Treatment options for central retinal artery occlusion

Prognostic factors for acute central retinal artery occlusion treated with hyperbaric oxygen: The Hong Kong study report number five

BACKGROUND

Central retinal artery occlusion (CRAO) is a potentially blinding disease, and hyperbaric oxygen therapy (HBOT) is becoming increasingly popular with the support of scientific evidence. Despite the presence of various acute management measures, there is no clear evidence on the gold standard treatment for CRAO.

AIM

To identify factors and imaging parameters associated with good visual outcome, which guide ophthalmologists in the triage of CRAO patients for HBOT.

METHODS

Patients who suffered from CRAO and had a symptom onset ≤ 6 h were recruited for a course of HBOT in a tertiary hospital after failing bedside treatment. Patient demographics, onset time, CRAO eye parameters, and past medical history were prospectively collected. Visual outcomes after HBOT were also analyzed.

RESULTS

A total of 26 patients were included; the female-to-male ratio was 1:1.6, and the mean age was 67.5 years ± 13.3 years (range 44–89 years). The mean duration of follow-up and mean visual acuity (VA) improvement were 10.0 mo ± 5.3 mo and 0.48 logarithm of minimal angle of resolution (logMAR) ± 0.57 logMAR (approximately 9 letters in ETDRS) (P = 0.0001, Z = -3.67), respectively. The 1 mm zone of central macular thickness (CMT) on optical coherence tomography was not associated with VA changes (P = 0.119); however, the 1-to-3 mm circular rim of CMT was fairly associated (P = 0.02, Spearman's coefficient = 0.45). Complete retinal perfusion time during fundus fluorescein angiography (FFA) was moderately associated (P = 0.01, Spearman's coefficient = 0.58) with visual outcome.

CONCLUSION

A thinner 1-to-3 mm circular rim of CMT, but not the central 1 mm zone, is associated with better visual outcome. A shorter perfusion delay on FFA is also associated with better visual outcome.

Management of vision loss associated with complications of cosmetic filler injections

Injectable cosmetic fillers have dramatically risen in popularity in recent years. However, as the use of such fillers has become more common, there have been many reports of vision loss secondary to misplaced filler embolizing to the ophthalmic artery resulting in ocular ischemia. Currently, there are no randomized control trials or widely validated clinical guidelines that dictate how injectors should manage ischemic complications of filler embolism. This review aims to explain the possible mechanisms by which a cosmetic filler embolus can occlude the ophthalmic artery, describe the types of treatments that have been attempted thus far, and delineate possible a stroke-like protocol that can be implemented in order to restore perfusion and recover vision after such ischemic complications have occurred.

Healing of ischemic injury in the retina

Neuro- and retinal degenerative diseases, including Alzheimer's, age-related macular degeneration, stroke, and central retinal artery occlusion, rob millions of their independence. Studying these diseases in human retinas has been hindered by the immediate loss of neuronal activity postmortem. While recent studies restored limited activity in postmortem CNS tissues, synchronized neuronal transmission >30 minutes postmortem remained elusive. Our study overcomes this barrier by reviving and sustaining light signal transmission in human retinas recovered up to four hours and stored 48 hours postmortem. We also establish infrared-based ex vivo imaging for precise sampling, a closed perfusion system for drug testing, and an ex vivo ischemia-reperfusion model in mouse and human retina. This platform enables testing of neuroprotective and neurotoxic effects of drugs targeting oxidative stress and glutamate excitotoxicity. Our advances question the irreversibility of ischemic injury, support preclinical vision restoration studies, offer new insights into treating ischemic CNS injuries, and pave the way for transplantation of human donor eyes.

Teaser

Reviving light signaling in postmortem human retinas challenges the irreversibility of ischemic injury and advances research to restore vision.

Polyarteritis nodosa initially presenting as ocular motility impairment and diplopia with subsequent development of bilateral central retinal artery occlusion: A case report

Purpose

Polyarteritis nodosa (PAN) is a systemic vasculitis of unknown etiology affecting medium- and small-sized arteries and can present with varied organ involvement, including ocular manifestations. Here, we report a unique case of PAN that initially presented with diplopia and ocular motility impairment, with subsequent development of bilateral central retinal artery occlusion (CRAO), a rare ocular manifestation of PAN.

Observations

A 58-year-old man presented with left abduction impairment and diplopia, which initially improved without intervention. However, similar symptoms recurred in the right eye later. The patient presented to the ophthalmology department and was initially suspected of having orbital myositis related to IgG4 disease owing to elevated IgG4 levels. Subsequently, the patient developed bilateral CRAO, confirmed using fundus fluorescein angiography, resulting in remarkable visual loss. Despite negative autoantibodies, a high inflammatory response, and symptoms suggestive of systemic involvement (myalgia, hematuria, muscle weakness, and gastrointestinal symptoms), PAN was diagnosed following laparotomy for intestinal perforation, revealing vasculitis in the medium-to-small arteries.

Conclusions and importance

This case underscores the importance of considering a possible diagnosis of PAN in patients with ocular motility impairments and diplopia, even in the absence of classic systemic symptoms. PAN can rapidly progress to severe visual dysfunction, including bilateral CRAO, as observed in this case. Consequently, early recognition and treatment of PAN are crucial, given its potentially severe complications and poor prognosis. Further, this report contributes to the limited literature on PAN, emphasizing the need for awareness of the rare ocular manifestations of systemic vasculitis.

Successful recovery of vision following intravenous thrombolysis using low-dose alteplase in central retinal artery occlusion

Central retinal artery occlusion (CRAO) is an ophthalmic emergency characterized by sudden loss of vision with a low chance of spontaneous recovery. This case report presents a 49-year-old female with sudden right eye visual loss, diagnosed as non-arteritic CRAO. Fundoscopic examination revealed retinal pallor, and optical coherence tomography demonstrated edema of the inner retinal layer, consistent with CRAO. Brain magnetic resonance imaging (MRI) showed an acute ischemic lesion in the right occipital subcortex. The patient received intravenous recombinant tissue plasminogen activator (IV rt-PA) at a lower-than-standard dose of 0.6 mg/kg within 4 h and 17 min of symptom onset, resulting in significant visual improvement. Extensive etiological investigation, including transesophageal echocardiography, uncovered a large, high-risk patent foramen ovale (PFO), leading to the diagnosis of PFO-associated CRAO and concomitant embolic stroke. This case suggests the effectiveness of low-dose IV rt-PA in treating CRAO, which might offer comparable efficacy to the standard dose while potentially minimizing bleeding risks. It also emphasizes the importance of considering cardiac comorbidities, particularly PFO, in younger CRAO patients, and underscores the need for a multidisciplinary approach and comprehensive stroke-etiology workups in CRAO management. This report contributes to the limited evidence on CRAO treatment in Japan, particularly in the context of lower tPA dosing and associated cardiac abnormalities. It underscores the importance of early diagnosis, treatment, and thorough etiological investigation in improving outcomes for CRAO patients.

Outcomes of Hyperbaric Oxygen Treatment for Central Retinal Artery Occlusion: A Single Center Experience

PURPOSE

To describe the outcomes of hyperbaric oxygen therapy (HBOT) for patients with central retinal artery occlusion (CRAO) at a single tertiary care center.

DESIGN

Retrospective clinical cohort study.

METHODS

Medical records of all patients diagnosed with CRAO who received HBOT at Mayo Clinic in Rochester, Minnesota from January 1, 2009 to December 31, 2020 were reviewed to confirm diagnosis, time from onset to presentation, exam findings, treatments, and follow-up data. Main outcome measures included final visual acuity (VA) and number of lines of improvement.

RESULTS

There were 41 patients diagnosed with CRAO who received HBOT during the 12-year study period. Median time from symptom onset to HBOT treatment was 9.5 h (interquartile range [IQR] 6.5, 14.0 h), and patients received a median of 4 HBOT sessions (IQR 2.5, 6.0 sessions). There were 20 patients who received HBOT within 9 h, 14 (70%) of which had clinically meaningful improvement in VA of ≥0.3 logMAR. In comparison, of the 21 patients treated after 9 h, 6 (28.6%) had VA improvement of ≥0.3 logMAR (P = .008). For all patients, the median logMAR VA at presentation was 2.00 (IQR 1.70, 2.30) and the median logMAR VA at follow-up was 1.94 (IQR 1.00, 2.00) (P < .001), with median lines of improvement of 3.0 (IQR 0.0, 7.0). For patients treated within 9 h, the median logMAR VA at presentation was 2.00 (IQR 1.93, 2.30) and the median logMAR VA at follow-up was 1.70 (IQR 0.54, 2.00). Patients treated within 9 h had statistically significant greater median lines of VA improvement than cases that were treated after >9 h from symptom onset at 5.9 (IQR 3.0, 10.0) and 0.0 (IQR 0.0, 3.0), respectively (P < .001). There was no difference in VA recovery associated with specific retinal exam findings such as cherry-red spot (P = .22) and cilioretinal artery perfusion (P = .36) compared to patients without those findings.

CONCLUSION

There was a statistically significant improvement in VA after HBOT treatment in CRAO patients among patients that received early HBOT, with patients receiving the most benefit when receiving treatment within 9 h. Randomized control trials in patients with CRAO are required to confirm the efficacy of HBOT.

Fovea Sparing Branch Retinal Artery Occlusions Imaged with Optical Coherence Tomography Angiography: Two Case Reports

Introduction

Central retinal artery occlusions and branch retinal artery occlusions (BRAOs) are ophthalmic emergencies that require workups for systemic risk factors. In the acute setting, BRAOs present with retinal whitening in a sectoral pattern on exam as well as hyperreflectivity and thickening of the inner retinal layers on optical coherence tomography (OCT). In the subacute to chronic phase, the retinal whitening dissipates, which may confound the diagnosis of remote arterial occlusions if there is no clearly visible plaque.

Case Presentations

A 66-year-old male presented with 20/25 visual acuity (VA) and an inferior visual field defect in the right eye, and a 69-year-old male presented with 20/60 VA and a superior visual field defect in the left eye. Exams of both patients showed ischemic retinal whitening with visible Hollenhorst plaques in the affected eyes. OCT demonstrated inner retinal edema. At follow-up, wide-field OCT angiography (OCTA) showed persistent capillary dropout following the same initial vascular distribution but sparing the fovea and papillomacular bundle. VAs at the most recent follow-up visits were 20/30 and 20/20, respectively.

Conclusion

These cases demonstrate the utility of wide-field OCTA in characterizing areas of capillary nonperfusion that can persist for years after the initial ischemic event. Additionally, patients with macula-involving BRAOs can have good VA outcomes if the fovea is spared.

Nd:Yag Laser Transluminal Embolysis: A Therapeutic Approach in Retinal Artery Occlusion

Background: Central and branch retinal artery occlusion (CRAO and BRAO) are critical causes of acute vision loss, predominantly affecting older adults with systemic vascular pathology. These occlusions typically result from embolic events, leading to partial or complete retinal ischemia. Methods: This retrospective case series report details of our 10-year experience using the 1064 nm Nd:YAG laser for Transluminal Nd:YAG Embolysis (TYE) in order to lyse visible emboli within the retinal arteries. Results: We conducted a retrospective case series involving 18 patients treated by TYE for different retinal arteries occlusions between 2014 and 2024. TYE effectively restored blood flow in the occluded arteries, with variable but generally favorable visual outcomes. Our article highlights significant clinical and interventional aspects of three treated patients: a BRAO case with multiple transluminal emboli, a case of double BRAO and a CRAO case. We also report the successful use of TYE for intraluminal lysing of an embolus located outside the optic disc. The procedures were well-tolerated, with minor complications such as preretinal or vitreous hemorrhages resolving spontaneously. Conclusions: TYE is a minimally invasive therapeutic option for retinal artery occlusion with visible emboli, particularly when intervention occurs shortly after the onset of symptoms. Compared to observation, TYE can improve visual outcomes and reduce the risk of permanent vision loss, presenting a significant advancement in the management of this ophthalmic emergency. The worldwide experience with TYE is continuously increasing. Further research with larger cohorts is recommended to validate these results and refine the treatment protocol.

Branch retinal artery occlusion from laser pointer misuse

Purpose

To report a case of branch retinal artery occlusion (BRAO) following exposure to a blue laser pointer in a healthy 22-year-old male.

Observations

A 22-year-old healthy male presented with sudden visual field impairment in his right eye, occurring 18 hours after exposure to a blue laser pointer. He complained of an immediate persistent curtain-like obstruction in the upper visual field of the affected eye. Clinical examinations revealed BRAO in the inferior half of the retina, confirmed by Optical coherence tomography (OCT) showing edema. Fluorescein angiography indicated delayed filling and a focal hyperfluorescence area, consistent with a leak. Due to a lack of established management, the patient was offered follow-up care. Though reperfusion was observed on fluorescein angiography one month later, thinning of the retinal layers was evident on OCT, and there was no visual recovery.

Conclusions and Importance

In conclusion, laser pointers, though often considered innocuous, can lead to serious ocular damage. The clinical implications of laser-induced retinal injury are severe and sometimes irreversible, warranting special attention. The observed clinical course underscores the complex nature of such injuries and emphasizes the importance of awareness and caution regarding laser pointer use.

Therapeutic Strategies for Retinal Artery Occlusion-A Literature Review

Retinal artery occlusion (RAO) is an emergency condition causing acute retinal ischemia and is considered an equivalent of ischemic stroke. The occurrence of an episode of RAO is associated with significant impairment of visual functions and correlates with an increased risk of future vascular events. Although RAO requires immediate diagnosis and treatment, there are currently no clear guidelines specifying optimal management. This review discusses current and future therapeutic strategies following an episode of RAO, including secondary prevention.

Molecular and Cellular Mechanisms Involved in the Pathophysiology of Retinal Vascular Disease-Interplay Between Inflammation and Oxidative Stress

Retinal vascular diseases encompass several retinal disorders, including diabetic retinopathy, retinopathy of prematurity, age-related macular degeneration, and retinal vascular occlusion; these disorders are classified as similar groups of disorders due to impaired retinal vascularization. The aim of this review is to address the main signaling pathways involved in the pathogenesis of retinal vascular diseases and to identify crucial molecules and the importance of their interactions. Vascular endothelial growth factor (VEGF) is recognized as a crucial and central molecule in abnormal neovascularization and a key phenomenon in retinal vascular occlusion; thus, anti-VEGF therapy is now the most successful form of treatment for these disorders. Interaction between angiopoietin 2 and the Tie2 receptor results in aberrant Tie2 signaling, resulting in loss of pericytes, neovascularization, and inflammation. Notch signaling and hypoxia-inducible factors in ischemic conditions induce pathological neovascularization and disruption of the blood-retina barrier. An increase in the pro-inflammatory cytokines-TNF-α, IL-1β, and IL-6-and activation of microglia create a persistent inflammatory milieu that promotes breakage of the blood-retinal barrier and neovascularization. Toll-like receptor signaling and nuclear factor-kappa B are important factors in the dysregulation of the immune response in retinal vascular diseases. Increased production of reactive oxygen species and oxidative damage follow inflammation and together create a vicious cycle because each factor amplifies the other. Understanding the complex interplay among various signaling pathways, signaling cascades, and molecules enables the development of new and more successful therapeutic options.

Prostanoid signaling in retinal vascular diseases

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

Acute monocular visual loss: time to call the stroke team?

A man in his 90s presented with acute monocular loss of vision; the emergency department triage alerted the stroke team. He underwent urgent parallel assessments by the stroke and ophthalmology teams and was diagnosed with central retinal artery occlusion. The ultimate decision was made to manage him conservatively, rather than with intravenous thrombolysis, and his visual function has remained poor. We discuss the current evidence for using intravenous thrombolysis in people with central retinal artery occlusion and use this case to exemplify the practical issues that must be overcome if ongoing randomised clinical trials of central retinal artery occlusion confirm a definite benefit from using intravenous thrombolysis.

Successful Treatment of Central Retinal Artery Occlusion With Tissue Plasminogen Activator Followed by Recurrent Retinal Ischemia

Purpose: To describe the use of intra-arterial tissue plasminogen activator (tPA) to treat central retinal artery occlusion (CRAO). Methods: A case and its findings were analyzed. Results: A 45-year-old man diagnosed with a CRAO and had cerebral angiography and treatment with intra-arterial tPA. After treatment, follow-up included optical coherence tomography (OCT), fundus photography, fluorescein angiography, and OCT angiography. The visual acuity (VA) improved from hand motions to 20/30 immediately after fibrinolysis. A vascular occlusion event the next day resulted in a decrease in VA to 20/400. After initiation of dual antiplatelet therapy, the patient's VA improved to 20/20. As the retina recovered, the evolution of retinal ischemic changes to a finding similar to paracentral acute middle maculopathy was seen on imaging. Conclusions: This is the first report describing a patient safely started on dual antiplatelet therapy that led to vision improvement after initial treatment with intra-arterial tPA for a CRAO resulted in recurrent vision loss.

Two Strokes in One Patient: An Interesting Case Report

Central retinal arterial occlusion (CRAO) causes a sudden and devastating visual loss. Transient blurring of vision may precede CRAO and is often ignored by the patient, as it may resolve spontaneously without permanent visual loss. However, this can be a warning sign of ischaemia, particularly in individuals with multiple risk factors. We report a case of a 50-year-old man with CRAO in his left eye. The patient had a history of transient blurring of vision in the same eye 15 days prior, which resolved without intervention. He also had a history of stroke 12 years ago and had been on anticoagulants but discontinued them three years before this episode. This, combined with chronic smoking and poorly controlled diabetes mellitus, likely contributed to a hypercoagulable state, leading to thrombus formation responsible for CRAO. Fundus examination revealed an opaque and oedematous macula with a cherry red spot and blurred optic disc margins. Treatment with ocular massage and paracentesis improved the patient's vision to finger counting at 2 m. The patient was started on aspirin and advised of strict blood sugar control. This case highlights the importance of recognising transient ischaemic symptoms and maintaining long-term anticoagulant therapy to prevent severe complications like CRAO.

The Spectrum of Isolated Retinal Artery Occlusion Secondary to Giant Cell Arteritis

We systematically reviewed the literature to investigate the clinical features of isolated arteritic retinal artery occlusion (A-RAO) associated with giant cell arteritis (GCA). The four primary types of A-RAO were central retinal artery occlusion (CRAO), hemi-central retinal artery occlusion (hCRAO), branch retinal artery occlusion (BRAO), and cilioretinal artery occlusion (CLRAO). The most reported presentation was unilateral CRAO, followed by bilateral CRAO, unilateral CLRAO, and bilateral BRAO. Most RAOs were accompanied by typical GCA signs and symptoms, which can help distinguish them from non-arteritic RAOs. When reported, temporal artery biopsy confirmed GCA in most cases. Patients with GCA may present with a broad spectrum of isolated unilateral and bilateral A-RAOs. [Ophthalmic Surg Lasers Imaging Retina 2024;55:536-540.].

Update on central retinal artery occlusion

The medical condition referred to as "central retinal artery occlusion" (CRAO) was first documented by Albrecht von Graefe in 1859. Subsequently, CRAO has consistently been identified as a serious medical condition that leads to substantial visual impairment. Furthermore, it is correlated with vascular complications that have the potential to affect crucial organs such as the brain and heart. A considerable amount of research has been extensively published on the various aspects of this topic, which is marked by notable debates and misconceptions, especially regarding its management and outcomes. The primary aim of this review article is to analyze the latest developments in the understanding of CRAO, which includes its causes, techniques for retinal imaging, systemic evaluation, and therapeutic strategies, such as vitrectomy. This review article offers readers a comprehensive learning experience to gain knowledge on the fundamental principles and recent advancements in CRAO.

Central Retinal Artery Occlusion: Visual Outcomes from a Large Northern California Cohort

PURPOSE

To assess visual acuity (VA) outcomes in a large cohort of patients diagnosed with nonarteritic central retinal artery occlusion (CRAO), and to ascertain whether time from symptom onset to presentation, presenting VA, or conservative treatment delivery (anterior chamber paracentesis, ocular massage, intraocular pressure lowering drugs, hyperventilation, or some combination of those) impacted ultimate VA outcomes.

DESIGN

Retrospective cohort study.

SUBJECTS

The study included 794 patients who presented with CRAO between 2011 and 2020. Within this cohort, 484 individuals presented within 30 days of symptom onset and had comprehensive documentation regarding the details of their presentation, management, and follow-up ≥ 90 days postdiagnosis.

METHODS

Retrospective chart review was conducted for all patients with a diagnosis of CRAO initially identified via International Classification of Diseases coding, followed by confirmation of diagnosis by 2 retina specialists. Cases of arteritic CRAO were excluded.

MAIN OUTCOME MEASURES

Visual acuity recovery, defined as improvement from ≤ 20/200 or worse at presentation to ≥ 20/100 ≥ 90 days after diagnosis.

RESULTS

Of the 794 identified patients, 712 (89.7%) presented with VA of ≤ 20/200. Similarly, 447 (92.4%) of the 484-patient subset that presented within 30 days and had comprehensive documentation presented with VA ≤ 20/200. Of the 441 of those patients with documented follow-up, 380 (86.2%) remained at that level. Of the 244 patients who presented within 4.5 hours of symptom onset, 227 (93%) presented ≤ 20/200 and 201 (92.6%) of the 217 of those with follow-up data did not improve beyond that threshold. There was no significant difference (P < 0.05) in final VA between patients presenting before versus after 4.5 hours from time of vision loss. There was also no significant difference (P < 0.05) in VA outcomes between patients who did or did not receive conservative treatment.

CONCLUSIONS

This large retrospective study further highlights the poor visual prognosis for patients with CRAO. Earlier time to presentation did not seem to impact final VA outcome, nor did conservative treatment efforts. Efficacious evidence-based treatment options are needed for this patient population.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Ink blot leakage in central retinal artery occlusion

PURPOSE

To describe a typical case of acute central retinal artery occlusion (CRAO) with an ink-blot pattern of hyperfluorescent leak on fundus fluorescein angiography (FFA).

CASE DESCRIPTION

A 21-year-old woman came to the clinic with one day of painless right eye vision loss. Her right eye had finger counting at ½ meter. Her right eye had a relative afferent pupillary defect, but her anterior segment and intraocular pressure of both eyes were normal.

RESULTS

The right eye fundus showed signs of acute CRAO with severe grade on optical coherence tomography (OCT). FFA imaging showed a mid-phase hyperfluorescent leak that persisted until the late stage. OCT scan through the hyperfluorescent spot showed absence of neurosensory detachment with normal retinal pigment epithelium, ruling out a central serous chorioretinopathy (CSCR). Ocular massage and anterior chamber paracentesis were performed. At the 10-day follow-up, the patient's visual acuity was counting fingers at ½ meter, and the OCT scan showed findings of CRAO chronicity. The hyperfluorescent spot disappeared on the subsequent FFA.

CONCLUSION

We report a case of ink-blot leakage on FFA, similar to that observed in CSCR in an eye with acute CRAO. We propose that the hyperfluorescent spot in our acute CRAO was likely caused by red blood cell aggregation or rouleaux formation.

Causes and management of sight threatening complications of dermal filler injections: A review

Injectable dermal fillers continue to increase in popularity in aesthetic medicine. Although rare, vision loss secondary to filler injections is a devastating complication associated with a poor visual prognosis. The mechanism for vision loss is thought to be related to retrograde embolization of the dermal filler from peripheral vessels in the face into the ophthalmic arterial system. Early recognition and prompt management are essential if vision is to be salvaged. The use of retrobulbar hyaluronidase is still contentious, however when administered by a specialist, this treatment gives the best chance at visual recovery and should be considered for all cases.

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

OBJECTIVES

Central retinal artery occlusion (CRAO) is a stroke of the retina potentially amenable to intravenous thrombolysis (IVT). We aimed to determine feasibility of an emergency treatment protocol and risk profile of IVT for CRAO in a comprehensive stroke center (CSC).

METHODS

We performed a retrospective, observational cohort study including patients with acute CRAO admitted to a CSC over 4 years. Patients are offered IVT if they present with acute vision loss of ≤ 20/200 in the affected eye, have no other cause of vision loss (incorporating a dilated ophthalmologic exam), and meet criteria akin to acute ischemic stroke. We collected socio-demographic data, triage data, time from onset to presentation, IVT candidacy, and rates of symptomatic intracranial hemorrhage (sICH)- or extracranial hemorrhage.

RESULTS

36 patients presented within the study period, mean (standard deviation (SD)) age of 70.7 (10), 52 % female, and median time (Q1, Q3) to ED presentation of 13.5 (4.3, 18.8) h. Patients within 4.5 h from onset presented more commonly directly to our ED (66.6 % vs 37.1 %, p = 0.1). Nine patients (25 %) presented within the 4.5 h window. Of those eligible, 7 (77 %) received IVT. There were no events of intracranial or extracranial hemorrhage.

CONCLUSIONS

Our study confirmed that IVT for acute CRAO is feasible. We found a high rate of treatment with IVT of those eligible. However, because 75 % of patients presented outside the treatment window, continued educational efforts are needed to improve rapid triage to emergency departments to facilitate evaluation for possible candidacy with IVT.

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.

Wilderness Medical Society Clinical Practice Guidelines for Treatment of Eye Injuries and Illnesses in the Wilderness: 2024 Update

A panel convened to develop an evidence-based set of guidelines for the recognition and treatment of eye injuries and illnesses that may occur in the wilderness. These guidelines are meant to serve as a tool to help wilderness providers accurately identify and subsequently treat or evacuate for a variety of ophthalmologic complaints. Recommendations are graded based on the quality of their supporting evidence and the balance between risks and benefits according to criteria developed by the American College of Chest Physicians.

A Review of Current Literature on Central Retinal Artery Occlusion: Its Pathogenesis, Clinical Management, and Treatment

The ocular analogue of a cerebral stroke is central retinal artery occlusion (CRAO), a medical emergency concerning the eyes. Most patients experience substantial acute vision loss with a visual acuity of 20/400 or worse, resulting in decreased quality of life (QoL) and decreased functional ability. An impending cerebral stroke and ischemic heart disease are also more likely. The four distinct clinical entities that make up CRAO are non-arteritic CRAO, transitory non-arteritic CRAO, non-arteritic CRAO with cilioretinal artery sparing, and arteritic CRAO. Depending on the CRAO type, clinical traits, visual results, and treatment all vary greatly. Contrary to current belief, there is a spontaneous improvement in the optical field and vision, mainly in the first week. The likelihood of instinctive development in optical acuity in the first seven days varies greatly. The pathogenesis, epidemiology, and medical features of CRAO will be described in this review, along with present and potential management future options.

Addressing retinal hypoxia: pathophysiology, therapeutic innovations, and future prospects

Retinal hypoxia stands as a pivotal yet often underappreciated factor in the etiology and progression of many retinal disorders such as glaucoma, hypertensive retinopathy, diabetic retinopathy, retinal vein occlusions, and retinal artery occlusions. Current treatment methodologies fail to directly address the underlying pathophysiology of hypoxia and aim to improve ischemia through alternative methods. In this review, we discuss the critical role of retinal hypoxia in the pathogenesis of various retinal diseases and highlight the need for innovative therapeutic strategies that address the root cause of these conditions. As our understanding of retinal hypoxia continues to evolve, the emergence of new technologies holds the promise of more effective treatments, offering hope to patients at risk of vision loss.

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.

Neuroprotection for Nonarteritic Central Retinal Artery Occlusion: Lessons from Acute Ischemic Stroke

Nonarteritic central retinal artery occlusion (NA-CRAO) is a variant of acute ischemic stroke (AIS) and is a cause of sudden severe loss of vision. There are guidelines by the American Heart Association and the American Stroke Association for the care of CRAO patients. This review explores the basis of retinal neuroprotection for CRAO and its potential for improving the outcome of NA-CRAO. Recently, there have been significant advances in research into the use of neuroprotection to treat retinal diseases, including retinal detachment, age-related macular degeneration, and inherited retinal diseases. Also, neuroprotective research in AIS has been extensive, and newer drugs tested, including Uric acid, Nerinetide, and Otaplimastat, with promising results. Progress in cerebral neuroprotection after AIS offers hope for retinal neuroprotection after CRAO; and a possibility of extrapolating research findings from AIS into CRAO. Combining neuroprotection and thrombolysis can extend the therapeutic window for NA-CRAO treatment and potentially improve outcomes. Experimented neuroprotection for CRAO includes Angiopoietin (Comp Ang1), KUS 121, Gene therapy (XIAP), and hypothermia. Efforts in the field of neuroprotection for NA-CRAO should focus on better imaging to delineate the penumbra after an acute episode of NA-CRAO (using a combination of high-definition optical coherence angiography and electrophysiology). Also, research should explore details of pathophysiologic mechanisms involved in NA-CRAO, allowing for further neuroprotective intervention, and closing the gap between preclinical and clinical neuroprotection.

Dibazol-induced relaxation of ophthalmic artery in C57BL/6J mice is correlated with the potency to inhibit voltage-gated Ca2+ channels

We aimed to explore the effect of dibazol on the ophthalmic artery (OA) and ophthalmic artery smooth muscle cells (OASMCs) of C57BL/6J mice as well as the underlying mechanisms. The OA of C57BL/6J mice was isolated under a dissecting microscope for primary OASMCs culture and myogenic tests. OASMCs were identified through morphological and immunofluorescence analyses. Morphology changes in the OASMCs were examined by staining using rhodamine-phalloidin. We performed a collagen gel contraction assay to measure the contractile and relaxant activities of the OASMCs. The molecular probe Fluo-4 AM was used to examine intracellular free Ca²⁺ levels ([Ca²⁺]_in). The myogenic effects of OA were examined using wire myography. Additionally, the whole-cell patch-clamp technique was used to investigate the mechanisms underlying the relaxant effect of dibazol on L-type voltage-gated Ca²⁺ channels (LVGC) in isolated cells. 10^-5 M dibazol significantly inhibited the contraction of OASMCs and increased the [Ca²⁺]_in response to 30 mM KCl in a concentration-dependent manner. Dizabol had a more significant relaxant effect than 10^-5 M isosorbide dinitrate (ISDN). Similarly, dibazol showed a significant dose-dependent relaxant effect on OA contraction induced by 60 mM KCl or 0.3 μM 9,11-Dideoxy-9α,11α-methanoepoxy prostaglandin F_2α (U46619). The current-voltage (I-V) curve revealed that dibazol decreased Ca²⁺ currents in a concentration-dependent manner. In conclusion, dibazol exerted relaxant effects on the OA and OASMCs, which may involve the inhibition of the Ca²⁺ influx through LVGC in the cells.

Exploratory clinical trial to evaluate the efficacy and safety of transdermal electrical stimulation in patients with central retinal artery occlusion

PURPOSE

To evaluate the efficacy and safety of transdermal electrical stimulation (TdES) using skin electrodes in patients with central retinal artery occlusion (CRAO).

METHODS

Five eyes of five patients with CRAO underwent TdES (10-ms biphasic pulses, 20 Hz, 30 min) six times at 2-week intervals. Only the affected eye was stimulated with 1.0-mA pulses in all patients. The primary endpoint was the best-corrected logMAR visual acuity. The secondary endpoints were changes in the best-corrected logMAR visual acuity, Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity, mean deviation of the Humphrey field analyzer (HFA) 10-2, and HFA Esterman test score. We also evaluated its safety.

RESULTS

The logMAR visual acuity at 12 weeks was improved by 0.1 or more in two patients and was maintained in two patients compared to the baseline. No obvious changes in the mean logMAR visual acuity, ETDRS visual acuity, mean deviation, and HFA Esterman score were observed at 12 weeks compared to the baseline. All five enrolled patients completed the study according to the protocol. No treatment-related adverse events were observed during this study.

CONCLUSION

In this study, logMAR visual acuity was slightly improved in two patients, confirming the safety of TdES. Since CRAO has no established treatment method, further research into the effects of TdES treatment in CRAO patients may be beneficial.

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.

The effect of COVID-19 pandemic and wearing face masks on ophthalmology practice: What is known so far? A narrative review

Face masks, along with other preventive measures, can help slow the spread of COVID-19. Despite the positive effect of the mask in combating the virus, it has some negative effects on the human body that must be followed up on and reduced. In this study, we discuss the impact of wearing face masks on the eye and the common issues associated with using them. The literature search was conducted using electronic databases such as PubMed and Google Scholar. Only articles published in English were included. A total of 39 relevant articles were deemed eligible. After the duplicate articles were removed, the titles and abstracts of 20 papers underwent full-text screening. The review comprised both prospective and retrospective investigations, case reports, and a series of reporting ocular symptoms following the use of face masks. The COVID-19 pandemic affected ophthalmology practices in managing patients. New factors must be considered, especially when dealing with anti-VEGF injections, such as the risk of endophthalmitis, tests and symptoms of patients with glaucoma, and the emerging symptoms associated with the COVID-19 vaccination. The use of face masks and breathing aids seemed to influence the tear film.

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.

Central Retinal Artery: A Human Fetal Cadaveric Study with Histological Correlation

The optic nerve is the second cranial nerve. It is supplied by the central retinal artery. It is said that this artery starts getting incorporated within the optic nerve at around the sixth week of gestation, and by the ninth week it is entirely inside the optic nerve. However, the point of incorporation lies in the intraorbital course of the optic nerve. The present study aimed at identifying the location of the central retinal artery inside the optic nerve, i.e. the peripheral or central position. Human fetuses of second and third trimester were dissected to expose the optic nerve. Morphometric measurements were taken and sectioned in 3 regions. These transverse sections were subjected to histological procedures. The results showed that the central retinal artery, at its entry into the optic nerve, was peripheral and inferior in 3 of 25 optic nerves and peripheral and lateral in the remaining optic nerves. However, the arteries were all centrally placed, close to the posterior pole of the eyeball. These findings are important for the ophthalmologist in identifying certain congenital anomalies of the eyeball in neonates.

Assessment of the impact of N95 respirators or surgical masks use on the retinal microvasculature

PURPOSE

To determine the possible impact of wearing N95 respirator or surgical masks on retinal vessel diameters and choroidal thickness in healthy healthcare workers.

METHODS

Diameters of peripapillary retinal arteries and veins and choroidal thickness values at the foveal center and at 1000 μm distances from the foveal center in both nasal and temporal directions were measured before mask wearing using a spectral-domain optical coherence tomography. After four hours (h) of N95 or surgical mask wearing vessel diameter and choroidal thickness measurements were repeated.

RESULTS

A total of 52 eyes from 52 participants (28 F [53.8%]; 24 M [46.2%]) were enrolled in this study. The mean age of patients was 34.58 ± 5.24 years (25-44 years). The diameters of all measured arteries [inferior temporal artery (p = 0.003), superior temporal artery (p < 0.001), inferior nasal artery (p = 0.003), and superior nasal artery (p = 0.004)] and veins,with the exception of superior nasal vein, (inferior temporal vein (p = 0.031), superior temporal vein (p = 0.027), inferior nasal vein (p < 0.001), and superior nasal vein (p = 0.063)] increased significantly after four hour use of N95 respirators and surgical maskswhen compared to baseline. There was also a significant diameter increase of the superior temporal (p < 0.001), inferior nasal veins (p < 0.001), and superior temporal artery (p = 0.037) for N95 respirators and surgical masks use, respectively. The differences in central subfoveal, temporal, and nasal choroidal thickness between baseline and after 4 h use of N95 respirators were statistically significant (From 366.73 ± 70.81 μm to 381.23 ± 69.29μm,p < 0.001 for the subfoveal; from 324.00 ± 64.13μm to 335.40 ± 61.35 μm, p = 0.007 for the temporal; from 297.40 ± 68.18 μm to 308.23 ± 74.51μm, p = 0.002 for the nasal thicknesses). Choroidal thickness values were also increased with surgical mask use. But only the increase in central subfoveal thickness was statistically significant (From 366.78 ± 71.00 μm to 372.58 ± 76.56 μm, p = 0.031 for the central subfoveal; from 297.42 ± 68.35 μmto 302.79 ± 73.05 μm, p = 0.068 for the nasal; from 324.01 ± 64.21μm to 330.33 ± 65.84, p = 0.117 for the temporal thicknesses).

CONCLUSION

With four hours use of N95 respirators or surgical face masks, retinal vessel diameters and choroidal thicknesses showed an increase in comparison to baseline measurements. Hemodynamic changes seen secondary to hypercapnia due to prolonged use of N95 respirators or surgical masks may also be observed in the retinal and choroidal circulation. Furthermore, the use of face masks should be taken into account while assessing the retinal microvasculature.

The effects of carbogen and hyperbaric oxygen treatment on fracture healing in rats

BACKGROUND

Bone fractures and fracture healing are one of the most common problems among orthopedic surgeons. In this study, we investigated the effects of hyperbaric oxygen (HBO) and carbogen (C) treatment on fracture healing in the experimental animal model.

METHODS

Twenty-four male Wistar-Albino rats were randomly divided into three groups as Group 1 (C inhalation therapy), Group 2 (HBO inhalation therapy), and Group 3 (control group), with eight rats in each group. HBO and C treatment were given to the rats in Group 1 and Group 2 1 week before the surgical procedure and 3 weeks after the surgical procedure. Following the surgical procedure, all rats were killed at the end of the 3rd week and the healing tissue in the fracture line was evaluated clinically, radiologically, and histopathologically.

RESULTS

Although there were higher histopathological, radiological, and clinical scores in the HBO and C groups in terms of frac-ture healing compared to the control group, there was no statistically significant difference between the groups.

CONCLUSION

There are many studies in the literature that examine the systemic and local effects of HBO and C treatments and show that they increase tissue oxygenation. Our study showed that HBO and C groups had no beneficial or harmful effects on fracture healing compared to the control group.

Central Retinal Artery Occlusion after Rhinoplasty Surgery: A Case Report and Literature Review

Aim

This study was aimed at reporting a case of central retinal artery occlusion (CRAO) after rhinoplasty. Case Report. Unilateral blindness occurred in a 22-year-old woman after rhinoplasty with a history of transient visual loss due to migraine aura and vasospasm. The physical examination of the patient revealed a visual acuity of no light perception in the right eye, a 4+ relative afferent pupillary defect, disc swelling, cherry-red spot in the macula, and ischemic retina in the right eye. Based on the diagnosis of CRAO, the patient underwent anterior chamber paracentesis (AC tap) along with treatment with mannitol and intravenous hydrocortisone. Visual acuity improved to 1/10 after a two-month follow-up.

Conclusion

Taking history is very important in rhinoplasty surgery, and vasoconstrictors should be limited in the patients with a suspected history of vasospasm.

Ocular ischaemia: signs, symptoms, and clinical considerations for primary eye care practitioners

Ischaemic stroke is a major disease burden as well as a leading cause of death. Early signs of ischaemic stroke can manifest in the eye, placing primary eyecare practitioners in an important position to identify patients at risk of ischaemic stroke and initiate suitable referral pathways. The vascular supply to the brain is reviewed with reference to vision including the various retinal signs and ocular symptoms associated with transient ischaemic attacks and ischaemic stroke. Using a range of clinical cases, the diverse clinical presentations of retinal embolic events, as well as other forms of vascular occlusion, are highlighted and the underlying pathophysiology is discussed. A succinct scheme for the assessment and management of ischaemic events for primary eye care practitioners is provided.

A review of the management of central retinal artery occlusion

Central retinal artery occlusion (CRAO), the ocular analog of a cerebral stroke, is an ophthalmic emergency. The visual prognosis for overall spontaneous visual recovery in CRAO is low. Furthermore, the risk of future ischemic heart disease and cerebral stroke is increased due to the underlying atherosclerotic risk factors. There is currently no guideline-endorsed treatment for CRAO. This review will describe the anatomy, pathophysiology, epidemiology, and clinical features of CRAO, and investigate the current and future management strategies.

Vision Loss Secondary to Facial and Periorbital Steroid Injection: A Systematic Review

PURPOSE

The risk of ophthalmic and retinal artery occlusions following facial and periorbital steroid injection has not been explored. This systematic review examines the prevalence, risk factors, and treatment outcomes of steroid-induced vision losses.

METHODS

A literature search in Evidence Based Medicine Reviews, MEDLINE, Embase, Pubmed, ClinicalTrials, and WHO ICTRP was performed for vision loss following facial and periorbital corticosteroid injections through July 2020.

RESULTS

Of 35 case reports, series, and reviews, 49 patients (56 eyes) with steroid-induced vision loss were analyzed. Injection sites predominantly involved the nose (45%) and periocular regions (10%). The most common type of steroid is triamcinolone (54%). Most cases were unilateral, except 7 cases of bilateral vision losses, 4 of which resulted from unilateral steroid injection. Symptoms were reported during or immediately after injections in 49% of cases. Most occlusions occurred in the ophthalmic (53%) or central retinal artery (33%). Vision most commonly presented as no light perception (37%), and 90% were 20/200 or worse. Final visual outcomes varied from 20/200 or worse (56%), 20/40 or better (30%), to in between (13%).

CONCLUSION

Most vision losses resulted from steroid injections in the nasal and periorbital area. Triamcinolone was the most common offending agent, likely due to large particle size, low solubility, and extensive particle aggregation. Dexamethasone has the opposite pharmacologic properties and has never been reported in association with vascular occlusion related vision loss. Careful steroid selection, injection techniques, and treatment strategies should be considered to prevent and treat artery occlusion.

CASE SERIES OF HYPERBARIC OXYGEN THERAPY FOR CENTRAL RETINAL ARTERY OCCLUSION

PURPOSE

To retrospectively report the outcomes of patients presenting to our facility with central retinal artery occlusion and receiving therapy with hyperbaric oxygen (HBO).

METHODS

This was a retrospective, chart review at a single hospital center. Patients with diagnosed central retinal artery occlusion were treated with HBO twice daily for 5 days during their inpatient stay for a total of 10 HBO treatments. Main outcome was change from the documented presenting best-corrected visual acuity to discharge best-corrected visual acuity. Thirty-nine patients with central retinal artery occlusion were included in the analysis during a 30-month period.

RESULTS

Twenty-eight of 39 patients (72%) had some improvement in acuity. There was a mean of 5.05 lines of improvement using a modified Snellen chart after completing their HBO treatment course. Patients treated within 12 hours of symptom onset showed the greatest improvement in their visual acuity (6.11 mean lines of improvement). Complications of therapy included middle ear barotrauma (10/39) and confinement anxiety (1/39) and did not interfere with the therapy regimen or hospital course.

CONCLUSION

This retrospective case series supports the use of emergent HBO therapy as a viable treatment option for patients with central retinal artery occlusion. Hyperbaric oxygen therapy was safely administered and well tolerated.

Thrombolysis for Central Retinal Artery Occlusion in 2020: Time Is Vision!

BACKGROUND

Acute nonarteritic central retinal artery occlusion (CRAO) is an eye stroke with poor visual prognosis and no proven effective therapies. Given advances in acute stroke care, thrombolysis in CRAO merits critical re-examination. We review the evidence for intravenous (IV) and intra-arterial (IA) tissue plasminogen activator (tPA) in CRAO management.

EVIDENCE ACQUISITION

MEDLINE, Scopus, and Cochrane online databases were systematically searched from 1960 to present, for reports of acute IV or IA therapy with alteplase or tenecteplase in nonarteritic CRAO patients. English language case reports, case series, interventional studies, or randomized controlled trials were included. The study type, age and number of subjects, the regimen administered, the time since symptoms' onset, visual outcome, and safety reports were noted.

RESULTS

Use of IV thrombolysis with alteplase was reported in 7 articles encompassing 111 patients, with 54% of them receiving IV tPA within 4.5 hours of symptom onset, and none developing symptomatic intracranial or ocular hemorrhage. Six studies described IA alteplase administration, with only 18 of a total of 134 patients (13.4%) treated within the first 6 hours after visual loss. The reported adverse events were minimal. Visual outcomes post-IV and IA thrombolysis were heterogeneously reported; however, most studies demonstrated benefit of the respective reperfusion therapies when administered very early. We found no reports of tenecteplase administration in CRAO.

CONCLUSIONS

In 2020, nonarteritic CRAO patients should theoretically receive the same thrombolytic therapies, in the same time window, as patients with acute cerebral ischemia. Eye stroke and teleeye stroke code encounters must include an expert ophthalmologic evaluation to confirm the correct diagnosis and to evaluate for ocular signs that may help guide IV tPA administration or IA management. Future research should focus on developing feasible retinal penumbra imaging studies that, similar to cerebral tissue viability or perfusion imaging, can be incorporated into the thrombolysis decision-making algorithm.

Detection of Central Retinal Artery Occlusion by Point-of-Care Ultrasound in the Emergency Department: A Case Series

Central retinal artery occlusion (CRAO) is a rare, but serious, diagnosis that can lead to blindness, most often due to thromboembolic disease. In the emergency department (ED), CRAO can present as acute, painless loss of vision. Physicians need quick ways to rule in this diagnosis due to the time-sensitive nature of the event. We describe two patients in this cases series who present to the same ED with unilateral painless vision loss and histories that include notable risk factors such as thromboembolic and atherosclerotic disease. Upon arrival, point-of-care ultrasound (POCUS) done at the bedside allowed for quick determination of CRAO. ​​​​​​​The importance of this case series is to emphasize the efficacy of POCUS in evaluating patients with painless vision loss in the ED setting. 

Clinical Manifestations and Visual Prognosis of Cilioretinal Artery Sparing Central Retinal Artery Occlusion

Purpose

To investigate the clinical manifestations and prognosis of eyes with cilioretinal artery sparing central retinal artery occlusion (CRAO).

Methods

A retrospective study was conducted on 90 eyes diagnosed with complete CRAO, including 16 cases of cilioretinal artery sparing CRAO. Clinical features, visual outcome, papillomacular bundle involvement, and remnant visual field were analyzed according to cilioretinal artery sparing.

Results

Among eyes with complete CRAO, the proportion of cilioretinal artery sparing CRAO was 17.8% (16 / 90). Mean initial best-corrected visual acuities (BCVAs) (2.04 ± 0.69 vs. 2.34 ± 0.47, p = 0.039) and final BCVAs (1.65 ± 0.87 vs. 2.22 ± 0.84, p = 0.001) were significantly better in eyes of the cilioretinal artery sparing group than the non-sparing group. The proportion with poor visual outcome (final BCVA <20 / 200) was 81.3% in the cilioretinal artery sparing group and 97.3% in the non-sparing group (p = 0.01). In sub-group analysis within cilioretinal artery sparing CRAO eyes, ischemic involvement of the papillomacular bundle at disease onset was significantly more frequent in the poor vision group (BCVA <20 / 200, 12 / 13 [92.3%]) than in the good vision group (BCVA ≥20 / 200, 1 / 3 [33.3%], p = 0.016) and it was associated with preserved central visual field.

Conclusions

Although cilioretinal artery sparing is common in CRAO and has a better prognosis than complete CRAO, the visual outcome is generally poor and only a small proportion of eyes has preserved small central visual field. Ischemic injury of the papillomacular bundle at the acute stage of CRAO correlates with poor visual outcome and could be a prognostic sign.

The actual role of thrombolytic treatment in central retinal artery occlusion

OBJECTIVE

The purpose of this study is to determine the application of thrombolytic treatment in central retinal artery occlusion (CRAO), its real benefit, safety and possible indications for treatment.

METHODS

We searched the PubMed, Cochrane and Google Scholar databases delving first into the effectiveness of the traditional treatment for CRAO, and then comparing them with new treatment strategies with intra venous or intra arterial fibrinolysis.

RESULTS

Whereas small retrospective and open-label observational trials support the use of thrombolytic therapy, multicenter randomized trials failed to demonstrate a significant visual improvement with this new strategy. Besides that, a greater risk of life threatening adverse event was observed in patients using thrombolytic treatment.

CONCLUSION

Until well-conducted clinical trials demonstrate a clear benefit of thrombolytic therapy for improving visual acuity and their benefit are weighted against the frequency and severity of adverse events, we could not recommend fibrinolysis for treating CRAO.

Central retinal artery occlusion after catheter ablation of atrial fibrillation

Central retinal artery occlusion (CRAO) is a rare but severe and urgent complication of atrial fibrillation ablation. Awareness of this ophthalmologic complication and prompt treatment are needed because ischemic damage to the retina is irreversible from 4 hours after the onset of CRAO.

The use of multimodal imaging in the evaluation of a patient with central retinal artery occlusion in the setting of asteroid hyalosis: a case report

Background

A central retinal artery occlusion (CRAO) is an ophthalmic emergency due to its strong association with cerebrovascular and cardiovascular morbidity and mortality. A timely diagnosis is necessary but difficult in the setting of dense asteroid hyalosis, as typical fundoscopic findings can be obscured. We present a case where multimodal imaging in an eye with an obscured fundus could lead to timely diagnosis and management of CRAO in a patient with acute vision loss.

Case presentation

A 94-year-old Caucasian woman with a history of exudative macular degeneration presented to the retina clinic with acute vision loss in one eye over the course of an afternoon. The patient had dense asteroid hyalosis, and a direct retinal exam was not possible. Multimodal imaging suggested a CRAO diagnosis. The patient received digital ocular massage directly prior to undergoing fluorescein angiography (FANG), which confirmed the diagnosis. The patient was transported from clinic to the emergency room for an emergency stroke workup, which revealed a spontaneous echo in the left atrial appendage, and the patient was started on antiplatelet therapy. When she presented for follow-up within a week, the patient noted that her vision had improved at the time of digital ocular massage and continued to improve thereafter. Her FANG showed marked reperfusion of the retina, and she subsequently has completely regained her baseline visual acuity.

Conclusions

Multimodal imaging is useful in evaluating visual loss in patients with acute vision loss. In addition, ocular massage is a simple, low-risk intervention that may have benefit in the treatment of acute CRAO. Patients who present to ophthalmologists with an acute CRAO need an emergency referral for evaluation of cerebrovascular and cardiovascular comorbidities.

Evaluation of the effect of n95 face mask used by healthcare professionals on choroidal thickness

PURPOSE

We aimed to show the changes in choroidal thickness (CT) with spectral domain optical coherence tomography (SD-OCT) after prolonged use of N95 mask.

METHOD

The healthcare workers who use the N95 face-mask, between 30-50 years of age who have best corrected visual acuity (BCVA) ≥10/10, spherical or cylindrical refraction errors less than 2 diopters, with normal intra ocular pressure (IOP), axial length (AL) between 22-24 mm included in the study. The choroid was imaged with enhanced depth imaging (EDI) techniques using SD-OCT. CT was measured, subfoveal, at 1000 μm nasal and temporal of the center of the fovea. Measurements were first made after wearing the N95 mask for at least 2 h without removing it and repeated 15 min after removing.

RESULTS

After 2 h of the N95 mask using without removal, the mean subfoveal CT was 293.56 ± 76.12(min:185, max:479), the mean temporal CT was 253.81 ± 63.48(min:172, max:384), the mean nasal CT was 239.18 ± 53.92(min:139, max:356). Fifteen minutes after removal of the N95 mask, the mean subfoveal CT was 250.56 ± 52.48(min:172, max:397), the mean temporal was 218.40 ± 53.58(min:129, max:354), the mean nasal CT was 210.67 ± 53.31(min:132, max:366). The differences in subfoveal, temporal and nasal CT between 2 h of N95 mask use and 15 min after removal of the mask were statistically significant (p < 0.05 for each).

CONCLUSION

Hypercapnia due to prolonged use of the N95 mask may cause choroidal hemodynamic changes and transient increased choroidal thickness.

Neuro-Ophthalmic Emergencies

Neuro-ophthalmic emergencies include optic nerve, central visual pathway, and ocular motility disorders that, if not identified and treated promptly, may lead to permanent vision loss, other significant morbidity, or mortality. This article provides a framework for approaching patients with neuro-ophthalmic symptoms and reviews the presentation, evaluation, and treatment of select emergent conditions that can cause them. Emergent causes of blurry vision, transient vision loss, papilledema, and diplopia, including giant cell arteritis, cardioembolic disease, and aggressive infection, are discussed.