scholarly journals Dissociation between red and white stimulus perception: A perimetric quantification of protanopic color vision deficiencies

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260362
Author(s):  
Denise Wetzel ◽  
Judith Ungewiss ◽  
Michael Wörner ◽  
Helmut Wilhelm ◽  
Ulrich Schiefer
Keyword(s):  
Visual Field ◽  
Color Vision ◽  
Field Extension ◽  
Control Group ◽  
Horizontal Meridian ◽  
Field Extensions ◽  
Kinetic Perimetry ◽  
Color Vision Deficiencies ◽  
The Right ◽  
Age Range

Significance Horizontal visual field extension was assessed for red and white stimuli in subjects with protanopia using semi-automated kinetic perimetry. In contrast to a conventional anomaloscope, the “red/white dissociation ratio” (RWR) allows to describe protanopia numerically. For the majority of subjects with protanopia a restriction for faint red stimuli was found. Purpose Comparing the horizontal visual field extensions for red and white stimuli in subjects with protanopia and those with normal trichromacy and assessing the related intra-subject intra-session repeatability. Methods The subjects were divided into groups with protanopia and with normal trichromacy, based on color vision testing (HMC anomaloscope, Oculus, Wetzlar/FRG). Two stimulus characteristics, III4e and III1e, according to the Goldmann-classification, were presented with semi-automated kinetic perimetry (Octopus 900 perimeter, Haag-Streit, Köniz/CH). They moved along the horizontal meridian, with an angular velocity of 3°/s towards the visual field center, starting from either the temporal or nasal periphery. If necessary, a 20° nasal fixation point offset was chosen to capture the temporal periphery of the visual field. For each condition the red/white dissociation ratio (RWR); Pat Appl. DPMA DRN 43200082D) between the extent of the isopter for red (RG610, Schott, Mainz/ FRG) and white stimuli along the horizontal meridian was determined. Results All data are listed as median/interquartile range: Five males with protanopia (age 22.1/4.5 years) and six males with normal trichromacy (control group, age 30.5/15.2 years) were enrolled. The RWR is listed for the right eye, as no clinically relevant difference between right and left eye occurred. Protanopes’ RWR for mark III4e (in brackets: control group) was 0.941/0.013 (0.977/0.019) and for mark III1e 0.496/0.062 (0.805/0.051), respectively. Conclusions In this exploratory “proof-of-concept study” red/white dissociation ratio perimetry is introduced as a novel technique aiming at assessing and quantifying the severity of protanopia. Further effort is needed to understand the magnitude of the observed red-/white dissociation and to extend this methodology to a wider age range of the sample and to anomalous trichromacies (protanomalia) with varying magnitude.

Effect of Lateral Eye Fixation on Cognitive Processes

1981 ◽  
Vol 52 (2) ◽  
pp. 487-490 ◽  
Author(s):  
Ronald A. La Torre ◽  
Anne-Marie La Torre
Keyword(s):  
Visual Field ◽  
Left Visual Field ◽  
Spatial Task ◽  
Right Visual Field ◽  
Control Group ◽  
Intelligence Scale ◽  
Eye Fixation ◽  
Lateral Eye ◽  
The Right ◽  
Spatial Problems

Fourth grade children responded to verbal and spatial problems drawn from the Wechsler Intelligence Scale for Children. 24 responded to verbal problems while attending to the right visual field and to spatial problems while attending to the left visual field; 24 fixed attention to the left visual field during verbal problems and to the right visual field during spatial problems. A final 24 children fixed their attention centrally while responding to both sets of problems. There were no significant differences among the groups for verbal performance. Spatial problems were dealt with least effectively during right visual-field eye-fixation. Perhaps right visual-field fixation during a spatial task leads to interference with capacity and from functional distance. Left visual-field fixation might be facilitating as a result of functional closeness but this facilitation is offset by interference with capacity making the over-all result not significantly different from that for the control group. Verbal centers may be insulated against effects of interference.

Attention Can Be Oriented to Intermediate Locations within the Large Area of the Visual Field

2002 ◽  
Vol 95 (3) ◽  
pp. 806-812 ◽  
Author(s):  
Soichi Ando ◽  
Masahiro Kokubu ◽  
Noriyuki Ktda ◽  
Shingo Oda
Keyword(s):  
Visual Field ◽  
Reaction Times ◽  
Equal Probability ◽  
Horizontal Meridian ◽  
Large Area ◽  
Random Location ◽  
The Right

The present study examined whether attention can be evenly distributed within the large area of the visual field. The stimulus was presented at one of four locations on the horizontal meridian (0°, 10°, 20°, and 30° to the right). In the Fixed Location condition, the stimulus appeared repeatedly at the same location. In the Random Location condition, the stimulus appeared at one of four locations as determined randomly with equal probability. Reaction times (RTs) in the Random Location condition were significantly Longer than those in the Fixed Location condition at the 0° and 30° locations, while there were no significant differences at the 10° and 20° locations. The differences in the RT between conditions were significantly larger at the 0° and 30° locations than those at the 10° and 20° locations. These results suggest that attention was oriented to intermediate locations within the large area of the visual field.

Comparison of Spatial Discrimination in the Temporal and Nasal Sectors of the Monocular Visual Field

1965 ◽  
Vol 20 (3_suppl) ◽  
pp. 1037-1045 ◽  
Author(s):  
Maria Wyke ◽  
Stephan L. Chorover
Keyword(s):  
College Students ◽  
Visual Field ◽  
Spatial Discrimination ◽  
Normal Male ◽  
Horizontal Meridian ◽  
Visual Spatial ◽  
Significant Difference ◽  
Male College ◽  
The Right ◽  
Visual Discriminations

A study comparing monocular visual spatial discrimination in temporal and nasal half-fields was undertaken with the Tuebinger perimeter of Harms (1960). Twenty normal male college students performed a series of spatial visual discriminations in which “standard” and “comparison” stimuli were successively presented at varying distances from a fixation point along the mid-horizontal meridian. The results show that under conditions of relatively prolonged presentation of the test stimuli (1.0 sec.) monocular visual discriminations of this type are performed better with the left eye than with the right. The superiority of the left eye was maintained irrespective of whether nasal or temporal half-fields were tested. Furthermore, for a given eye, there was no significant difference in the performance of nasal and temporal half-fields.

scholarly journals Obesity and age as factors in leg amputations in fatal motorcycle crashes

2019 ◽  
Vol 60 (1) ◽  
pp. 26-29
Author(s):  
Siobhan O’Donovan ◽  
Corinna van den Heuvel ◽  
Matthew Baldock ◽  
Roger W Byard
Keyword(s):  
Lower Limb ◽  
Motor Vehicle ◽  
South Australia ◽  
Control Group ◽  
Significant Information ◽  
The Road ◽  
The Right ◽  
Lower Leg Amputation ◽  
Leg Amputation ◽  
Age Range

The autopsy files at Forensic Science South Australia were searched over an 11-year period from January 2008 to December 2018 for all cases of motorcycle fatalities in which there had been lower-limb amputations. Six cases were identified, consisting of five male riders and one female pillion passenger. The age range was 48–67 years (average 59 years), which was significantly older than the control group (40.6 years; p < 0.01). All the decedents were overweight, with a body mass index (BMI) of 28.7–43.5 kg/m2 (average 34.9 kg/m2), which again was significantly greater than the control group (28.8 kg/m2; p < 0.05). Five of the incidents involved a collision between a motorcycle and a motor vehicle; the remaining case involved a collision with a tree. Five of the amputations were on the right side in the motorcycle-vehicle impacts, and they varied in severity from loss of a foot to a hind-quarter amputation. There was a single left lower-leg amputation which occurred during the collision with a tree, which was beside the road on the motorcyclist’s left. This study has shown that motorcyclists at greatest risk of lower-limb/pelvis amputations are older than the average rider with higher BMIs. This may be significant information given the increase in both BMI and age in many populations.

Optic Nerve Sheath Meningiomas: Visual Improvement after Stereotactic Radiotherapy

Neurosurgery ◽  
2002 ◽  
Vol 50 (5) ◽  
pp. 950-957 ◽  
Author(s):  
James K. Liu ◽  
Scott Forman ◽  
Gerard L. Hershewe ◽  
Chitti R. Moorthy ◽  
Deborah L. Benzil
Keyword(s):  
Visual Acuity ◽  
Optic Nerve ◽  
Visual Field ◽  
Color Vision ◽  
Stereotactic Radiotherapy ◽  
Optic Nerve Sheath ◽  
Dramatic Improvement ◽  
Visual Deterioration ◽  
Nerve Sheath ◽  
The Right

Abstract OBJECTIVE: The management of primary optic nerve sheath meningioma (ONSM) is controversial. Surgery often results in postoperative blindness in the affected eye and thus has been abandoned as a treatment option for most patients. When these tumors are left untreated, however, progressive visual impairment ensues, which also leads to blindness. Recently, radiation therapy has gained wider acceptance in the treatment of these lesions. Experience with stereotactic radiotherapy (SRT) in the treatment of ONSMs is limited because of the rare incidence of this tumor. We present a series of patients with ONSM who were treated with SRT. METHODS: Five patients (three women, two men), ranging in age from 40 to 73 years, presented with progressive visual loss with decreased visual field, visual acuity, and color vision affecting six eyes (one patient had tumor involving both optic nerves). One patient also presented with proptosis and diplopia. Five eyes had functional residual vision (range, 20/20 to 20/40), and one eye was completely blind. All five patients were diagnosed clinically and radiographically to have an ONSM. Three were intraorbital, one was intracanalicular as well as intraorbital, and one was a left ONSM extending through the optic foramen into the intracranial space and involving the right optic nerve. The five functional eyes were treated with SRT by use of 1.8-Gy fractions to a cumulative dose of 45 to 54 Gy. RESULTS: Follow-up ranged from 1 to 7 years, and serial magnetic resonance imaging revealed no changes in the size of the tumor in all five patients. Four patients experienced dramatic improvement in visual acuity, visual field, and color vision within 3 months after SRT. One patient remained stable without evidence of visual deterioration or disease progression. None had radiation-induced optic neuropathy. CONCLUSION: SRT may be a viable option for treatment of primary ONSM in patients with documented progressive visual deterioration, and it may be effective in improving or stabilizing remaining functional vision.

scholarly journals Statokinetic Dissociation (Riddoch Phenomenon) in a Patient with Homonymous Hemianopsia as the First Sign of Posterior Cortical Atrophy

2017 ◽  
Vol 9 (3) ◽  
pp. 256-260 ◽  
Author(s):  
Ryuichiro Hayashi ◽  
Shigeki Yamaguchi ◽  
Toshio Narimatsu ◽  
Hiroshi Miyata ◽  
Yasushi Katsumata ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Cortical Atrophy ◽  
Visual Field Defects ◽  
Posterior Cortical Atrophy ◽  
Unilateral Neglect ◽  
Homonymous Hemianopsia ◽  
Kinetic Perimetry ◽  
The Right ◽  
Field Defects

We report a 60-year-old woman with posterior cortical atrophy (PCA) who presented with left homonymous hemianopsia persisting for 5 years; the patient’s condition was observed using static, but not kinetic, perimetry. This statokinetic dissociation of hemianopsia, which is often called Riddoch syndrome, might have been caused by a dysfunction of the right primary visual and visual association cortices, representing a functional imbalance within a disturbed visual cortex. In patients with PCA and visual field defects, both static and kinetic perimetry may be useful for understanding the extent of degeneration in the visual cortex, in addition to examinations of unilateral neglect.

scholarly journals Eye disorders in patients with chronic alcoholism

2014 ◽  
Vol 95 (4) ◽  
pp. 519-523
Author(s):  
R R Fazlyeva ◽  
F R Saifullina
Keyword(s):  
Visual Field ◽  
Color Vision ◽  
Color Perception ◽  
Chronic Alcoholism ◽  
Fusion Rate ◽  
Control Group ◽  
Bulbar Conjunctiva ◽  
Main Process ◽  
Vascular Changes ◽  
Flicker Fusion

Aim. To study the features of ophthalmic disorders in patients with chronic alcoholism. Methods. Sixty patients (120 eyes) with chronic alcoholism (the main group), including 20 people (40 eyes) with the first stage, and 40 people (80 eyes) with the second stage of chronic alcoholism. Control group consisted of 30 healthy volunteers aged 18 to 46 years. All patients underwent ophthalmologic examination, which included visual acuity test, refractometry, biomicroscopy, biomicroophthalmoscopy, visual field test using chromatic and achromatic colors, color vision test using the tables by E.B. Rabkin (1972), tonometry, flicker fusion rate, and bulbar conjunctiva microcirculation examination. Results. In patients of the control group, eye condition complied with a person’s age, a few changes of the conjunctiva microcirculation were revealed, perivascular changes index was assessed as 1.26±0.05 points, vascular changes index - 1.2±0.05 points, capillary changes index - 1.28±0.05 points, intravascular changes index - 2.3±0.05 points, total conjunctival index - 5±0.13 points. Patients with chronic alcoholism showed reduction of central vision in 26% of cases; white color perception visual field decrease - in 80% of cases, red color - in 40%, green - in 13% of cases. Color perception change was an acquired one in 88% of cases, inherited - in 22% of cases; unilateral reduction of visual flicker fusion rate to red light was observed in 35% of cases, bilateral decrease - in 23% of cases. All patients with chronic alcoholism had bulbar conjunctiva microcirculation disorders: perivascular changes index was assessed as 3.48±0.06 points, vascular changes index - 11.25±0.32 points, capillary changes index - 10.51±0.06 points, intravascular changes index - 2.36±0.06 points, total conjunctival index - 27.61±0.48 points. Conclusion. Alcohol intoxication causes profound pathological changes in the eye seen as visual field decrease, color vision disorders, reduced flicker fusion rate, presence of perivascular, intravascular and vascular disorders of bulbar conjunctiva microvasculature, which should be considered at main process monitoring and choosing the appropriate treatment.

Visual Imagery Processing in Japanese Abacus Experts

1989 ◽  
Vol 9 (2) ◽  
pp. 91-102 ◽  
Author(s):  
Takeshi Hatta ◽  
Mayumi Miyazaki
Keyword(s):  
Visual Field ◽  
Visual Imagery ◽  
Right Visual Field ◽  
Control Group ◽  
Imagery Condition ◽  
Digit Sequence ◽  
Processing Ability ◽  
Group 2 ◽  
The Right ◽  
Imagery Processing

Two experiments were conducted to examine the ability of visual imagery processing in abacus experts. Abacus experts and normal control subjects (university students) with no abacus training were given word and picture matching tasks for Experiment 1, and digit sequence and abacus-picture matching tasks for Experiment 2. The pictures, comparison stimuli, were tachistoscopically presented in either the left or the right visual field. The results indicated that: 1) the abacus experts performed matching tasks under all conditions of both experiments faster than the control group; 2) the abacus experts showed a left visual field advantage regarding the imagery condition in both Experiments; and 3) the control group showed a right visual field advantage in the rehearsal conditions of both experiments and in the imagery condition of Experiment 2. The effects of abacus practice on imagery processing ability were discussed based upon the different patterns of visual field differences between the abacus experts and the control group.

Correlation of Metabolic Risk Factors with Sessile Serrated Lesions

2020 ◽  
Vol 29 (2) ◽  
pp. 175-179
Author(s):  
Melania Macarie ◽  
Simona Bataga ◽  
Simona Mocan ◽  
Monica Pantea ◽  
Razvan Opaschi ◽  
...  
Keyword(s):  
Risk Factors ◽  
Statistical Significance ◽  
Interval Cancer ◽  
Metabolic Risk Factors ◽  
Control Group ◽  
Anatomical Site ◽  
Metabolic Risk ◽  
Right Colon ◽  
Serrated Lesions ◽  
The Right

Background and Aims: The importance of sessile serrated lesions (SSLs) in the pathogenesis of colorectal carcinoma has been recently established. These are supposed to cause the so-called “interval cancer”, having a rapidly progressive growth and being difficult to detect and to obtain an endoscopic complete resection. We aimed to establish the most important metabolic risk factors for sessile serrated lesions. Methods: We performed a retrospective case-control study, on a series of 2918 consecutive patients who underwent colonoscopy in Gastroenterology and Endoscopy Unit, County Clinical Emergency Hospital, Târgu-Mureș, Romania between 1 st of January 2015-31 th of December 2017. In order to evaluate the metabolic risk factors for polyps’ development, enrolled participants were stratified in two groups, a study group, 33 patients with SSLs lesions, and a control group, 138 patients with adenomatous polyps, selected by systematic sampling for age and anatomical site. Independent variables investigated were: gender, smoking, alcohol consumption, obesity, arterial hypertension, diabetes, hypercholesterolemia, hypertriglyceridemia, hyperuricemia, nonalcoholic liver disease. Results: For SSLs the most common encountered localization was the right colon in 30.55% of cases. By comparative bivariate analysis between SSLs group and control group, it was observed that hypertension (p=0.03, OR 2.33, 95 %CI 1.03-5.24), obesity (p=0.03, OR 2.61, 95 %CI 1.08-6.30), hyperuricemia (p=0.04, OR 2.72, 95 %CI 1.28-7.55), high cholesterol (p=0.002, OR 3.42; 95 %CI 1.48-7.87), and high triglycerides level (p=0.0006, OR 5.75; 95 %CI 1.92-17.2) were statistically associated with SSLs development. By multivariate analysis hypertension and hypertriglyceridemia retained statistical significance. Conclusions: Our study showed that the highest prevalence of SSLs was in the right colon and hypertension and increased triglycerides levels were associated with the risk of SSLs development. These risk factors are easy to detect in clinical practice and may help identifying groups with high risk for colorectal cancer, where screening is recommended.

Visual asymmetries during face encoding Increased dwell time and fixations in the upper and left hemifields

2018 ◽  
Author(s):  
Fatima Maria Felisberti
Keyword(s):  
Face Recognition ◽  
Eye Movements ◽  
Visual Field ◽  
Face Processing ◽  
Dwell Time ◽  
The Other ◽  
Environmental Cues ◽  
Reading Habits ◽  
The Right

Visual field asymmetries (VFA) in the encoding of groups rather than individual faces has been rarely investigated. Here, eye movements (dwell time (DT) and fixations (Fix)) were recorded during the encoding of three groups of four faces tagged with cheating, cooperative, or neutral behaviours. Faces in each of the three groups were placed in the upper left (UL), upper right (UR), lower left (LL), or lower right (LR) quadrants. Face recognition was equally high in the three groups. In contrast, the proportion of DT and Fix were higher for faces in the left than the right hemifield and in the upper rather than the lower hemifield. The overall time spent looking at the UL was higher than in the other quadrants. The findings are relevant to the understanding of VFA in face processing, especially groups of faces, and might be linked to environmental cues and/or reading habits.

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