Cornea Donor Study

A web-based computer program was used to select and assign a cornea by donor age group from those available at the eye bank that met the study eligibility criteria. The program randomly selected a cornea based on a two-level minimization procedure which attempted first to balance for each surgeon the number of corneas from donors \>=66 and \<66 years old and then, when possible, to balance among age subgroups of 10-35, 36-50, 51-65, 66-70, and 71-75 years. The assignment was made without regard to recipient age or any other subject characteristics.