PRK

PRK (Photorefractive Keratectomy)
In some cases, patients are considered to be candidates for laser refractive surgery but they have certain characteristics that are discovered in their eyes during the examination which indicate that PRK might be an equally good or perhaps even a better choice.
 
PRK was the original laser refractive surgery and at one time was the most common available. It was introduced in the 1980's and even today it continues to demonstrate a high level of safety and effectiveness. PRK became less common by the end of the 1990's with the introduction of LASIK. Despite LASIK's shortened recovery time, PRK remains an option with its own set of advantages and may at times be suggested instead of LASIK. Unlike LASIK, a flap is not created during PRK. Instead, the cornea is treated directly with the excimer laser, altering its shape to provide the needed prescription.

The surgeon will consider PRK in the following cases: Patient has less than 8.00 D of near-sightedness but with a thin cornea A history of recurrent corneal erosion or corneal basement membrane dystrophy A history of dry eye that is difficult to treat Career opportunities, such as becoming a pilot A history of glaucoma, in which case a glaucoma specialist will be consulted
 

What is the process for PRK?
The first step of PRK involves the removal of the epithelial layer of the cornea. A solution is applied to the cornea to allow the epithelium to be removed (this layer will regrow naturally). Next, the excimer laser will alter the corneal shape very similar to LASIK surgery. In PRK, the actual laser time is less than 1 minute per eye. Once the laser treatment is completed, a contact lens will be placed on the cornea in order to reduce the discomfort and improve the healing time of the cornea. The entire surgery takes less than 20 minutes for both eyes. The outer layers of the cornea will heal back to normal within 3-5 days, although this amount of time varies between different patients.

What are common symptoms following PRK?
During the first day, before the healing has completed itself, it is common to experience irritation, discomfort, stinging, difficulty with opening the eyes, light sensitivity, redness and watery eyes. The degree of these symptoms varies greatly between individuals but is considered normal. Often vision is good on the first day but then blurs later as the cornea heals itself. Vision will be unstable and there is often variability in clarity from one day to the next or even throughout the same day. Once the cornea has healed itself, vision will gradually improve but it may take as long as 2 weeks before regular vision is obtained.
 

After PRK Surgery similar to LASIK, a patient do not let any water into the eyes and avoid rubbing and squeezing the eyes for 1 week. The surgeon will also prescribe medication during this time. The medication taken might vary between individuals and will depend on the healing rate of the cornea. The doctor will adjust medication based on the patient's needs.

Follow-up appointments are more frequent following PRK than for LASIK. It is important to inspect the contact lens to insure that infection does not occur. Due to the possibility of discomfort and blurry vision, it is important to plan ahead as it might be necessary to take a week off from work.
 

Follow-up Appointments with the Surgeon Before the cornea has healed over completely, the contact lens will be removed and patients will be allowed to wash their face and hair. The doctor will adjust medication as needed during visits. After the first month, the doctor will consider the frequency of appointments that are required. This will vary between individuals.
 

Side Effects Complications that occur in LASIK due to creation of a corneal flap will not occur in PRK as this step is not required. Side effects and complications that occur more frequently in PRK than LASIK are corneal haze and scarring, but this is better controlled now with application of a special solution to reduce the haze. Side effects that occur less frequently in PRK than LASIK include dry eyes.