# Retinal Mechanisms of Refractive Development

> **NIH NIH R01** · EMORY UNIVERSITY · 2022 · $208,012

## Abstract

Retinal mechanisms of refractive development
Abstract
 The rapid increase in myopia prevalence over the last 30 years suggests a role for the environment in
controlling refractive development. Accumulating evidence suggests that ambient light (e.g. sunlight) affects
eye growth during childhood by dopamine signaling. However, the characteristics of visual stimuli and
underlying retinal signals that regulate refractive development remain elusive. In this proposal, the knowledge
gap concerning whether retinal “gain adjustment” pathways for ambient irradiance may alter myopia
susceptibility will be addressed. Preliminary data shows that both dim and bright light are protective for lens-
induced myopia in mice and that myopic children spend less time in both dim and bright light. Furthermore,
dopamine activity is differentially modulated by an interaction effect of exposure to variable ambient lighting
and lens defocus. Thus, the hypothesize that retinal “gain adjustment” to ambient light determines an
organism’s susceptibility to myopia through dopamine signaling will be tested. It is proposed that retinal
detection of irradiance occurs through non-classical retinal pathways that have been reported to detect light
across a broad range of ambient conditions from starlight to sunlight. This proposal will determine which
photoreceptor pathways modulate the protective effects of scotopic and photopic light on lens induced myopia
and the role of dopamine signaling by pursuing three specific aims using mouse models. Aim 1 will evaluate if
rod pathway stimulation drives dopamine release and decreases myopic refractions under dim and bright
ambient conditions. Aim 2 will investigate if retinal transmission through Cx36 gap junctions provides protective
effects for LIM in dim and bright light via increased dopamine release. Aim 3 will determine whether ipRGCs
modulate refractive development by detecting visual stimuli under a full range of ambient conditions. The
expected outcomes will increase our knowledge of basic retinal dopamine signaling and further elucidate the
mechanisms underlying myopic eye growth. These results are expected to foster the development of new
therapeutic interventions for the growing number of myopic children.

## Key facts

- **NIH application ID:** 10808695
- **Project number:** 7R01EY016435-15
- **Recipient organization:** EMORY UNIVERSITY
- **Principal Investigator:** Machelle T. Pardue
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $208,012
- **Award type:** 7
- **Project period:** 2009-01-01 → 2025-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10808695

## Citation

> US National Institutes of Health, RePORTER application 10808695, Retinal Mechanisms of Refractive Development (7R01EY016435-15). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10808695. Licensed CC0.

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