Winter 1996
High-tech ophthalmology beams across South Texas By Will Sansom
An exciting new tool is identifying Laredo area residents who are at greatest risk for the blinding eye disease diabetic retinopathy. The tool, in pilot use, is a remote imaging system for looking at the retina, the light-sensing nerve layer in the back of the eye. It is the part of the eye that sends the brain signals determining what we see. The imaging system, provided by a grant to the Health Science Center's department of ophthalmology, is capable of capturing pictures of the retina and transmitting them electronically anywhere in the world — wherever a retina specialist is on hand to review the images. The goal of the project is to provide Laredo area residents with expedient exam and imaging results and to get the persons at risk of diabetic retinopathy into the offices of eye doctors in that Texas-Mexico border city.
"With this imaging system available on site, a technician can take pictures of the retina, digitize them on computer and send them by high-speed modem line to our reading center in the department of ophthalmology in San Antonio," said W.A.J. van Heuven, MD, professor and chairman of ophthalmology at the Health Science Center.
The system is placed aboard a mobile eye screening unit operated by the region's Lions Clubs and also sponsored by the H-E-B Grocery Company. A patient first receives a general eye screening, including a visual acuity test and an eye pressure test considered to be an indicator of glaucoma. If potential problems are indicated, the patient is sent to the imaging room aboard the mobile unit.
The remote system's Canon 60UVI Fundus Camera captures a color image of the back of the eye. The image is digitized and sent by modem to the Health Science Center's Robert F. McDermott Clinical Science Building. After a review in the retina division, headed by Bailey Lee, MD, the results are reported back to the mobile unit, where the patient receives on-the-spot counseling regarding treatment.
"Film and processing time involved with photography are eliminated," said Robert Hobson, South Texas diabetes program coordinator for the ophthalmology department. "Instead of the conventional two weeks or longer report time, both patient and technician can view images of changes in the eye in a matter of minutes. And since the patient is in the mobile unit when results come back from the retina specialist, no time is lost trying to contact the patient later. He has seen what the problem is and heard a specialist's opinion on what to expect in the future. This increases the likelihood that the individual will take steps to go to an eye doctor."Laredo, a town of 150,000, is the first pilot site selected by the department of ophthalmology for tests of the new system. "Recently the mobile unit spent four days at the Gateway Health Center in Laredo, where 249 patients received general screenings," Hobson said. "Most were diabetics. Of the 249, more than a third failed a visual acuity test. A significant number, 13, failed a glaucoma (eye pressure) test. Based on these factors, we selected the people who most needed the remote imaging."
Diabetes mellitus, a disorder of the body's ability to use and store sugar, causes many major complications. One of these is diabetic retinopathy, a progressive deterioration of the blood vessels feeding the retina. If left untreated, this condition can result in blindness. Blood vessels damaged by diabetic retinopathy may leak fluid or blood and also may develop other new blood vessels, which leak even more. This leaking and bleeding interferes with the visual function of the retina. The condition occurs frequently in juvenile diabetics and is the leading cause of new blindness among U.S. adults.
The longer a person has diabetes, the greater the risk.
"About 80 percent of the people with at least a 15-year history of diabetes have some blood vessel damage to their retina," according to Diabetes 2000, an education program of the American Academy of Ophthalmology. The 80 individuals who failed the vision test during the Laredo screenings were urged to see an eye doctor. Many referrals were set up immediately. "Very few of these people normally have contact with doctors, which is significant," Hobson said. "If 80 failed the test and only 30 of them have doctors, they're not getting the care they need, either for diabetic retinopathy or the underlying disease. Maybe they can't afford an eye doctor or they don't know that diabetes can cause eye deterioration. Education is an important component of this project."
Diabetes is a major problem in the heavily Hispanic border regions of Texas, including Laredo. Epidemiological studies have indicated that the rate of diabetes incidence among Hispanics is two to three times that of non-Hispanic whites.
"Regarding outreach, this remote imaging system could be the greatest tool ever," said Alfredo Treviño Jr., MD, one of five practicing ophthalmologists in Laredo. "Essentially, we're talking about an ophthalmologist looking after a patient even before the patient has been to an office. The whole essence of diabetes eye care is to follow patients for retinal changes. If the ophthalmologists here in Laredo could have pictures on hand of every diabetic's retina, we could prevent a lot of blindness.
"Most of the treatment for diabetes is preventive," he said. "Once a person is having symptoms, we're behind the eight ball. At that point, eye care services don't help as much and are very expensive."
"The remote imaging system is a highly cost-effective method of detecting eye disease and ultimately preventing blindness in diabetics," Dr. van Heuven said. "It costs the taxpayers an estimated $25,000 a year to support an individual who loses his or her sight due to diabetic eye disease. On the other hand, treatment in the form of early laser surgery can cost less than $2,000 per individual and often maintains his vision and quality of life. The patient who doesn't lose his sight can still work in most cases and is not dependent on the state. Medical costs are reduced in the long run. We would like to ask the state to support treatment of diabetic retinopathy while it is still treatable, and the remote imaging system is one way to find early cases that need this treatment."One of Dr. Treviño's patients is lifetime Laredo resident Maria Bolaños. A 69-year-old widow and retired restaurant worker, she recently visited the Lions mobile unit at the Gateway Center. Unlike many others in line to be examined, she had received previous treatment for her eye problems, including laser surgery in one eye. Mrs. Bolaños takes an insulin injection every day for diabetes and previously was diagnosed as at risk for diabetic retinopathy.
Yet, she had not been to Dr. Treviño for more than a year and decided to take advantage of the Lions mobile unit visit. She was understandably worried about blurred vision she was experiencing. "They examined me really well and I was very happy," she said in Spanish. "The doctor said I'm delicate, that I'm losing my eyesight little by little."
Dr. Treviño, however, held out hope that something can be done. "We can retreat her retinopathy with laser to 'dry up' the sensitive macular area," he said. The macula retinae is an irregular yellowish depression on the retina.
"Mrs. Bolaños is in the pipeline, but so many other people like her in our area are not receiving any eye care," Dr. Treviño said. "By identifying them, we can have more outreach. We can treat diabetic retinopathy and other conditions if we are aware of the people who need treatment." The retinal imager also can be used to detect glaucoma, a group of eye diseases characterized by an increase in intraocular pressure, causing blurred vision, loss of vision and in some cases, blindness.
"See your doctor soon" or "OK as tested," states the Lions mobile unit evaluation form handed to patients following their exam. This form is a reminder that the retinal imaging and other eye tests are but the first step in a needed regimen of eye care.
And how badly is care needed? It's estimated that a million Texas citizens are diabetic but don't know it. One survey indicated that a fourth to a half of all persons at high risk for diabetic retinopathy are not receiving sight-saving care. People with untreated diabetes are as much as 25 times more prone to blindness than the general population, but improved diagnostic and treatment procedures are available to prevent serious vision problems. Only a small percentage need lose their vision, doctors say. "But the key is, those who would benefit must be identified," Hobson said.
A remote imaging system in a traveling eye screening unit is definitely part of the answer.
