A ssessment of Glaucoma with Ocular Thermal Images using GLCM Techniques

This paper proposes a methodology for early detection and recognition of Glaucoma in ocular thermographs. Ocular thermography is an efficient tool not only to capture temperatures of corneal surface, but also to detect and visualize any changes on the Ocular surface temperature. The proposed method uses a linear transformation for pre- processing. Support vector machines (SVM) based classifier with the features collected from GLCM is used to classify the given ocular IR thermal image into Glaucoma from the normal eye. The efficacy of the proposed technique is proved over a number of ocular thermal image samples. In this paper, we are specifically interested in the mapping of ocular region and diagnosis of diseases pertaining to the same. Ocular thermography using infrared imaging systems has been used to investigate ocular tumors, retinoblastoma, glaucoma etc. The most common diseases that manifest in the eye are diabetic retinopathy, age-related macular degeneration, glaucoma and cardiovascular diseases. Above diseases damage the retina which can be observed in retinograms. In order to analyse the retinal structure and its changes over time, the retina should be imaged effectively. Retinal imaging techniques are developed in order to capture the retina morphology effectively and to model its changes over time. Fundus photography, Optical coherence tomography (OCT), Fluorescein angiography. Ocular IR thermography is a retinal imaging techniques that are widely used for the detection of various diseases and does not harm the subjects under investigation (2). Glau coma is invisible disease that can damage the eye's optic nerve and this leads to loss of vision and bli ndness. Eye has pressure just like our blood and an increase in intra ocular pressure (IOP) damages the optic nerve. Although the raised IOP is a significant risk factor for developing glaucoma, there is no set threshold for IOP that causes glaucoma. Glaucoma is similar to ocular hypertension, but with accompanying optic nerve damage (3). To understand glaucoma it is important to consider aqueous humor, the clear watery fluid that circulates through the anterior chamber. This fluid is not related to tears, or to the dense jelly-like substance called vitreous humor contained in the rear chamber. The function of aqueous humor is to nourish the area around the iris and the cornea and it exerts pressure to maintain the shape of the eye (4).