More evidence for early changes in the eye in Alzheimer’s disease comes from a study involving both rats and postmortem human retinas. Changes were found in the retinal pigment epithelial layer (which harbors the supportive cells located in the back of the eye) and in the thickness of the choroidal layer that has blood vessels providing nutrients to the retina.
The finding is consistent with growing evidence that glaucoma is a neurodegenerative disorder similar to Alzheimer’s.
 . Ocular Changes in TgF344-AD Rat Model of Alzheimer's Disease. Investigative Ophthalmology & Visual Science [Internet]. 2014 ;55(1):523 - 534. Available from: http://www.iovs.org/content/55/1/523