There is a fascinating study by colleagues from University College London (UCL) that has just been published in the Proceedings of the National Academy of Sciences that has found a "clear link between what causes Alzheimer's and one of the basic mechanisms behind glaucoma.”
The research could speed up the development of new treatments for Alzheimer's and revolutionize the treatment of glaucoma, the most common cause of blindness in the Western world.
If glaucoma is indeed confirmed as a marker or risk factor for Alzheimer's then the early warning signs it gives could help ensure that patients have more opportunities to delay the onset of dementia.
The researchers discovered that the same "plaque" proteins are a key process in the development of both diseases. Clumps - or plaques - of beta-amyloid proteins that kill brain cells in Alzheimer's patients, also kill optic nerve cells in the eyes of glaucoma sufferers. A link has bee suspected for some time: around 1.8-2.0% of the population will develop glaucoma, the figures in Alzheimer’s is as high as 25%.
Dr Francesca Cordeiro, who led the team at UCL's Institute of Ophthalmology, said:
“We've seen for the first time that there is a clear link between what causes Alzheimer's and one of the basic mechanisms behind glaucoma."
Glaucoma is a group of diseases of the optic nerve involving loss of retinal ganglion cells in a characteristic pattern of optic neuropathy. People with glaucoma gradually lose their wider field of vision. Many do not realize it until they barge into things.
The textbooks will tell you that glaucoma is caused by increased pressure in the eye, known as intraocular pressure. Standard treatments attempt to lower this pressure, but with only limited success. People with normal pressure can also suffer from glaucoma, suggesting it is not the only cause.
The researchers have shown that drugs that prevent the build-up of "plaque" proteins in the brains of people with Alzheimer's disease were successful in treating glaucoma in rats. One such drug, bapineuzumab, is already being used to treat Alzheimer's patients in clinical trials in Britain and the United States.
The UCL researchers showed that the effects on glaucoma were even stronger when combined with two other novel Alzheimer's treatments - "Congo Red" and a drug called a beta-secretase inhibitor.
This is very exciting work and we should know fairly soon whether these new approaches to treatment will help both glaucoma and Alzheimer’s disease.
Clearly this does not mean that everyone with Alzheimer's will develop glaucoma or vice versa. Both problems have multiple causes and can follow quite different trajectories. But links like these are the stuff of medical progress.