초록 ▼

A surgical technique for removing corneal tissue with scanned infrared radiation is disclosed which utilizes short mid-infrared laser pulses to provide a tissue removal mechanism based on photospallation. Photospallation is a photomechanical ablation mechanism which results from the absorption of in

A surgical technique for removing corneal tissue with scanned infrared radiation is disclosed which utilizes short mid-infrared laser pulses to provide a tissue removal mechanism based on photospallation. Photospallation is a photomechanical ablation mechanism which results from the absorption of incident radiation by the corneal tissue. Since photospallation is a mechanical ablation process, very little heat is generated in the unablated adjacent tissue. The disclosed surgical system includes a scanning beam delivery system which allows uniform irradiation of the treatment region and utilizes low energy outputs to achieve controlled tissue removal. A real-time servo-controlled dynamic eye tracker, based on a multiple-detector arrangement, is also disclosed which senses the motion of the eye and provides signals that are proportional to the errors in the lateral alignment of the eye relative to the axis of the laser beam. Temporal and frequency discrimination are preferably utilized to distinguish the tracking illumination from the ambient illumination and the surgical laser beam.

대표청구항 ▼

[ We claim:] [1.] A medical apparatus for removing corneal tissue from an eye of a patient, said apparatus comprising:a laser source that produces pulses of mid-infrared radiation, wherein said infrared radiation has a wavelength approximately corresponding to a corneal absorption peak, and wherein

[ We claim:] [1.] A medical apparatus for removing corneal tissue from an eye of a patient, said apparatus comprising:a laser source that produces pulses of mid-infrared radiation, wherein said infrared radiation has a wavelength approximately corresponding to a corneal absorption peak, and wherein said pulses have a duration of at least about 1 nanosecond; anda scanner-deflection means to direct the pulsed radiation across an area of said corneal tissue in a predefined pattern to remove portions of said corneal tissue primarily by photospallation.