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.

Exploring the role of N-acetyltransferases in diseases:a focus on N-acetyltransferase 9 in neurodegeneration

Acetyltransferases,required to transfer an acetyl group on protein are highly conserved proteins that play a crucial role in development and disease.Protein acetylation is a common post-translational modification pivotal to basic cellular processes.Close to 80%-90%of proteins are acetylated during translation,which is an irreversible process that affects protein structure,function,life,and localization.In this review,we have discussed the various N-acetyltransferases present in humans,their function,and how they might play a role in diseases.Furthermore,we have focused on N-acetyltransferase 9 and its role in microtubule stability.We have shed light on how N-acetyltransferase 9 and acetylation of proteins can potentially play a role in neurodegenerative diseases.We have specifically discussed the N-acetyltransferase 9-acetylation independent function and regulation of c-Jun N-terminal kinase signaling and microtubule stability during development and neurodegeneration.

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.

Dual‑Atom Nanozyme Eye Drops Attenuate Inflammation and Break the Vicious Cycle in Dry Eye Disease

Dry eye disease(DED)is a major ocular pathology worldwide,causing serious ocular discomfort and even visual impairment.The incidence of DED is gradually increasing with the highfrequency use of electronic products.Although inflammation is core cause of the DED vicious cycle,reactive oxygen species(ROS)play a pivotal role in the vicious cycle by regulating inflammation from upstream.Therefore,current therapies merely targeting inflammation show the failure of DED treatment.Here,a novel dual-atom nanozymes(DAN)-based eye drops are developed.The antioxidative DAN is successfully prepared by embedding Fe and Mn bimetallic single-atoms in N-doped carbon material and modifying it with a hydrophilic polymer.The in vitro and in vivo results demonstrate the DAN is endowed with superior biological activity in scavenging excessive ROS,inhibiting NLRP3 inflammasome activation,decreasing proinflammatory cytokines expression,and suppressing cell apoptosis.Consequently,the DAN effectively alleviate ocular inflammation,promote corneal epithelial repair,recover goblet cell density and tear secretion,thus breaking the DED vicious cycle.Our findings open an avenue to make the DAN as an intervention form to DED and ROSmediated inflammatory diseases.

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.

Influencing factors of ocular pain in dry eye disease patients at high altitude

AIM:To quantify the severity and frequency of ocular pain in Tibetan plateau patients with dry eye,and to evaluate the related factors affecting ocular pain.METHODS:A retrospective study included 160 cases of dry eye disease(DED)patients who were treated from July 2022 to June 2023.Age,gender,occupation,illness course,anxiety,plateau duration,plateau protection,ocular surface disease index scale(OSDI),break-up time(BUT),Schirmer I test(SIT),conjunctivitis,history of ophthalmic medication,autoimmune disease,the workload of daily near vision range,smoking and overnight stay were obtained via comprehensive ophthalmic assessment,and their duration was followed up.Logistic regression analysis was used to determine the related factors affecting ocular pain.RESULTS:Totally 77.5%(124/160)of DED patients had ocular pain,of which the severity of ocular pain was mild,moderate,and severe in 30.0%,36.3%,and 11.3%of patients,respectively.Frequency of ocular pain was reported occasional,half the time,frequent,and persistent pain in 19.4%,36.9%,16.9%,and 4.4%.OSDI score was 19.67±5.70(13 to 36),and the level of pain was lowly correlated with OSDI(rs=0.316,P<0.001).Logistic regression showed that in plateau DED patients,increased anxiety led to increased severity and frequency of ocular pain[odds ratio(OR)=3.662,5.613,2.387,and 4.870;all P<0.05],professional eye protection and improvement of daily sleep quantity decreased pain(OR=0.307,0.572,0.418,and 0.789;all P<0.05),while smoking and general protection of plateau did not affect the severity and frequency of ocular pain(all P>0.05).CONCLUSION:Ocular pain is a common complaint in high-altitude DED patients during the pandemic.Anxiety,eye protection,and adequate sleep during the epidemic period are significantly associated with the severity and frequency of ocular pain in patients with plateau DED,while symptoms of DED have relatively little influence on them.

Retinal nerve fiber layer defects and chronic kidney disease:the Kailuan Eye Study

AIM:To investigate whether retinal nerve fiber layer defects(RNFLDs)is a potential risk factor for chronic kidney disease(CKD)in Chinese adults.METHODS:The Kailuan Eye Study was a populationbased study that included 14440 participants.All participants underwent detailed assessments,RNFLDs were diagnosed using color fundus photographs.RESULTS:Overall,12507 participants[8533 males(68.23%)]had complete systemic examination data and at least one evaluable fundus photograph.RNFLDs were found in 621 participants[5.0%;95%confidence interval(CI):4.6%-5.34%],and 70 cases of multiple RNFLDs were found(11.27%).After adjusting multiple factors,RNFLDs was significantly associated with CKD severity,the ORs of CKD stage 3,stage 4 and stage 5 were 1.698,4.167,and 9.512,respectively.Multiple RNFLDs were also associated with CKD severity after adjusting multiple factors,the ORs of CKD stage 3 and stage 5 were 4.465 and 11.833 respectively.Furthermore,2294 participants had CKD(18.34%,95%CI:17.68%-18.99%).After adjusting for other factors,CKD presence was significantly correlated with the presence of RNFLDs.CONCLUSION:The strongest risk factors for RNFLDs are CKD and hypertension.Conversely,RNFLDs can be an ocular feature in patients with CKD.Fundoscopy can help detect systemic diseases,and assessment for RNFLDs should be considered in CKD patients.

Global trends in diabetic eye disease research from 2012 to 2021

Diabetic eye disease refers to a group of eye complications that occur in diabetic patients and include diabetic retinopathy, diabetic macular edema, diabetic cataracts, and diabetic glaucoma. However, the global epidemiology of these conditions has not been well characterized. In this study, we collected information on diabetic eye disease-related research grants from seven representative countries––the United States, China, Japan, the United Kingdom, Spain, Germany, and France––by searching for all global diabetic eye disease journal articles in the Web of Science and Pub Med databases, all global registered clinical trials in the Clinical Trials database, and new drugs approved by the United States, China, Japan, and EU agencies from 2012 to 2021. During this time period, diabetic retinopathy accounted for the vast majority(89.53%) of the 2288 government research grants that were funded to investigate diabetic eye disease, followed by diabetic macular edema(9.27%). The United States granted the most research funding for diabetic eye disease out of the seven countries assessed. The research objectives of grants focusing on diabetic retinopathy and diabetic macular edema differed by country. Additionally, the United States was dominant in terms of research output, publishing 17.53% of global papers about diabetic eye disease and receiving 22.58% of total citations. The United States and the United Kingdom led international collaborations in research into diabetic eye disease. Of the 415 clinical trials that we identified, diabetic macular edema was the major disease that was targeted for drug development(58.19%). Approximately half of the trials(49.13%) pertained to angiogenesis. However, few drugs were approved for ophthalmic(40 out of 1830;2.19%) and diabetic eye disease(3 out of 1830;0.02%) applications. Our findings show that basic and translational research related to diabetic eye disease in the past decade has not been highly active, and has yielded few new treatment methods and newly approved drugs.

Knowledge, Attitude, and Practices Regarding Diabetic Eye Disease among General Population in Medina City, Saudi Arabia

Background: Diabetic eye disease is known as a group of eye problems that diabetic patients may develop as a complication of diabetes and can lead to blindness. They may include Diabetic retinopathy (DR), Cataracts, and Glaucoma. Objectives: This study aims to assess the knowledge, attitude, and practices (KAP) around diabetic eye disease in the general population including patients with DM and non-diabetic people in Medina City, Saudi Arabia. Methods: This is a cross-sectional study involving 385 participants via a self-administered online Questionnaire started in January 2023 in Medina, Saudi Arabia. Results: In total, 339 participants with ages ranged from 18 to more than 60 years with a mean age of 26.8 ± 12.6 years old completed the questionnaire. The majority were females (74.6%), singles (67.8%), and had a university level of education (54.6%). Most of the study participants were found to have poor knowledge levels (67%) in comparison to 33% who had an overall good knowledge of diabetic eye diseases. Knowledge level was found to be higher among old-aged participants and those with a family history of DM (P = 0.001, P = 0.049) respectively. Regarding participants’ attitudes and practices, the study showed good attitudes toward eye care practice for diabetics with half of the participants (50%) reporting self-awareness as a reason that made them undergo the first eye screening. Conclusion: Participants in the present study have poor knowledge and awareness level of diabetic eye disease. Furthermore, positive attitudes and perceptions have been revealed by the participants toward the practice of providing eye care for diabetics. .

Pattern of Eye Diseases among Tea Workers

Background: Bangladesh’s tea industry is essential to the country’s economic expansion. Since tea workers in Bangladesh are marginalized within our community, they have limited access to comprehensive eye care services. Productivity and well-being are cornerstones of comprehensive health care strategy. Ocular disorders are influenced by life expectancy, sociodemographic status, and the epidemiological transition. In this context, the state of ocular health and the many eye illnesses remain to be significantly addressed. Purpose: To evaluate the pattern of eye diseases among tea workers in a tea estate of Bangladesh. Methods: This cross-sectional observational study was carried out in Halda Valley Tea Estate, Nazirhat, Fatickchari, Chattogram, Bangladesh, under the supervision of the Department of Community Ophthalmology, BSMMU, following ethical clearance and approval by the IRB board of BSMMU. With informed written consent and approval from the authority of the tea estate, a total of 110 tea workers were recruited. Socio-demographic characteristics, ocular findings, and patterns of eye diseases were determined and recorded. Results: The mean age of the study participants was 39.60 ± 11.63 years. The maximum (58.1%) study participants were 31 - 50 years old, female (64.5%), illiterate (82.7%), and tribal (71.8%) indigenes. Eye diseases were found in 94.5% of workers. Presbyopia (28.2%), cataracts (27.3%), and refractive error (26.4%) were the most common. Tea workers with eye diseases were significantly older than those who did not have any eye diseases (40.20 ± 11.57 vs. 29.17 ± 7.31 years, p Conclusion: A significant number of tea workers had eye diseases, of which presbyopia, cataracts, and refractive error were the most common.

Microbiome as an endocrine organ and its relationship with eye diseases:Effective factors and new targeted approaches

Microbiome is an endocrine organ that refers to both the complicated biological system of microbial species that colonize our bodies and their genomes and surroundings.Recent studies confirm the connection between the microbiome and eye diseases,which are involved in the pathogenesis of eye diseases,including age-related macular disorders,diabetic retinopathy,glaucoma,retinitis pigmentosa,dry eye,and uveitis.The aim of this review is to investigate the microbiome in relation to eye health.First,a brief introduction of the characteristics of the gut microorganisms terms of composition and work,the role of dysbiosis,the gut microbiome and the eye microbiome in the progression of eye illnesses are highlighted,then the relationship among the microbiome and the function of the immune system and eye diseases,the role of inflammation and aging and the immune system,It has been reviewed and finally,the control and treatment goals of microbiome and eye diseases,the role of food factors and supplements,biotherapy and antibiotics in relation to microbiome and eye health have been reviewed.

Bilateral Retinal Nerve Fiber Layer Loss and Recovery with Teprotumumab in Thyroid Eye Disease

Background: Thyroid Eye Disease (TED) is known to alter tissues of the orbital cavity, including the optic nerve. However, its effect on measured global Retinal Nerve Fiber Layer (gRNFL) is not well elucidated. This case evaluates the effect of teprotumumab on gRNFL in a patient with moderate TED. Observations: A 60-year-old female with controlled ocular hypertension and moderate TED received 8 standard IV teprotumumab infusions. Comprehensive ocular evaluations were performed pre-, during-, and post-treatment. Bilateral gRNFL thickness decreased (10 m OD;12 m OS) at 4 months post-treatment start, persisting at 8 months, but recovered at 20 months. Conclusions and Importance: Teprotumumab treatment in patients with TED led to a transient bilateral decrease in gRNFL thickness, which was restored to baseline levels with no adverse events reported. Monitoring gRNFL changes in teprotumumab-treated patients is crucial as gRNFL thinning indicates retinal ganglion cell damage. Teprotumumabs ability to dampen the IGF-IR inflammatory cascade may have reduced retinal inflammation, leading to recovery.

Mendelian randomization analysis:the causal relationship between statins and eye diseases

Background:The specific role of statins in the field of ophthalmology is not clear.Statins have the advantages of pleiotropic,relatively safety and low cost,and are a promising choice for the prevention and management of eye diseases.Nevertheless,there is a divergence of findings regarding the correlation between statin treatment and ocular conditions.Hence,our intention is to investigate the impact of statins on eye conditions through the utilization of Mendelian randomization(MR).Methods:The UK Biobank provided data on five statins,while the FinnGen database provided data on six eye diseases,including age-related macular degeneration,glaucoma,diabetic retinopathy,senile cataract,drug-induced cataract,and other cataracts.Causality exploration involved the utilization of various methods including inverse variance weighted(IVW),weighted median,weighted multivariate(weighted mode),and MR-Egger regression.To assess the reliability of the findings,funnel analysis,MR-Egger regression,leave-one-out method,and Cochran’s Q test were employed.Additionally,reverse MR analysis was performed to evaluate the potential for reverse causality between statin use and eye diseases.Results:Based on IVW analysis,there were three pairs of positive results with significant(P<0.05)causal relationship,including atorvastatin and drug-induced cataract(odds ratio(OR)=1.65E-05,95%confidence interval(CI):2.24E-09–0.12;P_(IVW)=0.02),rosuvastatin and drug-induced cataract(OR=2.77E-18,95%CI:7.53E-35–0.1;P_(IVW)=0.04)and fluvastatin with senile cataract(OR=0.5,95%CI:0.25–0.99;P_(IVW)=0.05).No significant causal relationship was observed between other types of statins and eye diseases.Sensitivity analysis found that the results were robust.Reverse MR analysis indicated no evidence of reverse causality between statin use and the examined eye diseases.Conclusion:Our study finally verified the strong causal relationship between three drugs and two diseases(atorvastatin and rosuvastatin and drug cataract,fluvastatin and senile cataract).This study confirms that statins may reduce the risk of certain eye diseases and provides new insights into the prevention and treatment of eye diseases.Furthermore,the lack of reverse causality reinforces the reliability of these associations.

Prevalence and risk factors for eye diseases, blindness, and low vision in Lhasa, Tibet

AIM: To determine the prevalence and risk factors for eye diseases, blindness, and low vision in Tibet, and to assist the development of eye disease prevention and treatment schemes.METHODS: We carried out a survey of eye diseases among a population living at high altitude. A total of 1 115 Tibetan permanent residents aged 40 years or older from the towns and villages of Qushui County, Lhasa Prefecture, Tibet Autonomous Region, participated in this study. All participants completed a detailed questio-nnaire, and underwent presenting and pinhole visual acuity tests,and a comprehensive ophthalmic examination.RESULTS: There were 187 blind eyes (8.43%), 231 eyes with low vision (10.41% ). The leading cause of visual impairment was cataract of 55.0% (101/187) blindness and of 50.2% (116/231) low vision, followed by fundus lesions of 22.9% blindness and 23.8% low vision, while only a low prevalence of glaucoma of 9.6% blindness and 1.7% low vision was observed. The analysis of 2 219 eyes showed that the most common external eye disease was pterygium (27.2%) in Tibet.CONCLUSION: The high prevalence of blindness and low vision in the Tibetan population at high altitude is a serious public health issue. There is a need to establish and maintain an appropriate effective eye care program in Tibet.

Inflammation and dry eye disease——where are we?

The presence of inflammation in dry eye disease(DED)results in increased patient symptomatology,ocular surface damage and worsening tear dysfunction.It also affects the health of meibomian glands and their secretions which further aggravates ocular surface disease.This article reviews current knowledge regarding ocular surface inflammation in DED and explores the relationships between the vicious cycles of DED,inflammation and meibomian gland dysfunction(MGD).The clinical evaluation of eyes with such changes,markers that identify the presence of inflammation on the ocular surface and current treatment options are discussed.

Therapeutic effect of Keap1-Nrf2-ARE pathway-related drugs on age-related eye diseases through anti-oxidative stress

Age-related eye diseases,including cataract,glaucoma,diabetic retinopathy(DR),and age-related macular degeneration(AMD),are the leading causes of vision loss in the world.Several studies have shown that the occurrence and development of these diseases have an important relationship with oxidative stress in the eye.The Keap1-Nrf2-ARE pathway is a classical pathway that resists oxidative stress and inflammation in the body.This pathway is also active in the development of age-related eye diseases.A variety of drugs have been shown to treat agerelated eye diseases through the Keap1-Nrf2-ARE(Kelch-like ECH-Associating protein 1-nuclear factor erythroid 2 related factor 2-antioxidant response element)pathway.This review describes the role of oxidative stress in the development of age-related eye diseases,the function and regulation of the Keap1-Nrf2-ARE pathway,and the therapeutic effects of drugs associated with this pathway on age-related eye diseases.

Factors influencing subjective symptoms in dry eye disease

AIM: To retrospectively investigate the association between dry eye symptoms and clinical or in vivo confocal microscopy parameters in patients with dry eye disease(DED), and to compare these parameters between eyes with DED and normal subjects.METHODS: This retrospective, cross-sectional, controlled study comprised 25 consecutive patients with non-Sj?gren dry eye disease and age-and sex-matched 25 healthy subjects. Each patient underwent a complete examination of the ocular surface in the following order: tear osmolarity measurements, InflammaDry test, tear break-up time, corneal fluorescein staining, Schirmer I test, subjective symptoms questionnaire using the dry eye-related qualityof-life score(DEQS), and in vivo confocal microscopy analysis of the central cornea. Beck depression inventory(BDI) as depressive scale and history of medications and smoking were also evaluated. Stepwise multiple regression analysis was used to assess the factors affecting the DEQS.RESULTS: In univariate analysis, DEQS was associated with tear break-up time(ρ=-0.48, P=0.01), oral medications, such as hypotensive drug(ρ=0.56, P=0.004) and antidepressant(ρ=0.57, P=0.003), and BDI(ρ=0.61, P=0.001) in patients with DED. In multiple regression analysis, explanatory variables relevant to the DEQS were the anti-depressant medications(P=0.04, partial regression coefficient B=21.04) and BDI(P=0.02, B=0.76, adjusted R2=0.54) in these patients. CONCLUSION: Our study shows a significant association between depression and dry eye symptoms. It suggests that dry eye symptoms associate with higher depressive symptoms and its medications, although our patients were not followed longitudinally.

Cosmetic blepharoplasty and dry eye disease: a review of the incidence, clinical manifestations, mechanisms and prevention

Dry eye disease is a multifactorial disease of the ocular surface and can be caused by a variety of iatrogenic interventions,especially ophthalmic surgical procedures.This article reviews the incidence,clinical manifestations,mechanisms and prevention of dry eye disease caused or worsened by cosmetic blepharoplasty,and focus on how to reduce and prevent the occurrence of postoperative dry eye disease and provide the basis for the selection of operation methods and the rational drug during the perioperative period.

New approaches for diagnosis of dry eye disease

We reviewed the literature for different diagnostic approaches for dry eye disease(DED) including the most recent advances, contradictions and promising diagnostic tools and technique. We performed a broad literature search for articles discussing different methods for diagnosis of DED including assessment of tear osmolarity, tear film stability, ocular biomarkers and others. Articles indexed in PubMed and google scholar were included. With the growing cosmetic industry, environmental pollution, and booming of digital screens, DED is becoming more prevalent. Its multifactorial etiology renders the diagnosis challenging and invites the emergence of new diagnostic tools and tests. Diagnostic tools can be classified, based on the parameter they measure, into tear film osmolarity, functional visual acuity, tear volume, tear turnover, tear film stability, tear film composition, ocular biomarkers and others. Although numerous methods exist, the most accurate diagnosis can be reached through combining the results of more than one test. Many reported tests have shown potential as diagnostic/screening tools, however, require more research to prove their diagnostic power, alone or in combination. Future research should focus on identifying and measuring parameters that are the most specific to DED diagnosis.

Evaluation of patients with dry eye disease for conjunctival Chlamydia trachomatis and Ureaplasma urealyticum

AIM：To determine the possibility of the development of dry eye disease（DED） as a result of persistent infection with Chlamydia trachomatis and Ureaplasma urealyticum in the conjunctiva of patients.METHODS： This study was conducted on 58 patients of age range 20-50 y,diagnosed with DED confirmed by Schirmer I test and tear breakup time.The non-dry eye control group included 27 subjects of the same age.Ocular specimens were collected as conjunctival scrapings and swabs divided into three groups： the first used for bacterial culture,the second and third taken to detect Chlamydia trachomatis and Ureaplasma urealyticum by direct fluorescent antibody（DFA） assay and polymerase chain reaction（PCR） method. RESULTS： Chlamydia trachomatis was detected in 65.5% and 76% of DED patients by DFA and PCR methods respectively.Ureaplasma urealyticum was found in 44.8% of DED infected patients using the PCR method.Both organisms were identified in only 37.9% of DED patients found to be infected.Control subjects had a 22%detection rate of Chlamydia trachomatis by DFA assay versus a 7% detection rate by PCR; while Ureaplasma urealyticum was detected in 3.7% of the controls by PCR method.The conjunctival culture revealed that gram positive microorganisms represented 75% of isolates with coagulase negative Staphylococci the most common（50%） followed by Staphylococcus aureus（20%）,whereas gram negative microorganisms occurred in 25% of cases,isolating Moraxella spp.as the most frequent organism. CONCLUSION： Our results tend to point out that Chlamydia trachomatis and Ureaplasma urealyticum were detected in a moderate percentage of patients with DED,and could be a fair possibility for its development.PCR is more reliable in detecting Chlamydia trachomatis than DFA technique.The presence of isolated conjunctival bacterial microflora can be of some potential value.