Epikeratophakia for Myopia Correction MARGUERITE B. McDONALD, MD, STEPHEN D. KLYCE, PhD,* HENRY SUAREZ, MD, ARTEMIOS KANDARAKIS, MD, MILES H. FRIEDLANDER, MD, HERBERT E. KAUFMAN, MDt Abstract: Epikeratophakia is based on the principles of the Barraquer refractive procedures, with modifications that simplify the surgical technique and eliminate the use of the microkeratome by placing the donor corneal tissue lens on the anterior surface of the cornea. Procedures developed to permit freeze-drying the preshaped lens for storage enable these lenses to be obtained from a central source, freeing the surgeon from the complexities of the computer and the cryolathe. The correction of theoretically unlimited amounts of myopia is possible with these lenses. In 12 eyes that underwent the final epikeratophakia procedure, the average desired correction achieved was 98%. [Key words: cornea, epikeratophakia, myopia, refractive surgery.] Ophthalmology 92:1417- 1422, 1985 Jose Barraquer and others have shown that refractive surgical procedures that modify corneal shape can give excellent optical and visual results. 1 The original proce- dures, however, involve expensive equipment, extensive training, complex computer calculations, and the use of a microkeratome to split the recipient cornea. The microkeratome is an ingenious but complicated device that applanates the cornea and excises a plano power lamella from the recipient cornea by sliding through a suction ring placed at the limbus. The suction ring is selected from a group of rings of varying heights, so that the corneal tissue to be excised protrudes above the track. The ring raises intraocular pressure and allows for better fixation of the globe; a series of applanation tonometers is used with the suction ring to ensure that the resected disc will be of the appropriate diameter. Another tono- meter is used to be sure that the intraocular pressure is above 65 mmHg and the cut is made. In most series, a From the Lions Eye Research Laboratories, Louisiana: State University Eye Center, Louisiana State University Medical Center School of Medicine, New Orleans. Presented in part at the Eighty·ninth Annual Meeting of the American Academy of Ophthalmology, Atlanta, Georgia, November 11-15, 1984. Supported in part by Public Health Service Grants EY03311 ,* EY02580,t and EY02377t from the National Eye Institute, National Institutes of Health, Bethesda, Maryland, and an unrestricted grant from Research to Prevent Blindness, Inc. Reprint requests to Marguerite B .. McDonald, MD, Louisiana State University Eye Center, 136 South Roman Street, New Orleans, LA 70112. small but significant incidence of perforations of the globe and irregular cuts induce high postoperative astigmatism. Epikeratophakia is a modification of the Barraquer procedures that leaves the optical zone of the patient's cornea untouched, except for de-epithelialization. This procedure places the donor tissue lens on the surface of the cornea, freeing the surgeon from the need to use the microkeratome. Other advances permit the do- nor tissue Iehses to be produced by a central source and freeze-dried for storage. These changes increase safety, simplify the preparation of the lens and the surgical tech- nique, and permit the procedure to be easily If necessary, the lens can be removed with no permanent damage to the cornea. Epikeratophakia was first developed to correct refractive error in unilaterally aphakic patients unable to wear con- tact lenses. 2 - 5 The donor tissue lens is obtained prelathed and preserved, and at surgery the lens is rehydrated in saline and the edges of the lens are sutured to an annular defect made in the de-epithelialized cornea. The thicker central optical zone of the lens increases the anterior cor- neal curvature, providing up to 25 diopters of additional correction. The surgical technique also has been adapted to flatten and reinforce the thinned and protruding cornea in patients with keratoconus. 6 • 7 In this case, the lens is not shaped to yield a dioptric correction, but is of equal thickness throughout. The epikeratophakia lens has been redesigned with a thinner optical zone and a thicker shoulder to provide the necessary corneal flattening for myopic correction. 8 In this report, the surgical and visual results are described 1417