Diamond knife in cataract surgery.

SURGEONS have always searched for sharper cutting instruments whether it be needles, scissors, or knives. The stainless steel blade has until recently been the sharpest knifeedge, but diamond knives$ are much sharper. The diamonds are of gem quality and the blades were developed originally for sectioning biological materials especially for electron microscopy. This paper presents their use in making the cataract incision, their first known use in human surgery. The cutting edge of a stainless steel knife blade magnified 1000 x is shown at the left of Fig. 1, while the perfect diamond knife-edge at the same magnification is on the right.