SMILE, or Small Incision Lenticule Extraction, is a modern form of laser eye surgery designed to correct common refractive errors. This procedure aims to reduce or eliminate the need for glasses or contact lenses, primarily addressing conditions like nearsightedness (myopia) and a specific range of astigmatism. It is considered a minimally invasive technique due to its approach to reshaping the cornea, the clear front surface of the eye.
Understanding How SMILE Works
SMILE surgery employs a sophisticated femtosecond laser to precisely alter the cornea’s shape. This laser creates a tiny, disc-shaped piece of corneal tissue, known as a lenticule, located within the intact corneal layers.
Once the lenticule is formed, the surgeon creates a very small incision on the corneal surface, typically ranging from 2 to 4 millimeters in length. Through this small opening, the surgeon carefully extracts the lenticule. Removing this tissue reshapes the cornea, allowing light to focus correctly onto the retina at the back of the eye, thereby improving vision.
Who Is a Candidate for SMILE?
SMILE surgery is generally suitable for individuals who meet specific criteria. Candidates are typically at least 18 years old, with some sources suggesting 22 years or older, and should have a stable vision prescription for at least one year. The procedure primarily treats nearsightedness, usually ranging from -1.00 to -10.00 diopters, and astigmatism up to 3 diopters.
Ideal candidates also possess healthy corneas and good eye health, without active eye diseases or certain corneal conditions. Conditions that might exclude a person include severe dry eye, very thin corneas, or certain systemic health conditions. Patients involved in contact sports or those with physically demanding occupations might find SMILE appealing due to its flap-free nature.
What Happens During SMILE Surgery?
On the day of the SMILE procedure, patients undergo pre-operative preparations that typically involve the application of numbing eye drops. The patient lies in a supine position under the laser, and a speculum is used to gently hold the eyelids open. The femtosecond laser then precisely creates the lenticule within the cornea and the small access incision.
The laser application itself is brief, often lasting only a few seconds per eye, and the entire procedure for both eyes can take about 15 to 20 minutes. Patients generally report no pain during the surgery, though some may experience a sensation of mild pressure on the eye.
Recovery and Expected Outcomes
Following SMILE surgery, patients may experience sensations like mild discomfort, a feeling of grittiness, slight blurriness, or increased light sensitivity. Vision improvement is rapid, with many patients noticing clarity the day after. Full visual stabilization typically occurs within days to a few weeks, though it can take up to a month for complete recovery.
Adherence to post-operative instructions, including the use of prescribed eye drops and avoiding certain activities like swimming or strenuous exercise, is important for healing. Follow-up appointments with the eye surgeon are scheduled to monitor recovery and vision progress. The procedure has a high success rate, with potential temporary side effects like mild dry eyes or halos around lights usually resolving as the eye heals.
SMILE Compared to Other Procedures
SMILE differentiates itself from LASIK and PRK through its unique approach to corneal reshaping. Unlike LASIK, which involves creating a hinged flap on the cornea’s surface, SMILE is a flapless procedure. This eliminates flap-related complications and may lead to less post-operative dry eye due to reduced corneal nerve disruption.
Compared to PRK, where the outer layer of the cornea (epithelium) is removed and allowed to regrow, SMILE is an internal procedure that leaves the corneal surface largely intact. This difference translates to a faster visual recovery time and less immediate discomfort for SMILE patients than for those undergoing PRK. While all three procedures aim to correct refractive errors, SMILE’s minimally invasive nature and flap-free design offer distinct advantages for certain patients and lifestyles.