Comparison of optical and ultrasound central corneal pachymetry.

In 100 eyes of 50 patients central corneal thickness was measured comparing optical to ultrasound pachymetry. With optical pachymetry the values were 1 to 40 micrometer (microns) lower in 64 eyes compared to ultrasound pachymetry. With ultrasound pachymetry the values were 1 to 18 microns lower in 26 eyes compared to optical pachymetry. In 10 cases no difference in pachymetry readings was seen between both techniques. The mean difference of optical pachymetry compared to ultrasound was 9 microns. Optical pachymetry is a no-touch form of corneal thickness measurement, with quick and precise central alignment, and can easily be done by a technician.