Refractive Surgery Procedures

• Radial keratotomy (RK)
• Astigmatic keratotomy (AK)
• Photorefractive keratectomy (PRK)
• Automated lamellar keratoplasty (ALK)
• Laser in-situ keratomileusis (LASIK)
• Laser thermal keratoplasty (LTK)
• Clear lens extraction (CLE)
• Phakic intraocular lenses (PIOL)

77k Image RADIAL KERATOTOMY (RK) has been the most commonly performed refractive procedure performed for the correction of nearsightedness (myopia). Using a high powered microscope the surgeon makes a series of radial microscopic incisions, typically 4 or 8, on the surface of the outer focusing lens of the eye (cornea) to reduce its curvature. RK is appropriate for patients with low to moderate myopia and has a 15 year track record with hundreds of articles published about results and complications. Some of our surgeons have been performing RK for 15 years.

66k Image ASTIGMATIC KERATOTOMY (AK) is similar to RK and is used to correct astigmatism. An astigmatic eye generally has a cornea shaped like a football or teaspoon, and relaxing incisions are performed in an attempt to make the cornea more round. AK is often combined with RK and has a similar long track record.

Two - 33k Images PHOTOREFRACTIVE KERATECTOMY (PRK) involves sculpting the surface of the cornea to a new curvature with a special cold laser (excimer) by vaporizing the surface layer through a series of precise laser pulses under computer control. PRK in the United States has recently been approved by the FDA for the correction of low to moderate myopia (up to -7 diopters). PRK for the correction of far-sightedness is currently under investigation in the United States and AEI surgeons have participated in this preliminary study. The refractive surgeons at AEI have performed PRK on hundreds of eyes over the past 5 years.

Two - 44k Images AUTOMATED LAMELLAR KERATOPLASTY (ALK) AND LASIK involves separating the surface layer of the cornea with a special instrument (microkeratome). This layer is temporarily folded back and a thin disc of corneal tissue is removed with a second pass of the microkeratome. ALK is primarily indicated for the correction of higher amounts of myopia and although satisfactory results can at times be obtained, a high percentage of eyes need additional procedures and an irregular corneal surface causing some distortion of vision is not uncommon. Many refractive surgeons feel that the procedure will be significantly improved when the tissue removal is performed with the excimer laser as in PRK. This combination of ALK and PRK is called LASIK and is currently legally being performed in the United States only under a special FDA investigation at selected centers.

LASER THERMAL KERATOPLASTY (LTK) is being studied for the correction of small amounts of farsightedness. A special laser (holmium) is used to slightly tighten the fibers in the cornea in an attempt to steepen its curvature. It is still an investigational procedure in the United States.

CLEAR LENS EXTRACTION (CLE) involves the removal of the internal lens of the eye, as in a cataract operation. A lens implant of a stronger power, as calculated by special measurements and formulas, is then placed inside the eye. AEI surgeons have utilized this procedure for selected farsighted patients over the age of 40 under a special investigational protocol.

88k Image PHAKIC INTRAOCULAR LENS (PIOL) involves placement of a lens implant inside the eye for the correction of either nearsightedness or farsightedness. This lens becomes in effect an internal contact lens inside the eye rather than on the surface of the eye. At the present time this lens is being studied outside the United States.