Clinical evaluation of a portable ultrasonic and a standard optical pachometer.
The clinical performance of a portable ultrasonic pachometer was compared with a modified optical pachometer on a group of normal subjects. The mean central corneal thickness according to optical pachometry using the "edge-to-edge" method of optical doubling was 0.553 mm (SD = +/- 0.022). The mean central corneal thickness using the ultrasonic device was 0.506 mm (SD = +/- 0.039). The differences between the means was statistically significant (at 1% level of probability). Based on the light distribution within the corneal optical section viewed during optical pachometry a hypothesis is derived supporting the notion that optical pachometry tends to overestimate corneal thickness rather than ultrasonic pachometry underestimating corneal thickness.
Patel
S
S
Department of Vision Sciences, Glasgow Caledonian University, Scotland.
Stevenson
R W
RW
D000293:Adolescent; D000328:Adult; D003315:Cornea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D009885:Ophthalmology / Q000295:instrumentation*; D055095:Optics and Photonics / Q000295:instrumentation; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000295:instrumentation