What is TransPRK?
What is TransPRK?
Transepithelial PhotoRefractive Keratectomy (TransPRK) is the most recent technique of laser refractive surgery. TransPRK may be known to some as No Touch LASIK, No Touch Laser Epi-LASIK, SmartSurface PRK or Transepithelial Surface Ablation (TESA).
Not to be confused with the first generation PRK, the TransPRK procedure uses a laser to remove the corneal epithelium and the stroma in a single step. PRK involves a mechanical scraping of the corneal epithelium, followed by the use of a laser to remove small amount tissue from the cornea. PRK was slowly overtaken by flap LASIK, due to its slow recovery, post-operative discomfort, and risk of corneal scarring.
LASIK (Laser in-situ keratomileusis) became so popular that it became a general term for laser refractive procedures, despite there being various techniques available in the market.
In actual fact, LASIK is a technique of laser correction involving the creation of a flap to expose and remove a small amount of corneal stroma, then putting the flap back into its position. The flap is traditionally created using a fine blade known as microkeratome, but can be created with a different laser machine known as femtosecond laser. The flap is a thin layer on the cornea surface usually 120-160 microns. The flap usually seals on its own without any sutures after 1-2 weeks. However, there is a risk of flap complications such as flap dislocation, epithelial ingrowth, diffuse lamellar keratitis (DLK), irregular astigmatism and higher risk of corneal ectasia compared to other laser refractive procedures.
Although LASIK may have a relatively quicker visual recovery, it may not be suitable for everyone. As LASIK procedure involves a flap creation, there will be a larger consumption of corneal tissue and hence, some patients with thin corneas or high prescriptions may not be suitable for LASIK. Those who have undergone LASIK will have a lower possibility of performing an enhancement or “touch up treatment”. Those who undergo a LASIK enhancement procedure will have a higher risk of corneal ectasia compared to TransPRK.
This is where TransPRK comes in. TransPRK is a flapless, bladeless, tissue saving surface ablation procedure, and it is a procedure suitable for almost everyone, despite being deemed unsuitable for LASIK.
No touch TransPRK
TransPRK is the only laser refractive procedure where no surgical instruments will be touching the eye. Other procedures involve some suction on the eye, and fine sharp instruments to complete the procedure.
Before your TransPRK procedure, you will have to undergo a full eye examination with our optometrist and ophthalmologist. One scan that you will undergo is a corneal topography scan with the Schwind Sirius machine. This machine provides a comprehensive measurement and analysis of your cornea, which be used in the customization of your TransPRK treatment.
Better choice for high myopia
The principle of laser refractive procedures is to remove an amount of corneal tissue. The higher your myopia, the more cornea tissue that will be vaporized, and the thinner the cornea will be after the procedure. Therefore, a tissue saving procedure is a better choice for those who have high myopia. With TransPRK, no flap is created and the tissue vaporization starts at the surface of the cornea, leaving more cornea tissue after your treatment compared to LASIK.
Why haven’t I heard of TransPRK before?
Because the laser technology was not good enough until recently.
TransPRK is not popular as LASIK because there were no laser machines that can perform this technique in one step. In the past, to perform a no-touch surface ablation procedure, the surgeon has to perform two separate laser steps, first one to remove the epithelium, re-programme the laser and another laser step to correct the refractive error. This consumed a lot of time and the exposure of the cornea to drying caused inaccurate results.
Up to date, only Schwind (a German laser company) has discovered the best way to rapidly remove the epithelium and stroma accurately in one step. The TransPRK procedure is safe, quick, and pleasant experience especially for those who are afraid of instruments touching their eyes. There have been extensive publications on the results, safety, and efficiency of TransPRK treatment and it is proven to be as good as LASIK, Epi-LASIK or lenticule extraction.