PRK Laser Eye Surgery

    Photorefractive Keratectomy - PRK laser surgery

PRK is a synonym for Photorefractive Keratectomy which was one of the first laser eye surgery procedures used to treat low refractive eyesight errors.

Its advantage over some other forms of laser eye surgery is that it is suitable for those with thin corneas.

PRK (or photorefractive keratectomy) is the second most popular laser treatment performed and its use is only exceeded LASIK. As in LASIK surgery, PRK reshapes the cornear with the use of an Excimer laser.  However, in PRK, rather than creating a flap in the cornea, thus preserving it, the surgeon removes the thin outer layer of corneal cells (the epithelium) and the laser treatment is applied to the underlying corneal tissue (the stroma).

Following PRK laser treatment the cornea is covered with a bandage contact lens that protects it whilst the epithelium grows back. This takes a few days after which time the bandage contact lens is removed.

Similar to the LASIK procedure, an Excimer laser is used in the PRK process. Cool ultraviolet laser light is used to ablate tissue from the surface of the cornea in order to shape it properly. This reshaping of the cornea allows light to focus correctly on the retina and results in clearer, more focused vision.

    Advantages and disadvantages of PRK over LASIK?

PRK can be used to treat eyesight problems of both nearsightedness and of  farsightedness. For the nearsighted, PRK can flatten a cornea that is too steep while for the farsighted, it can to steepen a cornea that is too flat. PRK can also be used to correct astigmatism by smoothing the contours of an irregular cornea.

PRK patients tend to experience more pain and discomfort during surgery than than those undergoing LASIK surgery and recovery and vision improvement times tend to be slower.

Although PRK provides results that a comparable to those achieved through LASIK it does entail more post-surgery recovery discomfort and longer result and healing times.

Surgeons often recommend PRK surgery to patients that have corneas that are either too thin or are too steep for LASIK or other surgery.

    What happens before the PRK procedure?

Prior to having PRK surgery your doctor needs to establish suitability. This is normally done during a thorough examination of your eyes where he will determine the best way to correct your vision. Corneal cameras will be used to take photographs of your eye and map the cornea. These will help identify any irregularities including the flatness or steepness that must be revised in order to have clear vision.

    The PRK procedure

To help prevent pain during the PRK procedure, anaesthetic drops are applied to the eye.

The epithelium, the outer layer of corneal cells, is removed by laser or the application of a dilute alcohol solution.

The underlying corneal tissue is the then reshaped using an Excimer laser.

In order to help healing and prevent infection anti-biotic and anti-inflammatory drops are applied to the eye. The eye is then covered with a bandage contact lens similar to the LASEK procedure.

The bandage contact lens is removed two or three days later after the epithelium has had a chance to grow back.