PRK – Photorefractive Keratectomy

PRK is used to correct or reduce myopia (shortsightedness or nearsightedness), hyperopia (longsightedness or farsightedness), and astigmatism. The PRK procedure flattens part or all of the cornea which in turn allow focal point of light to focus more closely on the retina. PRK differs from Lasik in that it does not create a permanent flap in the cornea, instead it uses the excimer laser exclusively from start to finish, essentially scraping the top level of the cornea. The benefits of PRK is that it is simple and non-intrusive as compared to lasik. As with all surgery there can be complications.

Lasik Eye Surgery

Lasik stands for laser-assisted in situ keratomileusis, and is a surgical procedure used to “cure” shortsightedness, longsightedness, or astigmatism. “Keratomileusis” is the carving of the cornea in order to reshape it. Lasik Permanently changes the shape of the cornea using a special lazer called an eximer lazer.

As the laser reshapes the cornea, it changes the angle at which you see images and therefore strengthens your vision significantly. This reshaping adjusts and strengthens the power of your cornea to focus on objects near and far. If you are nearsighted, your doctor uses the laser to flatten your cornea that is too-steep. If you are farsighted, your doctor uses the laser to make your cornea steeper because it is too flat. For astigmatism, the laser can be used to smooth an irregular cornea into a more smooth shape. There are few other procedures like Lasik Eye Surgery that can give you these amazing results and permanently change the shape of your cornea in just minutes.

The lasic procedure of lasik is:

  • A suction ring is placed on the eye to stabalize and monitor pressure
  • A microkeratome, a cutting instrument, is attached to the suction ring. This blade cuts a flap in the cornea
  • The exposed inner layer of the cornea is reshaped with an eximer lazer
  • The corneal flap is returned to the original position

The patient walks in to the surgery, have the procedure, and walk out again being awake the whole time. The doctor performing the surgery may also administer a mild oral sedative.

The marketing for this procedure says that lasik provides benefit to millions of people, however, it doesn’t really solve the underlying cause of poor vision. If they were myopic before, their eye is still mis-shapen. They may be able to see perfectly well after the surgery, but years down the line myopia may return. There are also possibilities of complications that could affect your vision.

Common Eye Disorders

Myopia (nearsighted or short sighted)

This is one of the most common vision disorders. It is the inability to focus on objects at a distance. The light rays are focused at a point in front of the retina, causing a blurring of the image. Myopia is typically caused by continued up close activity which causes the muscles to be in a state of constant contraction causing a lengthening of the eyeball. A person with myopia can see things up close, but they will not be as clear as they would be if the eyes were relaxed as in normal eyesight.

Hyperopia or hypermetropia (long sighted or far sighted)

This is the inability to fucus on objects at a close range. This is caused by tension that sortens the length of the eyeball, therefore becoming to short so that light rays are focused on an area behind the retina.

Astigmatism

Astigmatism is an unevenly shaped cornea, almost like a corrugated iron roof. It can be as a result of uneven tension of the extraocular muscles surrounding the eye. This uneven shape causes light rays to focus unevenly, some in front of and some behind the retina.

Presbyopia

This is commonly referred to as “aging vision”. This is the name given to the hardening of the lens and a tightening of the muscles often associated with aging. This condition occurs in nearly everyone at some point in their life, usually around the age of 40. This inflexibility causes ciliary muscle to be unable to change the shape of the lens.