1-Acanthamoeba keratitis
What Contact Lens Wearers
Need To Know
Acanthamoeba eye infections in contact lens wearers are rare but serious, and they often start because of improper lens handling and poor hygiene.
To avoid Acanthamoeba keratitis, contact lens wearers should follow lens wearing and cleaning instructions from both manufacturers and eye doctors very closely. Proper contact lens care greatly reduces the risk of all contact lens-related eye infections, including those caused by Acanthamoeba.
Prevention is always the best approach, because Acanthamoeba keratitis can be extremely difficult to treat; in fact, sometimes these infections require a corneal transplant, which is a serious surgical procedure.
What Are Acanthamoeba?
Acanthamoeba are naturally occurring amoeba (tiny, one-celled animals) commonly found in water sources, such as tap water, well water, hot tubs, and soil and sewage systems.
If these tiny parasites infect the eye, Acanthamoeba keratitis results. The condition was first diagnosed in 1973, with about 90 percent of cases involving contact lens wearers.
Acanthamoeba Outbreaks Among Contact Lens Wearers
In recent years, the U.S. Centers for Disease Control and Prevention (CDC) and other researchers have noted sporadic outbreaks of Acanthamoeba keratitis cases among contact lens wearers.
For example, in 2007 the CDC released several public health warnings regarding Acanthamoeba keratitis associated with use of the contact lens solution Complete MoisturePlus, manufactured by Abbott Medical Optics (AMO) — formerly Advanced Medical Optics.
The CDC said a sevenfold increase in the risk of developing Acanthamoeba keratitis associated with use of the contact lens solution prompted AMO to withdraw Complete MoisturePlus from the market. The contact lens solution itself was not contaminated, but it seemed to be ineffective in preventing Acanthamoeba keratitis.
The CDC has issued similar warnings concerning fungal eye infections associated with the use of Bausch & Lomb's ReNu With MoistureLoc contact lens solution, which was removed from worldwide markets in May 2006.
What Causes Acanthamoeba Keratitis?
Factors and activities that increase the risk of contracting Acanthamoeba keratitis include using contaminated tap or well water on contact lenses, using homemade solutions to store and clean contacts, wearing contact lenses in a hot tub and swimming or showering while wearing lenses.
Contact lens wearers need to us good hygiene to prevent eye infections caused by Acanthamoeba, an amoeba shown here greatly magnified. (Photo: U.S. Centers for Disease Control and Dr. George Healy)
A dirty lens case also can be a source of Acanthamoeba infection.
In addition, some scientists theorize that new U.S. Environmental Protection Agency regulations aimed at reducing carcinogenic (potentially cancer-causing) products such as disinfectants in the water supply may have inadvertently boosted microbial risks, including an increased likelihood of finding Acanthamoeba in water supplies.
Other researchers associate recent increases in contact lens-related eye infections with the introduction of "no-rub" lens care systems that may result in less effective contact lens cleaning and disinfection.
But regardless of the cause of the increase, Acanthamoeba can be killed easily, especially when rubbed off the lens surface during cleaning. In the end, good contact lens hygiene is the best way to prevent Acanthamoeba keratitis.
How Do You Know if You Have Acanthamoeba Keratitis?
Symptoms of Acanthamoeba keratitis include redness and eye pain after removing your contact lenses, as well as tearing, light sensitivity, blurred vision and a feeling that something is in your eye.
Advanced Acanthamoeba keratitis can cause a white "ring" to cover the iris, as well as redness in the white of the eye. (Also read about conjunctivitis, another cause of eye redness.)
With these types of symptoms, you should always contact your eye doctor. But keep in mind that Acanthamoeba keratitis is often difficult for your eye doctor to diagnose at first, because its symptoms are similar to pink eye symptoms and those of other eye infections.
Diagnosis of keratitis often occurs once it is determined that the condition is resistant to antibiotics used to manage other infections. A "ring-like" ulceration of your corneal tissue may also occur.
Unfortunately, if not promptly treated, Acanthamoeba keratitis can cause permanent vision loss or require a corneal transplant to recover lost vision.
How Can You Reduce the Risk of Getting Acanthamoeba Keratitis?
There are several easy ways to greatly reduce the chance of getting this sight-threatening condition — and, in fact, any type of contact lens-related eye infection:
1. Follow your eye doctor's recommendations regarding care of your contact lenses. Use only products that he or she recommends.
2. Never use tap water with your contact lenses. Do not swim, shower or use a hot tub while wearing them. If you do decide to wear your lenses while swimming, wear airtight swim goggles and afterward dispose of the lenses immediately.
3. Be sure to soak your lenses in fresh disinfecting solution every night. Don't use a wetting solution or saline solution that isn't intended for disinfection.
4. Always wash your hands before handling your lenses.
5. Unless you are wearing disposable contact lenses that are replaced daily, always clean your contacts immediately upon removal, rubbing the lenses under a stream of multipurpose solution — even if using a "no-rub" solution — and storing them in a clean case filled with fresh (not "topped off") multipurpose or disinfecting solution.
Take Care of Your Contact Lens Case
Cleanliness and proper care are equally important for contact lens cases.
Besides using good hygiene when handling contact lenses, clean and sterilize your lens cases, to avoid Acanthamoeba contamination. (Read more about soft contact lens care.)
Many eye doctors recommend that you rinse your contact lens case with hot tap water and leave it out to air dry when not in use.
Other doctors, citing that Acanthamoeba can be present in tap water, say you should use only contact lens disinfecting solution (or multipurpose solution) to rinse and clean your contact lens case. Ask your eye doctor for advice on this important matter.
When allowing your lens case to air-dry, research shows there is less risk of contamination if the case is placed face-down in an area of low humidity (in your bedroom rather than your bathroom, for example).
As an extra precaution, you might want to consider sterilizing your empty contact lens case once a week by submerging it in boiling water for a few minutes.
Many eye doctors also say you should discard and replace your contact lens case at least every three months to help prevent contamination.
Again, prevention is your best defense against Acanthamoeba keratitis. Always use good hygiene during contact lens use and care. And if you notice any unusual eye symptoms that might indicate an infection, immediately consult your eye doctor. .
Resources:
Diagnosis and successful medical treatment of Acanthamoeba keratitis. Archives of Ophthalmology. September 1995.
A comparative study of techniques for decreasing contact lens storage case contamination. Journal of the American Optometric Association. March 1994.
Impact of air-drying lens cases in various locations and positions. Optometry & Vision Science. July 2010.
2-Eye allergies
Eye allergies often are hereditary, and occur due to processes associated with other types of allergic responses.
When an allergic reaction takes place, your eyes may be overreacting to a substance perceived as harmful, even though it may not be. For example, dust that is harmless to most people can cause excessive production of tears and mucus in eyes of overly sensitive, allergic individuals.
Allergies can trigger other problems, such as conjunctivitis (pink eye) and asthma. Combined nasal and eye allergies create a condition known as rhinoconjunctivitis.
About 30 percent to 50 percent of U.S. residents have allergy symptoms. And about 75 percent of those symptoms affect the eyes.*
Allergy Symptoms and Signs
Common signs of allergies include:
• Red, swollen or itchy eyes
• Runny nose
• Sneezing and coughing
• Itchy nose, mouth or throat
• Headache from sinus congestion
Beyond more obvious symptoms, you also may feel fatigued and could suffer from lack of sleep.
What Causes Eye Allergies?
Many allergens are in the air, where they come in contact with your eyes and nose. Airborne allergens include pollen, mold, dust and pet dander.
Other causes of allergies, such as certain foods or bee stings, do not typically affect the eyes the way airborne allergens do. Adverse reactions to certain cosmetics or drugs such as antibiotic eye drops also may cause eye allergies.
Some people actually are allergic to the preservatives in eye drops such as those used to lubricate dry eyes. In this case, you may need to use a preservative-free brand.
General Eye Allergy Treatment
Avoidance. The most common "treatment" is to avoid what's causing your eye allergy. Itchy eyes? Keep your home free of pet dander and dust and keep pets off the furniture. Stay inside with the air conditioner on when a lot of pollen is in the air. Air conditioners filter out allergens, though you must clean the filters from time to time.
Make sure you wear wraparound sunglasses to help shield your eyes from allergens, and drive with the windows closed.
Medications. If you're not sure what's causing your eye allergies, or you're not having any luck avoiding them, your next step probably will be medication to alleviate the symptoms.
Over-the-counter and prescription medications each have their advantages; for example, over-the-counter products are often less expensive, while prescription ones are often stronger.
Eye drops are available as simple eye washes, or they may have one or more active ingredients such as antihistamines, decongestants or mast cell stabilizers that inhibit inflammation. Antihistamines relieve many symptoms caused by airborne allergens, such as itchy, watery eyes, runny nose and sneezing. Decongestants help shrink swollen nasal passages for easier breathing.
Relief for Watery, Itchy Eyes
Common causes of excessively watery eyes are allergies and dry eye syndrome — two very different problems.
With allergies, your body's release of histamine causes your eyes to water, just as it may cause your nose to run. It may seem illogical that watery eyes would result from dry eye syndrome. But this is sometimes true, because the excessive dryness works to overstimulate production of the watery component of your eye's tears.
Decongestants clear up redness. They contain vasoconstrictors, which simply make the blood vessels in your eyes smaller, lessening the apparent redness. They treat the symptom, not the cause.
In fact, with extended use, the blood vessels can become dependent on the vasoconstrictor to stay small. When you discontinue the eye drops, the vessels actually get bigger than they were in the beginning. This process is called rebound hyperemia, and the result is that your red eyes worsen over time.
Some products have ingredients that act as mast cell stabilizers, which alleviate redness and swelling. Mast cell stabilizers are similar to antihistamines. But while antihistamines are known for their immediate relief, mast cell stabilizers are known for their long-lasting relief.
Antihistamines, decongestants and mast cell stabilizers are available in pill form, but pills don't work as quickly as eye drops or gels to bring eye relief.
Nonsteroidal anti-inflammatory drug (NSAID) eye drops may be prescribed to decrease swelling, inflammation and other symptoms associated with seasonal allergic conjunctivitis, also called hay fever.
Prescription corticosteroid eye drops also may provide similar, quick relief. However, steroids have been associated with side effects such as increased inner eye pressure (intraocular pressure) leading to glaucoma and damage to optic nerve. Steroids also have been known to cause the eye's natural lens to become cloudy, producing cataracts.
Eye Allergies Self-Test
Please mouse over the image for common causes of eye allergies.
Take this quiz to see if you might have eye allergies. Always consult your doctor if you suspect you have an eye condition needing care.
• Do allergies run in your family?
• Do your eyes often itch, particularly during spring pollen season?
• Have you ever been diagnosed with "pink eye" (conjunctivitis)?
• Are you allergic to certain animals such as cats?
• Do you often need antihistamines and/or decongestants to control sneezing, coughing and congestion?
• When pollen is in the air, are your eyes less red and itchy when you stay indoors under an air conditioner?
• Do your eyes begin tearing when you wear certain cosmetics or lotions, or when you're around certain strong perfumes?
If you answered "yes" to most of these questions, then you may have eye allergies. Make an appointment with an optometrist or ophthalmologist to determine the best course of action.
Check the product label or insert for a list of side effects of over-the-counter medications. For prescription medication, ask your doctor. In some cases, combinations of medications may be used.
You may benefit from immunotherapy, in which an allergy specialist injects you with small amounts of the allergen to help you gradually build up immunity
Eye Allergies and Contact Lenses
Even if you are generally a successful contact lens wearer, allergy season can make your contacts uncomfortable. Airborne allergens can get on your lenses, causing discomfort. Allergens also can stimulate the excessive production of natural substances in your tears, which bind to your contacts and also become uncomfortable. Pollen maps can help you determine when allergens are present.
Ask your eye doctor about eye drops that can help relieve your symptoms and keep your contact lenses clean. Certain drops can discolor or damage certain lenses, so it makes sense to ask first before trying out a new brand.
Another alternative is daily disposable contact lenses, which are discarded nightly. Because you replace them so frequently, these types of lenses are unlikely to develop irritating deposits that can build up over time and cause or heighten allergy-related discomfor.
Resources:
*Allergic diseases of the eye. Medical Clinics of North America. January 2006.
Ocular allergy overview. Immunology and Allergy Clinics of North America. February 2008.
3-Amblyopia
Amblyopia, also known as lazy eye, is a vision development disorder in which an eye fails to achieve normal visual acuity, even with prescription eyeglasses or contact lenses.
Amblyopia begins during infancy and early childhood. In most cases, only one eye is affected. But in some cases, reduced visual acuity can occur in both eyes.
Particularly if lazy eye is detected early in life and promptly treated, reduced vision can be avoided. But if left untreated, lazy eye can cause severe visual disability in the affected eye, including legal blindness.
Amblyopia Signs and Symptoms
Because amblyopia typically is a problem of infant vision development, symptoms of the condition can be difficult to discern. However, a common cause of amblyopia is strabismus. So if you notice your baby or young child has crossed eyes or some other apparent eye misalignment, schedule an appointment for a children's eye exam immediately — preferably with an optometrist or ophthalmologist who specializes in children's vision.
Another clue that your child may have amblyopia is if he or she cries or fusses when you cover one eye. This may suggest that the eye you have covered is the "good" eye, and that the uncovered eye is amblyopic, causing blurred vision.
What Causes Amblyopia?
Strabismus is the most common cause of amblyopia. To avoid double vision caused by poorly aligned eyes, the brain ignores the visual input from the misaligned eye, leading to amblyopia in that eye (the "lazy eye"). This type of amblyopia is called strabismic amblyopia.
Sometimes, amblyopia is caused by unequal refractive errors in the two eyes, despite perfect eye alignment. For example, one eye may have significant uncorrected nearsightedness or farsightedness, while the other eye does not. Or one eye may have significant astigmatism and the other eye does not.
In such cases, the brain relies on the eye that has less uncorrected refractive error and "tunes out" the blurred vision from the other eye, causing amblyopia in that eye from disuse. This type of amblyopia is called refractive amblyopia (or anisometropic amblyopia).
Amblyopia Treatment
In some cases of refractive amblyopia, normal vision can be achieved simply by fully correcting the refractive errors in both eyes with glasses or contact lenses. Usually, however, at least some patching of the "good" eye is needed to force the brain to pay attention to the visual input from the amblyopic eye and enable normal vision development to occur in that eye.
Treatment of strabismic amblyopia often involves strabismus surgery to straighten the eyes, followed by eye patching and often some form of vision therapy (also called orthoptics) to help both eyes work together equally as a team.
Patching may be required for several hours each day or even all day long and may continue for weeks or months.
If you have a lot of trouble with your child taking the patch off, you might consider a specially designed prosthetic contact lens that prevents light from entering the good eye but does not affect your child's appearance. Though prosthetic contact lenses are more costly than a simple eye patch and require a contact lens exam and fitting, they can work wonders in difficult cases of amblyopia treatment when compliance with eye patching is poor.
You can help your child accept patching more readily. Here, Anissa's Fun Patches require no adhesive because they slide onto the temple of an eyeglass frame.
In some children, atropine eye drops have been used to treat amblyopia instead of an eye patch. One drop is placed in your child's good eye each day (your eye doctor will instruct you). Atropine blurs vision in the good eye, which forces your child to use the eye with amblyopia more, to strengthen it. One advantage of using atropine eye drops is that it doesn't require your constant vigilance to make sure your child wears the patch.
In one large study of 419 children younger than 7 years of age with amblyopia ranging from 20/40 to 20/100 prior to treatment, atropine therapy produced comparable results to eye patching (though improvement in visual acuity in the amblyopic eye was slightly greater in the patching group). As a result, some previously skeptical eye care practitioners are using atropine as their first choice for amblyopia treatment over patching.
However, atropine does have side effects that should be considered: light sensitivity (because the eye is constantly dilated), flushing and possible paralysis of the ciliary muscle after long-term atropine use, which could affect the eye's accommodation, or ability to change focus.
Help for Older Children and Adults With Lazy Eye
For years, experts believed that if amblyopia treatment was not initiated very early in life, no improvement in visual acuity was possible. The critical period for intervention was said to be around age 8.
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But it now appears that older children and even adults with long-stranding lazy eye can benefit from amblyopia treatment using computer programs that stimulate neural changes leading to improvements in visual acuity and contrast sensitivity.
One such program — called RevitalVision — has produced improved vision in older children with lazy eye and adults with long-standing amblyopia. The treatment generally consists of 40 training sessions of 40 minutes each, conducted over a period of several weeks.
In one clinical study of 44 amblyopic children and adults ranging in age from 9 to 54 years, 70.5 percent of the participants had a visual acuity improvement of 2 or more lines on a standardized eye chart after a full regimen of RevitalVision training sessions.
Currently, RevitalVision is the only FDA-approved computerized treatment for amblyopia. The program is approved for individuals age 9 and older with best corrected vision of 20/100 or better and little or no strabismus.
Other computer programs to treat lazy eye also are available and in use by eye doctors who specialize in children's vision and vision therapy.
Early Detection and Treatment is Important
Though modern amblyopia treatments might improve vision in older children and adults, most experts agree that early detection and treatment of lazy eye is preferred for normal visual development and the best visual outcomes from amblyopia treatment.
Amblyopia will not go away on its own, and untreated lazy eye can lead to permanent visual problems and poor depth perception. If later in life your child's stronger eye develops disease or is injured, he or she will depend on the poor vision of the amblyopic eye, so it is best to treat amblyopia early on.
Resources:
A comparison of atropine and patching treatments for moderate amblyopia by patient age, cause of amblyopia, depth of amblyopia, and other factors. Ophthalmology. August 2003.
Atropine an effective alternative to patching for amblyopia. Review of Ophthalmology. October 2003.
Perceptual learning improves contrast sensitivity and visual acuity in adults with anisometropic amblyopia. Vision Research. March 2006.
Correspondence from RevitalVision LLC. June 2010.
Judith Lee, Gretchyn Bailey and Vance Thompson, MD also contributed to this article.
4-Bells palsy
Bell's palsy is a temporary weakness or paralysis of the facial nerve known as the seventh cranial nerve. This nerve controls facial expressions, eyelid movement and the muscles of the forehead and neck.
Bell's palsy usually occurs suddenly, affecting the greater part of one side of the face. The cause often is unknown, but the condition has been associated with certain viruses. Statistics show that Bell's palsy affects about one person out of 60 or 70.
After the abrupt onset of Bell's palsy, most people develop maximum weakness within 48 hours. Prior to the onset, some people feel pain behind the ear.
While Bell's palsy may appear similar to a stroke, no other neurological signs or symptoms are present.
How Does Bell's Palsy Affect Eyes?
Most people with Bell's palsy are unable to blink on the affected side of the face. At the same time, the lower eyelid may turn outward (ectropion). The face and lips on the affected side become droopy, and you have little or no control over their muscle function.
Because the muscle that opens the eye is controlled by a separate cranial nerve, you can easily open the affected eye. But unfortunately you are unable to close the eyelid.
As a result, most people with Bell's palsy suffer from an extreme form of dry eye known as exposure keratitis.
Bell's Palsy Treatment and Recovery
Treatment for Bell's palsy usually includes generous use of ocular lubricants, such as non-preserved artificial tears and eye ointments. Many people require the eyelid to be patched or taped shut while sleeping, to keep it moist.
If you develop an outwardly turned eyelid, you may need surgery to repair it.
Approximately 80 percent of people with Bell's palsy recover within six months. But without proper care of the involved eye, you may suffer needless and permanent consequences such as corneal ulceration and scarring of your eye's clear front surface.
5-Blepharitis
Blepharitis is a common eyelid inflammation that sometimes is associated with a bacterial eye infection, symptoms of dry eyes or certain types of skin conditions such as acne rosacea.
Blepharitis has two basic forms:
• Anterior blepharitis, affecting the outside front of the eyelid where eyelashes are attached.
• Posterior blepharitis, linked to dysfunction of meibomian glands within the eyelids that secrete oils to help lubricate the eye.
It's common to have a mixture of both anterior and posterior forms of blepharitis at the same time, but in different degrees of severity.
Although eye doctors commonly diagnose blepharitis, it can be difficult to find permanent relief of the symptoms that can include burning, flaking, crusting, tearing, irritation, itching, redness in eyelid margins and a foreign body sensation.
Treatment for Blepharitis
If you are diagnosed with chronic blepharitis, your eye doctor will likely recommend an ongoing regimen of eyelid hygiene (see sidebar) that can include commercially developed, over-the-counter lid scrubs or other recommended cleansing agents. Eyelid hygiene is the cornerstone of treatment for most cases of blepharitis.
Besides a program of eyelid hygiene, the severity of the blepharitis and related symptoms may require supplemental treatment with topical and oral medicine.
In some cases of posterior blepharitis, eye doctors recommend nutritional supplementation with omega-3 fatty acids, such as flaxseed oil, to aid healthy function of meibomian glands that provide essential lubrication for eye and eyelid comfort.
Anterior Blepharitis
Symptoms of bacteria-caused staphylococcal blepharitis often are more severe and can even lead to loss of eyelashes.
Besides eyelid cleansing and hygiene, an antibiotic ointment for eyelids might be prescribed. Pink eye due to bacteria — a common type of eye infection — may occur simultaneously with blepharitis.
Viruses and other types of bacteria besides staphylococcus also can cause anterior blepharitis.
Without treatment, blepharitis caused by bacteria can cause long-term effects such as ectropion, thickened lid margins, dilated and visible capillaries, trichiasis and entropion. In cases of trichiasis and entropion, the cornea may exhibit significant erosion from eyelashes rubbing against the eye.
Seborrheic blepharitis is caused by seborrheic dermatitis, a skin condition that creates flaking and scaling — including on the eyelids. Regular cleansing with eyelid scrubs and gentle, non-detergent shampoos can provide significant relief and improve the appearance of eyelids.
The American Academy of Dermatology notes that the causes of these skin conditions are not well understood. But seborrheic dermatitis sometimes appears in a person with a weakened immune system. Fungi or certain types of yeast that feed on oils (lipids) in the skin also may lead to seborrheic dermatitis, with accompanying blepharitis.
With demodex blepharitis, microscopic mites (demodex folliculorum) and their waste materials could cause clogging of follicles at roots of eyelashes, and in some cases might be associated with development of skin conditions such as rosacea and blepharitis. A commercial eyelid scrub combined with tea tree oil may be effective for treating this type of blepharitis.*
Other reported treatments of demodex blepharitis include sulfur oil and steroids. An anti-parasitic gel (metronidazole) also has shown effectiveness as a treatment.
Another version of these mites (demodex brevis) can be found more generally in oil glands of the skin and eyelids, which also may contribute to blepharitis symptoms.
While presence of these tiny mites is common in everyone, researchers speculate that some people develop demodex blepharitis due to unusual allergic or immune system reactions leading to inflammation.
Eyelid Hygiene Relieves Blepharitis Symptoms
Use a cotton-tipped swab to apply cleaning solution recommended by your eye doctor. Rub gently around the edges of your upper and lower eyelids, but do not get cleaning solution in your eye.
Blepharitis can be difficult to manage because it is often chronic, meaning that it never goes away completely. Your eye doctor may recommend one or more of these steps involving good eyelid hygiene and massage:
• Apply a warm compress such as a washcloth to the outer eyelids.
• Cleanse the eyelids with a commercial lid scrub or other recommended product.
• Gently massage the outer eyelids.
A warm compress loosens the crust on your eyelids and eyelashes before you clean them. The warmth also can loosen any blocked residue in the oil-secreting meibomian glands in your eyelids.
To use a warm compress:
• Wash your hands, then dampen a clean washcloth with warm water.
• Place the washcloth over your closed eyes for several minutes.
• Open your eyes, and then use fingers to rub gently around the outer eyelids in a circular motion. Don't press too hard on the eyeball.
• Follow your doctor's recommendations on how often to use a compress and how long it should be kept in place.
When you first begin treatment, your eye doctor may suggest that you do this several times daily, for about five minutes each time. Later on, you might apply the compress once daily for a few minutes.
Cleaning the eyelids is essential to blepharitis treatment. Your doctor will recommend what cleansing agent to use, such as warm water only, baby shampoo diluted with warm water or a special over-the-counter product made specifically for cleansing the lids.
To clean eyelids:
• Wash your hands, then dip a clean washcloth, cotton swab or gauze pad into your cleaning solution.
• Make sure you squeeze out any excess moisture.
• Gently wipe across your lashes and lid margin.
• Rinse with cool water.
• Repeat the process for your other eye, but use a different washcloth, swab or pad.
Your eye doctor may have you clean your lids several times daily to start, and then once daily thereafter. — GW
Posterior Blepharitis
Posterior blepharitis involves dysfunction of oil-secreting meibomian glands within the eyelids. The openings of these glands are at the inner edge of the eyelids, and oils secreted by the meibomian glands help prevent tear evaporation.
Also called meibomian blepharitis, meibomitis or meibomian gland dysfunction (MGD), posterior blepharitis reduces meibomian gland output or produces abnormal oily secretions. Symptoms of posterior blepharitis include inflamed and thickened eyelid margins, eyelid crusting and other symptoms that are often difficult to manage. With this type of blepharitis, tears can even look foamy.
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Meibomian blepharitis sometimes is described as dry eye syndrome caused by meibomian gland dysfunction.
Rosacea blepharitis often is a component of ocular rosacea, which can cause eyelid inflammation linked to dysfunction of the skin's oil (sebaceous) glands. Acne rosacea is a common skin inflammation characterized by pimple-like bumps and facial redness — especially around the cheeks, nose, forehead and chin. As with certain forms of blepharitis, underlying causes of rosacea aren't well understood.
However, rosacea does appear to be linked to certain genetic tendencies and environmental factors, such as excessive sun exposure.
Clogged meibomian glands from posterior blepharitis also can cause a stye or chalazion to form. A stye, which is often uncomfortable, grows from an infected oil gland in the eyelid. A chalazion is a non-infected, usually painless nodule caused by inflammation of a blocked meibomian gland.
Is There a Cure for Blepharitis?
A complete blepharitis cure may not exist. But as explained above, good eyelid hygiene and prescription medicine are often effective in managing blepharitis, while warm compresses and lid massages can help unclog obstructed meibomian glands.
If you wear soft contact lenses, your eye doctor may prescribe RGP contacts instead or may recommend more frequent replacement of your soft contacts to reduce lens deposits that may be associated with your blepharitis. Depending on the severity of your symptoms, you may need to discontinue contact lens wear altogether for a while.
Blepharitis can cause inflamed eyelids, eye burning and dryness.
It's a good idea to minimize use of eye makeup, which can interfere with eyelid hygiene. If your doctor recommends an anti-dandruff shampoo for your scalp and eyebrows, make sure you keep the shampoo out of your eyes to avoid irritation.
Also, as mentioned above, certain eye doctors recommend nutritional supplementation with omega-3 fatty acids to improve function of the eyelid's oil glands.
Because blepharitis and dry eyes commonly occur together, your eye doctor may advise you to use over-the-counter or prescription eye drops to help relieve symptoms.
In severe cases of dry eye, especially without significant blepharitis, you may benefit from the insertion of punctal plugs in tear drainage channels in your eyelids to help increase the amount of lubricating tears on the surface of your eye. More moisture on the eye's surface can make your eyes feel better and healthier.
6-Cataracts
A cataract is a clouding of the eye's natural lens, which lies behind the iris and the pupil. The lens works much like a camera lens, focusing light onto the retina at the back of the eye. The lens also adjusts the eye's focus, letting us see things clearly both up close and far away.
The lens is mostly made of water and protein. The protein is arranged in a precise way that keeps the lens clear and lets light pass through it.
But as we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract, and over time, it may grow larger and cloud more of the lens, making it harder to see.
Researchers are gaining additional insights about what causes these specific types of proteins (crystallins) to cluster in abnormal ways to cause lens cloudiness and cataracts. One recent finding suggests that fragmented versions of these proteins bind with normal proteins, disrupting normal function.
Cataracts are classified as one of three types:
• A subcapsular cataract begins at the back of the lens. People with diabetes, high farsightedness or retinitis pigmentosa, or those taking high doses of steroids, may develop a subcapsular cataract.
• A nuclear cataract is most commonly seen as it forms. This cataract forms in the nucleus, the center of the lens, and is due to natural aging changes.
• A cortical cataract, which forms in the lens cortex, gradually extends its spokes from the outside of the lens to the center. Many diabetics develop cortical cataracts.
Cataract Symptoms and Signs
A cataract starts out small and at first has little effect on your vision. You may notice that your vision is blurred a little, like looking through a cloudy piece of glass or viewing an impressionist painting.
Hazy or blurred vision may mean you have a cataract.
A cataract may make light from the sun or a lamp seem too bright or glaring. Or you may notice when you drive at night that the oncoming headlights cause more glare than before. Colors may not appear as bright as they once did.
The type of cataract you have will affect exactly which symptoms you experience and how soon they will occur. When a nuclear cataract first develops, it can bring about a temporary improvement in your near vision, called "second sight." Unfortunately, the improved vision is short-lived and will disappear as the cataract worsens. On the other hand, a subcapsular cataract may not produce any symptoms until it's well-developed.
If you think you have a cataract, see an eye doctor for an exam to find out for sure.
What Causes Cataracts?
No one knows for sure why the eye's lens changes as we age, forming cataracts. Researchers are gradually identifying factors that may cause cataracts — and information that may help to prevent them.
Many studies suggest that exposure to ultraviolet light is associated with cataract development, so eye care practitioners recommend wearing sunglasses and a wide-brimmed hat to reduce your exposure.
Other types of radiation may also be causes. For example, a 2005 study conducted in Iceland suggests that airline pilots have a higher risk of developing nuclear cataract than non-pilots and that the cause may be exposure to cosmic radiation. A similar theory suggests that astronauts, too, are at risk from cosmic radiation.
August Is Cataract Awareness Month
It's almost inevitable: if you live long enough, at some point you will get cataracts. To delay the onset and minimize vision problems, follow these tips, based on recommendations by the American Academy of Ophthalmology:
Over 40? Get a baseline exam. With a comprehensive eye exam, your eye doctor can make a record of the current health of your eyes, check for early signs of disease and vision changes and tell you how often you'll need follow-up exams. If your family has a history of early cataracts, then don't delay: get an eye exam as soon as possible.
Learn about cataract risk factors. People at risk include diabetics, smokers, sun worshippers, and those with a family history of cataracts. Eye injury or inflammation will increase your risk. So will using steroids over a long period of time, especially if you're combining oral and inhaled steroids.
Reduce your risks. Wear sunglasses and a hat outside. Don't smoke. If you are diabetic, keep your blood sugar levels under control.
Learn when to consider cataract surgery. It's really up to you as to when to have the surgery. Cataracts create vision problems such as halos, blurriness, glare and dimmed colors, and when the symptoms worsen, your quality of life and ability to perform everyday tasks will diminish. There's no need to wait: get the surgery and get on with your life. Your eye doctor will also be able to advise you as to the best time for removal.
Other studies suggest people with diabetes are at risk for developing a cataract.
The same goes for users of steroids, diuretics and major tranquilizers, but more studies are needed to distinguish the effect of the disease from the consequences of the drugs themselves.
Some eye care practitioners believe that a diet high in antioxidants, such as beta-carotene (vitamin A), selenium and vitamins C and E, may forestall cataract development. Meanwhile, eating a lot of salt may increase your risk.
Other risk factors include cigarette smoke, air pollution and heavy alcohol consumption.
A small study published in 2002 found lead exposure to be a risk factor; another study in December 2004, of 795 men age 60 and older, came to a similar conclusion.
But larger studies are needed to confirm whether lead can definitely put you at risk and, if so, whether the risk is from a one-time dose at a particular time in life or from chronic exposure over years.*
Researchers say additional studies also are needed to confirm whether hormone replacement therapy (HRT) significantly increases chances that cataracts will form and progress to the point that surgical removal is required.
An eight-year study of more than 30,000 postmenopausal Swedish women found a 14 percent increased risk for cataract removal among those who used HRT at any time and an 18 percent increased risk for current HRT users.
HRT use combined with regular alcohol consumption appeared to create a 42 percent increased risk of cataract removal, compared with women who had never used HRT or alcohol.
The HRT study was reported in the March 2010 issue of Ophthalmology.
Cataract Treatment
When symptoms begin to appear, you may be able to improve your vision for a while using new glasses, strong bifocals, magnification, appropriate lighting or other visual aids.
An intraocular lens (IOL) is implanted in the eye in place of the clouded natural lens. Shown is Alcon's AcrySof Natural IOL; it filters out blue light, which may be harmful to eyes.
Think about surgery when your cataracts have progressed enough to seriously impair your vision and affect your daily life. Many people consider poor vision an inevitable fact of aging, but cataract surgery is a simple, relatively painless procedure to regain vision.
Cataract surgery is very successful in restoring vision. In fact, it is the most frequently performed surgery in the United States, with more than 3 million Americans undergoing cataract surgery each year. Nine out of 10 people who have cataract surgery regain very good vision, somewhere between 20/20 and 20/40.
During surgery, the surgeon will remove your clouded lens and in most cases replace it with a clear, plastic intraocular lens (IOL).
New IOLs are being developed all the time to make the surgery less complicated for surgeons and the lenses more helpful to patients. Presbyopia-correcting IOLs potentially help you see at all distances, not just one. Another new type of IOL blocks both ultraviolet and blue light rays, which research indicates may damage the retina (see illustration).
Read more on this website about what to expect if you have cataract surgery and how to deal with rare cataract surgery complications. Also, men should be aware that certain prostate drugs can cause intraoperative floppy iris syndrome (IFIS) during a cataract procedure.
Need To Know
Acanthamoeba eye infections in contact lens wearers are rare but serious, and they often start because of improper lens handling and poor hygiene.
To avoid Acanthamoeba keratitis, contact lens wearers should follow lens wearing and cleaning instructions from both manufacturers and eye doctors very closely. Proper contact lens care greatly reduces the risk of all contact lens-related eye infections, including those caused by Acanthamoeba.
Prevention is always the best approach, because Acanthamoeba keratitis can be extremely difficult to treat; in fact, sometimes these infections require a corneal transplant, which is a serious surgical procedure.
What Are Acanthamoeba?
Acanthamoeba are naturally occurring amoeba (tiny, one-celled animals) commonly found in water sources, such as tap water, well water, hot tubs, and soil and sewage systems.
If these tiny parasites infect the eye, Acanthamoeba keratitis results. The condition was first diagnosed in 1973, with about 90 percent of cases involving contact lens wearers.
Acanthamoeba Outbreaks Among Contact Lens Wearers
In recent years, the U.S. Centers for Disease Control and Prevention (CDC) and other researchers have noted sporadic outbreaks of Acanthamoeba keratitis cases among contact lens wearers.
For example, in 2007 the CDC released several public health warnings regarding Acanthamoeba keratitis associated with use of the contact lens solution Complete MoisturePlus, manufactured by Abbott Medical Optics (AMO) — formerly Advanced Medical Optics.
The CDC said a sevenfold increase in the risk of developing Acanthamoeba keratitis associated with use of the contact lens solution prompted AMO to withdraw Complete MoisturePlus from the market. The contact lens solution itself was not contaminated, but it seemed to be ineffective in preventing Acanthamoeba keratitis.
The CDC has issued similar warnings concerning fungal eye infections associated with the use of Bausch & Lomb's ReNu With MoistureLoc contact lens solution, which was removed from worldwide markets in May 2006.
Factors and activities that increase the risk of contracting Acanthamoeba keratitis include using contaminated tap or well water on contact lenses, using homemade solutions to store and clean contacts, wearing contact lenses in a hot tub and swimming or showering while wearing lenses.
Contact lens wearers need to us good hygiene to prevent eye infections caused by Acanthamoeba, an amoeba shown here greatly magnified. (Photo: U.S. Centers for Disease Control and Dr. George Healy)
A dirty lens case also can be a source of Acanthamoeba infection.
In addition, some scientists theorize that new U.S. Environmental Protection Agency regulations aimed at reducing carcinogenic (potentially cancer-causing) products such as disinfectants in the water supply may have inadvertently boosted microbial risks, including an increased likelihood of finding Acanthamoeba in water supplies.
Other researchers associate recent increases in contact lens-related eye infections with the introduction of "no-rub" lens care systems that may result in less effective contact lens cleaning and disinfection.
But regardless of the cause of the increase, Acanthamoeba can be killed easily, especially when rubbed off the lens surface during cleaning. In the end, good contact lens hygiene is the best way to prevent Acanthamoeba keratitis.
How Do You Know if You Have Acanthamoeba Keratitis?
Symptoms of Acanthamoeba keratitis include redness and eye pain after removing your contact lenses, as well as tearing, light sensitivity, blurred vision and a feeling that something is in your eye.
Advanced Acanthamoeba keratitis can cause a white "ring" to cover the iris, as well as redness in the white of the eye. (Also read about conjunctivitis, another cause of eye redness.)
With these types of symptoms, you should always contact your eye doctor. But keep in mind that Acanthamoeba keratitis is often difficult for your eye doctor to diagnose at first, because its symptoms are similar to pink eye symptoms and those of other eye infections.
Diagnosis of keratitis often occurs once it is determined that the condition is resistant to antibiotics used to manage other infections. A "ring-like" ulceration of your corneal tissue may also occur.
Unfortunately, if not promptly treated, Acanthamoeba keratitis can cause permanent vision loss or require a corneal transplant to recover lost vision.
How Can You Reduce the Risk of Getting Acanthamoeba Keratitis?
There are several easy ways to greatly reduce the chance of getting this sight-threatening condition — and, in fact, any type of contact lens-related eye infection:
1. Follow your eye doctor's recommendations regarding care of your contact lenses. Use only products that he or she recommends.
2. Never use tap water with your contact lenses. Do not swim, shower or use a hot tub while wearing them. If you do decide to wear your lenses while swimming, wear airtight swim goggles and afterward dispose of the lenses immediately.
3. Be sure to soak your lenses in fresh disinfecting solution every night. Don't use a wetting solution or saline solution that isn't intended for disinfection.
4. Always wash your hands before handling your lenses.
5. Unless you are wearing disposable contact lenses that are replaced daily, always clean your contacts immediately upon removal, rubbing the lenses under a stream of multipurpose solution — even if using a "no-rub" solution — and storing them in a clean case filled with fresh (not "topped off") multipurpose or disinfecting solution.
Take Care of Your Contact Lens Case
Cleanliness and proper care are equally important for contact lens cases.
Besides using good hygiene when handling contact lenses, clean and sterilize your lens cases, to avoid Acanthamoeba contamination. (Read more about soft contact lens care.)
Many eye doctors recommend that you rinse your contact lens case with hot tap water and leave it out to air dry when not in use.
Other doctors, citing that Acanthamoeba can be present in tap water, say you should use only contact lens disinfecting solution (or multipurpose solution) to rinse and clean your contact lens case. Ask your eye doctor for advice on this important matter.
When allowing your lens case to air-dry, research shows there is less risk of contamination if the case is placed face-down in an area of low humidity (in your bedroom rather than your bathroom, for example).
As an extra precaution, you might want to consider sterilizing your empty contact lens case once a week by submerging it in boiling water for a few minutes.
Many eye doctors also say you should discard and replace your contact lens case at least every three months to help prevent contamination.
Again, prevention is your best defense against Acanthamoeba keratitis. Always use good hygiene during contact lens use and care. And if you notice any unusual eye symptoms that might indicate an infection, immediately consult your eye doctor. .
Resources:
Diagnosis and successful medical treatment of Acanthamoeba keratitis. Archives of Ophthalmology. September 1995.
A comparative study of techniques for decreasing contact lens storage case contamination. Journal of the American Optometric Association. March 1994.
Impact of air-drying lens cases in various locations and positions. Optometry & Vision Science. July 2010.
2-Eye allergies
When an allergic reaction takes place, your eyes may be overreacting to a substance perceived as harmful, even though it may not be. For example, dust that is harmless to most people can cause excessive production of tears and mucus in eyes of overly sensitive, allergic individuals.
Allergies can trigger other problems, such as conjunctivitis (pink eye) and asthma. Combined nasal and eye allergies create a condition known as rhinoconjunctivitis.
About 30 percent to 50 percent of U.S. residents have allergy symptoms. And about 75 percent of those symptoms affect the eyes.*
Allergy Symptoms and Signs
Common signs of allergies include:
• Red, swollen or itchy eyes
• Runny nose
• Sneezing and coughing
• Itchy nose, mouth or throat
• Headache from sinus congestion
Beyond more obvious symptoms, you also may feel fatigued and could suffer from lack of sleep.
What Causes Eye Allergies?
Many allergens are in the air, where they come in contact with your eyes and nose. Airborne allergens include pollen, mold, dust and pet dander.
Other causes of allergies, such as certain foods or bee stings, do not typically affect the eyes the way airborne allergens do. Adverse reactions to certain cosmetics or drugs such as antibiotic eye drops also may cause eye allergies.
Some people actually are allergic to the preservatives in eye drops such as those used to lubricate dry eyes. In this case, you may need to use a preservative-free brand.
Avoidance. The most common "treatment" is to avoid what's causing your eye allergy. Itchy eyes? Keep your home free of pet dander and dust and keep pets off the furniture. Stay inside with the air conditioner on when a lot of pollen is in the air. Air conditioners filter out allergens, though you must clean the filters from time to time.
Make sure you wear wraparound sunglasses to help shield your eyes from allergens, and drive with the windows closed.
Medications. If you're not sure what's causing your eye allergies, or you're not having any luck avoiding them, your next step probably will be medication to alleviate the symptoms.
Over-the-counter and prescription medications each have their advantages; for example, over-the-counter products are often less expensive, while prescription ones are often stronger.
Eye drops are available as simple eye washes, or they may have one or more active ingredients such as antihistamines, decongestants or mast cell stabilizers that inhibit inflammation. Antihistamines relieve many symptoms caused by airborne allergens, such as itchy, watery eyes, runny nose and sneezing. Decongestants help shrink swollen nasal passages for easier breathing.
Relief for Watery, Itchy Eyes
Common causes of excessively watery eyes are allergies and dry eye syndrome — two very different problems.
With allergies, your body's release of histamine causes your eyes to water, just as it may cause your nose to run. It may seem illogical that watery eyes would result from dry eye syndrome. But this is sometimes true, because the excessive dryness works to overstimulate production of the watery component of your eye's tears.
Decongestants clear up redness. They contain vasoconstrictors, which simply make the blood vessels in your eyes smaller, lessening the apparent redness. They treat the symptom, not the cause.
In fact, with extended use, the blood vessels can become dependent on the vasoconstrictor to stay small. When you discontinue the eye drops, the vessels actually get bigger than they were in the beginning. This process is called rebound hyperemia, and the result is that your red eyes worsen over time.
Some products have ingredients that act as mast cell stabilizers, which alleviate redness and swelling. Mast cell stabilizers are similar to antihistamines. But while antihistamines are known for their immediate relief, mast cell stabilizers are known for their long-lasting relief.
Antihistamines, decongestants and mast cell stabilizers are available in pill form, but pills don't work as quickly as eye drops or gels to bring eye relief.
Nonsteroidal anti-inflammatory drug (NSAID) eye drops may be prescribed to decrease swelling, inflammation and other symptoms associated with seasonal allergic conjunctivitis, also called hay fever.
Prescription corticosteroid eye drops also may provide similar, quick relief. However, steroids have been associated with side effects such as increased inner eye pressure (intraocular pressure) leading to glaucoma and damage to optic nerve. Steroids also have been known to cause the eye's natural lens to become cloudy, producing cataracts.
Eye Allergies Self-Test
Take this quiz to see if you might have eye allergies. Always consult your doctor if you suspect you have an eye condition needing care.
• Do allergies run in your family?
• Do your eyes often itch, particularly during spring pollen season?
• Have you ever been diagnosed with "pink eye" (conjunctivitis)?
• Are you allergic to certain animals such as cats?
• Do you often need antihistamines and/or decongestants to control sneezing, coughing and congestion?
• When pollen is in the air, are your eyes less red and itchy when you stay indoors under an air conditioner?
• Do your eyes begin tearing when you wear certain cosmetics or lotions, or when you're around certain strong perfumes?
If you answered "yes" to most of these questions, then you may have eye allergies. Make an appointment with an optometrist or ophthalmologist to determine the best course of action.
Check the product label or insert for a list of side effects of over-the-counter medications. For prescription medication, ask your doctor. In some cases, combinations of medications may be used.
You may benefit from immunotherapy, in which an allergy specialist injects you with small amounts of the allergen to help you gradually build up immunity
Eye Allergies and Contact Lenses
Even if you are generally a successful contact lens wearer, allergy season can make your contacts uncomfortable. Airborne allergens can get on your lenses, causing discomfort. Allergens also can stimulate the excessive production of natural substances in your tears, which bind to your contacts and also become uncomfortable. Pollen maps can help you determine when allergens are present.
Ask your eye doctor about eye drops that can help relieve your symptoms and keep your contact lenses clean. Certain drops can discolor or damage certain lenses, so it makes sense to ask first before trying out a new brand.
Another alternative is daily disposable contact lenses, which are discarded nightly. Because you replace them so frequently, these types of lenses are unlikely to develop irritating deposits that can build up over time and cause or heighten allergy-related discomfor.
Resources:
*Allergic diseases of the eye. Medical Clinics of North America. January 2006.
Ocular allergy overview. Immunology and Allergy Clinics of North America. February 2008.
3-Amblyopia
Amblyopia begins during infancy and early childhood. In most cases, only one eye is affected. But in some cases, reduced visual acuity can occur in both eyes.
Particularly if lazy eye is detected early in life and promptly treated, reduced vision can be avoided. But if left untreated, lazy eye can cause severe visual disability in the affected eye, including legal blindness.
Amblyopia Signs and Symptoms
Because amblyopia typically is a problem of infant vision development, symptoms of the condition can be difficult to discern. However, a common cause of amblyopia is strabismus. So if you notice your baby or young child has crossed eyes or some other apparent eye misalignment, schedule an appointment for a children's eye exam immediately — preferably with an optometrist or ophthalmologist who specializes in children's vision.
Another clue that your child may have amblyopia is if he or she cries or fusses when you cover one eye. This may suggest that the eye you have covered is the "good" eye, and that the uncovered eye is amblyopic, causing blurred vision.
What Causes Amblyopia?
Strabismus is the most common cause of amblyopia. To avoid double vision caused by poorly aligned eyes, the brain ignores the visual input from the misaligned eye, leading to amblyopia in that eye (the "lazy eye"). This type of amblyopia is called strabismic amblyopia.
Sometimes, amblyopia is caused by unequal refractive errors in the two eyes, despite perfect eye alignment. For example, one eye may have significant uncorrected nearsightedness or farsightedness, while the other eye does not. Or one eye may have significant astigmatism and the other eye does not.
In such cases, the brain relies on the eye that has less uncorrected refractive error and "tunes out" the blurred vision from the other eye, causing amblyopia in that eye from disuse. This type of amblyopia is called refractive amblyopia (or anisometropic amblyopia).
Amblyopia Treatment
In some cases of refractive amblyopia, normal vision can be achieved simply by fully correcting the refractive errors in both eyes with glasses or contact lenses. Usually, however, at least some patching of the "good" eye is needed to force the brain to pay attention to the visual input from the amblyopic eye and enable normal vision development to occur in that eye.
Treatment of strabismic amblyopia often involves strabismus surgery to straighten the eyes, followed by eye patching and often some form of vision therapy (also called orthoptics) to help both eyes work together equally as a team.
Patching may be required for several hours each day or even all day long and may continue for weeks or months.
If you have a lot of trouble with your child taking the patch off, you might consider a specially designed prosthetic contact lens that prevents light from entering the good eye but does not affect your child's appearance. Though prosthetic contact lenses are more costly than a simple eye patch and require a contact lens exam and fitting, they can work wonders in difficult cases of amblyopia treatment when compliance with eye patching is poor.
You can help your child accept patching more readily. Here, Anissa's Fun Patches require no adhesive because they slide onto the temple of an eyeglass frame.
In some children, atropine eye drops have been used to treat amblyopia instead of an eye patch. One drop is placed in your child's good eye each day (your eye doctor will instruct you). Atropine blurs vision in the good eye, which forces your child to use the eye with amblyopia more, to strengthen it. One advantage of using atropine eye drops is that it doesn't require your constant vigilance to make sure your child wears the patch.
In one large study of 419 children younger than 7 years of age with amblyopia ranging from 20/40 to 20/100 prior to treatment, atropine therapy produced comparable results to eye patching (though improvement in visual acuity in the amblyopic eye was slightly greater in the patching group). As a result, some previously skeptical eye care practitioners are using atropine as their first choice for amblyopia treatment over patching.
However, atropine does have side effects that should be considered: light sensitivity (because the eye is constantly dilated), flushing and possible paralysis of the ciliary muscle after long-term atropine use, which could affect the eye's accommodation, or ability to change focus.
Help for Older Children and Adults With Lazy Eye
For years, experts believed that if amblyopia treatment was not initiated very early in life, no improvement in visual acuity was possible. The critical period for intervention was said to be around age 8.
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But it now appears that older children and even adults with long-stranding lazy eye can benefit from amblyopia treatment using computer programs that stimulate neural changes leading to improvements in visual acuity and contrast sensitivity.
One such program — called RevitalVision — has produced improved vision in older children with lazy eye and adults with long-standing amblyopia. The treatment generally consists of 40 training sessions of 40 minutes each, conducted over a period of several weeks.
In one clinical study of 44 amblyopic children and adults ranging in age from 9 to 54 years, 70.5 percent of the participants had a visual acuity improvement of 2 or more lines on a standardized eye chart after a full regimen of RevitalVision training sessions.
Currently, RevitalVision is the only FDA-approved computerized treatment for amblyopia. The program is approved for individuals age 9 and older with best corrected vision of 20/100 or better and little or no strabismus.
Other computer programs to treat lazy eye also are available and in use by eye doctors who specialize in children's vision and vision therapy.
Early Detection and Treatment is Important
Though modern amblyopia treatments might improve vision in older children and adults, most experts agree that early detection and treatment of lazy eye is preferred for normal visual development and the best visual outcomes from amblyopia treatment.
Amblyopia will not go away on its own, and untreated lazy eye can lead to permanent visual problems and poor depth perception. If later in life your child's stronger eye develops disease or is injured, he or she will depend on the poor vision of the amblyopic eye, so it is best to treat amblyopia early on.
Resources:
A comparison of atropine and patching treatments for moderate amblyopia by patient age, cause of amblyopia, depth of amblyopia, and other factors. Ophthalmology. August 2003.
Atropine an effective alternative to patching for amblyopia. Review of Ophthalmology. October 2003.
Perceptual learning improves contrast sensitivity and visual acuity in adults with anisometropic amblyopia. Vision Research. March 2006.
Correspondence from RevitalVision LLC. June 2010.
Judith Lee, Gretchyn Bailey and Vance Thompson, MD also contributed to this article.
4-Bells palsy
Bell's palsy usually occurs suddenly, affecting the greater part of one side of the face. The cause often is unknown, but the condition has been associated with certain viruses. Statistics show that Bell's palsy affects about one person out of 60 or 70.
After the abrupt onset of Bell's palsy, most people develop maximum weakness within 48 hours. Prior to the onset, some people feel pain behind the ear.
While Bell's palsy may appear similar to a stroke, no other neurological signs or symptoms are present.
How Does Bell's Palsy Affect Eyes?
Most people with Bell's palsy are unable to blink on the affected side of the face. At the same time, the lower eyelid may turn outward (ectropion). The face and lips on the affected side become droopy, and you have little or no control over their muscle function.
Because the muscle that opens the eye is controlled by a separate cranial nerve, you can easily open the affected eye. But unfortunately you are unable to close the eyelid.
As a result, most people with Bell's palsy suffer from an extreme form of dry eye known as exposure keratitis.
Bell's Palsy Treatment and Recovery
Treatment for Bell's palsy usually includes generous use of ocular lubricants, such as non-preserved artificial tears and eye ointments. Many people require the eyelid to be patched or taped shut while sleeping, to keep it moist.
If you develop an outwardly turned eyelid, you may need surgery to repair it.
Approximately 80 percent of people with Bell's palsy recover within six months. But without proper care of the involved eye, you may suffer needless and permanent consequences such as corneal ulceration and scarring of your eye's clear front surface.
5-Blepharitis
Blepharitis has two basic forms:
• Anterior blepharitis, affecting the outside front of the eyelid where eyelashes are attached.
• Posterior blepharitis, linked to dysfunction of meibomian glands within the eyelids that secrete oils to help lubricate the eye.
It's common to have a mixture of both anterior and posterior forms of blepharitis at the same time, but in different degrees of severity.
Although eye doctors commonly diagnose blepharitis, it can be difficult to find permanent relief of the symptoms that can include burning, flaking, crusting, tearing, irritation, itching, redness in eyelid margins and a foreign body sensation.
Treatment for Blepharitis
If you are diagnosed with chronic blepharitis, your eye doctor will likely recommend an ongoing regimen of eyelid hygiene (see sidebar) that can include commercially developed, over-the-counter lid scrubs or other recommended cleansing agents. Eyelid hygiene is the cornerstone of treatment for most cases of blepharitis.
Besides a program of eyelid hygiene, the severity of the blepharitis and related symptoms may require supplemental treatment with topical and oral medicine.
In some cases of posterior blepharitis, eye doctors recommend nutritional supplementation with omega-3 fatty acids, such as flaxseed oil, to aid healthy function of meibomian glands that provide essential lubrication for eye and eyelid comfort.
Anterior Blepharitis
Symptoms of bacteria-caused staphylococcal blepharitis often are more severe and can even lead to loss of eyelashes.
Besides eyelid cleansing and hygiene, an antibiotic ointment for eyelids might be prescribed. Pink eye due to bacteria — a common type of eye infection — may occur simultaneously with blepharitis.
Viruses and other types of bacteria besides staphylococcus also can cause anterior blepharitis.
Without treatment, blepharitis caused by bacteria can cause long-term effects such as ectropion, thickened lid margins, dilated and visible capillaries, trichiasis and entropion. In cases of trichiasis and entropion, the cornea may exhibit significant erosion from eyelashes rubbing against the eye.
Seborrheic blepharitis is caused by seborrheic dermatitis, a skin condition that creates flaking and scaling — including on the eyelids. Regular cleansing with eyelid scrubs and gentle, non-detergent shampoos can provide significant relief and improve the appearance of eyelids.
The American Academy of Dermatology notes that the causes of these skin conditions are not well understood. But seborrheic dermatitis sometimes appears in a person with a weakened immune system. Fungi or certain types of yeast that feed on oils (lipids) in the skin also may lead to seborrheic dermatitis, with accompanying blepharitis.
With demodex blepharitis, microscopic mites (demodex folliculorum) and their waste materials could cause clogging of follicles at roots of eyelashes, and in some cases might be associated with development of skin conditions such as rosacea and blepharitis. A commercial eyelid scrub combined with tea tree oil may be effective for treating this type of blepharitis.*
Other reported treatments of demodex blepharitis include sulfur oil and steroids. An anti-parasitic gel (metronidazole) also has shown effectiveness as a treatment.
Another version of these mites (demodex brevis) can be found more generally in oil glands of the skin and eyelids, which also may contribute to blepharitis symptoms.
While presence of these tiny mites is common in everyone, researchers speculate that some people develop demodex blepharitis due to unusual allergic or immune system reactions leading to inflammation.
Eyelid Hygiene Relieves Blepharitis Symptoms
Use a cotton-tipped swab to apply cleaning solution recommended by your eye doctor. Rub gently around the edges of your upper and lower eyelids, but do not get cleaning solution in your eye.
Blepharitis can be difficult to manage because it is often chronic, meaning that it never goes away completely. Your eye doctor may recommend one or more of these steps involving good eyelid hygiene and massage:
• Apply a warm compress such as a washcloth to the outer eyelids.
• Cleanse the eyelids with a commercial lid scrub or other recommended product.
• Gently massage the outer eyelids.
A warm compress loosens the crust on your eyelids and eyelashes before you clean them. The warmth also can loosen any blocked residue in the oil-secreting meibomian glands in your eyelids.
To use a warm compress:
• Wash your hands, then dampen a clean washcloth with warm water.
• Place the washcloth over your closed eyes for several minutes.
• Open your eyes, and then use fingers to rub gently around the outer eyelids in a circular motion. Don't press too hard on the eyeball.
• Follow your doctor's recommendations on how often to use a compress and how long it should be kept in place.
When you first begin treatment, your eye doctor may suggest that you do this several times daily, for about five minutes each time. Later on, you might apply the compress once daily for a few minutes.
Cleaning the eyelids is essential to blepharitis treatment. Your doctor will recommend what cleansing agent to use, such as warm water only, baby shampoo diluted with warm water or a special over-the-counter product made specifically for cleansing the lids.
To clean eyelids:
• Wash your hands, then dip a clean washcloth, cotton swab or gauze pad into your cleaning solution.
• Make sure you squeeze out any excess moisture.
• Gently wipe across your lashes and lid margin.
• Rinse with cool water.
• Repeat the process for your other eye, but use a different washcloth, swab or pad.
Your eye doctor may have you clean your lids several times daily to start, and then once daily thereafter. — GW
Posterior Blepharitis
Posterior blepharitis involves dysfunction of oil-secreting meibomian glands within the eyelids. The openings of these glands are at the inner edge of the eyelids, and oils secreted by the meibomian glands help prevent tear evaporation.
Also called meibomian blepharitis, meibomitis or meibomian gland dysfunction (MGD), posterior blepharitis reduces meibomian gland output or produces abnormal oily secretions. Symptoms of posterior blepharitis include inflamed and thickened eyelid margins, eyelid crusting and other symptoms that are often difficult to manage. With this type of blepharitis, tears can even look foamy.
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Meibomian blepharitis sometimes is described as dry eye syndrome caused by meibomian gland dysfunction.
Rosacea blepharitis often is a component of ocular rosacea, which can cause eyelid inflammation linked to dysfunction of the skin's oil (sebaceous) glands. Acne rosacea is a common skin inflammation characterized by pimple-like bumps and facial redness — especially around the cheeks, nose, forehead and chin. As with certain forms of blepharitis, underlying causes of rosacea aren't well understood.
However, rosacea does appear to be linked to certain genetic tendencies and environmental factors, such as excessive sun exposure.
Clogged meibomian glands from posterior blepharitis also can cause a stye or chalazion to form. A stye, which is often uncomfortable, grows from an infected oil gland in the eyelid. A chalazion is a non-infected, usually painless nodule caused by inflammation of a blocked meibomian gland.
Is There a Cure for Blepharitis?
A complete blepharitis cure may not exist. But as explained above, good eyelid hygiene and prescription medicine are often effective in managing blepharitis, while warm compresses and lid massages can help unclog obstructed meibomian glands.
If you wear soft contact lenses, your eye doctor may prescribe RGP contacts instead or may recommend more frequent replacement of your soft contacts to reduce lens deposits that may be associated with your blepharitis. Depending on the severity of your symptoms, you may need to discontinue contact lens wear altogether for a while.
Blepharitis can cause inflamed eyelids, eye burning and dryness.
It's a good idea to minimize use of eye makeup, which can interfere with eyelid hygiene. If your doctor recommends an anti-dandruff shampoo for your scalp and eyebrows, make sure you keep the shampoo out of your eyes to avoid irritation.
Also, as mentioned above, certain eye doctors recommend nutritional supplementation with omega-3 fatty acids to improve function of the eyelid's oil glands.
Because blepharitis and dry eyes commonly occur together, your eye doctor may advise you to use over-the-counter or prescription eye drops to help relieve symptoms.
In severe cases of dry eye, especially without significant blepharitis, you may benefit from the insertion of punctal plugs in tear drainage channels in your eyelids to help increase the amount of lubricating tears on the surface of your eye. More moisture on the eye's surface can make your eyes feel better and healthier.
6-Cataracts
The lens is mostly made of water and protein. The protein is arranged in a precise way that keeps the lens clear and lets light pass through it.
But as we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract, and over time, it may grow larger and cloud more of the lens, making it harder to see.
Researchers are gaining additional insights about what causes these specific types of proteins (crystallins) to cluster in abnormal ways to cause lens cloudiness and cataracts. One recent finding suggests that fragmented versions of these proteins bind with normal proteins, disrupting normal function.
Cataracts are classified as one of three types:
• A subcapsular cataract begins at the back of the lens. People with diabetes, high farsightedness or retinitis pigmentosa, or those taking high doses of steroids, may develop a subcapsular cataract.
• A nuclear cataract is most commonly seen as it forms. This cataract forms in the nucleus, the center of the lens, and is due to natural aging changes.
• A cortical cataract, which forms in the lens cortex, gradually extends its spokes from the outside of the lens to the center. Many diabetics develop cortical cataracts.
Cataract Symptoms and Signs
A cataract starts out small and at first has little effect on your vision. You may notice that your vision is blurred a little, like looking through a cloudy piece of glass or viewing an impressionist painting.
Hazy or blurred vision may mean you have a cataract.
A cataract may make light from the sun or a lamp seem too bright or glaring. Or you may notice when you drive at night that the oncoming headlights cause more glare than before. Colors may not appear as bright as they once did.
The type of cataract you have will affect exactly which symptoms you experience and how soon they will occur. When a nuclear cataract first develops, it can bring about a temporary improvement in your near vision, called "second sight." Unfortunately, the improved vision is short-lived and will disappear as the cataract worsens. On the other hand, a subcapsular cataract may not produce any symptoms until it's well-developed.
If you think you have a cataract, see an eye doctor for an exam to find out for sure.
What Causes Cataracts?
No one knows for sure why the eye's lens changes as we age, forming cataracts. Researchers are gradually identifying factors that may cause cataracts — and information that may help to prevent them.
Many studies suggest that exposure to ultraviolet light is associated with cataract development, so eye care practitioners recommend wearing sunglasses and a wide-brimmed hat to reduce your exposure.
Other types of radiation may also be causes. For example, a 2005 study conducted in Iceland suggests that airline pilots have a higher risk of developing nuclear cataract than non-pilots and that the cause may be exposure to cosmic radiation. A similar theory suggests that astronauts, too, are at risk from cosmic radiation.
August Is Cataract Awareness Month
It's almost inevitable: if you live long enough, at some point you will get cataracts. To delay the onset and minimize vision problems, follow these tips, based on recommendations by the American Academy of Ophthalmology:
Over 40? Get a baseline exam. With a comprehensive eye exam, your eye doctor can make a record of the current health of your eyes, check for early signs of disease and vision changes and tell you how often you'll need follow-up exams. If your family has a history of early cataracts, then don't delay: get an eye exam as soon as possible.
Learn about cataract risk factors. People at risk include diabetics, smokers, sun worshippers, and those with a family history of cataracts. Eye injury or inflammation will increase your risk. So will using steroids over a long period of time, especially if you're combining oral and inhaled steroids.
Reduce your risks. Wear sunglasses and a hat outside. Don't smoke. If you are diabetic, keep your blood sugar levels under control.
Learn when to consider cataract surgery. It's really up to you as to when to have the surgery. Cataracts create vision problems such as halos, blurriness, glare and dimmed colors, and when the symptoms worsen, your quality of life and ability to perform everyday tasks will diminish. There's no need to wait: get the surgery and get on with your life. Your eye doctor will also be able to advise you as to the best time for removal.
Other studies suggest people with diabetes are at risk for developing a cataract.
The same goes for users of steroids, diuretics and major tranquilizers, but more studies are needed to distinguish the effect of the disease from the consequences of the drugs themselves.
Some eye care practitioners believe that a diet high in antioxidants, such as beta-carotene (vitamin A), selenium and vitamins C and E, may forestall cataract development. Meanwhile, eating a lot of salt may increase your risk.
Other risk factors include cigarette smoke, air pollution and heavy alcohol consumption.
A small study published in 2002 found lead exposure to be a risk factor; another study in December 2004, of 795 men age 60 and older, came to a similar conclusion.
But larger studies are needed to confirm whether lead can definitely put you at risk and, if so, whether the risk is from a one-time dose at a particular time in life or from chronic exposure over years.*
Researchers say additional studies also are needed to confirm whether hormone replacement therapy (HRT) significantly increases chances that cataracts will form and progress to the point that surgical removal is required.
An eight-year study of more than 30,000 postmenopausal Swedish women found a 14 percent increased risk for cataract removal among those who used HRT at any time and an 18 percent increased risk for current HRT users.
HRT use combined with regular alcohol consumption appeared to create a 42 percent increased risk of cataract removal, compared with women who had never used HRT or alcohol.
The HRT study was reported in the March 2010 issue of Ophthalmology.
Cataract Treatment
When symptoms begin to appear, you may be able to improve your vision for a while using new glasses, strong bifocals, magnification, appropriate lighting or other visual aids.
An intraocular lens (IOL) is implanted in the eye in place of the clouded natural lens. Shown is Alcon's AcrySof Natural IOL; it filters out blue light, which may be harmful to eyes.
Think about surgery when your cataracts have progressed enough to seriously impair your vision and affect your daily life. Many people consider poor vision an inevitable fact of aging, but cataract surgery is a simple, relatively painless procedure to regain vision.
Cataract surgery is very successful in restoring vision. In fact, it is the most frequently performed surgery in the United States, with more than 3 million Americans undergoing cataract surgery each year. Nine out of 10 people who have cataract surgery regain very good vision, somewhere between 20/20 and 20/40.
During surgery, the surgeon will remove your clouded lens and in most cases replace it with a clear, plastic intraocular lens (IOL).
New IOLs are being developed all the time to make the surgery less complicated for surgeons and the lenses more helpful to patients. Presbyopia-correcting IOLs potentially help you see at all distances, not just one. Another new type of IOL blocks both ultraviolet and blue light rays, which research indicates may damage the retina (see illustration).
Read more on this website about what to expect if you have cataract surgery and how to deal with rare cataract surgery complications. Also, men should be aware that certain prostate drugs can cause intraoperative floppy iris syndrome (IFIS) during a cataract procedure.
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