PRK Versus LASIK

PRK (Photo Refractive Keratomileusis) is very similar to LASIK in that it is also a Laser driven procedure used to correct a patient’s vision. PRK has been around longer than the LASIK procedure and has been performed on thousands of patients worldwide. The main difference between PRK and LASIK is the first step of the procedures.

In PRK, the thin outer layer of the cornea (epithelium) is removed and discarded prior to reshaping the underlying corneal tissue with the VISX Star S4 excimer laser. The epithelium repairs itself (grows back over the corneal surface) within a few days after surgery.

In LASIK, a thin flap is created on the cornea with a the Bausch + Lomb Victus femtosecond laser. This flap is lifted to expose the underlying corneal tissue and is replaced after the cornea is reshaped with the VISX Star S4 excimer laser.PRK (Photo Refractive Keratomileusis) is very similar to LASIK in that it is also a Laser driven procedure used to correct a patient’s vision. PRK has been around longer than the LASIK procedure and has been performed on thousands of patients worldwide.

What is PRK?

PRK is a procedure performed on the outer layer of the eye. It differs from LASIK in that the patient does NOT have a flap created. Instead, a tiny amount of tissue is removed from the cornea (this layer is called the epithelium); this layer grows back in approximately four days. Once this layer is removed, the excimer laser treats the inner tissue of the cornea to give the patient the corrected vision they desire. A contact lens is placed over the cornea to help protect the eye while it heals.
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The cornea helps focus light to create an image on the back of the eye (the retina). The eye works much like a camera; the cornea is similar to a lens in the camera which focuses light to create the image on the film (the retina). It is very common to have an unusual shaped cornea and because of this, the image trying to target the retinal is out-of-focus (blurred). These imperfections in the cornea are called refractive errors. PRK helps reshape the cornea and rid the refractive errors so a patient can see clearly.
Types of Refractive Errors and CorrectionThere are three types of refractive errors:

1. Myopia (nearsightedness) & Correcting For Distance: persons with myopia have a harder time seeing objects in the distance but can usually see up close. LASIK is most commonly used to correct a patient’s vision to see better in the distance. This usually requires operating on both eyes. At Morris Eye Group we operate on both eyes on the same day.
2. Hyperopia (farsightedness): persons with hyperopia can see objects in the distance but not up close.
3. Astigmatism: a person with astigmatism usually sees blurred objects due to the shape of their eye. A person with astigmatism has an eye shaped like a football which elongates images. A person with no astigmatism has an eye that is shaped like a basketball. It is possible, and common, to have an astigmatism and be nearsighted or farsighted. In the past, lasers were not advanced enough to correct astigmatism. However, at Morris Eye Group our Custom Laser allows for us to correct astigmatism. This can be corrected on its own or in conjunction with nearsightedness or farsightedness.
4. Presbyopia: Presbyopia is a condition that affects most individuals around the age of 45. Presbyopia is a condition that occurs when the muscles inside the eye stop moving the lens back and fourth. This causes a patient to need reading glasses. A patient with presbyiopia can need correction for both distance and near vision. At Morris Eye Group we have the ability to help patients looking to achieve good vision for the distance and up close for reading. The only way to accomplish this through laser vision correction is by performing monovision. (Monovision is a technique where the patients dominate eye is corrected for the distance and the non-dominate eye is corrected for reading. The brain learns to use both eyes together so the patient can see far away and up close.  Patients first try this with contact lenses to make sure they like the vision, and then it can be performed through LASIK.)

CustomVue PRK
VISX™’s CustomVue procedure combines the technologies of the Wavefront and STAR S4 Excimer Laser systems for high-definition, high-accuracy laser vision correction. CustomVue makes it possible to perform customized refractive surgeries using measurements individually tailored to your eyes. This allows us to correct the very specific refractive errors that obscure each patient’s vision so you can enjoy the best post-operative vision quality possible. Other benefits of the CustomVue process include: faster treatment time and the elimination of pupil dilation.
PRK Is For Those Who:

1. Are at least 18 years of age
2. Have had a stable eye prescription for at least one year
3. Want to reduce or eliminate their dependence on glasses or contact lenses
4. For those with thinner corneas
5. Have occupations that may require this procedure (for example some military occupations)
6. Have been approved through a thorough exam with one of our doctors