Abstract
Purpose :
Optical coherence tomography angiography (OCTA) can quantify retinal vascular density and approximate retinal blood flow in a non-invasive manner. These measurements may be important in the evaluation and management of glaucoma and can potentially help elucidate the role of ocular blood flow in the pathophysiology of glaucoma. This study aimed to correlate OCTA-derived retinal vascular density with Humphrey visual field (HVF)-derived retinal sensitivity in patients with low tension open-angle glaucoma.
Methods :
Forty-two eyes from 21 clinically diagnosed patients with LTG (age 60 ± 10 years), underwent swept-source OCTA imaging (Plex Elite 9000, Carl Zeiss Meditec, Inc), and HVF testing (SITA-Standard 24-2 pattern). Retinal vascular densities (perfusion and vessel density) were measured within the 5mm macular region (centered on the fovea) of superficial vascular plexus (SVP), deep capillary plexus (DCP), and choriocapillaries (CC), as well as within 5 mm region of the optic nerve head (ONH). The perimetry testing provided the mean retinal sensitivities. Statistical analysis was performed with SPSS using bivariate Pearson correlation.
Results :
The OCTA-derived average retinal vessel density of the SVP, DVP, CC and ONH were 51.3 ±3.4%, 47.9±3.8%, 71.8±8.3%, and 54.5±5.7%, respectively. Mean global sensitivity measured by HVF was 26.41±3.9 dB . We found statistically significant correlations between: SVP perfusion density and HVF (r=0.418, p=0.006), CC perfusion density and HVF (r=0.306, p=0.049) and ONH perfusion density and HVF (r=0.381, p=0.013); however no statistically significant correlation was found between DVP perfusion density and HVF (r=0.224, p=0.153).
Conclusions :
A strong correlation between reduced retinal vascular density and lower retinal sensitivity in our LTG patients was found in all layers, except with the deep vascular plexus. This study provides additional evidence to support an association between ocular blood flow and glaucoma. Furthermore, the strongest correlation was found at the superficial vascular plexus, which supplies the inner retinal layers that are preferentially affected in glaucoma. OCTA-derived retinal vascular density has the potential to become an additional structural parameter in the evaluation and management of glaucoma.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.