ABSTRACT
BACKGROUND:
To investigate the differences of
perfusion in the
optic nerve head (ONH) between normal and glaucomatous
eyes using optical microangiography (OMAG) based
optical coherence tomography (OCT)
angiography technique.
METHODS:
One
eye from each subject was scanned with a 68 kHz
Cirrus 5000 HD-OCT-based OMAG prototype system centered at the ONH (Carl Zeiss Meditec Inc, Dublin, CA, USA). Microvascular images were generated from the OMAG
dataset by detecting the differences in OCT signal between consecutive B-scans. The pre-laminar layer (preLC) was isolated by a semi-automatic segmentation program. En
face OMAG images for preLC were generated using signals with highest
blood flow signal intensity. ONH
perfusion was quantified as flux, vessel area density, and normalized flux within the ONH. Standard t-tests were performed to analyze the ONH
perfusion differences between normal and glaucomatous
eyes.
Linear regression models were constructed to analyze the correlation between ONH
perfusion and other clinical measurements.
RESULTS:
Twenty normal and 21
glaucoma subjects were enrolled. Glaucomatous
eyes had significantly lower ONH
perfusion in preLC in all three
perfusion metrics compared to normal
eyes (P≤0.0003). Significant correlations between ONH
perfusion and
disease severity as well as structural changes were detected in glaucomatous
eyes (P≤0.012).
CONCLUSIONS:
ONH
perfusion detected by OMAG showed significant differences between
glaucoma and normal controls and was significantly correlated with
disease severity and structural defects in glaucomatous
eyes. ONH
perfusion measurement using OMAG may provide useful information for
detection and
monitoring of
glaucoma.