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Exercise does not increase visual field sensitivity.

The effect of exercise on visual field sensitivity was investigated for both static and kinetic visual fields using the Humphrey Field Analyser (HFA). The visual fields of 20 young visually normal subjects were measured before and after a 10-min controlled period of exercise. Ten of these 20 subjects then formed a control group, where the same experimental regime was followed without the exercise period. A significant increase in mean static sensitivity in the superior field was found as a result of exercise; however, this is likely to be a learning effect as a similar increase was also found for the control condition. Exercise had no other effect on either the kinetic or static visual fields.

Adult↗

Effect of altered central and peripheral visual field stimulation on correct recognition and visual evoked response.

Hemispheric asymmetry was assessed using combined electrophysiological (visual evoked response) and behavioral (percentage-correct-recognition) techniques. Right-handed, right-eyed, male undergraduates who viewed tachistoscopically exposed CVCs and random shapes in both central and peripheral visual fields were scored for their ability to recognize the stimuli correctly. Latency and amplitude of visual evoked responses were compared with correct recognition. Central and peripheral stimuli produced significant results. Superiority of the left hemisphere for verbal stimulus processing was supported. Small but consistent positive peak latencies of visual evoked responses also indicated language specialization of the left lobe. Results were interpreted as supporting hemispheric functional asymmetry. Additional findings of "cognitive masking" and marked reduction in intersubject variance in postive peak latencies of visual evoked responses by a central stimulus occurring at approximately 300 msec were also obtained. Mechanisms of iconic image storage, neuropsychological attentional theories, and differential hemispheric structural organization were discussed in interpreting results.

Adolescent↗

Clinical significance of detecting visual field loss.

The clinical effect of detecting visual field loss was studied in 66 patients with visual field defects. Fifty-two percent of defects were the result of conditions which were themselves considered to be significant. Visual field results were considered to have made vital and important contributions to that diagnosis in 28% and 23% of cases, respectively. The results also brought about a change in the intended management strategy in 39% of cases, but were also helpful in another 35% of cases. It was concluded that the clinical importance of regular perimetric examination is emphasized by these results, which may in turn contribute to the detection of unexpected visual field defects.

Adolescent↗

Providing a homogeneous visual field with an integrating sphere.

Homogeneous visual fields are widely used in visual perception and psychophysical studies. An integrating sphere can be guaranteed to provide a homogeneous diffuse source of illumination. We report here on a custom built integrating sphere, which provides a uniformly illuminated, unpatterned visual field. The apparatus allows for superior subject comfort over other methods. Binocular viewing is facilitated and the apparatus is highly adaptable to various experimental situations requiring a homogeneous visual field.

Alpha Rhythm↗

Short-wavelength automated perimetry can predict glaucomatous standard visual field loss by ten years.

Examination of visual fields using standard achromatic automated perimetry (SAP) is essential for glaucoma management. However, as many as 35-50% of retinal ganglion cells can be lost before a visual field defect is detected. Previous studies have indicated that examination of the short-wavelength (blue) sensitive color system may be able to detect early functional loss in glaucoma. Moreover, it has been reported to detect glaucomatous visual field loss as many as 5 years earlier than SAP. We describe the case of a patient who demonstrated visual field defects on short-wavelength automated perimetry (SWAP) ten years prior to developing visual field defects in SAP.

Female↗

A practical approach to measuring the visual field component of fitness to drive.

AIMS: To determine the level of agreement between merged monocular visual field tests (the integrated visual field) and the binocular Esterman visual field test in classifying patients' visual status for UK legal fitness to drive. To examine the link between these two tests and the useful field of view (UFOV) test, a test which is considered to be a surrogate for the visual capability for safe driving. METHODS: Primary open angle glaucoma patients with bilateral overlapping visual field defects were recruited prospectively. Patients performed the bilateral monocular field tests (to generate the integrated visual field), the Esterman test and the UFOV test on the same visit. Patients were classified as "pass" or "fail" by both the integrated visual field and the Esterman test. UFOV risk scores were calculated for each patient. RESULTS: 65 patients were recruited. Substantial agreement was found between the integrated visual field and the Esterman test in classifying patients as "pass" or "fail" (kappa = 0.69). No patients classified as "pass" by the integrated visual field test were classified as "fail" by the Esterman test. Eight patients who were classified as "pass" by the Esterman test were classified as "fail" by the integrated visual field test. The UFOV risk characteristics of these eight patients suggested they were more similar to those of the 13 patients who were classified as "fail" by both the tests, than the 44 patients who were classified as "pass" by both tests. CONCLUSIONS: The integrated visual field test agrees well with the current method (Esterman) of classifying visual fields with regard to legal fitness to drive in the United Kingdom in patients with glaucoma; it appears superior to the current method in identifying those with reduced fitness to drive as measured by the UFOV. The integrated visual field test could perform a valuable screening or diagnostic role in the assessment of glaucoma patients' fitness to drive.

Adult↗

Fastpac visual field screening.

In epidemiology, screening for visual field defects has traditionally been expensive, time consuming and laborious. To achieve cost- and time-effective visual field screening, a faster algorithm has been developed for the Humphrey perimeter called Fastpac, which is designed to achieve threshold perimetry in two-thirds the time of the standard algorithm. We compared the Fastpac and conventional full-threshold 24-2 fields obtained in 39 eyes of 36 participants. We divided the participants' fields into normal (14) and glaucomatous (25) visual field groups, and compared the test times, number of questions asked and statistical parameters generated for each field for Fastpac as compared to the standard algorithm. Then we divided the participants' fields into Fastpac and standard fields and again compared the test times, number of questions and statistical parameters. Finally we asked trained observers to judge the fields as being normal or abnormal, in a masked fashion, and found a high degree of agreement between the fields generated by Fastpac and standard. Fastpac offers accurate full-threshold screening in two-thirds the time of the conventional algorithm and would be very useful for large scale prevalence studies in ophthalmic epidemiology.

Adult↗

[Visual field in pseudophakia].

Estimation of the visual field in pseudophakic eyes was the aim of this study. Results were compared between the groups of anterior chamber lenses, posterior ciliary sulcus fixation lenses, posterior intracapsular lenses and the control group of phakic patients. Each group consisted of 25 subjects. Visual field measurements were done using dynamic method with Goldmann perimeter and visual field areas were determined by adequate computer program. Statistical analysis of data showed the reduction of visual field in pseudophakic groups when compared to the control group and no significant differences between different types of implants.

Adult↗

Pupil campimetry in patients with visual field loss.

Pupil campimetry is an objective test of the visual field. In pupil campimetry, the pupil light response elicited by focal light stimuli at different locations within the visual field is measured. Pupil campimetry was performed in patients with visual field loss because of different pathologies. The match between reduced pupil response and visual field loss was assessed. The pupil field of 23 patients was recorded by infrared video-pupillography with light stimuli generated on a computer screen. A visual field was obtained on the same day with the Tuebingen Automated Perimeter. Both fields were compared by subjective judgement. Six of nine patients with large, two of five patients with incomplete, and three of six patients with minor field loss showed matching defects in their pupil and their visual fields. In functional loss of visual field sensitivity, no pupil field defect was seen (three patients). In most patients, the loss of visual field sensitivity could be revealed objectively by pupil campimetry.

Adolescent↗

Visual fields in retinoblastoma survivors.

OBJECTIVE: To describe the visual field defects in retinoblastoma survivors and relate those defects to characteristics such as tumor size, tumor location, and treatment modality. METHODS: Thirty-one patients treated for retinoblastoma were included in this study. Humphrey visual fields were determined in 33 eyes. RESULTS: Twenty-seven patients (29 eyes, 68 tumors) had sufficient diagnosis and treatment data available for further analysis. Twenty-six of the 27 patients had both absolute and relative visual field defects. Four types of visual field defects were observed and correlated with location of the tumor and therapy to the individual tumors: (1) no residual defect, (2) absolute scotoma, (3) arcuate and sector scotoma, and (4) "pseudo"-visual field defects caused by relative enophthalmos resulting from radiation. CONCLUSIONS: Patients with retinoblastoma demonstrate a variety of long-term visual field defects after treatment for their intraocular disease. Characteristics that determine the size and type of defects are tumor size, tumor location, and treatment method.

Antineoplastic Agents, Alkylating↗

Detection and recognition of visual field defects resulting from lesions involving the visual pathways.

A prospective study of visual field defects associated with lesions of the visual pathway was carried out using kinetic and suprathreshold static stimuli with a view to establishing the most effective screening method for these field defects. The 215 abnormal fields so obtained showed that all field defects due to lesions of the visual pathways are detectable within 30 degrees of fixation and that not only is central field testing mandatory in excluding such a field defect, but more peripheral field testing alone is ineffective. This study also revealed that when kinetic fields are charted, it is probably not worthwhile searching for scotomata other than within the most central part of the field. Furthermore, where outer and inner isopter depression is not coextensive, inner isopters are always depressed more than outer isopters when the field defect is due to a lesion of the visual pathway.

Central Nervous System Diseases↗

Diffuse visual field loss in open-angle glaucoma.

Recent studies have suggested that diffuse field loss and localized visual field loss in glaucomatous patients may have different pathophysiologic mechanisms. Testing that hypothesis requires that some patients present with purely localized field loss and other patients with purely diffuse loss. This article describes four highly selected patients with elevated intraocular pressures, bilateral damage to the optic nerve head, one eye with a classic glaucomatous visual field defect and in the other eye, in the absence of opacities in the media, a diffuse loss of the visual field. Although purely localized loss is very common, the report illustrates purely diffuse loss in the absence of other causes.

Adult↗

Macular hole surgery-associated peripheral visual field loss.

To examine in more detail the peripheral visual field loss after macular hole surgery, we reviewed a series of 38 consecutive patients (44 eyes) with idiopathic macular hole who underwent vitrectomy and fluid-gas exchange. Ten (22.7%) eyes of 9 patients developed peripheral visual field loss shortly after successful surgery. This complication was characterized by mild to moderate wedge-shaped visual field loss that predominantly affected the inferotemporal periphery. Of these 9 patients, 2 complained of peripheral visual field loss, and the 7 others remained asymptomatic. The peripheral visual field loss remained unchanged for a mean follow-up of 18.5 months, except in one case of complete recovery. The thickness of the retinal nerve fiber layer was measured postoperatively to determine whether any damage to the optic nerve head had occurred during surgery. The information obtained in this study did not provide conclusive evidence for the understanding of the pathomechanism of the macular hole surgery-associated visual field loss. Peripheral visual field defect after otherwise uneventful surgery for idiopathic macular hole is probably not uncommon. This complication is variable in its severity and is usually permanent. Whether it is caused by any surgical trauma to the optic nerve head remains to be elucidated.

Aged↗

Plasticity and rigidity in the representation of the human visual field.

Neuronal plasticity in the mammalian visual system has been studied with a variety of experimental methods like induction of artificial squint and eye rotation. To investigate neuronal plasticity in the human visual system, we examined a patient with a congenital convergent squint of his left eye, who later suffered a vascular lesion in his left occipital lobe that led to an incomplete hemianopia in his right visual field. The examination revealed that the visual field representation in the striate cortex is rigidly prewired with reference to the anatomical fovea. In contrast, plasticity in the oculomotor system enables the patient to use a functional visual axis that does not correspond to the anatomical fovea. Local alterations of sensitivity within the visual field that indicate interactions among non-corresponding retinal points provide additional evidence of functional plasticity.

Esotropia↗

Usefulness of the Henson Central Field Screener for the detection of visual field defects, especially in glaucoma.

The Henson Central Field Screener is a recently marketed, relatively inexpensive campimeter with semi-automated registration of responses. The strategy used is suprathreshold, eccentricity-compensated, multiple stimulus static perimetry. The clinical usefulness of this apparatus was tested in a number of glaucoma patients, glaucoma suspects and normals, as well as in subjects with other ocular disorders, for whom stable visual fields as tested with other perimeters were available. The results obtained with the Henson Screener are generally in agreement with the known defects. The apparatus has some drawbacks, however.

Adolescent↗

Visual field loss in senile dementia of the Alzheimer's type.

BACKGROUND: Visual performance is impaired in patients with senile dementia of the Alzheimer's type (SDAT). We investigated the visual field topography of these deficits. METHODS: Humphrey automated perimetry (Program 30-2) was used to measure differential luminance sensitivity within the central 60 degrees of the visual field in SDAT patients (n = 61) and in visually and cognitively normal volunteer subjects of similar age (n = 61). Twenty-three SDAT patients were retested 18 months after the original examination. RESULTS: Reliable visual fields (by manufacturer's criteria) were obtained in 72.1% (44/61) of the control subjects and 55.7% (34/61) of the SDAT group. In the SDAT group, differential luminance sensitivity was significantly reduced relative to the control group. Visual sensitivity was reduced throughout the visual field, but deficits were most pronounced in the inferior visual field, where they presented most commonly as arcuate defects. Patients with more severe dementia exhibited greater reductions in visual sensitivity. On follow-up, 14 of 23 SDAT patients exhibited progression of visual field loss, whereas only two of 23 patients exhibited a regression of the visual field loss. CONCLUSIONS: Although automated perimetry requires considerable patient cooperation, many patients with SDAT can produce reliable visual field results. These patients exhibit significant reductions in global sensitivity. Visual field loss in SDAT is most pronounced in the inferonasal and inferotemporal arcuate regions of the visual field but also involves the central field.

Aged↗

On-road driving with moderate visual field loss.

PURPOSE: We examined the relationship between visual field extent and driving performance in an open, on-road environment using a detailed scoring method that assessed the quality of specific skills for a range of maneuvers. The purpose was to determine which maneuvers and skills should be included in future, larger scale investigations of the effect of peripheral field loss on driving performance. METHODS: Twenty-eight current drivers (67 +/- 14 years) with restricted peripheral visual fields participated. Binocular visual field extent was quantified using Goldmann perimetry (V4e target). The useful field of view (UFOV) and Pelli-Robson letter contrast sensitivity tests were administered. Driving performance was assessed along a 14-mile route on roads in the city of Birmingham, Alabama. The course included a representative variety of general driving maneuvers, as well as maneuvers expected to be difficult for people with restricted fields. RESULTS: Drivers with more restricted horizontal and vertical binocular field extents showed significantly (p < or = 0.05) poorer skills in speed matching when changing lanes, in maintaining lane position and keeping to the path of the curve when driving around curves, and received significantly (p < or = 0.05) poorer ratings for anticipatory skills. Deficits in UFOV performance and poorer contrast sensitivity scores were significantly (p < or = 0.05) correlated with overall driving performance as well as specific maneuver/skill combinations. CONCLUSIONS: In a small sample of drivers, mild to moderate peripheral visual field restrictions were adversely associated with specific driving skills involved in maneuvers for which a wide field of vision is likely to be important (however most were regarded as safe drivers). Further studies using similar assessment methods with drivers with more restricted fields are necessary to determine the minimum field extent for safe driving.

Aged↗

Visual fields in neuro-ophthalmology.

1. The gathering and interpretation of visual fields is important to a thorough neuro-ophthalmic evaluation. The technique of visual field measurement is essential to the proper characterization of visual field defects and must be tailored to each patient in respect to his or her ability to perform a particular test. 2. The techniques for visual field measurement include Amsler grid, confrontation using fingers or colored objects, tangent screen, manual bowl perimeters, and automated static perimeters. 3. The ability to characterize a visual field defect and interpret its relationship to disease involves a combination of knowledge of the anatomy of the visual pathways and the use of the appropriate visual field examination strategy. Once it has been determined--by simple and expeditious confrontation visual field techniques--whether the defect is present centrally or only in the peripheral visual field, a selection of more formal visual field examination can be made.

Humans↗