Is Excimer Laser Safe for Eyes

Invented in 1970, the Excimer Laser has served many medical purposes and continues to lead as a UV laser solution in the medical market.

There are several excimer lasers that have been approved by the FDA for use in vision correction surgery performed in the United States, including

• STAR S4 IR Excimer Laser System and iDesign Advanced WaveScan Studio System (Johnson & Johnson)
• Allegretto WAVE Eye-Q Excimer Laser System (Alcon)
• TECHNOLAS 217Z Zyoptix System for Personalized Vision Correction (Bausch + Lomb)
• Nidek EC-5000 with Navex Quest customization (Nidek)
• MEDITEC MEL 80 Excimer Laser System (Zeiss)

Though each of these lasers has its own unique set of features, research has shown that all FDA-approved excimer lasers produce comparable LASIK results.

Most experts agree that your surgeon’s skill and experience and an accurate evaluation of whether you’re a suitable LASIK candidate are far more critical factors affecting final LASIK outcomes than subtle differences between excimer lasers.

How do excimer lasers work?

The excimer laser emits a cool beam of ultraviolet light of a specific wavelength (typically 193 nanometers) to precisely remove corneal tissue. When the surface of the cornea is reshaped in the right way, it allows light rays to focus properly onto the retina for clear vision.

The high-energy pulses of ultraviolet light penetrate only a tiny amount of the cornea and have the ability to remove as little as 0.25 microns of tissue at a time. (One micron is a thousandth of a millimeter.)

An excimer laser corrects nearsightedness by flattening the cornea; it corrects farsightedness by making the cornea steeper. We can correct astigmatism by smoothing an irregular cornea into a more symmetrical shape.

Computer settings program excimer lasers to correct your specific refractive error. Your surgeon will program the excimer laser with the desired measurements to reshape your cornea and treat your prescription. The quantity and pattern of tissue removal are unique to each patient.

Most modern excimer lasers have automated eye-tracking systems that monitor eye movements and keep the laser beam on target during surgery. Studies have indicated that eye trackers produce better outcomes and decrease LASIK complications compared with past lasers that did not use eye-tracking systems.

Pupil size, ablation speed and patient comfort

Recently, increasing evidence has indicated that larger pupil sizes may affect the outcomes of laser vision correction. If your pupil expands in low light beyond the diameter of the laser treatment zone on the cornea, you may experience vision problems such as glare and halos at night.

Some surgeons believe the diameter of the laser ablation should be at least as large as your pupil in dim light. If you have larger pupils, it is important to consider the type of excimer laser, as it affects the size of the treatment zone (diameter) that can be created. You should discuss the issue with your surgeon.

Treatment times also differ among lasers, ranging from about 20 to 60 seconds or longer, depending on your refractive error. This can be important for your comfort during the procedure.

You also might want to ask whether your surgeon uses a femtosecond laser or a bladed surgical tool (microkeratome) to create the corneal flap in LASIK eye surgery and how these two approaches might differ in terms of your comfort. Many surgeons take opposing sides in the microkeratome vs. femtosecond LASIK debate.

While specific excimer laser technology plays a key role, ultimately, it is your surgeon’s skill and experience — and your suitability as a candidate — that will be the most important factors affecting your LASIK outcome.

Conclusion

Excimer lasers are gas lasers that emit strong pulses of light in the ultraviolet (UV) spectrum. The name excimer comes from the term “excited dimer.” This laser has the ability to remove extremely fine layers of surface material without causing any changes to the surrounding material. Today, a wide range of medical applications use excimer lasers, including the treatment of psoriasis, LASIK eye surgery, and many refractive ophthalmology treatments.

To keep protective laser eyewear intact, it is a beneficial idea to store them in a protective unit similar to the Clearly Safe Acrylic Safety Eyeglass Dispenser. You can mount this dispenser to the wall or tabletop, and it can hold multiple pairs.