Test time and efficiency of the dynamic strategy in glaucoma perimetry.
The dynamic strategy is a perimetric measurement procedure where by the luminance-step sizes are optimized according to physiological data. In contrast to the traditional 4- to 2-dB strategy, the step sizes are not constant but vary between 2 and 10 dB depending on the sensitivity. We examined 40 eyes of 40 glaucoma patients with both the traditional and the dynamic strategy using a modified Octopus 1-2-3 perimeter. A total of 16 visual field locations were examined using both strategies 3 times each in alternation. The order of the initial strategy was randomized. The variance of the three measurements was calculated as a measure of reproducibility. The quantity of presented stimuli was recorded as a measure of test time. After the elimination of starting points, absolute scotomata, and series of fields showing a significant trend during the session, 255 measured locations of 27 series were available for evaluation. The mean number of presentations (indicating test time) was 46% (dynamic strategy versus traditional strategy). The variance of the three measurements depended on the sensitivity. In the normal sensitivity range, the dynamic strategy had a markedly lower variance (58%). For relative defects, the variance was higher (141%-156%). According to a benefit/cost calculation, the efficiency of the dynamic strategy was better in all sensitivity ranges and reached a factor of 3 for high sensitivities. The dynamic strategy is considerably more efficient than the traditional strategy using fixed step sizes.
Weber
J
J
Universitäts-Augenklinik, Köln, Germany.
Klimaschka
T
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003362:Cost-Benefit Analysis; D005260:Female; D005901:Glaucoma / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D012684:Sensory Thresholds; D013997:Time Factors; D058609:Visual Field Tests / Q000191:economics / Q000379:methods*; D014794:Visual Fields; D014796:Visual Perception