Is SMILE Safer Than LASIK?

LASIK eye surgery is the most commonly performed laser refractive surgery to correct vision problems. LASIK improves vision and eliminates the need to wear glasses or contact lenses.

LASIK surgery may be done to correct one of these vision problems:

• Myopia (nearsightedness): Difficulty seeing distant objects
• Hyperopia (farsightedness): Difficulty with near vision
• Astigmatism: Uneven curvature of the cornea or lens, leading to distorted or blurred vision

LASIK is a short procedure and is usually completed in 30 minutes or less.

• Medication may be given to sedate extremely anxious patients.
• Numbing eye drops are placed in the eye, and the eyelids are held open with an instrument. 
• A small blade or cutting laser is used to make a small flap in the cornea.
  • The cornea is the clear layer covering the iris (colored part of the eye). 
  • The flap is folded to give access to the part of the cornea that has to be reshaped.
• A programmed laser beam is used to reshape the cornea, and a small amount of corneal tissue is removed.
• The flap is then repositioned and heals on its own without stitches.

LASIK surgery can be done in both eyes simultaneously. Patients can resume most normal activities soon after the surgery. Complete healing of the eyes takes two to three months. Vision may not be clear for two to three months after surgery. After surgery, patients may feel itching, watering, redness, and dryness of the eyes.

Small incision lenticule extraction (SMILE) is a newer type of laser refractive eye surgery based on LASIK. SMILE is most commonly used to treat myopia or nearsightedness in people who are not ideal candidates for LASIK. SMILE is less invasive than LASIK because it does not involve making a flap in the cornea to reshape. It involves using a single laser to flatten and reshape the cornea.

The setup, time taken, anesthesia used, and cost for SMILE surgery are very similar to those for LASIK. Healing and recovery time in SMILE surgery is about the same as those in LASIK, but the risk of scarring and dryness of the eyes is lower. You will also not be moved from one device to another because there is only one laser involved, so SMILE is a good option for people with myopia who have thin corneas.

The similarities between the two procedures include:

• Both are performed by an ophthalmologist (eye surgeon).
• Both involve using a guided laser.
• Both are performed under local anesthesia.
• Both are performed in under 30 minutes.
• Many of the side effects are similar such as blurry vision till the eyes heal, glares, halos, difficulty with seeing in the dark, increased light sensitivity, and dry eyes.
• The recovery time is the same.
• Postoperative care is the same.
• The basic eligibility criteria for both the surgeries are the same; they include the following:
  • Age over 21 years
  • No significant change in vision over the past year
  • Possibility of vision improvement to at least 20/40
  • Myopic prescription between −1.00 and −12.00 diopters
  • Not pregnant, breastfeeding, or on hormonal therapy at the time of surgery
  • Average pupil size about 6 mm in the dark

Main differences between small incision lenticule extraction (SMILE) vs LASIK include:

• LASIK can be used to treat all types of refractive errors, whereas SMILE is used to treat myopia with or without astigmatism. However, SMILE cannot treat isolated astigmatism.
• LASIK involves a flap to be surgically made in the cornea, so the excimer laser reaches the deeper parts of your eye. SMILE is used as a single laser to flatten and reshape the cornea.
• The risk of scarring is higher in LASIK than in SMILE.
• LASIK is not ideal in those with thin corneas. SMILE can be done in those with thin corneas.
• Both the procedures have good patient satisfaction, but the patient satisfaction of SMILE is slightly better.
• Because SMILE is a newer surgery, a fewer number of surgeons specialize in it.