Purpose
To compare the accuracy of postoperative pachymetry between Orbscan II (Bausch & Lomb) scanning-slit corneal topography/pachymetry
and the Pentacam (Oculus) rotating Scheimpflug camera.
Methods
Central corneal thickness (CCT) was determined in 24 patients (48 eyes) before and after laser in situ keratomileusis (LASIK)
or Epipolis LASIK (Epi-LASIK) procedures. All eyes were examined by Orbscan II and Pentacam prior to refractive surgery and
at the first, fourth, and twelfth week postoperatively. The residual CCT (RCCT) measured by each instrument was compared to
the theoretical RCCT.
Results
On the first, fourth, and twelfth week after the refractive surgery, the mean RCCT measurements by Orbscan II were 413 ± 72,
435 ± 65, and 440 ± 69 µm, respectively. Those of Pentacam were 434 ± 51, 436 ± 53, and 438 ± 50 µm, respectively. Orbscan
II measurements at the postoperative first and fourth week were significantly smaller than the theoretical RCCT (P < 0.01, P < 0.01, paired t test). There was no statistical difference between the theoretical RCCT and the Pentacam measurements at any stage.
Conclusion
The Orbscan II measurement values of postoperative corneas tended to be thinner than the theoretical values, but not those
of the Pentacam.
Key Words central corneal thickness - corneal opacity - laser in situ keratomileusis - Orbscan - Pentacam