An optical coherence tomography probe and laser combination device configured for real-time z-directional guidance of the incisional depth of a surgical procedure. It can be used alone or placed within the working channel of an endoscope. The device includes an OCT single mode fiber, and a laser fiber or laser hollow waveguide or electrical surgical wire positioned adjacent to the OCT single mode fiber. The single mode fiber is configured to move laterally when activated by an actuator to scan light data reflected from a sample that is positioned in front of a distal end of the device. The light data can be processed to generate a B-scan image. The device can collect data in real-time during lasing, or immediately prior to and following the cutting. The surgical tool, when coupled to a processor, can deactivate when the B-scan image identifies that the incision is within a predefined tolerance.