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NCT Number: NCT07554131

Evaluation of Echothiophate in Pediatric Patients With Refractory Amblyopia

The goal of this clinical trial is to see if a medicine called echothiophate iodide (Phospholine Iodide) can help treat children with refractory amblyopia. Amblyopia (also called lazy eye) is when one eye doesn't see as well as it should because the brain isn't using that eye correctly. Refractory amblyopia means a lazy eye that's very difficult to treat and it doesn't improve even after using common treatments, such as putting atropine eye drops in the stronger eye to encourage use of the weaker eye.

The main questions this study aims to answer are:

* Can adding echothiophate iodide eye drops help children who stopped improving with atropine alone start making progress again? * Does using atropine and echothiophate iodide eye drops together work better for older children and adolescents who typically do not respond well to atropine alone? * Besides improving eyesight, can echothiophate iodide eye drops also help with things like depth perception, seeing in crowded spaces, or noticing motion

Participants will be asked to:

* Participate in the study for a total of 14 weeks * Attend four clinic visits * Use atropine drops in the stronger eye nightly for a total 12 weeks * Use of echothiophate iodide eye drops in the weaker eye in addition to atropine use in the stronger eye, if vision does not improve after 4 weeks of use of atropine alone in the stronger eye * Upload weekly photos of the eyes * Have a slit lamp exam performed at each visit * Have Best Corrected Visual Acuity (BCVA) eye measurements taken at each visit. * Have Optical Coherence Tomography Angiography (OCTA) images taken at at each visit.

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Key information

Conditions

Refractory Amblyopia Amblyopia Brain Diseases Central Nervous System Diseases Eye Diseases Nervous System Diseases Neurologic Manifestations Pathological Conditions, Signs and Symptoms Sensation Disorders Signs and Symptoms Vision Disorders

Age range

3 year–17 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Dean McGee Eye Institute

Oklahoma City, Oklahoma, 73104, United States

Location contact

Crystal McAfee

CONTACT

[email protected]

405-271-6307

Rachel Dolan

SUB_INVESTIGATOR

Tammy Yanovitch, MD, MHSc

PRINCIPAL_INVESTIGATOR

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Children/adolescents between 3 and <18 years old with amblyopia who are currently undergoing atropine treatment who are deemed to no longer be improving.
  • Diagnosis of amblyopia associated with strabismus, anisometropia, or mixed types (as defined by previous PEDIG studies).
  • Wearing appropriate spectacle correction based on cycloplegic refraction using PEDIG protocol recommendations.
  • Currently undergoing atropine treatment (either 2x a week or every other day) with visual acuity in the amblyopic eye that has not improved with atropine treatment from participant's previous visit.
  • Cycloplegic refraction that has been completed within 6 months of enrollment.
  • Ability to measure visual acuity using standardized testing protocols.
  • Visual acuity in the amblyopic eye 20/40 to 20/100. Visual acuity in the non-amblyopic eye 20/30 or better with intraocular difference greater than or equal to 2 lines.

Exclusion criteria

  • Existing ocular conditions likely to interfere with treatment response (e.g., congenital cataract history, corneal opacities/scars, ptosis, retinal diseases).
  • Neurologic or systemic conditions that impact vision.
  • Severe developmental delays that might impact treatment adherence and outcome evaluation.
  • Current use of prisms or bifocals.
  • Active uveal inflammation or history of angle-closure glaucoma.
  • Concurrent use of other anticholinesterase medications.
  • Anticipated surgical procedures during the study period.
  • Prior surgical interventions for ocular conditions that could interfere with study outcomes.
  • Myopia with spherical equivalent >6D.
  • Any contraindications to the components of the medicine to be used in the study

Treatment and study plan

Echothiophate Iodide 0.125% Ophthalmic Solution

Drug

Participants will receive echothiophate iodide eye drops in addition to standard atropine therapy to assess whether the combination improves visual function in refractory amblyopia.

Primary outcomes

  1. Best Corrected Visual Acuity (BCVA)

    Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks, 14 weeks.

    Best Corrected Visual Acuity (BCVA) after 8 weeks of echothiophate iodide treatment and after a 2-week washout period (study-certified visual acuity tester masked to the patient's treatment group)

Secondary outcomes

  1. Interocular visual acuity difference

    Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks, and 14 weeks.

    Difference in BCVA between the amblyopic and fellow eye, measured in logMAR.

  2. Change in stereoacuity

    Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks

    Change in log arcseconds of stereoacuity assessed with the Randot Preschool Stereoacuity Test.

  3. Refractive error changes

    Time frame: 4 weeks, 8 weeks, 12 weeks (after completion of echothiophate treatment), 14 weeks (after two-week wash-out period).

    Changes in spherical equivalent refraction from baseline in the amblyopic eye, measured in diopters.

  4. Ocular alignment

    Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks, and 14 weeks.

    This measure evaluates the presence and magnitude of ocular deviation measured in prism diopters, assessed at distance and near fixation

  5. Contrast sensitivity

    Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks, 14 weeks

    The ability of the amblyopic eye to distinguish an object from its background under varying levels of contrast, assessed using a standardized contrast sensitivity chart (e.g., Pelli-Robson) and reported in log contrast sensitivity units.

  6. Quality of life measures using the Pediatric Eye Disease Investigator Group (PEDIG) Pediatric Eye Questionnaire (PedEyeQ)

    Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks, 14 weeks

    The PedEyeQ is an instrument specific to pediatric eye conditions designed to evaluate health-related quality of life in children with eye conditions. The assessment values are Rasch calibrated and scaled to score from 0 (worst) to 100 (best)

  7. Treatment adherence

    Time frame: From baseline to the end of treatment at 14 weeks.

    This measure assess the proportion of prescribed treatments completed as directed over the study period, including frequency and consistency of administration

  8. OCT-A foveal avascular zone (FAZ) area changes

    Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks

    Examine difference/change in OCT-A foveal avascular zone (FAZ) area between amblyopic and non-amblyopic eye with treatment. Units are in square millimeters (mm^2)

  9. OCT-A foveal avascular zone (FAZ) perimeter changes

    Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks

    Examine changes in OCT-A foveal avascular zone (perimeter) changes between the amblyopic and non-amblyopic eye with treatment measured in millimeters (mm).

  10. OCT-A foveal avascular zone (FAZ) circularity index changes

    Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks

    Examine changes in foveal avascular zone (FAZ) circularity index between the amblyopic and non-amblyopic eye with treatment. Circularity is measured by utilizing the FAZ area and perimeter by multiplying the area by 4 pi and dividing by the squared perimeter. This measurement is unitless.

  11. OCT-A vessel density changes

    Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks

    Examine the differences in OCT-A between amblyopic and non-amblyopic eye with treatment. Measured as the proportion of the area occupied by vasculature.

  12. OCT-A vessel diameter index (VDI) changes

    Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks

    Examine the changes in the VDI between amblyopic and non-amblyopic eye with treatment. Measured as the average vessel caliber in micrometers (µm).

  13. OCT-A perfusion density (PD) changes

    Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks

    Changes in PD between the amblyopic and non-amblyopic eye with treatment. Measured as the total area of perfused vasculature per unit area (%)

  14. OCT-A retinal thickness changes

    Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks

    Examine changes in retinal thickness between amblyopic and non-amblyopic eye with treatment. Measured in microns.

Study contacts

Contact information is provided by the study sponsor or research team.

Crystal McAfee

CONTACT

[email protected]

405-271-6307

Sponsors and collaborators

Lead sponsor

University of Oklahoma

Other

Collaborators

  • Fera Pharmaceuticals, LLC

Registry information

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Apr 28, 2026
Registry last updated
Apr 28, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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