Since the FDA approved LASIK eye surgery in 1999, millions of people have turned to LASIK to improve their vision. LASIK is now one of North America’s most frequently performed eye procedures.
This outpatient surgical procedure uses a laser to reshape the eye’s cornea, adjusting how light is focused on the retina. The surgery is typically completed in less than 15 minutes for both eyes. After having LASIK, most patients report clear vision within 24 hours.
Types of lasers used in LASIK Eye Surgery
All forms of laser refractive surgery, including LASIK, use a highly specialized excimer laser to correct refractive errors and reshape the cornea. These excimer lasers have revolutionized the laser eye surgery field. Over the years, the efficacy, predictability, and safety of LASIK and other similar procedures have vastly improved through the technological advancements of these lasers.
All of the approved excimer lasers in the United States meet the effectiveness and safety criteria established by the FDA. The different types each apply a slightly different pattern to track the eye and to deliver the laser beam during the procedure.
Modern excimer lasers include Wavefront-guided, slit-scanning, and spot-scanning. Each does something slightly different.
The most commonly used lasers in the LASIK procedure are spot-scanning lasers. Also known as “flying-spot” lasers, these machines use small-diameter laser beams to produce the treatment zone after being scanned across the cornea. Spot scanning lasers are often used to treat those with irregular astigmatism as they readily allow for customized treatments and have the potential to produce the smoothest corneal treatments.
These excimer lasers use small beams linked to a rotational device with slit holes that gradually enlarge, little by little increasing the ablation zone. These slit-scanning lasers are able to produce smoother treatments than the older broad-beam lasers. It’s important that your eye surgeon is highly experienced if they choose to use a slit-scanning laser as these have the highest risk of overcorrection or decentered ablation if the laser isn’t perfectly centered on the pupil.
Wavefront-guided treatments can be used with both slit- and spot-scanning lasers. These excimer lasers are connected to a device that allows the eye surgeon to look at how light travels through the eye to detect defects in the eye’s optical system. Using a wavefront device, your LASIK surgeon can create a unique LASIK treatment customized to the exact needs of each patient.
Which is the best laser?
There are several FDA-approved excimer lasers on the market today for refractive surgeries. While the technology continues to advance, one laser isn’t necessarily “better” than the next. Depending on a number of factors, including the current vision prescription, pupil size, cornea thickness, and the degree of refractive error, your ophthalmologist will be able to advise which laser is best for you.
The subtle differences between excimer lasers shouldn’t be your main concern – what is most important is your surgeon’s experience and skill level.
There are other elements of LASIK eye surgery that are as important to refining the procedure.
An automated eye-tracking system is used with most modern excimer lasers. These monitor the movement of the eye to ensure the laser beam stays on target during the procedure. Eye trackers are used to decrease complications and produce better results.
The size of your pupil can affect the outcome of laser vision correction. Vision problems, such as halos at night or glare, may occur if your pupil expands in low light beyond the diameter of the cornea’s laser treatment zone. This can be anticipated and minimized.
The type of laser used will often depend on the size of the patient’s pupils. The excimer laser used varies, depending on the size of the treatment zone.
Just as every pair of glasses or contact lenses is specifically customized for the patient, every LASIK surgery is customized. Wavefront technology allows for custom treatments and can measure more complex aberrations.
While all modern LASIK treatments can correct lower-order aberrations and add that to a wavefront treatment – wavefront-guided (WFG), or wavefront-optimized (WFO) – most LASIK lasers cannot perform wavefront-optimized treatments.
The WaveLight Allegretto laser at Barnet Dulaney Perkins Eye Center can safely accommodate both types of treatments. The WaveLight Allegretto laser is also the only laser in the United States approved by the FDA to reduce night glare.
Are you a good LASIK candidate?
There are many things to consider before you schedule a vision evaluation with your ophthalmologist for LASIK surgery. While LASIK is a good solution for many, not everyone is a good candidate. If you suffer from astigmatism, have a diagnosis for nearsightedness, or have a current prescription for glasses or contact lenses, you are likely a good candidate. However, those who are severely nearsighted or farsighted or have an autoimmune disease or uncontrolled diabetes may not be eligible.
Even if you have ruled out LASIK as a viable treatment option, other corrective vision procedures including Implantable Collamer Lens (ICL) or Refractive Lens Exchange (RLE) may be a more ideal option.