No abstract

No abstract

Carotid-cavernous fistulas (CCFs) result from an anomalous connection between the internal and/or external carotid arteries and the cavernous sinus.The cavernous sinus comprises a network of venous channels through which the cavernous portion of the internal carotid artery (ICA), the internal carotid sympathetic plexus, and cranial nerve (CN) VI course. The CNs III, IV, and V (first and second divisions) run within the dura of the lateral wall of the cavernous sinus [1]. Carotid-cavernous fistulas can be classified by: • etiology: traumatic or spontaneous; • flow volume and speed: high or low; • angiographic architecture: direct or indirect. The most commonly used classification scheme for the latter was established by Barrow et al. He divided CCFs into four types, depending on the arterial feeders. Type A fistulas represent direct communications between the ICA and the cavernous sinus, usually associated with high flow rates. Indirect fistulas (types B, C, and D) are dural CCFs fed by the this article is available in open access under Creative Common attribution-Non-Commercial-No Derivatives 4.0 International (CC BY-NC-ND 4.0) license, allowing to download articles and share them with others as long as they credit the authors and the publisher, but without permission to change them in any way or use them commercially

Background: The aim of this study was to evaluate the characteristics of the macular vessel density (VD) and the foveal avascular zone (FAZ) in glaucoma quantitatively using the optical coherence tomography angiography (OCT-A). Methods: Twenty-five eyes of 13 patients with primary open angle glaucoma (POAG) and 12 eyes of 6 healthy participants were enrolled retrospectively. Functional visual field (VF) and structural Spectral-Domain optical coherence tomography (SD-OCT) Retinal Nerve Fiber Layer Thickness (RNFLT) were assessed in all participants. OCT-A was performed on a fovea centered, 15x10 degrees, macular region. OCT-A scans were processed with MATLAB software and automatically graded to define FAZ parameters. The parafoveal VD in the superficial and deep retinal vascular plexus (SVP and DVP) was analyzed by quadrant and circular segmented zones. Results: Foveal Avascular Zone -Major Axis Length (p=0.02), Area (p=0.04), Equivalent Diameter (p=0.04) and Perimeter (p=0.04) were significantly larger in glaucoma than the control group. Regarding SVP and DVP, the average macular total VD were lower in glaucoma patients compared to the control group (p<0.01; p<0.01). Additionally, the inner circular region (p=0.04; p<0.01 respectively for SVP and DVP) and all quadrants except for North had a lower VD in glaucoma group compared to the control group. Assessment of the total VD successfully predicted RNFLT (p<0.001) and was significantly associated with the probability of glaucoma (p=0.009). Conclusion: OCT-A parameters, namely the FAZ morphology and the macular VD, were associated with glaucomatous functional and structural changes. The macular VD showed a considerable diagnostic value. It may be a modern biomarker, representing microvascular network disruption of the macular perfusion in glaucoma.