Repeatability and Concordance of VA Measured With ETDRS Numeric , Landolt C, and Letter Charts in Thai Individuals

NCT ID: NCT02810665

Last Updated: 2016-06-23

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

UNKNOWN

Total Enrollment

180 participants

Study Classification

OBSERVATIONAL

Study Start Date

2015-07-31

Study Completion Date

2016-07-31

Brief Summary

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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

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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

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Visual Nonspecific

Study Design

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Observational Model Type

CASE_ONLY

Study Time Perspective

CROSS_SECTIONAL

Study Groups

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Normal vision group

Individuals with VA 20/20 to 20/25

Visual acuity measurement by ETDRS chart

Intervention Type BEHAVIORAL

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.

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

Visual acuity measurement by ETDRS chart

Intervention Type BEHAVIORAL

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.

Interventions

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Visual acuity measurement by ETDRS chart

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.

Intervention Type BEHAVIORAL

Eligibility Criteria

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Inclusion Criteria

* Thai nationality
* More than 18 years of age
* Educational level: at least high school
* Able to read English alphabet
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Chiang Mai University

OTHER

Sponsor Role lead

Responsible Party

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Voraporn Chaikitmongkol

Instructor

Responsibility Role PRINCIPAL_INVESTIGATOR

Locations

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Voraporn Chaikitmongkol

Muang Chiang Mai, Chiang Mai, Thailand

Site Status RECRUITING

Countries

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Thailand

Central Contacts

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Voraporn Chaikitmongkol, MD

Role: CONTACT

66-53-93-5512

Onnisa Nanegrungsunk, MD

Role: CONTACT

66-53-93-5512

Facility Contacts

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Voraporn Chaikitmongkol, MD

Role: primary

66-53-935512

Onnisa Nanegrungsunk, MD

Role: backup

References

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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.

Reference Type RESULT
PMID: 9575537 (View on PubMed)

Ferris FL 3rd, Kassoff A, Bresnick GH, Bailey I. New visual acuity charts for clinical research. Am J Ophthalmol. 1982 Jul;94(1):91-6.

Reference Type RESULT
PMID: 7091289 (View on PubMed)

Kaiser 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.

Reference Type RESULT
PMID: 20126505 (View on PubMed)

Ruamviboonsuk 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.

Reference Type RESULT
PMID: 14516806 (View on PubMed)

Other Identifiers

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OPT-2558-03133

Identifier Type: -

Identifier Source: org_study_id

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