Common Eye Diseases
When the lens—the part of your eye directly behind the pupil—changes from clear to opaque, a cataract has developed. This clouding usually happens first in your central vision and then extends outward to the periphery. Blurry vision, double images, or sensitivity to bright sunlight may all be signs of cataracts.
Cataracts associated with aging are the most common. However, there are congenital cataracts, secondary cataracts due to disease, and traumatic cataracts following an eye injury.
Surgery is the only treatment, but the procedure is simple and usually successful. The surgeon will replace your eye’s natural lens 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 testing your vision 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 is caused when blood vessels in the retina—the paper-thin tissue lining the back of the eye—rupture and bleed into the fluid of the eye. This leads to blurred vision and may also cause a reddish tint. As the tiny ruptures heal, scars can form and damage the retina.
During the first three stages of diabetic retinopathy, no treatment is needed, unless you have macular edema. If you do need treatment, laser surgery is available for those with diabetic retinopathy. However, new hemorrhages may still occur.
Proliferative retinopathy is treated with laser surgery, in a procedure called scatter laser treatment, which helps 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 in your side vision, scatter laser treatment can save the rest of your sight.
Scatter laser treatment works best 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, to remove blood 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, your eyes have 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 your eye. Eventually, this can damage the optic nerve, a part of your eye that carries visual signals to the brain.
The gradual loss of sight caused by glaucoma begins on the outer edge, affecting peripheral vision. This is called chronic glaucoma, and accounts for about 90 percent of cases. Glaucoma can go undetected, because the increased pressure often is painless, stressing the importance of a regular dilated eye exam.
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 important. Glaucoma treatments include medications, laser trabeculoplasty (to help fluid drain out of the eye), conventional surgery, or a combination. 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 your 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, referred to as “dry” and “wet.” Dry macular degeneration is more common, and tends to progress more slowly.
Wet macular degeneration is characterized by bleeding in and under the retina. Often, it 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)
Eye care professionals treat certain cases of wet macular degeneration with laser surgery, though this is less common than other treatments. Performed in a doctor’s office or eye clinic, this treatment involves aiming an intense beam of light at the new blood vessels in your eyes to destroy them. However, laser treatment also may harm surrounding healthy tissue and cause more blurred vision. (NEI/NIH, 2013)
Both forms of macular degeneration can 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 is also a rare congenital form of macular degeneration.
Retinitis pigmentosa (RP)
Retinitis pigmentosa (RP) is a progressive, inherited eye disease characterized by deterioration of the retina. Typically, RP is diagnosed at a young age, and 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. The condition progresses differently in each individual. Many people retain some useful vision, while others experience total blindness. Usher Syndrome is a rare combination of RP and congenital hearing loss.
Hemianopsia is loss of vision on one side of the eye due to stroke or brain tumor. If the right half of the visual field is gone, the damage is to the left side of the brain, and vice-versa. Vision loss from a stroke or tumor is usually permanent. Often, people with hemianopsia learn to compensate by turning their head to accommodate the blind side.