Visual Impairment in Alzheimer's DiseaseThe documentation of a severe form of dementia by Alois Alzheimer in 1907 launched a massive investigation into the cause of this disorder. Some of the common symptoms of Alzheimer's disease include memory loss, impaired language ability, impaired judgment and learning (M. Wong et al., 1997). Alzheimer's disease (AD) is primarily a disease of the cerebral cortex. Alzheimer's disease is structurally marked by senile plaques, neurofibrillary tangles, and severe loss of neurons and synapses in the cerebral cortex. Alzheimer's disease is a neurodegenerative disease (Hof, Vogt, Bouras and Morrison 1997). Recent attention has focused on visual dysfunction in Alzheimer's disease (KU Loffler, DP Edward and MOM Tso 1995). Visual problems During the clinical evaluation of patients with mild to moderate AD dementia, visual difficulties such as: topographical agnosia, agnosia, alexia without agraphia and prosopagnosia are detected. Patients with AD The problem of describing individual components of a picture is consistent with the severity of cytochrome oxidase (CO) deficiencies in cortical association areas. Other deficits experienced by AD patients were texture discrimination, blue-violet discrimination, and motion detection at 4.72 degrees/s. When AD patients were compared to other age-matched controls, AD patients showed specific deficits in contrast sensitivity. Color vision deficits were only related to age (M. Wong-Riley, et al., 1997). Studies Selective degeneration of large ganglion cell axons was observed in the optic nerves of AD patients, suggesting impaired broadband vision. function. Although studies show that broadband visual abilities are not selectively impaired in AD. Dorsal studies of the LGN showed that magno- and parvicellular neurons were greatly affected in AD patients. Strangely, AD patients were impaired at low frequencies instead of high frequencies, as in older adults. This implies that the regions controlling the processing of low spatial frequencies in the primary visual cortex would be more affected than those controlling high frequencies (M. Wong-Riley, et al., 1997). The neuropathological examination of visually impaired brains in the study by Hof et al. (1997) revealed cortical atrophy dominating the posterior parietal cortex and the occipital lobe (Hof et al.). A study on beta-amyloid is considered to be an important factor in AD and has been found to be the main cause of senile plaques. AcetylcholineA number of neurotransmitters and neuromodulators, including acetylcholine (ACh), somatostatin, and glutamate, have been shown to be deficient in Alzheimer's disease. (ANNOUNCEMENT).