This week I am test driving a prismatic lens that is stuck to my left eye-glass lens. The thin plastic sheet covered with micro sized prisms is truly an amazing product of medical engineering. Affixed to my glasses, I think I perceive a single image.
I say I “think” partly because I am not sure what aligned stereoscopic vision looks like after struggling with weird vision for long. Stuff looks clearer, but only momentarily. I then need to blink and look about and refocus and it becomes clear again.
Maybe you perceive these next phenomena.
When I walk or ride in a vehicle, the world just seems to shake. Sometime when I am just sitting it feels like my eyes are jumping about having a little disco dance of their own. Now, with this prismatic lens, these sensations are feeling even more pronounced. Maybe because my vision seemed blurred that I didn’t notice these other things as much before. Maybe I was to nauseous to care.
I’m seeing my ophthalmologist for a follow-up next week, so being the investigator that I am, I decided to delve more deeply into the visual issues related to MSA so that I could improve my conversation with her. Dr. Viv is awesome and will happily engage in the conversation partly because she knows I get to the point and we keep it pretty much on target, unlike my eyes seem to do.
Possibly you have already had this conversation with your ophthalmologist, so feel free to add anything else using the comments section below. I thought I would develop a primer for myself and any others who are feeling visually afflicted. My research questions was simple: How does MSA impact vision?
First, oculomotor dysfunction is recognized by the Movement Disorder Society’s criteria for MSA diagnosis (2022) as means of establishing a clinically and clinically probable diagnosis of MSA within the core cerebellar features. Oculomotor dysfunction is an umbrella phrase for a number of phenomena that might be observed. In and of themselves, they would not suggest MSA, but seen within an array of other symptoms, they offer a suggestion for neurological investigation.
Diplopia - double vision - is our perceiving of two images of one thing. Lots of people have double vision for all sorts of reasons. While many research articles indicate diplopia as a symptom, this may be likely because as a patient we can perceive this more readily than other indicators. If you sense you are experiencing this, consider it as a conversation starter with your medical team.
Nystagmus - is the repetitive, uncontrolled eye movements from side to side, up and down, or in circular pattern that impacts perceptions of visual accuracy and depth. This phenomenon may be very difficult for you and I to perceive so having your ophthalmologist or neuro-ophthalmologist examine you for this is part of the screening for clinical diagnosis.
Saccadic Hypermetria - is the eye movement that overshoots the visually intended target. Saccadic refers to eye movement that shifts the centre of our gaze from one part of the visual field to another. Saccades are mainly used for orienting gaze towards an object of interest. Saccades may be horizontal, vertical, or oblique. With saccadic hypermetria, our eye doesn’t seem to get the message that it should stop on the target. I recall being asked to follow targets and stop both visually and using my fingers. I found myself failing to stop when the image stopped. Like nystagmus, saccadic hypermetria is recognized as an MSA symptom feature and needs to be investigated and established.
Vestibular Ocular Reflex dysfunction - refers to eye movements that are not sufficient enough to compensate your head motion. I can relate to this one. When my head moves while walking, my brain feels like it can’t keep up with the visual input because it seems like there is a micron delay with registering what I have seen. Add strobing light, such as flashing shadows or a flickering florescent light, and it seems even more pronounced and very disconcerting.
Blepharospasm (also called benign essential blepharospasm) is the occurrence of your eyelids blinking or twitching but you can’t seem to control. While this phenomenon may be evident, it is not considered within the diagnostic criteria but has been evidenced in patient studies. One study suggests that this symptom is more likely related to parkinsonianism (Armstrong, 2014)
Aside from the fact that all these have to do with our eyes and vision and our ability to perceive, I think you can see how they relate to create a rather revealing portrait of cerebellum function. The good news here is that with your medical team, these symptoms can be investigated easily and monitored overtime. There may not be much that can be done to treat any of these. However, I believe that in knowing that I have saccadic hypermedia is a contributing cause to my clumsiness in the kitchen or my poor texting abilities on my phone helps to reduce my anxiety. I know why it’s happening. And that allows me to be more conscious and calmly adapt in to it.
Journal Reflection
If you were to describe to a loved one, a care giver, or your doctor, how you see what you see, what would it sound like? Try using descriptive words and phrases. Finish the statement, “When I look at a page of writing it is like looking at….” Or, “When I drive in a car, the image is see looks ….”
Armstrong, R.A. (2014), Visual signs and symptoms of multiple system atrophy. Clin Exp Optom, 97: 483-491. https://doi.org/10.1111/cxo.12206
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