Abstract
Purpose:
To evaluate 3-D vascular architecture in diabetic retinopathy with Doppler optical coherence tomography (OCT).
Methods:
33 eyes of 26 patients with diabetic retinopathy (simple type: 16 eyes, pre-proliferative:10 eyes, proliferative: 7 eyes) were evaluated. 3-D vascular flow imaging (OCT angiography) was obtained using 1 µm swept source Doppler OCT (100,000 Ascan/s, axial resolution 6.4 µm). In a single scan, the system simultaneously provided both an intensity-based standard OCT image and a Doppler OCT image. High sensitive vascular image was obtained by calculating power of Doppler phase signals between two A-lines of two successive B-scans.
Results:
3-D vascular imaging of vascular lesions could be clearly detected with Doppler OCT. Doppler OCT images clearly depicted three dimensional vascular architecture of microaneurysm (22 eyes), neovascularization elsewhere (NVE: 4 eyes), and intraretinal microvascular anomaly (IRMA: 2 eyes). Microaneurysms were located in inner plexiform layers in 22 eyes and outer plexiform layers in 2 eyes. In one eye, NVE was located in the inner retina and standard OCT shows a focal hyperreflective mass at inner retinal NVE. After breaking through internal limiting membrane, new vessels in NVE formed loop formations, and were pulled towards the vitreous body. IRMAs were located in inner plexiform layers. In contrast to inner retinal NVE, the hyperreflective lesion was not confirmed in the area of IRMA in the standard OCT image.
Conclusions:
Doppler OCT is useful for detection and evaluation of the 3-D vascular structure of diabetic retinopathy. Doppler OCT allows visualization of the core vascular lesions in diabetic retinopathy without flurorescein dye.