Saturday, October 15, 2011
Parkinson's Disease and Eyesight, Notes from a Recent Telehealth Presentation
This is a tidied-up version of my notes from a Telehealth Session presented by Dr. Heavin Maier an Optometrist in Spokane. This was one of the more valuable of the telehealth sessions I have attended. There was a great deal of info that was news to me. I have tried to relay as much as I could here, but there are gaps when my attention wandered momentarily. I recommend that you visit their website to obtain a copy of the lecture on DVD or view it if and when they post it with their other on-line videos. Thanks to Dr. Maier for a comprehensive, well-organized and informative session.
General vision principles
We need to maximize vision as long as possible
Vision is one of two main senses that orient us in space, the other is proprioception. As balance and other orienting mechanisms fail, vision can help compensate.
Vision can help override cuing problems. For example tile grids or tape lines on floors that can help people unfreeze and walk normally when they see them.
Parts of the eye
Sclera: Tear film is compromised by age, some meds, and reduced blink rate. Normal blink rate 12x per minute. Some people with PD blink as few as 1x per min. This will lead to dry eye. Cornea: dry eye will cause chronic breakdown of the cornea. Sensitivity goes down infection goes up. Iris: The colored part of the visible eye, expands and contracts to regulate the amount of light that enters the eye. Lens: focuses light on the retina. Vitreous humor: Clear filling of eyeball, that's where the floaters are. Retina: An extension of the brain there are dopamine cells here affected by PD. Optic nerve: over a million fibers that carry signals to the brain, which converts them to images.
Comorbidities
As we age we develop comorbidities, other diseases that affect vision on top of Parkinson's. Some of these comorbidities and teatments for them follow.
Dry eye: Artificial tears can treat dry eye. Autodrop can help administer eyedrops. Cataracts: Cataracts caused by exposure to uv light. Cataract surgery very successful. Macular degeneration. Significant degradation but not total blindness. Glaucoma: elevated pressure in eye damages nerves. Diabetic retiopathy. After age 43, Focus problems. Get different glasses for different distances. Select different frames for different distances so you can easily tell them apart. Avoid trifocals and lined bifocals they can cause falls, confusion. Because of falls, shatterproof lenses are good.
Pd-specific impairments
Low contrast sensitivity: difficulty in distinguishing contrast. Sinemit helps. Filters help (like goggles for skiing) yellow, amber and pink.. Try them out. Double vision binocular and monocular. If you cover an eye and you still have double vision it's monocular. When the eyes work in tandem, the coordination can be thrown off by PD. Reduced visiospacial attention. Eye muscle movement difficulty. Quick eye movements are impaired and this reduces recognition, Abnormal color vision red- green distinction degenerates. Visual hallucinations. Opening the eyes while sleeping.
Eye fatigue, can be caused by wrong prescriptions. Different eyedrops for different types or causes of dry eye. Many Pd-related eye problems can be helped by your eye doctor. talk problems over with them.
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1 comment:
My mother is now 73 years old. About 10 years ago, she was diagnosed with Parkinson's disease. She is having stiffness and finding it difficult to walk. She tends to fall. Now, another problem that we are facing is that she is losing her memory day by day.
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