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.

Exploring Superselective Intraarterial Thrombolysis for Autologous Fat Injection-Induced Vision Loss.

BACKGROUND: Intravascular injection represents the most severe complication in fat transplantation procedures. Currently, the prognosis for patients who suffer from blindness due to fat transplantation-induced ocular vascular occlusion is far from optimistic. OBJECTIVES: The aim of this study was to explore and evaluate the efficacy and safety of arterial thrombolysis in the treatment of ocular vascular occlusion caused by fat transplantation. METHODS: We analyzed the data of 12 patients who underwent intraarterial thrombolysis and conservative treatments for facial autologous fat grafting-associated ocular vascular occlusion. Among the cases, there were 6 instances of ophthalmic artery embolism and 6 cases of central retinal artery occlusion. All patients suffered with sudden blindness, sometimes accompanied by eye pain, ptosis, strabismus, skin necrosis at the injection site, or cerebral microinfarction. They received symptomatic conservative treatments and intraarterial thrombolysis, encompassing mechanical vessel recanalization, vessel dilation, and dissolution of thrombus constituents. RESULTS: Following intraarterial thrombolysis, a noteworthy improvement in the blood flow of both the main trunk and peripheral branches of the ophthalmic artery was observed in the majority of patients when contrasted with their pretreatment status. One patient experienced a headache intraoperatively, while no significant discomfort was reported by the remaining patients. After conservative treatments and intraarterial thrombolysis, all patients experienced improvement in ocular symptoms, skin necrosis, and cerebral infarction. Three patients demonstrated improvement in visual acuity. These patients had surpassed the recommended time window for treatment, yet the occlusion of the ophthalmic artery was not complete. CONCLUSIONS: Intraarterial thrombolysis combined with conservative treatments achieves early perfusion and is expected to promote visual recovery. Hospitals that possess the necessary treatment capabilities are encouraged to establish this therapeutic pathway.

Implementation of a retinal stroke-code protocol results in visual recovery in patients receiving reperfusion therapies.

INTRODUCTION: Reperfusion therapies represent promising treatments for patients with Central Retinal Artery Occlusion (CRAO), but access is limited due to low incidence and lack of protocols. We aimed to describe the benefit of implementing a Retinal Stroke-Code protocol regarding access to reperfusion, visual acuity and aetiological assessment. PATIENTS AND METHODS: Prospective cohort study performed at a Comprehensive Stroke Centre. Criteria for activation were sudden monocular, painless vision loss within 6 h from onset. Eligible patients received IAT when immediately available and IVT otherwise. All patients were followed by ophthalmologists to assess best-corrected visual acuity (BCVA) and visual complications, and by neurologists for aetiological workup. Visual amelioration was defined as improvement of at least one Early Treatment Diabetic Retinopathy Study (ETDRS) letter from baseline to 1 week. RESULTS: Of 49 patients with CRAO, 15 (30.6%) received reperfusion therapies (12 IVT, 3 IAT). Presentation beyond 6 h was the main contraindication. Patients receiving reperfusion therapies had better rates of visual improvement (33.3% vs 5.9%, p = 0.022). There were no complications related to reperfusion therapies. Rates of neovascular glaucoma were non-significantly lower in patients receiving reperfusion therapies (13.3% vs 20.6%, p = 0.701). Similar rates of atherosclerotic, cardioembolic and undetermined aetiologies were observed, leading to 10 new diagnosed atrial fibrillation and five carotid revascularizations. CONCLUSION: A comprehensive acute management of CRAO is feasible despite low incidence. In our study, reperfusion therapies were safe and associated with higher rates of visual recovery. A similar etiological workup than ischemic stroke led to of high proportion of underlying aetiologies.

Therapeutic plasma exchange in refractory Susac's syndrome: A brief report.

Susac's syndrome (SuS) is an autoimmune endotheliopathy that typically presents with the clinical triad of encephalopathy, hearing loss, and branch retinal artery occlusion. It has a wide range of possible presentations, and its pathogenesis remains uncertain. Fulminant and refractory cases are difficult to treat, and no standard treatment protocol has been established. However, therapeutic plasma exchange (TPE) has been described as an adjunctive therapy in several SuS cases. Herein we present a case of a 63-year-old male with debilitating encephalopathy and recent hearing and vision loss, who responded favorably to TPE. Given this and other published reports of plasma exchange therapy for SuS, treatment protocols should consider TPE in early stages of disease.

Treatments for Acute Nonarteritic Central Retinal Artery Occlusion: Findings From a Cochrane Systematic Review.

Many interventions for nonarteritic central retinal artery occlusion (CRAO) are associated with serious complications and little effect on visual outcomes. We report on the findings of a Cochrane systematic review that searched seven databases for peer-reviewed articles reporting on treatments for acute nonarteritic CRAO. We assessed six randomized controlled trials, including interventions such as tissue plasminogen activator (t-PA), isovolumic hemodilution, eyeball massage, intraocular pressure reduction, anticoagulation, vasodilation, oxygen inhalation, laser embolysis, transcorneal electrical stimulation, thrombolysis, pentoxifylline, and enhanced external counterpulsation. However, none of the randomized controlled trials demonstrated significant improvement in visual acuity at 1 month compared to observation, and some patients treated with t-PA experienced serious adverse effects including intracranial hemorrhage. Proposed interventions for acute nonarteritic CRAO may not be better than observation, but the evidence is uncertain. Larger, well-designed studies are necessary to determine the most effective management option for acute nonarteritic CRAO. [Ophthalmic Surg Lasers Imaging Retina 2023;54:650-653.].

Susac syndrome - A review of current knowledge and own experience.

Susac syndrome is a rare connective tissue disorder. The pathology affects the small vessels of the brain, retina, and inner ear, and therefore the main symptoms of the disease include encephalopathy, visual disturbances, and sensorineural hearing loss. The aim of this article is to review the current medical knowledge on Susac syndrome and to present our clinical experience regarding this disease entity. In the paper, we are also presenting a case of a 25-year-old patient who was diagnosed with Susac syndrome on the basis of clinical presentation and additional test results. Susac syndrome should be differentiated from multiple sclerosis and other causes of multifocal brain damage as early diagnosis and treatment play a key role in later prognosis.

Outcomes of hyperbaric oxygen treatment for central and branch retinal artery occlusion at a major Australian referral hospital.

Introduction: This study analysed the treatment outcomes of patients that received hyperbaric oxygen treatment (HBOT) for retinal artery occlusion (RAO) at the Royal Brisbane and Women's Hospital in Brisbane, Australia between 2015 and 2021. Methods: Retrospective study from patient records including 22 eyes from 22 patients that received HBOT for either central RAO (17 patients) or branch RAO (five patients). Patients received the Royal Brisbane and Women's Hospital RAO protocol for their HBOT. Analysis included best corrected visual acuity pre- and post-treatment, subjective improvements, side effects and patient risk factors were also recorded. Results: Improvement in best corrected visual acuity was LogMAR -0.2 for central RAO on average with 8/17 (47%) experiencing objective improvement, 5/17 (29%) experienced no change and 4/22 (24%) experienced a reduction in best corrected visual acuity. Subjective improvement (colour perception or visual fields) was reported in an additional 4/17 patients, resulting in 12/17 (71%) reporting improvement either in visual acuity or subjectively. There was no improvement in the best corrected visual acuity of any of the five patients suffering from branch RAO. Cardiovascular risk factors present in the cohort included hypertension, hypercholesterolaemia, previous cardiovascular events, cardiac disease and smoking. Limited side effects were experienced by this patient cohort with no recorded irreversible side effects. Conclusions: Hyperbaric oxygen treatment appears a safe, beneficial treatment for central RAO. No benefit was demonstrated in branch RAO although numbers were small. Increased awareness of HBOT for RAO resulting in streamlined referrals and transfers and greater uptake of this intervention may further improve patient outcomes.

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.

Presence of Embolic Source and Outcome in Central Retinal Artery Occlusion.

OBJECTIVES: The etiology of central retinal artery occlusion (CRAO) is unclear in approximately 50% of patients, suggesting pathomechanical heterogeneity; moreover, little is known about outcomes according to etiology. This study investigated whether the presence of an embolic source affects outcome in CRAO. METHODS: CRAO patients within 7 days of symptom onset were retrospectively enrolled. Clinical parameters, including initial and 1-month visual acuity, CRAO subtype, and brain images, were reviewed. CRAO etiology was categorized as CRAO with or without an embolic source (CRAO-E+ and CRAO-E-). Visual improvement was defined as a decrease in logarithm of the minimum angle of resolution ≥0.3 at 1 month. RESULTS: A total of 114 patients with CRAO were included. Visual improvement was noted in 40.4% of patients. Embolic sources were identified in 55.3% of patients, and visual improvement group rather than no improvement group was more commonly associated with the presence of an embolic source. In multivariable logistic regression analysis, CRAO-E+ independently predicted visual improvement (odds ratio 3.00, 95% CI 1.15-7.81, p = 0.025). DISCUSSION: CRAO-E+ was found to be associated with a better outcome. CRAO-E+ may be more prone to recanalization than that CRAO-E-.

Retinal Vascular Occlusion and Underlying Generalized Vascular Diseases. / Retinale Gefäßverschlüsse als Ausdruck eines generalisierten Gefäßleidens.

Retinal vascular occlusion not only threatens vision loss but is also associated with other systemic risk factors and vascular diseases. Interdisciplinary cooperation is of great importance in these patients. The risk factors hardly differ between arterial and venous retinal occlusions, which is due to the special anatomy of retinal vessels. Major underlying conditions associated with retinal vascular occlusion include arterial hypertension, diabetes mellitus, dyslipidemia, cardiac disease, particularly atrial fibrillation, or vasculitis of large- and middle-sized arteries. Every new diagnosed retinal vascular occlusion should therefore be taken as an occasion to search for risk factors and possibly adjust an already existing therapy in order to prevent further vascular events.

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.

Management of ocular arterial ischemic diseases: a review.

PURPOSE: To summarize the existing treatment options regarding central retinal artery occlusion (CRAO), branch retinal artery occlusion (BRAO), arteritic anterior ischemic optic neuropathy (AAION), non-arteritic anterior ischemic optic neuropathy (NAION), and ocular ischemic syndrome (OIS), proposing an approach to manage and treat these patients. METHODS: A systematic literature search of articles published since 1st January 2010 until 31st December 2020 was conducted using MEDLINE (PubMed), Scopus, and Web of Science. Exclusion criteria included case reports, non-English references, articles not conducted in humans, and articles not including diagnostic or therapeutic options. Further references were gathered through citation tracking, by hand search of the reference lists of included studies, as well as topic-related European society guidelines. RESULTS: Acute ocular ischemia, with consequent visual loss, has a variety of causes and clinical presentations, with prognosis depending on an accurate diagnosis and timely therapeutic implementation. Unfortunately, most of the addressed entities do not have a standardized management, especially regarding their treatment, which often lacks good quality evidence on whether it should or not be used to treat patients. CONCLUSION: Ophthalmologic signs and symptoms may be a warning sign of cardiovascular or cerebrovascular events, namely stroke. Most causes of acute ocular ischemia do not have a standardized management, especially regarding their treatment. Timely intervention is essential to improve the visual, and possibly vital, prognosis. Awareness must be raised among non-ophthalmologist clinicians that might encounter these patients. Further research should focus on assessing the benefit of the management strategies already being employed .

Nationwide trends in emergency department utilisation for acute retinal ischaemia in the USA, 2011-2018.

BACKGROUND: Guidelines recommend urgent evaluation for transient monocular vision loss (TMVL) and retinal artery occlusion (RAO), but emergency department (ED) utilisation for these conditions is unknown. METHODS: We performed a retrospective longitudinal cross-sectional analysis of the Nationwide Emergency Department Sample (2011-2018), a database of all ED visits from a representative 20% sample of US hospital-based EDs. We identified patients aged 40 and older with a primary diagnosis of TMVL or RAO and calculated the weighted number of total visits and admission rate by year. We used joinpoint regression to analyse time trends and logistic regression to measure differences according to demographic characteristics and comorbidities. RESULTS: There were an estimated 2451 ED visits for TMVL and 2472 for RAO annually in the USA from 2011 to 2018. Approximately 36% of TMVL and 51% of RAO patients were admitted. The admission rate decreased by an average of 4.9% per year for TMVL (95% CI -7.5% to -2.3%) and 2.2% per year for RAO (95% CI -4.1% to -0.4%), but the total number of ED visits did not change significantly over time. Elixhauser Comorbidity Index and hyperlipidaemia were associated with increased odds of hospital admission for both TMVL and RAO. There were also differences in admission rate by insurance payer and hospital region. CONCLUSION: Of the estimated 48 000 patients with TMVL or RAO annually in the USA, few are evaluated in the ED, and admission rates are less than for transient ischaemic attack or ischaemic stroke and are decreasing over time.

Central retinal artery occlusion: a retrospective study of disease presentation, treatment, and outcomes.

OBJECTIVE: A central retinal artery occlusion (CRAO) represents a form of ocular stroke with poor visual prognosis. CRAO shares a common pathophysiology with cerebral ischemic stroke but presents unique diagnostic and management challenges leading to variability in clinical practice. This study aims to assess the presentation, treatment, and outcomes of CRAO at a tertiary care centre in Canada over 2 years and elucidate potential areas for improvement in the care of these patients. METHODS: Single-institution retrospective review including 27 patients diagnosed with CRAO from March 2018 to March 2020 in Edmonton, Alberta. RESULTS: Most patients with CRAO presented to eye care providers (14 of 27); others presented to the emergency department (10 of 27) or family physicians (2 of 27). Three patients (11.1%) presented within 4.5 hours of symptom onset. At presentation, 81% of patients had visual acuity of 20/400 or worse in the affected eye. No patients received thrombolysis. The majority of CRAO cases had a nonarteritic etiology (92.6%). All patients had at least one pre-existing vascular risk factor. Forty-eight percent of patients received escalated medical therapy. Ipsilateral carotid stenosis was identified in 5 patients (18.5%); 3 patients required carotid endarterectomy. Two patients were diagnosed with atrial fibrillation. Two patients experienced symptomatic cerebral ischemia within 6 weeks of CRAO. CONCLUSIONS: The majority of patients with CRAO presented to eye care providers, and few present within the potential window for thrombolysis of 4.5 hours, highlighting the need for public awareness strategies. Our cohort highlights the significant rate of systemic comorbidity that exists in these patients.

Efficacy and safety of a standardized hyperbaric oxygen therapy protocol for retinal artery occlusion.

Introduction: We aimed to assess the efficacy and safety of a standardized hyperbaric oxygen (HBO2) therapy protocol in patients with retinal artery occlusion (RAO). Methods: A retrospective study was conducted in our tertiary care center from July 2016 to September 2019. Patients experiencing central RAO and branch RAO for less than seven days were included. Once the diagnosis was made, patients were urgently referred to the HBO2 department to receive a first 90-minute HBO2 session at a pressure of 2.5 ATA. Patients underwent two daily sessions seven days a week for at least 15 days. If no reperfusion was seen on fluorescein angiography on Day 15, treatment was continued for an additional week with an assessment on Day 21. The primary endpoint was BCVA improvement defined as a decrease by 0.3 logMAR at one month. Results: Twenty-eight patients were included during the study period. Fifty-seven percent of patients were treated more than 12 hours after the onset of the first symptoms. The mean BCVA was 1.5 logMAR at the time of referral and improved to 0.9 logMAR after HBO2 (p=0.001). A multivariate analysis identified a high blood pressure (p=0.039) and a low initial BCVA (p=0.005) as poor prognostic factors. Conclusion: Performing HBO2 sessions twice daily at a pressure of 2.5 ATA appears to be an effective and safe treatment for RAO.

Systemic thrombolysis for acute central retinal artery occlusion in sickle cell disease: Case report.

INTRODUCTION: In sickle cell disease (SCD), blood oxygen content is decreased due to anemia and the Hb-SS phenotype, in particular leads to an increased blood viscosity, which limits tissue oxygen delivery. Nonetheless, vasculopathy, correlating with daytime oxygen saturation,1 thrombophilia and hyper coagulability are all underappreciated etiologies of stroke in SCD.2 As a result, there is less known about the role of systemic thrombolysis for the management of acute stroke in SCD. Given the lack of studies and cases reviewed in literature, we describe a patient with SCD found to have an acute stroke treated with both intravenous (IV) alteplase and exchange transfusion. RESULTS & DISCUSSION: We describe a 42-year-old African- American man with SCD (HbSS) who presented with an acute central retinal artery occlusion (CRAO) within an hour of onset and subsequently received IV thrombolysis with alteplase. His labs were significant for HbS 91%. He had no central vascular access to undergo emergent red blood cell (RBC) exchange so interventional radiology was consulted to minimize his bleeding risk after receiving tissue plasminogen activator (tPA). A right internal jugular catheter was placed with fluoro-guidance, resulting in minimal blood loss. After two sessions of RBC exchange, his HbS decreased to 26%. He reported an improvement of vision in his left eye the day following acute management and followed up with Hematology for secondary stroke prevention. IMPLICATIONS: In reviewing this case, we recommend that current clinical trials for management of acute stroke including an acute CRAO carefully consider including patients with sickle cell disease to receive simultaneous IV thrombolysis and RBC exchange. The benefits outweigh the risk of a permanent disabling deficit with significant functional impairment. And while considering care plans tailored to the projected needs of acute care management for this patient population, we also recommend implementing healthcare models that improve access to preventative care in settings where the majority of children and adults with SCD live.

Combined central retinal vein and cilioretinal artery occlusion in a 25-year-old woman.

We report a case of a 25-year-old woman with sudden and painless diminution in vision and central scotoma in her left eye (LE). She was a smoker and had been taking combined oral contraceptive (COC) pills for 1 year. On admission, the best-corrected visual acuity (BCVA) was 1,5/50 in the LE. Posterior segment examination revealed optic disc edema with flame-shaped retinal hemorrhages, mildly tortuous and dilated retinal veins. Moreover, retinal edema in the peripapillary and perimacular region, foci of hemorrhages and Roth's spots in the posterior pole, as well as pale superior papillomacular bundle were observed. Fundus fluorescein angiography (FFA) confirmed the delayed flow of contrast through the cilioretinal artery in the LE. The clinical picture suggested left central retinal vein (CRVO) with cilioretinal artery occlusion (CLRAO). All laboratory and imaging tests were normal except for homozygous methylenetetrahydrofolate reductase (MTHFR) gene mutation (A1298C genotypes). However, serum homocysteine (Hcy) level was normal. Low molecular weight heparin (LMWH) treatment was administered. Retinal lesions, as well as BCVA improved, but central scotoma remained. Abbreviations: aPTT = activated partial thromboplastin time, BCVA = best-corrected visual acuity, CBC = complete blood count, CLRAO = cilioretinal artery occlusion, COC = combined oral contraceptive, CRA = central retinal artery, CRP = serum C-reactive protein, CRVO = central retinal vein occlusion, CT = computed tomography, CTA = computed tomography angiography, ECG = electrocardiography, ESR = erythrocyte sedimentation rate, FERG = flash electroretinogram, FFA = fundus fluorescein angiography, GCA = ganglion cell analysis, GCL = ganglion cell layer, Hcy = homocysteine, ICGA = indocyanine green angiography, INR = international normalized ratio, IOP = intraocular pressure, IPL = inner plexiform layer, LE = left eye, LMWH = low molecular weight heparin, mfERG = multifocal electroretinogram, MTHFR = methylenetetrahydrofolate reductase, OCT = optical coherence tomography, RE = right eye, VF = visual field.

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.

Six Cases of Retinal Vascular Anomalies after Coronavirus Disease 2019: A Case Series.

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) and its rapid spread has resulted in unexplored clinical ophthalmological manifestations. This report aims to describe a series of retinal vascular anomalies diagnosed with the use of fluorescein angiography, following contraction of COVID-19. HISTORY AND SIGNS: Symptoms reported by patients were central scotoma (one case), inferior scotoma (one case), and a sensation of mild loss of vision during the COVID-19 follow-up (four cases). Best-corrected visual acuity was preserved in all patients, apart from one, who had a visual acuity of 0.4, decimal scale (6/15, Snellen) in the left eye. THERAPY AND OUTCOME: Clinical manifestations included bilateral retinal vasculitis (two cases), branch retinal vein occlusion (one case), branch retinal artery occlusion (one case), hemi-central retinal vein occlusion (one case), and optic disc edema due to central retinal vein occlusion (one case) occurring 0 - 8 months after COVID-19 contraction. Serological testing was performed in every patient to exclude any other recognized cause of retinal vascular occlusion and inflammation and to confirm immunity against the novel coronavirus. None of the patients required any ocular treatment. CONCLUSIONS: Arterial and venous occlusive as well as inflammatory retinal vascular pathologies can occur both during and after the acute phase of COVID-19 as manifestations of ocular long-term effects of COVID-19 and should be included in the differential diagnosis of retinal occlusive pathologies. This case series suggests that careful investigations, including fundoscopy and fluorescein angiography, should be required in patients with visual complaints, both in the acute and long-term follow-up of COVID-19.