4D imaging of vascular leakage by contrast-enhanced OCT (Conference Presentation)

Leaky vasculature is a key feature in a number of retinal diseases such as diabetic retinopathy and age related macular degeneration and is commonly associated with neovascularization. Currently, the only way to identify leaky vasculature is through fluorescence angiography, which lacks depth resolution and the ability to precisely localize leaky vessels. Here we present the first 4D tracking of leaky vasculature in a mouse model of sub-retinal neovascularization using contrast-enhanced OCT. A very-low-density-lipoprotein receptor kockout mouse model was imaged with OCT angiography at multiple time points following intravenous injection of Intralipid 20%, an OCT contrast agent. Compared to healthy vessels, leaky vessels appeared to become broader over time. By fitting a model to mean intensity projection profiles, the apparent width of the vessels was quantified as an indicator of leakage. A clear trend of increased leakage following the injection of contrast was observed in vessels that derive from retinal lesions. This finding was likely caused by the infiltration of Intralipid particles into the surrounding retinal tissue. Intralipid is an ideal OCT contrast agent as it is FDA approved for human use as an intravenous nutritional supplement and is highly scattering, which makes it a strong candidate for future clinical translation. To summarize, we have demonstrated 4D tracking of individual leaky vessels for the first time using contrast-enhanced OCT in a mouse model of neovascularization. This technique improves upon the capabilities of fluorescence angiography and may help pave the way for clinical translation of contrast-enhanced OCT methods for enhanced diagnostic specificity.