Laser eye surgery is a fairly recent innovation which can help provide a safe and highly effective method of correcting several visual problems. In many cases patients can often lose the need to constantly wear glasses. There’s two main traditional techniques used in laser eye surgery, LASIK (laser-assisted in situ keratomileusis) and PRK (Photorefractive keratectomy). However, new technology and innovation is constantly being developed and refined leading to better and safer procedures. The main differences between the two different types of surgeries, is the way in which the middle layer of the cornea, known as the stroma, is exposed before it is vaporised through use of a laser.
LASIK laser eye surgery
LASIK is the most commonly used type of refractive eye surgery and can be used to treat several sight related problems such as long sightedness, short sightedness and astigmatism. During the procedure a computer controls a laser which is used to reshape the cornea. In the vast majority of cases the surgery can greatly minimise the need for contact lenses or glasses. The surgery works by changing the shape of your cornea which then bends light properly and focuses the light onto your retina in the right way. In cases of myopia (near or short sightedness) the laser can be used to flatten the front surface of your eye. For long sightedness (hyperopia) the surgery can steepen the central cornea as the laser removes a precise amount of corneal tissue from the area. Similarly, astigmatism is corrected by reshaping the steepest part of your cornea in order to make it more spherical.
The LASIK surgery usually takes about an hour to complete and is typically performed as an outpatient procedure, meaning you can return home the same day. General anaesthetic is not used during the procedure, so you will be awake throughout. However to reduce any discomfort and to numb any pain a local anathestic is usually applied. It’s typical to experience blurred vision throughout the procedure. Firstly your surgeon will numb the area by using anaesthetic drops applied straight to the eyes, the eyes are then cleaned using an antibacterial wash. Special instruments are used to hold your eyelids in place in order to keep your eyes open during the procedure. Your surgeon will then apply a suction ring to the eye in order to provide the necessary pressure to the cornea before cutting it. Often, you will be asked to focus your vision on a coloured light to assist surgery, this is usually green or red.
Your surgeon will begin by making a cut on the surface of the cornea. A flap will be cut out and folded back using a special surgical blade known as a microkeratome, in order to expose the tissue underneath. The exposed tissue is then dried and the laser is put into position. The laser then begins to remove corneal tissue and reshapes the cornea while being guided by a computer, some patients report noticing a burning smell during this part of the treatment. Once the correct amount of tissue has been removed, the flap is then quickly put back into place and no stitches will be required. Once the surgery is complete you are free to leave, however it’s recommended you take care of yourself and get someone else to drive you home.
After the surgery
Immediately following the LASIK surgery, it’s normal for your eyes to feel itchy, watery and blurry. It’s typical for your surgeon to prescribe some pain medications or eye drops in order to reduce any discomfort. In order to promote healing, it’s also typical to wear eye patches while asleep at night. You should be able to see right after surgery although it won’t be very clear. It usually takes a couple of months for the eye to completely heal and your vision to stabilise. It’s worth noting that the clarity of your vision before surgery can often affect the results of achieveing crystal clear vision after the surgery. It’s normal to have several follow up visits with your surgeon over the next six months in order to monitor your healing and check for signs of complications. It’s usually recommended that you avoid using make up for a few weeks after surgery so that no foreign substances can contaminate your eyes. It’s also advised that you avoid any contact sports as this could put your eyes at an increased risk of trauma. Similarly any water-based activities such as saunas or swimming will have to be avoided for a while after surgery.
Although the majority of eye surgery is performed safely, as with all surgical procedures there are some risks involved. Complications can occur when the flap on the front of your eye is folded back during the procedure. This can include swelling, excessive tearing and infections. The outer tissue layer of the cornea is also at risk of growing in an abnormal way. If the amount of tissue removed was not enough then the clarity of vision experienced might not be as good as your expectations. This is called undercorrection and those who are nearsighted are also at an increased risk of this. In order to fix this type of problem, another surgical procedure may be required. Similarly, if too much tissue is removed then your vision can become over-corrected although this is much more difficult to fix than under correction. If an uneven amount of tissue is removed from the eye then it may lead to astigmatism. This happens when your eye moves too much during surgery and requires more surgery to correct.
Although it’s normal to experience dry eyes for the first few months following surgery, in some cases this can become severe. It’s normal to be prescribed eye drops in order to reduce discomfort but in excessive cases you may require another procedure and may need special plugs for your tear ducts. These can help to keep your eyes moist and prevent severe draining from your eyes. Difficulty seeing at night, glaring, double vision and halos can all occur after the surgery. Whilst eye drops are usually enough to handle these in rare cases more surgery will be required to fix these issues.