What You Need To Know About Cataract Surgery

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?

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?

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?

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?

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?

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

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.