Purpose:
To investigate the sensitivity and specificity of 10 variants of multifocal pupillographic perimetry in glaucoma.
Methods:
Ten stimulus protocols were examined in two blocks of experiments. Block one contained 22 normal and 23 glaucoma subjects; block two: 20 normal and 20 glaucoma subjects. All subjects were examined with HFA achromatic, SWAP and Matrix 24-2 perimetry, Stratus OCT, slit lamp and tonometry. Informed written consent was obtained from all subjects under ANU ethics approval 238/04. In all protocols multifocal stimuli were presented concurrently to both eyes with a dartboard layout, having 24 independent test regions/eye extending to 30 deg eccentricity. The test recording duration for each of the 10 protocols was 4 minutes, divided into 8 segments. Stimuli in each protocol could differ in the presentation rate per dartboard region (0.25, 1, 4 presentations/s), stimulus duration/presentation (66, 133 or 266 ms), flicker rate on each presentation (0, 15, or 30 Hz) or luminosity (80, 150 and 290 cd/m²). Background luminance was 10 cd/m². Since both pupils responded to stimuli from both eyes, 48 responses/eye were obtained giving 96 contraction amplitude and 96 delays for each 4 min test.
Results:
The simultaneously highest sensitivities and specificities, hereafter called accuracies, were estimated for contraction amplitudes, delays and linear discriminant models containing amplitude and delay. The Table gives percent accuracies (Right 2 columns) illustrating that the best performance was obtained at, shorter presentation durations, and the highest presentation rates, flicker rates and luminances. The top two Table rows show outcomes for the best nonflickered and flicked stimuli from the first block of 6 protocols (Table row 2). The bottom 4 rows of the Table show outcomes for the 4 protocols of block 2.
Conclusions:
In agreement with a previous study on 20 normal and 26 glaucoma subjects, flickering stimuli had good accuracies. This study indicates higher presentation and flicker rates combined with higher luminance stimuli can yield sensitivities and specificities around 95% for test durations equivalent to 2 min/eye.
Keywords: visual fields • perimetry • pupil