PRK (photorefractive keratectomy) is a type of refractive surgery to correct myopia (nearsightedness), hyperopia (farsightedness) and astigmatism. PRK was the first type of laser eye surgery for vision correction. Though PRK recovery takes a bit longer than recovery from LASIK eye surgery, PRK is still commonly performed and offers advantages over LASIK for some patients. PRK may be preferable to LASIK in certain patients with thinner corneas or with corneal surface irregularity or with chronic dry eyes since PRK disrupts less corneal tissue than a comparable LASIK surgery. With PRK, there is also less risk of infection or issues having to do with the flap and the related healing process. Like other types of laser eye surgery, PRK works by reshaping the cornea using an excimer laser, allowing light entering the eye to be properly focused onto the retina for clear vision. During PRK, an eye surgeon uses a laser to reshape the cornea. This laser, which delivers a pulsing beam of ultraviolet light, is used on the surface of the cornea.
With the PRK procedure, there is no flap created. Instead, the surgeon gently removes the epithelial tissue layer of the cornea, and then applies the excimer laser to the exposed cornea for the reshaping step. When the reshaping is complete, a contact lens bandage (a contact lens with essentially no prescription power) is placed over the cornea to allow the skin to grow back underneath.
Removing the epithelial layer is rather quick, taking less than 30 seconds. Surgeons vary in their technique but regardless of the technique used, the patient may experience a small amount of pressure on the eye and dim vision when the surgeon gets in the way of their vision. The reshaping step is next, and usually takes less than 30 seconds as well.
When the reshaping is complete, the patient receives the contact lens bandage and a few eye drops. After the procedure is completed, the patient can see fairly well, typically dramatically better than before the procedure without glasses on. That vision is short-lived however, as vision tends to get worse before it improves as the eye heals after PRK.
Healing and subsequent visual recovery after PRK takes longer because the epithelial tissue has to heal and become as regular and smooth as it was before removal. Full visual recovery typically takes about thirty days and has three general stages: initial healing, bandage contact lens removal, and full healing.
The patient wears the contact lens bandage for about 4-5 days as the epithelial tissue undergoes the initial healing phase where it seals the surface from where it was removed. During this time, the patient’s vision is typically fairly blurry and there is usually a relatively high amount of discomfort and light sensitivity.