A recent study by Poljac et al. [Poljac, E., Lankheet, M. J. M., & van den Berg, A. (2005). Perceptual compensation for eye torsion. Vision Research, 45(4), 485-496] concluded that there was complete perceptual compensation for ocular torsion, although they did not directly measure ocular torsion. Using a similar eccentric-gaze paradigm to induce changes in torsion, which were directly measured, we found inconsistent torsional eye movements at eccentric fixation, and also failed to detect a significant relationship between ocular torsion and the perception of line orientation. We then used a stimulus known to induce large changes in ocular torsion: on-centre yaw rotation. This stimulus induced a consistent change in the torsional position of the eye which positively correlated to subjects' visual perception of horizontal.
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http://dx.doi.org/10.1016/j.visres.2008.03.012 | DOI Listing |
J Ophthalmol
December 2024
Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan.
This study aimed to compare ocular torsion measurements to investigate normative objective cyclotorsion values in a population of healthy, full-term and preterm children. The participants enrolled in this study had an age range of 3-12 years and were divided into two groups, full-term (gestational age (GA) > 37 weeks) and preterm without retinopathy of prematurity (ROP) (GA ≤ 37 weeks). The disc-center-fovea angle (DFA) was used to evaluate ocular torsion using two different imaging modalities: optical coherence tomography (OCT) with a 55-degree field of view (FV) and conventional fundus photography (CFP) with a 45-degree FV.
View Article and Find Full Text PDFArq Bras Oftalmol
December 2024
Department of Ophthalmology, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
The paper starts discussing the teleological concept that eye motions - rotations and translations - serve to vision (which supports the notion that torsions are not voluntarily driven, since they do not contribute to expand the visual exploration of space). It proposes that the primary position of the eye (not "of gaze") , the standard condition to measure them, must be defined as the coincidence of the orbital (fixed) and the ocular (movable) system of coordinates. However this becomes only a theoretic concept, since practical operations to obtain it are almost unfeasible.
View Article and Find Full Text PDFAm J Audiol
November 2024
Department of Communication Disorders and Sciences, Viterbo University, La Crosse, WI.
Purpose: The purpose of this study was to evaluate the effect of noise exposure on otolith function measures of video ocular counter roll (vOCR), ocular vestibular evoked myogenic potential (oVEMP), cervical VEMP (cVEMP), and subjective visual vertical (SVV). Additionally, this study compared the vOCR results with other otolith function measures: cVEMP, oVEMP, and SVV.
Method: This was a cross-sectional, between-group prospective study that compared otolith function tests between noise exposure groups.
bioRxiv
October 2024
Department of Biomedical Engineering, The Ohio State University, Columbus, OH.
Traumatic optic neuropathy (TON) is a common cause of irreversible blindness following head injury. TON is characterized by axon damage in the optic nerve followed by retinal ganglion cell death in the days and weeks following injury. At present, no therapeutic or surgical approach has been found to offer any benefit beyond observation alone.
View Article and Find Full Text PDFPurpose: To evaluate the impact of refractive couplings in myopia and myopic astigmatism with two different keratorefractive lenticule extraction (KLEx) systems.
Methods: This was a retrospective evaluation of refractive outcomes with two different lasers studying 2,841 eyes undergoing small incision lenticule extraction (SMILE) (VisuMax 500; Carl Zeiss Meditec) and 2,528 eyes undergoing SmartSight (ATOS; SCHWIND eye-tech-solutions GmbH). Coupling effects (derived from the ratio between partial slopes) were determined for sphere and cylinder and for spherical equivalent, cardinal, and oblique astigmatism separately.
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