A Pilot Clinical Trial of Overminus Spectacle Therapy for Intermittent Exotropia

Intermittent Exotropia Clinical Trial

— IXT3  

Official title:

A Pilot Randomized Clinical Trial of Overminus Spectacle Therapy for Intermittent Exotropia

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02223650
• Other study ID #: IXT3
• Secondary ID: 2U10EY011751
• Status: Completed
• Phase: Phase 2/Phase 3
• First received: August 20, 2014
• Last updated: June 24, 2016
• Start date: December 2014
• Est. completion date: July 2015

Study information

• Verified date: June 2016
• Source: Jaeb Center for Health Research
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Data and Safety Monitoring BoardUnited States: Federal Government
• Study type: Interventional

Clinical Trial Summary

The objective of this short-term, pilot randomized trial comparing 2.50 diopters (D) overminus lens treatment vs. non-overminus (spectacles without overminus or no spectacles) in children with intermittent exotropia (IXT) 3 to <7 years of age is to determine whether to proceed to a full-scale, longer-term randomized trial.

Description:

The objective of this short-term, pilot randomized trial comparing 2.50D overminus lens treatment vs. non-overminus (spectacles without overminus or no spectacles) is to determine whether to proceed to a full-scale, longer-term randomized trial. This decision will be based primarily on assessing the initial (8-week) response to overminus by comparing treatment groups on the following outcomes:

• Mean distance IXT control score (each patient's score is the mean of 3 control scores) (primary outcome)

• The proportion of subjects with treatment response, defined as 1 or more points improvement in mean of 3 distance IXT control scores (secondary outcome)

• Adverse effects, near visual acuity outcomes, and spectacle wear compliance

Recruitment information / eligibility

• Status: Completed
• Enrollment: 58
• Est. completion date: July 2015
• Est. primary completion date: July 2015
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 3 Years to 6 Years

Eligibility

The following criteria must be met for the child to be enrolled in the study:

• Age 3 years to < 7 years

• Intermittent exotropia (manifest deviation) meeting all of the following criteria:

• Intermittent exotropia or constant exotropia at distance

• Mean distance control score of 2 points or more (mean of 3 assessments over the exam)

• Intermittent exotropia, exophoria, or orthophoria at near

• Subject cannot have a score of 5 points on all 3 near assessments of control

• Exodeviation at least 15? at distance measured by PACT

• Near deviation does not exceed distance deviation by more than 10? by PACT (convergence insufficiency type IXT excluded)

• No previous non-surgical treatment for IXT (other than refractive correction), including vision therapy for IXT, within the past 6 months.

• No previous substantial overminus treatment, defined as wearing spectacles that are overminused by 1.00D SE or more (treatment with lenses overminused by less than 1.00D SE is allowed at any time prior to enrollment).

• No vision therapy, patching, atropine, or other penalization for amblyopia during the last 2 weeks

• No prior strabismus, intraocular, or refractive surgery (including BOTOX injection)

• Cycloplegic refraction within 7 months, but NOT on the day of enrollment

• Spherical equivalent (SE) in both eyes between -6.00D and +1.00D inclusive

• Distance visual acuity 0.3 logMAR (20/40) or better (by ATS-HOTV) in both eyes

• No interocular difference of distance visual acuity more than 0.2 logMAR (2 lines)

• Child must be wearing refractive correction (pre-study spectacles) for at least 1 week if refractive error (based on cycloplegic refraction performed within 7 months) meets any of the following:

• SE anisometropia =1.00 D

• Astigmatism =1.00 D in either eye

• SE myopia =-0.50 D in either eye

• Refractive correction must meet the following criteria relative to the cycloplegic refraction:

• SE anisometropia must be within <1.0D of the SE anisometropic difference

• Astigmatism must be within <1.00D of full magnitude; axis must be within 10 degrees if =1.00D, and within 5 degrees if >1.00D.

• The SE of the spectacles must be within <1.00D of the full cycloplegic refraction SE.

• A correction that yields at least 1.00 D more minus SE than the cycloplegic refraction SE is considered previous substantial overminus lens treatment and the patient is not eligible.

• No current contact lens wear

• No abnormality of the cornea, lens, or central retina

• Gestational age = 32 weeks

• Birth weight > 1500 grams

• No Down syndrome or cerebral palsy

• No severe developmental delay which would interfere with treatment or evaluation (in the opinion of the investigator). Subjects with mild speech delays or reading and/or learning disabilities are not excluded.

• No disease known to affect accommodation, vergence, and ocular motility such as multiple sclerosis, Graves orbitopathy, myasthenia gravis, diabetes mellitus, or Parkinson disease

• No current use of any ocular or systemic medication known to affect accommodation or vergence, such as anti-anxiety agents (e.g., Librium or Valium), anti-arrhythmic agents (e.g., Cifenline, Cibenzoline), anti-cholinergics (e.g., motion sickness patch (scopolamine)), bladder spasmolytic drugs (e.g., Propiverine), hydroxychloroquine, chloroquine, phenothiazines (e.g., Compazine, Mellaril, Thorazine), tricyclic antidepressants (e.g., Elavil, Nortriptyline, Tofranil)

• Parent understands the protocol and is willing to accept randomization to overminus spectacles or non-overminus status

• Parent has home phone (or access to phone) and is willing to be contacted by Jaeb Center staff and Investigator's site staff

• Relocation outside of area of an active PEDIG site within next 8 weeks is not anticipated

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Exotropia
• Intermittent Exotropia

Intervention

Device:
• Overminus treatment
2.50D overminus spectacles
• Non-overminus treatment
spectacles without overminus or no spectacles

Locations

Country	Name	City	State
United States	Marshall B. Ketchum University	Fullerton	California
United States	Mayo Clinic	Rochester	Minnesota

Sponsors (3)

Lead Sponsor	Collaborator
Jaeb Center for Health Research	National Eye Institute (NEI), Pediatric Eye Disease Investigator Group

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Mean distance control score	A comparison of mean distance control scores (mean of the 3 assessments over the exam) between the 2.50D overminus group and the non-overminus group (spectacles without overminus or no spectacles) at 8 weeks.	8 weeks	No
Primary	Near control score	Control of exodeviation will be assessed in the habitual correction at distance (6 meters) and near (1/3 meter) using a standardized IXT control scale.	8 weeks	No
Secondary	Proportion of subjects with treatment response	A comparison of the proportion of subjects showing a "treatment response," defined as an improvement of at least 1 point in distance control (mean of the 3 assessments over the exam) between enrollment and 8 weeks.	8 weeks	No
Secondary	Symptom survey	A brief survey of symptoms that may be associated with overminus such as headaches, eye strain, and problems with spectacle wear will be administered to the parents of the subjects. Parents are asked to respond to the survey questions based on their observations of their child in the past 2 weeks. Response options are based on frequency of observations; never, rarely, sometimes, often, always, and not applicable.	8 weeks	Yes
Secondary	Stereoacuity	Stereoacuity will be assessed with habitual correction using the Randot Preschool stereotest at near (performed at 40 cm). A specific level of stereoacuity is not required for eligibility.	8 weeks	No
Secondary	Distance visual acuity	Monocular distance visual acuity testing with the habitual correction and without cycloplegia will be measured using the Amblyopia Treatment Study HOTV testing protocol on any certified visual acuity system.	8 weeks	No
Secondary	Binocular near visual acuity	Binocular near visual acuity will be tested in habitual correction using the ATS4 near visual acuity test.	8 weeks	No