Blepharospasm occurs when the muscle that closes the eyelid contracts or goes into spasm. The result may be repeated twitching of the eyelid, difficulty in keeping the eyelid open and sometimes the eyelid may close completely, thus interfering with vision.

The cause and treatment of blepharospasm are confusing because the levadopa drugs that are used to treat Parkinson’s sometimes cause it, but on other occasions these drugs can help to improve it. In mild cases, simply rubbing the eyelids may help. Occasionally, injections of a drug called botulinum toxin (Botox) are used to treat blepharospasm.

Hallucinations and Illusions

Illusions and visual hallucinations can be associated with Parkinson’s. They are more common in those who have had Parkinson’s for a long time. They can be related partly to the Parkinson’s itself and partly to the medication that is used to treat it. Older people and those with cognitive (memory) problems are more susceptible to this adverse effect of drugs. A reduction of the Parkinson’s medication is usually the first line of treatment. If the hallucinations persist, neuroleptic drugs may be tried. It is also important to remember that visual misinterpretations (illusions) may not be linked to Parkinson’s and may have some other cause, such as poor eyesight. The sudden onset of hallucinations or illusions may also be due to the effects of infection or other illness (this is often referred to as delirium). Do seek advice from your doctor if you are experiencing illusions or hallucinations.

Sensitivity to Contrast

Some people with Parkinson’s find they have difficulty seeing in low light levels. They may also be unable to clearly make out the shape of images, such as a light colored object on a light background. This may also affect the ease with which fine print can be read. The problem may improve with the treatment of the Parkinson’s with levodopa.

Visio-spatial Orientation

Some people with Parkinson’s seem to have difficulty in judging the space around them. They may not be able to accurately assess the distance between objects and might experience problems in negotiating their own route when walking past objects or through a narrow space. Problems of this type seem to be worse in people whose Parkinson’s affects the left side of their body. Some people are helped by reaching out to touch the sides of doorways or other objects. It is possible that an occupational therapist could help with advice about organizing space and carrying out everyday activities. It should be remembered that problems with visio-spacial orientation can affect driving as well as walking.

Glaucoma and Parkinson’s Medication

People with glaucoma may experience problems with some anti-Parkinson’s medications, namely the anticholinergic drugs and levodopa.

The use of anticholinergic drugs requires caution in people who have open angle glaucoma. Where no alternative is available the risk/benefit of using them should be assessed by the ophthalmologist and the Parkinson’s specialist, and explained to the person with Parkinson’s. An informed decision can then be made. However, anticholinergic drugs are not recommended for people who have the less-common closed angle glaucoma.

Likewise, levodopa is not recommended for people who have closed angle glaucoma. For people who have open angle glaucoma and who are receiving treatment for it, levodopa may be used with care, provided that the situation is monitored. It is helpful if the Parkinson’s specialist and the ophthalmologist work together when prescribing medication for people who have Parkinson’s and glaucoma. If you have glaucoma, always bring this fact to the attention of any doctor you see.

Summary

People with Parkinson’s can experience a range of problems with their eyes and eyesight. While these problems are sometimes related to the Parkinson’s or the drugs used to treat it, it is important to remember that many difficulties with eyesight will be due to other factors. Whatever the cause of the problem, it is important to seek professional advice. Your doctor is the best person to help you in the first instance. It is also important to consider that problems with the eyes and vision may interfere with the ability to perform activities such as driving. Once again, professional advice should be sought about this.

Adapted from an information sheet published by the Parkinson’s Disease Society of the United Kingdom.

Source: “The PFHC Bulletin”, Houston, TX

5