Analysis of the Hessburg-Barron vacuum trephine.

: We tested the Hessburg-Barron vacuum trephine on 23 human cadaver eyes for accuracy and quality of cut. The trephine was found to make accurate, spherical cuts in the anterior corneal stroma. With penetration, the cut became beveled, leaving the posterior corneal button diameter larger than the anterior diameter especially if the trephine was lifted. The results are discussed relative to conventional techniques.