Comparison of Visual Field Test Measurements With a Novel Approach on a Wearable Headset to Standard Automated Perimetry.

PRCIS: This study of inter-test comparability of a novel visual field application installed on an augmented-reality portable headset and Humphrey field analyzer Swedish interactive thresholding algorithm (SITA) Standard visual field test demonstrates the excellent correlation of mean deviation (MD) and mean sensitivity (MS). PURPOSE: To determine the correlation between visual field testing with novel software on a wearable headset versus standard automated perimetry. PATIENTS AND METHODS: Patients with and without visual field defects attributable to glaucoma had visual field testing in one eye of each patient with 2 methods: re:Imagine Strategy (Heru, Inc.) and the Humphrey field analyzer (Carl Zeiss Meditec, Inc.) SITA Standard 24-2 program. Main outcome measures included MS and MD, which were evaluated by linear regression, intraclass correlation coefficient (ICC), and Bland Altman analysis for assessment of the mean difference and limits of agreement. RESULTS: Measurements from 89 eyes of 89 patients (18 normal and 71 glaucomas) were compared with both instruments. Linear regression analysis demonstrated an excellent Pearson correlation coefficient of r = 0.94 for MS and r = 0.95 for MD. ICC analysis demonstrated high levels of concordance (ICC = 0.95, P < 0.001 for MS and ICC = 0.94, P < 0.001 for MD). Bland-Altman analysis determined a small mean difference between the two devices (Heru minus Humphrey) of 1.15 dB for MS and 1.06 dB for MD. CONCLUSIONS: The Heru visual field test correlated well with SITA Standard in a population of normal eyes and eyes with glaucoma.

Visual Influences on Auditory Behavioral, Neural, and Perceptual Processes: A Review.

In a naturalistic environment, auditory cues are often accompanied by information from other senses, which can be redundant with or complementary to the auditory information. Although the multisensory interactions derived from this combination of information and that shape auditory function are seen across all sensory modalities, our greatest body of knowledge to date centers on how vision influences audition. In this review, we attempt to capture the state of our understanding at this point in time regarding this topic. Following a general introduction, the review is divided into 5 sections. In the first section, we review the psychophysical evidence in humans regarding vision's influence in audition, making the distinction between vision's ability to enhance versus alter auditory performance and perception. Three examples are then described that serve to highlight vision's ability to modulate auditory processes: spatial ventriloquism, cross-modal dynamic capture, and the McGurk effect. The final part of this section discusses models that have been built based on available psychophysical data and that seek to provide greater mechanistic insights into how vision can impact audition. The second section reviews the extant neuroimaging and far-field imaging work on this topic, with a strong emphasis on the roles of feedforward and feedback processes, on imaging insights into the causal nature of audiovisual interactions, and on the limitations of current imaging-based approaches. These limitations point to a greater need for machine-learning-based decoding approaches toward understanding how auditory representations are shaped by vision. The third section reviews the wealth of neuroanatomical and neurophysiological data from animal models that highlights audiovisual interactions at the neuronal and circuit level in both subcortical and cortical structures. It also speaks to the functional significance of audiovisual interactions for two critically important facets of auditory perception-scene analysis and communication. The fourth section presents current evidence for alterations in audiovisual processes in three clinical conditions: autism, schizophrenia, and sensorineural hearing loss. These changes in audiovisual interactions are postulated to have cascading effects on higher-order domains of dysfunction in these conditions. The final section highlights ongoing work seeking to leverage our knowledge of audiovisual interactions to develop better remediation approaches to these sensory-based disorders, founded in concepts of perceptual plasticity in which vision has been shown to have the capacity to facilitate auditory learning.

Binocular Enhancement of Multisensory Temporal Perception.

Purpose: The goal of this study was to examine the behavioral effects and to suggest possible underlying mechanisms of binocularity on audiovisual temporal perception in normally-sighted individuals. Methods: Participants performed two audiovisual simultaneity judgment tasks-one using simple flashes and beeps and the other using audiovisual speech stimuli-with the left eye, right eye, and both eyes. Two measures, the point of subjective simultaneity (PSS) and the temporal binding window (TBW), an index for audiovisual temporal acuity, were derived for each viewing condition, stimulus type, and participant. The data were then modeled using causal inference, allowing us to determine whether binocularity affected low-level unisensory mechanisms (i.e., sensory noise level) or high-level multisensory mechanisms (i.e., prior probability of interring a common cause, pC=1). Results: Whereas for the PSS there was no significant effect of viewing condition, for the TBW, a significant interaction between stimulus type and viewing condition was found. Post hoc analyses revealed a significantly narrower TBW during binocular than monocular viewing (average of left and right eyes) for the flash-beep condition but no difference between the viewing conditions for the speech stimuli. Modeling results showed no significant difference in pC=1 but a significant reduction in sensory noise during binocular performance on flash-beep trials. Conclusions: Binocular viewing was found to enhance audiovisual temporal acuity as indexed by the TBW for simple low-level audiovisual stimuli. Furthermore, modeling results suggest that this effect may stem from enhanced sensory representations evidenced as a reduction in sensory noise affecting the measurement of physical asynchrony during audiovisual temporal perception.

Brief period of monocular deprivation drives changes in audiovisual temporal perception.

The human brain retains a striking degree of plasticity into adulthood. Recent studies have demonstrated that a short period of altered visual experience (via monocular deprivation) can change the dynamics of binocular rivalry in favor of the deprived eye, a compensatory action thought to be mediated by an upregulation of cortical gain control mechanisms. Here, we sought to better understand the impact of monocular deprivation on multisensory abilities, specifically examining audiovisual temporal perception. Using an audiovisual simultaneity judgment task, we discovered that 90 minutes of monocular deprivation produced opposing effects on the temporal binding window depending on the eye used in the task. Thus, in those who performed the task with their deprived eye there was a narrowing of the temporal binding window, whereas in those performing the task with their nondeprived eye there was a widening of the temporal binding window. The effect was short lived, being observed only in the first 10 minutes of postdeprivation testing. These findings indicate that changes in visual experience in the adult can rapidly impact multisensory perceptual processes, a finding that has important clinical implications for those patients with adult-onset visual deprivation and for therapies founded on monocular deprivation.

Judging Relative Onsets and Offsets of Audiovisual Events.

This study assesses the fidelity with which people can make temporal order judgments (TOJ) between auditory and visual onsets and offsets. Using an adaptive staircase task administered to a large sample of young adults, we find that the ability to judge temporal order varies widely among people, with notable difficulty created when auditory events closely follow visual events. Those findings are interpretable within the context of an independent channels model. Visual onsets and offsets can be difficult to localize in time when they occur within the temporal neighborhood of sound onsets or offsets.

Relationship between Reduced Accommodative Lag and Myopia Progression.

PURPOSE: To determine the relationship between accommodative lag and rate of myopia progression when Ghanaian myopic school children are either undercorrected or fully corrected with single vision lenses. METHODS: A 2-year single masked randomized control trial was conducted using 150 Ghanaian myopic children aged 10 to 15 years with mean baseline myopia of -1.98 ± 0.50D. The children were randomly assigned to wear either a full correction (n = 75) or +0.50D undercorrection (UC) (n = 75) single vision lenses. Repeated measurements which included refractive error and accommodative response at 33 and 28.6 cm for FC and UC, respectively, were performed using Open-Field Autorefractor whereas ocular biometry results were obtained using A-Scan ultrasonography. Results were based on the right eye and analyzed using STATA 11. RESULTS: After 24 months, the mean myopia progression of children in the FC group (-0.54 ± 0.26D) was not significantly different from that of the children in the UC group (-0.5 ± 0.22D) (p = 0.31). There was no significant difference between the mean values of the initial near lag and the average lag measured 24 months later in both groups (FC: initial lag -0.74 ± 0.17D, average lag -0.72 ± 0.15D, p = 0.44; UC: initial lag -0.57 ± 0.14D, average lag -0.58 ± 0.15D; p = 0.67). Also, there was no significant correlation between refractive change seen in 24 months and either the first near lag for both FC (r = -0.05, p = 0.43) and UC (r = -0.08, p = 0.43) or the average near lag of accommodation for both FC (r = -0.02, p = 0.49) and UC (r = -0.04, p = 0.49). CONCLUSIONS: This study showed no relationship between lag of accommodation and rate of myopia progression in children with progressing myopia. Different ethnic groups may respond differently to the same size of hyperopic blur.