Both LASIK (laser-assisted-in-situ keratomileusis) and PRK (photorefractive keratectomy) are used to correct nearsightedness (myopia), farsightedness (hyperopia) and astigmatism. Both procedures provide exceptional vision correction results, with nearly the same high percentage of patients achieving 20/20 vision or better.
So how do you decide which procedure is best for you? This is a discussion that takes place during your free LASIK screening. During a LASIK screening you will complete a health history form, have both ORB scans and Wavescans taken, and meet with the doctor to review the results and discuss which procedure is recommended for you.
LASIK is recommended for individuals who:
Have normal to above normal corneal thickness
Have regularly shaped corneas
Do not have corneal scarring
Desire a faster recovery
PRK is recommended for individuals who:
Have thinner corneas
Have irregularly shaped corneas
Have corneal scarring
Have corneal dystrophies or recurrent corneal erosions
Participate in contact sports or have occupations that put them at risk for trauma to the eye
LASIK and PRK are both laser vision correction treatments; surgical procedures to reshape the corneal surface. The difference between LASIK and PRK is “how” the surgical procedure is performed. A LASIK procedure uses a corneal flap to expose the treatment area. PRK does not use a flap, and instead removes the epithelium (outermost layer of cells) of the cornea to expose the treatment area.
During the LASIK procedure, a very thin corneal flap is created by using an IntraLase laser. The IntraLase procedure is 100% blade-free. The IntraLase laser uses an infrared beam of light to create the flap just below the surface of the cornea. This beam of light forms thousands of microscopic bubbles (2 to 3 microns in size) which are precisely positioned to define the corneal flap's dimensions and beveled edge, as well as the location of the corneal hinge. The entire process of creating the corneal flap, from start to finish, takes approximately 45 seconds. Once the corneal flap has been created and lifted, the laser vision correction treatment can begin.
During the PRK procedure, the outermost layer of the cornea (the epithelium) is removed by placing a small, circular instrument on the cornea and instilling a few drops of a mild alcohol solution. This is held in place for 30 to 45 seconds after which time the instrument and the alcohol are removed from the surface of the cornea. A second instrument, referred to as a buffing device, is used to wipe away the epithelial cells. Once the treatment area has been exposed, the laser vision correction treatment can begin.
During both the LASIK and PRK procedures, an excimer laser is used to sculpt and reshape the stromal layer of the cornea to correct nearsightedness (myopia), farsightedness (hyperopia) and astigmatism. The excimer laser uses computer-controlled, cool ultraviolet pulses to carefully reshape the cornea and correct imperfections in curvature that cause distorted vision.
During the LASIK procedure, when the cornea has been reshaped to meet the specifications of the patient's vision correction, the corneal flap is restored to its original position. There is no need for bandages or stitches. The corneal flap heals naturally.
During the PRK procedure, when the cornea has been reshaped to meet the specifications of the patient's vision correction, a soft contact lens is placed on the cornea as a “band aid” to protect the surface of the eye until the corneal epithelium regenerates and grows back. It typically takes 4 to 5 days for the epithelium to regenerate.
The most significant differences between LASIK and PRK are the initial discomfort and the speed of visual recovery.
LASIK recovery is much faster than that of PRK. Discomfort following LASIK is usually a mild burning or foreign body sensation; and short term, usually lasting 4 or 5 hours. Typically within 24 hours following the procedure, LASIK patients can return to normal daily activities - including driving, reading and computer use. Visual fluctuation may last a few weeks; commonly caused by dry eye as it can take up to 6 months for tear production to normalize.
PRK recovery is slower and can last a period of weeks to months in some cases. Because the corneal epithelial layer has been removed, there is more discomfort and fluctuation in vision during the first 4 to 7 days due to inflammation and corneal edema. Slight discomfort, light sensitivity and blurriness can last for several weeks; and three to six months to achieve peak acuity and clarity. Dry eye is usually temporary with PRK.
For both LASIK and PRK patients, it is important to follow doctor's orders and use eye drops as prescribed. Prescription eye drops (antibiotic and anti-inflammatory) are used to promote healing and to reduce discomfort following the procedure. Preservative-free, artificial tears are used to keep the cornea moist and aid in the healing process. It is important to wear polarized sunglasses to protect the cornea and reduce exposure to UV light.
According to the FDA, each year in the United States an estimated 600,000 people have laser vision correction procedures. Both procedures, LASIK and PRK, are safe and effective and receive high levels of patient satisfaction.
If you've been thinking about laser vision correction, the first step is scheduling a free LASIK screening to learn more about LASIK and PRK and which procedure would be best for you. Give our office a call at 208.377.8899 and schedule your free LASIK screening.
Check out our other LASIK blogs:
- LASIK Screenings
- LASIK: Eliminating Glare & Halos
- LASIK over 40
- Monovision LASIK
- Custom LASIK
- Different Lasers
- Preparing for LASIK
- LASIK Recovery