Refractive surgery in Valencia
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LASIK stands for Laser-Assisted in Situ Keratomileusis. It is a technique that uses Excimer laser to reshape the corneal stroma in order to correct the existing refractive error (myopia, hyperopia or astigmatism).
It is an outpatient procedure where the patient stays awake during the surgery, and anaesthetic eye drops are applied.
It is important for the patient not to wear contact lenses 3 to 21 days before the surgery (depending on the type of lenses and how frequently they are used) as they difficult the ophthalmological preoperative examination due to an effect known as corneal warpage.
Frequently, antibiotics are prescribed to minimize infection risk after surgery. Sedative drugs may be administered 30 minutes before the surgical treatment.
LASIK technique can be divided into of 3 basic parts:
The first step of this technique is creating a corneal tissue flap which will be folded back into its original position after corneal remodeling.
To do this, a blepharostat is used to hold the eyelids apart and avoid involuntary blinking. A suction ring is centered over the pupil to hold the eye still. The patient will feel a gentle pressure on his/her eye.
The flap can then be created in two ways:
- Using a high precision surgical instrument known as microkeratome, a thin corneal tissue flap is created leaving the corneal stroma exposed so that laser can act on it.
- Using femtosecond laser (femtoLASIK) which generates infrared light short pulses that reach a previously programmed depth of the cornea, forming microscopic air bubbles which separate corneal tissue.
The corneal tissue which is removed in order to allow the surgeon access to the corneal stroma is known as flap, and it stays in contact with the rest of the cornea by one of its ends so it can be folded back into place afterwards.
Once the hinged flap is removed, the patient’s vision will become very blurry and he/she will only be capable of seeing white lights around the laser’s red light.
The second step of this technique involves using Excimer laser to reshape the corneal stroma which was exposed in the previous step.
A series of laser pulses precisely vaporize corneal tissue without causing damage to adjacent areas. The amount of vaporized tissue is only some tens of microns thick, depending on the diopters which need to be corrected (approximately 17 microns per diopter).
This process lasts for about 10 seconds and during this time, a security system known as “eye-tracking”, detects the eye’s movements 4000 times per second redirecting the laser pulses to the corneal areas which are intended to receive the pulses.
Once corneal remodeling is done, the flap is folded back into its original position and it is verified that no air bubbles are formed. The flap naturally adheres to the cornea (without using stitches) until it completely recovers.
During this period, antibiotic and anti-inflammatory eye drops are prescribed, as well as lubricant eye drops as the eye’s moisture is reduced during a couple of weeks following the laser procedure.
LASIK procedure has shown to be safe and effective and has been perfected over the years. This is why only a reduced number of patients experience vision problems after surgery.
Most of the postoperative complications which may arise from LASIK procedure can be satisfactorily resolved with medical treatment within a short period of time after surgery, whilst others can be avoided by using Wavefront Laser technology or may need reoperation.
- Dry eye
- Blurred vision
- Vision of halos and glare
- Over or undercorrection
- Diffuse lamellar keratitis
Other Laser treatments