Refractive ErrorsDDVITNCT04756596
A Web-based Digital Distance Visual Acuity Test
An observational study of Refractive Errors and Low Vision, run by Democritus University of Thrace at 2 sites in Greece.
Trial summary
Primary objective of this study is the development and validation of a web-based application for the examination of the distance visual acuity of normal- and low-vision patients. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Refractive Errors, Low Vision, Vision Disorders
- What is being tested?
- DDVIT testing and ETDRS testing
- How many people
- 300 participants
- Where
- 2 sitesGreece
- Study dates
- 1 Feb 2021to 30 Jun 2022
- How long will I take part?
- 15 Days
- 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 75 years
- All sexes
- Adult, Older adult
Study population: Normal- and low-sighted participants aged 18 to 75 years.
Who may be able to join
- Patients of our outpatient ophthalmology clinic
- Age between 18 to 75 years
Who cannot join
- Dyslexia
- Attention-deficiency
- Former diagnosis of mental and/or psychiatric diseases
- Inability to cooperate
Trial locations and contacts
2 sites in 1 country.
Greece2 sites, 2 recruiting
- Recruiting
Department of Ophthalmology, University Hospital of Alexandroupolis
Alexandroupoli, Evros, 68100
Georgios Labiris, MD, PhD, 00302551030405, labiris@usa.net
- Not yet recruiting
Department of Computer Science and Biomedical Informatics, University of Thessaly
Lamía, Thessaly, 35100
Konstantinos Delibasis, PhD, 00306945548479, kdelibasis@gmail.com
About this study
Official title: Development and Validation of a Web-based Digital Distance Visual Acuity Test
Primary objective of this study is the development and validation of a web-based application for the examination of the distance visual acuity of normal- and low-vision patients.
Read the detailed description
Present study aims to develop and validate a web-based digital distance visual acuity test (Democritus Distance Vision Test - DDVIT). DDVIT is an application, which will be easily accessed through a simple internet connection. This application will provide the possibility of a simple but reliable examination of patients, establishing a commonly accepted way of measuring the distance visual acuity among rural doctors, general practitioners and ophthalmologists.
Specifically, present study aims to develop a new online distance visual acuity test (DDVIT) according to the standards of the Early Treatment Diabetic Retinopathy Study (ETDRS) test and to evaluate the level of agreement between the two visual acuity tests, as well as the test-retest reliability of the online DDVIT visual acuity test.
The first part of the study is the development of the online visual acuity test (letters, numbers, symbols) including the following smart features:
- Adjustment of the font size according to the size of the computer screen used for the examination
- Real time calculation of the patient-screen distance through a face detection system
- Automatic calculation of the reading time of each line (each logMAR)
- Entering the number of patient's reading errors for each line
- Automatic calculation of the visual acuity in the following score units:
- Number of Letters (max 85)
- Visual Acuity Score (max 100)
- logMAR
- Decimal
- Snellen Fraction
The calculation of various reading parameters resulting from the aforementioned features (visual acuity score in different units, reading duration (in sec) and number of errors for each slide (line), patient-screen distance for each slide) will be performed after the end of the examination. Except for the html format, a file in the format of Microsoft Excel and Pdf are also generated.
The second part of this study is the clinical validation of the DDVIT visual acuity test. In this part, the reading acuity measured with the DDVIT and ETDRS test are compared.
All the comparisons will take place in two groups: a) a Normal Vision Group (NVG), and b) a Low Vision Group (LVG) in order to estimate the visual acuity in a population with a wide range of vision.
- Conditions
- Refractive Errors, Low Vision, Vision Disorders
- Being tested
- DDVIT testing, ETDRS testing
- Keywords
- web application, distance visual acuity, smart features, face detection, text calibration
- Medical subject headings
- Refractive Errors, Vision, Low, Vision Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
DDVIT testingDiagnostic test
One randomly selected eye will be included for each study participant. Participants respond to the DDVIT test in standard environmental lighting conditions at 4 m viewing distance. Visual acuity will be evaluated.
ETDRS testingDiagnostic test
The same eye is included for each study participant. Participants respond to the standard ETDRS chart of our Ophthalmology Department in standard environmental lighting conditions at 4 m viewing distance. Visual acuity will be evaluated.
| Study group | Role | What they receive |
|---|---|---|
| Study group | 70 patients with normal vision (NVG) 30 patients with low vision (LVG) These patients will be tested on the DDVIT Receives: Diagnostic Test: DDVIT testing; Diagnostic Test: ETDRS testing |
What is being measured
The primary outcome is the main question the study is designed to answer.
Distance visual acuity using DDVIT vision test
The distance visual acuity of the one randomly selected eye of each participant will be evaluated by the examiner using DDVIT vision test.
Measured: 4 months
Distance visual acuity using ETDRS vision test
The distance visual acuity of the same eye of each participant will be evaluated by the same examiner using the web-based ETDRS vision test under the same predetermined environmental lighting conditions.
Measured: 4 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Feb 2021
- Study start1 Feb 2021
- Primary completion31 May 2022 (estimated)
- Study completion30 Jun 2022 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Refractive ErrorsStudies 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
- 300 participants (estimated)
- Target duration
- 15 Days
Sponsor and investigators
- Lead sponsor
- Democritus University of Thrace
- Sponsor type
- University, hospital or other
- Collaborators
- University of Thessaly
- Responsible party
- Principal investigator, Georgios Labiris, Democritus University of Thrace
- Investigators
- Georgios Labiris, MD, PhD, Study chair, Department of Ophthalmology, University Hospital of Alexandroupolis, Alexandroupolis, Greece
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04756596
- Sponsor's protocol ID
- ES1/Th6/21-1-2021
- Acronym
- DDVIT
- Status last verified
- Nov 2021
- First submitted
- 12 Feb 2021
- Last updated
- 16 Nov 2021
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 16 Nov 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Development and Validation of a Web-based Digital Distance Visual Acuity Test
- ClinicalTrials.gov ID
- NCT04756596
- Acronym / sponsor ID
- DDVIT / ES1/Th6/21-1-2021
- Conditions
- Refractive Errors, Low Vision, Vision Disorders
- Keywords
- web application, distance visual acuity, smart features, face detection, text calibration
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- Democritus University of ThraceUniversity, hospital or other
- Collaborators
- University of Thessaly
- Study start
- 1 Feb 2021 (actual)
- Primary completion
- 31 May 2022 (estimated)
- Study completion
- 30 Jun 2022 (estimated)
- First posted
- 16 Feb 2021 (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.
Primary objective of this study is the development and validation of a web-based application for the examination of the distance visual acuity of normal- and low-vision patients.
Detailed description
Present study aims to develop and validate a web-based digital distance visual acuity test (Democritus Distance Vision Test - DDVIT). DDVIT is an application, which will be easily accessed through a simple internet connection. This application will provide the possibility of a simple but reliable examination of patients, establishing a commonly accepted way of measuring the distance visual acuity among rural doctors, general practitioners and ophthalmologists.
Specifically, present study aims to develop a new online distance visual acuity test (DDVIT) according to the standards of the Early Treatment Diabetic Retinopathy Study (ETDRS) test and to evaluate the level of agreement between the two visual acuity tests, as well as the test-retest reliability of the online DDVIT visual acuity test.
The first part of the study is the development of the online visual acuity test (letters, numbers, symbols) including the following smart features:
- Adjustment of the font size according to the size of the computer screen used for the examination
- Real time calculation of the patient-screen distance through a face detection system
- Automatic calculation of the reading time of each line (each logMAR)
- Entering the number of patient's reading errors for each line
- Automatic calculation of the visual acuity in the following score units:
- Number of Letters (max 85)
- Visual Acuity Score (max 100)
- logMAR
- Decimal
- Snellen Fraction
The calculation of various reading parameters resulting from the aforementioned features (visual acuity score in different units, reading duration (in sec) and number of errors for each slide (line), patient-screen distance for each slide) will be performed after the end of the examination. Except for the html format, a file in the format of Microsoft Excel and Pdf are also generated.
The second part of this study is the clinical validation of the DDVIT visual acuity test. In this part, the reading acuity measured with the DDVIT and ETDRS test are compared.
All the comparisons will take place in two groups: a) a Normal Vision Group (NVG), and b) a Low Vision Group (LVG) in order to estimate the visual acuity in a population with a wide range of vision.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 15 Days
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Study group | – | Diagnostic Test: DDVIT testing, Diagnostic Test: ETDRS testing70 patients with normal vision (NVG) 30 patients with low vision (LVG) These patients will be tested on the DDVIT |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- Normal- and low-sighted participants aged 18 to 75 years.
Key inclusion criteria (2 listed)
- Patients of our outpatient ophthalmology clinic
- Age between 18 to 75 years
Key exclusion criteria (4 listed)
- Dyslexia
- Attention-deficiency
- Former diagnosis of mental and/or psychiatric diseases
- Inability to cooperate
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 |
|---|---|---|
| DDVIT testingOne randomly selected eye will be included for each study participant. Participants respond to the DDVIT test in standard environmental lighting conditions at 4 m viewing distance. Visual acuity will be evaluated. | Diagnostic test | Study group |
| ETDRS testingThe same eye is included for each study participant. Participants respond to the standard ETDRS chart of our Ophthalmology Department in standard environmental lighting conditions at 4 m viewing distance. Visual acuity will be evaluated. | Diagnostic test | Study group |
Primary outcome
Distance visual acuity using DDVIT vision test
Time frame: 4 months
The distance visual acuity of the one randomly selected eye of each participant will be evaluated by the examiner using DDVIT vision test.
Distance visual acuity using ETDRS vision test
Time frame: 4 months
The distance visual acuity of the same eye of each participant will be evaluated by the same examiner using the web-based ETDRS vision test under the same predetermined environmental lighting conditions.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Nov 2021.
- 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.
Georgios Labiris, MD, PhD study chair
Department of Ophthalmology, University Hospital of Alexandroupolis, Alexandroupolis, Greece
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Refractive Errors and Low Vision, run by Democritus University of Thrace at 2 sites in Greece.
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 4 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 16 Nov 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Greece. 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 Georgios Labiris, MD, PhD (00302551030405, labiris@usa.net), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Distance visual acuity using DDVIT vision test (time frame: 4 months). 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?
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 16 Nov 2021; AzTrials last refreshed its copy on 28 Oct 2026.