Automated Segmentation and Multifractal Analysis of High-Resolution Non-Invasive Capillary Perfusion Maps (nCPMs) of the Human Retina (IN4-1.002)

OBJECTIVE: To demonstrate the feasibility of automated segmentation and multifractal analysis of high resolution non invasive capillary perfusion maps (nCPMs) of the human retina. BACKGROUND: The retina provides a window to study the etiology and pathogenesis of cerebrovascular diseases. Pathologic retinal microvascular changes may reflect micro-angiopathic processes in the brain. Previous fractal analysis of the retinal vasculature is limited by its low resolution of the fundus photo for extracting vessel information. Recent advances in optical imaging enable visualization of the retinal microvasculature at the capillary level and construction of high resolution non-invasive capillary perfusion maps (nCPMs). DESIGN/METHODS: nCPMs were obtained using the Retinal Function Imager (RFI, Optical Imaging Ltd, Rehovot, Israel). Image segmentation was custom developed. After correcting non-uniform illumination of the image, morphological filters were used for extracting linear shapes which were mostly vessels and non-vessel structures. The grey-scale images were processed using thresholding in order to create the dense network in the nCPMs. Matlab9s bwmorph algorithm was used to skeletonize the segmented vascular network. Fractal analysis toolbox from Benoit (TruSoft Benoit Pro 2.0, TruSoft International Inc) was used to analyze the fractal dimension of the nCPMs. Multiple nCPMs of 2 healthy subjects were obtained and analyzed. RESULTS: The nCPM showed much more details of the microvascular network, which appeared to be very dense and balanced branching of the capillary network around the avascular zone (the fovea). The network was well preserved in the segmented image. Multifractal analysis (D0) of the nCPM was performed and the result was 1.92 ± 0.03. CONCLUSIONS: This study has demonstrated for the first time that automated segmentation and multifractal analysis of nCPMs are feasible. This approach may open a new era for studying retinal microvasculature and brain small vessel disease. Supported by: In part by the research grants NIH R01EY020607, NIH R01EY020607S, NINDS K24 NS 062737 (TR), NIH Center Grant P30 EY014801 and the grant from Research to Prevent Blindness (RPB). Disclosure: Dr. Jiang has nothing to disclose. Dr. Cabrera DeBuc has nothing to disclose. Dr. Rundek has nothing to disclose. Dr. Shen has nothing to disclose. Dr. Lam has received personal compensation for activities with Johnson & Johnson for serving on a scientific advisory board...... Dr. Wang has nothing to disclose. Dr. Shao has nothing to disclose.