Project Summary/Abstract
Physical Sciences Inc (PSI), in collaboration with Joslin Diabetes Center (JDC), proposes to enable
objective characterization of the photoreceptor response to light and thus quantification of differences between
normal and diseased eyes by adding controlled light stimulus capabilities to an existing high-resolution retinal
imaging platform and validating it on a group of volunteers at JDC. We aim to demonstrate the ability to induce
and measure vessel diameter changes and to induce and measure reflectivity, transmission, and length
changes in cone photoreceptors with the purpose of developing robust biomarkers for diabetic retinopathy
(DR). Functional testing of retinal circuitry can provide an unbiased evaluation of one’s vision and enable
early detection of retinal diseases and monitoring treatment results.
PSI has been developing and offering multiple types of commercial high-resolution retinal imagers for
more than fifteen years and is well known as one of the leaders in the field. Based on this experience, we
propose to develop and implement light flicker stimulus capabilities in our multichannel adaptive optics retinal
imaging (MAORI-X5) platform to objectively test retinal function. MAORI-X5 combines AO-assisted optical
coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) in one instrument and provides in
vivo cellular-level resolution imaging of retinal microstuctures. There is no commercially available SLO or
OCT system with light flicker capabilities. We propose to fill in this gap and enhance the capabilities of our
retinal imaging platform by implementing two types of light flicker: local, cone-level illumination for testing the
health and function of photoreceptors, and large area illumination for testing neurovascular coupling. Both
types of measurements will reveal the effects of light stimulation with cellular-level resolution. Adding stimulus
capabilities to MAORI-X5 enables investigations of neurovascular coupling and functional assessment of
retinal photoreceptors on a commercially available platform. We will validate the ability of the technique to
measure cellular level effects in Phase I as a proof-of-principle demonstration on a very limited cohort of ten
volunteers in collaboration with our clinical partner, Dr. Jennifer Sun, at JDC. A more extensive study will be
proposed to quantify these effects and demonstrate clinical usefulness in a subsequent Phase II.
PSI prior experience developing advanced ophthalmic imaging systems gives us a competitive advantage
in developing the proposed functionality. A successful completion of the Phase I and a subsequent Phase II
development will provide clinicians with a high-performance retinal imaging platform for functional imaging.
Early adaptors of this technology within the research community will grow our understanding of vision and
its disruption by DR, and will enable the investigation of the effects of new drugs and therapies. PSI, the only
company worldwide offering commercially AO-SLO-OCT instruments, proposes to develop the next generation
of retinal imaging research instruments as a reliable tool to quantify clinically the effects of DR on vision.
