Abstract
Purpose :
To demonstrate a novel, flexible multi-aperture approach to confocal, split-field and quad-field with an advanced multimodal AOSLO imaging platform in the inner retina using custom multi-aperture, multi-mode fiber cables. These cables distribute light falling on regions of the AOSLO focal plane to multiple detectors for simultaneous multi-offset image acquisition from forward scatterring inner retinal phase objects, such as nerve fiber, ganglion cell bodies, vascular structures, etc. Normal subjects and patients at collaborating sites are being imaged with PSI AOSLO platforms equipped with this new capability.
Methods :
We have modified the detection channel of an advanced multimodal AOSLO using custom fiber cables to distribute light to multiple detectors for simultaneous capture of spatially varying scattered light distribution from inner retinal phase objects. The fiber cables consist of a central confocal core (~1 or 2 Airy disk diameters) and an array of surrounding offset fibers. The selected pattern of fiber cores, offset displacements, offeset directions, and fiber diameters can be configured for enhancement of specific signatures associated with target structures' light scattering properties. Image processing allows combinations of sums and differences of images, as well as other combinations and statistical analyses, to yield novel imaging modalities customized for particular diagnostic enhancements.
Results :
Imaging with the multi-aperture AOSLO multi-core cable produce AOSLO images with greater, and nearly isotropic, sensitivity to small scale scattering and refractive/diffractive objects structures in the inner retina. Significant quality improvements in vascular wall imaging is made possible by simultaneous acquisition of orthogonal split-field pairs which reveal much more cellular detail without the ambiguity created by uniaxial (split-field) differencing. Examples of improved vascualar wall detail are shown in the first simltaneously acquired AOSLO indirect quad-field images yet obtained.
Conclusions :
This new approach and its natural expansion to a multiplicity of azimuthal and radial offsets create the potential for radically improved sensitivity and specificity for particular light scattering signatures of inner retinal phase objects of all kinds.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.