Abstract
Abstract: :
Purpose: Aim of this study was to evaluate the reproducibility and validity of the FDT screening procedure in analysis of single test location and by using an over-all score. Methods: FDT screening and conventional white/white perimetry (Octopus, G1) in all subjects: 173 ocular hypertensive eyes, 111 preperimetric open-angle glaucoma eyes (glaucomatous optic disc atrophy, elevated introcular pressure, no visual field defects in standard perimetry), 179 perimetric open angle glaucoma eyes (glaucomatous optic disc atrophy and visual field defects), 139 control eyes. Two minutes pause between FDT determination of right and left eyes for suppression of side effects. Four repeated measurements of both eyes in 15 glaucoma patients in a two hour temporal interval to judge reproducibility of all test location. The present screening strategy (procedure: C-20-5) starts testing at the normal 5% probability level. If a stimulus is not detected further targets are presented. This study uses data transfer (FDT-Viewfinder, Humphrey) and statistics software (SPSS 10) for case-wise recalculation of all missed localized probability levels and correlation with corresponding test location of conventional perimetry. Results: Analyses of repeated measurements in patients reveal that variation of single test points can be considerable for all peripheral and central stimulated areas of right and left eyes. However, the numbers of missed test-questions calculated globally or in quadrants are high significantly correlated with corresponding Octopus visual field defects (Spearman rank correlation). At a predefined specificity of 90% in control eyes, 25% of ocular hypertensive eyes, 36% of preperimetric glaucoma eyes and 88% of perimetric glaucoma eyes have been classified glaucomatous using an over-all score. Conclusion: The number of all missed test points might be valuable for differentiating eyes with glaucoma from normal and ocular hypertensive eyes. Scores of all patient groups are significantly increased in comparison to normals.