Theory and calibration of the Schiotz tonometer. I. The boundary surface of the cornea.

T JLo -onography as developed by Grant has been useful in both laboratory and clinic in elucidating the mechanisms of aqueous dynamics and of glaucoma and in assessing drug action. Tonography is the direct outgrowth of Friedenwald's" work on calibration of the Schi0tz tonometer. The present series of papers is devoted to a re-examination of some of the basic concepts of indentation tonometry in an attempt to improve tonography. In his initial publication on tonometry, Friedenwald stated: "Naturally, it is with the posterior surface of the cornea that we are concerned" (p. 1004). Later, he explained the differing indentation volumes obtained in eyes of different species on the basis of this assumption (p. 120, ff).