Fundus image analysis is playing an important role in the early detection of retinal eye diseases like diabetic retinopathy, glaucoma etc. Automated detection of hypertensive retinopathy (HR) is a recent development in this field. Segmentation of blood vessels, measurement of tortuosity, diameter measurement, finding the artery vein ratios (AVR) are few important measures for finding HR using digital fundus images. We propose a support system to assist the ophthalmologist in detecting HR in early stages. Segmentation of blood vessels is done using Radon transform, optic disk is detected by Hough transform and then the AVR is calculated. The proposed support system will help the ophthalmologist in the early detection of HR.

1. Abramoff, M. D. Garvin, M. K. Sonka, M. Retinal Imaging and Image Analysis, IEEE Reviews in Biomedical Engineering, Vol. 3, 2010
2. E. Grisan, M. Foracchia, and A. Ruggeri, "A novel method for the automatic grading of retinal vessel tortuosity," IEEE Transactions on Medical Imaging, vol. 27, pp. 310–319, 2008.
3. L. Pedersen,M. Grunkin,B. Ersbøll,K. Madsen,M. Larsen,N. Christoffersen,U. Skands. Quantitativemeasurement of changesin retinal vessel diameter in ocular fundus images" Pattern Recognition Letters Volume 21, Issues 13–14, December 2000, Pages 1215–1223
4. Chaudhari S , Chatterjee S, Katz N, Nelson M and Goldbaum M, "Detection of blood vessels in retinal images using two dimentional matched filters" IEEE Trans . Medical Imaging. Vol 8: 263-269, 1989
5. Hoover, A. , Kouznetsoza, V. , Goldbaum, M. (2000) Lo- cating blood vessels in retinal images by piecewise threshold probing of a matched filter response. IEEE Transactions on Medical Imaging, 19, 203-210.
6. M. Al-Rawi, H. Karajeh, Genetic algorithm matched filter optimization for automated detection of blood vessels from digital retinal images, Comput. Methods Programs Biomed. (2007).
7. Zana, F. and Klein, J. (2001) Segmentation of vessel-like patterns using mathematical morphology and curvature evaluation. IEEE Transactions on Image Processing, 10, 1010-1019
8. Sinthanayothin,C. ,Boyce,J. ,Williamson,T. ,Cook,H. ,Mensah, E. , Lal,S. ,Usher,D. ,2002. Automated detection of diabetic retinopathy on digital fundus images. Diabet. Med. 19,105–112.
9. João V. B. Soares, Jorge J. G. Leandro, Roberto M. Cesar Jr. , Herbert F. Jelinek, and Michael J. Cree. "Retinal Vessel Segmentation Using the 2-D Gabor Wavelet and Supervised Classification" IEEE Transaction on Medical Imaging, September 2006.
10. R. Pourreza, T. Banaee, H. R. Pourreza, R. Daneshvar, "A Radon transform based approach for extraction of blood vessels in conjunctival images", MICAI 2008, LNAI 5317, pp. 948–956, 2008.
11. Zhang, Q. , Couloigner, I. : Accurate Centerline Detection and Line Width Estimation of Thick Lines Using the Radon Transform. IEEE Transaction on Image Processing 24, 310–316 (2006)
12. Lee,S. ,Wang, Y. ,Lee,E. ,1999. A computer algorithm for automated detection and quantification of microaneurysms and haemorrhages in color retinal images. In: ,SPIE Conference on Image Perception and Performance,vol. 3663,pp. 61–71.
13. Goldbaum,M. ,Katz,N. ,Nelson,M. , Haff,L. ,1990. The discrimination of similarly colored objects in computer images of the ocular fundus. Invest. Ophthalmol. Vis. Sci. 31,617–623.
14. Li,H. ,Chutatape, O. ,2004. Automated feature extraction in color retinal images by a model based approach. IEEE Trans. Biomed. Eng. 51,246–254.
15. Sinthanayothin,C. ,Boyce, J. F. , Cook,H. L. ,Williamso n,T. H. , 1999. Automated localisation of the optic disc,fovea, and retinal blood vessels from digital colour fundus images. Br. J. Ophthalmol. 83.
16. Lowell,Hunter,A. ,Steel,D. ,Basu,A. ,Ryder,R. ,Fletche E. ,Kennedy,L. , 2004a. Optic nerve head segmentation. IEEE Trans. Biomed. Eng. 23,256–264
17. Foracchia,M. ,Grisan, E. , Ruggeri,A. , 2004. Detection of optic disc in retinal images by means of a geometrical model of vessel structure. IEEE Trans. Biomed. Eng. 23,1189–11 95
18. Hoover,A. , Goldbaum, M. , 2003. Locating the optic nerve in a retinal image using the fuzzy convergence of the blood vessels. IEEE Trans. Biomed. Eng. 22,951–958.
19. V. Stanton, B. Wasan, A. Cerutti, S. Ford, R. Marsh, P. P. Sever,S. A. Thom, and A. D. Hughes, Vascular network changes in the retinawith age and hypertension, Journal of Hypertension 13 (1995), 1724-1728.
20. Hubbard L. D. , Brothers R. J, King W. N. , et al. "Methods for evaluation of retinal microvascular abnormalities associated with hypertension/sclerosis in the Atherosclerosis Risk in Communities Study". Ophthalmology. Vol 106 No 12 1999 Page:2269—80.

Fundus Images Hypertensive Retinopathy Arteriovenous Ratio