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

Visual Nonspecific Clinical Trial

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

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT02810665
• Other study ID #: OPT-2558-03133
• Status: Recruiting
• Phase: N/A
• First received: June 16, 2016
• Last updated: June 20, 2016
• Start date: July 2015
• Est. completion date: July 2016

Study information

• Verified date: June 2016
• Source: Chiang Mai University
• Contact: Voraporn Chaikitmongkol, MD
• Phone: 66-53-93-5512
• Email: vchaikitmongkol[@]gmail.com
• Is FDA regulated: No
• Health authority: Thailand: Institutional Review Board
• Study type: Observational [Patient Registry]

Clinical 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.

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 180
• Est. completion date: July 2016
• Est. primary completion date: July 2016
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Thai nationality

• More than 18 years of age

• Educational level: at least high school

• Able to read English alphabet

Study Design

Observational Model: Case-Only, Time Perspective: Cross-Sectional

Related Conditions & MeSH terms

• Visual Nonspecific

Intervention

Behavioral:
• 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.

Locations

Country	Name	City	State
Thailand	Voraporn Chaikitmongkol	Muang Chiang Mai	Chiang Mai

Sponsors (1)

Lead Sponsor	Collaborator
Chiang Mai University

Country where clinical trial is conducted

Thailand, 

References & Publications (4)

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. — View Citation

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. — View Citation

Ricci F, Cedrone C, Cerulli L. Standardized measurement of visual acuity. Ophthalmic Epidemiol. 1998 Mar;5(1):41-53. Review. — View Citation

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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Concordance of VA tested with ETDRS alphabet, Landolt C and numeric visual acuity charts		Day 1	No
Secondary	Repeatability of VA tested with ETDRS alphabet, Landolt C and numeric visual acuity charts		Day 1	No
Secondary	Differences in testing duration of VA measurement across the 3 ETDRS charts		Day 1	No