Evaluation of dry eye disease symptomatology and mental health status among patients with different COVID-19 statuses

AIM:To evaluate dry eye disease(DED)symptomatology and mental health status in different COVID-19 patients.METHODS:A cross-sectional observational design was used.Totally 123 eligible adults(46.34%of men,age range,18-59y)with COVID-19 included in the study from August to November,2022.Ocular Surface Disease Index(OSDI),Five-item Dry Eye Questionnaire(DEQ-5),Hospital Anxiety and Depression Scale(HADS),and Pittsburgh Sleep Quality Index(PSQI)were used in this study.RESULTS:OSDI scores were 6.82(1.25,15.91)in asymptomatic carriers,7.35(2.50,18.38)in mild cases,and 16.67(4.43,28.04)in recurrent cases,with 30.00%,35.56%,and 57.89%,respectively evaluated as having DED symptoms(χ2=7.049,P=0.029).DEQ-5 score varied from 2.00(0,6.00)in asymptomatic carriers,3.00(0,8.00)in mild cases,and 8.00(5.00,10.00)in recurrent cases,with 27.50%,33.33%,and 55.26%,respectively assessed as having DED symptoms(χ2=8.532,P=0.014).The prevalence of clinical anxiety(50.00%)and depression(47.37%)symptoms were also significantly higher in patients with recurrent infection(χ2=24.541,P<0.001;χ2=30.871,P<0.001).Recurrent infection was a risk factor for high OSDI scores[odds ratio,2.562;95%confidence interval(CI),1.631-7.979;P=0.033]and DEQ-5 scores(odds ratio,3.353;95%CI,1.038-8.834;P=0.043),whereas having a fixed occupation was a protective factor for OSDI scores(odds ratio,0.088;95%CI,0.022-0.360;P=0.001)and DEQ-5 scores(odds ratio,0.126;95%CI,0.039-0.405;P=0.001).CONCLUSION:Patients with recurrent COVID-19 have more severe symptoms of DED,anxiety,and depression.

Systematic bibliometric analysis of research hotspots and trends on the application of premium IOLs in the past 2 decades

AIM:To analysis of research hotspots and trends on the application of premium intraocular lens(PIOLs)in the past 2 decades.METHODS:The literature search was performed on the Web of Science and included PIOLs studies published between January 2000 and December 2022.The retrieved literature was collated and analyzed by R-tool’s Bibliometrix package,CitNetExplorer,CiteSpace and other software.RESULTS:A total of 1801 articles about PIOLs were obtained,most of which were published in Spain and the United States.The organization that published the most articles was the University of Valencia in Spain.Alió JL,and Montés-Micó R,from Spain were the most influential authors in this field.The Journal of Cataract and Refractive Surgery and Journal of Refractive Surgery were the core journals for this field;the top 10 cited articles mainly focus on postoperative satisfaction with multifocal intraocular lens(IOLs)and postoperative results of toric IOLs.Through the keyword analysis,we found that trifocal IOLs,astigmatism and extended depth of focus(EDoF)IOLs are the most discussed topics at present,and the importance of astigmatism and the clinical application of the new generation of PIOLs are the emerging research trends.CONCLUSION:Bibliometric analysis can effectively help to identify multilevel concerns in PIOLs research and the prevailing research trends in the realm of PIOLs encompass the adoption of EDoF IOLs,trifocal IOLs,and their respective Toric models.

Proteomic study of vitreous in proliferative diabetic retinopathy patients after treatment with aflibercept:a quantitative analysis based on 4D label-free technique

AIM:To identify different metabolites,proteins and related pathways to elucidate the causes of proliferative diabetic retinopathy(PDR)and resistance to anti-vascular endothelial growth factor(VEGF)drugs,and to provide biomarkers for the diagnosis and treatment of PDR.METHODS:Vitreous specimens from patients with diabetic retinopathy were collected and analyzed by Liquid Chromatography-Mass Spectrometry(LC-MS/MS)analyses based on 4D label-free technology.Statistically differentially expressed proteins(DEPs),Gene Ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway representation and protein interactions were analyzed.RESULTS:A total of 12 samples were analyzed.The proteomics results showed that a total of 58 proteins were identified as DEPs,of which 47 proteins were up-regulated and 11 proteins were down-regulated.We found that C1q and tumor necrosis factor related protein 5(C1QTNF5),Clusterin(CLU),tissue inhibitor of metal protease 1(TIMP1)and signal regulatory protein alpha(SIRPα)can all be specifically regulated after aflibercept treatment.GO functional analysis showed that some DEPs are related to changes in inflammatory regulatory pathways caused by PDR.In addition,protein-protein interaction(PPI)network evaluation revealed that TIMP1 plays a central role in neural regulation.In addition,CD47/SIRPαmay become a key target to resolve anti-VEGF drug resistance in PDR.CONCLUSION:Proteomic analysis is an approach of choice to explore the molecular mechanisms of PDR.Our data show that multiple proteins are differentially changed in PDR patients after intravitreal injection of aflibercept,among which C1QTNF5,CLU,TIMP1 and SIRPαmay become targets for future treatment of PDR and resolution of anti-VEGF resistance.

Regulation of specific abnormal calcium signals in the hippocampal CA1 and primary cortex M1 alleviates the progression of temporal lobe epilepsy

Temporal lobe epilepsy is a multifactorial neurological dysfunction syndrome that is refractory,resistant to antiepileptic drugs,and has a high recurrence rate.The pathogenesis of temporal lobe epilepsy is complex and is not fully understood.Intracellular calcium dynamics have been implicated in temporal lobe epilepsy.However,the effect of fluctuating calcium activity in CA1 pyramidal neurons on temporal lobe epilepsy is unknown,and no longitudinal studies have investigated calcium activity in pyramidal neurons in the hippocampal CA1 and primary motor cortex M1 of freely moving mice.In this study,we used a multichannel fiber photometry system to continuously record calcium signals in CA1 and M1 during the temporal lobe epilepsy process.We found that calcium signals varied according to the grade of temporal lobe epilepsy episodes.In particular,cortical spreading depression,which has recently been frequently used to represent the continuously and substantially increased calcium signals,was found to correspond to complex and severe behavioral characteristics of temporal lobe epilepsy ranging from gradeⅡto gradeⅤ.However,vigorous calcium oscillations and highly synchronized calcium signals in CA1 and M1 were strongly related to convulsive motor seizures.Chemogenetic inhibition of pyramidal neurons in CA1 significantly attenuated the amplitudes of the calcium signals corresponding to gradeⅠepisodes.In addition,the latency of cortical spreading depression was prolonged,and the above-mentioned abnormal calcium signals in CA1 and M1 were also significantly reduced.Intriguingly,it was possible to rescue the altered intracellular calcium dynamics.Via simultaneous analysis of calcium signals and epileptic behaviors,we found that the progression of temporal lobe epilepsy was alleviated when specific calcium signals were reduced,and that the end-point behaviors of temporal lobe epilepsy were improved.Our results indicate that the calcium dynamic between CA1 and M1 may reflect specific epileptic behaviors corresponding to different grades.Furthermore,the selective regulation of abnormal calcium signals in CA1 pyramidal neurons appears to effectively alleviate temporal lobe epilepsy,thereby providing a potential molecular mechanism for a new temporal lobe epilepsy diagnosis and treatment strategy.

A retrospective study of 2228 cases with eyelid tumors

AIM： To describe the histopathologic and clinical features of eyelid tumor cases from Tianjin Eye Hospital during 2002 to 2015. METHODS： In this retrospective study, a total of 2228 cases of eyelid tumors with pathologic diagnoses were enrolled. The eyelid tumors were classified into three groups according to tumor origin： epidermal, adnexal and miscellaneous, including melanocytic, neural and vascular lesions. Inflammatory tumor-like lesions were excluded. The clinical characteristics of the eyelid tumors were analyzed, including age, gender and lesion location. RESULTS： Most eyelid tumors were epidermal in origin（1080, 48.5%）, followed by miscellaneous（885, 39.7%） and adnexal tumors（263, 11.8%）. Among all the tumors, 292（13.1%） were malignant lesions, 1910（85.7%） benign and 26（1.1%） premalignant lesions. Most malignant tumors originated from epidermal cells（60.0%）, followed by adnexal cells（34.6%）. The most common malignant tumors were basal cell carcinomas（56.5%） followed by sebaceous carcinoma（34.6%）, squamous cell carcinomas（3.8%） and lymphoma/plasmocytoma（1.7%）. The benign and premalignant eyelid lesions mostly originated from epidermal cells（46.4%） followed by miscellaneous cell sources（45.2%）, including melanocytic nevus（33.8%）, seborrheic keratosis（13.7%）, squamous cell papilloma（13.0%） and epidermal cysts（11.5%）. CONCLUSION： Eyelid tumors are mostly epithelial in origin. Benign tumors are significantly more common than malignant tumors with an obvious female predominance, and the most frequent malignant tumor are basal cell carcinoma, sebaceous carcinoma and squamous cell carcinomas. The tumor clinical features varied among the different subtypes.

The binocular intraocular lens power difference in eyes with different axial lengths

AIM:To investigate the binocular intraocular lens(IOL)power difference in eyes with short,normal,and long axial lengths(AL)using Lenstar LS 900 optical biometry.METHODS:A total of 716(1432 eyes)participants were included.The groups were categorized into short(group A:AL<22 mm),normal(group B:22 mm≤AL≤25 mm),and long AL groups(group C:AL>25 mm).The central corneal thickness(CCT),anterior chamber depth(ACD),lens thickness(LT),AL,anterior corneal keratometry,whiteto-white(WTW),pupil diameter(PD),as well as IOL power calculated using embedded Barrett formula were assessed.Bland-Altman plots were used to test the agreement of the binocular parameters.RESULTS:In group A,the CCT of the right eye was significantly thinner than that of the left eye(P=0.044)with a difference of-2±8μm[95%limits of agreement(LoA),-17.8 to 13.2μm].For group B,the PD and IOL power in the right eye were significantly lower than those of the left eye(P=0.001,<0.001)with a difference of-0.05±0.32 mm(95%LoA,-0.68 to 0.58 mm)and-0.18±1.01 D(95%LoA,-2.2 to 1.8 D).The AL of right eye was longer than that of the left eye(P=0.002)with a difference of 0.04±0.25 mm(95%Lo A,-0.45 to 0.52 mm).No significant difference was observed for all the binocular parameters in group C.The percentage of participants with binocular IOL power difference within±0.5 D were 62%(31/50),68.3%(339/496),and 38.8%(66/170)in groups A,B,and C,respectively.CONCLUSION:The binocular parameters related to IOL power are in good agreement,but the binocular IOL power difference of more than half of participants with long AL is more than 0.50 D.

Regulatory mechanisms of retinal ganglion cell death in normal tension glaucoma and potential therapies

Normal tension glaucoma(NTG)is a multifactorial optic neuropathy characterized by normal intraocular pressure,progressive retinal ganglion cell(RGC)death,and glaucomatous visual field loss.Recent studies have described the mechanisms underlying the pathogenesis of NTG.In addition to controlling intraocular pressure,neuroprotection and reduction of RGC degeneration may be beneficial therapies for NTG.In this review,we summarized the main regulatory mechanisms of RGC death in NTG,including autophagy,glutamate neurotoxicity,oxidative stress,neuroinflammation,immunity,and vasoconstriction.Autophagy can be induced by retinal hypoxia and axonal damage.In this process,ischemia can cause mutations of optineurin and activate the nuclear factor-kappa B pathway.Glutamate neurotoxicity is induced by the over-stimulation of N-methyl-D-aspartate membrane receptors by glutamate,which occurs in RGCs and induces progressive glaucomatous optic neuropathy.Oxidative stress also participates in NTG-related glaucomatous optic neuropathy.It impairs the mitochondrial and DNA function of RGCs through the apoptosis signal-regulating kinase-JUN N-terminal kinase pathway.Moreover,it increases inflammation and the immune response of RGCs.Endothelin 1 causes endothelial dysfunction and impairment of ocular blood flow,promoting vasospasm and glaucomatous optic neuropathy,as a result of NTG.In conclusion,we discussed research progress on potential options for the protection of RGCs,including TANK binding kinase 1 inhibitors regulating autophagy,N-methyl-D-aspartate receptor antagonists inhibiting glutamate toxicity,ASK1 inhibitors regulating mitochondrial function,and antioxidants inhibiting oxidative stress.In NTG,RGC death is regulated by a network of mechanisms,while various potential targets protect RGCs.Collectively,these findings provide insight into the pathogenesis of NTG and potential therapeutic strategies.

4D label-free proteomic analysis of vitreous from patients with rhegmatogenous retinal detachment

AIM:To identify metabolites,proteins,and related pathways involved in the etiology of rhegmatogenous retinal detachment(RRD)for use as biomarkers in diagnosing and treating RRD.METHODS:Vitreous specimens were collected and liquid chromatography-tandem mass spectrometry analysis was per formed using the four-dimensional label-free technique.Statistically significant differentially expressed proteins,gene ontology(GO)terms,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway representations,and protein interactions were analyzed.RESULTS:Nine specimens were subjected to proteomic analysis.In total,161 proteins were identified as differentially expressed proteins(DEPs),including 53 upregulated proteins and 108 downregulated proteins.GO functional analysis revealed that some DEPs were enriched in neuron-related terms and membrane protein terms.Moreover,KEGG analysis indicated that the cell adhesion molecule metabolic pathway was associated with the greatest number of DEPs.Finally,the evaluation of protein-protein interaction network revealed that DEPs were clustered in neuronal adhesion,apoptosis,inflammation and immune responses,correct protein folding,and glycolysis.CONCLUSION:Proteomic profiling is useful for the exploration of molecular mechanisms that underlie RRD.This study reveals increased expression levels of proteins related to heat shock protein content,glycolysis,and inflammatory responses in RRD.Knowledge regarding biomarkers of RRD pathogenesis may help to prevent the occurrence of RRD in the future.

Technique of using Cionni-modified capsular tension ring in the management of severely traumatic lens subluxation

AIM:To investigate the effect of Cionni-modified capsular tension ring(CTR)implantation in patients with severely traumatic subluxated cataracts.METHODS:All patients who totally had traumatic cataracts and lost zonule support and underwent cataract surgery were retrospectively analyzed.Corrected distance visual acuity(CDVA),extent of zonulysis,intraocular lens(IOL)position,intraoperative presentation,and complications were assessed.The primary outcomes included IOL centration stability and other postoperative complications.RESULTS:Twenty patients(20 eyes)were included in this study.The mean age in this study was 58.0±11.3y,and the average follow-up time was 17.3±12.8mo.Capsule bags were saved by Cionni-modified CTR.Nine eyes(45%)underwent simultaneously anterior vitrectomy due to the presence of vitreous in the anterior chamber.The preoperative mean CDVA was 0.83±0.24 log MAR,and the postoperative average CDVA was 0.23±0.30 log MAR(P<0.05).The horizontal and vertical IOL decentration after surgery was 0.27±0.12 mm and 0.41±0.19 mm,respectively;the vertical and horizontal IOL tilt after surgery was 5.5°±2.5°and 6.1°±2.2°,respectively.None of the eyes had obvious IOL decentration during the follow-up time.Eight eyes(40%)had posterior capsule opacification(PCO)that was severe enough to cause poor vision.Neodymium:YAG laser capsulotomy were performed on these eyes when the CTR was stabilized.CONCLUSION:With the help of Cionni-modified CTR,capsular bag preservation and better IOL concentration can be achieved without major complications in patients with severely traumatic subluxated cataracts.

Clinical and multimodal imaging features of acute macular neuroretinopathy lesions following recent SARS-CoV-2 infection

AIM:To describe the clinical characteristics of eyes using multimodal imaging features with acute macular neuroretinopathy(AMN)lesions following severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection.METHODS:Retrospective case series study.From December 18,2022 to February 14,2023,previously healthy cases within 1-week infection with SARS-CoV-2 and examined at Tianjin Eye Hospital to confirm the diagnosis of AMN were included in the study.Totally 5 males and 9 females[mean age:29.93±10.32(16-49)y]were presented for reduced vision,with or without blurred vision.All patients underwent best corrected visual acuity(BCVA),intraocular pressure,slit lamp microscopy,indirect fundoscopy.Simultaneously,multimodal imagings fundus photography(45°or 200°field of view)was performed in 7 cases(14 eyes).Near infrared(NIR)fundus photography was performed in 9 cases(18 eyes),optical coherence tomography(OCT)in 5 cases(10 eyes),optical coherence tomography angiography(OCTA)in 9 cases(18 eyes),and fundus fluorescence angiography(FFA)in 3 cases(6 eyes).Visual field was performed in 1 case(2 eyes).RESULTS:Multimodal imaging findings data from 14 patients with AMN were reviewed.All eyes demonstrated different extent hyperreflective lesions at the level of the inner nuclear layer and/or outer plexus layer on OCT or OCTA.Fundus photography(45°or 200°field of view)showed irregular hypo-reflective lesion around the fovea in 7 cases(14 eyes).OCTA demonstrated that the superficial retinal capillary plexus(SCP)vascular density,deep capillary plexus(DCP)vascular density and choriocapillaris(CC)vascular density was reduced in 9 case(18 eyes).Among the follow-up cases(2 cases),vascular density increased in 1 case with elevated BCVA;another case has vascular density decrease in one eye and basically unchanged in other eye.En face images of the ellipsoidal zone and interdigitation zone injury showed a low wedge-shaped reflection contour appearance.NIR image mainly show the absence of the outer retinal interdigitation zone in AMN.No abnormal fluorescence was observed in FFA.Corresponding partial defect of the visual field were visualized via perimeter in one case.CONCLUSION:The morbidity of SARS-CoV-2 infection with AMN is increased.Ophthalmologists should be aware of the possible,albeit rare,AMN after SARS-CoV-2 infection and focus on multimodal imaging features.OCT,OCTA,and infrared fundus phase are proved to be valuable tools for detection of AMN in patients with SARS-CoV-2.

Detection of macular ganglion cell complex loss and correlation with choroidal thickness in chronic and recurrent central serous chorioretinopathy

AIM:To investigate the association of ganglion cell complex thickness(GCCt),global loss volume percentage(GLV%),and focal loss volume percentage(FLV%)with structural and functional findings among patients with chronic central serous chorioretinopathy(CCSC)and recurrent central serous chorioretinopathy(RCSC)by optical coherence tomography(OCT).METHODS:Among 29 patients with monocular affected central serous chorioretinopathy(CSC),15 had CCSC,and 14 had RCSC.The GCCt,FLV%,GLV%,and subfoveal choroidal thickness(SFCT)and sublesional choroidal thickness(SLCT)values were determined using OCT,and the association of these characteristics with neural structure parameters,choroidal morphology,features and functional alterations were estimated for the CCSC and RCSC patients.RESULTS:In CCSC,the affected eyes had significantly lower GCCt values than the fellow eyes in the macular regions(all P<0.05),with the highest GCCt observed in the inferior area.A significant association was found between the GCCt in different regions and the change in best corrected visual acuity(BCVA;r=-0.696;-0.695;-0.694,P<0.05)in CCSC patients.A statistically significant moderate negative correlation indicated that long-term CCSC was associated with greater differences in the GCCt in different regions between affected and fellow eyes(r=-0.562;r=-0.556;r=0.525,P<0.05).Additionally,observation of thickened SFCT was associated with a worse FLV%(r=0.599;r=0.546,P<0.05)in both groups.Similarly,thickened SLCT was associated with FLV%in RCSC patients(r=0.544,P<0.05).CONCLUSION:The distribution and GCCt are associated with the duration and visual outcomes of CCSC,whereas there is no correlation among RCSC patients.FLV%may be instrumental in differentiating the various outer choroidal vessels(pachyvessels)in long-term CSC.These results suggest that neural structure parameters may aid in estimating and predicting the recovery of altered morphology and function in CCSC and RCSC patients.

Differentiation of isolated human umbilical cord mesenchymal stem cells into neural stem cells

AIM：To investigate whether umbilical cord human mesenchymal stem cell（UC-MSC）was able to differentiate into neural stem cell and neuron.·METHODS：The umbilical cords were o btained from pregnant women with their written consent and the approval of the Clinic Ethnics Committee.UC-MSC were isolated by adherent culture in the medium contains 20%fetal bovine serum（FBS）,then they were maintained in the medium contain 10%FBS and induced to neural cells in neural differentiation medium.We investigated whether UC-MSC was able to differentiate into neural stem cell and neuron by using flow cytometry,reverse transcriptase-polymerase chain reaction（RT-PCR）and immunofluorescence（IF）analyzes.·R ESULTS：A substantial number of UC-MSC was harvested using the tissue explants adherent method at about 2wk.Flow cytometric study revealed that these cells expressed common markers of MSCs,such as CD105（SH2）,CD73（SH3）and CD90.After induction of differentiation of neural stem cells,the cells began to form clusters;RT-PCR and IF showed that the neuron specific enolase（NSE）and neurogenic differentiation 1-positive cells reached 87.3%±14.7%and 72.6%±11.8%,respectively.Cells showed neuronal cell differentiation after induced,including neuron-like protrusions,plump cell body,obviously and stronger refraction.RT-PCR and IF analysis showed that microtubule-associated protein 2（MAP2）and nuclear factor-M-positive cells reached 43.1%±10.3%and 69.4%±19.5%,respectively.·CONCLUSION：Human umbilical cord derived MSCs can be cultured and proliferated and differentiate into neural stem cells,which may be a valuable source for cell therapy of neurodegenerative eye diseases.

Application of pediatric ocular trauma score in pediatric open globe injuries

AIM:To evaluate the predictive value of pediatric penetrating ocular trauma score(POTS)on the visual outcome in children with open globe injury.METHODS:A retrospective study in 90 children(60 males and 30 females)aged 1-15 y(average,7.48±2.86 y)with penetrating ocular trauma was performed.Each patient’s POTS was calculated.The effects of POTS on final visual acuity(FVA)were examined.Correlation between factors affecting POTS and the FVA was established.RESULTS:All patients presented with single-eye trauma.The follow-up time was 3-21 mo(average,10.23±3.54 mo).Among the 90 cases of penetrating wounds,71 eyes(78.89%)were injured in Zone I(wound involvement limited to the cornea,including the corneoscleral limbus),17 eyes(18.89%)were injured in Zone II(wound involving the sclera and no more posterior than 5 mm from the corneoscleral limbus),and 2 eyes(2.22%)were injured in Zone III(wound involvement posterior to the anterior 5 mm of the sclera).Analysis of POTS and FVA showed important correlation between them(r=0.414,P=0.000).Initial visual acuity(P=0.00),age(P=0.02),injury location(P=0.002),traumatic cataract(P=0.00),vitreous hemorrhage(P=0.027),retinal detachment(P=0.003),and endophthalmitis(P=0.03)were found to be statistically significant factors for the FVA outcome.CONCLUSION:Ocular trauma presents serious consequences and poor prognosis in children.The POTS may be a reliable prognostic tool in children with open globe injury.

Transfection with CXCR4 potentiates homing of mesenchymal stem cells in vitro and therapy of diabetic retinopathy in vivo

AIM：To investigate the effect of the overexpression of C-X-C chemokine receptor type 4（CXCR4） on homing of mesenchymal stem cells（MSCs） in vitro and therapeutic effects of diabetic retinopathy（DR） in vivo.METHODS：MSCs were infected by lentivirus constructed with CXCR4.The expression of CXCR4 was examined by immunofluorescence,Western blot,and quantitative polymerase chain reaction.CXCR4-overexpressing MSCs were cultured in vitro to evaluate their chemotaxis,migration,and apoptotic activities.CXCR4-overexpressing MSCs were intravitreally injected to observe and compare their effects in a mouse model of DR.The histological structure of DR in rats was inspected by hematoxylin and eosin staining.The expression of rhodopsin,neuron-specific enolase（NSE）,and inflammatory cytokines interleukin（IL）-6 and tumor necrosis factor（TNF）-α was examined by Western blot and immunohistochemical analyses.RESULTS：The transduction of MSCs by lentivirus was effective,and the transduced MSCs had high expression levels of CXCR4 gene and protein.Improved migration activities were observed in CXCR4-overexpressing MSCs.Further,reduced retinal damage,upregulation of rhodopsin and NSE protein,and downregulation of inflammatory cytokines IL-6 and TNF-α were observed in CXCR4-overexpressing MSCs in vivo.CONCLUSION：The homing of MSCs can be enhanced by upregulating CXCR4 levels,possibly improving histological structures of DR.CXCR4-overexpressing MSCs can be a novel strategy for treating DR.

Effect of the posterior corneal surface on total corneal astigmatism in patients with age-related cataract

AIM： To explore the effect of the posterior astigmatism on total corneal astigmatism and evaluate the error caused by substituting the corneal astigmatism of the simulated keratometriy （simulated K） for the total corneal astigmatism in age-related cataract patients. METHODS： A total of 211 eyes with age-related cataract from 164 patients （mean age： 66.8±9.0y, range： 45-83y） were examined using a multi-colored spot reflection topographer, and the total corneal astigmatism was measured. The power vector components J0 and J45 were analyzed. Correlations between the magnitude difference of the simulated K and total cornea astigmatism （magnitude differenceSimK-Tca）, anterior J0, and absolute meridian difference （AMD） between the anterior and posterior astigmatisms were calculated. To compare the astigmatism of the simulated K and total cornea both in magnitude and axial orientation, we drew double-angle plots and calculated the vector difference between the two measures using vector analysis. A corrective regression formula was used to adjust the magnitude of the simulated K astigmatism to approach that of the total cornea. RESULTS： The magnitude differenceSimK-Tca was positively correlated with the anterior corneal J0 （Spearman’s rho= 0.539; P〈0.001） and negatively correlated with the AMDR （Spearman’s rho=-0.875, P〈0.001）. When the anterior J0 value was larger than 1.3 D or smaller than -0.8 D, the errors caused by determining the total corneal astigmatism with the karatometric calculation tended to be greater than 0.25 D. An underestimation by 16% was observed for against the rule （ATR） astigmatism and an overestimation by 9% was observed for with the rule （WTR） astigmatism when ignoring the posterior measurements. CONCLUSION： Posterior corneal astigmatism should be valued for more precise corneal astigmatism management, especially for higher ATR astigmatism of the anterior corneal surface. We suggest a 9% reduction in the magnitude of the simulated K in eyes with WTR astigmatism, and a 16% addition of the magnitude of the simulated K in eyes with ATR astigmatism.

Surgery at early versus late for intermittent exotropia:a Meta-analysis and systematic review

AIM:To compare the outcomes between early surgery and late surgery for intermittent exotropia(IXT)with a Metaanalysis.METHODS:Scientific databases including PubMed,Embase,Web of Science,Cochrane and China National Knowledge Infrastructure were searched prior to December 16,2019.From this broad database search,we performed some Meta-analysis including eleven independent studies,to further evaluate the outcome(s)when comparing early versus late surgery for IXT.The boundaries between early and late surgery and the surgery methods were not inconsistent,so subgroup analyses were conducted by different boundaries of age at surgery and different surgical approaches.The pooled odds ratios(ORs)and the 95%confidence interval(CI)were estimated according to the random-effects model for high heterogeneity between studies.RESULTS:Eleven retrospective studies were included in this Meta-analysis.No significant difference between early and late surgery was observed for IXT patients(OR_(First follow-up)=0.88,95%CI 0.53-1.44,P=0.61;OR_(Final follow-up)=1.48,95%CI 0.94-2.31,P=0.09).However,sensitivity analysis performed by sequentially omitting individual studies showed that the final follow-up result was not stable.Subgroup analyses revealed that an earlier surgical procedure could lead to a better outcome in the 4-year boundary subgroup as well as the bilateral lateral rectus recession(BLR)subgroup for the final follow-up(OR_(4y)=2.64,95%CI 1.57-4.44,P=0.00;OR_(BLR)=2.25,95%CI 1.36-3.74,P=0.00).CONCLUSION:Early surgery for IXT provides a better long term follow-up outcome when patients are younger than 4 years old or choose the BLR surgical method.

Corneal biomechanical properties changes after coaxial 2,2-mm microincision and standard 3,0-mm phacoemulsification

AIM： To compare the changes in corneal biomechanics measured by ocular response analyzer （ORA） after 2.2-ram microincision cataract surgery and 3.0-mm standard coaxial phacoemulsification. METHODS： The prospective nonrandomized study comprised eyes with cataract that had 2.2-mm coaxial microincision or 3.0 -mm standard incision phacoemulsification. The corneal hysteresis （CH）, corneal resistance factor （CRF）, corneal-compensated intraocular pressure （IOPcc） and Goldmann-correlated intraocular pressure （IOPg） were measured by ORA preoperatively and at ld, 1-, 2-, 3- and 4-week postoperatively. Results were analyzed and compared between groups. RESULTS： In both groups, CH decreased in the immediate postoperative period （P〈0.05）, returned to the preoperative level at one week （P =0.249） in the 2.2-mm group, and at two weeks in the 3.0-mm group （P --0.264）; there was no significant change in CRF values. In 2.2-mm group, mean IOPcc and IOPg increased at ld postoperatively （both ,P〈0.05）, and returned to preoperative level at one week （,0 =0.491 and P =0.923, respectively）. In 3.0-mm group, mean IOPcc and IOPg increased at ld and lwk postoperatively （P =0.005 and ,P =0.029, respectively）, and returned to preoperative level at 2wk （P =0.347 and P =0.887, respectively）. CONCLUSION： Significant differences between preoperative and postoperative corneal biomechanical values were found for CH, IOPcc and IOPg. But the recovery time courses were different between the two groups. The 2.2-mm coaxial microincision cataract surgery group seemed recovery faster compared to the 3.0-mm standard coaxial phacoemulsification group.

Evaluation of a rat meibomian gland dysfunction model induced by closure of meibomian gland orifices

AIM： To find a stable, inexpensive, and reliable method to produce a rat meibomian gland dysfunction（MGD） model. METHODS： We inserted slim guidewires into the meibomian gland orifices of twelve Brown Norway rats and fulgurized every guidewire to destroy part of the meibomian gland. We then observed the morphological changes in the eyelid margin, and compared the data of tear breakup time（TBUT）, Schirmer I test, and the corneal fluorescence staining scores at different times（1, 2, 4, and 6 wk）. We observed pathological changes of the cornea, conjunctiva and meibomian gland, and we used real-time polymerase chain reaction to analyze epithelial growth factor（EGF）, interleukin-6（IL-6）, IL-8, tumor necrosis factor-α（TNF-α）, and Ki67. RESULTS： In the fourth week, compared with the control group, the TBUT of the model group began to decreased（P〈0.05）. The tear secretion remained stable（P〉0.05）. The corneal dots were significantly increased in the fourth week when the fusion stain began to appear（P〈0.05）. In the fourth week, partial meibomian gland openings had hoary secretions blocked, orifices were expanded, and there was a partial convex deformation. In the sixth week, the tissue section showed that the number of conjunctival goblet cells was decreased, epithelial cells were irregular, the epithelium was detached and rough, and meibomian glands were lost. The expressions of EGF, IL-6, IL-8, and TNF-α in corneal, conjunctival, and meibomian tissues were highly increased（P〈0.05）, but no statistical difference was found in the expression of Ki67 in corneal and conjunctival tissues（P〉0.05）. CONCLUSION： The MGD rat model, produced via electrocauterization of meibomian gland orifices, matched clinical manifestations and cytokine levels. Our research provides a new method of achieving an MGD animal model.

Mesenchymal stem cells-derived exosomes ameliorate blue light stimulation in retinal pigment epithelium cells and retinal laser injury by VEGF-dependent mechanism

AIM： To observe the effect of exosomes derived from human umbilical cord blood mesenchymal stem cells（h UCMSCs） on the expression of vascular endothelial growth factor-A（VEGF-A） in blue light injured human retinal pigment epithelial（RPE） cells and laser-induced choroidal neovascularization（CNV） in rats.METHODS： Exosomes were isolated from h UCMSCs and characterized by transmission electron microscope and Western blot. MSCs-derived exosomes were cultured with RPE cells exposed to blue light. The m RNA and protein expression of VEGF-A were determined by real time-polymerase chain reaction（PCR） and Western blot, respectively. Immunofluorescence assay was used for the detection of the expression level of VEGF-A. We injected different doses of MSCs-derived exosomes intravitreally to observe and compare their effects in a mouse model of laserinduced retinal injury. The histological structure of CNV in rats was inspected by hematoxylin-eosin（HE） staining and fundus fluorescein angiography. The expression of VEGF-A was detected by immunohistochemistry.RESULTS： Exosomes exhibited the typical characteristic morphology（cup-shaped） and size（diameter between 50 and 150 nm）. The exosomes marker, CD63, and h UCMSCs marker, CD90, showed a robust presence. In vitro, MSCsderived exosomes downregulated the m RNA（Exo-L： t=6.485, 7.959, 9.286; Exo-M： t=7.517, 10.170, 13.413; Exo-H： t=10.317, 12.234, 14.592, P〈0.05） and protein（Exo-L： t=2.945, 4.477, 6.657; Exo-M： t=4.713, 6.421, 8.836; Exo-H：t=6.539, 12.194, 12.783; P〈0.05） expression of VEGF-A in RPE cells after blue light stimulation. In vivo, we found that the MSCs-derived exosomes reduced damage, distinctly downregulated VEGF-A（Exo-H： t=0.957, 1.382; P〈0.05）, and gradually improved the histological structures of CNV for a better visual function（Exo-L： 0.346, Exo-M： 3.382, Exo-H： 8.571; P〈0.05）. CONCLUSION： MSCs-derived exosomes ameliorate blue light stimulation in RPE cells and laser-induced retinal injury via downregulation of VEGF-A.

Effect of rigid gas permeable contact lens on keratoconus progression: a review

The prevalence of keratoconus is 1/2000 in the general population and is high in adolescents.Keratoconus is a progressive disease,which has a great impact on patients’quality of life and mental health.It can be managed by surgical and non-surgical means,rigid gas permeable(RGP)contact lens as its main non-surgical method is widely used in clinic.The efficacy of wearing RGP contact lens has been confirmed to some extent,but some studies have found that wearing RGP contact lens has adverse effects,which may promote disease progression.In this paper,the advantages and disadvantages of RGP contact lens in controlling keratoconus were reviewed to provide more suggestions and references for the clinical application of RGP contact lens.