REDMOND, Wash., Dec. 1, 2003 — At inner-city clinics participating in a teleophthalmology program at Vanderbilt University in Nashville, Tenn., patients routinely show up for eye screenings only to find they are already in the advanced stages of diabetic retinopathy — the disease that damages retinal blood vessels in the eyes of many diabetic patients. Some have no idea they are diabetes sufferers.
Lawrence Merin recalls one such patient who came in off the street saying he did not feel well. After tests showed the man’s blood sugar was extremely high, staff at the clinic decided on the spot to check his retinas using digital-imaging equipment. The images showed the man had advanced diabetic retinopathy. He was quickly referred to an ophthalmologist, and received treatment that could potentially save his eyesight.
Tammy Scholes of Digital Healthcare Inc. takes a high-resolution digital image of Brian Stevens retina at the Leicester Royal Infirmary Screening Project in England.
For Merin, who is assistant professor of ophthalmology and director of ophthalmic imaging at Vanderbilt, no one should come that close to losing their eyesight through failure to obtain readily available care.
“Over and over again, healthcare problems are more effectively treated if they’re caught early,”
“Diabetic retinopathy is one of the ailments in which the outcome is remarkably better. Often, 20-20 vision can be preserved, provided that we identify and treat the retinal lesions before they become symptomatic.”
Eyesight is not the only health issue at stake. According to new findings reported recently in the Archives of Internal Medicine, diabetic retinopathy also predicts the risk of needing to have a foot or leg amputated. And, Merin says, lesions in the retina are predictive of possible stroke or heart attack.
Now, Vanderbilt is poised to become the first institution in the world to deploy new diabetic retinopathy screening software developed in Cambridge, England by Digital Healthcare Inc., and built on the Microsoft platform. The solution is being made available to Vanderbilt by the medical systems division of Canon U.S.A. — a leading manufacturer of instruments to photograph the retina. The use of Microsoft .NET technologies will enable application developers at customers like Vanderbilt to rapidly develop advance medical imaging techniques and solutions on site, Microsoft officials say.
About 16 million Americans actually suffer from Type-2 Diabetes, but up to 60 million are at risk through their lifestyle, experts say. Diabetic retinopathy is the leading cause of blindness for adult diabetics, with about 75 people losing their eyesight to the disease each day. Yet the onset of the disease is relatively simple to identify, and experts say it can be effectively treated if diabetic patients receive annual retinal screenings. Nationwide, about half of known diabetics receive screening care, but screening rates in many urban and rural areas are much lower — in part because of disparities in access to care, Merin says.
The two-year-old teleophthalmology program at Vanderbilt represents an innovative effort to improve screening rates by taking digital-imaging technology out into the community. The program Merin leads uses digital-imaging equipment at five inner-city clinics in central Tennessee to capture retinal images, which are then transmitted to ophthalmology specialists at the Vanderbilt Ophthalmic Imaging Center. About 7,500 patients receive screening examinations each year under the program.
In one low-income clinic, the digital screening procedure increased the number of diabetic patients obtaining eye care by a factor of 15. In a participating Veterans Administration clinic, patients who previously had to wait six months for a screening examination are now screened on request.
Digital Healthcare CEO Gerry Skews says his company’s offering constitutes
“a completely new platform for medical imaging”
capable of bringing significant improvements to the field.
Because of the scalability they facilitate, Microsoft .NET technologies are especially suited to the kind of high-volume imaging and screening needed to keep up with the growing numbers of diabetes sufferers, he says.
Microsoft .NET is a set of software technologies for connecting information, people, systems, and devices. It enables a high level of software integration through the use of Web services — small, discrete, building-block applications that connect to each other as well as to other, larger applications over the Internet.
“It’s a technology that for the first time allows us to scale up, from managing a couple of thousand patients to managing tens of thousands of patients,”
“It gives us higher speed, agility and enormous flexibility in how we develop applications. What took us 14 developer years [using traditional programming] has taken us about three developer years [using .NET technologies] to replace with something better.”
For more than two years, Digital Healthcare has supplied large-scale, systematic medical imaging and screening applications to companies around the world, from New Zealand and Western Samoa to Europe and the United States. But development of those offerings relied on programming that was slower and less flexible.
The basic aim of the Digital Healthcare application is to split patients into two groups — those who need more treatment and those who do not. Once identified, patients are managed using a scalable, relational database that is designed around events in a workflow module, also known as the care pathway. Key elements in the care pathway include patient call and recall, managing screening episodes, data transmission, digital triaging, and primary and secondary grading.
The care pathway database — essentially a software implementation of an engineering procedure known as a state machine — is used to manage a very large number of patients who are moving at different times via various
through the process. Typical states for a patient may be
“waiting for appointment,” “appointment booked,” “awaiting screening episode,” “primary grading, outcome,” “referral”
As events occur in the patient’s care journey, the patient is advanced from state to state. Patients’ progress through the system can be tracked and audited accurately and instantly. The database automatically instigates business logic at the appropriate time, such as a letter-writing module that generates and prints letters to the patient. It also automatically manages patient nonattendance — for example, by generating a flagging letter — and other compliance issues. In addition, it can be used to trigger reports, electronic or paper communications and, perhaps, education or care-plan amendments.
The system that defines and manages the patients through the care pathway is independent of the particular care journey, and of the operations carried out during that journey. That means the system can be integrated with different methods of scheduling clinics, generating recall letters and so on, while maintaining a single audit trail. It also means that the patient cannot be lost in the gaps between systems, Skews says.
He says the building of the care pathway on top of the medical imaging platform represents a unique contribution to the field, and can cut the time spent on moving a patient from one state to another from 20 minutes to about 20 seconds.
“Nobody has ever applied care-pathway management to high-throughput screening,”
“All the analysis is done in the system. The efficiency is tremendous because you’re not calling the patient in (needlessly).”
Skews says the solution would not have been possible without .NET technologies, which are at the heart of the solution’s modular nature and high potential for customization.
John Noakes, .NET adviser at Microsoft Ltd. in the U.K., which worked closely with Digital Healthcare during development of the solution, notes the importance of support for industry standards in .NET technologies.
“One of the key reasons for the rapid application development enabled by the solution is the ability of the .NET software to utilize, expose, consume and transfer medical and imaging data and information using industry standards such as XML,”
Noakes says. XML, or Extensible Markup Language, facilitates communication among like-minded computers by defining data elements in Web pages and business-to-business documents.
The potential medical applications of the solution are many.
“The same technology holds good for a mammography sample, or colonoscopy and any type of disease that needs to be tracked,”
From an information-sharing point of view, the solution represents a match made in heaven, Merin says.
“As there are a variety of electronic formats being developed, .NET technologies allow us to integrate the different formats more easily than what we have now,”
“Ultimately, the objective is not just to get the information, but to share it with the physicians.”
The solution uses a Canon CR6 45NM fundus camera — a standard workhorse for retinal screening that does not require patients to use special eye drops to dilate the pupil. Canon was the first company to commercialize this type of camera in 1976.
“If you want to screen many people in a short time, there’s not enough time to dilate the pupil,”
says Toru Yoneyama, senior manager of the Irvine, Calif.-based medical systems division of Canon U.S.A.
“Plus, people prefer not to have their pupils dilated because they may have to drive or go back to work.”
The Canon camera takes digital pictures of each retina. The digital images are then transmitted to a laptop computer attached to the camera. They can be displayed onscreen, then electronically stored on the laptop and transmitted at the click of a mouse via a high-speed Internet connection. Atlanta-based BellSouth Corp. provides the DSL lines, creating virtual private network links to a server at Vanderbilt.
“This whole program is designed to raise the national awareness of diabetes and how it can affect vision,”
“Diabetes is a serious health issue, and it is hoped that deteriorated vision from diabetes can be better managed, if not avoided, with early detection.”