Abstract
Purpose :
Wide field Optical Coherence Tomography Angiography (OCTA) imaging can be obtained by combining multiple cube scans taken at different locations. This typically requires the patient to fixate at different locations, which can be challenging for those with macular diseases. In addition, taking multiple scans increases the acquisition time and can cause eye fatigue, which can make the clinical protocol difficult to complete. We assessed a new montage protocol optimized to reduce the acquisition time and enhance the visualization of the retinal vasculature.
Methods :
Five normal and five eyes with vascular abnormalities were imaged on the PLEX® Elite 9000 Swept-Source OCT (ZEISS, Dublin, CA) to create wide-field OCTA images following two montage protocols: 1) Montage of five – 12x12 OCTA scans acquired at five different fixations: Central, Superior Temporal, Superior Nasal, Inferior Nasal, Inferior Temporal, and 2) Montage of two - 15x9 OCTA scans both acquired at central fixation.
The benefit of improved resolution from 25 um on the 12x12 montage to 18 um on the 15x9 montage was assessed by reviewing the vasculature details in the final montage images.
Results :
Figures 1 and 2 show side-by-side the montage image from five 12x12 OCTA scans (left) and from two 15x9 OCTA scans (right) of a healthy and diseased eye respectively. The blue square overlaid on the 12x12 montage image indicates the equivalent 70% field of view captured by the 15x9 montage. The 15x9 montage images reveal finer vasculature details, as can be seen in the foveal avascular zone. The average acquisition time of the 15x9 montage protocol was found to be 56 s +/- 3 s for the group of healthy eyes and 70 s +/-7 s for the group of diseased eyes. In comparison the average acquisition time was found to be statistically longer on the 12x12 montage protocol, with 130 s+/-14 s for the group of healthy eyes and 152 s +/-12 s for the group of disesed eyes.
Conclusions :
The proposed montage protocol of two 15x9 OCTA scans reveals finer vasculature details, and reduces the acquisition time by more than half when compared to five 12x12 OCTA scans.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.