The disclosure describes an optical fiber pressure sensor to measure sphincter pressure which may be incorporated into a therapeutic sphincter control system. The system senses sphincter pressure and sends the information to a stimulator that is capable of stimulation therapy to control sphincter contractility, thus reducing unwanted urinary incontinence. Measuring sphincter pressure is accomplished through the use of an optical fiber connected to flexible tube section placed through the sphincter, where properties of the emitted light are changed proportional to the pressure on the tube section. The light is returned to a light detector to measure light properties and create an electrical signal representative of the pressure on the tube section. The signal may then be sent by wireless telemetry to an implanted stimulator or external programmer.