Comparison of the Freiburg Visual Acuity Test (FrACT) With the EDTRS- and Landoltring Charts (FEL)

November 22, 2016 updated by: Schiefer Ulrich

Comparison of the Freiburg Visual Acuity Test (FrACT) With the EDTRS- and Landoltring Charts: a) Assessment of the Inter-test Agreement and the Test-retest Reliability b) Analysis of Examinees' / Examiner's Subjective Rating and of Test Durations

A) For the investigation of Visual acuity, inter-test agreement and the test-retest reliability were used three different visual acuity tests: ETDRS charts, Landoltring chart and Freiburg Visual Acuity Test (FrACt). The examinees passed each visual acuity test twice but the sequence of the visual acuity tests were randomize and so different for each examinee. The examinees were 24 adult Aalen university students (except students of ophthalmic optics in terms 2 - 7) with a minimal distant visual acuity without or with correction of 0.2. Another inclusion criteria was a maximum myopia of sph -2,00 dpt, a maximum hyperopia of sph +5,50 dpt and a maximum astigmatism of cyl 2,50 dpt. The Landolt C was projected in eight-orientations. For the FrACT Test we used two different devices for response input: a modified keypad with Landoltring symbols (FrACTk) and a haptic Landolt device with an adjustable Landoltring (FrACTh). The primary objective was the comparison between FrACTk and FrACTh. The secondary Objective contains the comparison between all visual acuity tests.

B) Background: Landolt Cs and letters are commonly used optotypes. In the explorative study we compare four different ways of applying them: The Freiburg visual acuity test (FrACT) using a keypad and a haptic Landolt device, a Landolt C chart in accordance to ISO 8596 and DIN 58220 with eight-orientated Landolt C and ETDRS charts. The aims of the survey were to determine examinee´s/examiner´s subjective ratings using Visual analogue scales (VAS), the inter-test agreement between the tests and test-retest reliability of the tests, concerning the test duration.

Subjects and Methods: Twenty-four adult examinees with a visual acuity of ≥ 0,2 were included in the explorative study. The visual acuity of one eye was measured monocularly, randomized with regard to the leading/non-leading eye. The subjects passed every visual acuity test twice in a randomized sequence of the visual acuity tests, which is maintained by a pre-specified randomization list, making use of forced choice.

Study Overview

Detailed Description

  1. FrACT (internet version 3.8.1) 1.1 haptic Landolt Ring device (FrACTh) 1.2 modified keypad with Landolt Ring symbols (FrACTk)
  2. ETDRS Visual Acuity Tester (Steinbeis Transferzentrum Biomedizinische Optik, Tübingen/Germany)
  3. Landoltring chart (Visus GmbH, Stuttgart/Germany)
  4. VISUCAT monitor with single optotype display(numbers; Argus Individuell Optic GmbG, Putzbrunn/Germany)
  5. Room illuminance level 250 lx, assessed with digital luxmeter (Peak Tech 5025, Peak Tech Prüf - und Messtechnik GmbH, Ahrensburg/Germany)
  6. Laptopdisplay (TravelMate, Acer, 8372 Taipeh/China):

    luminance level 151 cd/m2 , surround luminance level 75 cd/m2 , assessed with luminance meter (IS-110 Laptop Minolta, Tokyo/Japan)

  7. ETDRS Visual Acuity Tester:

    luminance level: 237 cd/m², surround luminance level 85 cd/m²

  8. Landoltring Chart:

    luminance level: 236 cd/m², surround luminance level 84 cd/m²

  9. VISUCAT:

    luminance level: 380 cd/m², surround luminance level 70 cd/m²

  10. Stopwatch (Apple iPhone 4S, Cupertino CA/USA)
  11. Laser Rangefinder (GLM 80 Professional, Bosch GmbH, Stuttgart/Germany)

Study Type

Observational

Enrollment (Actual)

25

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Baden-Württemberg
      • Aalen, Baden-Württemberg, Germany, 73430
        • University of Applied Sciences, Study Course Ophthalmic Optics

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Ophthalmologically normal subjects

Description

Inclusion Criteria:

  • age ≥ 18 years
  • Minimum distant visual acuity (without/with correction) 0.2 (Visucat, single letter optotypes [numbers], initial session). As long as minimum distant visual acuity limits are exceeded, test runs without optical corrections are preferred in order to enhance the spectrum/variety of tested visual acuity values
  • Ametropia:

maximum myopia sph -2.00 dpt maximum hyperopia sph +5.50 dpt maximum astigmatism cyl 2.5 dpt

  • informed consent

Exclusion Criteria:

  • Epilepsy / psychiatric disorders
  • Drugs affect the reaction time and / or determining the visual acuity, or the refractive power of the eye
  • Ophthalmic Education
  • Amblyopia
  • strabismus
  • Glaucoma IOP> 22 mmHg
  • Nystagmus
  • Diabetic retinopathy (blood sugar-related retinal disease)
  • Very dry eyes (sicca symptoms)
  • eye surgery back are less than 3 months
  • Infectious diseases (conjunctivitis, corneal inflammation, choroidal inflammation)
  • miosis drugs
  • Pronounced eye injuries
  • Other eye disorders that affect the image quality
  • Macular diseases
  • albinism

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
ophthalomogically normal subjects
Other Names:
  • VISUCAT
  • FrACT
  • ETDRS Chart
  • Landolt C

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
A) 1.Visual acuity (in terms of spatial resolution)
Time Frame: July - August, 2014 (1 month)
Comparison of visual acuity measurements, visualized by Bland-Altman plots
July - August, 2014 (1 month)
Inter-test agreement between FrACTh and FrACTk with regard to visual acuity results
Time Frame: July - August, 2014 (1 month)
Assessment of inter-test agreement between FrACTh and FrACTk by comparison between these two methods, visualized by Bland-Altman plots
July - August, 2014 (1 month)
Test-retest reliability of FrACTh and FrACTk with regard to visual acuity results
Time Frame: July - August, 2014 (1 month)
Assessment of test-retest reliability of FrACTh and FrACTk by repeated measurements, visualized by Bland-Altman plots
July - August, 2014 (1 month)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Examinees´ / examer's subjective ratings regarding the test procedures
Time Frame: July - August, 2014 (1 month)
Assessment of examinees´ / examiner´s subjective ratings, using box & whisker plots for analysis of the visual analogue scale (VAS) results
July - August, 2014 (1 month)
Test duration (in seconds)
Time Frame: July - August, 2014 (1 month)
Assessment of test duration and its comparison, using box & whisker plots and/or Bland-Altman plots
July - August, 2014 (1 month)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Ulrich Schiefer, Prof. Dr. med., University of Applied Sciences Aalen

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

June 1, 2014

Primary Completion (Actual)

October 1, 2014

Study Completion (Actual)

June 1, 2015

Study Registration Dates

First Submitted

July 21, 2014

First Submitted That Met QC Criteria

July 22, 2014

First Posted (Estimate)

July 23, 2014

Study Record Updates

Last Update Posted (Estimate)

November 23, 2016

Last Update Submitted That Met QC Criteria

November 22, 2016

Last Verified

November 1, 2016

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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