LASIK vs PRK — What’s the Difference & Their Pros and Cons?

Anyone who’s done even a little bit of research into laser eye surgery will quickly realise there’s more than just one type. There’s LASIK surgery, PRK surgery, SMILE eye surgery… you may have also come across terms like LASEK, epi-LASEK, and ASLA. If you’re serious about laser eye surgery, all the information can be a little overwhelming as you obviously want what’s best for you and your vision.  The two most common procedures are LASIK surgery and PRK surgery. Keep reading to find out what you need to know about LASIK vs PRK. 

LASIK vs PRK: How Do the Techniques Differ?

Both LASIK and PRK are types of laser eye surgery. Laser eye surgery is a group of procedures designed to reshape the cornea of the eye to permanently correct imperfect sight due to refractive error. Refractive error includes vision problems such as long-sightedness (hyperopia), short-sightedness (myopia), and astigmatism. 

The cornea is the transparent front surface of the eyeball. Along with the crystalline lens further into the eye, it acts to bend – or refract – light as it passes through. If the combined refracting power of the cornea and lens is too strong, you end up with myopia. If the refractive power is too weak, you get hyperopia. If the cornea and/or lens is unevenly curved, light passing through these structures at different angles can be refracted by different degrees, which results in two separate focal points. This is a condition known as astigmatism. 

Both LASIK and PRK surgery involve adjusting the curvature of the cornea so that light is focused to a clear point on the retina. This is achieved through a process called photoablation, which refers to the vaporisation of tissue using an excimer laser. The cornea is made of five layers of cells; photoablation is applied to the middle layer, known as the stroma. Though both techniques of laser eye surgery involve corneal photoablation, there is a key difference in the procedure when it comes to LASIK vs PRK. 

LASIK surgery stands for laser-assisted in situ keratomileusis. The main distinguishing feature of this technique of laser eye surgery is that it requires the creation of a hinged flap of corneal tissue. The surgeon achieves this by using either a bladed instrument called a microkeratome, or another type of medical laser called a femtosecond laser to cut across the top layer of cells, which includes the epithelium, underlying Bowman’s membrane, and part of the stroma. The flap is then opened to the side, exposing the stromal layer. From here, the excimer laser can then perform photoablation, which is guided by a computer algorithm using your biometric measurements taken at earlier consultations. After this is complete, the flap is replaced. Typically, the flap is cut such that the edges self-seal during the healing period rather than needing stitches. 

Conversely, PRK surgery doesn’t involve making a corneal flap. PRK stands for photorefractive keratectomy. Unlike LASIK surgery, PRK removes only the topmost layer from the cornea, the epithelium. This means that those with thinner corneas are more suitable for PRK over LASIK. Removing the epithelial layer is called debridement. It can be done in a number of ways, including using a manual tool to scrape away the cells (mechanical debridement) or applying an alcohol solution to loosen the cells before manually scraping them away (alcohol-assisted debridement). Once the epithelium has been removed, the excimer laser can perform photoablation on the stromal layers. During the recovery period after PRK surgery, the epithelial layer regenerates.  

LASIK vs PRK: the Pros and Cons

In terms of the final visual result, both PRK and LASIK surgery are considered to be equally successful and effective. The main difference between LASIK and PRK tends to be the recovery period and potential complications. 

The LASIK recovery period is considered to be much faster than that for PRK. This is due to the corneal flap being replaced rather than needing to wait for the epithelium to regrow. After the LASIK procedure, many people feel they can see clearly as soon as within a few hours; their vision continues to stabilise over the following few weeks. Conversely, visual recovery for PRK can four weeks or even longer for your vision to feel sharp. 

The discomfort felt during the PRK recovery period tends to be a little more intense than after LASIK. Again, this is due to the epithelial debridement. Your eyes can feel sore, red, and scratchy after either LASIK or PRK, but these sensations can be more severe and last for longer after PRK. Wearing a bandage contact lens, using eyedrops, and taking oral painkillers can help you to manage the discomfort. For many people, the recovery expectations after their laser eye surgery are a major pro for LASIK and a major con for PRK.

However, your lifestyle factors and usual activities can also be a significant consideration when it comes to deciding between LASIK and PRK. Due to the creation of the corneal flap, LASIK is subject to the possibility of unique flap-related complications. This can include the flap becoming dislodged or dislocated, or catching debris between the flap and stroma interface. For this reason, people who are at a higher risk of head or face trauma are often guided towards PRK, which doesn’t encounter such complications. Examples of activities that will be better off with PRK include martial arts, boxing, other contact sports, and the armed forces. 

Your ophthalmologist will be able to determine whether PRK or LASIK is more suitable for you. This comes after a thorough eye examination and a discussion about your lifestyle and hobbies. Call us now on 03 9000 0389 for a consultation.

Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.

References

Comparison of Three Epithelial Removal Techniques in PRK: Mechanical, Alcohol-assisted, and Transepithelial Laser.
https://pubmed.ncbi.nlm.nih.gov/26544564/

PRK vs LASIK.
https://www.webmd.com/eye-health/prk-vs-lasik#:~:text=Both%20LASIK%20and%20PRK%20use,which%20grows%20back%20over%20time.

What’s the Difference Between PRK and LASIK?
https://www.healthline.com/health/eye-health/prk-vs-lasik