Purpose: To compare central corneal thickness measurements obtained with Orbscan II using the acoustic equivalent correction factor (CF) and Pentacam in eyes screened for refractive surgery.
Methods: Central corneal thickness in 91 eyes of 51 volunteers with a spherical equivalent refraction ranging from -17.00 to +5.50 diopters (D) (mean: -3.75+/-4.19 D) was measured with both Orbscan II (CF) and Pentacam prior to refractive surgery.
Results: Central comeal thickness measurements ranged from 438 to 610 microm with Orbscan II (CF) and from 472 to 634 microm with Pentacam. The differences between Pentacam and Orbscan II (CF) measurements ranged from -43 to +52 microm (mean: -13.98+/-14.79 microm); these differences were statistically significant (P<.0001). No correlation was found between the difference in central corneal thickness and refractive error.
Conclusions: These results suggest measurements obtained with the Orbscan II (CF) are thinner than those obtained with the Pentacam. Further studies are needed to determine which instrument is more accurate in measuring central corneal thickness.