Gas suspected in dozens of eye surgery injuries

China's top health authority said on Friday that it is closely watching the ongoing investigation into what caused serious eye injuries, including blindness, among dozens of patients who received eye surgery at two hospitals nine months ago.

The National Health and Family Planning Commission said in a statement it will continue to guide the two hospitals involved in providing treatment to the victims and helping them seek compensation.

Impurities contained in perflutren, a medical gas commonly used to fill the hollow eye during surgery, may be the culprit. But experts have been unable to identify the impurities because of testing limitations and an insufficient amount of remaining samples, the China Food and Drug Administration said in a statement on Thursday night.