Corneal indentation during ultrasonic pachometry.
OBJECTIVE
This study attempted to determine whether the indentation of the cornea with an ultrasonic probe affects the corneal-thickness measurement.


METHODS
A solid-tip ultrasonic transducer was mounted into the spring arm of a standard Goldmann Applanation Tonometer. Five human subjects were studied. The visual axis of each cornea was marked with a corneal marker, and the ultrasonic transducer was placed on the visual axis. Corneal-thickness measurements were made during five tension settings of the tonometer: 0, 10, 20, 40, and 80. The R-F signals were received by using a 475 Textronix oscilloscope, and the thicknesses were digitally measured.


RESULTS
There was no trend for decreasing or increasing thickness measurements with increasing tension settings.


CONCLUSIONS
Corneal-thickness measurements by ultrasonic pachometry are not significantly affected by corneal indentation with the ultrasonic probe.
Solomon
O D
OD
Department of Ophthalmology, Case Western Reserve School of Medicine, Cleveland, Ohio, USA. info@eyeberspace.com
D000886:Anthropometry; D003315:Cornea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D006801:Humans; D011312:Pressure; D014463:Ultrasonography / Q000295:instrumentation*