To compare central corneal thickness measurements obtained by Pentacam with those obtained by IOLMaster 700, Cirrus anterior segment optical coherence tomography and Tomey specular microscopy in normal healthy eyes

Purpose: To compare central corneal thickness measurements obtained by Pentacam with those obtained by IOL Master 700, Cirrus Anterior segment optical coherence tomography and Tomey Specular microscopy in normal healthy eyes. Methods: Two hundred and six eyes of healthy subjects were included in the study. Each subject was assessed by four different methods of measuring central corneal thickness using Pentacam, IOL Master 700, Cirrus AS-OCT and Tomey Specular microscopy by a single examiner. Results: The mean CCT [+/- standard deviation (SD)] for Pentacam, IOL Master 700, Cirrus AS-OCT and Tomey Specular microscopy were Pentacam (Oculus), AS-OCT (Cirrus), IOL Master 700 and Specular microscopy (Tomey) were 523.75 (+/- 27.75), 525.29 (+/- 28.81),517.13 (+/- 28.43) and 512.82 (+/- 27.60) mu m, respectively. All the means were significantly different from one another (P < 0.000). The differences between pairs of mean central corneal thickness (CCT) for Pentacam and IOL Master, Pentacam and anterior segment-optical coherence tomography (AS-OCT), and Pentacam and Specular microscopy are statistically significant. Bland-Altman plots showed that pentacam and IOL Master 700 have the closest agreement, followed by AS-OCT. Specular microscopy was found to have the poorest agreement with Pentacam. Conclusion: We found that CCT measurements of Pentacam did not correlate with measurements of IOL Master, or AS-OCT or Specular microscopy. In clinical practice, the devices analyzed should not be used interchangeably due to low agreement regarding CCT values.