What is SMILE eye surgery?
More than 150 million Americans have poor vision due to refractive error. Refractive errors make your vision blurry or hazy, which makes reading difficult and can cause eye strain and headaches. You will need prescription glasses or contact lenses to see clearly. SMILE (small incision duckweed extraction) is a surgical procedure that works by reshaping your cornea. This focuses light precisely on your retina, giving you sharp vision. SMILE is a relatively new alternative to the well-established procedure of LASIK (laser-assisted in situ keratomileusis).
What is SMILE eye surgery?
SMILE is a type of surgery used to correct refractive errors. The four types of refractive error are nearsightedness (myopia), farsightedness (farsightedness), astigmatism (blurred vision at all distances), and presbyopia (inability to focus the eyes up close).
Your vision depends on your cornea and your lens, which focuses a clear image of the world in front of you on your retina. It requires refraction (bending) of light rays to form a sharp image on your retina. This refraction is carried out by the cornea and the lens. Alterations in the shape of the cornea cause a blurry image on the retina, which makes your vision blurry.
SMILE surgery changes the curvature of your cornea. This restores refraction to normal, giving you clear vision again. It reduces the need for glasses or contact lenses. You might even be able to see well without them. SMILE is relatively new. It was approved for the correction of myopia in 2016 and for astigmatism in 2018.
SMILE Surgery – What to expect
You should discuss with your eye doctor what to expect from this surgery. They will tell you not to expect perfect vision without glasses or contact lenses. It’s possible that your vision will improve that much, but it’s not certain. It is important to have realistic expectations.
After SMILE surgery, you will likely be able to perform most tasks without corrective eyewear. Your vision will definitely be better. But you may still need to use glasses for certain activities, like driving at night or reading.
Almost everyone who undergoes SMILE surgery achieves 20/40 visual acuity without glasses or contact lenses. About 88% (7 out of 8) achieve 20/20 vision without glasses or contact lenses.
SMILE surgery procedure
Prior to surgery, your eye doctor will perform a comprehensive eye exam. They will want to make sure you don’t have any eye problems, especially the cornea. Certain eye conditions may affect SMILE surgery or worsen after surgery. They will test your vision to make sure it hasn’t changed over the past year. It must also be within SMILE-correctable limits.
Your eye doctor will also check the thickness of your cornea and take precise measurements. They will then transmit these measurements to the computer which guides the SMILE laser.
SMILE is usually performed on an outpatient basis. You won’t need to spend the night in the hospital. This is a computer-assisted procedure and usually takes around 20 minutes. Your two eyes are treated together.
The procedure is done under local anesthesia. Drops of medicine are placed in your eyes to numb them. A femtosecond laser is used to cut a small, lens-shaped disc into the cornea. This disc is extracted through a small incision only 2 to 3 millimeters wide. This incision is also created by the femtosecond laser. This procedure reshapes the cornea to exactly reverse the refractive error of the eye.
SMILE Eye Surgery Side Effects
SMILE surgery is performed under topical (local) anesthesia which numbs the eyes. When the effect of the drug wears off, you will feel some discomfort. Tearing and redness are common. You may also experience pain and a gritty feeling that lasts for 6 to 12 hours.
SMILE carries risks of overcorrection or undercorrection. When this happens, you may need to continue wearing glasses or contact lenses. The procedure is generally safe, but you may have corneal abrasions or small tears at the incision site. These complications are minor and do not affect long-term vision.
SMILE vs. LASIK surgery
LASIK has been used for many years. It provides reliable refraction correction. Compared to SMILE, LASIK gives better uncorrected visual acuity and low contrast visual acuity. LASIK is approved for the correction of farsightedness (farsightedness).
On the other hand, SMILE recovers faster from dry eyes after the procedure. Because the incision is small, very few corneal nerves are damaged. Corneal sensation recovers sooner than with LASIK, which lifts a large flap of the cornea, damaging many nerves.
SMILE has some biomechanical advantages because it uses only a small incision. The cornea may retain more of its strength. SMILE may be better for you if you have an active lifestyle. LASIK raises a large flap of the cornea, which can be dislodged during vigorous activity.
SMILE is also more cost effective, as it requires only one laser. The femtosecond laser creates both the lenticule and the incision to extract it. LASIK requires a second laser (an excimer).
Is SMILE eye surgery right for you?
Like all surgical procedures, SMILE has certain requirements. These make it safe for you and increase the chances of success:
- You must be at least 22 years old.
- Your vision should be stable. Your eye prescription should not have changed in the past year.
- Your eyes and corneas should be healthy.
- Your myopia must be between -1 and -10.
- Your astigmatism must be less than 3 diopters.
Who should not have SMILE surgery?
SMILE surgery can correct your vision and free you from wearing glasses or contact lenses. But this procedure is not suitable for everyone. Certain conditions may make you unsuitable for this surgery:
- Thin corneas
- Irregular astigmatism
- Scars on the cornea
- Progressive ectasia (thinning of the cornea)
- Changing refraction (unstable)
- Cataracts in one or both eyes
- Diabetes, uncontrolled
- Previous eye surgery or disease
- Pregnancy or breastfeeding
Since SMILE is a relatively new procedure, experience with it is limited. The small incision in the cornea is an advantage. Recovery of corneal sensation is faster and dry eyes last less after SMILE than with LASIK. Currently, the procedure is only approved for myopia and astigmatism. As more trials are completed, the United States Food and Drug Administration may approve it for other uses. SMILE has good results and is a useful procedure for vision correction.