# Super-resolution imaging of the ocular fundus

> **NIH NIH R21** · UNIVERSITY OF COLORADO · 2020 · $161,680

## Abstract

Project Summary
Remarkable developments in ophthalmic imaging technologies, including optical coherence tomography (OCT)
and more recently adaptive-optics retinal imaging have enabled micron-level resolution and transformed
diagnosis and management of ophthalmic diseases. Unfortunately, still many of the retinal structures cannot be
resolved in vivo, let alone sub-cellular structures.
A key shortcoming shared by existing optical approaches for retinal imaging is that the attainable size of the
eye’s pupil sets a limit on the numerical aperture, and hence the lateral resolution. At the same time, in many
cases, illumination and detection pathways have to be separated within this sole aperture of the eye, further
constraining the achievable resolution. In addition, contrast variations among the structures of interest, noise of
the overall system, and eye motion artifacts further limit current approaches.
Time is ripe for another ophthalmic imaging revolution that overcomes existing constraints and enables the
uncovering of retinal structures at the cellular and sub-cellular level in the living eye. The objective of this
project is to address this unmet need by exploring speckle structured-illumination of the ocular fundus.
Furthermore, the project will investigate laser Illumination through the sclera to overcome the numerical-
aperture limitations inherent to pupil-based illumination.
The proposed approach allows the formation of speckle patterns on the ocular fundus that are randomly shifted
(scanned) by the naturally occurring involuntary fixational movements of the eye. The backscattered light is
collected through the pupil and post-processed to recover super-resolved retinal images, beyond the
capabilities of state-of-the art imaging modalities. Interestingly, the eye point spread function is obtained as a
by-product describing the aberrations of eye. Movement artifacts are avoided by collecting short exposure
image frames which are carefully registered before reconstruction. An eye movement sensing subsystem
enables sub-diffraction precision registration.
The investigators have assembled the required multifaceted expertise to explore, for the first time, these bold
ideas. It includes leaders in random media, super-resolution, and ophthalmic instrument development.
At the end of this project, we expect to be in a unique position to transfer the technique into practice through
the team’s existing wide cooperative network of ophthalmology departments. Armed with the unprecedented
spatial resolution of the proposed technique, these future interdisciplinary investigations can drive new insights
into retinal disease mechanisms and enable earlier diagnosis of retinal diseases, including some of the most
severe vision disabling conditions (e.g., retinal dystrophies, age-related macular degeneration, glaucoma),
while driving innovative therapies to protect cells before irreversible cell death and blindness occurs.

## Key facts

- **NIH application ID:** 10002236
- **Project number:** 5R21EY029584-02
- **Recipient organization:** UNIVERSITY OF COLORADO
- **Principal Investigator:** Kristina IRSCH
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $161,680
- **Award type:** 5
- **Project period:** 2019-09-01 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10002236

## Citation

> US National Institutes of Health, RePORTER application 10002236, Super-resolution imaging of the ocular fundus (5R21EY029584-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10002236. Licensed CC0.

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