Enlargement of Foveal Avascular Zone in Diabetic Eyes Evaluated by en Face Optical Coherence Tomography Angiography

Abstract

Our data suggest that diabetic eyes show retinal microcirculation impairment in the macula even before retinopathy develops. En face OCTA is a useful noninvasive screening tool for detecting early microcirculatory disturbance in patients with diabetes.

Optical coherence tomography angiography — novel method to access retinal microcirculation in patients with diabetic retinopathy

“…Currently, OCTA enables a regular FAZ assessment in diabetic patients. Further studies are necessary to evaluate the utility of this parameter in assessment of diabetic retinopathy progression [10,11].…”

Novel Retinal Imaging Technologies

“…SS-OC-TA may be able to overcome signal attenuation, such as from the RPE, media opacities, and any overlying hemorrhage. Takase et al, [6] detected the area of the foveal avascular zone (FAZ) by enface OCTA (AngioVue, Avanti OCT; Optovue), and then evaluated the diferences between healthy and diabetic eyes. They found that the FAZ area in the deep plexus layer was significantly larger in diabetic eyes than in healthy eyes.…”

Can Foveal Avascular Zone (FAZ) Assessment By OCT Angiography, Used For Grading Of Diabetic Retinopathy?

“…Our center reviewed literature regarding the OCTA applications in diabetics which is going to be published soon. Available reports are few, but interesting facts regarding the FAZ is published [7][8][9][10][11][12][13][14][15][16][17][18]. The FAZ in normal individual was described in the OCTA as an intact well-demarcated round or oval area of reduced capillary density with a border without gaps, holes or interruption of the capillary network in both superficial and deep plexuses.…”

“…This finding may also add to our knowledge regarding pathophysiology behind the ischemic changes in DR. The OCTA has increased feasibility of qualitative FAZ assessment; but the most impressing are regarding the quantitative FAZ assessments the FAZ size increased significantly by progression of retinopathy grade in almost all reports [9][10][11][12][13][14][15][16][17]. (Table 1) has summarized current available range of the mean FAZ size values in different grades of disease.…”

“…For further details, one may refer to references or wait for our review article to be published. Furthermore, the FAZ is enlarged in diabetics not only before developing to apparent DR but even before systemic diagnosis of DM, so it could also be used as a predictor for whom may need closer follow up [11,15]. Putting these findings alongside our previous knowledge regarding the FAZ characteristics such as being considered as a vascular index and correlated to presumed ischemic pathophysiology behind DR; being correlated with VA in DR [9,19]; being able to help treatment selection as DME patients with larger FAZ was reported to be non-responder to laser therapy, who may benefit more from Anti-VEGF treatments [20]; being influenced by treatment modalities (laser or Anti-VEGF therapies) that may lead to reperfusion and reduce the FAZ area [17]; these altogether propose the FAZ characteristics as a potential qualitative and quantitative index that not only can be used to grade the DR but also to predict DR, guide the selection of appropriate treatment, help to localize laser treatment targets and follow up the effect of treatment.…”