SEARCH · PubMed Health

Results for “Visual Fields”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 1,171 records · Page 65Linked to original sources

PubMed1993

Evaluating the visual field effects of blepharoptosis using automated static perimetry.

BACKGROUND: Quantitation of the effects of blepharoptosis on the visual field has largely been limited to manual kinetic perimetry using a single peripheral isopter. The authors evaluated the visual dysfunction caused by blepharoptosis using automated static full-threshold perimetry. METHODS: A custom static full-threshold 60 degrees test strategy on the Humphrey field analyzer was used to assess the visual fields of 20 volunteers at their normal baseline and after inducing mild and moderately severe blepharoptosis by applying gold weights to the eyelids. Threshold sensitivities were measured at points along the eight principal meridians, separated by 45 degrees, traditionally used to assess visual field impairment. RESULTS: For mild blepharoptosis, essentially all test points along the superior meridian were significantly depressed (P < 0.01), with an increase in slope secondary to greater decreases in sensitivity at more eccentric points. For moderately severe blepharoptosis, depression of the superior meridian was expectedly greater than that seen with mild blepharoptosis. Additionally, depression of the horizontal meridians and to a lesser extent the lower meridians also was noted. CONCLUSIONS: These results suggest that even mild blepharoptosis may be associated with depression of the superior visual field extending close to fixation. Ophthalmologists should be aware of the effect of blepharoptosis when testing for other ophthalmic or neurologic disorders using automated static perimetry. Full-threshold static perimetry can be used to quantitate the visual field loss associated with blepharoptosis as a means of evaluating visual impairment.

Adult↗

PubMed1987

[The visual field of pseudophakic patients. Perimetric and statistical study].

One hundred and twenty two visual fields were studied in 98 pseudophakic subjects, using cinetic perimetry according to Goldmann, in order to plot the internal (I1), medium (I2) and peripheral (I4) isopters. Computerized processing of data provided average results, allowing the following conclusions: In general, 20% of the total surface is lost in pseudophakia. This loss, as a consequence of prismatic effects of lenses, involves the internal isopters (26%) rather than the peripheral isopters (15%). Individually, these data can be modified by the location of the lens or by the diameter of its optical part: the more anterior or the smaller is the optical part, the narrower does the visual field become. Additional correction, particularly if exceeding 2 diopters is a supplementary factor of reduction. The perimetric consequences of pseudophakia are functionally latent. Nevertheless, the prismatic effects of intraocular lenses could account for the difficulties met in examination of peripheral fundus.

Adolescent↗

PubMed1986

[Data bank for analysis of the normal visual field using the 30/1 central program of the automated Humphrey perimeter].

Quantification is one of the most interesting improvements given by the automated perimetry. Such approach has, for instance, permitted the development by J. Flammer of quantification indices for JO program of Octopus. However, for working this concept needs quantitative data on normal visual field. Using an Humphrey automated perimeter and central threshold 30/1 program, we have gathered with the "quantification" program ley Thot Informatique, normal data on 178 visual field from 117 normal outpatients attending Ophthalmology Department of the Angers Hospital (58 females-59 males). Then, those data have been ranked by age, to obtain reference visual fields and corresponding standard-deviation fields. There is a decrease in visual sensitivity in the superior part of the 30 degrees field when compared to inferior. There is a decrease in visual sensitivity with ageing-about 1 dB by decade-more in the peripheral part of the 30 degrees field than in the central part. Standard deviation visual field is of considerable interest to valid pathologic visual field detects. There is an increase standard deviation for the peripheral part of the 30 degrees field. Finally, standard deviation is increased in elderly people as compared to younger.

Adult↗

PubMed1995

Primary argon laser trabeculoplasty vs pilocarpine. III. Long-term effects on visual fields.

In a prospective randomized study on primary argon laser trabeculoplasty vs pilocarpine in 82 newly detected open-angle glaucoma patients, visual field changes were analysed for absolute changes over 2 years on automated threshold perimetry and manual Goldmann perimetry. Regression analysis was also performed using the threshold perimetry examinations taken every second month. Analyses based on automatic perimetry were corrected for eventual bias due to cataract and induced miosis. There was significantly less decay of visual field in the group treated with laser. This was even more pronounced for eyes with capsular glaucoma, especially in the early stage. For the smaller group with simple glaucoma no significant advantage of laser could be shown. Successful intraocular pressure reduction significantly improved the visual field outcome. Laser trabeculoplasty is therefore recommended as primary therapy in capsular glaucoma.

Aged↗

PubMed1990

[A case of reflex epilepsy with binasal visual field defects attack induced by family computer game].

A 12-year-old male case of reflex epilepsy with visual field defects attack induced by a family computer game was reported. This patient showed binasal visual field defects attack when he was playing a family computer game. Neurological findings and ophthalmological examinations were normal. EEG showed spike and slow wave complex distributed on right occipital region. These paroxysmal waves were activated by checkerboard pattern reversal stimuli. Stimulus intensity was closely related with these activations, but not stimulus ratio was. Examinations of brain CT and brain MRI were normal. This patient complained of discomfort without visual symptoms when he suffered checkerboard pattern stimuli. A family computer game needs mental concentration, recognition, decision, alert state of consciousness and complex finger movement. Integration of these factors may have induced visual field defects attack. It is interesting that a family computer game is the inducer of reflex epilepsy with visual symptoms. The number of reflex epilepsy is thought to increase because of prevalence of family computer games.

Child↗

PubMed1996

Development of contrast sensitivity across the visual field in macaque monkeys (Macaca nemestrina).

Interpretation of measurements of visual performance in infants must be based on knowledge of the locus of highest sensitivity in the infant retina. While we know that adult contrast sensitivity and spatial resolution is highest at the fovea, recent anatomical data show that the infant fovea is relatively immature. We have studied that variation of contrast sensitivity across the visual field during development in infant monkeys in order to investigate the behavioral consequences of this immaturity. The results show that, unlike adults, the sensitivity of the infant foveal region is similar to that of the near periphery. Central contrast sensitivity and spatial resolution improve substantially relative to the periphery over the first 20-40 postnatal weeks. Thus, contrast sensitivity in the periphery is relatively mature in infants with respect to more central regions of the visual field. The maturation pattern seen behaviorally is consistent with physiological and anatomical maturation patterns in macaque monkey.

Aging↗

PubMed2002

Local visual field defects correlate with the multifocal electroretinogram (mfERG) in retinal vascular branch occlusion.

BACKGROUND: The value of multifocal electroretinography (mfERG) in the detection of localized retinal dysfunction in vascular branch disease at the posterior pole of the eye is investigated, and mfERG is compared with visual field defects. PATIENTS AND METHODS: 10 eyes of 7 patients were tested, of which 8 eyes had a branch retinal vein occlusion and 2 eyes a branch artery occlusion. First order mfERG's were performed with the VERIS (TM) system, using 61 and 103 hexagons, and visual fields with the OCTOPUS M1 macular program. The number of hexagons with a response density loss (nV/deg (2)) of more than -2.0 standard deviations or of more than - 1.5 StDev, respectively, found in the normal population was compared with the number of disturbed test locations or total sensitivity loss (dB) of M1. RESULTS: Local perimetric defects of various extent correlated well concerning localization and sensitivity loss with mfERG response density loss (nV/deg (2)). The best correlation was the total loss of M1 (dB) versus the number of hexagons out of 103, if the criterion of - 1.5 StDev was applied (p </= 0.001). In most cases, a diffuse but less severe response density loss of mfERG was also found at retinal places outside visual field defects and corresponding visible fundus changes. CONCLUSIONS: Local visual field defects in retinal vascular branch occlusion correlate well with mfERG if suitable criteria are applied.

Aged↗

PubMed1992

Clinical research and statistical analysis of a visual field awareness system.

This article discusses the clinical research and applications of the statistical analysis of a system called "The Visual Field Awareness System." This medical lens system allows patients with a visual field loss to 1) scan toward area of the loss, to see objects sooner and more clearly, and 2) demonstrate increased function and safety. Seventy-nine percent (27 of 34) of the patients in the sample received and accepted the prism treatment. Of this group, a minimum of 70 percent (19 of 27) continue to benefit from this treatment strategy. Statistically significant predictors of success are discussed. This study demonstrates that patients suffering visual field loss may show functional benefit by the utilization of this prism treatment along with vision rehabilitation.

Adult↗

PubMed1997

Improving the prediction of visual field progression in glaucoma using spatial processing.

PURPOSE: The authors show how the predictive performance of a method for determining glaucomatous progression in a series of visual fields can be improved by first subjecting the data to a spatial processing technique. METHOD: Thirty patients with normal-tension glaucoma, each with at least ten Humphrey fields and 3.5 years of follow-up, were included. A linear regression model of sensitivity against time of follow-up determined rates of change at individual test locations over the first five fields (mean follow-up 1.46 years; standard deviation = 0.08) in each field series. Predictions of sensitivity at each location of the field nearest to 1 and 2 years after the fifth field were generated using these rates of change. Predictive performance was evaluated by the difference between the predicted and measured sensitivity values. The analysis was repeated using the same field data subjected to a spatial filtering technique used in image processing. RESULTS: Using linear modeling of the unprocessed field series, at 1 year after the fifth field, 72% of all predicted values were within +/- 5 dB of the corresponding measured threshold. This prediction precision improved to 83% using the processed data. At the 2-year follow-up field, the predictive performance improved from 56% to 73% with respect to the +/- 5 dB criterion. CONCLUSIONS: Predictions of visual field progression using a pointwise linear model can be improved by spatial processing without increased cost or patient time. These methods have clinical potential for accurately detecting and forecasting visual field deterioration in the follow-up of glaucoma.

Adult↗

PubMed2000

Recovery of visual field constriction following discontinuation of vigabatrin.

Epilepsy patients treated with vigabatrin may develop symptomatic or asymptomatic concentric visual field constriction due to GABA-associated retinal dysfunction. The prevalence and course of this side effect are not established yet; in previously reported adult patients the visual disturbances seem to be irreversible. We present two patients with a significant improvement of visual field constriction and retinal function after the discontinuation of vigabatrin. These findings suggest that vigabatrin-associated retinal changes are at least partly reversible in some patients, and that these patients may benefit significantly from a withdrawal of vigabatrin. Larger scale clinical studies are needed to identify predictive factors both for the occurrence and reversibility of vigabatrin-associated visual field defects.

4-Aminobutyrate Transaminase↗

PubMed1995

Temporary amaurosis with persistent visual field defect following acute blood loss.

Visual loss and field defects commonly occur after acute blood loss. We present a case of bilateral permanent visual field defect in a 30-year-old man after a massive hemorrhage caused by large vessel injury during a right nephrectomy. His postoperative visual acuity decreased significantly, and his visual field showed peripheral constriction and inferior altitudinal field defect in both eyes. A year and a half after the operation, visual acuity recovered to the preoperative level, but the field did not show improvement. We advance that this is a possible result of extensive injury to the occipital area, excluding the corresponding area of the macula.

Acute Disease↗

PubMed1995

Classic migraine and visual field defects.

A series of 116 patients with classic migraine were studied to record visual field defects. Thirty-four (29.3%) subjects had defects of the field of vision, 11 of them bilaterally, which made a total of 45 (19.4%) eyes. Downward isopter depression from above and contraction of the field of vision were the most common damages. A homonymous hemianopic defect was found in seven patients. The area of depressed vision helps to some extent in anatomical localization of the damage. Its etiology has not been fully clarified. The authors recommend more extensive clinical examinations of the visual field, i.e. follow-up of each patient with classic migraine by periodical testing of the field of vision.

Female↗

PubMed2006

Early paracentral visual field loss in patients taking hydroxychloroquine.

OBJECTIVE: To review the natural history and ocular and systemic adverse effects of patients taking hydroxychloroquine sulfate who attended an ophthalmic screening program. DESIGN: Retrospective study. RESULTS: Records of 262 patients who were taking hydroxychloroquine and screened in the Department of Ophthalmology were reviewed. Of the 262 patients, 14 (18%) of 76 who had stopped treatment at the time of the study experienced documented adverse effects. Systemic adverse effects occurred in 8 patients (10.5%) and ocular adverse effects, in 5 (6.5%). Thirty-five patients (13.4%) had visual field abnormalities, which were attributed to hydroxychloroquine treatment in 4 patients (1.5%). Three of the 4 patients were taking less than 6.5 mg/kg per day and all patients had normal renal and liver function test results. CONCLUSIONS: The current study used a protocol of visual acuity and color vision assessment, funduscopy, and Humphrey 10-2 visual field testing and shows that visual field defects appeared before any corresponding changes in any other tested clinical parameters; the defects were reproducible and the test parameters were reliable. Patients taking hydroxychloroquine can demonstrate a toxic reaction in the retina despite the absence of known risk factors. Screening, including Humphrey 10-2 visual field assessment, is recommended 2 years after the initial baseline and yearly thereafter.

Adolescent↗

PubMed2002

The effects of vigabatrin on electrophysiology and visual fields in epileptics: a controlled study with a discussion of possible mechanisms.

PURPOSE: To compare the visual electrophysiology and visual fields of patients taking vigabatrin to those of a control group of epileptics on other anti-epileptic drugs (AEDs). METHODS: Fourteen epileptics treated with vigabatrin and 10 control patients treated with other AEDs underwent ERG and EOG. Goldmann visual fields were performed and analysed using standard software to measure areas contained within I4e isopters. RESULTS: The cone and rod b-waves of the ERG, the oscillatory potential amplitudes and Arden indices were reduced in vigabatrin-treated subjects and the oscillatory potentials delayed. The Arden indices were reduced due to an increased dark trough. The areas contained within the I4e isopter of vigabatrin treated subjects were reduced compared to the control group and these areas correlated well with oscillatory potential amplitudes and b-wave amplitudes in the vigabatrin group only. CONCLUSIONS: The use of vigabatrin is associated with a reduction of the ERG cone b-wave amplitude and oscillatory potentials which correlates with visual field loss. The Arden ratio is reduced in subjects taking vigabatrin but may recover after cessation. However, visual loss may persist in the presence of a recovered EOG. These findings suggest further effects of the drug than those mediated by GABA receptors, and support the contention that the cause of the field loss may be at least in part due to retinal effects. Possible mechanisms are discussed.

Adult↗

PubMed2003

Temporal characteristics of binocular rivalry: visual field asymmetries.

Very little is known about the mechanisms that drive the alternation between the two views during binocular rivalry. A key property of the rivalry process is the rate at which the two views alternate. Understanding the factors that affect the rate of the alternation is critical to the final understanding of the underlying process. Using a circular and a radial grating as the rivalry stimuli, we observed a significantly faster binocular rivalry when stimuli were presented in the right visual field than that in the left visual field for the right-handed observers, and a reversed asymmetry for the left-handed observers. In both groups, rivalry was faster for stimuli presented in the lower visual field than that in the upper visual field. This pattern of results suggests that (1) rivalry is likely a locally driven process and (2) the visual brain in the left hemisphere may be the faster one of the two hemispheres in right-handed people.

Adaptation, Ocular↗

PubMed1996

Effects of handedness and script types on visual-field differences in the mental addition task.

The effects of handedness and script types on the difference in performance in a mental addition task by visual field were examined. Right-handers, nonfamilial left-handers, and familial left-handers who were all native speakers of Japanese were asked to add two numbers presented in the visual half-fields tachistoscopically. The two numbers were displayed either to one visual field (left or right visual field) or to the center. The numbers were displayed in Arabic, in Kanji, or in Arabic and Kanji numerals (one in Arabic and the other in Kanji: Mixed stimuli). The subjects were asked to add the two numbers and to state the sum orally. In the right-handers group, a right visual-field advantage was found for the Arabic condition but not for the Kanji or Mixed stimuli. On the other hand, in the nonfamilial and familial left-handers group, no visual-field difference in any of the conditions was found. These findings suggest that pattern of cerebral lateralization for familial and nonfamilial left-handers is the same but it is different from that of right-handers.

Adult↗

PubMed1999

Quantitative visual fields under binocular viewing conditions in primary and consecutive divergent strabismus.

BACKGROUND: Although there have been a number of studies on the size of the suppression scotoma in divergent strabismus, there have been no reports on the full extent (i.e. size as well as depth) of this scotoma. METHODS: Binocular static perimetry was used to measure suppression scotomas in five patients with primary divergent strabismus and ten patients with consecutive divergent strabismus. Four control subjects were also included in the study. With two modified Friedmann visual field analysers, we measured the visual field of both eyes under monocular and binocular viewing conditions. The objective angle of squint ranged from 3 degrees to 25 degrees. Best corrected visual acuity was at least 0.4, but mostly 1.0 in both eyes. RESULTS: All subjects had normal visual fields for each eye under monocular viewing conditions. In 12 of the 15 subjects, we found a large area of suppression encompassing the projection of the fixation point as well as that of the fovea in the non-fixating eye under binocular viewing conditions. In 2 of these 12 patients, one with primary and one with consecutive divergent strabismus, the area of suppression was located nasally to the position of the fovea in the field of the non-fixating eye (nasal hemisuppression). In another two patients with divergent squint combined with vertical deviation, a small fixation-point suppression scotoma was found. The depth of suppression ranged from 3 dB to 16 dB. In one subject only, no suppression was found. CONCLUSIONS: Our findings indicate that the shape of the suppression scotoma is not related to the origin of divergent strabismus or to the angle of squint. Our results also indicate that the critical age for the development of suppression in divergent squint might be up to 14 years.

Adolescent↗

PubMed1980

Effects of a blacklight visual field on eye-contact training of spastic cerebral palsied children.

This study investigated the effects of a blacklight visual field on eye-contact training with visually impaired, spastic cerebral palsied children. Four subjects, aged 6 and 7 yr., identified as visually impaired in reference to the Callier-Azusa Scale, were given training in making eye contact with a stimulus object under both white and a blacklight visual field. A counter-balanced design was used so that two of the subjects began training under white light and two began with a blacklight visual field. An analysis of variance for repeated measures indicated a significant main effect for the lighting condition. All subjects performed better under the blacklight condition, even overcoming the expected practice effect when white light training followed blacklight training.

Attention↗