Cataracts
Cataracts are clumps of protein that collect on the lens of an eye and interfere with vision. Normally, light passes through the lens (the clear tissue behind the pupil) and focuses on the retina. The retina is the light-sensitive layer of the eye that sends visual signals to the brain. A cataract occurs when the normally clear lens becomes cloudy. Most cataracts develop slowly over time and are a natural result of aging. Once cataracts become large enough that vision loss interferes with everyday activities such as driving, reading, or watching television, they should be surgically removed.
Signs and Symptoms
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Decreased or blurred vision (often described as a "fog")
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Double vision
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Halo around lights
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"Second sight" -- when an individual who normally wears reading glasses can suddenly read without them
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Brown spots in the visual field
What Causes It?
A cataract develops when protein in the lens clumps together and blocks light from reaching the retina. It is not clear what causes these proteins to clump together, but some researchers speculate that cataracts may develop as a result of chemical changes in the lens that occur with aging. Other researchers believe that there may be several causes of cataracts, including smoking, diabetes, and excessive exposure to sunlight.
There are several different types of cataracts:
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Age-related cataracts -- those that develop with older age
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Congenital cataracts -- those that are present at birth or develop in early childhood, usually in both eyes
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Secondary cataracts -- those that develop in people with medical conditions (such as diabetes) or in those who use steroids
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Traumatic cataracts -- those that develop as a result of an eye injury
Who's Most At Risk?
The following factors may increase an individual's risk for developing cataracts:
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Being older than 50 years of age
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Genetic diseases (such as Down syndrome)
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Certain medications (such as steroids)
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Maternal infection (such as rubella), drug ingestion, or radiation therapy during pregnancy
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Metabolic disorders (such as diabetes mellitus)
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Eye disorders (such as glaucoma)
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High-voltage electrical injury
What to Expect at Your Provider's Office
People experiencing symptoms associated with cataracts should see an eye care professional. The care provider can make a diagnosis and help determine which treatment or combination of therapies is most appropriate.
Eye care professionals can detect cataracts with the following tests:
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Visual acuity test -- measures vision at various distances
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Pupil dilation -- the pupil is widened with eye drops to reveal more of the lens and retina
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Tonometry -- measures fluid pressure inside the eye
Treatment Options
Prevention
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Wear ultraviolet (UV)-blocking sunglasses
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Abstain from smoking cigarettes
Certain medications may help delay cataract formation (particularly in those with diabetes or other high-risk conditions), but none are known to reverse the progression of cataracts once they form.
Drug Therapies
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Eye drops (containing phenylephrine and homatropine) may be prescribed to dilate the pupil and provide better vision in some individuals
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Aldose reductase inhibitors may help prevent or delay cataract formation in people with diabetes
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Antibiotics and steroid eye drops may be prescribed following the removal of cataracts
Surgical and Other Procedures
In its early stages, a cataract usually does not interfere with vision. Over time, however, a cataract may grow larger and cloud over more of the lens, making it difficult to see.
When cataracts cause vision loss that interferes with everyday activities, such as driving, reading, or watching television, surgery is the only effective treatment. An eye care professional may also recommend that an individual have a cataract removed if the patient has other eye conditions, if the cataract threatens to cause another eye disorder, or if the presence of the cataract prevents examination or treatment of another eye problem.
During surgery, the cloudy lens is replaced with a substitute lens. Cataract removal is one of the most common operations performed in the United States today. According to the National Eye Institute, roughly 90% of people who have cataract surgery experience improved vision as a result.
Complementary and Alternative Therapies
A comprehensive treatment plan for cataracts may include a range of complementary and alternative therapies.
Nutrition and Supplements
Nutritional tips include the following:
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Eliminate all suspected food allergens, including dairy (milk, cheese, eggs and ice cream), wheat (gluten), soy, corn, preservatives and chemical food additives. Your health care provider may want to test you for food allergies.
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Eat more antioxidant-rich foods (such as green, leafy vegetables and peppers) and berries (such as blueberries, cherries, and raspberries). Berries contain high levels of beneficial antioxidants for eye health.
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Avoid refined foods, such as white breads, pastas, and sugar.
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Eat fewer red meats and more lean meats, cold-water fish, tofu (soy, if no allergy) or beans for protein.
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Use healthy cooking oils, such as olive oil or vegetable oil.
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Reduce or eliminate trans-fatty acids, found in such commercially baked goods as cookies, crackers, cakes, French fries, onion rings, donuts, processed foods, and margarine.
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Avoid coffee and other stimulants, alcohol, and tobacco.
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Drink 6 - 8 glasses of filtered water daily.
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Exercise moderately, if tolerated, 5 days a week.
You may address nutritional deficiencies with the following supplements:
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A multivitamin daily, containing the antioxidant vitamins A, C, E, D, the B-complex vitamins and trace minerals such as magnesium, calcium, zinc, and selenium.
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Omega-3 fatty acids, such as fish oil, 1 - 2 capsules or 1 tbsp. of oil one to two times daily, to help decrease inflammation. Cold-water fish, such as salmon or halibut, are good sources.
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Vitamin C, 500 - 1,000 mg two to three times daily, as an antioxidant.
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Coenzyme Q10, 100 - 200 mg at bedtime, for antioxidant support.
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Alpha-lipoic acid, 25 - 50 mg twice daily, for antioxidant support.
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Lutein, 2 - 6 mg daily, for antioxidant support in eye health.
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Zeaxanthin, 1 - 10 mg daily, for antioxidant support in eye health.
Herbs
Herbs are generally a safe way to strengthen and tone the body's systems. As with any therapy, you should work with your health care provider to get your problem diagnosed before starting any treatment. You may use herbs as dried extracts (capsules, powders, teas), glycerites (glycerine extracts), or tinctures (alcohol extracts). Unless otherwise indicated, you should make teas with 1 tsp. herb per cup of hot water. Steep covered 5 - 10 minutes for leaf or flowers, and 10 - 20 minutes for roots. Drink 2 - 4 cups per day. You may use tinctures alone or in combination as noted.
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Bilberry (
Vaccinium myrtillus
) standardized extract, 80 mg two to three times daily, for antioxidant and vision support.
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Ginkgo (
Ginkgo biloba
) standardized extract, 40 - 80 mg three times daily, for antioxidant support and blood flow.
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Green tea (
Camellia sinensis
) standardized extract, 250 - 500 mg daily, for antioxidant effects. Use caffeine-free products. You may also prepare teas from the leaf of this herb.
Homeopathy
Although very few studies have examined the effectiveness of specific homeopathic therapies, professional homeopaths may consider certain remedies for the treatment of cataracts based on their knowledge and experience. Before prescribing a remedy, homeopaths take into account a person's constitutional type -- your physical, emotional, and psychological makeup. An experienced homeopath assesses all of these factors when determining the most appropriate treatment for each individual.
Physical Medicine
Contrast hydrotherapy (alternating hot and cold water applications to the face or back of neck) may improve circulation to the head and facilitate the transport of nutrients to the eye. Hydrotherapy to eyes, head, or neck should be done only under supervision of a knowledgeable doctor.
Prognosis/Possible Complications
The National Eye Institute estimates that vision improves in about 90% of people who have cataract surgery. Complications from surgery are rare, but can include infection, bleeding, retinal detachment, inflammation (pain, redness, swelling), loss of vision, or light flashes. With prompt medical attention, such problems can usually be treated successfully.
Following Up
A health care provider may prescribe eye drops or medications to help healing and control the pressure inside the eye for a few days following surgery. An eye shield or eyeglasses may also be necessary. A health care provider will schedule eye exams as needed to check on progress.
Supporting Research
Bartlett H, Eperjesi F. An ideal ocular nutritional supplement?
Ophthalmic Physiol Opt
. 2004;24(4):339-49.
Bartlett JO, Jaanus SD.
Clinical Ocular Pharmacology
. 2nd ed. Boston, Mass: Butterworths; 1989:807-808, 414-416, 630.
Bast A, Haenen GR. Lipoic acid: a multifunctional antioxidant.
Biofactors
. 2003;17(1-4):207-13.
Branch WT Jr.
Office Practice of Medicine
. 3rd ed. Philadelphia, Pa: W.B. Saunders; 1994:584, 866-867.
Fauci AS, Braunwald E, Isselbacher KJ, et al, eds.
Harrison's Principles of Internal Medicine
. 14th ed. New York, NY: McGraw-Hill; 1998:168, 2208, 2558.
Fraunfelder FT, et al.
Current Ocular Therapy.
No. 3. Philadelphia, Pa: W.B. Saunders; 1990:613-618.
Fontani G, Corradeschi F, Felici A, et al. Cognitive and physiological effects of Omega-3 polyunsaturated fatty acid supplementation in healthy subjects. Eur J Clin Invest. 2005;35(11):691-9.
Gaby AR. The role of coenzyme Q10 in clinical medicine: Part 1.
Alt Med Rev
. 1996; 1(1):11-17.
Granado F, Olmedilla B, Blanco I. Nutritional and clinical relevance of lutein in human health.
Br J Nutr
. 2003;90(3):487-502.
Head KA. Natural therapies for ocular disorders, part two: cataracts and glaucoma. Altern Med Rev. 2001;6(2):141-66.
Kang JH, Pasquale LR, Willett W, et al. Antioxidant intake and primary open-angle glaucoma: a prospective study.
Am J Epidemiol
. 2003;158(4):337-46.
Lu M, Cho E, Taylor A, et al. Prospective study of dietary fat and risk of cataract extraction among US women.
Am J Epidemiol
. 2005;161(10):948-59.
Mody VC Jr, Kakar M, Elfving A, et al. Ascorbate in the rat lens: dependence on dietary intake.
Ophthalmic Res
. 2005;37(3):142-9. Epub 2005 May 3.
Murray MT, Pizzorno JE.
Encyclopedia of Natural Medicine
. Rocklin, Calif: Prima Publishing; 1998:193-196.
Newell FW.
Ophthalmology: Principles and Concepts
. St. Louis, Mo: Mosby; 1996:369-378, 516.
Pandi-Perumal SR, Srinivasan V, Maestroni GJ, et al., Melatonin. FEBS J. 2006;273(13):2813-38.
Rotsein OD. Oxidants and antioxidant therapy.
Crit Care Clin
. 2001;17(1):239-47.
Santosa S, Jones PJ. Oxidative stress in ocular disease: does lutein play a protective role?
CMAJ
. 2005;173(8):861-2.
Simopoulos AP. Omega-3 fatty acids in inflammation and autoimmune diseases.
J Am Coll Nutr
. 2002;21(6):495-505.
Yoon JH, Baek SJ. Molecular targets of dietary polyphenols with anti-inflammatory properties.
Yonsei Med J
. 2005;46(5):585-96.
West AL, Oren GA, Moroi SE. Evidence for the use of nutritional supplements and herbal medicines in common eye diseases.
Am J Ophthalmol
. 2006;141(1):157-66.
Wyngaarden JB, et al.
Cecil Textbook of Medicine
. 19th ed. Philadelphia, Pa: W.B. Saunders; 1992: 1077, 1308, 2270, 2358.
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Review Date:
8/7/2006
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Reviewed By: Ernest B. Hawkins, MS, BSPharm, RPh, Health Education Resources; and Steven D. Ehrlich, N.M.D., private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network.
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