Visual AcuityELEVENNCT04520243
Evaluation of Letters Versus Numbers (ELEVEN) Study
A study testing Visual acuity assessment by ETDRS charts in people with Visual Acuity, run by The University of Hong Kong at 1 site in Hong Kong.
Trial summary
This is a prospective randomised controlled trial to determine the performance of Best Corrected Visual Acuity (BCVA) scores using the ETDRS number chart were compared with ETDRS alphabet chart in healthy eyes of patients who do not recognise the English alphabet. Read more about this study
- Who is it for?
- Ages 50 years and olderHealthy volunteers can take part
- Conditions the study is for
- Visual Acuity
- What is being tested?
- Visual acuity assessment by ETDRS charts
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 59 participants
- Where
- 1 siteHong Kong
- Study dates
- 1 Aug 2019to 31 Jan 2020
- 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 50 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Hong Kong residents
- Age 50 years or above
- Attending Southern District Screening program
Who cannot join
- BCVA 20/200 or below
- Any clinically relevant ocular disease that might affect visual acuity
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Evaluation of Letters Versus Numbers (ELEVEN) Study: ETDRS Visual Acuity Chart Performance in an English Alphabet Illiterate Population
This is a prospective randomised controlled trial to determine the performance of Best Corrected Visual Acuity (BCVA) scores using the ETDRS number chart were compared with ETDRS alphabet chart in healthy eyes of patients who do not recognise the English alphabet.
Read the detailed description
BACKGROUND: The measurement of visual acuity is important in the clinical setting to assess visual function and treatment response, while in research to provide objective clinical outcomes. The current gold standard for visual acuity measurement in most research studies, including major clinical trials, is the Early Treatment Diabetic Retinopathy Study (ETDRS) chart designed by Bailey and Lovie. However, this may not be suitable for participants who are illiterate. Alternatives exist, including the ETDRS numbers chart, Landolt C chart and Tumbling E chart. Existing studies show that the Landolt C and Tumbling E charts are alternatives with agreement with ETDRS letters chart in healthy and diseased eyes. However, the charts are limited by their 25% (if four orientations) or 12.5% (if eight orientations) chance of guessing the orientation of the letter.
The ETDRS numbers chart may overcome this limitation, as it uses five unique numbers instead of a single rotating letter. There are few studies evaluating the different types of visual acuity measurement among those unfamiliar with the English alphabet. Though one study shows high repeatability and agreement between the ETDRS letters and numbers charts in healthy and diseased eyes of English literate individuals and shorter testing duration when using the numbers chart, this finding has not been validated in individuals unfamiliar with the English alphabet. This study aims to evaluate how the ETDRS letters and numbers charts compare in individuals unfamiliar with the English alphabet.
METHODS: Eligible subjects were divided into 2 groups according to level of literacy. Literacy was determined by self-reported exposure to the English alphabet and recognition of the 10 Sloan letters (C, D, H, K, N, O, R, S, V, and Z). Subjects included were classified into the 2 groups: group A, with no exposure to the English alphabet and recognition of <6/10 letters, and group B, with exposure to the English alphabet and recognition of ≥6/10 letters.
Testing: Each subject underwent 2 rounds of BCVA measurements using 2 types of ETDRS charts in randomized sequence as follows: LN or NL (L = ETDRS letters chart, N = ETDRS numbers chart) from Precision Vision® (PV). The randomization of the testing sequence was performed by a study coordinator independent of study recruiter, optometrist or investigator. Sequentially numbered, opaque and sealed envelopes were used for allocation concealment and opened by the optometrist prior to testing.
The tests were performed and recorded by a single optometrist in the same testing room with similar lighting conditions. For every round of testing, the right eye was examined first, followed by the left eye. For the right eye, numbers chart (PV No. 2702A) and letters chart (PV No. 2173) were used. For the left eye, the numbers chart (PV No. 2714A) and letters chart (PV No. 2174) were used. Different charts (with the same optotypes but in different order) were used for right and left eyes to minimize the effect of learning between consecutive tests.
- Conditions
- Visual Acuity
- Being tested
- Visual acuity assessment by ETDRS charts
- Keywords
- ETDRS visual acuity, English alphabet illiterate, ETDRS number chart
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Visual acuity assessment by ETDRS chartsDiagnostic test
All participants must complete VA measurement of both eyes using 2 charts including the ETDRS letters chart and ETDRS numbers chart.
| Study group | Role | What they receive |
|---|---|---|
| English alphabet illiterate group | Experimental | Individuals with no self-reported understanding of English alphabet and recognition of <6/10 Sloan Letters Receives: Diagnostic Test: Visual acuity assessment by ETDRS charts |
| English alphabet literate group | Active comparator | Individuals with self-reported understanding of English alphabet and recognition of ≥6/10 Sloan Letters Receives: Diagnostic Test: Visual acuity assessment by ETDRS charts |
What is being measured
The primary outcome is the main question the study is designed to answer.
BCVA Measurements
Assessment of BCVA using ETDRS numbers and letters chart and its comparison between the testing groups and intervention methods. All visual acuity tests were performed at 3 metres with at least 15 seconds between each chart. Subjects were asked to read as many optotypes as possible according to the ICO Visual Acuity Measurement Standard.
Measured: 1 day
Testing Duration
Assessment of testing duration using ETDRS numbers and letters and its comparison between the testing groups and intervention methods. The testing durations of each visual acuity test were measured and recorded by a single timekeeper with a standard digital chronometer.
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Aug 2020
- Study start1 Aug 2019
- Primary completion31 Jan 2020
- Study completion31 Jan 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (10)Papers the sponsor has linked to this study.
- Other trials for Visual AcuityStudies of the same condition, open and under way.
- More trials run by The University of Hong KongThe 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
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Prospective randomized controlled trial
- Masking
- None (open label)
- Enrolment
- 59 participants (actual)
Sponsor and investigators
- Lead sponsor
- The University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dr. Nicholas Fung, The University of Hong Kong
- Investigators
- Nicholas Fung, Principal investigator, Department of Ophthalmology, HKU
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04520243
- Sponsor's protocol ID
- ELEVEN
- Acronym
- ELEVEN
- Status last verified
- Aug 2020
- First submitted
- 17 Aug 2020
- Last updated
- 20 Aug 2020
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: By request to corresponding users
Publications
Bailey IL, Lovie JE. New design principles for visual acuity letter charts. Am J Optom Physiol Opt. 1976 Nov;53(11):740-5. doi: 10.1097/00006324-197611000-00006.
PubMed 998716Ferris FL 3rd, Bailey I. Standardizing the measurement of visual acuity for clinical research studies: Guidelines from the Eye Care Technology Forum. Ophthalmology. 1996 Jan;103(1):181-2. doi: 10.1016/s0161-6420(96)30742-2. No abstract available.
PubMed 8628551Kniestedt C, Stamper RL. Visual acuity and its measurement. Ophthalmol Clin North Am. 2003 Jun;16(2):155-70, v. doi: 10.1016/s0896-1549(03)00013-0.
PubMed 12809155Chaikitmongkol V, Nanegrungsunk O, Patikulsila D, Ruamviboonsuk P, Bressler NM. Repeatability and Agreement of Visual Acuity Using the ETDRS Number Chart, Landolt C Chart, or ETDRS Alphabet Chart in Eyes With or Without Sight-Threatening Diseases. JAMA Ophthalmol. 2018 Mar 1;136(3):286-290. doi: 10.1001/jamaophthalmol.2017.6290.
PubMed 29346499Koenig S, Tonagel F, Schiefer U, Bach M, Heinrich SP. Assessing visual acuity across five disease types: ETDRS charts are faster with clinical outcome comparable to Landolt Cs. Graefes Arch Clin Exp Ophthalmol. 2014 Jul;252(7):1093-9. doi: 10.1007/s00417-014-2670-y. Epub 2014 May 28.
PubMed 24867313Treacy MP, Hurst TP, Conway M, Duignan ES, Dimitrov BD, Brennan N, Cassidy L. The early treatment in diabetic retinopathy study chart compared with the tumbling-E and Landolt-C. Ophthalmology. 2015 May;122(5):1062-3.e1. doi: 10.1016/j.ophtha.2014.11.024. Epub 2015 Jan 10. No abstract available.
PubMed 25582784Kuo HK, Kuo MT, Tiong IS, Wu PC, Chen YJ, Chen CH. Visual acuity as measured with Landolt C chart and Early Treatment of Diabetic Retinopathy Study (ETDRS) chart. Graefes Arch Clin Exp Ophthalmol. 2011 Apr;249(4):601-5. doi: 10.1007/s00417-010-1461-3. Epub 2010 Jul 24.
PubMed 20658145Ruamviboonsuk 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 14516806Doig GS, Simpson F. Randomization and allocation concealment: a practical guide for researchers. J Crit Care. 2005 Jun;20(2):187-91; discussion 191-3. doi: 10.1016/j.jcrc.2005.04.005.
PubMed 16139163Universal C: Visual Acuity Measurement Standard. Visual Functions Committee 1984.
Study at a glance
From the registry record, last updated by the sponsor on 20 Aug 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Letters Versus Numbers (ELEVEN) Study: ETDRS Visual Acuity Chart Performance in an English Alphabet Illiterate Population
- ClinicalTrials.gov ID
- NCT04520243
- Acronym / sponsor ID
- ELEVEN / ELEVEN
- Conditions
- Visual Acuity
- Keywords
- ETDRS visual acuity, English alphabet illiterate, ETDRS number chart
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 59 participants (actual)
- Lead sponsor
- The University of Hong KongUniversity, hospital or other
- Study start
- 1 Aug 2019 (actual)
- Primary completion
- 31 Jan 2020 (actual)
- Study completion
- 31 Jan 2020 (actual)
- First posted
- 20 Aug 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.
This is a prospective randomised controlled trial to determine the performance of Best Corrected Visual Acuity (BCVA) scores using the ETDRS number chart were compared with ETDRS alphabet chart in healthy eyes of patients who do not recognise the English alphabet.
Detailed description
BACKGROUND: The measurement of visual acuity is important in the clinical setting to assess visual function and treatment response, while in research to provide objective clinical outcomes. The current gold standard for visual acuity measurement in most research studies, including major clinical trials, is the Early Treatment Diabetic Retinopathy Study (ETDRS) chart designed by Bailey and Lovie. However, this may not be suitable for participants who are illiterate. Alternatives exist, including the ETDRS numbers chart, Landolt C chart and Tumbling E chart. Existing studies show that the Landolt C and Tumbling E charts are alternatives with agreement with ETDRS letters chart in healthy and diseased eyes. However, the charts are limited by their 25% (if four orientations) or 12.5% (if eight orientations) chance of guessing the orientation of the letter.
The ETDRS numbers chart may overcome this limitation, as it uses five unique numbers instead of a single rotating letter. There are few studies evaluating the different types of visual acuity measurement among those unfamiliar with the English alphabet. Though one study shows high repeatability and agreement between the ETDRS letters and numbers charts in healthy and diseased eyes of English literate individuals and shorter testing duration when using the numbers chart, this finding has not been validated in individuals unfamiliar with the English alphabet. This study aims to evaluate how the ETDRS letters and numbers charts compare in individuals unfamiliar with the English alphabet.
METHODS: Eligible subjects were divided into 2 groups according to level of literacy. Literacy was determined by self-reported exposure to the English alphabet and recognition of the 10 Sloan letters (C, D, H, K, N, O, R, S, V, and Z). Subjects included were classified into the 2 groups: group A, with no exposure to the English alphabet and recognition of <6/10 letters, and group B, with exposure to the English alphabet and recognition of ≥6/10 letters.
Testing: Each subject underwent 2 rounds of BCVA measurements using 2 types of ETDRS charts in randomized sequence as follows: LN or NL (L = ETDRS letters chart, N = ETDRS numbers chart) from Precision Vision® (PV). The randomization of the testing sequence was performed by a study coordinator independent of study recruiter, optometrist or investigator. Sequentially numbered, opaque and sealed envelopes were used for allocation concealment and opened by the optometrist prior to testing.
The tests were performed and recorded by a single optometrist in the same testing room with similar lighting conditions. For every round of testing, the right eye was examined first, followed by the left eye. For the right eye, numbers chart (PV No. 2702A) and letters chart (PV No. 2173) were used. For the left eye, the numbers chart (PV No. 2714A) and letters chart (PV No. 2174) were used. Different charts (with the same optotypes but in different order) were used for right and left eyes to minimize the effect of learning between consecutive tests.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Prospective randomized controlled trial
| Arm | Type | Receives |
|---|---|---|
| English alphabet illiterate group | Experimental | Diagnostic Test: Visual acuity assessment by ETDRS chartsIndividuals with no self-reported understanding of English alphabet and recognition of <6/10 Sloan Letters |
| English alphabet literate group | Active comparator | Diagnostic Test: Visual acuity assessment by ETDRS chartsIndividuals with self-reported understanding of English alphabet and recognition of ≥6/10 Sloan Letters |
Who may qualify
- Ages
- 50 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Hong Kong residents
- Age 50 years or above
- Attending Southern District Screening program
Key exclusion criteria (2 listed)
- BCVA 20/200 or below
- Any clinically relevant ocular disease that might affect visual acuity
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 assessment by ETDRS chartsAll participants must complete VA measurement of both eyes using 2 charts including the ETDRS letters chart and ETDRS numbers chart. | Diagnostic test | English alphabet illiterate group, English alphabet literate group |
Primary outcome
BCVA Measurements
Time frame: 1 day
Assessment of BCVA using ETDRS numbers and letters chart and its comparison between the testing groups and intervention methods. All visual acuity tests were performed at 3 metres with at least 15 seconds between each chart. Subjects were asked to read as many optotypes as possible according to the ICO Visual Acuity Measurement Standard.
Testing Duration
Time frame: 1 day
Assessment of testing duration using ETDRS numbers and letters and its comparison between the testing groups and intervention methods. The testing durations of each visual acuity test were measured and recorded by a single timekeeper with a standard digital chronometer.
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 Aug 2020.
- Background: PubMed 998716Bailey IL, Lovie JE. New design principles for visual acuity letter charts. Am J Optom Physiol Opt. 1976 Nov;53(11):740-5. doi: 10.1097/00006324-197611000-00006.
- Background: PubMed 8628551Ferris FL 3rd, Bailey I. Standardizing the measurement of visual acuity for clinical research studies: Guidelines from the Eye Care Technology Forum. Ophthalmology. 1996 Jan;103(1):181-2. doi: 10.1016/s0161-6420(96)30742-2. No abstract available.
- Background: PubMed 12809155Kniestedt C, Stamper RL. Visual acuity and its measurement. Ophthalmol Clin North Am. 2003 Jun;16(2):155-70, v. doi: 10.1016/s0896-1549(03)00013-0.
- Background: PubMed 29346499Chaikitmongkol V, Nanegrungsunk O, Patikulsila D, Ruamviboonsuk P, Bressler NM. Repeatability and Agreement of Visual Acuity Using the ETDRS Number Chart, Landolt C Chart, or ETDRS Alphabet Chart in Eyes With or Without Sight-Threatening Diseases. JAMA Ophthalmol. 2018 Mar 1;136(3):286-290. doi: 10.1001/jamaophthalmol.2017.6290.
- Background: PubMed 24867313Koenig S, Tonagel F, Schiefer U, Bach M, Heinrich SP. Assessing visual acuity across five disease types: ETDRS charts are faster with clinical outcome comparable to Landolt Cs. Graefes Arch Clin Exp Ophthalmol. 2014 Jul;252(7):1093-9. doi: 10.1007/s00417-014-2670-y. Epub 2014 May 28.
- Background: PubMed 25582784Treacy MP, Hurst TP, Conway M, Duignan ES, Dimitrov BD, Brennan N, Cassidy L. The early treatment in diabetic retinopathy study chart compared with the tumbling-E and Landolt-C. Ophthalmology. 2015 May;122(5):1062-3.e1. doi: 10.1016/j.ophtha.2014.11.024. Epub 2015 Jan 10. No abstract available.
- Background: PubMed 20658145Kuo HK, Kuo MT, Tiong IS, Wu PC, Chen YJ, Chen CH. Visual acuity as measured with Landolt C chart and Early Treatment of Diabetic Retinopathy Study (ETDRS) chart. Graefes Arch Clin Exp Ophthalmol. 2011 Apr;249(4):601-5. doi: 10.1007/s00417-010-1461-3. Epub 2010 Jul 24.
- Background: 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.
- Background: PubMed 16139163Doig GS, Simpson F. Randomization and allocation concealment: a practical guide for researchers. J Crit Care. 2005 Jun;20(2):187-91; discussion 191-3. doi: 10.1016/j.jcrc.2005.04.005.
- BackgroundUniversal C: Visual Acuity Measurement Standard. Visual Functions Committee 1984.
- Individual participant dataSharing planned: Yes. By request to corresponding users
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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.
Nicholas Fung principal investigator
Department of Ophthalmology, HKU
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Visual acuity assessment by ETDRS charts in people with Visual Acuity, run by The University of Hong Kong at 1 site in Hong Kong.
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 3 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: finished, as of the sponsor's last update on 20 Aug 2020. 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 Hong Kong. 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?
BCVA Measurements (time frame: 1 day). The study lists 2 primary outcomes in all. 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 NCT04520243, which also lists 10 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 20 Aug 2020.