Rice-sized shunt helps glaucoma patients

12/07/2003

By RENEE C. LEE  / Associated Press

When Zain Ali was diagnosed with glaucoma eight years ago, he already
had firsthand knowledge of the eye-damaging disease.

Glaucoma gradually diminished his father's eyesight — first in one
eye, then the other — and eventually left him blind.

So earlier this year when Ali's ophthalmologist told him about a new
device that could stop further advancement of the disease and possibly
free him of medications, the 38-year-old Coppell resident welcomed it.

"It wasn't as much the medication," Ali said. " ... It was more a
relief that I could get rid of the problem."

Ali had an Ex-PRESS mini glaucoma shunt implanted in each eye in
surgeries about three months apart. The metal cylinders provide a
channel to release the build up of pressure inside the eye that can
damage the optical nerve and retina.

Shunts are not new in treating glaucoma, but what's different about
the mini shunt is its size — it's smaller than a grain of rice — and
its ability to greatly reduce intraocular pressure and reduce the need
for medication.

Doctors have seen about a 40 percent reduction in pressure in patients
with mini shunts, compared to conventional shunts, which have variable
reduction and are about 10 times larger than the new shunt, said Dr.
Karanjit Kooner, an ophthalmologist at the University of Texas
Southwestern Medical Center at Dallas.

"The reason we're impressed is that there's more pressure reduction in
more people and because there's less inflammation" after the surgery,
said Kooner, who operated on Ali.

Although the procedure is widely used in other countries, the mini
shunt is slowly gaining ground in the United States, said Andrea
Argenbright, spokeswoman for CIBA Vision, the Duluth, Ga.-based
manufacturer of the mini shunt.

About 700 ophthalmologists nationwide, including 50 in Texas, have
been trained do the procedure, which was approved by the Federal Drug
Administration in March 2002. About 300 actively use it, Argenbright
said.

"It's a difference in philosophy between U.S. and European doctors in
how they look at surgery," she said. European doctors are more likely
to start with surgery, while American doctors rely on medicine first,
surgery second, she said.

Kooner began using the procedure in November 2002 and has implanted
the mini shunt in 60 patients so far.

The procedure takes about 30 minutes and is less invasive than
conventional shunt surgery because a smaller incision is made on the
eye, resulting in less scar tissue and shorter healing time.

With conventional shunts, large amounts of scar tissues can sometimes
form and block the flow of pressure, making the shunt less effective.

More than 3 million people in the United States have glaucoma and more
than 5 million people are at risk of developing the disease — the
second leading cause of the blindness, according to the Glaucoma
Research Foundation.

Blacks, people over 45, people who have a family history of the
disease, and people with diabetes or systemic hypertension are more
prone to the disease. However, glaucoma can strike anyone, from
newborns to elderly people, Kooner said.

Symptoms usually include blind spots and difficulty reading and
driving at night. Most people, though, initially may not have any
symptoms.

"That's why it's important to have your eyes checked regularly,"
Kooner said.

Although glaucoma is incurable, it can be controlled with topical
medications, usually a variety of eye drops. Laser treatment also can
be used to clean out blocked passages in the eye. Shunts are used as a
last defense against blindness.

Kooner said the mini shunt is ideal for newly diagnosed patients who
have tried medicines and laser procedures, but not surgery.

The shunt was a good choice for Ali, who had been on numerous
medications, sometimes as many as a three at a time.

"You name it, I've been on it," he said. "I've tried all latest
medicines that came out. The doctor would be able to control the
pressure in my eyes and over time my eyes would get used to it and the
pressure would build up again."

With the shunts, Ali no longer needs medication and no longer worries
about going blind.

His only concern now is for his 9-year-old daughter and his 7-year-old
son, who are at risk of developing glaucoma because of their family
history.

"But I've noticed that now (doctors) do much more testing than they
used to," he said. "If people regularly go to the doctor for eye
exams, they'll catch it."

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On the Web:

Glaucoma Research Foundation, www.glaucoma.org 

CIBA Vision, www.cibavision.com