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Blue Light and AMD – ARVO 2006

While some do not consider the blue light-AMD link as proved, there is increasingly compelling evidence that this link exists.
A quick scan of a selection of studies from the 2006 ARVO meetings indicates the high level of concern about the relationship between blue light exposure and the development of AMD.  All of these papers show results that are consistent with the thesis that blue light exposure induces oxidative stress that contributes to the development of AMD. 

ARVO is the Association for Research in Vision and Ophthalmology  
 3799  Established Risk Factors for Age-Related Maculopathy Are Associated With a Relative Lack of Macular Pigment in Healthy Subjects J.M. Nolan et al  Age-related maculopathy (ARM), which may damage central vision, is the leading cause of severe visual impairment in elderly white populations in the Western World. Although the aetiopathogenesis of this disease remains unclear, there is a growing, and plausible, consensus that cumulative blue light damage and/or oxidative stress play a role.

1375 The Correlation of Blue Light Induced Apoptosis and Vascular Endothelial Growth Factor Production in Human RPE Cells  K.A. Rezaei et al. It is known that long term exposure to blue light induces apoptosis in human retinal pigment epithelial (RPE) cells. In this study we evaluated and correlated the effect of short term blue light exposure on apoptosis and vascular endothelial growth factor (VEGF) production in RPE cells.
Conclusions: ...Our findings indicate that blue light exposure may play a role in age related macular degeneration.


4818 Dimethylthiourea Protects Retinal Photoreceptors Against Blue Light Stress in Bovine and Primate Primary Cultures G.Vissvesvaran, et al   Light induced photoreceptor damage is believed to be associated with age related macular degeneration (AMD). The primary objective of this study was to investigate the effect of DMTU on blue light stress in bovine and primate primary retinal cell cultures.

2075  The Effect of A2-E and Its Photo-Derivatives to RPE-Cells M.Hammer et al   A2-E, a major component of the retinal pigment epithelium (RPE) lipofuscin, is known as a compound which can neither be degraded by nor eliminated from the cells and which is toxic as well as phototoxic to the cells. Illumination of A2-E with short wavelength light results in isomerisation, photo-oxidation, as well as photolysis.
Conclusions: Spectral shifts by bleaching with blue light as well as its retardation under oxygen depletion support the theory of photo-epoxidation of A2-E to oxiranes. The cytotoxicity of the oxiranes is demonstrated by the increased damage rate found in cells supplemented with blue light-irradiated A2-E.


2885 HPLC-ESI/MS Analysis of A2E and Its Relation With Carotenoids in Overlying Retina  B.Serban et al
A2E and its isomer iso-A2E, the major fluorophores of lipofuscin in human retinal pigment epithelium (RPE), are thought to be important mediators of light-induced oxidative damage associated with aging.  Understanding the biochemical mechanisms of their formation and function may provide helpful insight into the pathogenesis of age-related macular degeneration (AMD).

4801 Protective Effect of Crocin Against Blue and White Light Mediated Photoreceptor Cell Death in Bovine and Monkey Retinal Primary Cell Culture  A.Laabich et al,  Light exposure has been attributed to the incidence of age related macular degeneration (AMD).
Conclusions: These results show that blue and white fluorescent light selectively induce rods and cones cell death in this in vitro model.


1533  Blue Light Induces A2E Oxidation in Rat Eyes  A.R. Wielgus et al
Blue light induced retinal injury has been associated with age-related macular degeneration. A2E is a blue light absorbing retinal chromophore that increases with age..
Conclusions: It appears that blue light exposure promotes the oxidation of A2E and iso-A2E to A2E epoxides in the rat eyes. As these A2E oxides are toxic to retinal tissue, this may partially explain blue light induced retinal injury. These studies suggest that similar phototoxic effects may also take place in human eyes...


2071  OT-674 Protects Against Photooxidative Processes in RPE Cells  J.Zhou et al
The pathogenesis of AMD involves RPE cell degeneration and much consideration has been given to the role of oxidative damage in the demise of these cells.... As cells that are exposed to light, RPE may be at risk, at least in part, because they accumulate photoreactive compounds that constitute the lipofuscin of the cell.

2887 The Nonreceptor Tyrosine Kinase cAbl Is Involved in the Cell Death Pathway Activated in A2E-Laden RPE Irradiated With Blue Light  B.Cai, et al
Aging and some retinal disorders are accompanied by the accumulation of lipofuscin in retinal pigment epithelial cells (RPE). We have previously shown that the death of blue light irradiated RPE cells involves photooxidative mechanisms...

2895 Retinal Damage Caused by White Fluorescent Light in Rats Is Not Altered by Ultraviolet Cut-Off Filter  S.Kaidzu, et al    Intense light exposure to rodent eyes has been used as an experimental model of retinal degeneration. In this model, visible wavelengths of light are generally thought to elicit the retinal damage. However, white fluorescent bulbs, which are frequently used as a light source, radiate a broad spectrum of light including ultraviolet (UV) A, UVB, and visible light. Since rodent crystalline lenses transmit both UVA and visible light, UVA may also cause retinal degeneration in this model. We tested whether UVA is involved in the mechanism of retinal degeneration induced by white light exposure in rats. Conclusions: In this model of light-induced retinal degeneration, visible light, but not UV, is the major cause of retinal damage.

2076 Does Experimental Photodegradation of RPE Melanosomes Change Their Antioxidant Properties?  M.Zareba et al  Accumulation of oxidative damage over time by the RPE is believed to contribute to age-related diseases such as AMD..

5764  Human Retinal Progenitor Cells Rescue RPE Cells From Oxidative Damage R.S. Roque et al
Age-related macular degeneration (AMD), the most common cause of irreversible vision loss in the elderly, results from oxidative damage to the retinal pigment epithelium (RPE) and concomitant photoreceptor cell apoptosis due to loss of RPE trophic support.

1390 Blue-Light Irradiation Induces Oxidation of Phospholipids in Mouse Retina  M. Suzuki et al  Oxidative stress is suggested to be one of the key factors in the pathogenesis of age-related macular degeneration (AMD). We previously showed that oxidized phospholipids increased in AMD eyes compared with age-matched normal eyes. To establish an AMD animal model, we attempted to induce the oxidation of phospholipids in mouse retina by irradiating blue-light.
Conclusions: These results indicate that long term blue-light irradiation induces the oxidation of phospholipids in the ONL and RPE of mice. Blue-light may be useful for developing an animal model of AMD.


2890 Vitamin C Increases Light-Induced Toxicity of All-Trans-Retinal to Retinal Pigment Epithelial Cells in vitro B.Rozanowski et al   To determine whether ascorbate (vitamin C, AscH) can affect the susceptibility of retinal pigment epithelial cells in culture to light-induced toxicity mediated by all-trans-retinal (RAL) Conclusions: AscH can lead to an increase of phototoxic effects of RAL via shifting the mechanism of photooxidative damage from singlet oxygen-mediated to free radical-mediated.

2122  Macular Pigment Distribution in Patients With Age-Related Maculopathy U.E. Schnurrbusch et al
 Recent studies indicate that the density of macular pigment (MP) may play a central role in development and progression of age-related maculopathy (ARM).

2592  Retinal Degeneration and Neovascularization in Iron Overloaded Cp/Heph Deficient Mice is Exacerbated by Bright Light Exposure and Aging  C.King et al  Age-related macular degeneration (AMD) is the most common cause of vision loss in the United States in those 50 or older.....and since light can cause photo-oxidative damage, we tested whether bright light exposure exacerbates the retinal degeneration. Conclusions: These preliminary data imply that light exposure may hasten the retinal degeneration seen in aging...

2318  Human Bruch's Membrane From Elderly Donors Is a Source of Light-Induced Reactive Oxygen Species and Is Susceptible to Photooxidation M.B. Rozanowska et al  To determine the susceptibility of human Bruch's membrane (BrM) to photooxidation and its ability to photogenerate reactive oxygen species and induce lipid peroxidation.. Conclusions: Human BrM from elderly donors is susceptible to light-induced oxidation and contains potent photosensitizers generating superoxide, singlet oxygen, lidid hydroperoxides and secondary products of lipid peroxidation when excited with ultraviolet or blue light. It can be speculated that irradiation with blue light of BrM may prove toxic to cells of neighbouring retinal pigment epithelium and/or choroid.

2089 Dietary Superoxide Dismutase Protects Against Light-Induced Retinal Oxidative Stress in Young Senescence Accelerated Mice (SAM)  P.Sicard et al   Oxidative stress from reactive oxygen species has been implicated in many diseases including age-related macular degeneration, in which the retinal pigment epithelium is a primary target.
....These results demonstrate that our light-exposure conditions promote retinal oxidative stress...

                                 
1484 UV-Filter IOL versus Yellow Blue Light-Filter IOL in Combined Cataract Surgery With Vitrectomy: A Prospective Randomized Clinical Trial  C.I. Falkner et al  Conclusions: With evidence proved data that the blue light is an important variable in age-related macular degeneration (ARMD), the yellow blue light-filter IOL could rapidly become the standard in cataract surgery

 


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