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Changes in Amblyopia Using Optical Coherence Tomography

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ClinicalTrials.gov Identifier: NCT04092361
Recruitment Status : Not yet recruiting
First Posted : September 17, 2019
Last Update Posted : September 17, 2019
Sponsor:
Information provided by (Responsible Party):
Alyaa mohamed yousef ahmed elkabsh, Assiut University

Brief Summary:
There have been multiple trials to investigate the morphological changes in the macula and retinal nerve fiber layer of amblyopic eyes, due to the different published results and the lack of evident association between these changes and the patients' parameters. So, we perform this study to compare the variations in macular parameters (central thickness, average thickness, macular volume) and peripapillary thickness in different cases of amblyopic eyes versus the normal fellow eyes using spectral-domain optical coherence tomography. In addition, to estimate the relationship of optical coherence tomography variations with different defined patients' parameters (age, sex, best corrected visual acuity, spherical equivalent refractive error, and axial length).

Condition or disease Intervention/treatment
Amblyopia Device: optical coherence tomography

Detailed Description:

Amblyopia remains an important cause of low visual acuity,affecting 2% to 6% of the general population. Unilateral amblyopia is defined as reduced best-corrected visual acuity secondary to an abnormal visual experience during the critical period of visual development. Classic causes include strabismus, anisometropia, form deprivation or a combination of these factors .

The normal postnatal reduction (apoptosis) of retinal ganglion cells is arrested in amblyopia which would cause increase in retinal nerve fiber layer thickness as hypothesized by Yen et al .This also would affect the normal maturation of the macula, including movement of Henle's fibers away from the foveola. This would result in increased foveal thickness. Furthermore, because of the reduced apoptosis of retinal ganglion cells, the thickness of the ganglion cell layer in the macula would also be increased.

Optical coherence tomography : is a non-contact and non-invasive technique that help in assessment of retina abnormalities. The high resolving power (10um - Time Domain, 5um - Spectral Domain) provides excellent detail for evaluating the vitreo-retinal interface, neurosensory retinal morphology, and the retinal pigmented epithelial-choroid complex. It generates cross sectional images by analyzing the time delay and magnitude change of low coherence light as it is backscattered by ocular tissues. An infrared scanning beam is split into a sample arm (directed toward the subject) and a reference arm (directed toward a mirror). As the sample beam returns to the instrument it is correlated with the reference arm in order to determine distance and signal change via photodetector measurement. The resulting change in signal amplitude allows tissue differentiation by analysis of the reflective properties, which are matched to a false color scale. As the scanning beam moves across tissue, the sequential longitudinal signals, or A-scans, can be reassembled into a transverse scan yielding cross-sectional images, or B-scans, of the subject. The scans can then be analyzed in a variety of ways providing both empirical measurements (e.g. retinal thickness/volume) and qualitative morphological information.


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Study Type : Observational
Estimated Enrollment : 28 participants
Observational Model: Case-Crossover
Time Perspective: Cross-Sectional
Official Title: Macular and Retinal Changes in Unilateral Amblyopia Using Optical Coherence Tomography
Estimated Study Start Date : October 1, 2019
Estimated Primary Completion Date : October 1, 2020
Estimated Study Completion Date : October 1, 2021

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Amblyopia

Group/Cohort Intervention/treatment
anisometropic amblyopia Device: optical coherence tomography
It generates cross sectional images by analyzing the time delay and magnitude change of low coherence light as it is backscattered by ocular tissues. An infrared scanning beam is split into a sample arm and a reference arm. As the sample beam returns to the instrument it is correlated with the reference arm in order to determine distance and signal change via photodetector measurement. The resulting change in signal amplitude allows tissue differentiation by analysis of the reflective properties, which are matched to a false color scale. As the scanning beam moves across tissue, the sequential longitudinal signals, or A-scans, can be reassembled into a transverse scan yielding cross-sectional images, or B-scans, of the subject. The scans can then be analyzed in a variety of ways providing both empirical measurements (e.g. RNFL or retinal thickness/volume) and qualitative morphological information.

strabismic amblyopia Device: optical coherence tomography
It generates cross sectional images by analyzing the time delay and magnitude change of low coherence light as it is backscattered by ocular tissues. An infrared scanning beam is split into a sample arm and a reference arm. As the sample beam returns to the instrument it is correlated with the reference arm in order to determine distance and signal change via photodetector measurement. The resulting change in signal amplitude allows tissue differentiation by analysis of the reflective properties, which are matched to a false color scale. As the scanning beam moves across tissue, the sequential longitudinal signals, or A-scans, can be reassembled into a transverse scan yielding cross-sectional images, or B-scans, of the subject. The scans can then be analyzed in a variety of ways providing both empirical measurements (e.g. RNFL or retinal thickness/volume) and qualitative morphological information.

deprivational amblyopia Device: optical coherence tomography
It generates cross sectional images by analyzing the time delay and magnitude change of low coherence light as it is backscattered by ocular tissues. An infrared scanning beam is split into a sample arm and a reference arm. As the sample beam returns to the instrument it is correlated with the reference arm in order to determine distance and signal change via photodetector measurement. The resulting change in signal amplitude allows tissue differentiation by analysis of the reflective properties, which are matched to a false color scale. As the scanning beam moves across tissue, the sequential longitudinal signals, or A-scans, can be reassembled into a transverse scan yielding cross-sectional images, or B-scans, of the subject. The scans can then be analyzed in a variety of ways providing both empirical measurements (e.g. RNFL or retinal thickness/volume) and qualitative morphological information.




Primary Outcome Measures :
  1. To measure retinal layers and macular thickness changes in cases of unilateral amblyopia using optical coherence tomography in comparison with the other sound eye. [ Time Frame: from october 1st 2019 to october 1st 2020 ]
    Foveal thickness (mean thickness in the central 1000-μm diameter area) and central foveal thickness (mean thickness at the point of intersection of 6 radial scans) are 212 ± 20 and 182 ± 23 μm, respectively. Macular thickness measurements were thinnest at the center of the fovea, thickest within 3-mm diameter of the center, and diminished toward the periphery of the macula. The temporal quadrant was thinner than the nasal quadrant.



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Ages Eligible for Study:   16 Years to 40 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

all cooperative patients that fulfill inclusion criteria

  1. Age>16 and <40 years
  2. Patients with unilateral amblyopia ( anisometropic , strabismic and deprivational amblyopia )
Criteria

Inclusion Criteria:

  1. Age>16 and <40 years
  2. Patients with unilateral amblyopia ( anisometropic , strabismic and deprivational amblyopia ) .

Exclusion Criteria:

  1. Age<16 and >40 years.
  2. Patients with structural abnormality in their eye , mentally retarded patients .

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04092361


Contacts
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Contact: alyaa mohamed, post gradate +2001092246445 alyaelkabsh686@gmail.com
Contact: mohamed anwar, lecturer +2001006579873 mohamedanwar70@gmail.com

Sponsors and Collaborators
Assiut University

Publications:

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Responsible Party: Alyaa mohamed yousef ahmed elkabsh, principle investigator, Assiut University
ClinicalTrials.gov Identifier: NCT04092361     History of Changes
Other Study ID Numbers: OCT changes in amblyopia
First Posted: September 17, 2019    Key Record Dates
Last Update Posted: September 17, 2019
Last Verified: September 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Amblyopia
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Vision Disorders
Sensation Disorders
Neurologic Manifestations
Eye Diseases
Signs and Symptoms