BOSTON (AP) _ An ointment made with a hormone called nerve growth factor may prove to be the first effective treatment for ulcers of the cornea caused by lye burns and other problems.

Currently, doctors may surgically remove the ulcer, but this does not restore eyesight, and victims can be left with severely impaired vision. There is no good medical treatment.

Doctors in Rome experimentally treated 12 patients with nerve growth factor whose ulcers resulted from such things as lye burns, overuse of anesthetics for corneal abrasion, and the herpes zoster virus that causes chicken pox and shingles.

They found the ulcers began to heal within two weeks. All the patients had complete healing after 10 days to six weeks of treatment, and their vision improved considerably.

The study was conducted by Dr. Alessandro Lambiase and others from the University of Rome Tor Vergata. It was published in Thursday's New England Journal of Medicine.

In the United States, the herpes simplex virus that causes cold sores and genital herpes is the leading cause of corneal ulcers. Other common causes include bacteria, fungi and contact lenses.

In an editorial in the journal, Drs. Ronald E. Smith and Alfredo A. Sadun of the University of Southern California called the results impressive and provocative. But they noted that the study was preliminary and said the findings need to be confirmed.