The Main Glaucoma Pathology: the Most Characteristic Feature of Eye Diseases - Research Paper Example

 Glaucoma is a major health challenge that threatens the vision of the people affected by it. It mainly refers to a group of eye diseases that have an impact on the optic nerve, thereby resulting in loss of vision (Noecker, 2005). The most characteristic feature of most of these conditions is rise in intraocular pressure (Noecker, 2005). The condition affects 2 percents of people in the beyond-40 age group (Noecker, 2005). Due to ageing population, there is a rise in the number of glaucoma cases. Besides threat for loss of vision, glaucoma has a devastating impact on the physical, psychological, social, financial and spiritual aspects of the person. The aim of this paper is to describe various aspects of pathophysiology of glaucoma, common clinical manifestations, approach to management and implications for the patients and the family. There are basically 2 types of glaucoma, namely, the open-angle glaucoma and the closed angle glaucoma (Noecker, 2005). In the closed angle glaucoma, the drainage canals of the eye which drain the secretions of the eye get blocked resulting in raised intraocular pressure. This type of glaucoma can be either acute or chronic. In the acute angle closure glaucoma, the rise in intraocular pressure is sudden and occurs due to building up of aqueous humor. This condition is an ophthalmic emergency because of its potential to cause vision loss within hours of onset of the condition subsequent to damage of the optic nerve. Chronic angle closure glaucoma occurs gradually and may not present with any symptoms. This condition also can lead to vision loss. (Ali and Fraser, 2007). In the open-angle glaucoma, rise in intraocular pressure occurs even with open drainage system. Even this type of glaucoma leads to blindness without prior symptomatology. Other forms of glaucoma which merit importance are normal or low tension glaucoma in which damage to the optic nerve occurs despite normal intraocular pressure, childhood glaucoma which presents in childhood and resembles open-angle glaucoma, congenital glaucoma which manifests soon after birth and secondary glaucoma in which raised intraocular pressure ensues secondary to other structural and medical problems of the eye (Noecker, 2005). The main pathology in glaucoma is raised intraocular pressure. Normal intraocular pressure is between 10-21 mmHg (Noecker, 2005). In a normal eye, aqueous humor, which is a fluid produced in the posterior chamber of the eye flows through the aperture of the pupil into the anterior chamber of the eye. From the anterior chamber of the eye, aqueous humor flows through the canals of Schlem and then goes out of the eye. The main purpose of this fluid is to provide oxygenation, nutrition and support to the tissues of the eye. Whenever there is either and increased production of aqueous humor or an obstruction to drainage of the fluid, the amount of fluid in the eye increases, resulting in raised intraocular pressure (Noecker, 2005). Raised intraocular pressures presses on the optic nerve head and eventually causes damage to the nerve. The cause for development of vision loss is not because of raised intraocular pressure alone. There are many other factors which contribute to vision loss. Patients with glaucoma mainly present with vision loss (Ali and Fraser, 2007). In th initial stages, the person may develop blind spots in the peripheral vision due to damage of the optic fibers. In acute angle glaucoma, which is an acute condition, the patient presents with certain symptoms like severe pain of the eye, halos around lights, blurring of vision and other systemic symptoms like headache, nausea, vomiting and abdominal pain (Ali and Fraser, 2007). Glaucoma can result in vision loss affecting the day-to-day activities of the person and causing significant emotional, pyschological and social consequences. There can be loss of employment, thus affecting the economic condition of the patient. Since vision is the most important sensation to survive with comfort, impairment of this can affect the spiritual well being of the person. The main investigation in glaucoma is estimation of intraocular pressure. The most common method of determine intraocular pressure is the 'air puff test'. In this test, a rough estimate of the intraocular pressure is done by evaluating the response of the eye to jet of air that is directed to the eye (Noecker, 2005). This test can be employed only as a screening measure. Confirmatory test for raised intraocular pressure is direct tonometry using a tonometer which is placed on the external surface of the eye. The next test that is done is dilatation of the pupils and examination of the back of the eye. Depression or divot of the optic nerve head is suggestive of damage due to raised intraocular pressure and is known as 'cupping' of the optic nerve Noecker, 2005). This feature is an indication of advanced stage of glaucoma. Determination of the presence of visual field defects is evaluated using perimetry. Peripheral vision is the first to be effected and the aim of perimetry should be to determine peripheral vision deficits as early as possible so as to initiate treatment with interest to prevent further loss of vision.. There is enormous information in the internet pertaining to glaucoma. One such site which provides useful information is available at This four minute video titled "Glaucoma" by Stephen Vernon, Consultant Ophthalmologist at the University Hospital of Nottingham, is knowledge enhancing about glaucoma. According to Vernon, the most common form of glaucoma in the United States is open angle glaucoma. Vernon states that the incidence of glaucoma rises to 5-6 percent in population over 75 years and that people from African origin and people with family history of glaucoma have increased risk of developing the disorder. The video covers about the the clinical symptoms of the disease, measures to detect it and various treatment strategies available. Vernon stresses the importance of early detection especially through screening in high-risk population. He also stresses on the need for compliance with treatment. The video shows how the tests are done, how the various surgeries are performed and how the back of the eye appear in glaucoma, to benefit the understanding of the layman. The main treatment for glaucoma is lowering of intraocular pressure either by reducing the production of aqueous humor, or by increasing the drainage of the fluid. Both surgical and pharmacological methods exist to decrease intraocular pressure and the decision depends on the type of glaucoma. The most commonly used drugs for treatment of glaucoma are beta-adrenergic blocking agents like timolol, alpha-adrenergic agents like bromonidie and prostaglandin analogs like latanoprost. These drugs act either by reducing the production of acqueous humor or by improving the drainage of the fluid or by increasing secondary routes of drainage of the fluid or all. there are many surgical methods also to treat glaucoma (Noecker, 2005). In angle-closure glaucoma, iridotomy is useful in which a perforation is created in the iris through laser technology to drain fluid. Congenital glaucoma is unresponsive to medical management and hence must be treated surgically. other surgeries useful to treat glaucoma are flitering, trabeculoplasty and cyclophotocoagulation Noecker, 2005). Glaucoma is a group of disorders which can cause debilitating vision loss. The condition not curable, but is controllable with the above measures described. Early diagnosis and management is critical to prevent debilitating vision loss. Those with high risk of developing glaucoma must be evaluated through screening for high ocular pressures to prevent implications from vision loss. Diagnosed patients must exert to control the disease by adhering to treatment regimens and by regular follow-up. References Ali, M.N., and Fraser, S.G. (2007). Medicolegal aspects of glaucoma. Clinical Risk, 13, 12-16. Noecker, R.J. (2005). Glaucoma. Emedicinehealth. Retrieved on 22nd October, 2009 from http://www.emedicinehealth.com/glaucoma_overview/page15_em.htm#Authors%20and%20Editors Vernon, Steve. (n.d.). Glaucoma video presentation. Youtube. Retrieved on 22nd October, 2009 from http://www.youtube.com/watch?v=Mh_miF6KIio Read More