Florentina Freiberg and Maximilian Pfau contributed equally to this work.
To analyze foveal avascular zone (FAZ) dimensions and symmetry in patients with diabetic retinopathy (DR) compared to healthy controls using optical coherence tomography angiography (OCT angiography).
OCT angiography was performed via an Avanti® RTVue 100 XR OCT system (Optovue, Inc., Fremont, CA, USA) in patients with diabetes mellitus (DM) and healthy adults. A frame centered on the fovea was used for FAZ measurements. The borders of the superficial vascular layer were defined as 3 μm below the internal limiting membrane (ILM) and 15 μm below the inner plexiform layer (IPL), and for the deep vascular layer as15 μm and 70 μm below the IPL, respectively. Angles of maximum FAZ diameter were measured in all eyes by two graders.
In healthy eyes (N = 25), the FAZ surrounding vascular arcades were intact, showing a vertical or horizontal oval symmetrical formation with a maximum diameter usually on the horizontal or vertical axis. Diabetic eyes (N = 29) presented with disintegrity of the vascular arcades, resulting in an enlarged FAZ. In the superficial layer, the mean horizontal FAZ diameter was significantly larger in the DR group (753 μm ±272 μm) than in the control group (573 μm ±177 μm, p = 0.029). The difference was even more pronounced in the deep layer, with a mean value of 659 μm ±194 μm in the control group and 1009 μm ±342 μm in the DR group (p = 0.001). Furthermore, in the superficial layer, the angle of the maximum FAZ diameter was 0° (±15°) or 90° (±15°) in 72.0 % of healthy eyes. In eyes with DR, the angle was 0° (±15°) or 90° (±15°) in only 6.9 % of cases, due to the irregular configuration of the FAZ.
OCT angiography is capable of imaging retinal vasculature without dye injection. Our data suggest that it can detect disintegrity of the vascular arcades surrounding the FAZ, thus differentiating DM from healthy eyes. Vascular abnormalities were more pronounced in the deep vascular layer.
Early Treatment Diabetic Retinopathy Study Research Group (1991) Grading diabetic retinopathy from stereoscopic color fundus photographs--an extension of the modified Airlie House classification. ETDRS report number 10. Ophthalmology 98(5 Suppl):786–806
Early Treatment Diabetic Retinopathy Study Research Group (1991) Classification of diabetic retinopathy from fluorescein angiograms. ETDRS report number 11. Ophthalmology 98(5 Suppl):807–822
Kikai K (1930) Über die Vitalfärbung des hinteren Bulbusabschnittes. Arch Augenheilkd 103:541–553
Snodderly DM, Weinhaus RS, Choi JC (1992) Neural-vascular relationships in central retina of macaque monkeys (Macaca fascicularis). J Neurosci 12(4):1169–1193 PubMed
Mendis KR, Balaratnasingam C, Yu P, Barry CJ, McAllister IL, Cringle SJ, Yu DY (2010) Correlation of histologic and clinical images to determine the diagnostic value of fluorescein angiography for studying retinal capillary detail. Invest Ophthalmol Vis Sci 51(11):5864–5869. doi: 10.1167/iovs.10-5333 CrossRefPubMed
Jia Y, Bailey ST, Wilson DJ, Tan O, Klein ML, Flaxel CJ, Potsaid B, Liu JJ, Lu CD, Kraus MF, Fujimoto JG, Huang D (2014) Quantitative optical coherence tomography angiography of choroidal neovascularization in age-related macular degeneration. Ophthalmology 121(7):1435–1444. doi: 10.1016/j.ophtha.2014.01.034 CrossRefPubMedPubMedCentral
Jia Y, Wei E, Wang X, Zhang X, Morrison JC, Parikh M, Lombardi LH, Gattey DM, Armour RL, Edmunds B, Kraus MF, Fujimoto JG, Huang D (2014) Optical coherence tomography angiography of optic disc perfusion in glaucoma. Ophthalmology 121(7):1322–1332. doi: 10.1016/j.ophtha.2014.01.021 CrossRefPubMedPubMedCentral
Early Treatment Diabetic Retinopathy Study Research Group (1995) Focal photocoagulation treatment of diabetic macular edema. Relationship of treatment effect to fluorescein angiographic and other retinal characteristics at baseline: ETDRS report no. 19. Arch Ophthalmol 113(9):1144–1155 CrossRef
(1996) The absence of a glycemic threshold for the development of long-term complications: the perspective of the Diabetes Control and Complications Trial. Diabetes 45 (10):1289–1298
- Optical coherence tomography angiography of the foveal avascular zone in diabetic retinopathy
Florentina J. Freiberg
Magdalena A. Wirth
Matthias D. Becker
- Springer Berlin Heidelberg
Graefe's Archive for Clinical and Experimental Ophthalmology
Incorporating German Journal of Ophthalmology
Print ISSN: 0721-832X
Elektronische ISSN: 1435-702X