ReLEx Smile | Specialists & Treatment Information

What is ReLEx SMILE?

The SMILE technique is a keyhole surgical method that corrects nearsightedness ranging from -2 to -10 diopters and astigmatism of up to 5 diopters.

Laser eye surgery using the Smile procedure is now considered the safest and gentlest method in laser eye treatment.

“ReLEx” stands for Refractive Lenticule Extraction and means that doctors remove a refractive lenticule from within the intact cornea.

“SMILE” (Small Incision Lenticule Extraction) means that the surgeon removes the lenticule using a minimally invasive technique through a two-millimeter incision.

This procedure was developed by Prof. Dr. Marcus Blum and Prof. Dr. Walter Sekundo, who worked closely with Carl Zeiss Meditec AG.

How does the SMILE laser method work?

In the SMILE method, the surgeon first cuts a thin lens (lenticule) into the cornea. He then removes it through a minimally invasive incision (cap).  

With this technique, the cornea retains its natural structure, and tear film production remains virtually unaffected.

This procedure is also suitable for patients with very dry eyes, who are not candidates for LASIK.

Treatment with the SMILE laser is performed on an outpatient basis under local anesthesia. It takes only a few minutes and is completely painless. 

In the first few hours after the procedure, the eye may water and itch. At first, the patient’s vision will still be blurry. Just one day later, patients can see almost normally. Final stability is achieved after four to six weeks.

How do ReLEx SMILE and Femto-LASIK differ?

Femto-LASIK uses an excimer laser. The surgeon cuts the top layer of the cornea like a round lid (flap) and folds it aside.  

This flap carries various risks and side effects:

• Dry eyes
• Incision errors
• A sensation of a foreign body
• Flap detachment, in which the flap no longer reattaches

In the SMILE procedure, the femtosecond laser enables precise, three-dimensional cuts within the cornea. It creates a precisely calculated corneal disc, which the surgeon removes through a tiny incision.

A flap is a circular, wafer-thin layer of the outer cornea @ RFBSIP /AdobeStock

What requirements must be met?

To be eligible for ReLEx SMILE surgery, the patient must meet the following criteria:

• Myopia ranging from -2 to -10 diopters
• Astigmatism of no more than 5 diopters
• The cornea must not be too thin
• No significant changes in refractive error within the past year
• The patient must not be pregnant

The minimum age for the procedure is 18 years. ReLEx SMILE cannot be used in cases of cataracts.

What are the advantages and disadvantages of the ReLEx SMILE procedure?

The biggest advantage of ReLEx SMILE is that this method does not require a flap and is therefore extremely low-risk. Recovery is very quick. Patients can return to their normal daily routines shortly after surgery:

• Showering and light physical activity are possible as early as 30 minutes after the procedure.
• Endurance sports can be resumed without restriction after two weeks.
• Swimming or using the sauna is possible after three to four weeks

In summary, the following advantages result:

• A very gentle method, as it involves a minimal incision of only about 2 mm in length
• No flap (85 percent less incision area, no flap-related risks such as epithelial ingrowth or flap detachment)
• Tear flow remains intact, making it suitable even for very dry eyes
• Pain-free
• A silent and odorless procedure

As of today, ReLEx SMILE is one of the safest methods for laser eye surgery. To date, no serious complications or permanent side effects have been reported. 

However, the procedure is still very new, so there are no long-term studies available yet.

 The main limitation of ReLEx SMILE is that it can only be used to treat nearsightedness and astigmatism. Patients with farsightedness must opt for a different procedure. This method is not suitable for patients with a refractive error of less than -2 diopters. The lenticule to be extracted is too thin and may tear during removal.

What are the risks associated with the SMILE procedure?

Although ReLEx SMILE is considered a very gentle procedure, like all medical procedures, it carries certain risks. For example, there is a minimal risk of overcorrection or undercorrection, or of the surgical results regressing. Follow-up treatment using the same procedure is not possible and would have to be performed using the conventional LASIK technique (with a flap).

The following complications are possible:

• Mild abrasions and tears in the incision area
• Foreign body sensation (subsides shortly after surgery)
• In people with severe nearsightedness, reduced visual acuity at night and during twilight (temporary)

Complications that would result from lifting a flap (e.g., sensory disturbances and pain) are largely eliminated.

How much does SMILE laser surgery cost?

Compared to standard LASIK, the SMILE procedure is currently still very expensive. While LASIK treatments cost 1,000 euros, patients pay 2,000 euros per eye for a ReLEx SMILE procedure.

This makes the procedure too expensive for patients with limited financial means.

However, it is possible to deduct the costs of the procedure from your income tax. This indirectly reduces the total costs, albeit with a delay. Anyone with private supplemental vision insurance should inquire whether it covers the costs of SMILE surgery.