Author : Monika Shingavi and Dr. G.P Potdar

Age-related Macular Degeneration (AMD) is a common eye condition that leads to about 8% of all blindness worldwide. It is leading cause of vision loss among people age 50 and older. Optical coherence tomography angiography (OCTA) is recent non-invasive technique used for detection of various eye related diseases. It provides vascular information related to an eye. Mainly, it is used for detection of choroidal neovascularization region inside an eye. Quantitative analysis of OCTA helps in finding abnormalities and guiding the treatment for eye related diseases like diabetic retinopathy and age related macular degeneration. Vessel density is one of the quantitative measurement which has gained popularity and provides ability to quantify OCTA images in order to measure effectiveness of provided treatment. Local thresholding and global thresholding methods are used for binarization of OCTA images. Vessel density changes with respect to image size, device used, location scanned, plexus under consideration and the type of techniques used for binarization of an image. There is no standard technique for calculation of vessel density in OCTA images. There is no surety that the results obtained using one of the techniques will be similar to other techniques. Proposed method based on Otsu and component labelling algorithm provided better results as compared to all other methods by giving exact mapping with vessels in OCTA images.

Keywords: Age related macular degeneration(AMD); Choroidal neovascularization(CNV); Vessel Density; Optical Coherence Tomography Angiography(OCTA);  Thresholding; Otsu.