What is PRK?
The most recent development in vision correction is a procedure called Photorefractive Keratectomy or PRK. Although the approach is similar to RK, in that the cornea is modified to correct vision, the process is vastly different with remarkable improvements in patient risk and correction capabilities
Rather than making cuts in the cornea, the PRK process uses an excimer laser to sculpt an area 5 to 9 millimeters in diameter on the surface of the eye. As you can see from the diagram, this process removes only 5-10% of the thickness of the cornea for mild to moderate myopia and up to 30% for extreme myopia - about the thickness of 1 to 3 human hairs. The major benefit of this procedure is that the integrity and the strength of the corneal dome is retained. The excimer laser is set at a wavelength of 193nm, which can remove a microscopic corneal cell layer without damaging any adjoining cells. This allows the practitioner to make extremely accurate and specific modifications to the cornea with little trauma to the eye.
This ability to sculpt, rather than cut, opens up the arena for treating additional vision conditions. At this stage, there are excimer laser machines that with a combination of masks and computer controls, can reliably treat myopia, hyperopia and now astigmatism
PRK- Predictability and Safety
Although PRK sculpts only a tiny amount of tissue from the cornea, it is a surgical procedure and thus the outcome cannot be guaranteed. Any surgical procedure should be undertaken only after careful consideration of the likelihood of success and consequences of any possible risks or side effects. Thorough professional advice from a qualified eye surgeon or surgeons is required before any eye treatment is undertaken. Predictability can be defined in several ways- we favor a percentage approach to achievement of visual goals, with 20/20 uncorrected vision being ideal and 20/40 uncorrected vision being okay or acceptable. Uncorrected vision of 20/40 still allows driving without glasses. Most PRK facilities and machines report that 65-70% of patients with correction up to -6.00 diopters can expect 20/20 uncorrected vision post operatively. The percentage with 20/40 uncorrected acuity is 90-95%. Corrections less than -6.00 diopters will have better odds and corrections greater than -6.00 will have lower odds. The safety of the procedure is judged on the basis of the chance of a possible complication. Serious complications are extremely rare. Infection is the most worrisome complication and fortunately it can usually be eliminated with antibiotic medications. Other possible problems include delayed surface healing, corneal haze and or scarring, over or undercorrection, and the development of astigmatism. Some individuals can have a poor or excessive healing response. Again most complications remain treatable with medications or further surgery.
It is also important to separate the normally expected side effects of surgery and healing from real complications. Immediately after surgery some people have discomfort, although the use of bandage contact lenses and medications usually control this nicely. Light sensitivity is almost universal and halos and other unusual light effects can occur. Vision can be reduced while healing and from the normally planned overcorrection. Medical professionals and their associates consider this treatment as experimental as longterm side effects are not yet known. You must discuss and fully understand all of these possible side effects and problems prior to surgery. Hopefully, the information here will assist you in that process.
The cost of surgery is about $1850 per eye, its expensive because I have a thin cornea and its the one of the only options I have for my vision correction.
They also LADARWave® wavefront measuring device where they shoot a beam of light on your cornea to measure the contours so they can adjust the lazer to better fit your surgical procedure, the benefit with this is that you will be able to remove glare at night and a possiblity to have your eyes to be better than 20/20 vision.
On Thursday I will be given PRK surgery. Wish me good luck!
I'll tell you how it goes, BTW.
![:\](https://bluelight.org/xf/BL_Images/Orig_Emoji/wrygrin.gif "wry grin :\")
I refuse to wear my glasses all the time (I do wear them for driving and watching TV/movies), but it's gotten to the stage where I can't clearly see people's faces until they're about 3 meters away. It's like they've been smudged with an eraser. Driving without my glasses is impossible; unless I'm right under a street sign I wouldn't have a clue what it says.
