Ophthalmic surgical laser and method

Abstract

A laser-based method and apparatus for corneal and intraocular surgery. The preferred method of performing a surface ablation of cornea tissue or other organic materials uses a laser source which has the characteristics of providing a shallow ablation depth or region (about 0.2 .mu.m to about 5.0 .mu.m), a low ablation energy density threshold (about 0.2 to 5 .mu.J/(10 .mu.m).sup.2), and extremely short laser pulses (having a duration of about 0.01 picoseconds to about 2 picoseconds per pulse) to achieve precise control of tissue removal. The laser beam cross-sectional area is preferably about 10 .mu.m in diameter. The preferred laser system includes a broad gain bandwidth laser, such as Ti.sub.3 Al.sub.2 O.sub.3, Cr:LiSrAlF.sub.6, Nd:YLF, or similar lasers, with a preferred wavelength of about 830 nm, which is generally transmissive in eye tissue. Various surgical procedures can be performed to correct refractive errors or to treat eye diseases. The invention can be used to excise or photoablate regions within the cornea, capsule, lens, vitreoretinal membrane, and other structures within the eye. The invention provides an improved method of eye surgery which has accurate control of tissue removal, flexibility of ablating tissue at any desired location with predetermined ablation depth, an optically smooth finished surface after the surgery, and a gentle surgical beam for laser ablation action.

Dependencies are inferred from the claim text.