Pathogenic microRNAs Common to Brain and Retinal Degeneration; Recent Observations in Alzheimer’s Disease and Age-Related Macular Degeneration

OBJECTIVES We analysed different risk factors involved in the onset of both Alzheimer's disease (AD) and age-related macular degeneration (ARMD). The putative relation between both disorders was studied. METHODS We studied 57 subjects to determine the correlation between AD and ARMD. Thirty-three of the subjects suffered dementia (cases), whereas 24 of them (controls) did not. Firstly, anamnesis was performed for all individuals. We then examined the macular area of the eye using a non-midriatic TRV-50VT fundus camera. Significant odds ratio (OR) results were used as a statistical tool to survey the putative link between AD and ARMD. RESULTS The OR test results showed that ARMD was associated with Alzheimer's disease. The occurrence of ARMD was significantly higher for cases (42.4%) than for controls (25%). On this basis, we inferred a cause-effect relation linking both variables. Our dataset suggested that the control group was more protected against ARMD than the case group, as revealed by Fisher's exact test (P = 0.649). However, such a difference between both groups was not strongly supported. CONCLUSIONS We suggest that AD and ARMD may have common factors concerning etiology and pathogenesis. Our dataset did not allow us to show a significant relation between both disorders, which is likely due to sample size and/or to age differences in the two studied groups. Even so, we feel that the possibility of such an association is justified, and future surveys to test this possibility are warranted.