Approximately 75% of people with Parkinson’s disease (PD) experience oculomotor symptoms (pertaining to the movement of the eyes), along with changes in vision and eyelid function. Changes in vision can have a detrimental impact on quality of life and can increase the risk of falls.

Discuss all eye-related problems with your neurologist, because, like other symptoms of PD, vision problems can relate to inadequate medication management. A medication review and adjustment may be necessary. It is also important to be examined regularly by an ophthalmologist, preferably one specializing in neurological disorders. Do not make any changes to your medications without talking to your doctor. Remember, PD does not cause blindness or loss of vision.

 

Age-related Changes

Changes in vision due to aging are extremely common. As people age, many require stronger glasses, and some notice discomfort in their eyes. Age-related vision problems include:

  • dry eyes
  • changes in visual acuity (clearness or sharpness of vision), especially for smaller items, such as printed text
  • cataracts
  • macular degeneration
  • glaucoma

 

Eye Problems in Parkinson’s

Dry eyes and changes in visual acuity can be more common in people with PD, and treatment of these symptoms usually becomes a part of overall disease management. Blurred vision is often a side effect of medication. Drugs most commonly associated with blurred vision are anti-cholinergics, such as Artane and Cogentin. People with advanced Parkinson’s, who are on higher doses of medication, may also occasionally experience double vision (diplopia). Dopamine agonists, such as ReQuip, Mirapex, or Parlodel, are more likely to be the cause. Some ophthalmologists will recommend special glasses containing a prism to address the problem of double vision.

Macular degeneration and glaucoma are no more common in people with PD than in the general population. However, there is research that shows people with Parkinson’s may have a higher prevalence of cataracts than the general population. One study found that the incidence of cataract surgeries was slightly higher in individuals with PD both before and after their diagnosis, compared to those without Parkinson’s (Lampela et al., 2022). Additionally, Parkinson’s can cause a loss or reduction of colour vision because the disease causes a loss of retinal cells in the eye that depend on dopamine for processing and perceiving colour (Michael J. Fox Foundation, 2015).

Many people with PD are understandably concerned about eye surgery, particularly if they experience dyskinesia. People with PD can be candidates for cataract surgery and their dyskinesia can be effectively managed. Any concerns or fears about surgery should be discussed with your neurologist and ophthalmologist. Similar to movements such as walking or writing, movement of the eyes can be affected by a lack of dopamine in the brain. Rather than being smooth and effortless, eye movement can become jerky and require extra effort. Some of the important eye movements that can be affected by PD are:

Saccadic Eye Movement

This is defined as the rapid, involuntary eye movements that direct our gaze to an object of interest. Saccadic eye movement is required for activities such as driving, reading, and walking. The neural basis of saccadic eye movements involves a complex network of brain structures, including the basal ganglia, superior colliculus, thalamus, brainstem, and cerebellum (Srivastava et al., 2014).

Smooth Pursuit Eye Movement

This type of eye movement allows us to stabilize (or fix) our gaze on an object and follow it as it moves. A part of the brain affected by Parkinson’s called the basal ganglia is important for smooth eye movements. Studies indicate that specific areas within the basal ganglia, such as the caudate, globus pallidus, and thalamus, are active when these eye movements occur. A part of the basal ganglia called the Substantia Nigra pars reticulata (SNr) is believed to control both quick and smooth eye movements. In Parkinson’s disease, damage to the SNr likely affects its normal activity, leading to problems in these types of eye movements (Frei, 2021).

Vergence Eye Movement

This coordinated movement of both eyes in opposite directions t ensures the eyes remain focused together to avoid double vision. Brain areas damaged by Parkinson’s may result in difficulty with vergence eye movements (Gupta et al., 2021).

 

Parkinson’s can also affect the function of eyelids, including the following:

Blink Reflexes and Dry Eyes

Normally, we blink 15 to 20 times per minute, but Parkinson’s–and bradykinesia in particular–can reduce this motor function to as low as five to 10 times per minute (Kimura et al., 2017). This can cause the eyes to become very dry. Ask your doctor about eye drops and artificial tears.

Oculomotor Apraxia

Apraxia is the inability to perform voluntary functions. For some people with Parkinson’s, this includes the inability to open the eyes voluntarily, which is called apraxia of eyelid opening.

Blepharospasm

This is a form of dystonia that causes involuntary closure of the eyes. It is often associated with levodopa “off” periods. Improved medication management can alleviate this symptom, and in some cases, Botox injections can be helpful.

 

Sources

Ahlskog, J. (2005). The Parkinson’s Disease Treatment Book. New York. American Parkinson Disease Association (2007). Neuro-ophthalmology and Parkinson’s Disease. New York.

Frei, K. (2021). Abnormalities of smooth pursuit in Parkinson’s disease: A systematic review. Clinical Parkinsonism & Related Disorders, 4, 100085. https://doi.org/10.1016/j.prdoa.2020.100085

Gupta, P., Beylergil, S., Murray, J., Jacobs, J., Kilbane, C., Shaikh, A. G., & Ghasia, F. F. (2021, December 1). Effects of Parkinson disease on blur-driven and disparity-driven vergence eye movements. Journal of Neuro-Ophthalmology, 41(4), 442-451. https://doi.org/10.1097/WNO.0000000000001422

Kimura, N., Watanabe, A., Suzuki, K., Toyoda, H., Hakamata, N., Fukuoka, H., Washimi, Y., Arahata, Y., Takeda, A., Kondo, M., Mizuno, T., & Kinoshita, S. (2017). Measurement of spontaneous blinks in patients with Parkinson’s disease using a new high-speed blink analysis system. Journal of the Neurological Sciences, 380, 200-204. https://doi.org/10.1016/j.jns.2017.07.035

Lampela, P., Tolppanen, A. M., Kaarniranta, K., Hokkinen, K., & Hartikainen, S. (2022). Incidence of cataract surgeries in relation to diagnosis of Parkinson’s disease. Archives of Gerontology and Geriatrics, 104, 104842. https://doi.org/10.1016/j.archger.2022.104842

Michael J Fox Foundation (2015). Ask the MD: Vision and Parkinson’s Disease. https://www.michaeljfox.org/news/ask-md-vision-and-parkinsons-disease

Srivastava, A., Sharma, R., Sood, S. K., Shukla, G., Goyal, V., & Behari, M. (2014). Saccadic eye movements in Parkinson’s disease. Indian Journal of Ophthalmology, 62(5), 538-544. https://doi.org/10.4103/0301-4738.133482


Last updated: December 11, 2023