Measurement of Total Retinal Blood Flow in Patients With Diabetes and Healthy Subjects

The prevalence of diabetes and diabetes-associated complications is still increasing. Several major long-term complications of diabetes such as cardiovascular disease, chronic renal failure, diabetic retinopathy and others relate to the damage of blood vessels. Given that the eye provides the unique possibility in the human body to directly visualize blood vessels, much interest has been directed towards studying the ocular circulation. Although data of large epidemiological studies indicate that changes in retinal vessel caliber reflect other diabetes related factors, such as fasting glucose levels, there is still conflicting evidence on blood flow alterations in patients with diabetes. This is also related to the fact that up to now, methodological difficulties aggravate the assessment of blood flow changes in the retina in larger groups of patients. In the present study we propose to overcome this problem by using a technique called bi-directional Fourier Domain Doppler Optical Coherence Tomography (FDOCT), which we have developed in the recent years to measure retinal blood velocities. This technique allows for the non-invasive investigation of blood flow changes in human retina and will help us to better understand diabetes related vascular changes. The present study will use this technique to assess retinal blood flow changes in patients with diabetes and healthy subjects.