Cancer and Vision
Blurred vision, double vision, and other visual disturbances are sometimes early warning signs of cancer. Most people think of brain tumors as the most likely type of cancer to cause vision problems, but any kind of cancer can affect the eyes. How does that happen?
One cause is that cancer tumors produce hormones and proteins which enter the bloodstream and circulate throughout the body, affecting tissues and organs far away from the cancer itself.
Another cause can be the body’s immune response to a tumor. The result is a group of symptoms called Paraneoplastic Syndromes. They are degenerative conditions affecting the nervous system.
There are four categories of such syndromes, related to
- The skin
- The nervous system
- The blood
- The endocrine glands
Because they affect the nervous system, they cause symptoms related to loss of muscle control. An example is eye spasms and uncontrollable eye movements (nystagmus) caused in children by a tumor on the adrenal gland; and in adults by breast, lung, or ovarian cancer. Other examples are dizziness, slurred speech, difficulty with walking and balance, swallowing problems and seizures.
This is a paraneoplastic syndrome caused by tumors in the brain or spinal cord and by lung cancer, although most often it is caused by injuries to the head, neck, and spinal cord. Some nerves connecting the eye to the brain travel down the neck into the chest and back up into the brain. When cancer grows into these nerves it can cause Horner’s syndrome which includes a droopy eyelid, sunken eye, and small pupil on the affected side.
As unpleasant and unhealthy as it may sound, most traditional cancer treatments involve using toxic chemicals and/or radiation in an attempt to kill the cancer without killing the patient. It is a delicate balance which is difficult to endure, but can be successful. However, these treatments, and the medications used to help alleviate the damage and deterioration they cause, can be damaging to the eyes.
- Tear Duct Fibrosis
5-fluorouracil is a drug commonly used to treat cancer, which can cause the tear ducts to become blocked. Normally tears will drain into the nose. When this drainage is blocked tears leak out of the eyes excessively and eventually vision can be come blurred.
Radiation therapy and steroids are both used in cancer therapy and both can cause cataracts. Steroid use can also cause glaucoma.
All types of cancer can affect vision and eye health. You can help to protect your vision by working closely with your doctor on a comprehensive plan to minimize eye damage and vision loss. Part of that plan would be good nutrition.
If you have cancer or are experiencing vision problems that may be associated with cancer, contact an experienced ophthalmologist for answers to your vision questions. Berg Feinfield Vision Correction Center in Los Angeles, California includes many experienced ophthalmologists such as Dr. Alan M. Berg, M.D. who are eager to help you find the answers to your vision disorder and corrrection questions.