Visual NonspecificNCT02810665
Repeatability and Concordance of VA Measured With ETDRS Numeric , Landolt C, and Letter Charts in Thai Individuals
An observational study of Visual Nonspecific, run by Chiang Mai University at 1 site in Thailand.
Trial summary
This is a cross-sectional study to determine the repeatability and concordance of visual acuity level measured with the original ETDRS letter, ETDRS Landolt C, and ETDRS numeric chart in Thai individuals. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Visual Nonspecific
- What is being tested?
- Visual acuity measurement by ETDRS chart
- Type of treatment
- Lifestyle or therapy programme
- How many people
- 180 participants
- Where
- 1 siteThailand
- Study dates
- Jul 2015to Jul 2016
- How long will I take part?
- 1 Day
- 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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Participants with normal vision (VA of 20/20 to 20/25) and decreased vision (VA of 20/32 to 20/200 due to cataract, diabetic macular edema, or age-related macular degeneration) who gave consent to participate in this study
Who may be able to join
- Thai nationality
- More than 18 years of age
- Educational level: at least high school
- Able to read English alphabet
Who cannot join
None listed.
Trial locations and contacts
1 site in 1 country.
Thailand1 site, 1 recruiting
- Recruiting
Voraporn Chaikitmongkol
Muang Chiang Mai, Chiang Mai, 50200
Voraporn Chaikitmongkol, MD, 66-53-935512, vchaikitmongkol@gmail.com
Onnisa Nanegrungsunk, MD, tiennaneg@gmail.com
About this study
Official title: Repeatability and Concordance of Visual Acuity Level Measured With ETDRS Numeric Charts, ETDRS Landolt C Charts, and Original ETDRS Letter Visual Acuity Charts in Thai Individuals
This is a cross-sectional study to determine the repeatability and concordance of visual acuity level measured with the original ETDRS letter, ETDRS Landolt C, and ETDRS numeric chart in Thai individuals.
Read the detailed description
The ETDRS visual acuity chart has been used as a standard visual acuity measurement chart in ophthalmic clinical trials due to its proven high repeatability comparing to other visual acuity chart. However, the original ETDRS alphabet chart could not be used in every individual around the world, especially those who are non-english speakers. Landolt C chart has been a recommended chart to test visual acuity in those living in a country where English is not a common language, however, some difficulties including right-left confusion occurred when testing with the Landolt C chart, leading to the unreliable results of visual acuity measurement using the Landolt C chart. Recently, the ETDRS numeric chart was introduced by some medical equipment companies but there is limited information regarding the repeatability and concordance of the new ETDRS numeric chart comparing to the original ETDRS alphabet and Landolt C chart.
Therefore, this study aims to determine the repeatability and concordance of visual acuity level measured with the original ETDRS alphabet, the ETDRS Landolt C, and the ETDRS numeric chart. Results from this study would be able to suggest an appropriate ETDRS chart to be used in clinical studies in Thailand or other countries where English is not the native language.
- Conditions
- Visual Nonspecific
- Being tested
- Visual acuity measurement by ETDRS chart
- Keywords
- Repeatability, Concordance, Agreement, ETDRS visual acuity chart, numeric, Landolt C, Roman alphabet
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Visual acuity measurement by ETDRS chartBehavioural
All participants must complete VA measurement of the study eye using 3 charts including the original ETDRS alphabet, ETDRS Landolt C, and ETDRS numeric charts for 2 times, at least 30 minutes apart.
| Study group | Role | What they receive |
|---|---|---|
| Normal vision group | Individuals with VA 20/20 to 20/25 Receives: Behavioral: Visual acuity measurement by ETDRS chart | |
| Impaired vision group | Individuals with impaired vision: VA of 20/32 to 20/200 due to either cataract, diabetic macular edema, or age-related macular degeneration Receives: Behavioral: Visual acuity measurement by ETDRS chart |
What is being measured
The primary outcome is the main question the study is designed to answer.
Concordance of VA tested with ETDRS alphabet, Landolt C and numeric visual acuity charts
Measured: Day 1
Secondary outcomes (2)
Repeatability of VA tested with ETDRS alphabet, Landolt C and numeric visual acuity charts
Measured: Day 1
Differences in testing duration of VA measurement across the 3 ETDRS charts
Measured: Day 1
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jun 2016 (estimated)
- Study startJul 2015
- Primary completionJul 2016 (estimated)
- Study completionJul 2016 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Visual NonspecificStudies 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
- Case only
- Time perspective
- Cross-sectional
- Enrolment
- 180 participants (estimated)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- Chiang Mai University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Voraporn Chaikitmongkol, Chiang Mai University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02810665
- Sponsor's protocol ID
- OPT-2558-03133
- Status last verified
- Jun 2016
- First submitted
- 16 Jun 2016
- Last updated
- 23 Jun 2016
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- No
Publications
Ricci F, Cedrone C, Cerulli L. Standardized measurement of visual acuity. Ophthalmic Epidemiol. 1998 Mar;5(1):41-53. doi: 10.1076/opep.5.1.41.1499.
PubMed 9575537Ferris FL 3rd, Kassoff A, Bresnick GH, Bailey I. New visual acuity charts for clinical research. Am J Ophthalmol. 1982 Jul;94(1):91-6.
PubMed 7091289Kaiser PK. Prospective evaluation of visual acuity assessment: a comparison of snellen versus ETDRS charts in clinical practice (An AOS Thesis). Trans Am Ophthalmol Soc. 2009 Dec;107:311-24.
PubMed 20126505Ruamviboonsuk P, Tiensuwan M, Kunawut C, Masayaanon P. Repeatability of an automated Landolt C test, compared with the early treatment of diabetic retinopathy study (ETDRS) chart testing. Am J Ophthalmol. 2003 Oct;136(4):662-9. doi: 10.1016/s0002-9394(03)00394-5.
PubMed 14516806
Study at a glance
From the registry record, last updated by the sponsor on 23 Jun 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Repeatability and Concordance of Visual Acuity Level Measured With ETDRS Numeric Charts, ETDRS Landolt C Charts, and Original ETDRS Letter Visual Acuity Charts in Thai Individuals
- ClinicalTrials.gov ID
- NCT02810665
- Acronym / sponsor ID
- OPT-2558-03133
- Conditions
- Visual Nonspecific
- Keywords
- Repeatability, Concordance, Agreement, ETDRS visual acuity chart, numeric, Landolt C, Roman alphabet
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 180 participants (estimated)
- Lead sponsor
- Chiang Mai UniversityUniversity, hospital or other
- Study start
- Jul 2015
- Primary completion
- Jul 2016 (estimated)
- Study completion
- Jul 2016 (estimated)
- First posted
- 23 Jun 2016 (estimated)
- 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.
This is a cross-sectional study to determine the repeatability and concordance of visual acuity level measured with the original ETDRS letter, ETDRS Landolt C, and ETDRS numeric chart in Thai individuals.
Detailed description
The ETDRS visual acuity chart has been used as a standard visual acuity measurement chart in ophthalmic clinical trials due to its proven high repeatability comparing to other visual acuity chart. However, the original ETDRS alphabet chart could not be used in every individual around the world, especially those who are non-english speakers. Landolt C chart has been a recommended chart to test visual acuity in those living in a country where English is not a common language, however, some difficulties including right-left confusion occurred when testing with the Landolt C chart, leading to the unreliable results of visual acuity measurement using the Landolt C chart. Recently, the ETDRS numeric chart was introduced by some medical equipment companies but there is limited information regarding the repeatability and concordance of the new ETDRS numeric chart comparing to the original ETDRS alphabet and Landolt C chart.
Therefore, this study aims to determine the repeatability and concordance of visual acuity level measured with the original ETDRS alphabet, the ETDRS Landolt C, and the ETDRS numeric chart. Results from this study would be able to suggest an appropriate ETDRS chart to be used in clinical studies in Thailand or other countries where English is not the native language.
Study design
- Observational model
- Case only
- Time perspective
- Cross-sectional
- Target follow-up
- 1 Day
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Normal vision group | – | Behavioral: Visual acuity measurement by ETDRS chartIndividuals with VA 20/20 to 20/25 |
| Impaired vision group | – | Behavioral: Visual acuity measurement by ETDRS chartIndividuals with impaired vision: VA of 20/32 to 20/200 due to either cataract, diabetic macular edema, or age-related macular degeneration |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Participants with normal vision (VA of 20/20 to 20/25) and decreased vision (VA of 20/32 to 20/200 due to cataract, diabetic macular edema, or age-related macular degeneration) who gave consent to participate in this study
Key inclusion criteria (4 listed)
- Thai nationality
- More than 18 years of age
- Educational level: at least high school
- Able to read English alphabet
Key exclusion criteria (0 listed)
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 |
|---|---|---|
| Visual acuity measurement by ETDRS chartAll participants must complete VA measurement of the study eye using 3 charts including the original ETDRS alphabet, ETDRS Landolt C, and ETDRS numeric charts for 2 times, at least 30 minutes apart. | Behavioural | Impaired vision group, Normal vision group |
Primary outcome
Concordance of VA tested with ETDRS alphabet, Landolt C and numeric visual acuity charts
Time frame: Day 1
2 secondary outcomes
Repeatability of VA tested with ETDRS alphabet, Landolt C and numeric visual acuity charts
Time frame: Day 1
Differences in testing duration of VA measurement across the 3 ETDRS charts
Time frame: Day 1
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Jun 2016.
- Results publication: PubMed 9575537Ricci F, Cedrone C, Cerulli L. Standardized measurement of visual acuity. Ophthalmic Epidemiol. 1998 Mar;5(1):41-53. doi: 10.1076/opep.5.1.41.1499.
- Results publication: PubMed 7091289Ferris FL 3rd, Kassoff A, Bresnick GH, Bailey I. New visual acuity charts for clinical research. Am J Ophthalmol. 1982 Jul;94(1):91-6.
- Results publication: PubMed 20126505Kaiser PK. Prospective evaluation of visual acuity assessment: a comparison of snellen versus ETDRS charts in clinical practice (An AOS Thesis). Trans Am Ophthalmol Soc. 2009 Dec;107:311-24.
- Results publication: PubMed 14516806Ruamviboonsuk P, Tiensuwan M, Kunawut C, Masayaanon P. Repeatability of an automated Landolt C test, compared with the early treatment of diabetic retinopathy study (ETDRS) chart testing. Am J Ophthalmol. 2003 Oct;136(4):662-9. doi: 10.1016/s0002-9394(03)00394-5.
- 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.
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 Visual Nonspecific, run by Chiang Mai University at 1 site in Thailand.
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 4 inclusion and 0 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 23 Jun 2016. 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 Thailand. 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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Voraporn Chaikitmongkol, MD (66-53-93-5512, vchaikitmongkol@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Concordance of VA tested with ETDRS alphabet, Landolt C and numeric visual acuity charts (time frame: Day 1). 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 NCT02810665, which also lists 4 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 23 Jun 2016.