ARVO Annual Meeting Abstract | September 2016
Quantification of retinal blood flow shows promise as an early biomarker for diverse ocular pathologies such as diabetic retinopathy and glaucoma. We have developed a non-invasive retinal imaging device—the XyCAM RITM—that captures high-resolution fundus images and uses laser speckle contrast imaging (LSCI) to estimate retinal blood flow.
The right eye of 4 healthy individuals (58-59 years old, 2 male) received tropicamide for pupil dilation and was imaged using the investigational XyCAM RI in a clinical environment. Subjects’ heads were stabilized on a standard clinical chin rest and the XyCAM RI mounted on a slit lamp base for fine motion adjustment (Fig. 1A). Four imaging sessions were conducted on each subject, where each session comprised of an ophthalmologist focusing on a desired region of interest (ROI) in the subject’s retina, followed by rapid, automatic acquisition of 5 red-free fundus photographs (with green illumination) and 120 speckle images (using red laser illumination). For reference, color fundus photographs were also obtained using a Topcon TRC 50DX fundus camera.
At least 4 vessel ROIs were identified in each fundus photograph and retinal blood flow velocities (RBFV) were estimated within those ROIs using LSCI-based methods. For each subject, statistical analyses were completed using data from the session with the lowest variation in RBFV estimates.