Abstract
Purpose: :
To examine the relationship, if any, between cross-sectional areas of healthy cornea obtained by anterior segment optical coherence tomography (OCT) and corneal volume data provided by Scheimpflug imaging and ultrasonic pachymetry.
Methods: :
Nineteen consecutive eyes from patients without corneal disease were selected. All eyes underwent anterior segment OCT imaging, Scheimpflug imaging, and ultrasound pachymetry. The most central and centered corneal image was selected from the OCT images of each eye, and processing was performed by the data analysis package in Adobe Photoshop CS5.1 (Adobe Systems Incorporated, San Jose, CA) to yield a central 1mm area measurement. These areas were then compared to Scheimpflug imaging data of corneal volume of the central 3mm, 5mm, and 7mm, as well as to Scheimpflug imaging and ultrasonic pachymetry measurements of the central corneal thicknesses of the same eyes using linear regression analysis.
Results: :
Nineteen eyes were included in the study. Linear regression analysis showed a positive correlation between 1mm corneal cross-sectional areas obtained via anterior segment OCT and corneal volume as measured by Scheimpflug imaging for the central 3mm (R2=0.87, p<0.01), 5mm (R2= 0.82, p<0.01), and 7mm (R2=0.71, p<0.01). Pearson correlation coefficients were 0.93, 0.91, and 0.84, respectively. There was also a positive correlation between 1mm corneal cross-sectional areas on OCT and central corneal thicknesses obtained by Scheimpflug imaging (R2=0.91, p<0.01) and ultrasonic pachymetry (R2=0.84, p<0.01). Pearson correlation coefficients were 0.95 and 0.91, respectively.
Conclusions: :
In these eyes, derived central areas from OCT correlate well with with standard volumetric and pachymetric data. Anterior segment OCT may serve as a useful adjunct modality for extrapolating corneal volume data, in addition to Scheimpflug imaging or ultrasonic pachymetry. Further exploration of the possible advantages of OCT in volumetric analysis, given its higher resolution compared to Scheimpflug imaging, is needed.
Keywords: imaging/image analysis: clinical • cornea: clinical science • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)