Abstract
Purpose :
There is increasing evidence that vascular changes and insufficient blood flow to the optic nerve contribute to the pathogenesis of glaucoma. Optical coherence tomography angiography (OCTA) is a novel noninvasive imaging modality that can assess microvascular structure and function. Previous OCTA studies have demonstrated decreased peripapillary vascular flow and vessel density in glaucomatous eyes compared with control eyes. In this study, we used OCTA to evaluate macular changes in vessel density and inner retinal thickness in glaucomatous eyes.
Methods :
We acquired 3 x 3 mm macular OCTA scans (RTVue XR Avanti, Optovue Inc., Fremont, CA) of patients with primary open angle glaucoma (POAG), normal tension glaucoma (NTG), glaucoma suspect, or normal eyes. Parafoveal vessel density and inner retinal thickness (internal limiting membrane to inner plexiform layer) were measured.
Results :
We found a significant decrease in mean parafoveal vessel density in both POAG eyes (48.4±1.0%, N=18 eyes, P<0.05) and NTG eyes (45.6±1.1%, N=6 eyes, P<0.001) compared with normal eyes (51.3±0.6%, N=22 eyes). In eyes of glaucoma suspect patients, there was notably a greater parafoveal vessel density (55.1±0.8%, N=8 eyes, P=<0.005) compared with normal eyes. We also found a significant decrease in inner retinal thickness in POAG eyes (105.3±2.5μm, P<0.005) and NTG eyes (97.3±4.5μm, P<0.0001) but not glaucoma suspect eyes (120.6±2.5μm P=0.20) compared with normal eyes (116.1±1.7μm). Mean ages of the subject groups were 65.9 years for POAG, 69.0 years for NTG, 40.3 years for glaucoma suspects, and 64.9 years for normal controls.
Conclusions :
We demonstrate that there is a significant decrease in the parafoveal vessel density and inner retinal thickness in eyes of patients with POAG and NTG. Eyes of patients considered glaucoma suspects have a greater parafoveal vessel density compared with controls, although subjects in this group were significantly younger than normal patients. These findings demonstrate that OCTA may be a useful imaging modality for diagnosing and monitoring progression of glaucoma.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.