LASIK Vs PRK Head To Head Answers

LASIK vs. PRK: Head-to-Head Answers

In the field of refractive surgery, a surgery that correct visual acuity to reduce or eliminate the need for contacts and glasses, two eye surgical procedures stand out as the best – LASIK and PRK. Probably you have friends or someone you know who have tried any of these procedures, and find out in the end how best the procedures are. Well, many people these days question the differences and similarities between the LASIK and PRK. Thanks to some experts that their questions were answered.

Now, if you are one of those people out there planning for a refractive surgery but not sure which procedure to take, I have here below some of helpful information about LASIK and PRK. Just continue reading and I am sure you'll be amazed at how the procedures differ. After all, LASIK and PRK are worth noting.

Understanding LASIK

LASIK is one of the most commonly performed refractive surgeries in today's fast-paced technological society. You may hear people calling it "LASIX", but the term "LASIK" actually stands for Laser-Assisted-In-Situ-Keratomileusis. This refers to the use of a laser to reshape the cornea without invading the adjacent cell layers.

The LASIK eye surgery usually starts with anesthetic drops applied to numb your eye and prevent pain during the procedure. A device known as lid speculum is placed in the eye to hold the lids apart for the procedure. This is considered to prevent your eye from blinking. The cornea is then marked with a water-soluble ink which guides the replacement of the flap. Then, the suction ring is placed on the eye and your vision will go dark for about 20 seconds. The procedure is followed by the application of a precise flap-making instrument, known as microkeratome, which is used to create a thin flap of the corneal tissue. The surgeon or doctor will then raise the epithelium layer of the cornea in order to expose the portion beneath and is lifted and reflected to the side.

What removes the tissue under the flap and reshapes the cornea of the affected eye is the computer-controlled excimer laser. This laser will produce ultra-violet light and high energy pulses in less than 20 seconds. This is to reshape the internal cornea, also known as stroma, with accuracy up to 0.25 microns or 1/4000 of a millimeter. After which, the flap is put back into its original position. And, since the cornea bonds quickly, the healing is said to be rapid and the eye does not require stitches.

Understanding PRK

Another commonly performed refractive surgery is what many experts call as PRK. Basically, PRK is the acronym for Photo Refractive Keratectomy, the said precursor of LASIK eye surgery. This operation involves the use of an excimer laser to reshape the cornea. However, PRK works directly on the outer surface of the cornea. In PRK, the vision correction starts with the application of anesthetic drops to numb the eye and prevent pain during the procedure. A lid speculum is placed in the eye to hold the lids apart for the procedure, eliminating the possibility of blinking. Then, the surgeon will gently remove the surface corneal cells, which is scientifically known as epithelium. From there, the surgeon proceeds with the laser aspect of the PRK eye procedure.

Speaking of laser, it is nice to know that the laser used in PRK is computer driven for accuracy as well as precision. It is also programmed based on the refractive error that the patient has such as nearsightedness, farsightedness, or astigmatism. The eye correction surgery usually takes less than one minute for most patients. After the procedure, a soft bandage contact lens is placed on the eye for about three to five days until the epithelial layer redevelops.

Similarities and Differences between LASIK and PRK

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

Similarities

It is important to note in the first place that both LASIK and PRK are approved by the FDA as safe and effective. 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.

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.

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.

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.

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

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. 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.

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 approximately the same, the complications with LASIK are potentially more severe than with PRK.

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.

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 achieve optimal vision.

Advantages and Disadvantages of PRK and LASIK

So you've learned about the similarities and differences between PRK and LASIK. Now, let's take a look at their advantages and disadvantages. Note the following for you might consider a LASIK or PRK eye surgery in the future.

Shared Advantages of Both Procedures

? Both procedures employ excimer laser and with excellent precision and accuracy, resulting in highly effective vision improvement. ? More stable vision. ? No significant drop in structural strength of the eye, which is very important for patients at high risk for direct eye trauma. ? A far greater range of refractive correction than previously available.

Advantages of LASIK over PRK

Experts found out that LASIK offers more benefits than PRK. Here are some of its advantages:

? Less postoperative treatment and follow up needed ? Rapid recovery of visual acuity ? Little or no postoperative pain. Any initial soreness after LASIK eye surgery is usually gone by the following morning ? Capability of simultaneous bilateral treatment. Both eyes are actually treated at the same time. ? Preservation of normal corneal anatomy. It is interesting to know that the LASIK procedure preserves the epithelium, which is a thin protective layer that covers the cornea. Also, the LASIK procedure preserves the Bowman's Layer, a structural component just beneath the surface of the corneas that is removed during the PRK procedure. ? Reduced risk of light sensitivity, which may occur for a week or two after PRK. ? Rapid healing. The protective corneal flap created during LASIK helps reduce the need for the prolonged medication regimen required for surface PRK.

Shared Disadvantages or Potential Complications of PRK and LASIK

? Difficulties with eye coordination. This is typical in case when both eyes need correction but only one is operated on initially. With this, there may be problems with coordination between the corrected and uncorrected eyes. ? There is a risk of infection in both procedures. Infection is the most serious complication of most eye surgery, and this is extremely rare in LASIK. ? Blurring of night vision, causing halos or starbursting around bright lights. This is also common in LASIK than in surface PRK. ? Reduction of best corrected visual acuity. The patient may have much better uncorrected vision, but not as sharp as previous corrected vision. ? Risk of over or under correction, necessitating continued use of contact lenses or eyeglasses, and possibly more surgery. ? Laser procedures are most costly than more traditional methods. This is for the fact that both LASIK and PRK involve expensive technology and an extensive educational process for the surgeon, laser technicians, as well as surgical assistants. Nevertheless, most patients feel that the increased accuracy, lower re-treatment rate, and reduced time spent in office visits are well worth the difference in price.

Disadvantages or Complications Specific to LASIK

The disadvantages or complications of LASIK include problems with the instrument that makes the flap, the microkeratome, which result in incomplete flaps, irregular flaps, flaps within thin spots or holes in it, or a flap that comes totally off. These then require the procedure to be aborted, and the re-performed in about three months.

Occasionally, if scarring develops, the LASIK cannot be repeated and the patient must wear a contact lens for best vision. Also, rarely a flap may require suturing back in place, and even more rarely, a flap may be lost. This will make LASIK essentially a surface treated procedure with a more variable result and the possibility of significant corneal scarring. Also, if the flap is lost, a corneal transplant operation may be required.

Furthermore, there are some instances that adequate ring suction cannot be maintained, so LASIK cannot be performed.

Other uncommon flap problems may involve unwanted material like cotton fibers in the interface, infection, folds in the flap or epithelial ingrowth beneath it, which needs repositioning and cleaning of the flap.

Today, many patients prefer the LASIK procedure over PRK primarily because of the rapid vision recovery as well as minimal postoperative care. Many doctors also agree that patients with high amounts of nearsightedness should have LASIK, but for patients with lower to moderate amounts of myopia, either PRK or LSIK may be appropriate. But whatever the case maybe, LASIK is increasingly accepted as today's standard vision correction surgery procedure.