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PubMed1984

A comparison of visual field loss in primary open-angle glaucoma and the secondary glaucomas.

We compared the pattern of visual field loss in 148 patients with primary open-angle glaucoma and 63 patients with secondary glaucoma. The frequency with which each location in the visual field was defective was similar in the two conditions. The most common visual field defects in both varieties of glaucoma were superior arcuate scotomas and superior nasal steps. The similar distribution of visual field defects in primary and secondary glaucomas is consistent with a common mechanism for optic disc damage.

Computers↗

PubMed1994

Diabetes in primary open-angle glaucoma patients with inferior visual field defects.

We reviewed the charts of 144 randomly selected patients with primary open-angle glaucoma who had Aulhorn's stage 1, 2, or 3 visual field defects to investigate whether primary open-angle glaucoma patients with predominantly inferior visual field defects had a higher prevalence of diabetes mellitus than primary open-angle glaucoma patients without such visual field defects. Of the 59 patients with mainly inferior visual field defects in one or both eyes, 19 (32%) had diabetes mellitus, while 11 of 85 (13%) patients without such defects had diabetes mellitus. This difference was statistically significant (P = 0.0096). These results suggest that primary open-angle glaucoma patients with predominantly inferior visual field defects in one or both eyes are more likely to have diabetes and that such patients with no known history of diabetes may benefit from glucose tolerance testing to detect occult impaired glucose tolerance or diabetes mellitus.

Adult↗

PubMed1990

[Measuring the optic papilla with planimetry and the optic nerve head analyzer in glaucoma and suspected glaucoma. II. Correlations of the results of both methods with changes in the visual field, studied with the Octopus automatic perimeter].

Sixty-seven optic nerve heads of 40 patients with proven or suspected glaucoma were measured by planimetry and with the Rodenstock Optic Nerve Head Analyser (ONHA). The results were compared to visual field indices obtained with the Octopus program G-1. Good correlation of the results obtained by the two measurement procedures has been shown (Stürmer et al. 1989), between values for the disk area, the excavation area, and the cup/disk ratio. However, there is only weak correlation of values for the neuroretinal rim. The planimetrically measured neuroretinal rim area in the total population examined proved to be significantly correlated only with the visual field index for mean retinal sensitivity (MS; r2 = 0.106; P = 0.007) and short-term fluctuations (SF; r2 = 0.066; P = 0.036). After division of the population examined into different diagnostic groups, further statistically significant correlations between optic nerve head parameters and the various visual field indices were shown; here, the cup/disk ratio of both measurement procedures in two subgroups showed the best correlation with the visual field indices MS and mean defect (MD). Neither in the total population nor in any of the subgroups was a statistically significant correlation found between the volume of the excavation and one of the visual field indices. Comparing only the data for the temporal quadrant of the optic nerve head with the visual field did not improve the correlations. The best, i.e. highly significant, correlations were between optic nerve head parameters and the age of the patient. The correlation factors are much lower than other published data. A variety of factors could be responsible for these weak correlations: different optic nerve head configurations on the one hand, and localized or diffuse visual field defects on the other. In unselected cases it appears impossible to predict the visual field of a given optic nerve head. Both methods are suitable for follow-up, but not all anatomical configuration of the optic nerve head permit this.

Adolescent↗

PubMed1983

Optic disk and visual field correlations in primary open-angle and low-tension glaucoma.

If the amount of visual field loss is less than expected from the amount of optic disk cupping in low-tension glaucoma compared with primary open-angle glaucoma, it might imply a difference between the two conditions in the type of optic nerve lesion produced. To test this hypothesis, three observers independently examined, in a masked fashion, optic disk stereoscopic photographs of 127 eyes with primary open-angle glaucoma and 71 eyes with low-tension glaucoma. For each stereoscopic photograph the observer predicted whether the visual field loss would be mild, moderate, or severe. The visual field were then classified, according to the number of sectors defective on the Goldmann perimeter chart, as having mild (1 to 15 sectors), moderate (16 to 30 sectors), or severe (more than 30 sectors) visual field loss. For no observer did the frequency of underpredictions or overpredictions in the two conditions differ significantly. The results of this study, thus, did not support the theory that the optic disk damage in primary open-angle glaucoma differs from that in low-tension glaucoma.

Adult↗

PubMed2005

Comparison between monkey and human visual fields using a personal computer system.

To use monkeys as models for eye diseases that may lead to blindness, we need to develop a method to precisely measure its visual field and to understand similarities and differences in visual field properties between monkeys and humans. The visual field of monkey was not measured precisely although the necessity. We established a new system with personal computers for precise measurement of the monkey visual field. Four monkeys and three humans served as subjects. The luminance-contrast sensitivity of the central 24 degrees field was measured while the subject was fixating a small spot. During the measurement, we continuously recorded the eye position, and discarded the data when fixation was broken. Reliability indices demonstrated high and stable behavioral performance by both monkeys and humans. The luminance-contrast sensitivity was highest around the fovea, and declined as eccentricity increased. The blind spot was clearly detected 15 degrees temporally. The overall sensitivity was higher in humans than in monkeys and the sensitivity dropped more sharply in the periphery in monkeys than in humans. We recommend this system as a convenient and reliable way to measure visual functions in monkeys in basic ophthalmologic research or in assessment of the drug effects on the visual field.

Adult↗

PubMed1985

Informational content of visual field location in glaucoma.

Information Theory has been applied to produce estimates of how valuable each stimulus location on the Friedmann Visual Field Analyser mk. II is in detecting early glaucomatous visual field defects. The results indicate that stimuli in the superior arcuate region of the visual field and in the inferior nasal quadrant give the maximum amount of information. Stimuli in the extreme superior field (beyond 20 degrees), the inferior temporal quadrant and around the physiological blind spot give the least amount of information. It is suggested that these results can be used to develop computerised techniques for the analysis of visual field data.

Adult↗

PubMed1986

Computerized quantitative analysis of kinetic visual fields.

Kinetic perimetry is still a widely accepted and used means of assessing the visual field. Attempts at quantifying the area of vision for given isopters have been limited to area measurements on visual field charts, which are azimuthal equidistant polar map projections of the inside surface of the perimetry bowl. Such measurements distort the true size of scotomas (or seeing areas) when the boundaries measured are farther from the center of the field on the chart because of cartographic distortion inherent with this projection. We believe that the solid angle in steradians subtended by the scotoma or the seeing area is a more appropriate measure of the visual field than area on a flat representation. We used a simple computer program to determine the solid computer program to determine the solid angle for given isopters of graphed perimetric visual field data.

Computers↗

PubMed1999

Ganglion cell losses underlying visual field defects from experimental glaucoma.

PURPOSE: To investigate the relationship between ganglion cell losses and visual field defects caused by glaucoma. METHODS: Behavioral perimetry and histology data were obtained from 10 rhesus monkeys with unilateral experimental glaucoma that was induced by argon laser treatments to their trabecular meshwork. After significant visual field defects had developed, the retinas were collected for histologic analysis. The ganglion cells were counted by light microscopy in cresyl violet-stained retina sections, and the percentage of ganglion cell loss (treated to control eye counts) was compared with the depth of visual field defect (treated to control eye thresholds) at corresponding retinal and perimetry test locations. Sensitivity losses as a function of ganglion cell losses were analyzed for Goldmann III, white and Goldmann V, and short- and long-wavelength perimetry test stimuli. RESULTS: The relationship between the proportional losses of ganglion cells and visual sensitivity, measured with either white or colored stimuli, was nonlinear. With white stimuli, the visual sensitivity losses were relatively constant (approximately 6 dB) for ganglion cell losses of less than 30% to 50%, and then with greater amounts of cell loss the visual defects were more systematically related to ganglion cell loss (approximately 0.42 dB/percent cell loss). The forms of the neural-sensitivity relationships for visual defects measured with short- or long-wavelength perimetry stimuli were similar when the visual thresholds were normalized to compensate for differences in expected normal thresholds for white and colored perimetry stimuli. CONCLUSIONS: Current perimetry regimens with either white or monochromatic stimuli do not provide a useful estimate of ganglion cell loss until a substantial proportion have died. The variance in ganglion cell loss is large for mild defects that would be diagnostic of early glaucoma and for visual field locations near the fovea where sensitivity losses occur relatively late in the disease process. The neural-sensitivity relationships were essentially identical for both white and monochromatic test stimuli, and it therefore seems unlikely that the higher sensitivity for detecting glaucoma with monochromatic stimuli is based on the size-dependent susceptibility of ganglion cells to injury from glaucoma.

Animals↗

PubMed1990

Visual field defects in patients with insulin-dependent and noninsulin-dependent diabetes.

Automated perimetry (Humphrey 30-2) was used to quantitate visual field sensitivity in diabetic patients with either little or no retinopathy (n = 38) or mild background diabetic retinopathy (n = 19) and in visually normal controls (n = 40). Foveal thresholds were unaffected in the diabetic patients but significant reductions in visual field sensitivity, measured by both the mean deviation and the pattern standard deviation indices of visual field sensitivity, were observed in the diabetic patients. Subgroup analyses showed that this sensitivity reduction primarily occurred in noninsulin-dependent diabetic patients. Among the diabetic patients, 26.3% of the visual fields were flagged as "probably abnormal." This percentage was greatest among the noninsulin-dependent patients with mild background diabetic retinopathy (72.3%). The sensitivity reductions observed in the noninsulin-dependent patients with mild background diabetic retinopathy tended to be localized in the superior quadrants and correlated with the extent of retinal vascular compromise evident from vitreous fluorophotometry (r = 0.603). These findings imply that in diabetic patients visual field defects (1) often can be detected in patients with at most moderate retinopathy, (2) occur more frequently in noninsulin-dependent patients than in insulin-dependent patients, and (3) may result from subclinical microangiopathy.

Adult↗

PubMed1991

A comparison of unweighted and fluctuation-weighted indices (within the central 28 degrees of glaucomatous visual fields measured with the Octopus automated perimeter).

The main visual field indices of Flammer and the analogous ones of Heijl have been compared based on a population of 113 glaucomatous visual fields. It is shown that for the population studied, the differences between the two sets of indices are negligible for Octopus G1 program results and that they may thus be used interchangeably.

Glaucoma↗

PubMed1989

Quantitating the superior visual field loss associated with ptosis.

The effect of blepharoptosis on the superior visual field was assessed using a series of specially designed contact lenses to simulate ptosis in normal subjects. We found a progressive decrease in the superior visual field at the 90 degree vertical meridian, which was proportional to the degree of simulated ptosis. Our results were in close agreement with both a theoretical model and previous clinical observations. These results are important in evaluating patients contemplating ptosis surgery, as well as in visual field testing for neuro-ophthalmic disorders.

Adult↗

PubMed2002

Visual-field loss with optic nerve drusen and ocular hypertension: a case report.

BACKGROUND: Patients with optic nerve drusen are often asymptomatic and free of visual symptoms. However, ocular complications such as visual-field defects may develop. This article presents the case of a patient with optic nerve drusen, ocular hypertension, and a visual-field defect. The diagnosis and management of patients with such findings will be presented. CASE REPORT: A 75-year-old man came to the eye clinic with a history of being treated for glaucoma. On examination, optic nerve drusen were found in both eyes. Subsequent testing revealed ocular hypertension and a visual-field defect that could be related to either optic nerve drusen or glaucoma. After re-establishment of baseline intraocular pressures (IOP) and re-initiation of treatment, the patient is being monitored for IOP control and visual-field progression. CONCLUSION: Optic nerve drusen and glaucoma can both cause visual-field defects. When a patient manifests optic nerve drusen, ocular hypertension, and visual-field defects, a diagnostic and management dilemma exists. Regardless of the etiology for the field defects, a treatment regimen designed to reduce the intraocular pressure to a level that potentially reduces the risk of ocular sequelae is recommended.

Aged↗

PubMed2001

Perimetric visual field and functional MRI correlation: implications for image-guided surgery in occipital brain tumours.

OBJECTIVE: To compare the results of visual functional MRI with those of perimetric evaluation in patients with visual field defects and retrochiasmastic tumours and in normal subjects without visual field defect. The potential clinical usefulness of visual functional MRI data during resective surgery was evaluated in patients with occipital lobe tumours. METHODS: Eleven patients with various tumours and visual field defects and 12 normal subjects were studied by fMRI using bimonocular or monocular repetitive photic stimulation (8 Hz). The data obtained were analyzed with the statistical parametric maps software (p<10(-8)) and were compared with the results of Goldmann visual field perimetric evaluation. In patients with occipital brain tumours undergoing surgery, the functional data were registered in a frameless stereotactic device and the images fused into anatomical three standard planes and three dimensional reconstructions of the brain surface. RESULTS: Two studies of patients were discarded, one because of head motion and the other because of badly followed instructions. On the remaining patients the functional activations found in the visual cortex were consistent with the results of perimetric evaluation in all but one of the patients and all the normal subjects although the results of fMRI were highly dependent on the choices of the analysis thresholds. Visual functional MRI image guided data were used in five patients with occipital brain tumours. No added postoperative functional field defect was detected. CONCLUSIONS: There was a good correspondence between fMRI data and the results of perimetric evaluation although dependent on the analysis thresholds. Visual fMRI data registered into a frameless stereotactic device may be useful in surgical planning and tumour removal.

Adult↗

PubMed2001

Mapping of glaucomatous visual field defects by multifocal VEPs.

PURPOSE: To objectively measure a visual field and to sensitively detect glaucomatous visual field defects by measuring the contrast sensitivity function (CSF), using multifocal visual evoked cortical potentials (MVEPs). METHODS: MVEPs of normal subjects (n = 28) and of patients with glaucoma (n = 12) or ocular hypertension (OH, n = 1) were recorded. A multi-input procedure was used to obtain 37 local VEP responses to each scaled hexagon, composed of 24 triangular patterns, reversing in a counterphase manner. Two pattern contrasts of 32% and 8% were used for measuring the contrast threshold. To improve the signal-to-noise ratio, 37 MVEPs were averaged into 20 groups. The root-mean-square (RMS) measures at both contrasts were calculated. Contrast thresholds were estimated by extrapolating the regression line of the amplitude versus contrast to the mean noise levels. RESULTS: RMS amplitudes of each local MVEP decreased as the eccentricity increased and as the pattern contrast decreased in normal subjects. It was also revealed that the amplitudes were smaller in the upper-half field than those in the lower-half field. Compared with the RMS amplitudes, CSFs estimated by MVEPs were relatively constant without being strongly influenced by retinal eccentricity. In patients with glaucoma, the CSFs, even from the locations where the mean perimetric sensitivities ranged to more than 30 dB, were significantly smaller than those in the normal control subjects (P < 0.001, Mann-Whitney test). CSFs in the 20- to 30-dB and 100 to 20-dB groups were also significantly smaller than those in the more-than-30-dB or 20- to 30-dB groups, respectively (P < 0.001, Mann-Whitney test). A significant correlation was found between the logarithmic function of the CSF and perimetric sensitivity (r = 0.57, P < 0.001, n = 216). The CSFs were evaluated on the basis of normal SD. Mappings of the CSFs agreed well with those of the perimetric sensitivity in all patients with glaucoma and was even more sensitive in detecting slight optic nerve damage by glaucoma than was perimetry. CONCLUSIONS: Local optic nerve damage caused by glaucoma can be sensitively detected by measuring contrast sensitivity using the MVEP.

Contrast Sensitivity↗

PubMed2001

Concentric visual field restriction under vigabatrin therapy: extent depends on the duration of drug intake.

Vigabatrin (VGB) is a novel antiepileptic drug which inhibits GABA-transaminase (GABA-T) and thus increases the level of GABA in the CNS and in its neurons. In the last few years, evidence has been presented that VGB intake may be associated with concentric visual field restrictions. The aim of this study was to estimate the prevalence of visual field constrictions and to determine if, and to what extent, they depend on the duration of VGB treatment. Visual fields of 15 patients who were taking VGB, and 12 matched control patients who had never been exposed to VGB, were investigated using a kinetic Goldmann perimeter. One of the 12 matched control patients had a slightly restricted visual field whereas nine of the 15 VGB patients (60%) showed a moderate to severe concentric visual field restriction. The extent of the outer isopters (V4, I4, I3, I2) depended on the duration of VGB intake. VGB treatment was clearly associated with a high prevalence of concentric visual field restriction. Moreover, the degree of visual field restriction depended on the duration of VGB intake. Further work, including longitudinal studies, is needed to clarify whether these lesions are reversible or not.

Adolescent↗

PubMed1991

[Normal perceptual latencies during visual field measurement].

The perceptual latency (PL) to detect stimuli during visual field measurement is not a usual routine test. An automated perimeter ('moniteur ophtalmologique') was used to measure the central 30 degrees of vision with static targets in 50 normal subjects. The visual field was divided into four areas. The purpose of this study was to compare the PL in each area. An increase in the PL was observed, the nasal superior area being longer than the inferior temporal area. It seems that this psychophysical test is transmitted by a specific class of retinal ganglion cells: Y cells. We believe that PL could be a tool for detecting retinal ganglion cell damage.

Adult↗

PubMed2000

Number of ganglion cells in glaucoma eyes compared with threshold visual field tests in the same persons.

PURPOSE: To compare the number of retinal ganglion cells (RGCs) topographically mapped with specific visual field threshold test data in the same eyes among glaucoma patients. METHODS: Seventeen eyes of 13 persons with well-documented glaucoma histories and Humphrey threshold visual field tests (San Leandro, CA) were obtained from eye banks. RGC number was estimated by histologic counts of retinal sections and by counts of remaining axons in the optic nerves. The locations of the retinal samples corresponded to specific test points in the visual field. The data for glaucoma patients were compared with 17 eyes of 17 persons who were group matched for age, had no ocular history, and had normal eyes by histologic examination. RESULTS: The mean RGC loss for the entire retina averaged 10.2%, indicating that many eyes had early glaucoma damage. RGC body loss averaged 35.7% in eyes with corrected pattern SD probability less than 0.5%. When upper to lower retina RGC counts were compared with their corresponding visual field data within each eye, a 5-dB loss in sensitivity was associated with 25% RGC loss. For individual points that were abnormal at a probability less than 0.5%, the mean RGC loss was 29%. In control eyes, the loss of RGCs with age was estimated as 7205 cells per year in persons between 55 and 95 years of age. In optic nerves from glaucoma subjects, smaller axons were significantly more likely to be present than larger axons (R2 = 0.78, P<0.001). CONCLUSIONS: At least 25% to 35% RGC loss is associated with statistical abnormalities in automated visual field testing. In addition, these data corroborate previous findings that RGCs with larger diameter axons preferentially die in glaucoma.

Aged↗

PubMed2005

Visual field changes after laser in situ keratomileusis.

PURPOSE: To determine whether laser in situ keratomileusis (LASIK) affects the central 30-degree visual field. SETTING: University-based ophthalmology practice. METHODS: This nonrandomized clinical trial comprised 14 normal patients (27 eyes) scheduled to have LASIK for myopia or myopic astigmatism. Automated static perimetry was performed before and 6 months after surgery using the Octopus 1-2-3 perimeter and the Dynamic-32 test strategy. Patient data included sex, age, preoperative and postoperative refractive errors, preoperative and postoperative best corrected visual acuity, preoperative corneal thickness, programmed optical zone, programmed total ablation diameter, and duration of microkeratome suction. All surgery was performed using the same Alcon LADARVision 4000 excimer laser. The main outcome measures were the mean sensitivity (MS) change in the central 15-degree visual field and the MS change in the 15- to 30-degree visual field. A multivariate analysis of the MS change as a function of preoperative clinical parameters was performed. RESULTS: There was no significant change in the MS in the central 15-degree visual field; between 15 and 30 degrees, there was a statistically significant decrease of -0.82 dB +/- 1.40 (SD) (P=.01, 2-tailed t test). The decline in MS was positively correlated with refractive error and corneal thickness; it was negatively correlated with the programmed optical zone diameter. CONCLUSIONS: Automatic static perimetry can detect decreased sensitivity in the midperipheral visual field after myopic LASIK. It may be a useful quantitative subjective test for measuring the effects of future improvements in surgical technique on vision quality.

Adult↗