Alpha lipoic acid ('97, '99, '06. '13) - Diabetic Retinopathy
Oxidative stress is known to be a factor in many eye conditions (and other health conditions as well). These studies noted that alpha-lipoic acid (ALA) reduces oxidative in addition to other benefits.
The researchers evaulated the literature and recent studies and reviews the current understanding of the role of alpha-lipoic acid, a natural antioxidant. They pointed out that ALA prevents both micro- and macro- damage to blood vessels resulting from over production of free radicals by mitochondria, and protects the pericytes that surround and protect the cells that line blood vessels, including the fine capillaries in our eyes. They opined that ALA acts through multiple mechanisms to reduce oxidative stress, improve insulin sensitivity (in patients with type-2 diabetes), and reduces vascular endothelial growth factor (a protein that stimulates extraneous blood vessel growth.
Nebbioso, M., Pranno, F., Pescosolido, N. (2013). Lipoic acid in animal models and clinical use in diabetic retinopathy. Expert Opin Pharmacother, Sep;14(13):1829-38.
In an animal model extraneous capillary blood vessel growth is elevated (micro-neovascularization); in addition there is pericyte loss. Pericytes surround the cells that line blood capillaries and help to regular blood flow. Animals treated with the R form of alpha lipoic acid have reduced micro-neovascularization and increased amounts of pericytes which protect fine capillaries. In addition, there is reduced oxidative stress and normalization of other functions that govern capillary blood flow.
Lin, J., Bierhaus, A., Bugert, P., Dietrich, N., Feng, Y., et al. (2006). Effect of R-(+)-alpha-lipoic acid on experimental diabetic retinopathy. Diabetologia, May;49(5):1089-96.
Researchers found that alpha lipoic acid has the capacity to lessen formation of diabetic cataracts, as well as diabetic retinopathy, and therefore appears to be an ideal neuroprotective supplement in the treatment of all brain and neural disorders aggrevated or caused by free radical processes.
Packer, L., Tritschler, H.J., Wessel, K. (1997). Neuroprotection by the metabolic antioxidant alpha-lipoic acid. Free Radic Biol Med, 1997;22(1-2):359-78