Retinal Blood Flow Analysis With Ultra–High Speed and Ultra High Resulution Optical Coherence Tomography

Abstract

 

Purpose:

 

To demonstrate structural and functional cross sectional imaging of the retina at video rate by Spectral Domain OCT (SD–OCT). Doppler analysis allows measurement of blood flow velocity and pulsatility in arteries and veins.

 

Methods:

 

A clinical video rate OCT instrument was developed based on SD–OCT technology

 

Results:

 

In vivo OCT images were acquired at video rate (29 frames per second) with better than 3 µm axial resolution. Artifacts due to subject motion were significantly reduced, allowing mapping of true retinal and optic nerve head topography. Doppler OCT allowed determination of pulsatile retinal flow in arteries and veins, and quantitative determination of the cardiac cycle. Pulsatility as a function of artery and vein diameter was analyzed

 

Conclusions:

 

Functional SD–OCT allows for comprehensive screening of large area’s and 3–D volume rendering of optic nerve head and fovea structure and vasculature. Pulsatile flow in small veins was observed, that decreased with increasing vessel diameter. Accurate knowledge of retinal structure and blood flow dynamics is important in not only the treatment but also understanding the pathophysiology of many diseases, including glaucoma. Fig 1: Crossectional structural (left) and doppler flow image (right) of a human retina. Bottom panel: Flow velocity in the artery (blue) and vein (red) as a function of time for small vessels  

 

Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • blood supply • macula/fovea