| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1From the Institute of Ophthalmology, University College London, London, United Kingdom; 2Moorfields Eye Hospital, London, United Kingdom; the 3London School of Hygiene and Tropical Medicine, London, United Kingdom; and 4St. Thomas’ Hospital, London, United Kingdom.
PURPOSE. To determine the sensitivity to change and specificity achieved when published test–retest variability (TRV) data are used to determine whether measured changes in ETDRS logarithm of the minimum angle of resolution (logMAR) visual acuity reflect true clinical change or are attributable to measurement error alone.
METHODS. Various degrees of change in visual acuity were simulated in a group of normal subjects by adjusting test difficulty through manipulation of viewing distance. Sensitivity to simulated change and specificity were determined with change criteria derived from published Bland-Altman 95% ranges for TRV.
RESULTS. The relationship between viewing distance and measured acuity was as predicted theoretically. Simulated acuity change of 0.2 logMAR (two lines of letters) or greater can be reliably distinguished from no change (both sensitivity and specificity >95%) with the ETDRS chart, but a change of 0.1 logMAR or less cannot.
CONCLUSIONS. The use of 95% ranges for TRV to establish the smallest measured visual acuity change that can be reliably detected ensures a high specificity but does not take account of sensitivity. Use of change criteria derived from published 95% ranges results in a sensitivity of approximately 50% (assuming identical levels of TRV). Sensitivity may be improved by using a change criterion that is smaller than the minimum change sought, providing the change criterion is still at least as large as the 95% range for TRV, so that specificity is maintained. Reducing TRV allows smaller changes in acuity to be reliably detected.
This article has been cited by other articles:
|
|
 |
|
  E M Mowry, M J Loguidice, A B Daniels, D A Jacobs, C E Markowitz, S L Galetta, M L Nano-Schiavi, G R Cutter, M G Maguire, and L J Balcer Vision related quality of life in multiple sclerosis: correlation with new measures of low and high contrast letter acuity J. Neurol. Neurosurg. Psychiatry, July 1, 2009; 80(7): 767 - 772. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Williams, T. N. Moutray, and A. J. Jackson Uniformity of Visual Acuity Measures in Published Studies Invest. Ophthalmol. Vis. Sci., October 1, 2008; 49(10): 4321 - 4327. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. S. Zaveri, A. Conger, A. Salter, T. C. Frohman, S. L. Galetta, C. E. Markowitz, D. A. Jacobs, G. R. Cutter, G.-S. Ying, M. G. Maguire, et al. Retinal Imaging by Laser Polarimetry and Optical Coherence Tomography Evidence of Axonal Degeneration in Multiple Sclerosis Arch Neurol, July 1, 2008; 65(7): 924 - 928. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. M. Aldrich, A. W. Lee, C. S. Chen, R. F. Gottesman, M. N. Bahouth, P. Gailloud, K. Murphy, R. Wityk, and N. R. Miller Local Intraarterial Fibrinolysis Administered in Aliquots for the Treatment of Central Retinal Artery Occlusion: The Johns Hopkins Hospital Experience Stroke, June 1, 2008; 39(6): 1746 - 1750. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. W. Massof, J. T. Deremeik, W. L. Park, and L. L. Grover Self-Reported Importance and Difficulty of Driving in a Low-Vision Clinic Population Invest. Ophthalmol. Vis. Sci., November 1, 2007; 48(11): 4955 - 4962. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. G. Gonzalez, L. Tarita-Nistor, S. N. Markowitz, and M. J. Steinbach Computer-Based Test to Measure Optimal Visual Acuity in Age-Related Macular Degeneration Invest. Ophthalmol. Vis. Sci., October 1, 2007; 48(10): 4838 - 4845. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. J. Balcer, S. L. Galetta, P. A. Calabresi, C. Confavreux, G. Giovannoni, E. Havrdova, M. Hutchinson, L. Kappos, F. D. Lublin, D. H. Miller, et al. Natalizumab reduces visual loss in patients with relapsing multiple sclerosis Neurology, April 17, 2007; 68(16): 1299 - 1304. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Subramanian and C. Dickinson Spatial Localization in Visual Impairment Invest. Ophthalmol. Vis. Sci., January 1, 2006; 47(1): 78 - 85. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. K. Kiser, D. Mladenovich, F. Eshraghi, D. Bourdeau, and G. Dagnelie Reliability and Consistency of Dark-Adapted Psychophysical Measures in Advanced Eye Disease Invest. Ophthalmol. Vis. Sci., January 1, 2006; 47(1): 444 - 452. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Jalali, V. A. Essuman, and R. Thomas Clinical Application of the Revised Indications for the Treatment of Retinopathy of Prematurity Arch Ophthalmol, March 1, 2005; 123(3): 407 - 408. [Full Text] [PDF]
|
|
|
|
|
|
S. Malhotra, T. Bali, and R. Thomas The Question of Radial Optic Neurotomy in Central Retinal Vein Occlusion Arch Ophthalmol, October 1, 2004; 122(10): 1573 - 1574. [Full Text] [PDF]
|
|
|
|
|
|
D. A. Rosser, I. E. Murdoch, and S. N. Cousens The Effect of Optical Defocus on the Test-Retest Variability of Visual Acuity Measurements Invest. Ophthalmol. Vis. Sci., April 1, 2004; 45(4): 1076 - 1079. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
