LASIK And PRK - Similarities And Dissimilarities

Now that you’ve learned some basic facts about LASIK and PRK, let’s take a look at their similarities and differences:

Similarities Between LASIK And PRK

It is significant to note in the first place that both LASIK and PRK are approved by the FDA as safe and efficient. Both procedures also involved the use of an excimer laser to reshape the corneal tissue. And, with respect to results, expectations, risks and complications, LASIK and PRK are identical.

Results - When it comes to the procedure results, there does not seem to be a significant difference between the PRK and LASIK. Overall, both procedures show a percentage of patients achieving 20/20 to 20/40 at the end of six months. And, although some surgeons feel that the enhancements are safer and more accurate in LASIK patients, this claim has not yet been proven.
Side Effects - Numerous studies further show that both LASIK and PRK have a low rate of side effects. These merely include mild irritation, glare or halos which is more pertinent at night, ghost images, as well as under over correction with less than 3 percent are significant. Aside from that, both procedures may produce a decrease in the quality of night vision, also called decreased contrast sensitivity.
Procedure Duration - Both procedures are quite short. The surface PRK typically takes about three minutes of actual treatment time, while LASIK requires about one to two minutes additional actual treatment time. Also, there is said to be no discomfort during either procedure.
Thin Corneas - Basically, if the cornea of a patient is too thin to safely perform LASIK, then the PRK is the only available option for refractive surgery. However, studies have shown that although slightly more inconvenient with respect to rapidity of visual recovery, the results of both LASIK and PRK are comparable.
Complications - When it comes to complications, there are actually a lot of things to consider with both LASIK and PRK. In the first place, studies have revealed that the case of overcorrection occurs in about 1 percent of cases with PRK and LASIK. Then, about 10 to 15 percent of both LASIK and PRK patients may need a re-treatment or enhancement or touch up for under correction or regression back towards myopia.
Also, re-treatment is more common in patients who are more myopic or hyperopic and have higher amounts of astigmatism. And, with either PRK or LASIK, regression and under correction is very uncommon with less than 3.00 diopters myopia. Worth noting is the loss of best correctable vision worse than 2 lines is about 0.5 to 2 percent for both procedures.

Differences Between LASIK And PRK

Outside from those mentioned similarities between LASIK and PRK, there are also some differences between the two procedures that are worth noting. These include the following:

Patients who are poor candidates for LASIK may qualify for PRK - Though LASIK eye surgery offers rapid healing and no postoperative pain, PRK is said to be a superb alternative for patients who are not qualified to take LASIK. So, if you are unable to receive LASIK due to your thin corneas or large pupils, you may be able to receive PRK instead.
LASIK involves the creation of a corneal flap, PRK does not - In LASIK, the surgeon uses a surgical instrument called a microkeratome to create a corneal flap. A portion of that flap remains attached to the eye, as a hinge, while the remainder is gently lifted up and back exposing the inner cornea. Then, the cool beam laser resculpts the corneas and the flap is returned to its original position. On the other hand, PRK involves the removal of the top surface level of the cornea called the epithelium. This procedure is done to expose the inner cornea which the computer assisted laser will start to resculpt the curvature of the eye.
PRK results in a slower return of good vision - Experts have noted that patients of LASIK experience improved vision almost immediately, while following PRK, it can take three to six months for patients to attain optimal vision.
Complexity Differences - LASIK is said to be more complex than PRK with respect to both equipment and performance of the procedure itself. And, although the overall percentage of complications of surface PRK and LASIK are about the same, the LASIK complications are potentially more severe than with PRK.
Patients who receive PRK experience more postoperative pain - Studies further show that generally, patients experience some pain in the days following PRK because the procedure exposes deeper layers of the cornea. On the other hand, patients who undergo LASIK experience almost no pain, though some report mild discomfort in the eye for a day or so after the procedure. The discomfort is usually an itchy feeling.
The post-operative care of both procedures differ - In LASIK, a clear plastic shield is worn over the eye for the first 24 hours, and then nightly for ten nights. This is to prevent inadvertent rubbing of the eye. Also, eye drops are started after 24 hours and are used for only 4 days. In PRK, on the other hand, a therapeutic soft bandage contact lens is worn for five to ten days, depending upon the size of the treatment zone. This is to reduce discomfort. Then, antibiotic, anti-inflammatory and cortisone eye drops are used twice daily while the lens is on. After removal, the topical cortisone is applied for four times a day for one month. It is then tapered over the next one to three months. And, artificial tears are usually applied as needed.