En Face Optic Nerve Head Image Using StratusOCT With Eye Tracking System

Abstract

 

Abstract:

 

 

To create en face images of the optic nerve head (ONH) region using optical coherence tomography (OCT; StratusOCT, Carl Zeiss Meditec, Dublin, CA) with a new eye tracking system.

 

 

An eye tracking StratusOCT unit was developed by adding a retinal tracker, which detects eye motion from changes in reflectance of a beam aligned to the highest reflection from the optic nerve head, originating from the lamina cribrosa. Raster scanning of the ONH region (5 x 5 mm square) was performed by acquiring 256 linear OCT scans with 256 axial samples (A–scans) per each scan. Linear scans were performed in rapid succession using the eye tracking system. Acquisition time of a full raster scan required approximately 120 seconds. En face images were created by summing the three–dimensional OCT data set along the axial direction at each sampling point on the retina.

 

Five healthy volunteers were enrolled in this study. The retinal tracker was successfully engaged throughout the scans, including in between eye blinks. En face images were created with software of our own design utilizing the three–dimensional OCT data set. Registration of each scan line was not disturbed by eye motion although the acquisition time of the raster scans was lengthy. The images created provided detailed surface mapping of the scanned region.

 

 

 

StratusOCT with an integrated tracking system may provide a tool for retinal imaging with various new scanning protocols. High density raster scans and repeated scans with signal averaging to improve signal to noise are possible using tracking, which eliminates the deleterious effects of eye motion.

 

 

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • image processing