Overview
Photorefractive Keratectomy (PRK), an advanced surface ablation procedure, serves as an alternative to conventional LASIK. PRK is "flap-free" method, offering the same laser vision correction as LASIK but without the need for a corneal flap incision.
In PRK, the corneal epithelium, the outermost layer of cells, is removed. An excimer laser then reshapes the cornea to achieve the desired vision correction.
Are You A Suitable Candidate for PRK?
Consider PRK if you:
- Have thin corneas
- Are at a higher risk of eye trauma, due to either lifestyle or profession. This includes:
- Regular participation in contact or extreme sports such as soccer, rugby and martial arts
- Working in dynamic environments like the military
- Have myopia or hyperopia less than -5.00 dioptres and astigmatism not exceeding -2.5D
General eligibility for laser vision correction includes:
- Being at least 18 years old
- Having a stable eye prescription for a minimum of one year
- No existing eye conditions such as cataract or glaucoma
- Not being pregnant or breastfeeding
The PRK Procedure
Step 1: The procedure begins with anaesthetic eye drops to numb the eye, then an alcohol solution is used to dissolve the corneal epithelium, which is then removed with a special instrument.
Step 2: The pre-programmed excimer laser then ablates the corneal tissue. This reshapes the curvature of the cornea to correct the refractive error.
Step 3: A bandage contact lens is then used to cover the treated cornea to assist the healing process.
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The Epi-LASIK Procedure
Epi-LASIK, a newer variant of PRK, utilises a mechanical, blunt tissue separator instead of alcohol solution, reducing potential alcohol-related reactions and facilitating faster healing. The same laser as in LASIK and PRK is employed. After reshaping the cornea, the thin layer of cells is repositioned. Epi-LASIK is especially beneficial for those with thin corneas requiring significant vision correction.
Advantages of PRK
Unlike conventional LASIK, PRK eliminates the creation of a cornea flap, thus reducing risks like cornea flap dislodgement, wrinkles or infection. It is particularly suitable for individuals with very active lifestyles or those in professions with a higher risk of eye injury.
PRK involves less corneal tissue removal, making it a suitable choice for individuals with high myopia or thin corneas. This reduces the risk of postoperative corneal ectasia, a rare condition where a thinned cornea bulges forward, distorting vision.
Concerns Regarding PRK
- It may involve more discomfort and a longer recovery period compared to conventional LASIK.
- Optimal visual acuity may take several weeks to be attained.