Abstract
Purpose: :
To demonstrate the feasibility of integrating adaptive optics (AO) into a line scanning ophthalmoscope (LSO), and to facilitate moving adaptive optics imaging more quickly into routine clinical use.
Methods: :
The first bench-top AO-LSO instrument was assembled with significant advantages in size, complexity, and cost relative to current research AOSLOs. The AO-LSO produced high resolution retinal images with only one moving part, significantly reduced instrument footprint, and a smaller number of optical components. The AO-LSO retains a moderate field of view (5.5 deg), which allows montages of the macula or other targets to be obtained more quickly and efficiently. Acquisition software was developed to control and synchronize all instrument hardware, including the deformable mirror (DM), Hartmann-Shack wavefront sensor (HS-WS), galvanometer, and linear detector. In addition, we developed analysis software for automated registration and averaging, cone counting, and generation of montages.
Results: :
In preliminary human subjects testing, we characterized imaging performance in healthy eyes of 10 volunteers. We have demonstrated significant improvement in lateral resolution and depth sectioning with adaptive optics: photoreceptors could be resolved and counted within ~0.5 mm of the fovea; photoreceptor counts matched closely to previously reported histology; the capillaries surrounding the foveal avascular zone could be resolved, as well as cells flowing within them; individual 15-20 µm diameter nerve fiber bundles could be resolved, especially near the optic nerve head, as well as structures in the lamina cribrosa. We were able to rapidly acquire and stitch retinal images to map the photoreceptor mosaic across the entire macula (~15 deg.).
Conclusions: :
The prototype AO-LSO is an effective new retinal imaging tool providing many of the benefits of AO imaging, and a number of unique features, in a much simplified configuration. By making high-resolution ocular imaging more accessible, the AO-LSO instrument will facilitate the translation of adaptive optics technology to a growing number of clinics and laboratories. These researchers will, in turn, use this tool to increase our understanding of vision, eye disease and new drugs and therapies.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • photoreceptors