Femto-LASIK – the operation
Topical anesthetic drops are applied to your eyes. The eyes and the adjacent areas are disinfected and covered in a sterile manner. Then the eye is held open by inserting a lid speculum. Using a Femtosecond laser a fine flap 5-9 mm in diameter and 0.1 mm thick is cut in the cornea. The hinge is mostly located in the superior part of the cornea. The flap is lifted and folded back exposing the inner part of the cornea. The actual laser ablation is performed with an excimer laser. After the completion of ablation the flap is repositioned over the treatment area and the lid speculum finally removed.
Using the Schwind AMARIS laser significantly reduces the duration of the ablation (1.3 second for one diopter of correction). For example it can correct 5 diopter of myopia in just 6 seconds. During the operation a sophisticated eye tracking system registers your eye movements so that the laser beams will exactly follow your eye movements.
The wound healing of the cornea around the created flap usually takes one to two days. Full adhesion of the flap to the cornea takes a few weeks or months.
At the intervals of one day, one week and one month after the operation our doctors will perform a routine eye exam to monitor the healing process and to adjust the eye drop treatment.
Advantages of a Femto-LASIK operation
- Correction of myopia, hyperopia and astigmatism.
- Better quality of life, with freedom from glasses or contact lenses.
- Short ambulatory procedure in Bern.
- The most advanced and secure Laser technology with our AMARIS and Ziemer-LDV machines.
Pre and post operative examinations and the treatment itself are all performed on the same site by our doctors and laser specialists.
Advantages of the Femto-LASIK operations versus superficial treatment: Less pain during and after the operation. Quick vision recovery
Disadvantages of all laser procedures
Structural integrity of the cornea is slightly weakened, which should be considered in patients who practice martial arts.
Contraindications and Risks
Contraindications are conditions that serve as a reason not to perform a laser operation.
Thin cornea: the most important prerequisite to perform a Femo-LASIK operation is a sufficient thickness of the cornea. A thin cornea is a strong contraindication to the operation.
Chronic eye disease: A Femto-LASIK operation should not be performed if the patient has a chronic eye disease like keratoconus since the cornea will become even weaker.
Further contraindications are Glaucoma with visual field defects and cataract.
General disorders: Like collagen, autoimmune or wound healing disorders
Rapid changes in refractive errors: If the refractive errors significantly differ in two subsequent exams in short time intervals a vision correction should not be performed
Age: The candidate should be at least 18 years of age.
With a Femto-LASIK operation, as with any other refractive vision correction, or any surgery at all, there are certain risks. The type of risks and their frequency can depend on the amount of the correction and on the pupil size. There is always a possibility of slight under or over correction.
Keratectasia is the abnormal bulging of the cornea. It usually occurs because of structural weakening of the cornea after a laser ablation. The risk for developing a keratectasia increases with a decrease of the residual post-ablation corneal thickness. Residual corneal thickness is calculated by subtracting the amount of the flap thickness and the ablation depth from the original thickness of the cornea. As residual stromal thickness a minimal thickness of 0.25 mm is recommended. Furthermore genetic factors also seem to play a role.
In the first post-operative days a foreign body sensation is felt. In 15 to 20% of cases dry-eye symptoms are reported in the first weeks or months after a laser correction. This is usually because tear production and frequency of blinking are reduced. In general, artificial eye drops are prescribed for 1-3 months after a Laser correction.
The flap is usually very stable. Dislocation of the flap because of external influences is very rare. These are often reported after sport injuries (getting hit by a squash ball in the eye) or from a car accident triggering the airbag.