Abstract
Purpose :
Optical coherence angiography (OCA) technique non-invasively visualizes microvasculature of the posterior eye. However, from vascular imaging alone, it is difficult to delineate the related location of a vessel to the retinal pigment epithelium (RPE) and RPE integrity, which are an important factor to investigate macular degeneration. In this study, a combination of OCA and tissue pigment contrast is demonstrated to enhance the interpretation of vascular imaging.
Methods :
Twenty three eyes of 17 subjects have been examined, which include 10 age-related macular degeneration, 1 neovascular maculopathy, 6 polypoidal choroidal vasculopathy. Subjects were scanned with 1-µm multi-contrast Jones matrix optical coherence tomography (JM-OCT). The scanning rate of the system is 100,000 lines/sec. Four repeated B-scan for blood flow imaging, and volumetric scans were applied. Complex correlation based OCA and Makita’s quantitative degree-of-polarization-uniformity (mDOPU) were applied to contrast blood flow and pigmented tissue, respectively. They are combined to provide images of microvasculature with relative depth to the pigmented tissue. This microvascular-RPE images of macular degeneration are subjectively investigated.
Results :
A representative images with JM-OCT are shown in Fig. 1. The subject is right eye of an AMD patient (68 yo). OCA and mDOPU represent the vasculature and relative depth to pigmented tissue, where a vessel appeared with red, yellow to blue as it is blocked by more pigmented tissue above it. High and low pigmentation (yellow and black arrows) are observed at the side of the abnormal blood flow (white arrows). Their locations are corresponding to hyper- and hypofluorescence in fluorescence angiography and fundus autofluorescence. Abnormal vessel unblocked by pigmented tissue were observed in 14 eyse of 15 eyes with exudative lesion. In 4 eyes of 5 geographic atrophy eyes, partial choroidal vessels are unblocked due to less pigmentation of RPE. All 3 eyes with drusen and/or pigment epithelial detachment do not exhibit unblocked vessels except retinal vessels.
Conclusions :
Abnormality of vasculature and pigmentation of macular degeneration are visualized non-invasively using MC-OCT with OCA and mDOPU. The vascular imaging with MC-OCT might be powerful tool to detect and investigate vascular diseases of the posterior eye.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.