Abstract
Purpose: :
Optical coherence tomography (OCT) has revolutionized diagnostic retinal imaging but thus far has been limited primarily to the clinic setting. We have recently developed a microscope-mounted OCT (MMOCT) system to enable real time intra-surgical retinal imaging. The purpose of this study is to investigate the utility of this system for real time imaging of the retina during surgical manipulations.
Methods: :
A custom MMOCT scanner was constructed which mounts onto a Leica surgical microscope and interfaces optically and mechanically with an Oculus Binocular Indirect Ophthalmo Microscope (BIOM). We tested various instruments of different material compositions, compared different OCT scanning modalities, and developed hardware modifications in order to optimize real time retinal imaging during vitreoretinal surgical procedures in model eyes.
Results: :
MMOCT enables real time, non-contact cross-sectional imaging of retinal structures during surgical manipulations. Shadowing from surgical instrumentation, particularly metallic instruments, limits visualization of underlying retinal structures but can be improved by use of instruments composed of moderately reflective material such as silicone. Images can be visualized as summed voxel projections, which provide detailed spatial information but require cumbersome processing which limits their utility in real time imaging. Images can also be visualized as individual B-scans, which can be easily viewed in real time but provide limited three-dimensional information.
Conclusions: :
MMOCT may be useful for real time, cross-sectional retinal imaging during surgical manipulations. Further refinement of instrumentation, hardware, and software will likely be important in improving imaging quality, resolution, and speed. Future work will focus on optimizing MMOCT for the surgeon, particularly on identifying feedback that is relevant to the surgeon and on developing an integrated display to provide seamless real time imaging during surgical manipulations.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • vitreoretinal surgery • vitreoretinal surgery