초록 ▼

A apparatus and method for controlling an apparatus for removing tissue from the eye performs various types of corrections using a relatively large beam, but oscillating, or dithering, that being to prevent reinforcing ridges from being formed during the tissue removal process. Further, various type

A apparatus and method for controlling an apparatus for removing tissue from the eye performs various types of corrections using a relatively large beam, but oscillating, or dithering, that being to prevent reinforcing ridges from being formed during the tissue removal process. Further, various types of correction, such as hyperopia and astigmatism correction, are performed using a large beam that is scanned over the area to be ablated using overlapping shots. Further, the epithelium in the area to be treated is removed using an infrared fluorescent dye to dye the epithelium, and then observing the fluorescent patterns from the epithelium area to be removed. Once a certain area is no longer fluorescent after laser shots, smaller shots are then applied, selectively removing the epithelium from the remaining regions. Again, the fluorescence patterns are observed, and the process is repeated until no epithelium remains. At this point, all of the epithelium is removed, and further a map is created of the initial epithelial thickness at each point in the area from which the epithelium was removed. Using two astigmatism correcting ablation patterns intersecting at an angle, a lens is created capable of correcting for myopia, hyperopia, and astigmatism. Further, overlapping shots using a relatively large fixed spot size provide for reduced thermal heating, ridgeless treatment patterns, reduced shot count, and simplified equipment.

대표청구항 ▼

[ What is claimed is:] [1.] An apparatus for shaping the cornea by removing tissue from a region of the cornea that has an area to be subject to ablation to a desired treatment pattern, the area having a central point, the apparatus comprising:a laser that emits a laser beam having a suitable wavele

[ What is claimed is:] [1.] An apparatus for shaping the cornea by removing tissue from a region of the cornea that has an area to be subject to ablation to a desired treatment pattern, the area having a central point, the apparatus comprising:a laser that emits a laser beam having a suitable wavelength;an optical system coupled to said laser that receives the laser beam and images the laser beam onto the cornea;means coupled to the optical system for directing the optical system to provide the laser beam at a fixed spot size on the cornea, wherein the fixed spot size is a relatively large fraction of the area of the cornea to be subject to ablation; andmeans coupled to the laser and the means for directing the optical system for directing said laser to fire the laser beam and the optical system to image the laser beam in a series of shots at said fixed spot size, said series of shots including shots being centered at at least two distances from the central point, said series of shots including shots partially overlapping with prior shots, and said series of shots ablating the cornea to the desired treatment pattern, wherein said means for directing the optical system to provide the laser beam at a fixed spot size further comprises means for providing the laser beam at a spot size fixed between 2.0 mm and 3.5 mm in diameter.