What is PRK? How does it differ from LASIK?
The names and acronyms of the many types of laser eye surgery are confusing, and it’s common for our patients at Turner Eye Institute to ask for an explanation of the differences between all these procedures. Our San Leandro, Concord, and Castro Valley, CA, eye care specialists are pleased to explain!
Introducing your cornea
To understand how PRK works and how it differs from LASIK, it’s helpful to become more familiar with your cornea. This outer part of your eye has several layers. The primary layer is the stroma, which is the middle layer and makes up 90% of the thickness of your cornea. It has collagen tissue fibers that are arranged in a way that gives the cornea a high refractive index and translucency. These are the essential characteristics that you need for your eye’s lens to focus. The outermost cornea layer is a clear epithelial (skin) coating that protects the cornea from the surrounding environment.
If the surface epithelial layer of your cornea is damaged, it will heal and grow back. However, the collagen fibers of the stroma do not grow back. That’s how both LASIK and PRK work – your eye doctor will use a laser to sculpt the stroma layer, removing tiny amount of tissue and permanently reshaping the cornea. Once the cornea is changed to correct your vision condition, the light that enters your eye will be focused more acutely, giving you sharp vision without glasses or contact lenses.
PRK – Photorefractive Keratectomy
This type of laser eye surgery can help resolve nearsightedness, farsightedness, or astigmatism. It is most effective if your vision condition is mild or moderate. During PRK, your eye surgeon will use a cool pulsing beam of UV light on the outermost surface of your cornea.
Your eye surgeon will numb your eye with a topical anesthetic before precisely removing an area of surface epithelium in order to access your cornea. This removal is quick, and you may feel slight pressure on your eye. Then, an excimer laser will be used to reshape your cornea. The entire procedure takes about ten minutes, maximum.
After PRK, a bandage contact lens will be placed over your eye. You will need to wear this bandage for the first four or five days after surgery, so your eye can heal. The eye doctor will remove the lens about a week later, and usually by this point there is functional vision. Over the next six months, you will need to visit our San Leandro, Castro Valley, or Concord, CA, eye care center a few times for follow-up exams.
Throughout the first few weeks, your vision may switch back and forth from clear to blurry. Until it stabilizes, you may need eyeglasses to read or drive at night. Other side effects include dry eye. You will receive eye drops to prevent infection and keep your eyes moist. Gradually, your vision will improve, and you should experience the final results within a month to a few months.
What are the differences between PRK and LASIK?
Both PRK and LASIK are regarded to be safe and effective. Just like PRK, LASIK uses an excimer laser to correct vision by reshaping the stroma layer of the cornea. However, PRK is done differently. As opposed to LASIK, which just moves the outer layer of corneal tissue out of the way to perform the reshaping, PRK actually removes the tissue.
With PRK, the healing is slightly longer than it is with LASIK, because the epithelial tissue has to become as smooth and regular as it was before. After about a month, most people have 20/20 vision.
The advantages of PRK lie in the fact that there is no cutting of a corneal flap, like there is with LASIK. Although the recovery from PRK can be longer and more uncomfortable, the rate of complications with PRK are virtually nonexistent. The modern bladeless technology eliminates the risks. In addition, people who do not have a thick enough cornea to qualify as a candidate for LASIK will often qualify for PRK.
PRK vs. LASIK – which is for you?
To make this decision, call to book a consultation at Turner Eye Institute. Our eye doctor will evaluate your eyes to see if you are candidate for both procedures. If you qualify for both types of laser eye surgery, then we will discuss the pros and cons to make a decision. We have an eye care clinic located conveniently to serve you – choose from our Concord, Castro Valley, and San Leandro, CA, offices.