Microvascular Structure and Network in the Retina of Patients With Ischemic Stroke

Abstract

; and neurodegenerative diseases (including cognitive decline, dementia, and cerebral atrophy). [6][7][8] These findings further support the concept that microvascular pathology may play an important role in the development of a wide range of age-related brain diseases, such as stroke, dementia, and Alzheimer disease. These retinal microvascular changes not only may represent cerebral small-vessel damage 9,10 but also may be the result of downstream effects of proximal largeartery disease.11 Retinopathy signs are, however, relatively late indicators of target organ damage in the eye and probably Background and Purpose-Microvascular disease has been implicated in the pathogenesis of stroke. The retina provides a window to assess microcirculation noninvasively. We studied the association between quantitatively measured retinal microvascular characteristics and acute ischemic stroke. Methods-We conducted a case-control study with acute ischemic stroke patients recruited from a tertiary hospital in Singapore and controls from the Singapore Epidemiology of Eye Disease program matched by 10-year age strata, sex, and race. Strokes were classified using modified Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. Retinal vascular parameters were measured from retinal fundus photographs using a computer program. Logistic regression models for stroke were constructed adjusting for age, sex, race, and additionally for smoking, hypertension, diabetes mellitus, and hypercholesterolemia.

Retinal Vascular Fractals and Cognitive Impairment

“…Our data provide additional support that these changes in the retinal vascular network are associated with cognitive impairment. Furthermore, our findings that reduced arteriolar and venular fractal dimensions are associated with preclinical stages of dementia are in line with those of previous studies showing that these retinal parameters are linked not only to clinical outcomes such as acute ischemic stroke and dementia but also to markers of cerebral small vessel disease such as lacunar infarcts and cerebral microbleeds [8,9,24,25,26]. Pathophysiologically, a sparser network as reflected by a reduced fractal dimension is a consequence of retinal vessel rarefaction and collapse, which may lead to hypoxia in the retina [27].…”

“…With recent advances in digital retinal imaging and analysis techniques, we are now able to objectively quantify the structure and pattern of the retinal microvascular network, which may reflect earlier and more subtle changes before the appearance of overt signs. Novel retinal vascular parameters such as fractal dimensions, which reflect the optimality of the vascular network, are of particular interest as they have recently been found to be associated with both stroke and dementia [8,9]. In view of these associations with clinical disease, we hypothesized that these early retinal vascular network changes may also be present even in the preclinical stages of dementia.…”

Revolution of Alzheimer Precision Neurology. Passageway of Systems Biology and Neurophysiology

“…Recent studies applying non-invasive retinal imaging in live AD patients, which detected NFL thinning [466, 477], increased inclusion bodies [554, 555], reduced blood flow, microvasculature alterations, and oxygen saturation in arterioles and venules [479, 556, 557], and importantly, hallmark Aβ deposits [485], are encouraging first steps towards the development of practical tools for predicting disease risk and progression. Since the retina in other ND such as multiple sclerosis, ischemic stroke, and Parkinson’s disease also exhibits pathophysiological processes similar to those detected in the brain [501, 558–561], retinal imaging may also facilitate differential diagnosis for different proteinopathies, neurodegenerative and neurological diseases.…”

The Role of the Hypoxia Response in Shaping Retinal Vascular * Development in the Absence of Norrin/Frizzled4 Signaling

“…In humans, dilated and tortuous vessels in the posterior pole are associated with retinopathy of prematurity [54][55][56] and tortuous veins are associated with branch vein occlusion 57 . A recent study suggests that quantitative assessment of retinal microvascular tortuosity may have predictive value for cardiovascular health in the general population, as there is a statistically significant increase in tortuosity in subjects who have had an ischemic stroke compared to an age-matched control cohort 58 . It would be interesting to explore the mechanisms responsible for the development of vessel tortuosity in the Nrp1 mutant retina to determine whether it arises simply as a consequence of hypoxia due to underdevelopment of the deep vascular plexus or whether it also reflects aberrant regulation of EC proliferation due to loss of Nrp1 function.…”