Doctors told Christine Jablonski there was nothing they could do to save her vision, but her doctor daughter found an experimental treatment at Johns Hopkins’ Wilmer Eye Institute — central retinal artery occlusion — that returned her vision to normal.

The Baltimore Sun / GLENN FAWCETT

At first, Christine Jablonski didn’t worry about the blurry vision in her right eye. She dismissed it as a flake of morning mascara and went about her daily business in Ellicott City, Md. But within two hours, the eye went dark.

She rushed to Johns Hopkins Hospital, where doctors told her there was nothing they could do to restore her vision — she had suffered an “eye stroke” from a clot blocking a key blood vessel that supplies the retina.

But her daughter, a doctor, had heard about an experimental treatment pioneered by doctors at Hopkins’ Wilmer Eye Institute. The hospital’s Brain Attack Team, physicians who specialize in strokes of the brain, was called in. They ran a catheter from Jablonski’s groin to her eyeball and injected a clot-busting agent.

“I could see my vision coming back. It was like a curtain of color,” Jablonski said. Within two hours, her eyesight had returned to normal.

Her experience and reports of success with other volunteers in a seven-year Hopkins study raise hopes for as many as 50,000 people who suffer eye strokes each year and would otherwise face irreversible loss of sight in one eye.

But Hopkins doctors caution that the experimental procedure carries its own serious risks, and success seems to depend on treating the patient into as soon as possible. It didn’t work at all on almost 25 percent of patients in the study, and other authorities say more trials are necessary before they can recommend the procedure.

Still, the Hopkins team was heartened by the results: Their volunteers were 13 times more likely than those undergoing conventional therapies to show significant improvement with standard eye charts. They were almost five times as likely to have final visual acuity of 20/100 or better on a 20/20 scale.

“We have a disorder that was basically irreversible, but with our technique, we see that a majority of patients experienced some level of improvement in their vision,” said Dr. Eric Aldrich, a neurologist at the School of Medicine and lead author of a study published in the June issue of the journal Stroke. “No one has ever reported these types of results on such a large scale in North America.”

An eye stroke, technically known as a central retinal artery occlusion, occurs when a clot forms in a small blood vessel within the eye. The interruption of blood flow destroys the retina, the light-sensitive nerve layer that captures images. The attack is sudden and painless, but it causes partial or complete vision loss in one eye. The other eye is usually unaffected.

Eye stroke is more likely to occur in the elderly, Hopkins researchers said. The condition appears to have the same heightened risk factors as brain stroke and heart disease. Those include diabetes, high blood pressure, elevated cholesterol levels, smoking and a family history of cardiovascular problems.

Under Aldrich’s direction, a team of ophthalmologists, radiologists and neurologists developed a scheme to insert tissue plasminogen activator (TPA), a clot-dissolving agent, into an artery near the eye. They start by inserting a catheter into the patient’s femoral artery in the thigh. Then, using an X-ray video display to show the way, they thread the tube up the bloodstream to the eye, where they administer TPA by drip until the blood clot dissolves.

From 1999 to 2006, 21 patients received TPA, while another 21 in their study received conventional therapies. Overall, 76 percent of the TPA group improved their vision by at least one line on the Snellen chart — the eye chart with the big “E” at the top. Only 33 percent in the standard therapies group showed as much improvement.

In addition, a third of volunteers in the TPA group experienced an improvement of three lines or better, compared with 5 percent of patients in the standard group.

“This was a condition that has never had any useful treatment. We have done things to help the eye reduce the pressure, but none really work to any degree,” said Dr. Neil Miller, the team’s lead ophthalmologist.

All of the team’s patients were treated within 15 hours of losing vision. The time element is critical, Aldrich says, because the eye tissue dies gradually over the next few hours.

“Time is retina. If you restore blood to the tissue sooner, then you have a greater chance of recovery,” Aldrich said.Don’t delay if you lose vision

For patients, doctors say, the most important message from the new report is recognizing the warning signs of an eye stroke.

“If you lose vision abruptly, you need to go to the ER right away,” Dr. Neil Miller said. “Do not wait until the next day to see an ophthalmologist, because then it may be too late.”