A life without glassesThe different laser treatment option

Laser surgery techniques for refractive vision correction were well established, both scientifically and clinically, by the mid-80s. The basic principle behind all the methods is using a laser to model the outer corneal layer so that the focal point of the bundled incidental light is on the surface of the retina itself and not in front of or behind it. The original treatment methods, PRK and LASEK, manually removed the outer protective layer (epithelium) of the cornea before the laser surgery. The consequences often included post-operative pain and Laser surgery techniques, which involves a corneal flap (LASIK and Femto-LASIK) were then developed. Here, a mechanical cutting tool (microkeratome) or a femtosecond laser is used to create a thin flap of cornea which is just 120 micrometers thick. Almost a complete circle (270°) is cut in the upper layers of the cornea. The flap is then folded back like the cover of a book. Subsequently, the exposed corneal tissue is then ablated using an excimer laser in a separate stage of treatment. The greater the level of vision defect, the more tissue needs to be removed.

In the final stage of treatment, the corneal flap is then folded back into its original position. It then adheres in the original place over the coming weeks and months. The disadvantage is that the flap can shift or even tear off (flap displacement) as the result of rubbing or other physical contact after the operation. The ReLEx® SMILE principle: The high-precision VisuMax® femtosecond laser creates a small lens (lenticule) inside the intact cornea, the volume and form of which are determined by the degree of vision defect to be corrected. This lenticule is then removed in a minimally invasive procedure from the interior of the cornea through a small access measuring just a few millimetres. In contrast to earlier techniques, it is no longer necessary to fold back the cornea. There is no flap incision, the area of the incision is reduced to a minimum and the outer corneal layers remain more or less intact. All of which is made possible by a sensitive, precise and convenient treatment method.

The Treatment Steps

SMILE with VisuMAx

Step 1: In a single step the VisuMax femtosecond laser creates a thin lenticule and a small access measuring less than 4 mm in the intact cornea.

Step 2: The surgeon removes the lenticule through the small access. There is minimal disruption to the biomechanics of the cornea. No flap needs to be cut.

Step 3: The minimally invasive removal of the lenticule changes the shape of the cornea, correcting the refractive error of the eye.


Step 1: The femtosecond laser creates a corneal flap.

Step 2: The patient is moved to the excicmer laser.

Step 3: The surgeon opens the flap and folds it back to expose the lower corneal layer (stroma) beneath.

Step 4: The excimer laser ablates the pre-calculated amount of corneal tissue, point by point.

Step 5: After the laser surgery is compled, the flap is returned to its original position. It then adheres in the original place over time.

Advanced PRK

Step 1: The patient is moved to the excicmer laser.

Step 2: The outer surface of the cornea”epithelium” is removed and discarded.

Step 3: The excimer laser ablates the pre-calculated amount of corneal tissue, point by point

VisuMax femtosecond laser

The specially developed laser system used for the SMILE procedure is the ZEISS VisuMax femtosecond laser. In Femto-LASIK surgery it has already impressed patients and physicians alike with its sophisticated technology, its precision and its reliability. SMILE using the VisuMax from ZEISS now permits accuracy down to nearest micrometer precision.The high-precision femtosecond laser provides targeted correction of the vision defect while leaving the surrounding corneal tissue virtually unaffected.

A contact glass specially designed to match the individual anatomy of the cornea permits customized treatment in which the corneal tissue does not need to be unnecessarily compressed. This helps avoid temporary loss of vision caused by excessive intraocular pressure.An ergonomically designed and functionally versatile patient supporting system provides extra comfort and relaxation during treatment. The position of the patient is continuously monitored during the laser procedure and automatically adjusted and corrected, if necessary.

In recent years minimally invasive diagnostic and treatment methods have set new standards in modern medicine. This is because minimally invasive very often means minimum discomfort for the patient. In its SMILE method ZEISS has developed a new technique for the minimally invasive laser correction of vision defects. This innovative treatment technique yields a whole range of benefits:

Flapless Treatment

  • No folding back of a corneal flap
  • Lenticule preparation in the intact cornea
  • Minimally invasive access measuring just a few millimeters (80 % less lateral incision than in LASIK and Femto-LASIK)
  • Almost complete preservation of protective corneal layer (epithelium) and stabilizing outer corneal layers (Bowman’s membrane)
  • Maximum number of corneal nerves responsible for tear regulation remain intact
  • Practically painless during and after the procedure

Entire treatment carried out using femtosecond laser (all-femto)

  • Use of high-precision femtosecond technology
  • Outstanding predictability of results, even in cases of severe myopia (> -7.00 D )
  • Anatomically shaped contact glass avoids unnecessary compression of the cornea
  • No loss of vision during treatment
  • Noiseless and odorless treatment
  • Stabilization of visual acuity typically within 14 days

Single-Step Treatment

  • Entire laser correction in a single treatment step
  • No device change during the operation
  • Short procedure

Information about ReLEx SMILE

What makes SMILE with VisuMax so special? Unlike in all other laser eye surgery procedures, the corneal tissue is not ablated using an excimer laser. In ReLEx SMILE, proven femtosecond laser technology is the only technology used. A small lenticule is prepared inside the intact cornea using the femtosecond laser. This lenticule is removed through an access point just a few millimeters across. In fact, the cornea does not have to be opened at all – unlike with LASIK and Femto-LASIK.

There is no flap in advanced PRK either. How does this procedure differs from SMILE? In advanced PRK the top layer of the cornea is removed manually. The exposed deeper layer of the cornea are then ablated using an excimer laser. The disadvantages of this procedure is that it is associated with more pain in the early post-operative phase and the healing process takes a bit longer, with stabilisation of visual acuity that happens over time. Although very accurate for low to moderate myopia, advanced PRK is not necessarily recommended for high myopia, due to the risk of corneal haze


The pre-admission department on the 3rd floor enables you to complete admission documentation before the day of surgery. This streamlines the admission process on the day of the procedure.

The day of the surgery

  • You may have a light breakfast on the day of the surgery
  • On arrival at the Pretoria Eye Institute report to admissions on the 3rd floor
  • Approximately 2 hours before surgery you will be given eye drops. Some patients also may be given a mild sedative
  • The ophthalmologist and operating-nurse will be in the operating room
  • For LASIK a topical anaesthetic eye drops is applied
  • The skin around your eye will be cleaned
  • Sterile coverings will be placed around your head.
  • You might be able to see light and movement. Your face is covered with a light Sterile drape
  • You will spend 30 – 40 mInutes in the laser room

After Surgery

  • • After surgery your doctor will place a shield over your eye
  • After recovery you will go to the patient liaison area where you will receive information on the after surgery care of the eye as well as your medication
  • The personnel will inform you when you can go home

After Care

  • You will be given a course of antibiotic and anti-inflammatory eye drops – use as prescribed
  • You should wear the protective eye shield at night for a week
  • You will be required to moisturize the eye with preservative-free tears
  • Remember that proper post-operative care will minimise the risk of complications