” Vision is the art of seeing what is invisible to others.” ~ Jonathan Swift
The eyes have always held a great mystery for many since ancient times. Egyptians regarded them as one of the vital organs to be preserved for the after life to them see where they were going. Others claim the eyes are the window to the soul.
Whatever their mystical significance is one thing is for certain their function its even more complex yet! So important is vision that nearly 30% of supratentorial (this is the area of the brain that lies above the cerebellum and supports the occipital lobe) region of the brain is dedicated to the activity of deciphering, decoding and understanding what we see around us.
As a neurologist part of our exam is to evaluate eye function as it pertains to the brain. That is to say to ascertain that what we (you & me) are seeing is being processed appropriately by our brains.
Like everything else pertaining to the brain there are a myriad of intricate connections and pathways which can be disrupted along the way from the eye to the vision center (occipital lobe. Our job, then, is to find out where the problem is and try to find a solution if at all possible.
I have discovered as a neurologist and PD patient that this is not always an easy task nor is there always an easy solution.
Yet, I will attempt to give some advice on ways to make PD visual symptoms more manageable however possible.
One of my first signs of PD was significant dysfunction involving my visual system which nearly cost me my life a couple of times as well as my drivers license. Although, as a whole my vision problems are 110% improved from where they started from time to time they continue to challenge me in my activities of daily living. Just a couple of days ago I had an incident while driving through the bank teller which reminded me that all is not as it should. I bounced back and forth from side to side hitting the cement dividers like a ball in a Ping-Pong machine as I tried to exit onto the street with dignity intact avoiding eye contact with those around hoping that I had not taken out another chuck out of my tire which I had just replaced!
Obviously, my medication dose was no longer working as I would like it. Time to increase my dose but also time to see an eye doctor to make sure no new abnormalities had occurred causing this behavior.
As I said before vision is a crucial sense upon which we heavily rely on and when not working well it can wreak havoc in our lives.
Common Eye Problems with PD: There are 6 tiny Muscles which move our eyes continuously even in sleep they are moving -like other muscles in our body these too get STIFF & SLOW.
- decrease blinking
- decreased visual acuity- usually normal or near normal in PD- problem lies with contrast
- decreased color vision- colors become dull and less vibrant
- decrease in ability to detect contrast – worst with night, rain, subtle shades, glare
- double vision
- dry eyes
- visual hallucination
- decreased visual field- result into bumping into things, walls, other cars etc. due to loss of peripheral vision (caused by eye muscles being stiff and not moving in all directions)
- Impaired convergence- difficulty bringing eyes together in sync to view an object which is near by
- smooth pursuit is choppy – may cause trouble with reading
- saccades ( quick eye movements) in tracking or following objects quickly we undershoot- thus missing target.
UNCOMMON eye problems for PD but COMMON of PARKINSON’s PLUS Syndromes:
- Blepharospasm- abnormal blinking (increased) and sustained contraction of eye lids
- Apraxia of eyelid -inability or difficulty opening eyes on command usually have to use touch stimuli -open manually
- decrease vertical eye movements – sine qua non of PSP
****The retina has cells that produce levodopa.*****
As we begin to loose dopamine else where in our brains, guts, our eyes can become depleted as well especially if we are constantly using to read, watch TV, drive or perform any activity which requires visual precision and concentration.
So, I went to eye doctor yesterday and my color vision detection has decreased to my surprise while my ability to tell contrast has worsened. No wonder I am running over things can differentiate subtle things yet my convergence and visual fields have improved.
How do we address these troublesome visual issues and prevent our lives from losing quality and independence.
- Since our visual system is very much dependent on dopamine – the first line of treatment involves replacement! I have found personally that NEUPRO works best for this because it provides a continuous dose of dopamine agonist. Azilect works well too but does not last 24 hrs.
- Convergence insufficiency is a common problem- one way to help this is doing “Pencil push-ups” where you bring your pencil slowly towards your nose while you focus on it and then push arm away with eyes continuing to be fixed on pencil- repeat 10 times at least 2-3 times a day. Another thing is to add prisms to your reading glasses. Also, covering an eye with scotch tape or satin gift tape for a few hours then doing the other.
- decrease blinking/dry eyes- artificial tears- prefer preservative free- 3-4 times a day- more often if will be driving, reading or doing computer work because these activities cause a significant decline in tear secretion and distribution; decrease reading especially on kindle -e-books, get larger print with darker ink; decrease time on computer- take frequent breaks ( every hour 15 minutes) and do ‘push- pencil’ exercises. some medications may increase dry eyes like Artane or tricyclics e.g. Elavil.
- contrast deficits – have eye doctor tint your glasses yellow or brown which will help with subtle shades, at night, and with rain. have anti glare on your glasses as well. At home make paths and walk ways with distinct visual patterns /lines to avoid falling and bumping into things.
- visual field deficits – dopamine replacement – but prisms may also help with this.
- double vision in my experience usually due to medication effect- adjust medications
- visual hallucinations-usually a sign of underlying dementia- if not causing problems to patient – no need to treat- otherwise treat with anti-psychotics e.g. Seroquel/ Clozaril.
Sources: http://www.pdf.org- expert briefings-Gold, D. ” Vision more than meets the eye: Visons symptoms of PD”