| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 From the Department of Vision Sciences, Aston University, Birmingham; 2 Business School, Aston University, Birmingham, United Kingdom; and the 3 School of Optometry, University of Waterloo; the 4 Department of Ophthalmology, University of Toronto; and the 5 Glaucoma Research Unit, Toronto Hospital, Ontario, Canada.
PURPOSE. To determine, in stable glaucoma, the characteristics of the between-examination variability of the visual field recorded with the Humphrey Field Analyser (HFA; Humphrey Systems, Dublin, CA) using the homogeneous, LF(Ho), and heterogeneous, LF(He), components of the long-term fluctuation (LF), thereby providing a technique for separating progressive loss from fluctuation in sensitivity.
METHODS. The LF components were calculated using a two-factor analysis of variance (ANOVA) with replications and were determined between each pair of three successive HFA program 30-2 fields for each patient from two groups, each containing 30 patients with primary open-angle glaucoma. The interval between examinations for the first group was 6 to 9 months and for the second group was 3 weeks.
RESULTS. The group mean values for LF(Ho) ranged from 1.50 to 2.19 dB and for LF(He) from 1.70 to 2.05 dB. The average difference between examinations was within ±0.35 dB for each component, and the 95% limits of agreement for the two groups, respectively, were ± 2.31 and ± 2.39 dB for the LF(Ho) and ± 2.36 and ± 2.09 dB for the LF(He). The estimate of the 90% confidence limit for the LF(Ho) was 3.30 dB and for the LF(He), 3.60 dB. Little relationship was present between the LF components and the modulus differences in mean deviation (MD), the corrected pattern SD (CPSD), or the mean MD, mean short-term fluctuation, and mean CPSD, of the two fields.
CONCLUSIONS. Estimation of the LF components and of the corresponding confidence limits yields an expression of the normal between-examination variability of two consecutive fields that can be used as a reliability index. A value outside the confidence limits indicates the necessity for a confirmatory follow-up field.
This article has been cited by other articles:
|
|
 |
|
  P. Fogagnolo, A. McNaught, M. Centofanti, L. Rossetti, and N. Orzalesi The Effects of Intraocular Pressure Reduction on Perimetric Variability in Glaucomatous Eyes Invest. Ophthalmol. Vis. Sci., October 1, 2007; 48(10): 4557 - 4563. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. G. Strouthidis, A. Scott, A. C. Viswanathan, D. P. Crabb, and D. F. Garway-Heath Monitoring Glaucomatous Visual Field Progression: The Effect of a Novel Spatial Filter Invest. Ophthalmol. Vis. Sci., January 1, 2007; 48(1): 251 - 257. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. W. Gillespie, D. C. Musch, K. E. Guire, R. P. Mills, P. R. Lichter, N. K. Janz, and P. A. Wren The Collaborative Initial Glaucoma Treatment Study: Baseline Visual Field and Test-Retest Variability Invest. Ophthalmol. Vis. Sci., June 1, 2003; 44(6): 2613 - 2620. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S K Gardiner and D P Crabb Frequency of testing for detecting visual field progression Br. J. Ophthalmol., May 1, 2002; 86(5): 560 - 564. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Hutchings, S. L. Hosking, J. M. Wild, and J. G. Flanagan Long-term Fluctuation in Short-Wavelength Automated Perimetry in Glaucoma Suspects and Glaucoma Patients Invest. Ophthalmol. Vis. Sci., September 1, 2001; 42(10): 2332 - 2337. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
