Vertical Optokinetic Nystagmus and Saccades in Normal Human Subjects

Garbutt, Siobhan; Han, Yong Seop; Kumar, Arun N.; Harwood, Mark; Harris, Chris; Leigh, R. John

doi:10.1167/iovs.03-0066

Cited by 37 publications

(29 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Children and adults who had infantile-onset strabismus may retain the deficit of downward OKN, as their up-down OKN asymmetries can exceed those of control subjects. 25,28,29 Our findings in the strabismic NHPs are similar. Each of the strabismic NHPs had upward OKN gains equivalent to-but downward OKN gains substantially less than-those of the control NHPs.…”

Section: Vertical Okn Asymmetrysupporting

confidence: 67%

“…Garbutt et al 29 reported horizontal crosstalk during vertical OKN in strabismic adults. Their patients who had the classical stigmata of infantile-onset strabismus (LN and DVD, subjects 1-4) had weak downward OKN and the greatest crosstalk during downward OKN.…”

Section: Crosstalk and Directional Biases Of Horizontalvertical Oknmentioning

confidence: 99%

“…[19][20][21][22][23][24][25][26][27] In children and adults with strabismus and/or amblyopia, the asymmetry favoring upward OKN may be more pronounced. 25,28,29 Behavioral studies have shown that the postnatal development of binocular sensory and motor functions in infant NHPs parallels closely that of infant humans, but on a compressed time scale (i.e., 1 week of monkey development is equivalent to 1 month of human). 6,7,30,31 Infant NHPs with strabismus display the same constellation of perceptual and ocular motor abnormalities found in strabismic humans, including defective stereopsis, abnormal vergence, and horizontal OKN asymmetries.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Horizontal and Vertical Optokinetic Eye Movements in Macaque Monkeys With Infantile Strabismus: Directional Bias and Crosstalk

Ghasia

Tychsen

2014

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

show abstract

Section: Vertical Okn Asymmetrysupporting

confidence: 67%

Section: Crosstalk and Directional Biases Of Horizontalvertical Oknmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Horizontal and Vertical Optokinetic Eye Movements in Macaque Monkeys With Infantile Strabismus: Directional Bias and Crosstalk

Ghasia

Tychsen

2014

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

show abstract

“…Variation of the single threshold value, in cases in which only fixations and saccades are classified, is reported to substantially affect metrics such as number of detected saccades and fixations, average fixation duration, and saccade amplitude (Ceballos, Komogortsev, & Turner, 2009;Garbutt et al, 2003;Komogortsev, Gobert, Jayarathna, Koh, & Gowda, 2010;Poole & Ball, 2004). Frequently, researchers perform manual classification to avoid misidentification issues associated with automated algorithms.…”

Section: Introductionmentioning

confidence: 99%

Automated classification and scoring of smooth pursuit eye movements in the presence of fixations and saccades

2012

View full text Add to dashboard Cite

Ternary eye movement classification, which separates fixations, saccades, and smooth pursuit from the raw eye positional data, is extremely challenging. This article develops new and modifies existing eye-tracking algorithms for the purpose of conducting meaningful ternary classification. To this end, a set of qualitative and quantitative behavior scores is introduced to facilitate the assessment of classification performance and to provide means for automated threshold selection. Experimental evaluation of the proposed methods is conducted using eye movement records obtained from 11 subjects at 1000 Hz in response to a step-ramp stimulus eliciting fixations, saccades, and smooth pursuits. Results indicate that a simple hybrid method that incorporates velocity and dispersion thresholding allows producing robust classification performance. It is concluded that behavior scores are able to aid automated threshold selection for the algorithms capable of successful classification.

show abstract

“…Saccadic eye movements generally have short durations with only minor disturbances of the visual processing (Garbutt et al, 2003). These disturbances are prolonged in mature patients since eye-movement speed is significantly reduced.…”

Section: Regions In the Frontal Cerebral Cortexmentioning

confidence: 99%

The Oculomotor Systems Ability to Adapt to Structural Changes Caused by the Process of Senescence: A Review

Bruenech

Haugen

Bak³

et al. 2012

Scand J Optom Vis Sci

View full text Add to dashboard Cite

Age-related binocular vision anomalies are frequently encountered during clinical examination of mature patients. Observations of both concomitant and incomitant restrictions in eye motility indicate that all oculomotor system levels are implicated, from cortical neurons down to extraocular muscles. The system can make adaptations in response to changes induced by growth and ageing, which it does by monitoring and adjusting its own performance. This adaptive mechanism, which is important for maintaining motility, spatial orientation, and perceptual stability, seems to rely on extra-retinal information about eye position in relation to the head and trunk. Receptors in the extraocular muscles and the vestibular system, assumed to contribute to this type of information, also undergo age-related changes. This may compromise their ability to assist in the adaptive process and in potential calibrations of other neural systems. Furthermore, recent observations of a dual, common, final pathway and double insertions of distal extraocular muscles suggest that muscle and tendon receptors may facilitate other, still unresolved, functions in the visual system. Consequently, age-related changes in certain mechanoreceptors may have more severe implications for ocular motility and visual functions than previously assumed.This review aims to detail some of the most frequent neurogenic and myogenic age-related changes that take place in the human oculomotor system and relevant pre-motor structures. It will also address clinical implications of these changes and the potential adaptive mechanism they initiate.

show abstract

Vertical Optokinetic Nystagmus and Saccades in Normal Human Subjects

Cited by 37 publications

References 46 publications

Horizontal and Vertical Optokinetic Eye Movements in Macaque Monkeys With Infantile Strabismus: Directional Bias and Crosstalk

Horizontal and Vertical Optokinetic Eye Movements in Macaque Monkeys With Infantile Strabismus: Directional Bias and Crosstalk

Automated classification and scoring of smooth pursuit eye movements in the presence of fixations and saccades

The Oculomotor Systems Ability to Adapt to Structural Changes Caused by the Process of Senescence: A Review

Contact Info

Product

Resources

About