SMILE Lenticule Extraction: Suitability, Risks and Recovery

Small-incision lenticule extraction (commonly known as SMILE) is corneal refractive surgery in which a femtosecond laser creates a lens-shaped piece of tissue inside the cornea and a small access incision. The surgeon separates and removes the lenticule to change corneal power. It does not guarantee freedom from glasses or a permanent prescription.

Key Points

• Lenticule extraction has no LASIK-style flap, but it still removes corneal tissue permanently.
• Approved prescription ranges, devices and eligibility vary by country and platform.
• A smaller incision avoids flap-specific problems but does not eliminate dry eye, infection, ectasia or visual-quality risks.
• Enhancement after lenticule extraction can be less straightforward than after some other refractive procedures.
• Corneal shape, thickness, tear film, prescription stability and complete eye health must be assessed.

How Lenticule Extraction Works

A femtosecond laser creates two tissue planes that define the lenticule and then creates an incision. The surgeon manually separates the planes and removes the tissue. The change in corneal shape alters focus.

The laser does not remove the lenticule by itself, and the procedure is not contact-free. Docking and suction are used, and surgical separation is a critical step. Device software, calibration, centration, anatomy and technique all affect delivery.

Who May Be Considered

Suitability depends on a stable supported refractive error, corneal shape and thickness, tear film, pupil, age, eye health, medicines, pregnancy or breastfeeding status, occupation and expectations. A high prescription or relatively thin cornea does not automatically make the operation safe.

Keratoconus or ectasia risk, irregular tomography, active inflammation or infection, significant uncontrolled dry eye, uncontrolled glaucoma, relevant retinal disease or unrealistic expectations may require another option or no surgery.

Preoperative Assessment

Testing should include refraction and prescription stability, corrected and uncorrected vision, corneal topography or tomography, thickness, tear-film and eyelid assessment, pupil evaluation, eye pressure and examination of the eye. Contact lenses may need to stop before measurements.

The surgeon should confirm the locally approved treatment range, intended optical zone and residual tissue. Ask why lenticule extraction is recommended over glasses, contact lenses, PRK or LASIK for the examined eyes.

Procedure and Anaesthesia

Numbing drops are commonly used. During laser docking, vision may dim and pressure or discomfort may be felt. After the laser creates the planes, the surgeon separates and removes the lenticule through the incision.

Difficulty identifying or separating a plane, an incomplete incision, suction loss or retained tissue can change the procedure and may require postponement, conversion or further treatment. A quoted laser time is not the same as total operating time or a measure of safety.

Possible Benefits and Limitations

The procedure can reduce selected myopic prescriptions and astigmatism without a corneal flap. Avoiding a flap may be relevant to some occupations or activities. Some patients may experience less early surface disruption than with other techniques.

These potential differences do not establish universal superiority. Residual prescription, undercorrection, overcorrection, regression or induced astigmatism can leave a need for glasses, contact lenses or further surgery.

Risks and Complications

Potential problems include pain or discomfort, dry-eye symptoms, light sensitivity, glare, halos, starbursts, ghosting, reduced contrast, fluctuating vision, inflammation, debris at the interface and delayed visual recovery.

Incomplete or difficult lenticule removal, retained fragments, tears, decentration, infection, scarring, corneal ectasia, persistent neuropathic pain and permanent loss of best-corrected vision are possible. “Flap-free” does not mean complication-free.

Dry Eye and Corneal Strength Claims

Differences in incision and nerve effects may influence dry-eye symptoms compared with LASIK, but pre-existing tear-film disease and individual response remain important. Significant dryness can still occur and requires assessment and treatment.

Biomechanical models do not prove that an individual cornea cannot develop ectasia. Tissue removal, starting shape, residual thickness and susceptibility all matter. Marketing claims of a stronger or permanently stable cornea should not replace tomography and tissue calculations.

SMILE, LASIK and PRK

LASIK creates a flap and uses an excimer laser to reshape tissue. PRK removes the epithelium before excimer ablation. Lenticule extraction uses a femtosecond laser and manual tissue removal without a LASIK flap. Each has different eligibility, discomfort, recovery and enhancement pathways.

No procedure is best for everyone. Hyperopia, mixed astigmatism, very small corrections, corneal irregularity or a need for a particular custom profile may affect availability or suitability depending on the platform and regulator.

Enhancement and Future Eye Care

If correction is inadequate or later regresses, options may include glasses, contact lenses, surface laser, conversion of tissue planes or another procedure. Eligibility depends on remaining cornea and timing; enhancement is not guaranteed.

Keep preoperative measurements and the operative report. Corneal refractive surgery can affect future cataract lens calculations. It also does not prevent presbyopia, cataract, retinal disease or glaucoma.

Recovery and Warning Signs

Comfort and vision vary. Use prescribed drops and follow individual advice for shields, washing, screens, work, driving, sport, swimming, flying and make-up. Do not use a generic timetable to arrange travel or safety-critical work.

Seek urgent eye care for severe or increasing pain, sudden or worsening vision, marked redness, discharge, eye trauma, a new curtain or shadow, or flashes with a sudden increase in floaters.

Planning Care Through Revitalize

Confirm the ophthalmologist’s name, registration and procedure-specific experience, the contracted facility, exact device and approved range, tissue calculations, enhancement policy and emergency arrangements.

The Revitalize vision-correction guide explains the wider assessment pathway. A device name or remote quotation cannot establish suitability.

Independent Patient Information

• NHS: laser eye surgery and lens surgery
• US FDA: corneal refractive-surgery risks
• Royal College of Ophthalmologists: refractive surgery

Frequently Asked Questions

Is SMILE always safer than LASIK?

No. It avoids a flap but has different risks, limitations and enhancement options.

Does flap-free mean blade-free and risk-free?

It uses a laser and manual tissue removal without a LASIK flap; surgical risks remain.

Will I never need glasses again?

Not necessarily. Residual error, regression and future presbyopia can require correction.