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Stimulus motion increases measured visual field extent in children 3.5 to 30 months of age.

PURPOSE: To examine the influence of stimulus motion on measured visual field extent of 3.5- to 30-month-old children and adults. METHODS: Each subject was tested with LED-hybrid and LED-kinetic perimetry procedures, using a black double-arc perimeter. Targets in both procedures were identical in size, color, luminance, contrast, and flicker rate. However, in the LED-hybrid procedure, peripheral targets were sequentially illuminated from more peripheral to more central locations, whereas in the LED-kinetic procedure, a peripheral target on a black wand was manually moved centrally along the perimeter arm. A subset of subjects was also tested with white sphere kinetic perimetry (WSKP). RESULTS: The LED-kinetic procedure produced larger measured visual field extent than the LED-hybrid procedure in 3.5-, 11-, 17-, and 30-month-olds, but not in 7-month-olds or adults. Data from subjects tested with WSKP indicated that both stimulus motion and discrepancies in scoring methods contributed to the difference reported previously between visual field measurements obtained with WSKP vs. LED-hybrid perimetry. CONCLUSION: In infants and toddlers, measured visual field extent is larger for moving than for nonmoving targets. Further research is needed to determine whether the effect of motion is related to the visual system or to attentional factors.

Adult↗

Using motion perimetry to detect visual field defects in patients with idiopathic intracranial hypertension: a comparison with conventional automated perimetry.

Motion perimetry, a method of visual field testing that uses computer graphics to measure motion perception, quantitates a subject's ability to detect a coherent shift in position of dots in a defined circular area against a background of fixed dots. Motion size threshold is defined as the smallest detectable circular target in which dot motion is detected. Subjects respond by touching a computer monitor screen with a light pen, first when they see a target (reaction time) and a second time where motion targets are detected (localization). Reaction time (msec) to the stimulus and localization error (number of pixels from target center) are then calculated and stored. We tested on eye in each of 20 idiopathic intracranial hypertension (IIH) patients and 40 age-matched normal subjects by conventional automated perimetry (Humphrey visual field analyzer, program 24-2) and motion perimetry. Pointwise probability plots of individual abnormal test points for size threshold responses were generated for the IIH patients based on the 95% confidence limits of the normal subject responses. An analysis of the subjects' visual field pairs (motion versus conventional automated perimetry) was performed based on these probability plots. The IIH patients had an elevated mean motion threshold (p < 0.001) and reaction time (p < 0.001) compared with the normal subjects. There were no significant differences for the localization errors. Based on the probability plot analysis, there was good correlation of the visual field defects between the two perimetry tests. In addition, motion perimetry identified nerve fiber bundle-shaped defects in nine patients in whom they were not detected with conventional automated perimetry.

Adult↗

Progression of visual field loss in patients with retinitis pigmentosa of sporadic and autosomal recessive types.

PURPOSE: We examined the natural course of patients with retinitis pigmentosa of the eight sporadic and five autosomal recessive forms over 5 years. METHODS: We measured the areas of the visual fields by Goldmann perimetry using a digitizer and a computer software. RESULTS: The visual field of V-4 isopters in 4 sporadic cases was approximately 200 cm2 during 30 years after the initial examination, but decreased down to 40 cm2 in the next 10 years. The visual field was reduced to half the normal field in 3 autosomal recessive cases early below the age of 25 years. In 4 sporadic and 2 autosomal recessive cases, the inferior temporal visual field was the widest at the onset of the disease, but exhibited the most severe loss. The superior nasal area was the narrowest initially, and showed the mildest progression. CONCLUSIONS: The visual field in retinitis pigmentosa is constricted age-dependently with severe loss of the inferior temporal visual area and mild damage to the superior nasal area.

Adolescent↗

The relationship between central corneal thickness-adjusted intraocular pressure and glaucomatous visual-field loss.

BACKGROUND: Although measurement of central corneal thickness (CCT) is increasingly becoming an important component of glaucoma risk analysis, significant controversy exists regarding the benefit of calculating a corrected intraocular pressure (IOP) value from measured IOP and CCT data. METHODS: Three hundred forty-four male subjects were identified from a VA eye clinic with one of the following clinical diagnoses: ocular hypertension (OHT), primary open-angle glaucoma (POAG), normal tension glaucoma (NTG), and normal tension glaucoma suspect (NTGS). Using one eye per subject, multivariate logistic regression and correlational analyses were performed to determine relationships between glaucomatous visual-field loss and several glaucoma risk factors, including adjusted IOP values. RESULTS: Multivariate logistic regression analysis did not identify CCT-adjusted IOP values as independent risk factors for development of either NTG or POAG-related glaucomatous visual-field loss. CCT, however, was found to be strongly associated with both NTG and POAG-related visual-field loss. Correlational analysis revealed a weak correlation between Ehlers-adjusted pre-treatment IOP and severity of POAG-related visual-field loss, but no other adjusted IOP values significantly correlated with severity of visual-field loss in either POAG or NTG. CONCLUSIONS: Our results suggest that adjusted IOP, as calculated using current algorithms, is not useful within glaucoma risk analysis, since adjusted IOP was unable to predict either presence or severity of glaucomatous visual-field loss in this study. CCT, conversely, was found to be a robust and independent predictor of glaucomatous visual-field loss. These findings, while supporting routine CCT measurements for all glaucoma suspects, do not support routine clinical computation of adjusted IOP values using current algorithms.

Aged↗

Visual field defects for vergence eye movements and for stereomotion perception.

An objective visual field can be mapped in terms of stimulus-induced eye movement. The authors used the scleral coil technique to record vergence and conjugate eye movements while stimulating different visual field locations with a 3 X 3 deg target whose image vergence was oscillated. For each of three subjects tested there was a visual field location where vergence eye movements were much weaker than in a control location of equal retinal eccentricity. On the other hand, conjugate eye movements driven from these two locations by lateral motion were similar. Field defects for ocular vergence coincided with regions in which oscillating retinal disparity failed to produce a sensation of motion in depth, although visual responses to static disparity were normal, and psychophysical thresholds for lateral motion showed no defect with either binocular or monocular viewing. It was concluded, therefore, that the perceptual stereomotion scotomata were not due to a monocular loss, but to a defective binocular interaction between motion signals from the left and right eyes, and that this defective interaction was specific for opposed rather than parallel motion in the two eyes. Furthermore, the visual loss was specific for motion rather than for position. The correlation between the field defects for ocular vergence and stereomotion perception leads the authors to suggest that the same defect in binocular interaction is responsible for both the eye movement and sensory abnormalities. Two candidate hypotheses are proposed: one is framed in terms of a single population, and the other in terms of two populations of cortical neurons.

Blindness↗

Automatic testing of the visual field using electro-oculographic potentials.

The central visual field is tested using static perimetry on a tangent screen located 1 m from the patient. During the test electro-oculographic (EOG) potentials, associated with eye movements, are recorded. For this purpose two pairs of electrodes are placed in such a way that one pair records the vertical and the other the horizontal component of the EOG potential. The EOG signals that are produced when the tested eye moves toward the light target on the screen are digitized and fed into a computer programmed to relate each pair of signals to the specific lamp on the tangent screen. The results of the test appear on a computer-printed chart that shows the distribution of the lamps on the testing board together with the information whether the lamp was seen by the subject. This method of visual field testing is both objective and automatic.

Automation↗

Kinetic perimetry assessment of binocular visual field shape and size in young infants.

Kinetic perimetry was used to measure the extent of the binocular visual field in 8 directions in 77 full-term infants tested as neonates, 4-week-olds, or 8-week-olds. The apparatus consisted of a black, 4-arm arc perimeter, a centrally-located 6-deg stationary white sphere, and an identical sphere that served as the peripheral target. Neonates showed larger visual fields than did 4- and 8-week-olds, perhaps due to the strength of the older infants' fixation of the central target. Infants at all ages showed significantly smaller fields than did adults. However, visual field shape was similar in infants and adults.

Age Factors↗

[Effect of ocular hypotensive medications in preventing the progression of visual field damage in patients with normal-tension glaucoma].

PURPOSE: We investigated the effect of ocular hypotensive medications and the risk factors for progression of visual field damage in patients with normal-tension glaucoma (NTG). SUBJECTS AND METHODS: Sixty-four NTG patients (64 eyes) followed at least 4 years with ocular hypotensive medications were studied regarding the probability of visual field stability using the Kaplan-Meier life-table analysis and multiple regression analysis with the Cox proportional hazards model. RESULTS: Probability of visual field stability was 56% at the 76-month follow-up. Mean intraocular pressure during the follow-up period and generalized cup enlargement type classified according to the optic disc shape were found to have significant influence on the progression of visual field damage. CONCLUSION: These findings suggest that ocular hypotensive medications are effective in stabilizing the visual field. We need to pay attention to the optic disc shape in patients with NTG.

Adult↗

Long-term fluctuation of the visual field in glaucoma.

We examined 756 automated threshold visual fields of 167 eyes of patients with glaucoma to determine the magnitude of the long-term fluctuation at individual test locations. Eyes were grouped into clinically stable or nonstable groups according to predefined clinical criteria. At individual test locations with initial sensitivities of 25 to 30 dB in clinically stable eyes, the 5th to 95th percentile value for subsequent measurements was +/- 4 dB. For initial sensitivities of 20 dB, this 90% range was +/- 6 dB, and for sensitivities 15 dB or less, the 90% range of subsequent values spanned sensitivities from almost zero to normal values. Long-term fluctuation correlated with short-term fluctuation (r = .363, P less than .0005), but not with age or intraocular pressure. There was no correlation of long-term fluctuation with eccentricity after correcting for the decreased sensitivity associated with greater eccentricity. Long-term fluctuation was greater in the nonstable group than in the stable group (P less than .0005). These data provide limits for fluctuation in stable patients with glaucoma, which will help guide clinical decisions about visual field progression.

Adult↗

Predictive factors for glaucomatous visual field progression in the Advanced Glaucoma Intervention Study.

PURPOSE: To investigate the risk factors associated with visual field (VF) progression in the Advanced Glaucoma Intervention Study (AGIS) with pointwise linear regression (PLR) analysis of serial VFs. DESIGN: Prospective, multicenter, randomized clinical trial. PARTICIPANTS: Five hundred nine eyes of 401 patients from the AGIS with a baseline VF score of or=7 VF examinations, and >or=3 years of follow-up were selected. MAIN OUTCOME MEASURE: Visual field progression. METHODS: This is a cohort study of patients enrolled in a prospective randomized clinical trial (AGIS). Worsening of a test location on PLR analysis was defined as a change of threshold sensitivity of >or=1.00 decibels a year, with P<or=0.01. Visual field progression was defined as worsening of at least 2 test locations within a Glaucoma Hemifield Test cluster with PLR analysis. Multivariate logistic regression was used to determine risk factors associated with VF worsening. Intraocular pressure (IOP) fluctuation was defined as standard deviation of the IOP at all visits after the initial surgery. RESULTS: The mean (+/- standard deviation) follow-up time and baseline AGIS score were 7.4 (+/-1.7) years and 7.7 (+/-4.4), respectively. Visual field progression was detected with PLR analysis in 151 eyes (30%). Older age at the initial intervention (P = 0.0012; odds ratio [OR], 1.30; 95% confidence interval [CI], 1.11-1.50), larger IOP fluctuation (P = 0.0013; OR, 1.31; 95% CI, 1.12-1.54), increasing number of glaucoma interventions (P = 0.01; OR, 1.74; 95% CI, 1.14-2.64), and longer follow-up (P = 0.02; OR, 1.19; 95% CI, 1.03-1.38) were associated with increased odds of VF progression. When regression analyses were repeated in eyes with and without a history of cataract extraction, IOP fluctuation was the only variable to be consistently associated with VF progression. CONCLUSION: Both increasing age and greater IOP fluctuation increase the odds of VF progression by 30% (for each 5-year increment in age and 1-mmHg increase in IOP fluctuation). The higher risk conferred by IOP fluctuation was consistently observed in eyes with and without a history of cataract extraction.

Adult↗

Central visual fields for short wavelength sensitive pathways in glaucoma and ocular hypertension.

While conventional clinical visual acuity and kinetic visual fields may be essentially normal in ocular hypertension and early stages of glaucoma, other foveal aspects of vision (eg color, spatial and temporal contrast sensitivity) may be quite abnormal. Specifically, a selective vulnerability of the short wavelength sensitive (SWS) visual pathways in these conditions has previously been noted. Here we studied the central visual fields of 33 primary open angle glaucoma (POAG) patients, 32 ocular hypertensives (OHT), and 24 age-matched normal controls using blue and yellow test flashes on bright yellow backgrounds. SWS cone and MWS and/or LWS cone pathway sensitivities were measured at the fovea and at 2.5 degrees, 5 degrees, 10 degrees and 15 degrees eccentricities, in either the inferior temporal (for OHT) or horizontal nasal retina (for POAG). As expected, all groups had normal sensitivity to yellow flashes--detected by LWS and/or MWS cones--in these meridians. By comparison, for the blue flashes--detected by the SWS cones--the POAG and OHT groups had sensitivity deficits, uniformly across the central visual field, of about 6X and 1.8X, respectively, compared to normals. While six of 31 (19%) OHT subjects had localized glaucomatous field defects (greater than 0.4 log units) in the non-foveal inferior temporal retina, none of the 12 OHT subjects who were also tested in the horizontal nasal retina showed loss in this meridian. Finally, while no POAG subjects had localized sensitivity loss for yellow flashes in the horizontal nasal retina, four did show local field defects with blue test flashes.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

A simple analog of visual field retinal projection.

Basic biophysical principles of the eye, such as the retinal projection of the visual field, bidimensional image inversion, blind point determination, visual field and retinal quadrants, perimetric principles, and determination of scotoma, are seen on a working anatomic model of the eye and its visual field that can easily be constructed at very low cost and from easily obtained materials: an opaque glass globe, a styrofoam hemisphere, a wood screen, bulbs, sockets, wire, and switches. This model has been used for many years in our undergraduate medical physiology courses and has replaced the classical model of candle image inversion by a converging lens.

Audiovisual Aids↗

The correlation of the visual field with scanning laser ophthalmoscope measurements in glaucoma.

PURPOSE: To assess the relationship between Humphrey visual field data and optic disc topographical data collected by the Heidelberg Retina Tomograph (HRT) scanning laser ophthalmoscope in chronic glaucoma patients. METHODS: The mean deviation (MD) and corrected pattern standard deviation (CPSD) from Humphrey visual fields of 106 eyes of 106 patients with glaucoma were analysed for correlation with the multiple topographical measures calculated by the HRT. RESULTS: Significant correlations were found between MD of the visual field and several optic disc measurements. These included neuroretinal rim volume, mean nerve fibre layer thickness and cross-sectional area, and the cup shape measure. CPSD correlated significantly only with mean nerve fibre layer cross-sectional area. This pattern was common to the whole circumference of the disc with the exception of the directly temporal segment. CONCLUSION: Optic disc topography performed by HRT reflects the optic disc pathology in correlation with perimetry.

Aged↗

Trabeculoplasty and visual field decay: a follow-up study using computerized perimetry.

15 eyes with glaucomatous visual field defects were followed with computerized perimetry before and nearly one year after Argon Laser Trabeculoplasty. An expected reduction of the IOP was achieved, the pressure being on an average 25.7 mm Hg before and 17.7 after the treatment. Performance values obtained at computerized perimetry were used to trace the trend of visual field development. There was a visual field decay during the period preceding the intervention. This trend did not change after trabeculoplasty.

Computers↗

[Visual field analysis after laser in situ keratomileusis].

OBJECTIVE: To evaluate the effects of laser in situ keratomileusis (LASIK) on the patients' visual field. METHODS: 92 eyes of 46 patients with mild, moderate, and high degrees of myopia were undergone LASIK. Perimetry was performed before and 1 day, 1 month, 3 months, 6 months after LASIK surgery by Humphrey II-750 visual field analysis. The central 30 - 2 fast threshold program was used to examine the change in central 30 degree. Mean defect (MD) and pattern standard deviation (PSD) were record. All operations were performed by an experienced surgeon. Statistical analyses were performed by SPSS using the randomized complete block design ANOVA (two factors analysis of variance). Differences among variables were evaluated by q-test (Student-Newman-Kueuls method). RESULTS: 93.5% patients obtained estimated best correct visual acuity or better at six months after LASIK. No complications were found in the subjects. No difference was found in fundus examinations before and after surgery. Intraocular pressure was normal at all preoperative and postoperative examinations. MD was significant differences among preoperative and postoperative values (P < 0.05, for all comparisons) and was correlated with visual acuity post-LASIK significantly (P < 0.05). While PSD did not show significant differences before and after LASIK (P > 0.05) and was not correlated with visual acuity post-LASIK. The indexes of visual field were not correlated with the degree of myopia and the other surgical parameters (P > 0.05). CONCLUSION: In current research, no significant visual field change was demonstrated pre-LASIK and post-LASIK after 6 months follow-up. The study suggests that LASIK does not affect the retinal physiological functions.

Adolescent↗

[The retinal nerve fiber layer in glaucoma. II. The status of the nerve fiber layer and development of changes in the visual field. Prospective study].

PURPOSE: To determine whether retinal nerve fiber layer (RNFL) photographs can predict future glaucoma visual field damage. METHODS: In a prospective study 158 red free photographs of the RNFL were made from November 1994 to June 1995. 28 eyes of 19 patients with ocular hypertension (repeated intraocular pressure over 21 mmHg and normal visual fields--Peristat 433 Rodenstock--at first examination) could be re-examined for an average time of 42.3 (SD 4.5) months. RESULTS: Only in one eye with normal RNFL at the first examination typical glaucoma visual field defects appeared (6%), but in 6 of 12 eyes (50%) with photographically demonstrable RNFL defects. The difference was statistically significant. CONCLUSION: There is only a minor probability, that visual field defects would appear during 3-5 years in eyes with normal RNFL photographs (6%), but about 50% of eyes with originally found RNFL defects.

Adult↗

Spatial and temporal analysis by neurons in the representation of the central visual field in the cat's lateral suprasylvian visual cortex.

We studied quantitatively the receptive-field properties of 74 units recorded from the representation of the central visual fields in the cat's lateral suprasylvian (LS) visual cortex. In agreement with previous workers, we found that LS receptive fields tended to be large and to lack discernible spatial structure. They resembled the complex receptive fields of areas 17 and 18 in their general organization. We examined the responses of these neurons to moving optimally oriented sinusoidal gratings that varied in spatial and temporal frequency of drift. Most LS neurons were selective for the spatial frequency of sinusoidal gratings; 7% responded to all spatial frequencies below a cutoff value. In agreement with previous reports, the optimal spatial frequencies for LS neurons covered a wider range than is seen in either area 17 or 18 alone (0.05-1 cycle/deg), but are certainly included in the range covered by both these afferent areas. Individual neurons in LS responded to a range of spatial frequencies broader than is typical for neurons in areas 17 and 18. The effect of varying the drift rate of otherwise optimal gratings was similar in LS to that reported for areas 17 and 18. Most neurons were optimally responsive to drift rates between 0.5 and 4 Hz, and resolved frequencies as high as 10-30 Hz. A few neurons had optima higher than 6 Hz and resolved frequencies in excess of 30 Hz. We conclude that the receptive fields of LS neurons reflect rather closely the properties of their afferents from areas 17 and 18.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Methodological variations in estimating apparent progressive visual field loss in clinical trials of glaucoma treatment.

OBJECTIVES: To compare methods to estimate the incidence of visual field progression used by 3 large randomized trials of glaucoma treatment by applying these methods to a common data set of annually obtained visual field measurements of patients with glaucoma followed up for an average of 6 years. METHODS: The methods used by the Advanced Glaucoma Intervention Study (AGIS), the Collaborative Initial Glaucoma Treatment Study (CIGTS), and the Early Manifest Glaucoma Treatment study (EMGT) were applied to 67 eyes of 56 patients with glaucoma enrolled in a 10-year natural history study of glaucoma using Program 30-2 of the Humphrey Field Analyzer (Humphrey Instruments, San Leandro, Calif). The incidence of apparent visual field progression was estimated for each method. Extent of agreement between the methods was calculated, and time to apparent progression was compared. RESULTS: The proportion of patients progressing was 11%, 22%, and 23% with AGIS, CIGTS, and EMGT methods, respectively. Clinical assessment identified 23% of patients who progressed, but only half of these were also identified by CIGTS or EMGT methods. The CIGTS and the EMGT had comparable incidence rates, but only half of those identified by 1 method were also identified by the other. CONCLUSIONS: The EMGT and CIGTS methods produced rates of apparent progression that were twice those of the AGIS method. Although EMGT, CIGTS, and clinical assessment rates were comparable, they did not identify the same patients as having had field progression.

Disease Progression↗