The purpose of this work is to analyze the contribution of eye movements to the variability of the Zernike coefficients as determined with a Hartmann-Shack aberrometer. In order to isolate this effect we considered static aberrations tied to the eye pupil. We used several eye movements of different magnitude, both synthetic and corresponding to actual series recorded in our laboratory with different subjects. Our results show the relevance of the modal coupling induced by the estimation process and the benefit of correcting eye movements in order to get a better estimate of the ocular aberrations. They also show that eye movements during aberrometric measurements are an important source of apparent wavefront variability.
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http://dx.doi.org/10.1111/j.1475-1313.2009.00663.x | DOI Listing |
Br J Hosp Med (Lond)
December 2024
Department of Neurology, Wuhan Brain Hospital, General Hospital of Yangtze River Shipping, Wuhan, Hubei, China.
Arterial spin labelling (ASL) is a non-invasive magnetic resonance imaging (MRI) method. ASL techniques can quantitatively measure cerebral perfusion by fitting a kinetic model to the difference between labelled images (tag images) and ones which are acquired without labelling (control images). ASL functional MRI (fMRI) provides quantitative perfusion maps by using arterial water as an endogenous tracer instead of depending on vascular blood oxygenation level.
View Article and Find Full Text PDFDamage to the primary visual pathway can cause vision loss. Some cerebrally blind people retain degraded vision or sensations and can perform visually guided behaviors. These cases motivate investigation and debate on blind field conscious awareness and linked residual neural processing.
View Article and Find Full Text PDFJ Otolaryngol Head Neck Surg
January 2025
Département d'ORL du CHUS, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
Introduction: Vestibular migraine (VM), particularly its chronic variant, poses a diagnostic challenge. Patients suffering from VM may not have the characteristic headaches associated with the dizziness. In these cases, a marker for migraine pathology in general could help appropriately diagnose certain types of dizziness as migrainous despite these patients not meeting current diagnostic criteria for VM.
View Article and Find Full Text PDFJ Pak Med Assoc
January 2025
Department of Ophthalmology and Visual Sciences, Dow University of Health Sciences, Karachi, Pakistan.
Tolosa-Hunt Syndrome (THS) is an exceptionally rare disorder characterised by recurrent episodes of excruciating ophthalmoplegia, commonly affecting one side of the face and involving the third, fourth, sixth, and fifth cranial nerves. This syndrome results from non-specific inflammation affecting the cavernous sinus, superior orbital fissure (SOF), and/or orbital apex. In this case report, we present the clinical features, diagnostic evaluation, and management of a 46-year-old female with THS.
View Article and Find Full Text PDFMult Scler Relat Disord
January 2025
Corinne Goldsmith Dickinson Center for Multiple Sclerosis, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
Background: Oculomotor abnormalities are common in multiple sclerosis (MS) but are not quantitatively evaluated in clinical practice. Oculometric measures (OMs) are characteristics of eye movements captured while performing a visual task, e.g.
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