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Objective: This paper aims at quantifying biomarkers from the segmentation of retinal arteries in adaptive optics ophthalmoscopy images (AOO)., Methods: The segmentation is based on the combination of deep learning and knowledge-driven deformable models to achieve a precise segmentation of the vessel walls, with a specific attention to bifurcations. Biomarkers (junction coefficient, branching coefficient, wall to lumen ratio ( wlr)) are derived from the resulting segmentation., Results: reliable and accurate segmentations ( mse = 1.75 ±1.24 pixel) and measurements are obtained, with high reproducibility with respect to images acquisition and users, and without bias., Significance: In a preliminary clinical study of patients with a genetic small vessel disease, some of them with vascular risk factors, an increased wlr was found in comparison to a control population., Conclusion: The wlr estimated in AOO images with our method (AOV, Adaptive Optics Vessel analysis) seems to be a very robust biomarker as long as the wall is well contrasted.

Purpose: To assess the correspondence between interdigitation zone (IZ) reflectivity, ellipsoid zone (EZ) loss, inner retinal layer reflectivity, patterns of capillary dilation, and telangiectasia in eyes with early macular telangiectasia type 2 (MacTel)., Patients and Methods: Twenty-eight eyes of 22 patients with grade 0-2 MacTel (according to the MacTel project classification) and 28 healthy control eyes were included in this study. Multimodal imaging, including optical coherence tomography (OCT) angiography, adaptive optics flood illumination ophthalmoscopy (AO-FIO) and blue light reflectance (BLR), was performed. The EZ, IZ, and outer plexiform layer (OPL) were analyzed on the structural OCT C-scans. The vascular density (VD) was measured on the binarized and skeletonized angiograms of the superficial vascular plexus and deep capillary complex. The vascular diameter index (VDI) was calculated by dividing the binarized VD by the skeletonized VD., Results: On AO-FIO, cone density in the MacTel zone was significantly lower in MacTel eyes than in controls, even in areas located outside the EZ loss (P < 0.001). A distinctive pattern of IZ reflectivity attenuation extended beyond the area of EZ attenuation. The shape and size of a strong OPL hyper-reflectivity corresponded to the MacTel white area (MacTel zone) seen on BLR. Capillary dilation and rarefaction were colocalized with this area, extending beyond visible telangiectasia. The VDI was higher in MacTel eyes than in controls (P < 0.001)., Conclusions: These findings suggest that in early MacTel eyes, photoreceptor signal alteration, OPL hyper-reflectivity, and capillary dilation, potentially associated with Müller cell dysfunction, precede the EZ loss.