In vivo functional retinal optical coherence tomography.

An experimental design for noninvasive assessment of neural retinal tissue function with enhanced sensitivity is presented. By matching the response detection to a defined flicker frequency stimulus similar to heterodyne detection, the response signal will be shifted out of the low-frequency noise and the specificity of response detection will be strongly enhanced. Optimal measurement parameters are discussed, such as the function and timing of the response function to a single flash stimulus. The results indicate responses on the order of 200 ms that have been probed with our frequency-encoded approach using 5 Hz flickering. Preliminary results indicate the feasibility of our measurement concept to assess small changes in reflectivity with enhanced sensitivity. A functional tomogram for response localization and quantification is introduced.