Quantitative OCT Angiography of Retina Vessel Density for Early Glaucoma Diagnosis Nhat Tan Le 1 , Tan Thi Pham 1 , Thanh Hoan Ngo 2 1 Faculty of Applied Science, Ho Chi Minh City University of Technology, Vietnam National University Ho Chi Minh City, Vietnam 2 Department of Biomedical Engineering, International University, Vietnam National University Ho Chi Minh City lntan.sdh19@hcmut.edu.vn, ptthi@hcmut.edu.vn Abstract Glaucoma is the leading cause of irreversible blindness worldwide. Developed recently, OCTA is a promising non-invasive eyes imaging tool to glaucoma diagnosis in the early stage. This research designed a diagnosis support software based on analyzing color-density map and ROIs vessel density index on the OCTA images scanned peripapillary and macula area. Hessian-based filter and Otsu thresholding were used to detect and enhance small vessels. The program greatly detected areas of vascular dropout on glaucoma eyes. 1 Introduction Glaucoma is one of the most common eyes disease over the world. The main causes of glaucoma come from a type of liquid called aqueous humor, which were contained by anterior and posterior chamber of the eyeballs. This fluid carries out nutrients transport processes between the eyeballs and the vein system of the body. In glaucoma eyes, this liquid was blocked or interrupted, stuck in the chamber that make the pressure inside the eye (intraocular pressure) increase by time and cause damage to the retina at the bottom of the eyeballs. This research was focusing on open-angle glaucoma, which more common cases in glaucoma. Currently, glaucoma diagnosis methods were divided into two main groups: functional (Visual Field) and structural (eye’s imaging) of the eyes. Both groups have their own strengths and limitations. Visual Field has been shown to have high diagnostic accuracy and that is the reason why Visual Field was the one of standard method for glaucoma diagnosis despite of long testing time (5 to 15 minutes) and the patient answers. For the diagnosis group based on structural changes in glaucoma such as measuring intraocular pressure (IOP) by Tonometry, measuring drainage angle by Gonioscopy and more commonly checking retinal lesions by a lot of eye’s imaging methods such as ophthalmic funduscopy, optical coherence tomography (OCT) or especially optical coherence Kalpa Publications in Engineering Volume 3, 2020, Pages 212–222 Proceedings of International Sym- posium on Applied Science 2019 T.T. Truong, T.N. Tran, Q.K. Le and T.N. Nguyen (eds.), ISAS 2019 (Kalpa Publications in Engineering, vol. 3), pp. 212–222