UK scientists have shown that key proteins involved in Alzheimer's disease are also implicated in glaucoma, and that drugs being developed for the former could work as a treatment for the latter.
The new research, carried out at the University College London Institute of Ophthalmology and funded by the Wellcome Trust, involved developing a new technology for visualising nerve cell damage in the retina (known as detection of apoptosing retinal cells) and by using this, the researchers demonstrated that the protein beta-amyloid, which causes the 'plaque' lesions in the brains of Alzheimer's patients, also leads to nerve cell death in the retina. The results of the animal study have just been published in Proceedings of the National Academy of Sciences.
Francesca Cordeiro from UCL, who led the study, noted that "we've seen for the first time that there is a clear link between what causes Alzheimer's disease and one of the basic mechanisms behind glaucoma" but was quick to point out that “this doesn't mean that everyone with Alzheimer's will develop glaucoma or vice versa. Glaucoma has a number of risk factors."
Nevertheless, in the trial, when rats with glaucoma were administered a combination of experimental Alzheimer's drugs, including Elan and Wyeth’s investigational compound, the monoclonal antibody bapineuzumab, the results demonstrated that "the number of cells that are dying goes right down over a period of 16 weeks," Dr Cordeiro said. "It does not restore sight, but it stops them losing vision in the first place," she added.
Glaucoma affects over half a million people in the UK, and as many as 65 million people worldwide. Little is known about what exactly causes the disease, which results in damage to the optic nerve in the eye, although the disease is traditionally attributed to intraocular pressure.
However, this new research opens up a new avenue of treatment in glaucoma that does not involve treating the latter and Dr Cordeiro noted that “we are trying an approach that has never been tried before, not even to treat Alzheimer's disease. Our success in treating glaucoma in the lab by combining different Alzheimer's treatments represents a brand new treatment strategy."