rod system for scotopic conditions and a cone system for photopic conditions. Three types of cones mediate color vision; long (L), middle (M), and short (S) wavelength-sensitive cones. The distribution of the photoreceptors has been well investigated on postmortem eyes of humans and macaques. [1][2][3][4][5][6][7][8][9] These studies reported the anatomical densities of the different types of photoreceptors, but the results did not necessarily reflect their functional properties. Psychophysical experiments also have been used to assess photoreceptor function. [10][11][12][13][14][15] However, the results reflect not only the retinal function, but the visual function from the photoreceptors to the visual cortex.Approximately 50 years ago, the time course of the bleaching of photopigments was determined quantitatively by measuring the reflectance changes during bleaching and regeneration of the visual pigments in human retinas. [16][17][18][19][20][21][22] This method, retinal densitometry, was used to determine the in vivo kinetics of the photopigments of cones and rods quite accurately. The spatial distribution of the reflectance changes was determined later by examining images obtained by either a fundus camera or a scanning laser ophthalmoscope (SLO), that is, imaging fundus reflectometry. [23][24][25][26][27][28][29][30][31][32][33] With these techniques, the distribution of photoreceptors was mapped objectively and non-invasively as bleach-derived light reflectance changes in normal and diseased eyes. However, the responses of the different types of photoreceptors, especially rods and S-cones, could not be segregated accurately because the response time courses were not monitored accurately.We developed a new retinal densitometry system that can measure the retinal reflectance changes continuously after bleaching with...

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Novel snapshot imaging of photoreceptor bleaching in macaque and human retinas

Abstract: The topography of bleached photoreceptors obtained with a commercial fundus camera from one monkey and three healthy human subjects showed that this technique has potential as a new clinical method for examining photoreceptor function in both normal and diseased retinas.

Cited by 3 publications

References 35 publications

Slow Cone Reflectance Changes during Bleaching Determined by Adaptive Optics Scanning Laser Ophthalmoscope in Living Human Eyes

Slow Cone Reflectance Changes during Bleaching Determined by Adaptive Optics Scanning Laser Ophthalmoscope in Living Human Eyes

Lutein, zeaxanthin, and meso-zeaxanthin: The basic and clinical science underlying carotenoid-based nutritional interventions against ocular disease

Functional Topography of Rod and Cone Photoreceptors in Macaque Retina Determined by Retinal Densitometry

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