Abstract
Purpose :
To compare the vascular perfusion in the macular area with the retinal ganglion cell (RGC) density in patients with glaucoma and suspects.
Methods :
We performed a retrospective, observational clinical study to compare the RGC density obtained with fourier-domain optical coherence tomography (OCT - 3D-OCT, Topcon Corp), with macular blood vessel density determined by OCT angiography (OCTA - AngioVue, Optovue), in 32 eyes with open-angle glaucoma, 2 with exfoliation syndrome and ocular hypertension, and 8 glaucoma suspect eyes, based on the appearance of the optic disc (mean age: 65.66 ± 12.2 years, MD: -4.64 ± 5.05 dB). The superficial vascular layer located between the inner limiting membrane (ILM) and the posterior boundary of the RNFL was analyzed with OCTA AngioAnalytics software. OCT and OCTA (3 x 3 mm scans) images were aligned, and OCT RGC thickness and OCTA blood vessel density were compared by 7 regions – superior, nasal, inferior and temporal quadrants, superior and inferior hemifields, as well as the fovea (within 1mm from the foveola). All OCTA images with inadequate segmentation of the retinal layers, a signal strength index of <40, motion artifacts or significant macular epiretinal membranes were excluded from analysis.
Results :
Mixed effects modelling revealed a significant relationship between the RGC+ and vascular density in the fovea (P < 0.005), inferior quadrant (P < 0.001) and average inferior hemifield (P < 0.005). OCTA color-coded density maps and gray scale images showed correlation with the color-coded RGC+ OCT maps (see figure 1). No significant relationship was seen in the nasal and temporal quadrants.
Conclusions :
Glaucoma affects the RGC density in the macula, and the decreased blood supply at the affected area could be the result or consequence of glaucomatous damage. Previous studies have shown a correlation between a decreased RNFL thickness and a loss of blood vessels in the peripapillary region (Scripsema et al. IOVS 2016, Yarmohammadi et al. IOVS 2016). We demonstrated that this correlation is also present at the macula.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.