Prompt laser treatment of an eye disease commonly found in older Americans could prevent as many as 13,000 elderly people from going blind in the next year and spare an additional 60,000 serious visual impairment, government researchers said yesterday.
Officials of the National Eye Institute announced that a major federal study has produced the first scientific proof that a currently available laser technique can prevent serious visual loss in many victims of a previously untreatable condition known as senile macular degeneration (SMD).
This disorder, which strikes the center of vision in the retina, is considered the leading cause of new cases of blindness, particularly among the aged. Dr. Carl Kupfer, director of the federal eye research program, estimated that the new treatment could reduce the annual national incidence of blindness by nearly 14 percent.
The new director of the National Institutes of Health, Dr. James Wyngaarden, said the technique could "save as much as $2.5 billion in tax monies as well," because fewer programs would be needed for persons unable to take care of themselves due to blindness.
The study, which cost $1.5 million, involved over 200 patients at 12 centers around the country. It found that those who received the laser treatment were roughly twice as likely to maintain their vision or show improvement as those who did not.
But scientists involved in the study stressed that the laser technique would be helpful only to victims of a certain form of the degenerative eye disease who seek immediate treatment, and would be of no value to those who have already suffered permanent visual loss.
Dr. Stuart Fine, of the Johns Hopkins University Wilmer Ophthalmological Institute, said candidates for the laser therapy included individuals with a form of SMD characterized by the formation of abnormal new blood vessels in the eye. In most cases of SMD, vision slowly deteriorates, but in this form the deterioration can be rapid.
The study found that severe vision loss occurred in only 25 percent of the cases receiving laser treatment, as compared to 60 percent of those who did not receive treatment.
Patients were followed for up to two years, so it is not yet known whether the effects are temporary or permanent.
Fine said the findings were so "striking" that the federal sponsors took the rare step of stopping the study two years early so that patients could immediately benefit.
The therapy involves directing a beam of light into the affected eye to burn and seal off the damaged blood vessels and prevent further leakage and tissue destruction. It can be conducted in a single outpatient visit.
Fine estimated that most cities around the country already have laser facilities for treating other eye disorders. Among them are several major hospitals in the Washington metropolitan area.
Federal officials estimated that it would cost about $1,900 to treat both eyes.
Special tests must be conducted on each patient to see if the treatment would help, Fine said. A critical question is how close the blood vessel destruction is to the vital center, or macula, which is responsible for fine vision. Since the disease is progressive, time is of the essence.
Fine said that the laser is most effective within a "few days" or weeks after symptoms of blood vessel involvement appear, so patients must act quickly to receive the maximum benefit. Later treatment could be "counterproductive," causing additional visual damage, he said.
"Patients with senile macular degeneration must be made aware that blurred vision, distortion, and blank spots in the central vision are early warning symptoms of leakage," said Fine, who supervised the study.
The government advises that people over the age of 45 have regular eye examinations. Between examinations, doctors suggest a simple vision test: with one eye covered, look at something straight, like a telephone pole or a doorframe, to make sure it still looks straight. examinations.Between examinations, doctors suggest a simple vision test: with one eye covered, look at something straight, like a telephone pole or a doorframe, to make sure it still looks straight.