Discussion by Jack T. Holladay, MD, MSEE, FACS

Abstract

Intolerable refractive errors after penetrating keratoplasty are very common because the surgeon has little control over the power of the transplanted cornea. Correcting these patients with a secondary intraocular lens anterior to the primary lens prevents the dangers and inaccuracies of lens exchange. Because there is no power removed from the eye during the secondary implant, the correct power for the implant can be calculated from the current refraction and K-readings using a refraction formula.1 The axial length and the power of the existing lens are not necessary for intraocular lens power calculations from refraction.