You may have heard the terms LASIK, PRK and SMILE thrown around in the laser eye surgery world. All three procedures are used to correct refractive error, including myopia (short-sightedness), hyperopia (long-sightedness) and astigmatism.
But what is the difference between these procedures? And is one better than the other?
This article aims to delineate between the three procedures and provide clarity to guide you through your journey towards laser eye surgery.
What is LASIK?
Laser-assisted in situ keratomileusis (LASIK) is the best-known name within the field of laser eye surgery; as of 2016, more than 40 million LASIK procedures have been carried out around the world. The procedure is completely blade-free and uses special lasers to reshape the cornea.
How is it performed?
LASIK surgery involves two stages. The first step involves creating a small flap in the corneal tissue using a femtosecond laser called the Intralase. After this flap is created, a computer-controlled excimer laser is then used to reshape the corneal surface by shooting highly precise pulses of ultraviolet light. Once the cornea is reshaped, the flap is repositioned over the newly reshaped cornea without the need for any sutures.
Who is LASIK suitable for?
LASIK has been used to treat more eyes than any other laser vision treatment available today. It is suitable for a broad range of prescription types, including myopia, hyperopia and astigmatism.
What is PRK?
Photorefractive keratectomy (PRK) is an alternative procedure for those who are not suitable for iLASIK surgery.
How is it performed?
Similar to LASIK, PRK is completely blade-free and also uses lasers to reshape the corneal surface. The difference lies in the first step. Instead of creating a flap in the cornea, the front surface cells of the cornea (epithelial cells) are removed using a dilute alcohol solution or a brush. Once these cells are removed, the corneal surface is then reshaped using the computer-controlled excimer laser, just like LASIK. The final step involves placing a bandage contact lens which is worn for 5 days post-surgery.
Who is PRK suitable for?
PRK is generally recommended for those people with thinner corneas, irregularly shaped corneas or in certain cases of dry eye.
What is SMILE?
Small incision lenticule extraction (SMILE) is the newest technique used to correct a refractive error; first used in 2008. Like LASIK and PRK, it is blade-free and uses a laser to facilitate the procedure. However, the main difference lies in the method used to reshape the cornea. Instead of using an excimer laser to reshape the cornea, SMILE corrects the refractive error by pulling out a lenticule of corneal tissue.
How is it performed?
A computer-controlled femtosecond laser creates a thin lenticule of corneal tissue. This lenticule corresponds to the precise degree of refractive error that needs to be corrected. The same femtosecond laser then creates a very small incision to access and extract the lenticule, which is then removed.
Who is SMILE suitable for?
SMILE is preferred for people with dry eyes and those who have higher degrees of myopia (short-sightedness) without any significant corneal abnormality or epithelial disorder. However, it currently cannot be used to treat hyperopia (long-sightedness).
Ultimately, the most suitable procedure for you depends on the degree of your refractive error, the unique shape and thickness of your cornea, and lifestyle factors. This decision can only be made via a comprehensive assessment of your eye at a specialised laser eye clinic.
George St Eye Centre offers free laser assessments that are able to tell you which procedure type you are suitable for. Contact the team today on (02) 9230 0010 to discuss your surgery options.
Request your free laser eye assessment here.