Earlier detection of a complication of diabetes is now possible with a new optical technology. The new technology is a 78-gram device that attaches to eyeglasses. It features both IR LEDs and a CCD camera, and was designed to be worn for about 30 minutes during physicians’ appointments. During that time, it can monitor the patient’s pupils to detect the earliest signs of diabetic autonomic neuropathy. A prototype pupillometer designed to test for diabetic autonomic neuropathy in patients with diabetes. Courtesy of Mang Ou-Yang/National Chiao-Tung University. The new pupillometer emits four colored lights to stimulate the pupil, the researchers said. A beamsplitter attached to the device then filters the visible light that is reflected from the eye to the device’s camera. The images are processed to allow analysis of numerous parameters, including the pupil’s diameter and response time. The device was developed by a team from the National Taiwan University Hospital and National Chiao-Tung University. Diabetic autonomic neuropathy progressively affects the nerves that control vital organs, including the heart and gastrointestinal system. It can lead to problems such as fainting, incontinence, nausea and heart arrhythmias, as well as an increased risk of bacterial infection. The complication is common among those with both Type 1 and Type 2 diabetes. The original experimental setup of the pupillometer. On the right is an eye model, and on the left is the pupillometer device. Courtesy of Applied Optics. Current techniques often do not detect the condition until there is moderate nerve damage and organ dysfunction. At present, detection methods rely on observing changes in digestive speed, heart rate and blood pressure over time, which limits early diagnosis. “Compared to the existing diagnostic techniques, the pupillometer is a more reliable, effective, portable and inexpensive solution,” said lead researcher Mang Ou-Yang of National Chiao-Tung University. He noted that pupils are useful in detecting diabetic autonomic neuropathy because of the neurological conditions that are caused by diabetes. The eyes and pupil are dually innervated, receiving signals from both the parasympathetic and sympathetic divisions of the autonomic nervous system. These divisions control the pupil’s circular and radial muscles, respectively. While clinical trials with the pupillometer are ongoing, Ou-Yang said future work will include scaling down the device size, as well as expanding its capabilities to observe two pupils simultaneously. The research was published in Applied Optics (doi: 10.1364/AO.53.000H27). For more information, visit www.ntuh.gov.tw.