Benefits of SMILE Laser Eye Surgery over LASIK

Are you interested in laser surgery to correct your nearsightedness? In addition to LASIK, you now may have the option of a new laser procedure called SMILE.

Here are the basics about SMILE laser eye surgery, which gained FDA approval for use in the United States in September 2016.

SMILE is an acronym for Small Incision Lenticule Extraction (which is a mouthful and not very easy to remember).

In LASIK, a large opening is required to enable the excimer laser to reshape the underlying cornea. In SMILE, only a very small opening is needed (often less than 4 mm) to facilitate removal of the lenticule.

Currently, SMILE laser eye surgery is FDA-approved for the correction of mild to moderately high myopia (eyeglass prescriptions of -1.00 to -8.00 D), with no more than -0.50 D of astigmatism. Patients must be 22 years of age or older, with documentation that their eyeglass prescription has been stable for the past year.

In the SMILE procedure, the surgeon uses a femtosecond laser to create a small, lens-shaped bit of tissue (lenticule) within the cornea. Then, with the same laser, a small arc-shaped incision is made in the surface of the cornea, and the surgeon extracts the lenticule through this incision and discards it.

With the tiny lenticule removed, the shape of the cornea is altered, correcting nearsightedness. The corneal incision heals within a few days without stitches, and sharper vision occurs very quickly.

More than 600,000 SMILE procedures have been performed internationally, according to a press release issued by the U.S. Food and Drug Administration (FDA) in September 2016.

SMILE laser eye surgery is performed using a VisuMax femtosecond laser, which is proprietary technology of Carl Zeiss Meditec.

SMILE Benefits And Advantages

Research is showing SMILE produces virtually the same visual acuity as LASIK for the correction of nearsightedness, without the need to create a LASIK-style corneal flap.

In one study of 328 people who underwent the SMILE procedure, all but one had uncorrected visual acuity (UCVA) of 20/40 or better after surgery, and 88 percent had UCVA of 20/20 or better.

Research also has shown that fewer symptoms of dry eyes may occur after SMILE, compared with LASIK surgery. This is likely because fewer corneal nerves are disrupted during the SMILE procedure, since the corneal incision is significantly smaller than that required to create a LASIK flap. Also, because fewer nerves are cut, there may be less loss of corneal sensitivity following the SMILE procedure, compared with LASIK.

The very small SMILE incision may also result in the cornea having more biomechanical stability after SMILE, compared with its tensile strength (ability to maintain shape and thickness) after LASIK.

Limitations Of SMILE Laser Eye Surgery

Are there any downsides to SMILE when compared with LASIK or PRK?

The relatively new SMILE procedure is FDA-approved only for treatment of -1.00 to -8.00 D of myopia. But LASIK and PRK have been around longer and are approved for treatment of a broader range of nearsightedness — and treatment of astigmatism and farsightedness as well.

Research has shown that fewer dry eye symptoms may occur after SMILE, compared with LASIK — perhaps because the smaller SMILE incision disrupts fewer corneal nerves.

However, the treatment range for SMILE performed in the U.S. is expected to be expanded in the future. (In Europe, SMILE is approved to treat up to -5.00 D of astigmatism as well as nearsightedness.)

A potential risk of SMILE compared with LASIK is that if a patient has residual refractive error after SMILE and needs additional treatment, usually this enhancement procedure would need to be a PRK procedure rather than a second SMILE, for greater predictability of outcome.

Another potential risk of SMILE is an increase of higher-order aberrations (HOAs) in the eye after the procedure that could affect the quality of your vision, especially at night. One recent study found that some patients that underwent SMILE for the correction of moderate myopia (average of -4.34 D) and higher myopia (average of -7.16 D) experienced significant increases in HOAs after the laser surgery.

Finally, as with any newer vision correction surgery, it may be necessary for a surgeon to perform a significant number of SMILE procedures before he or she masters the surgical techniques required for optimum outcomes and minimal risks. Keep this in mind when considering SMILE (versus LASIK or other vision correction procedures) and discussing the procedure with your refractive surgeon.

SMILE Cost

Most U.S. refractive eye surgeons charge approximately the same price for SMILE laser vision correction as they do for all-laser custom LASIK surgery — somewhere in the range of $2,000 to $3,000 per eye.

A number of factors contribute to the total fee each surgeon charges, including the surgeon's experience, the practice location and whether follow-up exams and additional treatments (if needed) are included.

Is SMILE Right For You?

If you are nearsighted and meet the other criteria stated above, you might be a good candidate for SMILE laser vision correction. The next step is to have a comprehensive eye exam with your eye doctor and a consultation with a refractive surgeon.