Increased Wall:Lumen Ratio of Retinal Arterioles in Male Patients With a History of a Cerebrovascular Event

Abstract

Abstract-Arterial hypertension is a major risk factor for stroke, and retinal vessels can be regarded as a mirror of the cerebral vasculature. Whether vascular remodeling of retinal arterioles with ageing and hypertension plays a role in cerebrovascular risk stratification has not yet been adequately addressed. In study 1, retinal arteriolar structure was assessed in 182 normotensive volunteers and 117 patients with essential hypertension. In study 2, we compared retinal arteriolar structure among 74 normotensive volunteers, 47 patients with treated essential hypertension, and 18 subjects with a history of a cerebrovascular event. Retinal arteriolar structure was assessed using scanning laser Doppler flowmetry and automatic full-field perfusion imaging analysis. In study 1, wall:lumen ratio of retinal arterioles revealed a significant correlation with age (rϭ0.198; Pϭ0.001). In study 2, wall:lumen ratio was highest in patients with a history of a cerebrovascular event compared with treated hypertensive and normotensive subjects (0.46Ϯ0.08, 0.36Ϯ0.14, and 0.35Ϯ0.12; Pϭ0.007). When the treated group with hypertension was divided into 2 subgroups according to the quality of blood pressure control, patients with poor blood pressure control showed higher wall:lumen ratio than subjects with good blood pressure control (0.40Ϯ0.13 versus 0.31Ϯ0.13; Pϭ0.025). Thus, assessment of wall:lumen ratio of retinal arterioles emerged as an attractive tool to identify treated patients with hypertension with increased cerebrovascular risk.

Reliability of Different Image Analysis Methods for Scanning Laser Doppler Flowmetry

“…Possible limitations of the study include the small sample size (n = 13), the measurements not synchronized on the cardiac cycle, and the use of diffuse natural lighting rather than constant artificial lighting. 14 In conclusion, we found that default HRF software, using a cursor-based method, does not provide reliable measures of capillary circulation parameters from HRF topographs. Newer image analysis software (AFFPIA) utilizing the full field of topographic images improves the reliability substantially and provides high intraobserver reliability for repeated measures on the same images, and high intra-subject reproducibility for measures on different images taken from the same subject over a short period of time.…”

“…12 So, for a given cursor size, we would expect the AFFPIA reliability to be better than for HRF software. All image analysis issues that affect reliability will affect reproducibility as well as imaging-related issues, such as choice of location within the eye itself, distance between camera and eye, room lighting, sharpness of topographic image, and changes within the subject, such as level of relaxation 14 and ability to concentrate and fixate. 14,28,33,40,41 The effect these imaging-related factors have on reproducibility will likely increase as the time between images increases.…”

Central Pulse Pressure Is an Independent Determinant of Vascular Remodeling in the Retinal Circulation

“…13 Indeed, by using SLDF, we could show that WLR of retinal arterioles is increased in patients with hypertension and cerebrovascular events compared with treated hypertensives and normotensives. 17 Moreover, we have shown that WLR seems to be a robust indicator of the severity of hypertension, 26 the presence of early renal damage, 27 and, in contrast with arteriolar-to-venular ratio, is related to the extent of atherosclerotic damage in the carotid artery, as indicated by evaluation of the intima-media thickness. 28 Hence, the major and novel finding of this observational study is that central PP is a strong and an independent predictor of vascular remodeling (WLR) in the retinal circulation beyond classical CV risk factors and additional factors that are proposed to have an impact on vascular structure.…”

“…17 Briefly, an arteriole with the size between 80 and 140 µm of the superficial retinal layer in a retinal sample of 2.56×0.64×0.30 mm was scanned within 2 seconds at a resolution of 256 points × 64 lines × 128 lines. A specific length of the arteriole, reflecting arteriolar structure during 1 heart beat (1 systole and 1 diastole), was used for analyses, and the diameters were assessed every 10 µm of this specific length of the arteriole; the mean of measured diameters was finally considered for analyses.…”

Pilot Study for the Evaluation of Morphological and Functional Changes in Retinal Blood Flow in Patients with Insulin Resistance and/or Type 2 Diabetes Mellitus

“…An increased arterial retinal WLR has been described in patients with a history of cerebrovascular events. 33,34 In addition, an increased retinal WLR was found to be associated with an increased albumin excretion rate. 35 An increase in retinal arterial WLR can be a consequence of wall thickening, narrowing of the lumen, or a combination of both.…”