How does laser eye surgery work?
Laser eye surgery outcomes are consistently phenomenal when performed in the right hands, with the correct technology and in the right environment. The popularity of the procedure continues to grow with approximately 100,000 procedures in the UK each year.
Laser eye surgery is often selected by those who wish to avoid wearing glasses or contact lenses, or by those who’ve had problems with either. Often the choice is made because of career choice, with many who wish to join the police force, military or fire service (approved by the Home office in 2003) getting it done.
What is laser eye surgery?
Laser eye surgery is a procedure that is used to correct short sightedness (myopia), long sightedness (hypermetropia), astigmatism and now presbyopia (the need for reading glasses). It was introduced to the UK in 1995 by Sheraz Daya, Medical Director of Centre for Sight.
The treatment involves reshaping the cornea, the clear layer at the front of the eye. This reshaping is performed using an ‘excimer’ laser which helps the eyes to focus which in turn dramatically improves natural vision. In the LASIK procedure the reshaping takes place under a micro-thin flap fashioned using another laser, the femtosecond laser (introduced to the UK by Centre for Sight in 2004).
During a laser eye treatment, anaesthetic eye drops are applied to reduce any pain and the surgeon inserts a small ‘clip’ to keep the eyelid open.
In Lasik or IntraLASIK, the Intralase femtosecond is used first to create a thin flap. After this the excimer laser uses iris registration technology to recognise and track the eye. The flap is lifted and reshaping takes place. The whole procedure takes less than 7 minutes per eye.
This process is painless, though patients can expect to experience a little pressure when the Intralase laser creates the flap. After the procedure patients sometimes report a stinging sensation for a few hours.
Different procedures are used depending on your particular vision problem. Here is a quick summary of the most popular procedures for different eyesight issues:
LASIK (laser-assisted in situ keratomileusis)
This is the most common laser eye surgery procedure in the UK. It can be performed on short sighted, long sighted, astigmatic patients and those requiring reading glasses. Those with very high prescriptions (more than +5.00 or -8.00 may not be suitable and alternatives like the Implantable contact lens are a good alternative).
During the procedure the surgeon creates a small flap of very thin corneal tissue with the Intralase femtosecond laser. The exposed tissue is then reshaped using the laser and the corneal flap is replaced.
During the procedure the flap remains joined to the cornea like a hinge. This enables the tissue to be repositioned exactly, minimising healing time. The flap is kept in place by natural suction.
PRK (PhotoRefractive Keratectomy)
PRK is the predecessor to LASIK eye surgery and is now only used for correcting the eyesight of individuals with weak prescriptions.
During the treatment the entire epithelial (outer) layer is removed to expose the area and, unlike LASIK, no flap is created. The laser is then used to reshape your cornea.
In contrast to LASIK surgery, the recovery time with PRK is longer as it takes some time for new epithelial cells to regenerate on the surface of the eye. Healing time is typically 5 to 7 days.
LASEK (laser epithelial keratomileusis)
LASEK eye treatment uses a combination of methods used in LASIK treatment and PRK procedures. It is used to correct mild to moderate short sight and astigmatism.
As with PRK eye surgery, the corneal epithelium is separated but, instead of completely removing this tissue, the surgeon creates a flap – similar to the corneal flap made during LASIK eye surgery.
The laser is then applied to reshape the cornea. Once the laser eye surgery is finished, the epithelial tissue is repositioned and a bandage contact lens is placed on the eye by the surgeon to keep the epithelium in place as it heals.
Laser eye surgery is a permanent corrective treatment and is in the majority of patients completely stable. Some eyes can change over time and this is usually because of the crystalline lens inside the eye. Over the age of 42 or so, there may be a need to wear reading glasses. New treatments such as Supracor Lasik can now correct the need for reading glasses and they can be performed on those who have previously had laser eye surgery.
Complications during laser eye surgery are rare, occurring in less than 1% of cases. Your surgeon should evaluate you thoroughly to ensure you are a good candidate and they should explain the risks and benefits as well as what to expect.
Side effects can include:
- Initial halos around lights – these usually disappear in a few days, but they may take up to a couple of weeks to go depending on how quickly the cornea heals.
- Dry eyes – this is also temporary (patients need to have been evaluated and if present treated for dry eye prior to the procedure)
- Infection – this is rare at 1:10,000
- Over-correction, under-correction or regression which may need an enhancement or touch-up at 3 months. This at Centre for Sight occurs in about 1% of cases.
Laser eye surgery is advertised by many clinics at discounted prices. Sadly this is poor practice to entice patients to contact the clinic and get them into the system. Often they are subjected to so called “bait and switch” tactics. At Centre for Sight there is absolutely no “up-selling” and the surgeon will individually customise treatment for each eye choosing the best available option. Centre for Sight makes the procedure affordable by accommodating different payment options, including payment in small monthly instalments along with 0% interest for credit.
It is important that you choose a clinic that you can trust, where you see the surgeon in consultation and not an optician or sales counsellor. Be on guard for centres that offer a “deal”, as they say you get what you pay for. Finally always check that your surgeon is qualified and experienced before proceeding with your treatment.
- Treatment is quick and painless
- Short recovery time – most people are back at work in less than a week
- Immediate results
- Permanent correction to your vision
- Free from dependence on glasses and contact lenses
- Easier to engage in active sports and pursuits
Before and after your surgery
Before your surgery you will have a consultation with your eye surgeon. During this consultation the surgeon will:
- Perform a thorough eye examination
- Determine if you are a good candidate and discuss your treatment options
- Talk you through the risks, side effects and benefits of the treatment
- Discuss what to expect before, during and after your surgery
- Give you time to ask any questions
If you wear contact lenses, make sure you stop wearing them at least one week before consultation for soft lenses and 4 weeks before for hard lenses.
The day before your surgery:
- Stop using any make up, lotions, creams, and perfumes as they can interfere with the surgical procedure
- Arrange your transport from the clinic. You may be given a sedative that will leave you unable to drive.
Immediately after the procedure you may experience some discomfort or mild pain. You may want to rub your eyes but it’s very important to resist as this could dislodge the corneal flap. These symptoms will improve considerably within a few hours after surgery. Though recovery times are quick, you may want to consider taking a day or two off work.
Your doctor will give you eye drops to help prevent infection and decrease inflammation. You may also be advised to use artificial tears to help lubricate the eye. If you experience severe pain, redness or decreased vision you must contact your doctor immediately.
Centre for Sight established in 1996 is UK’s longest provider of LASIK laser eye surgery. Patients including eye surgeons and doctors travel nationally and internationally for laser eye surgery at the Centre. To learn more about laser eye surgery at the award-winning Centre for Sight, or to book a consultation, contact our team today.
Author Information
Authored by Sheraz Daya MD FACP FACS FRCS(Ed) FRCOphth, Consultant Ophthalmic Surgeon & Medical Director, June 2019.