September 1, 2008

Prosthetic lens a sight saver for Iraq vets

Robert Henline, a 36-year-old Army staff sergeant serving in Iraq, was riding with four other soldiers when their truck was hit by a roadside bomb. The San Antonio, Texas, resident was the only survivor of the April 2007 attack, but he sustained severe burns over 38 percent of his body, primarily his face, head, and left arm.

One eyelid was badly damaged, and over time his other eyelid wouldn't close because it was pulled open by healing skin grafts, leaving his hazel eyes exposed to the elements and painfully dry.

For a year, he wore goggles and smeared his eyes with ointment and drops.

"It was like driving in the rain without wipers," he said.

Then he tried a "liquid bandage" developed by a Boston researcher, which had been used for several years on patients with diseased or damaged corneas, but not on combat victims. The results were dramatic.

"I saw 20/15 right off the bat," he said in a recent interview.

Successes like Henline's have led the Army to begin using the device, which resembles a large contact lens, more widely. Ophthalmologist Dr. Perry Rosenthal of Needham, who invented the lens, trained an Army optometrist to fit it at a clinic at Brooke Army Medical Center in San Antonio.

Called the Boston Ocular Surface Prosthesis, the lens rests on the white of the eye and forms a dome over the cornea - the transparent, curved structure at the front of the eye that is instrumental in focusing light and has the richest nerve supply in the body. The space between the cornea and the lens is filled with artificial tears that bathe the eye and allow the cornea to heal somewhat.

"For soldiers who have lost their eyelids in incinerating roadside explosions, our device is often the only option for saving their eyes," Rosenthal said. The device also has been used to preserve and restore vision in soldiers with corneal injuries.

To function properly, the cornea must be perfectly smooth and hydrated. When eyes dry out, irregularities, called ulcers, can form on the surface of the ultra-sensitive cornea, damaging vision - sometimes to the point of legal blindness. For patients with eyelids, each blink can feel like sandpaper rubbing on the eye.

"Without a proper ocular surface, the cornea would melt," said Dr. Ernest Kornmehl, a Wellesley ophthalmologist and spokesperson for the American Academy of Ophthalmology. "This lens allows the [eye's] globe to stay intact."

Army doctors had tried to preserve the vision of soldiers such as Henline by frequently hydrating the eyes with ointment and lubricating drops and even performing tissue transplants, Rosenthal said.

"I had some soldiers who had severe burns in and around their eyes and weren't responding to standard therapy, and we'd exhausted all options," said Army lieutenant colonel Dr. Anthony Johnson, associate program director at Brooke. Johnson contacted another cornea specialist, who suggested Rosenthal's lens, which had been used on about 2,000 patients over the previous four years. Johnson flew Rosenthal to Texas.

Rosenthal's first patient, a soldier who was unconscious, had ulcerated corneas.

"I put the lenses on one day and went back the next, and the corneas had healed strikingly," Rosenthal said.

Since Rosenthal's visit, 17 more soldiers have been fitted with lenses. The Army's on-site clinic is fitting an average of two patients each week.

Rosenthal and his team custom-fit the lenses at the Boston Foundation for Sight, a Needham-based nonprofit research and treatment facility for corneal disease that Rosenthal founded. The foundation uses its 2,000-lens sample library for custom fitting, and fabricates each lens with a precision lathe.

For his trip to the Army medical base, Rosenthal developed a universal lens that doesn't require custom fitting. At the Army's request, he and his team are designing an improved universal lens for facial burn victims in military and civilian burn centers.

The foundation is also exploring collaboration with a start-up in Cambridge to develop a lens surface that kills bacteria, allowing it to stay in permanently. Now, Henline and other recipients have to take their lenses out every night to disinfect them.

Henline uses a lens just in his right eye. Eventually he'll wear a lens in his left, which has no lid and is bandaged, and additional plastic surgery aims to eliminate his need for a lens in his right eye.

Recovery from all his wounds is a long process " 'some day' is my motto," he said. So having his vision restored instantly with the lens was momentous.

"I was ecstatic," he recalled.

After trying the universal lens during Rosenthal's initial trip, Henline was custom-fitted at the foundation's Needham facility. "I was so happy and wanted to go watch something. I got to watch the Bruins play."

They lost, but seeing the action was a big win for Henline.