LASIK MD Laser Eye Surgery – LASIK Information Booklet

Thank you for choosing LASIK MD for your laser vision correction. We understand that this is an extremely important decision that could alter your life immeasurably. Like many patients, you may be feeling excited about the prospect of being freed from dependency on glasses or contacts, but you may also have questions about the procedure that you will be undergoing. In this package, we attempt to answer some of those questions, providing you with information about the benefits, potential complications, and steps of the procedure.

ABOUT LASIK MD

LASIK MD is Canada’s leading laser vision correction team. Our mission is to deliver premium quality care, using the highest surgical standards and the latest technology, at an affordable price.

The Role of the Medical Team

Your surgeon (ophthalmologist) and your optometrist are trained health care professionals experienced in the pre-operative, operative and post-operative management of LASIK and PRK. The Clinical Assistants are extensively trained in ophthalmic medical assisting. They perform a variety of pre- and post-operative tests and act under the supervision of the ophthalmologist.

Surgeon
Your surgeon has a Doctor of Medicine (MD) degree and is highly experienced in the medical and surgical management of refractive errors and eye diseases. In addition to four years of university, your surgeon has spent four years in medical school, followed by a 5-year residency in Ophthalmology.  

Optometrist
Your optometrist has attended four years of optometry school, has attained a Doctor of Optometry degree, is highly trained in diagnosing and treating refractive errors by non-surgical means, and has experience in providing post-operative care for LASIK and for PRK. Your optometrist, who will communicate closely with your surgeon to ensure the best possible surgical result, may be able to assume responsibility for your care as early as the day following surgery.

LASIK MD doctors have performed over 450,000 laser vision correction procedures across Canada, offering both LASIK (Laser In-Situ Keratomileusis) and PRK (Photorefractive Keratectomy). LASIK and PRK are referred to, collectively, as the “procedure” in the following materials, and are briefly described in the following sections.

Please read all of the material in this package carefully. Remember that we provide this package in addition to, but not as a replacement for, discussions with your surgeon and optometrist. In addition to speaking with the surgeon and optometrist, you may find it helpful to consult our Web site, at www.lasikmd.com, or to contact one of our consultants at 1 (866) 366-2020 if you have any other questions.

Please keep in mind that our Patient Care Representatives are not trained to give a medical diagnostic or to determine the specific price of a surgery. Pricing will vary depending on your prescription and the condition of your eyes. Specific pricing will be given to you following a series of painless tests at your pre-operative examination.

The eye is like a camera. The cornea is the clear, dome-shaped window that forms the front wall of the eye. The retina is the tissue in the back of the eye that acts like the film in a camera. The cornea at the front of the eye acts as a lens that focuses light onto the retina, producing an image on the retina that gets transmitted to the brain and interpreted as vision. The curve of the cornea determines the power of the corneal lens and whether the incoming light rays from distant objects focus directly onto the retina.

WHAT IS 20/20 VISION?

20/20 is a measurement of how clear your distance vision is. If your standard vision test reports 20/20, it means that you are able to see clearly at 20 feet what a person with normal vision can see clearly at 20 feet. On the other hand, if you have 20/40 vision, it means that you need to stand as close as 20 feet to see what a person with normal vision can see clearly at 40 feet.

REFRACTIVE ERRORS

When light does not focus directly on the retina, the eye has a refractive error. This means that with the appropriate “refractive correction” lens, incoming light rays become focused onto the retina producing clear vision.

Myopia (Nearsightedness)

In myopia, the eye is longer than normal, preventing light rays from focusing directly on the retina. The light rays come together at a point in front of the retina, and are out of focus on the retina. Distant objects are blurred, while nearby objects can be clear.

Hyperopia (Farsightedness)

In hyperopia, the eye is shorter than normal. The light rays come together at a point behind the retina, and are therefore out of focus on the retina. Nearby objects can appear blurry, while distant objects are clearer. Very farsighted patients will report that even distant objects appear blurry.

Astigmatism
In the normal eye, the cornea is curved the same in the horizontal and vertical directions, like a baseball. When light rays hit the cornea, they focus at a single point. In astigmatism, the curve of the cornea is not the same in the horizontal and vertical directions. The cornea looks like a football, with a steep curve on one side and a flat surface on the other. As a result, light rays entering the cornea do not focus at a single point, causing distorted vision. Most people with myopia or hyperopia have some degree of astigmatism. 
 

In all of these conditions, the person needs some type of corrective lens, such as glasses or contact lenses, to focus the light properly. LASIK and PRK are used to change the shape and curve of the cornea in order to correct or reduce these types of refractive errors.

LASIK

 
LASIK is a form of eye surgery in which a surgeon uses a precise flap-making instrument, called a keratome, to create a thin flap of corneal tissue. This flap is raised and laid back while still attached to the cornea.

The surgeon then uses a state-of-the-art excimer laser to remove a pre-determined amount of corneal tissue from the exposed bed of the cornea. The amount of tissue to be removed is calculated based on the pre-operative determination of the power of your eye; these measurements are usually in agreement with recent prescriptions for your glasses and/or contact lenses.

The flap is replaced and within minutes natural forces hold the flap down on the cornea. Usually, within a few hours, the surface layer of the cornea (epithelium) begins to grow over the cut edge of the flap to seal it into position. Within days, collagen bonds form within the cornea around the edge of the flap, permanently sealing it.

LASIK can be used to correct nearsightedness ( myopia), farsightedness ( hyperopia), and astigmatism.

PRK

PRK is a form of eye surgery in which a surgeon removes the surface layer of the cornea (called the epithelium) and then reshapes the corneal bed with the laser in the same way as LASIK. This technique is usually used for people whose cornea may be too thin to safely allow for the creation of the corneal flap required for LASIK.

The procedure is used to correct nearsightedness ( myopia), farsightedness ( hyperopia) and astigmatism.

For more information on Bausch & Lomb Zyoptix LASIK or PRK, please refer to the Customized Vision Solutions section of this document.

At LASIK MD, we can also offer customized vision solutions such as Zyoptix LASIK and the Zero Compression Hansatome Keratome. 

BAUSCH & LOMB ZYOPTIX LASIK 

STANDARD LASER TREATMENT ( LASIK or PRK vs. ZYOPTIX LASER TREATMENT

If you have a higher prescription, thin corneas and larger than the average pupils, then Zyoptix may be the technology best suited for your eyes and needs. For standard LASIK or PRK patients, you are also eligible for this latest technology for your laser vision correction treatment.

Rest assured that whichever laser eye correction procedure you choose, you have the experience and expertise of a surgeon that ensures the best possible vision results. You can also feel comfortable in knowing that thousands of patients have successfully undergone this procedure before you, and are delighted with their newfound vision.

THE ZYOPTIX ADVANTAGE

Latest state-of-the-art technology

• The Bausch & Lomb laser is the newest technology available in the world manufactured by precise German engineering.
• This latest technology is from Bausch & Lomb, the world leader in laser vision correction technology.


Increased Accuracy and Safety for Better Results

• The laser removes 20%-30% less corneal tissue. The less corneal tissue that is removed, the healthier it is for the eye.
• This laser is particularly beneficial for patients with thinner than average corneas, larger pupils, higher prescriptions.
• The laser allows for the most accurate and safest laser vision correction today.


Improved Quality of Day and Night Vision

• The laser is capable of larger treatment zone sizes for people with larger pupils. Better for night time vision quality. It also minimizes the risk of night time glares and haloes.
• The laser results in a corneal shape that is closer to the normal curvature of a healthy eye, for a better quality of both day and night vision.

          BAUSCH & LOMB ZERO COMPRESSION KERATOME

LASIK MD was the first center in the world – and is still one of the few centers in Canada – to offer this new technology. This is the latest Bausch & Lomb technology which saves corneal tissue through thinner, smoother and less swollen flaps, allowing for quicker visual rehabilitation. It is a safer technology that is gentle on tissues, avoiding surface skin problems (epithelial erosions).

Bausch & Lomb Zero Compression Keratome and Corneal Abrasions

The Zero Compression Keratome is a tool used during LASIK, which was developed to decrease the occurrence of corneal epithelial abrasions (“scratches”). This new and improved version of the Bausch & Lomb Hansatome offers significant benefits to patients. Among these is a decreased chance of corneal abrasions, which can lead to delayed healing. In addition, thinner flaps can be created for patients with thin corneas, large pupils or high prescriptions.

In comparison to the original Bausch & Lomb Hansatome, the Zero Compression Keratome significantly reduces the incidence of abrasions (as demonstrated by Table 1.1).

Table 1.1 Comparison of the Incidence of Corneal Abrasions in Bausch & Lomb’s Hansatome and Zero Compression Keratome (2000)

Corneal abrasions increase the chance of other complications, such as inflammation (50%), epithelial in-growth (10%), flap swelling (50%) and flap wrinkles (10%). However, without corneal abrasions, the chance of the latter complications decreases to less than 1%; with the exception of inflammation, which decreases to between 1% and 2%.

To be eligible for LASIK or PRK, you must be between 18-75 years of age. Other factors, such as the general health of your eye, will be examined at the pre-operative assessment.

Certain conditions may make you a questionable candidate for the procedure or cause additional risks or complications. If you have or may have any of these conditions, we suggest that you discuss them thoroughly with your optometrist and your surgeon, as they could interfere with the healing process and require additional care. Those conditions include, but are not limited to: 

• Eye inflammation or infection
• Severely dry eyes
• Certain rheumatological conditions (e.g. lupus, rheumatoid arthritis)
• Excessive corneal disease or scarring
• Degenerative disease of the cornea
• Diabetes with advanced retinal disease
• Inadequate corneal tissue

Please note that pregnant women are NOT eligible for surgery.

The procedure does not correct vision defects, such as those listed below, which do not arise from refractive errors. Patients with such conditions may be subject to additional risks and additional side effects and should discuss their condition with the surgeon and optometrist before deciding whether to have the procedure.


CATARACTS

Cataract is a condition that, if not treated, can cause reduced vision, correctable by cataract surgery. LASIK or PRK will not prevent cataracts, nor will it reverse the effect of a cataract that is beginning to appear. Please refer to www.cataractmd.ca for more information on this condition.

AMBLYOPIA

Amblyopia, or “lazy eye,” is a medical condition that develops in early childhood in which a person who has reduced vision in one eye relies on the other eye to focus. LASIK or PRK will not reduce or eliminate amblyopia. It will not improve the vision in the amblyopic eye. If the patient experiences side effects or complications from the procedure in the eye that is able to focus, he or she could experience a loss of vision because that eye would no longer be able to compensate for the other.

STRABISMUS

Strabismus is an eye disorder caused by a weakness in the eye muscles in which the eyes may not be aligned properly. LASIK or PRK will not correct, reduce, eliminate or prevent strabismus. Patients with strabismus may develop double vision as a result of or as a side effect of the procedure.

PRESBYOPIA

As we age, the crystalline lens of the eye may lose its ability to accommodate to nearby objects. This condition, known as presbyopia, usually begins around the age of 40, and can most often be comfortably corrected through the use of reading glasses. When farsighted people develop presbyopia, LASIK or PRK will improve their near vision, but reading glasses will still be required. LASIK or PRK will not prevent the need for reading glasses in patients over forty years of age.

Like any surgical procedure, LASIK and PRK involve the risk of less than perfect results, complications, or even serious injury from unforeseen causes. Although the vast majority of our patients experience a significant improvement in their vision, neither your surgeon, your optometrist, the Centre or its staff can promise or guarantee that the procedure will be 100% effective or make your vision better than it was before the procedure.

There is a slight possibility that the procedure or a complication arising from the procedure could cause your vision to be blurred, doubled, distorted, to have halos or other disturbances, including permanent loss of vision, and that these would NOT be correctable with glasses or contact lenses. In the event that a complication occurs, your surgeon will discuss and offer you advice on further treatment, which may involve medication or more surgery. In some rare instances, additional surgery may be needed in the form of a corneal transplant.

In addition, although excimer laser eye surgery has now been performed regularly since 1990, very long-term effects of the procedure (greater than 15 years) are unknown.

Although it is not possible to list every potential risk or complication that may result from the procedure, the most important ones are described below. Please note that serious complications are very rare and that the vast majority of our patients are highly satisfied with the results of their procedure.

INTRA-OPERATIVE COMPLICATIONS

Short Flap
A short (or incomplete) flap occurs when the microkeratome cannot complete its movement. As a result, the flap that is made is too small, leaving insufficient space for the laser treatment to be performed. The flap is simply repositioned and the laser is not performed. In the unlikely event that a short flap occurs, the recommendation is to wait between 3 to 6 months before making a new flap. Despite a slightly increased risk of a flap problem in comparison to an eye that has never had a short flap; the follow-up procedure remains very safe. At LASIK MD, the occurrence of short flaps is approximately 1 in 4,000 procedures.

Thin Flap
A thin flap or “buttonhole” occurs when the microkeratome creates a thinner than normal flap. As a result, the flap that is made is too thin to safely perform the laser treatment. In the unlikely event that a thin flap occurs, the recommendation is to wait between 3 to 6 months before making a new flap. Despite a slightly increased risk of a flap problem in comparison to an eye that has never had a thin flap; the follow-up procedure remains very safe. At LASIK MD, the occurrence of thin flaps is approximately 1 in 3,000 procedures.

Free Flap
A free flap (or cap) occurs when the flap becomes detached from the cornea. This complication is extremely rare with modern technology. In order to ensure perfect alignment once the laser treatment is complete, the surgeon marks the cornea before creating the flap. The visual outcomes for LASIK with a free flap are therefore typically the same as LASIK with a normal flap. A temporary suture or contact lens may be required to hold the flap in place. Depending on the situation, the surgeon may choose to continue the laser treatment before realigning the flap. At LASIK MD, the occurrence of a free flap is approximately 1 in 50,000 procedures.


Equipment Malfunction
The keratome and excimer laser are maintained according to the specifications of the manufacturer. Both pieces of equipment have emergency battery power supplies to complete the procedure if electricity is lost at any time. Despite this regular maintenance, the keratome or the excimer laser could malfunction, requiring the procedure to be stopped before completion. In some instances, this malfunction may result in a rescheduling of the procedure, possible damage to the cornea and/or a loss of vision. This occurrence is very rare. At LASIK MD, no patient has suffered a loss of vision related to equipment malfunction.

POST-OPERATIVE COMPLICATIONS

Flap Wrinkles
It is possible that a flap may dislodge or shift slightly in the first few hours after the operation. If the flap moves, it can occasionally leave small wrinkles on the surface. These wrinkles are easily removed by the surgeon when they are found. About 1% of patients may need to have wrinkles removed the day after surgery, without any visual significance. Only rarely that the wrinkles are so significant that the wrinkles may not be removed completely, therefore affecting vision.

Debris under the Flap
A small amount of debris or particles may be found under the flap after the surgeon has completed the LASIK procedure. Debris may result from the instruments used or consist of tear-film oil or floating material that is usually present in everyone’s eyes. The surgeon may decide in the immediate postoperative period to irrigate beneath the flap to remove this debris.

Flap Inflammation
Approximately 3% of patients experience a mild, temporary inflammatory reaction beneath the flap. This condition is Diffuse Lamellar Keratitis (also known as “DLK”). Patients with this type of inflammation may not show any symptoms at all or may experience blurred vision. This condition can generally be treated successfully with anti-inflammatory medication. In certain instances, irrigation under the flap is necessary, if the inflammation is severe. Very rarely, if the condition is not treated effectively in a timely fashion, corneal scarring can result in some loss of vision.

Infection
As with any surgical procedure, infection of the cornea is possible. Infections after LASIK procedures are typically treated with antibiotics and usually do not lead to permanent loss of vision. Severe infection, even if successfully treated with antibiotics, could lead to permanent scarring and loss of vision that may require corrective laser eye surgery or, if the infection is very severe, a corneal transplantation. The chance of this occurrence is extremely rare. The incidence of infection at LASIK MD is 1 in 50,000. This incidence rate compares with a known incidence rate of infection of 1 in 2,000 per year for contact lens wearers (1% rate over a 20-year period of contact lens wear).

Irregular Corneal Shape (Ectasia)
Certain corneas are genetically pre-disposed to be weaker than other corneas of the same thickness. A certain amount of corneal tissue (after the laser treatment removes tissue) is always left under the flap for the corneal shape to remain stable. In rare instances in which the cornea is pre-disposed to be weaker or “softer” than the average cornea, the tissue that is left under the flap is not sufficient enough to maintain stability. This insufficient tissue can lead to ectasia, a condition characterized by progressive corneal thinning. This change in corneal shape may require the patient to wear hard contact lenses or even a corneal transplant to restore vision. The chance of ectasia in a normal eye undergoing laser eye surgery is 1 in 10,000. This rate compares with a known incidence rate in the population of soft corneas that bend on their own (without surgery) of 1 in 2,000.

Halos, Starbursts
After the procedure, some patients may experience an optical effect called a “halo” or a “starburst” around lights at night or in dim light. These effects are for the most part temporary, typically lasting between 2 weeks to 3 months after surgery. These symptoms occur due to the residual water in the eyes that is eventually absorbed. Glare and halos may be permanent in 1-2% of patients and these complications are more likely to occur in patients with high levels of nearsightedness, farsightedness or with larger-than-average pupil size. The complication is rare with modern technology because it is able to make treatment sizes larger than the patient’s pupils.

Light Sensitivity and Fluctuating Vision
Patients may be extremely sensitive to light and glare or find that their visual acuity fluctuates after the procedure. These conditions are typically temporary and will go away within one to three months after the procedure as the eye heals and stabilizes. However, these conditions rarely remain permanent. For PRK patients, light sensitivity is common for a few days after surgery and rarely will persist for longer than four weeks.

Optical Imbalance
If the surgeon performs the procedure for each eye on different days, the eyes may not be able to balance and focus properly until the procedure is performed on both eyes because there will be a prescription difference between the two eyes.

Under-correction, Over-correction and Regression
In some cases, the exact removal of tissue performed by the laser is overridden by the healing response of the eye, which varies from one individual to another. While the laser treatment is designed to completely neutralize the refractive error of the eye (unless otherwise discussed with the surgeon) variation in the healing process can affect the treatment accuracy and result in an over- or under-correction. A more pronounced healing pattern can also cause regression, which is a partial decrease of the effect of the treatment, as the cornea replaces some of the tissue removed by the laser. Typically, a maximum of 1 to 2 diopters can regress and it means that the patient has a small remaining prescription which still blurs the vision.

The residual nearsightedness, farsightedness and/or astigmatism can be corrected with glasses, contact lenses or additional laser surgery in the majority of patients. A minority of patients may not be able to safely undergo laser re-treatment, most likely due to insufficient corneal tissue (thin cornea before surgery), or irregular corneal shape.

For very small amounts of regression, the risks of re-treatment may outweigh the potential visual benefit to the patient. If re-treatment is not recommended by the surgeon, some people may find that a very mild eyeglass prescription is necessary for driving, especially at night.

Fragility on Impact
For at least the first three months after the procedure, the corneal flap is considered fragile to direct trauma. When participating in sports or any other activities involving possible contact with the eye during this period, you should wear protective eyewear. In any event, it is advisable to protect your eyes from direct trauma after the procedure as much as possible.

Strabismus
Patients with pre-existing eye balance problems (the two eyes are not aligned) may have a deterioration of their symptoms, sometimes even resulting in double vision. This complication is rare and occurs only in patients with pre-existing balance problems.

Surface Skin Erosion
When making the corneal flap, an abrasion might occur on the outer surface of the cornea. This abrasion means that the surface skin has rubbed off. Patients with corneal erosion may experience more discomfort, a longer recovery period and may be at higher risk for further complications, including infection, inflammation, recurrent erosions or flap wrinkles. Depending on the size and severity of the abrasion, the surgeon might delay the surgery in the other eye. A contact lens may be placed in the eye to help with the healing. Most abrasions heal within 1-3 days. With the newer Zero Compression Keratome (ZCK), this complication occurs in less than 0.2% of cases.

Surface Skin Cells under the Flap
Corneal surface skin cells can sometimes grow under the edge of the flap, a condition known as epithelial ingrowth. The vast majority of these cells resorb and disappear on their own. However, if the cells continue to grow, they may affect vision. The surgeon may decide to lift the flap and remove these unwanted cells. This complication is very rare after a first procedure. It is more commonly seen after a re-treatment (3%) when the flap is lifted a second time.

Dry Eyes
Dry eyes are a common, yet typically temporary complication arising from LASIK or PRK. This condition can usually be treated with lubricating eye drops and occasionally with temporary inserts or “plugs” that prevent the normal drainage of tears into the nose. Dry eyes generally improve within a few months after surgery, but in rare instances, it can continue for longer periods of time, and may require long-term use of lubricant drops and permanent plugs. Patients who have dry eyes prior to LASIK or PRK are more likely to experience dry eyes after the procedure.

Excessive Corneal Scarring Called Haze (for PRK patients)
After PRK, a mild corneal scarring reaction is part of the normal healing process. It gradually subsides with little or no permanent effect on vision. However, if the scarring is excessive or does not go away, it can affect vision. The patient may need additional surface treatment to remove the scar. Excessive scarring is usually associated with higher levels of correction. This complication is much less common today as medications are used to prevent it.

Other Side Effects
Other possible side effects include a "bruising" of the white part of the eye that may last for 1-2 weeks after surgery, drug reaction and appearance of ‘’floaters’’ in the vision.

Other Extremely Rare Complications
Other risk