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.

Non-arteritic anterior ischemic optic neuropathy combined with branch retinal vein obstruction:A case report

BACKGROUND Non-arteritic anterior ischemic optic neuropathy(NAION)is an independent disease characterized by edematous optic discs.In eyes with branch retinal vein occlusion(BRVO),the arteries and veins in the ethmoid plate of the optic disc are relatively crowded;however,a combination of the two is clinically uncommon.Herein,we reported a patient with NAION and concealed BRVO,for which the treatment and prognosis were not similar to those for NAION alone.CASE SUMMARY Herein,we report a case of NAION with concealed BRVO that did not improve with oral medication.A week later,we switched to intravenous drug administration to improve circulation,and the patient’s visual acuity and visual field recovered.Hormonal therapy was not administered throughout the study.This case suggested that:(1)Fundus fluorescein angiography(FFA)can help detect hidden BRVO along with the NAION diagnosis;(2)intravenous infusion of drugs to improve circulation has positive effects in treating such patients;and(3)NAION with concealed BRVO may not require systemic hormonal therapy,in contrast with the known treatment for simple NAION.CONCLUSION NAION may be associated with hidden BRVO,which can only be observed on FFA;intravenous therapy has proven effectiveness.

Optical coherence tomography angiography of optic disc perfusion in non-arteritic anterior ischemic optic neuropathy

AIM：To compare the optic disc blood flow of non-arteritic ischemic optic neuropathy（NAION）eyes with normal eyes.METHODS：The optic disc blood flow densities of diagnosed non-acute phase NAION eyes（21 eyes,14 individuals）and normal eyes（19 eyes,12 individuals）were detected via Optovue optical coherence tomography angiography（OCTA）.The optic disc blood flow was measured via Image J software.Correlations between optic disc perfusion and visual function variables were assessed by linear regression analysis.RESULTS：The average percentage of the optic disc nonperfusion areas in the non-acute phase NAION patients（17.84%±6.18%）was increased,when compared to the normal control eyes（8.61%±1.65%）,and the difference was statistically significant（P〈0.01）.Moreover,there was a proportional correlation between the visual field mean defect（MD）and the optic disc non-perfusion area percentage,and the relationship was statistically significant（t=3.65,P〈0.01,R2=0.4118）.In addition,the critical correlation between the best corrected visual acuity（BCVA）and the optic disc non-perfusion area percentage was statistically significant（t=4.32,P〈0.01,R2=0.4957）.CONCLUSION：The optic disc non-perfusion area percentages detected via OCTA in NAION eyes were significantly increased when compared with the normal eyes.Both the BCVA and MD were correlated with the optic disc flow detected,revealing that OCTA may be valuable in the diagnosis and estimation of NAION.

Analysis of optic disc damage by optical coherence tomography in terms of therapy in non-arteritic anterior ischemic optic neuropathy

This study aimed to assess the relationship between the rate of nerve fiber loss in non-arteritic anterior ischemic optic neuropathy（NAION） and time delay before therapy.Total 24 patients received the same treatment within or after 2wk（early and late groups）.There were significantly lower level of destruction of nerve fibers（P=0.0014） and significantly better visual field sensitivity（P=0.039） in early group.The results indicate that therapy should be started within 2wk.The degree of ischemic damage due to NAION correlates well with retinal nerve fiber layer thickness and the ischemia-induced decrease in visual field sensitivity.

Optical coherence tomography evaluation of retinal nerve fiber layer thickness in non-arteritic anterior ischemic optic neuropathy and primary open angle glaucoma:a systematic review and Meta-analysis

AIM:To assess the differences in average and sectoral peripapillary retinal nerve fiber layer(p RNFL)thickness using spectral domain optical coherence tomography(SD-OCT)in patients with non-arteritic anterior ischemic neuropathy(NAION)compared with those with primary open angle glaucoma(POAG).METHODS:A comprehensive literature search of the Pub Med,Cochrane Library,and Embase databases were performed prior to October,2021.Studies that compared the p RNFL thickness in NAION eyes with that in POAG eyes with matched mean deviation of the visual fields were included.The weighted mean difference(WMD)with 95%confidence interval(CI)was used to pool continuous outcomes.RESULTS:Ten cross-sectional studies(11 datasets)comprising a total of 625 eyes(278 NAION eyes,347 POAG eyes)were included in the qualitative and quantitative analyses.The pooled results demonstrated that the superior p RNFL was significantly thinner in NAION eyes than in POAG eyes(WMD=-6.40,95%CI:-12.22 to-0.58,P=0.031),whereas the inferior p RNFL was significant thinner in POAG eyes than in NAION eyes(WMD=11.10,95%CI:7.06 to 15.14,P≤0.001).No difference was noted concerning the average,nasal,and temporal p RNFL thickness(average:WMD=1.45,95%CI:-0.75 to 3.66,P=0.196;nasal:WMD=-2.12,95%CI:-4.43 to 0.19,P=0.072;temporal:WMD=-1.24,95%CI:-3.96 to 1.47,P=0.370).CONCLUSION:SD-OCT based evaluation of inferior and superior p RNFL thickness can be potentially utilized to differentiate NAION from POAG,and help to understand the different pathophysiological mechanisms between these two diseases.Further longitudinal studies and studies using eight-quadrant or clock-hour classification method are required to validate the obtained findings.

Atherogenic indices in non-arteritic ischemic optic neuropathy

AIM:To evaluate the atherogenic indices and the relationship with visual acuity and bilateral sequential involvement in patients with non-arteritic ischemic optic neuropathy(NAION).METHODS:A total of 65 patients with NAION and 48 age-sex matched healthy individuals were included in this retrospective study.The demographic characteristics and laboratory findings of the patients and control subjects were obtained from the electronic medical records.The atherogenic indices were calculated using the lipid parameters.The association between visual acuity,bilateral sequential involvement,and atherogenic indices was investigated.RESULTS:The mean age was 63.8±12.5 y in the NAION group and 64.7±10.1 y in control group(P=0.707).Although there were no significant differences in terms of total cholesterol(TC)and low-density lipoprotein cholesterol(LDL-c)between two groups(P=0.089,0.091),all the nontraditional serum lipid ratios were significantly higher in NAION group(P<0.05).In the NAION subgroup analysis,with visual acuity≤20/200 had higher TC/high-density lipoprotein cholesterol(HDL-c),LDL-c/HDL-c,and non-HDL-c/HDL-c values than the patients in the NAION group with visual acuity>20/200(P=0.032,0.025,0.032,respectively).The values for the atherogenic indices were higher in NAION patients with bilateral sequential involvement in comparison to those with unilateral involvement(P=0.271,0.127,0.197,0.128,0.127,respectively).CONCLUSION:The study reveals a relationship between NAION and the non-traditional lipid ratios.Atherogenic indices may predict the visual loss severity and second eye involvement in patients with NAION.

Non-arteritic anterior ischaemic optic neuropathy in Malaysia: a 5 years review

AIM: To evaluate the clinical presentations and visual outcomes of non-arteritic anterior ischaemic optic neuropathy (NAION).METHODS: A retrospective study was conducted involving 18 consecutive patients (20 eyes) with NAION attending Hospital Universiti Sains Malaysia from January 2005 until December 2009.RESULTS: Most patients were Malay (94.4%),and followed by Chinese (5.6 %).The female-to-male ratio was 3.5:1.The age of patients ranged from 36 to 85 years (mean,57.1 years).The main risk factors in systemic diseases were hypertension (55.5%),diabetes mellitus (44.4%),and ischaemic heart disease (11.1%).Most patients (77.8%) presented with acute loss of vision while gradual onset was in 22.3% of cases.Majority had visual acuity worse than 1/60 (80%).The most common fundoscopic findings were peripapillary splinter haemorrhage (90%),sectorial swollen optic disc (60%) and hyperemic disc (60%).During follow up,20% of the patients showed stabilization in visual acuity,and 80% showed worsening of vision.CONCLUSION: Majority of patients with NAION presented with acute poor vision involving middle-aged and elderly individuals.Hypertension and diabetes mellitus were among the main risk factors involved.NAION can lead to permanent visual loss despite treatment.

Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION)—A Brief Review

Ischemic optic neuropathies could be a result of inflammatory and non inflammatory small vessel disease and have been classified as arteritic and non-arteritic anterior ischemic optic neuropathy respectively. This review has been intended to elucidate the epidemiology, etiology, pathogenesis, clinical picture and management of NAION and the literature search was completed using the published data in Pubmed, Medline, and Ovid over the last five decades.

Characterization of retinal microvasculature in acute non-arteritic anterior ischemic optic neuropathy using the retinal functional imager: a prospective case series

Background:Non-arteritic anterior ischemic optic neuropathy(NAION)is the most common cause of acute optic neuropathy in patients over 50 years of age,and many affected individuals are left with permanent visual deficits.Despite the frequency of NAION and its often devastating effects on vision,no effective treatment has been established.Further understanding of the acute vascular effects in NAION,using advanced ophthalmic imaging techniques like the retinal function imager,may shed light on potential treatment targets.Methods:Five patients with acute NAION underwent retinal functional imaging within 2 weeks of the onset of their visual symptoms,and at 1 month and 3 months after onset.Average arteriolar and venular blood flow velocities were calculated for each eye at each time point.The Wilcoxon rank sum test was used to compare blood flow velocity results with a normative database.Results:The average arteriolar blood flow velocity in the normative group was 3.8 mm/s,and the average venular blood flow velocity was 3.0 mm/s,versus 4.1 mm/s and 2.7 mm/s,respectively,in the NAION-affected group at presentation.Average arteriolar blood flow increased slightly to 4.2 mm/s one month after the acute NAION event,then decreased to 3.8 mm/s three months after the event.Average venular blood flow velocity was 2.8 mm/s 1 month after the NAION event and 2.7 mm/s 3 months after the event.Differences in blood flow velocity between the NAION-affected and control groups were not statistically significant at any time point;however,there was a trend toward increasing blood flow velocity initially after an NAION,with a decrease over time.Conclusions:This study demonstrates the feasibility of retinal function imaging to quantify macular blood flow velocity in patients with acute NAION.There were no statistically significant differences in blood flow velocity detected between NAION-affected eyes and healthy controls at any of the time points examined;however,there was a trend toward an increase in both arteriolar and venular BFV subacutely,then a decrease in the chronic phase after NAION,which could be suggestive of a mechanism of attempted compensation in the setting of acute ischemia.

Acute changes in ganglion cell layer thickness in ischemic optic neuropathy compared to optic neuritis using optical coherence tomography

AIM:To elucidate the changes of different ganglion cell layer(GCL)thinning patterns between the optic neuritis(ON)and non-arteritic anterior ischemic optic neuropathy(NAION).METHODS:A prospective,observational study was conducted to evaluate the timing of GCL changes between acute ON and NAION using optical coherence tomography.RESULTS:Thinning on optical coherence tomography in the NAION group occurs as early as 11 d after symptomatic onset of vision loss and follows an altitudinal pattern.The mean superior-inferior GCL thickness difference in the NAION cohort was clinically significant at 5.7μm in the NAION cohort compared to controls of 0.8μm(P=0.032),but not significant in the ON group compared to controls with both groups measuring 1.1μm.Global thinning was significant for the ON group compared to controls at 7.2μm(P=0.011)but not the NAION group compared to controls at 1.35μm.CONCLUSION:These findings suggest that future treatments for NAION should be given early,and possibly before 11 d in order to prevent GCL and irreversible vision loss.

Imageology of internal carotid artery siphon in nonarteritic anterior ischaemic optic neuropathy

AIM:To evaluate whether narrowing of internal carotid artery siphon(ICAS)may increase the risk of developing non-arteritic anterior ischaemic optic neuropathy(NAION).METHODS:Totally 30 consecutive patients who had unilateral NAION and 30 gender-matched control subjects were recruited in the present study.The diameter of ICAS of all the participants were measured using head-and-neck computed tomographic angiography(CTA).Color doppler flow imaging(CDI)was used to measure the haemodynamics parameters of ICAS and short posterior ciliary arteries(SPCAs)in all subjects.Comparison of parameters between the NAION patients and controls as well as between the two sides within the patients were performed.The correlation between the diameter of ICAS and NAION was analyzed.RESULTS:A comparison of parameters between the affected side of the NAION patients and the controls,including the diameter of ICAS,the resistance index(RI)of ICAS,the blood flow velocities of SPCAs and RI of SPCAs,showed significantly difference(P<0.01),while there was no significant difference in terms of the mean blood flow velocity(Vm)of ICAS;Similar results were found while comparing all the measurements of the affected and unaffected side of patients(P for RI of SPCAs<0.05).No marked difference was detected in nearly all parameters except for RI of ICAS and SPCAs between the unaffected side of the NAION patients and the controls(P<0.05).The diameter of ICAS were significantly positive correlated with both peak systolic velocity(PSV)of SPCAs and end diastolic velocity(EDV)of SPCAs in patients with NAION(r=0.514,P<0.01 and r=0.418,P<0.05,respectively).CONCLUSION:Narrowing of ICAS may increase the risk of developing NAION.