What is Lasik- Eye laser surgery

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LASIK is a surgical procedure intended to reduce a person's dependency on glasses or contact lenses. LASIK stands for Laser-Assisted In Situ Keratomileusis and is a procedure that permanently changes the shape of the cornea, the clear covering of the front of the eye, using an excimer laser. A mechanical microkeratome (a blade device) or a laser keratome (a laser device) is used to cut a flap in the cornea. A hinge is left at one end of this flap. The flap is folded back revealing the stroma, the middlesection of the cornea. Pulses from a computer-controlled laser vaporize a portion of the stroma and the flap is replaced.

Lasers are currently being used Worldwide for the correction of Nearsightedness, Farsightedness and Astigmatism.

"LASIK" is a recent advancement in the correction of refractive or focusing errors of the eye. This evolving laser technology offers new hope for sight without complete dependence upon corrective eye wear.

LASIK is a surgical procedure which combines a micro-keratome (an automated knife for shaving the cornea) and an Excimer Laser (an ultraviolet light beam) to reshape the cornea.

LASIK has quickly become the procedure of choice by leading eye surgeons around the world for the treatment of myopia, hyperopia and astigmatism. Patients in record numbers all across Canada and the United States enthusiastically embrace the LASIK procedure because of the dramatic results they enjoy, and their rapid visual recovery.

Once the Excimer laser treats the inner surface of the cornea, the protective flap of the cornea is gently replaced. No stitches or shots are used during the LASIK procedure, and most patients enjoy improved vision as soon as one day after the procedure.

LASIK is proving to be the most effective procedure available today for treating a wide range of myopic and astigmatic conditions. It is extremely surgeon dependent and requires extensive training and experience with the use of the microkeratome - the mechanical device used to create the protective flap under which the laser portion of LASIK is performed.

Laser vision correction is a permanent outpatient vision correction procedure performed by certified ophthalmologists in which tissue is removed from the surface of the eye using an excimer laser. Laser vision correction is designed to reduce a person's dependency on glasses or contact lenses by reshaping the outer surface of the cornea using the energy pulses of light emitted by the excimer laser.

Laser Surgery Why is it called "LASIK"?

The word LASIK is actually an acronym that stands for Laser Assisted in-Situ Keratomileusis. It is also sometimes referred to as Laser Intra-Stromal Keratomileusis, a procedure which uses an excimer laser system to reshape the stroma layer of tissue lying under the surface of the cornea. An automated microsurgical device called a microkeratome is used to create a thin flap on the surface of the cornea. The corneal flap is then laid back and the excimer laser reshapes the stromal layers of the cornea according to the patient's eye prescription. Once the laser has been applied the flap is closed and the laser procedure is complete. The procedure usually takes between 10 to 15 minutes, with the actual excimer laser treatment taking 15-90 seconds to perform.

The surface layer of the cornea remains intact and as a result, no bandage is required and LASIK patients experience virtually no pain or discomfort. Most LASIK patients can normally see well enough to drive a car the next day and complete healing is achieved within one to three months.

How does LASIK laser surgery corrects your vision?

Laser-in-situ Keratomileusis (LASIK) is a procedure used to reshape the cornea using a laser. This allows the cornea to better focus light on the retina so refractive errors are reduced or eliminated. The excimer laser that is used for LASIK uses a cool light beam to remove corneal tissue from the inner cornea. The beam of the laser is so accurate that it can cut notches in a single strand of human hair.

Can Anyone Guarantee 20/20 Vision?

No. No honest surgeon can absolutely guarantee a certain result from the surgery. We can quite accurately let you know the probability of you achieving 20/20 vision based on large domestic and international studies using this exciting technology.

95% of patients with low through moderate ranges of nearsightedness and/or astigmatism achieve normal or near normal natural vision from just one surgery with LASIK. For those who do not achieve this quality of vision from one surgery, enhancement surgery can usually give the rest of the desired correction.

People with high ranges 8 to 15 diopters of nearsightedness; 3 to 5 diopters of astigmatism also have a very good probability of achieving good natural vision, but an enhancement surgery is more likely to be necessary for full correction.  

What is the right age to have LASIK laser vision correction?

There is no strict age requirement. However, most individuals by the age of 20-21 have reached a point at which their glasses prescription will remain relatively stable. The key to being a good candidate is that your glasses and/or contact lens prescription should be relatively stable.

We have treated patients 19-70 years of age with LASIK. 

Does LASIK Laser surgery hurt?

No. The laser procedure itself is virtually painless. You will be aware of a support which helps to hold your eye open. A slight pressure may be felt during the procedure. You will be aware of the laser sounds while you watch a red flashing light..

The majority of patients experience no significant discomfort. Approximately 10% of patients experience more significant eye discomfort and may need to take recommended medications to relieve it.  Little to no discomfort is associated with LASIK. 

Give me a step-by-step of the LASIK procedure?

Throughout the procedure you are awake.  Eye drops are the only anesthesia. Sedation is not necessary, but you may take an oral tranquilizer. Your eyelids and lashes are cleansed for sterility and a sticky drape keeps your lashes out of the way. Your lids are gently opened. You look at a blinking red light which keeps your eye properly positioned. During the flap creation phase you have a sensation of pressure and a grayness of vision. Then the laser is used and you will hear a rapid clicking sound. The flap is replaced and it takes about 3 minutes for it to stick down. After the procedure, you will leave with an eye shield and eye drops to help your eye heal.  Also, your vision may be a little blurry for a few days.  The procedure takes under 10 minutes per eye.

Most patients are able to return to work in 24 hours, and over three or four weeks, have continuing improvement in their vision.      

How long will the correction last?

The laser correction will probably last for the rest of your life. The cornea is a very stable tissue. Current studies show that once the cornea has been modified by the current Excimer laser protocol such as LASIK, it tends to remain stable and stay modified permanently, as best we can determine through studying many thousands of patients. There are rare cases of regression, which may be corrected with further surgery, but the vast majority of corrected eyes remain stable. 

How accurate is the Excimer laser?

This is a human hair which has been sculpted by the Excimer Laser. Each pulse of the 193nm laser will ablate or eliminate one three-thousandths of one millimeter using cold energy. It is this level of unparalleled accuracy which allows the programmed Excimer laser to precisely sculpt the human cornea to reduce nearsightedness. 

What does the patient experience during the procedure?

Each patient goes through a comprehensive series of eye tests and examinations before consulting with the surgeon to discuss and plan the specifics of personal visual correction.

For the laser surgery itself, patients sit comfortably in a professional chair which is reclined to a horizontal position. Experience with new topical anesthetics and analgesics mean that no injections are necessary. The eye is anaesthetized with drops, to ensure a painless experience. The lids are gently held open with a lid support. Patients watch a flashing red light while the laser uses cold energy pulsed to precisely vaporize microscopic layers of tissue to correct the focus. Actual laser surgery time ranges from 10 to 90 seconds in most cases. Most patients are in the surgery suite for about 15 minutes. 

Are there any negative long term effects?

The medical community can only speak for the future by assessing the data from the surgeries performed under formal studies. Such studies on Excimer Laser refractive surgery have been carried out in the US under FDA scrutiny and by the international medical community. The Excimer Laser data to date reveals a very positive healing response of the eye giving doctors no reason to be significantly concerned about effects beyond ten years of study.

The laser penetration is so shallow and precise that it appears not to have a significant effect on living cell function even immediately beneath the treated optical zone. After healing, these eyes have not shown negative effects, giving doctors even more confidence about the ongoing health of the eye after LASIK surgery.  

What are the risks and side effects of laser LASIK surgery?

LASIK or Laser Assisted In-situ Keratomileusis adds a controlled lamellar keratectomy to the refractive laser ablation. The laser power treatment is thus performed under the surface of the cornea with some change in risks and benefits of the procedure. Possible risks of LASIK include:

• Creating a cap of corneal tissue instead of a flap by fully removing the top of the cornea rather than just lifting it -- This removed tissue still heals back into place but requires extra care in positioning.
• Loss or damage of the corneal cap.
• Infection -- Very rare and usually controlled with medications.
• Induced regular or irregular astigmatism
• Epithelial tissue growth underneath the new corneal flap -- This can usually be solved by lifting the flap and gently removing these tissue cells.
• Increased or decreased response to surgery -- Surgery can usually be enhanced or modified by lifting the cap and removing more tissue with the laser. Sometimes other types of surgery can be combined with LASIK to give improved results.

Side effects are generally minimal following LASIK surgery since most of the surface of the cornea has not been affected by the procedure. However, people who have the surgery may experience some light sensitivity and glare for a few days or weeks. Full visual stabilization may take several weeks.  

If I require surgery to correct defects, can both eyes to be treated at the same time?

It is possible for most candidates to have surgery on both eyes on the same day, conditional on the surgeon's approval and the patient's careful informed consent. Even the safest surgery carries some small statistical risks. Therefore, it is most conservative to separate surgeries for the two eyes by some measure of time, depending on patient need and situation. 

What are the long term effects of LASIK?

The 9 year follow-up of patients undergoing laser vision correction procedures is very stable. In fact the behavior of an eye that has had LASIK parallels the behavior of a normal eye that has not had surgery. LASIK has been performed since 1991. Based on what we have learned from performing eye surgery over time, we know that if an eye is "stable" in its vision at 2 years, then it should remain stable at 20 years and beyond. The eye behaves in a predictable manner. Since visual results from laser vision correction procedures have been stable after 9 years, then they should remain stable over a lifetime. 

How long do I have to wait until I drive and return to work after the surgery?

A patient is legal to drive with at least one eye 20/40 or better. However, most importantly, a patient should refrain from driving until they feel comfortable with the vision having changed in their operated eye.

Returning to work is largely dependent upon the individual and the type of work they do. Most people can return to work within 2 to 4 days of the surgery. Many choose to do light work, as in computer use, within hours of laser treatment. Obviously, operating heavy machinery or higher risk activities requires stability and adaptation to vision changes.  

What is the recovery time after the procedure and what can I expect?

All patients immediately after LASIK will see blurry. In fact, for the first six hours after LASIK normal symptoms include: blurred vision, light sensitivity, eye irritation (similar to the sensation that an eyelash is trapped between the eye and lid), and tearing. After the first six hours, these symptoms resolve.

All patients are instructed to use antibiotic and steroid eyedrops for about one week after surgery.

One cannot hurt the eye by using it after surgery. Therefore, watching TV, computer work, reading, etc will not affect the outcome of LASIK.

Restrictions after LASIK: no eye or eyelid rubbing or forceful eyelid closure (squeezing), no eyelid makeup, no swimming for 4 days.

Normal activity that does not include pressure on the eye such as walking, jogging, routine work is allowed the day after LASIK.

Discomfort is rare and minimal. Usually vision is immediately improved but may fluctuate for several weeks. For a week a shield is worn over the eye at night until complete healing occurs. The eyes and lids cannot be rubbed to protect the flap. Drops are used for several weeks. Glasses, if necessary, for reading and distance are prescribed in two weeks. Retreatment occasionally is necessary and is performed as soon as the eye is stable but usually no sooner than two months. 

Can I wear contact lenses after LASIK?

Most patients do not require the use of contact lenses after LASIK. There are some circumstances where contacts may be desirable or beneficial after refractive surgery. Generally, if a patient were able to wear contact lenses comfortably prior to surgery, they will be successful in wearing them again after surgery. As with initial lens wear, it may require some time to build up to the same number of hours that a patient was able to wear contact lenses before surgery.  

Will LASIK surgery be any good for me because I am over 50?

Laser LASIK corrective surgery work effectively to correct the general focus of eyes, no matter what your age. However, the fine focusing lens inside your eye firms with maturity and no longer provides the capability of clear reading vision past 50 years of age. This means that even if you have surgery, you will still need reading glasses to see clearly up close from about age 50 or 55 years of age. Laser surgery may be able to give you clear vision for all the other focal distances, without regular glasses, for the rest of your life. You may also wish to consider monovision.

If you are over 60 years of age, and have any degree of cataracts, you may benefit from waiting to have your vision corrected at the time of your cataract surgery. The lens placed in your eye at the time of cataract surgery can correct your nearsightedness or farsightedness. Most people develop cataracts sometime between 60 and 85 years of age. Arrangements can sometimes be made to have your cataract surgery early, even before you develop a noticeable cataract, for the sake of enhanced focusing benefits. However, health care plans will not cover any expense unless a significant cataract has developed. The earliest signs of cataracts are increasing glare such as with night driving, reading, and driving into sunset or in inclement weather. A careful eye examination will reveal the best option for your particular circumstance. 

Is this surgery permanent?

Yes, the results of LASIK are permanent. They are however "adjustable" such that future correction of near-sightedness, far-sightedness or astigmatism can be performed to "touch-up" the original procedure. 

Can my vision be worse than before the procedure?

In very rare cases, yes. In order for vision to turn out worse than it was before the surgery, a significant complication would need to arise. In our experience, these complications have not lead to loss of vision but in a slight reduction in the quality of vision and are generally associated with astigmatism or haze resulting from the surgery. Some of these complications are treatable with further surgery, but some are not.

In large studies approximately 3 patients in 100 will experience a measurable decrease in their best corrected vision. These uncommon patients most often have a significant improvement in their uncorrected vision. This means that they see better without glasses or contacts than they did before surgery, however the very best they can see with correction is diminished. In some cases this can be due to a temporary film related to healing. Other causes may be amenable to enhancement or further treatment.  Finally, as with any surgery, there are some risks of significant complications which encourage you to seek care by most highly trained and experienced surgeon. 

What is the worst possible complication from the surgery?

Amongst the worst possible complications of LASIK is a serious infection which could lead to a scarring of the cornea or possibly even loss of the eye. Infections only very rarely occur because the laser is performed under sterile surgical conditions immediately followed by the application of prophylactic antibiotics. When the rare infection does occur, it can usually be controlled with topical antibiotics resulting in little or no ultimate loss of vision. Even if the cornea should happen to become seriously scarred because of an infection, corneal transplants are usually possible to restore clear vision again.

( Courtesy: http://weinstockeyecare.com/  Dr. Weinstock is among the most well-known and respected Ophthalmologists in Canada. He is recognized as a pioneer in laser eye treatment in Canada and in 1990 was the first Ophthalmologists in Ontario and the second in Canada to use the Excimer laser for vision correction. A physician for over twenty years, Dr. Weinstock is an Associate Professor, Department of Ophthalmology, Faculty of Medicine at the University of Toronto.  )