Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Visual Fields”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,315 records · Page 73Linked to original sources
PubMed2006

Comparison of visual field defects using matrix perimetry and standard achromatic perimetry.

PURPOSE: To compare visual field (VF) defects found by Swedish interactive thresholding Algorithm (SITA) perimetry and Matrix perimetry, a new VF device that utilizes frequency doubling technology in a 24-2 test pattern. DESIGN: Prospective cross-sectional study. PARTICIPANTS: Fifty eyes from 50 subjects with SITA field defects were recruited for an observational study. METHODS: Swedish Interactive Threshold Algorithm and Matrix VF testing were performed on patients from a glaucoma practice. To evaluate the learning effect on the performance of the VF, we tested subsets of each group who had previous experience with standard automated perimetry (SAP). MAIN OUTCOME MEASURES: Test duration, mean threshold, mean deviation (MD), pattern standard deviation (PSD), glaucoma hemifield test, and number of abnormal points on the pattern deviation plot were evaluated for each device. RESULTS: Test duration was significantly shorter for Matrix (SITA, 357.0+/-85.6 seconds; Matrix, 319.5+/-16.5 seconds; P = 0.0002, paired t-test). Thirty-six percent of eyes with SITA VF defects showed a normal Matrix field. In 30 of 32 eyes (94%) where both devices showed VF defects, the defects were congruent. Mean threshold value was significantly lower with Matrix compared to SITA (P<0.0001, paired t-test), as was MD (-5.34+/-5.42 dB, -4.14+/-5.29 dB, respectively; P = 0.03, paired t-test). There was no significant difference in PSD between the 2 devices (P = 0.78, paired t-test). Matrix delineated significantly smaller (P = 0.005, Wilcoxon's test) and deeper (P<0.001, Wilcoxon's test) defects than those found with SITA. Similar results were observed in the subgroups with prior SAP experience. CONCLUSIONS: The Matrix examination did not detect 36% of abnormal SITA fields. Matrix field defects were smaller and deeper than those appearing in SITA perimetry.

Adult↗
PubMed1990

Shift toward left visual field advantage after short-term learning experience.

The purpose of the present study was to examine the effect of the short-term learning experience on visual field difference. Firstly, the random shape was briefly presented in a left or right visual field (Test 1), then the paired-associated learning task associated with the stimulus shape was carried out. Several days later the same laterality task was conducted again (Test 2). The results showed a shift toward left visual field advantage (LVF-A) between Tests in the relevant label learning group, a trivial shift toward RVF-A in the irrelevant/concrete label learning group, a shift toward RVF-A in the irrelevant/abstract label learning group, and no shift in no-learning group. The relationship between the direction of the shifts of cerebral hemispheric asymmetry and label types was discussed.

Adult↗
PubMed1997

Quantitative estimation of retinal nerve fiber layer height in glaucoma and the relationship with optic nerve head topography and visual field.

PURPOSE: The authors estimated the retinal nerve fiber layer height (RNFLH) measurements in patients with glaucoma compared with those in age-matched healthy subjects as obtained by the laser scanning tomography and assessed the relationship between RNFLH measurements and optic and visual field status. METHODS: Parameters of optic nerve head topography and RNFLH were evaluated in 125 eyes of 21 healthy subjects and 104 patients with glaucoma using the Heidelberg Retina Tomograph ([HRT] Heidelberg Engineering GmbH, Heidelberg, Germany) for the entire disc area and for the superior 70 degrees (50 degrees temporal and 20 degrees nasal to the vertical midline) and inferior 70 degrees sectors of the optic disc. The mean deviation of the visual field, as determined by the Humphrey program 24-2 (Humphrey Instruments, Inc., San Leonardo, CA, U.S.A) was calculated in the entire field and in the superior and inferior Bjerrum area. RESULT: Retinal nerve fiber layer height parameters (mean RNFLH and RNFL cross-sectional area) were decreased significantly in patients with glaucoma compared with healthy individuals. Retinal nerve fiber layer height parameters was correlated strongly with rim volume, rim area, and cup/disc area ratio. Of the various topography measures, retinal nerve fiber layer (RNFL) parameters and cup/disc area ratio showed the strongest correlation with visual field mean deviation in patients with glaucoma. CONCLUSION: Retinal nerve fiber layer height measures were reduced substantially in patients with glaucoma compared with age-matched healthy subjects. Retinal nerve fiber layer height was correlated strongly with topographic optic disc parameters and visual field changes in patients with glaucoma.

Female↗
PubMedDate not supplied

Evidence of an extended representation of the visual field in the superior colliculus of the rabbit (Oryctolagus cuniculus).

Electrophysiological mapping using multiple-unit criteria was employed to study the representation of the visual field in the superior colliculus of the rabbit. It was found that the contralateral superior colliculus of the rabbit has an extended representation beyond the representation of the zero vertical meridian or the line of decussation in the geniculostriate system. The amount of extended representation in the contralateral superior colliculus is coextensive with the extent of visual field represented ipsilaterally in areas 17 and 18 of the visual cortex. In agreement with previous findings, the representation of the visual field on the superior colliculus is extremely distorted. Finally, no evidence of an ipsilateral input can be produced.

Animals↗
PubMed2006

Refraction and aberration across the horizontal central 10 degrees of the visual field.

PURPOSE: The purpose of this study was to measure refraction and aberrations across the horizontal central visual field. METHODS: Cycloplegic refraction was measured on eight subjects at 13 points across the horizontal central 10 degrees of the retina using a Hartmann-Shack wavefront sensor. Refractions were converted into mean sphere (M), 90 degrees to 180 degrees astigmatism (J180), and 45 degrees to 135 degrees astigmatism (J45) components. For five subjects, higher-order aberrations were determined at the center and edges of the field. RESULTS: Subtle changes in refraction were found to exist across the central 10 degrees of the retina, with changes in mean best sphere varying by up to half a diopter across this region and with smaller changes in astigmatism. Horizontal coma, but no other higher-order aberrations, varied systemically across the visual field; it varied linearly with angle but at different rates for the different subjects. CONCLUSION: Subtle changes in cycloplegic refraction exist across the horizontal central 10 degrees of the retina. The results indicate the need for correct alignment when measuring objective refraction.

Adult↗
PubMed2006

Identification of 3D shape from texture and motion across the visual field.

Little is known about the perception of 3D shape in the visual periphery. Here we ask whether identification accuracy in shape-from-texture and shape-from-motion tasks can be equated across the visual field with sufficient stimulus magnification. Both tasks employed 3D surfaces comprising hills, valleys, and plains in three possible locations, yielding a 27 alternative forced-choice task (27AFC). Participants performed the task at eccentricities of 0 to 16 deg in the right visual field over a 64-fold range of stimulus sizes. Performance reached ceiling levels at all eccentricities, indicating that stimulus magnification was sufficient to compensate for eccentricity-dependent sensitivity loss. The parameter E(2) (in the equation F = 1 + E / E(2)) was used to characterize the rate at which stimulus size must increase with eccentricity (E) to achieve foveal levels of performance. Three parameter models (mu, sigma, and E(2)) captured most of the variability in the psychometric functions relating stimulus size and eccentricity to accuracy for all participants' data in the two experiments. For the shape-from-texture task, the average E(2) was 1.52, and for the shape-from-motion task, it was 0.61. The E(2) values indicate that sensitivity to structure from motion declines at a faster rate with eccentricity than does sensitivity to structure from texture. Although size scaling with F = 1 + E / E(2) eliminated most eccentricity variation from the structure-from-motion data, there was some evidence that E(2) increases as accuracy decreases in the shape-from-texture task, suggesting that there may be more than one eccentricity-dependent limitation on performance in this task.

Adult↗
PubMedDate not supplied

[Vigabatrin and alterations of the visual field].

INTRODUCTION: Since 1997 when Ecke et al described peripheral constriction of the visual field in three patients taking vigabatrin (VGB), and persistence of the changes after the drug was stopped, study of the visual fields of persons taking this antiepileptic drug has increased. OBJECTIVE: To evaluate the ocular repercussions of monotherapy with carbamazepine (CBZ), valproate (VPA) and VGB in children with epilepsy. PATIENTS AND METHODS: We made a blind retrospective study to evaluate visual side effects using Goldmann's campimetry and direct ophthalmoscopy in 9 children treated for 2.1 years with CBZ, 12 children treated with VPA for 3.1 years and 12 children treated for 2.1 years with VGB, all as monotherapy. In recent years visual evoked potentials (VEP) have also been assessed before starting treatment and every six months during treatment. RESULTS: One child treated with CBZ had changes in vision (blurred vision which disappeared on reducing the dose), 3 treated with VGB (diplopia which disappeared spontaneously in 2 and after reducing the dose in 1) and none of the group treated with VPA had these symptoms. All the campimetry done was found to be normal. Two of the 12 children treated with VGB had reduction in the amplitude of VEP, which became normal later. CONCLUSIONS: Since the changes in vision caused by VGB seem to be irreversible and asymptomatic in most cases, campimetric study is advisable in patients taking VGB, both when starting treatment and whilst this is being continued.

Adolescent↗
PubMed1989

Visual field interpretation with empiric probability maps.

Automated visual field charts may be difficult to interpret partly because of the magnitude and complex nature of normal threshold variability. We devised two types of empiric probability maps in which this variability is taken into account and the significances of measured threshold values are displayed. These maps are highly sensitive to nonobvious but significant paracentral field loss but will at the same time deemphasize false-positive patterns commonly found more peripherally. They also frequently show field defects before these are obvious in conventional threshold printouts. In addition, they differentiate between generalized loss of sensitivity and localized field defects.

Cataract↗
PubMed1980

Visual fields interpretation.

From the retina to the visual cortex, commonly encountered visual field defects are discussed. Retinal, optic nerve nerve head, optic nerve, optic tract, lateral geniculate, radiations and cortex lesion examples are described with predicted outcomes and possible variations of the field defects.

Brain Diseases↗
PubMed1991

Visual field restrictions with the M17 series protective mask.

The restrictions on the central and peripheral visual fields, resultant from wearing a M17 series mask, were measured on a subject with normal field of vision. The results showed a decrease in visual field in all meridians, with the nasal area being the most dramatically restricted.

Adult↗
PubMed1991

Influence of betaxolol and timolol on the visual fields of patients with glaucoma.

In a double-masked study, 40 patients with primary open-angle glaucoma were randomly assigned to treatment with betaxolol 0.5% or timolol 0.5% in both eyes twice daily. Visual fields and intraocular pressures were studied. Perimetry was performed with the Octopus G1 program two weeks after a washout period and three, six, 12, and 18 months after initiation of treatment. Both drugs reduced intraocular pressure. The reduction in intraocular pressure in the timolol-treated group was more pronounced than that in the betaxolol-treated group; the difference, however, was not statistically significant. In both treatment groups, the visual fields tended to improve during the first six months of treatment and remained stable or tended to deteriorate thereafter. The treatment effect on the visual field was better in the betaxolol-treated group than it was in the timolol-treated group (P = .041).

Aged↗
PubMed1986

[Visual field fluctuations in necrotic hypophyseal adenoma].

The authors report on an acute bitemporal visual field depression with spontaneous reversibility of the defects, associated with necrotic pituitary adenoma. As the same time as the visual field defects regressed it was established by computer tomography that the suprasellar portion of the pituitary tumor had diminished in size.

Adenoma↗
PubMed1994

Factors contributing to the progression of visual field damage in eyes with normal-tension glaucoma.

PURPOSE: To evaluate the contribution of various factors on the progression of visual field damage in normal-tension glaucoma. METHODS: Follow-up data of 56 eyes of 56 patients with normal-tension glaucoma, all of whom had an early stage of the disease with a mean deviation of -5 decibels or greater and were followed without therapy, were analyzed using regression analysis of survival data based on the Cox proportional hazards model. Factors studied were age, sex, presence or absence of diabetes or family history of glaucoma, refraction, systolic and diastolic pressures, cup:disc ratio, ratio of area of parapapillary atrophy to disc area, the mean deviations of the studied and contralateral eyes, and intraocular pressure and occurrence of disc bleeding during follow-up, both of which were treated as time-dependent variables. The progression of visual field damage was based on the glaucoma change probability analysis. RESULTS: Cup:disc ratio, ratio of area of parapapillary atrophy to disc area, and intraocular pressure were found to have significant influence on the progression of visual field damage in normal-tension glaucoma. CONCLUSION: Intraocular pressure may be involved in the development of normal-tension glaucoma. However, further prospective studies are needed to determine the validity of such a conclusion.

Female↗
PubMed1996

Relationship of nerve fiber layer defects and parafoveal visual field defects in glaucomatous eyes.

To evaluate the relationship between nerve fiber layer defects (NFLD) and parafoveal visual field defects in glaucomatous eyes, 23 eyes of 20 patients with open-angle glaucoma were studied by scanning laser ophthalmoscope (SLO). Only eyes in which the NFLD reached the temporal raphe in either hemisphere were used. We defined three topographic parameters of NFLD: 1) the angle (theta, degrees) of line 'A' from the optic disc center to the foveal pit, and line 'B' from the disc center to a point of the NFLD at the disc edge nearest line 'A'; 2) a horizontal distance (D1, mm) along the temporal raphe between the foveal pit and the internal edge of the NFLD; and 3) a vertical distance (D2, mm) between the foveal pit and either the superior or inferior internal edge of the NFLD. We defined the nearest defect location (in degrees from the fovea) as the nearest location with sensitivity loss of at least 6 dB (Humphrey visual field program 10-2). A highly significant correlation was found between each of the NFLD parameters and the nearest defect location (P < 0.001). The NFLD parameters we defined may be helpful for evaluating parafoveal visual function in glaucoma.

Adult↗
PubMed1997

Neuronal activity in the frontal eye field of the monkey is modulated while attention is focused on to a stimulus in the peripheral visual field, irrespective of eye movement.

We tested the hypothesis that the frontal eye field (FEF) is involved in attention to the peripheral visual field (PVF). Neuronal activity was recorded in the FEF of two monkeys while they were performing three oculomotor tasks. In the visual attention task (VAT), the monkeys released a lever when a test stimulus (TS) presented in the PVF dimmed while they were looking at a central fixation point (FP). In the visual saccade task (VST), the monkeys exhibited saccadic eye movements when the FP was extinguished. In the visual fixation task (VFT), the monkeys released the lever when the FP dimmed. Overall, the activities of 80 FEF neurons were examined. The responses to visual stimuli of 41 of these neurons (51%) were modulated during the VAT. Twenty-five neurons showed pre-saccadic activity. Of these, 13 neurons (52%) exhibited activity modulation during the VAT. Eighteen neurons showed no pre-saccadic activity. Of these, 10 neurons (56%) exhibited activity modulation during the VAT. These results suggest that the FEF is involved in selecting the visual stimuli relevant to performing a task irrespective of eye movements.

Animals↗
PubMed2006

Alteration of postural responses to visual field motion in mild traumatic brain injury.

OBJECTIVE: Balance deficits in individuals experiencing mild traumatic brain injury have been documented in numerous recent studies. However, long-lasting balance deficits and specific mechanisms causing these deficits have not been systematically examined. This article aimed to present empirical evidence showing destabilizing effects of visual field motion in concussed individuals up to 30 days postinjury. METHODS: Sixty student athletes participated in the pilot (n = 12) and major experiments (n = 48) before injury. Eight of these 48 subjects who experienced mild traumatic brain injury in athletic events were tested again on Days 3, 10, and 30 after the incident. Postural responses to visual field motion were recorded using a virtual reality environment in conjunction with balance (AMTI force plate) and motion tracking (Flock of Birds) technologies. RESULTS: The area of the center of pressure during upright stance did not change from Day 3 to 30 postinjury with respect to pre-injury status (P > .05). However, balance deficits induced by visual field motion were present up to 30 days postinjury. Destabilizing effect of visual field motion was observed via significant increase of the center of pressure data (P < .05) and reduced coherence value. CONCLUSION: Our data suggest the presence of residual sensory integration dysfunction in concussed individuals at least 30 days postinjury and may indicate a lower threshold for brain reinjury.

Adult↗
PubMed2000

Increased intraocular pressure and visual field defects in high resistance wind instrument players.

OBJECTIVE: In this twofold study, part 1 aimed to determine whether the playing of high resistance wind instruments elevates intraocular pressure (IOP) and if so, to investigate the mechanism of IOP elevation and whether its magnitude differs while playing high resistance versus low resistance instruments. The purpose of part 2 was to evaluate whether high resistance players have a greater incidence of glaucomatous changes than other musicians. DESIGN: Three case reports and a cross-sectional study. PARTICIPANTS: Two players of high resistance instruments and one player of high and low resistance wind instruments participated in part 1 of the study. Nine high resistance wind players, 12 low resistance wind players, and 24 nonwind players were recruited among professional musicians in the Boston area to participate in part 2. INTERVENTION: In part 1, IOP and uveal thickness changes were measured by pneumatonometry and ultrasound biomicroscopy in two participants playing their high resistance wind instruments (trumpet and oboe) and in a third participant playing both high (trumpet) and low (clarinet and saxaphone) resistance instruments. Each musician in part 2 underwent medical and musical history, measurement of IOP, Humphrey visual field testing, slit-lamp examination, gonioscopy, and dilated examination. MAIN OUTCOME MEASURES: Intraocular pressure and uveal thickness changes, and visual field loss and optic nerve head appearance were the main parameters measured in part 1 and part 2, respectively. RESULTS: In part 1, pneumatonometry showed IOP elevation dependent on the force of blowing, and ultrasound biomicroscopy revealed uveal thickening associated with IOP elevation. The magnitude of IOP elevation was dependent on the amount of expiratory resistance provided by the particular instrument. Part 2 showed that life hours of high resistance wind instrument playing had a significant relationship to abnormal visual field (P = 0.03) and corrected pattern standard deviation (CPSD) scores (P = 0.007) in univariate logistic regression and univariate linear regression, respectively. A 0.011-unit increase in CPSD for each 1000 life hours of high resistance wind playing was found. CONCLUSIONS: High and low resistance wind musicians experience a transient rise in their IOP while playing their instruments as a result least in part of uveal engorgement. The magnitude of IOP increase is greater in high resistance wind players versus low resistance wind players. High resistance wind musicians had a small but significantly greater incidence of visual field loss (abnormal fields and increased CPSD scores) than other musicians, which was related to life hours of playing. The cumulative effects of long-term intermittent IOP elevation during high resistance wind instrument playing may result in glaucomatous damage, which could be misdiagnosed as normal-tension glaucoma.

Aged↗