Preclinical evaluation of a new donor corneal trephination system

A new corneal trephination system developed by the University of Minnesota, Department of Ophthalmology and Vision Care/3M features a corneal holder that orients and stabilizes the donor cornea during storage, transportation, and trephination. A gravity corneal punch, and disposable trephine and cutting block minimize corneal button irregularities that in other devices may contribute to postoperative astigmatism. This new system was compared with the Iowa Press by evaluating trephinated corneas on the basis of profile projectors. Buttons trephined from 10 pairs of human corneas stored in (CSM) preservation solution at 4 degrees C were evaluated by measuring diameters and edge angles and correlating them with the trephine size used. In contrast with the Iowa Press, this new system produces corneal buttons that are consistently circular, parallel-edged, and identical in size to the trephine used.