This article is about some of the common and popular refractive eye surgeries performed currently to correct vision in people who are nearsighted, farsighted or who have astigmatism. The surgeries I am discussing today are LASIK (Laser in-situ Keratomileusis) and PRK (Photo Refractive Keratectomy).
These are one of the many vision correction surgeries which works by reshaping your cornea, the clear front part of your eye so that the light focuses on the retina in the back part of your eye.
Why are these surgeries done?
You complain of blurring of vision when the light doesn’t focus on your retina the way it should. We call this as a refractive error. The basic type includes:
• Myopia or nearsightedness. In this you see things clearly when they are close to you but things get blurry when they are far away.
• Hypermetropia or Farsightedness. In this the things which are far are clear whereas the things near to you are blur.
• Astigmatism. This can make anything blurry because of change in the shape of your eyeball.
How does Lasik Work?
First, a precise, thin hinged cornel flap is made using a microkeratome by a specially trained eye surgeon. The flap is then pulled back to expose the underlying corneal tissue, and the excimer laser reshapes the cornea in a unique pre-specified pattern for each patient. The flap is then gently repositioned onto the underlying cornea without sutures.
You should not undergo this procedure if you:
• Are younger than 18 years of age
• Are pregnant or breastfeeding
• Are taking certain medications like retinoic acids and steroids.
• Have a lot of changes to your vision prescription
• Have abnormal corneal topography (shape)
• Have certain eye conditions like Glaucoma, severe dry eyes, inflammations of the eye or eyelids, keratoconus or previous eye injuries and surgeries.
• Have health issues like diabetes, lupus, rheumatoid arthritis, immunodeficiency states (e.g., HIV).
• Are in a job which prohibits certain refractive procedures.
Risks of LASIK:
• Glare, visual aberrations, sensitivity to light and trouble driving at night
• Seeing haloes around images
• Dry eyes
• You may be over or under corrected
• You may still need glasses or contact lenses after surgery to achieve your best vision
• Your results may not be permanent which occurs occasionally
Advantages of LASIK surgery
Despite all the risks outlined above, LASIK has been proven to be a safe and effective procedure for most of the people with refractive error.
• LASIK is able to accurately correct most of the refractive errors
• The procedure usually lasts for 10 minutes which is fast and painless.
• As the laser is guided by a computer the procedure is very precise and accurate.
• Usually a single treatment is enough to achieve the required result however in few cases an enhancement surgery may be required which can be done even many years after the initial surgery.
LASIK vs PRK
PRK was the first type of laser eye surgery for vision correction. The main difference between LASIK and PRK is the first step of the procedures.
• In LASIK a flap is created on the cornea whereas in PRK the thin outer layer of cornea (epithelium) is removed and discarded. The epithelium grows back within a few days of surgery.
• PRK recovery is slower than LASIK
• PRK is comparatively painful than LASIK
• PRK has increased risk of infection post surgery