Retinal Artery Occlusion Research Articles

COVID-19 Vaccination and Ocular Adverse Events: A Self-Controlled Case Series Study From the Entire South Korean Population

This study aimed to assess the risk of ocular adverse events, including retinal artery occlusion (RAO), retinal vein occlusion (RVO), noninfectious uveitis (NIU), noninfectious scleritis (NIS), optic neuritis (ON), ischemic optic neuropathy (ION), and ocular motor cranial nerve palsy (OMCNP), following Coronavirus Disease 2019 (COVID-19) vaccination. Population-based self-controlled case series METHODS: This study utilized nationwide claims and vaccination data provided by the Korea National Health Insurance Service and Korea Disease Control and Prevention Agency. From the entire South Korean population of 52 million individuals, patients with incident RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, or OMCNP between January 2021 and March 2022 were included. The postvaccination risk period was defined as up to 56 days after COVID-19 vaccination. The relative incidence rate ratios (IRRs) for RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, and OMCNP during the risk periods were measured using conditional Poisson regression. The study included 6,590, 70,120, 137,958, 17,921, 15,492, 2,039, 49,089, and 11,312 cases of incident RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, and OMCNP, respectively. The IRRs (95% confidence interval) during the early risk period (0-28 days) were 0.95 (0.88-1.01), 0.96 (0.94-0.98), 0.93 (0.91-0.94), 0.93 (0.89-0.96), 0.96 (0.92-1.01), 1.04 (0.92-1.18), 0.98 (0.95-1.00), and 0.91 (0.86-0.96), respectively. In the late risk period (29-56 days), the IRRs were 0.96 (0.89-1.03), 0.93 (0.91-0.96), 0.96 (0.95-0.98), 1.00 (0.95-1.04), 0.96 (0.91-1.01), 1.00 (0.87-1.15), 1.01 (0.98-1.04), and 0.95 (0.90-1.01), respectively. COVID-19 vaccination did not increase the risk of incident RAO, RVO, anterior NIU, nonanterior NIU, NIS, ON, ION, or OMCNP during the postvaccination period.

Proteomic Analysis of Aqueous Humor in Central Retinal Artery Occlusion: Unveiling Novel Insights Into Disease Pathophysiology.

Central retinal artery occlusion (CRAO) is an ocular emergency that results from acute blockage of the blood supply to the retina and leads to a sudden vision loss. Other forms of ischemic retinopathies include diabetic retinopathy (DR), which involves chronic retinal ischemia and remains the leading cause of blindness in working-age adults. This study is the first to conduct a proteomic analysis of aqueous humor (AH) from patients with CRAO with a comparative analysis using vitreous humor (VH) samples from patients with DR. AH samples were collected from 10 patients with CRAO undergoing paracentesis and 10 controls undergoing cataract surgery. VH samples were collected from 10 patients with DR and 10 non-diabetic controls undergoing pars plana vitrectomy (PPV). Samples were analyzed using mass spectrometry. Compared with controls, AH levels of 36 differentially expressed proteins (DEPs) were identified in patients with CRAO. Qiagen Ingenuity Pathway Analysis (IPA) revealed 11 proteins linked to ophthalmic diseases. Notably, enolase 2, a glycolysis enzyme isoform primarily expressed in neurons, was upregulated, suggesting neuronal injury and enzyme release. Additionally, clusterin, a protective glycoprotein, was downregulated. ELISA was conducted to confirm proteomics data. VH samples from patients with DR exhibited changes in a distinct set of proteins, including ones previously reported in the literature. The study provides novel insights into CRAO pathophysiology with multiple hits identified. Proteomic results differed between DR and CRAO studies, likely due to the different pathophysiology and disease duration. This is the first proteomic analysis of CRAO AH, with the potential to identify future therapeutic targets.

Insight Into Systemic Lupus Erythematosus: Unveiling Central Retinal Artery Occlusion as an Initial Indicator

Insight Into Systemic Lupus Erythematosus: Unveiling Central Retinal Artery Occlusion as an Initial Indicator

Central retinal artery and Common Carotid artery occlusions following COVID-19 infection: A case report.

To report a case of central retinal artery and common carotid artery occlusions following COVID-19 infection in a young female with no other risk factors. Retrospective analysis of the medical notes of a patient hospitalized with COVID 19 infection at University Hospital Southampton. The patient was found to have dural venous sinus thrombosis and an acute infarct within the right parietal lobe. There was an occlusive thrombus within the right common carotid artery. Subsequently she was found to have a right central artery occlusion secondary to the right common carotid artery occlusion. COVID-19 infection can cause retinal artery occlusion via systemic thrombosis in previously healthy patients.

Neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in retinal artery occlusion: a meta-analysis.

The goal of this meta-analysis is to examine the association between Neutrophil-to-Lymphocyte Ratio (NLR) and Platelet-to-Lymphocyte Ratio (PLR) in patients with Retinal Artery Occlusion (RAO). The analysis aims to provide insight into the potential of NLR and PLR as inflammatory biomarkers for RAO. Following PRISMA guidelines, a systematic search in PubMed, Embase, and Scopus identified eight eligible studies. The analysis assessed serum NLR and PLR levels in RAO and non-RAO groups by employing standardized mean differences (SMDs). Sensitivity analyses and publication bias were examined. The diagnostic performance of these markers was evaluated with a quantitative synthesis. The meta-analysis, involving 1,444 participants, demonstrated significantly elevated NLR (SMD = 0.88, 95% CI: 0.49-1.28, P < 0.001) and PLR (SMD = 0.45, 95% CI: 0.16-0.73, P < 0.001) levels in individuals with RAO. Significant heterogeneity was noted. Sensitivity analysis showed robustness and no significant publication bias was found. Summary results of diagnostic performance revealed promising discriminatory power for NLR and PLR. The results support a possible connection between systemic inflammation, as indicated by NLR and PLR, and the occurrence of RAO. Although there was heterogeneity, sensitivity analyses showed the findings to be robust. While immediate diagnostic applications are limited, understanding the role of NLR and PLR in the pathological process of RAO provides valuable insights for developing future predictive models, risk management approaches, and treatment strategies. Further research exploring mechanistic insights and conducting prospective studies is warranted to validate their clinical utility. What is known Retinal artery occlusion (RAO) is a serious condition with potential links to systemic inflammation and thrombosis. Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are emerging inflammatory markers. What is new This is the first meta-analysis examining the association between NLR, PLR and RAO. Elevated NLR and PLR levels were observed in patients with RAO compared to controls. NLR and PLR show potential as indicators of systemic inflammation in RAO pathogenesis.

Evaluation of Retinal Arterial Occlusion and its Visual and Systemic Prognosis after Hyperbaric Oxygen Therapy.

To evaluate the systemic and ocular outcomes of patients with branch retinal artery occlusion (BRAO) and central retinal artery occlusion (CRAO) after hyperbaric oxygen therapy (HBOT). This is a single-institution study of 75 subjects diagnosed with BRAO (28, 37.3%) and CRAO (47, 62.7%) who visited the emergency department or stroke clinic. Twenty-seven (36%) subjects received HBOT on initial presentation (BRAO-14.3%, CRAO-48.9%). The primary outcome was the best corrective visual acuity (BCVA) change in non-HBOT and HBOT subjects. Secondary outcomes included subsequent development of an acute cerebrovascular accident (CVA)/stroke or neovascular glaucoma (NVG). Overall BCVA did not change from the initial presentation to the final timepoint (logMAR 1.5) in either the conservative management or HBOT cohorts for either BRAO subjects (non-HBOT-logMAR 0.4 vs. 0.6, p=0.658; HBOT-logMAR 0.1 vs. 0.4, p=0.207) or CRAO subjects (non-HBOT-logMAR 2.1 vs. 2.2, p=0.755; HBOT-logMAR 2.1 vs. 2.0, p=0.631). Seven (9.3%) subjects developed CVA (BRAO: non-HBOT-4.2% and HBOT-25.0%, p=0.207; CRAO: non-HBOT-16.7% and HBOT-4.3%, p=0.348) and five subjects (6.7%) developed NVG (BRAO: non-HBOT-4.2% and HBOT-0%, p=1.00; CRAO: non-HBOT-16.7% and HBOT-0%, p=0.109). Our findings suggest that HBOT does not significantly improve BCVA or mitigate the subsequent development of stroke and NVG in patients with RAOs.

Adapting the segment anything model for multi-modal retinal anomaly detection and localization

The fusion of optical coherence tomography (OCT) and fundus modality information can provide a comprehensive diagnosis for retinal artery occlusion (RAO) disease, where OCT provides the cross-sectional examination of the fundus image. Given multi-modal retinal images, an anomaly diagnosis model can discriminate RAO without the need for real diseased samples. Despite this, previous studies have only focused on single-modal diagnosis, because of: 1) the lack of paired modality samples; and 2) the significant imaging differences, which make the fusion difficult with small-scale medical data. In this paper, we describe how we first built a multi-modal RAO dataset including both OCT and fundus modalities, which supports both the anomaly detection and localization tasks with pixel-level annotation. Motivated by the powerful generalization ability of the recent visual foundation model known as the Segment Anything Model (SAM), we adapted it for our task considering the small-scale property of retinal samples. Specifically, a modality-shared decoder with task-specific tokens is introduced to make SAM support the multi-modal image setting, which includes a mask token for the anomaly localization task at the pixel level and a fusion token for the anomaly detection task at the case level. Since SAM has little medical knowledge and lacks the learning of the “normal” concept, it is infeasible to localize RAO anomalies in the zero-shot manner. To integrate expert retinal knowledge while keeping the general segmentation knowledge, general anomaly simulation for both modalities and a low-level prompt-tuning strategy are introduced. The experiments conducted in this study show that the adapted model can surpass the state-of-the-art model by a large margin. This study sets the first benchmark for the multi-modal anomaly detection and localization tasks in the medical community. The code is available at https://github.com/Jingtao-Li-CVer/MMRAD.

The temporal dynamic of bradykinin type 2 receptor effects reveals its neuroprotective role in the chronic phase of cerebral and retinal ischemic injury.

The activation of the bradykinin type 2 receptor is intricately involved in acute post-ischemic inflammatory responses. However, its precise role in different stages of ischemic injury, especially in the chronic phase, remains unclear. Following simultaneous cerebral and retinal ischemia, bradykinin type 2 receptor knockout mice and their controls were longitudinally monitored for 35 days via magnetic resonance imaging, fundus photography, fluorescein angiography, behavioral assessments, vascular permeability measurements, and immunohistochemistry, as well as glycemic status assessments. Without impacting the lesion size, bradykinin type 2 receptor deficiency reduced acute cerebral vascular permeability preventing the loss of pericytes and tight junctions. In the chronic phase of ischemia, however, it resulted in increased astrogliosis and cortical neuronal loss, as well as higher functional deficits. The retinal findings demonstrated a similar pattern. Bradykinin type 2 receptor deficiency delayed, but exacerbated the development of retinal necrosis, increased subacute vascular permeability, and promoted retinal ganglion cell loss in the chronic phase of ischemia. This investigation sheds light on the temporal dynamic of bradykinin type 2 receptor effects in ischemia, pointing to a therapeutic potential in the subacute and chronic phases of ischemic injury.

Comparative Proteomic Study of Retinal Ganglion Cells Undergoing Various Types of Cellular Stressors.

Retinal ganglion cell (RGC) damage serves as a key indicator of various retinal degenerative diseases, including diabetic retinopathy (DR), glaucoma, retinal arterial and retinal vein occlusions, as well as inflammatory and traumatic optic neuropathies. Despite the growing body of data on the RGC proteomics associated with these conditions, there has been no dedicated study conducted to compare the molecular signaling pathways involved in the mechanism of neuronal cell death. Therefore, we launched the study using two different insults leading to RGC death: glutamate excitotoxicity and optic nerve crush (ONC). C57BL/6 mice were used for the study and underwent NMDA- and ONC-induced damages. Twenty-four hours after ONC and 1 hour after NMDA injection, we collected RGCs using CD90.2 coupled magnetic beads, prepared protein extracts, and employed LC-MS for the global proteomic analysis of RGCs. Statistically significant changes in proteins were analyzed using the Shiny Go program to identify GO biological processes and molecular functions resulting from the treatment. We identified unique and common alterations in protein profiles in RGCs undergoing different types of cellular stressors. Additionally, we observed the absence of certain proteins in treated RGCs compared to the control group. Our study not only identified both unique and shared proteomic changes but also laid the groundwork for the future development of a therapeutic platform for testing gene candidates for DR and glaucoma.

Cataract Surgery and Incidence of Retinal Vascular Occlusion: Population-Based Cohort Study Using a Target Trial Emulation Framework

BackgroundPrevious studies suggested an association between cataract surgery and retinal vascular occlusion. However, the association may be attributable to detection bias because postoperative monitoring may be more frequent for those who receive cataract surgery than for those who do not. DesignPopulation-based cohort study using target trial emulation framework. MethodsWe included patients with cataract aged 50 years and older receiving cataract surgery or non-surgical interventions identified from the Taiwan National Health Insurance Research Database between 2003 and 2018, matched by propensity score. The primary outcome was retinal vascular occlusion. Cox proportional hazards models were used to compare surgery and control groups. Additional analyses were restricted to patients who had undergone fundoscopic examination within 6 months prior to cataract surgery to address the issue of detection bias. ResultsWe included 577,129 cataract surgery and control pairs. We found the hazard ratio (HR) for retinal vascular occlusion after cataract surgery was 1.23 (95% confidence interval (CI): 1.17-1.29), compared with the control group. Secondary outcome analyses yielded similar results for retinal artery occlusion (HR: 1.13, 95% CI: 1.02-1.26) and retinal vein occlusion (HR: 1.26, 95% CI: 1.20-1.33). However, no risk of retinal vascular occlusion was observed among patients who had received fundoscopic examinations (HR: 1.06, 95% CI: 0.98-1.15) at baseline. ConclusionsOur study underscored the importance of conducting complete baseline fundoscopic examinations before cataract surgery to clarify whether postoperative conditions are due to patients’ underlying diseases or unintended complications of cataract surgery.

Effects of Hyperbaric Oxygen Therapy in the Treatment of Patients With Central Retinal Artery Occlusion: A Retrospective Study.

Background Central retinal artery occlusion (CRAO) results in sudden, painless vision loss. As an analogous condition to acute ischemic stroke, CRAO is an ophthalmological emergency, but a standardized treatment is lacking. Hyperbaric oxygen therapy (HBOT) has been widely used in spite of the inconsistent results reported. Purpose To report the visual acuity (VA) outcomes in all patients submitted to HBOT with non-arteritic CRAO in a tertiary center. Methods This retrospective study included all adult patients with CRAO and symptoms lasting for less than 24 hours who were prescribed HBOT in the Hyperbaric Medicine Unit of a Portuguese hospital from March 2009 to February 2023. Patient demographic information, medical history, ophthalmologic evaluation, hospital of referral, time until HBOT, supplementary treatments, number of HBOT sessions, adverse effects, and patient subjective VA gain were collected. All patients were subjected to 90-minute HBOT sessions with 100% oxygen at 2.4 ATA. The primary outcome was VA change (dif-logMAR) before and after treatment. A clinically significant visual improvement was defined as a dif-logMAR≥0.3. Data were analyzed using IBM SPSS Statistics for Windows, Version 29 (Released 2021; IBM Corp., Armonk, New York, United States) (p<0.05 is considered significant). Results A total of 114 patients were included in this study; 68% (n=77) were male, with a mean age of 69 years, and were subjected to a median number of seven HBOT sessions. No serious adverse effects from HBOT were reported. The mean time delay from symptoms to treatment was 12 hours, and best-corrected visual acuity (BCVA) at baseline was counting fingers or worse in 84% (n=96) of the patients. A dif-logMAR≥0.3 occurred in 46% (n=52) of the patients, and 58% (n=66) reported subjective VA improvement after the treatment. A significant improvement between BCVA before HBOT (2.12±0.74) and after HBOT (1.67±0.74) was observed. The VA outcome was found to be related to the total number of sessions, age, obesity, supplementary treatments, and cherry-red spot (CRS) at presentation. There were no significant effects of the time delay from symptoms to treatment in the explanation of the VA outcome. Conclusions HBOT appears to be safe and has a beneficial effect on VA outcomes in patients with non-arteritic CRAO, particularly depending on the number of sessions. Patient factors such as age, obesity, and the presence of CRSs also appear to influence the VA outcome.

Injectable, antioxidative, and loaded with exosomes/Liproxstatin-1 hydrogel as a potential treatment for retinal ischemia–reperfusion by inhibiting ferroptosis and apoptosis

Retinal ischemia–reperfusion is a major cause of vision loss in a variety of ocular diseases, including glaucoma, age-related macular degeneration, diabetic retinopathy, and central retinal artery occlusion. Previous studies have reported the protective effects of injectable hydrogels in optic nerve injury, but reports of multifunctional hydrogels loaded with drugs and bioactive substances that synergistically promote neuroprotection are rare. Here, we designed an injectable, drug-loaded, and reactive oxygen species responsive multifunctional hydrogel. Upon intravitreal injection into a retinal ischemia–reperfusion injury model in mice, the hydrogel released exosomes and liproxstatin-1 over an extended period exceeding a month, leading to a significant recovery of visual function and reduction of retinal ganglion cell loss. The effect was superior to that of the common drug and exosome combination. The results of this study suggest that this multifunctional hydrogel is expected to advance retinal tissue engineering and provide an innovative strategy for acute neuroprotection in retinal ischemia–reperfusion injury.

Retina-Brain Homology: The Correlation Between Ophthalmic or Retinal Artery Occlusion and Ischemic Stroke.

The retina's similar structure and function to the brain make it a unique visual "window" for studying cerebral disorders. Ophthalmic artery occlusion (OAO) or retinal artery occlusion (RAO) is a severe ophthalmic emergency that significantly affects visual acuity. Studies have demonstrated that patients with OAO or RAO face a notably higher risk of future acute ischemic stroke (AIS). However, ophthalmologists often overlook multidisciplinary approach involving the neurologist, to evaluate the risk of AIS and devise clinical treatment strategies for patients with OAO or RAO. Unlike the successful use of thrombolysis in AIS, the application of thrombolysis for OAO or RAO remains limited and controversial due to insufficient reliable evidence. In this review, we aim to summarize the anatomical and functional connections between the retina and the brain, and the clinical connection between OAO or RAO and AIS, compare and review recent advances in the effectiveness and safety of intravenous and intra-arterial thrombolysis therapy in patients with OAO or RAO, and discuss future research directions for OAO or RAO. Our goal is to advance the development of multidisciplinary diagnosis and treatment strategies for the disease, as well as to establish expedited pathways or thrombolysis guidelines for vascular intervention.

Optical coherence tomography angiography evaluation of retinal and choroidal microvascular changes in pregnant women with a history of unexplained recurrent spontaneous abortions.

To study retinal and choroidal microcirculation by optical coherence tomography angiography (OCTA) in pregnant women with unexplained recurrent spontaneous abortion (RSA) and to compare them with healthy pregnant and nonpregnant subjects. Pregnant women with an unexplained history of RSA (group 1), healthy pregnant (group 2), and healthy non-pregnant women (group 3) were included in the study. After a thorough ophthalmologic examination:best-corrected visual acuity, intraocular pressure,slit-lamp biomicroscopy, fundus examination,autorefractometer, biometry, and axial length measurement; OCT and OCTA measurements were performed with Swept Source OCT-Angiography (Topcon Co, Japan). The nonpregnant group had higher values for central foveal superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density (VD) and lower values for superior, inferior, and mean VD compared with pregnant groups (p < 0.001). Choriocapillaris values (CC) VD were higher in groups 1 and 2 than in group 3 (p < 0.001). The group with unexplained RSA had a relatively smaller FAZ (foveal avascular zone) area than the group of healthy pregnant women (p:0.047). There were no statistically significant differences between groups in the retina, retinal nerve fiber layer, ganglion cell layer, and choroidal thickness (p > 0.05). Although our study did not identify any etiology in pregnant women with RSA, we observed detectable differences in FAZ area and vessel density values using OCTA, when comparing them with healthy pregnant women and healthy nonpregnant controls. We believe that OCTA, as used in many pathologies such as diabetic and hypertensive retinopathy and retinal vascular occlusion, can also be extended to unexplained RSA both to detect etiology and to monitor treatment in studies with a larger number of patients.

Comparative proteomic study of retinal ganglion cells undergoing various types of cellular stressors

Retinal ganglion cell (RGC) damage serves as a key indicator of various retinal degenerative diseases, including diabetic retinopathy (DR), glaucoma, retinal arterial and retinal vein occlusions, as well as inflammatory and traumatic optic neuropathies. Despite the growing body of data on the RGC proteomics associated with these conditions, there has been no dedicated study conducted to compare the molecular signaling pathways involved in the mechanism of neuronal cell death. Therefore, we launched the study using two different insults leading to RGC death: glutamate excitotoxicity and optic nerve crush (ONC). C57BL/6 mice were used for the study and underwent NMDA- and ONC-induced damage. Twenty-four hours after ONC and 1 h after NMDA injection, we collected RGCs using CD90.2 coupled magnetic beads, prepared protein extracts, and employed LC-MS for the global proteomic analysis of RGCs. Statistically significant changes in proteins were analyzed to identify changes to cellular signaling resulting from the treatment. We identified unique and common alterations in protein profiles in RGCs undergoing different types of cellular stresses. Our study not only identified both unique and shared proteomic changes but also laid the groundwork for the future development of a therapeutic platform for testing gene candidates for DR and glaucoma.

Thrombotic Microangiopathy Following Hematopoietic Stem Cell Transplantation: A Case of Purtscher-like Retinopathy.

Purtscher-like retinopathy (PLR) is a rare entity related with retinal ischemia due to endothelial dysfunction and embolization. We present a case of a 17-year-old patient who presented with PLR associated with transplant-associated thrombotic microangiopathy. Visual acuity was finger counting at 1 meter in both eyes. Fundoscopy demonstrated peripapillary cotton-wool spots and hypopigmentation in the middle peripheral retina. Both eyes showed signs of macular edema with intraretinal hemorrhages. Optical coherence tomography and fundus fluorescence angiography was performed to support the diagnosis. After systemic treatments and panretinal photocoagulation, the patient's vision improved and the macular edema resolved. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

Eye stroke protocol in in the emergency department

BackgroundVisual outcomes of acute central and branch retinal artery occlusions (CRAO/BRAO) are poor and acute treatment options are limited by delayed diagnosis. In the hyper-acute setting, the ocular fundus may appear “normal”, making recognition challenging, but is facilitated by retinal optical coherence tomography (OCT), which is seldom available in emergency departments (ED). We evaluated the use of non-mydriatic ocular fundus photographs (NMFP) combined with OCT to facilitate ultra-rapid remote diagnosis and stroke alert for patients with acute vision loss presenting to the ED. MethodsProspective evaluation of all CRAO/BRAO between 06/06/2023-06/06/2024 who had NMFP-OCT in our general ED affiliated with a stroke center. ResultsOver 1 year, 22 patients were diagnosed with CRAO, 4 with BRAO. Five patients presented within 4.5 hours of vision loss onset, 6 within 4.5 to ≤12 hours and 15 within >12 to 24 hours. On average, NMFP-OCT was performed within 141 minutes of presentation to the ED (range 27- 422 minutes). Diagnosis of acute RAO was made remotely with NMFP-OCT within 4.5 hours in 4 patients, 2 of whom received intravenous thrombolysis. Of the 9 patients with NMFP-OCT within 12 hours of symptom onset, 5 patients had subtle retinal whitening on color fundus photograph, but all had OCT inner retinal hyper-reflectivity/edema. ConclusionImplementation of NMFP-OCT in a general ED enables rapid remote diagnosis of CRAO/BRAO and facilitates initiation of an eye stroke protocol in acute patients. OCT complements color fundus photography and provides greater diagnostic accuracy in hyperacute cases with near-normal appearing ocular fundi.

Swept-source optical coherence tomography early findings in patients with carotid artery disease.

Ocular ischemic syndrome can be the first and only hint of life-threatening carotid artery disease. The early recognition of carotid stenosis-related retinal signs, as well as the comprehension of the pathophysiology behind retinal changes could become relevant for physicians to predict the risk of stroke. The aim of this study is to assess the carotid artery disease-induced early structural retinochoroidal changes by means of swept-source optical coherence tomography (SS-OCT). A prospective observational study was conducted in 72 eyes with carotid stenosis. According to the degree of stenosis, the participants were divided into a normal group (34 eyes), a mild-moderate stenosis group (22 eyes), a severe stenosis group (16 eyes). SS-OCT and OCTA were performed to scan macular fovea. Central macular thickness (CMT), subfoveal choroidal thickness (SCT) and foveal avascular zona (FAZ) area were the major measurements for our study. CMT was significantly thicker in group 3 when compared to group 2 and 1. SCT was significantly thinner in group 3 vs group 1, being thicker in group 2 when compared to group 1. No significant differences were obtained when comparing FAZ in the superficial and middle capillary plexus although it was significant when comparing the FAZ in the deep capillary plexus between group 1 and 3. internal carotid artery stenosis greater than 70% leads to a significant increase in CMT and a decrease in SCT prior the development of clinical findings of ocular ischemia syndrome.

Optimization of an Ischemic Retinopathy Mouse Model and the Consequences of Hypoxia in a Time-Dependent Manner.

The retina is one of the highest metabolically active tissues with a high oxygen consumption, so insufficient blood supply leads to visual impairment. The incidence of related conditions is increasing; however, no effective treatment without side effects is available. Furthermore, the pathomechanism of these diseases is not fully understood. Our aim was to develop an optimal ischemic retinopathy mouse model to investigate the retinal damage in a time-dependent manner. Retinal ischemia was induced by bilateral common carotid artery occlusion (BCCAO) for 10, 13, 15 or 20 min, or by right permanent unilateral common carotid artery occlusion (UCCAO). Optical coherence tomography was used to follow the changes in retinal thickness 3, 7, 14, 21 and 28 days after surgery. The number of ganglion cells was evaluated in the central and peripheral regions on whole-mount retina preparations. Expression of glial fibrillary acidic protein (GFAP) was analyzed with immunohistochemistry and Western blot. Retinal degeneration and ganglion cell loss was observed in multiple groups. Our results suggest that the 20 min BCCAO is a good model to investigate the consequences of ischemia and reperfusion in the retina in a time-dependent manner, while the UCCAO causes more severe damage in a short time, so it can be used for testing new drugs.

Morphological and functional abnormalities of ophthalmic artery in patients with ophthalmic vascular accidents.

By observing and comparing the morphological and functional differences of the ophthalmic artery (OA) in patients with ocular vascular accidents (OVAs) due to iatrogenic embolism or non-iatrogenic occlusion, we propose a classification system based on the characteristics of OA on invasive digital subtraction angiography (DSA). All patients undergoing ophthalmic arterial DSA within 1 week after the OVAs between January 2017 and December 2021 were enrolled and divided into different types, and the differences between iatrogenic embolism and non-iatrogenic occlusion categories were compared. A total of 27 eyes of 27 patients were included in this study. Based on the results of carotid/intracranial arterial DSA, the morphological and functional abnormalities of OA with OVAs can be divided into five types. The proportion of males (7.14%), ocular ischemic syndrome (OIS) (0.00%) and neovascular glaucoma (NVG) (0.00%) in the iatrogenic embolism category was significantly lower than that (84.62, 61.54, and 69.23%, respectively) of the non-iatrogenic occlusion category (p < 0.001, p = 0.001, p < 0.001, respectively). However, the proportion of no light perception (NLP) (100%), anterior segment ischemia (ASI) (71.43%), and orbital involvement (ophthalmoplegia and ptosis, 42.86%) eventually occurring in the former was significantly greater than that in the latter (23.08, 0.00, 0.00%, respectively) (p < 0.001, p < 0.001, p = 0.010, respectively). Ocular vascular accidents can be divided into five types based on the characteristics of OA on DSA.