Relationship Between Optical Coherence Tomography Angiography Peripapillary Vessel Density and Lamina Cribrosa Depth.

Abstract

To investigate the global and regional relationship between the pVD assessed by OCT-A and LCD assessed by enhanced depth imaging spectral-domain optical coherence tomography (SD-OCT). A total of 38 eyes of 38 healthy subjects and 38 eyes of 38 glaucoma patients were included. Peripapillary microvasculature and lamina cribrosa were imaged by OCT-A and enhanced depth imaging SD-OCT, respectively. The pVD and LCD were measured at temporal, superotemporal, superonasal, nasal, inferonasal, and inferotemporal sectors. Global and regional correlations between pVD and LCD were evaluated in all subjects. The pVD (59.0±2.6 vs. 54.4±5.4%) and LCD (318.5±76.4 vs. 404.6±92.5 μm) were significantly different between healthy and glaucoma subjects. The average pVD assessed by OCT-A was not significantly correlated with average LCD assessed by SD-OCT (r=-0.160, P=0.167). Regional correlation between pVD and LCD was statistically significant only in the inferotemporal sector (r=-0.301 and P=0.008). In the linear regression analysis, reduced pVD was independently associated with decreased visual field mean deviation and peripapillary retinal nerve fiber layer thickness but not with increased LCD. Global and regional correlations between pVD and LCD were poor except for the inferotemporal sector. This finding suggests that peripapillary microvascular impairment may not result directly from posterior lamina cribrosa displacement.