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PubMedDate not supplied

Visual fields in glaucoma: a clinical overview.

Static automated visual field testing is now an integral part of the detection and monitoring of primary open angle glaucoma. However, although many aspects of testing are automated, interpretation of the large amounts of data produced by these instruments is not. Two major challenges facing the practitioner are differentiating between the visual fields of a patient with early glaucoma and those of a normal patient, and identifying whether small reductions in sensitivity are due to a true defect or a product of other factors. This paper presents a clinical overview of how to systematically review visual field plots and how to recognise defects arising from patient factors, as well as some of the alternative testing techniques available for the assessment of the glaucoma patient.

Journal Article↗
PubMed1994

Correlation of asymmetry of visual field loss with optic disc topography in normal-tension glaucoma.

OBJECTIVE: To compare the differences in optic disc configuration with different stages of visual field loss in normal-tension glaucoma. DESIGN: Interocular pairwise comparisons. SETTING: Glaucoma clinic of a teaching hospital. PATIENTS: Thirteen patients with normal-tension glaucoma and asymmetric visual field loss of at least 2.5 dB in the mean defect of the visual field indexes. INTERVENTIONS: Areas under the optic disc profiles mapped from values for radial sections of the optic disc measured at intervals of 30 degrees and expressed as percentages of the area of a rectangle were obtained from stereophotographs with a computerized image analysis system. Visual fields were tested with automated perimetry (OCTOPUS), using program G1. MAIN OUTCOME MEASURE: Correlation analyses between the interocular differences in the areas under the optic disc profile and the interocular differences in the visual field indexes. RESULTS: The correlation coefficients between the interocular differences in mean defect and those of the area under the optic disc profile in the superior to temporal sections ranged from -.71 to -.61 (.007 < P < .028). The interocular differences in loss variance correlated with the differences in the area under the optic disc profile in the superior section (r = -.61, P = .0252). CONCLUSION: The differences in visual field loss between the two eyes in normal-tension glaucoma appear mainly to reflect morphometric changes in the superior half of the optic disc.

Aged↗
PubMed1987

Optic nerve dysfunction during gravity inversion. Visual field abnormalities.

Inversion in a head-down position (gravity inversion) results in an intraocular pressure of 35 to 40 mm Hg in normal subjects. We used computerized static perimetry to measure the visual fields of normal subjects during gravity inversion. There were no visual field changes in the central 6 degrees of the visual field compared with the baseline (preinversion) values. However, when the central 30 degrees of the visual field was tested, reversible visual field defects were found in 11 of 19 eyes. We believe that the substantial elevation of intraocular pressure during gravity inversion may pose potential risks to the eyes, and we recommend that inversion for extended periods of time be avoided.

Adult↗
PubMed1989

Different patterns of retinal correspondence in the central and peripheral visual field of strabismics.

We tested the state of retinal correspondence at different positions in the visual field of ten observers with strabismic and/or anisometropic amblyopia, four strabismic subjects with alternating fixation and three normal controls. Correspondence was evaluated by the subjective displacement of dichoptic stimuli; to estimate the displacement, we used red-green filters, Bagolini striated glasses, polarizing filters and a phase-difference haploscope. Strabismic observers (amblyopes and alternators) frequently showed variations in the angle of anomaly (ie, the amount of shift of space coordinates in the squinting eye) between different regions of the visual field. Correspondence tended to be closer to normal in the central field and more anomalous in the periphery. These findings cannot be explained by the progressive loss of localization sensitivity with increasing eccentricity. We suggest that the different patterns of retinal correspondence in the central and peripheral visual field of some strabismic observers might be due to a mechanism of selective stabilization of binocular connections in the peripheral visual field, where the larger corresponding areas overcome a limited misalignment of the eyes. In the central visual field, normal correspondence is preserved, and diplopia has to be prevented by interocular suppression.

Adolescent↗
PubMed1999

Does rate of stimulus presentation affect measured visual field extent in infants and toddlers?

PURPOSE: To evaluate the effect of stimulus presentation rate on the measurement of visual field extent in infants and toddlers. METHODS: Visual field extent was measured for 300 children (N = 60 at 3.5, 7, 11, 17, and 30 months) and 24 adults using hybrid static-kinetic perimetry. Flickering light-emitting diode (LED) stimuli were illuminated sequentially, peripherally to centrally at 10.2 degrees intervals, along 4 diagonal meridia at 2 stimulus presentation rates: 2 s/stimulus (equivalent to 5 degrees/s) and 3 s/stimulus (equivalent to 3 degrees/s). Rate of presentation was a between-subjects variable. RESULTS: No effect of stimulus presentation rate was found for adults. The faster rate of stimulus presentation yielded smaller measured visual field extent for children between the ages of 7 and 30 months. The apparent difference seen with 3.5-month-olds did not reach significance. CONCLUSIONS: Faster rates of stimulus presentation may result in underestimation of visual field extent in children between the ages of 7 and 30 months.

Adolescent↗
PubMed2006

Asymmetric visual field loss and retrobulbar haemodynamics in primary open-angle glaucoma.

PURPOSE: To investigate interocular differences in retrobulbar flow velocities in patients with asymmetric glaucomatous visual field loss. METHODS: Twenty-five patients with primary open-angle glaucoma (POAG) and asymmetric visual field loss were included in this study. Asymmetric visual field loss was defined as a difference of the global index mean deviation (MD) >6 dB between the two eyes. Flow velocities (peak systolic velocity PSV and end-diastolic velocity EDV) and resistive indices (RI) of the ophthalmic artery (OA), central retinal artery (CRA), and nasal and temporal posterior ciliary arteries were measured by means of colour Doppler imaging. RESULTS: MD of eyes with more severe glaucomatous visual field loss was -18.3+/-7.8 dB vs -6.8+/-5.5 dB (p<0.0001) in the less affected eyes. The PSV and the EDV of the CRA and the PSV of the OA were significantly decreased in eyes with more severe glaucomatous visual field loss (CRA PSV: 7.6+/-2.0 cm/s vs 8.3+/-1.7 cm/s, p=0.04; CRA EDV: 2.24+/-0.5 cm/s vs 2.55+/-0.6 cm/s, p<0.007; OA PSV: 29.7+/-9.9 cm/s vs 32.7+/-11.5 cm/s, p<0.02). None of the other differences in velocity or resistive index were significant. CONCLUSIONS: Patients with asymmetric glaucomatous visual field loss exhibit asymmetric flow velocities of the CRA and OA. Patients with more severe damage display reduced flow velocities in retrobulbar vessels in POAG.

Blood Flow Velocity↗
PubMed1987

Shift of visual field advantage by learning experience of foreign words.

Effects of Hebrew words learning on visual field advantage were examined with Japanese subjects. Subjects who showed no visual field advantage to Hebrew words in the first testing were assigned randomly into four experimental groups; learn pronunciation only, learn meaning only, learn both pronunciation and meaning, and learn nothing. After then, subjects were re-tested for Hebrew words discrimination. A right visual field advantage appeared in both pronunciation only and pronunciation plus meaning groups. These results suggest that mastery of pronunciation seems to be a crucial factor in producing a shift of visual field advantage.

Female↗
PubMed1988

Area of visual field and colour discrimination combined as a predictor of chronic open-angle glaucoma.

Area of visual field and colour discrimination were assessed in 167 eyes with ocular hypertension (from 100 women and 67 men with a mean age of 59.8 +/- 11.3 years). The patients were then followed for 3 years. During the follow-up period chronic open-angle glaucoma was diagnosed in 8 (8%) of the 100 eyes with a normal visual field and normal colour discrimination, 7 (14%) of the 50 eyes with a subnormal visual field or subnormal colour discrimination, and 17 (100%) of the 17 eyes with both a subnormal visual field and subnormal colour discrimination, a total of 32 eyes (19%). Our results suggest that chronic open-angle glaucoma develops early in ocular hypertensive eyes in which both the visual field and colour discrimination are subnormal. Glaucoma may not develop at all in eyes with normal values.

Adult↗
PubMed2002

[Development of an automatic discrimination system for glaucomatous visual fields based on neuro-fuzzy nets].

PURPOSE: To provide a useful tool in the diagnosis of glaucoma by developing an automatic system for visual field classification based on neuro-fuzzy rules. METHOD: A total of 212 visual fields (OCTOPUS 123 program G1X), from 198 patients, were analysed: 61 normal (controls) and 151 with glaucomatous damage (49% with incipient damage, 29.1% with moderate damage, and 21.9% advanced). Inclusion criteria for glaucomatous patients were: Visual acuity >0.5, IOP < 20 mm Hg (with treatment), refraction <5 Dp and previous perimetric experience. EXCLUSION CRITERIA: miotics, other ocular pathologies which could interfere with visual field examination, and for control subjects: visual acuity >0.5, no ocular pathologies and refraction < 5 Dp. A neuro-fuzzy classifier (NEFCLASS) is a system consisting in a series of fuzzy rules, obtained after a learning process, which attempts to assign to each piece of data input its corresponding output. Initially, the characteristics of each data input are established (input units). Then, based on previous knowledge, a set of rules are defined, and finally, the learning process allows the optimisation of the classifier parameters to generate an output. RESULTS: Input units were defined by using the mean defects calculated at specific areas of the visual field; five rules were then created which generated sensitivity and specificity values of 96.0% and 93.4% respectively. CONCLUSIONS: The use of neuro-fuzzy rules for visual field classification in normal vs glaucomatous can provide results which can match the quality of those obtained with other techniques such as discriminatory analysis or neural networks.

Aged↗
PubMed1999

Altering the pattern of panretinal photocoagulation: could the visual field for driving be preserved?

PURPOSE: To identify the area of retina required to provide the visual field for driving and to investigate whether the pattern of panretinal photocoagulation (PRP) for proliferative diabetic retinopathy could be altered to avoid treatment in this area whilst leaving the total number of burns constant. METHODS: A mathematical model of the emmetropic eye is used to calculate retinal dimensions corresponding to different angles of visual field. These are used to define retinal regions that correspond to the UK DVLC visual field criteria and regions that lie outside this area. Further calculation estimates the number of laser burns applied within these regions for both 500 microns and 200 microns diameter spot sizes and various burn spacings. RESULTS: Modelling of the number of burns applied in the normal pattern of PRP agrees with the number required to control proliferative retinopathy. Reducing burn spacing or extending treatment up to the ora serrata allows application of sufficient burns to control the disease without encroaching on areas of the retina that provide the driving field. CONCLUSION: It is theoretically possible to alter the pattern of PRP to avoid treatment in retinal areas concerned with the driving visual field whilst leaving the total number of burns constant. This suggests that a clinical trial of such a pattern PRP could be performed to assess adequate control of proliferative retinopathy along with preservation of the visual field required for driving.

Automobile Driving↗
PubMed2004

The lateralized emotional stroop task: left visual field interference in women.

In a visual hemifield emotional Stroop task, 54 women were asked to name the color of laterally flashed emotional and neutral words while ignoring their semantic content. Vocal reaction times for color naming were recorded. The participants exhibited significant emotional interference effects in the left visual field, which tended to be larger for negative words than for positive words. Participants with higher trait anxiety scores exhibited larger interference for positive words in the left relative to the right visual field. The outcome indicates that, in women, emotional Stroop interference arises in the right rather than in the left hemisphere, with a larger impact of negative than of positive words, and with trait anxiety modulating the lateralized interference for positive words.

Adolescent↗
PubMed2006

Visual field defects and retinal nerve fiber layer defects in eyes with buried optic nerve drusen.

PURPOSE: To evaluate the visual field with the use of automated perimetry and to evaluate the retinal nerve fiber layer (RNFL) with optical coherence tomography (OCT) in patients with buried optic nerve drusen (OND). DESIGN: Observational case control study. METHODS: Eyes with buried OND were defined as eyes with ultrasound-proved drusen that were not visible with indirect slit-lamp biomicroscopy. All eyes underwent automated perimetry. Some eyes underwent OCT to evaluate the RNFL. RESULTS: Fifty-eight eyes of 41 patients with buried OND were evaluated. Three eyes (5%) had inferior arcuate scotomas. The other 55 eyes did not have visual field defects. Twenty-one of the eyes without visual field defects underwent RNFL analysis with OCT. All 21 eyes had normal average RNFL thickness. Some eyes had focal RNFL defects, but it is not clear whether these defects were clinically significant. CONCLUSION: Visual field defects are uncommon in eyes with buried OND. Eyes with buried OND may have focal RNFL defects but have normal average RNFL thickness. In patients with buried OND and a visual field defect, consideration should be given to searching for other causes of the defect, especially if the defect is substantial.

Adolescent↗
PubMed1976

Effects of concurrent verbal memory on recognition of stimuli from the left and right visual fields.

Two experiments examined the effect of concurrently holding 0, 2, 4, or 6 nouns in memory on the recognition of visual stimuli briefly presented to the left or right visual fields. When stimuli to be visually recognized were complex visuospatial forms it was found that a relatively easy memroy load of 2 or 4 nouns improved visual recognition accuracy on right visual field (left-hemisphere) trials relative to the no-memory condition; however, a more difficult memory load of 6 nouns decreased visual recognition accuracy to a level slightly below the no-memory condition. There were no effects of concurrent verbal memroy on visual form recognition on left visual field (right-hemisphere) trials. When the stimuli to be visually recognized were words it was found that a relatively easy memroy load of 2 or 4 nouns improved visual recognition accuracy and a more difficult load of 6 nouns decreased visual recognition accuracy on both left and right visual field trials. The complete pattern of results indicates that several factors including cerebral hemisphere specialization, stimulus codability, selective perceptual orientation, and selective cerebral hemisphere interference interact in systematic ways to produce overall visual laterality effects.

Dominance, Cerebral↗
PubMed1976

Binocular visual field in strabismus.

The binocular visual field of 100 patients with a variety of manifest strabismus was analysed using a complex visual environment and polaroid dissociation. A significant area of the picture, both nasal and temporal to fixation, was suppressed by all patients. Eighty-nine per cent showed correct localisation and identification in an area which was not suppressed and was approximately 45 prism dioptres peripheral to fixation.

Humans↗
PubMed1981

[Effects of the unilateral cerebral activation by nonverbal loading on stimulus detection in each visual field (author's transl)].

The relation between the activation level of hemisphere and the laterality of visual detection was investigated under nonverbal loading conditions. In Exp. I, 10 (6 male and 4 female) right handed college students made "same-different" judgements for pairs of random forms (4th, 8th, and 12th polygons) serially presented. In Exp. II, another 10 (5 male and 5 female) subjects responded to similar with different association values. The main findings were as follows: (a) A test stimulus (8th polygon) was recognized more accurately in the left visual field, but this was due to the poor performance in the right visual field, (b) the factor of association value did not influence the visual field superiority, and (c) the task difficulty may be sole factor responsive to the visual field superiority. These results suggested that the visual laterality effects occurred only when the level of hemispheric loading was optimal.

Adult↗
PubMed2005

Pointwise linear regression for evaluation of visual field outcomes and comparison with the advanced glaucoma intervention study methods.

OBJECTIVE: To investigate pointwise linear regression (PLR) for longitudinal evaluation of visual fields and to compare results with those of the Advanced Glaucoma Intervention Study (AGIS) criteria. METHODS: We selected 509 eyes (401 patients) from the AGIS with 3 or more years of follow-up, 7 or more visual field examinations, and an AGIS reference score of 16 or lower. Visual field change at test locations was defined as a change of threshold sensitivity of 1 dB/y or higher and P<or=.01. Several sets of criteria were investigated for defining change of visual field series with PLR. MAIN OUTCOME MEASURES: Progression or improvement of visual field series with PLR and AGIS criteria. RESULTS: Mean (SD) follow-up time and baseline AGIS score were 7.4 (1.7) years and 7.7 (4.4), respectively. Pairwise agreement between AGIS and various PLR criteria ranged from 52% to 64% with the kappa statistic varying between 0.22 (95% confidence interval, 0.15-0.29) and 0.30 (95% confidence interval, 0.22-0.38). One hundred thirty-eight (27%) and 151 (30%) eyes progressed (85 eyes or 17% detected by both methods) while 72 (14%) and 11 (2%) eyes improved (5 eyes or 1% detected by both methods) based on AGIS and the most rigorous PLR criteria, respectively. CONCLUSIONS: Based on rigorous, clinically relevant criteria, PLR detects progression in a similar proportion of eyes compared with AGIS criteria. Pointwise linear regression may be superior to AGIS methods since it identifies fewer visual field series as improving.

Adult↗
PubMed1989

Unequal intraocular pressure and its relation to asymmetric visual field defects in low-tension glaucoma.

Fifty-nine low-tension glaucoma patients were reviewed with respect to asymmetry of intraocular pressure (IOP) and visual field defects. In the presence of unequal IOP the visual field damage is almost always greater on the side with higher mean IOP. However, only 13 of 47 patients with asymmetric visual field defects had a mean IOP difference between the two eyes of greater than or equal to 1 mmHg. Although in the case of IOP asymmetry visual field damage is greater in the eye with higher mean IOP, other factors must also play an important role in the development of visual field defects in low-tension glaucoma.

Glaucoma↗