Management of Central Retinal Artery Occlusion: A Scientific Statement From the American Heart Association

Risk of Stroke, Myocardial Infarction, and Death After Retinal Artery Occlusion

Importance

Patients with retinal artery occlusions (RAOs) are recommended to have emergent stroke workup, although the true risk of death and subsequent vascular events post-RAO is not clear.

Objective

To determine short-term and long-term rates of stroke, myocardial infarction (MI), and death in patients after RAO compared with a control cohort.

Design, Setting, and Participants

This retrospective cohort study used aggregated electronic health records from January 1, 2003, through April 14, 2023, from TriNetX, a network with data from more than 111 million patients. Patients with RAO and a cataract control group were identified and matched for age, sex, race, and comorbidities, including hypertension, diabetes, hyperlipidemia, and smoking status. Patients were excluded if they had a stroke or MI within 2 years before the diagnosis of RAO or cataract.

Exposure

International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, diagnosis code for RAO or age-related cataract.

Main Outcomes and Measures

Rate of death, stroke, and MI at 2 weeks, 30 days, 1 year, 5 years, and 10 years after RAO compared with matched controls.

Results

There were a total of 34 874 patients with at least 1 year of follow-up in the RAO cohort. The mean (SD) age at the RAO event was 66 (15.2) years. The rate of death after RAO diagnosis was higher than after cataract diagnosis at 2 weeks (0.14% vs 0.06%; relative risk [RR], 2.45; 95% CI, 1.46-4.12; risk difference [RD], 0.08%; 95% CI, 0.04%-0.13%; P < .001), 30 days (0.29% vs 0.14%; RR, 2.10; 95% CI, 1.49-2.97; RD, 0.15%; 95% CI, 0.08%-0.22%; P < .001), 1 year (3.51% vs 1.99%; RR, 1.78; 95% CI, 1.61-1.94; RD, 1.41%; 95% CI, 1.17%-1.66%; P < .001), 5 years (22.74% vs 17.82%; RR, 1.28; 95% CI, 1.23-1.33; RD, 4.93%; 95% CI, 4.17%-5.68%; P < .001), and 10 years (57.86% vs 55.38%; RR, 1.05; 95% CI, 1.02-1.07; RD, 2.47%; 95% CI, 1.25%-3.69%; P < .001). Risk of stroke after RAO was higher at 2 weeks (1.72% vs 0.08%; RR, 21.43; 95% CI, 14.67-31.29; RD, 1.64%; 95% CI, 1.50%-1.78%; P < .001), 30 days (2.48% vs 0.18%; RR, 14.18; 95% CI, 10.94-18.48; RD, 2.31%; 95% CI, 2.14%-2.47%; P < .001), 1 year (5.89% vs 1.13%; RR, 5.20; 95% CI, 4.67-5.79; RD, 4.64%; 95% CI, 4.37%-4.91%; P < .001), 5 years (10.85% vs 4.86%; RR, 2.24; 95% CI, 2.09-2.40; RD, 6.00%; 95% CI, 5.50%-6.50%; P < .001), and 10 years (14.59% vs 9.18%; RR, 1.59; 95% CI, 1.48-1.70; RD, 5.41%; 95% CI, 4.62%-6.21%; P < .001). Risk of MI after RAO was higher at 2 weeks (0.16% vs 0.06%; RR, 3.00; 95% CI, 1.79-5.04; RD, 0.11%; 95% CI, 0.06%-0.16%; P < .001), 30 days (0.27% vs 0.10%; RR, 2.61; 95% CI, 1.78-3.83; RD, 0.17%; 95% CI, 0.10%-0.23%; P < .001), 1 year (1.66% vs 0.97%; RR, 1.72; 95% CI, 1.51-1.97; RD, 0.59%; 95% CI, 0.42%-0.76%; P < .001), 5 years (6.06% vs 5.00%; RR, 1.21; 95% CI, 1.12-1.31; RD, 1.07%; 95% CI, 0.64%-1.50%; P < .001), and 10 years (10.55% vs 9.43%; RR, 1.12; 95% CI, 1.04-1.21; RD, 1.13%; 95% CI, 0.39%-1.87%; P = .003).

Conclusions and Relevance

This study showed an increased risk of death, stroke, and MI in patients with RAO at both short-term and long-term intervals after RAO compared with a matched control population diagnosed with cataract. These findings suggest a potential need for multidisciplinary evaluation and long-term systemic follow-up of patients post-RAO.

Long-term outcomes of intravenous fibrinolysis in central retinal artery occlusion

Central retinal artery occlusion (CRAO) is an ophthalmologic emergency that can lead to irreversible loss of vision. Intravenous thrombolysis (IVT) has been used experimentally for its treatment. Our study aimed to evaluate the effect of emergency IVT on CRAO and its impact on visual acuity outcomes. We conducted a retrospective observational study of patients with CRAO. A total of 46 patients with CRAO were analysed; 16 patients received IVT treatment (IVT group) while 30 did not (no-IVT group). Seven patients from the IVT group received IVT early, within 4.5 hours (h) after the onset of symptoms (early-IVT), and 9 patients received it beyond this timeframe (late-IVT). The median time-to-hospital was 8.5 h: 3 h for the IVT group and 24 h for the no-IVT group. The median time-to-treatment was 5 h. The median outcome of visual acuity was 0.05 in the early-IVT, 0.025 in the late-IVT, and 0.01 in the no-IVT group. Among patients who received IVT early, 86% exhibited significant visual improvement. This improvement was four-fold greater compared to all other groups (p = 0.040), including the late-IVT (p = 0.011) and no-IVT groups (p = 0.023). No complications of the treatment were reported. Our study confirms that the administration of IVT treatment for CRAO within the 4.5-h time window is both safe and effective.

Telemedicine for Acute Monocular Visual Loss: A Retrospective Large Telestroke Network Experience

Introduction: Central retinal artery occlusion (CRAO) is an under-recognized stroke subtype that may benefit from hyperacute reperfusion therapies. We aimed to evaluate the ability of telestroke activations to provide CRAO diagnosis and thrombolysis. Methods: This retrospective observational study investigates all encounters conducted for acute visual loss between 2010 and 2021 in our multicentric Mayo Clinic Telestroke Network. Demographics, time from visual loss to telestroke evaluation, ocular examination, diagnostic, and therapeutic recommendations were collected for CRAO subjects. Results: Out of 9,511, 49 encounters (0.51%) were conducted for an acute ocular complaint. Five patients had possible CRAO, and 4 presented within 4.5 h from symptom onset (range 1.5-5 h). None received thrombolytic therapy. All telestroke physicians recommended ophthalmology consultation. Conclusion: Current telestroke assessment of acute visual loss is suboptimal and patients eligible for acute reperfusion therapies may not be offered treatment. Teleophthalmologic evaluations and advanced ophthalmic diagnostic tools should complement telestroke systems.

Case report: acute isolated cilioretinal artery occlusion secondary to percutaneous coronary intervention

INTRODUCTION

This case report aims to describe in detail the acute isolated cilioretinal artery occlusion (CLRAO) secondary to complicated therapeutic percutaneous coronary intervention (PCI).

CASE DESCRIPTION

A 68-year-old Chinese man with coronary artery disease (CAD) complained of sudden, sharp chest pain. Coronary angiography revealed severe stenoses of the coronary arteries. The patient was then treated with PCI. One hour after the procedure, the patient presented with a sudden reduction in vision in the right eye. The patient was diagnosed with acute isolated CLRAO and treated with Salvia miltiorrhiza injections.

CONCLUSIONS

This is the report to provide a detailed description of acute isolated CLRAO secondary to therapeutic PCI treated with Salvia miltiorrhiza. The visual prognosis of the untreated patients is poor. Suitable management and prevention are essential for interventional cardiologists to prevent these complications.

Visual acuity assessment of central retinal artery occlusion patients with or without paracentral acute middle maculopathy via OCT-A

PURPOSE

The association between paracentral acute middle maculopathy (PAMM) and visual acuity in patients with central retinal artery occlusion (CRAO) is still unclear. The present study investigated the visual acuity of CRAO patients with and without PAMM.

METHODS

CRAO patients with PAMM or without PAMM were included. Optical coherence tomography angiography (OCT-A) was used to record the macular retinal thickness and density of shallow and deep vessels. The Best-corrected visual acuity (BCVA) was converted to a logarithm of the minimum angle of resolution (LogMAR) for statistical analysis.

RESULTS

There were 34 CRAO patients with PAMM (43.13%), other 30 CRAO patients without PAMM (46.87%). Compared with the no-PAMM group, PAMM group had better LogMAR BCVA (1.48 (0.49, 1.85) Vs. 1.85 (1.70, 1.96), P < 0.01). There was also a significant difference in retinal thickness of the central macular sulcus (328.00 (304.50-332.25) Vs. 352.50 (311.75-420.50), P = 0.01). A significant correlation between LogMAR BCVA and macular retinal thickness was found (r = 0.42; P < 0.01).

CONCLUSION

CRAO patients with PAMM had significantly better visual acuity and less macular edema. OCT-A can be used to distinguish different levels of damage due to CRAO.

Ophthalmologic Emergencies: Assessment and Management

There are an estimated 2-3 million emergency department (ED) visits in the United States for eye complaints. Although most patients who present to the ED have nontraumatic eye complaints, many seek treatment for eye trauma, which is a leading cause of unilateral blindness and vison impairment. Given the prevalence of eye-related emergencies, it is imperative that emergency care providers understand how to recognize and treat eye complaints to prevent permanent vision loss and disability. This article covers basic eye anatomy and physiology, discusses a systematic approach to the eye examination, and presents the evidence-based treatment of selected, common nonemergent and emergent eye complaints. For each complaint, essential history questions, examination techniques, differentials, and emergency management have been presented.

Central retinal artery occlusion in a young child affected by COVID-19: a first case report

BACKGROUND

Central retinal artery occlusion (CRAO) is an ophthalmic emergency, and its etiology is generally ascribed to vessel occlusion by a thrombus or embolus, eventually due to a hypercoagulable state. CRAO occurrence is described even in the pediatric population, but its incidence is very rare. SARS-CoV-2 infection has a multitude of presentations, and almost any organ may be involved including the ocular district. Cases of CRAO in patients affected by COVID-19 are reported in the literature in the adult population, but not in the pediatric one.

CASE PRESENTATION

We describe the case of a six-year-old otherwise healthy girl, who presented a sudden and complete bilateral vision loss after a one-day fever. All the clinical, ophthalmological, laboratory and instrumental investigations led to the diagnosis of a right CRAO and the suspicion of a contralateral posterior optic nerve affection. These manifestations could not be ascribed to any etiological condition apart from the documented ongoing mild SARS-CoV-2 infection. Treatment with anticoagulants and steroids was tried but the visual outcome was poor during the one-month hospitalization and at the last follow-up.

CONCLUSIONS

To the best of our knowledge, this is the first report of CRAO in the course of SARS-CoV-2 infection in the pediatric age. In our review of the literature, we found few cases of CRAO in adults with COVID-19; we highlighted differences in anamnestic, clinical, and interventional aspects and therefore we tried to summarize the state of the art on this topic to facilitate further studies. Even if rare, the prognosis of CRAO is poor and the thrombolytic treatment could be effective only if rapidly administered, so the disease suspicion should be high in a patient with sudden vision loss, also in pediatric age.

Sex differences in major adverse cardiovascular and cerebrovascular event risk among central retinal artery occlusion patients

To estimate the association between central retinal artery occlusion (CRAO) and major adverse cardiovascular and cerebrovascular events (MACCE), including their clinical characteristics, blood markers, and the contribution of CRAO to MACCE, as well as to assess any sex differences. This retrospective cohort study included continuous new-onset CRAO patients and 1:4 controls during the same period. Correlations of CRAO with the incidence of MACCE during follow-up and the sex-related differences were studied. One hundred and twenty-four CRAO patients and four hundred and ninety-six controls were enrolled. Neutrophil-to-lymphocyte ratio (NLR, P = 0.014) and high-sensitivity C-reactive protein (hs-CRP, P = 0.038) were tended to be higher in CRAO patients. After the follow-up period, 78 patients experienced MACCE. Multivariate Cox regression analysis showed that CRAO was a predictor of the occurrence of MACCE (HR 2.321, 95% CI 1.439-3.744, P = 0.001). Sex subgroups indicated that age, diabetes, current smoking, CRAO, NLR and hs-CRP increased the risk factor of MACCE in males (All P < 0.05) and CRAO, NLR, low-density lipoprotein cholesterol (LDL-C) and hs-CRP were independent influencing factors for females (All P < 0.05). New-onset CRAO significantly increases the probability of MACCE and is associated with a poor prognosis. The sex-related differences suggested that effective prevention of the occurrence of MACCE in high-risk patients requires that attention be given to individualized risk factors corresponding to sexes.

Visual Recovery in 2 Cases of Central Retinal Artery Occlusion Treated With Prompt Intra-ophthalmic Artery Fibrinolysis

BACKGROUND

Central retinal artery occlusion (CRAO) rapidly produces inner retinal ischemia and irreversible vision loss. Although many therapeutic interventions have been proposed, no interventions have proven effective in restoring vision in large randomized controlled trials and final visual outcome in most patients is very poor.

METHODS

Retrospective case series.

RESULTS

We describe 2 cases of CRAO occurring after uncomplicated cataract surgery under topical anesthesia and rapidly diagnosed. Both had very severe vision loss at presentation with dramatic improvement after intra-ophthalmic artery fibrinolysis administered 2.75 and 5.5 hours after symptom onset.

CONCLUSIONS

Sudden monocular vision loss is an ophthalmologic emergency as CRAO must be ruled out and if diagnosed, rapid intervention should be performed. Devastating vision loss can be prevented if interventional neuroradiology is trained and available on a 24-hour basis for administration of local intra-arterial thrombolysis.

Progress in central retinal artery occlusion: a narrative review

Central retinal artery occlusion (CRAO) is a catastrophic ophthalmic emergency that severely impairs a patient's visual function, often reducing visual acuity to counting fingers or worse. Progress in CRAO research has provided new information regarding its epidemiological characteristics and led to useful assessments through various ophthalmic examinations. Additional insights about CRAO have been gained through studies of its pathophysiological mechanisms, improving intervention timing and enhancing patient prognosis. Treatment for CRAO has evolved, particularly with assistance from surgical instruments and surgical robots. Although surgical treatment is now possible, this option is not widely recognized by ophthalmologists. Conservative therapies have limited benefits compared with the natural course of disease. Recently, pars plana vitrectomy plus endovascular surgery has received considerable interest among ophthalmologists because of its potential efficacy in the treatment of CRAO. Considering the inconsistencies in rationale and efficacy of CRAO treatment modalities, it is important to distinguish between treatment effects and the natural courses of various CRAO subclasses. This narrative review explores progress in CRAO epidemiology, pathophysiology, ophthalmic examination, and treatment.

Neovascular Glaucoma Complicating Central Retinal Artery Occlusion Despite Cilioretinal Artery Sparing

This case report aims to describe a case of unilateral central retinal artery occlusion (CRAO) with cilioretinal artery sparing, which was complicated by neovascular glaucoma (NVG). A 75-year-old Indian woman with underlying normal tension glaucoma presented with the sudden onset of painless generalized blurring of the right eye's vision for a week. Her right eye vision was hand motion with the presence of a right relative afferent pupillary defect. Fundus examination revealed retinal whitening over the macula sparing the papillomacular bundle with generalized retinal arteriolar attenuation, which was suggestive of right CRAO with cilioretinal artery sparing. Systemic examination revealed high blood pressure (175/75 mmHg) without ocular bruit or audible murmur on auscultation. Optical coherence tomography of the macula showed inner retinal thickening over the temporal macula. Ultrasound carotid Doppler and computed tomography angiography of the carotid showed more than 75% stenosis over the right distal internal carotid artery. Unfortunately, she developed rubeosis iridis over her right eye two weeks after her presentation, which required pan-retinal photocoagulation. She subsequently progressed to NVG, requiring maximum anti-glaucoma medications to stabilize intraocular pressure. In conclusion, CRAO is a sight-threatening medical emergency. Thorough investigations are required to determine the underlying cause so that early intervention can be done to reduce the risk of a similar attack in the fellow eye and the risk of a cerebrovascular event or cardiac ischemia, which could be life-threatening. The presence of a cilioretinal artery does not prevent ocular neovascularization in CRAO. Hence, patients should also be closely monitored after the initial diagnosis to prevent devastating complications such as NVG.

High prevalence of thrombophilic risk factors in patients with central retinal artery occlusion

INTRODUCTION

Central retinal artery occlusion (CRAO) is a common cause of blindness and visual morbidity. In the majority of cases, it is related to thrombotic embolism. Nevertheless, the role of inherited or acquired thrombophilic risk factors in CRAO pathogenesis has not been comprehensively studied.

METHODS

In 126 CRAO patients (66 [52.4%] men, median age 55 [range: 18-80] years) and 107 matched controls (56 [52.3%] men, median age 53 [range: 34-78] years) we evaluated classical atherosclerotic risk factors, including serum lipid profile and glucose level, analyzed intima-media complex thickness (IMT) of external carotid arteries, and performed transthoracic echocardiography. Furthermore, we established the prevalence of inherited and acquired thrombophilic risk factors, such as factor V Leiden (FVL) and prothrombin 20210 G/A genetic variants, plasma activity of factor (F) VIII, protein C and antithrombin activity, and free protein S levels. We also assessed the presence of antiphospholipid antibodies (APLA) and evaluated blood homocysteine in all enrolled subjects. Additionally, we estimated the occurrence of Val34Leu polymorphism of the A subunit of coagulation factor XIII (FXIII-A) in both groups as a potential thrombosis-protecting factor.

RESULTS

Among traditional atherosclerotic risk components, obesity/overweight and hypercholesterolemia were the most common in the CRAO group and occurred in 103 (81.7%) and 85 (67.5%) patients, respectively. CRAO patients also had elevated IMT and altered echocardiographic parameters, indicating diastolic cardiac dysfunction. In thrombophilia investigations, at least one laboratory risk factor occurred in 72.2% (n = 91) of CRAO patients, with APLA as the most frequent, detected in 38.1% (n = 48) of them (almost seven times more frequent than in controls, p < 0.001). Deficiencies in protein C activity and free protein S levels were also common in the CRAO group, reported in 17.5% (n = 22) and 19.8% (n = 25) of patients, respectively. Interestingly, among two analyzed prothrombotic genetic variants, only the FVL was related to CRAO, with the allelic frequency 2.4 times more prevalent than in controls (p = 0.044). Finally, the CRAO group was characterized by hyperhomocysteinemia, almost twice as common as in controls (p = 0.026). Antithrombin deficiency, elevated FVIII, and FXIII-A Val34Leu polymorphism were not associated with CRAO.

CONCLUSIONS

Our findings suggest that thrombophilia plays a vital role in the pathogenesis of CRAO. Thus, proper laboratory screening should be considered in the primary and secondary prevention of those episodes, with implementing appropriate therapy as needed.

Intravenous Thrombolysis for Central Retinal Artery Occlusion: A Look at the Literature for the Emergency Medicine Physician

Central retinal artery occlusion (CRAO) is a subtype of ischemic stroke and true ocular emergency presenting with acute, painless, monocular vision loss. Typical findings include poor visual acuity (VA), impaired color vision, relative afferent pupillary defect, and on fundoscopic evaluation, retinal edema, cherry red spot, and occasionally visualization of retinal artery emboli. While there are no proven treatments for CRAO, options include orbital massage, hyperbaric oxygen therapy, and intra-arterial or intravenous thrombolysis (IVT). This study reviews the current literature on the efficacy of IVT for patients affected by acute, symptomatic CRAO and provides an up-to-date, evidence-based background for emergency physicians (EPs) who evaluate and manage these patients.

Retinal stroke: research models, targets and experimental drugs

INTRODUCTION

Retinal artery occlusion (RAO), often caused by a microembolus and resulting in inner retinal ischemia, could be considered as the retinal analog to cerebral stroke. Although several therapeutic targets have been suggested in animal models of retinal ischemia and several potential treatments have been evaluated on small series of patients, central retinal artery occlusion (CRAO) is still rarely treatable in clinical practice.

AREAS COVERED

Here, we review several animal models of RAO, including increased intraocular pressure, laser, vasoconstriction, embolization and clamp. We also review the pathogenic mechanisms that contribute to cell death cascades during ischemia, and the therapeutic strategies targeting these events. These strategies aim to restore blood flow by fibrinolysis, increase the oxygen or glucose supply, decrease the energy demands, restrict ionic leak fluxes or reduce the detrimental effects of glutamate, calcium and free radicals. The current literature suggests that tPA treatment could be effective for CRAO.

EXPERT OPINION

Eye care professionals must make a rapid and accurate diagnosis and immediately refer patients with acute retinal stroke to specialized centers. CRAO management should also be facilitated by developing local networks to encourage collaboration among ophthalmologists, retina specialists and stroke neurologists.

Morphometric Analysis of the Ophthalmic and Central Retinal Arteries via the Endoscopic Endonasal Trans-ethmoidal Approach: Surgical Relevance of Vascular Components Within the Medial Intraconal Zones

BACKGROUND

The endoscopic endonasal approach (EEA) offers a minimally invasive route to treat medial intraconal space (MIS) lesions. Understanding the configuration of the ophthalmic artery (OphA) and the central retinal artery (CRA) is crucial.

METHODS

An EEA to the MIS was performed on 30 orbits. The description of the intraorbital part of the OphA was divided into 3 segments and classified as type 1 and type 2 and the MIS was divided into three surgical zones (A, B, C). The CRA's origin, course, and point of penetration (PP) were analyzed. The relationship between the position of the CRA in the MIS and the OphA type was analyzed.

RESULTS

The OphA type 2 was present in 20% of specimens. The site of origin of the CRA from the OphA was found on the medial surface in type 1 and on the lateral surface of type 2. The point of penetrationof the central retinal arterywas found in 87% of the specimens on the inferomedial surface, just anterior to the inferior muscular trunk, at an average distance of 9.5 mm ± 1 from the globe and 17 mm ± 1.5 from the AZ. The presence of the CRA in Zone C was associated only with OphA type 1.

CONCLUSIONS

OphA type 2 is a common finding and can compromise the feasibility of an EEA to the MIS. A detailed preoperative analysis of the OphA and CRA should be conducted prior to approaching the MIS due to the implications of the anatomical variations that can compromise safe intraconal maneuverability during an EEA.

Successful Mechanical Thrombectomy for Isolated Internal Carotid Artery Occlusion in a Patient with Monocular Blindness: A Case Report

We report a rare case of isolated internal carotid artery occlusion complicated by central retinal artery occlusion that was successfully treated with mechanical thrombectomy for internal carotid artery occlusion. A 59-year-old man visited the emergency room because of right monocular blindness. Magnetic resonance imaging showed multiple acute small embolic infarctions in the right frontal lobe, and magnetic resonance angiography revealed right internal carotid artery occlusion without the associated occlusion of the circle of Willis, which indicates the patency of the anterior and middle cerebral arteries. An electrocardiogram showed atrial fibrillation. Therefore, we performed mechanical thrombectomy with a stent retriever under continuous manual aspiration with a balloon-guiding catheter and confirmed complete recanalization, anterograde flow in the right ophthalmic artery, and retinal brush. The procedure was completed without complications, and the patient noticed an improvement in visual acuity immediately after the procedure. When a patient with atrial fibrillation complains of monocular blindness, it is important to consider internal carotid artery occlusion due to cardioembolism, to perform an examination promptly, and to consider early treatment, including mechanical thrombectomy.

Monocular Vision Loss in a Patient With Earache and Night Sweats

A 62-year-old patient with a history of painless vision loss in her right eye, right ear pain and fullness, discomfort over her frontal and maxillary sinuses, nasal congestion without discharge, drenching night sweats, cramps in her quadriceps, and weight loss presented to the ophthalmology department. Examination revealed normal tympanic membranes and a dry but otherwise normal nasal mucosa on flexible endoscopy. What would you do next?

Characterization of Oxygen Nanobubbles and In Vitro Evaluation of Retinal Cells in Hypoxia

Purpose

Vein or artery occlusion causes a hypoxic environment by preventing oxygen delivery and diffusion to tissues. Diseases such as retinal vein occlusion, central retinal artery occlusion, or diabetic retinopathy create a stroke-type condition that leads to functional blindness in the effected eye. We aim to develop an oxygen delivery system consisting of oxygen nanobubbles (ONBs) that can mitigate retinal ischemia during a severe hypoxic event such as central retinal artery occlusion.

Methods

ONBs were synthesized to encapsulate oxygen saturated molecular medical grade water. Stability, oxygen release, biocompatibility, reactive oxygen species, superoxide, MTT, and terminal uridine nick-end labeling assays were performed. Cell viability was evaluated, and safety experiments were conducted in rabbits.

Results

The ONBs were approximately 220 nm in diameter, with a zeta potential of -58.8 mV. Oxygen release studies indicated that 74.06 µg of O2 is released from the ONBs after 12 hours at 37°C. Cell studies indicated that ONBs are safe and cells are viable. There was no significant increase in reactive oxygen species, superoxide, or double-stranded DNA damage after ONB treatment. ONBs preserve mitochondrial function and viability. Histological sections from rabbit eyes indicated that ONBs were not toxic.

Conclusions

The ONBs proposed have excellent oxygen holding and release properties to mitigate ischemic conditions in the retina. They are sterile, stable, and nontoxic.

Translation Relevance

ONB technology was evaluated for its physical properties, oxygen release, sterility, stability, and safety. Our results indicate that ONBs could be a viable treatment approach to mitigate hypoxia during ischemic conditions in the eye upon timely administration.

Retinal Artery Occlusion as an Early Indicator of Macrovascular Complications in Diabetes

BACKGROUND

A characteristic of the retinal circulation is that arterial occlusion is embolic or secondary to vasculitis but rarely or never due to in situ atherosclerosis. Therefore, retinal artery occlusion suggests the presence of cardiac or large-vessel disease outside the eye. This cohort study examined the general risk of macrovascular disease in individuals with diabetes, with or without retinal artery occlusion.

METHODS

We retrieved data on 992 subjects with incident retinal artery occlusion and preexisting diabetes, registered in Denmark between January 1, 2000, and December 31, 2018. Each retinal artery occlusion subject was matched for age, sex, and diabetes duration, with 5 control subjects with diabetes but without retinal artery occlusion. We performed survival analyses to compare the risk of extraocular macrovascular disease between the 2 groups in a 5-year follow-up.

RESULTS

After 1 year, the incidence of macrovascular disease in subjects with retinal artery occlusion was approximately 21 per 100 person-years (95% confidence interval [CI]: 18.11-24.29), compared to 6.25 per 100 patient-years (95% CI: 5.57-7.00) in those without retinal artery occlusion. After 5 years, the cumulative incidences of macrovascular disease were 51.2% (95% CI: 47.9-54.7%) and 29.4% (95% CI: 28.0-30.8%) in patients with diabetes with or without retinal artery occlusion, respectively. Hazard rate ratios were 3.36 (95% CI: 2.79-4.05) after 1 year and 2.27 (95% CI: 2.04-2.53) after 5 years.

CONCLUSION

Among individuals with diabetes, those diagnosed with retinal artery occlusion had a higher general risk of macrovascular complications for at least 5 years after the occlusion event compared with those without retinal artery occlusion.

Central Retinal Artery Occlusion in a Young Patient With a Hidden Unusual Sickle Cell Trait

Sickle cell trait is considered a benign condition. Ophthalmic manifestations are infrequent but can result in significant visual deterioration. We present a case of a 33-year-old male, not known to have any medical illnesses, who presented to the ophthalmological emergency room complaining of a sudden onset of painless and profound left eye vision loss for 12 hours. The patient denied any medication use, past eye trauma, or surgery. On detailed ophthalmologic examination, the best-corrected visual acuity (BCVA) was 20/20 in the right eye and hand movement in the left eye. Dilated fundus examination of the left eye showed a central retinal artery occlusion (CRAO) with pale, white retinal swelling and a macular cherry-red spot. Fundus fluorescein angiography showed delayed arterial filling with persistently reduced macular perfusion. CRAO was diagnosed in an otherwise healthy young male. Systemic workup was negative except for protein electrophoresis, which showed sickle cell trait, and HbA1C was 7.8%. Later, atrophic macular changes with a pale optic disc were observed, and BCVA was reduced to light perception. CRAO in young patients amounts to diverse causes, which require extensive systemic workup. In addition, the concurrence of the sickle cell trait with diabetes mellitus might have a role in CRAO development.

Interventions for acute non-arteritic central retinal artery occlusion

BACKGROUND

Acute non-arteritic central retinal artery occlusion (CRAO) occurs as a sudden interruption of the blood supply to the retina and typically results in severe loss of vision in the affected eye. Although many therapeutic interventions have been proposed, there is no generally agreed upon treatment regimen.

OBJECTIVES

To assess the effects of treatments for acute non-arteritic CRAO.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2022, Issue 2); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 15 February 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing any interventions with another treatment in participants with acute non-arteritic CRAO in one or both eyes.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology and graded the certainty of the body of evidence for primary (mean change in best-corrected visual acuity [BCVA]) and secondary (quality of life and adverse events) outcomes using the GRADE classification.

MAIN RESULTS

We included six RCTs with 223 total participants with acute non-arteritic CRAO; the studies ranged in size from 10 to 84 participants. The included studies varied geographically: one in Australia, one in Austria and Germany, two in China, one in Germany, and one in Italy. We were unable to conduct any meta-analyses due to study heterogeneity. None of the included studies compared the same pair of interventions: 1) tissue plasminogen activator (t-PA) versus intravenous saline; 2) t-PA versus isovolemic hemodilution, eyeball massage, intraocular pressure reduction, and anticoagulation; 3) nitroglycerin, methazolamide, mecobalamin tablets, vitamin B1 and B12 injections, puerarin and compound anisodine (also known as 654-2) along with oxygen inhalation, eyeball massage, tube expansion, and anticoagulation compared with and without intravenous recombinant tissue plasminogen activator (rt-PA); 4) transcorneal electrical stimulation (TES) with 0 mA versus with 66% of the participant's individual electrical phosphene threshold (EPT) at 20 Hz (66%) versus with 150% of the participant's individual EPT (150%) at 20 Hz; 5) ophthalmic artery branch retrograde thrombolysis versus superselective ophthalmic artery thrombolysis; and 6) pentoxifylline versus placebo. There was no evidence of an important difference in visual acuity between participants treated with t-PA versus intravenous saline (mean difference [MD] at 1 month -0.15 logMAR, 95% confidence interval [CI] -0.48 to 0.18; 1 study, 16 participants; low certainty evidence); t-PA versus isovolemic hemodilution, eyeball massage, intraocular pressure reduction, and anticoagulation (MD at 1 month -0.00 logMAR, 95% CI -0.24 to 0.23; 1 study, 82 participants; low certainty evidence); and TES with 0 mA versus TES with 66% of EPT at 20 Hz versus TES with 150% of EPT at 20 Hz. Participants treated with t-PA experienced higher rates of serious adverse effects. The other three comparisons did not report statistically significant differences. Other studies reported no data on secondary outcomes (quality of life or adverse events).  AUTHORS' CONCLUSIONS: The current research suggests that proposed interventions for acute non-arteritic CRAO may not be better than observation or treatments of any kind such as eyeball massage, oxygen inhalation, tube expansion, and anticoagulation, but the evidence is uncertain. Large, well-designed RCTs are necessary to determine the most effective treatment for acute non-arteritic CRAO.

Central Retinal Artery Occlusion: Time to Presentation and Diagnosis

OBJECTIVE

To evaluate the presentation patterns of patients diagnosed with central retinal artery occlusion (CRAO) from 2011 to 2020.

DESIGN

Retrospective cohort study SUBJECTS: The present study was conducted in 484 patients presenting within 30 days of symptom onset with accurate documentation of time of symptom onset, time of presentation to the health care system, and time of presentation to an ophthalmologist.

METHODS

An independent chart review of patients with CRAO was conducted.

MAIN OUTCOME MEASURES

Demographic information including age, sex, and race were collected. Presentation patterns such as time of first symptoms, time of first contact with the health care system, and time of evaluation by an ophthalmologist were analyzed. Additionally, information regarding the medical venue or specialty of initial patient contact was collected.

RESULTS

A total of 247 (51%) patients contacted the health care system within 4.5 hours of system onset, whereas 86 (17.8%) patients waited over 24 hours. Only 81 (32.8%) of the 247 patients who presented within 4.5 hours saw an ophthalmologist within that time frame, whereas 172 (35.5%) of the entire cohort of 484 did not present to an ophthalmologist within 24 hours of vision loss. There was significant variability with regards to medical specialty of initial patient contact, with 292 (60.3%) patients first presenting to an emergency department and 133 (27.5%) patients first presenting to an ophthalmologist. Black and Hispanic patients presented later than patients of White, Asian, or other racial backgrounds (40.4 ± 10.2 hours versus 23.0 ± 3.4 hours, P = 0.05).

CONCLUSIONS

Although no level 1 evidence-based treatment is currently available for CRAO, thrombolytic therapy may be promising. Even though over half of patients with CRAO within our institution connected with the health care system within a potential window for thrombolytic therapy, most did not receive a definitive ophthalmic diagnosis within that time frame. Public health educational campaigns and infrastructure optimization must speed up presentation times, decrease the time to ophthalmic diagnosis, and target vulnerable populations to offer and research timely administration of thrombolytic therapy.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.

Efficacy and safety of intra-arterial thrombolysis in patients with central retinal artery occlusion: a systematic review and meta-analysis

PURPOSE

To investigate the efficacy and safety of intra-arterial thrombolysis (IAT) in patients with central retinal artery occlusion (CRAO).

METHODS

PubMed and EMBASE were searched for potentially eligible studies that reported IAT in CRAO patients from inception to Nov 8, 2021. Standard mean difference (SMD) was pooled to compare visual acuity (VA) at baseline with final in IAT patients. The rates and odds ratios (OR) were meta-analyzed to compare VA improvement in IAT with non-IAT patients, stratified to different times from onset to procedure, different definitions of VA improvement, and three CRAO stages. Adverse effects were recorded.

RESULTS

Fifteen studies were included, enrolling 507 CRAO patients who received IAT and 296 CRAO patients who did not. VA was significantly improved from baseline to final VA in IAT patients (SMD [LogMAR] 0.70, 95% CI [0.51, 0.90]). VA improvement rate was higher in IAT patients than that in non-IAT (56% vs 32%, OR 3.55, 95%CI [1.74, 7.24]), with greater OR in IAT within 6 h from onset to procedure (OR 4.60, 95%CI [1.24, 16.99]) than that beyond 6 h (OR 3.36, 95%CI [1.43, 7.85]). The benefit remained consistent when VA improvement was defined as ≥ 3 lines on the Snellen chart (OR 4.68, 95%CI [2.10, 10.41]) and was even greater when CRAO was incomplete. Five patients had a symptomatic intracranial hemorrhage and 21 patients had ischemic stroke or transient ischemic attack after IAT.

CONCLUSIONS

IAT treatment has certain potential in ameliorating VA in CRAO patients, which should be balanced against cerebral complications.

Point-of-care ultrasound in the detection of central retinal artery occlusion in a patient with recent COVID-19

Ocular emergencies are a frequent occurrence in the emergency setting. Fortunately, point-of-care ultrasound (POCUS) lends itself exceptionally well to ocular evaluation. Here, we present a unique case of central retinal artery occlusion rapidly diagnosed with POCUS in a patient with a recent COVID-19 diagnosis.

Perioperative Care of the Patient with Eye Pathologies Undergoing Nonocular Surgery

The authors reviewed perioperative ocular complications and implications of ocular diseases during nonocular surgeries. Exposure keratopathy, the most common perioperative eye injury, is preventable. Ischemic optic neuropathy, the leading cause of perioperative blindness, has well-defined risk factors. The incidence of ischemic optic neuropathy after spine fusion, but not cardiac surgery, has been decreasing. Central retinal artery occlusion during spine fusion surgery can be prevented by protecting eyes from compression. Perioperative acute angle closure glaucoma is a vision-threatening emergency that can be successfully treated by rapid reduction of elevated intraocular pressure. Differential diagnoses of visual dysfunction in the perioperative period and treatments are detailed. Although glaucoma is increasingly prevalent and often questions arise concerning perioperative anesthetic management, evidence-based recommendations to guide safe anesthesia care in patients with glaucoma are currently lacking. Patients with low vision present challenges to the anesthesia provider that are becoming more common as the population ages.

Risk Factors and Treatment Strategy for Retinal Vascular Occlusive Diseases

Retinal occlusive diseases are common diseases that can lead to visual impairment. Retinal artery occlusion and retinal vein occlusion are included in the clinical entity, but they have quite different pathophysiologies. Retinal artery occlusion is an emergent eye disorder. Retinal artery occlusion is mainly caused by thromboembolism, which frequently occurs in conjunction with life-threatening stroke and cardiovascular diseases. Therefore, prompt examinations and interventions for systemic vascular diseases are often necessary for these patients. Retinal vein occlusion is characterized by retinal hemorrhage and ischemia, which may impair visual function via several complications such as macular edema, macular ischemia, vitreous hemorrhage, and neovascular glaucoma. Even though anti-vascular endothelial growth factor therapy is the current established first-line of treatment for retinal vein occlusion, several clinical studies have been performed to identify better treatment protocols and new therapeutic options. In this review, we summarize the current findings and advances in knowledge regarding retinal occlusive diseases, particularly focusing on recent studies, in order to provide an update for a better understanding of its pathogenesis.

Changes in macrophage-like cells characterized by en face optical coherence tomography after retinal stroke

Purpose

The retina could serve as a window of neuroinflammation, but the in vivo changes in macrophage-like cell (MLC), such as microglia, in acute ischemic retinal stroke remain unclear. Thus, the current study aimed to investigate the in vivo changes in MLC characterized by en face optical coherence tomography (OCT) after acute ischemic retinal stroke.

Methods

Twenty patients with unilateral acute nonarteritic reperfused central retinal artery occlusion (CRAO) were participated in this study, and their contralateral eyes served as control group. A 3 μm en face OCT slab on the inner limiting membrane of the optic nerve head (ONH) region or macular region was used to visualize and binarize the MLCs. The MLCs were binarized and quantified using a semiautomated method. OCT angiography was used to evaluate the reperfusion status and obtain the structural data of the inner retina in the ONH and macula. The thickness of the ganglion cell complex in the macular region was measured. The optical intensity and optical intensity ratio of the inner retina were calculated to evaluate the ischemia severity.

Results

In the ONH region, decreased vessel densities of radial peripapillary capillaries accompanied by increased thickness of the retinal nerve fiber layer were found in the CRAO eyes in comparison to the unaffected eyes (p=0.001, p=0.009, respectively). In the macular region, significantly lower vessel densities in both the superficial and deep capillary plexus and increased thickness of the ganglion cell complex were also found in the CRAO eyes (all p ≤ 0.001). The ONH and macular MLC quantities and densities in CRAO eyes were significantly higher than those in the unaffected eyes (both p<0.001). Larger and plumper MLCs were observed in the CRAO eyes compared with their unaffected eyes. ONH and macular MLC densities were positively associated with the disease duration in the acute phase and the optical intensity ratio of inner retina.

Conclusions

The increased density and morphological changes of MLCs may indicate the aggregation and activation of MLCs following acute reperfused CRAO. The aggregation of MLCs may be more pronounced in CRAO eyes with longer disease duration and more severe ischemia. MLCs characterized by en face OCT may serve as an in vivo visual tool to investigate neuroinflammation in the ischemic-reperfusion process of stroke.

Retinal and optic nerve magnetic resonance diffusion-weighted imaging in acute non-arteritic central retinal artery occlusion

OBJECTIVES

Diffusion weighted imaging hyperintensity (DWI-H) has been described in the retina and optic nerve during acute central retinal artery occlusion (CRAO). We aimed to determine whether DWI-H can be accurately identified on standard brain magnetic resonance imaging (MRI) in non-arteritic CRAO patients at two tertiary academic centers.

MATERIALS AND METHODS

Retrospective cross-sectional study that included all consecutive adult patients with confirmed acute non-arteritic CRAO and brain MRI performed within 14 days of CRAO. At each center, two neuroradiologists masked to patient clinical data reviewed each MRI for DWI-H in the retina and optic nerve, first independently then together. Statistical analysis for inter-rater reliability and correlation with clinical data was performed.

RESULTS

We included 204 patients [mean age 67.9±14.6 years; 47.5% females; median time from CRAO to MRI 1 day (IQR 1-4.3); 1.5 T in 127/204 (62.3%) and 3.0 T in 77/204 (37.7%)]. Inter-rater reliability varied between centers (κ = 0.27 vs. κ = 0.65) and was better for retinal DWI-H. Miss and error rates significantly differed between neuroradiologists at each center. After consensus review, DWI-H was identified in 87/204 (42.6%) patients [miss rate 117/204 (57.4%) and error rate 11/87 (12.6%)]. Significantly more patients without DWI-H had good visual acuity at follow-up (p = 0.038).

CONCLUSIONS

In this real-world case series, differences in agreement and interpretation accuracy among neuroradiologists limited the role of DWI-H in diagnosing acute CRAO on standard MRI. DWI-H was identified in 42.6% of patients and was more accurately detected in the retina than in the optic nerve. Further studies are needed with standardized novel MRI protocols.

Retinal Infarction: A Pilot Study on the Efficacy and Safety of Intravenous Thrombolysis and Underlying Aetiologies

Background: Treatment of non-arteritic central retinal artery occlusion is still inconsistent. Therefore, the current study aimed to evaluate the efficacy of intravenous thrombolysis (IVT) and describe the prevalence of co-occurring ischemic brain lesions in patients with acute visual loss due to ischemia. Methods: We analysed 38 consecutive patients with acute visual loss between January 2015 and June 2020. Patients presenting within 4.5 h of symptom onset without any contraindication were treated with IVT. Patients underwent neurologic and ophthalmologic examination and diagnostic workup for the underlying aetiology. Follow-up was performed after 3 and 12 months. Results: Patients treated with IVT had a significantly better functional outcome at discharge compared to patients treated conservatively. No additional ischemic brain lesions were detected (0 of 38). Three patients had extracranial carotid artery stenosis ≥50%. Atrial fibrillation was present in four patients, three of whom already received oral anticoagulation. In the remaining 31 patients no embolic source was detected. However, the number of plaques were rated mild to moderate. Within three months, one patient developed transient visual loss while another suffered a contralateral transient ischemic attack. Conclusions: IVT may represent a safe and effective treatment option in patients with isolated visual loss due to ischemia. The aetiology was atherosclerotic burden rather than embolism caused by carotid stenosis or atrial fibrillation, bringing the current diagnostic procedure and therapy into question. Randomized trials are necessary to evaluate the efficacy and safety of IV thrombolysis and clarify the aetiology of isolated visual loss due to ischemia.

Light color efficiency-balanced trans-palpebral illumination for widefield fundus photography of the retina and choroid

A wide-field fundus camera, which can selectively evaluate the retina and choroid, is desirable for better detection and treatment evaluation of eye diseases. Trans-palpebral illumination has been demonstrated for wide-field fundus photography, but its application for true-color retinal imaging is challenging due to the light efficiency delivered through the eyelid and sclera is highly wavelength dependent. This study is to test the feasibility of true-color retinal imaging using efficiency-balanced visible light illumination, and to validate multiple spectral imaging (MSI) of the retina and choroid. 530 nm, 625 nm, 780 nm and 970 nm light emission diodes (LED)s are used to quantitatively evaluate the spectral efficiency of the trans-palpebral illumination. In comparison with 530 nm illumination, the 625 nm, 780 nm and 970 nm light efficiencies are 30.25, 523.05, and 1238.35 times higher. The light efficiency-balanced 530 nm and 625 nm illumination control can be used to produce true-color retinal image with contrast enhancement. The 780 nm light image enhances the visibility of choroidal vasculature, and the 970 nm image is predominated by large veins in the choroid. Without the need of pharmacological pupillary dilation, a 140° eye-angle field of view (FOV) is demonstrated in a snapshot fundus image. In coordination with a fixation target, the FOV can be readily expanded over the equator of the eye to visualize vortex ampullas.

Current diagnosis and treatment practice of central retinal artery occlusion: results from a survey among German stroke units

BACKGROUND

Central retinal artery occlusion (CRAO) is a neuro-ophthalmological emergency whose optimal management is still under debate and due to the absence of definite guidelines, practice is expected to vary. We aimed to characterize early evaluation as well as acute treatment and diagnostic approaches in German hospitals with a stroke unit (SU).

METHODS

In 07/2021, all 335 certified German SUs were invited to participate in an anonymous online survey endorsed by the German Stroke Society on emergency department care organization, diagnostic procedures, and treatment of patients with unilateral vision loss (UVL) subsequently diagnosed with CRAO.

RESULTS

One hundred and sixty-three (48.6%) of the 335 eligible centers responded. Most (117/135; 86.7%) stated that UVL patients were treated as an emergency, in 62/138 (44.9%) hospitals according to specific guidelines. First-line evaluation was performed by neurologists in 85/136 (62.5%) hospitals, by ophthalmologists in 43/136 (31.6%) hospitals. Seventy of 135 (51.9%) respondents indicated a lack of on-site ophthalmological expertise. Seventy-four of 129 (57.4%) respondents performed thrombolysis in CRAO and 92/97 (94.8%) stated that patients with CRAO-if admitted to neurology-were treated on a SU.

CONCLUSIONS

Our findings reflect notable heterogeneity in early intrahospital care of CRAO in German SUs but demonstrate a preference for work-up and management as acute stroke by the involved neurologists. Streamlining interdisciplinary emergency evaluation is essential for ongoing and future prospective trials.

Improving the Telemedicine Evaluation of Patients With Acute Vision Loss: A Call to Eyes

Acute vision loss related to cerebral or retinal ischemia is a time-sensitive emergency with potential treatment options including intravenous or intraarterial thrombolysis and mechanical thrombectomy. However, patients either present in delayed fashion or present to an emergency department that lacks the subspecialty expertise to recognize and treat these conditions in a timely fashion. Moreover, healthcare systems in the United States are becoming increasingly reliant on telestroke and teleneurology services for acute neurologic care, making accurate diagnosis of acute vision loss even more challenging due to critical limitations to the remote video evaluation, including the inability to perform routine ophthalmoscopy. The COVID-19 pandemic has led to a greater reliance on telemedicine services and helped to accelerate the development of novel tools and care pathways to improve remote ophthalmologic evaluation, but these tools have yet to be adapted for use in the remote evaluation of acute vision loss. Permanent vision loss can be disabling for patients and efforts must be made to increase and improve early diagnosis and management. Herein, the authors outline the importance of improving acute ophthalmologic diagnosis, outline key limitations and barriers to the current video-based teleneurology assessments, highlight opportunities to leverage new tools to enhance the remote assessment of vision loss, and propose new avenues to improve access to emergent ophthalmology subspeciality.

Central Retinal Artery Occlusion: Current Practice, Awareness and Prehospital Delays in Switzerland

Background and Purpose

Central retinal artery occlusion (CRAO) often leads to permanent monocular blindness. Hence, early recognition and rapid re-perfusion is of paramount importance. This study aims to describe prehospital pathways in CRAO compared to stroke and study the knowledge about CRAO.

Methods

(1) Description of baseline characteristics, prehospital pathways/delays, and acute treatment (thrombolysis/thrombectomy vs. standard of care) of patients with CRAO and ischemic stroke registered in the Swiss Stroke Registry. (2) Online survey about CRAO knowledge amongst population, general practitioners (GPs) and ophthalmologists in Eastern Switzerland.

Results

Three hundred and ninety seven CRAO and 32,816 ischemic stroke cases were registered from 2014 until 2019 in 20 Stroke Centers/Units in Switzerland. In CRAO, 25.6% arrived at the hospital within 4 h of symptom onset and had a lower rate of emergency referrals. Hence, the symptom-to-door time was significantly longer in CRAO compared to stroke (852 min. vs. 300 min). The thrombolysis/thrombectomy rate was 13.2% in CRAO and 30.9% in stroke. 28.6% of the surveyed population recognized CRAO-symptoms, 55.4% of which would present directly to the emergency department in contrast to 90.0% with stroke symptoms. Almost 100% of the ophthalmologist and general practitioners recognized CRAO as a medical emergency and 1/3 of them considered IV thrombolysis a potentially beneficial therapy.

Conclusions

CRAO awareness of the general population and physician awareness about the treatment options as well as the non-standardized prehospital organization, seems to be the main reason for the prehospital delays and impedes treating CRAO patients. Educational efforts should be undertaken to improve awareness about CRAO.

Association of Paracentral Acute Middle Maculopathy with Visual Prognosis in Retinal Artery Occlusion: A Retrospective Cohort Study

Background

The association between paracentral acute middle maculopathy (PAMM) and visual acuity in patients with retinal artery occlusion (RAO) is unknown. This study explored the clinical features and prognostic factors for visual acuity of RAO accompanied by PAMM.

Methods

This retrospective study included patients with RAO who underwent FFA and OCT examinations at Shenzhen Eye Hospital from July 2015 to June 2019. The changes in vision and macular structure were observed.

Results

Eighty-eight patients were included. There were 58 patients (65.9%) with central RAO (CRAO) and 30 (34.1%) with branch RAO (BRAO). Fifty-two eyes were diagnosed with PAMM, of which 33 eyes (63.5%) were from CRAO patients and 19 (36.5%) were from BRAO patients. At diagnosis, the PAMM group had significantly better logMAR BCVA values than the no-PAMM group (median (IQR), 1.35 (0.725–2) vs. 2.15 (1.47–2.3), P=0.002). In addition, the PAMM group had significantly better logMAR BCVA values during follow-up than the no-PAMM group (median (IQR), 1 (0.05–2) vs. 2 (1.15–2.3), P=0.001). After adjustment for age, gender, CRAO/BRAO, comorbidities, and symptom duration, PAMM was associated with good visual acuity improvement (RR = 3.29, 95% CI: 1.29–8.37, P=0.013).

Conclusion

PAMM was associated with good visual acuity improvement during follow-up in patients with RAO.

Central Retinal Artery Occlusion Is Related to Vascular Endothelial Injury and Left Ventricular Diastolic Dysfunction

Central retinal artery occlusion (CRAO) is an emergency state characterized by sudden, painless vision impairment. Patients with CRAO have an increased risk of cardiovascular events, including stroke, likely related to vascular endothelial damage. Therefore, we investigated flow-mediated dilatation (FMD) of the brachial artery as a marker of endothelial dysfunction, intima-media complex thickness (IMT) of the common carotid artery, pointing to the arterial wall atherosclerotic alteration, and transthoracic echocardiographic parameters in 126 consecutive CRAO patients (66 men [52.4%], median age 55 years) and 107 control participants (56 men [52.3%], matched by age, sex, and body mass index). Most CRAO patients (n = 104, 82.5%) had at least one internal medicine comorbidity, mainly hypercholesterolemia and hypertension, which coexisted in one-fourth of them. Furthermore, they had a 38.2% lower relative increase of FMD (FMD%) and a 23.1% thicker IMT compared to the controls (p < 0.001, both, also after adjustment for potential confounders). On echocardiography, the CRAO group was characterized by increased dimensions of the left atrium and thicker left ventricular walls, together with impaired left ventricular diastolic function. CRAO is related to vascular endothelial damage, atherosclerosis, and left ventricular diastolic cardiac dysfunction. Thus, non-invasive ultrasound assessments, such as FMD%, IMT, and echocardiography, may be helpful in screening patients with increased CRAO risk, particularly those with other comorbidities.

Contribution of Orbital Ultrasound to the Diagnosis of Central Retinal Artery Occlusion

We aimed to evaluate the diagnostic value of orbital ultrasound in the etiologic diagnosis of central retinal artery occlusion (CRAO). For this purpose, patients with CRAO evaluated at our center between 2011 and 2021 were reviewed. Demographic variables, vascular risk factors and ultrasound findings were collected. An orbital duplex was performed in all cases and complemented with other diagnostic explorations. We attended 36 cases of CRAO. In all patients, orbital ultrasound confirmed the diagnosis of CRAO: in 75% emboli material (spot sign) was observed in CRA and in 25% flow alteration in CRA without visible embolus. The positive spot sign (PSS) group differed from patients with negative spot sign (NSS) in terms of etiology: 8 PSS cases (29.6%) had a major cardioembolic cause, 4 (14.8%) a large vessel atheromatous disease, 15 (55.6%) an undetermined cause. Some 21 (77.8%) PSS patients had some minor cardioembolic cause, mainly calcifications of the left valves. In the NSS group, 2 (22%) were diagnosed with giant cell arteritis (GCA). In CRAO, the ultrasound spot sign could be a guide for the detection of embolic sources. Its absence makes it necessary to consider more strongly the possibility of arteritis. Furthermore, our findings suggest a key role of calcium embolism in PSS patients.

Stroke Risk before and after Central Retinal Artery Occlusion: A Population-based Analysis

PURPOSE

To determine the risk of stroke, transient ischemic attack (TIA), and transient monocular vision loss (TMVL) before and after a central retinal artery occlusion (CRAO).

DESIGN

Population-based, retrospective case series.

PARTICIPANTS

Patients diagnosed with a CRAO in Olmsted County, Minnesota, from 1976 to 2016.

METHODS

Patients living in Olmsted County with a diagnosis code of CRAO from 1976 to 2016 were reviewed. New CRAOs were confirmed, and stroke, TIA, and TMVL events in the 15 days before and after CRAO were recorded.

MAIN OUTCOME MEASURES

Incidence of stroke, TIA, and TMVL events in the 15 days before and after CRAO.

RESULTS

Eighty-nine patients with a CRAO were identified, providing an annual incidence of 2.58/100 000 (95% confidence interval [CI], 2.04-3.11). Median age at the time of CRAO was 76 years (range, 46-100 years); 56.2% were male, and 89.9% of the cohort was White. In the 15 days before and after CRAO, there were 2 ischemic strokes (2.2%), 1 hemorrhagic stroke (1.1%), 2 TIAs (2.2%), and 9 TMVL events (10.1%). Starting in 1999, 15 of 45 patients underwent magnetic resonance imaging within 2 months of CRAO. One patient (6.7%) had evidence of asymptomatic diffusion restriction, and 9 patients (60%) had a remote infarct.

CONCLUSIONS

This population-based study demonstrated that the risk of symptomatic ischemic stroke is 2.2% in the 15 days before and after a CRAO, which is slightly lower than most studies from tertiary centers. These data should be considered as practice recommendations are developed regarding the urgency of neurovascular workup in patients with acute CRAO.

Referral Patterns of Central Retinal Artery Occlusion to an Academic Center Affiliated With a Stroke Center

BACKGROUND

Central retinal artery occlusion (CRAO) is a medical emergency, and patients who present acutely should be immediately referred to the nearest stroke center. We evaluated practice patterns for CRAO management at one academic center over the last decade.

METHODS

This was a retrospective study on all adult patients diagnosed with a CRAO seen at one tertiary hospital and outpatient clinic affiliated with a comprehensive stroke center ("our institution") from 2010 to 2020. Our electronic medical records were searched for CRAO diagnoses, and patient medical records were reviewed. The exclusion criteria were incorrect diagnosis, unclear diagnosis, historical CRAO, or satellite clinic location. Demographics, distance and time to presentation to our institution, number and type of prior providers seen, diagnostic tests performed, and treatments provided were collected. Summary statistics of median, mean, and frequency were calculated and reported with measures of variance (interquartile range [IQR], ranges). F, Tukey, and Fisher exact tests were used for comparisons.

RESULTS

We included 181 patients with a diagnosis of CRAO (80 [44.2%] women; median age 69 years [range 20-101]). The median distance from patient's home to our institution was 27.8 miles (IQR 15.5-57.4; range 2.4-930). The median time from visual loss to presentation at our institution was 144 hours (IQR 23-442 hours, range 0.5-2,920) from 2010 to 2013, 72 hours (IQR 10.5-372 hours, range 0-13,140) from 2014 to 2016, and 48 hours (IQR 7-180 hours, range 0-8,030) from 2017 to 2020 (P = 0.07). 91/181 (50%) patients presented to an outpatient provider. 73/181 (40%) presented to an emergency department. Eighty-six percent presented within 1 week of visual loss onset, and rates of comprehensive inpatient evaluation for acute CRAO improved from 44% in 2010-2013 to 82% in 2017-2020 (P < 0.01).

CONCLUSIONS

Patients with CRAO often present late and only after evaluation by multiple outpatient providers. Improvement has occurred over the past decade, but delays underscore the barriers to performing clinical trials evaluating very acute treatments for CRAO. Educational interventions for healthcare providers and patients are necessary.

Efficacy of Intra-Arterial Thrombolysis for Acute Central Retinal Artery Occlusion: A Meta-Analysis

INTRODUCTION

The best management strategy still remains strong controversy for acute nonarteritic central retinal artery occlusion (CRAO). We thus performed a meta-analysis to determine the efficacy of intra-arterial thrombolysis (IAT) for visual improvement according to different times from symptom onset.

METHODS

We searched EMBASE, PubMed, and Web of Science for relevant studies assessing efficiency of IAT in patients with CRAO compared with standard therapy. Fixed-effects and random-effects models were performed.

RESULTS

Five eligible studies including 459 patients with acute CRAO were pooled in the meta-analysis. In all, 219 (47.7%) received IAT, and the mean time from symptom onset to IAT was 13 h. The pooled analysis demonstrates odds ratio (OR) for the procedure of IAT and any visual improvement to be 1.520 (95% confidence intervals [CIs] 1.258-1.837; p < 0.001). Subgroup analyses further indicated that the CRAO patients who received IAT achieved any visual improvement more easily within 6 h from symptom onset (OR = 1.703, 95% CI 1.219-2.381; p = 0.002), but not those beyond 6 h (OR = 1.260, 95% CI 0.973-1.632; p = 0.080).

CONCLUSION

Our meta-analysis of available published data supports IAT to be an alternative treatment option for CRAO patients within 6 h from symptom onset.

Emergency Department Presentation of Retinal Artery Occlusion

PURPOSE

To determine how often patients who present to the Emergency Department (ED) for retinal artery occlusions (RAOs) undergo brain imaging, cardiovascular testing, and are hospitalized.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

Patients who presented to the ED with a RAO in the National Emergency Department Sample (NEDS), a nationally representative US database.

METHODS

The NEDS was queried from 2006-2014 to identify patients who presented to the ED with the primary diagnosis of RAO. Patient and hospital characteristics were evaluated, and a multivariable regression was performed to determine predictors of hospitalization. Testing was categorized into three groups: 1) brain imaging - computed tomography and/or magnetic resonance; 2) carotid imaging - ultrasound, computed tomography, and/or magnetic resonance; 3) cardiac testing - electrocardiogram and/or echocardiogram. The number of tests performed for each category was recorded.

MAIN OUTCOME MEASURES

Proportions of patients undergoing brain imaging, carotid imaging, and/or cardiac testing. Rate and predictors for hospitalization.

RESULTS

Among 259,343,582 ED visits, 2, 802 had a primary diagnosis of RAO. Patients were mostly ≥ 65 years old (59%) and male (54%). Hypertension (59%), dyslipidemia (36%), and diabetes (20%) were the most common pre-existing cardiovascular diseases. Brain imaging, carotid imaging, and cardiac testing were performed in 20.3%, 7.1%, and 23.8% of patients, respectively; at least one test from each of these three categories was performed in 4.1% of patients. Half of the patients were hospitalized. Factors that increased the chances of hospitalization included (P < 0.05): age < 45 years old; female sex; being a smoker; presenting to a metropolitan hospital; having giant cell arteritis, carotid artery disease, atrial fibrillation, cardiac valve disease, obesity, dyslipidemia, hypertension, diabetes, and chronic ischemic heart disease.

CONCLUSIONS

Most patients who presented to the ED with a RAO did not receive emergent brain imaging, carotid imaging, or basic cardiac testing. A multidisciplinary approach is needed to raise awareness that RAOs should be treated as a precursor of stroke or a stroke equivalent.

Hyperbaric Oxygen Therapy for Central Retinal Artery Occlusion: Patient Selection and Perspectives

The central retinal artery occlusion (CRAO) is a rare ophthalmological emergency that can occur in the eye. CRAO can affect persons of any age, however it is most common in people over the age of 60. CRAO is associated with a number of risk factors, including giant cell arteritis, carotid artery atherosclerosis, cardiogenic emboli, hypertension, smoking, diabetes, and thromboembolic disease. The chance of each of these etiologies being present is assessed during the course of the investigation. Hyperbaric oxygen treatment (HBOT) is classified by the American Heart Association for CRAO at level IIb. In accordance with that, HBOT might be considered for the treatment of such a severe condition. HBOT can maintain retinal oxygenation during ischemic events by allowing oxygen to diffuse through choroidal capillaries that have been exposed to elevated partial pressures of oxygen. As a result, ischemia-related damage is reversed if applied within proper time frame. The amount of time that has passed prior to initiation of HBOT is considered to be the most critical factor in determining the best visual prognosis. According to the Undersea and Hyperbaric Medical Society, patients who are identified with CRAO after the onset of symptoms should be evaluated for HBOT within 24 hours. HBOT has the advantage of having a low risk profile, and it can be utilized to improve visual outcomes in proper patients.