Glaucoma refers to a complicated eye disease which often results to an irreversible loss of vision. This disease severely damages the optic nerve, a channel through which signals are sent to the brain for interpretation to the images seen by human beings, and thus compromising its ability to convey the light generated nerve impulses from the retina to the brain. This eye condition is often inherited and may not be manifested until the late stages of life. The common types of glaucoma include primary open-angle glaucoma, angle-closure glaucoma, and normal tension glaucoma. People who suffer from diabetes are usually prone to eye problems such as diabetic retinopathy, glaucoma and cataracts. The relationship between diabetes and open angle glaucoma, the commonly occurring type of glaucoma, has continued to intrigue researchers, with people suffering from diabetes having more likelihood (twice) as compared to people without diabetes condition.
Causes of Glaucoma
The commonly known cause for glaucoma is the increase in intraocular pressure, which usually occurs when the fluid pressure within the anterior chamber of the eye rises. An increase in the amount of aqueous humor, the fluid in the eye, exerts much pressure in the region between the iris and cornea, also known as the eye’s anterior chamber. This increased pressure damages the optic nerve and if not treated promptly, this condition may gradually result to permanent blindness. Other causes of glaucoma, which are not much prevalent, include serious eye infections, conditions which may cause eye inflammations, chemical or blunt injuries to the eyes, and sometimes corrective eye surgeries meant to treat other eye problems.
Poor regulation of blood to the optic nerve is another possible cause of glaucoma among individuals who have normal eye pressure. The aqueous fluid gets trapped and accumulates in the eye when the drainage system, referred to as trabecular meshwork, which drains the fluid into the blood system gets blocked, thus exerting pressure to the optic nerve and eventually affecting the vision of the concerned individual(Mapstone & Clark, 1985). The proper etiology of glaucoma can be well understood by considering the vascular component of the disease, similar to that of diabetes.
In diabetic patients, macrovascular complications leading to such conditions as cerebral blood-flow abnormalities is clearly linked to the development of glaucoma in these patients (Primus, Harris, Siesky & Guidoboni, 2011). This eye condition is usually characterized by gradual and progressive damage to the optic nerve tissues, which is manifested as subtle loss of side vision. If not detected and corrected early, glaucoma can eventually result to irreversible loss of vision.
Symptoms of Glaucoma
Typically, there are hardly any early warning symptoms or signs of glaucoma, and thus regular eye check-ups are essential and helpful in the early detection and treatment of open-angle glaucoma. Elevated intraocular pressure in the anterior chamber of the eye has an adverse effect on the delicate optical nerve tissues, which are thus damaged. African-Americans have a higher risk of developing glaucoma as compared to people from other races (Mapstone & Clark, 1985). According to a research study conducted by Washington University medicine researchers, the African-Americans have been found to have higher levels of oxygen in their eyes. This condition is presumed to facilitate oxidative stress responsible for the damage of the trabecular meshwork drainage system, resulting in increased intraocular pressure which damages the optical nerve tissues and eventually leading to blindness.
Glaucoma in Diabetics
Diabetics and people with hypertension are at a higher risk of developing open-angle glaucoma and subsequent irreversible loss of vision or permanent blindness as compared to the non-diabetic people. The relationship between diabetes and glaucoma has not been fully established, and it has intrigued many researchers as well as remaining a major controversy (Primus, Harris, Siesky & Guidoboni, 2011). There have been increased cases of glaucoma among patients suffering from diabetes, usually aged above forty years. Diabetes, a condition caused by the increase of sugar levels and decreased levels of insulin in the blood circulation, is associated with certain eye conditions such as cataracts, diabetic retinopathy, and chronic open angle glaucoma. According to National Glaucoma Research (2009), researchers have established that glaucoma effects among the increasing population of people with diabetes in the United States pose a significant threat of loss of vision, “depression, reduced independence, reduced mobility, and reduced quality of life” (p.1).
Individuals experiencing frequent episodes of Obstructive Sleep Apnea (OSA), a condition that causes the relaxation of the throat muscles d blockage of the airways, have a higher risk of manifesting “obesity, open- angle and normal-tension glaucoma conditions, diabetes and high blood pressure” (National Glaucoma Research, 2009, p.2). Whereas some researchers working on population-based studies have established that people with diabetes have an higher risk of development and severity of glaucoma, other studies which are similar show that there is no connection between the two conditions (Primus et al., 2011). Owing to the high glucose levels and high blood pressure in diabetic patients, they are twice as likely to develop diabetic proliferative retinopathy, a condition which causes the damage of the retinal blood vessels. If this condition is not promptly and appropriately treated, the diabetic patients have an increased risk of developing open-angle glaucoma and eventually lose their vision. This process involves the formation of new blood vessels in the retina to replace the damaged ones, thus causing constriction of the retina and formation of scars as the retina heals. This scarring process causes ripping of the retina and blockage of the fluid drainage system of the eye, thus resulting to increased intraocular pressure and subsequent damage of the optic nerve.
Treatment/Prevention for Glaucoma
Glaucoma does not have a specific treatment, and prevention against loss of vision is recommended and possible if the condition is detected early enough. Diabetic patients and other individuals who may be experiencing blurred vision or visibility problems ought to visit opticians and eye clinics for regular check ups (Glaucoma Research Foundation, 2011). The best treatment for glaucoma is the prompt, early diagnosis and appropriate treatment to prevent further development and associated irreversible blindness. Medical practitioners may prescribe the use of eye drops, pills to control the elevated intraocular pressure which if uncontrolled, gradually leads to damage of the optic nerve. In the case of retinopathy, laser may be used to eliminate the growth of new blood vessels in the retina, which may prevent development of glaucoma if permanent scarring had not taken place.
Glaucoma Research foundation. (2011). Diabetes and your eyesight. Retrieved on 17th December 17, 2011 from http://www.glaucoma.org/glaucoma/diabetes-and-your-eyesight.php
Mapstone, R. & Clark, C. (1985). Prevalence of diabetes in glaucoma, Clinical Research. British Medical Journal, 291. Retrieved on 17th December 17, 2011 from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1416219/pdf/bmjcred00456-0007.pdf
Primus, S., Harris, A., Siesky, B.A. & Guidoboni, G. (2011). Diabetes: a risk factor for glaucoma? British Journal of Ophthalmology, 95, 1621-1622. Retrieved on 17th December 17, 2011 from: http://bjo.bmj.com/content/95/12/1621.full.pdf