Retinal microvascular remodeling associates with adverse events in continuous-flow left ventricular assist device-supported patients.

BACKGROUND: Continuous-flow left ventricular assist device (cfLVAD) use is effective in supporting patients with end-stage heart failure (ESHF). Reduced flow pulsatility within the systemic circulation in cfLVAD-supported patients may lead to alterations within the microcirculation. Temporal changes in microvasculature in relation to adverse events in cfLVAD-supported patients have not been studied. We aimed to profile changes within retinal microvasculature and its association with adverse events. METHODS: Retinal photography was performed using Topcon TRC-NW8 nonmydriatic fundus camera in cfLVAD-supported patients and ESHF control patients. Specific retinal measurements were evaluated using a validated semiautomated program. Demographic and adverse event data were documented. RESULTS: Forty-eight patients were studied (n = 29 cfLVAD, n = 19 ESHF). There were significant trends in retinal arteriolar caliber (B = -0.53 µm, 95% confidence interval [CI]: -0.96 to -0.10, p = 0.016) and retinal fractal dimension parameters (B = 0.014, 95% CI: 0.001-0.002, p = 0.016) in linear mixed model regressions. Among cfLVAD patients, there was a significant association between the incidence of gastrointestinal bleeding and stepwise increases in retinal arteriolar-venular caliber ratio (hazard ratio: 3.03, 95% CI: 2.06-4.45, p = 0.005), a measure of arteriolar narrowing. CONCLUSIONS: We have observed for the first time that alterations in retinal microvasculature in cfLVAD-supported patients may be associated with gastrointestinal bleeding. While understanding these temporal changes may predict future adverse events in cfLVAD-supported patients, further multicenter studies are required to confirm the associations observed.

Deep learning-based image quality assessment for optical coherence tomography macular scans: a multicentre study.

AIMS: To develop and externally test deep learning (DL) models for assessing the image quality of three-dimensional (3D) macular scans from Cirrus and Spectralis optical coherence tomography devices. METHODS: We retrospectively collected two data sets including 2277 Cirrus 3D scans and 1557 Spectralis 3D scans, respectively, for training (70%), fine-tuning (10%) and internal validation (20%) from electronic medical and research records at The Chinese University of Hong Kong Eye Centre and the Hong Kong Eye Hospital. Scans with various eye diseases (eg, diabetic macular oedema, age-related macular degeneration, polypoidal choroidal vasculopathy and pathological myopia), and scans of normal eyes from adults and children were included. Two graders labelled each 3D scan as gradable or ungradable, according to standardised criteria. We used a 3D version of the residual network (ResNet)-18 for Cirrus 3D scans and a multiple-instance learning pipline with ResNet-18 for Spectralis 3D scans. Two deep learning (DL) models were further tested via three unseen Cirrus data sets from Singapore and five unseen Spectralis data sets from India, Australia and Hong Kong, respectively. RESULTS: In the internal validation, the models achieved the area under curves (AUCs) of 0.930 (0.885-0.976) and 0.906 (0.863-0.948) for assessing the Cirrus 3D scans and Spectralis 3D scans, respectively. In the external testing, the models showed robust performance with AUCs ranging from 0.832 (0.730-0.934) to 0.930 (0.906-0.953) and 0.891 (0.836-0.945) to 0.962 (0.918-1.000), respectively. CONCLUSIONS: Our models could be used for filtering out ungradable 3D scans and further incorporated with a disease-detection DL model, allowing a fully automated eye disease detection workflow.

The Australian Eye and Ear Health Survey (AEEHS): Study protocol for a population-based cross-sectional study.

INTRODUCTION: Vision and hearing impairments are highly prevalent and have a significant impact on physical, psychological and social wellbeing. There is a need for accurate, contemporary national data on the prevalence, risk factors and impacts of vision and hearing loss in Australian adults. OBJECTIVES: The Australian Eye and Ear Health Survey (AEEHS) aims to determine the prevalence, risk factors and impacts of vision and hearing loss in both Aboriginal and Torres Strait Islander and non-Indigenous older adults. METHODS AND ANALYSIS: The AEEHS is a population-based cross-sectional survey which will include 5,000 participants (3250 non-Indigenous aged 50 years or older and 1750 Aboriginal and Torres Strait Islander people aged 40 years or older) from 30 sites covering urban and rural/regional geographic areas, selected using a multi-stage, random cluster sampling strategy. Questionnaires will be administered to collect data on socio-demographic, medical, ocular and ontological history. The testing battery includes assessment of blood pressure, blood sugar, anthropometry, visual acuity (presenting, unaided, pinhole and best-corrected), refraction, tonometry, slit lamp and dilated eye examination, ocular imaging including optical coherence tomography (OCT), OCT-angiography and retinal photography, and automated visual fields. Audiometry, tympanometry and video otoscopy will also be performed. The primary outcomes are age-standardised prevalence of cause-specific vision and hearing impairment. Secondary outcomes are prevalence of non-blinding eye diseases (including dry eye disease), patterns in health service utilisation, universal health coverage metrics, risk factors for vision and hearing impairment, and impact on quality of life.

Prevalence and risk factors for impaired activities of daily living in patients with neo-vascular age-related macular degeneration who present for anti-VEGF treatment.

BACKGROUND/OBJECTIVES: To assess the prevalence and correlates of impaired activities of daily living (ADLs) in patients with neovascular age-related macular degeneration (nAMD) who present for anti-vascular endothelial growth factor (VEGF) therapy. METHODS: In a clinic-based cohort of 437 patients with nAMD who presented for anti-VEGF therapy, the Older American Resources and Services Scale (OARS) was administered to assess for impairments in basic, instrumental and total ADL. Logistic regression analyses were conducted to determine odds ratios (OR) and 95% confidence intervals (CI) for factors associated with ADL impairment. RESULTS: The prevalence of impaired basic, instrumental and total ADL was 37.76%, 67.82% and 39.59%, respectively. In multivariate-adjusted models, moderate visual impairment [OR 5.65, 95% CI (2.31-13.83) and blindness [OR 5.43, 95% CI (2.09-14.12)] were associated with greater odds of impaired total ADL. Depressive symptoms [OR 2.08, 95% CI (1.08-4.00)], the presence of any disability [OR 3.16, 95% CI (1.64-0.07)] and never driving [OR 4.00, 95% CI (1.60-10.00)] were also positively associated with total ADL impairment. Better vision-related quality of life (QoL) was inversely associated with impaired instrumental ADL whilst higher health-related QoL scores were associated with decreased odds of total ADL impairment. CONCLUSIONS: There is a high prevalence rate of ADL impairment among nAMD patients presenting for therapy. Visual impairment, never driving, poor physical and mental health increased the odds of experiencing ADL impairment whilst better VRQoL and HRQoL reduced the odds of impairment.

Acylcarnitine Abnormalities Implicate Mitochondrial Dysfunction in Patients With Neovascular Age-Related Macular Degeneration.

Purpose: Abnormalities in lipid metabolism are implicated in age-related macular degeneration (AMD), but the pathways involved remain unclear. We assessed whether acylcarnitine concentrations, a marker of lipid and mitochondrial metabolism, differed between patients with AMD and controls. Methods: In this cross-sectional case-control study, cases (n = 81) had neovascular AMD and controls (n = 79) had cataract with no other ocular pathology. Participants were recruited from eye clinics in Western Sydney, Australia, between 2016 and 2018. Plasma blood samples were collected and liquid chromatography mass spectrometry analyses performed to identify acylcarnitine concentrations. Acylcarnitine levels were adjusted for age, gender and smoking in multivariable models. Confirmation of key acylcarnitine identities was conducted using high mass accuracy liquid chromatography-tandem mass spectrometry. Results: After multivariable adjustment, C2-carnitine (acetylcarnitine) levels were significantly lower in patients with neovascular AMD compared to controls (0.810 ± 0.053 (standard error) compared to 1.060 ± 0.053), p = 0.002). C18:2-DC carnitine (a dicarboxylic acylcarnitine with a 18 carbon side chain and 2 double bonds), levels were significantly higher in patients with neovascular AMD compared to controls (1.244 ± 0.046 compared to 1.013 ± 0.046), p = 0.001). Other acylcarnitines examined were not significantly different between cases and controls. Conclusions: Reduced plasma levels of C2-carnitine (acetylcarnitine) and increased plasma levels of C18:2-DC carnitine were observed in patients with neovascular AMD compared to controls. These findings suggest mitochondrial dysfunction could be involved in the pathogenesis of neovascular AMD.

Retinal vascular signs in diabetes and hypertension - review

The retinal vasculature is a unique site where the microcirculation can be noninvasively imaged in vivo. This presents an opportunity to study otherwise inaccessible structural features of the microcirculation. Recently, a number of population-based studies have developed quantitative methods of measuring these retinal signs, and investigated how these signs relate to metabolic disorders such as diabetes, hypertension, obesity, and metabolic syndrome. These studies have reported fairly consistent associations of retinopathy lesions, arteriolar narrowing and venular dilation with these metabolic disorders, suggesting a microvascular component in either the pathogenesis or manifestation of these disorders. Further, several of these signs have been associated with future risk of cardiovascular outcomes, such as coronary heart disease and stroke, independently of traditional risk factors. This review will examine in detail the evidence linking retinal vascular signs with metabolic disorders and discuss their implications for research and clinical practice.

A vasculatura retiniana apresenta uma oportunidade única de observação não-invasiva da microcirculação e de suas estruturas in vivo. Recentemente, uma série de estudos populacionais desenvolveu métodos quantitativos de observação destes sinais retinianos e suas relações com distúrbios metabólicos, tais como diabetes, obesidade, hipertensão arterial e síndrome metabólica. Esses estudos demonstraram associações das lesões retinianas, entre elas estreitamento arteriolar e dilatação venular, com essas alterações metabólicas, sugerindo um componente microvascular na patogênese ou na manifestação destes distúrbios. Ainda, vários destes sinais foram associados com risco de doença cardiovascular, tais como doença arterial coronariana e acidente vascular cerebral independente dos fatores de risco clássicos. Esta revisão discute em detalhes as evidências entre os sinais retinianos e os distúrbios metabólicos e suas possíveis implicações na pesquisa e na prática clínica.