ReLEx stands for "refractive lenticule extraction". SMILE means "small incision lenticule extraction." This means lenticule removal through a small incision. In ReLEx SMILE, a disc of tissue in the shape of a lens, the lenticule, is removed from inside the cornea through one or two small incisions in the cornea. The tissue slice and corneal incisions are created using a femtosecond laser.


Specialists in the Field of ReLEx SMILE

Information About the Field of ReLEx SMILE

What is ReLEx SMILE?

ReLEx SMILE is a laser surgical procedure for the correction of refractive errors. The principle of all laser surgical procedures is to change the cornea's curvature to increase or decrease the eye's refractive power to compensate for the particular refractive error.

Laser surgical procedures performed entirely with the femtosecond laser are relatively new surgical methods. ReLEx FLEX has been carried out since 2006. This technique creates a slice of tissue through a double incision with the femtosecond laser.

The ophthalmic surgeon lifts the anterior corneal flap like a lid, removes the tissue slice, and folds the flap back. The ReLEX SMILE procedure is a further development method. In the SMILE, a lid is not used, and the surgeon pulls the tissue flap out of a tunnel a few millimeters short from the inside of the cornea. This provides more excellent cornea stability after surgery than methods with a "tissue lid."

For Whom Is ReLEx SMILE Advisable?

ReLEx SMILE can be used to correct myopia and astigmatism . The cornea must be entirely and und the incision sufficiently thick for the surgery. The more severe the refractive error, the more tissue must be removed to compensate for the refractive error.

The Refractive Surgery Commission of the German Ophthalmological Society and the Professional Association of Ophthalmologists of Germany has issued the following recommendations for using ReLEx SMILE:

ReLEx SMILE can be used for myopia up to -8 diopters and astigmatism up to 5 diopters. Surgery is also possible for simultaneous presbyopia. First, one eye is adjusted to distance vision. Then, the other one is corrected so that near vision is optimal.

ReLEx SMILE can be used to a limited extent for myopia up to -10 diopters. The Refractive Surgery Commission defines this limit: the procedure can be used, but the results are progressively worse and the side effects more frequent; comprehensive patient informing is essential.

The surgery must not be carried out for chronic progressive corneal diseases, cataracts , glaucoma with severe visual field loss, exudative macular degeneration, and a form of the corneal protrusion (keratoconus atypical disease pattern).

How Much Does ReLEx SMILE Cost?

Surgeries to correct refractive errors are not paid for by health insurance. ReLEx SMILE usually costs between 2000 and 2600 euros per eye. Therefore, it is essential to determine in advance which services are included in the price and whether there are additional costs for follow-up examinations.

The Process of the Surgery

Before the surgery, the eye is anesthetized with eye drops containing a local anesthetic and held open with an eyelid retractor. The patient lies on a couch under the femtosecond laser for the procedure. The couch moves up until the eye's cornea touches the contact glass of the femtosecond laser. Now the surgeon turns on the laser. The laser only needs 25 to 30 seconds to make the incisions. Then the surgeon uses fine instruments to loosen the slice of tissue created by the laser inside the cornea and pulls it out with tweezers through a small opening in the cornea. Then the resulting pocket is rinsed with a dialytic fluid, and finally, the corneas are carefully straightened. After the surgery, the patient is treated with antibiotic and anti-inflammatory eye drops for one to three weeks and tear substitutes for several weeks.

The Healing Process After Surgery

In the first few days after surgery, patients often have blurred vision, and their eyes may burn. During the first few weeks, vision may deteriorate slightly as the pit in the cornea partially refills with corneal tissue. After about six weeks, the final vision is usually achieved.

In 80 to 90 percent of cases, surgery's desired acuity is achieved if the desired vision has not been achieved so far. Another surgery using the same procedure is not possible with ReLEx SMILE. PRK (photorefractive keratectomy), for example, can be used instead.

What Are the Risks and Disadvantages?

Patients often suffer temporarily increased dryness in the eyes. Patients have fewer problems with dry eyes compared to other laser surgical procedures. Twilight vision may also be limited.

A particular advantage of ReLEX SMILE is the more excellent stability of the cornea after surgery than with "tissue lid" methods such as LASIK and ReLEx FLEx.

The surgical method also has disadvantages. The following complications may occur during surgery: the cornea is fixed to the contact lens via a suction system during lasering. During the surgery, there may be a loss of suction. Then the incision may be incomplete. In some cases, the surgery must be interrupted.

Errors in cutting the cornea are rare. Also rare is detachment of the cornea's top layer (epithelium). Sometimes irregular cut surfaces are formed, or the tissue slice is not entirely removed. In both cases, irregular corneal surfaces are created, impairing vision. Very rarely, inflammation during wound healing, infection with severe scarring, or weakening and protrusion of the cornea occurs.

What Are the Alternatives to Laser Surgical Procedures?

Surface treatments (PRK, trans-PRK, LASEK, EPI-LASIK) or LASIK can be alternatives to ReLEx SMILE.

In surface treatments, the doctor uses the excimer laser to ablate the cornea for refractive error correction superficially. While the epithelium is removed in PRK, Trans-PRK , or LASEK, in EPI-LASIK, the surgeon merely pushes it aside and then places it back over the defect. A contact lens is set for a few days to protect the cornea, under which the superficial wound heals in a few days. Surface treatments are often the less expensive laser surgical procedures. However, the disadvantage is that vision is usually limited during the initial period after surgery. In addition, there may be mild to moderate pain.

In LASIK, the surgeon partially separates a thin layer from the cornea using a sophisticated microscalpel called a microkeratome and folds it over. Then, corneal tissue is removed from the exposed inner corneal layer utilizing the excimer laser in a second step. Femto-LASIK is a newer form of LASIK. In this procedure, the microkeratome is replaced by the femtosecond laser. LASIK is the most frequently performed surgical method to correct refractive errors worldwide.

Which Doctors and Centers Are Specialized in ReLEx SMILE Surgery?

Experts in laser eye surgery best perform laser surgical correction for defective vision. Modern refractive surgery procedures now have a high level of quality. The specialized ophthalmologist examines the eye comprehensively, educates the patient, and recommends a suitable method depending on the degree of refractive error.

We will help you find an expert for your condition. All listed doctors and clinics have been reviewed by us for their outstanding specialization in presbyopia and are awaiting your inquiry or treatment request.

Source references:

  • Blum M., Sekundo W. (2017). Refraktive Lentikelextraktion – Technik der ReLEx/SMILE. Der Ophthalmologe 2017, 114:851-856
  • Kreutzer, T.C., Dirisamer M., Priglinge  S. (2015). ReLEx SMILE – Refraktive Lentikel Extraktion über
  • Kleinschnittinzision. Spektrum Augenheilkd (2015) 29:46–49 DOI 10.1007/s00717-015-0254-9
  • Kommission Refraktive Chirurgie der Deutschen Ophthalmologischen Gesellschaft und des Berufsverbands der Augenärzte Deutschlands e.V. (2019). Bewertung und Qualitätssicherung refraktiv-chirurgischer Eingriffe durch die DOG und den BVA – KRC- Empfehlungen. Link: (27.10.2020)

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