High- versus low-density multifocal pupillographic objective perimetry in glaucoma

Background: Multifocal pupillographic objective perimetry was compared using 24 and 44 regions per visual field. Design: Experimental design in a university setting. Participants: Twenty-seven normal control and 36 age-matched glaucoma patients. Methods: The four test variants differed in the mean interval between stimuli: 4, 1 or 0.25s; and the number of visual field regions tested within the central 60 degrees: 24 or 44. All subjects had their diagnostic status confirmed by optical coherence tomography, two forms of perimetry and slit-lamp biomicroscopy. Both eyes were measured concurrently in 2.73±0.45min/eye (mean±standard deviation), and tests were repeated about 2 weeks apart. Main Outcome Measures: The main outcome measures were: (i) mean change in light sensitivity due glaucoma; and (ii) areas under Receiver Operator Characteristic plots for detecting glaucoma. Results: For all four variants, consensual responses, female gender and age produced small but significant sensitivity differences, and sensitivity declined with age by ≤-0.27dB/decade (all P<0.0003). The best diagnostic accuracy (area under curve 93.2±3.89%) was produced by the one-presentation/s 44-region protocol. Across the four protocols, the effect of repeat testing was small (all methods ≤0.15dB). Conclusions: Presentation rate had little effect, but increasing the tested density from 24 to 44 regions/field improved diagnostic power. Given that multifocal pupillographic objective perimetry also provides information on response delay and afferent versus efferent defects at every visual field region, it may be a useful adjunct to perimetry.