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1. Automated visual fields are psychophysiologic tests that require attention to details for accuracy. 2. Glaucoma visual field defects reflect the local anatomy of the optic disc. 3. Visual fields in neuro-ophthalmology reflect pathology of the visual pathways and are important in diagnosis.
Recent research has shown that the useful visual field deteriorates in simulated car driving when the latter can induce a decrease in the level of activation. The first aim of this study was to verify if the same phenomenon occurs when driving is performed in a simulated road traffic situation. The second aim was to discover if this field also deteriorates as a function of the driver's age and of the vehicle's speed. Nine young drivers (from 22 to 34 years) and nine older drivers (from 46 to 59 years) followed a vehicle in road traffic during two two-hour sessions. The car-following task involved driving at 90 km.h(-1) (speed limit on road in France) in one session and at 130 km.h(-1) (speed limit on motorway in France) in the other session. While following the vehicle, the driver had to detect the changes in colour of a luminous signal located in the central part of his/her visual field and a visual signal that appeared at different eccentricities on the rear lights of the vehicles in the traffic. The analysis of the data indicates that the useful visual field deteriorates with the prolongation of the monotonous simulated driving task, with the driver's age and with the vehicle's speed. The results are discussed in terms of general interference and tunnel vision.
Ambiguity in the description of visual fields arises when a field measurement is specified as a number of degrees, without any reference to the measurement as a radius or diameter. Examples of confusing field descriptions in current literature are cited, with a recommendation for improved visual field notation.
The authors analysed the cases of 13 patients, operated upon for chronic glaucoma with marked visual-field defects. The visual field was examined with a Zeiss spherical perimeter. The field area was calculated in cm2 by planimetric method before the operation and then some months after it, and the obtained results were compared. Special attention was paid to vascular disturbances. In most patients with regular vascular system, post-operative examination had revealed an increase of the visual field. The best results were obtained in patients with medium-size defects: in these cases the increase in the visual field amounted to ca. 33%. The authors recommended proceeding to operative treatment in glaucoma patients without delay whenever there are defects in the visual field, even when they are very pronounced.
Human visual cortex is organized into distinct visual field maps whose locations and properties provide important information about visual computations. There are two conflicting models of the organization and computational role of ventral occipital visual field maps. We report new functional MRI measurements that test these models. We also present the first coordinated measurements of visual field maps and stimulus responsivity to color, objects and faces in ventral occipital cortex. These measurements support a model that includes a hemifield map, hV4, adjacent to the central field representation of ventral V3. In addition, the measurements demonstrate a cluster of visual field maps in ventral occipital cortex (VO cluster) anterior to hV4. We describe the organization and stimulus responsivity of two new hemifield maps, VO-1 and VO-2, within this cluster. The maps and stimulus responsivity support a general organization of visual cortex based on clusters of maps that serve distinct computational functions.
The accuracy for both a color-naming and a color-matching task as a function of visual field and sex was investigated in preschool children. Subjects were 17 boys and 17 girls ranging in age from 4.4 to 5.6 yr. Each subject was tested on both tasks, for which the target stimuli were presented tachistoscopically. Accuracy measures for each task were obtained separately for both left and right visual fields. A two-factor (sex x visual field) analysis of variance with repeated measures on the visual-field factor showed a significant difference between the sexes on the color-naming task only. No significant difference between visual fields was found for either task. However, significant interactions between sex and visual field for both the color-naming and color-matching tasks were obtained. t tests for simple main effects showed a significant right visual-field advantage for girls in naming colors. Conversely, a significant left visual-field advantage for color-matching was found for boys. Also, on the color-matching task, significant sex differences were found for both visual fields when compared separately. Boys were more accurate for left and girls more accurate for right visual field. Boys performed in a more strongly lateralized fashion on the color-matching task than did the girls, supporting the notion of greater lateralization among males.
PURPOSE: To assess the screening efficacy and practical use of two portable devices to detect moderate to severe visual field loss rapidly in population screening. METHODS: Henson visual field analysis and Damato campimetry for glaucoma were performed in a healthy adult population, to determine false-positive rates; in established glaucoma patients and suspects, to determine false-negative rates; and in a general adult population, to assess practical use in actual screenings. RESULTS: There were no false-positive test failures among the 82 normal subjects who completed the Henson two-step screening. Eighty of 83 normal subjects passed Damato campimetry, resulting in a false-positive rate of 3.6%. Among 83 glaucoma suspects and patients, the Henson test identified 49 (84%) of 58 subjects whose full-threshold fields from Humphrey perimetry were abnormal, 38 (97%) of 39 of whom had moderate to severe visual field loss. The Damato campimeter detected 55 (81%) of 68 subjects with any pathologic loss on full-threshold visual fields, 44 (92%) of 48 of whom had moderate to severe visual field loss. Among 1,278 subjects tested in general population screenings, 55 subjects (4.3%) failed either or both tests. CONCLUSIONS: The Henson visual field analyzer can discriminate moderately to severely diseased from normal visual fields with high sensitivity and specificity. The Damato campimeter can reliably detect moderate to severe visual field loss with a tolerably low false-positive rate. To overcome the weakness of glaucoma screening by tonometry alone, some forms of visual field testing may be acceptably brief (cost effective) and accurate (sensitive and specific).
OBJECTIVE: To investigate the correlation of different parameters of intraocular pressure (IOP) to visual field decay in open-angle glaucoma. DESIGN: Analysis of visual field decay during a prospective, randomized clinical trial comparing primary laser trabeculoplasty with medication. PARTICIPANTS: Of a total of 82 included eyes in 82 patients with newly detected high-pressure open-angle glaucomas, 76 (55 capsular, 21 simple) fulfilled the 2-year follow-up with the stated number of reliable visual field examinations and were included in this analysis. INTERVENTION: Automated perimetry and a daytime IOP curve were taken every second month during the 2-year follow-up. MAIN OUTCOME MEASURES: Six IOP parameters were evaluated and correlated to visual field outcome. The subgroups with the two types of glaucoma (capsular and simple) were analyzed separately. RESULTS: Visual field decay showed greater correlation to IOP variation (range and peak) and mean IOP than IOP at start or degree of IOP reduction. The relation between mean IOP and visual field decay in the whole group was not quite linear, with more decay at higher IOP levels. The association between IOP regulation and visual field decay was most pronounced in capsular glaucoma, whereas the results in the small group of simple glaucomas were inconclusive. CONCLUSIONS: Visual field prognosis in high-pressure open-angle glaucoma, essentially capsular glaucoma, is better in patients with smaller IOP variation and poorer in patients with high mean IOP.
Visual prognosis is a crucial theme in the counselling of individuals affected by a progressive retinal dystrophy. Unfortunately prognostic predictions are hampered by large interindividual differences in disease courses even within well defined nosological entities. Ten patients from 8 families affected by choroideremia were studied. The clinical signs in our patients were rather uniform. Deterioration of the peripheral visual fields typically began in the second decade of life, and progressed during the following one or two decades. Esterman transformation of peripheral visual field measurements was chosen as the best single indicator of visual impairment. Noticeable age differences in residual visual fields among patients were demonstrated. The age difference between the mildest and the severest cases amounted to 25 years. One of the expectations of the exploration of disease genes, is the potential predictive value of mutation identification with regard to phenotypic variability. Different presumed causative mutations were identified. Nevertheless, all the mutations are predicted to cause premature stops during translation, resulting in a non-functional or missing protein. Consequently, the observed age variation in the photopic visual field degradation must be due to still unrecognized factors, either constitutional and/or environmental.
Homonymous visual field defects usually occur with structural processes affecting retrochiasmal visual pathways. The responsible lesion is usually evident on magnetic resonance imaging or on other neuroimaging studies. When results of neuroimaging are normal, functional illness is often suspected. The authors report four patients with homonymous visual field defects who presented with no evident corresponding lesion on magnetic resonance or computed tomography imaging. Etiologies for the visual field defects included the Heidenhain variant of Creutzfeldt-Jacob disease, degenerative dementia, subtle occipital ischemia demonstrated only on positron-emission tomography scanning, and nonketotic hyperglycemia. Clinicians should be aware of the alternative etiologies of organic homonymous visual field loss in patients with normal neuroimaging.
PURPOSE: To compare two fast threshold strategies of visual field assessment; SITA Fast (HSF) and Tendency Orientated Perimetry (TOP), in detecting visual field loss in patients with glaucoma. METHODS: Seventy-six glaucoma, ocular hypertensive and normal patients had HSF and TOP performed in random order. Quantitative comparisons for the global visual field indices - mean deviation and defect (MD) for HSF and TOP, and pattern standard deviation (PSD) for HSF and loss variance (LV) for TOP - were made using correlation coefficients. Humphrey global parameters were converted to Octopus equivalents, and method comparison analysis was used to determine agreement between the two strategies. Test duration times were compared using t-test. Sensitivity and specificity for these two algorithms were determined according to predetermined criteria. RESULTS: High correlation coefficient values were obtained for MD measurements between HSF and TOP ( r=-0.89, P<0.0005) and for PSD (HSF) and LV (TOP) ( r=0.88, P<0.0005). Following conversion of HSF values to Octopus equivalents the TOP strategy estimated MD to be greater and LV to be less than HSF values, the difference increasing as the magnitude of the defect increased. The mean test duration time was 4.04 (0.87) min for HSF and 2.38 (0.34) min for TOP ( P<0.0005). Sensitivity of diagnostic criteria ranged from 86.4% to 89.2% for HSF and from 84.7% to 85.2% for TOP. Specificity ranged from 80.0% to 93.8% for HSF and from 76.5% to 86.7% for TOP. CONCLUSION: There was a high correlation between the HSF and TOP strategies for measurements of global indices. However, the TOP strategy tended to underestimate focal visual field loss compared with SITA Fast. The TOP strategy was faster than SITA Fast. The sensitivity and specificity of the two algorithms were similar. This study establishes the ability of these fast strategies to successfully assess visual fields in glaucoma patients with perimetric experience.
PURPOSE: To evaluate intraocular pressure (IOP) variations after automated visual field examination in patients with primary open-angle glaucoma and in healthy subjects. PATIENTS AND METHODS: Intraocular pressure was measured in 49 patients (94 eyes) with primary open-angle glaucoma and in 13 healthy subjects (26 eyes) before and immediately after automated visual field examination. All patients had stable IOP and were using local medication to treat glaucoma. The visual field test was performed with a Humphrey 630 VF analyzer and the Central 30-2 full-threshold program. RESULTS: Mean IOP increased significantly in glaucomatous patients immediately after automated visual field examination (P < 0.01), and returned to pretest values after 1 hour (P = 0.2). Mean IOP variation was 2.38 (range, -6-11) mm Hg. In 42 (44.68%) glaucomatous eyes, IOP increased more than 2 mm Hg, with a mean increase of 5.5 mm Hg. Elderly glaucoma patients showed a significantly higher IOP rise than younger patients. No significant IOP variation was detected in healthy subjects. CONCLUSION: Intraocular pressure varied significantly and tended to increase immediately after automated visual field examination in patients with primary open-angle glaucoma. Age seemed to contribute to these IOP changes, but other factors could be involved.
The visual field records of 45 eyes of 45 patients were evaluated to determine whether examination of the peripheral field of vision in patients with glaucoma and field defects adds useful information about the progression of visual field damage. The central scotoma mass, foveal sensitivity, and the central and peripheral mass of the visual field were quantified from measurements on the Tübinger perimeter. Most of the information on visual field progression was contained in the scotoma mass. When both scotoma mass and foveal sensitivity were known, central or peripheral isoptres did not add statistically significant information on progression. Evaluation of scotomas and assessment of central isoptres or of foveal sensitivity made perimetry of the peripheral isoptres redundant. The appearance of fresh peripheral scotomas or the quantification of changes in peripheral scotomas was not examined in the current study, and they would of course be important when they occurred.
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PURPOSE: To evaluate the clinical value of fixed visual field examination on thyroid-associated ophthalmopathy patient. METHODS: The fixed visual field examination was conducted on 27 thyroid-associated ophthalmopathy patients. RESULTS: When the ocular-motor deficit ratio is less than value -4, the patient's fixed visual field is between 0-15 degree; when the ocular-motor deficit ratio is less than value -3, the patient's fixed visual field is between 18-28 degree; when the ocular-motor deficit ratio is less than value -2, the patient's fixed visual field is between 28-38 degree; when the ocular-motor deficit ratio is less than value -1, the patient's fixed visual field is between 40-43 degree; when the ocular-motor system is normal, the patient's fixed visual is between 45-50 degree. CONCLUSION: The results from the fixed visual field examination can give direct and accurate evaluation on how and where the ocular muscle has been affected by the thyroid-associated ophthalmopathy.
OBJECTIVES: To investigate the effect of visual field defects on driving performance, and to predict practical fitness to drive. METHODS: The driving performance of 87 subjects with visual field defects due to ocular abnormalities was assessed on a driving simulator and during an on-road driving test. OUTCOME MEASURES: The final score on the on-road driving test and simulator indexes, such as driving speed, viewing behavior, lateral position, time-headway, and time to collision. RESULTS: Subjects with visual field defects showed differential performance on measures of driving speed, steering stability, lateral position, time to collision, and time-headway. Effective compensation consisted of reduced driving speed in cases of central visual field defects and increased scanning in cases of peripheral visual field defects. The sensitivity and specificity of models based on vision, visual attention, and compensatory viewing efficiency were increased when the distance at which the subject started to scan was taken into account. CONCLUSIONS: Subjects with visual field defects demonstrated differential performance on several driving simulator indexes. Driving examiners considered reduced speed and increased scanning to be valid compensation for central and peripheral visual field defects, respectively. Predicting practical fitness to drive was improved by taking driving simulator indexes into account.
Little is known about the relation between diurnal variations of intraocular pressure (IOP) and prognosis for glaucomatous visual field damage. The association between apparent progressive loss of visual field and the occurrence of IOP peaks was studied. Pressure peaks were detected by a self-tonometer in the natural environment of patients with glaucoma. The study groups consisted of patients with and without a strong indication of progressive visual field losses, all with IOPs of 22 mm Hg or less obtained in the ophthalmologist's office. Patients apparently undergoing progressive visual field loss were found to have significantly more frequent IOP peaks than patients with stable visual fields. A statistical evaluation indicated that, in a population with a 30% prevalence of progressive loss of visual field, 75% of the patients with peaks have progressive loss and 75% of those without peaks do not have visual field progression. Intraocular pressure peaks were thus shown to have an association with the apparent progression of vision loss independent of the mean IOP. Home tonometry appeared to be a promising tool for identifying patients at increased risk of developing visual field loss who may require intensified follow-up and an alteration in clinical management. However, the present study must be complemented by a prospective study.
PURPOSE: To evaluate the association between quantitative nerve fiber layer measurements and visual field loss in patients with primary open-angle glaucoma. METHODS: Quantitative retinal nerve fiber layer measurements were obtained in 53 patients with primary open-angle glaucoma by using confocal scanning laser ophthalmoscopy (cross-section area) and confocal scanning laser polarimetry (retardation ratio). For each eye, three images were obtained with each instrument. An image that was the mean of those three was created and used in all analyses. We investigated the association between global, regional, and hemifield differences in retinal nerve fiber layer measurements and visual field loss with linear regression techniques. RESULTS: The retardation ratio decreased with increasing mean visual field loss, measured both globally and regionally; R2 (the amount of variation explained by the model) ranged from 8% to 21%. Retinal nerve fiber layer cross-section area was not significantly associated with global measures of visual field loss. The inferior visual field mean deviation increased with decreasing superior retinal nerve fiber layer cross-section area (R2 = 8.2%, P = .04); superior visual field mean deviation was not associated with inferior retinal nerve fiber layer cross-section area (R2 = 2.6%, P = .25). Hemifield differences in visual field mean deviation increased with increasing hemifield differences in retinal nerve fiber layer cross-section area (R2 = 20.0%, P < .001), but not with retardation ratio (R2 = 0.9%, P = .48). CONCLUSIONS: Quantitative measures of the retinal nerve fiber layer using both confocal scanning laser ophthalmoscopy and confocal scanning laser polarimetry were correlated with visual field loss in glaucoma patients.