A cataract is a clouding of the crystalline lens (clear tissue behind the pupil) that causes a gradual loss of vision. When the lens becomes opaque, light is unable to reach the retina, resulting in blurred vision. Cataracts are variously classified according to cause (aging, first trimester rubella infection, myotonic dystrophy, Down syndrome, trauma, radiation), location (nuclear, cortical, subcapsular), severity (immature, mature, hypermature), and age of onset (congenital, juvenile, adult, age-related). Approximately one million cataract surgeries are performed each year in the United States, while 5 to 10 million individuals annually are disabled as a result of cataracts.

Aging is the most common cause of cataracts; in fact, most patients over 50 years of age demonstrate cataractous changes. However cataracts may also be congenital, hereditary, or associated with systemic, metabolic, or ocular diseases, trauma, radiation, maternal infection during pregnancy, electrical injuries, and drug use.

• Age over 50 years
• Genetic diseases (e.g., myotonic dystrophy, neurofibromatosis type 2, Lowe syndrome, Down syndrome)
• Drug therapy (e.g., miotics, steroids, phenothiazines)
• Maternal infection (e.g., rubella, cytomegalovirus), drug ingestion, or radiation therapy during pregnancy
• Metabolic disorders (e.g., diabetes mellitus, galactosemia, hypocalcemia)
• Ocular disorders (e.g., glaucoma, uveitis, retinal detachment, trauma)
• High-voltage electrical injury

• Decreased or blurred vision (often described as a "fog")
• Double vision
• Colored halo around lights
• Increased refractive power of lens, allowing patients to read without glasses (i.e., second sight)
• Brown spots in the visual field

There are over 200 conditions (i.e., syndromes, diseases) associated with cataract formation. Other corneal or retinal lesions are most often ruled out in a diagnosis of cataracts.

Physical examination is usually not helpful in determining the cause of cataracts. Lens opacity can be observed visually, especially mature cataracts, or by ophthalmoscopic or slit-lamp examination.

Laboratory tests almost never suggest the presence or cause of cataracts.

Ophthalmoscopic examination distinguishes the type of cataract: nuclear cataracts are centrally located and have a brown-colored center; cortical cataracts have irregular radiating spokes; and posterior subcapsular cataracts appear irregular and rough and are located on the back surface of the lens. In mature cataracts all of the lens protein is opaque; in immature cataracts, some of the lens protein is transparent; and in hypermature cataracts the lens protein becomes liquid.

Radiographic studies may be used to determine the presence of a metallic foreign body if lens opacity follows ocular injury.

• Ophthalmoscopic examination
• Slit-lamp examination
• Neodymium-YAG laser
• Ultrasound

The progression of lens opacities varies considerably among patients, and medical therapies are usually of short-term benefit only. For example, some cataracts may be managed with a change in prescription, especially those associated with refractive changes, and all cataracts may be treated temporarily by dilation of the pupil, which allows light to go around the opacity (glaucoma must be ruled out prior to use of mydriatics).

• Some studies have suggested that high-dose aspirin therapy given for other causes (e.g., arthritis) is associated with a decreased incidence of senile cataract; however, most of the evidence is speculative.
• Eye drops (e.g., phenylephrine [Neo-Synephrine, 2.5%], homatropine, 2%), to dilate the pupil to provide better vision in patients with nuclear sclerotic or posterior subcapsular cataract
• Aldose reductase inhibitors, to prevent conversion of sugars to polyols in galactosemic or diabetic patients, thereby preventing or delaying cataract formation
• Prophylactic antibiotics for three weeks following cataract extraction
• Steroid eye drops three to six weeks following cataract extraction

Cataract surgery is usually elective except in the presence of uveitis or glaucoma; surgery is recommended when the cataract interferes with the patient's work, hobbies, or activities of daily living; if the cataracts threaten to result in uveitis, iridocyclitis, or glaucoma; or if other ocular surgery is necessary, making visualization imperative.

Intracapsular cataract extraction—extraction of the entire lens, including the capsule of the lens. This can result in aphakic vision, which is corrected with contact lenses or eyeglasses.

Extracapsular cataract extraction—extraction of the anterior lens capsule, the nucleus, and the cortex, leaving the posterior capsule intact. This can result in secondary opacification of the posterior capsule, which is often treated by laser therapy in which a small opening is made in the posterior capsule.

Intraocular lens implantation—insertion of a plastic posterior chamber lens at the time of cataract extraction, which reduces the problems associated with aphakia. (Anterior chamber lens replacement may damage the corneal endothelium resulting in bullous keratopathy [edema of the corneal stroma]; thus, this procedure is rarely performed.)

Nutritional and herbal therapies help prevent and minimize the progression of cataract formation. Correcting underlying nutritional deficiencies and addressing contributing factors, such as diabetes, is essential to treatment.

• Increase dietary antioxidants which may protect against free radical damage to the eye, especially dark leafy greens and orange and yellow vegetables. Dark berries, particularly blueberries, are rich in flavonoids, which may be protective to the lens.
• Vitamin C (500 to 1,000 mg bid to tid) is found at high concentrations in the lens of the eye and has antioxidant activity.
• Glutathione is highly concentrated in the lens and protects against UV light. Supplementing with glutathionine (200 mg bid) or its amino acid precursors (L-cysteine 200 mg bid, L-glycine 100 mg bid, and L-glutamine 100 mg bid) may be beneficial.
• Selenium (200 mcg/day) is a co-factor for glutathionine peroxidase which helps keep glutathionine in its active state.
• Vitamin E (400 IU/day) protects against free radical damage.
• Zinc (15 to 30 mg/day) deficiency may contribute to cataract formation, especially with impaired glucose metabolism occuring with diabetes or age.
• Vitamin A (10,000 IU/day) and beta-carotene (50,000 IU daily) are antioxidants that protect against light-induced damage to the eye.

Herbs may be used as dried extracts (pills, capsules, or tablets), teas, or tinctures (alcohol extraction, unless otherwise noted). Dose for teas is 1 heaping tsp. herb/cup water steeped for 10 minutes (roots need 20 minutes).

• Dusty miller (Cineraria maritima) succus (preserved plant juice) 1 to 3 drops bid to affected eye. May cause eye irritation.
• Bilberry (Vaccinium myrtillus) (200 mg bid) to increase microcirculation and provide protective flavonoid support. Other flavonoids that may be used in addition to bilberry to decrease inflammation are quercetin (200 to 500 mg bid to tid) and rutin (200 mg tid).
• Ginkgo biloba (160 mg bid)

An experienced homeopath should assess individual constitutional types and severity of disease to select the correct remedy and potency. A homeopathic remedy may address causative factors and minimize the progression of cataract formation.

Contrast hydrotherapy. Alternate hot and cold applications to the face or back of neck to improve circulation to the head and facilitate the transport of nutrients to the eye. Alternate three minutes hot with one minute cold and repeat three times. This is one set. Do two to three sets per day.

Patients with cataracts can be monitored for progression of disease over a long period of time before opting for cataract surgery. Patients who have recently undergone cataract surgery should be monitored for rare but serious complications such as intraocular hemorrhage, postoperative infection, corneal decompensation, or problems with wound healing.

Patients who must take steroids for more than two years or who must take high doses of steroids for short periods must be monitored for steroid-induced cataracts.

Patients given cycloplegic mydriatics to dilate the pupils to delay cataract surgery must be monitored for intraocular pressure.

A number of agents are purported to delay cataract formation but none are known to reverse the progression of cataracts once begun. Prevention may be assisted by the use of UV-blocking sunglasses.

Use of contact lenses to correct aphakic vision after intracapsular cataract extraction is problematic (e.g., loss, infection, dislocation, corneal decompensation) and rarely successful in patients over 60 years old.

• Spectacle lenses to correct aphakic vision are unable to correct side vision, to which a number of patients are unable to adjust.
• Opacification of a retained posterior lens capsule is a common sequela, but it can be treated successfully with laser therapy.
• Cataract surgery predisposes individuals to retinal detachment and systoid macular edema.

Approximately 95% of patients who elect to have cataract surgery can expect improved vision almost immediately. After-cataract is a common inflammatory condition that most often results from changes in tissues left behind after extracapsular cataract surgery or after trauma; inflammation results in hemorrhagic, pigmentary, and fibrotic changes that may produce synechiae, pupillary distortions, glaucoma, and retinal detachment.

Age-related cataracts are not likely to be seen in women in their childbearing years. However, maternal infection, drug ingestion, or radiation therapy during pregnancy may cause cataracts in the fetus.

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