The Leading Cause of Blindness
Diabetes mellitus is the leading cause of blindness for the working age population in the developed world. The incidence of diabetes is increasing exponentially as our population ages and obesity rates continue to rise. In fact, as of 2010, 25.8 million Americans had diabetes. Among people older than 65 years, nearly 27% have diabetes. With the aging of the nearly 78 million Baby Boomers, the first of whom reached 65 in 2011, this presents a healthcare challenge. A substantial increase in the prevalence of diabetes in the coming decades can be anticipated.
The estimated lifetime risk of developing diabetes for an American born in 2000 is at least 40% for black persons and more than 50% for Hispanic women. With such a high prevalence, an increasing incidence of visually disabling disease can be expected.
Anecdotally, however, many clinicians working in systems that reward providers for better outcomes have seen a considerably reduced incidence of treatable retinopathy. Adherence to treatment, improved patient self-management, and use of evidence-based practices have undoubtedly reduced morbidity in diabetes and most likely reduced the incidence and severity of diabetic eye disease. Improved glycemic control can reduce the complications of diabetes, as illustrated in the Diabetes Control and Complications Trial. Conversely, eye care providers who work with new immigrants to the United States who have had little previous access to healthcare consistently report a much higher incidence of visually disabling disease from diabetes.
In the early 1970s, patients with diabetes were expected to be blind within 15-20 years of diagnosis. By 2010, it was acknowledged that for persons with diabetes who were able to maintain optimal glycemic control from the time of diagnosis, the rate of vision loss and longevity would differ little from that in people who do not have diabetes.
Teleretinal Imaging for Diabetic Eye Disease
Screening for retinal disease in patients with diabetes is still in many ways continuing the old paradigm. Patients spend time being evaluated in an eye doctor’s office. The visit requires that the patient endure the vision effects of the dilating eye drops and the restrictions that these impose over several hours. Furthermore, these examinations are expensive, and as the federal government takes a greater role in healthcare, it becomes a cost and coverage consideration.
The gold standard for screening for visually threatening diabetic eye disease has long been a dilated fundus examination by a licensed independent eye care provider (optometrist or ophthalmologist). Currently, about 20,000 ophthalmologists and 35,000 optometrists practice in the United States. With the standard for a diabetic retinal examination being every 1-2 years for each patient with diabetes (depending on the level of control), there are not enough eye care professionals to manage the burden of the roughly 26 million people with diabetes in the country. This is an important reason why patients with diabetes have historically often failed to achieve the annual Healthcare Effectiveness Data and Information Set (HEDIS) standard for retinal examinations in patients aged 18-75 years with diabetes.
Over the past 20 years, telemedicine programs have been developed to allow digital retinal photographs to be interpreted by an expert in a remote center. For the past 8 years, the Department of Veterans Affairs has deployed a care management pathway for patients with diabetes by working with multiple stakeholders to develop a program to screen for and assess risk for vision loss from this highly prevalent disease. More than 1 million patients have been screened to date, and although all of the data are not yet available, when segments of the population have been studied, results indicate that approximately 1% of patients have severe retinopathy.
Of greater importance, 75% of patients do not need immediate eye care. Therefore, patients who might present in subspecialty retina clinics can be deferred, clearing the schedule for those with diseases that require more immediate treatment.