A study of patients in England with the eye disease age-related macular degeneration (AMD) found no association between having AMD and subsequently developing dementia or Alzheimer disease (AD), according to a report published by JAMA Ophthalmology, a JAMA Network publication.
AMD and AD are diseases strongly associated with advancing age. They share environmental risk factors, including cigarette smoking, high blood pressure and high cholesterol and other features such as the depositing of plaques in the brain. But the genetic risk factors for AMD and AD seem to be different, according to the study background.
Tiarnan D.L. Keenan, M.R.C.Ophth, of the University of Manchester, England, and colleagues examined whether patients admitted to the hospital with AMD were more likely to develop AD or dementia in the following years. A group of 65,894 patients with AMD was constructed from data in the English National Health Service. A dementia group (168,092 patients) and a reference group (more than 7.7 million people) were assembled in similar ways. Researchers measured the risk of AD or dementia following AMD and the risk of AMD following AD or dementia.
The study indicates that risk of AD or dementia after AMD was not elevated. However, the study findings indicate that patients in England with dementia may be less likely to receive treatment for AMD and several factors may contribute to this, including that patients with dementia may be less likely to get their eyes examined.
“In conclusion, these data provide evidence that there is no positive association between AMD and dementia or AD. However, people with dementia in England are substantially less likely to undergo treatment for AMD than those without dementia. Potential barriers to care for these vulnerable individuals need to be examined and addressed in the near future,” the study concludes.
(JAMA Ophthalmol. Published online November 14, 2013. doi:10.1001/.jamaopthalmol.2013.5696.