Abstract
Purpose :
Optical Coherence Tomography Angiography (OCTA) is known to visualize retinal vasculature in the posterior segment of the eye with non-invasive, dye-less, technology. OCTA has not been investigated thoroughly to visualize the anterior segment. The goal of this study is to investigate the usability of OCTA to visualize anterior segment blood vessels of human eyes.
Methods :
The commercially available ZEISS AngioPlex for retinal applications was adapted to visualize anterior segment eye blood vessels in human eyes. With an anterior segment lens adapter (Corneal add-on lens module, also commercially available), the system could achieve 4.2x4.2 mm field of view for high resolution imaging and 8.4x8.4 mm for low resolution imaging. The nasal and temporal conjunctiva and sclera adjacent to the limbus of human eyes were imaged.
Results :
Anterior segment angiography was performed on 6 eyes of 3 normal subjects. For all 6 eyes, a detailed vasculature map was extracted from the adapted Cirrus AngioPlex. The imaging results of one example is demonstrated in Fig.1 and Fig.2. Fig.1 illustrates the corresponding area where the OCTA images was captured (the yellow square of Fig.1). Fig.2 is the OCTA results. Fig.2 (a) is the OCT intensity fundus image, which is obtained from integrating the OCT signal along the depth direction. Fig.2(b) is the corresponding OCT vasculature image. Fig.(c) and (d) are the B-scan structure and flow (red color in (d)) image of sclera, corresponding to the location marked by the light blue in Fig (a) and (b).
Conclusions :
The Cirrus-5000’s AngioPlex can be adapted to visualize anterior segment eye blood vessels, which may be useful for objective evaluation and monitoring progression of anterior neovascularization and vascular abnormalities in the future.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.