مهندسی پزشکی

Topography-assisted

Topography-assisted LASIK is intended to be an advancement in precision and reduce night vision side effects. The first topography-assisted device received FDA approval September 13, 2013.^[69][70]

History

Barraquer"s early work

In the 1950s, the microkeratome and keratomileusis technique were developed in Bogotá, Colombia, by the Spanish ophthalmologist Jose Barraquer. In his clinic, he would cut thin (one hundredth of a mm thick) flaps in the cornea to alter its shape. Barraquer also investigated how much of the cornea had to be left unaltered in order to provide stable long-term results.^[71] This work was followed by that of the Russian scientist, Svyatoslav Fyodorov, who developed radial keratotomy (RK) in the 1970s and designed the first posterior chamber implantable contact lenses (phakic intraocular lens) in the 1980s.

Laser refractive surgery

In 1980, Rangaswamy Srinivasan, at the IBM Research laboratory, discovered that an ultraviolet excimer laser could etch living tissue, with precision and with no thermal damage to the surrounding area. He named the phenomenon "ablative photo-decomposition" (APD).^[72] Five years later, in 1985, Steven Trokel at the Edward S. Harkness Eye Institute, Columbia University in New York City, published his work using the excimer laser in radial keratotomy. He wrote,

"The central corneal flattening obtained by radial diamond knife incisions has been duplicated by radial laser incisions in 18 enucleated human eyes. The incisions, made by 193 nm far-ultraviolet light radiation emitted by the excimer laser, produced corneal flattening ranging from 0.12 to 5.35 diopters. Both the depth of the corneal incisions and the degree of central corneal flattening correlated with the laser energy applied. Histopathology revealed the remarkably smooth edges of the laser incisions."^[73]

Together with his colleagues, Charles Munnerlyn and Terry Clapham, Trokel founded VISX USA inc.^[74] Marguerite B. MacDonald MD performed the first human VISX refractive laser eye surgery in 1989.^[75]

Patent

A number of patents have been issued for several techniques related to LASIK. Stuart I. Brown and Josef F. Bille filed a patent on surgical lasers in 1988.^[76] Samuel E. Blum, Rangaswamy Srinivasan and James Wynne filed a patent application on the ultraviolet excimer laser, in 1982, issued in 1988.^[77] In 1989, Gholam A. Peyman was granted a US patent for using an excimer laser to modify corneal curvature.^[78] It was,