Laser Eye Surgery Treatments: Guide to PRK/LASEK
Making all the necessary decisions when going ahead with Laser Eye Surgery can seem like a monumental task. Moreover, this is only made worse when you begin your research and are inundated with seemingly endless jargon and treatment options. But fear not, we’re here to help simplify things. The fact is, there are only really three Laser Eye Surgery treatments you need to know about: LASIK, ReLEx SMILE, and PRK/LASEK.
In fact, all Laser Eye Surgery treatments follow the same method: They all use laser technology to remove tissue from the stroma that makes up the body of the cornea – the clear window responsible for reflecting light into the eye. In refractive errors including myopia (short-sightedness), hyperopia (long-sightedness), and astigmatism, the cornea is shaped abormally, causing light to be directed ineffectively at the retina at the back of the eye.
By removing small areas of tissue, Laser Eye Surgery effectively reshapes the cornea. The treatment can therefore be used to correct a wide range of prescriptions.
But there are some key differences between the three main Laser Eye Surgery procedures: the method used to access the corneal tissue.
The Main Difference Between PRK/LASEK, LASIK, and SMILE Laser Eye Surgery
When performing Laser Eye Surgery, the surgeon must be able to access the stroma – the body of the cornea – which lies underneath the surface level (epithelium) of the cornea. This can be achieved in several ways, the specifics of which differentiate the three main types of Laser Eye Surgery procedures.
While the corneal epithelium is extremely thin, it is surprisingly strong, and continuously regenerates every 7-14 days. So, how does PRK and LASEK tackle this resilient barrier?
PRK/LASEK – The ‘Surface’ Procedures
PRK and LASEK are known as the surface ablation or ‘surface’ procedures. This is because they involve the complete removal of the surface of the cornea. The surface procedures are the oldest type of Laser Eye Surgery treatment. They were introduced in the 1980s , and while still extremely effective, they have become less popular, in favour of the newer LASIK treatment.
Let’s take a look at how they work.
Photo-Refractive Keratectomy (PRK)
PRK is the original Laser Eye Surgery procedure. It has been used to correct the vision of hundreds of thousands of patients since its introduction around four decades ago.
PRK was the first Laser Eye Surgery procedure to utilise the excimer laser – a crucial development in the Laser Eye Surgery field. This made it possible to move away from traditional scalpel-based refractive procedures, such as Radial Keratotomy (RK), which are rarely performed today.
In PRK an area of the epithelium is completely removed. The surface tissue is discarded, allowing the surgeon to access the cornea beneath. Once the procedure is complete, a temporary contact lens is placed over the exposed area of the eye to protect it until the cells of the epithelium have repopulated.
Laser Assisted Epithelial Keratomileusis (LASEK)
Soon after the introduction of PRK came the development of LASEK. This procedure was introduced as an alternative form of surface ablation, with the hope of reducing post-operative haze, speeding up visual recovery, and decreasing post-surgery discomfort. However, subsequent studies have found no evidence of significant outcome differences between the PRK and LASEK.
While PRK involves discarding the removed area of epithelium, in LASEK, this tissue is put back in place. Once again, a protective contact lens is placed over the treatment area until the edges of the epithelium fuse back together.
Generally, PRK and LASEK are only offered as treatment options when it is not possible to use LASIK. But that isn’t to say it is particularly a less effective option.
“With PRK we are able to treat all refractive errors. We are able to treat the full range of myopia, astigmatism and long-sighted treatments, hyperopia. However, it is less predictable for hyperopia when compared to short-sightedness, myopia and astigmatism.” – Mr Glenn Carp
The Pros of PRK/LASEK Laser Eye Surgery
While PRK and LASEK are only used in a small number of cases today, these older procedures can have their benefits. Examples of times when surface procedures may be a better option include:
A better option for patients with…
Thinner corneas
Some people understandably assume that thie prescription is the only factor that can affect their suitability for Laser Eye Surgery, but this isn’t the case. For example, patients with thinner corneas may not be eligible for LASIK surgery, as they cannot accommodate both the corneal flap and the removal of tissue required to correct their vision.
In these cases, PRK or LASEK may be better options.
Existing eye issues
Some patients can benefit from PRK/LASEK if they have co-existing eye issues that can be treated at the same time as correcting the refractive error – e.g., scars and loose surface epithelium.
An active lifestyle
For patients with a particularly active lifestyle, the risk of the corneal flap being dislodged after LASIK treatment can be increased. Therefore, in some cases, PRK/LASEK may be considered as an alternative treatment option.
The Cons of PRK/LASEK Laser Eye Surgery
PRK and LASEK remain extremely effective Laser Eye Surgery treatments; however, these procedures do have their drawbacks compared to newer techniques.
Longer recovery times
PRK/LASEK procedures involve removing the entire outer layer of the cornea to access the tissue underneath. Compared to procedures like LASIK and ReLEx SMILE, this is a much more invasive technique that requires longer healing times. It can take several days for epithelium cells to repopulate the treatment area, making the recovery times for surface procedures the longest of all Laser Eye Surgery treatments.
Safety and Comfort
Although the treatment itself is pain-free, thanks to the use of anaesthetic eye drops, PRK/LASEK can be associated with greater post-operative discomfort compared to alternative options. This discomfort is an expected part of the eyes’ healing process that can persist for several days. At London Vision Clinic, patients will be provided with an aftercare pack, which includes painkillers and lubricating eye drops.
Results with PRK/LASEK
At the London Vision Clinic, we now only use PRK for 5 to 10% of patients. These tend to be those with unusually thin or flat corneas for whom LASIK eye surgery would be impractical. Nonetheless, scientific studies suggest that there is no significant difference in expected outcomes between PRK/LASEK and newer iterations of Laser Eye Surgery.
Generally, your vision will be good enough to drive a car within two to three weeks following your LASEK eye surgery, but you may not achieve your best vision until between six weeks and three months after surgery.
If you’d like to learn more about PRK/LASEK – or any of our other Laser Eye Surgery treatments – get in touch with one of our friendly clinic coordinators today. Alternatively, Book a Consultation to find out if you could be a suitable candidate for Laser Eye Surgery.
