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Cataracts and Glaucoma

RUNNING HEAD: CATARACTS AND GLAUCOMA

Cataracts and Glaucoma in World Populations: Differences in Treatment

Vicki Herrin, Hampton Huddleston, Carmen Leyva

Stephen F. Austin State University

Cataracts and Glaucoma in World Populations: Differences in Treatment

When viewed from outer space, our planet appears blue and round. It appears to be one unified planet, but all things are not as they appear. When viewed closer, as from a satellite orbiting the planet, it becomes obvious that the planet is not the same all over. The conditions for living in diverse places on planet Earth are as diverse as the terrain. The lives of human beings are not the same everywhere. People do not live under the same conditions, climates, governments or economies. People do not all get the same medical care. Visual impairment is not uniformly distributed in the world; the least developed regions have the largest share (WHO Global Data, 2002).This paper will explore the two leading forms of blindness in the world as well as the inequality of treatment for these conditions in the world.

According to the World Health Organization (WHO), the top two causes of blindness in the world are cataracts and glaucoma. World eye care is greater in modern, industrialized nations and lesser in poorer, developing nations. The reason for greater care in modern countries is there are more trained eye doctors, plus the economic factors of surgical technology and the availability of drugs. A typical cataract surgery in a modern country such as the United States (US) would involve drugs at the beginning of surgery, to induce a calming effect, or possibly anesthesia, followed by removal of the cataract (occluded lens of the eye) and an intraocular implant of a plastic lens. Eye drops and dark wraparound sunglasses for going outdoors will follow surgery for a specific time period. The cost of this for one eye in San Antonio, TX is $3,500.00. Six months to a year after that, a laser may be used to remove scar tissue occluding the implanted lens. A new pair of glasses is then prescribed following an eye examination. Depending on the prescription plus the frame style, this is anywhere from $100.00 up to $1,000.00 or more. Cataract surgery is the most commonly performed type of surgery in the United States (All about vision). In developing countries 50-90% of all blindness is caused by untreated cataracts (WHO, 2002). In India there is a backlog of 9.3 million people waiting for cataract surgery, due to lack of trained eye doctors and surgical equipment (WHO, 2002). This is not just a statistic in developing nations. In England and Wales in 2001, there were 2.4 million people backlogged for cataract surgery who were visually impaired. That year, 161,000 cataract surgeries were done. At that rate, it would take 5 years to complete all the people waiting (WHO, 2001). This does not include all the new numbers added during those 5 years.

There is an increase in cataracts due to the thinning of the ozone layer, causing increased exposure to ultraviolet light (UVA and UVB). Cataracts are the leading cause of blindness in the world, affecting 25 million people (WHO, 2006). It is estimated that up to 20% of these cataracts are caused by increased exposure to UV light. This is especially true of India, Pakistan and areas in the “cataract belt” close to the equator (WHO, 2002). As the world’s population ages, the incidence of cataracts is on the rise. Prevention consists of reducing UV exposure with sunglasses that screen out UV light and using a hat with a brim. Other preventative measures linked to cataracts is not smoking, reducing alcohol consumption, and avoiding air pollution. In developing nations, air pollution is an unavoidable condition for many poor people, who lack the funds to relocate. People in developing nations don’t have a lot of resources or capital to pay for technology, drugs and training doctors. Education is their best option, along with a hat.

The WHO Global Initiative to Eliminate Avoidable Blindness is called “VISION 2020: The Right to Sight” and the focus is to eliminate cataracts and two other eye diseases through developed strategies and programs. Even though there was a lot of progress made in the surgical techniques used over the last 10 years in many countries, cataracts remain 48% of the leading causes of visual impairment in all areas of the world, except for the developed countries (WHO, 2002).

Worldwide, glaucoma is the second leading cause of blindness, and the leading cause of irreversible blindness (Wikipedia, 2010). The development of screening and management strategies for use at the primary care level for glaucoma is ongoing at the WHO. People who do not have regular eye exams may not know they have glaucoma until they begin to lose their vision. A loss of vision in the peripheral fields is where glaucoma is first noticed and if not treated, will eventually become tunnel vision ending in blindness. Approximately 2.5 million Americans have glaucoma, and worldwide there are 6 million people blind in both eyes from glaucoma (medicinenet.com, 2010).

Glaucoma is pressure inside the eye that can result in a damaged optic nerve. Detected by regular eye exams and screenings, glaucoma can be arrested. In an undeveloped nation, manually pressing on the eye can be the test method. An ophthalmoscope can look into the dilated eye for cupping around the optic disk. In industrialized nations, there is testing with technology, usually an exam begins with drops to numb the eye. Intraocular pressure can be detected using a tonometer or a tonopen to measure the pressure inside the eye in mercury millimeters (mmHg). An intraocular pressure of 20mmHg or less is considered safe. Anything over 20mmHg is cause for monitoring. If the pressure reading is 21mmHg or greater, it means there is pressure regarding the aqueous humor within the eye. The eye could be producing too much fluid, or there is a problem with the fluid not draining (All about vision, glaucoma 2010). Treatment is typically daily drops in the affected eye to keep the pressure down. Due to glaucoma being painless, one problem with drops is sometimes people will get careless about strict adherence in their application. Non-compliance with a subscribed program is a major reason for blindness caused by glaucoma (medicinenet.com 2010).

There are two major types of glaucoma: primary open angle and acute angle closure. There are several other less frequent forms: normal-tension glaucoma, pigmentary glaucoma, secondary glaucoma and congenital glaucoma (medicinenet.com 2010). Sometimes surgery is recommended for treating the problem at the source. Lasers can drill holes to let the fluid drain, or a shunt could be implanted to create a drainage way for the fluid. The cost in San Antonio for laser surgery to create a drainage hole is $900.00. Glaucoma affects 1 in every 200 people 50 and under and affects 1 in every 10 over 80, arresting this disease is possible with early detection (Wikipedia, 2010).

By 2020, it is estimated that the world population of 6 billion will increase by one third, mostly in developing countries (WHO, 2001). According to the WHO, at the same time, the elderly population of people over 65 will double in both developing and modern nations. If more people live longer, there will be greater numbers of people with cataracts and glaucoma. As the population of the world grows, so will the population of people who are blind.

References

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All about vision, Glaucoma. http://www.allaboutvision.com/conditions/glaucoma.htm

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Medicine net.com, Glaucoma. http://www.medicinenet.com/glaucoma/article.htm#tocbg

Retrieved August 3,2010

Wikipedia, Glaucoma. http://en.wikipedia.org/wiki/Glaucoma

Retrieved August 3, 2010

World Health Organization. Blindness. http://www.who.int/topics/blindness/en/

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http://www.who.int/blindness/causes/en/index.html Retrieved July 31, 2010

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