Abstract
Purpose :
The aim of the study was to evaluate optic nerve head (ONH), peripapillary and macular vasculature with Optical coherence tomography angiography (OCT-A) in preperimetric (PPG), primary open-angle glaucoma (POAG) and normal eyes, and to assess associations among the vasculature, structural and functional damage.
Methods :
This was an observational, cross-sectional study. Preperimetric, glaucomatous and healthy subjects underwent a comprehensive ocular examination included RNFL, GCC thicknesses and whole image(wiVD), inside disc (idVD), peripapillary(ppVD) and macular (mVD) vessel densities imaging with RTVue-XR Avanti. Vessel densities were collected at two different levels: nerve head(NH) and radial peripapillary capillary (RPC) for the optic disc scan, superficial and deep plexus for the macular scan. Analysis of variance (ANOVA), post-hoc test and linear regression analysis were used.
Results :
14 healthy, 33 PPG and 26 POAG eyes were included. wiVD and idVD in POAG (51.31±4.95%, 47.30±6.59%) and PPG eyes (55.12±4.66%, 51.39±5.42%) were significantly decreased compared to healthy eyes (59.47±3.07, 56.01±5.15%, p<0.001, p=0.004 for wiVD, p<0.001, p=0.01 for idVD). ppVD demonstrated a significant lower rate in POAG than healthy eyes in both NH and RCP segments (greatest reduction of 24.60% in inferotemporal region in RCP segment). PPG showed significant ppVD reduction of 7-11% in all sections of NH segment except for temporal sector and in RCP segment reduction of 8.84% and 8.29% in inferotemporal and superonasal sectors respectively. The mVDs were significantly lower in eyes with POAG vs normal eyes. Vessel density reduction was found in temporal, superior and inferior segments of parafoveal region of PPG eyes in superficial plexus. Regression analysis showed that the ONH vessel densities strongly associated with the RNFL thicknesses (r=0.81, p<0.001 for ppVD inferotemporal-RNFLinferior) and mVD of the deep plexus correlated with macular inner retinal layer thickness (r=0.61, p<0.001).
Conclusions :
Vessel densities in POAG and PPG eyes are significantly lower than healthy eyes both in the optic nerve head and macular regions. A diminished microvascular network is associated with RNFL and macular inner retinal layer thicknesses reduction. OCT-A may provide further information about pathophysiology of the onset and progression of glaucomatous disease.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.