• Dr. Shulman is highly experienced in all forms of ophthalmic surgery, and has performed over 10,000 procedures in nearly 30 years of practice in New York. He has written books on both refractive surgery and cataract surgery. All patients are treated by Dr. Shulman and seen by him at their pre-operative visit prior to the day of surgery. We can provide you with an analysis of the outcomes from patients with prescription similar to your own, who were treated by Dr. Shulman.
• The laser used by Dr. Shulman, the VisX S4 laser is the most commonly used laser system in the world, and has performed more procedures in the US than all other laser systems combined. The VisX Active Track 3-D Eye Tracking System ensures that the laser follows the movements of your eye in all three dimensions, so you can relax during your treatment - knowing the procedure will be delivered accurately.
• We offer the highest quality service at very affordable rates, further enhanced by interest free 0% and other finance options which are available to our refractive surgery patients, making the procedure even more affordable to you.
• We offer an initial assessment and discussion with our experienced refractive co-ordinator. This is a free, no obligation appointment, at which patients will be assessed for suitability, given the chance to ask any questions they may have, and receive all the information they need to decide on the best course of action for them. Our refractive co-ordinator will provide you with a single convenient personal contact before and after your surgery.
• We will treat you as an individual and take the time to find out what specific solution we can offer you to your particular visual and lifestyle demands. We will never recommend a procedure that we do not feel is in your best interests.

So why not call in and see us - find out for yourself why so many people are choosing to trust Eastside Eye Associates to deliver them the gift of clear vision and the freedom and benefits it brings to their everyday lives! Call us to schedule a free no-obligation assessment on (212) 861 6200, or email us and we will reply promptly and arrange a convenient time for you to come in. We are located in Manhattan, New York.

LASIK, PRK, LASEK, and Epi-LASIK

The golden age of vision correction promises to improve. Until the 1950s, patients needing vision correction settled for spectacles. In the 1950s, contact lenses became available, but there was only one choicehard lenseswith associated comfort problems. In the 1970s, soft contact lenses gave millions of patients relief from the discomfort of hard lenses, ushering in a revolution in contact lenses. A smorgasbord of soft lens choices evolved, from daily disposable, toric (correcting astigmatism), and continuous overnight wear to bifocal and multifocal lenses. Colored lenses can change brown eyes to blue, blue eyes to green, and every color in between. For those patients with too much astigmatism for soft lenses, the hard lens was replaced by a more comfortable gas-permeable lens that offered improved vision and comfort.

Now, the promise of regaining your natural eyesight, of being truly free of glasses or contact lenses, of literally turning back the clock to the days before you had to wear any type of corrective lenses, is here. Two types of procedures make that possible: LASIK and Surface Ablation (LASEK, PRK, and epi-LASIK). Other procedures may be suitable for some patients, but for most patients, Laser Vision Correction has propelled our golden age of vision correction to heights we could not have imagined as recently as ten years ago. A thorough exam or discussion with your doctor will determine if you are a candidate for this remarkable laser treatment.

LASIK (or laser-assisted in situ keratomilieusis) is the most commonly performed LVC in the world, accounting for more than 90% of LVC procedures. What makes LASIK so popular is the rapid improvement of vision when compared to other forms of LVC. No matter how strong your prescription is, the average LVC patient can usually pass a driver’s vision test twenty-four hours after surgery, often even after only one hour. This quick, often miraculous recovery is due to the microkeratomean instrument similar to a carpenter’s plane. The surgeon places the microkeratome on the cornea after using numbing eye drops and, using a suction device to lock the microkeratome into place, creates a corneal flap. This thin flap of corneal tissue is folded out of the way and the excimer laser removes a thin layer of corneal tissue to correct your visionflattening your cornea if you are myopic, steepening your cornea if you are hyperopic, or rounding it out if you are astigmatic. The surgeon then smoothes down the flap, fitting it back exactly where it came from, like a piece in a jigsaw puzzle, over the ablated area. The corneal flap adheres to the rest of the cornea within minutes and the procedure is over.

In matter of a few hours, patients burdened for years with wearing glasses or contact lenses often achieve vision so clear that the first word out of their mouths is an incredulous, “Wow.” Why does vision recover so quickly? The answer is that the corneal surface in the line of sight (visual axis) remains practically untouched. When the flap of corneal tissue is created, the U-shaped narrow seam is the only area of the cornea’s surface that is disrupted. The surface and center of the cornea, the part through which you see, is untouched. Within a few hours or overnight, the seam, or “gutter,” fills in with new cells that grow very rapidly across the seam. In the average patient, by the following morning the flap has adhered, the seam has healed, and that clock across the room is no longer the blur it was the day before.

The corneal flap also makes it easier to perform enhancements. If you did not achieve the level of vision you wanted, another laser treatment may be performed a few months or even years later. The surgeon carefully breaks the seal on the flap, lifting the flap once again as in the original procedure, and performs an additional laser ablation. Enhancements are usually very successful, but may not be advisable if your original, untreated cornea was thin.

If the rapidly healing corneal flap is largely responsible for the wow factor, it is also responsible for the majority of complications that can result from LASIK. The flap can be too thin, too thick, too small, irregular, incomplete, or “button-holed.” It can develop wrinkles, folds, and striaeall of which can lead to delayed or poor healing or a poor visual result. Fortunately, these problems occur in less than 1% of LVC patients and can usually be treated successfully.

Are You a Good Candidate for Laser Vision Correction?

Determining Your Candidacy

Are you a candidate for LVC? Based on the previous chapters, you should have a good idea if LVC is for you, if freedom from glasses or contact lenses is enough motivation to have surgery. Deciding you want to have LVC does not mean you can have it-you must have suitable eyes and even a suitable personality to become a satisfied LVC patient. The typical LVC patient should be over age eighteen (many surgeons prefer over twenty-one), have a stable refraction for two years, be in good health, and be free of contraindications (discussed later in this chapter).

One of the most important factors that determines whether you can have LVC is your prescription. A high myopic, hyperopic, or astigmatic prescription may make LVC ill advised. Despite the broad guidelines recommended by each laser manufacturer (most laser companies are approved for treating myopes up to –14.00), every eye surgeon has a comfort level, beyond which the results from LVC would be too unpredictable to recommend to patients. Generally, myopes above –10.00 or –11.00 D and hyperopes above +5.00 or +6.00 D are less successful than those with lower levels of refractive error. In myopia, the effect of LVC on your cornea is like flattening a mountain peak into a level plateau. If your cornea is flattened too much in an attempt to correct vision-let’s say you’re a –15.00 D myope-the quality of your vision will suffer, even if all your myopia is gone. Quality of vision is not well understood, but a cornea that is abnormally flat or steep may produce aberrations that adversely affect vision. A similar analogy exists for hyperopia, where converting a “plateau” cornea into a steep mountain may lead to inferior image quality. There are many exceptions to these guidelines, so each patient needs to discuss options with his or her physician. More on this later. Whether you are nearsighted, farsighted or astigmatic, a candidate for laser vision surgery must have a refractive error that has been stable for a period of at least two years. As with most parts of our bodies, our eyes and vision change over the course of our lives. If you have been wearing glasses since childhood or teen years, you probably went through a period of time, generally through your mid-twenties, when your prescription changed almost yearly. After that point, even into your early thirties, there was probably little or no change in your refractive error, and it stabilized. This explains why vision correction surgery is not performed on teenagers, whose eyes may change even several times a year. A prescription that endures for a two-year period is a good indication that most of the change is over.

The second issue to address is your cornea, eye and general health. There are other conditions that may preclude individuals from becoming vision surgery candidates:

• Herpes infections of the cornea-any eye surgery, including LVC, may reactivate herpes of the cornea.
• Keratoconus-a corneal condition that results in a thin, irregular, steep cornea. In most cases, no LVC procedure is advisable since this may weaken the cornea even further over the lifetime of the patient. A customized wavefront surface treatment may be possible. Your eye doctor can best advise on this often complex area.
• Excessive corneal scarring-scar tissue that affects corneal clarity would not be removed during LVC, so there would be no improve40 ment in best corrected vision. An exception might be a superficial scar, which could be ablated during LVC.
• Cataracts may make LVC unnecessary because vision is corrected with the insertion of an intraocular lens implant during cataract surgery.
• Intraocular pressure in patients with glaucoma (high intraocular pressure) may be more difficult to measure accurately following LVC, so patients with glaucoma need to discuss this with their doctor.
• Certain autoimmune conditions including lupus, rheumatoid arthritis, and inflammatory bowel diseases may cause the cornea to become inflamed or weak, so LVC, which might further thin the cornea, may not be advisable. There are exceptions, so talk to your eye doctor.
• Pregnancy, lactation, or menopause may cause unpredictable corneal healing.
• Severely dry eyes-LASIK, and to a much lesser degree Surface Ablation, may cause dryness of the cornea, and a dry cornea will not provide the same crisp vision as a moist, smooth cornea. A severely dry eye may weaken vision. Most dryness, however, can be treated, and some form of LVC is possible in most cases.
• Certain drugs such as Imitrex for migraine, Accutane for acne, and Cordarone for heart problems may affect your candidacy for surgery by causing irregular healing of the cornea. The contraindications above are not absolute. A thorough understanding of your specific vision condition, accompanied by a discussion of all your options with your eye doctor, should enable you to decide whether LVC is still appropriate for you.

Surface Ablation Option

Your ophthamologist may recommend Surface Ablation instead of LASIK if you have one or more of the following conditions:

• Thin corneas
• Extremely flat or extremely steep corneas, both of which increase the likelihood of LASIK flap problems
• Extremely dry eyes, which can be aggravated by LASIK
• Extremely deep set eyes or very tight, slit-like lids, which can prevent the microkeratome from creating a good flap
• Loose epithelium (basement membrane dystrophy)
• Aberrations and other imperfections of the corneal surface Avoiding a flap complication is not possible in all LASIK patients. A LASIK operation perfectly performed by the most experienced and skilled surgeon can still result in an incomplete, thin, or irregular flap, leading to healing problems such as striae, folds, or even a slipped flap. The use of the IntraLase laser to create the flap has reduced but not eliminated flap problems. If your eye doctor feels that you are in one of the higher risk categories, it may be best to avoid LASIK and choose Surface Ablation instead. The actual laser treatment to correct your vision in both LASIK and Surface Ablation is the same. More importantly, the results are the same, so the extra healing time may well be worth the extra safety of Surface Ablation. Approximately 5% of patients fare better with Surface Ablation, while 95% are good candidates for LASIK.

It’s Up to You

Thanks to science and technology, your ophthalmologist now has the tools necessary to perform a thorough and comprehensive exam of your entire eye and cornea. Keratometry and pachymetry measure the curvature and thickness of your cornea, and the corneal topographer generates a detailed topographical map of its surface. The more advanced aberrometer reveals a diagnostic portrait of the imperfections and aberrations of your entire optical system. Once the data is reviewed, your ophthalmologist can discuss the suitability of your eyes for the operation. Just as Marcy Syms believes the educated consumer is her best customer, the educated patient, one who understands the procedure-what is done and why it works-and is fully cognizant of the potential for problems or complications, is the best patient. To become an educated patient is the reason you are reading this book! Having eyes suitable for LVC is only half the equation for a satisfied patient. The other half of the equation must be a realistic mind-set with regards to expectations and motivation.

If you expect perfect vision with LVC, with a guarantee of a life totally free of glasses or contact lenses, then LVC is not for you. Any patient who is considering LVC must be prepared to wear glasses parttime. Part-time may mean while driving at night, sitting in the bleachers at Yankee Stadium, or reading fine print, but anticipating the need to wear glasses occasionally is a realistic expectation. Not all LVC patients must wear glasses part-time (most do not), but planning for the possibility will prevent disappointment. Refraction, eye health, and corneal integrity are all factors used to determine whether vision surgery is an option for you, but a realistic expectation is an equally important factor. Wearing a pair of glasses only when driving at night or looking at a newspaper is a dramatic improvement over having to put glasses on every morning in order to see the alarm clock. Knowing this prior to surgery is the key to success.

LVC Operation Day

The preparation for LASIK and Surface Ablation is similar. Surgery is performed using anesthetic eye drops, is usually painless, and generally takes just a few minutes per eye. Having surgery on both eyes in the same day is more common with LASIK than with Surface Ablation, because the more rapid vision recovery of LASIK permits most LASIK patients to function normally the next day. Surface Ablation is often done on each eye a week apart, since vision can take that long to recover. Having PRK or epi-LASIK on both eyes at the same time may leave you too blurred to work for a few days, but some patients still prefer bilateral same-day surgery just to get everything done at one time. You and your eye doctor will have decided on separate or same day surgery ahead of time. It is a good idea to have a friend or relative accompany you home, especially if both eyes are done together. LVC is usually performed in your eye doctor’s office or in an open access laser center-an office where the laser is used by several eye doctors on the staff. A mild sedative, such as oral Valium, is often helpful to calm any last minute jitters and to make you more relaxed and comfortable during the procedure. Antibiotic drops are often started a few days prior to the procedure and continued for a few days after surgery. Contact lens wearers will have stopped wearing contact lenses for 1-2 weeks or up to a month or more-less for soft and more for gas permeable lenses. Contact lenses can alter the shape of the cornea, which, in turn, can alter your true refraction and reduce your chances for a successful outcome. Women should thoroughly remove all eye makeup several days before LVC. Perfume or cologne should not be worn on surgery day because fumes have the potential to alter the laser beam. Air quality, temperature, and humidity are tightly controlled in the room containing the laser.

A specially trained ophthalmic laser technician will operate the laser, and a second technician may assist the doctor. The untreated eye will be covered with an eye shield so only the eye receiving surgery can focus on the fixation light in the laser microscope without interference from the other eye. The operating microscope attached to the laser delivery console will give your ophthalmologist a clear, magnified view of your cornea throughout the procedure.

After several anesthetic eye drops are administered, an adhesive drape-usually made from clear surgical plastic-is taped over your eyelashes to prevent lashes or debris from falling on the surgical field and potentially causing an infection. An eyelid speculum-a springlike clamp-is painlessly positioned between your lids to keep your eyes open wide. You will be required to look at the fixation light in the microscope, relax, and keep your eyes open. Your cooperation will help ensure a smooth procedure. Remember, there is virtually no pain during any type of LVC.

After your eyelids are cleaned, the eyelashes draped, and the speculum inserted between your lids, one or more alignment marks are made on your cornea with a blue, washable marking pen. These marks overlap the flap edge, so when the flap is repositioned and smoothed down at the end of the treatment, the marks line up, ensuring that the flap is repositioned correctly. The alignment marks, mostly used in LASIK, are washed away by your tears in a few hours.

The LASIK procedure starts with the creation of the corneal flap by the automated microkeratome. Most microkeratomes consist of two parts-a suction ring that resembles a metal washer attached to a vacuum tube, and the microkeratome head that creates the flap and acts like a carpenter’s plane. In addition to raising the pressure inside your eye and making the cornea firm enough for the flap to be cut, the suction ring holds your eye perfectly still during the procedure and acts as a platform and track for the microkeratome. Once the proper suction is achieved, your doctor will use a small, plastic, cone-shaped instrument called a handheld tonometer to quickly ascertain that the intraocular pressure is sufficiently high to perform the operation. Flap problems, such as an incomplete flap, irregular flap, or a thin flap can occur if the pressure in the eye is not high enough. The increased pressure will cause your vision to darken for about fifteen seconds. Your doctor will ask if your vision is dark as a way to confirm the increased pressure before stepping on the microkeratome foot pedal to make the flap. There is no pain, only a sensation of pressure. When the flap is made with the IntraLase, there is less sensation of pressure and less chance of a flap problem. Once the flap is created, your eye is ready for laser treatment.

Depending on your eyeglass prescription and whether you are nearsighted or farsighted, the laser ablation can last anywhere from five to ten seconds to over a minute or two. As you continue to look at the fixation light, you will hear a clicking sound as the laser emits painless pulses of the cool laser light. Most excimer lasers have a tracker, so if your eye does stray slightly, the laser beam will stay centered on your cornea as it tracks your involuntary eye movement. A laser treatment that is not sufficiently centered can result in reduced BCVA, glare, halos, and distortion, so the tracker is an important improvement in LVC surgery. If your eye moves too much, the laser will automatically stop until you regain fixation on the target in the microscope. If you are having a custom ablation treatment (VISX Wavescan) the laser will also lock on to the architecture of your iris, further ensuring a centered treatment. The centration of the laser beam is calibrated each morning and its accuracy checked throughout the day. Throughout the treatment, your eye doctor will be monitoring your eye through the microscope. Once the ablation is completed, your eye doctor will precisely reposition the flap, using the alignment marks as a guide. He will have first gently irrigated beneath the flap, using a mild saline solution to remove any debris left by your tears, eyelids, or microkeratome. The flap is given a final smoothing with a miniature sponge that resembles a tiny paintbrush, and then allowed to dry for several minutes before the speculum between your eyelids is removed. The procedure is now complete.

If you are having surgery on both eyes, the newly treated eye is patched and the procedure is repeated on your other eye. You’ll be escorted to a dimly lit recovery room to relax, and your companion may rejoin you there. Most surgeons prefer that you keep your eyes closed in the recovery area so the flap can begin to stabilize and rebond to your cornea.

Each surgeon has his or her own protocol for surgery and the recovery period, which includes not rubbing your eyes and careful showering. I encourage my patients to keep their eyes closed or take a nap for an hour upon arriving at home in order to give the flap a chance to start healing. Most surgeons will provide their patients with a goody bag containing a plastic shield and tape to protect your eye during sleep (a good idea for at least the first night) and antibiotic and antiinflammatory drops.

The average patient is able to resume regular activities and return to work within twenty-four hours of the procedure. Avoid rubbing your eye for at least a week to prevent dislodging the flap. For a week or two following the operation, you should wear a headband at the gym to prevent sweat from entering your eyes. Avoid hot tubs and swimming pools because they are possible sources of contamination. Sports that may result in an eye injury, such as tennis and basketball, should also be avoided for a week or two. Noncontact sports, such as golf, cycling, or jogging can be enjoyed sooner.

Your eyesight will remain blurry for several hours immediately following the procedure, but a night’s sleep will usually improve vision dramatically. Though each patient is different and eye healing rate varies, even within the same patient, by the next day most patients will already be able to pass a vision test for driving-20/40 uncorrected vision.

PRK, Epi-LASIK, and LASEK

From the patient’s perspective, there is little difference between having LASIK and Surface Ablation because the laser ablation is the same in all three forms of LVC. The main difference for the patient is more discomfort after surgery and longer healing, both helped by oral medication, eye drops, and the bandage soft contact lens used at the conclusion of Surface Ablation. This contact lens is placed on your eye by the doctor or technician and acts as a bandage to cover your cornea while it heals. Surface Ablation, unlike LASIK, requires longer than twenty-four hours for vision to improve to the point where you can drive. In the end, the results are the same-welcome to a world without eyeglasses or contact lenses.

Understanding Risks and Complications

For the vast majority of the greater than one million patients undergoing LVC each year, the results will be everything anticipated-an uneventful procedure, rapid, predictable healing, and eyesight so good that glasses or contacts will be a thing of the past. For a small group of LVC patients, anywhere from 1%–5% of the total, the results may be slightly disappointing. Healing may take longer than expected, vision may not be as sharp as anticipated, and an enhancement or other surgical procedure may be necessary to fine-tune the results. Unforeseen side effects may occur. You should understand what side effects can occur, what can go wrong, and what the chances are of having a less than perfect result.

As we shall see, complications vary greatly and do not necessarily adversely affect the final outcome of LVC. For example, during LASIK, the surface epithelial layer of the cornea may loosen (epithelial slide) or partly fall off (abrasion) when the flap is made by the microkeratome. Although healing will be slower than if this complication had not occurred, the outcome is usually excellent. True complications- those events that can blur, distort, or cloud your vision and cannot be fixed by glasses or contact lenses are very rare, about one in ten thousand. Infection, which can leave your eye permanently cloudy and require a corneal transplant, is extremely rare, perhaps one in ten to twenty thousand. Your eye doctor will prescribe antibiotic drops before the procedure that will further reduce the risk of infection. The following list explains the most common LVC complications. The list is not complete, and some complications are so rare as almost never to occur, such as a patient dying from a fatal heart attack during LVC. I know of no such occurrence, but it is possible, as in, “anything is possible.” But even the most common complications are unlikely to occur in the average patient. Complications that cause loss of best corrected visual acuity (BCVA) are more serious than other complications. Doctors worry less about complications that are correctable with glasses or contact lenses than about those complications that leave the patient with permanent, uncorrectable loss of vision, however mild. If a patient is expecting 20/20 after LVC, disappointment may occur if uncorrected vision is less than this. But if glasses or contacts can correct vision back to 20/20, there has not been a loss of that all important BCVA. In almost all instances, the eye will remain as healthy as before LVC, and glasses will likely be needed only part-time at most, or not at all.

Under-and Overcorrections

Undercorrections and overcorrections are not really complications, because an LVC procedure can be technically perfect but your cornea may respond more (overcorrection) or less (undercorrection) than in other patients. An under-or overcorrection results in retention of some degree of a myopic, hyperopic, or astigmatic refractive error following surgery. An undercorrection may not noticeably affect your vision and may only appear when you look at the eye chart during a follow-up exam. In some cases-such as nearsighted patients over forty-an undercorrection may be desirable, delaying for several years or more the need for reading glasses. Undercorrections are more likely in patients with higher levels of myopia, hyperopia, or astigmatism. The significance of an over-or undercorrection depends upon many factors, including your initial refraction and your age. If a –8.00 D myope has LVC and is undercorrected by only half or three-quarters of a diopter, it means that almost 95% of the –8.00 D refractive error was corrected, and the undercorrection may be of little or no consequence. On the other hand, if a –1.50 D myope retains the same –0.50 or –0.75 D undercorrection, only 50% of the refractive error would have been corrected-an unacceptable result for both patient and doctor. In these two examples, an overcorrection would result in a refractive error of +0.50 D or a +0.75 D. Whether or not retaining +0.50 D or +0.75 D would have a significant effect on vision depends more on the patient’s age than on the original refractive error.

For a twenty-five-year-old patient, the extra focusing required to correct the small amount of induced hyperopia would be effortless and automatic because more than enough reserve focusing power remains in the eye of a twenty-five-year-old. In fact, the same patient would be unaware of the overcorrection, would have 20/20 uncorrected vision, and would be quite satisfied. A forty-five-year-old patient, whether originally a –8.00 D or –1.50 D and ending up overcorrected to a refractive error of +0.50 D or +0.75 D, would be less happy compared to the twenty-five-year-old patient. At forty-five, the reserve focusing power is very low, and reading glasses would be required to correct the sudden burden of overcorrection and hyperopia. It is often more desirable to err on the side of an undercorrection in a forty-five-year-old to avoid overcorrecting.

In monovision, one eye of a myopic patient is intentionally left slightly nearsighted in order to give some reading vision for items such as a menu or price tag and to avoid reliance on reading glasses. Similarly, a +2.00 D forty-five-year-old hyperope might aim for an overcorrection to –1.00 D in one eye, so reading glasses would not be necessary except for small print. A +4.00 D hyperope would probably not be able to have monovision, because LVC is not as reliable over +4.00 D, and the treatment programmed into the laser would have to be at least +5.00 D for the +4.00 D patient to end up –1.00 D. The subtle nuances of over-and undercorrection should be discussed with your doctor. The higher your prescription, the higher the chances of over-and undercorrection but in the average patient the chances are usually less than 5%.

If you are unhappy with over- or undercorrected vision, you will need a second procedure known as an enhancement. Myopes with a slightly thin cornea may not have enough residual thickness for an enhancement following an initial LASIK operation. Enhancement procedures almost always follow the same pattern as the initial LASIK. Rather than cutting a new flap, the surgeon breaks the seal of the original flap and lifts it up and out of the way for the new laser treatment. Once this additional laser ablation is completed, the flap is replaced as in the original treatment. Occasionally, PRK or LASEK is performed as an enhancement for LASIK. If your original procedure was PRK or LASEK, the same procedure will usually be used for the enhancement operation, although LASIK can often be done instead. Enhancements carry the same low risk of infection as the original procedure, but the risk of epithelial ingrowth is higher.

Regression

Regression is the tendency for the eye to drift back toward its original refractive error-a delayed undercorrection. In most cases, this drifting back is minimal, and you need not worry that you will suddenly find yourself back at your original refractive error. Regression can occur as early as one or two months after the original surgery or more than a year later. The higher your refractive error, the greater is the chance for regression. That is why a –6.00 D myope with immediate post-surgery results of +0.50 D, will probably suffer a slight regression of 0.50 diopters and will finish happily with a zero refractive error. If the regression is significant, an enhancement procedure can be performed.

Glare Disability-Starbursts and Halos

Glare disability refers to a problem with light at night, such as seeing starbursts and halos while driving or looking at any light source in the dark. Glare disability can be a serious problem after LVC, making a patient with perfect 20/20 vision unhappy. The cause of halos and starbursts is somewhat controversial and was initially thought to be due to large pupils in the dark, such as at night. However, many patients with large pupils have no glare problems, and some with small pupils do. The cause may be in the centration of the laser treatment over the pupil, and the smoothness of the laser treatment itself. Glare disability, starbursts, and halos are much less common now, because surgeons more carefully measure pupil size before surgery and use smoother, wider laser treatment zones. For example, if the pupil dilates to 8 mm in the dark and the laser treatment or ablation is 6 mm, light from headlights and streetlights will hit the edge of the lasered/unaltered cornea and be diffracted into starbursts or halos. In daylight or in a lighted room, the pupil will usually be smaller than the 6 mm ablation zone, so glare disability is not an issue.

Besides correcting your vision, most laser treatments now smooth out the transition zone between the lasered and unlasered part of your cornea. This minimizes any glare that may occur if your pupil dilates too much at night. In general, glare is more of an issue with myopes, and the higher your prescription, the more likely it is that you may have some glare.

For patients with large pupils, custom ablation may be advisable because glare is less likely with a custom laser treatment (Chapter Nine). Ophthalmologists debate the relationship between glare and pupil size, but it is still a good idea to be aware of this issue before you decide to have LVC.

Other factors can also cause glare. Rarely, the cornea heals abnormally, causing the surface of the cornea to be irregular. If the eye drifts off-center during the procedure and if the ablation is not sufficiently centered on the cornea (decentered ablation), glare or poor vision may result. However, precise eye trackers on the laser make a decentered ablation much less common now.

Whatever the cause, glare disability in the form of starbursts and other annoying reflections often disappear in three to six months after LVC. If symptoms persist, new approaches using WaveScan-driven laser treatments promise to help these patients.