He added that the doctor was barred from the campus and any school-related events or activities.
“We certainly understand that substance abuse is a tragic and devastating disease,” the statement said. “But we are also bound to our responsibilities as a university to take the necessary actions concerning Dr. Puliafito’s status.”
Attempts to reach Dr. Puliafito on Saturday were unsuccessful. A phone number listed in public records with a Pasadena, Calif., residence was disconnected. A faculty page for him on the Keck School of Medicine website had been taken down.
The Los Angeles Times reported that he was seen on videos apparently smoking methamphetamine and consorting with addicts and criminals.
One woman told The Times that he was with her when she overdosed in a hotel room and that he had taken her to his campus office to use drugs. The woman, Sarah Warren, who worked as a prostitute, said they were “constant companions” after meeting in early 2015.
He resigned as the dean of the medical school less than a month after Ms. Warren overdosed. The Times, citing the Keck website, reported that he continued to accept new patients at campus eye clinics after his resignation.
A renowned eye surgeon responsible for several breakthroughs in ophthalmology, Dr. Puliafito led aggressive fund-raising efforts that garnered more than $1 billion for the medical school.
The university also announced on Friday that it had hired Debra W. Yang, a partner at the law firm of Gibson, Dunn & Crutcher in Los Angeles and a former member of the Los Angeles Police Commission, to investigate the doctor’s conduct and the university’s response.
“Our priority now is to obtain a clear picture of exactly what happened and to ensure the well-being and trust of our students at U.S.C., the patients at the Keck School and our entire university community,” the university said in an email on Saturday.
On Tuesday, a day after The Los Angeles Times published its report, C. L. Max Nikias, the university president, wrote in an open letter that Dr. Puliafito had been placed on leave and could not treat patients.
“We are concerned about Dr. Puliafito and his family and hope that, if the article’s assertions are true, he receives the help and treatment he may need for a full recovery,” he wrote.
“Reports of high-powered executives, doctors and others with substance abuse issues have become all too common — individuals who function in their workplace but have serious issues affecting their personal lives.”