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Recruiting NCT05394987

Optical Correction and Visual Functions of Adults With Amblyopia

No phase Interventional Amblyopia

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Spectacles.
Who it may be relevant to
Registry conditions: Amblyopia. Basic parameters: 18 years — 39 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
Canada, Hong Kong
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

Unsure about the terms? Read our patient guide →

Official title

Spectacle Correction for the Treatment of Amblyopia

Overview

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.

Interventions

  • Device Spectacles
    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. Anisometro

Primary outcome measures

  • Best corrected visual acuity of the amblyopic eye pre-intervention [Time frame: Approx. 5 mins, baseline (day 1 of spectacle wear)]
  • Best corrected visual acuity of the amblyopic eye post-intervention [Time frame: Approx. 5 mins, on completion of study (week 24)]
Secondary outcome measures (12)
  • Best corrected visual acuity of the amblyopic eye during intervention [Time frame: Approx. 5 mins, every 4 weeks from start of intervention]
  • Fellow eye distance visual acuity pre-intervention [Time frame: Approx. 5 mins, baseline (day 1 of spectacle wear)]
  • Fellow eye distance visual acuity post-intervention [Time frame: Approx. 5 mins, on completion of study (week 24)]
  • Fellow eye distance visual acuity during-intervention [Time frame: Approx. 5 mins, every 4 weeks from start of intervention]
  • Binocular distance visual acuity pre-intervention [Time frame: Approx. 5 mins, baseline (day 1 of spectacle wear)]
  • Binocular distance visual acuity post-intervention [Time frame: Approx. 5 mins, on completion of study (week 24)]
  • Binocular distance visual acuity during intervention [Time frame: Approx. 5 mins, every 4 weeks from start of intervention]
  • Near visual acuity of amblyopic eye pre-intervention [Time frame: Approx. 5 mins, baseline (day 1 of spectacle wear)]
  • Near visual acuity of amblyopic eye post-intervention [Time frame: Approx. 5 mins, on completion of study (week 24)]
  • Near visual acuity of amblyopic eye during intervention [Time frame: Approx. 5 mins,every 4 weeks from start of intervention]
  • Near visual acuity of fellow eye pre-intervention [Time frame: Approx. 5 mins, baseline (day 1 of spectacle wear)]
  • Near visual acuity of fellow eye post-intervention [Time frame: Approx. 5 mins, on completion of study (week 24)]

Eligibility criteria

Inclusion criteria

  • 18-39 (inclusive) years of age
  • Anisometropic amblyopia (difference of ≥0.50D spherical equivalent or ≥1.50D astigmatism between eyes) or mixed mechanism amblyopia (strabismus and anisometropia)
  • Best corrected visual acuity (BCVA) in the amblyopic eye of 0.3 logMAR to 1.0 logMAR (inclusive)
  • BCVA in the non-amblyopic eye of 0.1 logMAR or better, and an interocular VA difference of 2 logMAR lines or more
  • Difference of 1.00D or more between current refractive correction and study prescription
  • Good general health

Exclusion criteria

  • Other pathological ocular anomalies known to cause reduced visual acuity
  • Presbyopia (based on amplitude of accommodation)
  • Inability to tolerate prescribed refractive correction in spectacles (e.g., due to aniseikonia)
  • Contraindication to cycloplegic eye drops
  • Currently under amblyopia treatment/therapy
  • Inability to comprehend test instructions and/or provide consent
  • Eccentric fixation
  • >-6.00DS of myopia in either eye with spectacles
  • Bilateral amblyopia
  • Presence of amblyopia that is not due to strabismus and/or anisometropia
  • Presence of (current or previous) psychiatric, visual, or neurological disorders

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation
N/A
Model
Single group
Masking
Open label
Primary purpose
Treatment

Study locations

Canada · 1 center
  • University of Waterloo — Waterloo
Hong Kong · 1 center
  • Centre for Eye and Vision Research Limited — Hong Kong

Publications

  • 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. PMID 38950991

Identifiers

NCT: NCT05394987 · SPECTRA

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗