1. Intra-operator Reliability of Central Corneal Thickness Pachymetry Measurements
John C. Hwang, MD MBA
Edward S. Harkness Eye Institute
Columbia University Medical Center
Author has no financial interest

2. Purpose
To assess intra-operator reliability of central corneal thickness pachymetry measurements.

3. Methods
Ten serial pachymetry measurements were obtained on all ten eyes of ten consecutive glaucoma-suspect patients by a single operator (JCH) using the Kerasonix KSX1000 Ultrasonic Pachymeter (DGH Technology, Exton, PA).
Statistical analysis was conducted using Microsoft Excel 2003 spreadsheet package.

4. Results
Across all subjects, mean central corneal thickness was 548 microns (standard deviation 44.2 microns). Mean age was 60 years.
For each individual subject, the standard deviation of central corneal thickness, expressed as a percentage of mean central corneal thickness, was 1.5% on average (range %).

5. Conclusion
Intra-operator reliability of pachymetry measurements using Kerasonix KSX1000 Ultrasonic Pachymeter is imperfect.
Pachymetry readings may vary by +/- 3.0% using a 95% confidence interval.