Irrigation/aspiration apparatus

An irrigation/aspiration apparatus for ophthalmic surgery, comprising:

• an irrigation fluid supplying unit, including a changing unit that changes an irrigation rate of irrigation fluid to be supplied into a patient eye;
• an aspiration unit provided with a hand piece having an aspiration hole, an aspiration tube connected to the hand-piece, and a pump that generates vacuum pressure within the aspiration tube, the aspiration unit aspirating removed tissue along with the irrigation fluid supplied into the patient eye through the aspiration hole and the aspiration tube by the generated vacuum pressure;
• a pressure sensor that detects the vacuum pressure within the aspiration tube;
• and
• a control unit connected to the changing unit and the pressure sensor, that increases and decreases the irrigation rate during aspiration by controlling operation of the changing unit based on the detected vacuum pressure, wherein the control unit operates the changing unit so that the irrigation rate is a first set irrigation rate in a normal state, operates the changing unit so that the irrigation rate is a second set irrigation rate higher than the first set irrigation rate when the pressure sensor detects that the vacuum pressure exceeds a limit value at which a depth of an anterior chamber of the patient eye is held while maintaining the first set irrigation rate against a phenomenon in which an aspiration rate generated when an occlusion of the aspiration hole is removed rises sharply, and operates the changing unit so that the irrigation rate is returned from the second set irrigation rate to the first set irrigation rate when the pressure sensor detects that, after reaching at the second set irrigation rate, the vacuum pressure becomes less than a predetermined value which is set lower than a maximum vacuum pressure.