Lasik eye surgery is a type of laser eye surgery and accounts for over 90% of all procedures that are carried out. The other main type of laser eye surgery is Lasek, which is generally only considered if you are not suitable for Lasik, as the recovery period is considerably longer and more painful. You can read more about Lasek by clicking this link.

Lasik is an extremely safe, accurate and in most cases painless procedure and has been around a lot longer than most people realise. The first-ever Lasik procedure was actually carried out over 20 years ago and since then the procedure has improved both in terms of accuracy and safety.

The aim of laser eye surgery is to reshape the surface of your cornea (outer part of your eye) to eliminate the prescription in your glasses/contact lenses. Depending on whether you are long-sighted, short-sighted or have astigmatism, the laser reshapes the eye in a certain way. The following explains this:

• Long-sighted prescriptions (plus prescriptions): If you are long-sighted, this effectively means that your cornea is too weak to focus the image perfectly onto your retina. Laser eye surgery increases the power of the cornea by increasing its curvature (steepening), which in turn ensures the image is now focussed onto the retina and hence your vision is perfect.
• Short-sighted prescriptions (minus prescriptions): If you are short-sighted, this effectively means that your cornea is too powerful to focus the image perfectly onto your retina. Laser eye surgery reduces the power of the cornea by decreasing its curvature (flattening), which in turn ensures the image is now focussed onto the retina and hence your vision is perfect.
• Astigmatism: You can read how laser eye surgery corrects astigmatism here.

The way in which the laser reshapes the surface of your eye is exactly the same for both Lasik and Lasek; it is just where the laser is applied that is different. Lasek is considered a surface treatment as the laser is applied to the outer surface of the cornea, whereas during Lasik the inner layers of the cornea are lasered.

Lasik Procedure:

Understanding exactly what happens during the Lasik procedure is vitally important in deciding whether or not to go ahead and have the surgery.

People hear all sorts of things about what to expect during the Lasik procedure and more often than not, what they have heard is not true. For example, one of the biggest reasons that people decide against having Lasik eye surgery is the thought of having an injection in your eye. There are however no injections involved at all in the procedure. Your eyes are anaesthetised using eye drops, which at worst result in mild stinging of the eyes for about 20 seconds.

What To Expect On The Day of Surgery:

• Before you have the actual treatment you will most likely have a pre-surgery consultation with your surgeon. The surgeon will ensure that you fully understand exactly what to expect during the procedure and check that you are happy to proceed. The surgeon may well take a few final measurements to double-check everything is ok. After this, you are ready for surgery. Your surgery will be as follows:
• An Anaesthetic eye drop (not injection) is first applied to the eye. This will cause a slight stinging sensation but will wear off after 20 seconds or so. Within 1 minute your eyes will be completely numb.
• A small clip is used to ensure your eyelids are kept open so that you do not blink during the surgery.
• A thin layer of the cornea is then separated from the surface of your eye (a flap) using a microkeratome (scalpel) and then gently lifted, allowing the surgeon to access the inner layers of your cornea.
• If you are having Intralase Lasik, the flap is created using a laser.
• The laser is then applied to the inner layers of the cornea for any time up to one and a half minutes depending on your exact prescription requirements. The aim of the laser is to reshape your cornea to eliminate the prescription in your glasses/contact lenses. The higher your prescription the longer the laser will be applied for. The laser is typically applied for 10 seconds for every dioptre of your prescription. This means if your prescription is -5.00 then it will be 50 seconds.
• An antibiotic eye drop is instilled with the flap open to minimise the risk of infection. The surgeon then replaces the flap to its original position and smoothes it over and it is allowed to heal naturally. A bandage contact lens is often placed on to the eye following surgery in order to protect it.
• The whole procedure typically takes about 15 minutes.

• After Lasik surgery, you may experience mild discomfort with the most common symptoms being dryness, itchiness and light sensitivity. Some people barely have any discomfort at all but this varies depending on individual circumstances.
• After surgery, you will be required to wear sunglasses as you will be sensitive to light. Don’t forget to bring them with you on the day of the procedure.
• You will be prescribed antibiotics, anti-inflammatory’s and dry eye drops following your surgery to aid your recovery.
• As part of your aftercare programme, you will be given protective goggles for overnight wear. (This is to stop you rubbing your eyes during the night so you do not move the flap).
• Most people can return to work the next day but this is dependent on your symptoms and varies from person to person. Plan to have 2 days off work in case there are any complications after your surgery. If you work in a dry or dusty environment or your job requires a lot of physical exertion, then you may need longer off work.
• After Lasik eye surgery you will need someone with you to drive you home. Some people are able to drive within 24 hours of surgery but this depends on how quickly your eye heals. Your optician will advise you at your 1-day-post-operative appointment if you meet the legal driving requirements.
• After your surgery you should expect to have the following aftercare appointments: 1-day post-op, 1-week post-op, 1-month post-op, 3-month post-op and 6-month post-op. Attending your aftercare appointments is extremely important in ensuring a full recovery.

What are the potential Lasik complications?

• Wrinkled/uneven Flap: This can result in a distorted cornea which can cause blurred vision. This complication can generally be easily treated by re-lifting the flap and smoothing it over.
• Epithelial ingrowth/trapped debris: The epithelium (outer layer of the cornea) sometimes grows below the flap that is created during Lasik. Another Lasik risk is debris becoming trapped beneath the flap which like epithelial in growth, can cause your vision to be blurred after surgery. Both these cases can be treated easily by your surgeon by re-lifting the flap and thoroughly cleaning it before resealing it again.
• DLK: Diffuse Lamellar Keratitis can be a severe Lasik risk and occurs when dead cells which lie beneath the flap cause an inflammatory response. This can lead to scarring of the cornea which can result in reduced vision. Depending on how serious the inflammation is antibiotics and topical steroids may be used to treat it. In most cases, this condition can be successfully treated meaning no loss of vision occurs.
• Keratectasia: Although rare, this is of the most serious complications of Lasik. If during surgery the laser removes too much tissue (cornea) or the flap that is made is cut too deep, the structure/strength of the cornea can become compromised. This can result in the cornea bulging forward in an irregular manner resulting in astigmatism which causes blurred vision. This can often be treated with contact lenses, spectacles or possibly a laser enhancement.
• Retinal Haemorrhage/Retinal detachment: These are extremely rare Lasik risks and can be treated in most cases.

Prescription Parameters: Lasik Eye Surgery:

• Short-sightedness: -0.75 to -12.00DS.
• Long-sightedness: +0.75DS to +5.00DS.
• Astigmatism: Standard treatment: Up to +/- 3.00Dcyl. Wave front: up to +/- 6.00Dcyl.

This is only a rough guide to Lasik parameters as they vary widely from company to company, surgeon to surgeon and depends on the individual being treated.