Laser-assisted in situ keratomileusis (LASIK)

Published by Bupa's Health Information Team, January 2011.

This factsheet is for people who are planning to have laser-assisted in situ keratomileusis (LASIK) eye surgery, or who would like information about it.

LASIK eye surgery involves using a laser to change the shape of the cornea (the clear covering over the front of the eye).

You will meet the surgeon carrying out your procedure to discuss your care. It may differ from what is described here as it will be designed to meet your individual needs.

How LASIK eye surgery is carried out

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About LASIK eye surgery

LASIK stands for laser-assisted in situ keratomileusis. It uses a computer-controlled laser to change the shape of your cornea. LASIK can be used to correct or improve:

• short-sightedness (myopia)
  
• long-sightedness (hyperopia)
  
• an irregular-shaped cornea (astigmatism) 

To have LASIK you will need to be over the age of 21 and have healthy eyes. You will also need to have stable vision. This means that you have had less than a 0.5 dioptres change in your prescription over the last two to three years. Dioptres (D) is the unit of measurement used for the power of a lens.

LASIK isn't suitable if you:

• have age-related long-sightedness (presbyopia) – this is related to the weakening of your lens rather than the cornea
• have a condition that affects how your body heals, such as rheumatoid arthritis
• are pregnant or breastfeeding

Getting advice about LASIK

You will need to have a consultation with a surgeon to find out whether you’re suitable for LASIK.

Your surgeon will talk to you about the results you can realistically expect from LASIK, as these will vary from person to person.

During your appointment, you may have:

• a test that 'maps' the cornea to determine if LASIK is suitable for you
• a full eyesight test
• diagnostic tests, such as measuring the thickness of your cornea and the size of your pupils in various light conditions

What are the alternatives?

The non-surgical alternative is to continue wearing your glasses or contact lenses. Your surgeon will discuss the range of alternative surgical techniques available with you.

Preparing for your procedure

You will have to remove soft contact lenses at least one day before your appointment and hard/gas-permeable contact lenses at least one week before. This is because your contact lenses can affect the measurements of your eye. Your surgeon will tell you when you should stop wearing contact lenses.

LASIK is usually done as a day-case procedure. This means you have the procedure and go home the same day. LASIK is usually done under local anaesthesia. Anaesthetic drops will block feeling from the surface of your eye and you will stay awake during the operation. The procedure usually involves being at the hospital for around an hour.

Your surgeon will discuss with you what will happen before, during and after your procedure, and any pain you might have. This is your opportunity to understand what will happen, and you can help yourself by preparing questions to ask about the risks, benefits and any alternatives to the procedure. This will help you to be informed, so you can give your consent for the procedure to go ahead, which you may be asked to do by signing a consent form.

Your surgeon will explain how to prepare for your operation. For example, if you smoke you will be asked to stop, as smoking increases your risk of getting a wound infection and slows your recovery.

What happens during LASIK

You may be offered the option of either having each eye operated on separately or both eyes at the same time.

During the operation, you will lie back in a special chair. Your surgeon will place anaesthetic drops into your eye and may use a special eyelid clip to stop you blinking. You won't be able to see out of your eye while it's being treated, although you may see a red or green light.

Your surgeon will use a highly precise instrument with a blade or sometimes, a laser, to cut a very thin flap in your cornea. Your surgeon will open the flap (like the cover of a book) and use the computer-controlled laser to shape the cornea underneath. It will take about 30 seconds to remove the right amount of your cornea.

Your surgeon will then reposition the flap so that it can bond to the rest of your cornea. This takes minutes. You won't need any stitches.

You will have antibiotic eye drops put in your eye to help prevent you getting an infection.

What to expect afterwards

After the procedure, you may have some mild pain and your eye may feel uncomfortable for a few hours. If you need painkillers, take paracetamol or ibuprofen. Always read the patient information leaflet that comes with your medicine and if you have any questions, ask your pharmacist for advice.

You may also find that your vision is blurred which can make you feel disorientated. This should gradually improve within one or two days and your vision will usually stabilise within one to four weeks.

After your procedure you will need to:

• wear a protective shield over your eye for around 24 hours
• wear sunglasses or a hat when you leave the hospital or clinic as your eyes will be sensitive to the sun
• arrange for someone to drive you home
• have a friend or relative stay with you for the first 24 hours, especially if you have had both eyes treated
• use eye drops to prevent infection and promote healing – your nurse will give you advice about how to use them before you leave

You will be given a date for a follow-up appointment.

Recovering from LASIK eye surgery

You shouldn't go out into the sunshine without sunglasses after you have had LASIK eye surgery. You will need to wear them for three months. You should also not play contact sports, racket sports or go swimming for at least four weeks, or drive for the first one to two weeks.

For the first few days after having LASIK eye surgery you should not: 

• have a shower – if you can, have a bath instead
• wash your hair
• touch, rub or screw up your eyes or get anything in them – you might find that sunglasses help
• wear eye make-up

You should be able to return to work after two to three days.

If you experience more than mild pain, or you have any problems with your vision or increasing redness of your eye, contact your clinic or hospital.

What are the risks?

As with every procedure, there are some risks associated with LASIK. We have not included the chance of these happening as they are specific to you and differ for every person. Ask your surgeon to explain how these risks apply to you.

As the treatment is relatively new, there is limited evidence on the long-term effects.

Side-effects

These are the unwanted, but mostly temporary effects you may get after having the procedure.

After LASIK you may have:

• dry eye(s) for up to a year afterwards
• a glare around bright lights, causing a ‘halo’ or ‘starburst’ effect, which can make night-time driving difficult but shouldn't last more than six weeks
• a drooping eyelid, which should get better within a few weeks

Complications

This is when problems occur during or after the operation. Most people aren't affected.
Very rarely, complications can lead to reduced vision or blindness.

Specific complications of LASIK are rare but can include:

• mild or moderate haziness or scarring of your cornea
• slight over- or under-correction of short-sightedness – you may be offered another operation to improve this
• some return of short-sightedness
• accidental damage to your cornea - you may need stitches to keep it in place if it becomes loose
• problems with the flap that is cut in your cornea
• your vision getting worse

The amount of improvement that you have in your eyesight depends on how well your eyes heal, but it can't be guaranteed. If the operation doesn't achieve the result you hoped for, you may need further LASIK treatment.

For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.