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LASEK Laser Eye Surgery: An Alternative to LASIK

LASEK (or laser-assisted subepithelial keratomileusis) is a laser vision correction procedure that is similar to both LASIK and PRK. Like LASIK, LASEK can also be used to treat farsightedness, nearsightedness or astigmatism. It is also a type of laser presbyopia surgery when it is used for the treatment of age-related nearsightedness.

In all three procedures, an excimer laser is used to reshape the cornea and correct vision. The procedures differ in the preparation of the cornea prior to the excimer laser treatment.

But unlike PRK, where the superficial layer of the cornea (called the epithelium) is removed and discarded prior to the laser reshaping of the eye, with LASEK, the epithelium is loosened and removed, but is then replaced on the eye after the laser treatment.

LASEK vs. LASIK

In LASIK, a flap is created in the cornea prior to the excimer laser treatment. This flap, which is created with a femtosecond laser or a microkeratome, contains both the epithelium and underlying corneal tissue called the stroma. Generally, a LASIK flap is 120 to 160 microns thick.

In LASEK, a flap is created, but it is much thinner and consists only of the corneal epithelium. A LASEK flap is only 90 to 100 microns thick. The flap is repositioned after the excimer laser treatment, and new epithelial cells grow onto the eye to replace those in the flap.

Trephine used in LASEK surgery.
Image courtesy of Rhein Medical, Inc.

An advantage of LASEK compared with LASIK is that the LASEK flap leaves the entire corneal stroma intact, so more stromal tissue remains for reshaping by the excimer laser. For correction of equal amounts of myopia, this means the cornea will have greater residual thickness and biomechanical strength after LASEK than after LASIK.

In other words, it may be safer for some patients — especially those with thinner-than-average corneas — to have their myopia corrected with LASEK, compared with LASIK.

Studies show LASEK produces visual outcomes that are similar to those produced by LASIK. However, post-operative healing and visual recovery takes longer after LASEK, compared with recovery from LASIK eye surgery, and this may be bothersome to some people.

LASEK vs. PRK

In PRK, the corneal epithelium is removed and discarded prior to the excimer laser treatment. For this reason, PRK also is called "surface ablation," because no flap is replaced over the treated area of the cornea after surgery. Instead, a bandage contact lens is placed on the eye until a new epithelial layer grows back. This process takes a few days.

In LASEK, the ultra-thin epithelium is repositioned after the excimer laser treatment and reattaches to the eye. This process usually takes less time than that required for a completely new layer of epithelial cells to grow back after PRK.

So, theoretically at least, healing of the epithelial layer and visual recovery should occur faster after LASEK than after PRK. There also may be less post-surgical discomfort after LASEK, compared with PRK.

LASEK, like PRK, often is preferred over LASIK in cases when a person's cornea may be too thin for LASIK or the surgeon or patient prefers to avoid the creation of a corneal flap for other reasons.

LASEK produces visual outcomes that are similar to LASIK and PRK. Though it involves more post-operative discomfort than LASIK, proponents of the LASEK procedure say it offers greater comfort and faster healing after surgery compared with PRK.

But not everyone agrees.

A study published in the Journal of Refractive Surgery in 2008 found that people undergoing PRK tended to have less post-operative discomfort and healed slightly faster than people who had a specific type of LASEK surgery. So the debate continues.

The LASEK Procedure

The steps in LASEK surgery are:

Anesthetic eye drops are applied to the eye to prevent pain during the surgery.
The corneal epithelium is scribed with a hand-held surgical tool called a trephine. The trephine has a cylinder-shaped blade that forms the outline of the flap. A gap in the arc of the blade allows for the hinge of the flap.
A dilute alcohol solution is applied for the eye for about 30 seconds, and then is sponged off. The alcohol solution loosens and helps "float" the epithelium.
The epithelium is gently lifted from the eye and folded back.
An excimer laser is used to reshape the underlying corneal stroma.
The thin epithelial flap is put back in its original position. To keep the epithelium securely in place, a bandage contact lens is applied.

Because visual recovery takes longer after LASEK than LASIK, your surgeon may recommend performing LASEK on just one eye and waiting a few weeks before performing LASEK on the other eye.

A few days later (after the epithelium has had a chance to securely reattach to the eye), the bandage contact lens is removed.

After LASEK Surgery

You will be prescribed antibiotic and anti-inflammatory eye drops for use after surgery to prevent infection and promote healing. You also will be instructed to wear a protective shield over your eye.

Expect some discomfort for a few days after surgery. As the epithelium reattaches to the eye and heals, this discomfort will diminish. This usually takes place within several days after surgery, at which time your doctor will remove the bandage contact lens.

Vision recovery takes longer after LASEK than after LASIK. In some cases, vision is too blurred for driving for a few days after the procedure. Most LASEK patients attain good vision within four to seven days, but results can vary. In some cases, it can take three to six months for complete visual recovery.

Before consenting to LASEK surgery, ask your refractive surgeon how long vision recovery is likely to take in your case, and whether you may need to take a few days after surgery to recover before returning to work.

It may be necessary for you to continue to use anti-inflammatory eye drops for up to six months after LASEK surgery to prevent or reduce haziness in the cornea caused by inflammation.

LASEK Risks and Complications

As with LASIK, PRK and other types of refractive surgery, there are risks and possible complications associated with LASEK.

LASEK risks and complications are similar to those of LASIK, and include:

Dry eyes
Vision problems, such as poor night vision, glare, halos and haze
Incomplete or inaccurate vision correction
Infection following surgery

There may be a slightly greater risk of eye infection and corneal haze or scarring after LASEK, compared with LASIK. But serious complications following LASEK are rare.

Other Considerations

Since there is only a very thin epithelial flap in LASEK surgery, it can be used to treat corneas that are too thin for LASIK.

LASEK is typically used to correct up to -7.00 diopters (D) of nearsightedness and up to +6.00 D of farsightedness, with or without astigmatism.

During LASEK, the excimer laser can be programmed to deliver a standard laser treatment (ablation) or a customized, wavefront-guided ablation, like those used in wavefront LASIK.

Though vision recovery takes longer after LASEK than after LASIK and there is more post-operative discomfort, LASEK may be the better choice for you—especially if you have a profession or hobby that increases the chance of being hit in the eye (e.g., soldier, police officer, boxer, or racquet sports enthusiast)—because there's no risk of a LASIK-style flap being dislodged weeks, months or years after surgery.

Cost of LASEK

The cost of LASEK is comparable to the cost of LASIK surgery. Because LASEK is considered an elective surgical procedure, the costs associated with the surgery typically are not covered by health insurance.

You can lower your LASEK surgical costs by setting up a Health Savings Account (HSA) at your bank or contributing to flexible health benefits program at work.

Many refractive surgeons also offer financing programs that allow you to pay for the procedure over time at attractive interest rates or interest-free over a limited time frame.

Note: This information is for general education purposes only. It is not to be used as a substitute for medical advice from your eye doctor or refractive surgeon.