Ahemdabad: Fifteen patients, who were undergoing treatment for different eye ailments at the civic body-run C H Nagri Eye Hospital complained of partial loss of vision after they were given injection. The hospital carried out emergency operation to save the eyesight but there have been no improvement after the operation. Doctors say it may take more than a month to regain eyesight. Meanwhile the Food and Drug Department, Gujarat has cancelled Avastin drugs from a Sweden company after the incident.