“Flapless” LASIK (PRK)/Advanced Surface Ablation

AKA, Advanced Surface Ablation, AKA, “flapless” LASIK
Adopted from Dr. Soroudi’s Book: Advanced Refractive Surgery

As a laser refractive procedure, PRK was approved by FDA even before LASIK, and it is still the safest way to perform keratorefractive surgery. In the right candidate (e.g., near-sighted patients with or without astigmatism), PRK provides truly outstanding results while posing the least amount of risk to the patient. Studies have shown that there is also a lower risk of having dry eyes with PRK than LASIK.

In a nutshell, a cross section of the human cornea (which is only about ½ of a millimeter in thickness) looks very much like an onion (see below). It has a very thin (red) skin covering multiple white (clear) layers that are stacked up on top of one another.

The Human Cornea

In order to “reshape” the onion, the “red skin” of the onion is first gently washed away using 20% alcohol applied in a small metal well that is held on top of the anesthetized eye for about 30 seconds (see below). This does not damage the underlying cornea whatsoever.

A metallic well is gently placed on top of the anesthetized eye and a few drops of 20% Ethyl Alcohol is placed in the well for a period of about 30 seconds. This “loosens” the “epithelium” of the Cornea (the thin “red skin” of the onion), which is then gently removed using a sponge applicator under sterile conditions.

At this point, the same (excimer) laser that is utilized to do LASIK, is used to reshaped the underlying corneal tissue. A wavefront map of one’s eye can be utilized to also provide for a “custom” treatment (just as in LASIK).

Unlike LASIK, with PRK, there is no need for creating/”cutting” a “flap” as the reshaping (excimer) laser is applied directly to the surface of the cornea (hence the name “surface ablation.”)

Unlike LASIK, where a small “flap” is created to do the surgery, with PRK, the treatment is directly on the surface of the cornea, obviating the need to “cut” the Cornea

Once the procedure is complete, a soft, clear (“bandage”) contact lens is placed over the eye to protect it until the epithelial cells naturally grow back. This contact lens is effortlessly removed about 7-10 days later.

In the past, especially with the older laser platforms, there was a concern that once healed from PRK, the cornea may turn “hazy” and cause “glare.” The advent of the flying spot laser has really eliminated this problem, and there has been multiple studies that have shown that the application of a medication called “Mitomycin-C” over the treated area prevents any haze formation. Dr. Soroudi ONLY utilizes the most advanced FDA-approved “flying spot” laser in his practice, and applies Mitomycin-c for every patient for the best possible outcome every single time.

With PRK, the results are identical to (if not better than) LASIK, but vision recovers much slower, and because the epithelium has been removed, depending on the patient, there is always irritation and even pain for the first 2-3 days. This is alleviated very nicely using a topical anesthetic and non-steroidal anti-inflammatory eye-drops.

Unlike LASIK, where the visual acuity improves overnight, and the patient may return to work the next day however, with PRK, although one’s vision improves IMMEDIATELY, it takes at least a few days for it to get to a level where the patient is able to return to work, and it may take weeks until it reaches it maximum potential (especially in those with astigmatism). As a general rule, PRK patients are extremely happy after 3 days.

In the past, this technique was reserved for patients who have thin corneas, were apprehensive about LASIK, or have a history of other refractive procedures (e.g., Radial Keratotomy (RK)), but with the advent of the new “flying spot” lasers and the benefits of Mitomycin-c, this procedure has become the safest and most common refractice procedures in the United States.