Since Goldmann first described his version of the applanation tonometer in 1955,1 it has rapidly gained popularity. Mounted on the Haag-Streit slit lamp, the applanation tonometer is appearing in many United States clinics. However, although the actual measurement of the intraocular pressure with this instrument requires a certain technique, few articles of instruction in procedure have appeared in the English literature. In 1958, Moses2 presented a practical guide to the use of this instrument, and it is the purpose of this paper to add further practical points in its usage.
Criticism of indentation tonometry has focused on the role of scleral rigidity in measurements of intraocular pressure. The indenting plunger displaces a significant volume of fluid from the anterior chamber, causing distention of the ocular coats. The resistance to distention of the ocular coat, or the "scleral rigidity", requires a counterpressure to be exerted by the
JOSEPH AMDUR. The Applanation TonometerTechnique and Clinical Applications. AMA Arch Ophthalmol. 1960;63(1):66–69. doi:10.1001/archopht.1960.00950020068010