Vision Problems and Parkinson’s

Approximately 75% of people with Parkinson’s disease (PD) experience vision challenges, including issues with the eyeball or eyelids, eye movements, wearing of the retina, facial recognition, and spatial navigation and/or hallucinations. When exploring treatment options, it is important to differentiate between symptoms that might be PD related and the standard effects of aging. Some symptoms, especially hallucinations, might be impacted by levodopa and dopamine agents.

The Eyeball and Eyelid

Parkinson’s can impact blinking as well as the development of mucus tears – both of which are required to keep the eyeball moisturized and comfortable. Because of this, people with Parkinson’s (PwP) might develop dry eyes. To treat dry eyes, consider the following:

• Use artificial tears as frequently as needed. Gel-like artificial tears are better than watery artificial tears, since they are more similar to mucus tears.
• Slow the drainage of tears from your eyes using either a silicon puntal plug or lacrimal gel inserts. These are small devices that can be inserted into the tear duct to prevent rapid drainage of tears and mucus from the eye.

PwP may also experience blepharitis, or inflamed eyelids. This is a side effect of decreased blinking that can be caused by an excess of sebum, which is an oil that the skin produces. Symptoms of blepharitis include red eyes, swollen lids, excessive, watery tearing and light sensitivity. To treat it, you can place a warm compress on the eyelids for 5–10 minutes a day, up to four times a day. Wiping the lids with baby shampoo and water can also help. For acute flare ups or bad cases, a doctor may be able to prescribe antibiotics or topical steroids.

Eye Movements

PD can also impact the parts of the brain that control eye movement. This can lead to:

• Convergence insufficiency: this is the scientific term used to describe what happens when people have trouble moving their eyes inwards. This is the most common cause of double vision. While someone’s distance vision won’t be affected, close views (like reading) can lead to double vision. Convergence insufficiency can also cause blurred vision and discomfort. To treat it, you can wear an eye patch while reading, or, in consultation with an ophthalmologist or neuro-ophthalmologist, use prisms in your eyeglasses. Children who experience convergence insufficiency can sometimes correct the issue through exercises, however this method of dealing with the problem is less effective in older adults.
• Square wave jerks: this is a term for small, rapid eye movements to the left or right, which then return to the object in view. These jerking movements can be barely noticeable, but the more frequently you experience them, the more difficult it becomes to read. Unfortunately, there isn’t a way to treat it. Deep Brain Stimulation (DBS) can help, but not everyone is eligible for the surgery. In the meantime, if reading is impacted, opting for larger text and visuals should help.
• Vertical gaze palsy: This is difficulty in looking up and down. It can impact reading, going down stairs and eating meals. These activities can be especially challenging if the PwP is also experiencing a stiff neck.
• Ocular dyskinesia: An estimated 10–15% of the PwP who experience dyskinesia, or uncontrolled muscular movements of the limbs, will experience dyskinesia of the eye. This might be managed through medication dosage adjustment in consultation with a physician.

The Mind-Gaze Connection

Some PwP report problems with identifying faces, facial expressions and spatial dimensions. If problems with the retina and eyeball are ruled out, it is possible that these challenges are due to PD related cognitive changes. It is also estimated that 25% of patients with PD experience complex visual hallucinations. This may be a side effect of levodopa, dopamine agonists, or due to Lewy body dementia. In all cases, it is important to discuss any changes in vision with a physician.

The Specialist’s Role

Any adjustments to medications, as well as concerns with hallucinations or cognition, should be discussed with your family doctor, neurologist or movement disorder specialist. If you are experiencing vision issues in PD, you may want to talk to your doctor about obtaining a referral to a neuro-ophthalmologist. Neuro-ophthalmologists come from either a neurological or ophthalmology background (specialty in the anatomy, physiology and diseases of the eyeball and orbit) and are experts in the connection between the brain and the eye. They often have experience dealing with Parkinson’s patients and can accurately identify issues related to vision, eye movements and the eyeball.

This content was published in the Summer 2018 edition of our quarterly magazine, Viewpoints. The content was accurate as of this publication date.