Friday, August 27, 2010
Rare but devastating, eye cancer can strike anyone at any time and
treating it often requires radiation that leaves half of all
patients partially blind.
But a new technique developed by Scott Oliver, MD, assistant
professor at the University of Colorado School of Medicine, may
change all that.
Oliver has discovered that silicone oil applied inside the eye can
block up to 55 percent of harmful radiation, enough to prevent
blindness in most patients.
His findings, published in the July issue of the Archives
of Ophthalmology, may revolutionize the way eye cancer is
treated.
"If you get diagnosed with eye cancer you want to know, `Is this
going to kill me? Is this going to make me go blind?''' said
Oliver, director of the Ophthalmic Oncology Center at the Rocky
Mountain Lions Eye Institute on the University of Colorado's
Anschutz Medical Campus. "I believe this treatment will allow you
to keep your eye and keep your vision."
Oliver focused on choroidal melanoma of the eye or uveal cancer,
the most common and dangerous form of a disease that strikes over
2,000 people each year. It can spread quickly to the liver and
lungs which is often fatal. The cancer can occur in people of any
age - fair skin and sun exposure are thought to be a leading
cause.
Physicians often treat it with a technique called plaque
brachytherapy. Surgeons attach a gold cap containing radioactive
seeds to the white part of the eye. For one week the radiation
slowly incinerates the tumor but it also causes long-term
damage.
"Radiation injures blood vessels and nerves in the back of the
eye," Oliver said. "Half of all patients are legally blind in three
years in the treated eye."
In his quest to save their eyesight, Oliver experimented with a
series of substances that would block radiation from striking
critical structures while allowing it to hit the tumor. He
discovered that silicone oil, already used to treat retinal
detachment, could screen out a majority of harmful radiation.
"You don't have to block out all the radiation to protect the eye
because the vital structures in the eye can tolerate low doses of
radiation," he said.
Oliver experimented on cadaver eyes and tested the oil on animals
in the laboratory and found no harmful side-effects.
"We are now at the point where we can embark on a clinical trial,"
he said. "This is a significant development in the way we treat
this disease. In the past, we could save the eye with radiation but
we saved vision only half the time. With this treatment, I believe
we will do much better in the future."
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Thanks to University of Colorado Denver for this
article.