The sharpness of incision instruments in corneal tissue.

Because breadths of surgical blades are very difficult to measure directly, we designed a method to measure sharpness of a variety of instruments by determining the power they required to incise corneal tissue to a uniform depth. Diamond knives were the sharpest, followed by razor blade pieces individually prepared by a special new method. Ruby knives varied considerably. The method of measuring sharpness described may allow manufacturers to improve and stabilize production methods, as well as enable surgeons with such knowledge in advance of surgery to optimize wound healing and maximize cost-effectiveness.