A controversial operation that offered hope to elderly patients robbed of sight by a "stroke" of the eye does not improve vision and may actually make it worse, an ophthalmologist with the University of Maryland is reporting today.
Until other treatments are found, he said, better to leave the eye alone.
Dr. Shalom Kelman, a UM eye surgeon who directed a nationwide study at 25 medical centers, said patients treated with surgery were less likely to improve and more likely to get worse than were people who received no treatment at all.
The finding, published in today's Journal of the American Medical Association, prompted the National Eye Institute to issue a nationwide alert last month warning doctors to abandon the operation.
The operation was proposed in the late 1980s as a way of restoring sight to people afflicted with ischemic optic neuropathy, the most common cause of sudden blindness in the elderly. Much like a stroke, the disease occurs when the blood supply to the optic nerve is suddenly reduced or cut off.
This deprives the optic nerve of the nourishment it needs to transmit visual information from the retina to the brain. Within days, patients can become blind or left with impaired vision.
Once one eye is afflicted, a patient stands a 40 percent chance that the same thing will happen to the other eye within five years. The disease afflicts about 6,000 Americans each year, most of them between the ages of 60 and 80.
Dr. Kelman said the study was designed to settle questions about the operation's effectiveness. Surgeons performing the operation, called optic nerve decompression, cut tiny slits in the sheath covering the optic nerve, hoping that the release of pressure will trigger a greater flow of blood.
"Apparently, the surgical manipulation of an already damaged optic nerve isn't healthy for the optic nerve," said Dr. Kelman, director of neuro-ophthalmology at the University of Maryland School of Medicine.
For several years, many physicians voiced skepticism over the procedure's benefits. Although some of the surgery patients improved, nobody knew whether they were more or less likely to get better on their own. Also, critics said the operation never really had a clear scientific basis -- a physical reason why it should work. The operation is performed about 1,000 times each year in the United States.
Desperation may have also been a factor, said Dr. Leonard A. Levin of the University of Wisconsin School of Medicine. In a JAMA editorial, he wrote: "Faced with a patient acutely blinded in one eye by a disease for which there is no known treatment, a compassionate physician might well consider any reasonable option."
The study, sponsored by the National Eye Institute, was the first to measure the operation's effectiveness against the only known alternative, which is no treatment.
Physicians compared 119 patients who received the surgery with 125 who were closely monitored but offered no treatment. After six months, 43 percent of the untreated patients jumped three or more lines on a vision chart, compared with 33 percent of the patients who underwent surgery.
In addition, 12 percent of the untreated patients got worse after six months -- losing three or more lines -- compared with 24 percent in the surgery group.
Dr. Neil Miller, director of neuro-ophthalmology at the Johns Hopkins Wilmer Eye Institute, said the study should end the controversy.
"I believe this settles it quite clearly," Dr. Miller said. "This allows us to go on. So often, if you think you have a treatment, you don't look for anything else. Now, this allows us to say this form of treatment doesn't work -- let's turn our attention to something else."
At a national eye meeting this week in Tucson, Ariz., ophthalmologists are discussing drug therapies that might hold some potential to help people suffering from the disease. For now, there are no treatments -- only preventive measures such as the control of blood pressure and diabetes and the avoidance of tobacco products.