PROCEEDINGS ARTICLE | February 8, 2017
Proc. SPIE. 10045, Ophthalmic Technologies XXVII
KEYWORDS: Eye, Imaging systems, Blood, Optical coherence tomography, Image segmentation, Capillaries, Retina, Blood circulation, Angiography, Hemodynamics, Physiology, Retinal scanning, Intrinsic optical signal, Neurovascular coupling
It is well established that major retinal diseases involve distortions of the retinal neural physiology and blood vascular
structures. However, the details of distortions in retinal neurovascular coupling associated with major eye diseases are
not well understood. In this study, a multi-modal optical coherence tomography (OCT) imaging system was developed
to enable concurrent imaging of retinal neural activity and vascular hemodynamics. Flicker light stimulation was applied
to mouse retinas to evoke retinal neural responses and hemodynamic changes. The OCT images were acquired
continuously during the pre-stimulation, light-stimulation, and post-stimulation phases. Stimulus-evoked intrinsic optical
signals (IOSs) and hemodynamic changes were observed over time in blood-free and blood regions, respectively. Rapid
IOSs change occurred almost immediately after stimulation. Both positive and negative signals were observed in
adjacent retinal areas. The hemodynamic changes showed time delays after stimulation. The signal magnitudes induced
by light stimulation were observed in blood regions and did not show significant changes in blood-free regions. These
differences may arise from different mechanisms in blood vessels and neural tissues in response to light stimulation.
These characteristics agreed well with our previous observations in mouse retinas. Further development of the multimodal
OCT may provide a new imaging method for studying how retinal structures and metabolic and neural functions
are affected by age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), and other diseases,
which promises novel noninvasive biomarkers for early disease detection and reliable treatment evaluations of eye
diseases.
