Laser eye surgery is a refractive surgery procedure that is becoming increasingly popular.
Keratomileusis – this is the name given to surgical techniques in refractive surgery that can change the refractive power of the eye by processing the cornea.
Over the years, laser eye surgery methods have developed considerably.
As a result, patients suffering from defective vision can now enjoy precise and customized treatment.
You can find out more about the various laser eye procedures, their development and the advantages and disadvantages for you as a patient in this article.

PRK – laser eye surgery with a proven procedure

The laser eye procedure PRK (photorefractive keratectomy) is one of the oldest and most tried and tested methods.
The PRK method offers several advantages: In contrast to other laser eye treatments, no corneal flap is created here, which means that no flap-related complications can occur.
In addition, PRK surgery is possible for patients with a thin cornea.
The procedure can correct various visual defects: Short-sightedness (myopia), long-sightedness (hyperopia) and astigmatism.
The procedure can be used both as an initial treatment and as a follow-up treatment if the result of a previous eye operation was not optimal (especially with LASIK).
A short treatment time of 10 minutes per eye – after which patients can enjoy better vision.
Both eyes can be corrected in one session.

Procedure for PRK laser eye treatment

A preliminary examination takes place before every laser eye treatment.
The procedure itself is usually performed on an outpatient basis.
The procedure is as follows:

1. Anesthetic eye drops are applied and ensure a pain-free procedure.
2. The corneal epithelium is removed.
3. An excimer laser is used to treat the underlying cornea, thereby changing the refractive power of the eye.
4. A protective lens is inserted and ensures that the healing process goes as smoothly as possible.

However, it should be noted that the healing process with PRK methods generally takes longer than with other laser eye surgery methods.
In addition, patients who have been treated with PRK more frequently report post-operative pain.

Further development of the PRK method

LASEK – an advanced variant of PRK.
Laser treatment with LASEK is characterized by the fact that the corneal epithelium is first treated with alcohol.
The alcohol then allows the epithelium to be lifted with instruments and pushed aside.
This is followed by treatment with the excimer laser – as with PRK.
After the procedure, the epithelium is returned to its original position.
However, treatment with alcohol often leads to irritation and complications, which is why this method is used less frequently nowadays.

Trans-PRK – a gentle no-touch procedure for laser eye surgery

Trans-PRK (Transepithal Photorefractive Keratectomy) is an alternative and more innovative procedure to PRK methods.
Thanks to the no-touch procedure, Trans-PRK is considered a gentler method.
Patients enjoy a shorter healing time and a lower risk of complications.
Trans-PRK is suitable for people with a thin cornea.
It can be used to correct visual defects with the following application limits:

• Myopia up to -6 diopters
• Farsightedness up to +3 diopters
• Corneal curvature up to 5 diopters

Trans-PRK: difference to simple PRK treatment

In contrast to PRK and LASEK, with Trans-PRK the eye to be operated on is not touched and treated mechanically, but only by a laser.
This is why Trans-PRK is also known as a no-touch procedure.
After anesthetic eye drops have been applied, the epithelium is removed using an excimer laser.
This is followed by the actual treatment of the cornea – also using the excimer laser.
The therapeutic contact lenses that are then inserted provide the necessary protection after the laser operation.
The epithelium regenerates within a few days.

Femto-LASIK – laser eye surgery using the latest methods

The Femto-LASIK method is one of the more modern laser eye surgery procedures.
Here too, short-sightedness or long-sightedness and astigmatism can be corrected.
The range of application of Femto-LASIK is relatively wide, which is why the method is suitable for around 95% of all patients with glasses or contact lenses if there are no other reasons for exclusion.
The limit ranges are as follows:

• Myopia up to -10 diopters
• Farsightedness up to +4 diopters
• Corneal curvature up to 5 diopters

Femto-LASIK procedure

The operation itself only takes about 30 seconds per eye.
Including the preparation and follow-up of the eye operation, the procedure is completed in just a few minutes.
With Femto-LASIK, the top layer of the cornea is opened and folded to the side – a so-called flap is created.
A state-of-the-art femtosecond laser is used for this.
This enables particularly thin corneal flaps to be created.
After the eye has been prepared, the actual correction of the visual defect is carried out using an excimer laser.

Advantages and disadvantages of Femto-LASIK

Overall, it should be noted that a corneal flap is created during Femto-LASIK.
This means that laser surgery is associated with flap-related risks.
Flap-related complications include, for example

• Slipping of the flap
• Separation of the flap
• Flap folds

Femto-LASIK is generally considered to be a painless procedure.
Some patients only feel a sensation of pressure during the treatment.
The modern femtosecond laser ensures fast treatment.
In addition, the corneal flap created acts like a natural plaster, allowing the eye to recover quickly.
Accordingly, the healing time after femto LASIK treatment is short.
Patients notice improved visual acuity within a few hours.
The healing process is usually complete after around four weeks.

LASIK and Femto-LASIK: What is the difference?

Femto-LASIK is an innovation compared to the originally developed simple LASIK (laser in situ keratomileusis) treatment.
LASIK is an older and more common method of laser eye surgery.
A flap is created in both LASIK and Femto-LASIK – the procedures differ in how the flap is created.
With LASIK, a small incision is made in the cornea using a microkeratome.
This is a precise electronically controlled microscalpel.
The disadvantage of using a microkeratome is that the risk of infection is higher than with a laser procedure.
In addition, a laser can work more precisely.

ReLEX-SMILE – correction of high diopter values thanks to the latest treatment method

ReLEX-SMILE is considered one of the gentlest laser eye surgery methods.
It is a very popular method as it is suitable for many people with visual defects.
ReLEX-SMILE treatment can be carried out on patients who have dry eyes, a thin cornea or severe defective vision.
Using the innovative femtosecond VisuMax laser, extremely precise incisions of just a few millimetres can be made.
No flap needs to be created – the risks associated with flaps are eliminated.
One opening in the cornea is sufficient.
The laser is used to remove a lenticule inside the cornea, which corrects the visual defect.
The advantages of ReLEX SMILE treatment at a glance:

• Dry eyes are no obstacle – tear flow is hardly affected
• Stability of the cornea is maintained through a small incision
• State-of-the-art femtosecond laser technology
• Safe and precise
• Wide range of applications with regard to diopter values

Difference between SmartSight and ReLEx SMILE

Another laser eye surgery in which the surgeon uses lenticule extraction to correct the visual defect: SmartSight.
SmartSight is a step forward in the development of lenticule procedures.
The state-of-the-art surgical technology enables even more precise and safer procedures.
The procedure is identical for both methods.
The main difference between the two methods is the technology:

• SmartSight: Schwind ATOS Laser / ReLEx SMILE: ZEISS VisuMax femtosecond laser
• Smart Sight: 2-3 mm small incision / ReLEx SMILE: 2-4 mm small incision
• Smart Sight: 7D eye tracking / ReLEx SMILE: 6D eye tracking

Alternatives to laser eye surgery

Eyes cannot always be lasered – various reasons for exclusion can mean that the procedure is not possible.
This is often due to excessive visual defects or a particularly thin cornea.
Eye diseases such as cataracts or presbyopia can also prevent laser eye surgery.
For those for whom glasses or contact lenses are still not an alternative, refractive surgery offers further alternatives to laser eye surgery.

ICL – Lens implantation in refractive surgery

Implantable contact lenses(ICL) are often used when high diopter values are present and laser eye surgery is no longer possible.
An artificial lens (so-called phakic intraocular lens) is implanted in addition to the natural eye lens.
This procedure is extremely gentle on the corneal tissue, as no healthy tissue is removed.
The procedure is also reversible: if the visual acuity changes, the lens can be adjusted at any time.
ICL is suitable for patients with severe defective vision.
As with laser eye surgery, lens implantation can be performed on both eyes in one session.

Intraocular lenses – when eye diseases prevent laser eye surgery

Intraocular lenses (IOLs) are usually used for patients suffering from cataracts or presbyopia.
In this case, it makes no sense to preserve the natural lens because the focus is on healing the diseased tissue.
If an intraocular lens is implanted, the natural lens of the eye is first removed through an incision in the cornea.
The artificial lens is then implanted.
There are various artificial lenses that can be used for lens replacement, e.g. monofocal lenses or multifocal lenses.
Monofocal lenses only have one focal point.
This means that sharp vision is only possible for one distance (near or far).
A visual aid must still be used for the other distance.
Multifocal lenses, on the other hand, have several focal points and therefore enable sharp vision at different distances.

Conclusion: Seeing without glasses thanks to modern eye surgery

Refractive surgery now offers a solution for almost everyone who wants to do without glasses and contact lenses.
Be it lens replacement, lens implantation or laser eye surgery.
At the same time, the procedures are constantly being improved so that a life without visual aids is possible – high success rates, low risk of complications and a quick recovery.
Which treatment is ultimately best depends on many factors.
As part of a preliminary examination, ophthalmologists first determine whether your eyes are suitable for surgery and can then weigh up which procedure will provide the best result for you and your visual needs.