AmblyopiaNCT04092361
Changes in Amblyopia Using Optical Coherence Tomography
An observational study of Amblyopia, run by Assiut University.
Trial 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. Read more about this study
- Who is it for?
- Ages 16 to 40 years
- Conditions the study is for
- Amblyopia
- What is being tested?
- optical coherence tomography
- Type of treatment
- Medical device
- How many people
- 28 participants
- Where
- No sites listed yet
- Study dates
- 1 Feb 2021to 1 Oct 2022
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 to 40 years
- All sexes
- No healthy volunteers
- Child, Adult
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 )
Who may be able to join
- Age>16 and <40 years
- Patients with unilateral amblyopia ( anisometropic , strabismic and deprivational amblyopia ) .
Who cannot join
- Age<16 and >40 years.
- Patients with structural abnormality in their eye , mentally retarded patients .
Trial locations and contacts
No sites are listed yet.
About this study
Official title: Macular and Retinal Changes in Unilateral Amblyopia Using Optical Coherence Tomography
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).
Read the 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.
- Conditions
- Amblyopia
- Being tested
- optical coherence tomography
- Medical subject headings
- Amblyopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
optical coherence tomographyDevice
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.
| Study group | Role | What they receive |
|---|---|---|
| anisometropic amblyopia | Not described Receives: Device: optical coherence tomography | |
| strabismic amblyopia | Not described Receives: Device: optical coherence tomography | |
| deprivational amblyopia | Not described Receives: Device: optical coherence tomography |
What is being measured
The primary outcome is the main question the study is designed to answer.
To measure retinal layers and macular thickness changes in cases of unilateral amblyopia using optical coherence tomography in comparison with the other sound eye.
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.
Measured: from october 1st 2019 to october 1st 2020
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Sep 2019
- Study start1 Feb 2021 (estimated)
- Primary completion1 Oct 2021 (estimated)
- Study completion1 Oct 2022 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (9)Papers the sponsor has linked to this study.
- Other trials for AmblyopiaStudies of the same condition, open and under way.
- More trials run by Assiut UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case crossover
- Time perspective
- Cross-sectional
- Enrolment
- 28 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Assiut University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Alyaa mohamed yousef ahmed elkabsh, Assiut University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04092361
- Sponsor's protocol ID
- OCT changes in amblyopia
- Status last verified
- Jan 2021
- First submitted
- 7 Sep 2019
- Last updated
- 27 Jan 2021
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
McKee SP, Schor CM, Steinman SB, Wilson N, Koch GG, Davis SM, Hsu-Winges C, Day SH, Chan CL, Movshon JA, et al. The classification of amblyopia on the basis of visual and oculomotor performance. Trans Am Ophthalmol Soc. 1992;90:123-44; discussion 145-8. No abstract available.
PubMed 1494815Graham PA. Epidemiology of strabismus. Br J Ophthalmol. 1974 Mar;58(3):224-31. doi: 10.1136/bjo.58.3.224. No abstract available.
PubMed 4834596Kiorpes L, McKee SP. Neural mechanisms underlying amblyopia. Curr Opin Neurobiol. 1999 Aug;9(4):480-6. doi: 10.1016/s0959-4388(99)80072-5.
PubMed 10448162de Zarate BR, Tejedor J. Current concepts in the management of amblyopia. Clin Ophthalmol. 2007 Dec;1(4):403-14.
PubMed 19668517Choi MY, Lee KM, Hwang JM, Choi DG, Lee DS, Park KH, Yu YS. Comparison between anisometropic and strabismic amblyopia using functional magnetic resonance imaging. Br J Ophthalmol. 2001 Sep;85(9):1052-6. doi: 10.1136/bjo.85.9.1052.
PubMed 11520755Yen MY, Cheng CY, Wang AG. Retinal nerve fiber layer thickness in unilateral amblyopia. Invest Ophthalmol Vis Sci. 2004 Jul;45(7):2224-30. doi: 10.1167/iovs.03-0297.
PubMed 15223799Hee MR, Izatt JA, Swanson EA, Huang D, Schuman JS, Lin CP, Puliafito CA, Fujimoto JG. Optical coherence tomography of the human retina. Arch Ophthalmol. 1995 Mar;113(3):325-32. doi: 10.1001/archopht.1995.01100030081025.
PubMed 7887846Yoon SW, Park WH, Baek SH, Kong SM. Thicknesses of macular retinal layer and peripapillary retinal nerve fiber layer in patients with hyperopic anisometropic amblyopia. Korean J Ophthalmol. 2005 Mar;19(1):62-7. doi: 10.3341/kjo.2005.19.1.62.
PubMed 15929489Yakar K, Kan E, Alan A, Alp MH, Ceylan T. Retinal Nerve Fibre Layer and Macular Thicknesses in Adults with Hyperopic Anisometropic Amblyopia. J Ophthalmol. 2015;2015:946467. doi: 10.1155/2015/946467. Epub 2015 May 7.
PubMed 26064676
Study at a glance
From the registry record, last updated by the sponsor on 27 Jan 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Macular and Retinal Changes in Unilateral Amblyopia Using Optical Coherence Tomography
- ClinicalTrials.gov ID
- NCT04092361
- Acronym / sponsor ID
- OCT changes in amblyopia
- Conditions
- Amblyopia
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 28 participants (estimated)
- Lead sponsor
- Assiut UniversityUniversity, hospital or other
- Study start
- 1 Feb 2021 (estimated)
- Primary completion
- 1 Oct 2021 (estimated)
- Study completion
- 1 Oct 2022 (estimated)
- First posted
- 17 Sep 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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).
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.
Study design
- Observational model
- Case crossover
- Time perspective
- Cross-sectional
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| anisometropic amblyopia | – | Device: optical coherence tomography |
| strabismic amblyopia | – | Device: optical coherence tomography |
| deprivational amblyopia | – | Device: optical coherence tomography |
Who may qualify
- Ages
- 16 to 40 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
- 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 )
Key inclusion criteria (2 listed)
- Age>16 and <40 years
- Patients with unilateral amblyopia ( anisometropic , strabismic and deprivational amblyopia ) .
Key exclusion criteria (2 listed)
- Age<16 and >40 years.
- Patients with structural abnormality in their eye , mentally retarded patients .
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| optical coherence tomographyIt 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. | Device | anisometropic amblyopia, deprivational amblyopia, strabismic amblyopia |
Primary outcome
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.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Jan 2021.
- Background: PubMed 1494815McKee SP, Schor CM, Steinman SB, Wilson N, Koch GG, Davis SM, Hsu-Winges C, Day SH, Chan CL, Movshon JA, et al. The classification of amblyopia on the basis of visual and oculomotor performance. Trans Am Ophthalmol Soc. 1992;90:123-44; discussion 145-8. No abstract available.
- Background: PubMed 4834596Graham PA. Epidemiology of strabismus. Br J Ophthalmol. 1974 Mar;58(3):224-31. doi: 10.1136/bjo.58.3.224. No abstract available.
- Background: PubMed 10448162Kiorpes L, McKee SP. Neural mechanisms underlying amblyopia. Curr Opin Neurobiol. 1999 Aug;9(4):480-6. doi: 10.1016/s0959-4388(99)80072-5.
- Background: PubMed 19668517de Zarate BR, Tejedor J. Current concepts in the management of amblyopia. Clin Ophthalmol. 2007 Dec;1(4):403-14.
- Background: PubMed 11520755Choi MY, Lee KM, Hwang JM, Choi DG, Lee DS, Park KH, Yu YS. Comparison between anisometropic and strabismic amblyopia using functional magnetic resonance imaging. Br J Ophthalmol. 2001 Sep;85(9):1052-6. doi: 10.1136/bjo.85.9.1052.
- Background: PubMed 15223799Yen MY, Cheng CY, Wang AG. Retinal nerve fiber layer thickness in unilateral amblyopia. Invest Ophthalmol Vis Sci. 2004 Jul;45(7):2224-30. doi: 10.1167/iovs.03-0297.
- Background: PubMed 7887846Hee MR, Izatt JA, Swanson EA, Huang D, Schuman JS, Lin CP, Puliafito CA, Fujimoto JG. Optical coherence tomography of the human retina. Arch Ophthalmol. 1995 Mar;113(3):325-32. doi: 10.1001/archopht.1995.01100030081025.
- Background: PubMed 15929489Yoon SW, Park WH, Baek SH, Kong SM. Thicknesses of macular retinal layer and peripapillary retinal nerve fiber layer in patients with hyperopic anisometropic amblyopia. Korean J Ophthalmol. 2005 Mar;19(1):62-7. doi: 10.3341/kjo.2005.19.1.62.
- Background: PubMed 26064676Yakar K, Kan E, Alan A, Alp MH, Ceylan T. Retinal Nerve Fibre Layer and Macular Thicknesses in Adults with Hyperopic Anisometropic Amblyopia. J Ophthalmol. 2015;2015:946467. doi: 10.1155/2015/946467. Epub 2015 May 7.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Questions about this trial
What is this clinical trial studying?
An observational study of Amblyopia, run by Assiut University.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 27 Jan 2021. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact alyaa mohamed, post gradate (+2001092246445, alyaelkabsh686@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04092361, which also lists 9 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Jan 2021.