An observational study in Ophthalmologically Normal Subjects, sponsored by Schiefer Ulrich. Completed at 1 site in Germany. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2016-11-23.
Sponsored by Schiefer Ulrich · Observational
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.
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)
ETDRS Visual Acuity Tester:
luminance level: 237 cd/m², surround luminance level 85 cd/m²
Landoltring Chart:
luminance level: 236 cd/m², surround luminance level 84 cd/m²
VISUCAT:
luminance level: 380 cd/m², surround luminance level 70 cd/m²
This is the only study on the registry with Schiefer Ulrich as lead sponsor.
Counted across the registry records on this site, refreshed daily.
Ophthalmologically normal subjects
maximum myopia sph -2.00 dpt maximum hyperopia sph +5.50 dpt maximum astigmatism cyl 2.5 dpt
Exclusion Criteria:
Device: Methodology of visual acuity assessment
Also known as: VISUCAT, FrACT, ETDRS Chart, Landolt C
A) 1.Visual acuity (in terms of spatial resolution)
Comparison of visual acuity measurements, visualized by Bland-Altman plots
Time frame: July - August, 2014 (1 month)
Inter-test agreement between FrACTh and FrACTk with regard to visual acuity results
Assessment of inter-test agreement between FrACTh and FrACTk by comparison between these two methods, visualized by Bland-Altman plots
Time frame: July - August, 2014 (1 month)
Test-retest reliability of FrACTh and FrACTk with regard to visual acuity results
Assessment of test-retest reliability of FrACTh and FrACTk by repeated measurements, visualized by Bland-Altman plots
Time frame: July - August, 2014 (1 month)
Examinees´ / examer's subjective ratings regarding the test procedures
Assessment of examinees´ / examiner´s subjective ratings, using box \& whisker plots for analysis of the visual analogue scale (VAS) results
Time frame: July - August, 2014 (1 month)
Test duration (in seconds)
Assessment of test duration and its comparison, using box \& whisker plots and/or Bland-Altman plots
Time frame: July - August, 2014 (1 month)
This study is completed, as verified in Nov 2016. You cannot join it, but the record below documents what was studied.
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