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Kyrieleis plaques are described in literature as calcific-appearing segmented inflammatory deposits along retinal arterial branches. (1) This clinical finding is most commonly unilateral and typically adjacent to an area of active retinal infection or inflammation. (2) The plaques do not appear to be intraluminal or extravasal, but rather within the vessel walls. (3) Considered to be a dishonourable eponym, this rare clinical entity is often also documented as segmental retinal periarteritis. Kyrieleis plaques are a diagnosis of exclusion and should be differentiated from other presentations of retinal vessel damage including emboli, artery sheathing, sclerosis, and periphlebitis all of which may warrant prompt referral or comanagement.

Clinical Relevance: Central retinal artery occlusion (CRAO) is an ophthalmic emergency with a poor prognosis. Several initial CRAO presentation factors can influence the final visual outcome. Fluorescein angiography filling of retinal vessels in CRAO has not been studied in great detail., Background: The aim of this paper is to study the aberrant filling of the retinal vessels on fluorescein angiography in patients with CRAO and understand its clinical relevance., Methods: Cases of CRAO diagnosed between June 2017 and May 2022 and who had undergone a fundus fluorescein angiography were included. Comparisons were made between the cases with and without aberrant filling of the retinal vessel., Results: Twenty-two eyes of 22 patients (14 males and 8 females) with CRAO underwent fluorescein angiography. Ages of the patients ranged from 18 to 73 years, while time interval between development of acute onset vision problems and presentation to the retinal clinic ranged from a minimum of 1 day to a maximum of 30 days. Snellen visual acuity at presentation ranged from perception of light (PL +) to 6/6. On fluorescein angiography, aberrant flow of the fluorescein dye into the retinal vein was observed in four of the 22 (18%) eyes with CRAO. All these cases showed a patient's temporal cilioretinal artery. The cases with aberrant filling of the retinal vessels showed a better presenting visual acuity (6/6-6/60), lesser severity of inner retinal damage and a better final visual acuity (6/6-6/60) compared to CRAO cases without aberrant filling., Conclusion: Aberrant filling of the retinal vein can be seen on fluorescein angiography in eyes with CRAO and a patent temporal cilioretinal artery. Such eyes with aberrant retinal vessel filling have a better visual prognosis.

Objective: This paper aims at quantifying biomarkers from the segmentation of retinal arteries in adaptive optics ophthalmoscopy images (AOO)., Methods: The segmentation is based on the combination of deep learning and knowledge-driven deformable models to achieve a precise segmentation of the vessel walls, with a specific attention to bifurcations. Biomarkers (junction coefficient, branching coefficient, wall to lumen ratio ( wlr)) are derived from the resulting segmentation., Results: reliable and accurate segmentations ( mse = 1.75 ±1.24 pixel) and measurements are obtained, with high reproducibility with respect to images acquisition and users, and without bias., Significance: In a preliminary clinical study of patients with a genetic small vessel disease, some of them with vascular risk factors, an increased wlr was found in comparison to a control population., Conclusion: The wlr estimated in AOO images with our method (AOV, Adaptive Optics Vessel analysis) seems to be a very robust biomarker as long as the wall is well contrasted.

This study aimed to evaluate the impact of Fabry disease (FD) on retinal microvasculature using optical coherence tomography angiography (OCTA), arterial stiffness, and the resistive index (RI) of the central retinal artery (CRA) in early disease stages. Twenty-nine genetically confirmed FD patients and twenty-six healthy controls were enrolled. Vessel density (VD) values of the superficial, deep, and choriocapillaris plexuses (SCP, DCP, and CC) were measured via OCTA. CRA RI was studied using color Doppler and grayscale sonography, and aortic pulse wave velocity (PWV) was assessed with the Complior method. CRA RI was significantly lower in the control group compared to the Fabry group (p < 0.001). Central VD was found to be significantly higher in the control group compared to the Fabry group in all the retinal layers (SCP (p < 0.001), DCP (p < 0.005), CC (p < 0.001)). PWV was significantly higher in the Fabry group than in the control group (p = 0.03). Fabry disease patients demonstrate elevated arterial stiffness, increased CRA RI, and diminished retinal microvascular density compared to healthy controls, indicating early ocular damage. Continuous monitoring and targeted screening for organ impairment are crucial in FD management. Identifying biomarkers for assessing ocular vascular involvement and treatment response is imperative. Further research is needed., (© 2024. The Author(s).)

Purpose: To summarize the causes of retinal arterial microaneurysm combined with branch retinal artery occlusion., Methods: The case reports of retinal arterial microaneurysm combined with branch retinal artery occlusion were searched in PubMed, Web of Science, and CNKI databases before May 1, 2024. A total of nine participants from nine case reports were included to analyze factors leading to complications., Results: The reasons for this complication are as follows: complications during photocoagulation therapy. Intraretinal hemorrhage and exudation result in compression of adjacent or distal arteries, resulting in branch retinal artery occlusion. Embolus dislodgement or intraarterial embolus formation can block the artery, damage the wall, and provide conditions for the development of retinal arterial microaneurysm. In addition, it is necessary to be alert to the optic disk macroaneurysm, if hemorrhage or embolus formation in the macroaneurysm will affect the blood supply of the downstream artery, affecting a large range of the retina., Conclusion: Based on the review of case reports, we found that retinal arterial microaneurysm and branch retinal artery occlusion can cause each other. Acute vision loss can result when a complication occurs. In addition, retinal vascular diseases can reflect the whole body, suggesting that ophthalmologists need to pay attention not only to the patient's fundus but also to the patient's systemic diseases.

A 50-year-old man presented with headache. Examination showed left sided ataxic hemiparesis and elevated blood pressure. Brain imaging revealed an acute intracerebral hemorrhage in the right lentiform nucleus, deep and periventricular white matter hyperintensities, and predominantly deep cerebral microbleeds. Fundus examination showed important arteriolar tortuosity involving several blood vessels. In this young patient, we explain the diagnostic approach to intracerebral hemorrhage, the causes of cerebral small vessel disease, and the interpretation of biomolecular tests.

Objectives: The objective of this study was to prospectively evaluate the diagnostic efficacy of transorbital ultrasound (TOS) in patients newly diagnosed with giant cell arteritis (GCA), presenting with visual symptoms., Methods: Patients with newly diagnosed, untreated GCA were examined using TOS, assessing central retinal artery flow velocity [peak systolic velocity (PSV), end-diastolic velocity (EDV), resistance index (RI)], and optic nerve diameter (OND). Vascular ultrasound was conducted to evaluate the superficial temporal arteries, their branches, facial, axillary, carotid, and vertebral arteries., Results: We enrolled 54 GCA patients, 27 with visual symptoms, and 27 healthy controls. Eyes of GCA patients with visual symptoms demonstrated significantly lower PSV and EDV (PSV: β = -1.91; P = 0.029; EDV: β = -0.57; P = 0.032) and significantly elevated OND (β = 0.79; P = 0.003) compared with controls. RI did not significantly differ from controls (β = -0.06, P = 0.129). Vascular ultrasound identified an average of 8.7 (SD ± 2.8) pathological vessels per GCA patient. A significant negative association was observed between the number of affected vessels and both PSV (P = 0.048) and EDV (P = 0.040). No association was found with RI (P = 0.249), while a positive significant association was noted with OND (P < 0.001)., Conclusions: This study pioneers the application of TOS to assess structural eye changes in newly diagnosed, untreated GCA patients with visual symptoms. Our findings suggest reduced central retinal artery flow and increased optic nerve diameter as potential biomarkers for serious ocular involvement in GCA. The detected association between internal and external carotid artery involvement indicates a common pathophysiological mechanism underlying systemic and ocular manifestations of GCA., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Cilioretinal arteries are a common congenital anomaly of retinal blood supply. This paper presents a deep learning-based approach for the automated detection of a CRA from color fundus images. Leveraging the Vision Transformer architecture, a pre-trained model from RETFound was fine-tuned to transfer knowledge from a broader dataset to our specific task. An initial dataset of 85 was expanded to 170 images through data augmentation using self-supervised learning-driven techniques. To address the imbalance in the dataset and prevent overfitting, Focal Loss and Early Stopping were implemented. The model's performance was evaluated using a 70-30 split of the dataset for training and validation. The results showcase the potential of ophthalmic foundation models in enhancing detection of CRAs and reducing the effort required for labeling by retinal experts, as promising results could be achieved with only a small amount of training data through fine-tuning.

Central retinal artery occlusion (CRAO), like a stroke in the brain, is a critical eye condition that requiring urgent medical attention. Patients with CRAO present with acute loss of vision and the visual prognosis is poor with low chance of spontaneous visual recovery. Moreover, the risk of developing ischaemic heart disease and cerebral stroke is increased due to the presence of underlying atherosclerotic risk factors. Currently, there is no officially recommended treatment for CRAO. This review will describe the anatomy, pathophysiology, clinical features of CRAO, as well as exploring existing and potential future approaches for managing the condition., (© 2024. Crown.)

A major hurdle to therapeutic development in cerebral small vessel diseases is the lack of in-vivo method that can be used repeatedly for evaluating directly cerebral microvessels. We hypothesised that Adaptive Optics (AO), which allows resolution images up to 1-2 μm/pixel at retinal level, could provide a biomarker for monitoring vascular changes in CADASIL, a genetic form of such condition. In 98 patients and 35 healthy individuals, the wall to lumen ratio (WLR), outer and inner diameter, wall thickness and wall cross-sectional area were measured in a parapapillary and/or paramacular retinal artery. The ratio of vessel diameters before and after light flicker stimulations was also calculated to measure vasoreactivity (VR). Multivariate mixed-model analysis showed that WLR was increased and associated with a larger wall thickness and smaller internal diameter of retinal arteries in patients. The difference was maximal at the youngest age and gradually reduced with aging. Average VR in patients was less than half of that of controls since the youngest age. Any robust association was found with clinical or imaging manifestations of the disease. Thus, AO enables the detection of early functional or structural vascular alterations in CADASIL but with no obvious link to the clinical or imaging severity., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: Both hypertension and diabetes are known to increase the wall-to-lumen ratio (WLR) of retinal arterioles, but the differential effects are unknown. Here, we study the timing and relative impact of hypertension versus diabetes on the WLR in diabetic retinopathy (DR) to address this unresolved question., Methods: This prospective cross-sectional study compared the retinal arteriolar WLR in 17 healthy eyes, 15 with diabetes but no apparent DR (DM no DR), and 8 with diabetic macular edema (DME) and either nonproliferative or proliferative DR. We imaged each arteriole using adaptive optics scanning laser ophthalmoscopy and measured the WLR using ImageJ. Multiple linear regression (MLR) was performed to estimate the effects of hypertension, diabetes, and age on the WLR., Results: Both subjects with DM no DR and subjects with DME had significantly higher WLR than healthy subjects (0.36 ± 0.08 and 0.42 ± 0.08 vs. 0.29 ± 0.07, 1-way ANOVA P = 0.0009). MLR in healthy subjects and subjects with DM no DR showed hypertension had the strongest effect (regression coefficient = 0.08, P = 0.009), whereas age and diabetes were not significantly correlated with WLR. MLR in all three groups together (healthy, DM no DR, and DME) showed diabetes had the strongest effect (regression coefficient = 0.05, P = 0.02), whereas age and hypertension were not significantly correlated with WLR., Conclusions: Hypertension may be an early driver of retinal arteriolar wall thickening in preclinical DR, independent of age or diabetes, whereas changes specific to DR may drive wall thickening in DME and later DR stages., Translational Relevance: We offer a framework for understanding the relative contributions of hypertension and diabetes on the vascular wall, and emphasize the importance of hypertension control early in diabetes even before DR onset.

Objectives: A third of asymptomatic individuals with type 1 diabetes (T1D) show signs of cerebrovascular disease in brain MRI. These signs associate with advanced stages of diabetic retinal disease, but not in mild or moderate retinopathy. We aimed to evaluate a wider spectrum of retinal changes by exploring the relationship between quantitative measures of retinal vessel parameters (RVP) and cerebrovascular changes in T1D., Methods: We included 146 neurologically asymptomatic individuals with T1D [51% women, median age 40 (33.0-45.1) years] and 24 healthy, sex-matched and age-matched controls. All individuals underwent a clinical and biochemical work-up and brain MRI, which was evaluated for cerebral microbleeds (CMBs), white matter hyperintensities, and lacunar infarcts. RVPs, including central retinal arteriole (CRAE) and central retinal vein (CRVE) equivalents and the ratio of the two variables (arteriovenous ratio, AVR) were assessed quantitatively by a computer-assisted method (IVAN software, version 3.2.6) from fundus images., Results: Among T1D participants, those with CMBs had a lower arteriovenous ratio (AVR) compared with those without CMBs ( P  = 0.023). AVR was inversely associated with the amount of CMBs ( r  = -0.063, P  = 0.035). CMB prevalence was higher in those with AVR below the median (31%) compared with above the median (16%, P  < 0.001), and this difference was significant also after individuals with only no-to-mild retinopathy were included (28 vs. 16%, P  = 0.005). A correlation between blood pressure and CRAE ( r  = -0.19, P  = 0.025) appeared among those with T1D., Conclusion: Regardless of the severity of diabetic retinopathy, AVR is associated with the existence of CMBs in T1D., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: To investigate ocular and systemic factors associated with the retinal arterial wall-to-lumen ratio (WLR) and to determine the relative contribution of genetic and environmental variation to WLR in healthy adults., Methods: This cross-sectional twin study included 78 monozygotic and 67 dizygotic same-sex twin pairs aged 58.4 ± 9.8 (mean ± SD) years. Lumen diameter (LD) and outer diameter (OD) of a superotemporal retinal artery were measured using adaptive optics fundus photography, and the WLR was calculated. Linear mixed model regression analysis of associations with WLR comprised the descriptive variables ocular axial length (AL), intraocular pressure (IOP), height, weight, body mass index (BMI), smoking, blood pressure, high density (HDL), low density (LDL) and very low density (VLDL) lipoproteins, total cholesterol and triglycerides. The relative influence of genes and environment on WLR was calculated through polygenetic modelling., Results: Increasing age and arterial blood pressure were associated with a higher WLR, while increasing retinal artery OD and ocular AL were associated with a lower WLR. Sex, smoking status, BMI, IOP, cholesterol levels or triglycerides had no detectable impact on the WLR. Broad-sense heritability of WLR was 21% (95% CI: 1-41%), while environmental factors accounted for the remaining 79% of the interindividual variance (95% CI: 59-99%)., Conclusion: Retinal artery wall thickness was closely linked to increasing age and higher arterial blood pressure, the latter being mediated by the environment over genes., (© 2023 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)

Competing Interests: Competing interests: None declared.

Introduction: Congenital arterial peripapillary loops are rare entities and very few cases are described in literature., Case Description: A 25-year-old Asian man presented a diffuse vitreous hemorrhage in his Left Eye (LE). OCT-A revealed the presence of bilateral vascular loops at the optic nerve head. Fluorescein angiography (FA) confirmed the vascular abnormality in both eyes, with arterial filling in early phases and no dye leakage. At twenty days of follow up, the vitreous hemorrhage in the LE completely reabsorbed and BCVA improved from 20/63 to 20/20., Conclusion: Congenital peripapillary loops should be considered in the differential diagnosis of vitreous hemorrhage, especially in young patients with no history of ocular/head trauma. Multimodal imaging is highly recommended to properly manage the patients, avoiding unnecessary therapeutic choices., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Competing Interests: Competing interests: None declared.

Aim: To compare the efficacy of quantitative contrast-enhanced ultrasonography (CEUS) analysis and colour Doppler ultrasound (CDU) in evaluating central retinal artery (CRA) microcirculation in patients with diabetes mellitus (DM)., Materials and Methods: In this prospective study, a total of 55 patients (98 eyes) with DM were enrolled as the study group. They were compared to 46 age-matched healthy volunteers (92 eyes) who were selected as the control group. Each patient underwent CDU and subsequent CEUS examination. CDU and quantitative CEUS parameters were evaluated. The diagnostic efficiency of the diagnostic performance of CEUS and CDU was evaluated and compared, and the scale thresholds of predictive indicators for the diagnosis of proliferative diabetic retinopathy (PDR) were evaluated using receiver operating characteristics (ROC) curve analyses., Results: Group pairwise comparisons showed that the end diastolic velocity (EDV) and arrival time (AT) of CRA were significant predictors for PDR by CDU and by quantitative CEUS analysis, respectively (all p<0.05). The ROC curve analysis showed that the area under the curve value of AT was significantly higher than that of EDV (0.875 versus 0.634, p=0.0002). Accordingly, an AT cut-off value of 1.07 seconds resulted a sensitivity of 90.62 % and a specificity of 79.31 %., Conclusion: Quantitative CEUS analysis can improve the accuracy of clinical staging of diabetic retinopathy for the patients with DM, and the AT showed the best diagnostic efficiency., (Copyright © 2024 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Background: To evaluate the changes in retrobulbar circulation after strabismus surgery and to assess the relationship of these changes with choroidal thickness (CT)., Methods: This prospective study included 26 eyes of 26 patients who underwent strabismus surgery and 15 eyes of 15 healthy individuals as control group. The patients who had single horizontal muscle surgery were included in Group 1 (n = 14); and those who had surgery on both horizontal muscles were included in Group 2 (n = 12). Peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI) and pulsatility index (PI) of ophthalmic artery (OA), posterior ciliary artery (PCA), and central retinal artery (CRA) were measured using Color Doppler Ultrasonography. Subfoveal CT was measured via Optical Coherence Tomography. All measurements were obtained preoperatively, at 1st week and 1st month after surgery., Results: There were no differences regarding preoperative blood flow velocity parameters among the groups. OA RI increased significantly at 1st week and 1st month after surgery in Group 1 and 2 (P = 0.029 and P = 0.045, respectively). There was a significant increase in PCA PSV at 1st week in Group 1 (P = 0.002). There was no difference between the mean preoperative and postoperative CT among the 3 groups. A negative correlation between the percentage changes of CT and CRA EDV was found in Group 2 (P = 0.011)., Conclusion: Single and double horizontal rectus muscle surgery have a measurable effect on retrobulbar hemodynamics but these changes do not correlate with CT., (© 2024. The Author(s).)

Recent deep learning methods with convolutional neural networks (CNNs) have boosted advance prosperity of medical image analysis and expedited the automatic retinal artery/vein (A/V) classification. However, it is challenging for these CNN-based approaches in two aspects: (1) specific tubular structures and subtle variations in appearance, contrast, and geometry, which tend to be ignored in CNNs with network layer increasing; (2) limited well-labeled data for supervised segmentation of retinal vessels, which may hinder the effectiveness of deep learning methods. To address these issues, we propose a novel semi-supervised point consistency network (SPC-Net) for retinal A/V classification. SPC-Net consists of an A/V classification (AVC) module and a multi-class point consistency (MPC) module. The AVC module adopts an encoder-decoder segmentation network to generate the prediction probability map of A/V for supervised learning. The MPC module introduces point set representations to adaptively generate point set classification maps of the arteriovenous skeleton, which enjoys its prediction flexibility and consistency (i.e. point consistency) to effectively alleviate arteriovenous confusion. In addition, we propose a consistency regularization between the predicted A/V classification probability maps and point set representations maps for unlabeled data to explore the inherent segmentation perturbation of the point consistency, reducing the need for annotated data. We validate our method on two typical public datasets (DRIVE, HRF) and a private dataset (TR280) with different resolutions. Extensive qualitative and quantitative experimental results demonstrate the effectiveness of our proposed method for supervised and semi-supervised learning., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Purpose: The prospective study aimed to examine the central retinal artery (CRA) using computed tomography (CT)., Materials and Methods: Seventy adult outpatients comprising 32 men and 38 women, at a mean age of 60.6 ± 13.3 years, were enrolled in the study. The patients underwent contrast-enhanced CT. The scan timing was set to start 5.0 s after the circle of Willis began to be delineated., Results: The ophthalmic arteries (OphAs) were comfortably delineated in all. In 97% of the patients, the CRA was delineated from the original site on the OphA to a more distal segment coursing on the optic sheath. Unilateral and bilateral CRA delineations were observed in 44% and 53% of cases, respectively. The delineated CRAs demonstrated highly variable morphologies in terms of the course and length on the optic sheath. In addition, the distance between the original site of the CRA and the posterior limit of the bulb was measured. The mean distance was 18.6 ± 5.0 mm on the right and 17.8 ± 4.3 mm on the left, respectively. No significant right-to-left differences in the measurements (p > 0.05) were observed., Conclusions: If optimal scan timing is adopted, the CRA segments coursing on the optic sheath can be delineated using contrast-enhanced CT. CT may be a useful diagnostic modality for the CRAs and associated pathological conditions., (© 2023. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Purpose: To study the orbital perfusion parameters of ophthalmic artery (OA) and central retinal artery (CRA) in inactive TED and the changes following surgical decompression., Methods: Non-randomised clinical trial. 24 inactive moderate-to-severe TED orbits of 24 euthyroid cases underwent surgical decompression and examined again at 3 months. The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) of OA and CRA were evaluated using colour doppler imaging and normative database was established using 18 healthy controls., Results: The mean age was 39.38 ± 12.56 years and male: female ratio was 1: 1.18. Intraocular pressure was higher, and CRA-PSV, CRA-RI, OA-PSV, and OA-EDV were lower in TED in comparison to heathy orbits. The CRA-PSV, CRA-EDV, OA-PSV, and OA-EDV negatively correlated with proptosis and duration of thyroid disease. The area under curve of OA-PSV (95% CI:0.964-1.000, p < 0.001) and OA-EDV (95% CI:0.699-0.905, p < 0.001) helped in differentiating TED orbits from HC, and in predicting the severity of disease. Post decompression, CRA-PSV, CRA-EDV, OA-PSV, and OA-EDV improved, with decrease in CRA-RI and OA-RI in both lipogenic and MO., Conclusions: The orbital perfusion is reduced in inactive TED. The changes in OA flow velocities can help in differentiating inactive TED from healthy orbits and progression of TED. Sequential orbital CDI of OA and CRA can serve as an objective tool for case selection and monitoring response to surgical decompression., (© 2023. The Author(s), under exclusive licence to The Royal College of Ophthalmologists.)

Older individuals experience cardiovascular dysfunction during extended bedridden hospital or care home stays. Bed rest is also used as a model to simulate accelerated vascular deconditioning occurring during spaceflight. This study investigates changes in retinal microcirculation during a ten-day bed rest protocol. Ten healthy young males (22.9 ± 4.7 years; body mass index: 23.6 ± 2.5 kg·m -2 ) participated in a strictly controlled repeated-measures bed rest study lasting ten days. High-resolution images were obtained using a hand-held fundus camera at baseline, daily during the 10 days of bed rest, and 1 day after re-ambulation. Retinal vessel analysis was performed using a semi-automated software system to obtain metrics for retinal arteriolar and venular diameters, central retinal artery equivalent and central retinal vein equivalent, respectively. Data analysis employed a mixed linear model. At the end of the bed rest period, a significant decrease in retinal venular diameter was observed, indicated by a significantly lower central retinal vein equivalent (from 226.1 µm, CI 8.90, to 211.4 µm, CI 8.28, p = .026), while no significant changes in central retinal artery equivalent were noted. Prolonged bed rest confinement resulted in a significant (up to 6.5%) reduction in retinal venular diameter. These findings suggest that the changes in retinal venular diameter during bedrest may be attributed to plasma volume losses and reflect overall (cardio)-vascular deconditioning., (© 2023. The Author(s).)

Purpose: To assess changes in orbital vessels by Color Doppler Imaging (CDI) in patients with Primary Open Angle Glaucoma (POAG)., Methods: This cross-sectional study included 120 subjects - 60 patients with POAG and 60 controls, all of whom underwent full ophthalmological examinations and orbital CDI. The Ophthalmic Artery (OA), Central Retinal Artery (CRA) and Ciliary Arteries (CA) were identified, and for each of them, we measured Peak Systolic Velocity (PSV), End Diastolic velocity (EDV) and Resistivity Index (RI)., Results: The PSV of the OA and CRA were significantly lower in patients with POAG compared to normal controls (P<0.0001, < 0.009 respectively). The EDV in the OA, CRA and CA were significantly lower than in normal controls (P<0.0001). The RI of the OA, CRA and CA were significantly higher in patients with POAG compared to controls (P<0.0001). The EDV of the OA showed significant negative correlation with duration of glaucoma (r=-0.37, P<0.042). The EDV of the CA showed significant negative correlation with intraocular pressure (IOP) (r=-0.86 and P value 0.0001). The PSV and EDV of the CRA showed significant negative correlation with IOP (r=-0.45, r=-0.73, P values 0.011, and 0.0001 respectively), and the RI of the CRA showed significant positive correlation with IOP (r=0.42 and P value 0.021)., Conclusion: CDI is a feasible, noninvasive, safe tool for the assessment of hemodynamic changes in the orbital arteries of POAG patients. The orbital arteries showed significantly lower flow velocities and increased resistivity indices in patients with POAG compared to the control group, and these changes were correlated with glaucoma duration and IOP., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Purpose: Diabetic retinopathy (DR) is a leading cause of ocular morbidity. Its progression depends mainly on retinal vasculature and ocular blood flow. Color Doppler imaging (CDI) is a noninvasive imaging technique that measures blood flow velocity. The resistivity index (RI), calculated by the CDI, reflects the vascular resistance distal to the measuring location. RI is independent of the doppler angle and position of the patient, making it a reliable and reproducible parameter. To the best of our knowledge, there is only one study in literature studying the association between resistivity index (RI) of the central retinal artery (CRA) and severity of DR., Aim: To determine the association between RI of CRA and severity of DR. To determine the association between RI of CRA and spectral-domain optical coherence tomography (SD-OCT) biomarkers for DR., Methods: Type II diabetics visiting our OPD underwent DR screening and were graded into three categories according to ETDRS classification which include Group A-No diabetic retinopathy (No DR), Group B-Nonproliferative diabetic retinopathy (Moderate-Severe-Very Severe NPDR), and Group C-Proliferative diabetic retinopathy (PDR). SD-OCT was performed. Ultrasonic color doppler imaging was done. RI of the CRA was noted. It was compared between the three groups and its association with severity of DR and OCT biomarkers (central subfield thickness, cube average thickness and ellipsoid zone disruption) was studied., Results: 56 eyes of 28 patients were included in our study with 20 in Group A,14 in Group B, and 22 in Group C. RI of CRA compared within groups showed statistically significant association with severity of DR (P < 0.001). The presenting BCVA (LogMar) showed positive correlation with RI in all groups. OCT biomarker central subfield thickness showed a positive correlation with RI in Groups A (P < 0.001) and B. Ellipsoid zone (EZ) disruption showed a statistically significant association with RI in Group C (P < 0.001)., Conclusion: The RI of CRA is a reliable biomarker for the assessment of the severity of DR. Patients with high RI of CRA had higher chances of EZ disruption and presented with poor visual acuity., Competing Interests: None

Purpose: This cross-sectional study aimed to clarify the differences in the retinal venous narrowing ratio (VNR) at retinal arteriovenous crossing by optical coherence tomography (OCT) among the eyes with branch retinal vein occlusion (BRVO), fellow eyes of patients with BRVO, and eyes of individuals without BRVO and to determine factors that influence the VNR., Methods: We studied 31 eyes of young participants, 54 eyes of an older control group, 56 fellow eyes of patients with BRVO, and 48 eyes with BRVO. Cross-sectional OCT images were used to determine the VNR at two arteriovenous crossings per eye., Results: Overall, 378 arteriovenous crossings were analyzed. The VNR of arterial overcrossings of fellow eyes (27.7% ± 11.1%) and BRVO eyes (27.3% ± 9.76%) were significantly higher than those in the young (16.0% ± 7.9%, all P < 0.001) and control (22.0% ± 8.81%, P < 0.001, P = 0.003, respectively) groups. The VNR of arterial overcrossings was significantly larger than that of venous overcrossings (24.0% ± 10.5% vs. 20.6% ± 13.0%, P = 0.021). A linear mixed-effects model showed that the VNR was significantly higher in arterial overcrossings, crossings with larger arterial internal diameters, smaller venous internal diameters, and participants with older age and a BRVO history., Conclusions: The VNR in arterial overcrossings was higher in BRVO eyes and even in the fellow eyes. Thus, a higher VNR in arterial overcrossings may contribute to BRVO development, and crossings with factors contributing to higher VNR might be associated with a risk of BRVO.

To compare changes in ophthalmic artery (OA) and its branches in diabetics with and without diabetic retinopathy (DR) using color duplex imaging (CDI), and to correlate these changes with the disease variables. 60 eyes of 60 diabetic patients were enrolled, divided into 3 groups: without DR (Group A), with Non-Proliferative DR (Group B) and with Proliferative DR (PDR) (Group C). Laboratory testing including HbA1c was done. Patients underwent CDI, by which OA, Central Retinal Artery (CRA) and Ciliary Arteries were identified; for each of them we measured Peak systolic velocity (PSV), End Diastolic velocity (EDV) and Resistivity Index (RI). Results were compared to clinical, laboratory and fundus examination. OA EDV was significantly lower and OA RI was found to be significantly higher in Group C (p = 0.027 and 0.025 respectively). CRA PSV and EDV were significantly lower in Group C (p = 0.017 and 0.001 respectively). PCA RI was significantly higher in Group C (p = 0.008). HbA1c was negatively correlated with CRA PSV (p = 0.041), also it was negatively correlated with CRA EDV (p = 0.0001), as well as with PCA EDV (p = 0.002). There was direct significant correlation between HbA1c and PCA RI (p = 0.012). Duration since diagnosis was negatively correlated with CRA EDV (p = 0.004). Multivariate linear regression showed that DR is an independent predictor for low OA EDV, high OA RI, low CRA EDV and high PCA RI. DR is an independent risk factor for orbital and ocular vessels flow alteration, thus can be used as a prognostic tool in diabetic patients. CDI can be reliably used in diabetics to predict early changes or progression of DR., (© 2023. Springer Nature Limited.)

Purpose: To compare the angle of retinal arteries and macular vessel density and foveal avascular zone (FAZ) in early stage familial exudative vitreoretinopathy (FEVR) patients with inner retinal layer (IRL) persistence with FEVR patients without IRL persistence and normal people., Methods: This study enrolled 113 early stage FEVR patients and 55 age-matched normal subjects. FEVR patients were divided into IRL group and non-IRL group based on the presence or absence of IRL in fovea. The angle of superior temporal and inferior temporal branch retinal arteries on ultra-wide-field fundus images were measured. Superficial and deep vessel density of whole image, fovea and parafovea, the area and perimeter of FAZ, A-circularity index (AI, perimeter/standard circle perimeter with equal area) and vessel density around the 300-μm width of the FAZ (FD), central macular thickness (CMT) on 3 mm × 3mm OCTA were measured., Results: 30 FEVR patients in IRL group, 83 FEVR patients in non-IRL group, 55 normal people in control group were evaluated. BCVA were worst in IRL group ( p  < .001). The angle of retinal arteries was smaller in FEVR groups ( p  < .001) and were smallest in IRL group ( p  < .001). Superficial and deep vessel density of whole and parafovea area in FEVR patients were significantly lower than that in normal people ( p  < .05), AI were biggest ( p  = .01) and FD were smallest in IRL group ( p  < .001). CMT in IRL group were thicker than non-IRL group and control group ( p  < .05)., Conclusion: Worse BCVA, smaller angle of retinal arteries (more vessels traction), lower macular vessel density, smaller and more irregular FAZ and thicker CMT were observed in FEVR patients with IRL persistence even in early stage.

Competing Interests: Competing interests: None declared.

Background: Prepapillary vascular loops are a type of congenital vascular anomaly seen on or around the optic disk. Patients with this condition are usually asymptomatic and are detected incidentally on routine fundus examinations. Differential diagnosis for this condition includes neovascularization of the disk and collaterals on the disk. Prepapillary capillary loops are not associated with any systemic condition. They are usually unilateral in presentation, but can rarely be bilateral., Purpose: To discuss the new proposed classification of prepapillary capillary loops., Synopsis: : Prepapillary capillary loops are classified based on their location around the disk, loop characteristics such as elevation, shape, and covering, and presence of vitreoretinal traction., Highlights: The most common vascular loops are arterial in origin and rarely venous in origin. They can sometimes be associated with spontaneous and recurrent vitreous hemorrhage, branch retinal artery or vein occlusion, and subretinal hemorrhage. It is an important differential diagnosis in spontaneous vitreous hemorrhage. Treatment is symptomatic., Video Link: : https://youtu.be/gbq&#95;oP7Y2q4., Competing Interests: None

Purpose: To investigate the agreement between a fundus camera and a scanning laser ophthalmoscope in retinal vessel caliber measurements and to identify whether the presence of the central light reflex (CLR) explains potential discrepancies., Methods: For this cross-sectional study, we obtained fundus camera and scanning laser ophthalmoscope images from 85 eyes of 85 healthy individuals (aged 50-65 years) with different blood pressure status. We measured the central retinal artery equivalent (CRAE) and central retinal artery vein equivalent (CRVE) with the Knudtson-Parr-Hubbard algorithm and assessed the CLR using a semiautomatic grading method. We used Bland-Altman plots, 95% limits of agreement, and the two-way mixed effects intraclass correlation coefficient for consistency [ICC(3,1)] to describe interdevice agreement. We used multivariable regression to identify factors associated with differences in between-device measurements., Results: The between-device difference in CRAE (9.5  µm; 95% confidence interval, 8.0-11.1  µm) was larger than the between-device difference in CRVE (2.9  µm; 95% confidence interval, 1.3-4.5  µm), with the fundus camera yielding higher measurements (both P < 0.001). The 95% fundus camera-scanning laser ophthalmoscope limits of agreement were -4.8 to 23.9  µm for CRAE and -12.0 to 17.8  µm for CRVE. The corresponding ICCs(3,1) were 0.89 (95% confidence interval, 0.83-0.92) and 0.91 (95% confidence interval, 0.86-0.94). The between-device CRAE difference was positively associated with the presence of a CLR (P = 0.002)., Conclusions: Fundus cameras and scanning laser ophthalmoscopes yield correlated but not interchangeable caliber measurements. The CLR induces bias in arteriolar caliber in fundus camera images, compared with scanning laser ophthalmoscope images., Translational Relevance: Refined measurements could yield better estimates of the association between retinal vessel caliber and ophthalmic or systemic disease.

Purpose: To report the retinal vessel wall changes in a patient with acute branch retinal artery occlusion with fundus fluorescein angiography and adaptive optics imaging., Methods: Retrospective, observational case., Case Description: A 49-year-old female with cardiac ailment complained of sudden onset superior field loss for 4 days in her right eye. Her presenting visual acuity in the right eye was 20/20, N6. She was diagnosed with right eye infero-temporal branch retinal artery occlusion. A golden-yellow, round coloured embolus was noted on clinical examination obstructing the temporal division of the inferior branch of central retinal artery. Patient underwent ocular massage, anterior chamber paracentesis and oral Acetazolamide (Tab. Diamox 250 mg QID) medications. Vessel wall changes were noted using fluorescein angiography and adaptive optics retinal imaging at presentation and 10-day follow-up visit., Conclusion: This case highlights the importance of multimodal retinal imaging like fluorescein angiography and adaptive optics imaging in identifying and understanding the retinal vessel wall changes in the occluded vascular segment of the retina.

Purpose: This study monitored the dynamic changes in retinal vascular width and the AVR in full-term neonates within 1-10 days of birth., Methods: It was conducted at hospitals in the Anhui province from October 2020 to March 2022. A total of 700 full-term, healthy infants were chosen randomly within 10 days of birth, and the Star Pupil Medical Cloud Data System (XBDS) was used to collect fundus images. Infants within 6 days of birth were grouped into groups one to six, while those within the 7th to 10th days were grouped into group seven. The fundus photographs were imported into Image-Pro-Plus (IPP) software. The optic disc diameter was measured. The retinal artery and vein's diameter was measured at a distance between 0.5- and 1.0-disc diameter from the optic disc's margin. The AVR was also calculated. Finally, each group's retinal vessel diameters and AVR were compared separately to show their dynamic changes., Results: There were differences in the retinal artery diameter between groups one and two, three and four, four and five, and five and six. For retinal vein diameter, there were differences between groups one and two and groups six and seven. There were also differences in the AVR between all groups. In addition, there was a significant positive correlation between the small retinal artery and vein diameters., Conclusion: The retinal artery and vein diameters and AVR in neonates change dynamically during the first 10 days of life. The AVR undergoes the most dramatic change daily and is considerably smaller than the AVR in adults. Hence, this study found that the external environment undergoes significant changes following birth that affect the microcirculation. Then, the retinal central vascular system undergoes similar emergency and adaptive alterations.

Competing Interests: Competing interests: None declared.

Purpose: The aim of the study was to obtain the values of oxygen saturation in retinal vessels and ophthalmic blood flow parameters in a healthy Caucasian population and assess whether the oximetry parameters are affected by the flow rate or the vascular resistance., Methods: The spectrophotometric retinal oximetry and colour Doppler imaging (CDI) of retinal vessels were successfully performed with 52 healthy subjects (average age 29.7 ± 5.6 years). The retinal oximeter simultaneously measures the wavelength difference of haemoglobin oxygen saturation in retinal arterioles and venules. The arteriolar and venular saturation in both eyes was measured. The peak systolic (PSV) end diastolic (EDV) velocities, resistive (RI) and pulsatility (PI) indices were obtained for both eyes using CDI in the ophthalmic artery. A paired t-test and two sample t-tests were used for statistical analyses. The correlation was assessed using the Pearson coefficient correlation., Results: The mean oxygen saturation level was 96.9 ± 3.0% for the retinal arterioles and 65.0 ± 5.1% for the retinal venules. The A-V difference was 31.8 ± 4.6%. The mean of the measured haemodynamic parameters was PSV 46.6 ± 9.4 cm/s, EDV 12.0 ± 3.5 cm/s, PI 1.68 ± 0.38 and RI 0.74 ± 0.05. No significant difference in oxygen saturation and haemodynamic parameters was found between the left and the right eyes or the dominant and non-dominant eye. The oximetry and ultrasound values were sex independent. The Pearson correlation coefficient demonstrated a significant yet weak negative correlation between A-V difference and RI (r = -0.321, p = 0.020)., Conclusions: A negative correlation between A-V difference and resistance index was observed, suggesting that reduced oxygen consumption may reflect the increased vascular tone of the ophthalmic vessels, which is likely determined by autoregulatory mechanisms., (© 2022 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.)

Objective: The purpose of this study is to investigate the potential of using the tortuosity of branch retinal artery as a more promising indicator for early detection and accurate assessment of diabetic retinopathy (DR)., Design and Method: The diagnoses, consisting of whether DR or not as well as DR severity, were given by ophthalmologists upon the assessment of those fundus images from 495 diabetic patients. Meanwhile, benefiting from those good contrast and high optical resolution fundus images taken by confocal scanning laser ophthalmoscope, the branch arteries, branch veins, main arteries and main veins in retina can be segmented independently, and the tortuosity values of them were further extracted to investigate their potential correlations with DR genesis and progress based on one-way ANOVA test., Results: For both two comparisons, i.e., between non-DR group and DR group as well as among groups with different DR severity levels, larger tortuosity increments were always observed in retinal arteries and the increments in branch retinal vessels were even larger. Furthermore, it was newly found that branch arterial tortuosity was significantly associated with both DR genesis (p=0.030) and DR progress (p<0.001)., Conclusion: Based on this cohort study of 495 diabetic patients without DR and with different DR severity, the branch arterial tortuosity has been found to be more closely associated with DR genesis as well as DR progress. Therefore, the branch arterial tortuosity is expected to be a more direct and specific indicator for early detection of DR as well as accurate assessment of DR severity, which can further guide timely and rational management of DR to prevent from visual impairment or even blindness resulting from DR., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Song, Zhou, Liu, Du, Zhou, Zhu and Chen.)

Purpose: To determine the presence of unruptured retinal arterial macroaneurysms (RAMs) and to examine the characteristics of the detected lesions., Methods: This retrospective observational study included the affected and contralateral eyes of 50 patients (100 eyes) with symptomatic, unilateral, ruptured RAMs who visited the Department of Ophthalmology at the Kyoto University Hospital (April 2014-April 2020) and were followed up for at least 6 months after the onset. The presence and characteristics of unruptured RAMs were examined by reviewing the findings of color fundus photography and infrared scanning laser ophthalmoscopy performed before the onset or during the follow-up period., Results: Unruptured RAMs were detected in six of the 50 patients. Some patients had bilateral or multiple unruptured RAMs, and a total of 12 unruptured RAMs were detected in eight eyes of the six patients. Among the detected lesions, eight exhibited a longitudinal increase in their diameter during the follow-up period, whereas six exhibited ruptures., Conclusion: Unruptured RAM is not an uncommon retinal vascular abnormality and can enlarge and progress to ruptured RAM., (Copyright © 2022 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Opthalmic Communications Society, Inc.)

Purpose: This study aimed to evaluate ocular blood flow and, retinal, choroidal and retinal nerve fiber layer thickness in children with familial Mediterranean fever (FMF) with patients who had at least five attacks., Methods: Fifty-six patients with FMF and 56 healthy subjects were enrolled in the study. Each participant's choroidal thickness (CT) and retinal thickness (RT) measurements were performed in the foveola and at horizontal nasal and temporal quadrants within 500-μm intervals up to 1.500 μm from the foveola using spectral-domain optical coherence tomography as well as the retinal nerve fiber layer thickness (RNFLT). Disc boundaries were determined manually by identifying seven points on the inner edge of the scleral ring. Following complete ophthalmological evaluation, peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) values in the central retinal artery (CRA), ophthalmic artery (OA), and nasal posterior ciliary artery (NPCA) were measured using color Doppler ultrasonography (CDU) in the left eyes of the patients diagnosed with FMF and the controls. The results were subsequently compared., Results: No statistically significant differences were observed between the groups in terms of all RNFLT quadrant and RT measurements. All CT measurements were thinner in patients with FMF than in the controls (For Central and Temporal&#95;1500 p = 0.01; For Temporal&#95;500, Nasal 500 and Nasal&#95;1000 p < 0.001; Temporal&#95;1000 p = 0.002) except than the Nasal&#95;1500 point. For nasal&#95;1500 p = 0.121). The PSV and EDV values in the OA, CRA, and NPCA were significantly lower in patients with FMF compared to healthy controls (p < 0.001 for all). In contrast, the RI values of all arteries were significantly higher than in the control group (Regarding OA, CRA and NPCA RI, p = 0.003, p = 0.039, and p = 0.039, respectively)., Conclusions: The results of this study support the idea that chronic inflammation and frequent attacks in FMF may have an effect on decreased ocular blood flow and choroidal thinning., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)