Abstract | PURPOSE: METHODS: Initial verification of the hypothesis has been done primarily by rat and mouse lens organ culture studies under ambient as well as ultraviolet (UV) light irradiation and determining the effect of such irradiation on its physiology in terms of its efficiency of active membrane transport activity and the levels of certain metabolites such as glutathione and adenosine triphosphate as well as in terms of apoptotic cell death. In vivo studies on the possible prevention of oxidative stress and cataract formation have been conducted by administering pyruvate and caffeine orally in drinking water and by their topical application using diabetic and galactosemic animal models. RESULTS: Photosensitized damage to lens caused by exposure to visible light and UVA has been found to be significantly prevented by ascorbate and pyruvate. Caffeine has been found be effective against UVA and UVB. Oral or topical application of pyruvate has been found to inhibit the formation of cataracts induced by diabetes and galactosemia. Caffeine has also been found to inhibit cataract induced by sodium selenite and high levels of galactose. Studies with diabetes are in progress. CONCLUSIONS: Various in vitro and in vivo studies summarized in this review strongly support the hypothesis that light penetration into the eye is a significant contributory factor in the genesis of cataracts. The major effect is through photochemical generation of reactive oxygen species and consequent oxidative stress to the tissue. The results demonstrate that this can be averted by the use of various antioxidants administered preferably by topical route. That they will be so effective is strongly suggested by the effectiveness of pyruvate and caffeine administered topically to diabetic and galactosemic animals.
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Authors | Shambhu D Varma, Svitlana Kovtun, Kavita R Hegde |
Journal | Eye & contact lens
(Eye Contact Lens)
Vol. 37
Issue 4
Pg. 233-45
(Jul 2011)
ISSN: 1542-233X [Electronic] United States |
PMID | 21670697
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Review)
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Chemical References |
- Antioxidants
- Reactive Oxygen Species
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Topics |
- Animals
- Antioxidants
(pharmacology)
- Cataract
(etiology, metabolism, prevention & control)
- Humans
- Lens, Crystalline
(metabolism, radiation effects)
- Oxidative Stress
- Reactive Oxygen Species
(metabolism)
- Ultraviolet Rays
(adverse effects)
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