Refractive errors causing nearsightedness (myopia) or farsightedness (hyperopia) are some of the most common vision impairments causing blurry vision and trouble focusing clearly. Laser eye surgery can correct myopia, hyperopia, and astigmatism, which are all related to the shape of the eye or the cornea.

In the case of myopia, the cornea is often too steep, causing light to focus in front of the retina and blurring vision for far objects. With hyperopia, the corneas are often too flat (or the eyeballs too short), so light is focused behind the retina, causing close vision to be blurry. Astigmatism is when the cornea is shaped irregularly, which also causes disruptions to vision. LASIK (laser-assisted in-situ keratomileusis) is the most commonly performed corrective laser eye surgery for refractive errors, Mayo Clinic reports.

LASIK can be used to treat myopia, hyperopia, and astigmatism with a high level of safety and success. (Learn More) PRK (photorefractive keratectomy) is a form of LASEK (laser-assisted subepithelial keratectomy) surgery that is similar to LASIK, but instead of creating an epithelial flap in the cornea, it ablates the surface layer entirely. This can make it ideal for people who may not be eligible for LASIK due to thin corneas. PRK/LASEK has a longer healing time than LASIK, but it is often preferred by surgeons with less experience using multiple lasers.

ReLex SMILE (refractive lenticule extraction as small incision lenticule extraction) is a relatively new and advanced technique that can be less invasive. It can provide treatment for people struggling with higher levels of myopia. (Learn More)

There are risks associated with any type of corrective eye surgery and also many benefits. (Learn More) Your ophthalmologist can help you determine which procedure will be ideal for your eyes. Keep reading to learn more.

 

PRK/LASEK, LASIK, and ReLEx SMILE Explained

 

LASIK is a laser corrective eye surgery that has been performed for over 25 years. The Journal of Cataract and Refractive Surgery publishes that with over 16 million LASIK procedures performed around the globe, it is considered one of the most common and successful surgical procedures.

LASIK is an elective surgery that uses an excimer laser to cut a small flap in the cornea. This flap is then folded back to access the stroma (interior tissue of the cornea) underneath. A secondary laser, called a femtosecond laser, is used to ablate and permanently reshape the cornea to fix refractive errors, such as hyperopia (farsightedness when the cornea is too flat), myopia (nearsightedness when the cornea is too steep), and astigmatism (irregular shape of the cornea). The corneal flap is laid back down after the ablation and allowed to heal back in to place.

The entire procedure takes well under an hour, and you may be able to see better within a few hours. The U.S. Food and Drug Association (FDA) reports that over 95 percent of people who undergo LASIK are happy with the way they see after the procedure. Most people who get LASIK surgery benefit from 20/25 vision or better after the surgery, Mayo Clinic publishes.

Since LASIK is a surgical procedure that is considered elective, most insurance companies don't cover it. Even so, it can save you money and hassle over time, as it may eliminate the need for contacts or glasses.

LASIK carries some risks, such as potential for dry eyes, halos or glares around lights, or complications with the way the flap heals. Overall, LASIK is considered a safe procedure for people over the age of 18, in overall good health, with eye prescriptions that have been stable for at least a year.

LASEK/PRK is another form of laser eye surgery that involves separating the epithelial part of the cornea from the stroma, often with ethanol. Instead of creating a flap like with LASIK, this part is scraped away completely. PRK can be a great option for people with thin corneas who may not be eligible for LASIK.

Doctors who are less experienced with LASIK and creating the epithelial flap often prefer LASEK procedures. PRK can eliminate potential flap complications, and the epithelial tissue will grow back on its own, under specialized bandages, after a few days. The risk for visual aberrations (double vision, halos, poor night vision, and glares around lights) still exists and is considered minimal.

Healing and recovery time for PRK is slightly longer than with LASIK, but you may be able to return to contact sports and the like sooner as you will not have to worry about the flap being dislodged. PRK can also be a great option for people who have corneal scarring or dry eyes. The American Academy of Ophthalmology (AAO) reports that 90 percent of people who get PRK achieve 20/40 vision or better.

A newer advancement in laser corrective eye surgery, the ReLEx SMILE procedure, uses a femtosecond laser to make a disc-shaped lenticule inside the stroma. A small keyhole incision is made, and the corneal tissue is then removed through the small space.

This procedure uses only one laser, as opposed to traditional LASIK, and it is less invasive. Optometry Times reports, it can eliminate any flap-related complications since no flap is created. Higher myopic refractive errors can be treated with the ReLEx SMILE procedure as well. Fewer corneal nerves are severed; therefore, the risk of dry eyes is lower.

A report in Review of Ophthalmology states that the SMILE procedure can be very effective at treating myopia, but LASIK is still the preferred option for correcting hyperopia refractive errors.

Complications of the ReLEx SMILE procedure include suction issues, as a suction must be created with the eye to hold it in place for the delicate incision since the cornea is being cut and not just ablated; therefore, it is imperative that suction remains intact and the patient holds still. Fortunately, the laser procedure is done in mere seconds.

The FDA reports on a clinical study showing that close to 90 percent of those who had a SMILE procedure achieved 20/20 vision or better. According to the Ocular Surgery News journal Healio, SMILE has now been FDA-approved to also treat myopia with astigmatism, which expands patient eligibility for the procedure. The ReLEx SMILE procedure is one of the latest technological advancements in laser eye surgery.

woman receiving glasses in front of eye exam

Choosing Between LASIK, PRK/LASEK, and ReLEx SMILE

 

In order to make an informed decision between LASIK, PRK/LASEK, and the ReLEx SMILE procedures, you will need to understand the differences between them and what your expectations are for surgery and recovery. All three procedures have high success rates with some risks associated with them.

To be a candidate for any laser eye surgery, you will need to be at least 18 years old, and your eyes will need to be mature and stable. This means that your prescription must have been the same for at least one year, maybe two.

You will need to be in good physical and mental health and not suffer from diseases impacting the eyes or certain health conditions that may impact healing and recovery. Your doctor will screen you to ensure that you are healthy enough and eligible for laser eye surgery.

There are some questions to ask yourself when deciding between types of surgical corrections.

  • What type of refractive error do you have (myopia, hyperopia, or astigmatism)? LASIK and PRK/LASEK are able to correct for mild to moderate myopia, hyperopia, and astigmatism, and ReLEx SMILE is an option for significant myopia and myopia with astigmatism.
  • Do you suffer from dry eyes? PRK/LASEK tends to create fewer issues with postoperative dry eyes than LASIK. The ReLEx SMILE procedure may be an optimal choice, as it is less likely to sever as many nerves related to tear production.
  • Do you have thin corneas? When you have a surgical consult for laser eye surgery, the doctor will measure your eyes for the procedure. If your corneas are too thin for a LASIK flap to be created then PRK/LASEK or ReLEx SMILE may be better options.
  • Do you play contact sports or lead a particularly active lifestyle? LASIK can lead to flap-related complications. While PRK/LASEK may have a longer initial recovery time, there will be fewer issues with the flap moving or becoming dislodged through force down the line. The ReLEx SMILE procedure may also provide a more stable cornea over time than LASIK can.
  • What is your budget? Since corrective laser eye surgery is not generally covered by insurance, cost must be considered. In general, the cost for corrective laser eye surgery is about $2,000 per eye for customized care. Typically, the cost will vary depending on the type of care and treatment you will need, and there may not be a significant difference between the types of laser surgery used. Sometimes, ReLEx SMILE procedures will be more cost-effective since they are only using one specialized laser and the procedure is much shorter than LASIK or PRK/LASEK, but this is not always the case.Your surgical team can discuss options with you and help you budget for the procedure that is most suitable. Bargain procedures typically do not offer the level of care and attention required for an optimal experience. Payment plans and financial options are frequently available.

LASIK, PRK/LASEK, and ReLEx SMILE procedures can all potentially reduce the need for corrective eyewear. They can all improve vision and provide safe surgical options with relatively quick healing times.

Several studies have been done comparing the different options for surgically correcting refractive errors, showing that each has benefits and minimal risk. For example, the Peer-Reviewed Open Access Journal (PLOS One) reports that a one-year follow-up study of patients who underwent either a SMILE or LASEK procedure for a high degree of myopia showed similar positive visual outcomes.

Your ophthalmologist can walk you through the different options for correcting your vision, aid in establishing viable expectations, and determine what type of procedure will be right for you. Laser eye surgery is not for everyone, but it can offer significant positive results for many people.

LASIK Eye Surgery

LASIK—short for Laser-Assisted-In-Situ Keratomileusis—is the most commonly performed laser eye procedure in the world. It’s one of the safest and most effective ways to correct vision, and NVISION® surgeons are leaders in the LASIK field. NVISION® Eye Centers offer Custom LASIK, a procedure more customized to your individual eyes.

Learn More About LASIK

References

 

LASIK Eye Surgery. (December 2017). Mayo Clinic.

LASIK Outcomes: How Are We Doing and How Can We Do Better? (August 2016). Journal of Cataract & Refractive Surgery.

LASIK Quality of Life Collaboration Project. (September 2018). U.S. Food and Drug Administration.

Lasik Surgery: Is It Right for You? (March 2017). Mayo Clinic.

LASIK or LASEK: What's the Difference and What's Best for Me? (September 2018). The Telegraph.

What Is Photorefractive Keratectomy? (September 2017). American Academy of Ophthalmology.

Crack a SMILE or Raise a Flap? (February 2014). Review of Ophthalmology.

FDA Approves VisuMax Femtosecond Laser to Surgically Treat Nearsightedness. (September 2016). U.S. Food and Drug Association.

FDA Approves ReLEx SMILE for Myopia With Astigmatism. (October 2018). Healio.

Comparison of Post-Operative Visual Quality After SMILE and LASEK for High Myopia: A 1-Year Outcome. (August 2017). PLOS One.