Excimer Laser

What is an Excimer Laser?

The word excimer is a combination of “excited” and “dimer.” A dimer is a compound formed by the combination of two identical molecules. The excimer laser combines Argon and Fluoride gases which, when excited, produce a cold ultraviolet beam of light. The excimer laser was first used in the early l980s by IBM to etch very precise lines on tiny semiconductor chips without damaging these delicate devices with heat.

Of the many wavelengths produced by this excited dimer process, one was found to have enormous potential for medical applications. At this wavelength it was possible to use the laser to remove tiny molecules of tissue without damaging underlying tissue.

The excimer laser causes no significant damage to underlying tissue because the beam of light produced is cold. Tissue is removed or “ablated” by the light beam a few molecular layers at a time, rather than burned or exploded. The excimer laser is so precise that it can remove tissue 0.25 microns at a time. (One micron = one thousandth of a millimeter; 50 microns is less than the thickness of a human hair. It takes more than 200 laser pulses to etch through the width of a human hair.)

In 1983, ophthalmologists determined that because of its precision and absence of damage to underlying tissue, the excimer laser could be used to reshape the cornea. Highly automated, the modern excimer laser is controlled by a computer specifically programmed by the surgeon for each patient's correction to calculate the intensity and duration of the laser beam. The surgeon must design the treatment and direct the laser beam so that it reshapes the curvature of the cornea so light rays focus properly on the retina for crisp, clear vision. The surgeon's skill and experience is also crucial in creating and manipulating the LASIK “flap.”

Well over one million people have had their vision improved successfully with an excimer laser in facilities around the world. Patient satisfaction with the procedure is very high: in one study more than 95% of all patients who had the procedure reported that they would enthusiastically recommend it to co-workers, friends and relatives.

Which Excimer Laser is “Best” for LASIK?

With all the hype and misleading claims about LASIK eye surgery, this is one of the most common questions we hear. The answer isn't simple. It's like asking what's better, jeans or a suit? The answer depends on what the specific occasion requires. Depending upon your degree of astigmatism, size of your pupils, thickness of your cornea, and several other factors, the “best” laser to correct your vision (often to better than 20/20 without glasses) depends on your individual eyes and needs. Eyes differ from person to person and only an experienced, expert LASIK eye surgeon can choose the best technology for your eyes.

At Washington Eye, we are extremely fortunate to have multiple excimer lasers we can use to perform LASIK. Some are better for large pupils and others are better for thin corneas. And, contrary to what you may hear in radio ads, the type of laser device does not guarantee an excellent result any more than having a world class tennis player's racquet would assure its owner a championship at the US Open.

Be sure to ask any of our three board-certified, expert LASIK surgeons at your free LASIK vision correction consultation, which is the “best” laser. The Washington Eye Physicians and Surgeons are LASIK specialists servicing the Washington DC, Maryland and Virginia areas; as such, they will be able to answer this question (and many more) for you.