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PubMed1989

Investigation of visual field defects in strabismic and anisometropic amblyopes with the Octopus program G1.

Using the Octopus G1 program, we investigated the visual fields of amblyopic and healthy contralateral eyes in 21 patients with strabismic amblyopia and 14 patients with anisometropic amblyopia. All subjects had a visual acuity of 0.7-0.06. A central scotoma was detected in 85.7% of the patients with strabismic amblyopia and in 79% of those with anisometropic amblyopia. The mean maximal depth of central scotomas in subjects with strabismic amblyopia was 6.81 +/- 4.74 dB (mean +/- SD); in those with anisometropic amblyopia, it was 6.64 +/- 4.34 dB. This difference was statistically not significant. However, in patients with anisometropic amblyopia, the visual field indices MD (mean defect) and CLV (corrected loss variation) were significantly higher than in those with strabismic amblyopia (P less than 0.05 vs P less than 0.05); this was predominantly due to additional flat defects that occurred paracentrally and peripherally in subjects with anisometropic amblyopia. In both groups of patients, we found a significant negative correlation between visual acuity, on the one hand, and the maximal depth of the scotomas and the visual field indices (MD and CLV), on the other.

Adolescent↗

PubMed1986

Differences of visual field representation in the medial and lateral banks of the suprasylvian cortex (PMLS/PLLS) of the cat.

We have studied the orderliness of representation of visual space in the medial and lateral banks of the middle suprasylvian sulcus. Penetrations were made either parallel to the sulcus, in one bank or the other, or vertical, thus crossing the sulcus between the postero-medial (PMLS) and posterolateral (PLLS) divisions of this area. In some cases we found clear evidence for topographical order in the representation of the visual field with a tendency (greater in PMLS than in PLLS) for the receptive fields of cells recorded deeper in the walls of the sulcus to lie closer to the area centralis, but along many penetrations the receptive fields were so large and so scattered that no retinotopic arrangement could be discerned. In PMLS the receptive fields of the majority of units we studied were centered below and close to the horizontal meridian, whereas in PLLS they were distributed over both the upper and lower visual fields with an over-representation of the upper field. Receptive fields were significantly larger in PLLS (mean field area = 442.2 deg2) than in PMLS (mean area = 154.4 deg2); there was also less clear correlation between receptive field size and eccentricity in PLLS (correlation coefficient = +0.25) than in PMLS (corr. coeff. = +0.72). Analysis of the distance between the receptive field centres of consecutively recorded units demonstrated that the mean scatter in both PMLS and PLLS amounts to about half the average receptive field diameter. In summary the topographical representation of visual space is less orderly in PLLS, and may involve a wider area of the visual field. These findings may relate to the segregated visual cortical and extrageniculate thalamic connections that the medial and lateral banks of the LS receive.

Animals↗

PubMed2003

Rehabilitation of chronic post-stroke visual field defect with computer-assisted training: a clinical and neurophysiological study.

PURPOSE: Our aim was to study whether homonymous visual field defects could be restored in chronic stroke patients (N = 5) using computer-assisted training, and whether the possible beneficial effect could be maintained. Visual evoked potential (VEP) recordings were applied to evaluate whether they could demonstrate the possible training effects at the cortical level. METHODS: We applied a specially designed computer program in the training. Subjective assessment, static and kinetic perimetry, and pattern reversal hemifield VEP recordings were used to detect the possible changes. RESULTS: Two patients showed improvements immediately after the training in static perimetry. Further improvements were detected at a later follow-up in three patients. With kinetic perimetry, improvements were detected in three patients. The visual field defect was detected with VEP recordings in four patients before the training, and improvements could be verified with the method in three patients, two of which clearly improved in the static perimetry as well. CONCLUSIONS: In three patients, the visual defect diminished with the computer-assisted method. It seems evident that visual field defects resulting from stroke can be partially restored even in the chronic phase.

Adolescent↗

PubMed1999

Distance and near visual acuity, contrast sensitivity, and visual fields of 10-year-old children.

OBJECTIVE: To measure monocular distance visual acuity, near visual acuity, contrast sensitivity, and visual field extent in full-term, 10-year-old children tested according to the protocol used to test 10-year-old preterm children in the Cryotherapy for Retinopathy of Prematurity study. SUBJECTS AND METHODS: Subjects were 106 healthy, full-term children, 9.8 to 10.9 years of age, who had no ocular abnormalities other than ametropia. All were tested monocularly using Early Treatment and Diabetic Retinopathy Study distance and near visual acuity charts and Pelli-Robson contrast sensitivity charts, with refractive error corrected according to Cryotherapy for Retinopathy of Prematurity study criteria. Goldmann perimetry was tested without correction using the V-4-e and III-4-e stimuli along 8 meridia. A standard pediatric eye examination was performed on each subject. RESULTS: Mean (SD) distance visual acuity was 20/19.6 OD (0.082 log unit [lu]) and mean near visual acuity was 20/19.5 OD (0.100 lu). Mean (SD) contrast sensitivity was 1.69 OD (0.12 lu), with a mean (SD) of 36.4 (2.2) letters read. Visual field extent was larger for the V-4-e stimulus than for the III-4-e stimulus. CONCLUSIONS: The results provide the first monocular normative data from a large sample of 10-year-old children tested with Early Treatment and Diabetic Retinopathy Study distance and near visual acuity charts and the Pelli-Robson contrast sensitivity charts, and add to the literature on Goldmann perimetry in children.

Child↗

PubMedDate not supplied

The peripheral visual field in glaucoma: reevaluation in the age of automated perimetry.

With the advent of automated static perimetry has come the common practice of measuring only the central 30 degrees of vision in the diagnosis and management of glaucoma. While most glaucomatous field defects appear first in this portion of the visual field, the question remains as to how much useful information is being missed by ignoring the peripheral field, i.e., outside the central 30 degrees. Studies with both static and kinetic automated perimetry have revealed the same peripheral glaucomatous field defects previously recognized with manual perimetry, including generalized contraction, nasal steps, temporal sector defects, and hemianopic offsets. Of these, however, only measurement of the nasal periphery may add sufficient information to that obtained with static testing in the central 30 degrees to justify the added examination time; however, there are special situations in which peripheral field testing in other or all quadrants may be useful. Further study is required to establish optimum techniques for automated measurement of the peripheral visual field and to determine the significance of the results in the management of glaucoma.

Aging↗

PubMed2001

Development of the functional visual field.

Andries Sanders' dissertation examined selective mechanisms in the functional visual field, and much of his work since has been concerned with the stages that underlie visual information processing particularly while making saccades. We argue that the study of orienting in the functional visual field is timely because it deals with the relation of covert attention shifts, eye movements and head movements to their underlying neurology. In our paper we develop a method to study learning of sequences at all ages from infants to adults. Our studies focus on how learning influences anticipatory eye movements. We examined the learning of unambiguous and context dependent sequences by 4-, 10-, and 18-month-old infants and undergraduates. We found clear learning of unambiguous sequences at 4 months, but learning of context dependent associations was found only in 18-month-olds and in adults. We hypothesize that the learning of unambiguous sequences by 4-month-olds reflects maturation of a basal ganglia-parietal circuit related to adult implicit learning, while the learning of context dependent sequences requires development of frontal structures underlying more general attentional abilities.

Adult↗

PubMed1980

Sex and handedness as factors in visual-field organization for a categorization task.

When right-handed males categorize faces presented in the right and left visual fields as male or female, a right visual-field advantage results. Subjects in the present study were divided on the basis of Annett's model according to sex and handedness, males and females, right-handers, nonfamilial left-handers, and familial left-handers. It was predicted that males would show a field advantage consistent with the cerebral hemisphere specialized for speech production (the left hemisphere in the case of right-handers and nonfamilial left-handers, and the right hemisphere in the case of familial left-handers). It was also predicted that females would be either weakly or inconsistently lateralized. A signal-detection paradigm in general confirmed these predictions. It was also shown that a subject's ability to change decisional criteria appropriately over trials was a function of visual field for both males and females. Decision making over time may therefore reveal a fundamental duality distinguishing the cerebral hemispheres in both sexes. Some of the implications of these results are discussed.

Discrimination Learning↗

PubMed1991

[Changes in the visual field in diabetic retinopathy after grid laser coagulation of the posterior pole of the eye].

The influence of grid laser photocoagulation on the central visual field of 15 eyes with diffuse diabetic maculopathy was studied in a prospective clinical trial. Throughout the 3 month follow-up period, visual fields were monitored by static perimetry using a combination of 30-1 and 30-2 programs of the Humphrey Field Analyzer. Statistical analysis of all clinical parameters shows that visual acuity correlates very well with foveal light difference sensitivity. The overall sensitivity of the 30 degrees field, however, does not correlate significantly with either of them. During the follow-up period, patients' subjective vision improved significantly (p = 0.0234); for the overall sensitivity of the 30 degrees visual field there was a trend towards improvement (p = 0.0692). The sensitivities of the central 10 degrees and 3 degrees of the visual fields, of the fovea and visual acuity did not change. The results of the present study suggest that during the first 3 months after grid photocoagulation of diffuse diabetic macular edema, the treatment affects mainly the retina outside the macula. The improvement in patient vision may be due to these changes in the visual field.

Aged↗

PubMedDate not supplied

Visual field results after vitreous surgery in a case series of patients with open-angle glaucoma.

BACKGROUND AND OBJECTIVE: Visual field loss is a complication of vitrectomy and a concern for patients with glaucoma. Our objective was to determine whether vitrectomy is associated with new field defects in patients with glaucoma. PATIENTS AND METHODS: This retrospective case series involved 7 eyes of 7 patients, who had open-angle glaucoma and underwent vitrectomy for macular hole (2) or epiretinal membrane (5). RESULTS: Acuity improved by at least two lines in 5 eyes. Visual fields showed a change in mean deviation following vitrectomy (mean difference -1.50 dB, P=0.0006, paired Student's t-test). One eye had confirmed progression of a pre-existing visual field defect, but no new defects were apparent in the other eyes. Transient intraocular pressure rises requiring therapy occurred in 3 eyes. One eye developed macular edema, but no other operative complications occurred. CONCLUSIONS: The results of our small case series suggest that vitrectomy may be an acceptable intervention in eyes with glaucoma and co-existing macular problems.

Aged↗

PubMed1988

An investigation into perceptual completion in blind areas of the visual field.

The perceptual completion phenomenon refers to seeing a figure as complete when part of it falls in a blind area of the visual field. This phenomenon and the conditions for its occurrence were examined in three different situations: over the retinal blind spot, across the midline of the visual field in commissurotomized patients, and in the blind visual field in hemianopic patients. Responses of complete perception were obtained in each of the three conditions, but they were not all the result of a genuine perceptual completion process. Reports of vision over the retinal blind spot qualified as genuine perceptual completion. In the other two situations, reports suggestive of completion could be entirely eliminated in all but one hemianopic patient by manipulating parameters inherently involved in the evaluation of perceptual completion. The nature of perception, the characteristics and properties of the experimental task and stimuli, the mode of response, the patient's mental status, and eccentric eye fixation, all contributed towards reports of complete perception for reasons other than a process of completing the missing information. Evidence of completion was found in one patient who could see more distinctly in his affected field with bilateral stimulation than with stimulation of the affected field alone. The results suggest that perceptual completion in the hemianopic field is not a common phenomenon and that reports of complete perception are determined by many factors, not all related to seeing more than is objectively available. The results also indicate that the hemianopic defect does not function as an extended blind spot. Possible mechanisms underlying perceptual completion over the blind spot and the hemianopic field are suggested.

Adult↗

PubMed1998

The effects of cataract extraction on the visual field of eyes with chronic open-angle glaucoma.

PURPOSE: To investigate effects of cataract extraction and intraocular lens placement on the visual field of eyes with chronic open-angle glaucoma. METHODS: A retrospective review was conducted of 41 eyes of 41 patients with visually significant cataract and chronic open-angle glaucoma who had undergone automated static perimetry within 6 months before and 6 months after phacoemulsification with intraocular lens placement. RESULTS: Comparison of preoperative and postoperative testing showed that the mean visual acuity, foveal threshold, and mean deviation improved significantly (P < .0001), while the mean pattern standard deviation and corrected pattern standard deviation worsened significantly (P < or = .03). Eyes not receiving miotics preoperatively did not have a significant postoperative change in the mean pattern and corrected pattern standard deviations. Increasing severity of glaucoma-related visual field loss was significantly associated with less improvement in the postoperative mean deviation (P = .0001). Only two (5%) of 41 eyes had worsening of the mean deviation of 1.0 dB or greater. The foveal threshold improved more than the mean deviation did but not significantly more, except in eyes with severe visual field loss. CONCLUSIONS: Cataract extraction resulted in statistically significant improvement in visual acuity and foveal threshold in most eyes with glaucoma. In eyes with mild or moderate glaucoma-related damage, the mean deviation often improved significantly after cataract extraction, but improvement was less predictable in eyes with severe or end-stage damage. The pattern and corrected pattern standard deviations may be reliable indicators of glaucoma-related damage in eyes with cataract but without constricted pupils.

Aged↗

PubMed1983

Visual Field asymmetries for verbal and dot localization tasks in monolingual and bilingual subjects.

Visual Field asymmetries for verbal and dot localization tasks were examined in monolingual and bilingual subjects. Consistent right-visual-field advantages were found for verbal material in all groups, although bilingual subjects showed a reduced laterality for their second language in comparison with their native language. Monolingual subjects displayed left-visual-field advantages on the dot localization task, but no consistent asymmetries were shown by the bilingual subjects. The overall pattern of results is consistent with left-hemisphere involvement for the processing of verbal material, but the heterogeneity of performance on the dot localization task suggests that processing of such a task may be influenced by subjects' linguistic backgrounds.

Adult↗

PubMed1993

Blue-on-yellow perimetry can predict the development of glaucomatous visual field loss.

OBJECTIVE: The purpose of this investigation was to determine whether blue-on-yellow (B/Y) perimetry is capable of predicting the onset and location of impending glaucomatous visual field loss in patients with ocular hypertension. DESIGN: A Humphrey Field Analyzer (Humphrey Instruments, San Leandro, Calif) was modified to perform B/Y perimetry to isolate and measure the sensitivity of short-wavelength-sensitive mechanisms. Participants were tested annually with standard white-on-white (W/W) and B/Y automated perimetry for a period of 5 years. PATIENTS: The study population consisted of 38 patients with ocular hypertension and 62 age-matched normal control subjects. RESULTS: Initially, all 76 ocular hypertensive eyes had normal W/W automated perimetry results, with 67 eyes having normal and nine eyes having abnormal B/Y test results. Five years later, five of the nine ocular hypertensive eyes with initial B/Y abnormal results developed glaucomatous visual field loss measured by standard W/W automated perimetry, while none of the 67 ocular hypertensive eyes with initially normal B/Y results developed abnormal W/W perimetry results. CONCLUSIONS: Blue-on-yellow perimetry deficits are an early indicator of glaucomatous damage and are predictive of impending glaucomatous visual field loss for standard W/W automated perimetry. To our knowledge, this is the first prospective, long-term longitudinal study that demonstrates the ability to predict the onset of glaucomatous visual field loss in patients with ocular hypertension on the basis of psychophysical testing.

Adult↗

PubMed1992

Diazepam and its effects on visual fields.

A patient who experienced severe visual field loss whilst taking 100 mg of diazepam that reverted to normal on cessation of the drug is described. Diazepam affects GABA inhibitory neurones and the physiology of this in the retina and visual cortex is reviewed.

Aged↗

PubMed2006

Isolated bilateral lateral geniculate infarction producing bow-tie visual field defects.

CASE REPORT: We examined a unique case of stroke in a 29-year-old woman. Magnetic resonance imaging revealed isolated bilateral acute infarctions of the lateral geniculate bodies (LGB). Visual field testing demonstrated incongruous but homonymous bilateral visual field loss in a bow-tie configuration. COMMENTS: Isolated bilateral damage to the LGB is a rare event. Literature review has revealed only 4 previous incidents of bilateral damage to both LGB. We present a literature review and a case of bilateral LGB infarction producing visual field defects suggestive of bilateral lateral choroidal artery involvement in an individual with classic migraine.

Adult↗

PubMed1990

Association between intraocular pressure and loss of visual field in chronic simple glaucoma.

This paper reports the analyses on data from 747 patients with chronic simple glaucoma (CSG) recorded in the King's College Hospital glaucoma data base between January 1970 and February 1985, having a mean follow-up time of 5.1 years (mode 8 years) with the object of determining the relationship of intraocular pressure (IOP) and visual field loss in CSG. A highly significant negative relationship was found between the presenting visual field coefficient (FC) and the untreated IOP (r = -0.26, p = 0.0001) - that is, the higher the IOP on detection, the worse is the visual field. A weak negative correlation was present between the change of FC per year and the treated IOP (r = -0.06), p = less than 0.05). At treated IOPs less than or equal to 18 mmHg visual field loss averaged 0.6 unit per year and for IOPs greater than 18 mmHg the average loss was 1.2 units per year. The data confirm both the importance of a raised IOP in the causation of chronic glaucomatous visual field loss and the importance of reducing the IOP in patients with chronic simple glaucoma.

Adolescent↗

PubMed1990

Short-term fluctuation as an estimate of variability in visual field data.

The short-term fluctuation index (SF) is one of several values that provide an indication of a patient's response reliability during an automated perimetry examination. The authors investigated the number of visual field locations used and the number of determinations per location as factors affecting the SF estimate. A computer simulation program for perimetry was used to measure the SF index for 350 normal visual fields with various levels of response fluctuation. As expected, the variability of the SF estimate decreased as the number of locations used to estimate SF increased. There was a more important finding that, for an equal number of threshold estimates, a larger number of determinations at a smaller number of locations produced greater consistency in the SF estimate (eg, ten determinations at two locations instead of two determinations at ten locations). However, it is also important to sample from a representative spatial distribution of visual field locations. These results suggest that five determinations at four locations in the visual field is optimal for most clinical perimetric testing situations.

Computer Simulation↗

PubMed2004

A study on asymmetry of spatial visual field by analysis of the fMRI BOLD response.

The asymmetry of the left-right and upper-lower visual field is analyzed in this paper by a model approach based on the functional magnetic resonance imaging (fMRI) blood oxygenation level dependent (BOLD) response. The model consists of the convolution between a Gaussian function and the perfusion function of neural response to stimulus. The model parameters are estimated by a nonlinear optimal algorithm, and te asymmetry of the left-right and upper-lower visual field is investigated by the differences of the model parameters. The results from eight subjects show that reaction time is significant shorter and the response is significant stronger when the lower field is stimulated than that when the upper field is stimulated. For the left and right fields, the response is different. These results provide the fMRI BOLD response evidence of the asymmetry of spatial visual fields.

Algorithms↗