If you're wondering about that defining moment when renowned ophthalmologist Henry Kaplan decided to enter the profession, you can stop right now.

There was no vision-impaired loved one he was determined to help. There was no impassioned mentor.

Instead, it was the thrill of research that drew Kaplan to the eye.

"In medical school I had very little interest in ophthalmology because we had hardly any exposure to it," he recounts. "I was actually going to be a heart surgeon."

Then along came the Vietnam War--and a letter from President Nixon telling Kaplan that he had "volunteered" for the Air ForceÑto change his plans. The consummate New Yorker soon found himself deep in the heart of Texas, serving at Sheppard Air Force Base in tiny Wichita Falls.

Despite the culture shock, it proved a fortuitous move. By the time Kaplan was winding up his tour of duty he had decided to concentrate in transplant surgery and been granted a National Institutes of Health fellowship to help him achieve that goal.

He was looking for someone to serve under and discovered that his top choiceÑRupert Billingham, a scientist considered by many to have co-founded the fields of reproductive immunology and immunologic privilegeÑhad just moved from Pennsylvania to the University of Texas Southwestern Medical School in Dallas, a mere 125 miles away.

Kaplan took that as a good sign and went to work for him.

When I first met Billingham, he asked what I was interested in studying," Kaplan recalls. "I told him I just wanted to learn how to be a scientist and to do research."

Billingham recently had read a report on an eye study by a group at Johns Hopkins University, but was skeptical about the results.

"He wanted to know if I would be interested in looking into it," Kaplan says. "I knew extremely little about the eye but I told him that I could learn."

And learn he did.

Kaplan says the research, done in collaboration with Wayne StrielineÑtoday one of occular-immunology's dominant figures--"was an extremely productive time." Their first article was published in Nature, which, Kaplan notes with a grin, "is a good way to start one's career."

Kaplan enjoyed the investigations so much that he decided to remain in ophthalmology and quickly became ensconced as leader in the field.

His reputation as an eminent researcher convinced U of L that Kaplan should fill the university's William H. and Blondina Evans Chair of Ophthalmology and Visual Sciences, a post funded in part by the state's Research Challenge Trust Fund (Bucks for Brains) and a donation from the late William, '21M, and Blondina Evans. In addition, Kaplan directs the Kentucky Lions Eye Center.

Research Drama

While his entry into ophthalmology might not be a story filled with dramatic impact, the research that Kaplan and his colleagues are conducting certainly is. Their work has the potential to improve a patient's diminished vision, even for the aging. Someday soon they might even be able to restore a blind person's sight.

There are a number of ways they are going about this. Two of the more exciting studies involve tissue transplantation and the development of an artificial eye.

Just before coming to U of L, Kaplan was at Washington University in St. Louis, immersed in the nation's only study examining the potential benefits of retinal pigment epithelium (RPE) transplantation. RPE dysfunction is believed to be the main cause of many debilitating diseases, including age-related macular degeneration (AMD).

AMD is the leading cause of legal blindness in people over 50 in the Western World. According to the AMD Alliance International, some form of AMD affects approximately 25 to 30 million people and if the current trend continues over the next 25 years that number is predicted to triple.

Dry AMD, its milder form, accounts for nearly 90 percent of all cases. The chance for severe sight loss is much greater from the wet form of AMD, however, which involves abnormal vessel growth beneath the retina. Seventy percent of those diagnosed with wet AMD are legally blind in two years.

In St. Louis, Kaplan and a colleague pioneered a new surgical procedure to remove the abnormal vessel complexes. The success rate was nearly 50 percent in patients (usually younger people) whose vessels resulted from histoplasmosis, but when they tried the same thing on AMD patients the results were nil.

"When we removed the AMD patients' abnormal vessel complex, we were also removing the retinal pigment epithelium," Kaplan explains. "The two were so closely intertwined it was impossible to remove one without the other.

"So the logical next step in AMD patients would be to remove the complex and then replace the RPE cells."

Many people could benefit from this, Kaplan adds. As a practicing physician, he finds this prospect particularly exciting.

"Generally AMD patients come to us with their vision already decreased to something like 20/80 or even 20/200. Although we can usually arrest the rapid progression of the disease [through techniques such as laser therapy and photodynamic therapy], we can't recover vision back to 20/25. Theoretically, transplanted tissue would help recover that lost vision," Kaplan says.

Today Kaplan's eye team is on the verge of initiating a new clinical trial involving RPE tissue transplantation in AMD patients. And he is optimistic about the possibilities.

"I think this has the potential within five years to be a part of our treatment for certain diseases of the retina," Kaplan predicts.

A Futuristic Eye

In yet another ongoing study Kaplan's researchers are working with colleagues in Speed Scientific School and at Harvard University and the Massachusetts Institute of Technology (MIT) to develop a retinal prosthesis. The device would be used in patients blinded by damaged rods and cones as a result of AMD or hereditary retinal degeneration conditions.

Co-investigator Robert Keynton, Speeds' acting director of bioengineering, says that the goal is to give them enough sight to recognize faces and be able to move about a room.

The prosthesis consists of a camera attached to glasses, a receiver/transmitter located in the eye's vitreous cavity, and a chip located beneath the retina where it is intended to physically and functionally replace the damaged rods and cones.

In patients who received early versions of the prosthesis, the chip was implanted on the retina's surface rather than behind it. The researchers hope that the new approach will prove more successful at reconnecting the neural circuit.

Only four research groups in the world are working on a retinal prosthesis, the researchers say. U of L was invited to join the ongoing Harvard and MIT study due to its technology and biomedical research strengths. The U of L team will begin model testing soon.

Either of these studies has the potential to make a major impact on eye care and add greatly to the Kentucky Lions Eye Center's research reputation, Kaplan notes. That's right on target with where he wants to take the center.

Under the previous directorship of Drs. Thom Zimmerman and Chris Paterson, the center became well recognized for basic research science excellence, Kaplan says.

"We're augmenting that with immunology and AMD studies and, in addition, attempting to enhance its clinical presence and provide training for very talented physicians."

The ultimate goal is one that neatly wraps up Kaplan's multiple interests as a physician, researcher and teacherÑand matches the university's commitment to enhancing its community, too.

Simply put, Kaplan says, "We aim to bring the most contemporary medical and surgical eye care to patients in the area and throughout Kentucky."