Comparison of Central Corneal Thickness Measurements by Ultrasound Pachymetry, Orbscan, and Third Generation Optical Coherence Tomography (OCT3)

Abstract

Abstract: : Purpose: To determine and compare central corneal thickness (CCT) using OCT3, pachymetry, and Orbscan in normal human corneas. Methods: Twenty two eyes of 11 subjects were examined using the three modalities. Three corneal scans of each eye were obtained using OCT3. The raw data from OCT3 scans were exported and analyzed by Scion Image software (Scion corporation; Frederick, Maryland) to determine the average thickness. The results of OCT3 and Orbscan were compared with the mean of five ultrasound pachymetry measurements for each eye. Results: Ultrasound pachymetry was highly correlated with OCT3 (r=0.98; p<0.0001) and Orbscan (r=0.94; p<0.0001) CCT measurements. The mean CCT determined by OCT3, pachymetry, and Orbscan were 545 (SD=37) microns, 545 (SD=38) microns, and 574 (SD=51) microns, respectively. Conclusions: The data suggests that CCT measured by OCT3 correlates closely with results of ultrasound pachymetry. OCT3 exhibited a higher correlation with pachymetry than Orbscan. OCT3 offers an accurate and non-contact technique for evaluation of CCT.

Keywords: cornea: clinical science • topography • imaging methods (CT, FA, ICG, MRI, OCT, RTA, S