Keratoreformation by contact lenses after radial keratotomy

Abstract

Since the number of patients undergoing radial keratotomy has increased, more have required contact lens fitting to correct residual ametropia. A number of practitioners suggest that the postoperative changes stabilize after 12 months, so contact lens fitting on the unusual resultant corneal topography can begin. This paper discusses corneal and refractive changes that are revealed even when correctly fitting lenses are worn 1-5 years postoperatively. These changes indicate that lens wear may influence corneal topography and refraction even several years after radial keratotomy.

Contact lens fitting after photorefractive keratectomy.

“…[33][34][35][36][37] In PRK, the peripheral and mid peripheral corneal shape is not affected significantly and with newer laser software algorithms attempts have been made to provide a 'blended' transition zone between the central ablated zone and the untreated cornea. In addition, in our series, by 6 months the central corneal thickness had returned to 90% of the preoperative value and therefore the amount of tears pooling beneath the lens was not excessive.…”

Contact lens fitting for post‐radial‐keratotomy residual myopia

“…, 9,10 Hoffmann et al. 13 and Astin 14 have separately done studies on contact lens fitting after RK. Their fitting technique was based on Soper's technique for fitting contact lens over corneal transplants 15 .…”

“…The mean OD in our study was 9.64 ± 0.08 mm. The use of an overall diameter of 9.6 mm 9 and 10.0−11.0 mm 14 has been recommended. This is essential for proper centration as with a large contact lens, the mid‐peripheral knee is completely avoided, provided the lens is steep enough; hence, this ensures that the lens does not centre on the knee.…”

BCLA CLEAR – Medical use of contact lenses

“…When traditional corneal lenses are fitted after RK, or any myopic photoablation procedure which creates an oblate cornea, the contact lens vaults the flatter central cornea resulting in a plus powered lacrimal lens which must be compensated for with additional minus power in the lens [571]. Rigid corneal lenses also have a moulding effect that alters corneal power [572,573] and can improve vision temporarily after lens removal [546].…”