A new laser-activated drug won’t cure but will slow the loss of sight.
A promising new treatment for the most severe form of the leading cause of blindness in the U.S.–macular degeneration–is close to federal approval. The treatment, a drug called verteporfin that is activated by a laser, is no cure and will benefit only a small fraction of sufferers. But doctors say it can slow or even stop the loss of sight for those with a form of the disease that can blind patients within weeks or months and often causes the worst vision loss.
Until now, these patients had an agonizing choice. The only thing doctors could do was partially blind them with a laser to slow the course of the disease — a benefit they wouldn’t get for a couple of years.
“Most patients would say, `I don’t even know if I’m going to be alive in two years,’ ” said Dr. Philip Rosenfeld, an ophthalmologist at Bascom Palmer Eye Institute in Miami, where some of the research on the drug was done.
The treatment targets a form of the disease, called “wet” macular degeneration, that occurs when abnormal capillaries grow behind the macula, a small portion of the retina that is responsible for central vision. The vessels can bleed and scar, destroying light-sensing nerve cells and opening an ever-widening hole in a person’s sight.
The disease can take years to progress but often moves with lightning speed. Some patients notice a wavy line one day, a huge blur weeks later.
The “wet” disease, which gets its name from the bleeding capillaries, is less common than the “dry” form but more apt to cause blindness. The “dry” disease, which usually progresses over years or even decades, is caused by the deterioration of cells responsible for central vision. Only 10 percent of patients ever develop the wet form of the disease but they account for 90 percent of those with severe vision loss from macular degeneration.
There are an estimated 13 million to 15 million people suffering from macular degeneration in the U.S. and an estimated 250,000 in Miami-Dade, Broward and Palm Beach counties. The FDA has issued a letter stating it intends to approve the drug pending additional information.
The trial, directed by the Johns Hopkins Wilmer Eye Institute, found that the treatment helped the majority of wet macular degeneration patients who met a certain case definition — a predominance of fast-growing, leakier vessels rather than less aggressive blood vessels. When it worked, the treatment kept the condition from getting worse. Some patients’ vision improved.
Dr. Neil Bressler, an ophthalmologist who headed the study, said about 30 percent of the 200,000 Americans diagnosed each year with “wet” macular degeneration are candidates for the treatment. But patients must be treated early, while they have significant vision to save.
“The most difficult job we’re going to have is telling people that they’re not good candidates for this,” said Rosenfeld. “We don’t want to oversell this therapy. But there’s a population of patients out there for whom this treatment had a dramatic benefit.”
Still, far more patients will be eligible for the new treatment than could benefit from traditional laser therapy and they won’t lose any vision, said Dr. Robert Rosa, a Bascom Palmer professor who helped run the study.
One of them was Helen Bashover, 82, of Delray Beach, who first noticed a little blurriness about three years ago. Her doctors said the only thing they could do was give her traditional laser therapy but she stopped those after two treatments.
Because she already had lost the vision in one eye to a botched cataract operation, Bashover was desperate to save the sight she had left. She went to Bascom Palmer where doctors enrolled her in the clinical trial of verteporfin. Right away she saw such immediate improvement she was sure she was on the real drug and not the placebo. Three years later, her life has improved dramatically.
“I was blind and now I see,” she said. “I can do things by myself. I can read a book, I don’t burn myself on the stove, things you take for granted. Three years ago I couldn’t get on a bus, steps had to be counted for me and I used a blind cane. I no longer have to do any of that.”
In a simple office visit, patients receive an intravenous infusion of the drug, which collects in the abnormal blood vessels. About 15 minutes later, the doctor targets the vessels with a low-powered laser that “turns on” the drug, which causes tiny blood clots in the vessels that seal them off.
The procedure preserves the retinal cells needed for sight that were burned off by traditional laser treatments because they were in the way of the laser as it targeted the blood vessels underneath them.
