At least 2 years before my Parkinson’s diagnosis, I began experiencing difficulty with night vision particularly in depth perception which progressively got worst thus making driving at night not only increasingly more cumbersome but also more hazardous. Of course being a neurologist my mind went immediately to a differential diagnosis including rare disorders like Refsum’s Disease known for its accumulation of long chain fatty acids which leads to night blindness.
But never was PARKINSON’s DISEASE in my differential – well at least not idiopathic (cause unknown) regular garden variety PD! YES! Several Atypical Parkinson Syndromes or Parkinson Plus Syndromes ( e.g. PSP – Supranuclear palsy known for its limitations in vertical gaze causing patients to frequently trip on side walk or drop food on their shirts, or CBGD – corticobasalgangliadegeneration which is known for having visual spatial problems- not recognizing a part of your body as your own!)
Never really seen visual disturbances early on in PD as a preclinical- pre motor symptom (now with hind sight I can recall only one patient presenting this way but no one -several PD experts including myself- thought that the visual problems were part of the PD scenario!)
Although, for years many Parkinson patients have complained of visual deficits, they typically have been non specific and because Parkinson patients as a whole tend to be older, the problems have always been assumed to be related to AGE!! ( e.g. cataracts, glaucoma, macular degeneration, other eye disease).
I began to experience even more pronounced night vision loss without a clear etiology. My ophthalmologist assured me there was “Nothing” wrong with my eye sight other than mild near sightedness “normal” for my age. There were no abnormalities on my MRI of Brain to explain this and I did not have any neuromuscular deficits although at times my symptoms acted like I had a visual field defect! As my disease progressed with increasing slowness, stiffness, gait difficulty and worsening dystonia, I realized that so was my ability to judge distance especially at night. I knew that these symptoms had to be related. Although, at this time my neurologist still could not relate it to PD nor frankly could I! At the beginning, I thought it might also be stress or fatigue related from overworked muscles and severe eye strain since symptoms appeared to wax and wane.
Initially, I was left with my frustration and only means of treatment was to wear corrective lenses at night. However, the sense of NOT Knowing Exactly how close the cars where to me hit me one night as I was nearly run over by an 18 wheeler which had appeared to be several feet further than it actually was. As I began to merge unto oncoming traffic, the sound of the horn and the lights glaring at me of the 18 wheeler, nearly blinded me but somehow I managed to swerve off the road just in the nick of time before being flattened like a pancake. After that near death experience, I did not drive at night for a long time! I still did not know for sure that my visual problems were related to my Parkinson symptoms. Nevertheless, I had a high degree of suspicion. My visual perception failed me at the most inopportune times but particularly troublesome were the times I had to park the car in the garage. I always felt a sense of accomplishment getting my car into the confines of the garage. Only to discover that what appeared to be a perfect alignment from inside the vehicle was a mere façade as I performed yet another futile attempt to climb out of my car. For you see, I had once again wedged myself up against the wall without even realizing it. So, I try to back out without hitting the garage door which was not always successful. Sometimes, I would get stuck trying to climb out of the passenger side due to the stiffness and would be stuck there for a while! Other times, don’t even know how I would park my car nearly horizontally in my garage! I would depend on my husband to realign the car so I could exit successfully from the garage once again when I need to use the car the next time. Fortunately, I never knocked down a wall. Although, I came close several times leaving several dents in my car and the garage for posterity. Since I was on L-dopa, this did not happen daily but often enough that I had to paint the far left side wall of the garage neon orange to keep me from parking so close to it. The color would serve as visual contrast reinforcement and thus help me avoid hitting the door knob in the closet in the garage which is now all bent out of shape from parking car to close to the wall. During this time of visual fluctuations, parking close to two cars in close proximity was an impossibility never not without denting one on the way in or out!
For this reason, I had my ophthalmologist make me prisms to help with the depth perception which has improved my ability to judge distances dramatically!! This is what I would typically recommend for my PSP patients so I thought I would try… I did not want to have to give up my drivers license.
My husbands solution of course is even more practical. Trade in my Lexus for a “Smart Car.” This way I would be able to fit ANYWHERE!! If I could only get in and out of one without difficulty, I would drive the “Hello Kitty” model for a while just to make a statement and lead the world in ONE BIG PARKIE parade!.
Although, the idea of riding a HELLO KITTY “Smart Car” sounded good & funny in theory, in principal not so much. Therefore, I knew something had to be done before I lost my independence completely and had to be chauffeured around. Even though my friends were terrific, I did not want to be driven around if there was a solution for my problem. So, I began researching the matter. Initially, I did not find a lot of information until the last few years when the concept of non motor symptoms and premotor symptoms have finally taken root. This is the acceptance that these symptoms which are non dopamine derived can at times precede the motor symptoms, can be the MOST troubling and disrubtive to a persons quality of life yet are the most treatable as in the case of Visual disturbances. Even tough, vision problems is a dopamine problem it is classified in the non-motor symptomatology because it is a sensory issue- how we perceive and process the world!
We have missed visual problems in Parkinson’s because traditional tests do not tell the whole story in a persons ability to see. Acuity does not tell us how some one sees in regards to contrast in background ( i.e. shades of grey). It turns out that Parkinson’s causes a decrease in contrast perception and color discrimination because the retinas uses dopamine as a transmitter!- something which I had forgotten from my neurobiology. There is also decrease in actual acuity and voluntary eye movements with poor convergence which leads to blurred vision and at times double vision ( diplopia). There is also irritation of the surface of the eye causing a decrease blinking. Compromised vision can then lead to increase occurrence of hallucinations especially in elderly, with certain medications, or if a person has other eye problems or dementia.
The best treatment and gold standard for visual problems in PD is Levodopa. This can improve volitional eye movements and rate of blinking, Also any of the dopa- agonists. Ever since I started Neupro Patch all my visual field defects and vision problems including depth perception and trouble driving at night have dissipated. However, of note as of my last eye exam my acuity had changed significantly with advance of my illness! I assumed that the reason my symptoms were fluctuating despite being on L-dopa was the off states now that I have steady states of dopamine with agonist I don’t have fluctuations in vision….my hypothesis!
I recommend to everyone that you discuss with your physician any vision problems,
maintain good visual hygiene
yearly ophthalmologic exams,
corrective refraction and/or prisms
artificial tears if needed
rest your eyes!
if you do this you too will have no need for a “Smart Car!”
suggested reading for further information on the subject:
Visual Symptoms in Parkinson’s Disease by RA Armstrong-2011
http://www.ncbi.nlm.nih.gov>journal List> Parkinsons Dis> v.2011;2011
Dr. M. De Leon is a retired movement disorder specialist,
PPAC member and research advocate for PDF; Texas state assistant director for PAN (Parkinson’s Action Network).
You can learn more about her work at http://www.facebook.com/defeatparkinsons101
you can also learn more about Parkinson’s disease at http://www.pdf.org or at http://www.wemove.org