# Investigating fundamental properties and clinical applications of the optoretinogram

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA AT DAVIS · 2023 · $390,511

## Abstract

Abstract
This grant will investigate the optoretinogram (ORG)–an experimental, all optical assay of human photoreceptor
function–and its potential to reveal dysfunction at the cellular level. The ORG is based on adaptive optics optical
coherence tomography (AO­OCT), which is the only existing way to produce 3D images of the living human retina
with cellular resolution. It leverage our novel observation that light stimuli cause microscopic deformations in the
living photoreceptor outer segment (OS), along with OCT’s sensitivity to deformations in the tissue much smaller
than the wavelength of the imaging source. Aim 1 investigates the ORG’s ability to measure function in rods and
cones, by measuring responses in normal subjects and characterizing the signal’s sensitivity to changes in stimu­
lus energy, and factors affecting this sensitivity, such as spatial and temporal variance in response, computational
factors, and photon noise. Aim 2 investigates the mechanisms underlying light­evoked OS deformation. We will
rigorously determine the light levels at which the deformations are saturated, the effect of multiple flashes, and
the signal’s dependence on retinal eccentricity, all of which provide valuable information about the biochemical
processes causing the observed deformations. Aim 3 applies the ORG to well­characterized retinal disease, to
determine whether it is able to detect pathological dysfunction in photoreceptors suffering from known deficits.
Well­characterized deficits, in turn, offer natural experiments which may shed light on the biochemical and biome­
chanical determinants of the observed light­evoked deformations in the OS.

## Key facts

- **NIH application ID:** 10553620
- **Project number:** 5R01EY033532-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA AT DAVIS
- **Principal Investigator:** Ravi S. Jonnal
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $390,511
- **Award type:** 5
- **Project period:** 2022-02-01 → 2027-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10553620

## Citation

> US National Institutes of Health, RePORTER application 10553620, Investigating fundamental properties and clinical applications of the optoretinogram (5R01EY033532-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10553620. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*