The long-term objectives of the Tangential Laser Photorefractive Keratectomy project are the development of ultra-precise instruments and procedures for the correction of refractive errors of the eye. Refractive errors are a major public health issue, affecting the overwhelming majority of the American population in the form of myopia, hyperopia, astigmatism and presbyopia. Previous attempts to surgically correct these refractive errors have met with modest success. However, limitations in recision, predictability and long-term stability of the previous procedures have significantly restricted their post-operative results. By using high-energy photons in the ultraviolet wavelengths to break chemical bonds, and the diffraction-limited precision of coherent light sources (lasers) to tangentially ablate corneal tissue, secularly reflective corneal stromal surfaces have been created. Through the use of advanced computer assisted optical design, annular aspheric prismatic optical elements will be fabricated to create predictable, hemispheric domes of laser irradiation to ablate the cornea down to precise, ultra- smooth, spherical surfaces of pre-determined curvatures. The commercialization of the instruments and procedures to be developed is intended to permit the ophthalmic community to achieve clear, prosthesis-free, visual acuity for Americans.
