Effects of Scleral Search Coil Wear on Visual Function

Irving, Elizabeth L.; Zacher, James E.; Allison, Robert S.; Callender, M.G.

doi:10.1167/iovs.01-0926

Cited by 22 publications

(10 citation statements)

References 15 publications

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“…One of the driving forces behind the search for alternatives to the MSC system has been the inconvenience of having to use a Silastic annulus on the surface of the eye, as this may cause discomfort, corneal scratching and transient blurring of vision [15]. The duration of the recordings is restricted for these reasons to a maximum of about 20 min.…”

Section: Eye Movement Recordingsmentioning

confidence: 99%

A comparison between the magnetic scleral search coil and infrared reflection methods for saccadic eye movement analysis

Träisk

Bolzani

Ygge

2005

Graefe's Arch Clin Exp Ophthalmol

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Comparison of the main sequence plots of the IR and MSC eye tracking techniques reveals that the IR system yields higher values of maximum peak velocity and the constant, the differences being similar for eye movements in different directions. There are various possible explanations for the lower maximum velocity of the MSC recordings, e.g. slipping of the coil annulus on the surface of the eye and a change of the oculomotor command signal induced by wearing the coil. Also, artefacts associated with the IR recording system may cause over-estimations of the saccadic velocity and, furthermore, contribute to the higher variability of the IR recordings.

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Section: Eye Movement Recordingsmentioning

confidence: 99%

A comparison between the magnetic scleral search coil and infrared reflection methods for saccadic eye movement analysis

Träisk

Bolzani

Ygge

2005

Graefe's Arch Clin Exp Ophthalmol

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“…Therefore, the manufacturer of the search coil limits wearing time to 30 min. Irving et al [49] observed corneal deformations of more than 3 dpt in 2 of 6 subjects and visual acuity (Snellen) of less than 6/9 in 2 subjects. These effects appeared as early as 15 min after coil insertion and dissipated after coil removal.…”

Section: Search Coilmentioning

confidence: 97%

“…However, in eye movement experiments involving visual tasks, particularly with binocular search coil recordings, visual acuity should be checked. Even though most authors feel confident that the safety risks of the search coil are relatively minor [49,50], the discomfort induced by wearing eye coils makes it more difficult to work with untrained volunteers. Irving et al [49] asked subjects to rate the coil-induced discomfort on a scale between none (1) and 'extreme discomfort' (5).…”

Section: Search Coilmentioning

confidence: 99%

Eye Movement Recordings: Methods

Eggert

2007

Developments in Ophthalmology

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The development of oculomotor research is closely related to the development of the technology of eye movement recordings. The first part of this chapter summarizes some cornerstones of the history of eye movement recordings from the 18th century until today and explains the technical principles of the early antecedents of modern recording devices. The four most common recording techniques (electro-oculogram, infrared reflection devices, scleral search coil, and video-oculography) are then compared with respect to the most important system parameters: spatial resolution, temporal resolution, the capability to simultaneously record the multiple degrees of freedom of the eye, the setup complexity, system specific artifacts, and invasiveness. These features determine the suitability of these devices in particular applications.

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“…It is therefore also more comfortable to wear on the eye, e.g. of children and patients (Murphy et al 2001;Irving et al 2003). However, the restriction to head-restrained preparations, the necessity for a bite-board, the strong input-output nonlinearity, which, in combination with the limited measurement range, leads to ambiguities in the signals for angles exceeding about 20 • , as well as the method's sensitivity to mechanical vibrations and artefacts have so far prevented its widespread acceptance.…”

Section: Introductionmentioning

confidence: 99%

Applying double-magnetic induction to measure head-unrestrained gaze shifts: calibration and validation in monkey

et al. 2010

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The double magnetic induction (DMI) method has successfully been used to record head-unrestrained gaze shifts in human subjects (Bremen et al., J Neurosci Methods 160:75-84, 2007a, J Neurophysiol, 98:3759-3769, 2007b. This method employs a small golden ring placed on the eye that, when positioned within oscillating magnetic fields, induces orientation-dependent voltages in a pickup coil in front of the eye. Here we develop and test a streamlined calibration routine for use with experimental animals, in particular, with monkeys. The calibration routine requires the animal solely to accurately follow visual targets presented at random locations in the visual field. Animals can readily learn this task. In addition, we use the fact that the pickup coil can be fixed rigidly and reproducibly on implants on the animal's skull. Therefore, accumulation of calibration data leads to increasing accuracy. As a first step, we simulated gaze shifts and the resulting DMI signals. Our simulations showed that the complex DMI signals can be effectively calibrated with the use of random target sequences, which elicit substan-P. Bremen and R. F. Van der Willigen contributed equally to this work. way. Subsequently, we tested our paradigm on three macaque monkeys. Our results show that the data for a successful calibration can be collected in a single recording session, in which the monkey makes about 1,500-2,000 goal-directed saccades. We obtained a resolution of 30 arc minutes (measurement range [−60,+60] • ). This resolution compares to the fixation resolution of the monkey's oculomotor system, and to the standard scleral search-coil method.

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Effects of Scleral Search Coil Wear on Visual Function

Cited by 22 publications

References 15 publications

A comparison between the magnetic scleral search coil and infrared reflection methods for saccadic eye movement analysis

A comparison between the magnetic scleral search coil and infrared reflection methods for saccadic eye movement analysis

Eye Movement Recordings: Methods

Applying double-magnetic induction to measure head-unrestrained gaze shifts: calibration and validation in monkey

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