Plasma Proteomics to Identify Drug Targets and Potential Drugs for Retinal Artery Occlusion: An Integrated Analysis in the UK Biobank.

Retinal artery occlusion (RAO), which is positively correlated with acute ischemic stroke (IS) and results in severe visual impairment, lacks effective intervention drugs. This study aims to perform integrated analysis using UK Biobank plasma proteome data of RAO and IS to identify potential targets and preventive drugs. A total of 7191 participants (22 RAO patients, 1457 IS patients, 8 individuals with both RAO and IS, and 5704 healthy age-gender-matched controls) were included in this study. Unique 1461 protein expression profiles of RAO, IS, and the combined data set, extracted from UK Biobank Plasma proteomics projects, were analyzed using both differential expression analysis and elastic network regression (Enet) methods to identify shared key proteins. Subsequent analyses, including single cell type expression assessment, pathway enrichment, and druggability analysis, were conducted for verifying shared key proteins and discovery of new drugs. Five proteins were found to be shared among the samples, with all of them showing upregulation. Notably, adhesion G-protein coupled receptor G1 (ADGRG1) exhibited high expression in glial cells of the brain and eye tissues. Gene set enrichment analysis revealed pathways associated with lipid metabolism and vascular regulation and inflammation. Druggability analysis unveiled 15 drug candidates targeting ADGRG1, which demonstrated protective effects against RAO, especially troglitazone (-8.5 kcal/mol). Our study identified novel risk proteins and therapeutic drugs associated with the rare disease RAO, providing valuable insights into potential intervention strategies.

Imaging Hypoxia to Predict Primary Neuronal Cell Damage in Branch Retinal Artery Occlusion.

PURPOSE: To develop a reliable method to generate a mouse model of branch retinal artery occlusion (BRAO) using laser-induced thrombosis of a major artery in the mouse retina. Also, to develop a reliable method to detect retinal hypoxia as predictive biomarker for the risk of neuronal cell damage in BRAO. METHODS: A reliable and reproducible model of laser-induced BRAO was developed in mouse retina using Rose Bengal. To characterize retinal hypoxia in BRAO, pimonidazole immunostaining and HYPOX-4 molecular imaging methods were used. Terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) was used to characterize neuronal cell damage in the BRAO retina. Expression of mRNA in retinal tissues from BRAO and age-matched control retinas were analyzed using qRT-PCR. RESULTS: Occlusion of a branch retinal artery near the optic nerve head (ONH) caused a pattern of retinal tissue hypoxia covering about 12.5% of the entire retina. TUNEL-positive cells were localized in all layers in BRAO retinal tissue cross sections. In addition, qRT-PCR data analysis suggests that BRAO is associated with both inflammation and hypoxia. CONCLUSIONS: This study provides a reliable method for BRAO in mouse retina and demonstrates the utility of molecular imaging method to detect retinal hypoxia as predictive biomarker for the risk of neuronal cell damage in BRAO. In addition, our data suggest that BRAO retinas are associated with inflammation and also associated with hypoxia-related neuronal cell damage. PERSPECTIVES: Imaging areas of retinal hypoxia may provide accurate diagnosis, evaluating retinal tissue injury from BRAO.

Retinal Artery and Vein Occlusion Risks after Coronavirus Disease 2019 or Coronavirus Disease 2019 Vaccination.

PURPOSE: To evaluate the incidence of new retinal artery occlusion (RAO) and retinal vein occlusion (RVO) after the diagnosis of coronavirus disease 2019 (COVID-19) or vaccination against COVID-19 and compare the incidences with the population with neither. DESIGN: Nationwide population-based cohort study. PARTICIPANTS: From a nationwide population-based cohort, 8 418 590 patients were categorized into control (group 1), COVID-19 infection (group 2), and COVID-19 vaccination (group 3) groups. METHODS: The cumulative incidence of RAO and RVO was calculated in groups 1, 2, and 3 using the Kaplan-Meier method. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) based on the Poisson distribution for RAO and RVO according to each group and subgroup using Cox proportional hazards models, with group 1 as the reference. We conducted univariable and multivariable analyses for the risk factors of RAO and RVO according to each subgroup. MAIN OUTCOME MEASURES: Cumulative incidence and risks of incidence of RAO and RVO from the index date to day 60. RESULTS: In multivariable analysis, no significant increase in RAO and RVO risks after COVID-19 or COVID-19 vaccination were observed in either men or women. These results were observed consistently across various conditions in sensitivity analyses. In subgroup analysis, individuals who were vaccinated before infection showed no significant increase in RAO or RVO risks in both sexes compared with the control group. In the subgroup analysis of vaccinated patients, the HRs of RAO and RVO for different vaccine types did not show an increase compared with the control group; however, an exception was observed in women who received mRNA-1273 vaccines, who showed a higher RAO HR (4.65; 95% CI, 1.27-17.03; P = 0.021). CONCLUSIONS: Within 60 days of COVID-19 diagnosis or vaccination, RAO and RVO occurred rarely. We observed no increase in the HR of RVO and RAO relative to COVID-19 or COVID-19 vaccination except for a possible increase in the RAO HR in women who received mRNA-1273, for which the raw incidence was extremely low. Further investigation is required to validate this result. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

A Remote Consult Retinal Artery Occlusion Diagnostic Protocol.

PURPOSE: To report a novel protocol for diagnosis of retinal artery occlusions at the point of care using OCT and a remote consult model. DESIGN: Retrospective case series and evaluation of a diagnostic test or technology. PARTICIPANTS: Adult patients who presented with painless monocular vision loss and were diagnosed with a nonarteritic retinal artery occlusion. METHODS: OCT machines were placed in the stroke center or emergency department at 3 hospitals within our health system. Patients who presented with painless monocular vision loss were evaluated by the stroke neurology service and an OCT was acquired. The images were interpreted remotely by the retina service. An in-house ophthalmology consult was not required to make the final treatment decision. Eligible patients were treated with intra-arterial tissue plasminogen activator (IA-tPA). Patients were followed by ophthalmology during their admission when an in-house consultation service was available or otherwise evaluated immediately after discharge. MAIN OUTCOME MEASURES: Visual acuity (VA) before and after treatment with IA-tPA; time from last known well (LKW) to treatment; and time from presentation to treatment. RESULTS: In the first 18 months since the protocol went live, 59 patients were evaluated. Twenty-five patients (42%) had a confirmed retinal artery occlusion based on OCT and follow-up examination. Ten patients were eligible for treatment, and 9 patients received treatment with IA-tPA. There was a statistically significant improvement in mean VA from logarithm of the minimum angle of resolution (logMAR) 2.14 to logMAR 0.7 within 24 hours after treatment (P = 0.0001) and logMAR 1.04 after 4 weeks (P = 0.01). Clinically significant improvement was noted in 66% of patients within 24 hours and maintained through 1 month in 56% of all treated patients. The mean time to treatment from LKW was 543 minutes and from presentation at the stroke center was 146 minutes. CONCLUSIONS: We report the successful implementation of a remote consult protocol using point-of-care automated OCT. This novel paradigm demonstrates the potential utility of remote consult services for the diagnosis of time-sensitive ophthalmic emergencies. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Prostanoid signaling in retinal vascular diseases.

The vasculature of the retina is exposed to systemic and local factors that have the capacity to induce several retinal vascular diseases, each of which may lead to vision loss. Prostaglandin signaling has arisen as a potential therapeutic target for several of these diseases due to the diverse manners in which these lipid mediators may affect retinal blood vessel function. Previous reports and clinical practices have investigated cyclooxygenase (COX) inhibition by nonsteroidal anti-inflammatory drugs (NSAIDs) to address retinal diseases with varying degrees of success; however, targeting individual prostanoids or their distinct receptors affords more signaling specificity and poses strong potential for therapeutic development. This review offers a comprehensive view of prostanoid signaling involved in five key retinal vascular diseases: retinopathy of prematurity, diabetic retinopathy, age-related macular degeneration, retinal occlusive diseases, and uveitis. Mechanistic and clinical studies of these lipid mediators provide an outlook for therapeutic development with the potential to reduce vision loss in each of these conditions.

Improved visual outcomes of central retinal artery occlusion with local intra-arterial fibrinolysis beyond the conventional time window.

Local intra-arterial fibrinolysis (LIF) is a promising therapeutic option for CRAO. However, the narrow time window of 6 h has greatly limited the application of LIF. In this study, we explored the efficacy of LIF beyond the conventional time windows and compared the result with conservative therapy. This prospective study included 179 CRAO patients with baseline visual acuity (VA) ≤ 20/400 treated at Renmin Hospital of Wuhan University. The mean time from vision loss to presentation was 5.5 days. 58 patients received conventional standard therapy (CST) alone.121 patients underwent LIF. Main outcome was VA improvement ≥ 0.3 logMAR. Secondary outcome was a favorable VA outcome of 20/200 or better. Logistic regressions were performed to identify predictors of visual improvement. 43% patients in the LIF group experienced VA improvement versus 19% with CST (P = 0.002). LIF was associated with 4.0-fold higher likelihood of visual improvement compared to CST (P = 0.001). Poor baseline VA (light perception or no light perception) and shortened prothrombin time (PT) were associated with greater chance of visual improvement with LIF. However, LIF showed no significant advantage over CST for favorable VA outcomes. No major complications occurred. LIF beyond the therapeutic time window improved vision in functionally blind CRAO patients and showed better efficacy when compared with CST. PT may be a potential predictor of visual outcome after LIF. Our findings could complement existing time-based treatment guidelines and potentially allow for personalized decisions on the use of LIF beyond time windows.

Retinal artery occlusion in young patients without typical cardiovascular risk factors: etiologies, prognosis, and suggested work-up.

PURPOSE: To understand the etiology, work-up, and secondary systemic and ocular events of retinal artery occlusion (RAO) in young patients (≤ 45 years old) without typical cardiovascular risk factors. METHODS: Retrospective longitudinal case series of 18 young patients with RAO and without typical cardiovascular risk factors evaluated at the University of Michigan Medicine Health System between the year 2000 and 2022. Laboratory and imaging studies performed at the time of RAO diagnosis, along with systemic and ocular events during follow-up, were recorded. These data were combined with data from a literature review of 74 similar patients experiencing a RAO. RESULTS: Fifteen (83%) of patients were female and 10 (56%) suffered a branch retinal artery occlusion (BRAO). 56% of patients had one risk factor associated with cryptogenic stroke, most commonly a migraine history (33%). The most frequent etiology of RAO was vasculitis (28%), followed by idiopathic (22%) and patent foramen ovale (PFO, 17%). Three out of four patients with idiopathic RAOs developed new migraines around the time of RAO diagnosis, whereas none of the patients with a clear etiology had new onset migraines (n = 14). No patients suffered a stroke or myocardial infarction (MI) in the follow-up period (average 3.6 years ± 3.2 years). Two patients (11%) suffered a repeat RAO, both of whom were diagnosed with a vasculitis. Patients with isolated retinal vasculitis required repeat fluorescein angiograms for up to 2 years after the initial event to definitively identify the vasculitic etiology of the RAO. When our data are pooled with similarly healthy patients from previously published RAO series, structural/functional cardiac abnormalities and vasculitides are the most common identifiable etiologies for RAOs in this group. CONCLUSION: The most common identifiable etiologies of RAO in young patients with low cardiovascular risk are structural/functional cardiac abnormalities and vasculitides, with a small range of additional causes/associations accounting for remaining cases. We suggest a focused work-up algorithm to rapidly identify etiologies in this group while minimizing unnecessary testing. The long-term risk of systemic or ocular secondary events in these patients is low regardless of the etiology of their RAO.

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

PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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. KEY MESSAGES: 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.

Incidence rates of retinal vascular occlusive diseases from 2011 to 2020 in South Korea: a nationwide cohort study.

BACKGROUND: Retinal vascular occlusions, including retinal vein occlusion and retinal artery occlusion, are common causes of visual impairment. In order to evaluate the national medical burden and help improve ophthalmic health care policy planning, we investigated the incidence of retinal vascular occlusive diseases from 2011 to 2020 in Korea. METHODS: This study is a nationwide population-based retrospective study using data from the Korea national health claim database of the Health Insurance Review and Assessment (HIRA) service. We identified retinal vascular occlusive diseases registered from January 1, 2009, to December 31, 2020, according to the retinal vascular occlusion code (H34) and its sub-codes from international classification of disease, tenth revision diagnosis code. We used data from the entire Korean population based on the 2015 census of the population in Korea to calculate standardized incidence rates. RESULTS: We identified 348,775 individuals (male, 161,673 [46.4%]; female, 187,102 [53.6%]) with incident retinal vascular occlusion (H34), 10,451 individuals (males, 6,329 [60.6%]; females, 4,122 [39.4%]) with incident central retinal artery occlusion (H34.1), and 252,810 individuals (males, 114,717 [45.4%]; females, 138,093 [54.6%]) with incident retinal vein occlusion (H34.8) during the 10-year study period. The weighted mean incidence rate of retinal vascular occlusion was 70.41 (95% CI, 70.18-70.65) cases/100,000 person-years. The weighted mean incidence rate of central retinal artery occlusion was 2.10 (95% CI, 2.06-2.14) cases/100,000 person-years. The weighted mean incidence rate of retinal vein occlusion was 50.99 (95% CI, 50.79-51.19) cases/100,000 person-years. CONCLUSION: The total retinal vascular occlusion and retinal vein occlusion showed a decreasing trend until 2020. However, the central retinal artery occlusion decreased until 2014 and remained stable without a significant further decline until 2020. The incidence of total retinal vascular occlusion and retinal vein occlusion was higher in females than in males, while the incidence of central retinal artery occlusion was higher in males. All retinal vascular occlusive diseases showed an increasing incidence with older age; the peak age incidence was 75-79 years for total retinal vascular occlusion and retinal vein occlusion, and 80-85 years for central retinal artery occlusion.

Central retinal artery occlusion as the initial manifestation of mixed connective tissue disease in a young woman: a case report.

BACKGROUND: Retinal artery occlusions are rare amongst young adults, and relevant risk factors and etiology remain unclear. In this report, we present a case of central retinal artery occlusion (CRAO) as the initial manifestation of mixed connective tissue disease (MCTD) in a young woman. CASE PRESENTATION: A 22-year-old female presented to the emergency department with a sudden decrease in visual acuity in her right eye for 1 hour. She reported a similar episode in her left eye five years prior, which resolved spontaneously after 2 hours. Initially misdiagnosed with optic neuritis in the right eye at another hospital, she was referred to our institution the following day. Clinical examination revealed a CRAO in her right eye. A detailed medical history revealed that she had developed livedo reticularis (LR) on both lower limbs five years ago, which had been overlooked and untreated. Further rheumatologic history, hematologic tests, and an autoimmune work-up confirmed a diagnosis of mixed connective tissue disease (MCTD). CONCLUSION: In young patients presenting with CRAO, further examinations should be conducted to investigate systemic disease or an embolic source to prevent future sequelae.

Central retinal artery occlusion after intravitreal brolucizumab injection for treatment-naïve neovascular age-related macular degeneration; a case report.

BACKGROUND: To report a case of central retinal artery occlusion (CRAO) after intravitreal injection of brolucizumab for a treatment-naïve neovascular age-related macular degeneration (nAMD) patient without comorbid cardiovascular disease history. CASE PRESENTATION: A 79-year-old Asian male without a cardiovascular disease history such as diabetes or hypertension underwent three times of monthly consecutive intravitreal brolucizumab injections for treatment of progressed nAMD in his left eye. Two days after the third injection, the patient presented with acute painless visual loss. Typical retinal whitening with a cherry red spot was observed on the fundus photograph, and retinal swelling with hyper-reflectivity was also identified on the optical coherence tomography (OCT) scan. On the fundus fluorescein angiography, arm-to-retina time and arteriovenous transit time were remarkedly delayed, but clinical findings suggesting an intraocular inflammation (IOI) were not observed. Therefore, CRAO was diagnosed, and anterior chamber paracentesis was administrated immediately. However, there had been no improvement in visual acuity during the follow-up period of three months, despite prolonged oral steroid and anti-platelet agent medication. CONCLUSIONS: In rare cases, patients without cardiovascular comorbidities can develop CRAO after intravitreal brolucizumab injection without gross evidence of IOI. Therefore, CRAO should always be in consideration and careful observation is required after intravitreal brolucizumab injection for nAMD patients with old age, even if the patient does not have any other cardiovascular disease history.

Macular Structure Characteristics in Unilateral Idiopathic Full-Thickness Macular Hole and the Healthy Fellow Eyes.

INTRODUCTION: This study aimed to investigate the macular structure and foveal pit characteristics in the unilateral full-thickness macular hole (FTMH) patients and healthy fellow eyes. METHODS: Our retrospective investigation included patients with unilateral FTMH as the study group, and age- and sex-matched individuals without vitreomacular diseases as the control group, all from one medical center. FTMHs were categorized into those with epiretinal proliferation, those without epiretinal proliferation, or those lacking vitreomacular separation. Macular parameters including foveal base width (FBW), central foveolar thickness (CFT), central subfield thickness (CST), central subfield volume, and retinal artery trajectory (RAT) were measured via optical coherence tomography and fundus photography. Comparisons of these parameters were made among lesioned eyes, contralateral healthy eyes and normal controls, as well as among different subgroups. RESULTS: Sixty-eight unilateral FTMH patients (39 women and 29 men) and 68 normal controls were enrolled. The fellow eyes of unilateral FTMH showed larger FBWs (446.8 ± 98.2 µm) than controls (338.4 ± 80.6 µm, p < 0.001). The lesioned and fellow eyes of unilateral FTMH had smaller RAT values (0.19 ± 0.06 and 0.14 ± 0.04) than controls (0.37 ± 0.14, p < 0.001), indicating wider RAT in both groups. No significant macular structure parameter differences were observed among different FTMH subgroups. Females exhibited larger FBW, thinner CFT and CST, and wider RAT than the age-matched males (p < 0.05). CONCLUSIONS: Patients with unilateral FTMH had a wider RAT in both the lesioned and healthy eyes and a wider FBW in their healthy fellow eyes than in controls. Such macular structure characteristics may be prone to macular hole formation.

Analysis of the Effect of Superselective Ophthalmic Artery Thrombolysis for Central Retinal Artery Occlusion.

INTRODUCTION: The aim of the study was to investigate the clinical efficacy of superselective ophthalmic artery thrombolysis for central retinal artery occlusion (CRAO). METHODS: Retrospective study of CRAO patients who attended the Department of Ophthalmology of Affiliated Hospital of Weifang Medical University from January 2022 to July 2023, 138 CRAO patients with onset time of 1-3 days were selected for the study. Among them, 86 patients refused thrombolytic treatment and chose to adopt traditional treatment, which was categorized as the control group; 52 patients adopted superselective ophthalmic artery thrombolytic treatment, which was categorized as the observation group. The visual acuity of the patients treated with traditional modality on the 4th day after the onset of the disease and the visual acuity of the patients treated with superselective ophthalmic artery thrombolysis on the 1st postoperative day were recorded, and the visual acuity improvement after different modalities of treatment was compared between the two groups. RESULTS: In the control group, 77 (89.5%) of the treated patients had no improvement in visual acuity, 9 (10.5%) had improvement, 0 (0.0%) had significant improvement, and the total improvement was 9 (10.5%); in the observation group, 18 (34.6%) of the treated patients had no improvement in visual acuity, 21 (40.4%) had improvement, 13 (25.0%) had significant improvement, and the total improvement was 34 (65.4%). The total improvement rate of treatment in the observation group was 65.4%, which was significantly higher than the 10.5% in the control group, and the difference was statistically significant (p < 0.05). CONCLUSION: Superselective ophthalmic artery thrombolysis for patients with CRAO is clinically effective, promotes improvement in patient vision, and has a high safety profile.

Association between Breast Arterial Calcification on Mammography and Impaired Ocular Perfusion: A Novel Study Using Color Doppler Ultrasonography.

OBJECTIVES: To investigate the relationship between the mammography-detected breast arterial calcification (BAC) and orbital color Doppler ultrasonography (CDUS) results. METHODS: Our single-center study, included female patients who applied to our hospital between January and May 2022 and underwent mammography and orbital CDUS examinations. Two radiologists evaluated the mammograms, grouped the patients as BAC (+) and BAC (-), and performed orbital CDUS. Continuous variables obtained from CDUS were compared according to the presence of BAC. Also, receiver operating characteristics (ROC) analysis was used to determine the orbital CDUS threshold values for the presence of BAC. RESULTS: A total of 119 women were included with a median age of 62 years, 57 (47.90%) had BAC. Orbital CDUS examination was performed on both eyes of 119 patients (238 eyes in total). Peak systolic velocity (PSV) and end-diastolic velocity (EDV) values of the ophthalmic artery (OA) (P < .001) and EDV of the central retinal artery (CRA) (P < .001) were significantly lower in patients with BAC. Pulsatile index (PI) and resistive index (RI) values of OA (P < .001) and CRA (P < .001) were higher in patients with BAC. In ROC analysis, the cut-off values for the presence of BAC were calculated as OA PI ≥1.415 and OA RI ≥0.755 (P < .001); CRA PI ≥1.135 and CRA RI ≥0.655 (P < .001). CONCLUSIONS: Orbital perfusion disorders may be observed in patients with vascular calcification detected on routine mammography. Therefore, a more detailed evaluation of patients with BAC detected on mammography with orbital CDUS may enable early detection and treatment of ocular vascular problems.

Superselective Arterial Hyaluronidase Thrombolysis is an Effective Treatment for Hyaluronic Acid-Induced Retinal Artery Occlusion: Study in a Rabbit Model.

BACKGROUND: There are serious complications associated with hyaluronic acid (HA) facial injections, including vision impairment due to retinal artery ischemia. In this study, we put forth a clinically relevant model of retinal ischemia and reperfusion in rabbit. We used this to verify the efficacy of hyaluronidase intra-artery thrombolysis in the treatment of hyaluronic acid-induced retinal artery occlusion. METHODS: Retinal artery ischemia was induced by injecting HA into the ophthalmic artery (OA) of adult chinchilla rabbit, and reperfusion was achieved by intra-artery thrombolysis therapy with hyaluronidase following 60 min and 4 h of occlusion. Digital subtraction angiography (DSA) and fundus fluorescein angiography (FFA) were used to evaluate blood flow in the retina. Electroretinogram (ERG), hematoxylin and eosin staining and transmission electron microscope were used to evaluate the structure and function of the retina after ischemia and reperfusion following 60 min and 4 h of occlusion. RESULTS: DSA and FFA images confirmed occlusion of the ophthalmic and central retinal arteries, as well as reperfusion after hyaluronidase thrombolysis. ERG indicated retinal dysfunction following ischemia, and thrombolysis partially rescued its impairment following 4 h of occlusion. Hematoxylin and eosin staining and TUNEL staining revealed ischemia-induced histological damages in the retina at different time windows, and hyaluronidase thrombolysis partially mitigated these damages. CONCLUSIONS: We report a method to establish a HA-induced retinal artery occlusion animal model. Hyaluronidase intra-artery thrombolysis was used to recanalize the embolized OA at different time points. Using our method, we achieved retinal reperfusion, and an improvement was observed in the visual function of rabbits after hyaluronidase thrombolysis following 4 h of occlusion. We believe that hyaluronidase intra-artery thrombolysis is an effective method to treat HA-induced retinal artery occlusion in clinic. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Eye stroke protocol in in the emergency department.

BACKGROUND: Visual 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. METHODS: Prospective 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. RESULTS: Over 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. CONCLUSION: Implementation 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.

A case series on treatment of central and branch retinal artery occlusion with intravenous tenecteplase: Tenecteplase for retinal artery occlusions.

OBJECTIVES: Central and branch retinal artery occlusions are disabling ischemic strokes of the retina for which established acute treatments are lacking. This is the first published report of the use of intravenous tenecteplase (TNK) for retinal artery occlusion, in which we describe the clinical course of four patients with central retinal artery occlusion (CRAO) and one patient with branch retinal artery occlusion (BRAO). MATERIALS AND METHODS: Patients were retrospectively recruited to the study from two stroke centers. Clinical course was determined from review of electronic medical records. The primary outcomes of interest were short and long term complications as well as visual acuity at presentation and at any subsequent follow up. RESULTS: There were no hemorrhagic complications. None of the four patients with CRAO experienced functional visual recovery (defined as improvement to 20/100 or better). The patient with BRAO had functional visual recovery. CONCLUSIONS: Intravenous TNK may be a safe and reasonable treatment for CRAO and BRAO.

IV Thrombolysis for central retinal artery occlusion - Real-world experience from a comprehensive stroke center.

OBJECTIVES: Central retinal artery occlusion (CRAO) is a stroke of the retina potentially amenable to intravenous thrombolysis (IVT). We aimed to determine feasibility of an emergency treatment protocol and risk profile of IVT for CRAO in a comprehensive stroke center (CSC). METHODS: We performed a retrospective, observational cohort study including patients with acute CRAO admitted to a CSC over 4 years. Patients are offered IVT if they present with acute vision loss of ≤ 20/200 in the affected eye, have no other cause of vision loss (incorporating a dilated ophthalmologic exam), and meet criteria akin to acute ischemic stroke. We collected socio-demographic data, triage data, time from onset to presentation, IVT candidacy, and rates of symptomatic intracranial hemorrhage (sICH)- or extracranial hemorrhage. RESULTS: 36 patients presented within the study period, mean (standard deviation (SD)) age of 70.7 (10), 52 % female, and median time (Q1, Q3) to ED presentation of 13.5 (4.3, 18.8) h. Patients within 4.5 h from onset presented more commonly directly to our ED (66.6 % vs 37.1 %, p = 0.1). Nine patients (25 %) presented within the 4.5 h window. Of those eligible, 7 (77 %) received IVT. There were no events of intracranial or extracranial hemorrhage. CONCLUSIONS: Our study confirmed that IVT for acute CRAO is feasible. We found a high rate of treatment with IVT of those eligible. However, because 75 % of patients presented outside the treatment window, continued educational efforts are needed to improve rapid triage to emergency departments to facilitate evaluation for possible candidacy with IVT.

A unique complication of thyroidectomy for Hashimoto's thyroiditis: central retinal artery thrombosis.

BACKGROUND: Central retinal artery occlusion (CRAO) is a rare ophthalmological emergency and also a unique complication after thyroid surgery. METHODS: We present the first case of CRAO following thyroid surgery in a patient with Hashimoto's thyroiditis, along with a variety of interventions to overcome this complication. RESULTS: A 42-year-old female patient suffering from sudden vision loss following total thyroidectomy was diagnosed with CRAO. Hyperbaric oxygen therapy was started within the postoperative first 6 hours. CONCLUSION: Although it is extremely rare, it should be noted that patients may experience retinal artery occlusion following the thyroid surgery. Immediate evaluation of patients with visual impairment in the early postoperative period, and planning of emergent hyperbaric oxygen therapy for the management are critical.

Aetiology, Diagnosis and Treatment of Arterial Occlusions of the Retina-A Narrative Review.

Arterial occlusions of the retina are potentially sight-threatening diseases which often result in profound visual loss. The aim of this narrative review is to provide an overview of the aetiology, discuss major risk factors, describe the management and systemic assessments and evaluate existing therapies. For this review, an extensive literature search in PubMed was performed. Emboli from the heart or the carotid arteries can cause ophthalmic artery occlusion (OAO), central retinal artery occlusion (CRAO) and branch retinal artery occlusion (BRAO). Most patients with arterial occlusions have vascular risk factors such as arterial hypertension, hyperhomocysteinaemia, carotid stenosis and atrial fibrillation, which also increase the risk of cerebral stroke and myocardial infarction. Therapies such as ocular massage, thrombolysis and anterior chamber paracentesis have been suggested but are still equivocal. However, it is evident that retinal artery occlusion should be immediately treated and accompanied by interdisciplinary collaboration, since early diagnosis and the proper treatment of possible risk factors are important to reduce the risk of further damage, recurrences, other vascular diseases and mortality.