Eye cancer unable to ground commercial pilot


Methodist University Hospital 
returns Powell to cockpit


Special to the Advocate


MEMPHIS — Billy Powell flies for a living, so reading maps is vital to his work.


Powell said he knew something was wrong when he started having trouble reading flight maps. “When I was trying to read one of our approach plates one night in the airplane, I could see the first letters and the last letters, but I couldn’t see the letters in between.”


The resident of Maryville, Tenn., a town just south of Knoxville, was diagnosed with malignant melanoma of the choroid, the middle, vascular coat of the eye, between the sclera, the white outer coat of the eye, and the retina. He was referred to Matthew Wilson, MD, an ocular surgeon at Methodist University Hospital and associate professor of ophthalmology at the Hamilton Eye Institute at the University of Tennessee Health Science Center.


Melanoma is a condition that occurs when cells called melanocytes get too much sun, begin to grow abnormally and turn cancerous. Most people are familiar with this condition of the skin which results in skin cancer, but most people are unaware these same type of cells live inside the eye which can turn into melanoma causing eye cancer. While skin melanoma is linked to sun exposure, the cause of choroidal melanoma in not known.


“In the back of the eye, behind the seeing part of the eye which is the retina, there is a pigment layer called the choroid. The choroid supplies blood and nutrients to the eye, but it also absorbs some of the extra light that enters the eye,” explained Wilson. “Just as pigmented cells on the skin can turn into moles and melanoma, these same types of cells inside the eye can turn into a cancerous tumor.”


Symptoms vary depending on where the melanoma is located. For example, if the melanoma is positioned in the periphery of the eye, the patient may not exhibit any symptoms because the patient does not notice minor visual disturbances, such as flashing lights. A patient may notice a problem if the affected area grows large enough to detach the retina or to displace the lens in the eye distorting vision. Tumors can also occur in the area of central vision. Patients often seek treatment sooner for these tumors because they interfere with vision much sooner.


“Melanoma, that’s a scary word,” said Powell. His initial prognosis was that he wouldn’t be able to fly again. “I am very fortunate that I can continue my flying career.”


What saved his life and his eyesight is a procedure called episcelral radiation plaque therapy. Powell had the procedure performed in August 2006 at Methodist University Hospital.


“Teamwork is essential in the treatment of ocular cancer,” said Wilson. “By treating a very rare disease, it allows my team to provide the highest level of service to the patient because we are familiar with all aspects of the disease. My team works very closely with the radiation oncologists and physicists at Methodist University Hospital to create a custom plaque with the precise dose of radiation the patient needs.”


The plaque is actually a disc-shaped gold applicator about the size of a dime that holds radiation seeds the size of a grain of rice. The plaque is surgically placed and sewn over the area of the eye that needs to be treated and left in place for several days to deliver the appropriate dose of radiation.  After the recommended dose of radiation, the plaque is removed.  


A year later, two sets of blood tests and CT scans, there is not any sign of Powell’s cancer.

“Mr. Powell has had a phenomenal response to this treatment,” said  Wilson. “The tumor has shrunk and he has maintained excellent visual acuity.”


Wilson focuses on three goals when treating his patients. The first goal is to make sure the patient lives, the second is to keep the eye if at all possible and the third is to retain as much vision as possible.


Powell’s advice: If you notice any problems with your vision, make an appointment with your optometrist or ophthalmologist and find out what is happening with your vision.