New drugs restore vision in devastating form of elderly eye disease
Monday, July 1st 2002, 12:00 am
By: News On 6
BOSTON (AP) _ To doctors' amazement, experimental new medicines are rescuing people from the brink of blindness so they can read and drive and sometimes even regain perfect vision.
These lucky few are the first beneficiaries of a new category of drugs that many hope will revolutionize the care of common eye diseases.
Several competing medicines are in development, all based on similar principles. They are designed to stop the two top causes of adult blindness _ the ``wet'' form of macular degeneration, which affects the elderly, and diabetic retinopathy, the biggest source of blindness in working-age people.
Vision loss seems halted for most if they take the drugs soon after their symptoms begin. Some experience stunning reversals of what would have been inevitable blindness.
``I'm telling you, it's miraculous,'' says Eileen Russell.
Russell, 76, lost vision in her right eye four years ago. In May, her left eye also went bad, and she was declared legally blind.
But after four injections of one of the drugs her left eye is 20-25. She drives and reads and is thinking about returning to work as a nurse.
Around the country, about 70 patients with wet macular degeneration have been treated with the same drug as Russell, Genentech's rhuFab. About half were treated by Dr. Jeffrey Heier of Ophthalmic Consultants of Boston, who says, ``I can honestly say I have never seen anything as exciting as this.''
Experts caution that most of the results from the studies on this and similar drugs will not be known for at least a year or two. For now, the treatments are available only to study volunteers.
None of the drugs are intended for the more common but less aggressive ``dry'' kind of macular degeneration, nor will they work after eyesight has been gone for months.
Guessing the drugs' ultimate effectiveness based on early testing is risky. Still, doctors estimate that roughly one-quarter to one-third of people with newly diagnosed wet macular degeneration have had significant improvement in their eyesight. In most of the rest, loss of sight is stopped, at least temporarily.
An estimated 200,000 new cases of wet macular degeneration are diagnosed in the United States annually. About 4 million U.S. diabetics have some degree of retinopathy, and 24,000 go blind each year.
Both diseases result from misguided growth of blood vessels in the eyes. Since the new drugs attack this underlying problem, doctors hope they will work for both diseases.
The need for new treatments is expecially dire in wet macular degeneration, because nothing can be done for most victims. Blindness often follows within months or even weeks of the first symptoms.
It occurs when leaky blood vessels sprout behind the retina, probably in a mistaken attempt to fix the slow breakdown of light-sensitive cells that occurs with age. These vessels ooze fluid and damage fragile tissue that controls straight-ahead vision.
The new drugs vary, although most of them, like rhuFab, zero in on a growth-promoting protein called vascular epidermal growth factor, or VEGF. It appears to be an important trigger of damaging blood vessels in both forms of blindness.
Other drugs in testing include:
_Anecortave acetate from Alcon, a new steroid injected next to the eye once every six months for macular degeneration.
_Eyetech Pharmaceuticals' EYE001, which is injected into the eyeball like rhuFab for macular degeneration.
_Bausch & Lomb's Retisert implant, which exudes a steroid into the eye for up to three years and is being used for diabetic retinopathy and macular degeneration.
_Lilly's LY333531, the only pill among the new drugs; used to prevent worsening eye disease in diabetics.
Experts caution that until the big studies are finished, no one can be sure how well the drugs will work. No one knows how long patients will need to take them, how often disease will return or whether the repeated eye injections have any hazards.