Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Visual Fields”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 1,567 records · Page 87Linked to original sources
PubMed1989

Timolol treatment prevents or delays glaucomatous visual field loss in individuals with ocular hypertension: a five-year, randomized, double-masked, clinical trial.

A 5-year, randomized, double-masked, clinical trial was conducted to determine whether treatment with topical timolol maleate was effective in preventing or delaying the onset of glaucomatous visual field loss in subjects with ocular hypertension. Sixty-five individuals considered to be at moderate risk for developing open-angle glaucoma were recruited for the study. In each patient, one eye was chosen randomly to receive timolol twice-daily while the fellow eye received diluent (placebo). Timolol administration reduced IOP from baseline in the treated eyes over the course of the study by a mean +/- SD of 4.9 +/- 3.4 mm Hg. Timolol administration also produced a mean +/- SD contralateral reduction of IOP from baseline in the untreated fellow eyes of 2.9 +/- 3.1 mm Hg. The mean +/- SD difference in IOP between the treated and untreated eyes during the study was 2.3 +/- 2.6 mm Hg. Over the course of the study reproducible visual field loss developed in 4 timolol treated eyes and 10 placebo treated eyes (P = .039, McNemar test). Clinical progressive optic disc cupping was noted in four treated and eight untreated eyes (P = .11, McNemar test). In the 42 subjects who completed a minimum 4-year follow-up, baseline and final optic disc photographs were analyzed using a computer image analysis system to determine changes in the area of disc pallor. The mean +/- SD increase in optic disc pallor was 0.86% +/- 2.4% in the timolol treated eyes and 1.80% +/- 3.6% in the placebo treated eyes. This difference was statistically significant (P = .04, paired t-test). This study provides evidence that medical treatment prevents or delays the onset of glaucomatous visual field loss and optic disc damage in individuals with ocular hypertension. The magnitude of the protective effect of timolol was partially obscured by the contralateral reduction of IOP in the placebo treated fellow eyes.

Adult↗
PubMed2000

Isolation of short-wavelength sensitive mechanisms in normal and glaucomatous visual field regions.

PURPOSE: To determine whether "isolation" of short wavelength sensitive mechanisms (i.e., exclusive detection of a threshold stimulus by a short wavelength sensitive mechanism) is maintained in areas of glaucomatous visual field damage as measured with short-wavelength automated perimetry (SWAP). METHODS: Data from conventional automated perimetry and SWAP were analyzed for both eyes of 60 normal control subjects, 38 patients with ocular hypertension, and 22 patients with early to moderate glaucomatous field damage (mean defect better than -12 dB). Comparisons of results of SWAP and conventional perimetry were performed by determining the deviation from the mean normal sensitivity for the two procedures. Locations with sensitivity <3 dB for either procedure were rejected, as 3 dB is near the maximum stimulus luminance and may have introduced a bias by underestimating defects. The interval between deviation from normal (the isolation interval) on conventional perimetry and SWAP was examined to determine the likelihood of short wavelength mechanism isolation loss for different levels of glaucomatous visual field damage. RESULTS: Using normal isolation estimates of 13 dB and 10 dB as bases for determining the likelihood that isolation of short wavelength sensitive mechanisms may have been lost, it was found that this was an infrequent possibility, as low as 0.39 to 1.63% for normal control subjects and 2.53 to 10.44% for patients with glaucoma. CONCLUSION: Analyses indicate that isolation of short wavelength sensitive mechanisms is mostly maintained for SWAP, even in areas of moderate glaucomatous field damage. One limitation of SWAP for evaluating extensive glaucomatous damage is its dynamic range. This could be overcome by using a more intense stimulus light source.

Adult↗
PubMed2002

Long-term filtration and visual field outcomes after primary glaucoma triple procedure with and without mitomycin-C.

OBJECTIVE: To evaluate the long-term effectiveness of glaucoma management in patients undergoing primary glaucoma triple procedure (PGTP) with and without adjunctive subconjunctival mitomycin-C (MMC). DESIGN: Case-controlled study. PARTICIPANTS: Of the 203 eyes of 203 primary open-angle glaucoma (POAG) patients who had undergone PGTP and in whom reliable Humphrey visual fields had been obtained both before and after surgery at 13.5 +/- 8.9 and 27.9 +/- 8.9 months, 124 of the 144 eyes that received MMC during surgery were matched to the other 59 eyes that did not with respect to cup-to-disc ratio and risk factors for filtration failure in addition to other variables. MAIN OUTCOME MEASURES: Both preoperative and postoperative intraocular pressure (IOP), Humphrey visual fields and their global indices, number of glaucoma medications, and best-corrected visual acuity (BCVA). RESULTS: There were no significant differences in demographics between the two groups (P > 0.05 for each). Whereas both the control and the MMC groups attained significant decreases of mean IOP (18.5 +/- 5.7 mmHg-;15.6 +/- 4.6 mmHg, P = 0.0014; 19.3 +/- 7.0 mmHg-13.7 +/- 4.9 mmHg, P = 0.0001) and mean number of medications (2.1 +/- 1.3-1.3 +/- 1.3, P = 0.0001; 2.3 +/- 1.2-1.0 +/- 1.3, P = 0.0001) at 36 months after surgery, the MMC group had significantly lower mean IOP than the control group at all postoperative visits (P < 0.05 for each). The MMC group also tended to have less medical dependency after surgery than the control group. There was no significant difference in postoperative BCVA between the two groups. Patients in both groups had mean visual acuity of 20/30 or better. There was a significant worsening of corrected pattern standard deviation (CPSD) in the control group (3.97 +/- 3.18-5.17 +/- 3.36, P = 0.001) compared with no significant change in the MMC group (5.07 +/- 4.11-5.23 +/- 3.36, P = 0.93). The mean deviation did not change significantly in either group. CONCLUSIONS: The long-term glaucoma management in POAG patients with cataract undergoing PGTP indicates a successful outcome in final IOP, medical dependency, and BCVA. Furthermore, the MMC group had better IOP control and stable visual fields (CPSD), whereas the control group had a significant worsening of CPSD.

Aged↗
PubMed2006

Correlation of retinal nerve fiber layer measured by scanning laser polarimeter to visual field in ischemic optic neuropathy.

OBJECTIVE: To evaluate the relationship between retinal nerve fiber layer (RNFL) measurement with scanning laser polarimetry (SLP) and standard automated perimetry (SAP) in nonarteritic anterior ischemic optic neuropathy (NAION). METHODS: In this prospective observational case series, all subjects (28 eyes with NAION) underwent SAP and SLP. The RNFL retardation measurements and visual field test points were grouped into 6 corresponding sectors. The contralateral uninvolved eye was used as control. The relationship between RNFL retardation and SAP was evaluated with the Spearman nonparametric technique and linear regression analysis. The main outcome measure was correlation of SLP RNFL parameters and SAP. RESULTS: Global and sectoral SLP parameters showed a significant difference in affected eyes compared with controls. The strongest correlations were seen between mean deviation and number (r = -0.524; P = .004), ellipse modulation (r = 0.5026; P = .006), and maximum modulation (r = 0.526; P = .004). Superior sectoral visual field indexes showed a strong correlation with inferior RNFL changes (r = 0.522; P<.008). Linear regression confirmed a strong relationship between the superior sectoral visual field indexes and the inferior RNFL. CONCLUSION: Scanning laser polarimetry was able to identify structural changes of the RNFL globally and in the inferior SLP sector with functional loss in NAION.

Adult↗
PubMed2003

Effect of sleep deprivation and driving duration on the useful visual field in younger and older subjects during simulator driving.

Nine older subjects (40-51 years) and 10 younger subjects (18-30 years) took part in two one-hour driving sessions. They performed a very monotonous task during which they had to follow a vehicle either after a complete night of sleep or after one night of sleep deprivation. While driving their useful visual field was assessed by introducing signals that would appear on the whole road scene. The analysis of the data indicates that the ability to process peripheral signals deteriorates with age, driving duration and sleep deprivation. However, the effects of these three variables on the peripheral visual ability are not similar in a dual task. The driver's useful visual field changes with age and prolongation of the monotonous driving activity according to a tunnel vision phenomenon. On the other hand, a sleep debt deteriorates the useful visual field according to a general interference phenomenon. These results are discussed in terms of decrease in the level of arousal and increase of fatigue.

Adolescent↗
PubMed1997

Visual field loss resulting from cervical chiropractic manipulation.

PURPOSE: To report a complication of chiropractic cervical manipulation. METHOD: Case report. A healthy 39-year-old woman developed sudden left peripheral visual field loss after chiropractic neck manipulation. RESULTS: Visual field testing disclosed a left superior homonymous hemianopsia. A magnetic resonance imaging scan performed the day of the event disclosed acute infarction of the ventromedial aspect of the inferior right occipital lobe. CONCLUSION: Cerebral infarct may occur as a result of chiropractic neck manipulation.

Acute Disease↗
PubMed2000

Preservation of visual fields after peri-sellar gamma-knife radiosurgery.

Radiosurgical treatment of pituitary and peri-sellar tumors has become an increasingly utilized modality as an alternative to conventional radiotherapy and surgery. Such radiosurgery results in a relatively high dose of radiation to the optic chiasm. The clinical data establishing safe single-fraction doses to the chiasm is immature, although taken together previous literature suggests a recommended maximal dose of 8 Gy. Optic neuropathy, when it occurs, tends to take place within 2 years of treatment. We evaluated the visual fields of 20 sequential patients that received significant doses to the optic chiasm by Gamma-knife radiosurgery. There were 17 cases of pituitary adenoma and 3 cases of meningioma, and two patients refused follow-up testing. Preoperative visual field and cranial nerve examinations were done prior to radiosurgery and in follow-up, with a median follow-up of 24 months. There were no cases of quantitative visual field deficit induced by treatment. No patients developed symptomatic visual deterioration. Radiat. Oncol. Invest. 90:343-350, 2000. 2000 Wiley-Liss, Inc.

Adenoma↗
PubMedDate not supplied

[Alexia without agraphia, colour "agnosia" and right visual field defect: a syndrome of the posterior cerebral artery (author's transl)].

Two cases of alexia without agraphia are reported, with differences in the characters of the alexia and in the accompanying signs. The visual field defect was limited to quadranopia in both cases which was upper quadrantic and mild in one, lower quadrantic and severe in the other. These differences make it unlikely that a similar anatomical location of the lesion and a unique mechanism are responsible of all cases of alexia without agraphia. Persistance of visual inputs in the right visual field is partial in our cases, but alexia without hemianopsia does exist. These facts are against the mechanism of "splenio-cortical" disconnection proposed by Geschwind as the only explanation. A "cortical", or agnosic mechanism has been also claimed, with lesions of the lingual and fusiform gyri on the dominant side, as well as "subangular", mechanism, with intrahemispheric disconnection by a lesion located between the visual associative areas and the angular gyrus: in these last two situations an hemianopsia is not necessarily associated to the alexia without agraphia.

Agnosia↗
PubMed2001

The paracentral visual field in multiple sclerosis: evidence for a deficit in interneuronal spatial summation?

A visual complaint such as blurred or "washed-out vision" can be one of the early signs of multiple sclerosis (MS). Although visual deficits are commonly attributed to optic nerve demyelination even with preserved visual acuity, the results of a considerable number of visual studies are inconsistent with this interpretation [Camisa, Mylin, & Bodis-Wollner, Annals of Neurology 10 (1981) 532-539; Regan & Neima, British Journal of Ophthalmology 68 (1984) 310-315]. However, a retinal axonal (nerve fiber layer) defect can be detected in some eyes, this is not the rule. Routine visual field (VF) tests, with a low sampling rate may also be non-informative in MS and optic neuritis, possibly because the VF abnormalities may be small and spotty or they can be found between tested points. The present study combined the advantages of VF and contrast sensitivity (CS) testing by applying contrast perimetry (CP), to the central 16 degrees of the VF. Four paracentral VF quadrants were tested in clinically affected and unaffected eyes of 31 MS patients and 26 controls. The stimuli were vertical Gaussian apertured sinusoidal gratings (Gabors) of 1 cpd. CS was obtained as a function of the diameter of the Gábor ranging from 1 to 7.4 degrees. The CP data of controls and definite and probable MS groups were significantly different for each pattern size, but the largest difference was found at diameters 2.5-3.7 degrees. Our study adds to previous evidence showing that optic nerve pathology does not explain "subclinical" and manifest visual dysfunction in MS. Given previous studies revealing orientation dependent monocular visual deficits and our study results, parsimony suggests that MS affects a network relying on myelinated lateral axonal branches of the visual cortex, binding monocular columns of neurons with like-with-like specificity.

Adult↗
PubMed2006

[Multifocal visual evoked potential in retinitis pigmentosa and its comparison with visual field].

PURPOSE: To investigate the characteristics of the multifocal visual evoked potential (mfVEP) and to evaluate the potential of mfVEP as a way of objective perimetry in retinitis pigmentosa (RP). METHODS: The mfVEPs were obtained by using VERIS 4.9 visual evoked response imaging system for 12 RP patients (19 eyes) and 15 normal control subjects (30 eyes). The stimulative field consisted of 60 sectors in a dartboard configuration, the visual angle of one side was 26 degrees. The amplitude sums of P1 wave of the first slice of the second order kernel from patients with RP were compared with values from control subjects. The central 30 degrees visual fields were obtained in the RP patients. Correlation between sensitivity sums of visual field and amplitude sums of P1 wave was performed in the same area. RESULTS: The amplitude sums of P1 wave decreased significantly at all rings in RP group compared with those of normal control group (P < 0.05). Except for inferior ring 1 and inferior ring 2, there was correlation between sensitivity sums of visual field and amplitude sums of P1 wave at the other rings (P < 0.05). CONCLUSION: There was a certain correlation between visual field and mfVEP. The mfVEP can be a method to evaluate visual function objectively in RP.

Adult↗
PubMed1986

[Study of the visual field using automated static perimetry following panretinal photocoagulation in the diabetic].

Twelve diabetic patients presenting a preproliferative or proliferative retinopathy were the subjects of our study. We studied the modifications of the visual fields, analyzed by computerized perimetry, after panretinal photocoagulation (PRP). For every patient, two techniques of PRP were applied, one on each eye: C: conventional scattered treatment, G: cluster technique. Computerized perimetry was done within 10 days prior to PRP, and 4 to 8 weeks following it. We used the Octopus 500, programs 36 (0 to 30 degrees) and 44 (30 to 60 degrees). It appears that, before any treatment, there is a loss of retinal sensitivity excepted the more central zone. Concerning the loss of sensitivity, although the number of laser burns, is greater in group G, there is no statistical significative difference between the 2 groups. Nevertheless, it seems to be more heterogeneous in group G. However, we have not studied the visual field modifications after confluent PRP using up to 5,000 500 micron laser burns. Although there is a loss of retinal sensitivity after PRP, none of our patients complained of it. PRP seems to us to be the only treatment able to prevent the natural evolution of preproliferative or proliferative diabetic retinopathies.

Adult↗
PubMed2005

Diurnal IOP fluctuation: not an independent risk factor for glaucomatous visual field loss in high-risk ocular hypertension.

PURPOSE: To establish whether intraocular pressure (IOP) fluctuations contribute to the risk of developing glaucoma in patients with high-risk ocular hypertension. METHODS: Ninety patients included in the Malmö Ocular Hypertension Study were examined every 3 months with office-hours diurnal tension curves and computerised perimetry. Patients were followed up prospectively for 10 years or until glaucomatous visual field loss could be demonstrated. Poststudy data were included in the analyses, extending maximum follow-up to 17 years. RESULTS: After 17 years, 37 patients had developed glaucomatous visual field defects. When applying univariate Cox regression analyses, mean IOP of all measurements during the prospective part of the study was a significant risk factor for developing glaucoma (95% confidence interval [CI] 1.08-1.39), while IOP fluctuations were almost significant (95% CI 0.98-1.93). When separating effects of mean IOP level and mean IOP fluctuation using Cox multiple regression analysis, only IOP level came out as significant (95% CI 1.09-1.38), and IOP fluctuations did not contribute to the risk (95% CI 0.80-1.60). IOP fluctuation depended linearly on IOP level (p<0.0001), i.e. IOP fluctuation was larger in eyes with higher IOP levels. CONCLUSION: IOP fluctuations were not an independent risk factor for the incidence of glaucomatous visual field loss in subjects with ocular hypertension.

Aged↗
PubMed1994

Errors in the diagnosis of visual field progression in normal-tension glaucoma.

BACKGROUND: Despite strictly defined criteria for visual field progression in the ongoing Normal-tension Glaucoma Study, the authors noted a surprisingly large number of patients reaching the endpoint. Traditional methods could not be used to check the diagnostic accuracy of their criteria, because no "gold standard" was established for distinguishing true change from physiologic long-term fluctuation. METHODS: The authors developed a statistical method based on the results of duplicate tests for progression in their subjects. This method allowed the authors to assess the sensitivity, specificity, and predictive values of their diagnostic criterion. It also estimated the true incidence of progression and provided standard errors for the estimates. RESULTS: The authors found that their original strict criteria for progression, based on duplicate testing, produced false calls of progression 57% of the time. By raising the requirement for deterioration and by repeating the entire sequence of duplicate testing once more, the authors have successfully reduced the rate of false calls to 2%. CONCLUSION: Accuracy in recognizing progression is improved by not accepting small changes as evidence of progression and by confirming the findings on repeat testing.

Diagnostic Errors↗
PubMed1983

Visual fields for frontal plane motion and for changing size.

Thresholds were measured in 15 subjects for 2-Hz oscillations of size and for 2-Hz oscillatory motion in the frontal plane using test squares of side lengths 0.5 degrees, 1.0 degrees and 2.0 degrees. Size-oscillation thresholds were lowest (i.e. sensitivity was greatest) for the 2.0 degrees square while thresholds were highest (i.e. sensitivity was least) for the 0.5 degrees square in 28 of 34 tests. Frontal plane motion thresholds, on the other hand, did not generally depend on square size. Equal-threshold contours in the visual field were roughly elliptical in 10 of 13 subjects for both types of oscillation. None of 13 subjects had visual field defects for oscillating-size or frontal plane motion, in contrast with the known incidence of stereo-motion scotomata. One subject was known to be selectively "blind" to stereoscopically-oscillating disparity in some areas of the visual field, but oscillating-size sensitivity was normal in these regions, thus preserving an alternative basis for motion-in-depth judgments.

Adult↗
PubMed2002

A left visual field advantage in perception of gaze direction.

Previous work has found a left visual field (LVF) advantage for various judgements on faces, including identity and emotional expression. This has been related to possible right-hemisphere specialisation for face processing, and it has been proposed that this might reflect configural processing. We sought to determine whether a similar LVF advantage may also exist for gaze perception. In two experiments, normal adult subjects made judgements for seen gaze direction (left, right or straight). To assess how visual field may influence perception of gaze direction, eye stimuli were briefly presented unilaterally or bilaterally. In the latter case, the gaze direction of the two seen eyes could be congruent or incongruent (i.e. the two eyes could gaze in the same or different directions). For unilateral displays, performance was more accurate for LVF stimuli than RVF. With bilateral incongruent gaze, the LVF eye influenced judgements more strongly than the RVF eye. No such LVF advantage was found in a control experiment, in which subjects judged pupil size for similar eye stimuli. Taken together, these results reveal a LVF advantage for perception of gaze direction. Since only the eye region was visible, our results cannot be due to a LVF bias in processing the entire face context. Instead they suggest lateralisation specifically in processing the direction of seen gaze.

Adult↗
PubMed1988

Experimental induction of an abnormal ipsilateral visual field representation in the geniculocortical pathway of normally pigmented cats.

In the normally pigmented neonatal cat, many ganglion cells in temporal retina project to the contralateral dorsal lateral geniculate nucleus (LGNd) and medial interlaminar nucleus (MIN). Most of these cells are eliminated during postnatal development. If one optic tract is sectioned at birth, much of this exuberant projection from the contralateral temporal retina is stabilized (Leventhal et al., 1988b). To determine how the abnormal projection from the contralateral temporal retina is accommodated in the central visual pathways, neuronal activity was recorded in the visual thalamus and cortex of adult cats whose optic tracts were sectioned as neonates. The recordings showed that up to 20 degrees of the ipsilateral hemifield is represented in the LGNd and MIN. Recordings from areas 17 and 18 of the intact visual cortex showed that up to 20 degrees of the ipsilateral visual field is also represented and that the ipsilateral representation is organized as in a Boston Siamese cat (Hubel and Wiesel, 1971; Shatz, 1977; Cooper and Blasdel, 1980) or a heterozygous albino cat (Leventhal et al., 1985b). The extent of the ipsilateral visual field representation was greater in area 18 than in area 17; the extent of the ipsilateral hemifield representation in areas 17 and 18 varied with elevation, increasing with distance from the horizontal meridian. The receptive fields of cells in the LGNd and visual cortex subserving contralateral temporal retina were abnormally large. Otherwise, their receptive field properties seemed normal. In the same animals studied physiologically, HRP was injected into the ipsilateral hemifield representation in the LGNd and MIN of the intact hemisphere. The topographic distribution of the alpha and beta cells, respectively, labeled by these injections correlated with the elevation-related changes in the ipsilateral visual field representation in areas 18 and 17. Our results indicate that the retinotopic organization of the mature geniculocortical pathway reflects the abnormal pattern of central projections of ganglion cells in neonatally optic tract sectioned cats. Thus, if they do not die, retinal ganglion cells normally eliminated during development are capable of making seemingly normal, functional connections. The finding that an albino-like representation of the ipsilateral hemifield can be induced in the visual cortex of normally pigmented cats suggests that the well-documented defects in the geniculocortical pathways of albinos are secondary to the initial misrouting of ganglion cells at the optic chiasm (Kliot and Shatz, 1985) and not a result of albinism per se.

Albinism↗
PubMed2005

Comparison of visual evoked potentials, automated perimetry and frequency-doubling perimetry in early detection of glaucomatous visual field loss.

The present study compares frequency-doubling perimetry (FDP), automated perimetry (AP) and visual evoked potentials (VEP) for their ability to diagnose early glaucoma. In present study 224 patients of Clinic for Eye Diseases, Clinical Hospital "Sestre Milosrdnice" that had diagnosis of open angle glaucoma and glaucomatous visual field loss proven by automated static perimetry on only one eye were performing all three tests. Visual evoked potentials, automated perimetry and frequency-doubling perimetry were performed four times in each patient with six months period in between testing. Significant difference was proven between frequency-doubling perimetry and automated perimetry in favor for FDP in early detection of glaucomatous field loss. There was no significant difference between FDP and VEP neither between VEP and AP measurements. The results of this study indicate that frequency-doubling perimetry is significantly better method for early detection of glaucomatous visual field loss than automated static perimetry.

Automation↗