Normalization of retinal nerve fiber layer thickness measurements made by time domain-optical coherence tomography

A method of normalizing thickness measurements of a retinal nerve fiber layer in a two-dimensional optical coherence tomography image and a three-dimensional optical coherence tomography image, each image containing said layer comprising the steps of:

• (A) performing at least one circle scan in said two-dimensional image to obtain a thickness of said layer;
• (B) establishing image registration between said two-dimensional image and said three-dimensional image;
• (C) generating a two-dimensional thickness map of said thickness of said layer from said three-dimensional image;
• (D) performing at least three concentric circle scans for each of the superior hemi-sphere and the inferior hemi-sphere of said layer in said two-dimensional thickness map to delineate space coordinates of a center of gravity of said thickness in each respective hemi-sphere;
• (E) generating at least one polynomial function based on said space coordinates of said respective centers of gravity to create a plurality of fitting curves;
• and
• (F) performing a mathematic interpolation of said plurality to obtain thickness measurements along a virtual path in said two-dimensional thickness map, whereby said thickness measurements of said layer are normalized along said virtual path.