Cataracts: Cataracts are clumps
of protein that collect on the lens of an eye and interfere with
vision. Normally, light passes through the lens (the clear tissue
behind the pupil) and focuses on the retina. The retina is the light-sensitive
layer of the eye that sends visual signals to the brain. A cataract
occurs when the normally clear lens becomes cloudy. Most cataracts
develop slowly over time and are a natural result of aging.
and Alpha Lipoic Acid
It is believed that antioxidants
may protect the lens against damage caused by free radicals. It
is also thought that ALA’s ability to encourage the production
of the antioxidant glutathione would help to protect our eyes from
developing cataracts. The following study helps to demonstrate this.
In this experiment, one group of
newborn rats was given a drug called (BSO) that inhibits production
of glutothione. Another group of newborn rats were given BSO along
with an injection of lipoic acid. Newborn rats do not open their
eyes until the 6th week of life, but from past experiments it was
known that when these glutathione-deprived rats did open their eyes,
they would all have cataracts. Would lipoic acid protect against
cataracts caused by glutathione deficiency? At the end of the 6
weeks all of the rats that were given just the BSO developed cataracts.
Yet almost all of the rats that were also given lipoic acid supplementation
had remained cataract free. Further testing showed glutathione levels
were much higher in eye lens of the rats treated with lipoic acid
but severely depleted in those that were not treated with lipoic
acid. Maitra et al (1) suggest alpha-lipoic acid's protective effect
for BSO-induced cataract formation is probably due to its protective
effects on lens antioxidants. The lens antioxidants glutathione,
ascorbate, and vitamin E were depleted to 45, 62, and 23% of control
levels, respectively, by BSO treatment, but were maintained at 84-97%
of control levels when R-alpha-lipoic acid was administered.
P, Nourooz-Zadeh J, Tritschler HJ, Wolff SP. Activation of aldose
reductase in rat lens and metal-ion chelation by aldose reductase
inhibitors and lipoic acid. Free Radic Res 1996;25:337-346)
Glaucoma: Glaucoma is a slowly progressing disease
that causes damage to the eye's optic nerve and can result in blindness.
Open-angle glaucoma, the most common form of the disease, affects
about three million Americans. It is the leading cause of blindness
for African-Americans. Because there are usually no symptoms at
first, half of the people with this disease don't know they have
it. With early treatment, serious vision loss and blindness can
usually be prevented.
A clear fluid flows in and out of
the space at the front of the eye, nourishing nearby tissues. Glaucoma
causes the fluid to pass through too slowly or to stop draining
altogether. As the fluid builds up, the pressure inside the eye
increases, causing damage to the optic nerve and vision loss.
and Alpha Lipoic Acid - Forty-five patients with stage
I and II open-angle glaucoma (OAG) were administered either 75 mg
of alpha-lipoic acid for 2 months or 150 mg for 1 month. A control
group of 31 patients with OAG were administered only local hypotensive
therapy. The greatest improvement of biochemical parameters (gamma-glutamyl
transpeptidase and non-protein SH-groups), visual function, and
the coefficient of efficacy of liquid discharge was observed in
the patients administered the higher dose of alpha-lipoic acid.
Preliminary evidence indicates that 150 mg of alpha lipoic acid,
taken daily for one month, significantly improves visual function
in people with glaucoma.*
Filina AA, Davydova NG, Endrikhovskii SN, et al. Lipoic acid as
a means of metabolic therapy of open-angle glaucoma. Vestn Oftalmol