Visual loss among those over 65 is common, with 1/3 of this age group experiencing some form of eye disease. Common causes of vision loss and blindness in the elderly include the following:
- Age-Related Macular Degeneration (AMD): the leading cause of blindness in those 65 and older
- Diabetic Retinopathy: the primary cause of blindness in those 25-65
- Glaucoma: the most common cause of blindness in African Americans
- Cataract: the leading cause of blindness worldwide
This disease is the leading cause of legal blindness in the U.S. It affects fine detail vision, and therefore impacts on reading, driving, and other activities of daily living. AMD causes a darkened brown or gray-green smudged area in the central vision, not total blackness. However, the peripheral vision is typically spared.
AMD is rare before the age of 65, and increases in frequency with age. A family history of AMD is the second most common risk factor. Other predisposing conditions include high blood pressure, cardiovascular risks, and smoking. Light colored eyes and UV light exposure have not been shown to be risk factors.
AMD occurs as "dry" or "wet" types. The dry type is the most common. It causes yellow patches on the retina, called drusen, the hallmark of AMD. Drusen, however, dont usually affect vision. Wet AMD is more severe, and is caused by leaking blood vessels that result in scarring. Most patients with AMD that loose vision do so because they develop the wet type.
Treatment for AMD includes observation, vitamin supplementation (A, C, E, and Zinc), smoking cessation, laser photocoagulation and medication placed directly into the eye.
Most blindness due to diabetes induced eye changes (retinopathy) can be prevented with early detection and treatment. However, half of diabetic patients dont get regular eye examinations.
The most important risk factors for diabetic retinopathy are the duration of diabetes and the quality of diabetes control. After 15-20 years most patients with diabetes have some degree of detectible retinopathy. Other risks include high blood pressure, high cholesterol, kidney disease, congestive heart failure, and pregnancy during diabetes.
Diabetes can cause an overgrowth of blood vessels in the retina, and leakage of blood and fluid in the retina causing swelling and scarring. Early regular vision screening allows laser therapy before vision loss occurs. Diabetics should have a slit-lamp visual exam annually.
There are several types of glaucoma, which is a condition of increased eye pressure. Primary Open Angle Glaucoma is the most common. As with high blood pressure, patients are usually asymptomatic until very late in the disease, after vision loss has occurred. Another type, Angle Closure Glaucoma, presents as sudden pain and redness in the eye.
Risk factors for glaucoma include increased pressure in the eye, a family history of glaucoma, older age, and possibly diabetes and cardiovascular disease. High blood pressure is not a risk factor. Glaucoma affects peripheral vision first and central vision later. Treatment of glaucoma involves lowering eye pressures with eye drops, laser therapy and surgery.
Cataract surgery is one of the most common surgical procedures performed in the U.S. each year. Nevertheless, it is a common cause of blindness our country. Cataracts cause a slow progressive vision loss, with reduced contrast vision. The greatest risk for cataract is age. In addition, other risk factors include UV light exposure, steroid use, diabetes, smoking, and prior eye trauma. Vitamin supplements do not help. Surgery is highly effective and UV protective sunglasses are recommended to reduce risk.
The information in this article was presented in September 2007 by David Quillen, M.D., Chair, Department of Ophthalmology, Penn State College of Medicine, during the Family Medicine Seminar Series at Mount Nittany Medical Center. This series is sponsored by the Department of Family and Community Medicine, Penn State Hershey College of Medicine and Mount Nittany Medical Center. The Family Medicine Seminar Series is held monthly in the Mount Nittany Medical Center Dreibelbis Auditorium (Entrance D, rear of building), 6:00-7:30 pm. Call 814.231.7087 to register for the series. Upcoming topics include:
- October 25, 2007: "Updates in Breast Cancer Management & Breast Imaging", Rena Kass, M.D., Surgical Director-Breast Program, and Susan Schetter, D.O., Chief-Breast Imaging, Penn State Hershey Medical Center
- November 15, 2007: "The Human Genome Project", Sharon Reilly Kardia, PhD., University of Michigan, School of Public Health
Michael Flanagan, M.D., FAAFP is an associate professor of Family and Community Medicine at Penn State Hershey College of Medicine. Dr. Flanagan is board certified in Family Medicine, practices at Penn State Family Medicine, and is on staff at Mount Nittany Medical Center.