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PubMedDate not supplied

Association between watershed zone and visual field defect in normal tension glaucoma.

PURPOSE: To evaluate the association between the watershed zone and glaucomatous optic nerve head (ONH) damage. METHODS: We performed indocyanine green fluorescence angiography with a scanning laser ophthalmoscope in 54 eyes of 27 patients with normal tension glaucoma (NTG). RESULTS: We identified 7 eyes of 8 patients (14.8%) with a watershed zone not including the ONH, 32 eyes of 20 patients (59.3%) with the watershed zone partially including the ONH, and 10 eyes of 14 NTG patients (25.9%) with the watershed zone including the ONH. Of the 27 NTG patients, 10 patients (37.0%) had different types in each eye. CONCLUSIONS: In these patients, the mean deviation of visual field indices was greater in the eye with the watershed zone, which included a larger part of the ONH than in the contralateral eye. Conversely, the eye with the greater mean deviation had a watershed zone that included a larger part of the ONH. The location of the watershed zone appeared to influence the progression of the visual field defect.

Adolescent↗
PubMed2003

Association between scanning laser polarimetry measurements using variable corneal polarization compensation and visual field sensitivity in glaucomatous eyes.

OBJECTIVE: To compare the association between scanning laser polarimetry (SLP) retinal nerve fiber layer (RNFL) measurements and automated perimetry sensitivity using both SLP manufacturer-assumed fixed and subject-specific variable corneal polarization magnitude and corneal polarization axis values. METHODS: An SLP was modified to enable the measurement of corneal polarization magnitude and corneal polarization axis so that compensation for corneal birefringence could be corrected on a subject-specific variable basis. Seventy-three eyes from the University of California, San Diego, Diagnostic Innovations in Glaucoma Study with early glaucoma or suspected glaucoma (abnormal Swedish Interactive Threshold Algorithm [SITA] or full-threshold automated perimetry results and/or glaucomatous-appearing optic disc by consensus grading of stereoscopic optic disc photographs) (mean [SD] SITA mean deviation, -2.74 [3.71] dB; range, 1.72 to -14.72 dB) were included. Subjects were imaged with SLP using the manufacturer-assumed fixed corneal compensation values and subject-specific variable corneal compensation values and tested with SITA automated perimetry. Scanning laser polarimetry and SITA data were obtained within 3 months of each other. MAIN OUTCOME MEASURES: The relationship between regional SLP RNFL measurements (24 parameters) and corresponding regional SITA raw thresholds were evaluated using linear regression for both (fixed corneal compensation and variable corneal compensation) SLP configurations. RESULTS: No fixed corneal compensation SLP measurements were significantly associated with corresponding SITA visual field zone sensitivities after corrections for multiple comparisons. Seven variable corneal compensation RNFL parameters (superior, inferior, or mean RNFL thickness measurements) were significantly associated with their corresponding visual field zones with R2 values ranging from 0.13 (ellipse average) to 0.20 (superior average). CONCLUSION: Variable corneal compensation to correct for subject-specific corneal polarization magnitude and corneal polarization axis improves the relationship between SLP-measured RNFL thickness and visual function measured by SITA perimetry.

Adult↗
PubMed1986

On the possible dangers of using horizontal word displays in visual field studies.

In a sample of 100 four-letter words, there was more information about the identity of the words in the first letter than in the last letter. However, information asymmetry did not correlate with visual field differences in a lexical decision study. It therefore may be possible to use horizontally displayed short words in visual field studies without being concerned about peripheral factors. Different factors affect the recognition of vertical and horizontal displays, and the use of vertical displays is not advised.

Form Perception↗
PubMed2001

Risk factors for progression of visual field abnormalities in normal-tension glaucoma.

PURPOSE: To uncover risk factors for the highly variable individual rates of progression in cases of untreated normal-tension glaucoma. METHODS: Visual field data were assembled from 160 subjects (160 eyes) enrolled in the collaborative normal-tension glaucoma study during intervals in which the eye under study was not receiving intraocular pressure-lowering treatment during prerandomization and postrandomization intervals. Analyses included multivariate analysis of time-dependent Cox proportional hazard, Kaplan-Meier analysis of "survival" without an increment of visual field worsening, and comparison of slopes of change in mean deviation global index over time. RESULTS: Most migraine occurred in women, but analysis demonstrated that gender and presence of migraine contribute separately to the overall risk. The risk ratio for migraine, adjusted for the other variables was 2.58 (P =.0058), for disk hemorrhage was 2.72 (P =.0036), and for female gender 1.85 (P =.0622). The average fall in the mean deviation index was faster in nonmigrainous women than in nonmigrainous men (P =.05). Suggesting genetic influence, Asians had a slower rate of progression (P =.005), and the few black patients enrolled had a tendency for faster progression. However, self-declared history of family with glaucoma or treated for glaucoma did not affect the rate of progression. Neither age nor the untreated level of intraocular pressure affected the rate of untreated disease progression, despite their known influence on prevalence. CONCLUSIONS: Whereas risk factors for prevalence help select populations within which to screen for glaucoma, the factors that affect the rate of progression help decide the expected prognosis of the individual's untreated disease and thereby the frequency of follow-up and aggressiveness of the therapy to be undertaken.

Aged↗
PubMed2005

Association of a common coding polymorphism (N453S) of the cytochrome P450 1B1 (CYP1B1) gene with optic disc cupping and visual field alteration in French patients with primary open-angle glaucoma.

PURPOSE: To investigate a role of common polymorphisms of the CYP1B1 gene in French patients with primary open-angle glaucoma (POAG). METHODS: Six common CYP1B1 variants, 5 coding and one in promoter, were compared in 224 unrelated French Caucasian POAG patients, excluding those with a CYP1B1 mutation, and in 47 population-matched controls with a normal ophthalmic examination. Allelic associations were assessed with the D' and r2 parameters. An effect of the representative variants on subphenotypes, including the age and the intraocular pressure at diagnosis, the cup to disk ratio, and the visual field alteration, was tested by multivariate analyses. RESULTS: Allele and haplotype frequencies were similar in patients and in controls. Five variants formed two groups with tightly correlated alleles while the sixth one, N453S, was independent. The age and the intraocular pressure at diagnosis were not influenced by any of the variants. In contrast, the 453*Serine allele was associated with decreased cupping of the optic disk (Odds ratio=0.32, 95% CI: 0.15-0.70; p=0.0036) and with a milder alteration of the visual field (p=0.025). CONCLUSIONS: The common N453S coding variant of CYP1B1 is potentially a factor of severity in POAG patients.

Alleles↗
PubMed2002

Effects of visual-field inversions on the reverse-perspective illusion.

The 'reverse-perspective' illusion entails the apparent motion of a stationary scene painted in relief and containing misleading depth cues. We have found that, using prism goggles to induce horizontal or vertical visual-field reversals, the illusory motion is greatly reduced or eliminated in the direction for which the goggles reverse the visual field. We argue that the illusion is a consequence of the observer's inability to reconcile changes in visual information due to body movement with implicit knowledge concerning anticipated changes. As such, the reverse-perspective illusion may prove to be useful in the study of the integration of linear perspective and motion parallax information.

Adult↗
PubMed1997

[Visual field defect in eyes with branch retinal artery occlusion].

There have been few clinical studies that analyzed quantitatively the visual field defects observed in eyes with branch retinal artery occlusion. In the current report we retrospectively studied Humphrey static perimetric results in 7 eyes and Goldmann kinetic perimetric results in 8 eyes with branch retinal occlusion. All but one eye showed altitudinal-like field defects. The static perimetric results demonstrated large difference between sensitivities in each pair of upper and lower measured points adjacent to the horizontal line nasal to Mariott's scotoma, which indicated a steep slope between the defective field and the normal area. The defective field showed either absolute scotoma or sensitivity loss of 20 dB or larger.

Adolescent↗
PubMed1987

A computerized system for measuring detection sensitivity over the visual field.

A device is described for comprehensively measuring the capability of human operators to detect and react to visual signals occurring at a variety of locations throughout the functional visual field. The system is completely automated and computerized, and provides both documentation files and descriptive graphics of the operator's performance immediately upon completion of testing. Sensitivity of detection can be measured for red, yellow, and green stimulus colors in a testing configuration which mimics commonplace surveillance of the ordinary viewing field. An abbreviated listing of the main operating program software is provided.

Computer Systems↗
PubMed1991

[Automatic perimetry of the central visual field in diseases of the macula].

We developed a program for testing the central 12 degrees of the visual field with a spatial resolution of 1.6 degrees that was easy to operate. The program was designed for the Octopus computer-perimeter and created by means of the SARGON-utility. Our way of examining differed slightly from the standard Octopus procedure. We tested 16 normal eyes and 13 eyes of patients with various diseases of the central retina. Our normal values of differential threshold sensitivities were about 1.8 dB below the normal values of the Octopus system. Sensitivity and specificity of the program were nearly identical irrespective of using our normal values or the Octopus normal values for the calculation of the above mentioned parameters. Sensitivity was 84.6%, specificity 87.5%. The ability of the program to correctly localize retinal defects was shown. The program was designed for follow-up of patients having undergone paramacular lasercoagulation.

Adult↗
PubMedDate not supplied

Visual field (Octopus 1-2-3) in normal subjects divided into homogeneous age-groups.

PURPOSE: To determine the values in decibels of retinal sensitivity within the central 26 degrees of the visual field of normal subjects divided into homogenous age groups using the Octopus 1-2-3; to compare the values of retinal sensitivity we have found with those considered normal in the statistical package obtained by a multicenter study performed in 1994 with Octopus 201. METHODS: 181 subjects divided into 6 homogeneous age groups (10 to 19 yr; 20 to 29 yr; 30 to 39 yr; 40 to 49 yr; 50 to 59 yr and 60 year-old or older) were evaluated. Data on visual sensitivity and age, average sensitivity of central and paracentral regions and eccentricity were calculated. RESULTS: The average visual sensitivity of all groups was 26.77 +/- 1.74 dB. Correlation between visual sensitivity and age evaluated by linear regression was 28.4 - 0.040 x (age) for the whole sample and 28.7 - 0.050 x (age) for subjects aged 20 or more. Sensitivity reduction by eccentricity was -0.30 dB/degree for the whole sample and for subjects aged 20 or more. CONCLUSIONS: Correlation between retinal sensitivity values and age based on the autoperimeter Octopus 201 (average sensitivity of 31.2 - 0.064 x age) is different from that found in this study: average sensitivity of 28.4 - 0.040 x (age) for the whole sample; 28.7 - 0.050 x (age) for subjects aged 20 or more. Values obtained with the Octopus 1-2-3 autoperimeter cannot be compared with those by other Octopus models (101, 201 and 500) due to their distinct features.

Adolescent↗
PubMed1978

Perimetry of contrast detection thresholds of moving spatial sine wave patterns. I. The near peripheral visual field (eccentricity 0 degrees-8 degrees).

Contrast detection thresholds for moving spatial sine wave gratings were obtained, at the fovea, and at eccentricities of 1 degree, 2 degrees, 4 degrees, 6 degrees, and 8 degrees on the nasal horizontal meridan, for two subjects. The target field subtended 30 X 30 minutes of arc. The spatial frequency range extended from 2 cpd up to the spatial resolution limit, the temporal frequency range from 0.1 Hz up to the CFF. Mean retinal illuminance was 10 trolands. We find for these conditions: (i) Contrast detection thresholds are higher, the higher the spatial and/or temporal frequency of the stimulus. (ii) Acuity appears to be independent of the temporal frequency, the CFF appears to be independent of the spatial frequency. (iii) The higher the eccentricity, the higher the contrast detection threshold for any drifting sine wave pattern. The threshold doubles roughly any 2 degrees-3 degrees for spatial frequencies of 2-20 cpd, except that the visual field for a given fineness of grating is blind beyond a certain critical eccentricity. This critical eccentricity is a monotonically decreasing function of the spatial frequency of the grating. These measurements do not support the hypothesis that coarse patterns are preferentially detected at extrafoveal sites in the visual field.

Adult↗
PubMed1995

Correlation of visual field with scanning confocal laser optic disc measurements in glaucoma.

OBJECTIVE: To evaluate the correlation between structural optic disc measurements that were obtained with a scanning confocal laser tomograph and functional measurements that were obtained with automated static threshold perimetry. DESIGN: Cross-sectional study. SETTING: An American school of medicine. PATIENTS: Forty-six patients (mean +/- SD age, 63 +/- 10 years) with early to moderate glaucoma (average mean deviation +/- SD, -4.8 +/- 6.2 dB). INTERVENTIONS: Automated static threshold perimetry (performed with either the Octopus G1 program, Interzeag, Schlieren, Switzerland, or the Humphrey 24-2 program, Allergan Humphrey, San Leandro, Calif) and confocal optic disc tomography (performed with the Heidelberg Retina Tomograph, Heidelberg [Germany] Engineering GmbH) were performed on one randomly selected eye per patient. MAIN OUTCOME MEASURE: The correlation between the visual field indexes, namely, the mean deviation and corrected pattern SD, and the topographic measurements for the optic disc and nerve fiber layer. RESULTS: A statistically significant correlation was found between the third central moment of the frequency distribution of the depth values for the optic disc structures and the visual field indexes. Pearson correlation coefficients were r = -.65 (P < .0001) and r = .55 (P < .0001) for the mean deviation and corrected pattern SD, respectively. CONCLUSION: The third central moment of the depth distribution for the optic disc measurements is strongly related to the overall shape of the optic disc cup and is a robust indicator of the degree of glaucomatous optic nerve damage.

Cross-Sectional Studies↗
PubMed1996

Left and right visual field advantages are a function of scotopic and photopic retinal adaptation, respectively, in simple reaction time to near-threshold targets.

Modulation of stimulus luminance in a tachistoscopic face discrimination task has been found to significantly invert visual hemifield advantage in reaction time (RT) (Sergent, 1982a, Sergent, 1982b). However, there is no more physiological rationale for that than for a similar effect, say, of retinal adaptation, and it is even conceivable that the latter may have confounded the former in past experiments. The experiments reported here were therefore designed to tease out the relative contributions of stimulus luminance and of background illumination (i.e., retinal adaptation) in a simple RT task. Two equally difficult conditions of dim targets were set up, one with light-adapted subjects and one with dark-adapted subjects. Similarly, two equally difficult conditions of bright targets were set up with light and dark-adapted subjects. It was found that dim targets (near detection threshold) yielded a significant right visual field RT advantage in light-adapted subjects and that dim targets (equally near detection threshold) yielded a significant left visual field RT advantage in dark-adapted subjects. Future experiments will determine whether cone-mediated RT to detection is left hemisphere dominant and whether rod-mediated RT to detection is right hemisphere dominant.

Adaptation, Ocular↗
PubMed1993

Masking and visual field effects on a lateralized rod-and-frame test.

The rod-and-frame test (RFT) has been widely used in the study of sex differences in spatial abilities. However, laterality studies involving this test are very scarce. An experiment was conducted to investigate whether laterality effects would be affected by post-stimulus masking. Ninety-six subjects participated in the experiment. For half the subjects, stimuli were followed by a blank screen, while for the other half, stimuli were followed by a mask. An overall left visual field advantage (LVFA) was found in the task. An interaction of sex of subjects, masking conditions, and frame tilt was also found. Further analyses showed that the sex by angle of frame interaction was significant when a mask was presented after the stimuli, but not when no mask followed the stimuli. Data tended to confirm the hypothesis that the LVFA was only significant when a mask was presented after the stimuli. These findings demonstrate the usefulness of a masking procedure in visual field studies, whereas the right hemisphere advantage found on the RFT is consistent with previous findings with visuo-spatial tasks.

Adolescent↗
PubMed1975

Optic disk topography and visual field defects in patients with increased intraocular pressure.

One hundred one eyes of 54 ocular hypertensive patients were studied to determine the value of optic disk evaluation in predicting the presence or absence and the location and type of visual field defects by means of binocular slit-lamp examination and projected 35-mm monocular color slides. We suspected visual field loss erroneously in only one patient, and failed to detect ten (16%) of 61 eyes with field defects. An examiner experienced in slit-lamp evaluation of the optic disk can accurately predict the presence, absence, and location of field defects in most cases by stereoscopic evaluation of disk topography.

Adult↗
PubMed1995

Projections from the 17/18 visual area transition zone to the ipsilateral visual field representation in the cat superior colliculus.

We demonstrate by retrograde tracing methods that the transition zone between visual cortical areas 17 and 18--where a representation of the ipsilateral visual field (IVF) has been described--projects to the IVF representation in the ipsilateral superior colliculus. The stratum griseum superficiale is the target of this retinotopically organized cortical projection to the rostral part of the superior colliculus.

Animals↗
PubMed1975

A quantitative study of the projection area of the central and the paracentral visual field in area 17 of the cat. I. The precision of the topography.

1. In the course of long oblique penetrations through the postlateral gyrus a variation in the position of the receptive fields (RF-scatter) of single cells recorded extracellularly is observed. This is superimposed on the continuous topological representation of the retina. Spezifying the RF-positions by the azimuthal and elevation coordinates of their geometrical centers, the standard deviation (SD) of the mean RF-positions of cells recorded in 200 mum long horizontal sections of cortex is calculated and the total radial scatter of RF-positions (Sanderson, 1971) as defined: (see article) is determined. The radial scatter is found to have its smallest value (1 degree visual angle (v.a.)) in the projection area of the functional center of the area centralis increasing to 3-4 degrees v.a. at 10 degrees eccentricity. 2. The mean RF-diameter as defined: (see article) is centrally 0.7 degrees v.a. increasing to 2.6 degrees v.a. at 10 degrees eccentricity. The ratio of the largest RF-diameter to the smallest RF-diameter is between 7-9 and remains almost constant over the central 10 degrees of the projection area. The magnification factor (M) as defined: mm Cortex/degree v.a. is centrally 2.3, decreasing paracentrally to 0.6. 3. The cells in area 17 whose RFs have the same direction in the visual field constitute the spatial subunit of the retinocortical projection. The diameter of the spatial subunit is calculated as: (see article). The spatial subunit functionally represents, therefore, that part of the visual field whose location and area is calculated by averaging over the RFs of the individuals of its cell population. It is found that the cells belonging to a spatial subunit are distributed within a cortical cylinder of 2.6-2.8 mm in diameter, the peak of the distribution coinciding with the central axis of the cylinder. 4. Within the projection area of the central 10 degrees of the retina in area 17 the spatial subunits have the same diameter. This suggests that each retinal ganglion cell is functionally connected with an equal number of cells in area 17 irrespective of its position within the retina and that, therefore, the retinocortical projection is organized on the basis of a stereotyped schema if a basic spatial relationship is concerned.

Animals↗