Abstract
Purpose :
In vivo assays enable longitudinal imaging of pathogenesis and response to novel therapeutics. Optical coherence tomography (OCT) and OCT angiography (OCT-A) allow for noninvasive visualization of structural and functional changes in the retina, respectively. We propose novel biometric algorithms to quantify changes in retinal vasculature to quantify longitudinal changes in a zebrafish model of retinal vascular leakage.
Methods :
In vivo zebrafish retinal datasets were imaged using a custom-built spectral domain OCT system (855±45 nm and 125 kHz line-rate) under an IRB-approved protocol (Fig. 1(a)). OCT-A volumes were acquired with a 5 repeated B-scans at each position and vascular maps were calculated using wOMAG in post-processing (Fig. 1(b), (c)). Animals were anesthetized using a 0.14% Tricaine solution and imaged air. A subset of study animals was treated with 10 µM diethylaminobenzaldehyde (DEAB) and 0.04% dimethyl sulfoxide in 1 L of water for 26 h to induce vascular leakage. Wild-type (WT, nWT=10) and vascular leakage model (nDEAB=10) zebrafish were imaged longitudinally in both eyes at multiple time-points: tWT=10 and tDEAB=6 (pre-treatment and 1, 3, 6, 8, 10 days post-treatment). Custom-developed segmentation algorithms were used to extract biometric features from OCT-A vessel maps including vessel segment length, curvature, and branch angle (Fig. 1(d)).
Results :
OCT-A vascular maps showed distinct biometric features that may be used to uniquely identify each animal. WT animals showed no significant changes in vascular biometry during longitudinal time-points (Fig. 1(e)-(g)). We observed retinal vascular occlusion followed by reperfusion in DEAB treated animals (Fig. 1(h)-(m)).
Conclusions :
OCT-A enabled noninvasive visualization of retinal vascular occlusion and reperfusion. These preliminary results motivate potential applications of OCT-A as a tool for studying pathogenesis and therapeutic screening in zebrafish models of vascular disease.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.