Abstract
Purpose: :
To demonstrate that Stratus OCT central corneal thickness (CCT) measurements correlate to measurements made with the Visante OCT, (both from Carl Zeiss Meditec, Dublin, CA) and show that the repeatability of the measurements made by the two devices are comparable.
Methods: :
Three corneal scans each from the Stratus OCT and Visante OCT were acquired on a total of 68 eyes from 68 subjects. The focus of the Stratus OCT beam was changed to image the cornea to measure CCT. For the Stratus OCT, two methods were used for CCT measurements, the caliper method and the scan profile method. In the former method, calipers were placed on the anterior and posterior corneal surface of the OCT image. In the latter method, the scan profile distance was measured between reflectivity peaks corresponding to the anterior and posterior corneal surface. For the Visante OCT, the corneal scans were measured with the flap tool. The average CCT measurements from the Stratus OCT for each method were calculated and compared with the average CCT measurements from the Visante OCT.
Results: :
Results show that the mean CCT measured by the Visante OCT and Stratus OCT caliper and scan profile methods are very similar. The mean difference between measurements of the Stratus OCT and Visante OCT is -2.59 µm for the caliper method and -0.28 µm for the scan profile method. Stratus OCT measurements correlate very closely with the Visante OCT measurements, with a correlation number of 0.957 and 0.972 for the caliper and scan profile measurement methods, respectively. The repeatability standard deviation of both devices are comparable. Table 1 summarizes the results.
Conclusions: :
There is excellent correlation between CCT measurements of the Stratus OCT and the Visante OCT. Repeatability of CCT measurements from both devices is excellent and comparable.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • anterior segment • cornea: clinical science