STORY BY

Camille Webb

 

Vision Quest

An experimental treatment for blindness in premature babies
takes one medical pioneer on a journey from ‘Grace’ to gratitude

Part III of a III-part series on
Healthy Futures for our Tiny Treasures

Editor’s Note:  The US Food and Drug Administration (FDA) has recently rescinded approval of Avastin as a treatment for breast cancer. Avastin is still in use successfully for other types of malignancies and for neovascular ocular conditions. Its successful use in treating retinopathy of prematurity is featured in this story. 

 

Kelly and Brad Henry have two daughters. Both were born prematurely and like many babies born very early, both needed treatment for the same serious eye condition. But, there the parallels end.

Grace Henry had the best treatment available for her in 2004, but still lost her left eye. She has enough vision in her right eye to attend school, but is legally blind. Her little sister Evelyn, who arrived six years later, has normal vision.

Although they are only a few years apart in age, the Henry girls were born in different eras from the standpoint of a condition called retinopathy of prematurity (ROP), one of the leading causes of blindness in infants born prematurely.

On one side of the divide was laser therapy, a procedure involving general anesthesia with intubation of a fragile infant. It may cause lasting side effects such as loss of peripheral vision and nearsightedness. On the other is a simple, inexpensive two-minute injection of a drug.

The treatment that saved Evelyn Henry’s sight was pioneered in the US by the girls’ ophthalmologist, Helen Mintz-Hittner, MD, in the Richard S. Ruiz, MD, Department of Ophthalmology and Visual Science at The University of Texas Health Science Center at Houston (UTHealth) Medical School.

Mintz-Hittner was all too familiar with ROP, a condition which affects the eyes of infants born before 30 weeks of gestation. ROP is seen more and more frequently as smaller and smaller premature babies survive. It has reached epidemic levels in developing nations.

“When babies are born early, the blood vessels in the retina – that ordinarily grow from the back of the eye toward the front of the eye – from the optic nerve toward the cornea – stop growing forward. The front of the retina has no vessels,” explains Mintz-Hittner. In the pre-term infant, those vessels must continue to develop in the higher levels of oxygen found outside of the uterus.

The front of the retina without vessels gives out a growth factor encouraging more vessels to grow. It’s called vascular endothelial growth factor (VEGF). “When you have severe retinopathy of prematurity occurring, the VEGF levels become very high,” she continues.

“If the baby is very small and very sick, the blood vessels can become abnormally tortuous and grow like diabetic vessels, which bleed and form membranes instead of growing out like they’re supposed to. When that happens, those membranes can cause the retina to detach, and that’s what winds up causing the blindness.”

Although laser stops the blood vessels from growing abnormally and halts the disease, it is far from an ideal solution. “What you do with laser is kill the peripheral retina, the front part of the retina. It’s a very destructive process. You destroy the source of the endothelial growth factor, so the disease does goes away.  [But] You stop the vessels from growing forward permanently.”

The quest begins

Because of the complications from laser therapy, Mintz-Hittner was looking for a better way to treat ROP. She found it in Avastin, an anti-vascular endothelial growth factor normally used to treat, among other things, colorectal cancer, age-related macular degeneration and diabetic retinopathy.

Use of the drug Avastin was proving successful in other parts of the world, and Mintz-Hittner decided it was time to move ahead in the US. In clinical trials, she and her colleagues compared Avastin’s use to conventional laser therapy in treating severe cases of ROP in the smallest and sickest of babies. The average baby in her study weighed about 1.5 pounds.

A routine screening allows the doctor to pick up these cases at a stage where the retinas are not detached and the vessels are not bleeding too much, so they can be treated. The procedure itself is simple. “We inject the drug behind the lens into the center of the eye, into the jelly part of the eye, with a very, very tiny needle that’s self sealing,” she explains. “It’s done very quickly and a very small amount is injected. The drug goes in, inactivates this growth factor and makes the disease stop without having to destroy the peripheral retina.”
This simple injection saves the infant’s vision, including the peripheral vision, and lessens nearsightedness.

‘I want the drug’

Even before the results were published in the New England Journal of Medicine, the news coming out of the clinical trial was so spectacular that 15 hospitals participating in the research, , including Children’s Memorial Hermann Hospital, stopped using lasers and began to use Avastin.

Avastin was still in clinical trials when Evelyn was treated with it, but the Henrys didn’t have to think twice about trying the new approach. “Brad and I didn’t even have to discuss it,” she says. “I was rocking Evelyn, and I said, ‘There’s no question. I want the drug. There has to be a better standard of treatment.’”

Evelyn received drug therapy to treat ROP in 2010. “She has normal developing vision,” Henry says of the outcome. “The ROP stopped growing. They didn’t have to dig a trench in her eye like they did Grace with the lasers. As of today, Evelyn has had no side effects.”

Henry says Evelyn notices things and people across the room much faster than Grace. “Just in general – sight-wise – you can see the huge difference between the two,” she says. “It’s hard with Grace because it’s right there in front of her, but she just doesn’t see it.  Grace has no depth perception. She runs into everything.”

But Henry says they feel lucky that Grace does see well enough to function. And, she adds, “Grace’s experience in a way helped fuel everybody to find something different.”

Although she is eager to know the 10 to 15 year outcomes, Mintz-Hittner says the results so far are unbelievable. The children have “virtually perfect eyes without any reported side effects systemically.”

“I don’t think we can withhold this treatment from babies for that many years. If it were my baby, I’d want it to have Avastin. That was the situation with Mrs. Henry. She wanted her baby to have Avastin, and I think rightly so.”

Edited by Cynthia J. Johnson, PhD

 

 

Last Updated: 11-23-2011

 

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