We compared photopic and scotopic multifocal pupillographic stimuli in age-related macular degeneration (AMD). Both eyes of 18 normal and 14 AMD subjects were tested with four stimulus variants presented at photopic and 126 times lower luminances. The multifocal stimuli presented 24 test regions/eye to the central 60°. The stimulus variants had two different check sizes, and when presented either flickered (15 Hz) for 266 ms, or were steady for 133 ms. Mean differences from normal of 5 to 7 dB were observed in the central visual field for both photopic and scotopic stimuli (all p < 0.00002). The best areas under receiver operating characteristic plots for exudative AMD in the photopic and scotopic conditions were 92.9 ± 8.0 and 90.3 ± 5.7% respectively, and in less severely affected eyes 83.8 ± 9.7% and 76.9 ± 8.2%. Damage recorded at photopic levels was possibly more diffusely distributed across the visual field. Sensitivity and specificity was similar at photopic and scotopic levels.
Multifocal pupillographic objective perimetry (mfPOP) has recently been shown to be able to measure cortical function. Here we assessed 44 regions of the central 60 degrees of the visual fields of each eye concurrently in 7 minutes/test. We examined how foveally- and peripherally-directed attention changed response sensitivity and delay across the 44 visual field locations/eye. Four experiments were completed comparing white, yellow and blue stimulus arrays. Experiments 1 to 4 tested 16, 23, 9 and 6 subjects, 49/54 being unique. Experiment 1, Experiments 2 and 3, and Experiment 4 used three variants of the mfPOP method that provided increasingly improved signal quality. Experiments 1 to 3 examined centrally directed attention, and Experiment 4 compared effects of attention directed to different peripheral targets. Attention reduced the sensitivity of the peripheral locations in Experiment 1, but only for the white stimuli not yellow. Experiment 2 confirmed that result. Experiment 3 showed that blue stimuli behaved like white. Peripheral attention showed increased sensitivity around the attentional targets. The results are discussed in terms of the cortical inputs to the pupillary system. The results agree with those from multifocal and other fMRI and VEP studies. mfPOP may be a useful adjunct to those methods.