Abstract
Purpose: :
To investigate 4 variants of multifocal pupillographic perimetry in glaucoma to test the effects of balancing luminances across the field to match the sensitivity of the pupillary field.
Methods: :
We tested 21 normal and 21 glaucoma subjects. Glaucoma subjects had moderate to severe visual fields in at least one eye. All subjects were examined with HFA achromatic, SWAP and Matrix 24-2 perimetry, Stratus OCT. Visual fields were classified according to their HFA mean defects: mild <=6 dB, moderate 6 to 12 dB, severe > 12 dB. Informed written consent was obtained from all subjects. Multifocal stimuli having 44 test regions/eye, extending to 30 deg eccentricity, were presented concurrently to both eyes using a prototype of the TrueField Analyser. Recording duration was 4 minutes, divided into 8 segments of 30 s. Individual 30 s segments were repeated if more than 15% of the data was lost due to blinks of fixation losses, both automatically monitored in real time. Pupil diameter was monitored under infrared illumination. Four stimulus protocols were examined which differed in terms of mean presentation intervals (MPI) of 1 or 4 s per region. One each of the 1 and 4 MPI stimuli had their luminances balanced so that responsive field regions received less light than less responsive regions. The mean test luminances were 210 cd/m2, and the background was at 10 cd/m2. Measures of field loss included the N-worst amplitudes, response delays, or pair-wise linear combinations of those.
Results: :
Diagnostic performance was assessed by areas under ROC curves (AUCs). For all visual field severities the best AUCs were produced by the balanced 1 s MPI stimulus protocol. For severe fields the mean of the 3 regional amplitudes that most deviated from the normative data gave an AUC of 1.0 ± 0.0 (mean ± SE), the corresponding AUCs for moderate and mild fields were 0.82 ± 0.11 and 0.764 ± 0.06.
Conclusions: :
In this preliminary study balancing seemed to improve diagnostic accuracy. The pupillographic method eliminates several problems associated with subjective testing as employed in conventional perimetry.
Keywords: perimetry • visual fields • pupil