A proposal is described for development of a solid state laser light source, operating at a wavelength of 213nm, for use in photorefractive keratectomy or corneal shaping. Successful development of such a source will eliminate the requirement for toxic gas used in current excimer laser systems and may offer additional advantages. Such a source should aid the acceptance of photorefractive keratectomy as a useful procedure. The laser source will be designed to produce a sufficient energy for corneal ablation, with a smooth intensity profile across the beam cross section, and with small variations in pulse to pulse energy content. Use of a beam profilometer with ultraviolet sensitivity will be essential for this work. The laser light will be obtained by an efficient three stage mixing process in nonlinear crystals that converts the 1064 nm output of a Nd:YAG laser to 213nm. Interaction of the light source with corneal tissue will be evaluated in terms of ablation threshold, ablation rate, and surface roughness as determined by TEM analysis. These parameters are required for the design of a commercial corneal sculpting machine that operates at 212 nm.
