Eye Diseases
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Cataract
A cataract is a clouding of all or part of the normally clear lens within your eye (behind the iris, the colored part of the eye), which results in blurred or distorted vision. Cataracts are most often found in persons over age 55, but they are also occasionally found in younger people. Contrary to what some think, cataracts are not a growth or tumor, or a film on the surface of the eye; it is simply when a normally clear structure inside the eye becomes cloudy or hazy.
No one knows exactly what causes cataracts, but it is known that a chemical change occurs within your eye to cause the lens to become cloudy. This may be due to advancing age, heredity or an injury or disease. Excessive exposure to ultraviolet radiation in sunlight, cigarette smoking or the long-term use of certain medications are also risk factors for the development of cataracts.
Although cataracts develop without pain or discomfort, a person may notice some symptoms of a developing cataract. These include blurred or hazy vision, "starbursts" around lights at night, increased sensitivity to glare or the feeling of having a film over the eyes. A temporary improvement in near vision may also indicate formation of a cataract.
Currently, there is no proven method to prevent cataracts from forming. During a comprehensive eye examination, your optometrist can diagnose a cataract and monitor its development and prescribe changes in eyeglasses or contact lenses to maintain good vision.
If your cataract develops to the point that it affects your daily activities, your optometrist can refer you to an eye surgeon who may recommend surgery. During the surgery, the eye's natural lens is removed and usually replaced with a plastic artificial lens. Some new technology in cataract surgery includes lens implants which can focus for reading as well as distance; ask your optometrist about these exciting innovations. After surgery, you can return to your family optometrist for continuing care.
Conjunctivitis
Conjunctivitis is an inflammation or infection of the conjunctiva, the thin transparent layer of tissue that lines the inner surface of the eyelid and covers the white part of the eye. Conjunctivitis, often called “pink eye,” is a common eye disease, especially in children. It may affect one or both eyes. Some forms of conjunctivitis can be highly contagious and easily spread in schools and at home. While conjunctivitis is usually a minor eye infection, sometimes it can develop into a more serious problem.
Conjunctivitis may be caused by a viral or bacterial infection. It can also occur due to an allergic reaction to irritants in the air like pollen and smoke, chlorine in swimming pools, and ingredients in cosmetics or other products that come in contact with the eyes. Sexually transmitted diseases like Chlamydia and gonorrhea are less common causes of conjunctivitis.
People with conjunctivitis may experience the following symptoms:
- A gritty feeling in one or both eyes
- Itching or burning sensation in one or both eyes
- Excessive tearing
- Discharge coming from one or both eyes
- Swollen eyelids
- Pink discoloration to the whites of one or both eyes
- Increased sensitivity to light
Glaucoma
Glaucoma is an eye disease in which the internal pressure in your eyes increases enough to damage the nerve fibers in your optic nerve and cause vision loss. The increase in pressure happens when the passages that normally allow fluid in your eyes to drain become clogged or blocked. The reasons that the passages become blocked are not known.
Noticeable symptoms of glaucoma may be a gradual loss of side vision (above) or blurred vision (below).
Glaucoma is one of the leading causes of blindness in the U.S. It most often occurs in people over age 40, but can occur at any age. People with a family history of glaucoma, African Americans, and those who are very nearsighted or diabetic are at a higher risk of developing glaucoma.
The most common type of glaucoma develops gradually and painlessly, without symptoms. A rarer type occurs rapidly and its symptoms may include blurred vision, loss of side vision, seeing colored rings around lights and pain or redness in the eyes.
Glaucoma cannot be prevented, but if diagnosed and treated early, it can be controlled. Vision lost to glaucoma cannot be restored, but proper treatment can significantly reduce the likelihood of further vision loss. That is why the American Optometric Association recommends annual eye examinations for people at risk for glaucoma (your doctor may, depending on your condition, recommend more frequent examinations). A comprehensive optometric examination will include a tonometry test to measure the pressure inside your eyes; an examination of the retina (the nerve layer inside your eyes) to evaluate the condition of the optic nerve for damage; and a visual field test to check for changes in central and side vision which can be a sign of glaucoma.
The treatment for glaucoma often includes prescription eye drops and medicines to lower the pressure in your eyes. Since glaucoma is a disease which is usually painless and chronic, patients with glaucoma must keep taking their drops until their doctor tells them to stop, or risk losing their sight. Your optometrist can test for and diagnose glaucoma, and in Connecticut, most optometrists are licensed to prescribe medicines to treat glaucoma. In some cases, your optometrist may refer you to a specialist for laser treatment or surgery, if medicines do not adequately control your eye pressure.
Keratoconus
Keratoconus is a vision disorder that occurs when the normally round cornea (the front part of the eye) becomes thin and irregular (cone) shaped. This abnormal shape prevents the light entering the eye from being focused correctly on the retina and causes distortion of vision.
In its earliest stages, keratoconus causes slight blurring and distortion of vision and increased sensitivity to glare and light. These symptoms usually appear in the late teens or late 20s. Keratoconus may progress for 10-20 years and then slow in its progression. Each eye may be affected differently. As keratoconus progresses, the cornea bulges more and vision may become more distorted. In a small number of cases, the cornea will swell and cause a sudden and significant decrease in vision. The swelling occurs when the strain of the cornea's protruding cone-like shape causes a tiny crack to develop. The swelling may last for weeks or months as the crack heals and is gradually replaced by scar tissue. If this sudden swelling does occur, your doctor can prescribe eyedrops for temporary relief, but there are no medicines that can prevent the disorder from progressing.
Eyeglasses or soft contact lenses may be used to correct the mild nearsightedness and astigmatism that is caused by the early stages for keratoconus. As the disorder progresses and cornea continues to thin and change shape, rigid gas permeable contact lenses can be prescribed to correct vision adequately. In most cases, this is adequate. The contact lenses must be carefully fitted, and frequent checkups and lens changes may be needed to achieve and maintain good vision.
In a few cases, a corneal transplant is necessary. However, even after a corneal transplant, eyeglasses or contact lenses are often still needed to correct vision.
Macular Degeneration
Macular Degeneration is the leading cause of blindness in America. It results from changes or deterioration to a part of the retina called the macula, which is responsible for the central part of your vision. The retina is the light-sensing lining of the inside of the eye, and the macula is the area of the retina with the highest concentration of cone cells, which supply color and detail vision. If the macula deteriorates or is damaged, a person's peripheral (side) vision remains intact, but the ability to see color and detail is threatened. The most common cause of macular degeneration is age; it is usually referred to as AMD, or age-related macular degeneration. Recent studies have shown that smoking can more than double the risk of developing AMD; other risk factors include having a family history of AMD, and being female or Caucasian.
About 85% of those with macular degeneration have the dry form, for which there is no known treatment. Dry AMD is caused by a breakdown of the underlying blood supply to the macula, resulting in the slow death of the cells of the macula and loss of vision in that area. The less common wet form is caused by leakage of blood or fluid under the macula, causing the macula to detach from its underlying blood supply, resulting in a faster but similar vision loss. Wet AMD may respond to laser procedures, if diagnosed and treated early.
Some common symptoms are a gradual loss of ability to see objects clearly, distorted vision, a gradual loss of color vision and a dark or empty area appearing in the center of vision. AMD may also cause straight lines, such as road stripes or door edges, to appear as if they have a wave or bump in them. AMD can be hard to notice, however, because you may not be able to see any of these symptoms unless you cover the other eye.
Central vision that is lost to macular degeneration cannot be restored. However devices such as magnifiers, that enlarge print, or telescopes that enlarge more distant objects, can be prescribed, and can often help. An evaluation by a Doctor of Optometry who specializes in low vision can ensure that someone with AMD will get the most out of their remaining vision.
Recent research indicates certain vitamins and minerals may help prevent or slow the progression of macular degeneration. Ask your Doctor of Optometry about these. After age 60, an annual, comprehensive optometric eye examination is important to help detect diseases like AMD, maintain eye health, and maximize your visual function.
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