PRK: The Beginning of Eye Surgery

What is Photorefractive Keratectomy?

PRK stands for photorefractive keratectomy, the first type of laser eye surgery. “Kerato” refers to the cornea. “Keratectomy” means removing some of the corneal tissue.

Photorefractive keratectomy was developed in the 1980s, but was not approved for use in the U.S. by the FDA until 1995. While there are newer types of laser surgery, photorefractive keratectomy may still be the better choice in certain cases. Patients with very thin corneas or very large pupils tend to have better results with this surgery than other procedures.

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How Does It Work?

You may be more familiar with the terms nearsighted and farsighted. Nearsighted vision results from corneas that are too curved. Farsighted vision results from corneas that are too flat. Astigmatism is another refractive error. Astigmatism results from corneas that are oval, or football shaped.

PRK works in the same way Lasik, LASEK, Epi-Lasik and other laser surgeries do. During PRK your eye surgeon uses an excimer laser beam to reshape the cornea.

An excimer laser beam is a cool laser beam that removes very tiny amounts of corneal tissue. This makes it easy for the surgeon to control how he is shaping the cornea.

Your eye surgeon guides the laser beam to destroy only enough corneal tissue to create an optimum shape that gives you the clearest vision. PRK is different from other laser eye surgery methods because it removes the epithelium.

Pros and Cons of

  • Although photorefractive keratectomy destroys the epithelium covering the eye, it grows back in six to eight weeks.
  • Your vision will become clearer as the epithelial cells grow back. It will be clearest when healing is complete.
  • photorefractive keratectomy, Epi-LASIK preserves the biomechanical integrity of the cornea better than epithelial flap procedures (Lasik or Lasek).
  • Surface ablation reduces the risk of surgically induced keratoconus (bulging of the cornea).
  • There may be more discomfort with photorefractive keratectomy than other laser surgery procedures.
  • Photorefractive keratectomy also has more incidences of corneal haze than other methods.
  • Photorefractive keratectomy recovery may take longer than Lasik or Lasek procedures.
  • Indications for Photorefractive Keratectomy

    PRK is indicated if you:

  • have large pupils
  • have very thin or flat corneas.
  • are between the ages of 18 and 40
  • have a stable corrective lens prescription (no change within two years)
  • have normal tearing (moisture)

  • have vision within a correctable range
  • Photorefractive Keratectomy Not Recommended

    Photorefractive keratectomy is not indicated if any of the following conditions or situations apply to you:

  • you engage in hobbies or professional activities that are rough or pose risk of hitting eyes
  • you have prior eye injury that would prevent successful outcomes or increase risk
  • you have dry eye
  • you have had lens prescription changes within two years
  • you have cataracts
  • you have glaucoma
  • you are pregnant or nursing (lactating)
  • you have corneal scarring
  • you have autoimmune disorders
  • you are taking steroids or immunosuppressants
  • you have eye disease or abnormalities that will slow healing such as:
  • diabetic retinopathy
  • ocular hypertension
  • autoimmune disorders
  • Herpes simplex of the eye
  • hypertension
  • have keratoconus (irregularity in dome shape of the cornea)
  • Risks Associated with photorefractive keratectomy

    photorefractive keratectomy has risks that are similar to other laser eye surgery procedures. Though rare, the ones that occur most often include:

  • over- or under-corrections
  • halos or star bursts around lights
  • dry eye
  • infection
  • permanent damage or death of epithelial cells from the alcohol used in photorefractive keratectomy
  • corneal scarring
  • eyelid droop
  • chronic discomfort
  • possible intolerance of contact lenses (sometimes needed if additional correction is required)

  • Return From PRK TO Laser Eye Surgery