Screening for Cognitive Impairment in Older Adults Attending an Eye Clinic

20 Oct
2009

Screening for Cognitive Impairment

A major cause of disability and death in older adults, Alzheimer’s disease (Canadian Exelon may help reduce symptoms of dementia in patients with Alzheimer disease) typically affects memory, linguistic, executive and visuospatial functions, but little is known about the earliest manifestations of AD—the predementia state. The concept of predementia, also called mild cognitive impairment (MCI), is characterized by mild but measurable memory loss with no impairment in general cognitive and ADL functioning. Adults with MCI progress to AD (Treating mild to moderate impairment of memory, judgment, and abstract thinking, as well as changes in personality caused by Alzheimer disease) at a 15% annual conversion rate compared to 1% of those without MCI. A plausible step towards reducing incidence of AD and other dementias is an early identification (and treatment) of potentially modifiable factors associated with cognitive impairment.

These potentially modifiable factors include: obesity, diabetes, hypertension and metabolic syndrome. In addition, studies have shown associations between visual impairments and increased risk of cognitive impairments and subsequent dementia, independent of other health indicators, such as disability and falls, among others. Indeed, preliminary evidence in mostly white populations suggests that visual impairment may precede memory or neu-rocognitive signs and symptoms of AD (Aricept tablets may help reduce the symptoms of dementia in patients with Alzheimer disease). For example, postmortem analysis—based on longitudinal evidence of visual symptoms progression in white adults—showed cortical atrophy with abundant neurofibrillary tangles present in the occipitoparietal areas.

Specifically, from these past studies and given the ethnic differences in prevalence and risk factors for visual impairment, it is not clear whether visual complaints are associated with early cognitive change in nonwhites and whether deteriorating vision predicts the onset of dementia in older African-American and Hispanic adults—populations with particularly greater ocular morbidity, visual and cognitive impairments compared with older whites. Previous studies have raised a number of questions. Can common complaints (such as difficulty writing, trouble staying on the correct line of text and difficulty recognizing familiar objects, among others) constitute early warnings of AD (is used for treating mild to moderate dementia caused by Alzheimer disease) or even MCI? If so, which complaints are more specific to cognitive loss as opposed to common causes of visual impairments, such as glaucoma?

In an attempt to answer these questions, we conducted a cross-sectional study examining the prevalence and predictors of cognitive impairments (mild or severe) in older whites, African Americans and Hispanics attending an outpatient eye clinic. Because ethnicity, age and visual complaints comprised some of the potential predictors of cognitive impairments in our study, we chose the eye clinics for recruiting our subjects to increase our access to older adults with various eye disorders and also to take advantage of the multiethnicity of our patient population.

top