Distortion Correction of Visante Optical Coherence Tomography Cornea Images

Area of Science:

• Ophthalmology
• Biomedical Optics
• Medical Imaging

Background:

• Quantitative biometry from anterior segment optical coherence tomography (AS-OCT) is prone to inaccuracies due to spatial and optical distortions.
• Previous distortion correction equations for the Visante AS-OCT have lacked reproducibility.

Purpose of the Study:

• To calculate distortions in Visante AS-OCT images.
• To provide equations for correcting corneal parameters, specifically the central corneal radius of curvature, for the Visante AS-OCT in both young and older subjects.

Main Methods:

• Contact lenses with known radii of curvature and thickness were imaged using Visante AS-OCT.
• Custom Matlab software was used to analyze contact lens images and calculate distortions.
• The developed distortion correction algorithm was applied to corneal measurements from 54 human subjects (24 young, 30 older).

Main Results:

• Post-correction root mean square errors for contact lens radii and powers were significantly reduced.
• Intraclass correlation coefficients for intrasession and intersession repeatability of corneal parameters exceeded 0.88 in both age groups, indicating high reliability.

Conclusions:

• A reproducible distortion correction algorithm for the Visante AS-OCT was successfully developed.
• The algorithm enables accurate extraction of human corneal radius of curvature measurements from AS-OCT images.