Study: remote screening can help detect diabetic eye disease

Philadelphia-An Internet-based screening approach performs well in identifying patients with treatable diabetic eye disease, according to a study in Optometry and Vision Science.

Using digital photographs of the eye taken at the doctor's office or clinic, eyecare practitioners can reliably detect hard exudates-a key early sign of diabetes-related macular edema, reports the new research by Jorge A. Cuadros, OD, PhD, of UC Berkeley School of Optometry, and colleagues.

The researchers evaluated the use of the EyePACS tele-ophthalmology system to detect edema resulting from leaky blood vessels in the retina at the back of the eye.

"Edema that is detected close to the line of sight can and should be treated to slow or avoid any loss of vision," says Dr. Adams. "However, about one-third of all people with diabetes don't realize they have diabetes, and about 20% of those with recently diagnosed already have some changes in the blood vessels at the back of the eye."

In EyePACS and similar remote screening programs, primary-care doctors or nurses take digital photographs of the eye, which are then sent for remote viewing and diagnosis by an optometrist or ophthalmologist.

One sign these specialists look for is small, yellow, hard exudates-an indicator of current or very recent edema. In their study, Dr. Cuadros and coauthors sought to determine whether hard exudates in clinic photographs are an accurate indicator of clinically significant macular edema in patients with diabetes.

The study included 103 adults with type 2 diabetes, seen at a public health clinic, who were considered at high risk for macular edema. The photos were sent for review by eyecare specialists, who looked for hard exudates close to the line of sight as an indicator of clinically significant macular edema.

Within a few months, patients returned to the clinic for specialist examination, including dilation of the pupil and stereo views of the interior of the eye-the standard test for diabetic eye disease. The dilated exams showed clinically significant macular edema in about 15% of patients.

Hard exudates detected on the digital photographs were an accurate indicator of macular edema.

"The presence of hard exudates allowed correct detection of actual edema close to 90% of the time," says Dr. Adams. "Just as important, the test was close to 80% accurate in correctly identifying when no edema was present." Thus the screening procedure had a sensitivity of 90% and specificity of 80%.

To prevent vision loss, it's important to identify and treat diabetic eye damage as early as possible. Remote screening tests have been developed to increase the number of diabetic patients screened for eye disease. That's especially important in groups without access to specialist vision care, like the public clinic patients evaluated in the new study. Dr. Cuadros is inventor of the EyePACS system, which is used to screen nearly 36,000 patients each year at the UC Berkeley School of Optometry Digital Health Clinic.

Although further research is needed, the new results show that that remote screening-and specifically the detection of hard exudates in nondilated eye photographs-can accurately identify patients with diabetic eye disease.

Dr. Cuadros and coauthors conclude, "Low-cost and reliable methods of detecting clinically significant macular edema, such as the use of a hard exudate surrogate marker described here, are needed to meet the challenge of widespread screening for this vision-threatening condition."