Method and apparatus for precision laser surgery

Abstract

A system for effecting precision laser surgery includes an intensified surgical video microscope directed at the tissue to be operated upon and having zoom capability. The surgical microscope presents a microscopic image on a video screen in front of the surgeon. Preferably, the video screen is divided into multiple separate sections, with the microscopic video image in one section and precise cross sectional and plan views indicating location presented in the other sections of the screen. These additional views may be generated using Moire interferometry by projecting a Ronchi ruling on the surface of the tissue, in viewing the projection with a camera to obtain all necessary information for contour tracking of the subject surface. Interior elements and interfaces of, for example, the eye are also sensed by a light beam and precisely located and mapped by a computer forming a part of the device. The imaging system of the invention enables the surgeon to have before him abundant visual information on the video screen with indication of precisely where, in three dimensions, a focused surgical laser beam is directed at any time. The system also includes tracking system for following the movements of the subject tissue, for example an eye during surgery. The tracking system is fast enough to track such movement, preferably at the maximum repetition rate of the laser plus a sufficient margin for safety, but at all times faster than the frame rate for the video displays at which the video screen is retraced.