MCRD PARRIS ISLAND, S.C. -- The Department of the Navy began a study 10 years ago with a - then experimental - eye surgery to correct refractive error. The experimental program employed SEAL team members who were dependent on glasses and thus, less operationally sound.
By 1995, the procedures, Laser-Assisted In-Situ Keratomileusis and photorefractive keratectomy, better known by their acronyms LASIK and PRK, became mainstream as civilians dependent on glasses flocked to their ophthalmologists to lose the lenses.
Back on the SEAL teams, the guinea pig sailors showed better reaction times with less hesitation according to Navy Capt. Steven Schallhorn, who performed the surgeries at Naval Center San Diego in 1993.
They were less worried about losing their glasses or having contact lenses floating or flying away, and the special gas mask inserts were no longer needed, meaning better peripheral vision for the special operations forces, all because they no longer depended on glasses to have perfect, or near-perfect vision.
Refractive surgery methods
Lasers are used to reshape the cornea - the clear covering on the front of the eye - in LASIK, according to Schallhorn, who is now head of ophthalmology at National Naval Medical Center, Bethesda, Md.
The surgeon cuts the flap in the cornea, leaving a hinge at one end.
The flap is pulled out of the way, then a laser reshapes the exposed corneal tissue and the flap is put back and left to heal.
The procedure takes about one minute. Typically, the patient has 20/20 vision within the hour.
The are comfortable and do well straightaway.
They comfort level isn't the same with PRK, the method used in the Navy SEAL study.
There's no flap cutting, so the laser ablates the tissue on the surface of the cornea, which feels like a corneal abrasion, according to Schallhorn.
Consequently, PRK patients must wear bandage contact lenses for about four days. Improved vision comes more slowly. As the epithelium heals, vision gets better and the discomfort goes away. In all, the discomfort and vision defects are gone within two to three days.
Refracting results
Military results for the surgery are actually better than out in the civilian world because of the selection process.
"This is one of the safer surgeries you can have when you've been properly screened," said Lt. Michael Sunman, Optometry Department head for Beaufort Naval Hospital. The risk factor of negative results is about one tenth of one percent. Risks are much the same as any other minor eye surgery - improper healing, infection, halos, and increases in contrast.
"With the military, PRK is the preferred method of surgery. Though LASIK has less discomfort involved," said Sunman, "It is not the preferred method of surgery. There are no long term studies of the healing of the flap."
The problem comes with the increase in pressure variances with pilots, divers and submariners. Though no problems have surfaced with LASIK patients, PRK provides the same results without risking the integrity of the eye.
"Out in the real world, there aren't any problems," explained Sunman. "There aren't any real tests of the limits either."
Who can have it
Current policy states any active duty person can apply for the procedure. Surgeries are done through the Warfighter's Program, which makes the procedure a readiness issue, therefore, those who can benefit the most, will come first.
PRK and LASIK are best used for nearsighted people, but they also work for farsightedness and astigmatism, but they don't work for cataracts or diseased retinas.
What to do
For any active duty service member interested in the surgery, start with a trip to optometry to talk to the optometrists.
"We follow the BUMED guidelines, which says we need to have two eye exams, one year apart to show stability," said Sunman. The eye exams must show that vision is stable enough to correct. Applicants must be 21 and there are other screening factors to consider before surgery.
When a service member applies for the surgery, their names go into a database, according to Capt. Hubert Jamison, Depot optometrist. "There is a long waiting list," he said. "And there are no guarantees of being selected."