Regimens of Intermittent Occlusion Therapy for Amblyopia in Children

Salus University

Status

Terminated

Conditions

Amblyopia

Treatments

Device: IO-therapy Glasses

Study type

Interventional

Funder types

Other

Identifiers

NCT02767856

HJW1604

Details and patient eligibility

About

This study is designed to answer the question: What if the Intermittent Occlusion (IO-therapy) glasses were prescribed all day (12-hours) in which the total time of treatment only took 4 weeks instead of the current treatment time (4 hours) in which it takes 12 weeks?

Children aged 3- to 8-years with untreated moderate unilateral amblyopia will be enrolled and randomized into 2 groups: 1) Intense 12-hour IO-therapy Group for 4 weeks treatment; or 2) Standard 4-hour IO-therapy glasses Group for 12 weeks treatment.

Enrollment

32 patients

Sex

All

Ages

3 to 8 years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

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

Age 3 to < 8 years
Unilateral amblyopia associated with strabismus (comitant or incomitant), anisometropia, or both

Criteria for strabismus: At least one of the following criteria must be met:
- Heterotropia at distance and/or near fixation on examination (with or without spectacles)
- History of strabismus surgery
- Documented history of strabismus which is no longer present (which in the judgment of the investigator could have caused amblyopia)
Criteria for anisometropia: At least one of the following criteria must be met:
- >0.50 D difference between eyes in spherical equivalent
- >0.50 D difference between eyes in astigmatism in any meridian
Amblyopic eye has no myopia (> -0.25 D spherical equivalent).
Visual acuity, measured in each eye without cycloplegia within 7 days prior to enrollment using the ATS single-surround HOTV letter protocol as follows:
- Visual acuity in the amblyopic eye between 20/40 and 20/80 inclusive
- Visual acuity in the sound eye 20/32 or better
- Inter-eye acuity difference ≥ 2 logMAR lines (i.e., amblyopic eye acuity at least 2 lines worse than sound eye acuity)
No previous amblyopia treatment within 6 months.
Spectacle correction (if applicable) for measurement of enrollment visual acuity must meet the following criteria and be based on a cycloplegic refraction within 6 months:
- Requirements for spectacle correction:
- For patients meeting criteria for only strabismus
  - Hypermetropia if corrected must not be undercorrected by more than +1.50 D spherical equivalent, and the reduction in plus sphere must be symmetric in the two eyes. Otherwise, spectacle correction is at investigator discretion.
- For patients meeting criteria for anisometropia or combined-mechanism
  - Spherical equivalent must be within 0.50 D of fully correcting the anisometropia
  - Hypermetropia must not be undercorrected by more than +1.50 D spherical equivalent, and reduction in plus must be symmetric in the two eyes
  - Cylinder power in both eyes must be within 0.50 D of fully correcting the astigmatism
  - Cylinder axis in the spectacle lenses in both eyes must be within 6 degrees of the axis of the cycloplegic refraction
Spectacles meeting above criteria must be worn either:
- for 4 weeks immediately prior to enrollment, or
- until visual acuity in amblyopic eye is stable (defined as two consecutive visual acuity measurements at least 4 weeks apart with no improvement of one line or more)
- An acuity measurement done any of the following ways may be considered the first of two consecutive measurements:
  - in current glasses,
  - in trial frames with full correction of hypermetropia with cycloplegia, or
  - in new glasses.
Wearing optimal spectacle correction for a minimum of 4 weeks at the time of enrollment.
Ocular examination within 6 months prior to enrollment.
Gestational age > 34 weeks and birth weight > 1500 grams
Parent willing to accept randomization
Parent willing to be contacted and has access to phone
Parent does not anticipate relocation outside area within study period.