INTRODUCTION

Keratoconus is a disease of the cornea characterized by thinning of the central tissue, resulting in protrusion similar to a cone, hence the name keratoconus.  It usually develops in the teenage years or early 20's, and less frequently, in the third or fourth decade of life.  Initially, glasses might give sufficient vision but later contact lenses probably will be required to substitute a smooth spherical surface for the irregularity of the cone  When contact lenses no longer provide crisp vision, corneal transplantation is required. Full thickness corneal transplant (penetrating keratoplasty) is the traditional operative method to remove the original cornea and replace it with the donor cornea.

DEEP ANTERIOR LAMELLAR KERATOPLASTY (DALK)

A more advanced operation to replace the defective keratoconus cornea is the DALK procedure.  In this operation all, or almost all, of the abnormal corneal tissue is removed, leaving  behind a thin, normal layer of tissue on the back of the cornea.  This 15 micron thick residual tissue contains a critical layer of cells, the endothelium, essential to keeping the cornea clear.  What is most important is that this tissue cannot be rejected since it is your tissue.  While immune rejection of the corneal tissue that is transplanted is possible, this is least significant and least likely to result in transplant failure.  Hence, baring other corneal disruptions, this is potentially a transplant for life.  Dr Pfister has a 15 year history of performing this operation with substantial visual success.  The quality of vision is as good or better than full thickness transplants.  DALK has now become the gold standard for keratoplasty in keratoconus.  Watch the video.