Spotlight on Eyecare

Dr. Vitale has been meeting with the principal investigator Dr. Clemente Trempe in order to develop patient protocols and the introduction of a simple non-invasive test which may allow an early diagnosis of Alzheimer disease.

The Shepens Retina Foundation is the nation's largest research center for ocular disease location in Boston.

Alzheimer's Signature Eye Findings

Alzheimer's disease is a brain disease that is caused by the deposition in the brain tissue of material called beta-amyloid plaques. Not surprisingly, the optic nerve would show early signs of the disease. The reason is that the retina and optic nerve are the only brain tissue that is actually visible (through the pupil). They are extremely sensitive. Using special instrumentation, it is now possible to corroborate a clinical diagnosis of early Alzheimer's disease (AD) by taking special measurements in the optic nerve and the retina and possibly the lens. Many diseases can affect the optic nerve and retina at an early stage, such as glaucoma and other neurodegenerative diseases. In AD, however, the optic nerve and retina are affected early in a very specific fashion.

The first characteristic in early cases of AD is that the retinal vessels show a marked narrowing of the retinal blood column. This is because the blood vessel wall thickness is augmented by collagen deposition on the vessel walls.

A second characteristic in that when we measure the thickness of the retinal nerve fiber layer with a special instrument called the Stratus OCT, in early AD it is affected in a unique fashion: it is usually reduced in the upper portion of the fibers surrounding the macula, or center of the retina.

Laboratory for Early Detection of Neurodegenerative Diseases

Director: Clement L. Trempe, M.D.

Over 40% of Americans over the age of 85 eventually develop Alzheimer's Disease (AD). We are hopeful that our research will confirm that the eyes are the windows to the brain and will eventually be the way that patients are screened for the earlydetection of AD at a time when the disease can be prevented.

Aside from continuing to study the effect of systemic diseases on the eye, we plan to continue to study the ocular changes that are associated with various neurodegenerative diseases such as Alzheimer's and Parkinson's disease.

Patients with AD have a very special type of cataract produced by the accumulation of beta amyloid protein in the periphery of their lens. These proteins are the same ones that accumulate in the brain of AD patients. These protein deposits are also seen in the lens of many older patients who have good visual acuity and are neurologically normal. We have also observed the same lens changes in patients with early AD who are under treatment by their neurologist.

Besides the lens, other parts of the eyes are also involved in AD and PD, and those will also be investigated.

• The same type of beta amyloid protein that accumulates in the lens periphery of patients with AD also accumulates in drunsen, which are spots in the macular area and are the early signs of macular disease. The realtion of those early macular changes in relation to the future development of AD will also be investigated.
• The pathophysiological neurodegenerative process in the optic nerve of patients with glaucoma is identical to the process seen in the brain of AD patients. And there is epidemiologic and clinical evidence that patients with glaucoma are more prone to develop AD later in life.