Keratomileusis, from Greek κέρας (kéras: horn) and σμίλευσις (smíleusis: carving),The word is derived from Greek κέρας - keras (root: kerat-) "horn, cornea" and σμίλευσις - smileusis "carving

or corneal reshaping, is the Surgery, surgical improvement of the

refractive In physics, refraction is the redirection of a wave as it passes from one medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commonly observed phenomeno ...

state of the

cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical power ...

by surgically reshaping it. It is the most common form of

refractive surgery Refractive eye surgery is optional eye surgery used to improve the refractive state of the eye and decrease or eliminate dependency on glasses or contact lenses. This can include various methods of surgical remodeling of the cornea (keratomileu ...

. The first usable technique was developed by

José Ignacio Barraquer José Ignacio Barraquer Moner (24 January 1916 – 13 February 1998) was a Spanish ophthalmologist and inventor born in Barcelona who did most of his life's work in Bogotá, Colombia. His original pioneering investigations on corneal transpla ...

, commonly called "the father of modern refractive surgery." The most common modern procedure,

LASIK LASIK or Lasik (''laser-assisted in situ keratomileusis''), commonly referred to as laser eye surgery or laser vision correction, is a type of refractive surgery for the correction of myopia, hyperopia, and an actual cure for astigmatism, since ...

, is performed by lifting the front surface of the eye by forming a thin hinged flap under which the shape of the cornea is changed by using an

excimer laser An excimer laser, sometimes more correctly called an exciplex laser, is a form of ultraviolet laser which is commonly used in the production of microelectronic devices, semiconductor based integrated circuits or "chips", eye surgery, and microm ...

or other surgical device. A

microkeratome A microkeratome is a precision surgical instrument with an oscillating blade designed for creating the corneal flap in LASIK or ALK surgery. The normal human cornea varies from around 500 to 600 micrometres in thickness; and in the LASIK procedur ...

is usually used to cut the flap, but a

femtosecond A femtosecond is a unit of time in the International System of Units (SI) equal to 10 or of a second; that is, one quadrillionth, or one millionth of one billionth, of a second. For context, a femtosecond is to a second as a second is to about 31. ...

laser can also be used to make the flap. Before the advent of the excimer laser, keratomileusis was performed using a

cryolathe A cryolathe is a device used for freezing and grinding human corneal tissue into different refractive powers. See also *Epikeratophakia *Keratomileusis *Refractive surgery References External links

* Medical equipment {{medical-equipment- ...

, which froze thin flaps of corneal tissue and lathe cut them much like one cuts the lens of a pair of glasses. After thawing, these reshaped flaps were placed under the front flap to correct visual improvement. LASIK is currently the most commonly performed keratomileusis procedure.

Notes

Eye surgery {{treatment-stub