Contact lens fitting for post‐radial‐keratotomy residual myopia

Abstract

For correction of post-radial-keratotomy residual myopia, contact lens fitting parameters can be determined by a regression formula using keratometric and refractive values.

Comparison of Axial and Tangential Topographic Algorithms for Contact Lens Fitting After LASIK

“…A large range exists in the literature, from fitting 0.1 mm to more than 0.4 mm (0.50 D to more than 2 D) steeper than the flat or mean postoperative keratometry value. 4,[15][16][17][18] Only two studies have used CVK maps to guide in the selection of base curves after b Significant and high correlation between gas-permeable lens base curve and corneal curvature.…”

“…9 -11 Several studies in the literature that discuss methods for fitting patients who have undergone photorefractive keratectomy (PRK) or LASIK use manual keratometric readings for base curve selection. 4,[12][13][14][15][16][17][18] Because CVK has become the standard method to measure the corneal curvature after LASIK, we sought to find the optimal use of CVK data to which clinicians should refer when fitting GP lenses.…”

BCLA CLEAR – Medical use of contact lenses

“…Using corneal topography, efficient base curve selection has been reported by selection of the lens base curve equal to the value 3.5-4.0 mm superior to the visual axis on an axial map [570]. 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].…”