Neurological Disorders and Glaucoma - An Overview
ABSTRACT Due to the anatomic location of the N. opticus to the brain and its embryological development as a "bulging part of the brain", a close connection between the opticoneuropathy and certain neurological diseases exists. Glaucoma is a chronic neurodegenerative disorder and many cellular and molecular mechanisms of the chronic neurodegenerative diseases are common in the brain. For example, elevated levels of multiple biomarkers of Alzheimer's disease were found in the aqueous humor of patients with primary open-angle glaucoma. Also a decreased cerebrospinal fluid pressure (CSFP) has been demonstrated in patients with glaucoma and Alzheimer's disease. The resulting translaminar pressure difference is seen as one of the pathogenic mechanisms of the formation of the optic neuropathy in both diseases. Other hypotheses, such as the influence of oxidative stress, excitotoxicity, mitochondrial dysfunction, genetic factors and vascular factors play additional roles in the pathogenesis of the different diseases. Experimental studies have shown that dopaminergic amacrine cells are present in the retina. The dopamine in the retina is necessary for the light adaptation and the signal processing in the rods and cones. Parkinson's disease is characterised by a loss of dopaminergic neurons in the basal ganglia-substantia nigra pars compacta of the midbrain. These decreased levels of dopamine also have an effect on the eye and the afferent signal processing. So there are reductions in visual acuity, disturbances in colour vision and contrast sensitivity and reduction of the retinal nerve fiber layer in patients affected with Parkinson's disease. With the examples of Alzheimer's disease, Parkinson's disease and the chronic inflammatory disease multiple sclerosis, we demonstrate the association between the neurological diseases and the opticoneuropathy in primary open-angle glaucoma.
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ABSTRACT: The purpose of the current study was to reveal the occurrence rate of glaucoma among patients with Alzheimer's disease (AD). All 112 patients of four nursing homes in Upper Bavaria, Germany, who met the diagnostic criteria of probable AD, were incorporated into the study. Visual field defects and/or optic disc cupping compatible with the diagnosis of glaucoma were found in 29 out of 112 patients with AD (25.9%). When compared to a control group (5.2%) and to the prevalence of glaucoma in western countries revealed in a number of glaucoma surveys (2.6-4.7%), patients with AD may have a significantly increased occurrence rate of glaucoma. In addition, ocular hypertension with normal visual fields and normal optic nerve heads was not found in patients with AD. The prevalence of ocular hypertension in the control group was 7.8% and parallels previous surveys. Therefore, we assume that the optic nerve seems to be less resistant to elevated intraocular pressure levels in AD patients.European Neurology 02/2002; 47(3):165-8. DOI:10.1159/000047976 · 1.36 Impact Factor
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ABSTRACT: To evaluate the reproducibility of optical coherence tomograph (OCT) retinal nerve fiber layer (RNFL) measurements in normal and glaucomatous eyes by means of the commercially available OCT 2000 instrument (Humphrey Systems, Dublin, CA). Prospective instrument validation study. One eye each from 10 normal subjects and 10 glaucoma patients. Twenty subjects underwent a total of eight scanning sessions during two independent visits. In each session, five circular scans centered on the optic nerve head were performed. The first two sessions were performed by two experienced technicians. Followed by a 30-minute break, a third and a fourth session was completed by the same technicians. This sequence was duplicated on a second visit. Intrasession, intersession, intervisit, and interoperator reproducibility of quadrant and global RNFL measurements were calculated by use of a components of variance model. RNFL thickness. The coefficient of variation for the mean RNFL thickness was significantly smaller (P = 0.02) in normal eyes (6.9%) than in glaucoma eyes (11.8%). The estimated root mean squared error based on the statistical model using three scans per patient was 5.8 and 8.0 micrometer for normal and glaucoma eyes, respectively. A components of variance model showed most of the variance (79%) to be due to differences between patients. Only a modest contribution to variability was found for session (1%), visit (5%), and operator (2%). With the commercially available OCT, our results indicate that the RNFL measurements are reproducible for both normal and glaucomatous eyes.Ophthalmology 01/2001; 107(12):2278-82. DOI:10.1016/S0161-6420(00)00341-9 · 6.17 Impact Factor
Article: Optic neuritis in multiple sclerosis[Show abstract] [Hide abstract]
ABSTRACT: To review the clinical features, natural history, potential pathogenic mechanisms, differential diagnosis, and management of optic neuritis in multiple sclerosis. Relevant literature regarding optic neuritis in multiple sclerosis from 1970 to the present was reviewed. Optic neuritis is an acute inflammatory optic neuropathy. It is the most common type of optic neuropathy causing acute visual loss in young adults (peak age at 30-40 years), especially among women. Patients usually present with an acute reduction of visual acuity, orbital pain exacerbated by eye movements, dyschromatopsia, and an afferent papillary defect, with or without swelling of the optic nerve head. Visual field testing most often reveals central defects, but others, such as centrocecal, can also occur. Magnetic resonance image (MRI) scanning of the brain should be undertaken in all cases of acute optic neuritis for diagnostic and prognostic purposes. The brain lesions of multiple sclerosis are commonly seen as T2 ovoid high-signal white matter lesions on MRI scans of the brain located in perivenular regions perpendicular to ventricles with variable enhancement. For atypical presentations of optic neuritis, additional laboratory tests, such as cerebrospinal fluid analysis, serologic tests, and visual evoked potentials, prove to be useful in the diagnosis and subsequent management of the patient. The recommended treatment for optic neuritis is intravenous steroids, as shown in the Optic Neuritis Treatment Trial (ONTT). Optic neuritis is often the initial presentation of multiple sclerosis. Recent advances in the understanding of the immune basis for multiple sclerosis has led to earlier and more effective treatment of this disease.Ocular Immunology and Inflammation 10/2002; 10(3):161-86. DOI:10.1076/ocii.10.3.161.15603 · 1.44 Impact Factor