Abstract: Surgical instruments are disclosed for manipulating selected tissue in a body cavity under visual inspection. The preferred instrument includes a probe in which a blade is positioned, wherein the probe includes a lateral aperture near its distal end. The blade can be extended outwardly from the probe along a path which is essentially perpendicular to the longitudinal axis of the probe. After the blade has been extended it can be used to effectively divide tissue. An optical system can be received in the probe for viewing through the lateral aperture in the probe.