What is laser vision correction?
Laser correction of vision defects is a method enabling the patient to achieve good visual acuity without the necessity to use glasses or contact lenses. The activity of a computer-controlled laser beam enables to change the shape of superficial layers of the cornea, by removing its thin layer. The possibility of correcting the defect depends on the corneal thickness and curvature. Superficial methods (PRK, Trans PRK, LASEK, EBK) allow for the correction without corneal incision, and the procedure is performed only on the superficial layer of the tissue. On the other hand, intrastromal methods require creation of a flap from the superficial part of the cornea or microlens in the internal layers. The flap may be created with the use of microkeratome or femtosecond laser, while the microlens only with the use of a femtosecond laser.
At our Centre, we can correct the following vision defects with an excimer laser:
- myopia from -1.0 to -8.0 Dsph,
- astigmatism up to 4,5 Dcyl,
Two laser types are used for vision correction:
- Excimer lasers – gold standard in the field of laser correction of vision defects,
- Femtosecond lasers – initially used to create a corneal flap in LASIK/femtoLASIK procedures, currently also to correct myopia (SMILE procedure).
PRK
This method is used to correct myopia from -1.0 to -6.0 D and astigmatism up to 2.5 D.
The procedure starts with eye anaesthesia using eye drops, followed by removal of corneal epithelium. Then, with the use of computer-controlled laser beam, the shape of superficial corneal layers is changed. The procedure takes a few minutes and is completely painless. The recovery of corneal epithelium may take a few days, and the patient may feel discomfort and pain in the eye during that time. In order to reduce these complaints, the patient wears a contact lens directly after the surgery, and uses suitable eye drops. Possible complications include corneal haze, which typically regresses within a few months. The rate of this complication increases together with the size of the corrected defect.
Trans PRK
is the latest method of superficial correction of vision defects. It involves laser removal of the corneal epithelium with concurrent removal of the vision defect. During the surgery, virtually no surgical instruments are used. After the procedure, a contact lens dressing is applied and adequate medication is used until healing. The cornea heals faster than after classic PRK; also, there are milder complaints of pain. The procedure requires suitable software and the use of Shwind Amaris laser. Possible complications are the same as in PRK
LASEK
is a method used to correct myopia up to -8.0 D. It does not remove the corneal epithelium, but with the use of a special alcohol-based technique, the epithelium is shifted from the site of laser action. This shortens the recovery period and reduces complaints of pain. Corneal haze occurs much less frequently. The procedure lasts a bit longer than PRK.
EBK
is a superficial method, where the epithelium is removed with a special tip. Healing and outcomes are similar to those in LASEK.
LASIK
belongs to intrastromal methods and is a complex procedure. It involves excision of the superficial corneal flap, removal of deeper corneal layers with a laser, and returning the flap to its original position after the completed procedure. The main advantage of this procedure is fast recovery. Drawbacks include a possibility of serious complications associated with the flap. Thanks to cooperation with a French company, HTM, we offer the procedures of TransPRK, LASEK, EBK and Wavefront GUIDED LASEK with the use of Schwind Amaris 500 Hz Laser. HTM has an international quality certificate regarding the laser installation and use ISO 9001:2000.
FAQ
In order to take part in qualification tests, the subject must be at least 21 years old and must not have worn contact lenses for at least two weeks.
Possible contraindications to the procedure include: pregnancy and breastfeeding, diabetes, autoimmune diseases, rheumatoid arthritis, epilepsy, permanent steroid drugs, thyroid dysfunction, implanted pacemaker, severe allergy.
It is a procedure carried out in order to remove a vision defect, involving a change in the power of light refraction by the cornea with a laser; the patient may achieve good visual acuity without the necessity to use glasses or contact lenses.
Yes, potential contraindications include: past viral keratitis, past ophthalmic zoster, keratoconus or other degenerative process of the cornea, nystagmus, high level degenerative myopia, lacrimation deficit, glaucoma, cataract, retinal detachment, degenerative processes of the retina.
During qualification, the following examinations (ophthalmological history) are performed:
- visual acuity at near and far distance, with and without correction, slit lamp examination,
- computed tomography of the cornea,
- pupil width examination,
- measurement of intraocular pressure,
- Schirmer test, fundoscopic examination.
The patient should remove contact lenses for at least two weeks and bear in mind that during the examination he/she will receive pupil-dilating eye drops. The visit may last about 40 minutes.
Yes. Do not wear contact lenses for 2 weeks before the procedure, do no use creams, deodorants, perfumes for 24 hours before the procedure, be careful not to irritate the eyes with soap or shampoo. You can have normal food before the procedure, but do not have drinks including caffeine (coffee, coca-cola).
No, the procedure is performed under local anaesthesia using anaesthetic eye drops.
No, you cannot drive a car directly after the procedure.
In order to undergo laser correction procedure, one must be at least 21 years old, and have a stable vision defect.
Sport can be practised more or less a week after the procedure, and swimming a month after.
No, laser correction procedures are only commercial procedures.
No. A breast-feeding woman cannot undergo the procedure of laser correction, either. It is best to wait for about 3 months after feeding discontinuation.
-myopia from -1.0 to -8.0 Dsph,- astigmatism to 4.5 Dcyl, and hyperopia to +4.0 Dsph
The duration of the laser correction procedure is about 30 minutes, including the time of patient preparation.
Yes. After the procedure, the patient must observe the following rules: apply the eye drops prescribed by the doctor; the patient receives a prescription for the eye drops with precise information how and when to use them. Directly after the procedure, the patient must wear sunglasses and protect the eyes against entering of soap, shampoo, cosmetics, dust and other foreign substances. The patient must not smoke or stay in smoke-filled places.
Excessive or incomplete correction; reduced visual acuity with optimal correction of the defect; corneal haze – the level of the haze depends on the size of the corrected defect (it is usually transient and regresses spontaneously or after treatment); increased intraocular pressure; infection causing conjunctivitis and/or keratitis; recurrent deficits in the corneal epithelium caused by its abnormal adhesion – this complication is treated by the administration of lubricating agents.