The Impact of the Eye in Dementia: The Eye and its Role in Diagnosis and Follow‐up

Over the last few decades, the importance of ophthalmic examination in neurodegenerative diseases of the CNS has reportedly increased. The retina is an extension of the CNS and thus should not be surprising to find abnormal results in both the test exploring visual processing and those examining the retina of patients with CNS degeneration. Current in vivo imaging techniques are allowing ophthalmologists to detect and quantify data consistent with the histopathological findings described in the retinas of Alzheimer’s disease (AD) patients and may help to reveal unsuspected retinal and optic‐nerve repercussions of other CNS diseases. In this chapter, we perform an analysis of the physiological changes in ocular and cerebral ageing. We analyse the ocular manifestations in CNS disorders such as stroke, AD and Parkinson’s disease. In addition, the pathophysiology of both the eye and the visual pathway in AD are described. The value of the visual psychophysical tests in AD diagnosis is reviewed as well as the main findings of the optical coherence tomography as a contribution to the diagnosis and monitoring of the disease. Finally, we examine the association of two neurodegenerative diseases, AD and glaucoma, as mere coincidence or possible role in the progression of the neurodegeneration.

Do 5-Year-Old Children Perform Dual-Task Coordination Better Than AD Patients?

A cross-sectional study was carried out to examine the pattern of changes in the capacity to coordinate attention between two simultaneously performed tasks in a group of 570 volunteers, from 5 to 17 years old. Method: The results revealed that the ability to coordinate attention increases with age, reaching adult values by age 15 years. Also, these results were compared with the performance in the same dual task of healthy elderly and Alzheimer disease (AD) patients found in a previous study. Results: The analysis indicated that AD patients showed a lower dual-tasking capacity than 5-year-old children, whereas the elderly presented a significantly higher ability than 5-year-old children and no significant differences with respect to young adults. Conclusion: These findings may suggest the presence of a working memory system’s mechanism that enables the division of attention, which is strengthened by the maturation of prefrontal cortex, and impaired in AD. (J. of Att. Dis. 2016; 20(2) 87-95)

Macular Thickness as a Potential Biomarker of Mild Alzheimer's Disease

Although several postmortem findings in the retina of patients with Alzheimer's disease (AD) are available, new biomarkers for early diagnosis and follow-up of AD are still lacking. It has been postulated that the defects in the retinal nerve fiber layer (RNFL) may be the earliest sign of AD, even before damage to the hippocampal region that affects memory. This fact may reflect retinal neuronal-ganglion cell death and axonal loss in the optic nerve in addition to aging.