A Phase 2 interventional study of Echothiophate Iodide 0.125% Ophthalmic Solution in Refractory Amblyopia, sponsored by University of Oklahoma. Not yet recruiting at 1 site in United States. Open to participants aged 3 Years to 17 Years. Per ClinicalTrials.gov, last updated 2026-04-28.
Sponsored by University of Oklahoma · Phase 2, Interventional, and Treatment
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:
Participants will be asked to:
189 studies on the registry are indexed under Amblyopia; 41 are open to participants now.
This study's planned enrollment of 20 is below the median of 60 across 137 interventional studies indexed under Amblyopia.
Browse Amblyopia studies →University of Oklahoma is the lead sponsor of 432 studies on the registry; 100 are open to participants now.
Of its 42 completed or terminated interventional studies of FDA-regulated products, 16 (38%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Single-group interventional Arm - Atropine + Echothiophate Combination Therapy
Drug: Echothiophate Iodide 0.125% Ophthalmic Solution
Participants will receive echothiophate iodide eye drops in addition to standard atropine therapy to assess whether the combination improves visual function in refractory amblyopia.
Best Corrected Visual Acuity (BCVA)
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)
Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks, 14 weeks.
Interocular visual acuity difference
Difference in BCVA between the amblyopic and fellow eye, measured in logMAR.
Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks, and 14 weeks.
Change in stereoacuity
Change in log arcseconds of stereoacuity assessed with the Randot Preschool Stereoacuity Test.
Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks
Refractive error changes
Changes in spherical equivalent refraction from baseline in the amblyopic eye, measured in diopters.
Time frame: 4 weeks, 8 weeks, 12 weeks (after completion of echothiophate treatment), 14 weeks (after two-week wash-out period).
Ocular alignment
This measure evaluates the presence and magnitude of ocular deviation measured in prism diopters, assessed at distance and near fixation
Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks, and 14 weeks.
Contrast sensitivity
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.
Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks, 14 weeks
Quality of life measures using the Pediatric Eye Disease Investigator Group (PEDIG) Pediatric Eye Questionnaire (PedEyeQ)
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)
Time frame: Baseline, 4 weeks, 8 weeks, 12 weeks, 14 weeks
Treatment adherence
This measure assess the proportion of prescribed treatments completed as directed over the study period, including frequency and consistency of administration
Time frame: From baseline to the end of treatment at 14 weeks.
OCT-A foveal avascular zone (FAZ) area changes
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)
Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks
OCT-A foveal avascular zone (FAZ) perimeter changes
Examine changes in OCT-A foveal avascular zone (perimeter) changes between the amblyopic and non-amblyopic eye with treatment measured in millimeters (mm).
Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks
OCT-A foveal avascular zone (FAZ) circularity index changes
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.
Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks
OCT-A vessel density changes
Examine the differences in OCT-A between amblyopic and non-amblyopic eye with treatment. Measured as the proportion of the area occupied by vasculature.
Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks
OCT-A vessel diameter index (VDI) changes
Examine the changes in the VDI between amblyopic and non-amblyopic eye with treatment. Measured as the average vessel caliber in micrometers (µm).
Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks
OCT-A perfusion density (PD) changes
Changes in PD between the amblyopic and non-amblyopic eye with treatment. Measured as the total area of perfused vasculature per unit area (%)
Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks
OCT-A retinal thickness changes
Examine changes in retinal thickness between amblyopic and non-amblyopic eye with treatment. Measured in microns.
Time frame: 4 weeks, 8 weeks, 12 weeks, 14 weeks
Plan to share: Undecided
No publications or documents are linked to this record.
Start is estimated for Jun 2026; primary completion for Dec 2026, 6 months later.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.