Visual Impairment in Alzheimers Disease :: Opthamology Alzheimers Disease Essays

Visual Impairment in Alzheimers DiseaseThe documentation of a severe form of dementia by Alois Alzheimer in 1907 began a massive investigation of the cause of this disorder. Some of the plebeian symptoms of Alzheimers Disease consist of memory loss, impaired language ability, impaired judgement, and skill (M. Wong, et al. , 1997). Alzheimers Disease (AD) is mainly a disease of the cerebral cortex. Alzheimers is marked structurally by the olden plaques, neurofibrillary tangles, and severe loss of neurons and synapses in the cerebral cortex. Alzheimers is a neurodegenerative disorder ( Hof, Vogt, Bouras, and Morrison 1997). Recent attention has been focused on opthalmic disfunction in Alzheimers Disease (K. U. Loffler, D. P. Edward, & M. O. M. Tso 1995). Visual ProblemsDuring the clinical evaluation of patients with mild to mitigate dementia of the AD type, optical difficulties such as topographic agnosia, visual agnosia, alexia without agraphia, and prosopagnosia are detected. A D patients have The problem of describing the individual components of a picture is consistent with the severity of cytochrome oxidase (C.O.) deficits in the association cortical areas. opposite deficits experienced by AD patients were texture discrimination, blue-violet discrimination, and 4.72 deg/sec motion detection. When AD patients were compared to other age-matched controls, AD patients had shown specific deficits in contrast sensitivity. Deficits in tint vision were only age-related (M. Wong-Riley, et al. , 1997). StudiesSelective degeneration of large ganglion cell axons was discover in the optic nerves of AD patients, which suggested an impairment of broad-band channel visual function. Although studies show that the broad-band visual capabilities are not selectively impaired in AD. Dorsal LGN studies have shown that both the magno- and parvicellular neurons were greatly affected in AD patients. Strangely, AD patients were impaired at low frequencies instead of the high frequencies, worry in old age. This implies that regions controlling the low spacial frequency bear on in the primary visual cortex would be affected to a greater extent than those for high frequency processing (M. Wong-Riley, et al. , 1997). The neuropathologic examination of the brains with visual impairment in the Hof et al. (1997) study revealed cortical atrophy dominating on the posterior parietal cortex and occipital lobe(Hof et al.). A study by Beta-amyloid is considered an important work out in AD and was shown to be the major cause in senile plaques. AcetylcholineA number of neurotransmitters and neuromodulators, including acetylcholine (ACh), somatostatin and glutamate have been found to be deficient in Alzheimers disease (AD).