ReLEx SMILE

Small Incision Lenticule Extraction

SMILE Surgery: The Most Advanced Technique for Getting Rid of Glasses

What Is the Ideal Age for Surgery?

What is SMILE?

SMILE (Small Incision Lenticule Extraction) is the third generation of refractive surgery, which corrects myopia (-1 to -10 diopters) and astigmatism (up to -5 diopters) without creating a corneal flap, offering:

Lower risk of dry eye vs. LASIK

Faster recovery than PRK

Maximum safety in thin corneas

Ideal Age for SMILE Surgery

Optimal Range: 20 to 45 years

<18 years

NO, Unstable prescription

18-25 years

Yes (with evaluation), Must have stable prescription for ≥1 year

25-40 years

Ideal, Maximum long-term benefit

40+ years

Depends. If presbyopia is present, combine with other techniques

Why Is This Age Ideal?

Stable prescription: Hormonal changes in adolescents can alter the results.

Optimal cornea: Better healing compared to older patients.

Maximum benefit: You enjoy more years without dependence on glasses.

Over 45? We can evaluate:

SMILE + monovision (if you agree to wear glasses for near vision occasionally)

Intraocular lenses (IOLs) if you have advanced presbyopia

Advantages of SMILE in Young Adults

Athletes: No risk of flap displacement (ideal for boxing, martial arts)

Digital professionals: Faster recovery to return to screens

Thin corneas: Safer option than LASIK

ReLEx SMILE Refractive Surgery: Current Technology and Advantages

ReLEx SMILE (Small Incision Lenticule Extraction) is the third generation of laser refractive surgery, designed to correct myopia and astigmatism without creating a corneal flap (as in LASIK) or removing the epithelium (as in PRK).

Advanced Technology Used

The procedure is performed with the ZEISS VisuMax femtosecond laser, the only one approved for SMILE. Its design includes:

Ultra-fast pulses (femtoseconds) that create plasma bubbles in the corneal stroma without generating heat.

Low-pressure suction system for greater comfort and safety.

Submicroscopic precision (tissue cutting with a margin of error of ±5 microns).

How Does ReLEx SMILE Work? (Step by Step)

Creation of an Intrastromal Lenticule:

The laser carves a microscopic lens (lenticule) within the cornea, following customized parameters based on the prescription.

Peripheral Microincision (2–4 mm):

A small cut is made to manually extract the lenticule.

Corneal Reshaping:

By removing the lenticule, the cornea adopts a new curvature that corrects the refractive error.

Current Clinical Benefits

Minimal Corneal Trauma:

By not creating a flap, the risk of ectasia (corneal deformation) is reduced and corneal biomechanics are preserved.

Less Postoperative Dry Eye:

Corneal nerves are less damaged than in LASIK.

Safety in Patients with Thin Corneas or Mild Dry Eye:

Viable option where LASIK would be contraindicated.

Rapid return to activity:

Ideal for athletes, military personnel, and high-risk occupations.

Current Limitations

Surgeon Dependence: Manual lenticule removal requires experience.

Proprietary Technology: Only available with the ZEISS VisuMax laser.

Who is an Ideal Candidate?

Patients with myopia of -1 to -10 diopters or astigmatism up to 5 diopters.

Athletes or individuals exposed to trauma (e.g., boxers, police officers).

Mild to moderate dry eye, which contraindicates LASIK.

Why is ReLEx SMILE more expensive than LASIK?

ReLEx SMILE (Small Incision Lenticule Extraction) is a more advanced technique than LASIK, and its higher cost is due to technological, safety, and logistical factors. Here are the main reasons:

1. Newer and More Specialized Technology

High-precision femtosecond laser:

ReLEx SMILE requires a specific laser (VisuMax by ZEISS), which is more expensive than the excimer lasers used in LASIK.

Only a few manufacturers produce these systems, limiting competition and keeping prices high.

Exclusive Patent:

ReLEx SMILE technology is protected, preventing cheaper generic alternatives.

2. More Complex Procedure

Without corneal flap:

ReLEx SMILE extracts an intrastromal lenticule through a microincision, which requires greater surgical skill.

LASIK, by creating a flap, is technically simpler.

Longer learning curve: Surgeons require more training to master SMILE.

3. Clinical Advantages That Justify the Cost

Lower risk of dry eye (saves more corneal nerves than LASIK).

No flap-related complications (displacement, infections).

Greater corneal stability (ideal for thin corneas or patients with early keratoconus).

4. Higher Operating Costs

More Expensive Equipment:

The VisuMax laser has a higher acquisition and maintenance cost than excimer lasers.

Disposable Supplies:

Each ReLEx SMILE procedure uses unique cartridges and accessories.

Less Availability:

Not all clinics have the equipment, which reduces price competition.

Is it worth paying more?

Yes, if you have high myopia, thin corneas, or dry eyes.

No, if your prescription is low and your cornea is thick (LASIK/PRK may be sufficient).

ReLEx SMILE has a 95% satisfaction rate in well-selected patients, with a lower risk of long-term complications compared to LASIK (Journal of Refractive Surgery, 2023).

Why aren't all patients candidates for ReLEx SMILE in refractive surgery?

SMILE (Small Incision Lenticule Extraction) is a revolutionary technique for correcting myopia and astigmatism, but it's not suitable for all patients. Its application depends on anatomical factors, specific prescriptions, and ocular conditions. Here are the main limitations:

1. Uncovered refractive errors

Does not correct hyperopia or presbyopia

SMILE only treats myopia (up to -10D) and astigmatism (up to -5D).

For hyperopia or presbyopia (presbyopia), LASIK, PRK, or premium intraocular lenses are recommended.

Out-of-Range Prescriptions

Very high myopia (>-10D): May require ICLs (phakic intraocular lenses).

Astigmatisms >5D: May require combined techniques (e.g., SMILE + toric laser).

2. Corneal Conditions

Cornea that is too thin or irregular

Requires a minimum corneal thickness (generally ≥480–500 µm).

If keratoconus or irregular corneas are present, SMILE is contraindicated (risk of ectasia).

Alternatives: Cross-linking + PRK or ICL lenses.

Corneal Opacities or Scarring

The femtosecond laser cannot work adequately if there is scarring (e.g., from ocular herpes).

3. Other Anatomical Limitations

Severe, Uncontrolled Dry Eye

Although SMILE is less aggressive than LASIK, it may temporarily worsen dry eye.

4. General Factors

Age and Refractive Stability

Patients <18 years: Prescription not yet stable.

Recent changes in prescription (>0.5D in the last year).

Pregnancy or breastfeeding

Hormones can alter corneal shape (wait 3–6 months after breastfeeding).

Ocular or systemic diseases

Advanced glaucoma, diabetic retinopathy, or autoimmune diseases (e.g., lupus).

Alternatives if you are not a candidate for SMILE

LASIK/FEMTOLASIK: For hyperopia or thicker corneas.

PRK: Safe option for thin corneas (no flap).

ICL lenses: Ideal for high myopia (>-10D) or inadequate corneas.

Multifocal intraocular lenses: If you have presbyopia.