Other Methods of Laser
What is PRK?
The widest and mostly preferred method is Lasik for the improvement of refraction impairment. Before the lasik technique was developed, when PRK (Photorefractive Keratomileusis) with Excimer Laser was initiated for the treatment of visual impairment it was applied in the eye without removing flap. The reliability and efficiency of PRK has been proved. However, it has disadvantages such as pain and long duration of recovery.
The application areas for PRK
- The eyes with corneal layer of inadequate thickness for lasik
- Eyes with suspected irregularities in the cornea
- Sportive professionals (karate, boxing, etc.)
The application of PRK
The eyes are narcotized with drops. The uppermost corneal layer (epithelium) is incised with a spatula or removed by applying alcohol. Excimer laser is applied over the surface and the contact lens is replaced as dressing. This lens is removed on the 3rd or 4th day following the recovery of epithelium. Pain may be experienced within the first 24 hours so analgesics may be taken. Antibiotic and anti-inflammatory drops are used for 2-3 weeks.
What is the common point of LASIK and PRK methods?
Both methods used Excimer Laser with the aim of shaping cornea.
What is Lasek?
Lasek (Laser Epithelial Keratomileusis): It is technically the modified form of PRK method.
This method is preferred to be applied in patients with thin cornea or uneven corneal surface topography which are not eligible for lasik.
How is the treatment performed?
The uppermost layer of the cornea (epithelium) is cut out with keratom or femtosecond laser and a flap of a thickness of 110-160 microns is removed during lasik operation. Cornea shaping ablation is performed under this flap. We call it deep ablation. In the case of PRK method, the surface of the cornea is incised with a spatula and excimer laser is applied over the surface (surface ablation). The epithelium is covered with alcohol for 25-30 seconds and then this layer is removed as a whole with the help of a trepan and spatula during lasek operation, and when the laser is applied the removed epithelium is put back in its position. A contact lens is put over the eye after the operation as a dressing for 4 days to ensure protection for the eye during the recovery phase.
Side effects are seen within the first 2 days such as irritation, stinging and watering, and it requires 4-7 days for the recovery of vision. It is superior than PRK method since it is less painful and recovery is faster. Special techniques such as wavefront, Q mod and T-CAT may be used with both PRK and LASEK.
Other customized methods
Topography-Guided Lasik (T-CAT)
Unlike wavefront, it is a method applied depending on the corneal topography (cornea map).
- Corneal irregularities
- Asymmetric Astigmatism
- Eyes which have previously undergone Lasik
-Eyes which have previously undergone operations such as cataract or cornea transplant.
Customized methods are to be performed only in case they are required. Applying these methods in the normal eyes will not change the result.