Laser Vision Care FAQ

How do I prepare for my procedure?

There are no restrictions on eating, drinking or medications immediately prior to your procedure. However, you should avoid alcohol and medications that cause drowsiness.

Contact lenses change the shape of your cornea. Since this is the area that's treated, it's important to allow time for your cornea to return to its normal curvature.

Removing Contact Lenses

  • Soft contact lenses should be removed at least 72 hours (3 days) before your procedure.
  • Hard or gas permeable contact lenses should be removed at least 4 to 6 weeks before your procedure.
  • Patients who have worn rigid contact lenses for over 20 years may need to remove them for up to 8 to 12 weeks.

Your eye doctor can help you make this determination and even fit you with disposable contact lenses or glasses in the interim.

Is it covered by insurance or flexible benefits programs?

Most insurance companies do not cover LASIK and PRK, but we encourage you to check with your provider. While LASIK and PRK are often deemed elective and not covered, they may be tax deductible depending on your filing status. Please consult your accountant. In the U.S., if your company has a flexible benefits program you can usually include LASIK and PRK in it. Also, your center can discuss the many financing options we make available to you.

How can it change my life?

This remarkable procedure takes only a few minutes to perform, but can have a tremendous impact on your life. Before having laser vision correction, most of our patients couldn't imagine waking up in the morning and seeing the alarm clock. They never dreamed they'd be able to drive a car, watch a movie, or enjoy sports such as swimming and skiing without contacts or glasses. For many, poor eyesight had even been a barrier to entering the career they wanted. Since they were children, this dependence on glasses and contacts has shaped their lives, memories, and the way they feel about themselves.

Now, these same patients are pursuing life with new confidence, enthusiasm, and ease thanks to laser vision correction. Their dependence on glasses and contacts for distance vision has been significantly reduced, and in most cases eliminated entirely.

What kind of results can I expect?

While laser vision correction has proven overwhelmingly successful in reducing dependence on glasses and contact lenses, the degree of improvement may vary from individual to individual. How well and how quickly your vision improves depends on how well you heal and the severity of your prescription.

Although we can't promise patients "perfect" or 20/20 vision, most laser patients with mild to moderate prescriptions do achieve 20/20 vision or are within I to 2 lines of 20/20 vision on an eye chart. This means they no longer need glasses or contacts to drive, play sports, watch movies and TV, or participate in careers requiring excellent vision such as police and fire departments.

With these remarkable results, and an exceptional safety record, laser vision correction is considered the procedure of choice for most suitable candidates.

During your pre-procedure consultation, your doctor will help determine the range of your probable outcome - based on your particular prescription, healing profile and expectations. The results and research gained from tens of thousands of procedures are shared throughout our network, allowing doctors to continually fine tune techniques, more effectively forecast visual results, and counsel new patients.

Will my vision be corrected forever?

People often ask how long the benefits of their procedure will last. Laser vision correction has been common in many countries around the world since the late 1980's. In addition, many clinical studies have looked at the long-term effects of the excimer laser on the cornea. While the long-term effects beyond six years have not been studied, every study performed so far has shown without exception that there are no long-term negative effects of the laser on the eye's integrity or strength.

The first nearsighted patient's eye ever treated with laser vision correction was in the United States in 1987. That patient achieved 20/20 vision following treatment and is still 20/20 more than a decade later.

Today, most experts around the world are confident that they will discover no long-term problems with laser vision correction. They also believe, based on the excellent results seen to date, that laser vision correction will become the most commonly-performed refractive procedure in the world.

What will my recovery be like?

Most patients notice dramatic visual results within the first few days following their procedure. However, the speed of visual recovery depends on personal healing patterns. LASIK patients usually see quite well the next day, but patients with higher prescriptions may recover more slowly from either procedure.

PRK patients are fitted with a bandage contact lens. This very thin, clear lens, along with eye drops, dramatically reduces any discomfort you may have. Don't be concerned if you've never used contact lenses before. We will insert and remove the lens for you. PRK patients may experience some irritation or discomfort for a few days. Sleep is strongly recommended shortly after your procedure.

LASIK patients do not receive a contact lens. They may receive an eye patch to protect the flap while sleeping during the first few days. LASIK patients may experience some irritation or discomfort, but this usually only lasts for a few hours. Sleep is strongly recommended after the procedure, and most patients are quite comfortable after taking a short nap.

Along with resting, both LASIK and PRK patients often find that placing a cold compress over the eyes is soothing.

What is a PRK procedure like?

PRK is a painless, outpatient procedure that usually takes about 10 minutes to perform. During PRK, computer-controlled pulses of cool laser light are applied to the surface of your cornea to delicately reshape your eye's curvature. Your cornea's new curvature is shaped to duplicate your contact lens or glasses prescription. This allows you to reduce or eliminate your dependence on glasses or contacts.

To effectively reshape your cornea, your doctor will gently remove the protective surface layer (epithelium) from the eye. This epithelial layer is regenerated within three to five days.

The laser process is completed in approximately 30 to 60 seconds. A clear "bandage" contact lens will be placed on your eye and you'll receive additional eye drops. The bandage lens is usually worn for three days, and then removed by your doctor. After the PRK procedure, your eye may feel irritation or a foreign body sensation for a few days, but this discomfort can usually be effectively managed with medication if needed.

Should you treat one eye or both eyes on the same day?

The decision to have both eyes treated the same day depends on various factors and the final determination should be made in consultation with your eye doctor and your surgeon.

Although it is always safest to treat one eye at a time, our patients cite many advantages to having both eyes treated the same day. These include convenience, possibly less time off from work, improved balance between your two eyes, improved vision, and less chance of night glare. In our experience, most patients prefer to have both eyes treated the same day, or within a few days or weeks of each other.

Why have I always had poor vision?

Certain vision problems, such as nearsightedness (myopia), farsightedness (hyperopia), astigmatism and presbyopia are considered "refractive" because they relate to your eye's ability to properly bend (or refract) light rays entering the eye. The proper refraction of light onto the retina creates "normal" eyesight. Refractive visual problems are measured in units called diopters. Diopters represent the level of correction needed in lenses to normalize vision. The more nearsighted or farsighted you are, the higher your prescription in diopters.

Myopia

More than 70 million people in North America (about one in four) are nearsighted. Myopia is the medical term for nearsightedness. It occurs when your eye is too long in relation to the curvature of your cornea. Myopia causes light rays entering the eye to focus in front of the retina, producing a blurred image.

The term "nearsighted" means that you can see objects that are "near" to you more clearly than distant objects. The more myopic you are, the more blurred distant objects appear, the higher your prescription in diopters, and the thicker your glasses.

Hyperopia

Hyperopia is the medical term for "farsightedness." Hyperopia occurs when your eye is too short in relation to the curvature of your cornea. Light rays entering your eye focus behind the retina, producing a blurred image. Some farsighted people can use their focusing muscles to pull the image forward onto the retina, allowing them to see clearly. But others who cannot overcome the effects of severe hyperopia, need reading glasses or bifocals.

Astigmatism

Many patients with myopia and hyperopia have some degree of astigmatism, or ovalness, to their cornea. It occurs when your cornea is shaped more like a football than a basketball. As a result, you experience distortion or tilting of images due to the unequal bending of light rays entering your eyes. People with high degrees of astigmatism have blurred vision for both near and distant objects. Astigmatism is also measured in diopters.

Presbyopia

Presbyopia is part of the normal process of aging. It develops as the lens of the eye loses some of the flexibility that characterizes a younger eye. Everyone experiences the effects of presbyopia, typically between the ages of 40 and 50. Nearsighted people who become presbyopic may require bifocals in their forties, and those who never needed glasses before may require reading glasses.

Mild myopia counteracts presbyopia. That is why, if you're slightly myopic, you can remove your glasses and still be able to read, even after presbyopia sets in. After having laser vision correction, your myopia may be gone, and you will need reading glasses for fine print to correct your presbyopia like other normally sighted individuals.

Since the excimer laser has no effect on your lens or your focusing muscles, it cannot be used to treat presbyopia. However another solution - monovision - can often help.

Will it hurt?

The LASIK and PRK procedures themselves are completely painless. There are no needles. Instead, anesthetic drops are used to numb the eye just before surgery begins. After your LASIK procedure, your eye may feel a foreign body sensation or irritation for a few hours, but most patients are quite comfortable after taking a short nap. Dryness in your eyes can last for several days. Following a PRK procedure, you may experience irritation for several days.

What is laser vision correction and what problems can it correct?

With the advent of laser technology, vision correction has entered a new era. Today, laser vision correction is recognized as the most important development since the introduction of the contact lens three decades ago. Correction of nearsightedness, farsightedness and astigmatism with the excimer laser is the most technologically advanced method available to reduce your dependence on glasses and contact lenses. This exciting refractive technology uses a cool laser beam of light to gently reshape the front surface of your eye. Over one million laser vision correction procedures have been performed, in 52 countries around the world, for more than a decade.

Laser vision correction has been used since the late 1980's to successfully correct nearsightedness (myopia) and astigmatism. Two laser vision correction procedures, LASIK (Laser In Situ Keratomileusis) and PRK (Photorefractive Keratectomy) are available. Unlike the PRK procedure, the use of the excimer laser for LASIK has not been specifically approved by the U.S. Food and Drug Administration (FDA) in the U.S. However, the doctor and patient are free to choose the LASIK procedure, and it is the most frequently performed procedure at our centers today. Both PRK and LASIK are compared in detail later.

What happens on my day of my procedure?

It's natural to feel a mixture of eager anticipation and nervousness before your procedure. On the day of your procedure, you should arrive at the center as rested and relaxed as possible. Please allow approximately two to four hours for the entire process. Wear comfortable clothing and avoid eye makeup, perfume, hair spray and earrings. Be sure to bring someone to drive you home, or make other arrangements for transportation.

The success of your laser procedure depends on the expertise of your doctors and also the safety, accuracy and sophistication of the equipment. Our primary objective is to provide you with the most advanced technology, best results, and greatest degree of safety. Automated equipment is used to test your vision, measure, and map your eye. Over 6,000 separate points on the eye are measured - creating a topographical map of your eye's shape.

We will review your clinical findings and explain what you can expect during and after your procedure. You will need to sign an informed consent prior to your procedure which we will go over with you. Most importantly, you will meet with your surgeon to discuss any remaining questions or concerns. You will also arrange for payment of your procedure.

Immediately prior to your procedure, your eyelids and lashes will be cleaned and antibiotic, antiinflammatory, and anesthetic drops will be placed in your eyes. A mild sedative may be given. Once you are prepared for your procedure, you will be escorted to the laser suite for treatment.

The information from your eye exam is used to program the advanced computer software. The computer calculates the required corneal change and directs the laser to make this change. Your surgeon programs and operates the laser, maintaining control throughout your entire procedure.

What is a LASIK procedure like?


1. Anesthetic drops are
applied to the eye.

2. A hinged flap is created by
the surgeon and folded back.

3. The inner corneal layer
is reshaped with the laser.

4. The surgeon closes the flap.

5. The flap adheres naturally
and securely.

LASIK is a painless, outpatient procedure that usually takes about 10 minutes to perform. During LASIK, the surgeon first creates a protective corneal flap revealing the inner corneal tissue. This flap is now created using a laser known as Interlase.

This protective flap is temporarily folded back, and computer-controlled pulses of cool laser light are applied to the inner layers of your cornea. The inner layers are gently reshaped to duplicate your contact lens or glasses prescription. This allows you to reduce or eliminate your dependence on glasses or contacts. The flap is closed and heals naturally and securely.

Surgical skill is a key component in the creation of the corneal flap, and the experience and success of our surgeons with this procedure is unsurpassed. Because the surface layer (epithelium) of the cornea is preserved, discomfort following LASIK procedures is much less likely.

After the LASIK procedure, your eye may feel irritation or a foreign body sensation for a few hours, but most patients are quite comfortable after taking a short nap. Dryness in your eyes may last for several days.

How can monovision delay my need for reading glasses?

When you have laser vision correction, one eye can be intentionally left slightly nearsighted. This is called monovision, and it allows you to maintain your ability to read after presbyopia begins. Your other eye will be fully corrected for distance vision. Gaining this near vision means giving up some distance sharpness. (Many people have already elected monovision correction with their contacts or glasses.)

Monovision is helpful for near-tasks such as reading your watch, opening the mail, scanning a menu or article, but not for reading fine print or reading for a prolonged time. Almost everyone will require reading glasses at some point. For active individuals, such as those who play golf or tennis, or who drive a great deal at night, monovision may not be suitable.

Fully correcting both eyes for optimal distance vision will help avoid the need for driving glasses, but reading glasses may be required. During your consultation, you and your eye doctor can decide which choice is best for you.

Am I a good candidate?

Yes, if you're at least 18 years old, in good general health, and have good eye health with no diseases such as cataracts or glaucoma. Laser vision correction can treat a very broad range of nearsightedness, astigmatism, and farsightedness. In most cases, even patients with the most severe degrees of nearsightedness, astigmatism, and farsightedness can be treated. Good candidates have realistic expectations.

To find out if laser vision correction is right for you, talk with your own eye doctor. Alternatively, you may schedule a consultation at a nearby center. At the consultation your doctor will confirm if you are a good candidate for laser vision correction, explain the procedure, and answer your questions so that you can make an informed decision. He or she will explain what results you can reasonably expect by measuring your prescription and thoroughly examining your eyes. Even if you're not a candidate now, you may become one in the future.

Laser vision correction isn't for everyone. Some patients (for example those with corneal or retinal diseases) will never be candidates. The best way for you to determine this is with a thorough exam from your eye doctor.

Will my activities be restricted?

Many patients return to work the next day, others a few days later. You will need to restrict the activities mentioned below. Otherwise, as long as you follow your doctor's instructions, you should be free to resume all your normal activities.

  • Wait one full day before taking a shower.
  • Resume driving after one day to one week, as your doctor advises.
  • Sunglasses should be worn for the first few days.
  • Read and watch TV in moderation the first few days.
  • Do not wear eye makeup for one week.
  • Do not rub your eyes for one week.
  • Do not exercise for one week.
  • Avoid swimming, hot tubs, and whirlpools for one week.
  • Avoid gardening and dusty environments for one week.
  • Avoid contact sports that could result in an eye injury for one month.
  • Smoking is allowed, but you will probably find smoke very irritating.

What kind of follow up care will I need?

After LASIK
1 day
1 week
1 month
3 months
6 months
12 months
After PRK
1 day
2 days
3 days
1-2 weeks
1 month
2 months
3 months
4 months
6 months
12 months

Follow-up care and eye medications are just as important to your results as your actual procedure. Ideally, this care can be provided by your own eye doctor, but it may also be performed at the center. Periodic examinations are required to ensure that your eye is healing as expected and there is no evidence of infection, and to measure your visual progress. You must also use prescribed antibiotic and antiinflammatory eye drops during your recovery. LASIK patients use drops for four to seven days, and PRK patients continue drops for one to four months, depending on their prescription. PRK patients only must have the bandage contact lenses removed on the third day. Each appointment takes about five to 15 minutes.

Eye Exams Are Important: We strongly recommend that everyone, not only laser vision correction patients, have a dilated eye exam performed by their eye doctor every year. This is a proactive way to ensure that your eye is healthy and functioning properly. The retinal portion of the exam is especially important if you are nearsighted, since nearsighted eyes are at greater risk of retinal disease.

What's the difference between LASIK and PRK?

LASIK and PRK are both effective laser procedures for the correction of nearsightedness and astigmatism. Some doctors and patients are comfortable with the PRK procedure. However most doctors and patients prefer LASIK because of the following advantages:

  • Faster visual recovery
  • Less risk of discomfort after surgery
  • Less risk of infection
  • Less risk of corneal haze or scarring
  • Less need for anti-inflammatory eye drops
  • Fewer post-operative visits
  • Ability to treat a wider range of prescriptions

Since the surface of the cornea (epithelium) is preserved, LASIK patients see well the day following their procedure. PRK patients require about three days for the epithelium to heal and allow clearer vision. Although these differences in healing patterns exist, patients can feel comfortable in their choice of either procedure. Your eye doctor, together with your surgeon, will help determine the most suitable procedure for you, based upon your examinations and consultations.

How does the excimer laser work?

The excimer laser was invented to etch microchips more than two decades ago at IBM's Watson Laboratories. Subsequently, the remarkable discovery was made that the excimer can also be used to re-sculpt human tissue, particularly the cornea, with a great degree of precision.

Today, the excimer provides accuracy, predictability, and the capability to correct a wide range of refractive errors. This Argon-Fluoride gas laser emits computercontrolled pulses of cool ultraviolet light with an unparalleled degree of precision. Each pulse of the excimer laser can remove 39 millionths of an inch of tissue in as little as 12 billionths of a second. In fact, the excimer laser can remove as little as 1/40 of a human cell. This precision leaves the integrity of the eye unchanged. The excimer works by breaking molecular bonds. It is the ability of the excimer laser to remove a single cell without damaging the remaining cells that allows doctors to perform laser vision correction with precision. We perform two procedures with the excimer laser: LASIK and PRK. Both procedures can achieve the same results, but employ different methods.

Are there any risks?

The chance of having a vision-reducing complication has been documented in a number of clinical studies to be less than 1%. There have been no reported cases of blindness resulting from PRK or LASIK.

Expectations

While only a very small number of patients experience a complication, all patients have certain expectations. It is vital to make sure that those expectations are realistic, before proceeding with PRK or LASIK.

The most common expectation is to become free of glasses and contact lenses. While it is true that all patients who undergo laser vision correction significantly reduce their dependence on glasses and contacts, most patients will eventually require reading glasses, and some may even require a thin pair of glasses for critical distance activities such as night driving. It is best for you to think of laser vision correction as a procedure that reduces your dependence on glasses or contacts.

Under-correction and over-correction

There are two phases to your procedure: the surgical phase and the healing phase. Both are equally important to your outcome. The speed of visual recovery, the quality and sharpness of your vision, and your final outcome will be determined by your healing pattern, pre-operative prescription, ocular findings and corneal shape. Typically, distance vision clears first, followed by reading vision.

The more severe your initial prescription, the more correction you will need, the more healing you will require, and the greater the chance you will not be fully corrected in just one procedure. Enhancement procedures usually are performed a minimum of one to four months after the initial LASIK procedure, and a minimum of four to six months after the initial PRK procedure. We estimate that about 10% of patients require a second procedure to enhance their final results. On the other hand, some patients experience an overresponse or over-correction, leaving them somewhat farsighted. In FDA trials, less than 1 % of PRK patients experienced signiflcant over-correction or undercorrection,

Infection

Infection rarely occurs since patients receive antibiotic drops both before and after the procedure. Following your prescribed eye drop regimen is very important. Most minor infections are treated easily, but should be treated quickly. The risk of infection is greatest 48 to 72 hours following the procedure. In FDA trials, less than I% of PRK patients experienced infection.

Healing haze

Healing haze is a term for the collagen protein that develops on the surface of your eye following PRK. Almost everyone develops trace amounts of haze. It is invisible to the naked eye and usually patients are not even aware that they have haze. Healing haze clears gradually over the months following your procedure, and can be reduced by using antiinflammatory eye drops. Patients with a history of keloid formation, poor healing, or with high prescriptions, are at greater risk for healing haze and are best treated with LASIK. In FDA trials, less than 1% of PRK patients experienced haze.

Night glare

Even before having laser vision correction, many people experience poor night vision or night glare such as haloes and starbursts. Night glare is common immediately following the procedure and lasts for about three or four months.

If you treat one eye at a time, or are extremely nearsighted with large pupils, you may notice night glare for a longer period. By the time both of your eyes are treated, or six months have passed, night glare tends to decrease to minimal levels. Some patients may benefit from glasses when driving at night. In FDA trials, this condition occurred in less than 4% of PRK patients. The risk is significantly reduced with LASIK.

Loss of best corrected vision

A small number of patients experience a slight loss of visual sharpness following laser vision correction. You may lose the ability to read the bottom few lines of the eye chart which you could read with your glasses before the procedure. In many cases, sharpness improves over a period of six to 12 months. In some instances, patients' natural vision following the procedure is actually better than their pre-procedure best-corrected vision was. In FDA trials, less than I% of PRK patients experienced a loss of best corrected vision.

Corneal flap risks

While LASIK offers a faster recovery, this procedure does have specific risks due to the creation of a corneal flap. A corneal flap which is irregular, too short, or too thin, can prevent the procedure from being completed. In such a case, the corneal flap is closed, and the eye allowed to heal. Three to six months later, the procedure can be performed.

As long as the corneal flap heals smoothly, patients can achieve an excellent result. However if irregularities in the flap persist, a loss of best-corrected vision may result.

Other corneal flap risks include displacement of the flap and epithelial ingrowth. Epithelial ingrowth means that epithelial cells grow beneath the corneal flap prior to the sealing of the corneal flap margins. Although most cases do not require any treatment, severe epithelial ingrowth can disrupt corneal flap integrity. It is usually treated within one month by lifting the flap and cleaning the area.

Pain or discomfort

There is no pain during the actual PRK and LASIK procedures, but some irritation or discomfort may be experienced after surgery. PRK patients may experience some irritation, sensitivity to light, and watering or swelling of their eyes for a few days following the procedure. For LASIK patients, irritation, if any, usually lasts only for a few hours. A relatively small number of PRK patients experience severe discomfort, which usually can be treated with medication.

Actual outcome data for LASIK is not available because it is currently under investigation by the FDA. Ask your eye doctor for the latest information.

How does my eye work?

The primary function of your eye is to focus light. You need glasses or contact lenses when your eyes cannot focus light properly.

Your eye works like a camera. Light rays enter the eye through the cornea, which provides most of the focusing power. Light then travels through the lens where it's fine-tuned to focus properly on the retina on the back of the eye.

The retina acts like film in the camera. Light is changed by the retina into electric impulses that are carried by the optic nerve to the brain. Light must be focused precisely on the retina for you to see clearly.

A brief description of the various parts of the eye follows. This will help you better understand the terminology and process behind different vision correction procedures.

 


Anatomy of the eye

A Glossary of Terms

Cornea

The cornea is sometimes referred to as the "window of the eye." It provides most of the focusing power when light enters the eye. The cornea is composed of five layers of tissue. The outer layer (the epithelium) is the eye's protective layer. It is the cornea which is sculpted in both PRK and LASIK.

Pupil

The pupil is the "black circle" in your eye. The primary function of the pupil is to control the amount of light entering your eye. When you are in a bright environment, the pupil becomes smaller to allow less light to pass through. When it is dark, the pupil expands to allow more light to reach the back of your eye.

Lens

The lens is the clear structure located behind the pupil. Its primary function is to provide fine-tuning for focusing and reading, which it accomplishes by altering its shape. At the age of 40 to 50, the lens becomes increasingly rigid and presbyopia sets in, usually making reading glasses necessary. As you age beyond 60, the lens becomes progressively cloudy and hard. Cataracts may form and this clouding may eventually interfere with your vision.

Iris

The iris is the colored part of your eye. The primary function of the iris is to control the size of the pupil. This is achieved through contraction or expansion of the muscles of the iris.

Retina

The retina consists of fine nerve tissue that lines the inside wall of the eye and acts like the film in a camera. Its primary function is to capture and transmit images.

Optic Nerve

The optic nerve carries images to the brain.

Sclera

This is the "white part" of your eye. The sclera's purpose is to provide structure, strength, and protection for your eye.

Vitreous Gel

This is the clear "gel-like" substance located inside the eye's cavity. It provides the spherical shape to your eye.

Welcome to the Toronto Eye Clinic Laser Vision Care FAQ