Risk factors of non-arteritic anterior ischaemic optic neuropathy and central retinal artery occlusion

AIM:To investigate the difference in risk factors between non-arteritic anterior ischaemic optic neuropathy(NAION)and central retinal artery occlusion(CRAO)and develop a predictive diagnostic nomogram.METHODS:The study included 37 patients with monocular NAION,20 with monocular CRAO,and 24 with hypertension.Gender,age,and systemic diseases were recorded.Blood routine,lipids,hemorheology,carotid and brachial artery doppler ultrasound,and echocardiography were collected.The optic disc area,cup area,and cup-to-disc ratio(C/D)of the unaffected eye in the NAION and CRAO group and the right eye in the hypertension group were measured.RESULTS:The carotid artery intimal medial thickness(C-IMT)of the affected side of the CRAO group was thicker(P=0.039)and its flow-mediated dilation(FMD)was lower(P=0.049)than the NAION group.Compared with hypertension patients,NAION patients had higher whole blood reduced viscosity low-shear(WBRV-L)and erythrocyte aggregation index(EAI;P=0.045,0.037),and CRAO patients had higher index of rigidity of erythrocyte(IR)and erythrocyte deformation index(EDI;P=0.004,0.001).The optic cup and the C/D of the NAION group were smaller than the other two groups(P<0.0001).The diagnostic prediction model showed high diagnostic specificity(83.7%)and sensitivity(85.6%),which was highly related to hypertension,the C-IMT of the affected side,FMD,platelet(PLT),EAI,and C/D.CONCLUSION:CRAO patients show thicker C-IMT and worse endothelial function than NAION.NAION and CRAO may be related to abnormal hemorheology.A small cup and small C/D may be involved in NAION.The diagnostic nomogram can be used to preliminarily identify NAION and CRAO.

OCTA characteristics in non-arteritic central retinal artery occlusion and correlation with visual acuity

AIM:To observe the retinal and choroidal circulations in patients with non-arteritic permanent central retinal artery occlusion(NA-CRAO)via optical coherence tomography angiography(OCTA)and analyze their correlation with visual acuity.METHODS:Sixty-two eyes with clinically confirmed acute NA-CRAO were included in the study and divided into:A type(mild n=29),B type(moderate n=27)and C type(severe n=6)based on the degree of visual loss,retinal edema,and arterial blood flow delay in fundus fluorescence angiography(FFA).Contralateral healthy eyes were used as the control group.Best-corrected visual acuity(BCVA),slit lamp microscopy,indirect ophthalmoscopy,fundus color photography,OCTA,and FFA were performed.Spearman’s correlation analysis was used to determine the correlations between retinal and choroidal vessels and visual acuity.RESULTS:There were no statistically significant differences in age,gender,and intraocular pressure among the three types and the control group(P>0.05).Vessel density in deep capillary plexus(VD-DCP)significantly decreased(P<0.05)in all three types of NA-CRAO patients compared to the control group.Vessel density in superficial vascular plexus(VD-SVP)significantly decreased(P<0.05)in type A patients and choriocapillaris flow area significantly decreased(P<0.05)in type B and type C patients compared to the control group;while outer retinal flow areas significantly increased in the type A(P<0.05)and decreased in type C patients(P<0.05).The retinal thickness significantly increased in type C group(P<0.05).The VD-SVP at fovea in the type A was significantly lower than both of type B and C.The VD-SVP at nasal parafovea in type A and B was significantly lower than type C(P<0.05).The logMAR BCVA of type A was significantly better than that of type B and C groups(P<0.05).Spearman’s correlation analysis showed that the logMAR BCVA was positively correlated with VD-SVP at fovea(r=0.679,P=0.031)and nasal parafovea(r=0.826,P=0.013).CONCLUSION:OCTA is valuable for assessing retinal ischemia,and evaluating visual impairment.Deep retinal vasculature is commonly affected in all NA-CRAO types.VDSVPs at fovea and nasal parafovea can serve as reliable markers of visual impairment in NA-CRAO.

Central retinal artery resistive index and optical coherence tomography in assessment of glaucoma progression

AIM: To assess the relation between central retinal artery(CRA) resistive index(RI) and retinal nerve fiber thickness measured by optical coherence tomography(OCT) in assessment of disease progress in cases of open angle glaucoma.METHODS: Twenty-three patients with diagnosed open angle glaucoma were included in this study. They were examined by colored duplex ultrasonography of CRA with estimation of RI of CRA and ophthalmic artery(OA)with estimation of CRA/OA RI ratio as well as OCT measurement of the average retinal nerve fiber layer(RNFL) thickness in order to assess the disease progress.RESULTS: There was strong inverse relation between the increased RI in CRA as well as the increased CRA/OA RI ratio and the decrease in average RNFL thickness in cases of open angle glaucoma.CONCLUSION: Assessment of CRA RI can indirectly assess the vascular changes associated with glaucoma and can assess the degree of retinal atrophy helping in evaluating prognosis thus guiding the choice of treatment.

Central retinal artery occlusion and traumatic optic neuropathy following blunt ocular trauma

Dear Editor,We are writing to present a case report of central retinal artery occlusion（CRAO）and traumatic optic neuropathy（TON）with immediate visual loss caused by blunt facial trauma with a soccer ball.CRAO is an ophthalmic emergency with an estimated incidence of 10 in 1 million.

Neuropathy optic glaucomatosa induced by systemic hypertension through activation endothelin-1 signaling pathway in central retinal artery in rats

AIM： To evaluate effect of hypertension on retinal ganglion cell（RGC） apoptosis, intraocular pressure（IOP）,and the activation of endothelin-1（ET-1） signaling pathway in central retinal artery（CRA） in rats.METHODS： The experimental study was performed on20 male Sprague Dawley rats that were divided into control group, and hypertension groups. The hypertension was induced by subcutaneous deoxycorticoacetate（DOCA）10 mg/kg twice a week and administered 0.9% Na Cl solution daily for 2, 6, and 10 wk. Blood pressure（BP） was measured using animal BP analyzer. IOP was measured by handheld tonometry. Retinal tissue preparations by paraffin blocks were made after enucleation. The expression of ET-1, e NOS, ET-1 receptor A（ETRA）, ET-1receptor B（ETRB）, and phosphorylated myosin light chain kinase（MLCK）, and caldesmon（Ca D） in CRA and RGC apoptosis were evaluated through immunofluorescent staining method then observed using laser scanning confocal microscopy. RESULTS： BP significantly increased in all of the hypertension groups compared to control（P =0.001）.Peak IOP elevation（7.78±4.14 mm Hg） and RGC apoptosis（576.15±33.28 Au） occurred on 2wk of hypertension. ET-1expression（1238.6±55.1 Au） and e NOS expression（2814.2±70.7 Au） were found highest in 2wk of hypertension,although the ratio of ET-1/e NOS decreased since 2wk.ETRAreached peak expression in 10 wk of hypertension（1219.4 ±6.3 Au）, while ETRBsignificantly increased only in 2 weeks group（1069.2 ±9.6 Au）. The highest MLCK expression（1190.09±58.32 Au）, Ca D（1670.28±18.36 Au）were also found in 2wk of hypertension.CONCLUSION： Hypertension effects to activation of ET-1 signaling pathway significantly in CRA, elevation of IOP, and RGC apoptosis. The highest value was achieved at 2wk, which is the development phase of hypertension.

Prevalence of SARS-CoV-2 among central retinal artery occlusion patients:A case series-HORA study report No.3

Introduction:COVID-19 patients are susceptible to hypercoagulability,thromboembolic,and vasculitis state;central retinal artery occlusion(CRAO)could be caused by hyperviscosity syndrome,thromboembolic accidents,and vasculitis.Evolving case reports are correlating CRAO with COVID-19 patients.Our case series aims to reveal the prevalence of SARS-CoV-2 among CRAO patients under the COVID-19 pandemic.Methods:Medical records of all CRAO patients who attended our tertiary referral hospital,during COVID-19 local outbreak(March to November 2020),were reviewed.Respiratory tract samples were tested for SARS-CoV-2 by the validated Xpert Xpress SARS-CoV-2 assay.If patients were able to cooperate,oropharyngeal saliva samples were obtained.Otherwise,nasopharyngeal and deep throat swabs were taken by registered nurses.Results:A total of 15 CRAO patients(7 males,8 females)were identified during the 9-month study period.The mean age was 72.1-years(range 45-88 year).None of the patients were infected by SARS-CoV-2 before their CRAO disease episodes.Three patients had a history of CRAO over the contralateral eye.No patient was diagnosed with COVID-19 up to their last follow-up(mean 255.4 days,range 152-341 days).Without any COVID-19 positive case,correlation statistical tests on SARS-CoV-2 infection and CRAO were not established.Conclusions:Some of the presumed COVID-19 related CRAO cases may be just coincident with at-risk patients,as COVID-19 is prevalent across the world.More in-depth research,with adjustment to known confounding risk factors,is needed to establish a genuine correlation.

Localized Administration of Tissue Plasminogen Activator through the Ophthalmic Artery in the Setting of Central Retinal Artery Occlusion

Treatment of central retinal artery occlusion (CRAO) has been an ambiguous entity in the medical community. Many interventions have been explored;however, a standard of care has yet to be defined. Recent studies have suggested localized intra-arterial fibrinolysis as a promising method;however, a timeframe for optimal treatment initiation continues to be investigated. This case demonstrates an instance of CRAO treated with local fibrinolysis, however, what could be due to delayed time-to-treat, final visual outcomes were unfavorable. In conjunction with supporting literature, we believe optimization of thrombolytic protocols should be sought after to facilitate successful treatment outcomes. In addition, we encourage community awareness of the signs and symptoms of CRAO in hopes that earlier patient presentations will lead to swifter interventions and overall preservation of ocular function.

Sequential bilateral central retinal artery occlusion as the primary manifestation of systemic lupus erythematosus

Bilateral central retinal artery occlusion （CRAO） has been rarely reported as the primary manifestation in patients with systemic lupus erythematosus （SLE）. The severe retinal vaso-occlusive diseases usually cause devastating and permanent damage to visual function in spite of vigorous treatment. A 42-year-old Chinese woman presented with abrupt bilateral vision loss. The diagnosis of bilateral CRAO was suggested by the ocular presentation and fluorescein angiography. Laboratory studies showed positive results of antinuclear antibody, anti-Ro/SSA anti-La/SSB; decreased levels of C3, C4 complement and normal levels of antiphospholipides antibodies （APAs）. Her visual acuity deteriorated despite systemic steroid and immunosuppressant treatment. Severe vaso-occlusive retinopathy may be an earlier manifestation of SLE without elevated level of APAs.

Acute retinal arterial ischemia

Acute retinal arterial ischemia,which includes transient monocular vision loss(TMVL),branch retinal artery occlusion(BRAO),central retinal artery occlusion(CRAO)and ophthalmic artery occlusion(OAO),is most commonly the consequence of an embolic phenomenon from the ipsilateral carotid artery,heart or aortic arch,leading to partial or complete occlusion of the central retinal artery(CRA)or its branches.Acute retinal arterial ischemia is the ocular equivalent of acute cerebral ischemia and is an ophthalmic and medical emergency.Patients with acute retinal arterial ischemia are at a high risk of having further vascular events,such as subsequent strokes and myocardial infarctions(MIs).Therefore,prompt diagnosis and urgent referral to appropriate specialists and centers is necessary for further work-up(such as brain magnetic resonance imaging with diffusion weighted imaging,vascular imaging,and cardiac monitoring and imaging)and potential treatment of an urgent etiology(e.g.,carotid dissection or critical carotid artery stenosis).Since there are no proven,effective treatments to improve visual outcome following permanent retinal arterial ischemia(central or branch retinal artery occlusion),treatment must focus on secondary prevention measures to decrease the likelihood of subsequent ischemic events.

Modulation of valosin-containing protein by Kyoto University Substances(KUS) as a novel therapeutic strategy for ischemic neuronal diseases

Retinal ischemia causes several vision-threatening diseases, including diabetic retinopathy, retinal artery occlusion, and retinal vein occlusion. Intracellular adenosine triphosphate（ATP） depletion and subsequent induced endoplasmic reticulum（ER） stress are proposed to be the underlying mechanisms of ischemic retinal cell death. Recently, we found that a naphthalene derivative can inhibit ATPase activity of valosin-containing protein, universally expressed within various types of cells, including retinal neural cells, with strong cytoprotective activity. Based on the chemical structure, we developed novel valosin-containing protein modulators, Kyoto University Substances（KUSs）, that not only inhibit intracellular ATP depletion, but also ameliorate ER stress. Suppressing ER stress by KUSs is associated with neural cell survival in animal models of several neurodegenerative diseases, such as glaucoma and retinal degeneration. Given that a major pathology of ischemic retinal diseases, other than intracellular ATP depletion, is ER stress-induced cell death, KUSs may provide a novel strategy for cell protection in ischemic conditions. Hence, we investigated the efficacy of KUS121 in a rat model of retinal ischemic injury. Intravitreal injections of KUS121, which is clinically preferable route of drug administration in retinal diseases, significantly suppressed inner retinal thinning and retinal cell death, and maintained visual functions. Valosin-containing protein modulation by KUS is a promising novel therapeutic strategy for ischemic retinal diseases.

Correlation of ischemic ophthalmopathy with lacunar infarction

AIM:To investigate the correlation of ischemic ophthalmopathy(IO)with lacunar infarction(LI),an ischemic lesions in the cerebrovascular system.METHODS:Totally 204 cases of IO without any nervous system symptom and previously diagnosed LI served as the observational group.All 204 cases without IO,nervous system symptoms and previous LI served as the control group.Age and sex between the two groups matched well.LI was diagnosed by magnetic resonance imaging(MRI)and the results of the two groups were statistically analyzed and compared.RESULTS:IO included 174 eyes of 156 patients with non-arteritis anterior ischemic optic neuropathy(NAION),42 eyes of 36 patients with central retinal artery occlusion(CRAO)or branch retinal artery occlusion(BRAO)and 12 eyes of 12 patients with ocular ischemia syndrome(OIS).The detection rate of LI(72.54%)in IO group was obviously higher than that(15.68%)in the control group(P<0.001).IO was positively correlated with LI(r=0.573,P<0.05).In addition,most infarction sites located in the basal ganglia(67.57%),which were not the vital areas of cerebrum and not easy to be found due to their small size.The majority of those first visited IO patients(72.54%)without nervous system symptom and previously diagnosed LI had already suffered from LI.CONCLUSION:According to our studies,there is a positive correlation between IO and LI.IO can be used as an important predictor for the present of LI,especially obvious signs of the patient.

Observation on Efficacy of Puerarin in Treating Diabetic Retinopathy

Objective: Using the principle of promoting blood circulation to remove stasis to observe central retinal arterial and venous blood flow indexes, and hemorrheology of diabetic retinopathy patients with puerarin. Methods: Thirty patients with diabetic retinopathy were randomly divided into the treated group (n=15) and the control group (n=15). The treated group was given puerarin 400 mg per day intravenously dripping. The control group was given Mikebao 500 μg intramuscularly, once per day. Both groups were treated for 3 consecutive weeks as one treatment course. Two courses later, hemorrheologic parameters, central retinal arterial and venous blood flow indexes were observed. Results: Comparison before and after treatment showed red blood cell aggregation index, the whole blood viscosity rate, plasma viscosity rate, fibrinogen and erythrocyte sedimentation rate, have all improved obviously ( P <0.05, P <0.01). Compared with the control group, there was significant difference ( P <0.05, P <0.01). With the treated group before and after treatment, the peak systolic velocity (PSV) of central retinal artery, their end diastolic volume, the acceleration, the central retinal venous reflux velocity have improved respectively. Naked eye visions were also improved, compared with the control group, the difference was significant ( P <0.01). Conclusion: Puerarin could reduce blood viscosity, improve microcirculation, and play a positive therapeutic role in diabetic retinopathy.