Glaucoma, Alzheimer’s disease show similarities in animal model

Molecular similarities may exist between glaucoma and Alzheimer’s disease, and that relationship may help researchers design methods of diagnosing and treating glaucoma.

Stuart J. McKinnon, MD, PhD, at the University of Texas San Antonio found changes in the optic nerves of rats and mice that mimic changes in the brains of Alzheimer’s patients. According to Dr. McKinnon, specific proteases called caspases are activated in chronic neurodegenerations such as Alzheimer’s disease, as well as in retinal ganglion cells after optic nerve transection.

In both rat and mouse models, Dr. McKinnon reported in the September issue of Frontiers in Bioscience, the optic nerves seem to accumulate the same amyloid-beta protein that is the underlying cause of neuron death in patients with Alzheimer’s disease.

A group of Swedish researchers found similar correspondences in patients with Alzheimer’s disease and pseudoexfoliation syndrome. S. Janciauskiene and T. Krakau at University Hospital Malmo concluded that “Alzheimer’s peptide is present in the aqueous humor of patients with pseudoexfoliation syndrome and glaucoma, suggesting that these diseases may share common features in the biochemistry and etiologies with Alzheimer’s.” In a report in Documenta Ophthalmologica, they raised the possibility that these proteins may reflect early amyloid-related changes in the eye.

In an interview with the San Antonio Express-News, Dr. McKinnon also referred to a German study that reported a higher incidence of glaucoma in patients with Alzheimer’s disease. In short, he said, “there is more evidence that amyloid beta may be bad for the eye.”