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| Name | Class |
|---|---|
| The Hong Kong Polytechnic University | OTHER |
| University of Waterloo | OTHER |
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Amblyopia is a developmental anomaly resulting from abnormal visual experiences in early life. Amblyopia causes reduced visual acuity in the absence of a pathology. Adult sensory systems are believed to be structurally invariant beyond early, critical periods of development. However, recent evidence suggest that visual functions in adults with amblyopia can be improved with optical correction alone. This study aims to investigate whether improvements in best corrected visual acuity and other visual functions can result following appropriate optical correction in adults with amblyopia. Functional measures relating to vision, binocular vision, and eye movements will be used to assess the efficacy of refractive correction for improving vision. This study will help us better understand the improvements in visual functions following optical correction, as well as the mechanisms underlying neuroplasticity in adults with amblyopia.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Optical correction | Experimental | Prescription of spectacles for full-time wear to correct refractive error |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Spectacles | Device | Prescription of refractive error correction in spectacles. Refractive error to be determined as part of standard optometric eye exam (performed by registered optometrist). Guidelines for optical correction for the prescription of the study spectacles (based on Pediatric Eye Disease Investigator Group [PEDIG] amblyopia clinical trial protocols): Hypermetropia: not undercorrected by >+1.50D spherical equivalent and the reduction in plus sphere must be identical between the two eyes. Anisometropia: full correction of the anisometropic difference. Astigmatism: cylinder power in each eye should be within ≤±0.50D of fully correcting the astigmatism for each eye. If cylinder power is ≥1.00D, the prescribed axis in both eyes should be within ≤±6 deg of the cycloplegic refraction axis. Appropriate refractive error correction will be prescribed. Participants will be instructed to wear the optical correction full-time (i.e., >50% of waking hours) for the duration of the study. |
| Measure | Description | Time Frame |
|---|---|---|
| Best corrected visual acuity of the amblyopic eye pre-intervention | The size of the smallest line of letters read accurately on an ETDRS chart. | Approx. 5 mins, baseline (day 1 of spectacle wear) |
| Best corrected visual acuity of the amblyopic eye post-intervention | The size of the smallest line of letters read accurately on an ETDRS chart. | Approx. 5 mins, on completion of study (week 24) |
| Measure | Description | Time Frame |
|---|---|---|
| Best corrected visual acuity of the amblyopic eye during intervention | The size of the smallest line of letters read accurately on an ETDRS chart. | Approx. 5 mins, every 4 weeks from start of intervention |
| Fellow eye distance visual acuity pre-intervention |
| Measure | Description | Time Frame |
|---|---|---|
| Electrical potentials pre-intervention | Electroencephalography (EEG) measures: Visual evoked potentials for high and low contrast stimuli (monocular: fellow eye and amblyopic eye) | Approx. 60 mins, baseline (day 1 of spectacle wear) |
| Electrical potentials post-intervention |
Inclusion Criteria:
Exclusion Criteria:
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| Name | Role | Phone | Extension | |
|---|---|---|---|---|
| Benjamin Thompson, PhD | Contact | +852-3169-9631 | ben.thompson@cevr.hk | |
| Ken WS Tan, PhD | Contact | +852-3169-9631 | ken.tan@cevr.hk |
| Name | Affiliation | Role |
|---|---|---|
| Benjamin Thompson, PhD | Centre for Eye and Vision Research Limited | Principal Investigator |
| Ken WS Tan, PhD | Centre for Eye and Vision Research Limited | Study Director |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| University of Waterloo | Recruiting | Waterloo | Ontario | N2L 3G1 | Canada |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 38950991 | Derived | Tan KWS, Park ASY, Cheung BWS, Wong GHT, Thompson B; SPECTRA study team. SPEctacle Correction for the TReatment of Amblyopia (SPECTRA): study protocol for a prospective non-randomised interventional trial in adults with anisometropic/mixed mechanism amblyopia. BMJ Open. 2024 Jul 1;14(6):e080151. doi: 10.1136/bmjopen-2023-080151. |
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Anonymized data will be shared on request
After publication of study results for an indefinite period.
Upon reasonable request and approved by the study principal investigator.
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| ID | Term |
|---|---|
| D000550 | Amblyopia |
| ID | Term |
|---|---|
| D001927 | Brain Diseases |
| D002493 | Central Nervous System Diseases |
| D009422 | Nervous System Diseases |
| D014786 | Vision Disorders |
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| ID | Term |
|---|---|
| D005139 | Eyeglasses |
| ID | Term |
|---|---|
| D007909 | Lenses |
| D055096 | Optical Devices |
| D004864 | Equipment and Supplies |
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Within-subject, pre-post interventional study, measuring the effect of optical correction on visual function.
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|
The size of the smallest line of letters read accurately on an ETDRS chart. |
| Approx. 5 mins, baseline (day 1 of spectacle wear) |
| Fellow eye distance visual acuity post-intervention | The size of the smallest line of letters read accurately on an ETDRS chart. | Approx. 5 mins, on completion of study (week 24) |
| Fellow eye distance visual acuity during-intervention | The size of the smallest line of letters read accurately on an ETDRS chart. | Approx. 5 mins, every 4 weeks from start of intervention |
| Binocular distance visual acuity pre-intervention | The size of the smallest line of letters read accurately on an ETDRS chart. | Approx. 5 mins, baseline (day 1 of spectacle wear) |
| Binocular distance visual acuity post-intervention | The size of the smallest line of letters read accurately on an ETDRS chart. | Approx. 5 mins, on completion of study (week 24) |
| Binocular distance visual acuity during intervention | The size of the smallest line of letters read accurately on an ETDRS chart. | Approx. 5 mins, every 4 weeks from start of intervention |
| Near visual acuity of amblyopic eye pre-intervention | The size of the smallest line of letters read accurately on a near ETDRS chart. | Approx. 5 mins, baseline (day 1 of spectacle wear) |
| Near visual acuity of amblyopic eye post-intervention | The size of the smallest line of letters read accurately on a near ETDRS chart. | Approx. 5 mins, on completion of study (week 24) |
| Near visual acuity of amblyopic eye during intervention | The size of the smallest line of letters read accurately on a near ETDRS chart. | Approx. 5 mins,every 4 weeks from start of intervention |
| Near visual acuity of fellow eye pre-intervention | The size of the smallest line of letters read accurately on a near ETDRS chart. | Approx. 5 mins, baseline (day 1 of spectacle wear) |
| Near visual acuity of fellow eye post-intervention | The size of the smallest line of letters read accurately on a near ETDRS chart. | Approx. 5 mins, on completion of study (week 24) |
| Near visual acuity of fellow eye during intervention | The size of the smallest line of letters read accurately on a near ETDRS chart. | Approx. 5 mins, every 4 weeks from start of intervention |
| Near binocular visual acuity pre-intervention | The size of the smallest line of letters read accurately on a near ETDRS chart. | Approx. 5 mins, baseline (day 1 of spectacle wear) |
| Near binocular visual acuity post-intervention | The size of the smallest line of letters read accurately on a near ETDRS chart. | Approx. 5 mins, on completion of study (week 24) |
| Near binocular visual acuity during intervention | The size of the smallest line of letters read accurately on a near ETDRS chart. | Approx. 5 mins, every 4 weeks from start of intervention |
| Amblyopic eye contrast sensitivity pre-intervention | Computer-based measurement of contrast sensitivity | Approx. 10 mins, baseline (day 1 of spectacle wear) |
| Amblyopic eye contrast sensitivity post-intervention | Computer-based measurement of contrast sensitivity | Approx. 10 mins, on completion of study (week 24) |
| Amblyopic eye contrast sensitivity during intervention | Computer-based measurement of contrast sensitivity | Approx. 10 mins, every 4 weeks from start of intervention |
| Stereopsis pre-intervention | Smallest disparity on the Randot preschool test reported accurately. | Approx. 5 mins, baseline (day 1 of spectacle wear) |
| Stereopsis post-intervention | Smallest disparity on the Randot preschool test reported accurately. | Approx. 5 mins, on completion of study (week 24) |
| Stereopsis during intervention | Smallest disparity on the Randot preschool test reported accurately. | Approx. 5 mins, every 4 weeks from start of intervention |
| Angle of strabismus pre-intervention | Prismatic power required to neutralise the angle of deviation on alternating prism cover test. | Approx. 5 mins,baseline (day 1 of spectacle wear) |
| Angle of strabismus post-intervention | Prismatic power required to neutralise the angle of deviation on alternating prism cover test. | Approx. 5 mins, on completion of study (week 24) |
| Angle of strabismus during intervention | Prismatic power required to neutralise the angle of deviation on alternating prism cover test. | Approx. 5 mins, every 4 weeks from start of intervention |
| Amblyopic eye fixation stability pre-intervention | Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA). | Approx. 5 mins, baseline (day 1 of spectacle wear) |
| Amblyopic eye fixation stability post-intervention | Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA). | Approx. 5 mins, on completion of study (week 24) |
| Amblyopic eye fixation stability during intervention | Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA). | Approx. 5 mins, every 4 weeks from start of intervention |
| Fellow (non-amblyopic) eye fixation stability pre-intervention | Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA). | Approx. 5 mins, baseline (day 1 of spectacle wear) |
| Fellow (non-amblyopic) eye fixation stability post-intervention | Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA). | Approx. 5 mins, on completion of study (week 24) |
| Fellow (non-amblyopic) eye fixation stability during intervention | Eye position recorded with high-speed eye tracker during fixation as quantified by bivariate contour ellipse area (BCEA). | Approx. 5 mins, every 4 weeks from start of intervention |
| Interocular suppression pre-intervention | Computer-based measurement of interocular suppression. | Approx. 10 mins, baseline (day 1 of spectacle wear) |
| Interocular suppression post-intervention | Computer-based measurement of interocular suppression. | Approx. 10 mins, on completion of study (week 24) |
| Interocular suppression during intervention | Computer-based measurement of interocular suppression. | Approx. 10 mins, every 4 weeks from start of intervention |
| Quality of life pre-intervention | Questionnaire scores for:
| Approx.15-20 mins, baseline (day 1 of spectacle wear) |
| Quality of life post-intervention | Questionnaire scores for:
| Approx. 15-20 mins, on completion of study (week 24) |
Electroencephalography (EEG) measures: Visual evoked potentials for high and low contrast stimuli (monocular: fellow eye and amblyopic eye) |
| Approx. 60 mins, on completion of study (week 24) |
| Electrical potentials during intervention | Electroencephalography (EEG) measures: Visual evoked potentials for high and low contrast stimuli (monocular: fellow eye and amblyopic eye) | Approx. 60 mins, 12 weeks from baseline (day 1 of spectacle wear) |
| Centre for Eye and Vision Research Limited | Recruiting | Hong Kong | Guangdong | 00000 | Hong Kong |
|
| D012678 | Sensation Disorders |
| D009461 | Neurologic Manifestations |
| D005128 | Eye Diseases |
| D012816 | Signs and Symptoms |
| D013568 | Pathological Conditions, Signs and Symptoms |