Macula, degeneration

P-carotene is only one of many antioxidants, which can be detected in the skin. Other carotenoids, for example, lutein and zeaxanthine, are preferentially found in the macula lutea, the so-called yellow spot in the eye. Here, carotenoids are subject to a metabolism typical for that tissue, which cannot be found in other tissues (e.g., formation of meso-zeaxanthine). In addition, they can specifically be absorbed into the macula. In the macula, they protect the retinal pigment epithelial cells against oxidative damage from UV light. Indeed, these two carotenoids can be protective against age-dependent macula degeneration. 

SnEt2 Puryltin (Miravant) 665 (30 000) 0.71 1.2 150-200 1500-2000 Metastatic breast carcinoma, basal cell carcinoma. Macula degeneration cancers ... 

AO/FRS [dietary vitamin protects visual macula by absorbing blue light] active against age-related macula degeneration (leading cause of irreversible blindness)... 

Vision Many people experience visual decline as they age (Fig. 5) (137,146). Moreover, there are typical diseases in the geriatric populations that affect the application of medicines. Macula degeneration and glaucoma diseases reduce the visual capabilities and may lead to blindness. A number of diabetic patients also show reduced visual potency. A special insulin pen has been developed, which is easy to handle and where the graduations are enlarged to facilitate the adjustment of the correct dose (Fig. 6). Impaired vision hinders one s ability to self-administer medication and to read instructions for the... 

The high resolution optical coherence tomography (Sect. 7.13) is used to measure the thickness and possible wrinkles of the retina, which might lead to its detachment resulting in blindness. In Fig. 10.53 such an optical coherence tomogram of the retina is shown. Measurements at definite time intervals can show changes of the macula degeneration, a decease which is often found for elder people. 

Schalch, W. (2001). Possible contribution of lutein and zeaxanthin, carotenoids of the macula lutea, to reducing the risk of age-related macular degeneration A review. HKJ Ophthalmology 4 31—42. 

Hahn, P, Milam, AH, and Dunaief, JL, 2003. Maculas affected by age-related macular degeneration contain increased chelatable iron in the retinal pigment epithelium and Bruch s membrane. Arch Ophthalmol 121, 1099-1105. 

Age-related macular degeneration (AMD) is the main cause of irreversible blindness in the Western world and affects 20% of people older than 65 years (Krinsky and others 2003). The macula, or yellow spot, is part of the retina and is the area of maximum visual... 

Several studies have linked lutein to a lower risk for eye, skin and other health disorders, probably through its antioxidant activity. Lutein is apparently metabolized to zeaxanthin, an isomer, and several other compounds which protect the macula from ultraviolet radiation. The suggestion is that lutein may play a positive role in reducing macular degeneration. Other reports have linked lutein to a reduction of risk of cancer.13 Regardless, lutein is currently being promoted as an important dietary supplement. 

Measurement of choroidal blood flow by laser doppler in the macula also shows that the blood flow and blood volumes are reduced in old eyes and even more so in AMD patients. When RPE cells are removed from Bruch s membrane, the choriocapillaris degenerates, raising the question of whether the changes in choriocapiUaris are primary or secondary to the changes in RPE (Burke and Soref, 1988). Finally, RPE cells produce substances that stimulate both the formation and the regression of CNV in animal models. 

Suzuki, M. et al. Oxidized phospholipids in the macula increase with age and in eyes with age-related macular degeneration. Mo/. Vis. 13(2007) 772-8. 

In contrast, epidemiologic studies relating the intake of lutein and zeoxanthin with decreased incidence of age-related macular degeneration have received progressive support. These two carotenoids are concentrated in the macula (the central portion of the retina) and are called the macular carotenoids. 

There is evidence that CoQ-10 in combination with fish oil (omega 3 fatty acid) or flax seed oil will reduce damage to blood vessels and may delay degeneration of the macula. 

Two essential carotenoids, lutein and zeaxanthin, play an important role in the visual process. For the treatment of age-related macular degeneration (AMD), knowledge of the isomeric composition within the macula is of particular interest [7], Full assignment of isomeric configuration is possible by the registration of two-dimensional proton-proton correlated NMR spectra. Figure 7-7 shows, as an example, the COSY stopped-flow NMR spectrum of all-trans zeaxanthin isolated from ox retina. 

Age-related macular degeneration accounts for about half of all registerable visual impairments in the United Kingdom. It typically results in the loss of central vision (see Figure 41.1). Since most of the color receptors are in the macula (the central area of the retina), those with macular degeneration see colors less vividly. 

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