International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 03 Issue: 06 | June-2016 www.irjet.net p-ISSN: 2395-0072 © 2016, IRJET | Impact Factor value: 4.45 | ISO 9001:2008 Certified Journal | Page 201 Automatic Detection of Glaucoma Using 2-D DWT Kiran S M 1 , Dr. D N Chandrappa 2 1 PG Student, Dept of ECE, SJB Institute of Technology, Banglore, India 2 Professor, Dept of ECE, SJB Institute of Technology, Banglore, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Glaucoma is dangerous eye disease causes permanent blindness when it is untreated in earlier stages. Until the disease reaches to an advanced stages it shows no symptoms hence regular eye test is very important. Since glaucoma damages an optic nerve head, the disease can be detected automatically by analyzing retinal fundus images. The automatic analysis involves using structural and texture features of retinal images. This paper compiles an automatic system for glaucoma analysis using texture features extracted from retinal images. The texture features are extracted using 2-D discrete wavelet transforms. The image features obtained from five different wavelet filters Daubechies (db3), Symlet (sym3) and biorthogonal (Bior 3.3, Bior 3.5, Bior 3.7) are used to classify the images as glaucomatous and non glaucomatous. The system is able to detect the disease with an accuracy of 91.66%. Key Words: Glaucoma, Optic nerve head, Fundus images, structural features, texture features and wavelet 1. INTRODUCTION Along with the development of information technology, many computer-aided healthcare systems are implemented to provide a solution in the developing areas where medical resources are scarce. An example is about the diagnosis and treatment of glaucoma. Glaucoma is a group of eye diseases with common characteristics that result in damage of human visual system. The changes occurred in retinal structures such as eye’s optic nerve, which gradually lead to blindness or vision loss Glaucoma is the second largest cause of blindness in the world. According to survey around 2.3% of the total population got affected by glaucoma and is predicted to affect around 11.1 million people (around 2.86%) by 2020 [1]. Among the retinal diseases 13% of cases being affected by glaucoma. Very dangerous thing about glaucoma is that it shows no symptoms in earlier stages. That is no pain, no vision change etc. If remain untreated, the patient may start losing his side vision. Gradually he feels like looking through a tunnel. Glaucoma is non reversible but can be controlled by detecting the disease in earlier stages. In advanced stages glaucoma patient usually shows thinness of the cornea, high eye pressure and abnormal optic nerve anatomy. The main cause for glaucoma is increased intraocular pressure in the eye. To maintain healthy vision human eye produces a small amount of fluid called aqueous fluid or aqueous humour. It plays very important role in maintaining intraocular pressure and provides nutrition for various tissues. An imbalance is created in fluid flow when drainage system is blocked or eye produces an excess of fluid and hence pressure is increased inside the eye. Due to this high intraocular pressure optic nerve head is progressively damaged and causes vision loss. Based on how the introcular pressure is increased, glaucoma is classified as two types. (1) Open-angle glaucoma: This type of glaucoma can also be named as chronic glaucoma. It is most common type of glaucoma and symptoms are very slow to develop. It causes when an aqueous fluid is over produced or when eye drainage system is clogged over time. Due to this the fluid can’t thrown out of the eye. Around 80% of glaucoma patients are suffering from chronic glaucoma. (2) Closed-angle glaucoma: This is also called as acute narrow angle glaucoma. Around 10% of glaucoma patients are affected by Narrow angle glaucoma. Although it is rare it is very serious form of disease. It occurs in the people who have very narrow space between iris and cornea. As the eye ages, the pupil grows this leads to blocking of this narrow space. Hence, fluid flow is restricted this leads to increase in intraocular pressure. Because of sudden increase in pressure inside the eye, this type of glaucoma is very painful. There are three different methods are available for glaucoma detection, they includes: a) Assessment of raised intraocular pressure (IOP): Glaucoma can be present with or without increased intraocular pressure. Therefore intraocular pressure assessment is not effective tool for glaucoma detection. b) Assessment of abnormal visual field: Abnormal visual field test requires special equipments only present in territory hospitals hence it is unsuitable for glaucoma screening. c) Assessment of changes in retinal structure: In the inner surface of the eye, retina has light sensitive neuron layers. Eye diseases such as diabetic retinopathy, macular degeneration and glaucoma affect the neuron layer. Hence an eye retinal fundus images are analysed for detection of glaucoma. There exist two central issues to glaucoma recognition using fundus images: i. Use of image texture features (pixel intensity, textures, spectral features, parameters of histogram