Acute retinal arterial occlusive disorders

Airborne fine particulate matter (PM2.5) damages the inner blood-retinal barrier by inducing inflammation and ferroptosis in retinal vascular endothelial cells

This study was the first to explore the effect of airborne fine particulate matter (PM_2.5) exposure on the inner blood-retinal barrier (iBRB). In this study, retinal vascular permeability and diameter were enhanced in the PM_2.5-exposed animal model (1 mg/mL PM_2.5, 10 μL per eye, 4 times per day, 3 days), together with observable retinal edema and increased inflammation level in retina. PM_2.5-induced cell damage in human retinal microvascular endothelial cells (HRMECs) occurred in a time- and dose-dependent manner. Decreased cell viability, proliferation, migration, and angiogenesis, as well as increased apoptosis and inflammation, were observed. Iron overload and excessive lipid oxidation were also discovered after PM_2.5 exposure (25, 50, and 100 μg/mL PM_2.5 for 24 h), along with significantly altered expression of ferroptosis-related genes, such as prostaglandin-endoperoxide synthase 2, glutathione peroxidase 4, and ferritin heavy chain 1. Moreover, Ferrostatin-1, an inhibitor of ferroptosis, evidently alleviated the PM_2.5-induced cytotoxicity of HRMECs. The present study investigated the in vivo effects of PM_2.5 on retinas, revealing that PM_2.5 exposure induced retinal inflammation, vascular dilatation, and caused damage to the iBRB. The crucial role of ferroptosis was discovered during PM_2.5-induced HRMEC cytotoxicity and dysfunction, indicating a potential precautionary target in air pollution-associated retinal vascular diseases.

Bridging a Century-Old Problem: The Pathophysiology and Molecular Mechanisms of HA Filler-Induced Vascular Occlusion (FIVO)—Implications for Therapeutic Interventions

Biocompatible hyaluronic acid (HA, hyaluronan) gel implants have altered the therapeutic landscape of surgery and medicine, fostering an array of innovative products that include viscosurgical aids, synovial supplements, and drug-eluting nanomaterials. However, it is perhaps the explosive growth in the cosmetic applications of injectable dermal fillers that has captured the brightest spotlight, emerging as the dominant modality in plastic surgery and aesthetic medicine. The popularity surge with which injectable HA fillers have risen to in vogue status has also brought a concomitant increase in the incidence of once-rare iatrogenic vaso-occlusive injuries ranging from disfiguring facial skin necrosis to disabling neuro-ophthalmological sequelae. As our understanding of the pathophysiology of these injuries has evolved, supplemented by more than a century of astute observations, the formulation of novel therapeutic and preventative strategies has permitted the amelioration of this burdensome complication. In this special issue article, we review the relevant mechanisms underlying HA filler-induced vascular occlusion (FIVO), with particular emphasis on the rheo-mechanical aspects of vascular blockade; the thromboembolic potential of HA mixtures; and the tissue-specific ischemic susceptibility of microvascular networks, which leads to underperfusion, hypoxia, and ultimate injury. In addition, recent therapeutic advances and novel considerations on the prevention and management of muco-cutaneous and neuro-ophthalmological complications are examined.

Giant Cell Arteritis Presenting With Ocular Symptoms: Clinical Characteristics and Multimodal Imaging in a Chinese Case Series

Purpose

To evaluate demographic and clinical characteristics of a Chinese population with giant cell arteritis using multimodal imaging focusing on ophthalmic examinations.

Design

Retrospective observational case series.

Materials and Methods

In the neuro-ophthalmology division of the Eye, Ear, Nose, and Throat Hospital, Shanghai, we evaluated the demographic and clinical characteristics of patients diagnosed with giant cell arteritis between January 2016 and June 2021. Results of routine ophthalmic examinations including fundus examination, optical coherence tomography, color duplex ultrasonography of ocular and superficial temporal arteries, orbital magnetic resonance imaging, and superficial temporal artery biopsy were evaluated.

Results

A total of 15 patients (22 eyes; ten male and five female) were evaluated with a mean age of 77.0 ± 8.5 years. Among them, seven had bilateral involvement that occurred simultaneously or sequentially. Twelve patients presented with arteritic anterior ischemic optic neuropathy, two with arteritic anterior ischemic optic neuropathy combined with cilioretinal artery occlusion, and one with cotton-wool spots. In acute stages of optic neuropathy and retinopathy, optical coherence tomography revealed optic disc edema, thickening of the inner retinal nerve fiber layer and ganglion cell layer, and loss of layer structure. In late stages, optical coherence tomography revealed diffuse atrophy of the inner retina. The “halo” sign was observed in 12 patients in the superficial temporal artery ultrasound, and seven out of eight patients who underwent biopsy demonstrated classic giant cell arteritis pathological changes. Most patients having poor visual acuity but ability to perceive light; 10/22 eyes had permanent vision loss.

Conclusion

Although rare in Asians, giant cell arteritis may be underdiagnosed among elderly Chinese patients presenting with anterior ischemic optic neuropathy. Non-invasive superficial temporal artery ultrasound detecting inflammatory thickening of the intima as the “halo” sign combined with routine elevated erythrocyte sedimentation rate and C-reactive protein may be helpful in diagnosing patients with a high probability of having giant cell arteritis.

Macular Vascular Imaging and Connectivity Analysis Using High-Resolution Optical Coherence Tomography

Purpose

To characterize macular blood flow connectivity in vivo using high-resolution optical coherence tomography (HighRes OCT).

Methods

Cross-sectional, observational study. Dense (6-µm interscan distance) perifoveal HighRes OCT raster scans were performed on healthy participants. To mitigate the limitations of projection-resolved OCT-angiography, flow and structural data were used to observe the vascular structures of the superficial vascular complex (SVC) and the deep vascular complex. Vascular segmentation and rendering were performed using Imaris 9.5 software. Inflow and outflow patterns were classified according to vascular diameter and branching order from superficial arteries and veins, respectively.

Results

Eight eyes from eight participants were included in this analysis, from which 422 inflow and 459 outflow connections were characterized. Arteries had direct arteriolar connections to the SVC (78%) and to the intermediate capillary plexus (ICP, 22%). Deep capillary plexus (DCP) inflow derived from small-diameter vessels succeeding ICP arterioles. The most prevalent outflow pathways coursed through superficial draining venules (74%). DCP draining venules ordinarily merged with ICP draining venules and drained independently of superficial venules in 21% of cases. The morphology of DCP draining venules in structural HighRes OCT is distinct from other vessels crossing the inner nuclear layer and can be used to identify superficial veins.

Conclusions

Vascular connectivity analysis supports a hybrid circuitry of blood flow within the human parafoveal macula.

Translational Relevance

Characterization of parafoveal macular blood flow connectivity in vivo using a precise segmentation of HighRes OCT is consistent with ground-truth microscopy studies and shows a hybrid circuitry.

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

Background

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

Methods

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

Results

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

Conclusion

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

Overview of the retina and imaging in patients with severe acute respiratory syndrome coronavirus 2

INTRODUCTION

The role of the human eye in severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) is still under investigation. The pathophysiology of the ocular findings is arduous when dealing with critically ill Covid-19 patients with comorbidities. Multiorgan involvement and the effects of inflammation, infection and systemic treatment on the retina are complex, and comparison of studies is difficult. Most studies in human patients have investigated the anterior segment, whereas few reports deal with the posterior segment of the eye. The present review aims to evaluate the retinal manifestations and imaging features in COVID-19 patients.

METHODS

Studies on the retinal manifestations and retinal imaging in COVID-19 patients published through June 2021 were reviewed. We included cross-sectional and case-control studies, case series, case reports and correspondence in the analysis.

RESULTS

Flame-shaped hemorrhages, cotton wool spots, augmented diameter and tortuosity of retinal vessels were found on funduscopic examination. Peripapillary, macular retinal nerve fiber layer and ganglion cell layer thickness alterations were reported on spectral domain optical coherence tomography. Reduced vessel density of the superficial and deep retinal capillary plexus on optical coherence tomography angiography was reported.

CONCLUSIONS

Retinal complications may arise in COVID-19 patients. Although no consensus on presentation is currently available, retinal funduscopy and imaging has shown neuronal and vascular alterations. Systemic neurological complications and microangiopathy are associated with SARS-COV-2; thus, as the retina has a neuronal and vascular component, funduscopy and retinal imaging on COVID-19 patients can provide further insight to SARS-COV-2 disease and the follow-up of patients.

Early menopause is associated with increased risk of retinal vascular occlusions: a nationwide cohort study

This nationwide population-based cohort study evaluated the association between female reproductive factors and the incidence of retinal vein occlusion (RVO) and retinal artery occlusion (RAO) using data provided by the Korea National Health Insurance Service. A total of 2,289,347 postmenopausal women over 50 years of age who participated in both national health screening and cancer screening in 2013 or 2014 were included. Data on female reproductive factors, including age at menarche, age at menopause, parity, history of hormone replacement therapy, and oral contraceptive pill usage, were collected. Patients were followed up until December 2018, and incident cases of RVO and RAO were identified using registered diagnostic codes from claim data. During an average follow-up period of 4.90 years, 7461 and 1603 patients were newly diagnosed with RVO and RAO, respectively. In the multivariable-adjusted Cox proportional hazard model, patients who experienced menopause after 55 years of age had a lower risk of RVO and RAO development compared to those who had menopause before 45 years of age, with a hazard ratio (95% confidence interval) of 0.83 (0.76–0.95) for RVO and 0.80 (0.66‒0.98) for RAO. In conclusion, early menopause was an independent risk factor for future development of RVO and RAO.

Retinal Manifestations in Patients with COVID-19: A Prospective Cohort Study

The recent outbreak of the Coronavirus SARS-CoV-2 has been declared a worldwide pandemic. Within various multi-organ involvement, several ocular manifestations have been described, such as conjunctivitis and retinopathy. The prevalence and severity of retinal lesions and their relation to the severity of the systemic disease are unknown. We performed a prospective, observational study on 172 consecutively hospitalized patients with acute confirmed COVID-19 infection. All patients underwent screening widefield fundus photography at the time of hospital admission. Despite no ocular or vision-related symptoms, we found cotton wool spots (CWS) and/or hemorrhages in 19/172 patients (11%). Diabetes history, overweight, and elevated C-reactive protein were more frequently observed among patients with retinal abnormalities, while a history of systemic hypertension was more frequently observed among patients without retinal findings. At a 3-month follow-up visit, CWS had subsided in all patients.

Paracentral Acute Middle Maculopathy Associated With Anterior Ischemic Optic Neuropathy and Cilioretinal Artery Occlusion in Giant Cell Arteritis

ABSTRACT

Paracentral acute middle maculopathy (PAMM) is a relatively new optical coherence tomography finding, defined by hyperreflectivity in the inner nuclear layer. In this article, we present a case of a 73-year-old woman who presented with transient vision loss followed by the sudden onset of complete vision loss to counting fingers at 1 foot for one day in the left eye. Dilated examination showed a right cotton wool spot, left pallid optic disc edema, and retinal edema in the distribution of the cilioretinal artery. OCT demonstrated hyperreflective band at the level of the inner nuclear layer, compatible with PAMM. Clinical and laboratory findings were consistent with GCA, for which she was prescribed high-dose oral prednisone, with confirmation of GCA on a subsequent temporal artery biopsy. PAMM may be seen in the context of GCA, and OCT of the macula serves as an important adjunct to define the retinal manifestations of this condition.

High-density Lipoprotein Cholesterol and the Risk of Future Retinal Artery Occlusion Development: A Nationwide Cohort Study

PURPOSE

To evaluate the association between high-density lipoprotein (HDL) cholesterol levels and the future risk of retinal artery occlusion (RAO).

DESIGN

Population-based cohort study.

METHODS

This study used data provided by the Korean National Health Insurance Service. A total of 9,316,212 individuals aged > 40 years who participated in the Korean National Health Screening Program in 2013 or 2014 were included. Data on risk factors - including age, sex, income level, systemic comorbidities, behavioral factors, and baseline lipid profiles - were collected from health screening results and claims data. Patients were followed up until December 2018 and incident cases of RAO were identified using registered diagnostic codes from claims data. A prospective association between HDL cholesterol level and incident RAO was investigated using the multivariable-adjusted Cox proportional hazard model.

RESULTS

During an average follow-up period of 4.93 years, 9878 patients were newly diagnosed with RAO. Compared with those with low HDL cholesterol levels (< 40 mg/dL), patients with high HDL cholesterol levels (≥ 60 mg/dL) had a lower risk of future RAO development, with a hazard ratio (95% CI) of 0.78 (0.73-0.83) in the age-adjusted and sex-adjusted model and 0.88 (0.83-0.95) in the full-adjusted model. The younger subgroup (< 60 years) had an HR of 0.81 in the high HDL cholesterol group compared with the low HDL cholesterol group, while the older subgroup (≥ 60 years) had an HR of 0.93 (P for interaction = .012).

CONCLUSION

A low HDL cholesterol level is an independent risk factor for the development of RAO.

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.

Unexplained arterial thrombosis: approach to diagnosis and treatment

Arterial thrombotic events in younger patients without a readily apparent etiology present significant diagnostic and management challenges. We present a structured approach to diagnosis with consideration of common causes, including atherosclerosis and embolism, as well as uncommon causes, including medications and substances, vascular and anatomic abnormalities, systemic disorders, and thrombophilias. We highlight areas of management that have evolved within the past 5 years, including the use of dual-pathway inhibition in atherosclerotic disease, antithrombotic therapy selection in embolic stroke of undetermined source and left ventricular thrombus, the role of closure of patent foramen ovale for secondary stroke prevention, and the thrombotic potential of coronavirus disease 2019 infection and vaccination. We conclude with a representative case to illustrate the application of the diagnostic framework and discuss the importance of consideration of bleeding risk and patient preference in determining the appropriate management plan.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Frequency of Carotid Intraplaque Hemorrhage on Vessel Wall Imaging in Patients With Retinal Artery Occlusion: A Cross-Sectional Prevalence Study

BACKGROUND

Intraplaque hemorrhage (IPH) in a carotid artery plaque viewed on vessel wall imaging has been shown to be associated with ischemic stroke. Whether such an association between carotid IPH and retinal artery occlusion (RAO) exists remains unknown.

METHODS

This was a cross-sectional prevalence study. Medical and imaging records of all patients who underwent neck MRA with plaque imaging sequences at our institution from 2015 to 2020 were retrospectively reviewed. Fourteen patients with confirmed RAO and plaque imaging performed within 6 weeks of presentation were included. A group of 211 patients without a prior ischemic event (RAO, stroke, etc.) with plaque imaging were used as controls. A single artery from control patients was randomly selected. The prevalence of IPH and degree of ipsilateral carotid stenosis were compared between RAO and control patients. Multiple regression analysis was performed to determine independent associations between variables and RAO.

RESULTS

Five patients (35.7%) with RAO had imaging evidence of ipsilateral IPH in contrast to 7 of 211 (3.3%) patients in the control group (odds ratio [OR]: 16.2, 95% confidence interval [95% CI]: 4.3-61.1, P = 0.0002). Of the 5 patients with RAO and ipsilateral IPH, only one (20.0%) was found to ipsilateral carotid stenosis greater than 70%. Carotid IPH was the only variable that was independently associated with RAO (OR: 12.6, 95% CI = 2.2-73.6, P = 0.005).

CONCLUSIONS

Carotid IPH is independently associated with RAO. The use of plaque imaging in the evaluation of patients with acute RAO is therefore supported.

Vitrectomy and manipulation of intraocular and arterial pressures for the treatment of nonarteritic central retinal artery occlusion

The purpose of this study is to describe a surgical technique and report the functional outcome of treating nonarteritic central retinal artery occlusion (CRAO) in 2 eyes of two consecutive male patients. Two males (A) and (B) presented 6 days and few hours, respectively, after symptom onset with the clinical features typical of CRAO, including sudden severe deterioration of vision to counting fingers and a cherry-red spot in the left and right fovea, respectively. While A had been on recent treatment for hypertension and hyperlipidemia, B had no significant medical history. Both patients underwent surgery, A, 9 days, and B, <15 h after symptom onset. Surgery involved a vitrectomy, lowering of intraocular pressure (<3 mmHg), and gradual increase of arterial pressure to 165/100 mmHg (through the slow injection of intravenous adrenaline). Intraoperatively, this resulted in immediate perfusion and visible dilation of the blood-filled central retinal artery (CRA) and retinal arteriolar network and dilatation of the central retinal vein. The final vision settled to 6/60 in A and 6/36+1 in B. Although preoperative macular infarction persisted in both eyes as demonstrated by optical coherence tomography angiography, both patients claim a convincing subjective visual benefit. The procedure appeared to have positively changed the natural history of the disease in both eyes. Vitrectomy with the manipulation of intraocular and arterial pressures significantly increases ocular perfusion along the entire CRA, which can dislodge CRA thrombo-emboli and has the potential to restore retinal perfusion and improve visual outcome if undertaken before irreversible retina damage. This is a relatively straightforward technique and should join the list of surgical techniques for treating CRAO.

Retinal diffusion restrictions in acute branch retinal arteriolar occlusion

This study sought to investigate the occurrence of retinal diffusion restrictions (RDR) in branch retinal arteriolar occlusion (BRAO) using standard brain diffusion-weighted imaging (DWI). Two radiologists assessed DWI MRI scans of BRAO patients for RDR in a retrospective cohort study. Inter- and intrarater reliability were calculated using Kappa statistics. Detection rates of RDR were compared among MRI scans with varying field strength, sequence type and onset-to-DWI time intervals. 85 BRAO patients (63.1 ± 16.5 years) and 89 DWI scans were evaluated. Overall sensitivity of RDR in BRAO was 46.1% with visually correlating low ADC signal in 56.1% of cases. Localization of RDR matched distribution of fundoscopic retinal edema in 85% of patients. Inter- and intra-rater agreement for RDR in BRAO was κ_inter = 0.64 (95% CI 0.48–0.80) and κ_intra = 0.87 (95% CI 0.76–0.96), respectively. RDR detection rate tended to be higher for 3T, when compared to 1.5T MRI scans (53.7% vs. 34.3%%; p = 0.07). RDR were identified within 24 h up to 2 weeks after onset of visual impairment. RDR in BRAO can be observed by means of standard stroke DWI in a substantial proportion of cases, although sensitivity and interrater reliability were lower than previously reported for complete central retinal artery occlusion.

A Vision-Saving Straw in a Retinitis Pigmentosa Patient

We report a case of binocular retinitis pigmentosa (RP) with completely different visual acuity between 2 eyes, which may be contributed by the presence of cilioretinal arteries (CRAs) in 1 eye. A 66-year-old female patient complained of blurred vision after binocular cataract surgeries. Examinations revealed her right eye had 20/25 central visual acuity, but the fellow eye only had light perception. Subsequent fundus photography of both eyes firmed the diagnosis of binocular RP. However, there were some significant differences in retinal vessels, which were attenuated in her left eye in contrast to several spared retinal arterioles in the right eye. Optical coherence tomography angiography showed that the spared vessels might be CRAs. Our case provides an evidence that macular blood flow may contribute to the survival of cone cells in RP.

Cerebral angiographic features of central retinal artery occlusion patients treated with intra-arterial thrombolysis

BACKGROUND

Central retinal artery occlusion (CRAO) is an ischemic stroke of the eye. The atherosclerotic lesions in the intracranial segment of the carotid artery (CA) and the ophthalmic artery (OphA) are not well defined. We aimed to investigate the cerebral angiographic features of CRAO patients and assess the relationship between the angiographic features and outcomes after intra-arterial thrombolysis (IAT).

METHODS

We included 101 acute non-arteritic CRAO patients treated with IAT. We analyzed the detailed angiographic features of the OphA and ipsilateral CA, visual acuity, fundus photography, and fluorescein angiography.

RESULTS

Of the 101 patients, 38 patients (37.6%) had steno-occlusive lesions in the OphA, and 62 patients (61.4%) had atherosclerotic lesions in the ipsilateral CA. The patients with a higher degree of stenosis in the OphA showed a higher degree of stenosis (P=0.049) and a more severe morphology of plaque (P=0.000) in the ipsilateral CA. Additionally, although the visual outcome was not associated with these angiographic features, the lower degree of stenosis and less severe morphology of plaque in the ipsilateral CA resulted in a significant improvement in early reperfusion rate (P=0.018 and P=0.014, respectively) and arm-to-retina circulation (P=0.016 and P=0.002, respectively) of the eye after IAT.

CONCLUSIONS

There was a significant correlation in the severity of steno-occlusive lesions between the OphA and the ipsilateral CA in patients with CRAO. The patients with less severe angiographic features in the CA showed a more improved retinal reperfusion after IAT. The angiographic findings in the CA may serve as a predictive marker for the vessel integrity of the OphA and recanalization outcome after IAT.

Time Course and Clinical Correlates of Retinal Diffusion Restrictions in Acute Central Retinal Artery Occlusion

BACKGROUND AND PURPOSE

Retinal diffusion restrictions were recently identified as a regular finding in acute central retinal artery occlusion. We sought to investigate the influence of technical MR imaging and clinical parameters on the detection rate of retinal diffusion restrictions on standard brain DWI.

MATERIALS AND METHODS

In this retrospective cohort study, MR imaging scans of patients with central retinal artery occlusion were assessed by 2 readers for retinal diffusion restrictions on DWI performed within 2 weeks after vision loss. The influence of clinical and technical MR imaging parameters and the time interval between symptom onset and DWI on the presence of retinal diffusion restrictions were evaluated.

RESULTS

One hundred twenty-seven patients (mean age, 69.6 [SD 13.9] years; 59 women) and 131 DWI scans were included. Overall, the MR imaging sensitivity of retinal diffusion restrictions in acute central retinal artery occlusion was 62.6%-67.2%. Interrater and intrarater agreement for retinal diffusion restrictions was "substantial" with κ_inter= 0.70 (95% CI, 0.57-0.83) and κ_intra= 0.75 (95% CI, 0.63-0.88). Detection of retinal diffusion restrictions did not differ with differences in field strengths (1.5 versus 3T, P = .35) or sequence type (P = .22). Retinal diffusion restrictions were consistently identified within the first week with a peak sensitivity of 79% in DWI performed within 24 hours after symptom onset. Sensitivity of retinal diffusion restrictions declined in the second week (10.0%, P < .001). Absence of retinal diffusion restrictions was more prevalent in patients without fundoscopic retinal edema (60% versus 27.1%, P = .004) and with restitution of visual acuity at discharge (75% versus 28.4%, P = .006).

CONCLUSIONS

Retinal diffusion restrictions in acute central retinal artery occlusion can be reliably identified on DWI performed within 24 hours and 1 week after onset of visual impairment. Detectability of retinal diffusion restrictions is dependent on the clinical course of the disease.

Risk of Stroke, Myocardial Infarction, and Death Among Patients With Retinal Artery Occlusion and the Effect of Antithrombotic Treatment

Purpose

To evaluate the risk of future stroke, myocardial infarction (MI), and death of patients with retinal artery occlusion (RAO) and the effect of various antithrombotic treatments as secondary prevention.

Methods

This cohort study was based on nationwide health registries and included the entire Danish population from 2000 to 2018. All patients with RAO were identified and their adjusted risks of stroke, MI, or death in time periods since RAO were compared with those of the Danish population. Furthermore, antithrombotic treatment of patients with RAO was determined by prescription claims, and the association with the risk of stroke, MI, or death was assessed using multivariate Poisson regression models and expressed as rate ratios (RR) with 95% confidence intervals (95% CIs).

Results

After inclusion, 6628 individuals experienced a first-time RAO, of whom 391 had a stroke, 66 had a MI, and 402 died within the first year after RAO. RAO was associated with an increased risk of stroke, MI, or death which persisted for more than 1 year for all three outcomes but was highest on days 3 to 14 after RAO for stroke, with an adjusted RR of 50.71 (95% CI, 41.55–61.87), and on days 14 to 90 after RAO for MI and death, with adjusted RRs of 1.98 (95% CI, 1.25–3.15) and 1.64 (95% CI, 1.28–189), respectively. Overall, antithrombotic treatment was not associated with any protective effect the first year.

Conclusions

Patients with RAO had an increased risk of stroke, MI, or death. No protective effect of antithrombotic treatment was shown.

Translational Relevance

These findings are relevant to the management of patients with RAO.

Indocyanine green angiography imaging findings in artery occlusions

PURPOSE

To describe the multimodal imaging features including indocyanine green angiography (ICGA) in cases diagnosed clinically as central retinal artery occlusion (CRAO) at its different disease stages.

METHODS

In this retrospective observational study, patients diagnosed clinically as CRAO or hemi-CRAO were included. All patients underwent multimodal imaging with optical coherence tomography (OCT), fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were studied. Analysis of ICGA images in different stages of artery occlusions and its correlation with accompanying FFA and OCT images was done.

RESULTS

Eight such studies in five patients were available for analysis. The most important observation noted on ICGA was the presence of hypercyanescent spots seen during the acute stages of the disease in four of the five cases. The spots were accompanied by retinal vessel staining on FFA in the corresponding region. As the disease showed signs of resolution, the hypercyanescent spots on ICGA and retinal vessel staining on FFA disappeared. The hypercyanescent spots seen on the ICGA were noted due to the red blood cell aggregation or 'rouleaux' formation. In addition, choroidal perfusion abnormalities were noted on ICGA in all five cases in the acute stage.

CONCLUSION

Choroidal perfusion changes can be identified in acute phase of retinal artery occlusion. Rouleaux formation in the retinal circulation occurs due to the slowing of the blood flow following artery occlusion. These are seen as hypercyanescent spots in the late phase on ICGA.

[Update on intravenous lysis treatment : The REVISION trial]

BACKGROUND

To date, no evidence-based treatment for acute non-arteritic central retinal artery occlusion (CRAO) exists. Considering the limited ischemia tolerance of the retina and the results of multiple case series, increasing expectations are directed towards an early intravenous thrombolysis within 4.5 h after CRAO onset.

OBJECTIVE

The current literature regards timely retinal reperfusion as the only potentially beneficial therapeutic option to treat non-arteritic CRAO. Available data on the efficacy and safety of thrombolysis in CRAO are presented and discussed. On the basis of these data, the prospective, randomized, double-blind, placebo-controlled REVISION trial (early REperfusion therapy with intravenous alteplase for recovery of VISION in acute central retinal artery occlusion) will shortly be initiated in 25 centers across Germany in order to investigate early intravenous thrombolysis in acute CRAO. The main inclusion criteria of the REVISION trial are outlined, which may help ophthalmologists to identify study candidates and facilitate rapid referral to a study center.

CONCLUSION

The efficacy of intravenous thrombolysis in acute ischemic stroke is critically time dependent. This may also be assumed in acute CRAO; however, definite evidence still needs to be provided. Until then, the motto "time is retina" should be applied and intravenous thrombolysis should be offered to CRAO patients as part of randomized trials (such as REVISION). According to the current literature, other acute treatment approaches (such as paracentesis) are not indicated.

Central and Branch Retinal Artery Occlusion-Do They Harbor the Same Risk of Further Ischemic Events?

Purpose: Retinal artery occlusion (RAO) is associated with an increased risk of cardiovascular events such as ischemic stroke and myocardial infarction, but whether different RAO subtypes such as central retinal artery occlusion (CRAO) or branch retinal artery occlusion (BRAO) carry similar risk of these events is unclear. Our aim was to determine whether the risk of cardiovascular events differs between CRAO and BRAO. Methods: This single-center, retrospective study included 131 patients hospitalized in our clinic in 2010–2020 with CRAO or BRAO confirmed by ophthalmic examination. Data on demographics, previous ischemic stroke and myocardial infarction, comorbidities, the results of echocardiographic and ultrasound carotid artery examinations and laboratory tests were assessed. Data on ischemic stroke, myocardial infarction, and all-cause mortality occurring after RAO were obtained from the Polish National Health Service, which collects data on all publicly funded hospitalizations. Using these data, Kaplan-Meier analyses and Cox proportional hazard regression were performed. Results: Ischemic stroke occurred in 9.9% of patients after RAO: 10.6% in the CRAO group and 8.1% in the BRAO group (p = 0.662). Myocardial infarction occurred in 2.3% of patients after RAO: 2.1% in the CRAO group and 2.7% in the BRAO group (p = 0.843). All-cause mortality occurred in 22.9% of patients after RAO: 25.5% in the CRAO group and 16.2% in the BRAO group (p = 0.253). The composite endpoint of ischemic stroke, myocardial infarction, and all-cause mortality after RAO occurred in 28.2% of patients: 30.9% in the CRAO group and 21.6% in the BRAO group (p = 0.338). There was no difference between CRAO and BRAO in median time to ischemic stroke (32 vs. 76.4 months; p = 0.352), all-cause mortality (35.9 vs. 36.3 months; p = 0.876) or composite endpoint (37.5 vs. 41.5 months; p = 0.912) after RAO. The Kaplan-Meier analysis showed no differences between CRAO and BRAO in ischemic stroke, myocardial infarction, all-cause mortality, or the composite endpoint; similar results were obtained in analyses of patients with and without cardiovascular events before RAO. Conclusions: The prognosis for ischemic stroke, myocardial infarction, and all-cause mortality is similar in patients with CRAO and BRAO. Ischemic strokes occur with a similar frequency before and after RAO. Myocardial infarctions are observed significantly more frequently before an episode of RAO than after. The results of our study indicate that both CRAO and BRAO require expanded diagnostics to assess the risk of recurrent cardiovascular events, especially ischemic strokes, to implement appropriate prophylaxis and reduce mortality.

Safety and Efficacy of Selective Intra-arterial Thrombolysis for Central Retinal Artery Occlusion

PURPOSE

The purpose of this study was to determine the efficacy and safety of selective intra-arterial thrombolysis in patients with central retinal artery occlusion (CRAO).

METHODS

Medical records for 44 eyes of 44 patients diagnosed with acute non-arteritic CRAO and thrombolysis between October 2010 and February 2019 were analyzed retrospectively. Based on visual acuity, fundoscopic findings, and fluorescein angiography, the patients were classified into three stages: incomplete, subtotal, and total. The perfusion state using the best-corrected visual acuity (BCVA), arm to retina time, and arteriovenous passage times, after 1 month, 6 months, and at the final visit after the procedure, were compared with baseline readings.

RESULTS

Improvement of visual acuity was confirmed in 31 out of 44 patients (70.45%). The mean BCVA of 44 patients changed from 1.65 ± 0.78 logarithmic minimum angle of resolution (logMAR) at the first visit to 1.18 ± 0.91 logMAR at the last visit (p = 0.114). The BCVA according to CRAO stage was 0.08 ± 0.11 logMAR for the incomplete stage at the first visit, 0.06 ± 0.05 logMAR (p = 0.933) 1 month after the procedure, and 0.05 ± 0.07 logMAR (p = 0.933) at the last visit. In the subtotal stage, the results were 1.81 ± 0.54 logMAR at the first visit, 1.63 ± 0.76 logMAR (p = 0.035) 1 month after the procedure, and 1.36 ± 0.85 logMAR (p = 0.014) at the last visit. For the total stage of BCVA, the result at the first visit was 2.36 ± 0.25 logMAR, and it was 2.30 ± 0.30 logMAR (p = 0.510) 1 month after the procedure, and 2.42 ± 0.30 logMAR (p = 0.642) at the last visit. Reperfusion was observed in 40 patients out of the 44 (90.91%).

CONCLUSIONS

Selective intra-arterial thrombolysis can be helpful in patients with subtotal CRAO in terms of visual improvement and retinal arterial reperfusion.

Cilioretinal artery occlusion with paracentral acute middle maculopathy associated with COVID-19

The purpose of the study is to describe cilioretinal artery (CILRA) occlusion that is presumed to be associated with COVID-19 without severe respiratory distress and inform ophthalmologists of unusual ocular presentations of COVID-19. Here, we present the first case of a patient with isolated CILRA occlusion and paracentral acute middle maculopathy (PAMM) after recently polymerase chain reaction-proven COVID-19. A 26-year-old female patient presented with a visual field defect in her left eye for 2 days and decreased vision compared to her right eye. It was learned that the patient had a laboratory-proven COVID-19 infection with mild respiratory symptoms that did not require hospitalization 2 weeks ago. Fundus examination revealed retinal edema in the left eye area supplied by the CILRA. Spectral-domain optical coherence tomography revealed a prominent hyperreflective band at the inner nuclear layer level. These findings led us to the diagnosis of isolated CILRA occlusion and PAMM associated with recent COVID-19. CILRA occlusion and PAMM could be associated with the inflammatory and procoagulant condition caused by the SARS-CoV-2 infection.

Changes of Peripapillary Region Perfusion in Patients with Chiasmal Compression Caused by Sellar Region Mass

Purpose

To evaluate the peripapillary vessel density (pVD) and the peripapillary nerve fiber layer (pRNFL) thickness in patients with chiasmal compression caused by sellar region mass using optical coherence tomography angiography (OCTA).

Methods

This is an observational, cross-sectional study of 31 patients (31 eyes) with chiasmal compression caused by sellar region mass and 34 healthy controls (34 eyes). Automated perimetry and OCTA were performed. The pVD and pRNFL thickness were compared between the two groups. The impact of tumor diameter, duration of symptoms, and cavernous sinus (CS) invasion on visual dysfunction, pVD, and pRNFL thickness was also analyzed. Furthermore, we divided the patients into two subgroups according to whether there was an absolute defect in the central visual field and evaluated their pVD and pRNFL thickness, respectively.

Results

Compared to the healthy control group, there was a statistically significant decrease in pVD and pRNFL thickness in patients with chiasmal compression (p < 0.05), especially in patients with substantial absolute defects in the central visual field. Tumor diameter, duration of symptoms, and CS invasion did not appear to be associated with pVD and pRNFL thickness. There was a significant positive correlation between the pVD and pRNFL thickness in patients with chiasmal compression (p < 0.001).

Conclusion

pVD and pRNFL thickness are significantly decreased in patients with chiasmal compression revealed by OCTA, especially in patients with more severe visual field defects. A significant correlation between pVD and pRNFL thickness was demonstrated, which provides a clue for the study of the mechanism of changes in retinal perfusion in compressive optic neuropathy. It requires considerable attention that OCTA may play an important role in disease monitoring of sellar region mass. Hence, further studies are needed to verify whether OCTA is helpful to predict the prognosis of visual function after decompression surgery.

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.

Prevalence of Cilioretinal Arteries: A systematic review and a prospective cross-sectional observational study

PURPOSE

To review studies focusing on cilioretinal arteries (CLRA) in order to assess the overall prevalence and establish the prevalence of CLRA in a Hungarian Caucasian population. METHODS #1: Systematic literature review of published studies with at least 100 participants. METHODS #2: Non-mydriatic digital colour photographs were taken of 1000 consecutively enrolled healthy Caucasian young adult volunteers. Images were graded by two trained independent observers. Number and location of identified cilioretinal arteries were recorded and statistically analysed. RESULTS #1: Prevalence of CLRA ranges from 6.9% to 49.5%. Detection with fluorescein angiography yields the highest values followed by fundus photography and ophthalmoscopy. Unilateral presence of CLRA is between 70.30% and 93.65%, and temporal location is between 80.77% and 100%. RESULTS #2: We found at least one CLRA in 36.5% of the participants and in 22.75% of all the examined eyes. Cilioretinal arteries (CLRA) were unilateral in 75.34% and bilateral in 24.66%. Of all the identified CLRA, 96.16% were originating from the temporal rim of the optic disc. We identified at least one temporal CLRA supplying the macula in 28% of the participants and 16.95% of the examined eyes.

CONCLUSION

Prevalence of CLRA varies depending on identification method. Unilateral presence is unequivocally more frequent similarly to temporal location. From a risk of bias standpoint, high-quality studies are rare. Our data on the distribution pattern of CLRA are similar to that in the international literature. Based on our findings, we assume that slightly more than one-third of the Hungarian Caucasian population has a CLRA.

Determination of Ischemia Onset Based on Automatically Generated Spectralis SD-OCT Values in Acute Central Retinal Artery Occlusion

Acute central retinal artery occlusion (CRAO) induces a time-dependent increase in retinal thickness. By manually measuring the relative retinal thickness increase (RRTI) in comparison to the contralateral eye based on optical coherence tomography (OCT), ischemia onset within the past 4.5 hours could be determined with 100% sensitivity and 94.3% specificity. To enable examiner-independent and quicker diagnostics, we analyzed the RRTI using the automatic retinal thickness measurement. In this retrospective study, 28 eyes were evaluated with an acute CRAO (<46 hours). All patients received a Spectralis SD-OCT image of both eyes. The RRTI was calculated for the ETDRS sectors using the Segmentation Module for Single Retinal Layer Analysis. Receiver operating characteristic (ROC) analysis was performed to determine patients ≤4.5 hours by RRTI. In all sectors, time to OCT (TTO) and RRTI correlated positively. The optimal cutoff point to detect CRAOs ≤4.5 hours was between 18.7% nasally and 22.9% RRTI temporally. Sensitivity and specificity varied between the sectors with 90-95% sensitivity and 89-100% specificity. In conclusion, the automatic measurement of RRTI also allows the differentiation of CRAOs within a possible therapeutic time window ≤4.5 hours and CRAOs ≥4.5 hours with a high sensitivity and specificity. Additionally, it offers quicker, easier, and a user-independent assessment of ischemia onset, helping to set a base for establishing automatic indices generated by the OCT machines.

Assessment of Trends in the Incidence Rates of Central Retinal Artery Occlusion in Korea From 2002 to 2015

Importance

Central retinal artery occlusion (CRAO) is associated with and shares common risk factors with cardiovascular diseases. Over the past several decades, the incidence rates of stroke and ischemic heart disease have substantially decreased in high-income industrialized countries. However, little is known regarding current trends in CRAO incidence rates.

Objective

To estimate trends in the incidence rates of CRAO in Korea.

Design, Setting, and Participants

This nationwide population-based cohort study was designed on September 7, 2017, and used data from the Korean National Health Insurance Service from January 1, 2002, to December 31, 2015. Individuals with incident CRAO between 2002 and 2015 were identified using the CRAO diagnostic code (H34.1) from the International Classification of Diseases, Tenth Revision. Unadjusted CRAO incidence rates were calculated using the number of CRAO cases identified and the corresponding midyear population, which was obtained from resident registration data. Standardized incidence rates were calculated based on the 2015 census population, and weighted mean annual incidence rates with 95% CIs were computed based on the Poisson distribution. To identify trends in incidence rates, joinpoint regression analysis was performed using standardized incidence rates, and annual percentage changes (APCs) were calculated across the 12-year study period. Data were analyzed from May 1, 2019, to April 30, 2020.

Main Outcomes and Measures

Temporal trends in CRAO incidence rates (measured as cases per 100 000 person-years) and age-standardized APCs in CRAO incidence rates using joinpoint and birth cohort analyses.

Results

Among 50 million residents of Korea, 9892 individuals (5884 men [59.5%]) with incident CRAO between 2002 and 2015 were identified. The mean age of Korean individuals diagnosed with CRAO was 62.4 years (range, 0-97 years); among men and women, the mean age was 61.5 years (range, 0-96 years) and 63.6 years (range, 0-97 years), respectively. The mean standardized incidence rate of CRAO was 2.00 cases per 100 000 person-years (95% CI, 1.97-2.04 cases per 100 000 person-years) among the entire population, 2.43 cases per 100 000 person-years (95% CI, 2.37-2.49 cases per 100 000 person-years) among men, and 1.61 cases per 100 000 person-years (95% CI, 1.57-1.66 cases per 100 000 person-years) among women. The highest incidence rate (9.85 cases per 100 000 person-years; 95% CI, 9.10-10.60 cases per 100 000 person-years) was observed among those aged 80 to 84 years (13.74 cases per 100 000 person-years [95% CI, 12.16-15.32 cases per 100 000 person-years] for men and 8.04 cases per 100 000 person-years [95% CI, 7.21-8.86 cases per 100 000 person-years] for women). The incidence rate in the overall study population decreased over time (APC, -3.46%; 95% CI, -4.3% to -2.6%), and this decreasing trend was more evident in women (APC, -4.56%; 95% CI, -5.7% to -3.4%) than in men (APC, -2.90%; 95% CI, -3.9% to -1.9%). The decrease in the incidence rate was more evident among participants younger than 65 years (APC, -6.80%; 95% CI, -8.3% to -5.2%) than among those 65 years and older (APC, -0.57%; 95% CI, -1.5% to -0.4%). Among participants born after 1930, a decrease in the CRAO incidence rate over time was observed in every age group, while the same decreasing trend was not present among those born before 1930.

Conclusions and Relevance

This study found that the CRAO incidence rate has been decreasing among residents of Korea, especially among women, individuals younger than 65 years, and individuals born after 1930. This observed decrease may be associated with the development of a national health care system and the general improvement in chronic disease management.

Macular vessel density in patients recovered from COVID 19

Purpose

The purpose is to evaluate macular vascular densities (VDs) using optical coherence tomography angiography (OCTA) in patients effected by coronavirus disease-2019 (COVID-19).

Methods

The superficial (SF) and deep macular VD of 50 patients with SARS CoV2 pneumonia who had positive polymerase chain reaction (PCR) tests and who recovered after receiving treatment and 55 healthy age- and gender-matched controls were compared using OCTA. Blood inflammation parameters were also recorded.

Results

There was no statistically significant difference between the two groups in terms of age and gender (p = 0.147 and p = 0.504, respectively). Nor was there a difference with respect to smokers between the two groups (p = 0.231). In COVID-19 patients, the VDs in superior hemi quadrant, superior quadrant and inferior quadrant, were significantly lower (p = 0.033, p = 0.029 and p = 0.042, respectively) in superficial plexus. It was also significantly lower in parafovea, superior hemi and superior quadrants (p = 0.026, p < 0.001 and p = 0.004, respectively) in deep plexus. In addition, white blood cell and neutrophil counts were significantly negatively correlated with the VD of the deep parafovea, deep superior quadrant and deep superior hemi quadrant (p < 0.05). There was no difference between the patient and control groups in both superficial and deep foveal avascular zone (FAZ) (p = 0.101 and p = 0.691 respectively).

Conclusion

In COVID-19 disease, VD is low in some sectors in both SF and deep layers, but no change in FAZ. The effect of COVID 19 disease on the retina and whether it makes the retina sensitive to damage can only be understood with long-term follow-up.

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

PURPOSE

Central retinal artery occlusion (CRAO) is a form of acute ischemic stroke that causes severe visual loss and is a harbinger of further cerebrovascular and cardiovascular events. There is a paucity of scientific information on the appropriate management of CRAO, with most strategies based on observational literature and expert opinion. In this scientific statement, we critically appraise the literature on CRAO and provide a framework within which to consider acute treatment and secondary prevention.

METHODS

We performed a literature review of randomized controlled clinical trials, prospective and retrospective cohort studies, case-control studies, case reports, clinical guidelines, review articles, basic science articles, and editorials concerning the management of CRAO. We assembled a panel comprising experts in the fields of vascular neurology, neuro-ophthalmology, vitreo-retinal surgery, immunology, endovascular neurosurgery, and cardiology, and document sections were divided among the writing group members. Each member received an assignment to perform a literature review, synthesize the data, and offer considerations for practice. Multiple drafts were circulated among the group until consensus was achieved.

RESULTS

Acute CRAO is a medical emergency. Systems of care should evolve to prioritize early recognition and triage of CRAO to emergency medical attention. There is considerable variability in management patterns among practitioners, institutions, and subspecialty groups. The current literature suggests that treatment with intravenous tissue plasminogen activator may be effective. Patients should undergo urgent screening and treatment of vascular risk factors. There is a need for high-quality, randomized clinical trials in this field.

Optical Coherence Tomography Angiography of Nonarteritic Cilioretinal Artery Occlusion Alone

Cilioretinal artery occlusion (CLRAO) is a rare disease. Here, we report the case of a 70-year-old man with nonarteritic cilioretinal artery occlusion alone. The patient was allergic to fluorescein. Therefore, we followed the retinal circulation with optical coherence tomography angiography (OCTA). OCTA at 40 days postonset showed partial improvement in the retinal circulation.

The Nationwide incidence of retinal artery occlusion following dialysis due to end-stage renal disease in Korea: 2004 through 2013

PURPOSE

To examine the incidence and risk of retinal artery occlusion (RAO) in patients who have undergone dialysis in Korea.

METHODS

A nationwide, population-based study using South Korean national health insurance data from 2004 to 2013 was used for analysis. All patients who began dialysis between 2004 and 2013 and the same number of controls were selected via propensity score matching. The incidence of RAO in the dialysis and control cohorts was calculated for 2004-2013 using washout data from 2003. The multivariable Cox proportional hazards model was used to evaluate the risk of developing RAO in dialysis patients. Cumulative RAO incidence curves were generated using the Kaplan-Meier method. Whether dialysis modalities influenced the incidence of RAO was also evaluated.

RESULTS

76,782 end-stage renal disease (ESRD) patients on dialysis were included in the dialysis cohort and 76,782 individuals were included in the control cohort. During the study period, 293 patients in the dialysis cohort and 99 patients in the control cohort developed RAO. The person-years (PY) incidence of RAO was significantly higher in the dialysis cohort than in the control cohort (dialysis=1.1/1000 PY; control=0.3/1000 PY; p<0.001). The incidence of RAO was not significantly different between the two methods of dialysis (hemodialysis vs. peritoneal dialysis)(p=0.25;log-rank test).

CONCLUSION

The current study provided epidemiological evidence that undergoing dialysis for ESRD was associated with an increased risk of developing RAO. The incidence of RAO rapidly increased as the duration of dialysis increased. These results strengthen the significant role of the renal function in retinal vascular disease.

Cerebral magnetic resonance imaging of coincidental infarction and small vessel disease in retinal artery occlusion

There are several reports in the literature on the association between non-arteritic retinal artery occlusion (NA-RAO) and acute ischemic stroke. We investigated the burden of small vessel disease (SVD) and cerebral coincident infarction observed on cerebral magnetic resonance imaging (MRI) in patients with newly diagnosed NA-RAO. In this retrospective, observational, case-series study, consecutive patients with NA-RAO who underwent cerebral MRI within one month of diagnosis between September 2003 and October 2018 were included. The classification of NA-RAO was based on ophthalmologic and systemic examinations. We also investigated the co-incident infarction and burden of underlying SVD, which were categorized as white matter hyperintensity lesion (WMH), cerebral microbleeds (CMB), and silent lacunar infarction (SLI). Among the 272 patients enrolled in the study, 18% presented co-incident infarction and 73% had SVD, which included WMH (70%), CMB (14%), and SLI (30%). Co-incident infarction, WMH, and SLI significantly increased with age: co-incident infarction was observed in 8% of young (< 50 years) patients and 30% of old (≥ 70 years) patients. The embolic etiology of RAO (large artery atherosclerosis, cardioembolism, and undetermined etiology) was significantly associated with the prevalence of SVD (82%: 70%: 64%, P = 0.002) and co-incident infarction (30%: 19%: 8%; P = 0.009). Therefore, high co-incidence of acute cerebral infarction and underlying SVD burden warrant careful neurologic examination and appropriate brain imaging, followed by management of NA-RAO. Urgent brain imaging is particularly pertinent in elderly patients with NA-RAO.

Hyperbaric oxygen treatment of central retinal vein occlusion with cilioretinal artery occlusion secondary to hormonal treatment: Case report and review

INTRODUCTION

This report describes a case of central retinal vein occlusion (CRVO) and cilioretinal artery occlusion (CLRAO) after hormonal treatment for induction of ovulation that was successfully treated with hyperbaric oxygen.

CASE REPORT

A 48 year-old woman was admitted to our department for sudden blurred vision in her left eye. The patient had a history of 3-months hormonal treatment for induction of ovulation. The best corrected visual acuity was 7/10 (20/32) in the left eye and 10/10 (20/20) in the right eye. Fundus examination of the left eye revealed flame-shaped haemorrhages, whitening of the retina along the distribution of cilioretinal artery and tortuous retinal veins. Fluorescein angiography confirmed the combination of a non-ischaemic CRVO with CLRAO. The patient was treated with a 2 h session of hyperbaric oxygen at 253 kPa (2.5 atmospheres absolute) once daily for a total of 30 sessions. Best corrected visual acuity improved to 10/10 (20/20) in the left eye.

CONCLUSIONS

CRVO and CLRAO are both occlusive disorders. HBOT is a safe low-cost treatment modality that can be beneficial in some ocular pathologies. It can maintain oxygenation of the retina through the choroidal blood supply, decrease oedema and preserve compromised tissue adjacent to the ischaemic area.

Retinal vascular occlusions

Acute retinal vascular occlusions are common causes of visual impairment. Although both retinal artery occlusions and retinal vein occlusions are associated with increased age and cardiovascular risk factors, their pathophysiology, systemic implications, and management differ substantially. Acute management of retinal artery occlusions involves a multidisciplinary approach including neurologists with stroke expertise, whereas treatment of retinal vein occlusions is provided by ophthalmologists. Optimisation of systemic risk factors by patients' primary care providers is an important component of the management of these two disorders.

Efficacy of YAG Laser Embolysis in Retinal Artery Occlusion

Objective:

To compare the anatomical and functional success between conventional medical method and Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) laser embolysis in retinal artery occlusion.

Methods:

This randomized control trial was conducted at Armed Forces Institute of Ophthalmology (AFIO) Rawalpindi from July 2018 to May 2020. A total of 14 eyes of 14 patients were received with fovea involving branch or hemiretinal artery occlusion within 24 hours of onset of symptoms. They were divided randomly in two groups. Initial treatment was given to all cases, and seven eyes received Nd:YAG laser treatment for embolysis. Both groups were analysed for anatomical success (reperfusion) and functional success (defined as improvement in visual acuity to better than 6/60 on Snellen’s visual acuity chart from baseline visual acuity).

Results:

In conventional group, anatomical success was achieved in 2 (28.6%) eyes, while significant visual improvement was seen in 3 (42.8%) eyes. In Nd:YAG laser embolysis group, anatomical success was achieved in 5 (71.4%) eyes, while significant visual improvement was seen in 6 (85.7%) eyes. All eyes which showed functional improvement underwent Nd:YAG laser embolysis within 6 hours of onset of symptoms.

Conclusions:

Nd: YAG laser embolysis is more effective in management of fovea threatening retinal artery occlusion, as compared to conventional medical treatment, if performed within six hours of onset of symptoms.

Cilioretinal Arteries in Highly Myopic Eyes: A Photographic Classification System and Its Association With Myopic Macular Degeneration

Purpose: To develop a photographic classification for cilioretinal arteries and to investigate its association with myopic macular degeneration (MMD). Methods: One thousand six hundred ninety-two highly myopic eyes of 1,692 patients were included. The presence of a cilioretinal artery was determined by fundus photographs, and a photographic classification was proposed. MMD was classified according to the International META-PM Classification. Associations of the cilioretinal artery and its classifications with MMD and visual acuity were analyzed. Results: Of the eyes tested, 245 (14.5%) had a cilioretinal artery. The cilioretinal arteries were classified into four categories (temporal "cake-fork," 35.92%; temporal "ribbon," 53.47%; "multiple," 6.53%; "nasal," 4.08%) and 3 distributions based on whether its visible branches reached the central foveal area. Eyes with cilioretinal arteries had significantly less MMD of grade ≥3 and better visual acuity than those without (P < 0.01). Multiple linear regression analysis showed that younger age, male sex, shorter axial length, and the presence of a cilioretinal artery were associated with better visual acuity in highly myopic eyes (all P < 0.05). The "nasal" category presented more MMD with grade ≥3 and worse visual acuity than the other categories (P < 0.05), whereas the "multiple" category contained no eyes with MMD grade ≥3. The cilioretinal arteries reaching the central foveal area showed less MMD of grade ≥3 and better visual acuity than those not (P < 0.05). Conclusions: We propose a photographic classification for cilioretinal arteries that has good clinical relevance to visual functions. The cilioretinal artery may potentially afford protection against MMD.

Bilateral retinal artery occlusions with carotid artery occlusions-ocular and cerebral hemodynamic changes

Purpose

To introduce a case of bilateral retinal artery occlusions with carotid occlusions to achieve a fuller understanding of hemodynamic flow changes and the origin of emboli.

Observations

A 58-year-old male presented with binocular vision loss. Fundus examination revealed bilateral retinal whitening with multiple emboli. Cherry red spot was surrounded and shaped by white edematous ischemic retina. FAG showed retinal refilling but not to the macula and choroidal background. Carotid arteriography and color Doppler images demonstrated bilateral carotid occlusions. CT angiography showed compensatory flows perfused from vertebral arteries for the brain. Orbital color Doppler images revealed bilateral reversed ophthalmic flows indicating another compensatory flow arising from external carotid/ophthalmic collaterals to both eyes.

Conclusions and Importance

Reversed ophthalmic flow indicates the presence of external carotid/ophthalmic collaterals as the source of ocular blood supply and the origin of emboli. In this case, all the embolic, hemodynamic, and serotonin mechanisms may be responsible for the pathogenesis. RAO with multiple emboli is an important sign warning critical flow changes of carotid occlusions.

Investigation of macular and optic nerve head structural changes using spectral domain optical coherence tomography in internal carotid artery stenosis

PURPOSE

To demonstrate differences in optic nerve head (ONH), retinal nerve fiber layer (RNFL), and macular thickness in patients with internal carotid artery (ICA) stenosis using spectral domain optical coherence tomography (SD-OCT).

METHODS

A case-controlled study was conducted in 31 patients with a diagnosis of unilateral ICA stenosis (the percentage of stenosis was between 65 and 85%), and 53 age- and sex-matched healthy subjects (control group) from March 2016 to April 2018. The ONH parameters, RNFL, and macular thicknesses in the nine macular quadrants according to the Early Treatment Diabetic Retinopathy Study (ETDRS) were measured using SD-OCT.

RESULTS

The average macular thickness and outer macular quadrants measurements were lower in the ICA stenosis group (P < 0.05). The thickness of the fovea and inner macular quadrants was similar in healthy and patient eyes. Similarly, the ONH and RNFL profiles based on SD-OCT parameters were similar between the groups. There was a negative weak correlation between mean macular and RNFL thicknesses and the duration and percentage of ICA stenosis.

CONCLUSION

The average macular thickness and measurements of outer macular quadrants in the ICA stenosis group were lower than in the control group. Macular changes may occur before symptomatic ocular ischemic syndrome (OIS). SD-OCT macular measurements may be beneficial in the early detection of OIS due to ICA stenosis.

Retinal findings in hospitalised patients with severe COVID-19

AIM

To identify retinal findings using dilated eye examination, which are possibly related to SARS-CoV-2 infection in hospitalised patients with confirmed severe COVID-19.

METHODS

In this cross-sectional study, hospitalised patients with confirmed severe COVID-19 in a single referral centre for the treatment of COVID-19, in Santo André, São Paulo Metropolitan Area, Brazil, underwent dilated eye examination of both eyes performed by a retina specialist. Findings were recorded using a portable digital fundus camera. Retinographies were analysed by two retina specialists. Medical records were reviewed for assessment of patient demographics, baseline comorbidities and clinical data.

RESULTS

There were a total of 18 patients, nine (50%) male, median IQR age of 62.5 (12) years. Ten of the 18 patients (55.6%; 95% CI 33.7 to 75.4) had abnormalities on dilated eye examination. The main findings were flame-shaped haemorrhages (N=4; 22.2%; 95% CI 9.0 to 45.2) and ischaemic pattern lesions (cotton wool spots and retinal sectorial pallor) (N=4; 22.2%; 95% CI 9.0 to 45.2), with one patient having both cotton wool spots and flame-shaped haemorrhages.

CONCLUSION

These findings suggest that patients with severe COVID-19 have acute vascular lesions of the inner retina including flame-shaped haemorrhages and cotton wool spots. Further studies controlling for confounding factors are necessary to properly assess these findings so as to increase the understanding of COVID-19 pathophysiology and to identify new therapies.

Predictive Factors for Pre-operative Recurrence of Cerebrovascular Symptoms in Symptomatic Carotid Stenosis

OBJECTIVE

Across stroke subtypes, carotid artery stroke carries the highest risk of recurrence. Despite initiation of best medical therapy (BMT), some patients suffer recurrent neurological events before undergoing carotid endarterectomy (CEA). The aim was to identify clinical predictors of early recurrent events in patients with symptomatic carotid stenosis (sCS) awaiting CEA on modern BMT.

METHODS

The Helsinki Carotid Endarterectomy Study 2 (HeCES2) is a cross sectional, longitudinal, prospective, and consecutive cohort study, which enrolled 500 symptomatic or asymptomatic patients with carotid stenosis scheduled for CEA in a tertiary stroke centre. Symptomatic patients were included for this analysis (n = 324).

RESULTS

Of all 324 patients with sCS, 39 (12%) had a recurrent cerebrovascular event at a median of six days after the index symptom: four had an ischaemic stroke (1.2%), 16 a hemispheric transient ischaemic attack (TIA; 4.9%), and 19 amaurosis fugax (AFX; 5.9%). The recurrence rate was 4.0 % (n = 13) within 48 h and 9.9% (n = 32) within two weeks. None of the patients (n = 108) presenting with ocular symptoms (AFX or retinal artery occlusion) suffered recurrent hemispheric TIA or stroke. In Cox regression analysis, comorbid hypertension (hazard ratio [HR] 6.58, 95% confidence interval [CI] 1.33-32.47), hemispheric TIA as the index symptom (HR 3.42, 95% CI 1.70-6.90), the number of prior attacks (HR 1.12, 95% CI 1.08-1.15), and high low density lipoprotein/high density lipoprotein ratio (HR 1.51, 95% CI 1.09-2.11) were independently associated with an increased risk of recurrent event, while a history of major cardiovascular event (HR 0.33, 95% CI 0.11-0.96) and high serum fibrinogen level (HR 0.59, 95% CI 0.41-0.86) were associated with a decreased risk.

CONCLUSION

More than every tenth patient with sCS experienced an early recurrent cerebrovascular event prior to scheduled CEA, despite optimal medication. However, stroke recurrence was lower than in earlier observational studies, which could be explained by improved care pathways, more aggressive medication, and expedited CEA. All recurrent strokes occurred in patients initially presenting with minor stroke.

Combined retinal vascular occlusion: Demography, clinical features, visual outcome, systemic co-morbidities, and literature review

Purpose:

To document the clinical features, systemic association, and treatment outcome of patients with a combined retinal vein and artery occlusion (CRVAO) and review of literature.

Methods:

A retrospective chart review of patients diagnosed with CRVAO at a tertiary eye care center. Patient's demographic details and associated ocular and systemic factors were recorded. Treatment included laser photocoagulation, anti-vascular endothelial growth factor (VEGF) intravitreal injection or transscleral cyclophotocoagulation (TSCPC), alone or in combination. At last, follow- up treatment response was measured in visual acuity status, regression of neovascularization, and control of intraocular pressure (IOP). All cases reported in the current decade were analyzed and compared with this study.

Results:

Seventeen eyes with CRVAO accounted for 0.3% of total vascular occlusion (total 5151 patients were seen in this period). The mean age was 48.12 ± 17.5 years (range: 12-87 years) and there were 9 females. Nine eyes had CRVO + CRAO; 6 eyes had BRVO + BRAO, and one patient each had CRVO + BRAO and CRAO + BRVO. Fluorescein angiography (FA) showed delayed 'arm to retina' time (>20 seconds) in all 10 eyes and delayed arteriovenous transit time in 9 out of 10 eyes. Optical coherence tomography (OCT) showed hypereflective inner retinal layers (16 eyes) and neurosensory detachment (7 eyes). The most common systemic associations were hypertension and dyslipidemia (n = 7 people; 41.18%) each. Four patients (23.5%) had a plaque in carotid arteries with normal 2D echocardiography. Ten (59%) eyes were treated with intravitreal bevacizumab + laser; four (23.5%) eyes were treated with laser only, and three (17.6%) eyes were treated with laser + anti-VEGF + TSCPC. At last follow up, vision improved in 9 (52.9%) eyes; stable in 3 (17.7%) eyes, and reduced to perception of light in 5 (29.4%) eyes.

Conclusion:

Combined CRVAO is a rare emergency leading to acute vision loss. Early diagnosis and treatment for ocular complications and systemic evaluation for cardiovascular risk factors are needed.