The gut-eye axis:from brain neurodegenerative diseases to age-related macular degeneration

Age-related macular degeneration is a serious neurodegenerative disease of the retina that significantly impacts vision.Unfortunately,the specific pathogenesis remains unclear,and effective early treatment options are consequently lacking.The microbiome is defined as a large ecosystem of microorganisms living within and coexisting with a host.The intestinal microbiome undergoes dynamic changes owing to age,diet,genetics,and other factors.Such dysregulation of the intestinal flora can disrupt the microecological balance,resulting in immunological and metabolic dysfunction in the host,and affecting the development of many diseases.In recent decades,significant evidence has indicated that the intestinal flora also influences systems outside of the digestive tract,including the brain.Indeed,several studies have demonstrated the critical role of the gut-brain axis in the development of brain neurodegenerative diseases,including Alzheimer’s disease and Parkinson’s disease.Similarly,the role of the“gut-eye axis”has been confirmed to play a role in the pathogenesis of many ocular disorders.Moreover,age-related macular degeneration and many brain neurodegenerative diseases have been shown to share several risk factors and to exhibit comparable etiologies.As such,the intestinal flora may play an important role in age-related macular degeneration.Given the above context,the present review aims to clarify the gut-brain and gut-eye connections,assess the effect of intestinal flora and metabolites on age-related macular degeneration,and identify potential diagnostic markers and therapeutic strategies.Currently,direct research on the role of intestinal flora in age-related macular degeneration is still relatively limited,while studies focusing solely on intestinal flora are insufficient to fully elucidate its functional role in age-related macular degeneration.Organ-on-a-chip technology has shown promise in clarifying the gut-eye interactions,while integrating analysis of the intestinal flora with research on metabolites through metabolomics and other techniques is crucial for understanding their potential mechanisms.

Different Cultures and Different Fates—On Cultural Meanings of “Bluest Eye” in Morrison'sThe Bluest Eye

The Bluest Eye is Toni Morrison’s first novel.After its publication,it receives many criticisms.This article aims to ana lyze Pecola and Claudia’s understandings about black culture,then to clarify that different interpretations of the very name"the bluest eye"lead to different fates.With different visions of the black heritage,Pecola and Claudia have different perception of the world and thus have widely divergent outcomes in the painful circumstances.

Loss of Self-identity--A Comparative Analysis of Everything I Never Told You and The Bluest Eyes

As a non-mainstream group with a large proportion in the pluralistic society of the United States,the literary forms of the black and Asian groups have always attracted much attention.The Bluest Eyes and Everything I Never Told You appeared in different social times and told about different ethnic and cultural backgrounds,they both involved the exclusion of non-mainstream ethnic groups by the mainstream white society and the denial and loss of personal identity of the two different ethnic groups in the face of the mainstream culture.This paper will make a comparative analysis of these two works.By comparing the loss of self-racial identity of the protagonists in the two novels,this paper will make an in-depth discussion of the survival status of African Americans and Asians,and reveal the self-identity loss of black people and Asian people in the mainstream culture.Through comparative analysis,more scholars pay attention to this issue,which is of great practical significance to further understand the literary dynamics of African American and Asian ethnic groups.

Causes of Pecola＇s Tragedy in The Bluest Eye

Toni Morrison has a unique status in American literature. She is the winner of the National Book Critic Circle Award, the Pulitzer for Fiction and many other literary awards. She was granted the Nobel Prize for literature in 1993, thus becoming the first A^can-American writer to receive this honor. Her first novel The Bluest Eye （1970） tells the story of the bitter and tragic experience suffered by Pecola, a little black girl, and loss of black people＇s self-respect, confidence, value, and culture. The present paper, first of all, gives a brief introduction of the story Then the paper explores the root causes of Pecola＇s tragedy from two aspects： The cause of racial oppression and self-hatred, and the cause of the loss in her independent consciousness. The paper concludes that Pecola is the victim and scapegoat of racial oppression, self-hatred and the loss of her independent consciousness existing in the black community

Research on Culture Goods and the Image of Mixed-blood in The Bluest Eye

The Bluest Eye is Toni Morrison’s maiden work,through which Morrison carried out independent thinking on the question of“What is beauty?”In The Bluest Eye,the image of mixed-blood is characterized as a self-satisfied beautiful girl or lady due to light skin color.However,Morrison shatters their proud aesthetic edifice through satirical techniques.Firstly,this paper starts with the analysis of Shirley Temple on the blue-and-white cup and Mary Jane on candy wrapper as culture goods,in order to reveal the aesthetic standards of the mainstream.Next,through close reading,this paper,taking the example of a high-yellow child Maureen Peal,and the graceful sugar-brown lady Geraldine,makes deep analysis on their sense of superiority and artistic characteristics,and aims to better understand Morrison’s satirical techniques and interpretation of beauty.

Metaphors and Symbols in The Bluest Eye

Toni Morrison as a great African-American writer produces many perfect novels. In her novels the shining points not only lie in the internal full-bodied black cultural tradition, but also lie in the absorption of the black folk oral literature and a great number of African myth and legend. She also gets influences from the skill of the Western Magical Realism of which the most important things are the use of metaphors and symbols. There are a lot of extremely profound symbolic images in Toni Morrison's novels. The Bluest Eye is the typical representation of these shining points. Above all, there is a great significance to analyze the symbolic images for achieving a deeper understanding of Toni Morrison's novels.

The Neurotic Men: A Neo-Freudian Interpretation of The Bluest Eye

The Novel The Bluest Eye portrays several male characters who behave in neurotic ways. The Neo-Freudian psychoanalysis is employed to analyse Cholly, Junior and Soaphead Church, suggesting that they have the neurotic needs for power, affection and withdrawal respectively, thus helping develop the utilization of Neo-Freudian theory in the study of this novel.

Miniature of The Bluest Eye—A Stylistic Approach to the First Fragment

Morrison’s The Bluest Eye begins with a fragment—a triply-repeated story.In the second narration,all punctuation disappears,along with the capital letters.In the third telling,the spacing between the sentences fades,which creates a sense of incomprehensible linguistic chaos.A stylistic approach is adopted to interpret underlying meanings:insanity of the protagonist Pecola and dark sides of American society.Methodically,it is the first time that optics is employed to interpret story,and stylistics can nourish itself from natural sciences.

A Mirror of Black People’s Life——An Analysis of The Bluest Eye

As an African American writer, Toni Morrison is good at portraying diversified characters in her books to show the real life of black people and their cultural identities. Morrison regards The Bluest Eye as a broken mirror in which black people's true life is presented.

An Analysisof Pecolain The Bluest Eye Basedon Aristotle's Theoryof Tragedy

Based on the theory of tragedy in Poetics by Aristotle, this paper analyzes Pecola, a protagonist in The Bluest Eye written by Toni Morrison, from the four aspects of the"completeness"of plot, the"Reversal"and"Recognition"of plot, the Character and the tragic effect: pity and fear to prove that the theory of tragedy is still practical and conductive to the analysis of literary works even until nowadays.

Psychometric validation of the Chinese version of the dry eye-related quality-of-life score questionnaire

AIM:To psychometrically validate the Chinese version of the dry eye-related quality-of-life score questionnaire(DEQSCHN)among Chinese patients with dry eye.METHODS:This study involved 231 participants,including 191 with dry eye disease(DED)comprising the dry eye disease group,and 40 healthy participants forming the control group.Participants were required to complete the DEQS-CHN,and Chinese dry eye questionnaire and undergo clinical tests including the fluorescein breakup time(FBUT),corneal fluorescein staining(CFS),and Schirmer I test.To assess the internal consistency and retest reliability,Cronbach’sαand the intraclass correlation coefficient(ICC)were employed.Content validity was assessed by item-level content validity index(ICV)and an average scale-level content validity index(S-CVI/Ave).Construct validity was assessed by confirmatory factor analysis.The concurrent validity was assessed by calculating correlations between DEQS-CHN and Chinese dry eye questionnaire.Discriminative validity was evaluated through nonparametric tests,with receiver operating characteristic(ROC)curve serving as conclusive indicators of the questionnaire’s distinguishing capability.RESULTS:The Cronbach’sαcoefficients for frequency and degree of ocular symptoms,impact on daily life,and summary score were 0.736,0.704,0.811,0.818,0.861,and 0.860,respectively,and the ICC were 0.611,0.677,0.715,0.769,0.711,and 0.779,respectively.All I-CVI scores ranged from 0.833 to 1.000,with an S-CVI/Ave of 0.956.Confirmatory factor analysis results exhibited a wellfitting model consistent with the original questionnaire[χ^(2)/df=2.653,incremental fit index(IFI)=0.924,comparative fit index(CFI)=0.924,Tucker-Lewis index(TLI)=0.909,and root mean square error of approximation(RMSEA)=0.065].There was a moderate positive correlation between the DEQS-CHN and the Chinese dry eye questionnaire(r^(2)=0.588).The dry eye group demonstrated significantly higher scores compared to the control group,and the area under the curve(AUC)value was 0.8092.CONCLUSION:The DEQS-CHN has been demonstrated as a valid and reliable instrument for assessing the impact of dry eye disease on the quality of life among Chinese individuals with DED.

Different concentrations of hyaluronic acid eye drops for dry eye syndrome: a systematic review and Meta-analysis

AIM:To compare high or low concentration of hyaluronic acid eye drops(HY)for dry eye syndromes(DES).METHODS:Randomized controlled trials(RCTs)comparing various concentrations of HY were searched in PubMed,Embase,Web of Science,Cochrane,SinoMed,CNKI,Wanfang Database,CQVIP,and Chinese journals databases between inception and July 2023.Pooled standardized mean differences(SMD)or weighted mean difference(WMD)with 95%confidence intervals(CI)from RCTs evaluating Schirmer’s I test(SIT),corneal fluorescein staining score(CFS),tear breakup time(TBUT),DES score(DESS),and Ocular Surface Disease Index(OSDI)were calculated.Sensitivity analysis,Egger’s test and Meta-regression analysis were performed for all indicators.RESULTS:We conducted a Meta-analysis of 10 RCTs that met the inclusion criteria,involving 1796 cases.High-concentrations group significantly improved the outcome of CFS according to random effects modelling(SMD,-3.37;95%CI,-5.25 to-1.48;P=0.0005).The rest of the results were not statistically significant,including indicators such as SIT,TBUT,DESS and OSDI.CONCLUSION:For dry eyes with positive corneal staining,a high concentration of HY is recommended,whereas in other cases,a high concentration of HY does not offer a more pronounced advantage over a low concentration of HY in the treatment of dry eyes.

Analyze interleukin-1β,interleukin-6,and tumor necrosis factor-αlevels in dry eye and the therapeutic effect of cyclosporine A

BACKGROUND Dry eye is a common eye disease.Artificial tears supplements are widely used for the treatment of dry eyes.However,multiple adverse effects have been observed in patients receiving long-term treatment with artificial tears,which may affect the therapeutic effect.AIM To analyze the characteristics of interleukin-1β(IL-1β),interleukin-6(IL-6),and tumor necrosis factor-alpha(TNF-α)levels in patients with dry eye and the therapeutic effect of artificial tears combined with cyclosporine A.METHODS A total of 124 dry eye patients treated at The First People’s Hospital of Xining from April 2020 to April 2022 were selected as the observation group,while 20 healthy individuals served as the control group during the same period.Levels of inflammatory markers,including IL-1β,IL-6,and TNF-α,were analyzed.The observation group was further divided into a study group and a control group,each consisting of 62 patients.The control group received artificial tears,whereas the study group received a combination of artificial tears and cyclosporine A.Inflammatory markers,Schirmer’s test(SIT),tear break-up time(TBUT),corneal fluorescein staining(CFS),National Eye Institute Visual Function Questionnaire-25(NEI-VFQ-25)scores,and adverse events(AEs)were compared between the two groups.RESULTS The observation group exhibited significantly elevated serum levels of IL-1β,IL-6,and TNF-αin comparison to the healthy group.Following treatment,the study group demonstrated substantial reductions in IL-1β,IL-6,and TNF-αlevels relative to the control group.Moreover,after treatment,the study group experienced a marked decrease in CFS scores and significant increases in both SIT and BUT levels when compared to the control group.Additionally,significant improvements were observed in the primary symptom of dry eye and secondary symptoms such as photophobia,foreign body sensation,fatigue,red eye,and burning sensation within the study group.Furthermore,post-treatment NEI-VFQ-25 scores across all dimensions exhibited significant enhancements in the study group compared to the control group(P<0.05).It is noteworthy that significant AEs were reported in both groups throughout the treatment period.CONCLUSION Cyclosporine A combined with artificial tears is effective in treating dry eye,yielding enhanced outcomes by improving SIT and TBUT levels,reducing CFS scores,and ameliorating vision-related quality of life.

Influencing factors of self-management ability among dry eye patients in west China

AIM:To investigate the current situation and influencing factors of self-management ability in dry eye patients in west China.METHODS:A total of 265 patients clinically diagnosed with dry eye received a convenience survey questionnaire at West China Hospital of Sichuan University.All participants completed the rating scale of health self-management skill for adults(AHSMSRS),Huaxi Emotional-Distress Index(HEI),e-health literacy scale(e-HEALS)and Brief Illness Perception Questionnaire(Brief-IPQ).A generalized linear model was employed to establish a multivariate linear model with demographic data,psychological state,e-HEALS,and illness perception as independent variables and health selfmanagement skill score as the dependent variable.RESULTS:The mean score for health self-management skill was 165.58±15.79.Multivariate analysis revealed that advanced age,better illness perception and improved psychological state were associated with better health selfmanagement ability among dry eye patients.Furthermore,the health self-management ability of patients with a disease duration less than 1y was found to be higher compared to those with a disease duration exceeding 1y.CONCLUSION:The health self-management ability of dry eye patients in west China is relatively high.Age,duration of disease,illness perception and psychological state are the influencing factors on the health selfmanagement ability of dry eye patients.

Effectiveness of intravitreal ranibizumab for diabetic macular edema in vitrectomized versus non-vitrectomized eyes:a Meta-analysis

AIM:To evaluate the effectiveness and safety of intravitreal ranibizumab(IVR)for diabetic macular edema(DME)in vitrectomized versus non-vitrectomized eyes.METHODS:The PubMed,EMBASE,Web of Science,Cochrane,EBSCO were comprehensively searched for studies comparing vitrectomized and non-vitrectomized eyes with DME.Clinical outcomes of best-corrected visual acuity(BCVA),central macular thickness(CMT),the mean number of intravitreal injection and adverse events were extracted and analyzed.RESULTS:Six studies involving 641 eyes were included.Final visual gain significantly improved and CMT significantly reduced in vitrectomized eyes at 6mo and 12mo visits(P<0.05).Although the mean reduction in CMT among non-vitrectomized eyes was significantly greater than in vitrectomized eyes at the 6mo[mean difference(MD)=53.57,95%confidence interval(CI):28.03 to 78.72,P<0.0001]and 12mo(MD=49.65,95%CI:19.58 to 79.72,P=0.01),no significant difference was detected in improvement in BCVA at either 6mo(MD=0.05,95%CI:-0.02 to 0.13,P=0.14)or 12mo(MD=0.03,95%CI:-0.04 to 0.09,P=0.43).Injection number of ranibizumab in non-vitrectomized eyes was significantly less than that in vitrectomized eyes during 6-month period(MD=0.60,95%CI:0.16 to 1.04,P=0.008),while there was no statistically significant difference between the two groups during 12mo of follow-up.CONCLUSION:Evidence from current study suggests that IVR was useful for both vitrectomized group and nonvitrectomized group with DME.Although less reduction in macular thickness is found in vitrectomized group,visual improvement between two groups is similar.

Distribution of pathogenic bacteria and antimicrobial sensitivity of eye infections in Suzhou

AIM:To investigate the types of bacteria in patients with eye infections in Suzhou and their drug resistance to commonly used antibacterial drugs.METHODS:The clinical data of 155 patients were retrospectively collected in this study,and the pathogenic bacteria species and drug resistance of each pathogenic bacteria were analyzed.RESULTS:Among the 155 patients(age from 12 to 87 years old,with an average age of 57,99 males and 56 females)with eye infections(160 eyes:74 in the left eye,76 in the right eye and 5 in both eyes,all of which were exogenous),71(45.81%)strains were gram-positive bacteria,23(14.84%)strains were gram-negative bacteria and 61(39.35%)strains were fungi.Gram-positive bacteria were highly resistant to penicillin and erythromycin(78.87%and 46.48%respectively),but least resistant to vancomycin at 0.Gram-negative bacteria were highly resistant to cefoxitin and compound sulfamethoxazole(100%and 95.65%respectively),but least resistant to meropenem at 0.Comparison of the resistance of gram-positive and gram-negative bacteria to some drugs revealed statistically significant differences(P<0.05)in the resistance of both to cefoxitin,cotrimoxazole,levofloxacin,cefuroxime,ceftriaxone and ceftazidime,and both had higher rates of resistance to gram-negative bacteria than to gram-positive bacteria.The distribution of bacterial infection strains showed that Staphylococcus epidermidis was the most common strain in the conjunctiva,cornea,aqueous humor or vitreous body and other eye parts.Besides,Fusarium and Pseudomonas aeruginosa were also among the most common strains of conjunctival and corneal infections.CONCLUSION:Gram-positive bacteria are the dominant bacteria in eye infections,followed by gram-negative bacteria and fungi.Considering the resistance of gramnegative bacteria to multiple drugs,monitoring of bacteria should be strengthened in eye bacterial infections for effective prevention and control to reduce complications caused by eye infections.

Dry eye disease in systemic lupus erythematosus: a cross sectional study

AIM:To explore ocular surface manifestations of dry eye disease(DED)and its influencing factors in systemic lupus erythematosus(SLE)patients.METHODS:Ophthalmological examinations were conducted in SLE patients(n=43)and controls(n=41),including Ocular Surface Disease Index(OSDI),objective scatter index(OSI),tear meniscus height(TMH),lipid layer thickness(LLT),non-invasive Keratograph tear breakup time(NIKBUT),corneal fluorescein score(CFS),Schirmer I test.DED was diagnosed according to the Tear Film and Ocular Surface Society Dry Eye Workshop II Criteria.SLE patients were further divided into DED group and non-DED group,the disease activity,clinical manifestations and laboratory investigations were compared between the two groups.The disease activity was evaluated by Systemic Lupus Erythematosus Disease Activity Index 2000(SLEDAI-2K).Receiver operative characteristic(ROC)curve and multiplefactor binary logistic regression were performed.RESULTS:SLE patients showed higher OSDI[9.1(2.8-15.9)vs 6.3(2.2-7.5),P=0.035],higher OSI[1.67(1.09-2.60)vs 0.96(0.87-1.60),P=0.001],higher CFS[1(0-2)vs 0(0-1),P=0.001],lower LLT[65(42-100)vs 100(79.5-100),P=0.010],and lower NIKBUT[8.03(4.02-9.73)vs 9.67(5.26-12.71),P=0.030]than controls.The 32.6%of SLE patients had DED,which was higher than 12.2%of healthy controls.DED group showed higher SLEDAI-2K score[9.7±6.1 vs 5.4±3.4,P=0.025],higher anti-cardiolipin antibody(ACL)[8.7(3.5-13.2)vs 3.6(2.0-6.9),P=0.035],and higher proportion of patients with cutaneous eruption[42.9%vs 6.9%,P=0.015]than non-DED group.According to multiple-factor binary logistic regression analysis,the SLEDAI-2K score(OR=1.194,P=0.041)and cutaneous eruption(OR=7.094,P=0.045)could be consider as risk factors for DED in SLE patients.The ROC curve of the combined factors including age,disease duration,SLEDAI-2K score,ACL,and cutaneous eruption was analyzed,with a sensitivity of 0.786,a specificity of 0.793,and an area under curve of 0.820.CONCLUSION:Ocular surface affection is frequent in SLE patients,and patients with high disease activity and cutaneous eruption show increased risk of DED.

A finite element model of the eye matched with in vitro experiments for the prediction of traumatic retinal detachment

This study aimed to conduct finite element(FE)analysis matched with an in vitro experiment to analyze traumatic retinal detachments(TrRD)resulting from blunt trauma and provide stress and strain thresholds to predict the occurrence of TrRD.The in vitro experiment was performed on forty-eight porcine eyes using a pendulum device.We examined dynamic mechanical responses at four energy levels.A FE model,based on experimental results and published data,was used to simulate TrRD.Fifty-one additional eyes underwent immediate pathological examination following blunt impact.A dynamic variation of velocities was observed post-impact,displaying an approximate cosine oscillation-attenuation profile.Energy absorption increased as the initial energy and differed significantly at four energy levels(p<0.001).FE simulation showed a peak strain of 0.462 in the anterior vitreous body and a peak stress of 1.408 MPa at the cornea at the high-energy level.During the energy transfer,the stress was initially observed in retinal region along the impact direction at the separation.TrRD were observed in injured eyes,where a few detachments were detected in control eyes.Correlations were performed between the proportion of pathological outcomes and FE results.In conclusion,this study suggests that stress contributes to the development of retinal detachment,providing an indicator to distinguish the occurrence of TrRD.

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.

Efficacy of recombinant human epidermal growth factor plus sodium hyaluronate eye drops in diabetic dry eye post-cataract surgery

BACKGROUND Dry eye syndrome(DES)after diabetic cataract surgery can seriously affect the patient’s quality of life.Therefore,effective alleviation of symptoms in patients with this disease has important clinical significance.AIM To explore the clinical effect of recombinant human epidermal growth factor(rhEGF)plus sodium hyaluronate(SH)eye drops on DES after cataract surgery in patients with diabetes.METHODS We retrospectively evaluated 82 patients with diabetes who experienced DES after cataract surgery at Tianjin Beichen Hospital,Affiliated Hospital of Nankai University between April 2021 and April 2023.They were classified into an observation group(42 cases,rhEGF+SH eye drops)and a control group(40 cases,SH eye drops alone),depending on the different treatment schemes.The therapeutic efficacy,dry eye symptom score,tear film breakup time(TFBUT),basic tear secretion score[assessed using Schirmer I test(SIt)],corneal fluorescein staining(FL)score,tear inflammatory markers,adverse reactions during treat-ment,and treatment satisfaction were compared between the two groups.RESULTS Therapeutic efficacy was higher in the observation group compared with the control group.Both groups showed improved TFBUT and dry eye,as well as improved SIt and FL scores after treatment,with a more pronounced improvement in the observation group.Although no marked differences in adverse reactions were observed between the two groups,treatment satisfaction was higher in the observation group.CONCLUSION rhEGF+SH eye drops rendered clinical benefits to patients by effectively ameliorating dry eye and visual impairment with favorable efficacy,fewer adverse reactions,and high safety levels.Thus,this treatment should be promoted in clinical practice.