[Novel Examination Procedures for the Assessment of Retinal Artery Occlusion by OCT Angiography]

Background Retinal artery occlusion (RAO) is the most common primary angiopathy of the retina. With an incidence of 0.01 - 0.15%, this it is a rather rare disease, but is associated with irreversible damage to the retina and a poor prognosis for visual acuity. Since the 1960s - when fluorescence angiography (FA) was developed -, there has been little change in diagnostic investigations. FA is still the standard procedure for the assessment of retinal artery occlusions. With the development of OCT angiography (OCT-A), new multimodal imaging procedures have become possible. Patients/Methods We used Zeiss AngioPlex^®-OCT-A technology in combination with the CIRRUS^™ HD-OCT 5000 (Carl Zeiss Meditec, Inc., Dublin, USA) to create 6 × 6 mm and 3 × 3 mm volume scans of the area of non-perfusion in patients with RAO. Qualitative OCT-A analysis was performed on retinal images segmented into the superficial and deep retinal capillary plexus. In addition to this, volumetric scans can be segmented to any specific depth of the retina. On the basis of 4 cases, we demonstrate that OCT-A can be used to evaluate RAO. We present typical OCT-A findings. Results OCT-A images allow the detection of non-perfused areas in patients with acute and chronic RAO. The zones of reduced vascular perfusion are differently distributed in the superficial and deep retinal capillary plexus. In both acute and chronic cases of RAO, OCT-A offers important information on retinal vascular perfusion. Conclusion OCT-A can be used in the diagnosis and monitoring of acute and chronic cases of RAO. The advantages of OCT-A are that this technique is non-invasive and allows three dimensional microvascular visualisation within seconds. Although artefacts and the currently limited field of view can make it difficult to interpret OCT-A images reliably, these findings suggest that OCT-A may in future replace FA in the assessment of RAO in most patients.