Glaucoma Could Be Treated With Alzheimer's Drugs, New Study

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Main Category: Eye Health / Blindness
Also Included In: Alzheimer's / Dementia
Article Date: 08 Aug 2007 - 7:00 PDT

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Scientists from the UK, France and Italy have suggested that drugs normally used to treat Alzheimer's Disease could be effective in treating glaucoma, a leading cause of irreversible blindness in the world. So far the tests have only been carried out on animals but human tests are planned for later this year or early next year.

The study is published in the American journal Proceedings of the National Academy of Sciences (PNAS) and is available as an early online issue.

Alzheimer's Disease is a devastating neurodegenarative condition that affects over 20 million people worldwide, most of them over the age of 65. It develops when deposits and tangles of misfolded amyloid beta proteins start collecting in the brain which leads to death and loss of brain cells and eventually to loss of memory and cognitive skills and progressive inability to lead a normal daily life.

In this study led by Dr Francesca Cordeiro of the Institute of Ophthalmology at University College London, scientists found evidence of a similar process involving amyloid beta proteins in the development of glaucoma, a disease where the optic nerve is damaged.

Until now the only clue to the development of glaucoma has been elevated pressure inside the eye, but some people with normal eye pressure can also get it and lose their sight, so for some time scientists have wondered what else could be happening.

Cordeiro and colleagues examined retinas where the retinal ganglion cells (RGC) in the optic nerve had died off (a key feature of glaucoma) and noticed they were accompanied by plaques of amyloid beta protein similar to the ones in brains of people with Alzheimer's Disease.

They were also able to induce RGC "apoptosis" (cell death) using various timed doses of amyloid beta proteins in the lab.

The team then tested the effects of drugs normally used to treat Alzheimer's Disease on the rate of development of glaucoma in rats. They used three different drugs, each targetting a different part or stage of the growth of amyloid beta protein plaques. Each drug slowed down RGC apoptosis to some extent, but using all of them together (triple therapy) was more effective.

Cordeiro and colleagues concluded that:

"Our work suggests that targeting the [amyloid beta] pathway provides a therapeutic avenue in glaucoma management."

"Furthermore, our work demonstrates that the combination of agents affecting multiple stages in the [amyloid beta] pathway may be the most effective strategy in [amyloid beta] related diseases", they added.

Readers should be assured that this study is not suggesting you are at higher risk of Alzheimer's Disease if you have or are at higher risk of glaucoma.

"Targeting amyloid-{beta} in glaucoma treatment."
Li Guo, Thomas E. Salt, Vy Luong, Nicholas Wood, William Cheung, Annelie Maass, Giulio Ferrari, Françoise Russo-Marie, Adam M. Sillito, Michael E. Cheetham, Stephen E. Moss, Frederick W. Fitzke, and M. Francesca Cordeiro.
Proc. Natl. Acad. Sci Published online before print August 7, 2007
doi: 10.1073/pnas.0703707104

Click here for Abstract.

Click here for more information about glaucoma (Glaucoma Research Foundation).

Written by: Catharine Paddock
Copyright: Medical News Today
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