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.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
20
Participants will receive echothiophate iodide eye drops in addition to standard atropine therapy to assess whether the combination improves visual function in refractory amblyopia.
Dean McGee Eye Institute
Oklahoma City, Oklahoma, United States
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
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