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PubMed1985

Perception of line orientation in the center and periphery of the visual field.

Perception of orientation in the center and periphery of the visual field were compared. The stimuli were bright lines 1 degree long. They were presented equiprobably in 18 orientations from 0 degree to 180 degrees at the center or at 20 degrees in the periphery of the visual field. Stimulus duration was 50 msec and its intensity was twice above the detection threshold for each localization. Percentage of errors, response standard deviation, stimulus standard deviation from the orientation assigned and information transmitted were studied. No scale or standard stimulus were presented. At both stimulus localizations the accuracy of orientation was high and the errors larger than 20 degrees were less than 10% of all responses. There was a small but significant foveal superiority in accuracy and information transmitted. For central vision, the percentage of errors, response standard deviation and stimulus standard deviation all showed an oblique effect, i. e. a lower performance with oblique lines than with vertical or horizontal. For the peripheral vision, some measures (response standard deviation) showed an oblique effect and others (stimulus standard deviation and percentage of errors) did not. This makes difficult the conclusions about the presence of an oblique effect at the periphery. Further studies by methods free of response bias are necessary.

Fovea Centralis↗

PubMed1998

Representation of foveal visual fields in the ventral bank of the superior temporal sulcus in the posterior inferotemporal cortex of the macaque monkey.

Using anesthetized and immobilized monkeys, this study investigated the representation of the visual field in the superior temporal sulcus in the posterior inferotemporal cortex. Of 1043 neurons in the posterior inferotemporal cortex including the sulcus and the gyrus, and surrounding areas that were tested, 540 (52%) responded to visual stimuli and their receptive fields were mapped. In the ventral bank of the superior temporal sulcus at the level corresponding to the posterior middle temporal sulcus, the foveal visual fields, which were dominant, were represented ventrally and the parafoveal visual fields dorsally. The upper and lower visual fields were represented intermingledly and no segregation between the representation of the upper and lower visual fields was seen. In the lateral convexity of the gyrus, the foveal visual fields were represented dorsally and the peripheral visual fields ventrally with the foveal visual fields being predominant. The upper visual fields were represented posteriorly, however locations and sizes of the representation of the upper and lower visual fields varied between hemispheres. The receptive field sizes of neurons in the sulcus were almost the same as those in the gyrus, and these receptive field sizes were intermediate between those of anterior inferotemporal neurons and V4 neurons. These findings suggest that the cortex in the sulcus in the posterior inferotemporal cortex is involved in the central vision, similarly to the cortex in the gyrus.

Animals↗

PubMed2000

[Reading speed in movement in the peripheral visual field].

BACKGROUND: Moving and distracting stimuli often occur in the peripheral visual field during visual tasks in daily life. Do they influence reading performance? METHOD: In 30 normal subjects with a normal visual acuity we investigated eye movements by electronystagmography (ENG) during silent reading of a standardized text. The 17 degrees-wide text was presented at a distance of 1 m, ENG was recorded bitemporally. Blinks were monitored via vertical ENG electrodes. For surrounding stimulation we presented a bar stimulus moving at 30 degrees/s. Three experimental conditions were compared: [1] no peripheral motion, [2] peripheral motion to the right, and [3] peripheral motion to the left. We quantitatively analyzed reading speed and blink frequency. RESULTS: Reading speed and blink frequency was nearly identical in the three experimental conditions, they differed by 1-8%. CONCLUSIONS: Although the full periphery was stimulated, and the moving stimulus was noticed by our subjects, reading was not affected by surrounding optokinetic stimulation. Attentive reading does not appear to be affected by visual motion in the periphery.

Adult↗

PubMed2003

Visual field and optic disc progression in patients with different types of optic disc damage: a longitudinal prospective study.

OBJECTIVE: To evaluate the incidence of visual field and optic disc progression in glaucoma patients with distinct patterns of optic disc damage. DESIGN: Prospective, observational case series. PARTICIPANTS: One hundred five patients with open-angle glaucoma. METHODS: Baseline optic disc photographs of 105 study eyes of 105 patients were reviewed by 2 masked observers and classified according to patterns of disc damage into the following categories: focal, myopic, senile sclerotic, and generalized disc damage. Patients were followed up every 6 months with standard automated perimetry (SAP), high-pass resolution perimetry (HRP), and scanning laser tomography (SLT) with the Heidelberg Retina Tomograph. MAIN OUTCOME MEASURES: Visual field (SAP and HRP) and optic disc (SLT) progression were determined according to predefined criteria. RESULTS: Twenty-four eyes were classified into the focal, 8 into the myopic, 12 into the senile sclerotic, and 28 into the generalized group. Eyes from 33 patients could not be classified by the observers into any of these groups and were excluded from further analysis. Although intraocular pressure during follow-up was similar among the four groups, some differences in frequency of progression were observed. Patients with senile sclerotic discs had the lowest rates of visual field progression (both with SAP and HRP) and optic disc progression, although the differences were significant only for optic disc progression (P = 0.05). CONCLUSIONS: Patients with senile sclerotic discs showed a tendency towards less visual field and optic disc progression when compared with patients with other types of disc damage.

Aged↗

PubMed1992

Visual field defects in vascular lesions of the lateral geniculate body.

Corresponding retinal nerve fibres begin their path in the eyes and end in a single visual cortical cell. Because of this arrangement, lesions in the anterior visual pathway produce incongruent visual field defects and in the posterior pathway congruent field defects. The lateral geniculate body is on the anterior third of the visual pathway. A lesion of this nucleus produces moderately to completely congruent visual field defects. Five patients with ischaemic lesions of the lateral geniculate body are reported. Two patients had a wedge-shaped homonymous hemianopia, two other cases had congruent superior homonymous quadratic defects and the fifth a quadruple sector defect. The lateral geniculate body has a dual blood supply from the anterior choroidal artery (branch from internal carotid artery) and from the lateral choroidal artery (branch from the posterior cerebral artery). A schematic diagram has been devised which shows that a knowledge of the visual field disrupted can identify the arterial system involved.

Aged↗

PubMed2005

Retinal nerve fiber layer thickness measured by optical coherence tomography and its correlation with visual field defects in early glaucoma.

BACKGROUND AND PURPOSE: To study the relationship between retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT) and visual field defects in early glaucomatous eyes and to study the diagnostic ability of OCT in distinguishing early glaucomatous eyes from normal eyes. METHODS: We studied 68 eyes from primary open-angle glaucoma patients with early visual field defect (mean deviation > -6 dB), and 94 normal eyes from healthy age- and gender- matched individuals. All participants underwent 3.4-mm diameter circular OCT scans and Humphrey 30-2 mode visual field testing. The average and segmental RNFL thickness values were compared between the 2 groups. The correlation between the mean deviation in the visual field examination and RNFL thickness was evaluated. The area under the receiver operating characteristic (ROC) curve was used to distinguish normal eyes from early glaucomatous eyes. RESULTS: There was a significant difference in RNFL thickness between the 2 groups based on the following parameters: average thickness; superior, inferior, and nasal quadrant thickness; and 1-7, 11, 12 o'clock hour segment thickness (p < 0.05). In the glaucoma group, superior and inferior quadrant thicknesses and average RNFL thickness significantly correlated with the visual field index (superior quadrant thickness, r = 0.36; inferior quadrant thickness, r = 0.32; average RNLF thickness, r = 0.35; p < 0.05). The average RNFL and inferior quadrant thickness of early glaucomatous eyes had the widest areas under the ROC curves (0.812 and 0.793, respectively). CONCLUSIONS: Measurement of average and inferior quadrant RNFL thickness by OCT is useful in detecting early glaucomatous change.

Adult↗

PubMed2005

Retinal nerve fiber layer thickness in the fellow eyes of normal-tension glaucoma patients with unilateral visual field defect.

PURPOSE: To quantitatively evaluate retinal nerve fiber layer (RNFL) thickness in the fellow eyes of normal-tension glaucoma (NTG) patients with unilateral visual field defect. DESIGN: Observational case-control study. METHODS: Twenty-nine NTG patients with unilateral visual field defect were enrolled in this study. All 29 fellow eyes showed normal visual field. Thirty-one normal eyes of 31 subjects served as controls. The RNFL thickness around the optic disk was determined using Fast RNFL thickness (3.4) of optical coherence tomography. Average and segmental (4 quadrants and 12 clock- hours) RNFL thickness measurements were compared among the three groups. RESULTS: RNFL thicknesses were significantly different among the three groups in the average, superior quadrant (11 and 12 clock-hour segments), and inferior quadrant (6 clock-hour segment) (P = .00, one-way ANOVA and Tukey's tests). CONCLUSIONS: RNFL thickness reductions are already present in the fellow eyes of NTG patients with unilateral visual field defect.

Case-Control Studies↗

PubMed2005

ERP topography and human perceptual learning in the peripheral visual field.

We studied human perceptual learning in the peripheral visual field in 16 healthy adults. Horizontal or vertical vernier stimuli were presented simultaneously at 8 locations at an eccentricity of 4 degrees . One of the stimuli displayed an offset, and subjects were asked to detect the target offset. Training was performed with either vertical or horizontal stimuli by the repeated presentation of stimuli. Discrimination performance was also measured with the untrained stimuli. Before and after the psychophysical experiment, EEG was recorded from 30 electrodes over the occipital areas (between the inion and Cz) while targets were presented at all locations as vernier onset/offset stimuli. The EEG was averaged for each orientation separately. Improvement in discrimination performance was observed in about 70% of the subjects with the trained orientation only. The evoked potential maps displayed three components occurring between 80 and 160, 180 and 260, and 280 and 340 ms. The potential field topography of the first and third component showed significant differences before and after learning. In addition, field strength (global field power) of the second and third component increased with learning. No effects were seen with the untrained stimuli in the psychophysical and electrophysiological experiments. Our findings suggest that perceptual learning in the peripheral visual field is specifically related to neurophysiological changes induced by training, and it is not caused by unspecific changes of spatial attention. The changes of electrical brain activity reflect short-term plasticity related to human perceptual learning.

Adolescent↗

PubMed2003

Regional variability in visual field sensitivity during hypercapnia.

PURPOSE: Previous investigations have demonstrated a relative vascular autoregulatory inefficiency of the inferior compared to the superior retina in healthy subjects breathing increased CO(2). The purpose of this study was to determine whether the superior and inferior visual field sensitivities of healthy eyes are similarly affected during mild hypercapnia. DESIGN: Experimental study. METHODS: Visual field analysis (Humphrey Field Analyser; SITA standard 24-2 program) was carried out on one randomly selected eye of 22 subjects (mean age, 27.7 +/- 5 years) during normal room air breathing and isoxic hypercapnia. The Student paired t-tests were used to compare the visual field indices mean deviation (MD) and pattern standard deviation (PSD) for each breathing condition. A secondary, sectoral analysis of mean pointwise sensitivity was performed for each condition. In each case a P value of <.01 was considered statistically significant (Bonferroni corrected). RESULTS: Visual field MD was -0.23 +/- 0.95dB during room air breathing and -0.49 +/- 1.04dB during hypercapnia (P =.034). Sectoral pointwise mean sensitivity deteriorated by 0.46dB (P =.006) in the upper visual hemifield during hypercapnia, whereas no significant difference was observed for the lower hemifield (P =.331). CONCLUSIONS: The upper visual hemifield exhibited a significantly greater degree of deterioration in pointwise visual field mean sensitivity compared to the lower hemifield during hypercapnic conditions. This suggests that the upper visual hemifield and hence inferior retina is more susceptible to insult during hypercapnia than the superior retina in healthy individuals. A regional susceptibility of inferior retinal function to altered vascular or metabolic effects may account for the earlier and more frequent inferior nerve fibre damage associated with glaucomatous optic neuropathy.

Adult↗

PubMed1989

Visual fields of monocularly deprived macaque monkeys.

The effects of postnatal monocular deprivation have been studied in macaque monkeys using behavioral perimetry field testing. The types of deprivation were: (1) early eyelid suture at 22-26 days after birth and then reverse suture at 10-13 months postnatally, (2) late eyelid suture beginning at 3 or 5 months postnatally and continued for 18 months, and (3) long-term occlusion by contact lenses. Response levels were normal for group 1 monkeys with some reduction in visual field extent. A reduced response level but no change in visual field extent was observed for the deprived eyes of group 2 monkeys. One monkey from group 3 that wore an occluder lens from birth to 19 months postnatally had no responses in any part of the visual field. Two other monkeys of group 3, whose occlusion started at 9 or 12 days of age and lasted for 2 years, had no responses to stimuli presented to the previously occluded eyes in their nasal visual fields and had reduced levels of response to stimuli presented in their temporal fields. The results indicate that the effects of monocular deprivation on macaque monkeys are affected by the start, length and type of deprivation. Some of these results are also consistent with a model of binocular competition in which the magnitude of the competition declines along a nasal-to-temporal gradient of visual field eccentricity. However, a mechanism that is independent of binocular competition is needed to account for the loss of responses to stimuli presented in the monocular visual segment.

Animals↗

PubMed1989

[A comparison of central visual field measurement by automated perimetry in optic neuritis due to multiple sclerosis and of unknown etiology].

We compared the visual field in 46 eyes of 34 cases with optic neuritis, which included 17 cases with multiple sclerosis (MS) and 17 cases with unknown causes. The visual field examination was measured by program 31 of the Octopus automated perimeter, which tests the central 30 degree field in a 6-degree grid. All eyes had visual acuity of 0.2 or better. The mean visual acuity was 0.97 in MS and 0.83 in the unknown etiology cases. There were no differences in the rate of abnormalities in the 30 degree-field between MS and unknown cases. The mean sensitivity loss of the abnormal visual field with MS was significantly greater than that of the unknown cases. The 30 degree field was divided into 3 sections. MS had almost the same mean sensitivity loss in each section. The cases of unknown etiology had a greater mean loss in 0-10 degrees than that in the other sections. We could conclude therefore that diffuse visual field loss was caused by MS and central depression of 0-10 degrees in the 30 degree field was secondary to an unknown cause. In comparison to the affected eyes seventeen eyes with normal visual acuity and no history of optic neuritis were tested by program 31. Results showed that 3 eyes had abnormal points in 10-30 degree sections.

Adolescent↗

PubMed1999

Optic disc surface smoothness and visual field indices.

BACKGROUND: In order to ascertain whether the optic disc surface smoothness (ODSS) could be used to predict the amount of visual field damage in glaucomatous eyes, the correlations between ODSS and visual field indices were evaluated. METHODS: One eye was randomly chosen from each of 40 normals and 50 patients with glaucoma. The morphology of the optic disc surface was analyzed using the Topcon IMAGEnet X Rev-3.51b. In order to define the level of "smoothness" of the optic disc surface, the differences of the relative position of each surface point was studied by measuring the standard deviation (SD) from the average height of the points (number of points ranged from 623 to 1883 depending on the size of the disc area) that identify the optic disc surface. All the subjects were also examined with the Humphrey perimeter (Program 30-2) and the results were analyzed by Mann-Whitney U-test and Spearman rank correlation coefficient. RESULTS: The difference in ODSS between the glaucomatous and the normal eyes was statistically significant. No significant correlation was found between age and ODSS. A significant correlation was found between ODSS and mean deviation (MD) and between ODSS and corrected pattern standard deviation (CPSD). In the glaucoma group there were significant correlations between ODSS and the perimetric indices MD and CPSD; no correlations were found in the normal group. CONCLUSION: The ability of ODSS to reflect the level of visual field change in glaucomatous eyes appears to be rather limited, even if statistically significant. This fact does not limit the clinical usefulness of ODSS as a diagnostic parameter in consequence of its strong correlations with the other morphometric parameters and its high sensitivity and specificity in separating normal from glaucomatous eyes.

Female↗

PubMed1992

Do computerised visual fields and automated optic disc analysis assist in the choice of therapy in glaucoma?

The choice of therapy in patients with glaucoma is determined by the presence of damage in the visual field or optic disc or by change in the appearance of the optic disc or visual field over time. Computerised visual fields and automated optic disc analysis can assist in this determination. Automated optic disc analysis permits the measurement of neuroretinal rim area which is more closely related to the presence of pathology than cup/disc ratio. Simple ophthalmoscopic techniques may also be used to estimate the size of the neuroretinal rim area. Automated perimetry allows accurate diagnostic information to be obtained in a reliable manner. This permits easier diagnosis of glaucoma as well as easier long term follow up for change. The availability of automated techniques in ophthalmology has helped the clinician in the choice of therapy. The use of astute clinical judgement remains however of the utmost importance.

Diagnosis, Computer-Assisted↗

PubMed1998

Correlation of peripapillary nerve fiber layer thickness by scanning laser polarimetry with visual field defects in patients with glaucoma.

PURPOSE: To assess the correlation between the results of peripapillary scanning laser polarimetry of the retinal nerve fiber layer (NFL) and automated visual field testing in patients with open-angle glaucoma. METHODS: Visual fields from 42 patients with varying stages of glaucoma were scored using Collaborative Initial Glaucoma Treatment Study (CIGTS) criteria. Mean deviation, pattern standard deviation, and CIGTS total and hemifield visual field scores were correlated with peripapillary NFL thickness measured by scanning laser polarimetry using summed, ratio-based, and modulation parameters. RESULTS: Mean deviation and CIGTS total and upper hemifield score were significantly correlated with NFL retardation values using summed, ratio-based, or modulation parameters. The CIGTS lower hemifield score was significantly correlated with modulation parameter values only. Correlation of CIGTS scores was significantly stronger with modulation parameters than with summed parameters (total and lower hemifield scores) and ratio-based parameters (lower hemifield only) by the Hotelling t test. CONCLUSION: Relative NFL thickness measured by scanning laser polarimetry correlates well with visual field defects seen on Humphrey perimetry of patients with open-angle glaucoma. Modulation parameters, in which the superior and inferior peak NFL thickness (as measured by scanning laser polarimetry) are adjusted for the patient's average minimum NFL thickness in the nasal and temporal quadrants, provided stronger correlation than summed parameters and ratio-based parameters.

Adult↗

PubMed2004

Visual field of high-pass resolution perimetry in normal subjects.

PURPOSE: To investigate the properties of the visual field of high-pass resolution perimetry in normal subjects. METHODS: Four centers collected normative data for high-pass resolution perimetry. In two of the centers the subjects were stratified by age. One eye was tested per subject using high-pass resolution perimetry (Ophthimus). We tested 640 normal subjects and describe their visual field results by test location. We also analyzed the data by concentric zone, age, and by testing center. RESULTS: The individual test location averages confirmed a reduction in resolution with eccentricity. Resolution thresholds increased with age by 0.025 dB per year (P < 0.001). The mean ring size increased by about 1 dB from age 20 to 70. Among centers there were significant differences in the means and the change in threshold with age (P = 0.009). CONCLUSION: The normal visual field of high-pass resolution perimetry is characterized by an increase in threshold with eccentricity. We found significant differences among the centers that were likely due to multiple factors including differences in subject selection criteria. Whether such differences occur with other perimetric techniques is unknown.

Adult↗

PubMed1998

Intraocular pressure as a risk factor for visual field loss in pseudoexfoliative and in primary open-angle glaucoma.

OBJECTIVE: To analyze the relationship between intraocular pressure (IOP) and visual field loss in patients with primary open-angle glaucoma (POAG) and in those with pseudoexfoliative glaucoma (PEXG). DESIGN: A cross-sectional, observational study. PARTICIPANTS: Thirty-one patients with PEXG and 31 patients with POAG that was newly diagnosed were included in this study. MAIN OUTCOME MEASURES: The authors recorded the untreated IOP and the amount of the visual field loss, at presentation, in both study groups. RESULTS: The authors found a significant relationship between IOP and visual field mean deviation (MD) index (P = 0.0001, r = 0.68) in PEXG but not in POAG eyes (P = 0.7). CONCLUSION: The authors found that untreated IOP levels can explain the amount of visual field loss, as measured by the MD index, much better in patients with PEXG than in comparable patients with POAG. Thus, vulnerability of the optic nerve head to increased IOP appears to be different in these two diagnostic categories.

Aged↗

PubMed2000

Body sway induced by depth linear vection in reference to central and peripheral visual field.

PURPOSE: A significant correlation between the magnitude of linear vection and the degree of body sway induced by a visual stimulus perceived as moving in depth was previously described (Jpn J Physiol 49: 417-424, 1999). The purpose of this study was to examine the role of the central and peripheral visual fields in inducing vection and body sway. METHODS: Ten healthy volunteer students who had no vestibular or neurological disorders served as subjects. A depth optokinetic stimulus (DOKS) was projected onto a head-mounted display (HMD) and was perceived to move in depth. Different amounts of the central or peripheral visual field were masked independently. The magnitude of the linear vection induced by the DOKS was evaluated by verbal assessment and compared with the magnitude of induced body sway. Body sway was monitored by a video-motion-analyzer that recorded the movement of the head, shoulder, hip, knee and ankle. RESULTS: The magnitude of vection was correlated with the frequency of DOKS and also with the amplitude of body sway (r = 0.74). When the central visual field was restricted by 10 to 30%, there was almost no change in the induced body sway and vection. However, when central occlusion was greater than 40%, depth perception and induced body movement were greatly reduced. With increasing amounts of peripheral field occlusion from 50 to 90%, there was a greater reduction of both vection and body sway. CONCLUSION: Vection is strongly correlated with body movement, and vection and body sway were more dependent on stimulation of the peripheral visual field.

Adult↗

PubMed1998

Acquired pits of the optic nerve in glaucoma: prevalence and associated visual field loss.

PURPOSE: This study was performed to determine the prevalence of acquired pits of the optic nerve (APON) in glaucoma and the characteristics of associated visual field loss. SUBJECTS AND METHODS: Stereoscopic optic disc photos from 235 patients with a low-tension variety of primary open-angle glaucoma (LTG) and 251 primary open-angle glaucoma patients with intraocular pressures higher than 21 mmHg (HTG) were examined for the presence of typical APON as defined by a standard photograph (Fig 1). Associated visual field loss was evaluated with automated perimetry and patterns of field loss were identified. RESULTS: Out of a total of 486 patients, 63 APON were found in 51 eyes of 44 glaucoma patients. APONs were more prevalent in women. Acquired pits were more frequently (p<0.001) located inferiorly (70%) than superiorly (30%). There was a significantly higher prevalence (p<0.001) of APON in LTG patients (12.7%) than in HTG patients (5.6%). Dense visual field defects within five degrees of fixation occurred in 96% of patients with APON. CONCLUSION: Acquired pits of the optic nerve are more often located at the inferior optic disc than at the superior disc and are nearly always associated with visual field loss close to fixation. In a glaucoma referral center setting, APON are more prevalent in lower pressure glaucoma than in higher pressure glaucoma.

Adult↗