Corrective Eye Laser Surgery
LASIK
Introduction |
Important Information |
Risks & indications |
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Myopia |
How an eye functions |
Are you a candidate |
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Hyperopia |
About Excimer laser |
Step by step LASIK |
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Astigmatism |
Pre-OP information |
Other procedures |
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Presbyopia |
Day of Surgery |
Frequent questions |
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About the Surgeon |
Days after Surgery |
Mono Vision |
Information on LASIK
Laser Assisted In-Situ Keratomileusis (LASIK) is a form of laser surgery to correct nearsightedness, farsightedness and astigmatism. LASIK combines the computer controlled accuracy of the excimer laser with the comfort and quick recovery provided by the flap of a Lamellar Keratoplasty or LK. LASIK is quickly becoming the procedure of choice by many refractive surgeons.The present options for vision correction include glasses, contact lenses and a number of refractive surgical procedures. The latest procedures, using the Excimer laser are PRK and LASIK.
The information provided is to help you make an informed decision about LASIK versus PRK. LASIK is a method of improving the curvature of the cornea by reshaping the inner layers of corneal tissue with the Excimer laser, rather than by recontouring the corneal surface, as with PRK.
There are cases where it is appropriate to have LASIK on only one eye, but it may be necessary to have both eyes treated with LASIK to achieve a satisfactory result.
People with specific eye or general health problems (including lupus, severe dry eyes, rheumatoid arthritis, cataracts and glaucoma) may not be eligible for LASIK.
The post-operative risks of LASIK are similar in type to those involved with PRK however the statistical probability of many of them occurring are significantly reduced.
There are basically four advantages to LASIK versus PRK. These are:
· The ability to correct severe and extreme cases of myopia (up to -15.00 Dioptres), astigmatism (up to 8.00 Dioptres) and hyperopia (up to +6 Dioptres), with greater predictability of results and decreased probability of regression.
· Reduced risk of healing-haze, or scar tissue (0.1% vs 2-5% for PRK).
· Reduced risk of post-operative pain.
· Faster visual recovery, this allows both eyes to be safely treated on the same day.
Laser Assisted In-Situ Keratomileusis (LASIK)
Utilising the accuracy and precision of the excimer laser, LASIK changes the shape of the cornea to improve the way light is focused or refracted by the eye.
First a thin layer of the cornea, the corneal cap is lifted as an instrument called a microkeratome glides across the cornea. Then in less than 60 seconds, ultra-violet light and high energy pulses from the excimer laser reshape the internal cornea with an accuracy of up to 0.25 microns. The degree of correction is controlled by a computer program in the excimer laser. By adjusting the pattern of the laser beam, it is possible to treat high levels of nearsightedness, and astigmatism. After the tissue has been reshaped the corneal flap is replaced in its original position. Because of the corneas extraordinary natural bonding quality, healing is rapid and does not require stitches.
LASIK is performed as an outpatient procedure in the comfort and convenience of an excimer laser suite. The entire process takes less than 30 minutes. The procedure is done using "eye drop" anaesthesia. Some patients report slight, post-operative discomfort that can usually be alleviated with medications. Both eyes can be treated on the same day. Many patients see a dramatic improvement in their vision within the first day. For others, vision may be blurry and fluctuate for several weeks. Most patients return to their normal activities within a day or two.A New Kind of Freedom
Since the early 1970's, nearsighted and astigmatic people have been treated successfully with a manual refractive surgery called Radial Keratotomy (RK). It is a painful process which never the less allowes patients to enjoy a lifestyle free from the dependence of corrective eyewear.
For many years Radial Keratotomy (RK) and Astigmatic Keratotomy were the only techniques readily available to change the shape of the cornea. These Russian developed procedures use controlled incisions to effectively correct low amounts of nearsightedness and astigmatism. This has all changed with the advanced use of laser surgery.
back to topMyopia - Nearsightedness
In Myopia the cornea and the lens are too strong for the eye, causing light rays to focus in the front of the retina. This condition permits clear close-up vision, but objects at a distance are blurred or indistinguishable. Concave or minifying glasses are needed to place images properly on the retina.
Hyperopia - Farsightedness
This condition occurs when an eye is too short for the cornea's curvature. Light rays entering the eye focus behind the retina, and as a result a blurred image is produced. Convex spectacle lenses or plus lenses are needed to place the image forward onto the retina.
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Astigmatism
Astigmatism occurs when the cornea is shaped more like a football than a basketball. As a result, patients with this condition experience distortion or tilting of images because of unequal bending of light rays entering the eye.
The decision to have LASIK done is an important one that ultimately only you can make. It is important that you have a realistic expectation of the outcome and that your decision is based on facts not on hopes or misconceptions. The goal of LASIK is to reduce your dependence on visual aids, it cannot correct every condition.
It cannot correct a condition known as Presbyopia, or aging of the eye which normally occurs around age 40-42 which may require the use of reading glasses. In fact, people over 40 who have their distance vision improved may find that they need reading glasses after the procedure. Your doctor will provide you with additional information that will allow you to make an informed decision
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The LASIK surgery is performed by Dr. Lee Lenton.
Dr. Lenton is a member of the Royal Australian College of Ophthalmologists, the American Academy of Ophthalmology and the American Cataract & Refractive Surgery Society. In 1995, Dr. Lenton was one of the first surgeons to perform LASIK in Australia. He is a specialist LASIK surgeon and was the first in Australia to master same day LASIK surgery for both eyes and perform it routinely. To date, he has performed over 3500 procedures throughout Australia and Asia.Dr. Lenton is involved in training Australian and overseas ophthalmologists in the LASIK procedure, and has lectured as well as performed live teaching demonstrations in Australia, Singapore, Vietnam and mainland China.
· LASIK is a permanent operation to the cornea; it cannot be reversed.
· Alternatives to LASIK include glasses, contact lenses.
· Some occupations do not accept applicants who have had any refractive surgery.
· The following risks of LASIK surgery should be noted:· Pain: you will not have any pain or discomfort during the procedure itself. With new techniques, as few as one patient in ten has pain after the procedure, which is treated with strong medication for the first 24 hours. Most patients experience only some irritation, light sensitivity and watering of their eyes for a few days.
· Regression: Regression is a shift back towards myopia, hyperopia or astigmatism, following Excimer laser procedure. This may necessitate an additional procedure or the use of glasses. Most people only require a single procedure.
· LASIK requires greater surgical skill and training than PRK. Patients undertake a greater surgical risk with this procedure, but the post-operative risks are reduced and the benefits are clear and dramatic.
· The risk of having a serious vision-threatening complication is much less than 1%. However the Excimer laser procedure, like all surgical procedures, has limitations and risks.
· The benefits of LASIK surgery are:
· No pain during the operation and a possibility of slight pain after surgery.
· Wound healing time is approximately 12 to 24 hours for LASIK as apposed to PRK which is 3 to 6 months approximately.
· You will be able to function without your glasses within 24 hours of surgery.
· Nearsightedness may be reduced so that the amount of time during the day contact lens or eyeglasses are used is reduced or eliminated.
· LASIK may be an alternative to eyeglasses in some who are intolerant of contact lenses.
· Another alternative to correct nearsightedness.
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Your eye focuses light to form images or "pictures", very much like a video camera. Your eye changes these images into electrical signals, which are then sent back to your brain. If your eye is out of focus, what you see will be blurred.
The cornea at the front of the eye bends (or refracts) the light rays onto your retina. This clear tissue is responsible for two-thirds of the focusing power of your eye. The lens within your eye finishes the job of focusing the light onto your retina.
The eye focuses light by bending (or refracting) all light rays to meet at a single point. If the focusing process works perfectly, a sharp image of the object you are looking at will be focused exactly on the retina and you will see a clear image (emmetropia). However, if the light focuses either in front of or behind the retina, the image on the retina (and the image you see) will be blurred, and you are said to have a refractive error. There are three main types of refractive error, called nearsightedness (Myopia), farsightedness (Hyperopia) and astigmatism.
The cornea determines the focusing power of the eye. The steeper the cornea is curved, the more the light rays are bent. If the cornea is curved too much, the image focuses in front of the retina and the eye is nearsighted. If the cornea is not curved enough (too flat), the image focuses behind the retina and the eye is far-sighted. If the curve is not spherical (more like a football than a basketball) the image is not focused correctly on the retina and the eye is astigmatic.
Therefore altering the shape of the cornea may correct the vision
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The Excimer Laser
The excimer laser is a unique type of "cold" laser that does not burn or cut tissue. Instead, using ultra-violet rays, it gently breaks the molecular bonds between cells so that controlled amounts of tissue can be literally vaporised away one microscopic layer at a time. The tissue can be removed from the surface on the cornea as in PRK, or from the interior of the cornea after a thin flap of surface tissue has been lifted as in the LASIK procedure.
The advent of the excimer laser has allowed surgeons to take corrective corneal refractive surgery to a new level of precision. For nearly 25% of the population excimer Laser Assisted In-Situ Keratomileusis, or LASIK, could represent the first step towards less dependence of corrective lenses.back to top
If you are interested in having LASIK you will need to have a pre-treatment examination to determine if your eye condition is right for the treatment.
Your pre-treatment examination will involve a complete medical and eye history, in which both eyes will be examined by a vision and eyeglasses check, a microscopic examination, a glaucoma test, and computerised mapping of your cornea.
Prior to coming to the surgery please talk with your doctor about your normal schedule for taking any prescribed medications. Also, talk with your doctor about the advisability of eating or drinking immediately prior to the surgery. You should arrange for someone to drive you home after the surgery, and to your next doctor's appointment. You should not drive until the doctor gives you permission to do so.
back to topJust prior to surgery you will be given some drops in your eyes. You will be escorted into the room that contains the laser system You will see a large machine with an arm sticking out that has the microscope attached to it. Also you may see a computer screen, a surgeon's chair and the patient’s reclining chair. You will be asked to sit in the patient chair. You will be laying face up towards the microscope and the ceiling. Your eye will be numbed with more drops.
Overall the surgery will take approximately 15 to 20 minutes, however the use of the laser beam lasts only 1 to 2 minutes. The surgeon will place an instrument between your eyelids to hold them open during treatment Try to keep your eye open without squeezing since this will allow you to relax more. The surgeon will ask you to look up through the bottom of the microscope. You will see coloured lights in the centre of the microscope tube. The fixation light is very important in keeping your eye positioned properly during the laser surgery. The surgeon will instruct you how and when to look at these coloured lights.
The surgeon will then take you through a practice session with the laser to familiarise you with the sights and sounds of the treatment so that you will be prepared for what to expect during the actual treatment. Remember you and your surgeon are a team. Co-operate with your surgeon to get the best possible result.
After the training session, the treatment will begin with the surgeon using a surgical instrument (Keratome) to slice a thin layer of cornea. Only after the surgeon has lifted the thin flap, refocused the microscope and asked you to fixate on the coloured lights will the laser treatment be performed.
After your treatment, your doctor will place some drops into your eyes. You will be given a shield to be used at night for protection and comfort and you can wear your own sunglasses home. The treatment itself is painless because of the numbing drops. When these eye drops wear off, your eyes will likely feel a little irritated or gritty. The doctor will prescribe medication to make you more comfortable during your immediate post-treatment period.
back to topYou may be sensitive to light and glare and have the feeling that something is in your eye for the first few days. Sunglasses may be worn to make you more comfortable during this time. Initially your eyes may be overcorrected making you hyperopic (far-sighted) and objects up close may be blurry. This is part of the normal healing process.
back to topRisks and Side Effects
Pain: You will not have any pain or discomfort during the procedure itself. Most patients experience only some irritation, light sensitivity, and watering of their eyes for a few days.
Infection: The risk of infection is about 0.2%. All patients must be careful for the first week and avoid certain activities like swimming and gardening. You will receive antibiotic drops for use after the operation to reduce this risk.
Haze: As your eyes heal, you will have blurred vision for approximately the first week of the procedure. This is the surface cells smoothing out and the clearing of microscopic swelling. Almost everyone develops "trace" degrees of haze.Indications and Use of the Excimer Laser to Perform LASIK
Risks:
Immediate Early Post-treatment Complications
The following complications are associated with the normal post-treatment healing process and include a possibility of slight post-operative pain (first 24 hours), double vision, feeling something is in the eye, shadow images, light sensitivity, and tearing and pupil enlargement. These symptoms are temporary and occur in many patients during the early post-treatment period.· Long Term Post-treatment Adverse Events
Anterior Stromal Reticular Haze, Glare, Halo, Loss of best Spectacle Corrected
Visual Acuity, Improper Correction, Induced Astigmatism, Pressure Elevation and
Night Vision Difficulties.Anterior Stromal Reticular Haze: Loss of perfect clarity of the cornea, usually not affecting vision.
Glare: Glare, especially from bright lights may be seen particularly in the early months after treatment.
Halo: Halo or hazy rings surrounding bright lights may be seen particularly at night after treatment.
Loss of Best Spectacle Corrected Acuity: A decrease in best-corrected visual acuity with glasses.
Improper Correction: It is possible that the treatment could result in under correction, where some degrees of myopia ('nearsightedness) may occur requiring the use of glasses or contact lenses. Improper correction may also result in overcorrection (or hyperopia) which may or may not require the use of glasses or contact lenses. It is possible that Improper Correction may increase dependence on reading glasses or require the use of reading glasses at an earlier age.Induced Regular/irregular Astigmatism: A change in astigmatism that may then distort vision and may or may not require patients to continue to wear glasses or contact lenses.
Pressure Elevation: An increase in the intra-ocular (inner eye) pressure due to usage of post-treatment medications may occur which is usually resolved by drug therapy or discontinuation of post-treatment medication
Lens Opacity Cataract: Opacity or cloudiness of the lens that may prevent a clear image from forming on the retina may occur. Cataracts may be caused by the use of post-treatment medication.
Night Vision Difficulties: Tasks that are performed without difficulty during the day are performed with visual difficulty in low light or night time conditions.
back to topYou may be a candidate for LASIK if you are over 18 years of age and have a healthy cornea. Candidates must not have had a significant change in their prescription in the last 12 months. People with certain medical conditions or women who are pregnant may not be suitable candidates.
The decision to have LASIK done is an important one that ultimately only you can make. It is important that you have a realistic expectation of the outcome and that your decision is based on facts not on hopes or misconceptions. The goal of LASIK is to reduce your dependence on visual aids, it cannot correct every condition. It cannot correct a condition known as Presbyopia, or aging of the eye which normally occurs around age 40-42 which may require the use of reading glasses. In fact, people over 40 who have their distance vision improved may find that they need reading glasses after the procedure.
Range: myopia (nearsightedness)
-1.00 to -15.00 Dioptres of correction with astigmatism of (6.00 dioptres) or hyperopia up to + 6 Dioptres.
Discuss with your doctor's office how you will pay for the treatment since laser correction is not covered by Medicare or Private Health Funds, this treatment is however Tax deductible.
Be fully informed about the risks and benefits of LASIK as compared to other available treatments.
Your doctor will provide you with additional information that will allow you to make an informed decision
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For more than three decades, modern vision correction has been constantly evolving as new technology and innovation have become available. LASIK is currently the most commonly performed laser vision correction procedure in Australia. Depending on your particular circumstances and prescription, other options may better suit your vision correction needs.
Take some time to learn about the different procedures currently available to correct your vision:
Contact Lens Implant ( Phakic IOL )
Corneal Rings implant
Clear Lens Extraction
ALKIntracorneal Rings (ICRs)
Intracorneal rings are plastic inserts placed in the cornea. The rings flatten the central cornea to correct low levels of nearsightedness (myopia). Unlike other refractive surgery procedures, intracorneal rings can be removed. When the inserts are removed the cornea returns to its preoperative shape and one is again nearsighted.
The procedure is generally performed on an outpatient basis using drops for an anaesthetic. It is a quick procedure and can take less than half an hour.
Research is being done on intracorneal rings to correct farsightedness and astigmatism.
Complications with intracorneal rings are rare, but include undercorrection, overcorrection, induced astigmatism, infection, glare, haloes and extrusion of the insert. Minimal scarring may also occur in the area of the rings.
Phototherapeutic Keratectomy (PTK)
PTK is an excimer laser surgical procedure that removes roughness or cloudiness from the cornea. The cornea is the smooth clear window of the eye in front of the colored iris that helps bend light rays so they focus directly on the retina, the light-sensing layer of cells at the back of the eye. If the corneal surface is rough or cloudy, the rays of light do not focus properly on the retina and images are blurry.
Until recently, the rough cornea was scraped smooth with a surgical blade, while the cloudy cornea required a partial or full corneal transplant. More recently, phototherapeutic keratectomy, or PTK, is an option.
The excimer laser allows some abnormal corneas to be treated with a cool beam of light that evaporates tissue. The principal advantage of laser surgery over conventional surgery is the laser is able to create a smoother corneal surface than a blade and smaller amounts of tissue can be removed.
Potential complications after PTK include poor wound healing, excessive corneal flattening resulting in farsightedness, and irregular astigmatism or poor vision that cannot be corrected completely with glasses.
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The first step in answering the question of whether or not LASIK will solve your visual problem is to have a thorough eye examination. This may be done by your family optometrist or general practitioner. Should your refraction error fall within the ranges of correction for LASIK more comprehensive tests will be needed to complete the evaluation.
SHARING THE VISION EYESIGHT LASER CENTRES are working closely with many optometrists recognising them as colleagues in professional eye care. Your initial pre-operative assessment may be performed by an optometrist. If you are suitable for laser correction, your optometrist will refer you to the Centre, an appointment will be made with an eye surgeon experienced in laser surgery. Post operative care will be performed by the surgeon in association with your optometrist. These two eye care professionals will carefully monitor your eyes in the weeks and months following your surgery.
At Sharing the Vision Eyesight Laser Centres we believe in open communication between eye care specialists sharing information to benefit both the patient and the eye care specialist. In a friendly non-clinical environment, our highly trained and experienced staff strive to provide ultimate comfort for patients. Our optimal customer service induces an above average patient satisfaction.
Q: How successful is LASIK?
A: Very successful. Most patients who have had LASIK visual correction are able to pass a driver's test without the aid of glasses or contacts. Sometimes a touch-up procedure may have to be done.
Q: Will I need LASIK more than once?
A: No. LASIK is a procedure which permanently alters the shape of the cornea, it is therefore irreversible and once the refraction has stabilised there should be no need for further treatment. It cannot correct a condition known as presbyopia, or aging of the eye which normally occurs around the age of 40, which may require the use of reading glasses.
Q: Can I throw my glasses away after LASIK?
A: Most (95%) of patients have normal vision after LASIK. They can function without the aid of glasses or contact lenses. Some may need glasses for driving at night, but this is mainly restricted to patients with high refractive error who have a higher risk of under correction.
Q: What is the highest prescription that can be treated with LASIK?
A: Presently, most surgeons prefer to stay in the range +6 D to -15D for LASIK,
although medical literature contains reports of treatments being attempted as high as -20D of myopia and +10D of hyperopia. Such cases usually require small optical zone diameters (that would be expected to create a compromise in vision quality) and ablation into the deep stroma (potentially compromising long-term stability and corneal integrity).Q: Does LASIK surgery weaken the cornea?
A: LASIK cuts across the corneal tissue, and the laser removes only some tissue, thereby having a minimal effect on the cornea’s resistance. PRK surgery is also considered to have a minimal effect on corneal rigidity, though the loss of Bowmans layer is thought to potentially reduce the cornea’s resistance to penetrating injury.
Q: Do I need to take time off from work?
A: We advise a day of rest following the procedure, but LASIK patients may return to work the day after the procedure if they choose.
Q: How soon after LASIK can I drive?
A: A patient may drive within 24 hours after the surgeon has confirmed your vision is adequate for driving safely.
If you have any questions regarding LASIK you are welcome to call us. We can arrange for you to be assessed at a time convenient for you.
Sharing the Vision Free call 1800 807 363 or email.
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Refractive surgery involves a number of procedures which off an opportunity to decrease or eliminate your dependency on spectacle correction. Unfortunately, from the ages between 40 to 50 years of age, presbyopia begins to occur. Presbyopia is where the lens in the eye no longer has the ability to accommodate or focus for near vision. As such, for anyone aged within this range or above, if the refractive error is corrected for distance vision, they will require near spectacles. If you are shortsighted you will be able to take your spectacles off and read. Correcting your distance vision will mean you need a reading correction.
Monovision offers an opportunity to decrease your dependence on near spectacles. In this situation, one eye is fully corrected for distance vision and the other eye is corrected for reading. It is worthwhile noting that the eye corrected for near vision will be blurred in the distance, but the two eyes working together compensate this slight compromise to your vision.
Not everyone is suitable for the monovision correction. Monovision has been shown to have a small effect on driving performance, with regards to depth perception. We recommend a trial with contact lenses to simulate monovision prior to surgery to assess how you cope visually with your day to day activities and driving. If you have a commercial vehicle licence requiring good distance vision in both eyes, you will not be a candidate for monovision. If you are actively involved in sporting activities requiring very good general vision and/or depth perception, monovision is also not an option for you.
The strength of the monovision or the near vision eye is specifically chosen to suit your needs. For example, some people may wish to keep reasonable distance vision in the near eye and have only limited near focus for situations such as reading a menu at a restaurant or grocery shopping without the need for near spectacles. These people would still require near spectacles for general prolonged reading or fine print. Alternatively, some people may wish to be capable of reading very fine print. Your visual tasks and general lifestyle are very important in determining the monovision strength.
For some people with monovision, night driving spectacles may be required. In the dim illumination, the pupil size increases which causes a decrease in the depth of focus for the eyes. This means that you can notice some blur with your distance vision and could include such situations as night drive, theatre, or movies. Spectacles in this situation is dependent on how the patient feels they are coping.
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