Purchase this article with an account.
A. M. Abbey, R. H. Silverman, C. E. Starr; Comparative Peripheral Corneal Thickness by Ultrasound Pachymetry, Artemis-2, Orbscan, and Pentacam. Invest. Ophthalmol. Vis. Sci. 2009;50(13):3683.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To determine reproducibility and to compare mean values of peripheral corneal thickness obtained using contact ultrasound pachymetry, the Artemis-2 ultrasound arc-scanner, Orbscan IIz, and Pentacam.
The peripheral corneal thicknesses of 26 eyes (13 healthy subjects) were measured using the 4 different modalities. Measurements were recorded 4 mm from the pupil center at 0o, 90o, 180o, and 270o. Each patient began with a Pentacam pachymetry map of each eye. This was followed by an Orbscan pachymetry map. Artemis-2 scans were performed with duplicate corneal maps. Finally, ultrasound pachymetry was performed on each eye. We then determined differences in corneal thickness between techniques. We compared the results statistically using ANOVA, correlation analysis, and Bland-Altman plots.
The mean differences between techniques + SD at 0o were 5.6+18.9 microns (Pentacam - Orbscan), 87.0+27.7 microns (Pentacam - Artemis-2), 108.3+37.2 microns (Pentacam - contact ultrasound), 82.0+24.0 microns (Orbscan - Artemis-2), 102.7+37.3 microns (Orbscan - contact ultrasound), and 22.4+36.8 microns (Artemis-2 - contact ultrasound). One way ANOVA showed a significant difference between the four different modalities of measuring peripheral corneal thickness at 0o (F=47.38, p<0.0001). Pentacam and Orbscan measurements correlated well (R2 =0.810). Artemis-2 measurements did not correlate as well with Orbscan (R2 =0.736) or Pentacam (R2 =0.666). Contact ultrasound did not correlate well with Orbscan (R2 =0.240), Pentacam (R2=0.305), or Artemis-2 (R2=0.385). Data analysis of peripheral corneal thickness measurements at 90o, 180o, and 270o showed findings similar to those at 0o.
There was a high degree of agreement between the Orbscan and Pentracam in measurement of peripheral corneal thickness. The Artemis-2 showed a high degree of agreement with contract ultrasound pachymetry. However, Artemis-2 pachymetry values were on average approximately 85 microns thinner than both Orbscan and Pentacam. Contact ultrasound pachymetry values were on average approximately 105 microns thinner than both the Orbscan and Pentacam.
This PDF is available to Subscribers Only