Age-Related Eye Diseases
When you reach bifocal age, be sure to have routine eye exams because your risk for certain eye diseases increases significantly. Here is a brief summary of age-related eye conditions to be aware of:
Cataracts
A cataract is a clouding of the eye's natural lens, which is located behind the pupil.
According to the National Eye Institute (NEI), approximately 20.5 million Americans age 40 or older in 2004 had cataracts in at least one eye, and this number is expected to rise to 30.1 million by 2020.
The treatment for vision loss from cataracts is cataract surgery, which usually can fully restore vision.
In a cataract eye surgery, the surgeon removes the eye's cloudy lens and replaces it with a clear intraocular lens (IOL) implant. A cataract operation takes only a few minutes.
Modern IOLs used in cataract surgery include Crystalens, which is an accommodating IOL that can restore vision at all distances and reduce your need for reading glasses after cataract removal.
Glaucoma
Glaucoma is a term that describes a variety of related conditions that damage to the optic nerve, which transmits visual information from the eye to the brain. In most cases, glaucoma is caused by high eye pressure — either because too much fluid is produced in the eye or because the intraocular fluid (called the aqueous) drains too slowly from the eye.
Usually there are no noticeable glaucoma symptoms until permanent vision loss has occurred. For this reason, glaucoma sometimes is called the "silent thief of sight."
Though anyone can get glaucoma, risk for the disease increases with age, particularly after age 40.
Most cases of early glaucoma are detected during a routine eye exam. There are a variety of glaucoma tests that can be used during the exam to measure your eye pressure and visual field. The "air puff" machine is one type of instrument commonly used to measure eye pressure.
If your eye doctor believes you have glaucoma or are at high risk of the disease because of elevated eye pressure, he or she will recommend glaucoma treatment. The most common treatment is medicated eye drops, though sometimes glaucoma surgery is recommended.
Glaucoma eye drops are formulated to either reduce fluid production in the eye or increase outflow of fluid from the eye. Glaucoma surgery is designed to increase fluid outflow to reduce eye pressure and prevent (or halt) optic nerve damage.
Macular Degeneration
Macular degeneration is progressive damage to the central retina (macula), causing vision loss. The macula is responsible for central vision (used for recognizing faces, for example) and color perception. Central vision loss can make it impossible to drive, read, watch TV and do many other daily tasks we take for granted.
An Amsler grid is a simple screening device used to rule out and monitor vision changes caused by macular degeneration. It is simply a card or piece of paper with a square grid pattern of straight lines and a small black dot (fixation point) in the center of the grid. If, when looking at the fixation point, you see lines that look distorted or bent, you may have AMD.
If a central vision problem is detected with the Amsler grid, a more detailed visual field test may be performed to determine if vision loss from macular degeneration has occurred.
Like glaucoma, macular degeneration can cause permanent vision loss. New drugs are being developed and used for macular degeneration treatment and show some promise in reducing vision loss from AMD in many patients.
Many people with vision loss from macular degeneration are considered to have low vision. This is the term used to describe permanently impaired vision in both eyes that is not blindness — some usable vision remains.
Low vision aids are optical devices that help people with impaired vision use their remaining vision as efficiently as possible. Examples include special magnifiers and telescopes, which can be hand-held or mounted on special eyeglass frames. Extra-powerful reading glasses also can be considered a low vision aid.
Your eye doctor may refer you to a low vision specialist if you have significantly impaired vision from macular degeneration, glaucoma or other eye disease. This specialist can determine the best low vision aids for your needs and teach you how to use low vision products.
Diabetic Retinopathy
Diabetic retinopathy is damage to the retina caused by diabetes. In most cases, diabetic retinopathy (DR) occurs as the result of long-standing or uncontrolled diabetes. Currently, DR is the leading cause of blindness from eye disease among Americans under age 65.
Diabetic retinopathy can cause serious damage to blood vessels that nourish the retina, causing them to leak blood into the eye. If significant bleeding occurs in the eye, a surgical treatment called vitrectomy may be needed to remove the blood to restore vision.
Diabetic retinopathy treatment usually consists of managing the underlying disease through diet, exercise and oral or injected medication. In some cases, eye surgery called laser photocoagulation is performed to seal leaking blood vessels or increase blood flow to the central retina.
Diabetic retinopathy, like glaucoma and macular degeneration, often causes low vision.
Preventing Age-Related Eye Diseases
Research shows that maintaining a healthy, active lifestyle can reduce your risk for age-related eye diseases like cataracts, macular degeneration and diabetic retinopathy. Obesity significantly increases your risk of vision problems later in life, and it appears that good nutrition and plenty of exercise are key to a lifetime of good vision.
It is also important to have routine eye exams — even if you aren't experiencing vision problems. Your eye doctor can detect warning signs of glaucoma and other problems and help you prevent or lessen vision loss from this and other age-related eye diseases.