Laser/Light Applications in Ophthalmology: Visual Refraction
Laser technology is only around half a century old. The first experimental laser, demonstrated by Maiman in 1960, was produced by a ruby crystal powered by a flashlamp.1 However the first use of laser in the field of refractive surgery was demonstrated in 1983 by Trokel and Srinivasan who showed that argon-fluoride excimer laser of 193 nm could cleanly remove corneal stromal tissue with minimal damage to adjacent stroma.2 This technology was developed for ophthalmic use after being applied to etch computer chips for IBM in the late 1970s. Initially, the laser was used to create radial keratotomy incisions3,4; later it was used to ablate the corneal tissue in the central visual axis. This later procedure was termed photorefractive keratectomy (PRK) by Trokel and Marshall. The first PRK in a seeing human eye was performed by Mc Donald and coworkers in 1988.5 Since its inception, refractive laser technology has grown exponentially. In the US, The Food and Drug Administration (FDA) first approved the excimer laser for the treatment of mild to moderate myopia in October 1995. Later, it was approved for correction of hyperopia and astigmatism.
KeywordsExcimer Laser Surface Ablation Infectious Keratitis Photorefractive Keratectomy Corneal Haze
Acknowledgment The authors would like to thank Advanced Medical Optics, Inc. (AMO, USA) for providing color photographs used in this chapter.
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