Laser eye surgery methods at a glance: Laser eye surgery with Femto LASIK, Lasek, Trans-PRK, ReLEx SMILE / SmartSight & Co.

Laser eye surgery offers an excellent way to correct visual defects such as short-sightedness, long-sightedness and astigmatism and finally see clearly without glasses or contact lenses. But with so many methods available, choosing the right treatment can be overwhelming. In this blog post, we explain in detail how the various laser eye surgery methods differ, including LASIK, Femto-LASIK, LASEK, Trans-PRK, SmartSight, ReLEx SMILE and the use of the YAG laser for secondary cataracts. You will learn all about the procedure, the suitability criteria and the advantages and disadvantages of each method.

Laser eye surgery with LASIK and Femto-LASIK

What is the LASIK procedure?

Suitability for LASIK depends on several factors:

• Short-sightednessUp to -10 diopters can usually be corrected with LASIK.
• FarsightednessUp to +4 diopters are normally treatable.
• Astigmatism (curvature of the cornea)Up to 5 diopters can be corrected.

What is Femto-LASIK with flap:

Femto-LASIK is a further development of classic LASIK and is often regarded as the more advanced and precise method. Here are the main differences between Femto-LASIK and classic LASIK:

Flap creation

• LASIK: In classic LASIK, the flap in the cornea is cut with a mechanical microkeratome. This instrument has a small blade that cuts the top layer of the cornea to create the flap.
• Femto-LASIK: In femto-LASIK, the flap is cut with a femtosecond laser. This laser works extremely precisely and enables the flap to be created very finely and evenly without the use of a blade.

Precision and safety

• Precision: The femtosecond laser offers greater precision and control over the depth and thickness of the flap, which reduces the risk of complications. This accuracy is particularly beneficial for patients with thinner corneas.
• Safety: Since Femto-LASIK replaces the mechanical incision with a laser incision, the risk of flap complications such as uneven incisions or flap displacement is minimized.

Healing and comfort

• Healing: Both procedures have a fast healing time, but some studies suggest that Femto-LASIK may have a lower rate of dry eyes and faster stabilization of vision.
• Comfort: Patients often report greater comfort during and after femto LASIK because the procedure is less invasive and the femtosecond laser allows for more consistent flap creation.

Technology

• Technology: Femto-LASIK uses state-of-the-art laser technology, making it a more advanced and often preferred method. The use of the femtosecond laser ensures that the treatment is customized and extremely precise.

Costs

• Cost: Femto LASIK is generally more expensive than traditional LASIK, as it requires more advanced technology and possibly a longer treatment time. However, the higher cost may be justified by the potentially greater safety and precision benefits.

Advantages of the femtosecond laser

Greater precision and control

• Precise flap creation: The femtosecond laser enables very precise and uniform creation of the flap in the cornea. This leads to improved accuracy in determining the thickness and diameter of the flap, which is particularly important for patients with thin corneas.
• Individual adaptation: The technology allows the flap to be individually adapted to the specific anatomical conditions of each eye. This means that the treatment can be optimally tailored to the patient’s needs.

Improved security

• Reduced risk of flap complications: Because the femtosecond laser cuts the cornea without a mechanical blade, the risk of uneven cuts, flap displacement or other mechanical complications is reduced.
• Lower complication rate: Studies show that the use of the femtosecond laser is associated with a lower rate of complications during and after the procedure, which increases the safety of femto-LASIK.

Faster healing and better comfort

• Gentle procedure: The femtosecond laser works with ultra-short pulses of light, which are minimally invasive and put less strain on the surrounding tissue. This leads to faster healing and less post-operative discomfort.
• Lower rate of dry eyes: Patients often report fewer dry eyes after Femto LASIK, as the more precise flap creation affects fewer nerves in the cornea.
• More stable vision: By precisely adapting the flap to the individual corneal structure, vision can be stabilized more quickly, resulting in faster visual recovery.

Extended treatment options

• Wider range of applications: The femtosecond laser allows treatment of a wider range of patients, including those with thinner corneas or irregular corneal surfaces that would be less suitable for traditional LASIK.
• Combination with other procedures: The femtosecond laser can also be used in combination with other refractive procedures such as SMILE technology or in the creation of tunnel channels for intrastromal ring segments.

Trans-PRK and PRK laser eye surgery instead of glasses & contact lenses

Trans-PRK and PRK are both established procedures for the correction of refractive errors such as myopia, hyperopia and astigmatism. Although they pursue similar goals, they differ in their implementation and some specific aspects.

Trans-PRK can correct a wide range of visual defects, taking into account the following diopter limits:

• Short-sightedness (myopia): Up to -8 diopters can be effectively corrected with Trans-PRK.
• Farsightedness (hyperopia): Up to +3 diopters can be treated.
• Astigmatism (curvature of the cornea): Correction of up to 4 diopters is possible.

How does PRK or trans-PRK work – from the preliminary examination to correction

• PRK (photorefractive keratectomy):
  • Manual removal of the epithelium: In classic PRK, the uppermost cell layer of the cornea, the epithelium, is removed manually. This is done either with a special scraper or by applying an alcoholic solution that dissolves the epithelium.
  • Lasering the cornea: Once the epithelium has been removed, the underlying corneal tissue is ablated using an excimer laser to correct the refractive power of the eye.
  • Healing: The epithelium regenerates within a few days, but this may be associated with some discomfort and a longer healing time.
• Trans-PRK (transepithelial photorefractive keratectomy):
  • Non-contact removal of the epithelium: With Trans-PRK, the epithelium is not removed manually but by laser. This is done in a single step using the excimer laser, which precisely removes both the epithelium and the underlying corneal tissue.
  • Lasering the cornea: After removing the epithelium and part of the cornea, the corneal tissue is further lasered to perform the required correction.
  • Healing: As the epithelium is removed without contact, healing is often perceived as more pleasant. The discomfort after the procedure is generally less than with classic PRK.

Advantages and disadvantages of trans-PRK for defective vision

Advantages of the Trans-PRK

• Non-contact epithelial removal: Trans-PRK uses the excimer laser to remove the corneal epithelium without contact. This reduces the risk of infection and injury caused by manual manipulation.
• Gentle method: As the epithelium is removed and the cornea is lasered in a single step, the procedure is gentler on the eye overall. This results in less post-operative discomfort compared to classic PRK.
• Shorter healing time: Patients often report faster visual recovery and less pain after the operation. Regeneration of the epithelium usually takes place within three to four days.
• Lower risk of dry eyes: As the nerves in the cornea are less affected during trans-PRK, the risk of dry eyes after the procedure is lower.
• No flap complications: Unlike LASIK, there is no flap creation with Trans-PRK, avoiding complications such as flap shifting or wrinkling.
• Suitability for thin corneas: Trans-PRK is particularly suitable for patients with thin corneas who may not be candidates for LASIK.

Disadvantages of the Trans-PRK

• Longer healing phase compared to LASIK: Although healing is faster than with classic PRK, it takes longer compared to LASIK. Patients can expect blurred vision and slight pain for a few days.
• Postoperative complaints: Pain, sensitivity to light and a foreign body sensation in the eye may occur in the first few days after the procedure. However, this is temporary and improves as soon as the epithelium has regenerated.
• Visual fluctuations: Visual acuity may fluctuate in the first few weeks after surgery until the cornea has fully stabilized.
• Recovery time: Patients must be prepared for a longer recovery period during which they may not be able to resume their normal activities immediately.
• Limited suitability for high diopters: For very high diopter values or special corneal conditions, Trans-PRK may be less suitable and alternative methods could be considered.

Laser eye surgery: Lenticule extraction with SmartSight or ReLEx SMILE

Lenticule extraction is a modern and minimally invasive laser eye surgery procedure for correcting vision defects such as myopia and astigmatism. Two well-known methods of lenticule extraction are SmartSight and ReLEx SMILE. These procedures offer precise vision correction without the creation of a flap, as is the case with LASIK.

How lenticular extraction works

Lenticular extraction takes place in several precise steps:

1. preparation:

• Preliminary examination: A thorough preliminary examination is crucial to determine the patient’s suitability. This involves checking the visual acuity, thickness and topography of the cornea as well as the general health of the eye.
• Anesthesia: Local anesthetic drops are administered to desensitize the eye and prevent pain during the procedure.

2. creation of the lenticel:

• A femtosecond laser is used to precisely cut a small, disc-shaped part of the cornea called the lenticule. This step takes place in the middle layer of the cornea and is extremely precise.

3. extraction of the lenticel:

• ReLEx SMILE: The lenticule is removed via a tiny incision of around 2-4 mm. The surgeon uses special instruments to carefully extract the lenticule, which changes the refractive power of the eye and corrects the visual defect.
• SmartSight: The principle is similar, although the technology and the exact procedure may vary slightly. The lenticule is also removed through a small incision, resulting in a precise correction of vision.

4th degree:

• After removal of the lenticule, a tiny incision remains in the cornea, which can heal without stitches. The natural healing process of the cornea ensures rapid recovery and stabilization of vision.

Advantages of lenticel extraction

• Minimally invasive: Since no flap is created, the integrity of the cornea is largely preserved, eliminating the risk of flap complications.
• Fast recovery: Patients often report faster visual recovery and less post-operative discomfort compared to other procedures such as LASIK.
• Stability and safety: The precise laser technology ensures stable and safe results, especially when correcting short-sightedness and astigmatism.
• Less dry eyes: The minimally invasive technique means that less nerve tissue in the cornea is affected, which reduces the risk of dry eyes.

Suitability criteria (short-sightedness / curvature of the cornea)

SmartSight technology can correct a wide range of visual defects, whereby the following diopter limits apply:

• Short-sightedness (myopia): Correction up to -10 diopters.
• Astigmatism (curvature of the cornea): Correction up to 5 diopters.

Farsightedness (hyperopia) cannot currently be corrected by lenticule extraction.

Differences between SmartSight and ReLEx SMILE

SmartSight and ReLEx SMILE are both modern lenticule extraction procedures for the correction of vision defects such as myopia and astigmatism. Both methods aim to improve vision using minimally invasive techniques, but differ in some key respects, particularly with regard to the lasers used.

SmartSight

• Laser technology: SmartSight uses the Schwind ATOS femtosecond laser. This laser is known for its high precision and fast cutting, which enables particularly uniform and controlled creation of the lenticule.
• Laser functions: The Schwind ATOS femtosecond laser offers advanced technologies such as real-time pupil detection and cyclotorsion compensation. These functions help to ensure the exact position of the lenticule and compensate for eye movements during the procedure.
• Advantages of the technology: The use of the Schwind ATOS laser leads to high precision in lenticule extraction and minimizes the risk of deviations during the procedure. This can lead to faster healing and more stable vision.

ReLEx SMILE

• Laser technology: ReLEx SMILE is based on ZEISS technology and uses the VisuMax femtosecond laser. The VisuMax laser is also known for its precision and gentleness and enables the creation of the lenticule in a closed corneal environment.
• Laser functions: The VisuMax femtosecond laser is characterized by its ability to create and extract the lenticule through a small incision of approximately 2-4 mm. This method does not require a flap and therefore reduces the risk of flap-related complications.
• Benefits of the technology: The closed environment in which the VisuMax laser operates helps to maintain the integrity of the cornea and reduce post-operative discomfort. Patients often report rapid visual recovery and minimal pain.

YAG laser for secondary cataracts:

After cataract surgery, some patients may experience clouding of the posterior lens capsule, a condition known as posterior capsular opacification. The YAG laser (yttrium aluminum garnet laser) is used to effectively treat this opacity. In YAG laser capsulotomy, a focused laser beam is used to painlessly and precisely open the clouded posterior capsule, allowing light to reach the retina again unhindered. This minimally invasive procedure takes only a few minutes and results in an immediate improvement in visual acuity by restoring clear vision without the need for incisions or prolonged recovery time.

Seeing without glasses despite presbyopia: PresbyMAX

PresbyMAX is an advanced laser eye procedure that has been specially developed to correct presbyopia. Presbyopia occurs naturally after the age of 40, when the flexibility of the eye lens diminishes and near vision becomes more difficult. PresbyMAX uses precise laser technology to sculpt the cornea to create multiple focal points that allow sharp vision at different distances. This multifocal correction allows patients to read again without glasses and enjoy clear vision at near, intermediate and far distances. The procedure is minimally invasive, takes only a few minutes per eye and generally leads to a rapid visual recovery. PresbyMAX therefore offers an effective and permanent solution for people who want to correct their presbyopia and improve their quality of life.

Would you like to have your eyes lasered? Vision correction at EyeLaser Vienna:

Would you like to have your eyes lasered and finally see without glasses or contact lenses? Arrange a non-binding preliminary examination with our experienced ophthalmologists! During this comprehensive examination, we will check your eye health and determine which laser eye surgery method – be it LASIK, Femto-LASIK, Trans-PRK, SmartSight or ReLEx SMILE – is best suited to correcting your visual defect. Our experts will take into account your individual corneal thickness, diopter values and specific visual defects to recommend the safest and most effective treatment for you. Let us advise you and find out how you can improve your vision in the long term. Make an appointment today and start into a clear future!

Make an appointment now