Visual impairment affects many people and as one ages, the likelihood of vision loss increases significantly. Over the age of 65, we all have a 1 in 4 chance of developing vision loss. With these odds, chances are you probably know someone who lives with vision loss right now.
Some basic information helps to better understand the loss of vision. It is important to remember that any two people, even with the same visual condition, may be affected differently and that a person’s vision may fluctuate from day to day.
When the lens—the part of the eye directly behind the pupil—becomes opaque, a cataract has developed. This clouding usually occurs first in the central vision and then extends outward.
Blurry vision, double images or intolerance to bright sunlight can be signs of developing cataracts.
Cataracts associated with aging are the most common. There also are cataracts that exist at birth, secondary cataracts due to disease and cataracts that follow injury to the eye. Surgery is the sole treatment, and this simple procedure usually is successful. The eye’s natural lens is replaced with a lens implant, contact lens or glasses.
Sometimes a cataract should be removed even if it does not cause problems with your vision. For example, a cataract should be removed if it prevents examination or treatment of another eye problem, such as age-related macular degeneration or diabetic retinopathy. If your eye care professional finds a cataract, you may not need cataract surgery for several years. In fact, you might never need cataract surgery. By having your vision tested regularly, you and your eye care professional can discuss if and when you might need treatment.
If you choose surgery, your eye care professional may refer you to a specialist to remove the cataract. (NEI/NIH, 2013)
One of the possible complications of diabetes is diabetic retinopathy. Vision loss comes when weakened blood vessels in the retina, a paper-thin tissue that lines the back of the eye—rupture and bleed into the eye. This causes blurred vision and may have a reddish tint. As the tiny ruptures heal, scars form that can damage the retina.
Treatment with laser surgery is available. However, new hemorrhages may occur.
During the first three stages of diabetic retinopathy, no treatment is needed, unless you have macular edema. Proliferative retinopathy is treated with laser surgery. This procedure is called scatter laser treatment. Scatter laser treatment helps to shrink the abnormal blood vessels. Your doctor places 1,000 to 2,000 laser burns in the areas of the retina away from the macula, causing the abnormal blood vessels to shrink.
Although you may notice some loss of your side vision, scatter laser treatment can save the rest of your sight. Scatter laser treatment works better before the fragile, new blood vessels have started to bleed. Even if bleeding has started, scatter laser treatment may still be possible, depending on the amount of bleeding. If the bleeding is severe, you may need a surgical procedure called a vitrectomy. During a vitrectomy, blood is removed from the center of your eye. (NEI/NIH, 2013)
The National Eye Institute reports vision loss from diabetes can be prevented 90 percent of the time with early detection and regular dilated eye exams.
Normally there is a constant production and drainage of fluid (aqueous humor), which gives the eye its shape and keeps the eye lubricated. But if excess fluid is produced, or if the drainage system falters, pressure increases in the eye. Eventually, this damages the optic nerve, which carries visual signals to the brain.
Glaucoma can go undetected, because the increased pressure often is painless, stressing the importance of a regular dilated eye exam.
The gradual loss of sight begins on the outer edge, affecting peripheral vision. This is called chronic glaucoma, and accounts for about 90 percent of cases.
Rare acute glaucoma is characterized by severe headache or eye pain, and sudden loss of vision.
People who experience acute glaucoma must receive immediate medical attention.
Immediate treatment for early-stage, open-angle glaucoma can delay progression of the disease. That’s why early diagnosis is very important.
Glaucoma treatments include medicines, laser trabeculoplasty (to help fluid drain out of the eye), conventional surgery, or a combination of any of these. While these treatments may save remaining vision, they do not improve sight already lost from glaucoma. (NEI/NIH, 2013)
Macular degeneration is the leading cause of blindness in people over age 55.
The macula, a tiny area in the center of the retina, contains millions of light-sensing cells that produce detailed central vision. As people age, the macula can deteriorate, causing a blurred or dark area in the center of the visual field.
There are two types of macular degeneration, and they commonly are referred to as “dry” and “wet.”
The dry form is more common, and tends to progress more slowly than the wet.
The wet form is characterized by bleeding in and under the retina. The wet form often can be treated by injections. If you get this treatment, you may need multiple injections. Your eye care professional may give them monthly. Before each injection, your eye care professional will numb your eye and clean it with antiseptics. To prevent the risk of infection, a doctor may prescribe antibiotic drops. (NEI/NIH, 2013)
Another treatment is photodynamic therapy. This technique involves laser treatment of select areas of the retina. First, a drug called verteporfin will be injected into a vein in your arm. The drug travels through the blood vessels in your body, including any new, abnormal blood vessels in your eye. Your eye care professional then shines a laser beam into your eye to activate the drug in the blood vessels. Once activated, the drug destroys the new blood vessels and slows the rate of vision loss. This procedure takes about 20 minutes. (NEI/NIH, 2013)
Another option is laser surgery. Eye care professionals sometimes treat certain cases of wet AMD with laser surgery, though this is less common than other treatments. This treatment is performed in a doctor’s office or eye clinic. It involves aiming an intense beam of light at the new blood vessels in your eyes to destroy them. However, laser treatment also may destroy some surrounding healthy tissue and cause more blurred vision. (NEI/NIH, 2013)
Both forms may impair reading, driving or anything that requires detailed sight. Usually a person’s peripheral vision remains, and can be enhanced with low-vision aids.
There also is a rare congenital form of macular degeneration.
Retinitis Pigmentosa is a progressive, inherited eye disease characterized by deterioration of the retina.RP usually is diagnosed at a young age. Typically it begins with night blindness, followed by a gradual loss of vision that starts on the edges and ends in tunnel vision.Much research is going on worldwide in an effort to find a cure, but at this time there is no treatment for RP.RP progresses differently in each individual. Many people retain some useful vision, although it can lead to total blindness.
Usher’s Syndrome is a rare combination of RP and congenital hearing loss.
Hemianopsia is loss of vision on one side of an eye due to stroke or brain tumor. If the right half of vision is gone, damage is in the left side of the brain, and vice versa. Vision loss from stroke or tumor usually is permanent. Those people affected by hemianopsia learn to compensate by turning their heads to accommodate the blind area.
We offer many classes, support groups, and opportunities for recreation and socializing with others who are experiencing vision loss. To learn more on how we can help you or someone close to you live with their vision loss, please call us at 612-871-2222.
Image credits: National Eye Institute