Assessing visual acuity across five disease types: ETDRS charts are faster with clinical outcome comparable to Landolt Cs
- 305 Downloads
Given the diversity of visual acuity tests being employed across the world, we compared two frequently applied tests: ETDRS charts and an eight-orientation projected Landolt C test in accordance with ISO 8596 and DIN 58220 part 3. The goals of the investigation were to determine (i) test agreement and (ii) test–retest reliability, to assess (iii) test durations, and (iv) the acceptance of the tests by the examinees as well as the subjects’ coping with the tests as rated by the examiner.
Seventy-five adult subjects with a visual acuity of ≥0.2 (4/20) were included in one of the following groups: normal, media opacity, maculopathy, optic neuropathy, (post)chiasmal lesion, or amblyopia. Visual acuity testing was carried out monocularly, in balanced randomized order and in two runs for each test on the same eye, applying forced choice.
Agreement: Within each group, all tests were performed similarly, within ±0.048 logMAR. Reliability: Across all subject groups, with a probability of 95 %, test–retest differences were <0.18 logMAR for both ETDRS and Landolt tests. Duration: The Landolt test lasted, on average, 1.8 times longer than ETDRS charts (p < 0.001). Acceptance: Examinees preferred the ETDRS test (p < 0.001), the examiner on average had no preference.
The Landolt C test and the ETDRS test yielded comparable results in visual acuity and test–retest reliability in all disease groups. The ETDRS test was usually faster and more accepted by both examiners and examinees than the Landolt test.
KeywordsVisual acuity Test–retest reliability Reproducibility Landolt C ETDRS chart Duration Acceptance Comparison Agreement
We express our gratitude to the Deutsche Ophthalmologische Gesellschaft (DOG), which supported this research project financially. We thank our subjects for their participation in this study. Also thanks to the staff of the neuro-ophthalmologic department of the University Eye Hospital Tuebingen, where this study was carried out, for their support.
Conflict of interest statement
Author Ulrich Schiefer is consultant for HAAG-STREIT Inc., Koeniz, Switzerland and SERVIER Inc., Suresness, France.
All other authors: conflict of Interest—None.
- 2.NEI Clinical Studies (2000) Early Treatment Diabetic Retinopathy Study (ETDRS). http://www.nei.nih.gov/neitrials/static/study53.asp. Accessed 14 Feb 2014
- 4.International Organization for Standardization (2009) ISO 8596:2009 Ophthalmic optics—Visual acuity testing—Standard optotype and its presentation. http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=52487. Accessed 10 Sep 2013
- 5.Deutsches Institut für Normung (2013) DIN 58220 Teil 3—Sehschärfebestimmung: Prüfung für Gutachten. http://www.nafuo.din.de/cmd?level=tpl-art-detailansicht&artid=189487179. Accessed 14 Feb 2014
- 6.Bach M (2013) Freiburg Visual Acuity & Contrast Test, homepage. In: Freibg. Vis. Test FrACT. http://michaelbach.de/fract/. Accessed 5 Jun 2013
- 8.Teichler G (2009) Untersuchungen zum Vergleich der Sehzeichen Landolt-Ring, E-Haken und Sloan-Buchstaben (ETDRS-Letters) sowie zur Reproduzierbarkeit der Visusbestimmung (with English summary). Thesis <http://geb.uni-giessen.de/geb/volltexte/2009/7249/>, Justus-Liebig-Universität
- 9.World Medical Association (1964) Declaration of Helsinki—Ethical Principles for Medical Research Involving Human Subjects. http://www.wma.net/en/30publications/10policies/b3/. Accessed 26 Apr 2013
- 10.Deutsche Ophthalmologische Gesellschaft (2013) Empfehlungen der DOG zur Qualitätssicherung bei sinnesphysiologischen Untersuchungen und Geräten. 7–23Google Scholar
- 11.Kingdom FAA, Prins N (2009) Psychophysics: a practical introduction. Academic, LondonGoogle Scholar
- 12.Heinrich SP, Krüger K, Bach M (2011) The dynamics of practice effects in an optotype acuity task. Graefes Arch Clin Exp Ophthalmol 249:1319–1326Google Scholar
- 14.Wesemann W, Schiefer U, Bach M (2010) New DIN norms for determination of visual acuity. Ophthalmol Z Dtsch Ophthalmol Ges 107:821–826Google Scholar
- 15.Steinbeis Transfer Center Biomedical Optics and Function Tests—ETDRS Visual Acuity Tester. http://www.uak.medizin.uni-tuebingen.de/stz/etdrs.htm. Accessed 26 Apr 2013
- 17.Precision Vision Revised 2000 Series ETDRS Translucent Eye Charts for use in clinical studies and low vision evaluation. http://precision-vision.com/index.cfm/category/36/revised-2000-series-etdrs-charts.cfm?CFID=38487182&CFTOKEN=743288e2a63ab233-5A83B749-DB92-AA06-57F3F9DBE8BB3A57. Accessed 7 Aug 2013
- 18.Krzanowski W (2010) An introduction to statistical modelling, 1. Wiley, ChichesterGoogle Scholar
- 19.Sheskin DJ (2007) Handbook of parametric and nonparametric statistical procedures, 4. Chapman & Hall / CRC, Boca RatonGoogle Scholar
- 21.Cleveland WS, McGill R (1984) The many faces of a scatterplot. J Am Stat Assoc 79:807–822Google Scholar
- 22.Petersen J (1993) Erroneous vision determination and quantitative effects. Ophthalmol Z Dtsch Ophthalmol Ges 90:533–538Google Scholar