My Health Guides

What You Need To Know About Cataract Surgery

noreply@blogger.com (Trey Koehler) — Sun, 03 Sep 2006 18:44:00 +0000

When you schedule a cataract operation, your surgeon may require that you have a medical workup first. Since these operations are now commonly performed in an outpatient setting, your general practitioner can order the necessary tests. The whole operation procedure, either cataract surgery alone or a combined cataract and filtering operation, can take ninety minutes to perform if the case is uncomplicated. Depending on your condition and the surgeon's preference, you may stay overnight in the hospital or you may go home after the operation.

During the operation, if you are having local anesthesia, your surgeon will inject the anesthetic around your eye. It may hurt, but the discomfort will last for only a few seconds. The surgeon will then perform the cataract surgery. If you are having glaucoma surgery at the same time, that will be done immediately after the intraocular lens implant has been put in place.

After the operation, your eye will be bandaged overnight. In the morning, your eye will be checked by your surgeon and your IOP measured. You will most likely be advised to take an assortment of drops, including antibiotics to prevent infection and steroids to reduce inflammation. You will also be given an eye shield, a perforated plastic oval to fit over your eye, to protect your eye when you sleep, and you will be advised not to bend your head, lift anything heavy, or strain during bowel movements (a stool softener can be used if necessary to prevent this problem). Otherwise, you can assume your daily activities. Some surgeons say you can shower; others advise against it.

Within four to five weeks, depending on how quickly your eye stabilizes, you may then be fitted with glasses. Many ophthalmologists prefer to implant lenses that make the eye slightly myopic and then correct distance vision with eyeglasses or contact lenses, especially with patients who are already nearsighted. They have found that people who are accustomed to viewing the world myopically don't adapt well if their vision is fully corrected.

The decision as to what strength lens implant to use is based on a combination of measurements, including the curvature of the cornea, the depth of the anterior chamber, and the dimensions of the eye itself. You have something to say about the strength of the intraocular lens as well. You are entitled to discuss in advance with your doctor what you feel will be most comfortable for you.

At this stage, unfortunately, bifocal intraocular lenses are not available, so you may decide on a reading-strength intraocular lens with additional correction (glasses or contact lenses) for distance. This combination feels familiar to most nearsighted people. Some doctors and patients have opted to have one eye fitted with a reading-strength lens and the other with a distance lens. While this arrangement is convenient and eliminates the need for glasses, it makes it impossible for the eyes to converge and work together properly, which is important for close work and depth perception.

As with any type of surgery, complications can arise with cataract removal, and people with glaucoma may be more likely than others to experience some problems. Pupillary block is uncommon, but it may occur as a complication of cataract surgery. In this condition, the aqueous fluid is unable to squeeze through the space between the lens and the iris, and pressure builds up, pushing the iris forward to block the drainage channel. This can cause a dramatic increase in intraocular pressure. Pupillary block can be corrected with an iridectomy or iridotomy. Studies indicate that there are fewer cases of pupillary block if extracapsular extraction is used.

Another difficulty may occur if the intraocular pressure decreases to a critical stage. While people who have glaucoma want to have low intraocular pressures, too-low pressure may result if the aqueous fluid passes from the anterior chamber too rapidly, causing the chamber to flatten. When the chamber is flat, parts of the eye like the iris and cornea, which are normally kept apart by the fluid, can touch and stick together - and that is a decidedly undesirable event. An IOP under 5 mm Hg may be an indication that this is happening.

Bleeding may also be a problem. Any intervention into your eye (or any other part of your body, for that matter) can cause the disruption of blood vessels. Most often these bleeding vessels can be cauterized or will seal themselves, but in some cases it may take a day or so for such a situation to resolve. In most cases it does resolve, but until the blood clears away your vision will be blurry.

If you have a fragile cornea, something called corneal decompensation may occur. In this condition, the cornea begins to lose cells and is unable to regain its former shape and consistency. This problem occurs if your cornea has a scarcity of cells, which may result from laser treatment or the use of medication. Glaucoma patients are more prone to this effect.

Your eye may also react to the implanted lens material by forming adhesions at the lens's points of contact. If the lens is improperly positioned, chronic iritis (inflammation of the iris) may result. If there is recurrent bleeding, neovascularization may develop, promoting a condition similar to the neovascular glaucomas. In some cases, a Cataract operation can also precipitate an attack of narrow-angle glaucoma, for with this operation there can be a slight shifting of the parts in the eye, and these - the pupil, the ciliary body, or even trapped air - can block the angle through which the aqueous fluid flows.

What Is Making My Eyes Dry?

noreply@blogger.com (Trey Koehler) — Sat, 02 Sep 2006 18:44:00 +0000

There are two basic problems that can be causing your eyes to become dry and lack the usual tears: either you're not making enough tears, or the tears you're making aren't as good as they used to be. Occasionally dry eyes may be caused by a third problem: the eye itself can't get the tears where they need to go.

Perhaps your eyes don't make enough tears. This condition, called KCS (for keratoconjunctivitis sicca), usually occurs in both eyes but can be worse in one eye than the other. One of the most common causes of tearing deficiency is simply age. Like skin and hair, our tears tend to "dry up" slightly as we get older; we just make fewer tears. For most of us this decrease isn't terribly noticeable, but for some people tear production can drop off significantly - enough to produce the classic dry-eye symptoms of irritation, redness, grittiness, burning, or eye fatigue. (KCS is also more common in older women than in other
groups, probably because of the hormonal changes that occur with age.)

Other health problems can hamper tear production. One of these is injury to the lacrimal glands, from infection or trauma; the effect of the injury may be temporary or permanent. Another is Bell's palsy, a condition that affects the facial nerves; its effects too may be either temporary or permanent. People with this ailment are often unable to close one eye or blink on one side of the face, and that eye also produces fewer tears. As you may imagine, the combination of not being able to blink and making fewer tears causes major problems with dryness.

Autoimmune disorders can impede tear production. Sjogren's syndrome is the miserable trio of symptoms - dry eyes, dry mouth, and joint pain - that may be associated with other autoimmune disorders, such as rheumatoid arthritis, systemic lupus erythematosus, and scleroderma. (The term secondary Sjogren's syndrome is used to describe dry eyes associated with any other disease.) Other systemic ("whole body") diseases, such as sarcoidosis, leukemia, lymphoma, and chronic thyroid problems, often diminish tear production, as well.

Occasionally medications decrease the tear-making ability in some people. For instance, as you may already know too well, antihistamines and decongestants for allergies and colds dry out everything - eyes in addition to sinuses. Diuretics, taken to lower blood pressure and ease water retention, may decrease tear production. Hormone replacement therapy and even birth control pills also can lead to dry eyes. Other potentially eye-drying medications include certain eye dilators, motion sickness inhibitors, antidepressants, oral acne medications, and opiate-based pain medications.

Even if your tear production is just fine, your eyes can still be dry if the quality of tears is poor. Remember the ingredients in each tear; they're all important, and when the balance of them is off, your tears (and your eyes) may suffer as a result. Diseases in the eye or body can cause a drop in either the mucin or the lipid portion of tears.

What Is Glaucoma & Where Did It Originate From?

noreply@blogger.com (Trey Koehler) — Fri, 01 Sep 2006 18:43:00 +0000

Glaucoma is now believed to be the end product of a number of distinct structural and systemic diseases characterized by high pressure inside the eye and optic nerve damage. This pressure can damage and even kill the sensitive nerve cells in the back of the eye, causing loss of sight. Glaucoma is not a new disease. The ancient Greeks gave us the term glaucoma, which they used to describe all eye diseases leading to blindness. In the first several centuries A.D., cataracts, which are amenable to treatment, began to be distinguished from glaucoma, which could not be treated. The association of glaucoma with increased pressure in the eye is often attributed to Richard Banister, an English oculist and author of the first book on ophthalmology in English, who made this observation in 1622 . Banister noted that if you felt an eye with glaucoma by rubbing on the eyelids, the eye felt more hard and solid than normal.

Today, a diagnosis of glaucoma is based on three factors: intraocular pressure (IOF), the pressure within the eye, which is typically elevated; characteristic changes in the visual field, specifically a loss of peripheral vision; and signs of damage to the optic nerve. Very often the first indication that glaucoma may be present is an increase in IOP. Since the 1930s, eye doctors have distinguished between two primary forms of the disease: open-angle and narrow-angle glaucoma. These determinations were based on the width of the angle formed by the meeting of the iris and the cornea. Grades I and II glaucoma (glaucoma in the presence of 10-degree and 20-degree angles, respectively) were designated narrow-angle glaucoma; grades III and IV glaucoma (glaucoma in the presence of 30-degree and 40-degree angles, respectively) were termed open- angle glaucoma.

Angle-closure glaucoma - glaucoma caused by a narrow angle and/or close proximity of structures within the eye to each other - may be considered a structural problem. Open-angle glaucoma is divided into a number of different varieties. The most common type of glaucoma is primary open-angle glaucoma. The other glaucomas that make up the open-angle family are variously called structural or secondary, or glaucoma as an end product of a disease.

Today, researchers have recorded more than a dozen distinct forms of glaucoma, and there may be more. Some scientists claim that they can differentiate between as many as forty different types of glaucoma. Although primary open-angle glaucoma accounts for the majority of cases of glaucoma, many people do have other forms. As the differences among glaucomas become clearer, and the root causes are better identified, researchers may be able to develop specific treatments for controlling each individual type of glaucoma.

What Is A Low-Vision Specialist?

noreply@blogger.com (Trey Koehler) — Thu, 31 Aug 2006 18:43:00 +0000

This is the doctor who can do more for the visually impaired than anyone else when it comes to coping with vision loss that is unresponsive to medication or surgery. A low-vision specialist may be an ophthalmologist or an optometrist, but his or her specialty is to equip and train the visually impaired to function as sighted, using the vision they have left.

A low-vision patient is defined as one whose vision cannot be corrected with ordinary spectacles. The low-vision specialist equips a patient with hand magnifiers or magnifying spectacles that allow the patient to read print, including the gauges or dials on shop equipment and kitchen appliances. He or she equips a person with hand-held telescopic devices or telescopes mounted in glasses that allow the patient to see more detail when viewing distant objects. If the doctor is really good, he or she will do much to neutralize some of the emotional problems that are blocking the patient's adjustment to functioning better. The specialist teaches skills like scanning and eccentric viewing that improve functional ability.

Low-vision aids do exist that a person can select for himself or herself, when following the
do-it-yourself route, however, exercise caution, because pitfalls exist when buying aids. The low-vision specialist helps people avoid these mistakes.

What Makes a "Good" Low-Vision Specialist?

All doctors are not equally competent - a truth that also applies to low-vision specialists. There is a great deal of variance in their performance. How can the visually impaired locate a good low-vision specialist? The best one can do is to give guidelines. You must then evaluate the performance of your own doctor.

Measuring the best acuity and determining the theoretical magnification needed are not always enough to produce a well-cared-for patient. Many factors control the outcome of the rehabilitation. In fact, the definition of "low-vision rehabilitation" is: Multidisciplinary vision care preceding blind training of the visually impaired to obtain maximum visual independence and social adjustment. In simpler language, this means: (1) the doctor must take the whole patient into consideration; (2) the doctor must help the patient regain as much independence as possible; and (3) the doctor must help the patient readjust to life and to his social situation under these new circumstances,

Professional care requires the doctor to become very involved and spend a lot of time discussing the condition of the vision and discussing what could be accomplished, along with how and why certain treatments would or would not work. For the low-vision specialist to prescribe properly and train properly, he must do the counseling and train the patient himself.

What Are The Chances That Eye Surgery Will Give You Improved Vision?

noreply@blogger.com (Trey Koehler) — Wed, 30 Aug 2006 18:42:00 +0000

As a patient, what are the important statistics for you to know, and how can you interpret outcomes? First of all, you likely want to know your chances of achieving at least 20/40 vision. This is a key number since 20/40 vision is required to drive legally without eyeglasses or contacts. Second, you probably also want to know your chances of achieving optimal 20/20 vision. Third, you may wish to know the likelihood of needing an enhancement procedure after the initial surgery. All of the above numbers will vary according to the surgeon you choose and your prescription. Below are eye conditions and your chances of success based on statistics of operations.

Mild Myopia: A patient with mild myopia, or nearsightedness, has a nearly 100 percent chance of achieving 20/40 vision or better and being able to drive without eyeglasses or contacts. The chance of achieving 20/20 vision without correction is 98 percent, but this statistic includes patients who require an enhancement procedure, as well as those who do not. The chance that a patient with mild myopia will need an enhancement procedure is 1 percent. Mild myopia is defined as less than -3.00 diopters, with or without astigmatism.

Moderate Myopia: After the initial procedure, nearly 100 percent of patients with moderate myopia achieve 20/40 vision or better. Of these, 88 percent achieve 20/20 vision or better. There is a 3 percent chance of needing an enhancement procedure if you fall into this category. After undergoing an enhancement, almost 100 percent of patients see 20/40 or better and 96 percent see 20/20 or better. Moderate myopia is defined as a refractive error between -3.00 and -6.00 diopters.

Severe Myopia: These patients have a 99 percent chance of seeing 20/40 or better after the initial procedure. Patients with severe myopia have a 6 to 8 percent chance of needing an enhancement procedure, after which they have a 99 percent chance of seeing 20/40 or better and a 90 percent chance of seeing 20/20 or better. Severe myopia is defined as a refractive error between -6.00 and -9.00 diopters.

Extreme Myopia: Patients with extreme myopia have an 89 percent chance of achieving 20/40 vision or better after the initial procedure. Because of the high level of correction, approximately 12 to 16 percent of this group will need enhancements. After enhancement, 77 percent of patients will have 20/20 vision or better.

Many patients with extreme myopia do well. However, other variables such as the thickness and the steepness of the cornea come into play. Patients in this group need to thoroughly discuss the risks and benefits of LASIK, as well as other options, with their doctor. Although enhancement rates are higher in this group of patients, there may be limitations on what can be done due to other variables in the eye. Extreme myopia is considered a refractive error higher than -9.00 diopters.

Astigmatism: Patients with mild astigmatism can expect nearly identical outcomes and enhancement percentages to those patients with myopia only. The presence of moderate or high degrees of preoperative astigmatism will reduce your chance of achieving 20/20 vision after the initial procedure, making it more likely that you will want to have an enhancement. Mild astigmatism is defined as a refractive error of 1.00 diopter or less.

Hyperopia: The statistics on LASIK outcomes for patients with hyperopia come from a multi-center trial that was conducted for FDA approval of an excimer laser called the VISX Star S2. The participating LASIK surgeons treated patients with hyperopia in the range of +1.00 to +6.00 .diopters. In this study, after the initial LASIK procedure 91 percent of the patients achieved 20/40 vision or better, and 53 percent saw 20/20 without eyeglasses. Patients treated for hyperopia should be aware that their healing time is slightly longer than for patients with myopia, and the chance that they will need an enhancement is slightly higher. These numbers are variable, depending on the patient's original prescription and the skill and experience level of the surgeon.

What Are The Chances Of Regression After LASIK Surgery?

noreply@blogger.com (Trey Koehler) — Tue, 29 Aug 2006 18:41:00 +0000

Most LASIK patients do not regress after surgery. After the initial few months, the curvature of the cornea should remain reasonably stable. Mapping the cornea with computerized topography shows that the majority of LASIK patients achieve a stable refraction within the first three months after surgery. People with high myopia, however, may require six months or longer.

Persons who do experience a drop in the effect of the procedure usually were severely myopic before surgery. Doctors do not know why these patients occasionally regress, but we surmise that the problem is related to the depth of the laser ablation and the healing process. The more treatment necessary, the more the stroma or middle layer of the cornea must remodel itself during the first couple of years after surgery. In addition, the epithelium may grow back a little thicker over the lasered area, especially in highly myopic patients. To overcome large amounts of nearsightedness, the laser must make a deeper ablation than to treat mild cases. The deeper the treatment, the more the body tries to fill in the depression, or "divot," with new epithelium. This natural healing response may contribute to slight-to-moderate post-surgical regression in highly myopic patients.

LASIK neither slows nor hastens the normal progression of nearsightedness. Some myopic patients, unfortunately, naturally continue to get a little more nearsighted throughout their life. If the eyeball gets slightly longer or if the crystalline lens starts to develop a cataract, the person will become more myopic even though the corneal curvature is stable. No matter how much near-sightedness naturally progresses with time, patients still should see better without glasses if they have LASIK.

Consider, for example, a thirty-year-old man with -7 diopters of myopia. Over a five-year period, with or without surgery, he may naturally develop another diopter of refractive error. Without any surgery, his correction would now be -8 diopters (severe myopia). But let's say he had LASIK at thirty, and his correction was reduced to -1 diopter (mild myopia). Five years pass. His eyeball naturally elongates so that his refractive error increases to -2 diopters. At this time, he might wish to consider a re-treatment or enhancement procedure.

Scientists have noticed that people who do large volumes of close work tend to be more myopic than people who work outdoors, such as construction workers, who must focus in the distance. As you may know, when you look at a near object, your eyes converge. Pulled inward during years of reading, your eyeball could become slightly longer. An increase of only 1 millimeter in the length of the eyeball will increase myopia by as much as 3 diopters. If you squeeze a tennis ball and quickly let go, it will go back to its original shape. If you squeeze the ball sixteen hours a day for ten years, it is not unreasonable to postulate that the ball's shape could elongate slightly.

Visual And Voice Aids For The Visually Impaired PC User

noreply@blogger.com (Trey Koehler) — Mon, 28 Aug 2006 18:40:00 +0000

There are special software programs available to enlarge print and graphics on computer screens. Sometimes this software creates problems for computers in a network, though there should be no problem with stand-alone computers. These products enable the visually impaired to read a computer screen with ease. These products enlarge print on the screen up to two or three inches tall. Print size is adjustable. People with a very low visual acuity can usually use them. Test a product before buying it, or make sure that you have return privileges if it is ordered from an online catalog.

Carefully study the description of each product for needed features and hardware requirements. Large-print stick-on labels affixed to the keys of the keyboard help the partially sighted computer user. These come in both black letters on a white background and white letters on a black background. The letters and numbers are usually large and bold, and there are labels for special keys.

Today, voice synthesizers can be added to a computer's software package to make a computer talk. Voice-recognition software is also available that allows the user to give the computer voice commands and to dictate text. Inquire about Microsoft's Speech, Dictation, and Voice software. MS Voice allows the user to give voice commands, such as "Start Microsoft Word," to the computer. MS Dictation allows the user to dictate letters or other text into the computer. Despite decades of research in this field, the accuracy rate for transcribing voice into text on the screen remains at about 90 to 95%. The software has provisions for correcting these mistakes.

People with a vision of 20/120 may use a computer successfully with a special work-area modification. They may use a platform with a built-to-hold the monitor at eye level and bring it closer to the face. They could mount a small fluorescent-light fixture under this shelf to illuminate the keyboard and use glasses with +18 D. lenses to read the screen.

Several other possibilities exist for those with only modest visual impairment. None of the following methods will help patients with significant vision loss. The standard screen used with computers measures about fifteen inches. Substituting a nineteen-inch screen makes the print on the screen two times larger. Monitors are available with screens even larger than nineteen inches. The larger the screen, the larger the print.

The Macintosh computer includes a feature to enlarge the print. Let a dealer demonstrate it for you. Microsoft Windows also includes a feature to enlarge print on the screen. Some, but not all, features in Windows allow you to select the size font you wish to use.

Those using DOS-based software might try using the DOS MODE command to change from an eighty-column display to forty. To do this, type in MODE 40 from a C:\ prompt. This command can also be placed in your autoexec.bat file so that it is executed each time you turn on the computer. This will increase print size on the screen.

Understanding Vision As “Memory”

noreply@blogger.com (Trey Koehler) — Sun, 27 Aug 2006 18:40:00 +0000

A baby comes into the world as a blank slate. He opens his eyes, and the eyes do their job, but there is no "vision" because the memory bank is empty The infant has not yet learned to identify the millions of codes sent to the brain by the eyes. We all know that a baby doesn't focus his eyes for several months after birth. Why should he? His eyes are sending messages not yet understandable to the brain because it has no knowledge of these codes. The day will come, however, when the bottle that has been poked into the infant's mouth repeatedly for weeks will register in memory.

"Yesterday when I saw 'OFFOOF,' I got something to eat." Today the eye sends the message "OFFOOF," and the child remembers that this code means "bottle" or "nourishment." He finally "sees" or recognizes (which literally means "to know again") the bottle.

Seeing, therefore, is memory. People must learn how to see. They must learn all the specialized codes for every object in their environment. Seeing for adults is routine; they give it no thought. For infants, it is a learning process that continues for years.

Children who lose all vision before about age seven cannot visualize or conceptualize things described to them. Their visual memories have too little information to work with. If, however, they lose all vision after about age seven, their visual memory is large enough to support visualization and to understand descriptions of things they have never seen.

When disease destroys visual ability and reading becomes difficult and infrequent, people forget the code for words they have not seen in a long time. After about a year, they forget seldom-used words like "enhance" and "numb," to list only two examples. Different people lose different words. Reading ability may regress to the first or second-grade level if one remains unable to read for about five years.

It can be painful to watch such people try to read. Anyone working in vision rehabilitation has helped patients regain reading ability who have not read for more than a year. They read along just fine until they come to a seldom-used word, and then they stop. They sit there staring at the word, embarrassed because they can't identify it. It may be a word they use in everyday speech, but they don't recognize it on paper, because they have forgotten the code for the word.

If this happens to you, spell the word aloud. This simple procedure is usually sufficient to recognize the word. Before reading further, look at the word again. Begin rebuilding the memory of how that word looks. Memorize the code!

Understanding The Treatment For Farsightedness

noreply@blogger.com (Trey Koehler) — Sat, 26 Aug 2006 18:39:00 +0000

If you are farsighted, or hyperopic, light comes to an imaginary focal point behind your retina. The farsighted eyeball is too short from front to back for the power of the cornea, causing a blurred image up close. (The length of your eye may be too short from front to back, or your cornea may be flatter than normal, or both.) Almost all newborn babies are farsighted; those who aren't often become markedly nearsighted as adults. Since many hyperopic patients can see distant objects well when they are young, they are called farsighted.

To correct farsightedness, a laser surgeon makes the center of the eye's window steeper by removing tissue in a carefully blended circular pattern around the mid-periphery of the cornea. Even though the laser is not aimed at the line-of-sight, the effect of treatment is directly over the pupil. After surgery, the central cornea has a steeper curve with more light blending ability that can focus incoming light nearer the retina instead of behind it. Although both hyperopic and myopic LASIK procedures remove tissue to the same depth for the same number of diopters of refractive error, much more tissue is removed from the cornea to treat farsightedness. Refractive surgery for farsightedness can improve both near and distance vision, although you may still need glasses to read if you are over forty.

While it is true that the farsighted eye focuses light at a theoretical point beyond the retina, hyperopia is more complex than this brief explanation implies. Without the added light bending power of the flexible crystalline lens inside your eye, even parallel light rays reflected off distant objects "focus" behind your sensitive photoreceptors. Causing an even more blurred image, the divergent rays from close objects "come together" still further behind your retina than light from far away.

So to help you understand farsightedness on a practical level, you need to keep in mind how the two lenses of your eye - your powerful fixed corneal lens and your adjustable crystalline lens inside your eye - work together to focus light. In the youthful eye, the flexible crystalline lens can "morph" itself, becoming thicker to bring close objects into view and remaining flatter to look in the distance. Instantly changing shape, this amazing lens becomes rounder (more highly curved) for near vision to add more focusing power to your optical system. Doctors call this process "accommodation".

The crystalline lens of the farsighted eye not only must become thicker for near vision, but also for distance. In some hyperopic patients, this elastic lens is unable to compensate enough to allow clear close vision. If you need correction for farsightedness, both of your lenses working in concert lack enough focusing power to "pull" the image forward onto your retina. Put yet another way, the combined power of your corneal and crystalline lenses fails to bend light enough to focus it on your photoreceptors.

If you are farsighted, you may suffer from fatigue or headaches because of the way your eyes focus. Normally, when you look at a close object, both eyes naturally move inward toward each other. The same nerves that control the muscles that cause your eyes to converge also govern the focusing power of your crystalline lens. Your adjustable lens and your eye muscles are designed to work together to provide good single, binocular near vision. But when a farsighted person looks in the distance - as each lens adjusts to overcome hyperopia - the eyes try to turn toward the nose. Since you must look straight ahead to see far away, your brain instantly counteracts this automatic response and tells the eye muscles to move your eyes outward. Such focusing problems can cause eye strain, double vision, or both.

The Relationship Between Free Radicals & Eye Damage

noreply@blogger.com (Trey Koehler) — Fri, 25 Aug 2006 18:39:00 +0000

The idea that nutrition is important for the eyes is supported by the growing evidence of the danger of free radicals. Cataracts may be partially caused by free radical activity in the lens of the eye. Glaucoma researchers have begun to examine the relationship between free radical activity and the destruction of nerve tissue in the eyes. There is some evidence that if oxidation is counteracted by antioxidants, visual field loss due to glaucoma may be decreased.

Free radicals are fragments of molecules that are highly reactive - that is, they readily enter into chemical reactions with other substances because they have unpaired electrons spinning in their orbit. These electrons seek out other electrons to counterbalance them, and they may snatch an electron from an adjacent molecule or donate an unmatched electron from their own structures, in the process destabilizing the hapless compound that is their target. Many molecules and fragments of molecules may behave in this fashion, but the most dangerous are different forms of oxygen. When an oxygen molecule encounters another substance and snaps up or sheds one of its electrons, the resulting compound is said to be oxidized.

There is a positive side to free radicals. The reaction that allows the blood to carry oxygen to all of the body's cells involves free radicals. Free radicals are responsible for the immune system's ability to squelch pathogens; for the digestive system's ability to break down the food we eat; and for the nervous system's ability to fire up muscles, thoughts, and feelings. However, if there are more free radicals than the body can control, they may begin to attack the cells and cause serious damage.

Free radicals are generated in the course of various metabolic actions, such as the conversion of glucose (simple sugar) into cellular energy. The majority of the free radicals formed in this way are well contained and either reused or eliminated, but some of them escape, and researchers believe that these escaped free radicals may cause cellular damage.

Free radicals are also generated when iron, copper, and/or other naturally occurring metals react with oxygen. Normally, your body protects you from excesses of these elements, especially iron, by storing this element within the hemoglobin in red blood cells or by supplying a protein to ferry it from one place to another. But if something goes wrong with this system, or if there is simply too much of certain metals for the body to deal with, a chain reaction is set up that contributes to the production of free radicals that oxidize fats.

Oxidized fats are the type most likely to accumulate in the blood vessels, causing arterial damage. It is possible that many diseases are a result of free radical damage. Type II (adult-onset) diabetes and Parkinson's disease fall into this category. Certain cancers may be caused by reactions between free radicals and DNA that pave the way for uncontrolled replication of cells. Free radicals may also be behind joint pains by diminishing the quantity of lubricant in the joints or interfering with the elasticity of the tendons.

The Advantages Of Hard Contact Lenses

noreply@blogger.com (Trey Koehler) — Thu, 24 Aug 2006 18:33:00 +0000

The notion of putting a corrective lens on the eye to achieve better vision is certainly nothing new. In fact, Leonardo da Vinci came up with this brilliant idea some 450 years ago. (Although no lenses were manufactured at that time, detailed drawings and descriptions were made.) A. E. Fick, a scientist in Zurich, manufactured the first contact lens in 1887 but soon found out that the human eye didn't like wearing lenses made of actual glass. It took a major innovation, in the 1940s, to produce the ancestors of the contact lenses we wear today: plastics. Those original lenses were made of a material called PMMA, which in fact was so well tolerated by the human eye that it's still used for hard contact lenses, for intraocular lens implants, and for orthopedic purposes.

Soft contact lenses didn't become available in this country until 1972, when Bausch and Lomb first introduced them to the American market. The original soft lenses tended to be more comfortable than the hard lenses available at the time, but because they were limited to just a few sizes, these lenses didn't fit many people. The big difference between hard and soft contact lenses was that the new soft lenses allowed oxygen to pass through them - not just around the lens, as with hard contacts. This made for a much healthier lens environment, because it enabled the eye to "breathe" with a lens in place. Lack of oxygen to the cornea can lead to decreased vision from corneal swelling and epithelial cell damage. Since 1972, contact lenses have changed and improved considerably. Now, lenses are designed to correct almost any vision problem and are available in special designs for extended wear, cosmetic changes (like eye color), and disposability.

Contact lenses come in an impressive variety of materials, sizes, shapes, thicknesses, and colors. In general, they're divided into two major categories: hard and soft. Hard contacts have evolved significantly since their introduction in the 1940s. Initially their design improved as manufacturing techniques improved, but in the late 1970s came a major breakthrough: the development of hard contacts that "breathed" like soft lenses. We call these lenses rigid gas-permeable contacts, or RGPs.

The RGP lenses are more flexible and fit better than earlier hard lenses, and they last longer (with respect to "wear and tear") and sometimes provide better vision than soft lenses. They're manufactured by computer-controlled lathes that can create any kind of surface needed to correct someone's vision. For example, if you have a high degree of astigmatism, an RGP lens can be ground with a curvature to match your cornea perfectly - providing a healthier, more comfortable fit, and vision that's usually superior to that offered by your glasses.

Another significant advantage to RGP lenses is that they can provide in effect, a new cornea for people with a corneal problem that distorts vision. Because this lens maintains its shape on the eye - as opposed to molding itself to the eye, the way a soft lens does - it masks a corneal irregularity, helps correct the optical surface, and improves vision.

Providing A Safe Atmosphere For The Visually Impaired

noreply@blogger.com (Trey Koehler) — Wed, 23 Aug 2006 18:33:00 +0000

Anyone who has raised a child knows what it means to childproof your home. A simple low-hanging tablecloth can spell disaster if tugged on by a toddler. Objects placed on a table can tumble on a child, causing harm. An alert parent safety-checks the home to avoid such accidents.

The same care that goes into reducing household hazards to young children should be applied in homes where a person with visual problems lives, especially an older and/or disabled person. At least 40% of all accidents occur in the home. Below is a list of pointers to help you avoid household accidents:

1. Get sufficient lighting. With age or deteriorating vision, you need more light, as much as two to three times the amount a healthy teenager needs to see the same object. Use fluorescent lights in the kitchen and bathroom. For close work, use bulbs and lamps that are especially designed for persons with low vision.

2. Make the color work for you. Falls can be prevented by choosing single-color carpeting rather than floral and other types of patterns, which can be visually confusing and may cause missteps. Call attention to such hazards as floor heights that differ from one room to another by laying down strips of colored tape at the intersections or by using different-colored floor coverings.

To aid in the kitchen and dining room, choose tableware and dishes that contrast with your tablecloths and/or place mats. Light-colored plates display food better than dark plates do.

3. Be aware of your visual limitations. One problem associated with progressive glaucoma is the loss of peripheral vision. When you can no longer see your toes when standing up straight, you can be sure that you are missing objects in your path.

4. Learn your home environment well, and keep things organized. Never leave objects on stairs or in travel pathways, and ask every person in the household to help out by keeping objects in familiar places. Getting about can become a problem if your vision deteriorates. To gain confidence, reconstruct your home in your mind's eye, noting the placement of each object. Once you have fully learned the territory you can move about easily.

Safety Precautions If You Have Glaucoma

Some people with glaucoma are fortunate enough to be able to continue to drive. Depending upon the state you live in, the following requirements may apply: You may be able to obtain a restricted license with as little as 20/70 vision in a single corrected good eye. For an unrestricted license, your best corrected distance acuity must be generally 20/40 or better.

If your vision is between 20/40 and 20/70 and you have a visual field of not less than 104 degrees, you may be issued a restricted license that carries special restrictions such as a shorter than normal renewal period, permission to drive only in daytime, special mirror requirements, or limitations on highway driving.

If your visual acuity is less than 20/70 but better than 20/100, you may be permitted to drive if you wear bioptic telescopes and can see 20/40 through this equipment and have a 140-degree visual field. Driving with bioptic telescopes requires practice, and you cannot apply for a license until you have undergone specific training.

Medication can sometimes affect your driving ability. In addition, be especially careful when driving at night. Low light may impair your ability to track a moving object, navigate your automobile down the road, and discern objects from their backgrounds, any of which can produce hazardous conditions when piloting a moving vehicle.

If driving is part of your lifestyle, practicing a few essential safety precautions can help you to avoid problems and stay on the road. Below are 11 recommendations from the American Optometric Association:

1. Use proper glasses for both day and night driving.
2. Avoid the use of sunglasses or tinted lenses for night driving.
3. Wear good-quality sunglasses in sunlight.
4. Avoid driving at dusk or at night if possible.
5. Clean your glasses regularly.
6. Choose narrow-temple eyeglass frames. Wide temples interfere with side vision.
7. Be an alert driver. Watch the road ahead, and check each side for vehicles, children, animals, or other hazards. Keep your head and eyes moving, and glance frequently in the rear view mirror and at the instrument panel.
8. Pace yourself to the flow of traffic.
9. Opt for a car with a clear windshield.
10. Maintain your headlights (adjusted properly) and taillights and keep your windshield clean.
11. Always wear your seatbelt. Air bags are good for additional safety, but remember that an air bag does not take the place of your seat belt.

Whether your glaucoma is relatively minor or causes a major handicap, you owe it to yourself to take an active part in your treatment. By learning all that you can about the particular form of glaucoma you have, and by understanding the effects of medication and surgical interventions, you will find yourself in a position to discuss your course of treatment with your doctor intelligently.

Keep in mind that you have a right to disagree with your doctor if you are in a nonemergency situation. You have a right to seek a second opinion and even a third if you so desire. By the same token, if you do not follow your doctor's recommendations, you need to understand that you are responsible for any harm that results.

Powerful Chinese Methods May Help Relieve Symptoms Of Glaucoma

noreply@blogger.com (Trey Koehler) — Tue, 22 Aug 2006 18:32:00 +0000

In China, grade-school children are taught to massage around their eyes, because it is believed that this simple exercise - based on the ancient tradition of acupuncture - will alleviate eyestrain and thwart myopia. Acupuncture, the practice of therapeutically inserting small, sharp needles into specific points of the body, has gained respectful attention in the Western medical community. This practice is best known for its effects on the nervous system. Acupuncture appears to release body chemicals known as endorphins and enkephalins, which are the body's natural painkillers.

Acupuncture is based on the ancient Chinese philosophic principle of yin and yang. In this philosophy, the earth is represented by the female principle, the yin. The heavens are represented by the male principle, the yang. When the natural universe is in harmony, yin and yang are in balance. The body too contains yin and yang, and when these forces are out of balance, sickness and disease occur. To correct the imbalance, points along twelve meridians, or lines, that run along the body are stimulated, enabling chi (vital energy, or the life force) to flow more freely. Various points along the meridians correspond to different organs and parts of the body.

Can acupuncture cure glaucoma? Neither acupuncturists in China nor those in this country make such claims, but they do say that treatment can help relieve some of the symptoms. Many of us would prefer not to explore an "iffy" situation or a situation that we are unfamiliar with. What we can do, however is to practice shiatsu, a type of massage or body work. Shiatsu acts on the same points along the meridians prescribed in acupuncture for the health of the eyes.

When these points are massaged, energy flows more freely, balancing the body's various systems. The exercises below take no more than ten to fifteen minutes, depending upon the length of your massage:

1. With your thumbs on your temples and your index fingers bent against your brow, massage the exact center of your eyebrows fifty times. Now move your thumbs about an inch to the right. Massage fifty times. Return to center and move your thumbs an inch to the left. Massage fifty times.
2. Massage your lower eye socket, just beneath the pupil, fifty times.
3. Place your index fingers in the upper inner corners of your eyes. You will feel a tender spot. Massage that area gently in a rotary motion fifty times.
4. Place your index fingers on the outer corners of your eyes. Massage that area in a rotary motion fifty times.
5. Place your fingers on the area just below the tear duct. Massage that area in a rotary motion fifty times.
6. Press your thumbs into the hollows of your temples. Massage these areas fifty times.
7. Feel the hollows just above the center of your eyebrows. Massage fifty times.
8. Press your thumbs on your upper forehead, near the hairline. Massage fifty times.
9. Place your index finger and middle finger directly below your nose. Remove your middle finger. With your index finger, press and push upwards towards your eyes. Repeat this exercise fifty times.
10. Place your index fingers just below your earlobes. Feel the hollow. Massage upwards fifty times.
11. Place your thumbs just beneath the bony structure at the back of your head, where your neck meets your head. You will feel hollows and possibly tenderness. Massage fifty times.
12. Do a circular massage starting with your eye sockets and increasing the range of your massage until you take in your whole face.
13. With your thumbs, find the hollows in the back of your head, just below the top of your scalp. They should feel like the soft spots on a baby's head. Massage fifty times. Then massage the back of your scalp fifty times.

When doing the massage, use pressure that is firm but not uncomfortable. Apply pressure for ten seconds or so, then release for a few seconds before applying pressure again. While the pressure should be firm enough to stimulate the point in question, it should not be acutely painful. If it is, either decrease the pressure or discontinue the massage.

Learn The 7 Levels Of The Visual Disability Scale

noreply@blogger.com (Trey Koehler) — Mon, 21 Aug 2006 18:32:00 +0000

20/20: This is considered standard normal vision.

20/25 to 20/65: Subnormal vision, but not seriously impaired. Those below 20/45 have difficulty reading a newspaper, but most can hold it closer to their face and still read with good light. Many states will license people to drive with visual acuity as low as 20/60, but most such drivers will carry restricted licenses. Telescopic glasses allow all of this group to drive as long as their state permits it and if they do not also have serious field loss. These people have excellent object and travel vision, except for those who have lost considerable field vision as well as visual acuity.

20/70: Mildly impaired. This is the point where people really begin to feel handicapped. Reading newspapers is very difficult without magnification, and most states refuse to license persons to drive with a visual acuity this low unless they are equipped with telescopic glasses. Object and travel vision are still excellent, except for those who have lost field vision as well.

20/75 to 20/200: Moderately impaired. This group can still function as sighted in most regards with the use of low-vision aids. Object vision for this group is poorer, but it is still adequate for almost all activities. These people can see the car but may have trouble identifying its make and model. Recognizing friends may be difficult, but they see the person. Travel vision is still quite good unless there is also field vision loss.

Reading is the primary problem for this group, but good equipment and training eliminate this problem. People in this group can be equipped and trained to read using numerous low-vision aids. All members of this group should be able to drive with telescopic glasses unless there is also serious peripheral-vision loss, or other limiting factors.

20/200 to 20/800: Seriously impaired, but still with travel vision and reduced but useful object vision. People in this group can read with low-vision aids of various kinds. Those below 20/500 might consider learning Braille, but even then it certainly isn't mandatory. These people will not be able to drive, even with telescopic glasses. Object vision diminishes but is still useful. Travel vision is still adequate, although those at the lower end of the scale may sometimes trip over curbs. Crossing streets can be hazardous for people at the lower end of this scale because they cannot see distant oncoming cars.

20/800 to 20/1200: Severely impaired. At this level of visual acuity a person loses travel vision. People suffering a loss of peripheral vision may find a white cane useful or even necessary before this point is reached, but at this stage, use of the white cane becomes necessary, regardless of the cause of vision loss. Some in this group are able to use very strong magnifiers to read large print. A +50 diopter lens will give almost all in this group the ability to read textbook-size print.

20/1200 to 20/6000: Very severely impaired. Many doctors reject the use of visual acuity figures this low. While it is true that letter sizes larger than 700 do not exist on test charts, there are mathematical equivalents. Doctors categorize this level as the ability to see a hand moving one foot away, without the ability to count fingers. People in the 20/1200 to 20/6000 group are dependent on the white cane or a guide dog for independent mobility. A video visual aid for reading print is the aid of choice and the only aid that provides visual access to print. Voice synthesizers are available that convert print into speech. Persons in this group are legitimate users of such equipment.

This group has little object vision, but as long as there is any light perception, that vision is useful. For example, a man walking down the street with his white cane sees two shadows ahead. He sees light between the two objects. He probably can't tell what the objects are, but he knows there is space enough between them for him to pass through.

How To Treat Corneal Abrasions

noreply@blogger.com (Trey Koehler) — Sun, 20 Aug 2006 18:31:00 +0000

The cornea is truly the eye's window. It's the transparent, domed "watch glass" that sits over the sclera (the "white" of the eye). Through this clear porthole the iris and pupil are easily visible; looking further still beyond them, we can see all the way to the back of the eye - the vitreous, retina, and optic nerve.

The wafer-thin cornea (amazingly, only about 1 millimeter thick) is like a cake with five layers, each with its own special function. On top are epithelial (outer lining) cells; this vital layer (also called the epithelium) protects the rest of the cornea and provides a smooth surface for tears.

Next comes the cellophane-thin Bowman's membrane; then the tough, transparent stroma, the bulk of the cornea (the cake itself); then another layer of cellophane, called Descemet's membrane. These middle three layers act as scaffolding, providing structural support to the cornea as it arches over the front of the eye. Last is the single layer of endothelial (inner lining) cells (also called the endothelium). Because this important layer touches the aqueous of the eye's anterior chamber, it serves as a sort of "bilge pump," keeping the cornea free of excess moisture. When this pump malfunctions, the cornea can swell, and this can distort or even damage vision.

The cornea normally does not contain any blood vessels. However, it is rich in sensory nerve fibers: under the epithelial layer alone are about seventy of them, which helps explain why the cornea is so sensitive to pain. The epithelial cells act as a protective blanket, like enamel on a tooth, insulating the nerve fibers from the world. When that blanket is frayed - or, continuing the tooth analogy, when the enamel is cracked or has a cavity - those ultra sensitive nerves react painfully. Even a small loss of epithelial cells can be excruciating, if it exposes these nerve endings.

Corneal Abrasions

Because of the abundance of nerves throughout its layers, even a slight injury or irritation to the cornea can result in a lot of discomfort or pain. An abrasion - a scrape of the epithelium, or outer surface - is the most common injury to the cornea. It can happen so easily - when the eye gets too close to a baby's fingernail, for instance, or the corner of an envelope, or a tree branch. All of a sudden it feels as if there's a hot poker in your eye.

Other symptoms include redness, a feeling like there's a piece of grit in your eye, and extra sensitivity to bright lights. Because it's often difficult to see the actual injury with the naked eye, eye doctors rely on special fluorescent dyes, which target and highlight areas of damage, to help us determine the extent of the wound. Fortunately, despite the severe discomfort and blurred vision that often accompany corneal abrasions, these injuries usually heal fairly quickly, sometimes in a matter of hours, sometimes within a few days - and don't leave any lasting damage.

For treatment, basically, the cornea must heal itself, and all we can do is provide the best conditions possible. (Think of skin injured by a scrape or burn; it hurts until your skin lays down new layers of cells, which insulate the nerves beneath.) Thus, the main treatment for a corneal abrasion is simply to patch the eye. It's not quite as easy as it sounds - in other words, you shouldn't try to do it yourself with an eye patch from the drugstore - because to be effective, the eye patch must immobilize the eyelid and prevent it from rubbing over the injured area. The epithelial cells need time to multiply and coat the injury, which means that the patch needs to be tight enough to keep the eyelid still. It takes several eye patches - generally three - to create enough bulk to secure the lid. (Eye doctors either stack three patches over the eyelid or use two, with the one directly on the eyelid folded in half.)

The eye pads are fixed over the eyelid with at least four pieces of surgical tape, extending from the forehead to the cheek. Sometimes, when eye patches can't be tolerated or when the abrasion doesn't appear to be healing, eye doctors apply a special "bandage" contact lens over the abrasion. Bandage contact lenses allow the patient to avoid having to cope with the nuisance of wearing a large and bulky eye patch and enables the abraded eye to see while it heals.

How To Treat Astigmatism

noreply@blogger.com (Trey Koehler) — Sat, 19 Aug 2006 18:31:00 +0000

Many nearsighted or farsighted patients also have what is called “astigmatism”, which is a refractive error whereby light is not focused to a single point. Vision is indistinct at every distance because the cornea - which should be dome-shaped - is "out-of-round" or shaped rather like the back of a spoon. Such a cornea is more steeply curved in one direction than the other, having two "axes" that are usually perpendicular to each other. Depending on the person, 0.5 diopters or more of astigmatism starts to cause noticeably blurred vision.

Laser surgery can smooth out the astigmatic cornea's curvature, changing the shape of the central cornea (mainly the central 6 or 7 millimeters) to look more like a symmetrical soup bowl than the back of a lopsided spoon. To correct astigmatism surgically, which is more difficult than treating nearsightedness, physicians selectively remove tissue to make the curvature of the steepest and flattest "meridians" (the corneal curves of greatest and smallest refractive power) more alike. For example, if you have simple myopic astigmatism, the curvature of the meridians can be evened out by lasering tissue from the steepest meridian to make it flatter - thereby moving the light-bending effect of this forward axis back toward the retina. Less tissue would be removed from the other, flatter meridian.

Some refractive surgeons target astigmatism with a specially "masked" broad-beam laser that is driven by customized computer software. Since the surface topography of the cornea is digitized, or put in numerical form, the computer knows which areas are elevated. During a more modern surgical technique using a "flying-spot" laser, a fast, small-beam laser dances around the cornea, chipping away at the higher spots and avoiding the flatter areas.

There are other causes of astigmatism besides irregularities on the front surface of your cornea. The back of your cornea also can be malformed. Furthermore, since your eye is a two-lens system, problems with the front and back curvature of your crystalline lens inside your eye can cause astigmatism. In fact, any misalignment of the internal components of your eye can blur images placed on your retina. A few people have astigmatism because of a disparity between their line-of-sight (the visual axis which goes from what they are looking at to the light-sensing photoreceptors on the retinal fovea) and their optic axis (the way the light strikes the retina). Densely packed with receptors, the fovea - a tiny depression in the retina - is the area of clearest vision. In these patients, the rays of light fail to strike the fovea correctly. Laser surgery is unable to treat these problems.

Currently, refractive surgeons can only correct the part of your astigmatic error caused by irregularities in the curvature of the front surface of your cornea. Consequently, the more disparity between treatable surface corneal astigmatism and total astigmatism, the less predictable the surgical result. To even out the cornea's front surface, the laser can be programmed to make the cornea more bowl-shaped. Unfortunately, some patients have noticeable astigmatism caused by problems inside their eyes. These patients will still have residual astigmatism after surgery, even if the front of the cornea is treated. In fact, many eyes that manifest no refractive astigmatism (as measured during an eye exam) actually have astigmatic defects inside the eye, but they are counterbalanced by astigmatism on the surface of the cornea. This is one instance in which two wrongs do make a right, because the error in one lens offsets that in the other to provide clear focus.

How Amazing Technology Is Used To Literally Map Out Your Cornea

noreply@blogger.com (Trey Koehler) — Fri, 18 Aug 2006 18:30:00 +0000

A remarkable innovative technique called "corneal topography" can generate a computer printout that shows the curvature and the "hills and valleys" of your cornea. By studying these brightly color-coded contour maps, your physician can diagnose corneal shape abnormalities and monitor changes in the front surface of your eye. A thorough understanding of the various elevations of your eye's bubble-like window can help your doctor decide whether you are a candidate for refractive surgery. If you decide to have LASIK, a specialist can literally take "before and after" pictures that show surgically-induced changes in your corneal topography. Used in evaluating your results, these maps show the pre and post-surgical dioptric (refractive) power of your cornea. Rare complications usually can be easily pinpointed. For a nearsighted person, such elevation "photos" should show the flattening effect of the operation on the cornea.

To create topography maps of your cornea, high resolution video cameras that are attached to a specially programmed computer photograph your eye's front surface and profile. Each half-diopter change in elevation, which has a different light-focusing power, is represented by a different shade of color. The steeper curvatures, or "hills," are colored in warm shades of reds, oranges, and yellows while the flatter "valleys" are cool shades of light and dark blue. The middle areas are green. In other words, the steepest elevations with greatest refractive power are bright red and the lowest elevations with the least dioptric power are dark blue.

Kept in your chart, these elevation maps graphically illustrate the different refractive power of many points on your cornea and most irregularities in its surface. Corneal topography helps your doctor see how the pattern of your astigmatism looks on paper. As you now know, this refractive error is often caused by unevenness in the curvature of the cornea's surface. Topographic maps may also enable your physician to rule out subclinical keratoconus (a cone-shaped steepening and thinning of the cornea that causes irregular astigmatism). In addition, he can diagnose subtle conditions with corneal topography that might be missed with less sophisticated tests.

Your eye doctor will compare the astigmatism shown on your corneal maps to the total refractive astigmatism that your glasses correct. These measurements don't always agree. Some astigmatism is caused by irregularities within the eye. Laser surgery corrects only corneal astigmatism. Hence, corneal topography helps your doctor predict how much of your astigmatism can be successfully treated with the laser.

Corneal maps also can help your doctor find the best contact lens fit for you. A computer generated image of your cornea can quickly "try on" many different types of contact lenses from the computer's large database of soft, soft toric (for astigmatism), and rigid gas permeable lenses without placing a single lens in your eye.

Getting To Know Your Eye Care Professionals

noreply@blogger.com (Trey Koehler) — Thu, 17 Aug 2006 18:29:00 +0000

Getting your eyes and your glasses checked can be a fairly simple procedure or a very complicated one, depending on the problem and on who's doing the checking. Routine eye examinations can be performed by ophthalmologists and by optometrists, and parts of routine eye exams can be done by technicians who may or may not have a specific degree or certification. Let's take a moment to define and discuss the different types of eye care professionals.

Ophthalmologists: An ophthalmologist is a medical doctor, a graduate of an accredited medical school with an M.D. degree. This means that you can expect him to have a pretty good understanding of the illnesses that can befall the rest of your body, and the ramifications of such ailments (diabetes, for instance) for your eyesight. Ophthalmologists can also be doctors of osteopathic medicine (D.O.). In addition, a board-certified ophthalmologist must have completed at least three years of residency training beyond the M.D. degree and passed extensive written and oral examinations in diseases and surgery of the eye.

Many ophthalmologists provide total eye care, beginning with the comprehensive medical eye examination. They prescribe glasses and contact lenses, diagnose eye diseases and disorders, and perform the appropriate medical, surgical, and laser procedures necessary to treat them.

Other ophthalmologists perform eye exams and diagnose and treat diseases of the eye but limit themselves to a fairly narrow range of surgical procedures, referring patients needing different procedures to other ophthalmic subspecialists. And some subspecialists (doctors who concentrate on treating specific diseases and performing certain procedures) do not perform routine eye exams at all.

Similar to many other branches of medicine, ophthalmology has become increasingly sub-specialized over the last twenty years. Although some policymakers are fond of making the blanket statement that "there are just too many specialists," the undisputed fact is that anyone who needs a surgical procedure wants the operation to be done by a surgeon who has performed that very same procedure, someone who does it every day, or at least several times a week, someone who is deeply familiar with every detail of the operation, and with every expertise of that particular body part, rather than by a generalist whose job is to know a little bit about everything and who might have done that procedure only a few times before.

This means that if and when you need a surgical procedure, consider getting a second opinion, and find the best, most experienced physician you can to perform it. Think about it: it's your precious vision at stake here, and your one chance to get the job done right. It's also true that most surgeons want to do only the operations that they do really well.

Optometrists: An optometrist is someone who has earned a doctor of optometry (O.D.) degree after completing four years of post-graduate-level optometry school, following a four-year undergraduate college degree. Optometry school covers the structure and function of the eye, mechanisms of vision and optics, and the diagnosis and treatment of eye disease. Some optometry schools have even developed collaborative arrangements with medical schools to give optometry students the opportunity to develop a better understanding of how the eye relates to the human body and its overall condition.

Optometrists traditionally limited their scope of practice to non-medical treatment of eye problems. This included prescribing glasses and contact lenses to improve the quality of vision and the use of vision therapy to improve the overall functioning of the visual system.

Optometrists were taught how to diagnose eye diseases and look for signs of associated systemic (whole body) diseases so that the patient could be referred to the appropriate physician. Currently, however, many optometrists are learning how and being licensed to treat non-complicated eye disease and how to manage surgery patients along with ophthalmologists.

Opticians: An optician is an eye care professional that is licensed to fit, adjust, and dispense eyeglasses and other optical devices following the written prescription of an ophthalmologist or optometrist. In some states opticians can also fit and dispense contact lenses.

Most eye care professionals agree that each of these specialists has a separate yet complementary role in eye care, and in the future, you're likely to see these three groups working more closely together. This will allow for a more comprehensive approach to eye care, one that can also be cost-efficient for patients and their insurance companies, as well as for eye care providers.

Focusing On The Retina: A Lesson About How Our Eyes Work

noreply@blogger.com (Trey Koehler) — Wed, 16 Aug 2006 18:28:00 +0000

The retina is a lining inside the eye covering the entire back half of the eyeball. With respect to vision, this is where the real action takes place. Millions of retinal cells, nature's microchips, constantly flash messages to your brain. These countless bits of information are carried on nerve fibers, somewhat like electrical impulses that travel on fiber-optic strands.

Your brain decodes these messages, much as your telephone and television set decode electrical impulses. For the transmission of information to the brain, the cells of the retina are divided into two basic cell types: the rods and the cones. The rods function best in dim light, the cones under lighted conditions.

There are about 7 million cones and 125 million rods. The cones are snappy little numbers that spring to attention the moment light hits them. They handle fine details and color. The rods, on the other hand, are laggards, taking about ten minutes to come to attention when you enter a dim or darkened room. Their job, in addition to helping you see in the dark, is to distinguish black and white.

Your sight is further refined by the connection of each rod and cone to a type of cell called a bipolar cell. The job of the bipolar cells is to relay messages to the over 1.9 million ganglion cells, which carry the messages to the brain. The bipolar cells have a lot of responsibilities. They are divided into two types, the magno cells, numbering about 10% of the total, and the parvo cells, which are much more numerous at 90% of the total.

The magno cells make it possible to distinguish shapes in indistinct light and to see in the dark. Thanks to these cells, you can find a quarter on a wood floor in dim light or locate that black suit in the back of your closet. Loss of magno cells may impair your ability to read, causing difficulty in separating the details of letters, spaces, and the breaks between words. The parvo cells fill in the details, like a painter adding texture, line, and color to the sketch.

Since there are fewer ganglion cells than there are rods and cones, several hundred rods and cones are connected to each ganglion cell, forming a field around the cell. If you were to lose ganglion cells, it would affect your ability to see well in dim light, cause difficulty in contrasting similar shades of color, and make detail fuzzy. Cataracts can cause similar symptoms.

The macula, in the center of the retina, contains the richest supply of ganglion cells. It is the hub of sight. If you lose cells in this region, it robs you of the ability to see things in the center of the visual field and compromises your ability to fixate (to focus the eyes on a specific point or object). You need to fixate in order to read, for example. Otherwise, the letters seem to jump around on the page.

Macular failure is a condition most often associated with age-related macular degeneration (AMD), a disease that primarily affects the elderly. With glaucoma, damage to the macula generally does not occur until the final stages of the disease. Glaucoma patients experience visual loss in their peripheral areas first.

Unfortunately, there are fewer cells in this area, so if you lose any of them, your peripheral vision decreases. While this type of vision loss is not as disabling as the loss of central vision experienced by people with AMD, it is, nevertheless, worrisome, for you find your side vision, and your top and bottom vision, falling away.

In the center of the macula is a tiny body of densely packed cone cells, each with its own connecting ganglion cell. The fact that each cone cell in this area gets its own ganglion cell is an indication of how important this area is for seeing. This body, the fovea, is your spyglass; it makes you able to spy a squirrel at the side of the tree, see a statue decorating the corner of a high building, or look miles into the distance on a clear day.

Birds of prey, such as hawks and vultures, possess not one, but two, foveas that act as magnifiers, enabling them to locate objects that even the sharpest of human eyes cannot detect. Such birds can detect the presence of a creature that might become lunch from 9,000 to 13,000 feet in the air.

Perhaps the most remarkable feature of our sight apparatus is that the eye produces actual images on the retina. A tiny inverted image appears continuously during the act of seeing. This image is slowed down or sped up depending upon the strength of the light source, the eye's ability to fixate, and the general health of the rods, cones, and nerve cells. For example, in a dim light, you may find it takes a bit longer to discern the outlines or details of an object. A similar situation occurs if you have cataracts or have trouble fixating because of a loss of cone cells in the eye.

Exercise Your Way To Better Eyesight

noreply@blogger.com (Trey Koehler) — Tue, 15 Aug 2006 18:27:00 +0000

Stimulating perception is one of the most effective methods of improving eyesight. Although your eyes respond to light and images and send these signals to your brain, it is your brain that ultimately decides what you see of the world around you. It is the information stored in your brain that is reactivated by what you see.

Using magnetic resonance imaging (MRI) and advanced computer programs to map specific areas of the brain, scientists have been able to observe both what happens to the signals the optic nerve sends to the visual cortex and how the cortex interprets them. It turns out that the more information you possess about the visual world, the more adept your brain is at interpreting what the eyes see from even a minimum of clues. For example, you can recognize a person you know well from nothing more than the sight of a familiar tilt of the head, the curve of a chin, or a hairstyle.

The basis for recognizing other persons and objects begins when a baby learns to know its mother as separate from self. Afterwards, the things a person knows and learns influence how he experiences different objects. What we know determines how we see an object. Seeing becomes perception only through knowledge of the object.

Unfortunately, if you have glaucoma, the drops, the cataracts, and the decreased vision often corrode your desire to examine objects carefully. You may find you have little interest in examining the features of a person's face, or looking at paintings. Yet developing your perceptual powers can actually help you to overcome the debilitating effects of glaucoma and its treatments. Perception-sharpening exercises like those outlined below can help.

Before performing any of these 11 exercises, take a few minutes to practice your breathing. Breathe in from your diaphragm or stomach, through your nose; breathe out through your mouth. Your breathing should be slow and steady. Now you can begin the exercises. For the following perceptual exercises, pretend that you are an artist or a writer and that you must examine details.

1. Look at a building. Observe the brickwork, the inset of the windows, the door frame, the roof. If you can read the building address, look at each number individually. Keep your eyes traveling over the surface of the building. Do not stare at one spot.

2. Bring a friend. Look at your friend's face - the eyebrows, eyelashes, nose, cheeks, mouth. Pretend you are going to draw the face and you want to represent each feature.

3. Look at a tree. Then look at the bark, a twig, a leaf, the veins in the leaf, and so on.

4. Blink a lot. Blinking is nature's way of lubricating your eyes.

5. Slowly open and close your eyes, one at a time. Move your head back and forth with your eyes closed, then, for a fraction of a second, open each eye slowly. By opening each eye very slowly, you can eventually blink with only one eye at a time.

6. Draw a large E in black magic marker on a sheet of paper. Look first at the lower bar, then at the upper bar, the vertical bar, and the center bar. Picture the E in your mind. Then step five feet away from the E. Blink slowly a few times. Look at the E again, then blink slowly again a few more times. Never stare. If you can see the E, move back a few feet. Repeat this sequence until you can no longer see the E.

7. Stimulate the cells responsible for peripheral vision. Extend your arms out to each side. Wiggle your fingers. Can you see the motion? If not, bring your arms closer to your body until you glimpse your wiggling fingers.

8. Close your eyes. Visualize a large circle. Pretend there is a pencil affixed to your nose. Trace around the circle. Squeeze it into an oval. Trace around the oval. Make it into a figure-eight. Trace around the figure-eight. Write your name, tracing each letter.

9. Tape a piece of paper over the bridge of your nose. Hold your index fingers in front of you and move them first clockwise, then counterclockwise, then have one finger go clockwise and the other counterclockwise. Follow the motions with your eyes.

10. When reading, sit where you can see a wall calendar or some other item with large type. If you can find an eye chart, hang it on the wall. Raise your eyes occasionally to look at it. If you read in daylight, look out the window after every five or six pages. Focus on a distant object when you do so.

11. Pause occasionally in your reading and remember the last word you read. Visualize the whiteness around the word. Think of the blackness of the letters. Look at the word again.
Remember to avoid staring. Move your eyes around the object. When you think of it, shift your eyes. You see best when your eyes make saccadic movements, that is, tiny automatic movements that your eyes make to fixate on objects. Your eyes will experience the least fatigue when viewing an object consisting of words or letters with quick glances.

In addition to perceptual exercises, the following are 4 tension relieving exercises that may be helpful:

1. Massage your jaw. Yawn. Allow yourself to make noises. releases facial tension.

2. Feel the sternocleidomastoid muscle - the muscle that runs from behind your ear, down the side of your neck, and into your shoulders. Place four fingers on each side of the muscle and massage the muscle, checking along the whole area for tension and sore spots. Massage twenty times.

3. Do shoulder rotations, ten times with each shoulder.

4. Move your head loosely around in a circle, first clockwise, the counterclockwise, ten times each.

These exercises should relieve tensed-up muscles and promote healthy circulation. Many of us become tensed up when we concentrate on an activity. Tension in the body restricts blood flow, and restricted blood flow to the optic nerve is implicated in glaucoma.

Do You Have A Burning Desire To Obtain Perfect Vision?

noreply@blogger.com (Trey Koehler) — Mon, 14 Aug 2006 18:27:00 +0000

The eye has a passion to see. Forty percent of the input to your brain comes from your eyes. Your vision affects every aspect of your life. Through your sight, you behold the flutter of a butterfly wing, the icy chill of a confidant's betrayal, and the adoration in your lover's smile. Penetrating your mind like a swift sword, a single image can unleash a cascade of shattering emotions. In the batting of an eye, a compelling look has weakened the mightiest will, commanding its total surrender.

Focused shafts of light amplified by your retina and interpreted by your brain, can trigger a complex series of chemical reactions within your body. Turning up the heat, adrenaline quickens your pulse. Your heart pumps primal hormonal messages throughout your bloodstream. Capable of igniting love at first sight, a mere glance can break your vulnerable heart or steal it for a lifetime. Only with your eyes, can you completely capture the moment. If you miss the magic, it is gone in an instant, never to return.

If you are nearsighted or farsighted, you may fantasize about waking up in the morning able to see the landscapes of your world without glasses or contact lenses. You probably yearn to have clear, comfortable, binocular vision without sticking something in or in front of your eyes. The simple pleasures of keen eye-sight that many people take for granted elude your gaze.

Today, the realization of a long-awaited goal - the dream of relatively accurate unaided vision - is now possible by surgically treating the eye. At last, modern medical technology is able to answer the prayer for reduced dependence on corrective lenses for nearsightedness, farsightedness, and astigmatism. As much an art as a science, an amazing new refractive eye operation that can now refocus your eyes is changing lives forever. By harnessing the power of today's sophisticated computers and the remarkable precision of the laser, a specially trained ophthalmologist can improve your vision without glasses.

Looking at the surgical field through the high magnification of a microscope, a refractive surgeon can reshape your cornea - the transparent window of the eye - using a cool, invisible light scalpel called an excimer. The difference of a tiny fraction of a millimeter in the steepness of this corneal lens can dramatically improve the quality of your life. By bringing shimmering oak leaves, pink rose petals, and your child's angelic face into more perfect view, better vision can set you free to take in the world around you. As the history of vision correction surgery shows, realizing the dream of clear, unaided eyesight has never been easy.

Do You Get Enough Antioxidants For Your Eyes?

noreply@blogger.com (Trey Koehler) — Sun, 13 Aug 2006 18:26:00 +0000

There are many antioxidants that work in your favor for eye-health. For example, vitamin A is a powerful antioxidant that is known primarily for its effect on the retina, especially that of improving night vision. The body converts vitamin A, found in animal tissues, to the fat-soluble compound retinol for storage in the liver. Once vitamin A is stored in the liver, zinc is needed to liberate it for transport to the eyes as needed. Vitamin A is found in fish, fish liver oil, eggs, and liver.

It is possible to use beta-carotene, one of a class of substances known as carotenoids, as a substitute for vitamin A, because beta-carotene is a precursor of vitamin A and is converted into retinol in the liver. Eye experts have found that taking supplemental vitamin A palmitate in combination with manganese has been helpful to some people with glaucoma.

Beta-carotene sources in food vary immensely. Sweet potatoes top the list; raw carrots follow. At the low end are apples. In between lie a host of fruits and vegetables, including purslane (best known as a common weed, but now also grown commercially for use in salads), butternut and hubbard squash, mangoes, dandelion greens, kale, turnip greens, beet greens, red pepper, papaya, cantaloupe, Swiss chard, fresh or dried apricots, bok-choy, mustard greens, collards, tomatoes (also sauces and juices), broccoli, nectarines, prunes, tangerines, asparagus, romaine lettuce, avocados, plantains. Also included are savoy cabbage, Brussels sprouts, green peas, peaches, oranges, and bananas.

In natural sources, you not only get beta-carotene, but all the carotenoids as well, plus a host of other compounds necessary for optimum health. People who have diabetes may lose their ability to convert beta-carotene to retinol, and so must take vitamin A in its fat-soluble form. Fat-soluble vitamin A is found in fish liver oil, eggs, and liver. Air pollution, nitrates, nitrites (commonly used in fertilizers), and cooking and canning destroy or weaken vitamin A's effectiveness.

The carotenoids, of which beta-carotene is only one, are gaining ground among natural ways of achieving eye health. In addition to beta-carotene, two carotenoids that relate directly to eye health are lutein, which is present in spinach, marigolds, sunflowers, and kale, and lycopene, which is found in tomatoes.

Lutein has received considerable attention, especially for the problem of macular degeneration. Studies suggest that a high intake of foods rich in lutein may protect the retina from oxidative damage leading to degeneration of the macula. Super foods include kale, spinach, collard greens, broccoli, Brussels sprouts, leaf lettuce, green peas, and summer squash.

Foods that contain a moderate amount of lutein include cabbage, marigold, carrots, corn, green beans, and tomatoes. Lutein is also available in supplement form, either by itself or as part of one of the eye therapy supplementations. However, lutein and beta-carotene should not be taken together at the same time because they compete for absorption in your gut. Therefore it is better to take your beta-carotene, say, at breakfast and your lutein with your dinner, especially if you're having a salad dressed with olive oil. Both lutein and beta-carotene are more readily absorbed with a bit of fat.

Discover Step-By-Step What The LASIK Experience Is All About

noreply@blogger.com (Trey Koehler) — Sat, 12 Aug 2006 18:24:00 +0000

On the day of your LASIK procedure, it is natural to experience both excitement and nervousness. Patients who feel most at ease on that day are those who have asked questions, read about the LASIK procedure, and perhaps talked with former patients. Understanding LASIK and trusting your surgeon are important to helping you feel confident, calm, and prepared on the day of your procedure. You won't be able to drive immediately after the procedure, so it is recommended that you have someone drive you to the surgery center and pick you up when you're ready to leave.

How should I prepare for the day of my surgery?

Make an effort to arrive at the center rested and relaxed. You should plan to spend up to three hours at the laser center, although this amount of time varies from center to center. Wear comfortable clothing the day of your surgery. Do not wear makeup, skin moisturizer, perfume, or cologne, since LASIK requires clean, sterile conditions. Earrings should not be worn.

How the LASIK procedure performed?

LASIK is performed while the patient is awake. However, if you are experiencing anxiety, the surgeon may give you a mild oral sedative. Many surgeons talk to the patient throughout the procedure, so the individual knows what is happening and what to expect next.

What happens before the surgery?

Before the surgery begins, your face will be cleaned with a disinfectant, and you will be asked to wear a surgical cap. You will be given an antibiotic eye-drop and possibly an anti-inflammatory eye-drop. These may sting for a few seconds.

What happens during the procedure?

Once in the laser suite, you will be positioned comfortably on your back, under the excimer laser. Your surgeon will give you anesthetic eye-drops to numb the surface of your eyes. Your eyelashes will be taped out of the way, and an eyelid speculum will be placed between your eyelids, to keep you from blinking. The speculum sometimes causes mild pressure or discomfort to your eyelids at first, but with the numbing drops, these sensations dissipate.

The surgeon will make small reference marks on your cornea with water-soluble ink. These marks will serve as positional guides when it is time to realign the corneal flap. A suction ring is then placed on your eye to hold it in position to maintain pressure within the eye. Keeping the eye pressurized is essential for the keratectomy, or flap-making process, which comes next. Your vision will dim during this step.

Next the surgeon will create the corneal flap, using the microkeratome, the small instrument with a blade that passes over the eyeball. The extremely thin flap is made from the outermost 25 percent of the cornea. (The average cornea is only about the thickness of a credit card.) This flap-making process takes about thirty seconds. When the microkeratome is making the flap, you may feel slight pressure and the instrument will block out light as it passes over your pupil.

Next, the surgeon will ask you to fix your vision on a target light - usually red, green, or yellow. Then, the surgeon will gently lift back the hinged flap. At this point your vision will become blurry.

The surgeon will now perform the laser procedure. This usually takes twenty to ninety seconds. You will not feel any pain as the laser sculpts the cornea by vaporizing small amounts of tissue. This process is called photoablation. You will also hear a clicking or buzzing sound with each pulse of the laser. The surgeon is reshaping your cornea.

During the laser procedure, individuals have different responses to staring at the fixation light. Some patients report that the fixation light becomes a blur. Others report that it seems to momentarily disappear. If this happens and your eye starts to wander, the surgeon will stop the laser. You will be coached to look again at the target light so the laser procedure can resume.

Once the process of reshaping your corneal tissue is complete, the excimer laser will be turned off. Using a sterile saline solution, the surgeon will flush the treated surface of the eye to ensure that any debris is washed away. The surgeon then carefully replaces the corneal flap to its original position, using the ink marks as guides.

It takes about one to five minutes for the eye to create a natural vacuum to hold down the flap. The cornea has the unique ability to seal itself back into place. No sutures are necessary. Your eyes will be dried with a sterile cloth, and the eyelid speculum will be removed. You will now be able to blink normally. At this point, you will be asked to sit with your eyes closed for about thirty minutes. Then your physician will examine your eyes one more time to ensure that the corneal flap is properly positioned.

Patients who have undergone LASIK experience some discomfort, which may last six to eight hours. Patients describe this as a sensation of having sand or a dirty contact lens in their eye. Tylenol, aspirin, ibuprofen, or similar over-the-counter pain medications can help. By the following day, this sensation is usually gone.

Immediately after surgery, expect your vision to be somewhat blurred, similar to looking through a glass of water or wearing a dirty contact lens. However, upon awakening later in the day or the next morning, you should experience improved vision. Most patients report dramatic improvement within twenty-four hours.

Complete List Of Vitamins That Aid In The Health & Proper Function Of Your Eyes

noreply@blogger.com (Trey Koehler) — Fri, 11 Aug 2006 18:20:00 +0000

The following is a list of vitamins that are necessary for good health and that can affect the health and optimum functioning of your eyes.

Vitamin D: This vitamin is vital for the metabolism of calcium and regulates the absorption of calcium and phosphorus from the intestinal tract. A deficiency of vitamin D results in rickets in young children; irritability, weakness, and softening of the bones in adults; and underutilization of calcium and phosphorus in bone and tooth formation in people of any age. Vitamin D may have a direct effect on the eyes, and it is vital for maintaining overall good health.

The body can usually produce all the vitamin D it needs; in the presence of sunlight, two cholesterol-related compounds in the skin are converted into vitamin D. Food sources of vitamin D include butter, egg yolk, fish liver oils, fatty fish such as salmon, tuna, herring, sardines, and liver and oysters. Supplements are available, but rarely necessary or even advisable, as vitamin D is one of the few vitamins that you can overdose on.

The B Vitamins: The group of B vitamins can have a profound effect on the health of the eyes. The B vitamins act as coenzymes. They are the ones that see to it that oxidation reactions essential to cell growth and carbohydrate metabolism occur as they should. Below is a list of members of the vitamin B family.

Vitamin B1 (Thiamine): This member of the vitamin B group is important in the metabolism of carbohydrates; energy production; the synthesis of RNA, niacin, and fatty acids; and the transmission of nerve impulses. In the body, thiamine is used in the production of an enzyme that is a natural cholinesterase inhibitor .

A deficiency of thiamine can lead to impaired vision and damaged nerves. One study found that among a group of people who ate a diet deficient in the B vitamins, there was a preponderance of open-angle glaucoma, while there was no glaucoma among those who ate a more balanced diet. Food sources of thiamine include brewer's yeast, peas, wheat germ, pasta, peanuts, whole grains, beans, liver, and pork.

Vitamin B2 (Riboflavin): This vitamin is involved in the breakdown of dietary fat, the synthesis of fatty acids, the activation of vitamin B6 and folic acid, and the synthesis of corticosteroids, red blood cells, and glycogen, the form in which energy-supplying glucose is stored in the muscles and liver. A deficiency of riboflavin can affect the mucous membranes and moist tissues in the eyes and nose. It also maintains the supply of glutathione, a major antioxidant, in the lens of the eye.

Dietary sources of riboflavin include brewer's yeast, broccoli, wheat germ, almonds, milk, cottage cheese, yogurt, pasta, kidney, liver, and heart. Processing foods destroys this vitamin, and pasteurization of milk products depletes it.

Vitamin B3 (Niacin, Niacinamide): Vitamin B3 occurs in two forms, niacin and niacinamide. Niacin is often used to lower blood pressure because it dilates blood vessel. It is also helpful for lowering the level of cholesterol in the blood. Because of its effect on blood vessels, some ophthalmologists consider it useful for increasing the flow of blood to the optic nerve.

Food sources of niacin include brewer's yeast, peanuts, soybeans, and whole grains, as well as high-quality protein foods such as eggs, milk, poultry, fish, meat, and liver. Cooking depletes foods of niacin, and alcohol destroys it. If taken in supplement form, niacin can cause a temporary flush shortly after ingestion, and if taken in excess doses over prolonged periods of time, it may cause liver damage.

Niacinamide is not believed to have these effects, however, it is not considered as effective at lowering cholesterol or increasing circulation. The body can make niacin from the amino acid tryptophan, but thiamine, riboflavin, and vitamin B6 are needed for this process.

Vitamin B6 (Pyridoxine): Vitamin B6 is involved in many metabolic processes, including the breakdown of amino acids (important for protein formation), fats, and carbohydrates; the release of glycogen from the liver to supply energy; and the synthesis of antibodies, red blood cells, DNA, and elastin.

Food sources of vitamin B6 include soybeans, lima beans, legumes in general, avocados, bananas, walnuts, buckwheat, peanuts, chicken, steak, tuna, kidney, beef, pork, veal, and salmon. Oral contraceptives and other drugs may deplete this vitamin, and older people often have deficiencies.

Vitamin B12: Vitamin B12 is necessary, along with folic acid, for the synthesis of RNA and DNA; helps to maintain nerve tissue; and is active in glucose metabolism. A 1958 study of the effect of vitamin B12 on optic nerve tissue revealed that it increases the strength of the tissues in new cases of glaucoma, but is not effective for long-standing cases. A later study, in 1969, confirmed that it is beneficial for optic neuropathy provided the treatment is started within six months of visual deterioration.

In a 1976 study on laboratory monkeys, scientists produced severe vitamin B12 deficiency in the animals, and five of them developed gross visual impairments. Autopsies of the deficient animals showed degeneration of the peripheral visual pathway. No abnormalities were found in a B12-supplemented control animal.

Food sources of vitamin B12 include liver, oysters, poultry, fish, clams, salmon, and eggs. Since this vitamin is found mainly in animal foods, strict vegetarians may need to take supplements, as may older people, people who consume alcohol, and women who take birth control pills, who may have trouble absorbing B12 from foods.

Folic Acid: Folic acid, another of the B vitamins, prevents anemia, is important for new cell growth, and is vital in the early months of fetal development (a deficiency has been linked to spina bifida). Experts have found that some patients with visual problems improve when folic acid is added to their diet. It is easy to get enough folic acid if you eat a lot of raw green, leafy vegetables and fresh, ripe raw fruits. Folic acid is also present in liver, eggs, asparagus, bean sprouts, garbanzo beans, whole wheat, and salmon. Cooking destroys folic acid.

Pantothenic Acid: Pantothenic acid might be called a brain chemical. A deficiency may result in nerve and optic degeneration. Pantothenic acid is important for energy production and the synthesis of red blood cells, cholesterol, and steroids. It also stimulates antibodies and intestinal absorption.

Major sources of pantothenic acid include liver, kidney, heart, brewer's yeast, sunflower seeds, peanuts, buckwheat flour, royal bee jelly, egg yolk, bran, fish, and whole-grain cereals. Before modern food processing, deficiencies of this nutrient were uncommon. However, growing foods in sterilized soils and fumigating stored foods with methyl bromide greatly reduces the amount of the vitamin in foods.

Biotin: Biotin is an energy metabolizer and a synthesizer of antibodies, niacin, and digestive enzymes. A daily supplement of biotin lowers blood sugar levels in diabetics, and a similar dose has been effective in lowering IOP in some patients. Biotin is normally produced by the bacteria in the intestines. As a result, it is possible to become deficient in biotin if you take heavy doses of antibiotics.

Food sources of biotin include liver, kidney, egg yolk, milk, yeast, whole grains, cauliflower, active culture yogurt, nuts, legumes, and fish. If you are interested in experimenting with biotin supplementation, seek the advice of your health care provider.

Choline: Choline, also called a brain chemical, is synthesized with the aid of pantothenic acid and acetylcholine, that trusty chemical messenger so important in the management of glaucoma. It is also a major component of lecithin, an important compound for controlling the buildup of plaque in the arteries. Healthy individuals normally produce choline.

Unprocessed foods, egg yolks, soybeans, fish, cereal, legumes, lecithin, and liver are also rich sources of choline. Most fatty foods contain choline, but cannot, unfortunately, be recommended because of all the other negative effects they may have.

Choosing Your Eye Doctor: 13 Questions You Must Ask When Searching

noreply@blogger.com (Trey Koehler) — Thu, 10 Aug 2006 18:20:00 +0000

When picking the individual doctor you wish to have for your vision problem, how do you know whether you've got the right person? This can be a tough decision. There are as many different types of individual doctors as there are types of people. One of the best sources of good doctors is word of mouth. If you have a friend who wears glasses or contacts, and has been with a good doctor for several years, there's a good chance that this doctor will be good for you too.

When looking for a doctor, don't bypass an experienced practitioner for a young professional fresh out of school. Although recent graduates may possess the latest technical knowledge, there's something to be said for experience in any field. And, some new doctors are so cautious that they may keep you in the chair for hours doing every test in the book instead of just the ones related to your problem.

To avoid the high costs of setting up offices of their own, new graduates of optometry school sometimes begin their practices in chain-store operations, which are usually located in shopping malls. In these kinds of stores, you may find young doctors with good technical knowledge but little time to apply it because of the large numbers of patients the stores book into each time slot. These young doctors often don't stay around for very long - usually just long enough to get on their feet financially - so if you frequent these stores for your eye care, there is little chance that you'll see one doctor more than one time.

On the other hand, you should also be cautious of older doctors who have been in the same location since prehistoric times. If they have been keeping up with the advancements in eye-care technology and knowledge, they are perfectly fine doctors to see, but things change fast and not everyone keeps up. Since all states require continuing education as part of the relicensing process for optometrists, checking to make sure that your doctor has a valid license should give you some comfort that he or she has kept abreast of at least the most important developments in the field.

To become familiar with the doctors on your list of possibilities and to make an intelligent choice from among them, you should inquire about their educational and professional backgrounds. You could ask each doctor for a resume and any office promotional materials. Here are a few questions to ask their receptionists when telephoning their offices for the first time:

1. How long has the doctor been in practice?

2. How long does the examination take?

3. Will your eyes be dilated for the examination?

4. How much does the examination cost?

5. Does the doctor specialize in (or have experience with) the particular condition or service you are interested in?

6. Will a case history be taken? (Be sure the doctor sits down and talks about your problems, medical history, medications, and lifestyle.)

7. How extensive is the examination form? (Although the form will probably look mysterious, see how big it is and how much of it should be filled out by the end of the examination. Be suspicious of an examination form that's the size of an index card.)

8. Is a full range of distance and near-vision tests included in the examination?

9. Is a glaucoma test a regular part of the examination?

10. Does the doctor work with a number of different contact lens companies? (If you want contact lenses, it's important to have a doctor who is not tied to one manufacturer. There are many different kinds of contacts available now.)

11. Will the doctor describe the different tests while performing them?

12. Does the doctor offer treatment alternatives (for example, contact lenses, glasses, or vision therapy) according to the patient's preferences?

13. Does the doctor regularly refer patients to other doctors when appropriate or necessary?

Much of what you determine about a doctor will be based on just plain old gut feelings about the office in general. If you feel you aren't getting high-quality, personalized service from your eye doctor, you may want to go elsewhere. Sometimes it takes a little faith and trust to find a good eye-care professional. A good doc is hard to find, but once you find one, stay with him or her, and appreciate the good vision care.