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A visual field screening protocol for glaucoma.

In this prospective evaluation of the reliability and efficiency of an optimized visual field screening protocol for glaucoma, we tested 145 eyes (73 patients) with increased intraocular pressures to determine the location of early glaucomatous visual field defects. The field examination, which was used as a control, and protocol testing were performed on a manual Goldmann perimeter using kinetic and suprathreshold static techniques, respectively. Of the 145 eyes tested, kinetic Goldmann perimetry detected 43 eyes with glaucomatous defects. The screening protocol detected 39 defective eyes. There were four false-negative tests and one false-positive test. The false-negative rate of just under 10% was within the range predicted from earlier data. The computer-generated optimal protocols performed as predicted and provided an excellent screening technique for the detection of early glaucomatous visual field defects.

Clinical Trials as Topic↗

Predicting subsequent visual field loss in glaucomatous subjects with disc hemorrhage using retinal nerve fiber layer polarimetry.

PURPOSE: To predict progression of visual field loss after an episode of disc hemorrhage in glaucoma patients on the basis of retinal nerve fiber layer (RNFL) GDx polarimetry measurements analyzed by wavelet-Fourier analysis (WFA). METHODS: Retrospective GDx data from 16 subjects (10 progressors and 6 non-progressors based on visual fields) obtained near the time of disc hemorrhage were analyzed to predict which patients would have visual field progression. Polarimetry scans throughout a follow-up period (31 months average) were also analyzed to compare field progression to RNFL thickness change after the hemorrhage. Mean RNFL thickness inferred from the polarimetry data at sixteen 22.5 degrees sectors at distances of 1.6, 1.7, and 1.8 disc diameters were used. Data were analyzed by applying to appropriate regions of disc hemorrhage patients a structural analysis (WFA) we had developed previously. A linear discriminant function (Fischer) was produced and a leave-one-out method using separate training and test data was used to assure validity of the results. RESULTS: Patients who subsequently progressed were successfully predicted with moderate success (sensitivity / specificity was 0.77 / 0.88 with ROC area = 0.858). A separate analysis comparing pre- and post-hemorrhage RNFL sector thickness revealed clear evidence of RNFL thinning at the inferior and superior sectors before progression of visual field. The thinning of RNFL thickness was not restricted to regions corresponding to the location of the hemorrhage. CONCLUSION: Wavelet-Fourier analysis can differentiate progressors from non-progressors with moderate accuracy. Comparison to a prior study of this same cohort emphasizes that relatively small regions must be considered (as opposed to larger quadrants) to see these significant changes in RNFL.

Aged↗

Influence of elderly executive cognitive function on attention in the lower visual field during step initiation.

BACKGROUND: There is a well-established relationship between poor executive cognitive abilities and elderly fall risk, but the precise mechanism underlying this relationship is unknown. Older persons frequently fall or trip on objects below eye level, and it was hypothesized that the pathological mechanism linking low executive function and fall risk is a selective impairment in the resolution of visual attention in the lower visual fields. OBJECTIVE: To determine if normally sighted older persons living in the community with deficits in executive cognitive abilities have a reduced resolution of visual attention in the lower visual fields compared to elderly and younger subjects with high executive abilities. METHODS: Eye and head angulations were monitored as subjects fixated on a point rear-projected at eye level at the end of a 3- meter walkway. Visual stimuli were briefly presented (<300 ms) in the peripheral visual field (with and without distractors) to directly cue the selection of the right or left foot to lead a step over a foam obstacle resting at the subject's feet. No saccades were allowed until the stimulus was extinguished, at which time a down-saccade-step sequence moved the foot over the obstacle. The resolution of visual attention (tested with gratings) and the influence of target eccentricity in the upper and lower visual fields were evaluated. The primary outcome measures were step error and obstacle contact rate, saccade occurrence after extinguished stimulus and the log of cue-saccade latency (limb-independent reaction time). RESULTS: All groups experienced greater stepping errors than expected by chance when stimuli were presented in the lower versus upper visual field and with increasing eccentricity. However, the obstacle contact rate was greater, cue-saccade latency was prolonged, and fewer down-saccades were generated in the elderly group with poor executive abilities compared to those with high executive function and younger subjects. CONCLUSIONS: Loss of visual attention in the lower visual fields was not unique to elderly subjects with poor executive function. However, slowed processing time and reduction in the frequency of down-saccades associated with a low level of executive function potentially account for the mechanism linking executive abilities and fall risk.

Accidental Falls↗

Visual fields in patients who have undergone vitrectomy for complications of diabetic retinopathy. A prospective study.

BACKGROUND: To determine the extent of visual field loss in patients who had required a pars plana vitrectomy secondary to complications of proliferative diabetic retinopathy. METHODS: Patients that had undergone a vitrectomy on at least one eye for treatment of either vitreous haemorrhage or tractional retinal detachment were selected for study. ETDRS acuity and Humphrey binocular Esterman visual field testing were performed and compared to the minimum standards for safe driving as defined by the Royal College of Ophthalmologists in 1999. In addition to this Goldman kinetic visual fields using a III4e and V4e stimulus size and central 24-2 threshold test with the SITA-fast strategy were performed on the vitrectomised eye. RESULTS: 20 patients (n = 20) were recruited. Mean visual acuity in the eye being tested was 0.20 (Snellen 6/9.5). Results from the Humphrey field analyzer showed a mean number of abnormal stimulus locations of 71.2% (p < 0.005). 70% of patients had sufficient binocular acuity to drive and of these 71.4% were shown not to have a minimum visual field for safe driving on binocular Esterman field analysis. CONCLUSION: Vitrectomy potentially allows retention/restoration of good visual acuity in patients with complications of proliferative diabetic retinopathy. However patients may be suffering from unrecognized visual impairment consequent upon extensive visual field loss which in over two thirds of patients may be sufficiently severe to preclude safe driving.

Adult↗

Vertical inversion of the visual field and REM sleep mentation.

The effects of the vertical inversion of the visual field on REM sleep mental activity were examined to explore the potential involvement of this activity in information processing. In a first experiment, four male subjects slept in the laboratory for two sessions of 6 consecutive nights: 2 adaptation nights, 2 nights of polysomnography and 2 nights of dream collection. During the days preceding Nights 3, 4, 5, 6 of each session, the subjects wore glasses which, during the second session, completely inverted (rotation of 180 degrees) their visual field. In a second experiment with four other male subjects, the order of conditions was reversed and the experimental condition (visual inversion) was introduced twice. The data of the two experiments were combined. Overall, following visual inversion, there were significant increases in the proportion of dreams containing motor and visual difficulties (P < 0.005), misfortunes (P < 0.05) and dreamer confusion (P < 0.05) and a decrease in dreamer participation (P < 0.05). Only 4 of the 8 subjects experienced incorporations of the inverted visual field into their dreams and they tended to perform better on two of three tests of adaptation to the visual inversion. The observed changes in dreams are consistent with the notion of continuity between waking and dreaming since they appear to reflect the waking preoccupation and psychological state associated with visual inversion.

Adolescent↗

Increased visual field area with antireflective coated lenses in the presence of glare.

Visual fields were charted with the Goldmann perimeter for five subjects wearing corrective spectacles with noncoated lenses and then lenses with antireflective coatings of mmagnesium fluoride in both the absence and the presence of a source of glare (back-scattered reflection from the posterior surface of their lenses). There was a greater reduction in temporal isopters than nasal isopters in the presence of glare with both types of lenses, but the coated lenses were superior to the noncoated lenses in reducing the effect of glare on the visual field area.

Adult↗

[Detection of glaucomatous nerve fiber damage. Laser polarimetry in comparison with equivalent visual field loss].

PATIENTS AND METHODS: A total of 45 eyes of 45 patients were equally divided into three age-matched groups (controls, glaucoma, suspected glaucoma). All patients were examined using laser polarimetry and automated visual field testing. We compared the agreement of the location of visual field defects with changes in the nerve fiber layer. In addition we calculated the change in NFLT along a peripapillary circle at four different distances of the optic disc margin. RESULTS: The localization of nerve fiber defects corresponds to the localization of the visual field defect exactly in eight of 15 eyes and roughly in another five. Six of the eyes suspected of having glaucoma showed pathological results with the nerve fiber analyzer (NFA) although visual fields were normal. There was a significant difference for NFLT change towards the periphery between the three groups. CONCLUSION: While the NFA does not always allow a definite correlation between morphological defects and resulting functional impairment, a decrease in the NFLT with increasing distance from the optic disc margin seems helpful for clinical classification. The value of this new method has yet to be proven in longitudinal clinical studies.

Adult↗

Eight-axis visual-field mapping for targets embedded in a homogeneous competing background.

The binocular functional visual field for a detection task, with a peripherally presented target embedded in a homogeneous competing background, was mapped on 8 axes passing through the fixation point. The boundary of the field for each axis was based on the number of "correct" responses on the axis, where a "correct" response was defined in terms of the size of the error made by the subjects in estimating the target position. The visual fields for 6 subjects (4 men and 2 women) were very irregular in shape, and these were differences among subjects. The 8-axis area correlated highly with area based on only the horizontal and vertical axes but the latter area gave no indication of even gross irregularities in shape of the visual field.

Adult↗

Anomalous kinetic visual fields found in family members of patients with a confirmed diagnosis of Gilles de la Tourette syndrome.

Three visual manifestations of Gilles de la Tourette syndrome (TS), a neuropsychiatric disorder, have been previously reported. In this paper we report anomalies in the measured kinetic paracentral visual field of TS patients and their family members. We found that 96% of TS patients exhibited paracentral kinetic visual field defects (nasal and temporal steps, enlargement, "ringing," and/or baring of the blind spot). Ninety-three percent of fathers of TS children and, surprisingly, about 80% of mothers exhibit these characteristic visual field anomalies. Sample data and examples of family studies are reported.

Adolescent↗

Influence of a dilated pupil on the visual field in glaucoma.

PURPOSE: The author studied the effects of pupillary dilation on perimetry in a group of glaucomatous patients receiving timolol therapy. PATIENTS AND METHODS: A prospective study compared the visual fields of 23 patients with primary open-angle glaucoma of varying severity (mean defect: 3.84; short-term fluctuation: 1.91; pattern standard deviation [SD]: 3.61; corrected pattern SD: 3.12) before and after instillation of phenylephrine 10% using the Octopus 1-2-3 projection perimeter (INTERZEAG AG, Schlieren, Switzerland). RESULTS: The mean defect became impaired by an average of 3.01 (SD +/- 1.52) dB after administration of phenylephrine (p < 0.001). The pattern SD and the corrected pattern SD also became impaired with dilation by 1.51 dB (p < 0.01) and 1.73 dB (p < 0.05), respectively, after dilation. These changes varied across the visual field. The outer zone of the visual field had the greatest impairment after dilation with phenylephrine. CONCLUSIONS: Pupillary dilation in patients with glaucoma produces a nonuniform decrease in threshold sensitivities that is statistically greater on outer zone of the visual field.

Accommodation, Ocular↗

A given visual field location has a wide range of perceptive field sizes.

Increment thresholds were measured at the intersections of a modified Hermann Grid at several retinal locations and at photopic, mesopic and scotopic adaptation levels. On a concentric perceptive field explanation of the illusion, these results suggest that a broad distribution of perceptive field sizes exists at each visual field location. The peak of this distribution lies close to the previously reported perceptive field size at that location. As the adaptation level decreases, the distribution shifts upwards in size. At scotopic levels lateral inhibition only occurs for large stimuli. The size distribution can be used to account for the spatial extent of some contrast phenomena.

Adaptation, Ocular↗

The relationship between the visual field and the optic nerve head in glaucomas.

In a retrospective study of 50 eyes with chronic open-angle glaucoma we compared the findings obtained using stereochronoscopy (Sc), papillometry (Pm) and visual-field measurements. We found relationship between the neuroretinal-rim area and the visual-field findings measured using the Octopus glaucoma program, G1. There was only a weak relationship between the Sc findings and the visual-field measurements. This suggests that Sc detects a type of damage that is not detectable either using Pm or by visual-field examinations. Our results also suggest that quantitative perimetry detects the same kind of damage as that revealed by Pm. The neuroretinal-rim area was best correlated with short-term fluctuation, but was also very significantly correlated with mean damage and corrected loss variance.

Adolescent↗

Normal visual fields measured with Octopus Program G1. I. Differential light sensitivity at individual test locations.

Exact knowledge of the normal variation of visual fields and the influence of age upon them is essential to differentiate normal from abnormal results, e.g., in glaucoma suspects. This study evaluates the normal variability of differential light sensitivity at individual test locations and incorporates a data base of a multicenter study performed with Octopus 201 perimeters using Program G1. The 824 fields thus obtained included 139 fields of 139 healthy volunteers who had undergone two previous visual fields and completed all three phases of the program. Sensitivity decreased linearly with age, an effect which for individual test locations ranged between 0.036 and 0.107 dB/year and which became more pronounced towards the periphery. On average, the age-related effects explained only 17% of the interindividual variation (range 4%-31%). The interindividual variation within a test averaged 4.6 dB2 and revealed a moderate, but quadratic increase towards the periphery. The intra-individual short-term variation was considerably lower, averaging 2.2 dB2. There was a similar modest, quadratic increase of the intra-individual variation towards the periphery. The results may help distinguish incipient disease manifestations from normal variation of perimetric results. Furthermore, the results give insight into the calculation of global visual field indices.

Adult↗

Risk factors for progressive visual field loss in primary open angle glaucoma.

PURPOSE: The aim of this study was to evaluate routine ophthalmic data to identify clinically useful risk factors for progressive visual field loss in patients with primary open-angle glaucoma (POAG) already receiving intraocular pressure-lowering treatments. METHODS: A retrospective cohort study design was used. Routine ophthalmic data for all subjects were obtained from case records with the knowledge that baseline clinical data had been collected in a standardised manner. Progression was defined according to the AGIS visual field defect scoring system. Variables evaluated as candidate risk factors for progression were assessed by survival analysis. Factors exerting a significant effect on survival were subsequently tested in a Cox proportional hazards model. RESULTS: A cohort of 108 eligible POAG patients was followed over an average of 3.6 years, with an average visual field intertest interval of 8 months. The incidence rate of progressive loss among the cohort was 5.4 cases per 100 person years. Increasing age was found to be independently associated with a small but significantly increased risk of glaucomatous visual field defect progression (hazard ratio 1.07, P=0.022), and a borderline association was also demonstrated with being male (hazard ratio 2.76, P=0.057). CONCLUSIONS: This retrospective investigation has provided preliminary information on factors associated with increased risk of progressive glaucomatous visual field loss that may inform clinical care strategies. Lack of concordance with other studies suggests that further prospective investigations are needed if risk stratification strategies are to be employed in caring for patients with chronic open-angle glaucoma.

Age Factors↗

Deformation of the useful visual field with state of vigilance, task priority, and central task complexity.

In a dual-task situation, peripheral perception can deteriorate due to different variables related to the experimental situation, such as central task complexity and the relative priority given to the two tasks. Recent studies have also shown that individual characteristics (such as the state of vigilance) can alter the useful visual field. The ability to perceive signals presented at different places in the visual field decreases in situations that lead to episodes of low vigilance. In Exp. 1, 27 subjects (18-29 years) had to perform a monotonous and prolonged dual-monitoring task involving central and peripheral vision. The test was carried out with two different sets of instructions regarding priority: the more important task was either the central task or the peripheral one. In Exp. 2, 18 subjects (18-30 years) performed the same test, but this time with two levels of complexity of the central task, either a simple monitoring activity or the same monitoring task coupled with a counting activity. Elliptical interpolation of the data enabled assessment of the deformation of the useful visual field in both experiments. The analysis of the parameters of the elliptical model indicated that the useful visual field mainly shrinks on the vertical axis, as the individual becomes drowsy. The useful visual field also shrinks on the horizontal axis when the peripheral task has priority and the monitoring activity is prolonged, or when the central task is complex.

Adolescent↗

Comparison of frequency doubling perimetry with humphrey visual field analysis in a glaucoma practice.

PURPOSE: To determine the sensitivity and specificity of frequency doubling perimetry with Humphrey visual field testing used as the gold standard. METHODS: Frequency doubling perimetry and Humphrey visual field testing (24-2) were performed on 29 consecutive patients in a glaucoma practice. Data for the right eye were used to calculate sensitivity, specificity, and receiver operating characteristic curves. RESULTS: For the frequency doubling perimetry in screening mode, and with an abnormal glaucoma hemifield test used as the gold standard, the area under the receiver operating characteristic curve was 89.3%, 81.5%, or 75.0% for the presence of mild, moderate, or severe relative defects, respectively. Similar results were found with the use of mean deviation (P <.05) to define Humphrey visual field defects. For frequency doubling perimetry in threshold mode, the area under the receiver operating characteristic curve was 93.4% with the presence of any defect (P <.05) used as the criterion for an abnormal case, and an abnormal glaucoma hemifield test as the gold standard. In all cases, the threshold mode detected defects better than the screening mode.

Adolescent↗

Comparison of clinical optic disc assessment with tests of early visual field loss.

PURPOSE: Clinical optic disc assessment may identify glaucomatous optic neuropathy prior to a patient developing visual field abnormalities on achromatic automated peri-metry (AAP). Tests targeting axons that are selectively damaged or whose redundancy is low, such as short wavelength automated perimetry (SWAP) and frequency doubling perimetry (FDP), may detect visual field loss before it is seen on AAP. This study investigated whether patients in whom characteristic glaucomatous optic disc damage was present without AAP abnormalities had visual field abnormalities with SWAP and FDP. METHODS: A sample of patients (n = 50) with ocular hypertension (normal AAP) were selected, who had SWAP, FDP and stereofundus photography performed. The photographs were then analysed by two glaucoma subspecialists who were masked to the assessments of the other and to the patients' SWAP and FDP results. A categorization of the optic discs was made as either normal or abnormal and this was compared with their SWAP and FDP findings. RESULTS: On comparing SWAP and FDP with clinical optic disc assessment as the 'gold standard', the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 33%, 92%, 57% and 81%, respectively, for SWAP and 25%, 89%, 49% and 79%, respectively, for FDP. CONCLUSION: In glaucoma suspects, the study suggests that SWAP and FDP identify subjects with early glaucomatous optic neuropathy missed by AAP.

False Positive Reactions↗

Visual field changes in methotrexate therapy. Case report and review of the literature.

PURPOSE: To present a unilateral central visual field defect in a patient with psoriatic arthritis treated with Methotrexate and folic acid supplement, probably induced by toxic posterior optic neuropathy. The scotoma incompletely resolved after cessation of Methotrexate (MTX) therapy. METHODS: Serial fundoscopic, perimetric and electrophysiological examination as well as comprehensive neurological investigation including lumbar puncture, carotid sonography, electroneurography, and MRI of the brain. RESULTS: A female patient with psoriatic arthritis on long-standing Methotrexate (MTX 15 mg IM/once a week) therapy suffered first from an acute attack of central visual field defect in her right eye and later on from two subsequent deteriorations of her scotoma within one year. A demyelinating retrobulbar optic neuritis was excluded through repeated comprehensive neurological investigations and unresponsiveness to systemic corticosteroid therapy. A MTX-induced posterior optic neuropathy was suspected and the patient experienced improvement of her visual field defects only six weeks after discontinuing MTX therapy. Further improvement was observed through follow-up perimetric examinations half a year after cessation. CONCLUSIONS: Central scotoma with unremarkable optic disc can occur after long-standing treatment with MTX and despite folic acid supplementary therapy. This is most probably due to posterior optic neuropathy. Early cessation of the drug or change to another antimetabolite therapy can stop the deterioration of the visual field changes and even improve them. The exact pathomechanism is still unclear and the involvement of only one eye requires more investigation. MTX-induced posterior optic neuropathy should be included in the differential diagnosis of toxic optic neuropathy. This is getting more frequent than before because of the nowadays standard use of MTX in treatment of many autoimmune collagen diseases.

Antirheumatic Agents↗