ABSTRACT
A. INTRODUCTION Full-thickness penetrating keratoplasty (PK) is a common ocular surgery, in which recipient cornea is removed and replaced with tissue obtained from a cadaveric donor. This surgery is useful in a variety of conditions that result in corneal opacification, edema, scarring, irregularity, or thinning. An estimated 41,000 PKs are performed in the United States each year (1). A variety of factors may influence postoperative refractive error and astigmatism. The antemortem curvature and cylinder of the donor cornea will affect the final result; this information, however, is not available to the surgeon. Thinning of the recipient cornea, as in keratoconus, has been reported to lead to increased cylinder after PK (2). Trephination technique and graft sizing also may affect postoperative refractive error; enhanced effect of suture tension on the central cornea should theoretically occur in smaller grafts.
