Photogrammetric Analysis of Corneal Trephination

Stephen C. Pflugfelder, Thomas J. Roussel, David Denham, William Feuer, Sid Mandelbaum, Jean Marie Parel

Research output: Contribution to journalArticlepeer-review

27 Scopus citations


We used a high-magnification shadow photogrammetric system to evaluate corneal buttons trephined from human donor globes. Whole eyes were trephined with one of five instruments: nonguarded blades held by hand or placed on a handle, Barraquer-Mateus motorized trephine, Hessberg-Barron suction trephine, or Hanna microkeratotrephine. Corneoscleral buttons were punched with one of three punches: Cottingham, Katena Lieberman guillotine, or a modified Lieberman guillotine with an increased impact force (BPEI 2). The precision (how closely buttons approximated the trephine diameter), accuracy (repeatability), acircularity (deviation from roundness), and straightness (verticality of edges) of cut were calculated from the diameter and edge profile angle measurements of buttons cut by the different instruments. These results were statistically compared. The Hanna microkeratotrephine instrument had the greatest precision and accuracy, least acircularity, and straightest edges. Of the corneal punches evaluated, the Cottingham instrument had the greatest precision; however, the BPEI 2 punch cut with the greatest accuracy and the straightest edges.

Original languageEnglish (US)
Pages (from-to)1160-1166
Number of pages7
JournalArchives of ophthalmology
Issue number8
StatePublished - Aug 1992

ASJC Scopus subject areas

  • Ophthalmology


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