Age-related changes of vergence under natural viewing conditions

Rambold, H.; Neumann, G.; Sander, T.; Helmchen, Christoph

doi:10.1016/j.neurobiolaging.2005.01.002

Cited by 43 publications

(36 citation statements)

References 30 publications

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“…The lack of an enhancing effect at brief presentation times could also be due to vergence eye movements. This is because studies have shown that the latency of accommodative vergence increases with age and that disparity-driven accommodation declines with age (Heron et al, 2001; Rambold et al, 2006). Yet, since we did not measure eye movements in our current study, we can only speculate that this issue contributed (at least in part) to our observed results.…”

Section: Discussionmentioning

confidence: 99%

Self-motion perception in the elderly

Lich

Bremmer

2014

Front. Hum. Neurosci.

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Self-motion through space generates a visual pattern called optic flow. It can be used to determine one's direction of self-motion (heading). Previous studies have already shown that this perceptual ability, which is of critical importance during everyday life, changes with age. In most of these studies subjects were asked to judge whether they appeared to be heading to the left or right of a target. Thresholds were found to increase continuously with age. In our current study, we were interested in absolute rather than relative heading judgments and in the question about a potential neural correlate of an age-related deterioration of heading perception. Two groups, older test subjects and younger controls, were shown optic flow stimuli in a virtual-reality setup. Visual stimuli simulated self-motion through a 3-D cloud of dots and subjects had to indicate their perceived heading direction after each trial. In different subsets of experiments we varied individually relevant stimulus parameters: presentation time, number of dots in the display, stereoscopic vs. non-stereoscopic stimulation, and motion coherence. We found decrements in heading performance with age for each stimulus parameter. In a final step we aimed to determine a putative neural basis of this behavioral decline. To this end we modified a neural network model which previously has proven to be capable of reproduce and predict certain aspects of heading perception. We show that the observed data can be modeled by implementing an age related neuronal cell loss in this neural network. We conclude that a continuous decline of certain aspects of motion perception, among them heading, might be based on an age-related progressive loss of groups of neurons being activated by visual motion.

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Section: Discussionmentioning

confidence: 99%

Self-motion perception in the elderly

Lich

Bremmer

2014

Front. Hum. Neurosci.

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“…Reason for this apparent robustness of the ocular nerves a propos aging may be due to the high level of motor activity in the muscles supplied by these nerves as suggested by Sturrock [44]. There are differing schools of thought about the relationship between gaze disorders and aging [45][46][47][48][49][50]; however, after the studies in our laboratory on all three ocular motor nerves (III, IV and VI), we believe that there may be other factors that affect the function of these nerves that eventually cause diplopia and different gaze disorders [7]. Axonal profiles contained either within the frame or touching the green lines were counted; whereas those that touched the 'forbidden' red lines were excluded.…”

Section: Resultsmentioning

confidence: 99%

The Human Trochlear and Abducens Nerves at Different Ages - a Morphometric Study

Ramkumar¹,

Sharma²,

Jacob³

et al. 2015

Aging and disease

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The trochlear and abducens nerves (TN and AN) control the movement of the superior oblique and lateral rectus muscles of the eyeball, respectively. Despite their immense clinical and radiological importance no morphometric data was available from a wide spectrum of age groups for comparison with either pathological or other conditions involving these nerves. In the present study, morphometry of the TN and AN was performed on twenty post-mortem samples ranging from 12-90 years of age. The nerve samples were processed for resin embedding and toluidine blue stained thin (1µm) sections were used for estimating the total number of myelinated axons by fractionator and the cross sectional area of the nerve and the axons by point counting methods. We observed that the TN was covered by a welldefined epineurium and had ill-defined fascicles, whereas the AN had multiple fascicles with scanty epineurium. Both nerves contained myelinated and unmyelinated fibers of various sizes intermingled with each other. Out of the four age groups (12-20y, 21-40y, 41-60y and >61y) the younger groups revealed isolated bundles of small thinly myelinated axons. The total number of myelinated fibers in the TN and AN at various ages ranged from 1100-3000 and 1600-7000, respectively. There was no significant change in the cross-sectional area of the nerves or the axonal area of the myelinated nerves across the age groups. However, myelin thickness increased significantly in the AN with aging (one way ANOVA). The present study provides baseline morphometric data on the human TN and AN at various ages.

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“…Recently, two groups have separately investigated the change in binocular vision with age and early and late onset myopia. The first group found that the transient component of the vergence velocity and onset is delayed in aged populations [15]. The second group found that increases in the low-frequency components (between 0-0.6 Hz) of the signal mediated increases in the microfluctuations of the accommodative system [16].…”

Section: Discussionmentioning

confidence: 99%

Vergence Variability: A Key to Understanding Oculomotor Adaptability?

Petrock

Reisman

Alvarez

2006

2006 International Conference of the IEEE Engineering in Medicine and Biology Society

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Vergence eye movements were recorded from three different populations: healthy young (ages 18-35 years), adaptive presbyopic and non-adaptive presbyopic(the presbyopic groups aged above 45 years) to determine how the variability of the eye movements made by the populations differs. The variability was determined using Shannon Entropy calculations of Wavelet transform coefficients, to yield a non-linear analysis of the vergence movement variability. The data were then fed through a k-means clustering algorithm to classify each subject, with no a priori knowledge of true subject classification. The results indicate a highly significant difference in the total entropy values between the three groups, indicating a difference in the level of information content, and thus hypothetically the oculomotor adaptability, between the three groups.Further, the frequency distribution of the entropy varied across groups.

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Age-related changes of vergence under natural viewing conditions

Cited by 43 publications

References 30 publications

Self-motion perception in the elderly

Self-motion perception in the elderly

The Human Trochlear and Abducens Nerves at Different Ages - a Morphometric Study

Vergence Variability: A Key to Understanding Oculomotor Adaptability?

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