Quality ControlLC_EntryNCT04299659
Comparison of Four Methods for Entering the Gap Position of Landolt Cs
An observational study of Quality Control and Validation Study, run by Aalen University at 1 site in Germany.
Trial summary
The aim of this study is to investigate and compare the validity of four different input methods for Landolt Cs, i.e. the proportion of correct gap positions in relation to the total number of performances. Read more about this study
- Who is it for?
- Ages 18 to 80 yearsHealthy volunteers can take part
- Conditions the study is for
- Quality Control, Validation Study
- What is being tested?
- Landolt C entry method
- How many people
- 24 participants
- Where
- 1 siteGermany
- Study dates
- 22 Jul 2022to 30 Jun 2023
- 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 18 to 80 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Healthy, young subjects recruited for the students and or co-workers of the Aalen University of Applied Sciences
Who may be able to join
- Age: ≥ 18 years
- Informed consent
- (Distance) visual acuity with best correction: ≥ 0.8
- (Distant) ametropia: ≤+8.0 Diopters (spherical equivalent)
- Anisometropia ≤ 3 dpt
- Astigmatism ≤ 2.5 dpt
Who cannot join
- Prolonged reaction time caused by drugs (medications)/ drugs/alcohol
- Movement disorders (of hands) such as Parkinson's disease
- Indication of amblyopia (strabismus surgery, occlusion therapy etc.)
- Eye movement disorders/double vision
- Defective stereo vision (according to LANG [I] stereo test)
- Presence of a relative afferent pupil defect ("swinging flashlight test)
- Any hint of visual pathway lesion or other chronic or progressive eye disease
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Comparison of Four Methods for Entering the Gap Position of Landolt Cs With Respect to Validity, Retest Reliability, Examination Duration and Test Subject Satisfaction
The aim of this study is to investigate and compare the validity of four different input methods for Landolt Cs, i.e. the proportion of correct gap positions in relation to the total number of performances. The four input methods are a numeric keypad, an eight-positions rocker switch, a remote control and voice feedback.
Read the detailed description
The measurement of visual acuity is the most frequent and one of the most important ophthalmological functional investigations. Therefore, it is particularly important to find a measuring procedure with as little input errors as possible.
The 8-position Landolt C (LC) is the internationally accepted, well-standardised optotype for the determination of visual acuity.
Usually, the subjects informs the examiner verbally about the perceived position of each LC. According to the current literature, about 20 to 30 % of the population suffers from a right/left weakness. Furthermore, language barriers are an additional considerable hurdle.
Therefore, it is important to find an input method for the LC gap positions with minimal entry mistakes. In oder to avoid the thresholding procedure and its inherent difficulties, highly supra-threshold (10 times above the previously determined individual central visual acuity threshold) 8-position LCs are presented.
The study compares four input methods for entering of the Landolt C gap positions: a modified numeric keypad, an 8-position rocker switch, a modified TV remote control and voice/verbal feedback.
Each subject will perform all four input methods, with 2 test runs of 16 Landolt C presentations, each. A forced-choice method will be applied, i.e. the test is not continued until the test person has responded ot each single presentation. Regardless of whether the entry was correct or incorrect, the next Landolt C is displayed.
The optotypes are presented using modified version of the Freiburg Visual Acuity and Contrast Test (FrACT), which allows to present the 8-position Landolt Cs in a standardized way on a video display unit (VDU).
The sequence of the input methods is randomized. This study is carried out in a "within-subject design", i.e. all test persons go through all test conditions and serve as their own controls.
- Conditions
- Quality Control, Validation Study
- Being tested
- Landolt C entry method
- Keywords
- psychophysics, visual acuity, response, response entry, validity, retest reliability, reproducibility, evaluation, optotype, Landolt C
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Landolt C entry methodDiagnostic test
Four different methods for entering the Landolt C gap position are compared
What is being measured
The primary outcome is the main question the study is designed to answer.
validity
Proportion of correct gap position entries in relation to the total number of LC presentations by the four different entry methods
Measured: Through study completion, an average of 3 months
Secondary outcomes (3)
retest reliability
Comparison of the correct gap position entry between first and second test run by the four different entry methods
Measured: Through study completion, an average of 3 months
Examination duration
Comparison of the examination duration of the the four different entry methods and by the first and second run
Measured: Through study completion, an average of 3 months
Subjects´ satisfaction
Subjects´ evaluation (using a questionnaire) for the four different entry methods
Measured: Through study completion, an average of 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Mar 2020
- Study start22 Jul 2022
- Primary completion1 Mar 2023
- Study completion30 Jun 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Quality ControlStudies of the same condition, open and under way.
- 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 24 participants (actual)
Sponsor and investigators
- Lead sponsor
- Aalen University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Ulrich Schiefer, M.D., Study chair, +49 7361 576-4605
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04299659
- Sponsor's protocol ID
- LC Entry_2020
- Acronym
- LC_Entry
- Status last verified
- Jul 2023
- First submitted
- 1 Mar 2020
- Last updated
- 20 Jul 2023
- 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 20 Jul 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Four Methods for Entering the Gap Position of Landolt Cs With Respect to Validity, Retest Reliability, Examination Duration and Test Subject Satisfaction
- ClinicalTrials.gov ID
- NCT04299659
- Acronym / sponsor ID
- LC_Entry / LC Entry_2020
- Conditions
- Quality Control, Validation Study
- Keywords
- psychophysics, visual acuity, response, response entry, validity, retest reliability, reproducibility, evaluation
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 24 participants (actual)
- Lead sponsor
- Aalen UniversityUniversity, hospital or other
- Study start
- 22 Jul 2022 (actual)
- Primary completion
- 1 Mar 2023 (actual)
- Study completion
- 30 Jun 2023 (actual)
- First posted
- 9 Mar 2020 (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.
The aim of this study is to investigate and compare the validity of four different input methods for Landolt Cs, i.e. the proportion of correct gap positions in relation to the total number of performances. The four input methods are a numeric keypad, an eight-positions rocker switch, a remote control and voice feedback.
Detailed description
The measurement of visual acuity is the most frequent and one of the most important ophthalmological functional investigations. Therefore, it is particularly important to find a measuring procedure with as little input errors as possible.
The 8-position Landolt C (LC) is the internationally accepted, well-standardised optotype for the determination of visual acuity.
Usually, the subjects informs the examiner verbally about the perceived position of each LC. According to the current literature, about 20 to 30 % of the population suffers from a right/left weakness. Furthermore, language barriers are an additional considerable hurdle.
Therefore, it is important to find an input method for the LC gap positions with minimal entry mistakes. In oder to avoid the thresholding procedure and its inherent difficulties, highly supra-threshold (10 times above the previously determined individual central visual acuity threshold) 8-position LCs are presented.
The study compares four input methods for entering of the Landolt C gap positions: a modified numeric keypad, an 8-position rocker switch, a modified TV remote control and voice/verbal feedback.
Each subject will perform all four input methods, with 2 test runs of 16 Landolt C presentations, each. A forced-choice method will be applied, i.e. the test is not continued until the test person has responded ot each single presentation. Regardless of whether the entry was correct or incorrect, the next Landolt C is displayed.
The optotypes are presented using modified version of the Freiburg Visual Acuity and Contrast Test (FrACT), which allows to present the 8-position Landolt Cs in a standardized way on a video display unit (VDU).
The sequence of the input methods is randomized. This study is carried out in a "within-subject design", i.e. all test persons go through all test conditions and serve as their own controls.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Healthy, young subjects recruited for the students and or co-workers of the Aalen University of Applied Sciences
Key inclusion criteria (6 listed)
- Age: ≥ 18 years
- Informed consent
- (Distance) visual acuity with best correction: ≥ 0.8
- (Distant) ametropia: ≤+8.0 Diopters (spherical equivalent)
- Anisometropia ≤ 3 dpt
Key exclusion criteria (7 listed)
- Prolonged reaction time caused by drugs (medications)/ drugs/alcohol
- Movement disorders (of hands) such as Parkinson's disease
- Indication of amblyopia (strabismus surgery, occlusion therapy etc.)
- Eye movement disorders/double vision
- Defective stereo vision (according to LANG [I] stereo test)
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 |
|---|---|---|
| Landolt C entry methodFour different methods for entering the Landolt C gap position are compared | Diagnostic test | – |
Primary outcome
validity
Time frame: Through study completion, an average of 3 months
Proportion of correct gap position entries in relation to the total number of LC presentations by the four different entry methods
3 secondary outcomes
retest reliability
Time frame: Through study completion, an average of 3 months
Examination duration
Time frame: Through study completion, an average of 3 months
Subjects´ satisfaction
Time frame: Through study completion, an average of 3 months
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 20 Jul 2023.
- Individual participant dataSharing planned: No
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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.
Ulrich Schiefer, M.D. study chair
+49 7361 576-4605
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Quality Control and Validation Study, run by Aalen University at 1 site in Germany.
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 7 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 20 Jul 2023. 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 Germany. 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?
validity (time frame: Through study completion, an average of 3 months). 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 20 Jul 2023.