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K.E. Nowomiejska, R. Vonthein, E. Krapp, S. Rauscher, A. Hermann, J. Paetzold, U. Schiefer; High Resolution Assessment of Kinetic Isopters on the Stimulus Size and Luminance Response Surface . Invest. Ophthalmol. Vis. Sci. 2003;44(13):1955.
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Purpose: To estimate age-dependent isopters for local kinetic thresholds for a broad range of stimulus conditions (luminance, size), while considering individual reaction time. Methods: We enrolled 9 eyes of 9 normal subjects, 3 of the second, fifth, and eighth decade each. RE / LE was chosen at random; results of LE were mirrored. Semi-automated kinetic perimetry (SKP) was carried out with the OCTOPUS_101 perimeter (INTERZEAG Inc., Schlieren, Switzerland). Background luminance and stimulus velocity were kept constant at 10 cd/m2 and 3°/s, respectively. According to the Goldmann classification, we used 12 combinations of stimulus size and luminance, namely: V4e, V2e, V1e, IV2e, III4e, III3e, III1e, II2e, I4e, I3e, I1e, I1a. For each stimulus condition, four centripetal stimuli were presented in random order along 24 meridians that were 15° apart. Individual reaction time was assessed by placing (at least two) centripetal vectors within the central visual field region, i.e. within the isopter of the related stimulus characteristics. Local kinetic thresholds (i.e. related eccentricity values) were corrected for the distance covered in individual geometric mean reaction time. Mean local kinetic thresholds were described by a response surface over stimulus size and luminance, considering also age, and stimulus - isopter shape interactions in a linear model, resulting in a closed isopter. The model additionally accounted for censoring of the thresholds at the cupola edges. Results: Model fit was good (R²=0.88). Isopters are a flat oval for dim, small stimuli and look oblique pear-shaped for bright, large targets. Conclusions: This is the first study on age-related normative values of local kinetic threshold values, obtained with semi-automated kinetic perimetry over a variety of stimulus luminance-size combinations, which are each corrected for individual reaction time. Age-related normative isopters may now be interpolated for all kinds of Goldmann stimulus settings with the Octopus_101 perimeter.
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