Vision and Parkinson Disease 

By Amanda Gomez COTA/L, OTS

Individuals diagnosed with Parkinson disease are more prone to specific vision loss, due to the loss of dopamine and muscle control. Below are listed a few of the most common eye symptoms and diseases individuals may experience. 

Dry Eye

Dry eyes occurs when you experience less blinking movement needed for your eyes to see clearly. Additionally, apraxia of the eyelid may occur which is characterized by the ability to close your eyes however the ability to open is difficult. 

Diplopia 

Diplopia is the cause of double vision. Diplopia can be caused from the weakness in the body’s voluntary muscles. Some individuals may experience specific binocular horizontal diplopia with nearsighted vision and may occur due to convergence insufficiency. Convergence is when your eyes move together.

Macular Degeneration

Macular degeneration can cause central vision loss. There are two different types of macular degeneration. Dry macular degeneration occurs when the retina (the retina is the layer in the back of the eye that converts the light received into a visual image) deteriorates. Wet macular degeneration is when blood vessels grow under the retina. Some research studies have shown patients with age related macular degeneration are at a higher risk to develop Parkinson disease.

There are leading factors between both age-related macular degeneration and Parkinson disease. A research study conducted with 20,848 enrolled participants throughout 1996 to 2013 has found how multiple comorbidities can increase the risk of developing Parkinson disease. Participants with hyperlipidemia was noted that it may reduce the risk of Parkinson disease. Although participants with diabetes, cerebrovascular disease, and hypertension can increase the risk of Parkinson disease (Chen., et al., 2021).  An additional research study consisting of 20,000 participants found participants diagnosed with age-related macular degeneration have a high risk to develop Parkinson disease, this research was followed through for five years. The increased risks established in this research article consisted of diabetes, high blood pressure, osteoporosis, calcium channel blockers, and statins (Kelley, 2021). Furthermore, Parkinson and age-related macular degeneration have similarities affecting dopamine, oxidative stress, and thinning of the retinal nerve (Kelley, 2021). For individuals with age-related macular degeneration, they rely on dopamine for the retina to transmit information provided to produce a visual image. Oxidative stress occurs from the large amount of oxygen consumed by the brain and retina cells, most can be seen through inflammation. Additional studies have found thinning of the retinal nerve affecting both Parkinson disease and age-related macular degeneration, leading to visual dysfunctions in both diseases (Kelley, 2021). Although research has found patients with macular degeneration developing Parkinson disease there is no scientific knowledge to identify the pathological cause between the two diseases.

For caregivers that would like to have an insight on what their loved one is currently seeing, (for example, dry eye, cataracts, glaucoma, diplopia, or macular degeneration), download on your phone Sim by Via Opta. This application provides information and different eyesight stages for each diagnosis.

Vision Quality

Vision loss can affect the individual’s visual acuity, color sensitivity, and contrast sensitivity. Visual acuity is the ability of the eye to distinguish shapes and the details of the objects presented in a distance. In other words, your eyes can help you distinguish the different types of flowers in a floral shop. Color sensitivity is the way your eyes respond to light in different wavelength. The most controversial example is the famous dress all around the internet many people saw the dress only in black and blue, while others say the dress in white and gold. The difference in image color resulted from the lighting in which the picture was seen. Contrast sensitivity is the ability to perceive and detect objects from their background. As an example, drinking coffee in a light-colored mug. 

Techniques to Improve Vision

1. Use adequate lighting with no glare.
2. Organize and declutter physical and visual environment.
3. Improve contrast between objects 
   (eliminate patterned background, incorporate white and black contrast, blue and yellow)
4. Use large font 14 to 16 or larger.
5. Attend driver evaluations.
6. Scan the environment for obstacles.
7. If central vision is loss learn to rotate the head or turn the trunk to view objects using the peripheral vision. 
8. Learn to use other senses to compensate for vision impairment.
9. Use tactile markers (dump dots) to mark the most frequent used settings for appliances.
10. Use auditory or talking items (examples: clocks, medication reminders, siri, alexa).
11. Use tactile paper for writing.
12. Refer to low vision specialists for optical devices.

References

American Occupational Therapy Association. (2022). Low Vision and Older Adults. Low Vision and older adults. https://learning.aota.org/app/197103202#read/section/pdf-download 

Chen, PY.J., Wan, L., Lai, JN. et al. Increased risk of Parkinson’s disease among patients with age-related macular degeneration. BMC Ophthalmol 21, 426 (2021). https://doi.org/10.1186/s12886-021-02196-8

Etminan, M., Samii, A., & He, B. (2018). Risk of parkinson’s disease in patients with neovascular age-related macular degeneration. Journal of Current Ophthalmology, 30(4), 365–367. https://doi.org/10.1016/j.joco.2018.08.004 

Kelley, S., (2021). AMD and other eye conditions associated with Parkinson’s Disease. All about vision. https://www.allaboutvision.com/conditions/related/macular-degeneration-and-parkinsons-risk/

U.S. Department of Health and Human Services. (2020). Cataract tables. National Eye Institute. https://www.nei.nih.gov/learn-about-eye-health/eye-health-data-and-statistics/cataract-data-and-statistics/cataract-tables