Ophthalmology

Laser Eye Surgery

Introduction to Laser Eye Surgery

Laser eye surgery is a fairly straight forward, non-invasive procedure that is carried out to correct poor eyesight. The procedure reshapes the cornea using an excimer laser.

Written by Doctify Team 27/04/2020

What is Laser Eye Surgery?

Laser eye surgery is a form of refractive surgery, which uses computer-guided lasers to change the shape of your cornea to correct:

  • Near-sightedness (Myopia), which can blur vision at distance
  • Farsightedness (Hyperopia), which can blur vision at near
  • Astigmatism, which can blur vision at distance and near
  • Presbyopia, age-related deterioration which makes it harder to see close up

Am I suitable for laser eye surgery?

To be suitable for laser eye surgery, you must be:

  • 18 or over
  • Not pregnant or breastfeeding
  • Sight has not changed significantly in two years
  • No serious eye disease should be present

What do I need to do before my laser surgery consultation?

You will need to wear glasses and leave out contact lenses for 48 hours to 1 week (2 weeks for hard lenses) prior to the initial pre-op examination. This is very important to ensure your cornea is at its normal shape (which can change temporarily from the use of contact lenses), which allows accurate measurements to be taken.

At your consultation, in order to determine if you are suitable for laser eye correction, a number of ophthalmic tests will be undertaken, including; measuring your vision, pupil size and corneal thickness. Eye drops will be used to dilate your pupils. This will also increase your sensitivity to light (therefore bring sunglasses if possible) and you should not drive for the rest of the day.

How do I decide which laser eye surgery to have?

1. LASIK (Laser assisted in-situ keramtosis)

Suitable for the treatment of Myopia, Hyperopia, Astigmatism and Presbyopia. Prior to the procedure anaesthetic eye-drops are given and the whole process takes less than 2 minutes per eye. The LASIK procedure uses one laser to create a flap on the front layer of the cornea and then a second laser is used to reshape the cornea under the area of the flap. The flap is then closed and seals naturally, just like the front layer of the skin. All LASIK procedures carried out at Optegra use femtosecond and excimer lasers; no blades of any sort are used. Furthermore, all LASIK treatments are carried out as wavefront-optimised treatments, to minimise any aberrations from the treatment. This can be particularly important in maintaining good night vision for patients, especially those with high prescriptions and large pupil. In some patients, vision may be even better than glasses or contact lenses.

How long before I can see well?

LASIK has a very quick recovery time. Within 24 hours many patients will already have the majority of their vision. Clarity continues to improve further over the course of a week. Generally patients can resume working activities 48 hours following LASIK.

2. PRK / LASEK (laser assisted sub-epithelial keratomileusis)

Suitable for the treatment of Myopia, Hyperopia and Astigmatism. PRK (photorefractive keratectomy) alters the shape of the front of the eye. This is achieved by using a dilute concentration of ethanol applied onto the cornea for 20-40 seconds in order to loosen and remove the front layer of the cornea. The excimer laser is then used to reshape the middle layer of the cornea. LASEK is when all the above measures are used but the surgeon will attempt to replace the epithelial cells back onto the surface.

How long before I can return to normal after PRK/LASEK ?

With both PRK and LASEK a contact lens is inserted once the procedure is complete, this is normally removed after 4 days and protects the surface of the eye during the healing process. The vision will be blurred for the first 4 days, but once the contact lenses are removed, your sight should be significantly improved and continue to get better further as the days go by. We generally recommend 1 week off work for a LASEK procedure to ensure adequate visual recovery.

3. SMILE (small incision lenticule extraction)

Suitable for the treatment of myopia and astigmatism. SMILE can also be performed for higher prescriptions, thinner corneas and those with dry eyes. SMILE uses a femtosecond laser to cut away a disc of tissue within the middle layer of the cornea which is then removed through a 2-3 mm incision on the front layer. This is sometimes referred to as a keyhole procedure, as no flap is created on the front layer of the cornea.

How soon will my eyesight be perfect?

Just as LASIK does, SMILE also has a very quick recovery time. Within 24 hours many patients will already have the majority of their vision. Clarity continues to improve further over the course of 1-4 weeks. Generally patients can resume working activities 48 hours following SMILE.

4. PTK (photo therapeutic keratectomy)

Suitable for the treatment of Recurrent Epithelial Erosion Syndrome, Basement Membrane Disorder, corneal scarring and irregular corneas. PTK gently removes irregular tissue on the surface of the cornea to create a smooth surface. PRK may also be combined with LASEK when additional correction is required to improve sight.

When can I drive after laser eye surgery?

You should be able to drive the next day with LASIK or SMILE. It can take a week or more with LASEK. Driving at night may be impacted temporarily during the healing period, but this is generally short term with all of the procedures.

Risks and complications of eye laser surgery

  • Dry eyes can be caused due to a reduction in tear production. Duration and level of dryness vary widely amongst individuals, but may take up to 12 months before symptoms of dry eyes clear up completely. There are many methods of management and your individual dry eye status will be discussed at the consultation stage and an appropriate treatment plan set in place. Individuals with conditions including blepharitis (inflamed eyelid margins), autoimmune diseases and women after the menopause have a higher chance of suffering with dry eyes after treatments with laser surgery.
  • Night vision can be impacted by glare and halos, however this normally clears up within a month and it is very rare for it to be a long term complication
  • Sensitivity to light can occur temporarily.
  • Reduced contrast vision can occur temporarily, but in rare cases may persist.
  • Corneal infection is extremely rare. This can cause corneal scarring, reduced vision and in severe cases, a corneal transplant may be needed.
  • Scratchiness or discomfort, which mainly occurs early in the first week following laser eye surgery. This can be eased with the ocular lubricants which we provide.
  • Neuropathy, or nerve pain is rare and normally temporary.
  • Under correction and overcorrection can result in one or both eyes becoming either marginally short or long-sighted. This can normally be rectified with further laser surgery
  • The flap created with LASIK can move, reducing vision and causing discomfort, as long as this is treated quickly it is normally simple to immediately rectify by repositioning the flap. This would normally occur if patients rub their eyes during the early healing period or if ocular trauma occurs.
  • Epithelial ingrowth occurs when skin cells from the front surface of the cornea grow into the area under the flap (in LASIK) or cap (in SMILE). This can be treated with further surgery to lift the flap and remove the ingrown skin cells or in the case of SMILE, simply washing out the area under the cap.
  • Ectasia is when the cornea weakens and starts to bulge, this is very rare and methodical tests are carried out during assessments prior to laser surgery which detect underlying corneal weakness to prevent laser surgery being performed on individuals predisposed to developing ectasia.

Questions to ask prior to laser eye surgery

  • How many procedures have you carried out in the last 12 months?
  • What percentage of patients had complications that lasted longer than 6 months?
  • Is there a charge if further eye laser surgery is required?

Find out more about other relative procedures:

Summary
  • There are a few risks with laser eye surgery, as with any procedure and complications can occur
  • If eyesight has become an issue to you, or it affects your work or personal life then finding a laser eye surgeon could make a huge difference to you
  • Laser eye surgery can be used for people who are both long-sighted and short-sighted, as well as those with astigmatism.