Comparison of Optical Coherence Tomography Angiography to Indocyanine Green Angiography and Slit Lamp Photography for Corneal Vascularization in an Animal Model.

Abstract

Corneal neovascularization (CoNV) could be treated&#xa0;by novel anti-angiogenic therapies, though&#xa0;reliable and objective imaging tools to evaluate corneal vasculature and&#xa0;treatment efficacy is still&#xa0;lacking. Optical coherence tomography angiography (OCTA) -currently designed as&#xa0;a retinal vascular imaging system- has been&#xa0;recently adapted for anterior-segment and showed good potential&#xa0;for successful imaging of CoNV. However, further development requires an animal model where parameters can be studied more carefully with histological comparison. Our study evaluated the OCTA in suture-induced CoNV in a rabbit model compared to indocyanine green angiography (ICGA) and slit-lamp photography (SLP). Overall vessel density measurements from OCTA showed good correlation with ICGA (0.957) and SLP (0.992). Vessels density by OCTA was higher than ICGA and SLP (mean&#x2009;=&#x2009;20.77&#x2009;&#xb1;&#x2009;9.8%, 15.71&#x2009;&#xb1;&#x2009;6.28% and 17.55&#x2009;&#xb1;&#x2009;8.36%, respectively, P&#x2009;<&#x2009;0.05). OCTA was able to depict CoNV similarly to SLP and ICGA, though it could better detect small vessels. Moreover, the depth and growth of vessels could be assessed using en-face and serial-scans. This study validated the OCTA in a rabbit model as a useful&#xa0;imaging tool for translational studies on CoNV. This may&#xa0;contribute to further&#xa0;studies on OCTA for anterior-segment including serial&#xa0;evaluation of emerging anti-angiogenic therapies.