Topographical mapping, depth measurement, and cutting systems for performing radial keratotomy and the like

摘要

A system for performing radial keratotomy and the like includes a topographical mapping template attachable to the cornea and a hand-held probe movable within the confines of the template. The template generates a topographical grid of voltage variances on the surface of the cornea, and the probe senses the voltages present at locations within this grid to establish its position. The probe may include a transducer device and a surgical blade which is adjustable to various depths of incision based upon control signals generated by the transducer device. The transducer device itself preferably includes one or more depth measurement units, each of which emits energy from the epithelium layer of the cornea upon the underlying endothelium layer and detects the intensity of the reflected energy. The distance between the point of emission and the point of detection is successively increased until a significant drop in the reflected intensity occurs. The measurement unit then accurately derives the distance between the epithelium layer and the endothelium layer and generates the control signal based upon this calculated distance.