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Visual Field Examinations (visual + field_examination)

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Medical Sciences	100%

Selected Abstracts

Evaluation of cerebrospinal fluid pressure in patients with Alzheimer's disease as a possible cause of glaucoma

ACTA OPHTHALMOLOGICA, Issue 2009
S KIEKENS
Purpose To investigate whether cerebrospinal fluid (CSF) pressure and trans-lamina cribrosa pressure gradient play a role in the pathogenesis of glaucoma. Our hypothesis is that a low cerebrospinal fluid (CSF) pressure may be correlated with the presence of glaucoma. The first objective is to investigate whether the CSF pressure in Alzheimer's disease (AD) patients with glaucoma is lower than in AD patients without glaucoma. The second goal is to evaluate an animal model with AD for the incidence and prevalence of glaucoma. If glaucoma is present histopathological analysis will be performed on retina and optic nerve, to search for Alzheimer-type changes. Methods Newly diagnosed AD suspects will undergo a lumbar puncture with CSF manometry, during neurological work-up. Ophthalmological evaluation consists of best corrected visual acuity, slit lamp biomicroscopy, gonioscopy, fundoscopy and pachymetry. Diagnosis of glaucoma or ocular hypertension will be made on the basis of visual field examination, optic disc evaluation and IOP measurement. Correlation between CSF pressure, trans lamina cribrosa pressure gradient and the presence of glaucoma will be calculated. The prevalence of low tension glaucoma will be compared to the prevalence of chronic open angle glaucoma with elevated IOP. In the second part of the project a genetically modified strain of mice with AD will be examined and screened for the development of glaucoma. Opthalmological examination will consist of IOP measurement, corneal pachymetry, optic disc evaluation and visual evoked potentials with flash. Histopathological analysis will be performed by the team of Prof De Deyn PP. Results will follow Conclusion will follow [source]

Tilted disc syndrome may mimic false visual field deterioration

ACTA OPHTHALMOLOGICA, Issue 6 2008
Marja-Liisa Vuori
Abstract. Purpose:, Tilted disc syndrome is a congenital anomaly of the eye characterized by mostly upper temporal visual field defects. The aim of the present study was to evaluate the effect of gradual myopic correction in the improvement of visual field defects associated with tilted disc syndrome. Methods:, The visual field was examined in 38 eyes of 24 patients using standard Goldmann perimetry. The isoptres IV-4e, I-4e, I-3e and I-2e were plotted. The defective isoptres were tested again with gradually increasing myopic correction until no further change was noted. Results:, The most common type of defect was a relative upper temporal defect (19 eyes). Temporal relative defects were found in five eyes, upper altitudinal field defects in six eyes, an enlarged blind spot in four eyes, and an inferior field defect in one eye. The visual field defect partly or totally disappeared with increased myopic correction in 18 (50%) eyes. The mean improvement was 17.0 ± 6.2 degrees and the mean additional myopic correction was 3.1 ± 1.5 D. Conclusions:, Even a small change in near correction during visual field examination may imply worsened or improved visual field defects in tilted disc syndrome. To prevent a false interpretation of field deterioration in a patient with tilted disc syndrome and glaucoma, visual field assessment should include examination with the myopic correction that provides the maximal improvement of the defective visual field. [source]

Vigabatrin and Epilepsy: Lessons Learned

EPILEPSIA, Issue 7 2007
John M. Wild
Summary:,Purpose: The risk factors for visual field loss attributable to vigabatrin (VAVFL) are equivocal. This multinational, prospective, observational study aimed to clarify the principal/major factors for VAVFL. Methods: Interim analysis of three groups with refractory partial epilepsy, stratified by age (8,12 years; >12 years) and exposure to vigabatrin (VGB). Group I comprised participants treated with VGB for ,6 months, Group II participants previously treated with VGB for ,6 months who had discontinued the drug for ,6 months and Group III those never treated with VGB. Perimetry was undertaken at least every six months, for up to 36 months; results were evaluated masked to drug exposure. Results: Based upon 563 participants in the locked data set, 432 yielded one or more Conclusive visual field examinations. For Group I, the frequency of VAVFL at the last Conclusive examination was 10/32 (31.2%) for those aged 8,12 years and 52/125 (41.6%) for those aged >12 years. For Group II, the proportions were 4/39 (10.3%) and 31/129 (24.0%). No cases resembling VAVFL manifested in Group III. VAVFL was associated with duration of VGB therapy (Odds ratio [OR] 14.2; 95% CI 5.0 to 40.5); mean dose of VGB (OR 8.5; 95% CI 2.2 to 33.2); and male gender (OR 2.1; 95% CI 1.2 to 3.7). VAVFL was more common with static than kinetic perimetry (OR 2.3, 95% CI 1.3 to 4.2). Conclusions: The therapeutic benefit of VGB is counteracted by the progressive accrual of the risk of VAVFL with continued exposure and with increase in mean dose. [source]

Determining rates of visual field progression in glaucoma

ACTA OPHTHALMOLOGICA, Issue 2008
B CHAUHAN
Purpose To provide practical guidelines on detecting rates of visual field progression in glaucoma Methods Using a mixture of real patient data, computer simulation and statistical analysis, the frequency of visual field examinations for detecting various rates of visual field change were determined. Results Our results show that the ability to detect rates of visual field change depends critically on the magnitude of the change we wish to detect and the variability of visual fields. They also show that performing only one visual field per year will lead to failure to detect very significant visual field loss. The statistical power to detect clinically meaningful rates increases with 2 or 3 examinations per year Conclusion This study provides guidance to general ophthalmologists and glaucoma specialists on detecting rates of visual field progression in glaucoma. Commercial interest [source]

Vigabatrin: longterm follow-up of electrophysiology and visual field examinations

ACTA OPHTHALMOLOGICA, Issue 5 2003
Peter Hardus
Abstract. Background:,To report the results of repeated electrophysiological and visual field examinations in patients with vigabatrin-associated visual field loss (VGB-VFL) and the relationship between these electrophysiological findings, the cumulative dose of vigabatrin and the extent of visual field loss. Methods:,Twenty-two eyes of 11 patients with VGB-VFL were studied. All patients underwent surgery for therapy-resistant epilepsy. Repeated electro-oculograms (EOGs) and flash electroretinograms (ERGs) were made and the cumulative dose of vigabatrin and the visual field loss were recorded after a period of 37,47 months. Results:,The visual field loss was stable in patients who had stopped vigabatrin at the time of the first examination. There was a slight increase in VFL in patients who continued vigabatrin. During the second EOG and ERG, abnormalities in scotopic and photopic a-wave latencies and in scotopic b-wave amplitude were found in more than 50% of patients. Only b-wave latency became normal, while EOG, a-wave latency, a-wave amplitude and b-wave amplitude stayed abnormal. The amount of VFL and the cumulative dose of vigabatrin were statistically correlated with the b-wave amplitude, mainly photopic, found during the first and second examinations. Conclusion:,After 4 years, EOG, flash ERG and visual field loss had not improved in patients with VGB-VFL. The statistically significant correlation found during the first examination between the amount of VFL and the cumulative dose of vigabatrin with the (mainly photopic) b-wave amplitude remained constant. [source]