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Abstract
The majority of ocular pathologies originate from a functional deterioration of intraocular tissues. This age-related deterioration often occurs as a result of changes within the eye. There is growing interest in the role of natural or synthetic compounds, such as carnitine, for blocking, or slowing, the progress of this deterioration. L-carnitine and its derivatives are involved in numerous physiological reactions, including sugar aerobic metabolism, oxidative phosphorylation, fatty acid oxidation and osmosis. While carnitine levels in human ocular tissue are unknown, animal studies indicate that carnitine is differentially distributed within the eye with the highest concentrations reported in the iris, ciliary body and the choroid-retina. In patients with age-related macular degeneration (AMD), acetyl-L-carnitine improved four parameters of visual function, including visual field mean defect, visual acuity, foveal sensitivity and ocular fundus alterations. L-carnitine has also demonstrated antioxidant properties in animal models of oxidative damage. This article reviews the potential use of L-carnitine and its derivatives in age-related ocular pathologies, such as AMD, cataract, glaucoma and dry eye syndrome.
The origin of most ocular pathologies can be linked to a functional deterioration of intraocular tissues. Such age-related deterioration often occurs as a result of changes within the eye. In recent years, there has been a great deal of interest in the role of natural or synthetic compounds for blocking, or slowing, the progress of this deterioration.
Carnitine (β-hydroxy-γ-trirnethyl-arnrnonium butyrate) is an amine synthesized from lysine and methionine in a vitamin C-dependent process, which occurs primarily in the liver and kidneys. L-carnitine plays a role in a variety of physiological reactions including sugar aerobic metabolism (Krebs cycle), oxidative phosphorylation and, most importantly, fatty acid oxidation in the mitochondrial matrix.[1] Most recently, the role of L-carnitine as an osmolyte has also been demonstrated.121 High concentrations of L-carnitine have been observed in the mammalian ocular lens,[3] where osmolytes play an essential part in preserving ocular lens transparency.[2,4,6]
This article reviews the possible use of L-carnitine and its derivatives in age-related ocular pathologies, including age-related macular degeneration (AMD), cataract, glaucoma and dry eye syndrome.
1. Age-Related Ocular Changes
Ocular lens proteins, situated in a regular arrangement in the aqueous phase in fibre neoplasms, play a key role in retaining light and preventing it from dispersing. The ocular lens...