Pediatric Retinal Lab

Le Bonheur, UT Developing Pediatric Retinal Laboratory*

With the financial backing of the Mid-South Lions Club, the University of Tennessee, Memphis Department of Ophthalmology and Le Bonheur Children's Medical Center are collaborating to create a retinal electrophysiology center for the Mid-South. UT Memphis recruited ophthalmologist Alessandro Iannaccone, M.D. from the University of Pennsylvania to help create the lab and to become director of the Center for Visual Electrophysiology.

The Lions Club donated more than $42,000 to the project, says Lions Executive Director Brad Baker.

Since arriving in Memphis in November, Iannaccone, who is a member of the International Society for Clinical Electrophysiology of Vision, has been working on plans for the center.

"Electrophysiology is actually one of the best ways to assess damage," says Iannaccone, adding that electrophysiology can detect subtle dysfunction that occurs before anatomical dysfunction becomes noticeable.

Ophthalmologist Barrett Haik, M.D., chair of the Department of Ophthalmology at UT Memphis, says the Mid-South has a definite need for this type of center, as the closest currently is located in St. Louis. The goal of the new electrophysiology center is to find defects early enough when they are reversible to alter treatments to protect a child's vision, says Haik.

Iannaccone says that the field of hereditary eye diseases probably will benefit the most from electrophysiology assessment of visual function. Hereditary eye diseases are often separated into two main categories: those that affect the optic nerve and those that affect the retina, such as retinitis pigmentosa, which is an X chromosome-linked genetic disease.

"There are children born with hereditary defects that will cause them to lose vision over a significant period of time," Haik says. "Being able to identify those children and properly prepare them for the future is very important, as well as to counsel them in terms of their risks of passing on diseases to the next generation and to monitor any new treatments that may be beneficial in halting these conditions."

Haik says that some drugs used for treatment of cancer have side effects that can compromise vision in some children, and electrophysiology can help predict this occurrence. Then doctors can alter the treatment that a child is receiving.

"That's exactly what we're hoping to do," Haik says. "We see patients who are going to receive certain types of radiation or chemotherapy for tumors that are in the eye and also for tumors that are around the eye. We'll be monitoring their retinal function before and after radiation and chemotherapy.

"It may be that we can't alter the treatment, because we have to protect the child's life first. On the other hand, we may find strategies that allow us to give medicine that can block that damage inside the eye itself" he says.

"You've got to make sure that there's a reasonable outcome that justifies" exposing a child to radiation, Haik says.

Working with children often poses problems for doctors hoping to obtain verbal responses from their patients. One of the most important reasons for developing a visual electrophysiology center for children is the fact that electrophysiology assessments do not require verbal cooperation on the part of the child.

"Most of the children we deal with are preverbal," says Haik. Electrophysiology assessments, unlike visual fields and eye charts, do not require a child to give an answer back to the doctor.

"It a very objective test that tells you what's functioning or what isn't, and the child doesn't have to tell you a word," Haik says.

Because a typical exam includes a test that requires putting an electrode on the eye, small children may not want to undergo testing. "We are going to have the potential also to do exams under anesthesia, so that is always an option" for a child who is unwilling or unable to cooperate or is anxious," says Iannaccone.

The center is under construction on the ground floor of Le Bonheur near the emergency department entrance on Adams. It will contain an office, a testing room, a waiting room and a recovery room. The center also will have a special adaptation room, which children will enter before undergoing testing.

"You want their retina to adapt a stable condition, and darkness is the most stable," Iannaccone says. Adaptation typically takes about 30 minutes.

"We have special electrodes that we use to record a signal," says Iannaccone. He says that one way is to use flashes of light, and the responses are monitored by the electrodes to be displayed on a computer screen.

"Electrophysiology itself isn't the end to everything, but it's a very important tool," Haik says. "It will guide either treatment of further molecular genetic testing that we're working on, and hopefully various treatments in the future, such as gene therapy."

* The article above originally appeared in the August 8, 1997 issue of Health Care News. It is reprinted with permission.