A Review on the Extraction of Quantitative Retinal Microvascular Image Feature <s> The Image Processing Techniques for Analyzing and Detecting the Abnormal Features of the Retinal Vasculature in Stroke <s> BACKGROUND ::: Retinal microvascular abnormalities reflect damage from hypertension and other vascular processes. We examined the relation of such abnormalities to incident stroke. ::: ::: ::: METHODS ::: A cohort of 10358 men and women (aged 51 to 72 years) living in four US communities underwent retinal photography and standard grading for retinal microvascular abnormalities. The calibres of all retinal arterioles and venules were measured after digital conversion of the photographs, and a summary arteriole-to-venule ratio (AVR) was calculated as an index of arteriolar narrowing (smaller AVR indicates greater narrowing). Cases of incident stroke admitted to hospital were identified and validated by case record reviews. ::: ::: ::: FINDINGS ::: Over an average of 3.5 years, 110 participants had incident strokes. After adjustment for age, sex, race, 6-year mean arterial blood pressure, diabetes, and other stroke risk factors, most retinal microvascular characteristics were predictive of incident stroke, with adjusted relative risks of 2.58 (1.59-4.20) for any retinopathy, 3.11 (1.71-5.65) for microaneurysms, 3.08 (1.42-6.68) for soft exudates, 2.55 (1.27-5.14) for blot haemorrhages, 2.26 (1.00-5.12) for flame-shaped haemorrhages, and 1.60 (1.03-2.47) for arteriovenous nicking. The relative risk of stroke increased with decreasing AVR (p=0.03). The associations were similar for ischaemic strokes specifically, and for strokes in individuals with hypertension, either with or without diabetes. ::: ::: ::: INTERPRETATION ::: Retinal microvascular abnormalities are related to incident stroke. The findings support a microvascular role in the pathogenesis of stroke. They suggest that retinal photography may be useful for cerebrovascular-risk stratification in appropriate populations. <s> BIB001 </s> A Review on the Extraction of Quantitative Retinal Microvascular Image Feature <s> The Image Processing Techniques for Analyzing and Detecting the Abnormal Features of the Retinal Vasculature in Stroke <s> BACKGROUND AND PURPOSE ::: The retinal and cerebral vasculature share similar anatomic, physiological, and embryological characteristics. We reviewed the literature, focusing particularly on recent population-based studies, to examine the relationship between retinal signs and stroke. Summary of Review- Hypertensive retinopathy signs (eg, focal retinal arteriolar narrowing, arterio-venous nicking) were associated with prevalent stroke, incident stroke, and stroke mortality, independent of blood pressure and other cerebrovascular risk factors. Diabetic retinopathy signs (eg, microaneurysms, hard exudates) were similarly associated with incident stroke and stroke mortality. Retinal arteriolar emboli were associated with stroke mortality but not incident stroke. There were fewer studies on the association of other retinal signs such as retinal vein occlusion and age-related macular degeneration with stroke, and the results were less consistent. ::: ::: ::: CONCLUSIONS ::: Many retinal conditions are associated with stroke, reflecting possible concomitant pathophysiological processes affecting both the eye and the brain. However, the incremental value of a retinal examination for prediction of future stroke risk remains to be determined. <s> BIB002 </s> A Review on the Extraction of Quantitative Retinal Microvascular Image Feature <s> The Image Processing Techniques for Analyzing and Detecting the Abnormal Features of the Retinal Vasculature in Stroke <s> The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in close to a 1,000 research articles and reports (see www.epib.nl/rotterdamstudy). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods. <s> BIB003 </s> A Review on the Extraction of Quantitative Retinal Microvascular Image Feature <s> The Image Processing Techniques for Analyzing and Detecting the Abnormal Features of the Retinal Vasculature in Stroke <s> BACKGROUND AND PURPOSE ::: Small vessel disease plays a role in cerebral events. We aimed to investigate the prevalence and patterns of retinal microvascular signs (surrogates for cerebral small vessel disease) among patients with transient ischemic attack (TIA) or acute stroke and population control subjects. ::: ::: ::: METHODS ::: Patients with TIA or acute stroke aged ≥49 years admitted to hospitals in Melbourne and Sydney, Australia, were recruited to the Multi-Centre Retina and Stroke Study (n=693, 2005 to 2007). Control subjects were Blue Mountains Eye Study participants aged ≥49 years without TIAs or stroke (n=3384, 1992 to 1994, west of Sydney). TIA, ischemic stroke, or primary intracerebral hemorrhage was classified using standardized neurological assessments, including neuroimaging. Retinal microvascular signs (retinopathy, focal arteriolar narrowing, arteriovenous nicking, enhanced arteriolar light reflex) were assessed from retinal photographs masked to clinical information. ::: ::: ::: RESULTS ::: Patients with TIA or acute stroke were older than control subjects and more likely to have stroke risk factors. After adjustment for study site and known risk factors, all retinal microvascular signs were more common in patients with TIA or acute stroke than in control subjects (OR, 1.9 to 8.7; P<0.001). Patients with TIA and those with ischemic stroke had similar prevalences of nondiabetic retinopathy (26.9% versus 29.5%; OR, 0.8; 95% CI, 0.5 to 1.6), diabetic retinopathy (55.5% versus 50.0%; OR, 1.3; 95% CI, 0.4 to 3.6), focal arteriolar narrowing (15.6% versus 18.4%; OR, 0.8; 95% CI, 0.4 to 1.5), and arteriovenous nicking (23.0% versus 17.8%; OR, 1.4; 95% CI, 0.7 to 2.7). ::: ::: ::: CONCLUSIONS ::: Patients with TIA and acute stroke may share similar risk factors or pathogenic mechanisms. <s> BIB004 </s> A Review on the Extraction of Quantitative Retinal Microvascular Image Feature <s> The Image Processing Techniques for Analyzing and Detecting the Abnormal Features of the Retinal Vasculature in Stroke <s> There is no agreement on the systematic exploration of the fundus oculi (FO) in hypertensive patients, and it is unknown whether the evolution of retinal microcirculatory alterations has prognostic value or not. The aim of this study was to investigate whether the evolution of the arteriole-to-venule ratio (AVR) in newly-diagnosed hypertensive patients is associated with better or worse evolution of target organ damage (TOD) during 1 year. A cohort of 133 patients with newlydiagnosed untreated hypertension was followed for 1 year. At baseline and follow-up, all patients underwent a physical examination, self-blood pressure measurement, ambulatory blood pressure monitoring, blood and urine analysis, electrocardiogram, and retinography. The endpoint was the favourable evolution of TOD and the total amount of TOD, according to the baseline AVR and the baseline and final difference of the AVR. A total of 133 patients were analyzed (mean age, 57 � 10.7 years; 59% men). No differences were found in the decrease in blood pressure or antihypertensive treatment between quartiles of baseline AVR or baseline-final AVR difference. Patients with a difference between baseline and final AVR in the highest quartile (>0.0817) had a favorable evolution of left ventricular hypertrophy (odds ratio, 14.9; 95% confidence interval, 1.08‐206.8) and the amount of TOD (odds ratio, 2.22; 95% confidence interval, 1.03‐6.05). No favorable evolution was found of glomerular filtration rate. There is an association between the evolution of the AVR and the favorable evolution of TOD. Patients with greater increase of AVR have significantly better evolution of left ventricular hypertrophy and amount of <s> BIB005
The microvascular structure of retinal blood vessel plays a significant role in diagnosing the possibility of causing stroke. Researchers found from population-based studies that diabetic retinopathy signs like microaneurysm and hard exudates and the hypertensive retinopathy signs like arteriovenous nicking and focal retinal arteriolar narrowing were also associated with the acute stroke and stroke mortality even if the people were free from other stroke risk factors BIB002 BIB004 . A cohort study in BIB001 investigated that the most retinal microvascular features that predicted incident stroke and ischemic stroke and that adjusted relative risk with any retinopathies are microaneurysm, soft exudates, bolt haemorrhages, flame-shaped haemorrhages, arteriovenous (AV) nicking, and decreasing Artery to Vein Ratio (AVR) BIB002 BIB001 BIB005 BIB003  .