Amblyopia
Conditions
Keywords
amblyopia, perceptual learning, dichoptic therapy, visual acuity
Brief summary
Interest in developing alternative methods for the treatment of amblyopia (lazy eye) has long been a topic of interest among clinicians and researchers. Occlusion or penalization of fellow eye do not always provide the desired visual acuity improvement. Moreover, occlusion is associated with a high risk of recurrence and non-compliance. Here, it is presented a protocol of a randomized clinical trial to evaluate the safety and clinical efficacy of a novel home-based system, based on a computer game. The goal of this prospective clinical trial is to compare in visual acuity improvements in patients with amblyopia, following conventional patching therapy or this novel computer-based therapy. The main questions it aims to answer are: * Does computer-based therapy equal or improve patching therapy? Can it be used as an alternative to patching? * Does computer-based therapy used in combination with pathching solve amblyopia when patching fails alone (persistent amblyopia)? Participants will be divided in two groups according to the previous occlusion o penalization of fellow eye. Both groups will be divided in two subgroups, experimental and control. Researchers will compare subgroups outcomes in order to asses this novel approach.
Detailed description
Amblyopia is a common neurodevelopmental abnormality that results in physiological alterations of the visual pathways and impaired vision in one eye or, less commonly, in both.Disruption of normal visual development early in life may result in perceptual, oculomotor and clinical abnormalities such as instability of fixation, anomalous retinal correspondence, and lack of stereoacuity.Amblyopia has a prevalence of around 2-4% in children and is associated with refractive error (anisometropia or isometropia) and strabismus. The Pediatric Eye Disease Investigator Group (PEDIG) has produced several studies that analyze the most effective therapies for amblyopic eye. The gold standard treatment prescribed for this condition combines spectacle correction of the refractive error with penalization and/or occlusion of the dominant eye Interest in developing alternative methods for the treatment of amblyopia (lazy eye) has long been a topic of interest among clinicians and researchers. Occlusion or penalization of fellow eye do not always provide the desired visual acuity improvement. Moreover, occlusion is associated with a high risk of recurrence and non-compliance. This randomized clinical trial is designed to evaluate the safety and clinical efficacy of a novel home-based system, based on a computer activity that uses dichoptic Gabor Patches and band-filtered noise masks. It combines the concepts of perceptual learning, dichoptic training, home based therapy and gamification. The goal of this prospective clinical trial is to compare in visual acuity improvements in patients with amblyopia, following conventional patching therapy or this novel computer-based therapy. The main questions it aims to answer are: * Does computer-based therapy equal or improve patching therapy? Can it be used as an alternative to patching? * Does computer-based therapy used as coadjuvant to pathching solve amblyopia in patients where patching fails alone (persistent amblyopia)? Participants will be divided in two groups according to the previous occlusion o penalization of fellow eye. Both groups will be divided in two subgroups, experimental and control. Researchers will compare subgroups outcomes in order to asses if this novel approach may lead to greater improvements in vision performance in amblyopic children as substitution of occlusion treatment in novel amblyopia or as coadjutant in persistent amblyopia.
Interventions
DEVICEVisionary: computer exercises using dichoptic Gabor Patches and band-filtered noise masks
Visionary exercises are computer gammified activities that run on a computer with internet connection to facilitate home therapy. Patient must wear anaglyph glasses. Visual stimuli consists in dichoptic Gabor Patches presented to the amblyopic eye. Frequency is adjusted to actual patient visual acuity, and contrast to actual patient performance (contrast sensitivity). A band-filtered noise mask at the same frequency than the Gabor patch is presented to the fellow eye in certain ocassions.
DEVICEPatching
PEDIG (Pediatric Eye Disease Investigator Group) recommended amblyopia treatment. Consist on covering a child's better-seeing eye with a patch for 2 hours per day for mild and moderate amblyopia or 6 hours per day for severe amblyopia
Sponsors
VisionaryTool, S.L.
Hospital de Merida
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Masking description
Ophthalmologists at the Pediatric Ophthalmologic Unit (Care Provider and Outcomes Assessor) will decide if volunteers meet inclusion criteria. They will assign the patient to GA or GB. They will be responsible for final and after treatment visual evaluations. The Quality Service of the Merida Hospital (Investigator) will randomize GA and GB volunteers into treatment or control subgroups. This service will be responsible for the custody of documentation and the statistical final analysis. Visionary team (Investigator) will communicate the patient about the treatment (occlusion or Visionary software, or both). Optometrists at the Pediatric Ophthalmologic Unit (Outcomes Assessor) will oversee BCVA and stereoacuity measurements during treatment.
Intervention model description
Participants will be divided in two groups: GA, 60 participants without previous occlusion treatment; GB, 60 participants with previous occlusion or penalization. In GA, participants will be assigned to an Experimental subgroup (GA-E) or to a Control subgroup (GA-C). GA-E volunteers will be prescribed computer-based exercises (Visionary). GA-C patients will be prescribed occlusion. In GB, all participants will receive occlusion. There will be two subgroups, Experimental (GB-E) and Control (GB-C), and both will be prescribed exercises using Visionary. In GB-E the computer will adjust Gabor patches frequency to visual acuity, as normal; but in GB-C Gabor frequencies will always be low. Importantly, those patients with deviations (10 to 25 prismatic diopters) will be assigned to experimental or treatment subgroups following an independent randomization.
Eligibility
Sex/Gender
ALL
Age
4 Years to 12 Years
Healthy volunteers
No
Inclusion criteria
* The sample will be made up of children with amblyopia from 4 to 12 years old (amblyopia will be defined as the best corrected visual acuity less o equal to 0.8 in decimal units or \> 2 lines of difference between both eyes). Strabismus inclusion criteria will be \< 25 prismatic diopters, with a deviation ≥ 2 prismatic diopters.
Exclusion criteria
* Subjects with nystagmus, ocular pathology o cognitive delay will be excluded.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| BCVA Best Corrected Visual Acuity | Treatment will last 12 weeks, with BCVA measurements every 2 weeks. The stability control post treatment will last 12 months, with BCVA controls at 3, 6 and 12 months. | Best Corrected Visual Acuity is the measurement of the ability to distinguish shapes and the details of objects at a given distance wearing full refraction. Different optotipes are used to measure clinically this ability (e.g. Snellen E, ETDRS, etc.). Refraction must be calculated under cyclopegia following PEDIG criteria. Crowding bars can be added to the optotypes. In this study, amblyopic eye BCVA will be measured using visual acuity chart ETDRS whitout crowding bars, in logarithmic scale. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Stereoacuity | Treatment will last 12 weeks, with stereoacuity measurements every 2 weeks. The stability control post treatment will last 12 months, with stereoacuity controls at 3, 6 and 12 months. | In this stuty Randot Preschool Stereoacuity Test (Stereo Optical, Inc., Chicago, USA) will be used to asses stereoacuity in arc seconds. This is a random dot stereogram that measures global stereopsis (or cyclopean stereopsis) and does not contain monocular cues. Stereoacuity is measured at a constant distance of 40 cm. |
Countries
Spain
Contacts
Primary ContactMaria Perez-Benito, Dra
Backup ContactAna Sanchez-de-la-Morena, Dra
Outcome results
None listed