The Implications of the Results of Computerized Perimetry in Normals for the Statistical Evaluation of Glaucomatous Visual Fields

The normal visual field changes both shape and height with age. Inter-individual, intratest and inter-test variation are not constant across the visual field but depend on eccentricity. Deviations of measured thresholds from the age-corrected normal threshold are non-Gaussian showing significant eccentricity-dependent negative skewness and positive kurtosis. These observations must be taken into account when results of visual field testing are subjected to statistical analysis, or misleading results may be obtained. The degree of perimetric experience of the tested patient as well as the results of reliability tests are other important factors worth considering in the (statistical) evaluation of visual fields. The prevalence of field defects in the normal population might be considerably higher than previously recognized. All field loss in glaucoma suspects should not automatically be attributed to glaucoma.

[1]  C. Johnson,et al.  Mass visual field screening in a driving population. , 1980, Ophthalmology.

[2]  F. Hollows,et al.  Intra-ocular pressure, glaucoma, and glaucoma suspects in a defined population. , 1966, The British journal of ophthalmology.

[3]  J Katz,et al.  Asymmetry and variation in the normal hill of vision. , 1986, Archives of ophthalmology.

[4]  G. Lindgren,et al.  Variability of computerized threshold measurements across the central field in a normal population , 1987 .

[5]  J Flammer,et al.  Influence of age on the visual fields of normal subjects. , 1986, American journal of ophthalmology.

[6]  A Heijl,et al.  COMPUTER TEST LOGICS FOR AUTOMATIC PERIMETRY , 1977, Acta ophthalmologica.

[7]  J. Dalen.  Automated Perimetry in Aviation Medicine , 1983 .

[8]  H. Hécaen.  Handbook of sensory physiology VII/4, visual psychophysics : Edited by O. Jameson and M. C. Hurvich, Springer-Verlag, Berlin, 1972, 812 pp. D.M. 151.70 , 1973 .

[9]  C. Richter.  Automatic Perimetry in Glaucoma , 1986 .

[10]  B. Bengtsson.  The prevalence of glaucoma. , 1981, The British journal of ophthalmology.

[11]  Anders Heijl,et al.  The Humphrey Field Analyzer: Concepts and Clinical Results , 1985 .

[12]  S M Drance,et al.  Studies on the effects of age on the central and peripheral isopters of the visual field in normal subjects. , 1967, American journal of ophthalmology.

[13]  R. Parrish,et al.  Static and kinetic visual field testing. Reproducibility in normal volunteers. , 1984, Archives of ophthalmology.