Retinal Artery Research Articles

Combined simultaneous bilateral central retinal artery and vein occlusion in a patient with lymphoma of the pancreatic head

Combined occlusion of retinal artery and vein is a rare event, and its occurrence in both eyes concurrently in a young patient is an even rare phenomenon. We report such a case in which a 45-year-old female presented with sudden loss of vision, 2 weeks following the third cycle of chemotherapy. Fundus findings and investigations pointed toward combined bilateral simultaneous retinal artery and vein occlusion. Vision did not improve despite treatment. To our knowledge, this extreme presentation of total occlusive disease and its association with lymphoma of the pancreas is the first to be reported in the literature. This case highlights the prothrombotic state induced by pancreatic malignancy and warrants periodic monitoring in such patients.

Retrospective Cohort Study of Sickle Cell Disease and Large Vessel Retinal Vascular Occlusion Risk in a National United States Database

To determine if differences exist in the risk of developing large vessel retinal vascular occlusions in patients with sickle cell states. Retrospective cohort study. Patients with sickle cell disease or trait evaluated by an ophthalmologist were compared to matched controls without sickle cell disease or trait also evaluated by an ophthalmologist. This study used deidentified data from a national database (2006-2024), using International Classification of Diseases 10 codes to select for retinal vascular occlusions. Propensity score matching was performed with respect to age, sex, race, ethnicity, smoking, hypertension, diabetes, dyslipidemias, and obesity, resulting in HbSS, HbSC, and sickle cell trait (SCT) cohorts and matched control cohorts. Risk ratios and 95% confidence intervals (CI) of retinal vascular occlusion diagnosis, including central retinal artery occlusion (CRAO), branch retinal artery occlusion (BRAO), central retinal venous occlusion (CRVO), branch retinal venous occlusion (BRVO), and corneal dystrophy as a negative control, given sickle cell disease or trait. After propensity score matching, HbSS (n=10,802, mean ± standard deviation age of 38.6 ± 20.6 years), HbSC (n=4,296, 34.3 ± 17.8 years), and SCT (n=15,249, 39.8 ± 23.7 years) cohorts were compared to control cohorts (n=10,802, 38.7 ± 20.7 years; n=4,296, 34.6 ± 18.0 years; n=15,249, 39.9 ± 23.8 years, respectively). Patients with sickle cell disease (HbSS) had higher risk of developing any retinal vascular occlusion (RR 2.33; 95% CI 1.82-3.00), CRAO (RR 2.71; 95% CI 1.65-4.47) and BRAO (RR 4.90; 95% CI 2.48-9.67) than matched controls. Patients with HbSC disease had higher risk (RR 3.14; 95% CI 1.95-5.06) of developing any retinal vascular occlusion than matched controls without sickle cell disease. Patients with sickle cell trait did not have higher risk of developing retinal vascular occlusions (RR 1.01; 95% CI 0.81-1.26) than matched controls. In a retrospective cohort study, patients with HbSS sickle cell disease have an increased risk of developing retinal vascular occlusions, and more specifically CRAO and BRAO compared to patients without sickle cell disease.

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.].

Hyaluronic acid induced blindness and orbital ischemic syndrome: a case report

The incidence of filler-induced blindness is unknown due to the few reported cases in the literature, nevertheless, it represents a devastating complication. There is no effective treatment for the filler-induced blindness and ophthalmoplegia. However, retrobulbar hyaluronidase treatment has been used with some apparent beneficial results. We report a case of a 29-year-old female patient who presented with right eye blindness, ophthalmoplegia, and ptosis secondary to dorso-nasal hyaluronic acid injection as a cosmetic treatment. She was treated immediately with intravenous corticosteroids and dorso-nasal and retrobulbar hyaluronidase in an outpatient clinic. After 6 days, the patient was admitted to our institution with a clinical diagnosis of ptosis, ophthalmoplegia, ischemic ocular syndrome, and ophthalmic and central retinal artery occlusion in her right eye. The ptosis and eye movements improved on her follow-up, but the vision loss was permanent due to severe optic nerve and retinal ischemia. Brain MRI ruled out central nervous system involvement.

WITHDRAWN: LSAC-Net: A lightweight scale-aware CNN with densely connected focal modulation for retinal blood vessel segmentation

The diagnosis of sight-threatening eye conditions typically involves segmenting retinal structures in fundus images. The segmentation process enables clinicians to identify alterations in retinal morphology, facilitating the detection and diagnosis of various eye diseases. Despite recent developments in image processing, current approaches often fail to partition delicate arteries precisely. Although deep learning has great potential for segmenting medical images, the accuracy of the segmentation process may be limited due to its dependence on repetitive convolution and pooling processes, which may impair the representation of edge information. In this study, we present LSAC-Net, a pixel-level convolutional neural network (CNN) designed specifically for retinal vessel segmentation. Moreover, it is lightweight, with only 37.5 K learnable parameters. LSAC-Net integrates a unique scale-aware feature extraction block (SAFEB) and a densely connected focal modulation block (DCFMB) to improve segmentation accuracy. In addition, careful selection of filter numbers to avoid overlap effectively shortens training times and boosts computational performance, both of which improve overall model efficiency. We performed extensive tests on different aspects of retinal images to evaluate the robustness and generalizability of LSAC-Net. In particular, a thorough evaluation of the model's precision in retinal artery segmentation, a crucial task for ophthalmological diagnosis and treatment, was carried out. We evaluated the performance and efficacy of LSAC-Net with a particular focus on RBV. The model obtains 98.65% specificity, 97.54% accuracy, and 98.88% area under the curve surpassing existing approaches. Experimental results confirm that LSAC-Net is robust, generalizable, and maintains a high level of segmentation accuracy. These features highlight LSAC-Net's potential as a useful instrument for accurate and timely retinal image segmentation in a variety of therapeutic contexts.

Survey comparing the treatment of central retinal artery occlusion with hyperbaric oxygen in Australia and New Zealand with the recommended guidelines as outlined by the Undersea and Hyperbaric Medical Society.

Central retinal artery occlusion (CRAO) presents suddenly causing painless loss of vision that is often significant. Meaningful improvement in vision occurs in only 8% of patients with spontaneous reperfusion. Hyperbaric oxygen treatment (HBOT) is considered to be of benefit if commenced before retinal infarction occurs. The Undersea and Hyperbaric Medical Society (UHMS) guidelines on the management of CRAO were last amended in 2019. This survey questioned Australian and New Zealand (ANZ) hyperbaric medicine units (HMUs) about the incidence of CRAO cases referred and compared their subsequent management against the UHMS guidelines. An anonymous survey via SurveyMonkey® was sent to all 12 ANZ HMUs that treat emergency indications, allowing for multiple choice and free text answers regarding their management of CRAO. One-hundred and forty-six cases of CRAO were treated in ANZ HMUs over the last five years. Most (101/146) cases (69%) were initially treated at a pressure of 284 kPa. This was the area of greatest difference noted in CRAO management between the UHMS guidelines and ANZ practice. Few ANZ HMUs strictly followed the UHMS guidelines. We suggest a more simplified management protocol as used by the majority of ANZ HMUs.

Susac syndrome: ophthalmological and auditory manifestations in a patient with headache: case report

IntroductionThe first case reports of Susac Syndrome emerged in 1979 due to two young female patients presenting with the clinical triad of multifocal encephalopathy, occlusion of the central retinal artery branch, and sensorineural hearing loss, as well as histopathological findings of microinfarctions in the gray and white matter of the brain. The clinical features of the syndrome have been documented in approximately 500 cases published worldwide, making it extremely rare. Headache is a prominent complaint by patients with Susac syndrome. Its pathophysiology remains unknown, with immune and genetic factors being most related to the retino-cochleo-cerebral clinical manifestations. Since its first description, the scientific community has been paying greater attention to the syndrome, especially with advances in medical technology and the availability of complementary exams.Case reportIn this study, We present a case report of a woman experiencing progressive pulsatile temporal headaches for two years, associated with decreased visual acuity for three months and simultaneous hypoacusis on the left, who was incorrectly diagnosed and treated for multiple sclerosis.CommentThe literature review discusses Susac Syndrome and its microvascular complications, highlighting the multidisciplinary approach necessary for accurate diagnosis and comprehensive long-term management.

Early REperfusion therapy with intravenous alteplase for recovery of VISION in acute central retinal artery occlusion (REVISION): Study protocol of a phase III trial.

Meta-analyses of case series of non-arteritic central retinal artery occlusion (CRAO) indicate beneficial effects of intravenous thrombolysis when initiated early after symptom onset. Randomized data are lacking to address this question. The REperfusion therapy with intravenous alteplase for recovery of VISION in acute central retinal artery occlusion (REVISION) investigates intravenous alteplase within 4.5 h of monocular vision loss due to acute CRAO. This study is the randomized (1:1), double-blind, placebo-controlled, multicenter adaptive phase III trial. Primary outcome is functional recovery to normal or mildly impaired vision in the affected eye defined as best-corrected visual acuity of the Logarithm of the Minimum Angle of Resolution of 0.5 or less at 30 days (intention-to-treat analysis). Secondary efficacy outcomes include modified Rankin Score at 90 days and quality of life. Safety outcomes include symptomatic intracranial hemorrhage, major bleeding (International Society on Thrombosis and Haemostasis definition) and mortality. Exploratory analyses of optical coherence tomography/angiography, ultrasound and magnetic resonance imaging (MRI) biomarkers will be conducted. Using an adaptive design with interim analysis at 120 patients, up to 422 participants (211 per arm) would be needed for 80% power (one-sided alpha = 0.025) to detect a difference of 15%, assuming functional recovery rates of 10% in the placebo arm and 25% in the alteplase arm. By enrolling patients within 4.5 h of CRAO onset, REVISION uses insights from meta-analyses of CRAO case series and randomized thrombolysis trials in acute ischemic stroke. Increased rates of early reperfusion and good neurological outcomes in stroke may translate to CRAO with its similar pathophysiology. ClinicalTrials.gov: NCT04965038; EU Trial Number: 2023-507388-21-00.

Myelin Oligodendrocyte Glycoprotein-Associated Disease Optic Neuritis With Concurrent Combined Central Retinal Artery and Vein Occlusion.

Myelin Oligodendrocyte Glycoprotein-Associated Disease Optic Neuritis With Concurrent Combined Central Retinal Artery and Vein Occlusion.

Central Retinal Artery Occlusion Associated with Takayasu Arteritis.

Takayasu arteritis is a chronic inflammatory vasculitis with granulomatous panarteritis particularly impacting large vessels including the aorta and its branches, especially the subclavian arteries, with clinical manifestation dependent on the involved artery. Sequelae of the active disease vary, including stenosis, occlusions, or aneurysmal dilatations of the large vessels. The prevalence of Takayasu arteritis is higher in the Asian population and in Japan, but quite low in the United States, varying from 0.9-8.4 per million people. Ocular manifestations are rare and lead to a delay in diagnosis and appropriate treatment. Ocular manifestations include Takayasu retinopathy, anterior ischemic optic neuropathy (AION), retinal artery occlusion (RAO) and retinal vein occlusion (RVO). We present two cases in which central retinal artery occlusion (CRAO) was associated with Takayasu arteritis. CRAO is an ophthalmic emergency with an incidence of 1.9 per 100,000 person years in the United States; only 5% of cases are arteritic, which can be observed with inflammatory vasculitides secondary to the formation of immune deposits.

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.

Spontaneous brain activity in patients with central retinal artery occlusion: a resting-state functional MRI study using machine learning.

Central retinal artery occlusion (CRAO) is a serious eye condition that poses a risk to vision, resulting from the blockage of the central retinal artery. Because of the anatomical connection between the ocular artery, which derives from the internal carotid artery, and the anterior middle cerebral artery, hemodynamic alterations and sudden vision loss associated with CRAO may impact brain functionality. This study aimed to examine alterations in spontaneous neural activity among patients with CRAO by resting-state functional MRI. In addition, we selected the amplitude of low-frequency fluctuation (ALFF) and fractional amplitude of low-frequency fluctuation (fALFF) values as classification features for distinguishing CRAO from healthy controls (HCs) using a support vector machine classifier. A total of 18 patients diagnosed with CRAO and 18 HCs participated in the study. Resting-state brain function images and structural images were acquired from both groups. Aberrant changes in spontaneous brain functional activity among CRAO patients were investigated utilizing ALFF and fALFF analysis methods. Group differences in ALFF/fALFF values were assessed through a two-sample t-test. Subsequently, a machine learning classifier was developed to evaluate the clinical diagnostic potential of ALFF and fALFF values. In comparison to HCs, individuals with CRAO exhibited significantly higher ALFF values in the left cerebellum_6, vermis_7, left superior frontal gyrus, and left inferior frontal gyrus, triangular part. Conversely, the CRAO group displayed notably lower ALFF values in the left precuneus and left median cingulum gyri. Furthermore, higher fALFF values were observed in the left inferior frontal gyrus, triangular part, whereas lower fALFF values were noted in the right cerebellum_Crus2, left precuneus, right angular gyrus, left angular gyrus, right supramarginal gyrus, right superior parietal gyrus, and left precuneus. Utilizing the ALFF/fALFF values, the receiver operating characteristic curves (area under the curve) yielded 0.99 and 0.94 through machine learning analysis techniques. CRAO patients exhibit atypical neural activity in the brain, characterized by ALFF and fALFF values predominantly localized in the frontal, parietal, and cerebellar regions, which are closely linked to visual cognition and motor control impairments. Furthermore, ALFF and fALFF could serve as potential neuroimaging markers beyond the orbit among CRAO.

Efficacy and safety of hyperbaric oxygen therapy monitored by fluorescein angiography in patients with retinal artery occlusion

AimsTo assess the efficacy and safety of a standardised hyperbaric oxygen therapy protocol (HBOT) monitored by fluorescein angiography (FA) in patients with retinal artery occlusion (RAO).MethodsIt is a prospective, non-comparative,...

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

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

Optical coherence tomography angiography features of retinal artery occlusion: A case series

Optical coherence tomography angiography features of retinal artery occlusion: A case series

VESCL: an open source 2D vessel contouring library.

VESCL (pronounced 'vessel') is a novel vessel contouring library for computer-assisted 2D vessel contouring and segmentation. VESCL facilitates manual vessel segmentation in 2D medical images to generate gold-standard datasets for training, testing, and validating automatic vessel segmentation. VESCL is an open-source C++ library designed for easy integration into medical image processing systems. VESCL provides an intuitive interface for drawing variable-width parametric curves along vessels in 2D images. It includes highly optimized localized filtering to automatically fit drawn curves to the nearest vessel centerline and automatically determine the varying vessel width along each curve. To support a variety of segmentation paradigms, VESCL can export multiple segmentation representations including binary segmentations, occupancy maps, and distance fields. VESCL provides sub-pixel resolution for vessel centerlines and vessel widths. It is optimized to segment small vessels with single- or sub-pixel widths that are visible to the human eye but hard to segment automatically via conventional filters. When tested on neurovascular digital subtraction angiography (DSA), VESCL's intuitive hand-drawn input with automatic curve fitting increased the speed of fully manual segmentation by 22× over conventional methods and by 3× over the best publicly available computer-assisted manual segmentation method. Accuracy was shown to be within the range of inter-operator variability of gold standard manually segmented data from a publicly available dataset of neurovascular DSA images as measured using Dice scores. Preliminary tests showed similar improvements for segmenting DSA of coronary arteries and RGB images of retinal arteries. VESCL is an open-source C++ library for contouring vessels in 2D images which can be used to reduce the tedious, labor-intensive process of manually generating gold-standard segmentations for training, testing, and comparing automatic segmentation methods.

Central retinal artery occlusion or retinal stroke: a neurosonologist's perspective.

In central retinal artery occlusion (CRAO) or retinal stroke, which is usually a vision-threatening condition, timely diagnosis is imperative to improve the chances of retinal preservation and to establish adequate secondary prevention measures. Even though retinal strokes have been traditionally assigned to the field of ophthalmology, while considering reperfusion therapy as the only way to avoid permanent vision loss, we suggest prompt evaluation of CRAO causes (primarily related to cardiovascular risk factors) performed by a well-organized interdisciplinary team (ophthalmologist and neurologist) in a neurovascular center with stroke expertise. Therefore, the most suitable adjunct method for rapidly diagnosing non-arteritic CRAO could be target transorbital ultrasound, performed by an experienced neurologist/neurosonologist in the stroke unit. Consequently, after an ophthalmological assessment, a final decision on thrombolytic therapy could be made. We accept that further research is obviously needed to determine whether transorbital ultrasound could replace ophthalmological investigation in the case of a suspected acute retinal stroke. We assert that retinal stroke requires interdisciplinary treatment in cooperation with neurologists and ophthalmologists, with an additive value for each to achieve the best results for the patient.

Unilateral Vision Loss after Posterior Fixation for Traumatic Atlantoaxial Dislocation: A Case Report with Literature Review

AbstractPostoperative vision loss following spine surgery is a rare and devastating complication with variable incidence. Various risk factors have been identified in the literature. A 16-year-old male presented with neck pain, spastic quadriparesis, and tingling paraesthesia in the left upper limb for the past 3 years. Radiological workup was suggestive of atlantoaxial dislocation with occipitalization of the posterior arch of the atlas (C1). The patient was prone to a horseshoe headrest and underwent occipito-C2-C3 fixation by removing the posterior rim of foramen magnum. Postoperatively, the patient complained of loss of vision in the right eye. Ophthalmology evaluation revealed a loss of perception of light in the right eye due to central retinal artery occlusion. An injectable steroid was started, but there was no improvement in vision in the involved eye. Proper head positioning and avoidance of intraoperative hypotension are modifiable factors to avoid such devastating complications.

Prevalence and Distribution of Macular Fluid with Central Retinal Artery Occlusion and Anterior Ischemic Optic Neuropathy [Letter

Prevalence and Distribution of Macular Fluid with Central Retinal Artery Occlusion and Anterior Ischemic Optic Neuropathy [Letter

Prevalence and Distribution of Macular Fluid with Central Retinal Artery Occlusion and Anterior Ischaemic Optic Neuropathy [Response to Letter

Prevalence and Distribution of Macular Fluid with Central Retinal Artery Occlusion and Anterior Ischaemic Optic Neuropathy [Response to Letter