Three dimensional non-invasive vascular imaging of proliferative diabetic retinopathy by optical coherence angiography

Abstract

 

Purpose

 

To evaluate the proliferative diabetic retinopathy with Doppler optical coherence angiography (OCA). To evaluate the three dimensional architecture of neovascularization in proliferative diabetic retinopathy.

 

Methods

 

We prospectively examined 22 eyes of 18 patients with proliferative diabetic retinopathy using 1060 nm swept-source Doppler optical coherence tomography (OCT). The scanning range was 6.0 x 6.0 mm on the retina with 256 A-scans × 2048 B-scans, and scanning speed was 100,000 A-scan/s. High sensitive vascular image was obtained by calculating a squared power of the phase resolved Doppler signal obtained from two A-lines in two successive B-scans. Using three dimensional vascular image (Doppler OCA) and three dimensional intensity OCT image at macula and optic disc, we evaluated three dimensional vascular architecture at proliferative membrane.

 

Results

 

Proliferative membranes could be detected in 15 eyes of 11 patients in three dimensional intensity OCT images. In Doppler OCA images, blood flow at the epicenter could be detected in 12 eyes. Among them, 11 eyes had neovascularization of the disc (NVD), and 5 eyes had neovascularization elsewhere (NVE). Epicenters with NVEs were sporadically distributed in all eyes. Epicenters with NVDs were sporadically distributed in 7 eyes, and were found clustered in 4 eyes. The extents and locations of NVD and NVE were corresponded well with the fluorescein angiography images. In 3 eyes, blood flow could not be detected at the epicenters, and absence of neovascular vessels was confirmed in fluorescein angiography images.

 

Conclusions

 

Doppler OCA is useful for detection and evaluation of the 3-D vascular structure of proliferative membrane. Doppler OCA assists non-invasive assessment of proliferative diabetic retinopathy.

 

 

Keywords: 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 499 diabetic retinopathy • 550 imaging/image analysis: clinical