Compact telescope design for light scanning systems
Scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) are retinal imaging modalities commonly utilized in the clinic to diagnose retinal diseases. SLO is a confocal imaging technique similar to confocal microscopy that can acquire high contrast 2D en-face retinal images in real time. OCT is an interferometric imaging technique that allows for high resolution depth sectioning and has the capability of producing high-resolution 2D cross sectional images (B-scans) of the retina at and exceeding video rate. The combination of SLO and OCT has been shown to provide more comprehensive retinal imaging, which have previously implemented into a handheld system. However, this system was relatively heavy as a handheld dev ice. The main features that constrained the minimum size and weight of this system were: 1) bulky galvanometer and resonant scanners, 2) the separation of OCT and SLO scanners, and 3) the separation of OCT and SLO illumination and collection paths.
A new Duke technology, an ultra-compact SLO and spectral domain OCT handheld probe, weighing only 94 g which makes it possible for handheld purposes. This was possible due to the use of a single microelectromechanical systems (MEMS) scanner for both SLO and OCT, a custom compact optical design that utilizes a converging beam prior to the scanner, and a single fiber input for both SLO and OCT illumination and collection.
A portable, handheld SLO-OCT probe would be useful in acquiring motion-corrected OCT volumes in young children, as well as patients that are supine, under anesthesia, or otherwise unable to maintain the required posture and fixation.