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LASIK Eye Surgery
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What Is LASIK Surgery?
LASIK is a type of laser eye surgery that can remove the need for wearing contact lenses or glasses. This section below will give you an summary of what’s involved in LASIK surgery, what you can expect afterwards and other important aspects of the surgery, including the risks involved. There’s also a glossary of terms that you can familiarise yourself with, so you feel knowledgeable as you consider this form of surgery for correcting your vision.
LASIK stands for Laser-Assisted in Situ Keratomileusis and is one of the most common forms of laser eye surgery today. The procedure uses a laser or blade device to permanently alter the shape of your cornea (the clear layer that covers our eye) by cutting a flap in it to reveal the corneal tissue underneath. Below is a great summary video of how LASIK surgery works from the folks at BrainStuff.
In essence it is the reshaping of the cornea during the surgery that improves vision and corrects a range of eyesight problems including:
- Myopia – Also known as shortsightedness or nearsightedness, the laser will be used to flatten the eye’s cornea to correct this problem.
- Hyperopia – Also known as farsightedness or longsightedness, the cornea is made steeper by directing the laser in the central area to remove tissue.
- Astigmatism – To make the cornea more spherical, the laser is concentrated on the area of the cornea that is most steep.
How Does LASIK Compare To Other Laser Eye Treatments?
An acronym of Laser In Situ Keratomileusis, LASIK surgery is now the most common form of laser eye surgery procedure. LASIK is used to correct both short and long-sightedness. However, for people who require higher prescriptions it may not be the best form of treatment.
LASIK treatments are performed by the surgeon cutting across the cornea and subsequently raising a flap of tissue. The excimer laser is then used to reshape the exposed surface and the flap is replaced.
Wavefront-Guided LASIK and LASEK
Rather than a one size fits all treatment, this is is a tailor-made form of laser eye surgery where treatment is customised to a patient’s particular eye shape and prescription through the use of computerised 3D imaging technology.
LASEK (Laser-Assisted Epithelial Keratomileusis) involves peeling back the epithelium (the thin layer of cells that cover the cornea) exposing Bowman's layer. This is then reshaped with a laser beam and the epithelium is replaced. Retaining the flap is considered to prevent any complications while at the same time speeding up healing.
LASEK with Wavefront 3D imaging can provide the best results (see the Wavefront tab below).
Who is it for?
This procedure is suitable for people with common sight problems, such as nearsightedness, farsightedness and astigmatism.
Wavefront is a type of technology utilised in LASIK and LASEK procedures. Special software creates a 3D 'map' of the patient’s eye so treatment can be customised to a patient’s particular eye shape and prescription.
This 3D imaging technology often has different names due to the variations on the machines & software used in different clinics (e.g. iDesign in Optical Express).
Who is it for?
This customised treatment is designed to be a superior alternative to standard LASIK and LASEK procedures. This is perfect for people who rely on perfect vision for their jobs and are happy and able to pay the extra (it is more expensive than standard LASIK and LASEK treatments).
ReLEx SMILE (Refractive Lenticule Extraction and Small Incision Lenticule Extraction), is a relatively new minimally-invasive 'key-hole' laser eye treatment which offers a great alternative to LASEK and LASIK treatment.
Rather than creating a flap in the cornea for the laser, this procedure involves making a small hole in the cornea using a state of the art laser that places a series of pulses in the centre of the cornea. which will heal on its own afterwards.
Although it is more expensive than the other techniques, very good results have been achieved using this method. This technique allows surgeons to treat patients with even higher prescriptions than previously deemed possible. The procedure is even suitable for many patients with thinner corneas, drier eyes, or contact lens intolerance.
PRK
An acronym of Photorefractive Keratectomy, PRK surgery is a form of eye correction was widely used since the early 1980s, but since the introduction of LASIK and LASEK, it’s now widely used in the correction of high prescriptions. Reshaping of the cornea is done without creating a flap of tissue using the excimer laser. This is normally the cheapest form of laser eye surgery.
TransPRK
An acronym for transepithelial photorefractive keratectomy, TransPRK by Schwind is the most advanced version of surface treatments. It is the only surface treatment where no contact between the eye and an instrument is required.
What Are The Different Types Of LASIK Eye Surgery?
Before you start looking for an eye surgeon to carry out your surgery, it’s important that you understand the different types of LASIK eye surgery that are available. With a number of different procedures that can vary quite significantly (in both the technology used and price of the operation), you may find that one type of LASIK surgery will be better for you than another.
- Standard LASIK: Of all of these types of laser eye surgery, LASIK is the most invasive as the cornea is deeply cut to create the flap for the laser. However, when it comes to the outcome, this is advantageous, as the deep tissue of the cornea won’t grow back so your vision won’t return to what it was before. And, because the epithelium isn’t damaged, it is one of the best procedures for a fast recovery time.
- IntraLASIK (IntraLase):This also falls into this same category as standard LASIK surgery because the procedure is the same apart from the fact that a laser is used to make the flap in the cornea instead of using a sharp blade (a microkeratome).The laser should provide surgeons with greater accuracy, thus providing the patient with a better outcome.
- Epi-LASIK: This differs from IntraLASIK and LASIK because only the epithelium (the outer layer of cells of the cornea) are removed before the laser is used to remodel it. In Epi-LASIK, a thin plastic blade is used to cut this layer before using an epithelial separator to fold it back. Epi-LASIK doesn’t use any alcohol to soften the epithelium (something that’s found in LASEK surgery) because many feel this can damage the eye’s delicate covering and can cause the patient more discomfort after the operation.
- H-LASIK (Hyperopic Laser-Assisted in Situ Keratomileusis): Instead of just correcting one problem with the eye, H-LASIK looks to correct hyperopia and astigmatism at the same time. Recovery can be slightly longer than standard LASIK but H-LASIK is generally preferred over H-PRK (Hyperopic Photorefractive Keratectomy) as it provides a faster recovery time. The procedure involved in this surgery is much the same as LASIK.
- Wavefront: With advanced technology, Wavefront provides custom laser eye surgery as it collects data about the patient’s eye before the surgery. It precisely measures the imperfections in the eye to give three-dimensional measurements that will help to guide the laser during LASIK surgery. This provides a greater degree of accuracy, personalising the visual outcome that is achieved for the patient. Because standard measurements are relied on in other procedures, this makes it the most sophisticated but expensive of procedures with average LASIK costs varying from £1,500 to £1,900 per eye.
What Risks Are Involved In LASIK Surgery?
Thankfully, most patients are delighted with the results they achieve after LASIK but, as with any other procedure, there are some risks involved. That’s why it’s important to understand the potential complications and limitations involved in laser eye surgery before you commit to the operation.
Below are some of the complications that can occur as a result of LASIK – take your time to read through these and try not to be influenced by family or friends, or even your surgeon, when considering this form of corrective eye surgery.
- Loss of Vision: Some patients find that as a result of their treatment they lose certain lines of vision – this cannot be corrected with surgery, contact lenses or glasses.
- Visual Symptoms that are Debilitating: Double vision, halos and/or glare are all reported vision problems that patients have suffered from, which can seriously affect how they see at night. Even if one has good vision, some patients find that they can’t see well in low contrast (e.g. in fog or at night) and this is something that has occurred after they’ve had the treatment.
- Over- Or Under-Treatment: When the amount of correction is more or less than desired. 20/20 vision will only be achieved by a certain amount of patients without the need for contacts or glasses. In some cases, additional treatment may be required but this isn’t always possible and contact lenses or glasses may still be required after surgery. Even if you’ve only ever had a weak prescription for your glasses before surgery, you may still require them afterwards; or if you had to use reading glasses before, you may still need them after.
- Dry Eye Syndrome: Laser eye surgery can sometimes result in the eye becoming dry as it isn’t able to produce the amount of tears needed to keep it comfortable and moist. As a result, the eye can become very uncomfortable and it may result in reduced quality of vision due to a variety of symptoms, including blurring. Sometimes, this condition is permanent and may require the use of plugs or intensive drop therapy to try and improve it.
- Large Refractive Errors: For any type of vision problem with a large refractive error, this might not be the right surgery for you as results don’t tend to be as good in patients with these types of problems. If you do have a large refractive error, you should manage your expectations with your surgeon, understanding that even after surgery it’s likely that you’ll still need contacts or glasses.
- Diminished Sight for Farsighted Patients: The vision you achieve after surgery may decrease the older you get if you’re a farsighted patient. This can occur if you have different results between your vision exam before dilating drops and after dilating drops.
- There’s No Long-Term Data: LASIK was first introduced in the 1990’s, which means it’s still a relatively new form of technology. Because of this, a lot of elements of LASIK surgery remain unknown, including how effective it is and how safe it is on a long-term basis.
LASIK Eye Surgery Procedure
What To Expect Before Surgery
If you’ve decided that LASIK surgery is the best option for you, you’ll need to arrange an initial consultation and evaluation with a specialist eye doctor to make sure you’re an eligible candidate for the procedure. Knowing what to expect and how you can prepare for your examination can help you to get the results you’re looking for:
If you wear contact lenses – it’s a good idea to remove these and wear your glasses instead before you go for your initial consultation. The shape of your cornea will be altered by your contact lenses and this can last for several weeks, even after you’ve taken them out (this depends on the type of contact lenses you use). If you don’t leave your contact lenses out for enough time, you may not give your cornea the chance to resume its normal shape before your evaluation, which could severely affect the outcome of your surgery.
The consequences of a misevaluation during your consultation include a poor surgical plan and inaccurate measurements, which may result in worsened vision after your surgery. The measurements that are taken during the examinations (which help to determine how much of your corneal tissue will need removing) may need to be repeated a week or so after the first consultation you have and before your surgery, just to make sure there have been no changes, particularly if you wear hard or RGP (rigid gas permeable) lenses.
Below you’ll find some recommendations of how long you should leave certain types of contact lenses out before your evaluation (it’s also worth consulting your eye specialist for their advice too):
Soft Contact Lenses – Stop wearing these types of contact lenses at least 2 weeks before you go for your first eye examination.
RGP or Toric Soft Lenses – Stop wearing these types of contact lenses at least 3 weeks before you go for your first eye examination.
Hard Lenses – Stop wearing these types of contact lenses at least 4 weeks before you go for your first eye examination.
Once in your consultation, there are several things that you should tell your doctor before you proceed with the surgery. These include whether you have any present or past eye medical conditions and what medications you are taking, including any ones you’re allergic or think you may be allergic to, and over-the-counter medications.
During your eye exam, your doctor should discuss whether they think you are a good candidate for the surgery; what the alternatives, benefits and risk of the surgery are; what you can expect before, during and after the procedure; and what you’ll be responsible for before, during and after the procedure.
You should also have plenty of time to ask the doctor any questions that you may have about your surgery. Make sure you take the time to think about the benefits and risks that your surgeon has discussed with you, reviewing any information that has been given to you. Then, if you do have any further questions before your surgery, consult your doctor first before you sign the consent form that you will be given.
It’s important that you don’t feel pressured at any time by friends, family or your doctor, as it is not their decision to make. Carefully consider what options there are available to you as well as the advantages and disadvantages of the surgery.
The Day Before Your Procedure
You should stop using any perfumes, make-up, lotions or creams as these, along with any debris found in your eyelashes, can increase your risk of infection. Sometimes, you may find that your eye doctor asks you to clean your eyelashes for a certain amount of time before surgery to get rid of any debris or residue that might be contained in them.
You should also arrange transportation for your surgery, especially after your operation, as the medicine you may be prescribed, along with the initial after-effects of the surgery, can make your vision blurry. Therefore, even if you don’t drive, you should make sure there’s someone who can help to get you home after your procedure.
What To Expect During Surgery
You can expect the surgery to take from 30 minutes to 1 hour, and you won’t be required to stay overnight. You can also have both of your eyes operated on at the same time, and you’ll be awake throughout the entire procedure because only a local anaesthetic is used to numb the area.
In the operating room, you’ll be seated in a reclining chair and made to feel comfortable. A numbing drop will then be placed in your eye (this may sting slightly). Once the numbness has set in, the area around your eye is cleaned and a lid speculum is put into place – this is an instrument that helps to keep your eyelids open throughout the procedure.
Your doctor may then use a blade device (a microkeratome) on your cornea to cut out the flap. If they do, they’ll also place a ring on your eye to apply a high pressure that will create suction on the cornea, and this will cause your vision to dim. Sometimes, there may be a red or green light that you’re asked to focus on while this part of the operation is carried out. This is also the part of the procedure where you may feel some discomfort due to the pressure being applied, but this isn’t something to worry about. The microkeratome blade is attached to this suction ring, and they’ll use this to make the incision that allows them to access the corneal tissue underneath your cornea.
Alternatively, your doctor may use a laser device to cut the flap, and when they do this, they’ll use a clear plastic plate to flatten the cornea. Again, your vision may become blurry and some discomfort may be experienced. The laser is then concentrated on the cornea tissue, which creates lots of small bubbles of water and gas that help to separate the corneal tissue, which creates a flap. Once this has been done, the plate will be removed.
Regardless of whether your doctor uses the mechanical blade or the laser, you will still be able to see but you can expect your vision to fluctuate between being clear and blurred for the rest of the operation. The doctor will lift back the flap on its hinge before drying the tissue underneath that has been exposed.
You’ll then be asked to stare at a light as the laser is put in position above your eye; this light is used to keep your eye in the same position once the laser is activated (please note – if you do struggle to stare at a fixed point for a minute or more, you might not be a good fit for this type of surgery). This isn’t the same laser that is used to remove your corneal tissue.
As soon as your eye is in the right position, the laser will be started by the surgeon. This is when you may become aware of new smells and sounds – for example, a ticking sound can be heard from the laser, and you may smell burning (almost like the smell of burning hair) as the laser removes your corneal tissue; but again, this isn’t anything to worry about.
The laser will work at transforming the shape of your cornea and will have been programmed by your doctor prior to your surgery. The laser will vaporise a certain amount of tissue, depending on what is required and what measures were taken during your examinations. Once this has been done, the flap will be placed back into its original position.
To protect your eye after surgery, a shield should be placed over it – especially as there are no stitches holding the flap in place (it bonds back together naturally within a very short period of time). You’ll have to wear this protective shield all of the time, even whilst you’re asleep, because it will prevent you from putting pressure on your eye or rubbing it – and will also protect it from any accidents or debris until the flap has healed completely.
What To Expect After Surgery
An itching or burning sensation may occur straight after your procedure or you may feel like you’ve got something in your eye. It’s normal to experience some discomfort following your surgery, and some also experience mild pain. If this is the case, your doctor may advise that you take some mild pain relief. You may also find that your eyes water or tear and that your vision becomes blurry or hazy at times. When experiencing these symptoms, your first instinct may be to rub your eye but it’s important that you don’t. This could move the flap out of position, meaning you’ll require more treatment.
Other common after effects include seeing halos around lights, starburst, glare or sensitivity to light; you may also find that your eye looks bloodshot or red. However, all of these symptoms should start to clear up within a few days of your procedure, which is why doctors recommend that you take a few days off from work after your surgery to allow these symptoms to subside.
If you do start to experience severe pain or your vision and/or symptoms start to worsen, you should contact your doctor immediately – don’t just wait for your scheduled follow-up appointment. This scheduled appointment should occur a day or two after your procedure as well as at regular intervals for the first six months after the surgery.
At your first post-procedure visit, your doctor will remove the shield, examine your eye and test your vision. They may also provide you with certain eyedrops that you need to use to prevent any inflammation and/or infection. Some may also advise that you need to lubricate your eye using artificial tears. You shouldn’t start wearing contacts in the eye that has been operated on again, even if your vision is still blurry.
It’s advisable that you wait at least one to three days after your surgery before you play in any non-contact sports. When you start these again will depend on your doctor’s advice, how you feel in yourself and how much activity you will be undertaking. For strenuous sports that involve contact (e.g. karate, football and rugby), you should avoid these for at least a month after your surgery. And when you do partake in these again, it’s important that you protect your eye from getting bumped or hit by anything.
You should also avoid make-up, creams and lotions around your eye until your doctor advises (this will be approximately two weeks after your surgery) to help prevent infections. You may also be advised to wash your eyelashes for a certain amount of time after, and you should also avoid using whirlpools, hot tubs or swimming pools for 1 to 2 months.
For the first few months after you’ve had laser eye surgery, your vision may change and fluctuate, meaning you can’t expect it to be 100% straight after. Your vision may not stabilise properly until three to six months after your surgery and visual symptoms such as halos, glare, and difficulty driving at night, may continue to occur during this period. Should you find that you do require further corrective treatment, you should wait until you’ve had two consistent eye measurements taken at two different consultations which are at least 3 months apart.
It’s also important to note that even though being operated on again may help to improve how you view things, it’s unlikely that other visual symptoms like halos or glare will correct themselves. However, if after your surgery, whether it’s your first or second, you do start to develop any other symptoms or you become concerned about the health of your eyes, you should contact your doctor immediately as this could signal that there’s something wrong. If these signs aren’t treated quickly enough, it could lead to further complications such as vision loss.
A Glossary of LASIK Terms
When reading through all of the literature you may be presented with before your surgery, you may find that there are some terms you’re unfamiliar with. Below is a glossary of terms that you may come across, which should help you to understand what’s involved in your surgery:
Ablate: The act of removing something in surgery.
Ablation Zone: The area where tissue will be removed during the operation.
Accommodation: How able the eye is to change focus from near objects to those in the distance.
Acuity: The sharpness or clearness of vision.
All-Laser LASIK: Referring to the type of LASIK surgery that is carried out using a laser device instead of a blade device when cutting the flap in the cornea.
Astigmatism: When irregularities in the lens or cornea cause images on the retina to become distorted.
Cornea: The front part of the eye that’s clear and provides our focusing power by refracting (bending) the light.
Diopter: This is what the refractive error of an eye is measured in. If it is a positive value, this means the eye has hyperopia; if it is a negative value, this means the eye has myopia.
Dry Eye Syndrome: This is a common side-effect after surgery and occurs when the eye doesn’t produce enough moisture or tears to keep it comfortable and moist. Blurred vision, scratching, burning or stinging sensations are some of the symptoms.
Endothelium: Found on the inside of the cornea surface, this is an inner layer of cells.
Epithelium: The outer layer of cells found on the cornea, defending the eye against infection.
Excimer Laser: This is used to remove corneal tissue during surgery and is an ultraviolet laser.
Farsightedness: Another term for hyperopia.
FDA: The Food and Drug Administration who regulate medical devices in the U.S.
Flap and Zap: A term for LASIK that’s sometimes used (slang).
Ghost Image: When viewing an object, if you see the same image again but fainter, this is the ghost image.
Glare: Decreased vision when bright lights scatter across it.
Halos: When there are optical imperfections in front of or in the eye, rings (halos) may appear around lights.
Haze: The sensation of looking through fog or smoke caused by corneal clouding.
Higher Order Aberrations: These are refractive errors that can’t be corrected using contacts or glasses and aren’t nearsightedness, astigmatism or farsightedness.
Hyperopia: When distant objects are seen clearly but those close-up aren’t.
Informed Consent Form: Something you may have to sign before your procedure which details the alternatives, benefits and risks involved in your surgery.
In Situ: In place.
Iris: Located behind the cornea but in front of the lens, this is the coloured ring of tissue that you can see in your eye.
Keratectomy: Removing corneal tissue through surgery.
Keratotomy: Cutting the cornea with a surgical incision.
Keratitis: Inflammation of the cornea.
Kerato: Relationship to the cornea (prefix).
Keratoconus: When images are distorted or blurred due to an irregular corneal surface (cone-shaped).
Keratomileusis: Reshaping the cornea by carving it.
Laser: Light Amplification by Stimulated Emission of Radiation – used to vaporise tissue with the powerful beam of light that is produced.
Laser Keratome: A laser that’s used to cut the flap in the cornea.
LASIK: Laser-Assisted in Situ Keratomileusis – refers to cutting the flap in the cornea before using a laser to reshape the tissue underneath.
Lens: With its ability to change shape, the lens is another part of the eye that helps it to focus.
Microkeratome: Used during LASIK surgery, this device is fixed to the eye through suction and a sharp blade is used to cut through the cornea to create a flap.
Monovision: When the two eyes are adjusted so one can see in the distance and one can see objects close up.
Myopia: When close-up objects are seen clearly but those in the distance aren’t.
Nearsightedness: Another term for myopia.
Ophthalmologist: A doctor that specialises in eyes.
Optician: An expert who can make and fit glasses and may also offer contact lens solutions.
Optometrist: Someone who can diagnose, manage and treat eye diseases and visual problems.
Overcorrection: This is one of the potential complications of LASIK surgery and means that the amount of correction is over the amount that was required.
PRK: Photorefractive Keratectomy – where the surface layer of the cornea is removed by gently scraping it and using a computerised laser to reshape it.
Presbyopia: When objects are moved closer and you are unable to maintain a clear focus. This occurs due to age and the elasticity of lens being lost.
Pupil: The black dot you’ll see in the centre of your eye that adjusts depending on the light. In bright light, it gets smaller whilst in dark light it will get bigger.
Radial Keratotomy (RK): This is a type of surgery that’s used to try and treat myopia and involves using radial cuts to flatten the cornea.
Refraction: A test that determines how refractive the eye is. It’s also a measure of how light bends when transferred from one object to another.
Refractive Errors: When the eye isn’t focusing properly – e.g. astigmatism, myopia or hyperopia.
Refractive Power: How able the eye is at bending light as it passes through it.
Retina: This lines the inside of the eye and is a light-sensitive tissue that captures the images we see and sends it to the brain.
Sclera: The outer layer of our eye which is tough and white and helps to protect our eye, along with the cornea.
Stroma: The thickest layer of corneal tissue.
Undercorrection: This is one of the potential complications of LASIK surgery and means that the amount of correction is under the amount that was required.
Visual Acuity: Refers to how clear our vision is and how able our eyes are at distinguishing shapes or details.
Vitreous Humor: The gel that fills the centre of our eye and lies in front of the retina, behind the lens.
Wavefront: This is a measure of the total refractive errors in an eye, including astigmatism, farsightedness and nearsightedness, as well as other errors that can’t be corrected using contacts or glasses.
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