Depth-multiplexing spectral domain OCT for full eye length imaging with a single modulation unit

Abstract: Measuring the axial length of the eye is emerging as a crucial approach to measure progression and monitor management of myopia. The high cost of current swept-source OCT devices, the preferred method for such measurements, limits their broad use, especially in lower-income communities.While spectral domain (SD) OCT is a more affordable option, its limited imaging range falls short for full eye length measurement. Existing depth-multiplexing (DM) techniques for SD-OCT provide a workaround by capturing images at multiple depths within the eye. However, these methods typically require multiple light modulation units or detectors for simultaneous imaging across depths, adding complexity and cost. In response, we propose a novel DM-SD-OCT approach that utilizes a single light modulation unit for depth encoding. This innovative method facilitates the capture of images at multiple depths within the eye using a single line scan camera, with subsequent computational demixing. Our implementation of this system successfully enabled simultaneous acquisition and demixing of signals from three distinct depths within the eye. The system's effectiveness was demonstrated using a model eye, confirming its potential as a cost-effective solution for comprehensive eye length measurement in clinical myopia research.