By Dr. Gerard Muraida
Eyesight is a blessing. Vision of 20/20 is an even bigger gift. We depend on our vision to navigate our environment. We appreciate the beauty of sunrises, the colorful blossoms of flowers, and of course the magnificent New Mexico sunsets.
As we age, a variety of conditions affect our ability to see. The most common causes of vision loss in seniors are age-related macular degeneration (AMD), glaucoma, diabetic retinopathy, and cataracts.
AMD is the leading cause of vision loss in people age 65 years and older. It is characterized by degeneration of the macula, the area of the retina responsible for central vision. Risk factors for AMD include advancing age, family history of AMD, and cardiovascular risk factors such as hypertension and cigarette smoking.
There are two types of AMD: nonexudative (or “dry”) and exudative (or “wet”).
Of those individuals afflicted with AMD, 90 percent will have the dry, nonexudative type. Dry AMD accounts for 10 percent to 20 percent of severe vision loss. Dry AMD causes vision loss by the deposition of protein clumps referred to as drusen. The immune system has been noted to play a role in dry AMD, and new immune suppressant medications have been approved by the Federal Drug Administration.
Exudative AMD is much more severe and is responsible for 80 percent to 90 percent of severe vision loss. Abnormal blood vessels form in the retina and leak fluid causing a distortion in vision. Until recently, wet AMD was treated with periodic intraocular injections, and dry AMD was treated with special antioxidant vitamins. However, a recent publication of the American Academy of Ophthalmology reported that longer-acting versions of the standard eye-injected medications are being released. These medications may allow for quarterly injections instead of monthly injections. Retinal specialists are the physicians authorized to treat both forms of AMD.
Another cause of vision loss in seniors is open-angle glaucoma. Elevated pressure within the eye can lead to optic nerve damage and visual field loss. It is a significant cause of blindness in the United States and is the most common cause of blindness among Black Americans. An estimated 1 million Americans older than 65 have experienced loss of vision associated with glaucoma, and about 75 percent of persons who are legally blind because of glaucoma are over the age of 65.
The most prevalent form of glaucoma is primary open-angle glaucoma. The main treatment for it has been eye drops aimed at decreasing the pressure within the eye. Minimally invasive surgery is also sometimes called for.
Cataracts are a thickening disease of the lens of the eye, causing distorted vision. Although cataracts are the leading cause of blindness worldwide, this is not true in the United States. Cataract extraction with intraocular lens implantation is an operation performed well over 1 million times per year in the United States. Restoration of vision is achieved in over 99 percent of cases.
Diabetic retinopathy is a complication of poorly controlled diabetes mellitus. It is divided into two categories: proliferative and non-proliferative. Non-proliferative diabetic retinopathy leads to macular swelling and distorted central vision.
Proliferative type diabetic retinopathy is characterized by newly formed retinal blood vessels. This can lead to retinal bleeding and even retinal detachment.
Treatment aimed at halting the development of new blood vessels comes in the form of injections into the eye. Laser photocoagulation is another option to stop new blood vessel formation.
No matter what the current health of your eyesight, prevention is key to preserving it. Maintain a normal blood pressure. Protect your eyes from sunlight by wearing sunglasses that block ultraviolet radiation and a hat with a wide brim when you are outside. Stop smoking, stay active, and keep your blood sugar within normal limits.
If you spend a lot of time at the computer or focused on one thing, take a break every 20 minutes to look about 20 feet away for 20 seconds to prevent eye strain.
Be sure to ask your health care provider to perform an annual eye exam.
