Tainted eye drops specially prepared by a pharmacist caused a severe infection that cost one woman an eye and similar infections in at least a dozen other people, doctors say.

After the woman whose eye had to be removed came in for treatment this week, surgeons at Allegheny General Hospital discovered the drops were contaminated by a bacteria, Dr. John Kennerdell, chairman of the hospital's ophthalmology department, said Thursday."Once this type of bacteria gains access to the inside of the eye it causes a very devastating infection," Kennerdell said. "That's why it's so dangerous."

The prescription eye drops prepared at Hieber's Drug Store by pharmacist and owner Joseph Kilkeary were designed to ease inflammation after cataract surgery.

"I've been selling these drops for years without a problem," Kilkeary said.

He said 20 to 25 customers bought the drops in October. They have been told to quit using them and return them to the pharmacy or their doctors.

Thirteen people were hospitalized for treatment in Pittsburgh, doctors said. One man who used the drops but shows no sign of infection was under observation.

Doctors removed the woman's right eye last week after antibiotics failed. The other 12 are receiving large doses of antibiotics. Two have impaired vision and could lose an eye, Kennerdell said.

Pharmacists commonly mix solutions not offered by drug companies when doctors prescribe them, said Harvey Miller, a Food and Drug Administration spokesman in Philadelphia.