According to the Centers for Disease Control and Prevention, Vision Health Initiative, over 3.4 million Americans are either blind or have poor vision; this number is expected to double by the year 2030. In addition, they estimate that 80 million suffer from eye diseases that could lead to blindness. To reverse this trend, the major diseases that need attention are that of diabetic retinopathy, both forms of glaucoma, cataracts and age-related macular degeneration.
Diabetic Retinopathy
Diabetes mellitus is the most common cause of blindness in the United States. There are 23.5 million Americans with diabetes; 4.1 million have diabetic retinopathy, disease in the retina due to diabetes. Diabetes causes this disease because the high blood glucose levels damage the small blood vessels that are in the eye. As a result, diabetics face microaneurysms, hemorrhages, abnormal blood vessels and scarring in their eyes. All of this interferes with the flow of blood. Without the proper blood flow, the retina will not be able to get the oxygen that it needs.
Open-Angle Glaucoma
According to Douglas Rhee, M.D., assistant professor at Harvard Medical School, approximately 3 million Americans have glaucoma, the second-most common cause for blindness. This number includes both the open-angle and angle-closure types, but open-angle glaucoma is the most common type of glaucoma. Normally, your eyes have a fluid called aqueous humor. This watery fluid is secreted within your eyes and flows through your pupils and into what is called the anterior chamber (an area in front of your pupil and behind your cornea). From there, the fluid will leave your eyes through a Schlemm's canal and be reabsorbed into veins. In open-angle glaucoma, similar to a clogged drain, the aqueous humor drains too slowly because of blockage near the Schlemm's canal. The pressure inside of your eyes will gradually increase and cause you to lose your vision. Both eyes are usually affected; the changes will be in your peripheral vision first and will then move central.
Acute Angle-Closure Glaucoma
This is a medical emergency because, in this type of glaucoma, it is not a gradual blockage, as in open-angle glaucoma. Here, the blockage is sudden. This results in a rapid increase of the pressure inside your eye. You will experience pain, have a red eye, blurry vision and may feel nauseous. In addition, you might see rainbow-colored halos when looking at lights.
Cataracts
This is the term that is used whenever there is an opacity in your lens. Your vision will be blurry, because light will not be able to pass through your lens as it should. Cataracts, in fact, are the number one reason for decreased vision in America, most commonly due to aging. But this condition can also occur as a result of trauma, diabetes and infection, and can even be hereditary. As in diabetic retinopathy, where the high blood glucose levels cause damage to the retina, the high levels damage the lens as well.
Age-Related Macular Degeneration
This is the number one reason for the permanent vision loss of both eyes for the elderly population. There are actually two types; in the type called dry, you slowly, gradually lose your central vision. There is no pain, and you still have your peripheral vision, so you are able to safely move around. The second type is called wet. In this type as well, you lose your central vision and keep your peripheral vision, but you will lose your vision much more quickly.
References
- "Centers for Disease Control and Prevention: Why is Vision Loss a Public Health Problem?"
- "Current Medical Diagnosis and Treatment 2009"; Stephen McPhee, M.D., Maxine Papadakis, M.D.; 2009
- "The Merck Manual: Glaucoma."
