Abstract
Purpose :
To compare two alternative methods of acquiring and montaging Swept Source OCT (SS-OCT) en-face images of the human retina to achieve wide-field structural OCT en-face images.
Methods :
The study was performed on three healthy dilated eyes using a ZEISS SS-OCT (ZEISS, Dublin, CA) prototype with an instantaneous optical field of view of 60degrees and a 100kHz swept source laser at 1050nm. The system has a scan depth of 3.0mm, a lateral resolution of 20microns, and an axial resolution of 5.5microns. Cube scans were taken over a 9x9mm and 12x12mm area with 500x500 and 512x512 A-scans respectively. The subjects’ fixation was controlled using the internal fixation target. The ZEISS SS-OCT prototype provides retina tracking at 20Hz tracking speed.
Method 1: acquisition of 9 cube scans in a 3x3 pattern, using 9x9mm cubes; Method 2: acquisition of 4 cube scans in a 2x2 pattern, using 12x12mm cubes. After acquisition, the scans were exported and retinal montages created using an intelligent, semi-automated image stitching and blending algorithm.
Results :
Images were acquired on three healthy eyes. For each eye we acquired nine OCT 9x9mm volumes and four 12x12mm volumes. Acquisition of the images took less than 10 minutes for nine acquisitions (method 1) and less than 5 minutes for four acquisitions (method 2). Patient alignment had to be corrected between individual cube acquisitions. The resulting montages cover an area of approximately 18x18mm using method 1 and approximately 21x21mm using method 2.
Conclusions :
Montaging of structural OCT images allows for the creation of a large field-of-view OCT en-face image. Montages up to approximately 21x21mm were demonstrated.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.