Review: The Changing Status of Radial Keratotomy for Myopia: Part I

Abstract

The basic principles of radial keratotomy for myopia were described in 1898: radial incisions flatten the cornea in the direction of the incision, deep incisions are more effective, and some of the resuit diminishes as the cornea heals. Most surgeons now agree on optical zone diameters between 3.0 and 4.0 mm, four to eight incisions, and use of a diamond micrometer knife, but consensus has not been reached on the value of deepening incisions and on how to use preoperative variables in designing the operative technique.

Results of the Prospective Evaluation of Radial Keratotomy (PERK) Study 4 Years After Surgery for Myopia

“…Patients selected for the study met strict entry criteria: (1) at least 21 years of age, (2) bilateral simple myopia with the spherical equivalent of the cycloplegic refraction between -2.00 and -8.00 D and with 1.50 D or less of re¬ fractive astigmatism, (3) visual acuity correctable to at least 20/20 with specta¬ cles, (4) stability of refraction docu¬ mented by clinical records with 0.50 D or less change in the year preceding the baseline examination or 1.00 D or less change in the preceding 3 years, (5) removal of contact lenses for 2 weeks with three subsequent weekly central keratometric readings within 0.50 D of each other with regular mires, (6) ab¬ sence of active or residual ocular disease and no systemic disease likely to influ¬ ence corneal wound healing, (7) signing of informed consent documents after reading a prepared booklet and having an interview with the surgeon, and (8) completion of a baseline examination.…”

Stellenwert der Radiären Keratotomie

“…Die freie optische Zone wird von minimal 3 bis maximal 5 mm in '/2 mm Stufen variiert (19, 1, 25). 40% des optischen Effektes wird bereits mit den ersten 4 Inzisionen erreicht, 90% mit den nachsten 4 Schnitten (34, 36,13…”