PRK or photorefractive keratectomy used to be the most common laser eye surgery procedure until Lasik came along. LASEK is a derivative of PRK whereby the top layer of the cornea, the epithelium is loosened with 20% alcohol. This removed and then replaced. The thinking is that LASEK is less painful than PRK and less likely to produce long term haze. This has not been found to be true, however the procedure is popular especially in centres on the high street.

Both PRK and LASEK are more painful than LASIK or IntraLASIK (as performed at Centre for Sight) and visual recovery can take a few days to a week compared with usually the following day with IntraLASIK.

Both PRK and LASEK are performed with an excimer laser (Bausch and Lomb Z100), which uses a cool ultraviolet light beam to precisely remove ("ablate") very tiny bits of tissue from the surface of the cornea in order to reshape it. When you reshape the cornea in the right way, it works better to focus light into the eye and onto the retina, providing clearer vision than before.

Nearsighted / shortsighted and farsighted people can benefit from PRK or LASEK. With shortsighted people, the goal is to flatten the too-steep cornea; with farsighted people, a steeper cornea is desired. Also, the Excimer laser can correct astigmatism, by smoothing an irregular cornea into a more normal shape.

Your doctor will examine your eyes to determine exactly what kind of vision correction you need and how much laser ablation is needed. The Orbscan IIz and Tomey TMS 2 corneal topographers will be used; this is an instrument that photographs your eye and creates a kind of "map" of your cornea. These devices will display the corneal and help the doctor decide suitability and what procedure to perform.

PRK and LASEK are day case procedures; you walk into the Laser centre, have PRK or LASEK, and walk out again. In fact, the actual surgery usually takes just a few minutes, and you're awake the whole time. Occasionally, the doctor will give a mild oral sedative beforehand.

PRK can be very uncomfortable afterwards. Because of this, many practitioners advocate only performing one eye at a time. LASEK can be performed on both eyes on the same day, but not you will not be able to work or function properly for a few days and possibly up to one week.

At Centre for Sight, as we have the Intralase laser and are able to perform IntraLASIK, we have very little reason to perform either PRK or LASEK. IntraLASIK eliminates major flap complications (a motivating factor to undergo LASEK) and is also able to treat thin corneas not suitable for traditional blade LASIK eye surgery.