scholarly journals Visual function alterations in essential tremor: A case report

2015 ◽  
Vol 08 (05) ◽  
pp. 1550040 ◽  
Author(s):  
David P. Piñero ◽  
Begoña Monllor ◽  
Vicenta Moncho ◽  
Vicent J. Camps ◽  
Dolores de Fez
Keyword(s):  
Essential Tremor ◽  
Color Vision ◽  
Visual Function ◽  
Visual Pathways ◽  
Normal Pattern ◽  
Complete Evaluation ◽  
Spatial Frequencies ◽  
Color Vision Tests ◽  
Global Values ◽  
Fundoscopic Examination

Our purpose is to report alterations in contrast sensitivity function (CSF) and in the magno, parvo and koniocellular visual pathways by means of a multichannel perimeter in case of an essential tremor (ET). A complete evaluation of the visual function was performed in a 69-year old patient, including the analysis of the chromatic discrimination by the Fansworth–Munsell 100 hue test, the measurement of the CSF by the CSV-1000E test, and the detection of potential alteration patterns in the magno, parvo and koniocellular visual pathways by means of a multichannel perimeter. Visual acuity and intraocular pressure (IOP) were within the ranges of normality in both eyes. No abnormalities were detected in the fundoscopic examination and in the optical coherence tomography (OCT) exam. The results of the color vision examination were also within the ranges of normality. A significant decrease in the achromatic CSFs for right eye (RE) and left eye (LE) was detected for all spatial frequencies. The statistical global values provided by the multichannel perimeter confirms that there were significant absolute sensitivity losses compared to the normal pattern in RE. In the LE, only a statistically significant decrease in sensitivity was detected for the blue-yellow (BY) channel. The pattern standard deviation (PSD) values obtained in our patient indicated that there were significant localized losses compared to the normality pattern in the achromatic channel of the RE and in the red-green (RG) channel of the LE. Some color vision alterations may be present in ET that cannot be detected with conventional color vision tests, such as the FM 100 Hue.

2005 Verriest Medal awarded to Professor John D. Mollon

2006 ◽  
Vol 23 (3-4) ◽  
pp. ii-ii
Keyword(s):  
Color Vision ◽  
Full Spectrum ◽  
Visual Neuroscience ◽  
Evolutionary Origins ◽  
University Of Cambridge ◽  
Color Vision Tests ◽  
Spectral Coding ◽  
History Of ◽  
The University

The International Colour Vision Society awarded the 2005 Verriest Medal to John D. Mollon, Professor of Visual Neuroscience at the University of Cambridge, UK. This award is bestowed by the Society to honor long-term contributions to the field of color vision. If the field of color vision were itself a rainbow, then Professor Mollon's contributions cover nearly its full spectrum, including the isolation and elucidation of basic chromatic coding mechanisms and the constraints that they impose on human (and more generally primate) visual performance, the genetic basis of spectral coding mechanisms, the ecological influences on and evolutionary origins of chromatic discrimination. He has been instrumental in the design of several new color vision tests and has extensively exploited abnormal models, both congenital and acquired, to further our understanding of normal mechanisms. He is especially appreciated for his keen and profound sense of the history of science, in particular with respect to the field of color vision. He has been a member of the society for over 25 years and is currently serving on its board of directors. He organized the 2001 ICVS meeting in Cambridge, celebrating the bicentennial of Thomas Young's lecture on color vision.

Quantitative scoring methods of the Farnsworth D15 and Waggoner computerized D15 color vision tests in clinical practice

2021 ◽  
Author(s):  
Ali Almustanyir ◽  
Reema Alduhayan ◽  
Mosaad Alhassan ◽  
Kholoud Bokhary ◽  
Balsam Alabdulkader
Keyword(s):  
Clinical Practice ◽  
Color Vision ◽  
Scoring Methods ◽  
Color Vision Tests ◽  
Quantitative Scoring

Clinical Color Vision Testing and Correlation With Visual Function

2015 ◽  
Vol 160 (3) ◽  
pp. 547-552.e1 ◽  
Author(s):  
Jiawei Zhao ◽  
Sarita B. Davé ◽  
Jiangxia Wang ◽  
Prem S. Subramanian
Keyword(s):  
Color Vision ◽  
Visual Function

scholarly journals The Order of Information Transfer into Short- Term Memory from Visual Pathways with Different Spatial-Frequency Tunings

2020 ◽  
Vol 13 (2) ◽  
pp. 72-89
Author(s):  
D.S. Alekseeva ◽  
V.V. Babenko ◽  
D.V. Yavna
Keyword(s):  
Spatial Frequency ◽  
Information Transfer ◽  
Short Term Memory ◽  
Frequency Tuning ◽  
Visual Pathways ◽  
Input Image ◽  
Target Face ◽  
Short Term ◽  
Term Memory ◽  
Spatial Frequencies

Visual perceptual representations are formed from the results of processing the input image in parallel pathways with different spatial-frequency tunings. It is known that these representations are created gradually, starting from low spatial frequencies. However, the order of information transfer from the perceptual representation to short-term memory has not yet been determined. The purpose of our study is to determine the principle of entering information of different spatial frequencies in the short-term memory. We used the task of unfamiliar faces matching. Digitized photographs of faces were filtered by six filters with a frequency tuning step of 1 octave. These filters reproduced the spatial-frequency characteristics of the human visual pathways. In the experiment, the target face was shown first. Its duration was variable and limited by a mask. Then four test faces were presented. Their presentation was not limited in time. The observer had to determine the face that corresponds to the target one. The dependence of the accuracy of the solution of the task on the target face duration for different ranges of spatial frequencies was determined. When the target stimuli were unfiltered (broadband) faces, the filtered faces were the test ones, and vice versa. It was found that the short-term memory gets information about an unfamiliar face in a certain order, starting from the medium spatial frequencies, and this sequence does not depend on the processing method (holistic or featural).

DEMO_ESTIMULS, A TOOL FOR THE DESIGN OF COLOR VISION TESTS IN THE CLASSROOM

2016 ◽  
Author(s):  
María José Luque ◽  
Dolores de Fez Sáiz ◽  
María del Carmen García-Domene ◽  
María Amparo Díez-Ajenjo ◽  
Pascual Capilla
Keyword(s):  
Color Vision ◽  
Color Vision Tests

Prospective analysis of visual function changes in patients with dermatochalasis after upper eyelid blepharoplasty

2019 ◽  
Vol 30 (5) ◽  
pp. 978-984
Author(s):  
Meryem Altin Ekin ◽  
Seyda Karadeniz Ugurlu
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Visual Function ◽  
Spherical Aberration ◽  
Higher Order ◽  
Rank Test ◽  
Higher Order Aberrations ◽  
Upper Eyelid ◽  
Spatial Frequencies ◽  
The Difference

Objective: To evaluate the changes of visual acuity, contrast sensitivity, astigmatism, and higher order aberrations after blepharoplasty in patients with dermatochalasis. Methods: Two hundred six eyelids of 103 patients with dermatochalasis were prospectively studied. Visual acuity, contrast sensitivity, corneal topography, astigmatism degree, and higher order aberrations were examined and recorded before and at 1 month after upper eyelid blepharoplasty. Change in contrast sensitivity and astigmatism values were determined according to margin reflex distance of patients, which were classified into three following groups: <2 mm, 2–3 mm, and ⩾ 4 mm. A Wilcoxon signed rank test was performed to compare the difference. Results: No significant differences were observed for visual acuity (p = 0.157). The contrast sensitivity of patients significantly increased at all spatial frequencies both under glare and nonglare conditions (p < 0.05). The mean refractive astigmatism significantly decreased from ‒1.01 ± 1.3 to ‒0.79 ± 0.71, postoperatively (p = 0.029). In patients with marginal reflex distance < 2 mm, mean contrast sensitivity was increased (p < 0.001) and mean astigmatism was decreased significantly (p < 0.001) compared with those with ⩾ 2 mm. Higher order aberrations decreased significantly from 0.62 ± 0.41 µm to 0.55 ± 0.38 µm (p = 0.038) after blepharoplasty. Root mean square of the vertical trefoil (p = 0.038), vertical coma (p = 0.002), horizontal trefoil (p = 0.027), third-order aberration (p = 0.005), secondary vertical stigmatism (p = 0.001), spherical aberration (p = 0.023), secondary horizontal astigmatism (p = 0.002), fourth-order aberration (p = 0.024), vertical pentafoil (p = 0.015), secondary horizontal coma (p = 0.035), secondary horizontal trefoil (p = 0.030), and horizontal pentafoil (p = 0.048) were decreased significantly. Conclusion: Upper eyelid blepharoplasty in patients with dermatochalasis has a significant improvement in visual function in terms of contrast sensitivity, astigmatism, and higher order aberrations.

Visual Function during Acute Hypoglycaemia

1996 ◽  
Vol 6 (1) ◽  
pp. 81-86 ◽  
Author(s):  
H. Tabandeh ◽  
L. Ranganath ◽  
V. Marks
Keyword(s):  
Visual Acuity ◽  
Contrast Sensitivity ◽  
Visual Function ◽  
Blood Glucose Concentration ◽  
Visual Pathways ◽  
Metabolic Disturbances ◽  
Sensitivity Testing ◽  
Hypoglycaemia Unawareness ◽  
Visual Symptoms ◽  
Binocular Function

Hypoglycaemia symptoms are of particular interest in view of the importance of hypoglycaemia unawareness. Visual symptoms arising during acute hypoglycaemia may be the result of metabolic disturbances in the visual pathways within the central nervous system or impairment of the refractive apparatus of the eye and binocular function. This study investigated the effect of hypoglycaemia upon visual acuity, binocular interaction and contrast sensitivity. Various aspects of visual function were examined in ten normal subjects before, during and after acute insulin-induced hypoglycaemia. A simultaneous study of hypoglycaemic symptoms enabled us to relate the objective findings to the symptoms as reported by the subjects. Snellen visual acuity, fusion and stereopsis were not affected by hypoglycaemia. Five subjects noted visual disturbance. Eight developed significant impairment of contrast sensitivity, which closely matched the lowered blood glucose concentration. These observations suggest that hypoglycaemic visual symptoms are due to neuroglycopenia of central visual pathways rather than changes within the refractive apparatus or abnormality of binocular function. Although these symptoms are not a constant feature of the hypoglycaemic state, subtle impairment of visual function occurs in most cases. Contrast sensitivity testing can be useful for assessment of fine changes in visual function.

THE SIGNIFICANCE OF THE TMC AND HRR COLOR-VISION-TESTS AS TO RED-GREEN DEFECTIVENESS

1972 ◽  
Vol 49 (10) ◽  
pp. 847-858 ◽  
Author(s):  
J. J. Vos ◽  
W. Verkaik ◽  
J. Boogaard
Keyword(s):  
Color Vision ◽  
Color Vision Tests
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