# Binocular Vision, Amblyopia, and Refractive Development

> **NIH NIH R01** · RETINA FOUNDATION OF THE SOUTHWEST · 2020 · $550,329

## Abstract

Project Summary/Abstract
Amblyopia is a neurodevelopmental vision disorder that affects 3% of children. It results from discordant
visual experience during childhood, most often from strabismus or anisometropia. Strabismic and
anisometropic amblyopia impair the visual acuity and contrast sensitivity of one eye. Typically, disrupted
binocular vision (reduced or nil stereoacuity and interocular suppression), and ocular motor abnormalities are
also present. These deficits are associated with reduced fine motor skills and reading speed even during
binocular viewing. In turn, these associated deficits may affect academic success and self-esteem in children.
During the current project period, we identified an association between abnormal binocular vision and fixation
instability, discovered that interocular suppression precedes the onset of amblyopia, that the severity of
suppression is correlated with the depth of amblyopia, that suppression is reduced with binocular amblyopia
treatment, and investigated new binocular amblyopia treatments designed to reduce suppression and improve
visual acuity. While our binocular treatment led to sustained improvement in visual acuity, these early studies
were limited in 4 respects: 1) the treatment protocols were designed for short-term treatment trials, lasting <4
weeks so the maximum improvement with binocular treatment is unknown, 2) none of the treatment protocols
were specifically designed to improve stereoacuity, 3) visual acuity was the primary outcome measure in all of
the studies, so we know little about the relative effectiveness of patching versus binocular treatment in
rehabilitating fine motor kills, reading speed, and self-esteem, and 4) the treatments have only been applied to
amblyopic children age 4 years and older. Our collaborative research group is now poised to address these
critical issues. In Aim 1, we will evaluate the effectiveness of enhanced binocular amblyopia treatments in
achieving a more complete and stable recovery. In Aim 2, we will evaluate the effects of successful amblyopia
treatment (patching or binocular treatment) on fine motor skills, reading speed, and self-perception. In Aim 3,
we will evaluate a novel visual acuity measurement for <3-year-old children using a device that induces and
measures reflexive eye movements (OKN) to moving fields of vanishing optotypes. Upon conclusion, our
investigation of enhanced binocular treatment protocols and the effects of amblyopia treatment on the
performance of everyday tasks will inform the design of new, more effective amblyopia treatments and the
adoption of new outcome measures (reading, fine motor skills, and self-esteem) for clinical trials. In addition,
we will have an accurate method to diagnose and monitor amblyopia in 1- to 3-year old children that will allow
us to conduct future amblyopia treatment trials in this age range.

## Key facts

- **NIH application ID:** 9852447
- **Project number:** 5R01EY022313-08
- **Recipient organization:** RETINA FOUNDATION OF THE SOUTHWEST
- **Principal Investigator:** Eileen Elizabeth Birch
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $550,329
- **Award type:** 5
- **Project period:** 2012-05-01 → 2023-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9852447

## Citation

> US National Institutes of Health, RePORTER application 9852447, Binocular Vision, Amblyopia, and Refractive Development (5R01EY022313-08). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/9852447. Licensed CC0.

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