Longitudinal Chromatic AberrationNCT06449976
Application and Clinical Evaluation of Longitudinal Chromatic Aberration Technique in Ophthalmology
A study testing blue light defocus and blue light filtering in people with Longitudinal Chromatic Aberration and Blue Light Defocus Manipulation, run by Beijing Tongren Hospital at 1 site in China.
Trial summary
Our study aims to delve into the effects of shifting the focal point of blue light from video or text displayed on a terminal screen forward on the axial length of the eye, ocular blood flow, visual fatigue, and visual function, that is, its relationship with Video Display Terminal (VDT) syndrome and myopia. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Longitudinal Chromatic Aberration, Blue Light Defocus Manipulation
- What is being tested?
- blue light defocus and blue light filtering
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 21 participants
- Where
- 1 siteChina
- Study dates
- 1 Jun 2024to 30 Aug 2024
- Phase
- Interventional
- 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 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Adult population, regardless of gender
- Refractive error is less than or equal to -2.5D and both eyes achieve corrected visual acuity of 0.8 or higher.
- Normal intraocular pressure with no organic pathology.
- No apparent symptoms of dry eye.
- Willing to cooperate to complete all the tests.
- Voluntarily signing the informed consent form.
Who cannot join
- Individuals with strabismus and amblyopia exist.
- Suffering from congenital eye conditions such as congenital cataracts or congenital retinal diseases.
- Those who have undergone intraocular surgery (such as cataract removal, intraocular lens implantation, etc.).
- Individuals with refractive media opacity (such as corneal lesions, lens opacity, etc.).
- Abnormal intraocular pressure (IOP) (IOP < 10 mmHg or IOP > 21 mmHg, or a bilateral IOP difference of ≥5 mmHg).
- Only one eye meets the inclusion criteria.
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- Active corneal infections such as bacterial, fungal, viral, or other acute or chronic anterior segment inflammations.
- Currently using medications that may lead to dry eye or affect vision and corneal curvature.
- Other ocular conditions, such as dacryocystitis, eyelid disorders and abnormalities, abnormal intraocular pressure, and glaucoma.
- Unable to undergo regular eye examinations.
Trial locations and contacts
1 site in 1 country.
China1 site
Beijing Tongren Hospitol, Capital Medical University
Beijing, Beijing Municipality, 100730
About this study
Our study aims to delve into the effects of shifting the focal point of blue light from video or text displayed on a terminal screen forward on the axial length of the eye, ocular blood flow, visual fatigue, and visual function, that is, its relationship with Video Display Terminal (VDT) syndrome and myopia. By examining the decoding ability of the adult subjects' retina to the clarity of the signal, we will attempt to develop a novel, non-invasive strategy to curb the elongation of the eyeball associated with myopia. Concurrently, we will also focus on the pathophysiological mechanisms underlying VDT syndrome and explore its potential link to the progression of myopia, providing new scientific evidence for the prevention and treatment of this ocular condition. This research is expected to provide robust support for addressing the global issue of myopia and the health challenges posed by VDT syndrome. Ultimately, by integrating global eye health issues with the challenges brought about by VDT syndrome, we will propose intervention and prevention strategies, offering new insights for the advancement of ophthalmology and public health sectors, thereby promoting visual acuity and ocular health for the population.
- Being tested
- blue light defocus and blue light filtering
- Keywords
- Longitudinal chromatic aberration, Reading efficiency, Visual function, Visual fatigue, Fundus blood flow, Axial length, Total refraction difference value
- Medical subject headings
- Asthenopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
blue light defocus and blue light filteringBehavioural
Subjects are asked to watch a terminal display device for 50 minutes, featuring texts and videos with different defocusing treatments. Specifically, they will start by watching text for 5 minutes, followed by 40 minutes of video, and then another 5 minutes of text, totaling a visual task duration of 50 minutes. The participants will complete a total of 4 sets of tests in a random order.
| Study group | Role | What they receive |
|---|---|---|
| Blue Light 0D Defocus Group | Experimental | This is the group that performs visual evoked tasks using videos and texts that are not defocused in the blue channel. In this group, the impact of standard video modes on the axial length of the eye, refractive fatigue, and visual function is assessed, including but not limited to indicators such as reading efficiency, blinking detection, and retinal fundus blood flow. Receives: Behavioral: blue light defocus and blue light filtering |
| Blue Light 1D Defocus Group | Experimental | Group using blue channel defocused 1D videos and texts for visual evoked tasks. Participants will engage in a 50-minute visual evoked task using videos and texts processed with 1D blue channel. The impact of standard video mode on axial length of the eye, refractive labor, and visual function will be assessed, including but not limited to indicators such as reading efficiency, blinking detection, and retinal fundus blood flow. Receives: Behavioral: blue light defocus and blue light filtering |
| Blue Light 2D Defocus Group | Experimental | The group uses blue channel defocused 2D videos and texts for visual evoked tasks. Participants will undergo a 50-minute visual evoked task using videos and texts processed with the 2D blue channel. The effects of standard video mode on the eye's axial length, refractive labor, and visual function are assessed, including but not limited to indicators such as reading efficiency, blinking detection, and retinal fundus blood flow. Receives: Behavioral: blue light defocus and blue light filtering |
| Blue Light 1D Defocus with Partial Filtration Group | Experimental | The group uses videos and texts processed with the blue channel 1D defocus and 30% blue light filtering for visual evoked tasks. Participants will engage in a 50-minute visual evoked task using videos and texts that have been processed with the 1D blue channel and partially filtered for blue light. The impact of the standard video mode on the eye's axial length, refractive labor, and visual function is evaluated, including but not limited to indicators such as reading efficiency, blinking detection, and retinal fundus blood flow. Receives: Behavioral: blue light defocus and blue light filtering |
What is being measured
The primary outcome is the main question the study is designed to answer.
Ocular Fundus Blood Flow
The study measured the sub foveal choroidal thickness, superficial vessel complex (SVC) density, and deep vessel complex (DVC) density, analyzing changes in retinal blood flow under the two modes.
Measured: The total duration of the visual task is 50 minutes. Retinal blood flow is measured for each subject at 0 minutes, 25 minutes, and 50 minutes during the visual task, resulting in a
Secondary outcomes (5)
Visual fatigue
The visual fatigue questionnaire utilized in this study consists of a self-report survey with a total of 19 items. It is designed to comprehensively assess the severity of visual fatigue symptoms, with a scoring system ranging from 1 to 7. Higher scores indicate more severe symptoms, encompassing three primary domains: ocular symptoms, visual discomfort, and psychological aspects triggered by visual fatigue.
Measured: Each participant will complete the visual fatigue questionnaire, followed immediately by a VEP task, and then re-assess visual fatigue immediately afterward. This sequence will occur twice per group, totaling eight assessments per participant.
Measurement of Accommodative Sensitivity with Flip-Chart Post-VEP Tasks
This clinical study involves the assessment of accommodative sensitivity for both monocular and binocular vision using a flip-chart immediately following each visual evoked potential (VEP) task. The measurement will quantify the number of optotypes correctly identified within one minute, indicative of the subject's accommodative capacity.
Measured: Each participant will have five measurements: a baseline, and four post-VEP tasks, with immediate flipchart tests after each task.
Blink Frequency
Use electronic devices to record the number of clicks within 3 minutes and calculate the frequency.
Measured: Blink frequency 3 minutes after the start of each visual evoked task and 3 minutes before the end.
Reading efficiency
The number pairs were read in the first and last 5 minutes of the visual evoked task, and the number of number pairs read per minute was counted.
Measured: The test was recorded 5 minutes after the start and 10 minutes before the end.
AC/A Ratio Measurement Post-VEP Tasks
This study involves the measurement of the AC/A ratio, which is a critical parameter in binocular vision assessment, reflecting the relationship between accommodation (focus adjustment) and convergence (ocular alignment). The AC/A ratio will be determined using the prism bar technique, which involve adding lenses to stimulate accommodation and measuring the resulting changes in convergence.
Measured: Each participant will undergo five AC/A ratio measurements: at baseline and immediately after each of four VEP tasks.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Jun 2024
- Study start1 Jun 2024
- Primary completion30 Aug 2024
- Study completion30 Aug 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Longitudinal Chromatic AberrationStudies of the same condition, open and under way.
- More trials run by Beijing Tongren HospitalThe 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This study is designed with a total of four groups, where participants will sequentially and randomly undergo all the intervention procedures.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 21 participants (actual)
Sponsor and investigators
- Lead sponsor
- Beijing Tongren Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06449976
- Sponsor's protocol ID
- BeijingTH-202405
- Status last verified
- May 2024
- First submitted
- 4 Jun 2024
- Last updated
- 3 Sep 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Sep 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Application and Clinical Evaluation of Longitudinal Chromatic Aberration Technique in Ophthalmology
- ClinicalTrials.gov ID
- NCT06449976
- Acronym / sponsor ID
- BeijingTH-202405
- Keywords
- Longitudinal chromatic aberration, Reading efficiency, Visual function, Visual fatigue, Fundus blood flow, Axial length, Total refraction difference value
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 21 participants (actual)
- Lead sponsor
- Beijing Tongren HospitalUniversity, hospital or other
- Study start
- 1 Jun 2024 (actual)
- Primary completion
- 30 Aug 2024 (actual)
- Study completion
- 30 Aug 2024 (actual)
- First posted
- 10 Jun 2024 (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.
Our study aims to delve into the effects of shifting the focal point of blue light from video or text displayed on a terminal screen forward on the axial length of the eye, ocular blood flow, visual fatigue, and visual function, that is, its relationship with Video Display Terminal (VDT) syndrome and myopia. By examining the decoding ability of the adult subjects' retina to the clarity of the signal, we will attempt to develop a novel, non-invasive strategy to curb the elongation of the eyeball associated with myopia. Concurrently, we will also focus on the pathophysiological mechanisms underlying VDT syndrome and explore its potential link to the progression of myopia, providing new scientific evidence for the prevention and treatment of this ocular condition. This research is expected to provide robust support for addressing the global issue of myopia and the health challenges posed by VDT syndrome. Ultimately, by integrating global eye health issues with the challenges brought about by VDT syndrome, we will propose intervention and prevention strategies, offering new insights for the advancement of ophthalmology and public health sectors, thereby promoting visual acuity and ocular health for the population.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 4
- Model description
- This study is designed with a total of four groups, where participants will sequentially and randomly undergo all the intervention procedures.
| Arm | Type | Receives |
|---|---|---|
| Blue Light 0D Defocus Group | Experimental | Behavioral: blue light defocus and blue light filteringThis is the group that performs visual evoked tasks using videos and texts that are not defocused in the blue channel. In this group, the impact of standard video modes on the axial length of the eye, refractive fatigue, and visual function is assessed, including but not limited to indicators such as reading efficiency, blinking detection, and retinal fundus blood flow. |
| Blue Light 1D Defocus Group | Experimental | Behavioral: blue light defocus and blue light filteringGroup using blue channel defocused 1D videos and texts for visual evoked tasks. Participants will engage in a 50-minute visual evoked task using videos and texts processed with 1D blue channel. The impact of standard video mode on axial length of the eye, refractive labor, and visual function will be assessed, including but not limited to indicators such as reading efficiency, blinking detection, and retinal fundus blood flow. |
| Blue Light 2D Defocus Group | Experimental | Behavioral: blue light defocus and blue light filteringThe group uses blue channel defocused 2D videos and texts for visual evoked tasks. Participants will undergo a 50-minute visual evoked task using videos and texts processed with the 2D blue channel. The effects of standard video mode on the eye's axial length, refractive labor, and visual function are assessed, including but not limited to indicators such as reading efficiency, blinking detection, and retinal fundus blood flow. |
| Blue Light 1D Defocus with Partial Filtration Group | Experimental | Behavioral: blue light defocus and blue light filteringThe group uses videos and texts processed with the blue channel 1D defocus and 30% blue light filtering for visual evoked tasks. Participants will engage in a 50-minute visual evoked task using videos and texts that have been processed with the 1D blue channel and partially filtered for blue light. The impact of the standard video mode on the eye's axial length, refractive labor, and visual function is evaluated, including but not limited to indicators such as reading efficiency, blinking detection, and retinal fundus blood flow. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Adult population, regardless of gender
- Refractive error is less than or equal to -2.5D and both eyes achieve corrected visual acuity of 0.8 or higher.
- Normal intraocular pressure with no organic pathology.
- No apparent symptoms of dry eye.
- Willing to cooperate to complete all the tests.
Key exclusion criteria (10 listed)
- Individuals with strabismus and amblyopia exist.
- Suffering from congenital eye conditions such as congenital cataracts or congenital retinal diseases.
- Those who have undergone intraocular surgery (such as cataract removal, intraocular lens implantation, etc.).
- Individuals with refractive media opacity (such as corneal lesions, lens opacity, etc.).
- Abnormal intraocular pressure (IOP) (IOP < 10 mmHg or IOP > 21 mmHg, or a bilateral IOP difference of ≥5 mmHg).
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 |
|---|---|---|
| blue light defocus and blue light filteringSubjects are asked to watch a terminal display device for 50 minutes, featuring texts and videos with different defocusing treatments. Specifically, they will start by watching text for 5 minutes, followed by 40 minutes of video, and then another 5 minutes of text, totaling a visual task duration of 50 minutes. The participants will complete a total of 4 sets of tests in a random order. | Behavioural | Blue Light 0D Defocus Group, Blue Light 1D Defocus Group, Blue Light 1D Defocus with Partial Filtration Group, Blue Light 2D Defocus Group |
Primary outcome
Ocular Fundus Blood Flow
Time frame: The total duration of the visual task is 50 minutes. Retinal blood flow is measured for each subject at 0 minutes, 25 minutes, and 50 minutes during the visual task, resulting in a
The study measured the sub foveal choroidal thickness, superficial vessel complex (SVC) density, and deep vessel complex (DVC) density, analyzing changes in retinal blood flow under the two modes.
5 secondary outcomes
Visual fatigue
Time frame: Each participant will complete the visual fatigue questionnaire, followed immediately by a VEP task, and then re-assess visual fatigue immediately afterward. This sequence will occur twice per group, totaling eight assessments per participant.
Measurement of Accommodative Sensitivity with Flip-Chart Post-VEP Tasks
Time frame: Each participant will have five measurements: a baseline, and four post-VEP tasks, with immediate flipchart tests after each task.
Blink Frequency
Time frame: Blink frequency 3 minutes after the start of each visual evoked task and 3 minutes before the end.
Reading efficiency
Time frame: The test was recorded 5 minutes after the start and 10 minutes before the end.
AC/A Ratio Measurement Post-VEP Tasks
Time frame: Each participant will undergo five AC/A ratio measurements: at baseline and immediately after each of four VEP tasks.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Sep 2024.
- Individual participant dataSharing planned: No
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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing blue light defocus and blue light filtering in people with Longitudinal Chromatic Aberration and Blue Light Defocus Manipulation, run by Beijing Tongren Hospital at 1 site in China.
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 6 inclusion and 10 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: finished, as of the sponsor's last update on 3 Sep 2024. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Ocular Fundus Blood Flow (time frame: The total duration of the visual task is 50 minutes. Retinal blood flow is measured for each subject at 0 minutes, 25 minutes, and 50 minutes during the visual task, resulting in a). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 3 Sep 2024.