Seven patients who underwent ophthalmic procedures at the civic-run HBT Trauma Care Hospital in Jogeshwari (East) have suffered varying degrees of vision loss.

While three are feared to have completely lost sight in one eye, four others have regained some degree of vision. It is suspected that the patients caught pseudomonas, a severe bacterial infection, through contaminated instruments or from the operation theatre which may have lacked infection control measures.

The patients, two men and five women aged between 40 and 80 years, were all operated upon on January 4. While six patients had undergone cataract procedures, one patient had undergone a secondary intraocular lens implantation surgery.

The infection came to light the next day, when the doctors began opening their bandage dressings. Besides some redness, the patients had no vision in the operated eye. The patients were put on medication for infection control and were shifted to KEM Hospital in Parel, which has tertiary care facilities.

“By Friday, three patients had no vision and four patients had regained some degree of vision,” said eye surgeon Dr. Anil Chaudhari, whose team operated on all the patients. Six patients were discharged and only one remained admitted to the hospital.

The operation theatre was shut down and an internal inquiry was ordered when the infection came to light. The matter was also discussed in the Brihanmumbai Municipal Corporation’s standing committee meeting on Friday.

Swabs have been collected from the operation theatre for identifying the source of contamination. The swabs collected from the eyes of the patients have tested positive for pseudomonas, which is known to be a serious hospital-acquired infection.

“As many as 20 tiny instruments go inside the eye during the procedures. There has to be a common source of infection. An investigation is on,” Dr. Chaudhari said, adding that the report will be out next week.

A senior eye surgeon, who did not wish to be named, said that such bulk infections happen when the instruments are not sterilised thoroughly or the operation theatre lacks a proper filtration system.

The HBT Trauma Care Hospital, opened in 2013, is among the newest civic hospitals. Many patients have often complained about rat infestation and unhygienic conditions in the hospital.