Navy offers newest technology: laser eye surgery keeps Sailors mission ready

All Hands, August, 2007 by Rebekah Blowers, Brien Aho

For Sailors and Marines who wear glasses or contacts, the thought of waking up in the middle of the night and fumbling around on the night stand or in their rack for their glasses to see the alarm clock is a nuisance. So is not being able to qualify on mission-essential weapons without squinting through the sites. Most people would like to be able to be rid of their impaired vision.

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Sailors and Marines may now have that opportunity thanks to the Navy offering the newest technology in laser eye surgery through a new piece of equipment called IntraLase.

The new procedure offers the Navy many benefits--the most important being that Navy personnel can now be fully operational faster. According to Capt. Joseph Pasternak, a surgeon at National Naval Medical Center (NNMC), Bethesda, Md., Photo-Refractive Keratectomy (PRK) takes up to three months to heal. With IntraLase, only takes a few days.

"Instead of three months out of work, it could mean two weeks. Our goal is to try to make our warfighters operational that much quicker," said Pasternak.

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Refractive surgery reduces dependence on glasses and contact lenses. Light must be focused precisely on the retina of the eye for an image to be seen clearly. The light is focused by the eye through a process called refraction or bending of light. When someone is "nearsighted," the light is focused in front of the retina and the person can see objects close up but not far away.

Laser surgery uses an Excimer Laser and shaves down microns of the cornea to flatten the shape of the eye and thereby improve someone's vision.

"[There is a] clear dome of collagen above the cornea. The combination of your corneal curvature and your eye length determines whether you are nearsighted or farsighted," said Pasternak. "Think of the cornea bending the light too much so the image is focused in front of your retina. If we do something to change that shape, we can do something to change the bending of the light coming onto the retina. We not only flatten the cornea, but make it rounder.

"The Eximer Laser is high-tech sand paper. It's basically removing a little piece of corneal tissue each laser pulse. Each time that laser pulses and hits your cornea, it's going to remove a micron of tissue," Pasternak added.

If they were using PRK, the laser sculpts the surface of the cornea beginning at the clear dome of collagen above the cornea and works its way down to alter the refractive state of the eye. PRK is not the same thing as LASIK. According to Pasternak, LASIK cuts a flap in the clear dome of protein tissue around the eye with a blade and then shapes the cornea, while IntraLase cuts that flap with a laser.

"IntraLase creates little gas pockets within the cornea and splits the tissue by creating gas bubbles. That's what's doing the corneal separation rather than a mechanical shearing. It's the most predictable, safest way to create the flap," said Pasternak.

The procedure goes by pretty fast according to Kevin Gray, manager of the Laser Vision Center, NNMC Bethesda.

"The procedure usually takes about 20 minutes. Most of it is prepping the patient. Actually cutting the flap only takes about 20 seconds. And depending upon how much treatment they get under the IntraLase laser that's anywhere from 20 to 60 seconds," Gray said.

Pasternak said that during the procedure, the patient's eyes are kept open with a lid spreader and are treated with a blink suppressor, a numbing agent and a suction ring that Pasternak compared to a vice grip for an eyeball so it doesn't move during the surgery.

"The flap is going to be to a micron level of proficiency, so we get exactly what we're looking for. After the laser is used on the cornea, we put the flap back down and ideally there are no wrinkles or layers in it. The precision is still based on the Excimer laser taking away the exact amount of tissue we're trying to get rid of," Pasternak said.

According to the ophthalmology team at NNMC Bethesda, there are many benefits of IntraLase versus other kinds of refractive surgeries. The biggest two are faster vision recovery and less discomfort for the patient.

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"There's a much quicker visual impact. You don't lose as much time away from your operational duties or from work. The decreased pain is what really sells it. The reason it's less painful is because when we make that cut, those nerve endings are less disturbed. It's a little like having a paper cut. It takes about four hours for your eye to seal that cut edge," said Pasternak.

Gray said that just about everyone who has been eligible for PRK is eligible for IntraLase LASIK.

"Sailors can go see their local optometrist and get an eye exam. Then they can receive a refractory surgery consult which will get faxed to us or any of the other laser vision centers. Then, depending on their priority, they are seen. If they are a high priority, we get them in as soon as we can," said Gray.

As with any surgery there are some risks associated with IntraLase. The main one being that wrinkles can develop on the flap when it's healing back onto the eye or inflammation can occur under the flap, creating ridges or bumps.