daily activities are impaired, a person’s quality of life can suffer.
CAUSES AND TYPES OF LOW VISION Eye and brain injuries, as well as certain genetic conditions, can cause sudden reduced vision. This is especially true in younger individuals. Reduced vision in older people tends to develop gradually with chronic, progressive diseases. Many times, there are no alerting symptoms until you have lost significant vision, which is why doctors encourage annual comprehensive eye exams.
AGE-RELATED MACULAR DEGENERATION BY KIMBERLY DOUGLAS, OD, FAAO
LIVING WITH LOW VISION Millions of Americans experience low vision as a result of common ocular diseases. It is also common to hear people use the term “legally blind” without an understanding of what it truly means. Understanding the causes of low vision, and knowing what it means to be legally blind, allows the individuals affected and the people around them to make adjustments to minimize the impact of these visual impair-
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ments on their everyday lives. ccording to the World Health Organization (WHO), low vision is defined as a visual acuity of 20/60 to 20/200, and less than 20 degrees of peripheral vision in the best seeing eye with the best possible correction. Those who are unable to achieve better than 20/200 vision or 10 degrees of peripheral vision with the best glasses, contact lenses, or other traditional methods are considered to be legally blind. Individuals who have poor vision without glasses or contact lenses but see well with them, are not actually legally blind. Adults over 50 are most commonly affected by reduced vision, as they are more prone to advanced ocular diseases. These diseases include macular degeneration, glaucoma, diabetes, and sometimes cataracts. As these conditions progress later in life, they start to affect one’s ability to read, drive, use the computer, see the television, and even recognize familiar faces. Once these 62
CIRCA Magazine
Central vision loss can be caused by advanced age-related macular degeneration (AMD). The macula is the light-sensitive area of the retina that is responsible for seeing the details of objects directly in front of you. AMD is a leading cause of low vision and affects the ability to read, write, and see people’s faces. There are two types of AMD with varying levels that progress slowly over time. Dry AMD tends to be less visually significant, as most people do not notice much vision loss until later in this stage. While eye vitamins are recommended to slow progression of AMD, there is no cure at this time. As the disease advances, many will start to notice straight lines becoming wavy or central visual distortion. This is much more common in wet AMD, where there is a more significant impact to vision. In this type, patients notice more central vision missing, trouble with low lighting, and a dampening of colors. There are ocular injections to help treat this stage of the condition, but once vision is permanently lost, it cannot be restored. AMD is more common in people over the age of 50, those who have a family history, Caucasians, and smokers (including former smokers). To reduce the risk of AMD, patients are encouraged to adopt a healthy lifestyle with the cessation of smoking, increasing green leafy vegetable intake, regular exercise, and the use of UV protection when outdoors.
GLAUCOMA There are a variety of types of glaucoma – all of which can lead to peripheral vision loss if not managed and treated in time. Openangle glaucoma is the most common type in the United States and is a very slowly progressing condition that causes damage to the optic nerve. Glaucoma also typically presents with no symptoms until the disease becomes advanced. African-Americans and Hispanics have an increased risk of glaucoma. Its true cause is unclear. There is often an association with elevated intraocular pressure, but this is not always the case. The treatment usually consists of drops to lower eye pressure,
| January • February • March 2022
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