An ophthalmic surgical system, comprising: a syringe pump connected with an actuation line, the syringe pump being configured to provide an injection pressure for viscous fluid injection in a vitreous chamber of an eye of a patient or an extraction pressure for viscous fluid extraction from the vitreous chamber of the eye of the patient; a controller configured to: set a pressure threshold value; receive sensor data relating to an intraocular pressure of the eye; and control the syringe pump to regulate the viscous fluid injection or extraction based on a comparison (506, 606) of the intraocular pressure to the pressure threshold value; and a foot pedal system configured to receive user input for controlling the viscous fluid injection or extraction in or from the vitreous chamber of the eye; wherein the syringe pump is configured to alternatively provide the injection pressure or the extraction pressure for the viscous fluid injection or extraction in or from the vitreous chamber of the eye of the patient; the controller is further configured to determine whether the intraocular pressure is above an upper pressure threshold value and control the syringe pump to reduce or stop the injection pressure in response to the intraocular pressure being above the upper pressure threshold value; determine whether the intraocular pressure is below a lower pressure threshold value and control the syringe pump to reduce or stop the extraction pressure in response to the intraocular pressure being below the lower pressure threshold value; to control the syringe pump based on the user input received at the foot pedal system when the intraocular pressure is below the upper pressure threshold value and above the lower pressure threshold value; and to override the user input received from the foot pedal system when the intraocular pressure is above the upper pressure threshold value or below the lower pressure threshold value. a syringe pump connected with an actuation line, the syringe pump being configured to provide an injection pressure for viscous fluid injection in a vitreous chamber of an eye of a patient or an extraction pressure for viscous fluid extraction from the vitreous chamber of the eye of the patient; a controller configured to: set a pressure threshold value; receive sensor data relating to an intraocular pressure of the eye; and control the syringe pump to regulate the viscous fluid injection or extraction based on a comparison (506, 606) of the intraocular pressure to the pressure threshold value; and set a pressure threshold value; receive sensor data relating to an intraocular pressure of the eye; and control the syringe pump to regulate the viscous fluid injection or extraction based on a comparison (506, 606) of the intraocular pressure to the pressure threshold value; and a foot pedal system configured to receive user input for controlling the viscous fluid injection or extraction in or from the vitreous chamber of the eye; wherein the syringe pump is configured to alternatively provide the injection pressure or the extraction pressure for the viscous fluid injection or extraction in or from the vitreous chamber of the eye of the patient; the controller is further configured to determine whether the intraocular pressure is above an upper pressure threshold value and control the syringe pump to reduce or stop the injection pressure in response to the intraocular pressure being above the upper pressure threshold value; determine whether the intraocular pressure is below a lower pressure threshold value and control the syringe pump to reduce or stop the extraction pressure in response to the intraocular pressure being below the lower pressure threshold value; to control the syringe pump based on the user input received at the foot pedal system when the intraocular pressure is below the upper pressure threshold value and above the lower pressure threshold value; and to override the user input received from the foot pedal system when the intraocular pressure is above the upper pressure threshold value or below the lower pressure threshold value. determine whether the intraocular pressure is above an upper pressure threshold value and control the syringe pump to reduce or stop the injection pressure in response to the intraocular pressure being above the upper pressure threshold value; determine whether the intraocular pressure is below a lower pressure threshold value and control the syringe pump to reduce or stop the extraction pressure in response to the intraocular pressure being below the lower pressure threshold value; to control the syringe pump based on the user input received at the foot pedal system when the intraocular pressure is below the upper pressure threshold value and above the lower pressure threshold value; and to override the user input received from the foot pedal system when the intraocular pressure is above the upper pressure threshold value or below the lower pressure threshold value.