Technique without Cutting and without Contact: PKR or Trans-PRK

Eye surgery with PRK or Trans-PKR?

Of all the surface techniques, our preference is for Trans-PKR since we have been experimenting with it, which combines the advantages of PKR while minimising its disadvantages.
Trans-PKR is the only 100% laser technique, with no contact whatsoever with the patient's eye.
It combines all the safety advantages of PRK, of which it is an improvement, with less pain and faster results than conventional PRK.
Its recovery is slower than with Lasik, however.

PKR (Photorefractive Keratectomy) and TransPKR (Transepithelial PRK) are two refractive surgery techniques used to correct visual defects such as myopia, astigmatism, and in some cases, hyperopia. Although similar in their goal, they differ in their surgical approach, postoperative comfort, and healing process. Let’s compare them to better understand their respective advantages.

What is PKR?

PKR is one of the oldest refractive surgery techniques, introduced in the 1980s. It consists of:

1. Remove the corneal epithelium (the surface layer of the cornea) manually or using diluted alcohol to soften it.
2. Using an excimer laser to reshape the corneal stroma underneath to correct visual defects.
3. Place a bandage lens to protect the cornea for a few days while the epithelium grows back.

What is TransPKR?

TransPKR, also called transepithelial PKR, is an evolution of traditional PKR. It differs in that:

1. The excimer laser performs both epithelial removal and corneal stromal remodeling in a single step, without manual intervention or the use of alcohol.
2. Epithelial removal is performed more uniformly, reducing the risk of collateral damage.
3. As with PKR, a bandage lens is placed after the procedure.

Comparative study: PKR vs TransPKR

Criteria	PKR	TransPKR
Method	Manual epithelial removal	One-step laser ablation
Duration of the intervention	Longer (2 steps)	Shorter (1 step)
Post-operative pain	Moderate to high	Generally weaker
Recovery	4-7 days for recovery	3-5 days, faster healing
Precision	Less consistent	More homogeneous, reduces irregularities
Risk of infection	Slightly greater	Lower, less handling
Dry eyes	Frequent	Less frequent

Advantages of TransPKR over PKR

1. Improved comfort: By avoiding the use of alcohol to remove the epithelium, TransPKR causes less post-operative pain.
2. Faster recovery: Since epithelial ablation is performed more precisely by the laser, epithelial regeneration is faster.
3. Reduced risk of infection and inflammation: Since the procedure is performed entirely by laser, there is less contact with the eye, thus reducing the risks.
4. Better visual quality: Regular corneal reshaping often leads to better post-operative vision quality.

Disadvantages of each technique

• PKR :
  • More painful after surgery.
  • Longer recovery time.
  • Increased risk of corneal opacities (haze).
• TransPKR :
  • Generally higher cost due to advanced technology.
  • Less accessible in some centers compared to traditional PKR.

Conclusions of clinical studies

Several comparative studies show that TransPKR offers faster recovery and improved comfort compared to conventional PKR. According to publications in ophthalmological journals, patients operated on by TransPKR generally experience less post-operative pain and have visual results comparable to or slightly better than those operated on by standard PKR. Complication rates (such as corneal haze) are also reduced with TransPKR.

However, the choice between the two techniques depends on the patient's profile, the characteristics of their cornea, and the recommendations of the ophthalmic surgeon.