Dynamic profile of ocular refraction in pediatric cataract patients after lens surgeries

AIM: To study the change in ocular refraction in patients with pediatric cataracts(PCs) after lens extraction. METHODS: A total of 1258 patients who were undergoing cataract extraction with/without intraocular lens(IOL)implantation were recruited during preoperative examinations between Jan 2010 and Oct 2013. Patient ages ranged from 1.5 mo to 14y. Follow-ups were conducted at1 wk, 1, and 3 mo postoperatively and every 3 mo in the first year, then 6 mo thereafter. Ocular refraction [evaluated as spherical equivalent(SE)] and yearly myopic shift(YMS)were recorded and statistically analyzed among patients with age at surgery, baseline ocular refraction, gender,postoperative time and laterality(bilateral vs unilateral). RESULTS: By Dec 31st 2015, 1172 participants had been followed for more than 2y. The median follow-up period was 3y. The critical factors affecting the ocular refraction of PC patients were baseline ocular refraction, postoperative time for both aphakic and pseudophakic eyes. YMS grew most rapidly in young childhood and early adolescence. CONCLUSION: After lens surgeries, ocular refraction in PC patients shows an individual difference of change.Further concerns should be raising to monitor the rapid myopic shift at early adolescence of these patients.

Relative peripheral refraction in school children with different refractive errors using a novel multispectral refraction topographer

AIM:To compare relative peripheral refraction(RPR)in Chinese school children with different refractive errors using multispectral refraction topography(MRT).METHODS:A total of 713 eyes of primary school children[172 emmetropia(E),429 low myopia(LM),80 moderate myopia(MM),and 32 low hypermetropia(LH)]aged 10 to 13y were analyzed.RPRs were measured using MRT without mydriasis.MRT results showed RPR at 0-15°(RPR 0-15),15°-30°(RPR 15-30),and 30°-45°(RPR 30-45)annular in the inferior(RPR-I),superior(RPR-S),nasal(RPR-N),and temporal(RPR-T)quadrants.Spherical equivalent(SE)was detected and calculated using an autorefractor.RESULTS:There were significant differences of RPR 15-30 between groups MM[0.02(-0.12;0.18)]and LH[-0.13(-0.36;0.12)](P<0.05),MM and E[-0.06(-0.20;0.10)](P<0.05),and LM[-0.02(-0.15;0.15)]and E(P<0.05).There were also significant differences of RPR 30-45 between groups MM[0.45(0.18;0.74)]and E[0.29(-0.09;0.67)](P<0.05),and LM[0.44(0.14;0.76)]and E(P<0.001).RPR values increased from the hyperopic to medium myopic group in each annular.There were significant differences of RPR-S between groups MM[-0.02(-0.60;0.30)]and E[-0.44(-0.89;-0.04)](P<0.001),and LM[-0.28(-0.71;0.12)]and E(P<0.05).There were also significant differences of RPR-T between groups MM[0.37(0.21;0.78)]and LH[0.14(-0.52;0.50)](P<0.05),LM[0.41(0.06;0.84)]and LH(P<0.05),and LM and E[0.29(-0.10;0.68),P<0.05].A Spearman’s correlation analysis showed a negative correlation between RPR and SE in the 15°-30°(P=0.005),30°-45°(P<0.05)annular(P=0.002),superior(P<0.001),and temporal(P=0.001)quadrants.CONCLUSION:Without pupil dilation,values for RPR 15-30,30-45,RPR-S,and T shows significant differences between myopic eyes and emmetropia,and the differences are negatively correlated with SE.

Feasibility of smart intraocular lens

Dear Editor,Wearable biosensors are monitoring implantable devices that provide real-time detection of biomarkers by means of non-invasive measurements[1].There is a high demand for novel sensors that can be comfortably used by the patients for clinical monitoring of ocular diseases.Transducers implanted into eyes have been improved and they have the capacity to monitor parameters such as intraocular pressure(IOP),and also have the possibility of recording lactic acid,glucose or cortisol levels[2-3].

Guiding function of positron emission tomographycomputed tomography examination in the diagnosis and treatment of ocular adnexal mucosa associated lymphoid tissue lymphoma

AIM:To explore the role of positron emission tomographycomputed tomography(PET-CT)examination in the diagnosis and treatment of ocular adnexal mucosa associated lymphoid tissue lymphoma(OAML).METHODS:The general clinical data,postoperative PET-CT results,treatment regimens,and the prognosis of 21 histopathologically confirmed OAML patients between October 2017 and September 2021 were collected.Among the 21 patients,five patients underwent surgical treatment alone,13 patients underwent surgical treatment combined with radiotherapy,and three patients underwent surgical treatment combined with chemotherapy.RESULTS:The follow-up period ranged from 8 to 79mo,with four cases of recurrence and no deaths.Through PETCT examination,two patients exhibited both local ocular metabolic elevation and systemic metastasis,and one of these patients had cervical lymph node metastasis,while the other had submandibular and parotid gland metastasis.Nine patients showed only local ocular metabolic elevation,while 10 patients had no abnormal metabolic activity locally.CONCLUSION:PET-CT examination plays a crucial role in detecting residual lesions and recurrence following tumor resection,aiding in precise disease staging,and facilitating the development of personalized treatment plans,ultimately improving patient prognosis.

Single-cell RNA sequencing analysis of the retina under acute high intraocular pressure

High intraocular pressure causes retinal ganglion cell injury in primary and secondary glaucoma diseases,yet the molecular landscape characteristics of retinal cells under high intraocular pressure remain unknown.Rat models of acute hypertension ocular pressure were established by injection of cross-linked hyaluronic acid hydrogel(Healaflow■).Single-cell RNA sequencing was then used to describe the cellular composition and molecular profile of the retina following high intraocular pressure.Our results identified a total of 12 cell types,namely retinal pigment epithelial cells,rod-photoreceptor cells,bipolar cells,Müller cells,microglia,cone-photoreceptor cells,retinal ganglion cells,endothelial cells,retinal progenitor cells,oligodendrocytes,pericytes,and fibroblasts.The single-cell RNA sequencing analysis of the retina under acute high intraocular pressure revealed obvious changes in the proportions of various retinal cells,with ganglion cells decreased by 23%.Hematoxylin and eosin staining and TUNEL staining confirmed the damage to retinal ganglion cells under high intraocular pressure.We extracted data from retinal ganglion cells and analyzed the retinal ganglion cell cluster with the most distinct expression.We found upregulation of the B3gat2 gene,which is associated with neuronal migration and adhesion,and downregulation of the Tsc22d gene,which participates in inhibition of inflammation.This study is the first to reveal molecular changes and intercellular interactions in the retina under high intraocular pressure.These data contribute to understanding of the molecular mechanism of retinal injury induced by high intraocular pressure and will benefit the development of novel therapies.

Medical and surgical approach to ocular surface reconstruction

Ocular surface disease(OSD)can have a severe impact on patients as it can lead to visual impairment and persistent discomfort.Ocular surface reconstruction(OSR)is an approach to the management of ocular diseases that cause structural damage to the ocular surface.OSR encompasses both medical and surgical treatment options.In this review,we discuss the medical and surgical strategies used in OSR.Medical management often aims to treat tear insufficiency,inflammation,and keratinization.Surgical treatments may be employed for a variety of reasons,including failure of medical management.This may include improving the oculo-palpebral structures in order to improve lid positioning and tear film.Additional therapies focus on improving tear production,such as through salivary gland transplantation.In situations where the ocular surface is so severely damaged that there is loss of limbal stem cells,limbal stem cell transplant(LSCT)may be indicated.Other surgeries such as amniotic membrane transplant(AMT)and conjunctival flaps(CFs)can help promote corneal healing.Finally,in severe situations where the cornea is beyond salvage,corneal transplantation,such as a penetrating keratoplasty(PKP),can be considered.OSR often requires a combination of medical and surgical approaches targeted to each specific patient’s presentation in order to achieve optimal outcomes.

Topical ocular administration of DPP-Ⅳ inhibitors:a new approach for treating diabetes-induced retinal neurodegeneration

Retinal neurodegeneration plays a significant role in the pathogenesis of diabetic retinopathy(DR),the leading cause of preventable blindness.In fact,the American Diabetes Association has defined DR as a highly specific neurovascular complication(Solomon et al.,2017).Therefore,it is no longer acceptable to consider DR as merely a microvascular complication.In this regard,the term diabetic retinal disease(DRD)has been proposed as a broader term comprising microangiopathy and neurodegeneration.However,there are currently no treatments available that directly target the neurodegenerative changes of DR.This paper will give new insights into the translational research in this field with particular emphasis on glucagon-like peptide 1/dipeptidyl peptidase IV(GLP-1/DPP-IV)inhibitors.

Visualizing traumatic brain injury:ocular clues for diagnosis and assessment

Traumatic brain injury (TBI) is defined as damage to the brain resulting from an external sudden physical force or shock to the head.It is considered a silent public health epidemic causing significant death and disability globally.There were 64,000 TBI related deaths reported in the USA in 2020,with about US$76 billion in direct and indirect medical costs annually.

Ocular myositis--a diagnostic dilemma

Dear Editor,Orbital myositis is a relatively rare entity but is the next most common cause of extra ocular muscle disease after thyroid associated orbitopathy(TAO)[1-2].It was first described by Gleason in 1903 as an orbital pseudotumour and then renamed in 1930[3].It usually affects young females than males.Extraocular muscles differ from skeletal muscles by a smaller unit size and higher motor neuron discharge,higher blood flow and volume of mitochondria fractions that allow inflammatory cells to reach and circulate easier,causing inflammation[4].Clinical findings include moderate to severe orbital pain,painful diplopia increased with eye movement,exophthalmos,swollen eyelids,conjunctival hyperemia or chemosis usually.Contrast enhanced magnetic resonance imaging(CEMRI)is the most sensitive modality which discloses enhancement or thickening of inflamed extraocular muscle.

Lacidipine,thiamine pyrophosphate and their combination on the ocular ischemic syndrome induced by bilateral common carotid artery ligation

AIM:To investigate the effect of lacidipine,thiamine pyrophosphate(TPP)and the combination of lacidipine and TPP against oxidative and inflammatory eye damage induced by bilateral common carotid artery ligation in rats.METHODS:Male albino Wistar rats were categorized as those who underwent sham surgery(SG),right and left common carotid cross-clamping and unclamping procedure(CCU),lacidipine+CCU(LCCU),TPP+CCU(TCCU),and combination of lacidipine and TPP(LTC)+CCU(LTCCU).One hour before anesthesia,the LCCU(n=6)received lacidipine(4 mg/kg,orally)and the TCCU(n=6)received TPP(20 mg/kg,intraperitoneally).The SG(n=6)and CCU(n=6)received the same volume of distilled water from the same route.After anesthesia(60 mg/kg ketamine,intraperitoneally),the necks of the rats were opened in the midline.Ischemia was created for 10min by placing clips on the right and left common carotid arteries.Rats in the SG only underwent subcutaneous incision.After 10min,the clips were removed and reperfusion was achieved for six days.Then,the animals were euthanized(120 mg/kg ketamine,intraperitoneally)and the levels of oxidant,antioxidant and proinflammatory cytokines in the eye tissues were determined.The retinal tissue of the eye was also examined histopathologically.RESULTS:Lacidipine,TPP,and LTC significantly prevent the increase in malondialdehyde,tumor necrosis factoralpha,interleukin-1β(IL-1β),and IL-6 levels,decrease in total glutathione levels,superoxide dismutase and catalase activities and histopathological retinal damage in eye tissue induced by bilateral common carotid artery ligation in rats.The impact of these drugs on protection is determined to be LTC>lacidipine>TPP.CONCLUSION:As a result of the study,it is concluded that LTC may be more effective than lacidipine and TPP alone in treating ocular ischemic syndrome.

Ocular Complications in Diabetic Patients: Prevalence, Impact on Quality of Life, and Implications for Healthcare

Introduction: Diabetes, a chronic disease characterized by persistent hyperglycemia, poses a major global health challenge. In Gabon, 10% of the population is affected by this condition, highlighting the need to actively understand and manage it. Ocular complications of diabetes, including diabetic retinopathy, glaucoma, and cataracts, have a devastating impact on patients quality of life and represent a crucial issue for healthcare systems. Methodology: This study conducted in Libreville from February 9, 2022, to April 15, 2022, was cross-sectional, longitudinal, and descriptive, with prospective data collection. Participants were diabetic patients regularly followed in the endocrinology department of CHUL, who were referred for a comprehensive ophthalmological examination at CHUO. Sampling was exhaustive, with strict inclusion criteria aimed at ensuring the representativeness of the study population. Results: The mean age of participants was 57.5 ± 13.2 years with a male-to-female ratio of 0.8. Personal histories were dominated by hypertension, while family histories were dominated by diabetes. Ocular complications of diabetes included refractive disorders (78.9%), cataracts (31.7%), glaucoma (78.9%), and diabetic retinopathy (13.7%). These ocular complications had a significant impact on participants’ quality of life, leading to impaired vision (78.9%), difficulties in carrying out daily activities (62.2%), the need for caregiver assistance (50.3%), high levels of stress and anxiety (68.9%), regular medication intake (71.4%), adherence to a specific diet (55.9%), and frequent blood glucose monitoring (74.5%). Conclusion: This study highlights the major impact of diabetic ocular complications on patients’ quality of life.

Digital measuring the ocular morphological parameters of guinea pig eye in vivo with Python

AIM:To quantitatively measure ocular morphological parameters of guinea pig with Python technology.METHODS:Thirty-six eyeballs of eighteen 3-weekold guinea pigs were measured with keratometer and photographed to obtain the horizontal,coronal,and sagittal planes respectively.The corresponding photo pixels-actual length ratio was acquired by a proportional scale.The edge coordinates were identified artificially by ginput function.Circle and conic curve fitting were applied to fit the contour of the eyeball in the sagittal,coronal and horizontal view.The curvature,curvature radius,eccentricity,tilt angle,corneal diameter,and binocular separation angle were calculated according to the geometric principles.Next,the eyeballs were removed,canny edge detection was applied to identify the contour of eyeball in vitro.The results were compared between in vivo and in vitro.RESULTS:Regarding the corneal curvature and curvature radius on the horizontal and sagittal planes,no significant differences were observed among results in vivo,in vitro,and the keratometer.The horizontal and vertical binocular separation angles were 130.6°±6.39°and 129.8°±9.58°respectively.For the corneal curvature radius and eccentricity in vivo,significant differences were observed between horizontal and vertical planes.CONCLUSION:The Graphical interface window of Python makes up the deficiency of edge detection,which requires too much definition in Matlab.There are significant differences between guinea pig and human beings,such as exotropic eye position,oblique oval eyeball,and obvious discrepancy of binoculus.This study helps evaluate objectively the ocular morphological parameters of small experimental animals in emmetropization research.

Ocular surface in patients with different degrees of myopia

AIM:To investigate the clinical features of the ocular surface in patients with different degrees of myopia.METHODS:A cross-sectional study was conducted involving 122 participants with myopia in Beijing Tongren Hospital from February to June,2023.After completing the Ocular Surface Disease Index(OSDI)score scale,measurements were taken for refraction,biometric parameters and ocular surface parameters.The prevalence,severity and related parameters of the dry eye among different groups based on axial length(AL)were compared.Correlation analysis was performed between ocular surface parameters and refraction/biometric measurement parameters.RESULTS:Statistically significant differences were observed in refractive error,corneal thickness,anterior chamber depth,and subfoveal choroidal thickness among the groups(all P<0.05).With the increase in AL,the incidence and severity of dry eye increased significantly(P<0.05).Moreover,the tear film break-up time(BUT)shortened(P<0.05),and the corneal fluorescein staining(CFS)points increased significantly(P<0.05).OSDI scores were positively correlated with AL and spherical equivalent(SE;both P<0.05);BUT was negatively correlated with AL,SE,and corneal astigmatism(AST;all P<0.05);Schirmer I test(SIT)results were negatively correlated with AL and SE(both P<0.05).CONCLUSION:AL elongation is a risk factor for dry eye onset in myopic participants.The longer the AL,the more severe the dry eye is,with the increased CFS spots and tear film instability.Additionally,SE and AST exhibit negative correlations with dry eye symptom scores and ocular surface parameters.

Comparison of ocular biometric parameters between two swept-source optical coherence tomography devices and Scheimpflug tomography in patients with cataract

AIM:To assess and compare the variations and agreements across different ocular biometric parameters using swept-source optical coherence tomography(SS-OCT)and Scheimpflug tomography in patients diagnosed with cataract.METHODS:This prospective case series was conducted at Tianjin Medical University Eye Hospital.In total,212 eyes from 212 patients scheduled for phacoemulsification were included.Eyes were evaluated preoperatively using two SSOCT devices(IOLMaster700 and CASIA2)and Scheimpflug tomography(Pentacam).Central corneal thickness(CCT),anterior chamber depth(ACD),aqueous depth(AQD),white-to-white distance(WTW),flat simulated keratometry(Kf),steep simulated keratometry(Ks),mean keratometry(Km),and total corneal keratometry(TKm)were measured.Intraclass correlation coefficient(ICC),95%confidence intervals(CI)and limits of agreement(LoA)widths were conducted to assess differences and correlations between devices.RESULTS:All parameters,except for Ks,were significantly different.Pairwise comparison revealed no significant differences between keratometry obtained by IOLMaster 700 and Pentacam.LoA widths of all paired comparisons for Ks were>0.80 D.Except for WTW between IOLMaster 700 and CASIA2 and between CASIA2 and Pentacam,other Pearson’s coefficients between devices showed a strong correlation(all r>0.95).The ICC of WTW(ICC=0.438,95%CI 0.167-0.625)showed poor reliability.The reliability of CCT,ACD,and AQD was excellent(all ICC>0.95),whereas that of TKm was good(ICC=0.827,95%CI 0.221-0.939).A significant linear correlation was also observed among devices.CONCLUSION:The ocular parameters derived from the use of IOLMaster700,CASIA2,and Pentacam exhibit significant discrepancies;as such,measurements from these devices should not be deemed as interchangeable.

Unlocking the versatile potential:Adipose-derived mesenchymal stem cells in ocular surface reconstruction and oculoplastics

This review comprehensively explores the versatile potential of mesenchymal stem cells(MSCs)with a specific focus on adipose-derived MSCs.Ophthalmic and oculoplastic surgery,encompassing diverse procedures for ocular and periocular enhancement,demands advanced solutions for tissue restoration,functional and aesthetic refinement,and aging.Investigating immunomodulatory,regenerative,and healing capacities of MSCs,this review underscores the potential use of adipose-derived MSCs as a cost-effective alternative from bench to bedside,addressing common unmet needs in the field of reconstructive and regenerative surgery.

Deep Transfer Learning Models for Mobile-Based Ocular Disorder Identification on Retinal Images

Mobile technology is developing significantly.Mobile phone technologies have been integrated into the healthcare industry to help medical practitioners.Typically,computer vision models focus on image detection and classification issues.MobileNetV2 is a computer vision model that performs well on mobile devices,but it requires cloud services to process biometric image information and provide predictions to users.This leads to increased latency.Processing biometrics image datasets on mobile devices will make the prediction faster,but mobiles are resource-restricted devices in terms of storage,power,and computational speed.Hence,a model that is small in size,efficient,and has good prediction quality for biometrics image classification problems is required.Quantizing pre-trainedCNN(PCNN)MobileNetV2 architecture combined with a SupportVectorMachine(SVM)compacts the model representation and reduces the computational cost and memory requirement.This proposed novel approach combines quantized pre-trained CNN(PCNN)MobileNetV2 architecture with a Support Vector Machine(SVM)to represent models efficiently with low computational cost and memory.Our contributions include evaluating three CNN models for ocular disease identification in transfer learning and deep feature plus SVM approaches,showing the superiority of deep features from MobileNetV2 and SVM classification models,comparing traditional methods,exploring six ocular diseases and normal classification with 20,111 images postdata augmentation,and reducing the number of trainable models.The model is trained on ocular disorder retinal fundus image datasets according to the severity of six age-related macular degeneration(AMD),one of the most common eye illnesses,Cataract,Diabetes,Glaucoma,Hypertension,andMyopia with one class Normal.From the experiment outcomes,it is observed that the suggested MobileNetV2-SVM model size is compressed.The testing accuracy forMobileNetV2-SVM,InceptionV3,andMobileNetV2 is 90.11%,86.88%,and 89.76%respectively while MobileNetV2-SVM,InceptionV3,and MobileNetV2 accuracy are observed to be 92.59%,83.38%,and 90.16%,respectively.The proposed novel technique can be used to classify all biometric medical image datasets on mobile devices.

Intra-and interobserver reliability of ocular surface analyzer LacryDiag

AIM:To invastigate intra-and interobserver reliability of interferometry,tear meniscus height(TMH)measurement and meibography(MBG)of an ocular surface analyzer,LacryDiag(Quantel Medical,France).METHODS:Five consecutive measurements and subsequent analysis of interferometry,TMH,and MBG were recorded by two examiners using the LacryDiag.To assess intra-and interobserver reliability,we used Cohen’s kappa for categorical variables(interferometry),or intraclass correlation coefficient for continuous variables(TMH,MBG).RESULTS:Thirty eyes of 30 examinees were included.For both observers,there was excellent intraobserver reliability for MBG(0.955 and 0.970 for observer 1 and 2,respectively).Intraobserver reliability for observer 1 was substantial for interferometry(0.799),and excellent for TMH(0.863).Reliability for observer 2 was moderate for interferometry(0.535)and fair to good for TMH(0.431).Interobserver reliability was poor for interferometry(0.074)and fair to good for TMH(0.680)and MBG(0.414).CONCLUSION:LacryDiag ocular surface analyzer in our study proves to be a reliable noninvasive tool for the evaluation of TMH and MBG.As for interferometry,poor interobserver reliability,fair to good intraobserver reliability for observer 1,and moderate for observer 2,leave room for improvement.

Annexin A1 in the nervous and ocular systems

The therapeutic potential of Annexin A1,an important member of the Annexin superfamily,has become evident in results of experiments with multiple human systems and animal models.The anti-inflammatory and pro-resolving effects of Annexin A1 are characteristic of pathologies involving the nervous system.In this review,we initially describe the expression sites of Annexin A1,then outline the mechanisms by which Annexin A1 maintains the neurological homeostasis through either formyl peptide receptor 2 or other molecular approaches;and,finally,we discuss the neuroregenerative potential qualities of Annexin A1.The eye and the nervous system are anatomically and functionally connected,but the association between visual system pathogenesis,especially in the retina,and Annexin A1 alterations has not been well summarized.Therefore,we explain the beneficial effects of Annexin A1 for ocular diseases,especially for retinal diseases and glaucoma on the basis of published findings,and we explore present and future delivery strategies for Annexin A1 to the retina.

Ocular biometric characteristics of Han ethnicity in Tianjin and Uyghur ethnicity in Xinjiang undergoing cataract surgery

AIM:To analyze and compare the differences among ocular biometric parameters in Han and Uyghur populations undergoing cataract surgery.METHODS:In this hospital-based prospective study,410 patients undergoing cataract surgery(226 Han patients in Tianjin and 184 Uyghur patients in Xinjiang)were enrolled.The differences in axial length(AL),anterior chamber depth(ACD),keratometry[steep K(Ks)and flat K(Kf)],and corneal astigmatism(CA)measured using IOL Master 700 were compared between Han and Uyghur patients.RESULTS:The average age of Han patients was higher than that of Uyghur patients(70.22±8.54 vs 63.04±9.56y,P<0.001).After adjusting for age factors,Han patients had longer AL(23.51±1.05 vs 22.86±0.92 mm,P<0.001),deeper ACD(3.06±0.44 vs 2.97±0.37 mm,P=0.001),greater Kf(43.95±1.40 vs 43.42±1.69 D,P=0.001),steeper Ks(45.00±1.47 vs 44.26±1.71 D,P=0.001),and higher CA(1.04±0.68 vs 0.79±0.65,P=0.025)than Uyghur patients.Intra-ethnic male patients had longer AL,deeper ACD,and lower keratometry than female patients;however,CA between the sexes was almost similar.In the correlation analysis,we observed a positive correlation between AL and ACD in patients of both ethnicities(rHan=0.48,rUyghur=0.44,P<0.001),while AL was negatively correlated with Kf(rHan=-0.42,rUyghur=-0.64,P<0.001)and Ks(rHan=-0.38,rUyghur=-0.66,P<0.001).Additionally,Kf was positively correlated with Ks(rHan=0.89,rUyghur=0.93,P<0.001).CONCLUSION:There are differences in ocular biometric parameters between individuals of Han ethnicity in Tianjin and those of Uyghur ethnicity in Xinjiang undergoing cataract surgery.These ethnic variances can enhance our understanding of ocular diseases related to these parameters and provide guidance for surgical procedures.

A robust triaxial localization method of AE source using refraction path

Acoustic emission(AE)localization algorithms based on homogeneous media or single-velocity are less accurate when applied to the triaxial localization experiments.To the end,a robust triaxial localization method of AE source using refraction path is proposed.Firstly,the control equation of the refraction path is established according to the sensor coordinates and arrival times.Secondly,considering the influence of time-difference-of-arrival(TDOA)errors,the residual of the governing equation is calculated to estimate the equation weight.Thirdly,the refraction points in different directions are solved using Snell’s law and orthogonal constraints.Finally,the source coordinates are iteratively solved by weighted correction terms.The feasibility and accuracy of the proposed method are verified by pencil-lead breaking experiments.The simulation results show that the new method is almost unaffected by the refraction ratio,and always holds more stable and accurate positioning performance than the traditional method under different ratios and scales of TDOA outliers.