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At least 1,153 records · Page 64Linked to original sources
PubMed1996

[A case of Rathke's cleft cyst in association with anterior communicating artery aneurysm presenting a rare visual field defect].

We report a case of Rathke's cleft cyst associated with anterior communicating artery aneurysm. The patient was 60-year-old woman who developed visual disturbance two months before admission to our hospital. Visual acuity on the right was 0.06 and on the left was 0.08. The visual fields showed a complete temporal hemianopsia on the left eye and an incomplete temporal hemianopsia of the right eye with a central defect of the temporal visual field. CT and MR imagings showed an intra- and suprasellar mass lesion with no enhancement. Angiography showed bilateral A1 elevations and anterior communicating artery aneurysm. The operation was performed through interhemispheric approach. Suprasellar cystic mass compressed upward the optic nerves and chiasm, and aneurysmal dome stuck in the central region of chiasm. This anatomical disorders affected to the optic chiasm resulted in a rare visual field defect. Neck clipping of aneurysm and opening of the cyst were performed. A diagnosis of Rathke's cleft cyst was made. Following surgery, her visual fields resolved but she suffered from diabetes insipidus.

Craniopharyngioma↗
PubMed1992

Measurement of retinal nerve fiber layer thickness and its functional correlations with the visual field.

We have developed a technique for stereophotogrammetric measurements of retinal nerve fiber layer thickness at the disc margin. This technique has a reproducibility ranging from 3.9% to 6.0% in normal, ocular hypertensive and high pressure open angle glaucomatous eyes. The presence of a halo or scleral crescent had no effect on the reproducibility of the measurements. The measurements have shown that ocular hypertensive eyes have about an 18% decrease of retinal nerve fiber layer thickness compared to normals. High pressure open angle glaucomatous eyes have about a 43% decrease in retinal nerve fiber layer thickness compared to normals. This technique allows the development of maps of retinal nerve fiber layer thickness so that localized changes at the disc margin can be detected. The thinnest nerve fiber layer occurs primarily in the temporal segment. This technique has also correlated measurements of nerve fiber layer thickness with other measurements of the optic disc, particularly showing a significant correlation with area of pallor as well as measurements of the width of optic disc cup at about halfway between surface and the bottom of the cup. A significant correlation with visual field loss has been shown in high pressure open angle glaucomatous eyes, primarily with the temporal quadrant of the retinal nerve fiber layer and the nasal visual field. The rate of the visual field change in primary open angle glaucoma has been correlated with the initial nerve fiber layer thickness, with the greater the retinal nerve fiber layer thickness the greater the rate of the visual field loss during follow-up. These findings suggest that retinal nerve fiber layer thickness discriminates between normal, ocular hypertensive eyes as well as those with open angle glaucomas and may be useful in following patients with open angle glaucoma prior to development of the visual field loss.

Glaucoma, Open-Angle↗
PubMed1985

The projection of the visual field onto the lateral geniculate nucleus of the ferret.

The projection of the visual field onto the dorsal lateral geniculate nucleus (LGN) of the ferret was mapped electrophysiologically. The nucleus contains a single orderly map of the contralateral visual hemifield. The upper visual field is represented dorsally and rostrally in the nucleus; central fields are found in the medial and caudal sections of the LGN; and peripheral fields are represented most laterally. The ipsilateral eye is represented in laminae A1 and C1 up to eccentricities of 20-30 degrees. Lines of projection run perpendicular to the laminar borders. The ferret LGN resembles that of the cat rotated approximately 110 degrees clockwise in the sagittal plane, viewing the right nucleus from its lateral aspect; it differs from the cat in having a larger monocular segment.

Animals↗
PubMed1986

Visual field defects in cats with neonatal or adult immunological loss of retinal ganglion cells.

Behavioral perimetry methods were used to assess the monocular visual fields of 12 cats that had received intraocular injections of antibodies against large (alpha/Y) retinal ganglion cells. The antibodies produced defects in head and eye orientation responses to stimuli presented in the nasal visual field of the treated eye; responses to stimuli in the temporal visual hemifield were normal. Similar results were seen in cats that received antibody injections at 4 weeks of age or as adults. In the context of previous results, these findings suggest that a loss of Y cells in the lateral geniculate nucleus is sufficient to reduce geniculocortical function for head and eye orientation to visual stimuli in the nasal visual field.

Animals↗
PubMed1998

The representation of the ipsilateral visual field in human cerebral cortex.

Previous studies of cortical retinotopy focused on influences from the contralateral visual field, because ascending inputs to cortex are known to be crossed. Here, functional magnetic resonance imaging was used to demonstrate and analyze an ipsilateral representation in human visual cortex. Moving stimuli, in a range of ipsilateral visual field locations, revealed activity: (i) along the vertical meridian in retinotopic (presumably lower-tier) areas; and (ii) in two large branches anterior to that, in presumptive higher-tier areas. One branch shares the anterior vertical meridian representation in human V3A, extending superiorly toward parietal cortex. The second branch runs antero-posteriorly along lateral visual cortex, overlying motion-selective area MT. Ipsilateral stimuli sparing the region around the vertical meridian representation also produced signal reductions (perhaps reflecting neural inhibition) in areas showing contralaterally driven retinotopy. Systematic sampling across a range of ipsilateral visual field extents revealed significant increases in ipsilateral activation in V3A and V4v, compared with immediately posterior areas V3 and VP. Finally, comparisons between ipsilateral stimuli of different types but equal retinotopic extent showed clear stimulus specificity, consistent with earlier suggestions of a functional segregation of motion vs. form processing in parietal vs. temporal cortex, respectively.

Brain Mapping↗
PubMed2006

Intraocular pressure before and after visual field examination.

PURPOSE: To evaluate the influence of visual field (VF) examinations using modern techniques with short examination times on the intraocular pressure (IOP). METHODS: Sixty-one consecutive patients, aged 28-90 years, 40 women and 21 men, were examined. Forty patients were treated for glaucoma and 21 were untreated patients with ocular hypertension or suspected glaucoma. Twenty-one subjects were examined using the Humphrey Field Analyzer, using SITA programs, and 40 with high-pass resolution perimetry (HRP). Goldmann applanation tonometry was performed immediately before and after the VF examinations. RESULTS: A difference in IOP of more than 2 mm Hg before and after the VF examination was observed in 14 of the 61 patients (23%). The maximum change in each direction was 4 mm Hg. The mean differences were not significant. All eight subjects with increasing IOP after VF examinations were examined using the HRP technique (P=0.04). CONCLUSION: Modern VF techniques with short examination time do not seem to significantly influence IOP.

Adult↗
PubMed1997

Mapping visual field with positron emission tomography by mathematical modeling of the retinotopic organization in the calcarine cortex.

We developed an objective and quantitative method of mapping the human visual field with positron emission tomography (PET) and magnetic resonance image (MRI). The regional cerebral blood flow (rCBF) images were acquired with H2(15)O-PET under visual fixation as well as under visual stimulation with flickering diodes arranged along the ring at 0 degree, 3 degrees, 7 degrees, 14 degrees, 21 degrees, or 29 degrees from the fixation point. After coregistration of PET and MR images, we extracted the surface of the calcarine cortex from the MR images and unfolded it to a two-dimensional (2-D) elliptic plane, on which the activated PET images were superimposed. Then we transformed the unfolded calcarine cortex into the visual field coordinates using the complex logarithmic function proposed by Schwartz. A large individual variation was observed in the retinotopical organization as well as in the morphology of the calcarine cortex. The formula was valid only within 15 degrees from the center of the visual field. The constant parameter in the formula was estimated to be 1.5. The cortical linear magnification factor was 12.1, 2.8, and 1.6 at 0, 5, and 10 degrees, respectively. The areas of the central 10 degrees and 40 degrees in the visual field correspond to 50% and 81% of the calcarine surface, respectively.

Adult↗
PubMed1991

Influence of missed catch trials on the visual field in normal subjects.

A total of 20 healthy individuals purposely missed an increasing number of individual catch trial questions (false positive or negative errors or fixation losses) when tested on the Humphrey Field Analyzer to determine the effect on the normal visual field. As determined by Statpac, the global indices and probability maps became significantly altered from those for the control fields at a prevalence of 20% for false negatives and 33% for fixation losses and false positives. However, the perimeter's recorded prevalence of missed catch trials showed a wide distribution from the percentage purposely missed. A high prevalence of missed catch trials was also indicated by a greater than normal mean defect and number of questions asked. This study suggests that although the number of missed catch trials are often recorded inaccurately, they help to identify unreliable normal visual fields, as do the mean defect and the number of questions asked.

Adult↗
PubMed2006

[Improvement in glaucomatous visual field thresholds after reduction of intraocular pressure: clinical vs. surgical treatment].

PURPOSE: To verify the influence of modality of treatment in regions of the glaucomatous visual field after reduction of intraocular pressure (IOP). METHODS: Glaucoma patients that had undergone a reduction of IOP of at least 20% in a period of 2 months were retrospectively selected and divided into 2 groups: 1) after trabeculectomy; 2) after clinical treatment. Visual field global indices and thresholds (average, divided according to the severity based on the Pattern Deviation plot) were compared before and after IOP reduction. RESULTS: Thirty-one eyes of 22 patients were selected (15 in group 1, and 16 in group 2). Both groups showed good ability regarding improvement of different regions of the visual field after IOP reduction. Only the percentage of reduction of IOP (52.3+/-18.9% and 37.8+/-15.2% for groups 1 and 2, respectively, p=0.02) and the percentage of improvement in the points damaged at p<0.5% (186.0+/-213.3% and 30.1+/-35.2% for groups 1 and 2, respectively, p=0.02) were different, but not statistically significant after alpha error correction between groups. CONCLUSION: The reduction of IOP above 20% may be associated with improvement in regions of the glaucomatous visual field, regardless of treatment modality.

Aged↗
PubMed2000

[Changes to visual acuity and the visual field in a case of meningioma operated at the anterior level].

It's presented a midline meningioma of anterior level case which preoperative has an importance affectation of the visual acuity and visual field, and postoperative in dynamic is founded the important improvement of visual acuity and visual field. It's discussed visual field topography and atrophy optic pathophysiology. It's a neuro-ophthalmology case example, where the cooperation neurosurgery-ophthalmology permit medical solution and restored in social life of the patient.

Female↗
PubMed2004

[Proposed scoring system for assessment of functional impairment due to visual field defects].

INTRODUCTION: The purpose of the study is the development of a scoring system for the assessment of functional impairment due to visual field defects, based on the Esterman grid, but adapted to the existing system in the Federal Republic of Germany. METHODS: The score areas and the evaluation rules were altered iteratively, until the functional score by the new system matched as much as possible the score obtained from the existing system of geometrical defect patterns. RESULTS: The visual field is divided into 100 score areas, which are smaller in the visual field center and in its lower region, respectively. The areas inside the reference isopter are counted and taken as total function in percent. Areas with monocular perception are rated with 3/4 points. Functional impairment is defined as the difference of total function to 100%. For 9 of 20 defect patterns, the functional scores are equal. Another six patterns differ by 1-4%. The remaining 5 of 20 patterns differ by 6-8% in either direction. CONCLUSION: The new system is easier to apply, more consistent, and covers irregular defect patterns. The level of functional impairment is nearly identical with both systems. A transition to the scoring system would considerably increase the certitude and the quality of assessment especially in difficult cases.

Disability Evaluation↗
PubMed1992

The relationship between intraocular pressure and visual field progression in glaucoma.

The purpose of this study was to determine the intraocular pressure characteristics in glaucoma suspects and patients whose visual fields were classified as stable or progressing over a long-term follow-up. We present data from 64 patients who received either medical or laser treatment and who were followed up for a median of 7.4 years. The visual fields of 27 patients were classified as stable and 37 as progressing using predetermined criteria on either the Tübinger or Goldmann perimeter. Patients with initially normal and initially abnormal fields were analysed separately to avoid bias. There were no significant group differences in the mean, highest or interquartile range of intraocular pressure in the follow-up. The largely overlapping distributions over a wide spectrum of the pressure variables in patients with stable and progressing fields show that intraocular pressure alone cannot separate these two groups of patients. Our study does not suggest that pressure reduction in glaucoma has no beneficial effect, but that there may be other factors which determine the fate of the visual field in glaucoma.

Aged↗
PubMed1990

Central visual field changes after panretinal photocoagulation in proliferative diabetic retinopathy.

This study comprises 53 eyes, divided into two groups A and B, with proliferative diabetic retinopathy which were treated with panretinal photocoagulation (PRP). Its purpose is to investigate the alterations in the central 15 degrees and 30 degrees of the visual field and in each quadrant separately. In both groups A and B, PRP covered the periphery and mid-periphery. In group A, it stopped 2 disc diameters (DD) from the upper temporal and lower margin of the fovea including the papillomacular bundle, while in group B, PRP stopped 3 DD from the upper temporal and lower margin of the fovea and 1 DD of the nasal margin of the optic disc. The investigation revealed, in group B after PRP, an improvement of the retinal sensitivity in the central 15 degrees of the visual field (p less than 0.01). In the 30 degrees of the visual field a deterioration after PRP was noted in both groups A and B, the deterioration being however much more prominent in group A. Comparing the results between groups B and A after PRP, a difference in the retinal sensitivity in favour of group B at 15 degrees and 30 degrees of the visual field was found. As regards regression of neovascularization and visual acuity, no statistically significant difference has been observed between the two groups.

Adult↗
PubMed2005

Serial follow-up in traumatic optic neuropathy using scanning laser polarimetry and visual field testing.

A 40-year-old male patient suffered from traumatic optic neuropathy in his right eye. Scanning laser polarimetry was arranged at 2 weeks, 9 weeks, 13 weeks, 24 weeks, and 34 weeks after the trauma. Manual or automated visual field testing was also arranged at 1 week, 5 weeks, 16 weeks, and 28 weeks correspondingly. The data revealed using scanning laser polarimetry (program GDx, version 1.0.05; Laser Diagnostic Technologies, San Diego, Calif, USA) were nearly normal at 2 weeks after trauma, but lower visual field loss was revealed using visual field testing within 2 weeks after the trauma. The superior hump of the GDx deviated from normal at about 9 weeks and some GDx parameters (the Number, Superior/Nasal, Ellipse Modulation (Ellipse Mod.), Maximal Modulation (Max. Mod.), Symmetry, Superior Ratio (Super. Ratio)) became worse later in the series. We propose that visual field defects might be present before retinal nerve fiber layer loss. In this case, scanning laser polarimetry for evaluating the severity of traumatic optic neuropathy was limited especially within 2 weeks after the trauma.

Adult↗
PubMedDate not supplied

[Retinal nerve fibers and automated visual fields during the course of primary open-angle glaucoma].

Retinal nerve fiber examination is confronted with the results of automatic exploration of visual field with Octopus. 99 eyes affected by open angle glaucoma were studied during a period of 4 years or less. Analysis is done in accordance with the course under therapy. Good pressure results are obtained. Meanwhile visual field indexes show a slow deterioration under medical treatment, a stabilisation after laser trabeculoplasty and a marked improvement after surgery (trabeculectomy). Retinal nerve fiber are clear prior affected in comparison with visual field in early glaucoma, and a perfect agreement is demonstrated in mature cases.

Adult↗
PubMed1982

Visual-field differences in picture-word interference.

Picture-word interference refers to the fact that if a picture (i.e., line drawing) is presented centrally with a word superimposed, picture-naming latency is longer than if that same picture is presented alone. This phenomenon, like the Stroop phenomenon, seems to be strongly influenced by the nature of the to-be-ignored word. That is, if the word names a member of the picture's semantic category additional interference is observed; however, if the word is replaced by a phonetically unviable consonant string interference is reduced. In the present experiments these effects were examined in the situation where the picture-word stimuli were presented unilaterally in either the left or right visual field. For right-visual-field presentations, phonetic and semantic factors both influenced performance just as in central presentations. As such, these results can be satisfactorily explained in terms of response competition processes. However, the results for the left-visual-field presentations were quite different. Although substantial interference was observed for all types of stimuli, the amount of interference was essentially independent of the linguistic nature of the superimposed letter string. These results do not appear to be explainable in terms of response competition processes. Instead, it is suggested that the best way to explain these results is in terms of the perceptual capabilities of the right hemisphere.

Cerebral Cortex↗