The evaluation of retinal hemodynamics is an import diagnostic subject and has been one of the most difficult challenges in ophthalmology. The retina provides direct optical access to both the central nervous system and afferent and efferent central nervous system vasculature. This unique feature has provided generations of ophthalmologists with the ability to evaluate multi-system diseases without invasive diagnostic testing, using direct and indirect ophthalmoscopy, and slit lamp biomicroscope examination. These techniques, however, cannot directly quantify retinal blood velocity, nor do they detect preclinical alterations predictive of eventual significant morbidity. The trend toward preventive medicine prescribes a more sensitive technique to reliably quantify subtle changes in retinal hemodynamics. The main objective of this Phase II project is to test the feasibility of the proposed imaging technique for the measurement of human retinal velocities.
Specific aims of Phase II include (1) to develop an advanced prototype, (2) to improve algorithms, (3) to conduct clinical research, (4) to investigate accuracy and utility, and (5) to examine commercial application issues. The proposed imaging method employs spatial averaging of the dynamic events, only one image is needed for blood velocity calculations. It allows acquiring of full-field retinal images in near realtime. The short exposure time reduces the effects of motion artifacts. This new technology has the potential to improve ocular management of patients. The speckle imager can be incorporated in a fundus camera at a fraction of the cost of a laser Doppler device. A noninvasive, realtime retinal imager allows the physicians to record and keep track of patients' retinal hemodynamics to detect early signs of ocular disorders.
