The influence of sampling errors on test-retest variability in perimetry.

PURPOSE To determine whether visual fields measured by standard automated perimetry (SAP) can be distorted by higher-spatial-frequency image components and, in particular, whether test-retest variability of SAP fields can be explained by the combination of small scale fixational drift, small stimulus size, and coarse spatial sampling of the visual fields. METHODS Standard SAP test patterns have points 6° apart. The amplitude spectra of the perimeter's 10-2 fields (model 511 Humphrey Field Analyser [HFA]; Carl Zeiss Meditec, Inc., North Ryde, NSW, Australia) were assessed to see whether their finer grained sampling revealed spatial frequencies that could cause distortions of standard fields because of undersampling. Model visual fields were then constructed whose spectra were similar to the 10-2 fields, and test-retest variability was examined for Goldmann sizes III to VI stimuli and Gaussian fixational drift with standard deviations of 0.075° to 0.3°. RESULTS The 10-2 fields showed significant spatial frequency content up to 0.25 cyc/deg, three times the highest frequency that a 30-2 or 24-2 sample grid can resolve. As reported for SAP, test-retest variability increased with scotoma depth, and increasing the stimulus size from III to VI caused a reduction in test-retest variability, as did reduced fixation jitter. CONCLUSIONS With fixation drift half the size of that exhibited by good fixators, many of the features of SAP test-retest variability were reproduced. Reducing test-retest variability may therefore involve using large test stimuli that are blurry in appearance and that overlap somewhat when placed on the perimetric test grid. Overlap across the meridians should perhaps be avoided.

[1]  K. Woodward,et al.  The effective dynamic ranges of standard automated perimetry sizes III and V and motion and matrix perimetry. , 2010, Archives of ophthalmology.

[2]  B. Chauhan,et al.  Signal/noise analysis to compare tests for measuring visual field loss and its progression. , 2009, Investigative ophthalmology & visual science.

[3]  Michael Wall,et al.  Repeatability of automated perimetry: a comparison between standard automated perimetry with stimulus size III and V, matrix, and motion perimetry. , 2009, Investigative ophthalmology & visual science.

[4]  A Heijl,et al.  Practical recommendations for measuring rates of visual field change in glaucoma , 2008, British Journal of Ophthalmology.

[5]  V. P. Costa,et al.  Sensitivity and specificity of frequency-doubling technology, tendency-oriented perimetry, SITA Standard and SITA Fast perimetry in perimetrically inexperienced individuals. , 2006, Acta ophthalmologica Scandinavica.

[6]  Paul H Artes,et al.  Threshold and variability properties of matrix frequency-doubling technology and standard automated perimetry in glaucoma. , 2005, Investigative ophthalmology & visual science.

[7]  Chris A Johnson,et al.  Visual Field Quality Control in the Ocular Hypertension Treatment Study (OHTS) , 2005, Journal of glaucoma.

[8]  Klaus Rohrschneider,et al.  Fundus perimetry with the Micro Perimeter 1 in normal individuals: comparison with conventional threshold perimetry. , 2005, Ophthalmology.

[9]  M. Nicolela,et al.  Effects of blur and repeated testing on sensitivity estimates with frequency doubling perimetry. , 2003, Investigative ophthalmology & visual science.

[10]  Yuko Ohno,et al.  Properties of perimetric threshold estimates from Full Threshold, SITA Standard, and SITA Fast strategies. , 2002, Investigative ophthalmology & visual science.

[11]  T. Maddess,et al.  Comparison of three tests using the frequency doubling illusion to diagnose glaucoma , 2001 .

[12]  R. Cumming,et al.  Sensitivity and specificity of tests to detect eye disease in an older population. , 2001, Ophthalmology.

[13]  L. Zangwill,et al.  Comparison of long-term variability for standard and short-wavelength automated perimetry in stable glaucoma patients. , 2000, American journal of ophthalmology.

[14]  P. Artes,et al.  Response variability in the visual field: comparison of optic neuritis, glaucoma, ocular hypertension, and normal eyes. , 2000, Investigative ophthalmology & visual science.

[15]  A. James,et al.  Testing for glaucoma with the spatial frequency doubling illusion , 1999, Vision Research.

[16]  B C Chauhan,et al.  Test-retest variability of frequency-doubling perimetry and conventional perimetry in glaucoma patients and normal subjects. , 1999, Investigative ophthalmology & visual science.

[17]  J. Caprioli,et al.  Test-retest variability of blue-on-yellow perimetry is greater than white-on-white perimetry in normal subjects. , 1998, American journal of ophthalmology.

[18]  K. Rohrschneider,et al.  Normal values for fundus perimetry with the scanning laser ophthalmoscope. , 1998, American journal of ophthalmology.

[19]  A. James,et al.  Evidence for spatial aliasing effects in the Y-like cells of the magnocellular visual pathway , 1998, Vision Research.

[20]  Song-Chun Zhu,et al.  Filters, Random Fields and Maximum Entropy (FRAME): Towards a Unified Theory for Texture Modeling , 1998, International Journal of Computer Vision.

[21]  D. Shin,et al.  Analysis of reliability indices from Humphrey visual field tests in an urban glaucoma population. , 1997, Ophthalmology.

[22]  F. Fitzke,et al.  High spatial resolution automated perimetry in glaucoma , 1997, The British journal of ophthalmology.

[23]  B. Chauhan,et al.  Variability in patients with glaucomatous visual field damage is reduced using size V stimuli. , 1997, Investigative ophthalmology & visual science.

[24]  J. D. Tompkins,et al.  Characteristics of frequency-of-seeing curves in normal subjects, patients with suspected glaucoma, and patients with glaucoma. , 1993, Investigative ophthalmology & visual science.

[25]  A. Heijl Perimetric point density and detection of glaucomatous visual field loss , 1993, Acta ophthalmologica.

[26]  A Heijl,et al.  Test-retest variability in glaucomatous visual fields. , 1989, American journal of ophthalmology.

[27]  G. Trick,et al.  Assessing the utility of reliability indices for automated visual fields. Testing ocular hypertensives. , 1989, Ophthalmology.

[28]  B. Gloor,et al.  Wie sehen Glaukomgesichtsfelder wirklich aus , 1984 .

[29]  P J Airaksinen,et al.  VISUAL FIELD AND RETINAL NERVE FIBRE LAYER IN EARLY GLAUCOMA AFTER OPTIC DISC HAEMORRHAGE , 1983, Acta ophthalmologica.

[30]  Ronald N. Bracewell,et al.  The Fourier Transform and Its Applications , 1966 .

[31]  D. G. Green,et al.  Optical and retinal factors affecting visual resolution. , 1965, The Journal of physiology.

[32]  J. Piltz,et al.  Test-retest variability in glaucomatous visual fields. , 1990, American journal of ophthalmology.

[33]  W S Geisler,et al.  Sampling-theory analysis of spatial vision. , 1986, Journal of the Optical Society of America. A, Optics and image science.

[34]  J. Weber,et al.  What is the most suitable grid for computer perimetry in glaucoma patients? , 1986, Ophthalmologica. Journal international d'ophtalmologie. International journal of ophthalmology. Zeitschrift fur Augenheilkunde.

[35]  J. Stürmer,et al.  What do glaucomatous visual fields really look like in fine-grid computerized profile perimetry? , 1985, Developments in ophthalmology.