An Optical Coherence Tomography Angiography Study of the Relationship Between Foveal Avascular Zone Size and Retinal Vessel Density

Abstract

PURPOSE. To assess the relationship between the size of the foveal avascular zone (FAZ; area and perimeter) and vessel density (VD) at various retinal regions using optical coherence tomography angiography (OCTA) in patients with open-angle glaucoma (OAG).METHODS. In this retrospective cross-sectional study, OAG eyes were grouped according to the presence/absence of central visual field (CVF) defects. A control group of normal eyes was also included. OCTA images were obtained from the optic nerve (4.5 3 4.5 mm 2 ) and macular (3 3 3 mm 2 ) area, in which VDs were measured in the circumpapilla, parafovea, and fovea regions. Partial correlation analyses between FAZ parameters representing size and VDs at different retinal regions were performed. The correlation between FAZ parameters and macular ganglion cell-inner plexiform layer thickness (mGCIPLT) and CVF mean sensitivity (MS) was also assessed. For spatial correspondence, correlations between FAZ parameters and corresponding VD, mGCIPLT, and CVF-MS measurements were assessed at each hemiretina. RESULTS.A total of 126 OAG eyes and 40 controls were reviewed. Overall, FAZ parameters showed statistically significant correlations with VDs measured at the fovea, parafovea, and circumpapilla (FAZ area: r ¼ À0.603, À0.385, À0.256; P < 0.001, < 0.001, and 0.003, respectively). These correlations were observed regardless of the presence of CVF defects (all P < 0.05). FAZ size showed significant spatial correlations with VD, mGCIPLT, and CVF-MS measurements at each hemiretina.CONCLUSIONS. OCTA-derived FAZ area and perimeter showed statistically significant correlations with VDs measured at various retinal locations with spatial correspondence in OAG.

OCT angiography measured changes in the foveal avascular zone area after glaucoma surgery

“…Recent studies have reported that FAZ area is related to central visual-function status in patients with glaucoma. 9 10 27 28 Kwon et al reported an enlarged FAZ area in the perifoveal region, which was spatially correlated with central VF loss in patients with glaucoma. 27 They subsequently demonstrated that the FAZ area has significant diagnostic value in discriminating glaucomatous eyes with central VF defects from normal eyes.…”

Macular vessel density and foveal avascular zone parameters in patients after acute primary angle closure determined by OCT angiography

“…Recent OCTA studies have demonstrated VD dropout in glaucomatous eyes, such as POAG, NTG and PACG 4 , 10 , 25 , 26 . For PACG eyes, the pathogenesis is different from other types of glaucoma 27 , 28 ; thus, circulation alterations may be different in the development of this disease 3 , 11 .…”

Differentiation of Diabetic Status Using Statistical and Machine Learning Techniques on Optical Coherence Tomography Angiography Images

“…The "adjacent area sum" measure represents the sum of all ischemic areas found around the FAZ in the entire image. Rather than direct measurement of the area of FAZ, 9,10 we found in preliminary studies that using morphologic techniques to measure the areas of capillary dropout not within, but surrounding the FAZ (Fig. 1), was more significant despite this precise measure not being previously reported.…”