Etiology and drug sensitivity of bacterial keratitis in recent 40 years in China: a Meta-analysis / 中华实验眼科杂志

Objective:To evaluate the distribution and drug sensitivity of pathogenic bacteria in patients with bacterial keratitis in recent 40 years in China.Methods:A Meta-analysis was conducted.Five databases including PubMed, ScienceDirect, Embase, CNKI and Wanfang Data Knowledge Service Platform were searched.The research was limited to the hospital-based cross-sectional studies published in Chinese and English between 1980 and 2020, without limitations of subject.Two researchers followed the inclusion and exclusion criteria to complete literature retrieval, data extraction and methodological quality evaluation.The literature quality was assessed with reference to a methodological scoring system for rates. Q test and I2 test were used to quantify the degree of heterogeneity of the included literature.According to the heterogeneity, the fixed effects model or random-effects model was used to calculate the combined rates indicators to perform the Meta-analysis. Results:Twenty-seven original studies were incorporated, including 50 046 cases of bacterial keratitis.A random-effects model for the Meta-analysis showed that the positive rate of bacterial culture in bacterial keratitis was 28% (95% CI: 0.24-0.32). Among the culture-positive bacteria, the percentages of gram-positive cocci and gram-negative bacilli were 57% (95% CI: 0.52-0.62) and 32% (95% CI: 0.28-0.37), respectively.The percentages of gram-positive bacilli and gram-negative cocci were 8% (95% CI: 0.06-0.10) and 1% (95% CI: 0.01-0.02), respectively.In the recent 40 years, the proportion of gram-positive cocci isolated from corneas in China was on the rise, and the proportion of gram-negative bacilli was on the decline.Among them, coagulase-negative Staphylococcus accounted for 23% (95% CI: 0.17-0.30), followed by Pseudomonas aeruginosa 18% (95% CI: 0.14-0.23), Streptococcus pneumoniae 8% (95% CI: 0.06-0.12), Staphylococcus aureus 6% (95% CI: 0.04-0.08), Corynebacterium 4% (95% CI: 0.03-0.07), and Escherichia coli 4% (95% CI: 0.02-0.06). The results of the drug sensitivity test showed that gram-positive cocci were highly sensitive to vancomycin, moxifloxacin, levofloxacin and ofloxacin. Pseudomonas aeruginosa was most sensitive to tobramycin, and Escherichia coli was most sensitive to ofloxacin. Conclusions:This Meta-analysis indicates that the proportion of gram-positive cocci isolated from corneas in China has been on the rise, while the proportion of gram-negative bacilli was on the decline during the recent 40 years.Coagulase-negative Staphylococcus and Pseudomonas aeruginosa have become the most common pathogens of bacterial keratitis in China.The sensitivity of various bacteria to commonly used antibiotics shows a downward trend.The sensitive antibiotics should be selected correctly according to the drug sensitivity results.

Design and Implementation of User-oriented Auxiliary Treatment Instrument for Meibomian Gland Dysfunction / 中国医疗器械杂志

Dry eye is a common ophthalmic disease caused by eye maladjustment due to meibomian gland dysfunction (MGD), which is often accompanied by symptoms such as increased tear film osmotic pressure and ocular surface inflammation. In the treatment of dry eye patients, dredging gland obstruction caused by meibomian gland secretion is an effective treatment method. Based on electrothermal effect and hyperelasticity of the silicone, an auxiliary treatment instrument for MGD is designed, which can improve the blood circulation of the glands through heat compress and massage to achieve the purpose of dredging the meibomian glands. The therapy device can display the temperature and pressure during the treatment in real time, so that the surgeon can grasp the progress of the treatment in real time. The therapy device constructs a user-oriented interactive interface based on parametric modeling method, which can be customized by 3D printing according to the user's eyeball geometric parameters. The designed therapeutic device was finally tested on New Zealand white rabbits. The experimental results show that the therapeutic device has significant effectiveness and safety, as well as clinical application prospects.

The profound influence of standardized practice education on the training of medical postgraduates / 中华医学教育探索杂志

Aiming at the problems of medical practice education in China (lack of standardization, continuity and guarantee mechanism), this paper gives a deep analysis of the causes and effects of the above current problems, so as to put forward suggestions and specific measures for standardizing practice education for medical postgraduates. Practice education should be standardized by constructing a system, sustained by training medical ethics, and innovated by sharing information. In this paper, the concept of practice education for medical postgraduates and the specific measures for constructing a standardized system are specifically introduced to provide useful references for the establishment of practice education model and evaluation system that are suitable for the comprehensive development of medical postgraduates in China.

Application of machine learning in auxiliary diagnosis of corneal related diseases / 中华实验眼科杂志

Machine learning, as the main technical direction of artificial intelligence, can help ophthalmologists to interpret and analyze the large amount of data generated by imaging equipment, and also simplify the diagnosis and treatment process.The early diagnosis and classification of keratoconus became the most important application of machine learning.The modeling methods of machine learning for diagnosing keratoconus usually included neural network and decision tree method.The sensitivity and specificity of these models for diagnosing keratoconus were more than 85%.Because there were large number of research parameters for the diagnosis of keratoconus and no adequate public data sets, it was difficult to evaluate the advantages and disadvantages of different research methods, which limited the clinical application of machine learning in the evaluation of keratoconus.The corneal refractive surgery preoperative evaluation had clinical problems of large data volume and difficult decision-making.Machine learning can assist in evaluating whether the patient is suitable for refractive surgery, of which specificity and sensitivity were above 90%.It was also able to predict postoperative visual quality with ocular parameters.In addition, machine learning can also help us to count corneal endothelial cell density and assess corneal epithelial damage.Machine learning method and big data modeling evaluation can assist doctors in accurate diagnosis and personalized evaluation of keratopathy.This article reviewed the recent literature on the application progress of machine learning in corneal-related diseases in recent years.

Three-dimensional Reconstruction of Retinal Vessels Based on Binocular Vision / 中国医疗器械杂志

In robot-assisted eye surgery, such as retinal vascular bypass surgery, precise positioning of operating points is required. In this study, a binocular vision-based 3D reconstruction method is proposed to locate the incision points on retinal vessels. Vessels in the image were extracted by CLAHE algorithm to remove the influence of background, then stereo matching was performed. Finally, the retinal vessel image was reconstructed by using the principle of parallax in binocular vision. Experimental results show that this method can accurately locate the incision points on retinal vessels and meet the requirements of ophthalmic surgery.

Lipid layer thickness of tear film and its association with clinical characteristics in different types of dry eye patients / 中华实验眼科杂志

Objeetive To investigate tear film lipid layer thickness (LLT) and its association with clinical symptom and sign in different types of dry eye patients.Methods A serial case-observational study was carried out.Three hundred and six eyes of 306 dry eye patients were included in Beijing Tongren Hospital from April to August 2016.Ocular surface disease index (OSDI) questionnaire,eyelid slit lamp examination,the measurement of tear film lipid thickness (LLT),tear film break-up time (TBUT),Schirmer Ⅰ test (S Ⅰ t) and the infrared meibomian photography were performed on the patients.The 157 patients with OSDI ＞12 and eyelid score ≥2 served as the MGD group;53 patients with OSDI ＞12 and S Ⅰ t value ＜ 5 mm/5 minutes served as ADDE group;96 patients with OSDI＞12,eyelid score ≥2 and S Ⅰ t value ＜ 5 mm/5 minutes served as MGD/ADDE group.Tear film LLT was detected with LipiView(R) ocular surface interferometer and the association of LLT with clinical characteristics of the patients was analyzed.This study protocol was approved by Ethic Committee of Beijing Tongren Hospital and written informed consent was obtained from each patient prior to any relative medical examination.Results Tear film LLT of the participants was normally distributed with the average was (60.41±18.57)nm.LLT in the MGD group,ADDE group,MGD/ADDE group were (57.04 ± 18.26),(63.52 ± 18.44) and (60.56 ± 18.71) nm,respectively,with a significant difference among the three groups (F =2.347,P =0.035),and the LLT value was significantly lower in the MGD group than that in the ADDE group (t =2.077,P =0.039).The LLT value showed negative correlations with the severity of dry eye symptom,S Ⅰ t and meibomian gland loss rate (r=-0.201,P=0.003;r=-0.146,P=0.005;r=-0.156,P=0.046).OSDI score was significantly correlated with LLT only in the MGD group (r =-0.285,P =0.000).No significant correlation was seen between LLT and S I t in all the groups (all at P＞0.05).In the MGD/ADDE group and MGD group,the correlation between LLT and meibomian gland loss rate was significantly greater than the overall correlation (r=-0.335,-0.248,-0.156).The dry eye symptoms in OSDI questionnaire like foreign body sensation,eye pain,discomfort when watching TV or computer showed significant correlations with LLT (r =-0.243,-0.205,-0.223,-0.258,all at P ＜0.05).Conclusions The tear LLT is appeared to be varied in different types of dry eye.The LLT is thinner in the dry eyes with MGD and thicker in the dry eyes with ADDE.There are association between tear LLT and foreign body sensation,eye pain,discomfort when watching TV or computer.

Pathogenesis and treatment of overwhelming inflammation induced by Pseudomonas aeruginosa keratitis in rabbit / 中华实验眼科杂志

Background Infectious keratitis is common blinding eye disease in China.Inflammatory runaway reaction often occurs in infectious keratitis, and its mechanism and treating approach are worthy of research.Objective This study was to investigate the clinical manifestation,mechanism and treatment outcome of doxycycline in overwhelming inflammation induced by Pseudomonas aeruginosa keratitis.Methods Pseudomonas aeruginosa suspension was intrastromal injected in 60 right eyes of 60 New Zealand white rabbits,and gatifloxacin eye drops was frequent instilled for consecutive 3 days to establish corneal inflammatory runaway reaction models,and 42 eyes with worse keratitis were defined as overwhelming inflammation.Then the models were randomly divided into gatifloxacin treatment group (15 rabbits), combined treatment group (gatifloxacin with doxycycline treatment, 15 rabbits) and balance salt solution (BSS) control group (12 rabbits), and corresponding eye drops was topically administered in the rabbits 8 times per day for 14 days.The symptoms of the models were observed under the slit lamp microscope on day 1,3,7 and 14 after treatment,and the corneal infiltration area was calculated.The corneal morphology was examined by using hematoxylin-eosin staining.The expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9 in the corneal tissue were examined by immunohistochemistry.The contents of tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β) in corneal homogenate were detected by ELISA.The use and care of the animals complied with the ARVO Statement.Results The inflammatory scores were lower and infiltration area of cornea was smaller 7 days after treatment than those before treatment in the combined treatment group and gatifloxacin treatment group (both at P＜0.05).Hematoxylin-eosin staining result showed that the inflammation response of cornea subsided 14 days in comparison with 5 days after treatment in the combined treatment group, with the proliferation and rearrangement of fiberal tissue.The MMP-2 and MMP-9 were strongly expressed in corneal tissue with overwhelming inflammation in day 5 after treatment, however, the expression intensity weakened in 14 days after treatment in the combined treatment,showing significant differences in the absorbance between them (all at P＜0.05).ELISA assay showed that the contents of TNF-α and IL-1β in corneal tissue were significantly lower in the combined treatment group than those in the BSS group (P =0.00,0.03).In addition, contents of TNF-α and IL-1β in corneal tissue were significantly declined at day 14 in comparison with day 5 and day 7 after treatment in the combined treatment group (all at P＜0.05).Conclusions Overwhelming inflammatory keratitis models can be successfully established by corneal intrastromal injection of Pseudomonas aeruginosa suspension and immediately frequent 3-day instillation of gatifloxacin eye drops in rabbits.The topical application of doxycycline plays treating effect on overwhelming inflammatory keratitis by inhibiting the release of pro-inflammatory cytokines and MMPs.

In vitro antimicrobial efficacy of riboflavin-UVA for common bacteria in ophthalmology / 中华实验眼科杂志

Background Staphylococcus aureus,Staphylococcus epidermidis and Pseudomonas aeruginosa are common pathogenic bacteria in ophthalmology.To seek an optimal antimicrobial method is critical for the prevention of infection.Objective This study was to investigate the antimicrobial efficacy of riboflavin-ultraviolet A (UVA) on Staphylococcus aureus,Staphylococcus epidermidis and Pseudomonas aeruginosa.Methods Ten strains of frozen Staphylococcus aureus,Staphylococcus epidermidis and Pseudomonas aeruginosa were incubated to culture dishes and resuscitated for 2 times.The bacteria were put into bacterial dilution to prepare the suspension of 0.5 Mclntosh concentration and then the suspension was diluted 10-folds.UVA was used to irradiate the culture dishes added 0,0.1％,0.5％ riboflavin for 10,20,30 minutes with the exposure intensities of 1,2,3 mW/cm2,and the optimal bacteriostatic condition was evaluated by measuring the diameters of inhibition zone.Staphylococcus aureus,Staphylococcus epidermidis and Pseudomonas aeruginosa were divided into normal control group,riboflavin group,UVA group and photodynamic therapy (PDT) group (riboflavin+UVA),and colony forming unit was compared among the groups.Results The optional experimental conditions of PDT inactivating microorganisms were determined as UVA wavelength 370 nm,UVA exposure rate 3 mW/cn2,UVA exposure time 30 minutes and riboflavin 0.1％.The colony forming units were decreased in turn in the normal control group,riboflavin group,UVA group and PDT group (F =110.990,190.841,118.197,all at P =0.000).Compared with the normal control group,the colony forming units were significantly decreased in the UVA group (t =14.640,7.550,5.320,all at P＜0.05),and the colony forming units were significantly decreased in the PDT group (t =25.480,14.750,12.920,all at P＜0.05).The colony forming units decreased by 46.4％-50.2％ in the UVA group and 91.6％-96.7％ in the PDT group.There was no significant difference in colony forming units between the normal control group and the riboflavin group(t =0.660,0.470,0.510,all at P＞0.05).Conclusions PDT can effectively inactivate common bacteria in ophthalmology.This result suggests that PDT has a potential in the treatment of microbial keratitis.

Questionnaire survey of depression prevalence and associated risk factors in elder patients with low-vision in Beijing suburb / 中华全科医师杂志

To explore the prevalence and risk factors of depression in low-vision elder patients aged 60-85 years residing at Beizhuang Township,Miyun county.The activity of daily living scale (ADL) and geriatric depression scale (GDS) were used for diagnosis and grade the severity of depression.The prevalence rate of depression was higher in low-vision patients (36.2％) than in the control group (15.5％,P ＜0.05).The need for assistance in daily activities was higher in low-vision patients than in the control group(x2 =13.57,P ＜0.01).Patients with good economic conditions,being cared by relatives and living with their spouse had lower levels of ADL and GDS (all P ＜ 0.05).

The relationship between the genotype and clinical factors of filamentous fungus causing-keratitis / 眼科研究

Background The study on the classification of fungi is very important for the diagnosis and treatment of fungal keratitis.Identifying the different species of filamentous fungi is a critical factor for the application of anti-fungal drug in treating keratitis.ObjectiveThis report studies the relationship between the genotype of filamentous fungi and the clinical factors.MethodsFifty-two patients with filamentous fungal keratitis determined by clinical and laboratory examination were recruited in Tongren Hospital from January 2006-December 2006.The lesions were graded on the severity of the corneal ulcer and the presence of hypopyon.The filamentous fungal keratitis was treated with topical and systemic administration of anti-fungal drugs or corneal transplantation.The isolates were cultured in potato culture and identified by morphological characteristics based on the Nelson criterion and genotyped by the rDNA ITS method.The clinical data was retrospectively analyzed.ResultsForty-eight species (eubacteria are bacteria,not fungi)of fungus were identified by morphological characteristics,and the filamentous fungi were divided into 4 types based on the phylogenetic relationships within the rDNA ITS of the 52 filamentous fungi.The morphological characteristics and genotype were confirmed in 48 strains of eubacteria and 31 strains of 52 filamentous fungi (90.3%).The 4 groups of fungi were classified by genotype as follows:group 1 represents 22 strains including 20 strains of Fusarium solani and 2 strains of Fusarium oxysporum;group 2 represents 12 strains including 8 strains of Fusarium moniliformis,3 strains of Fusarium proliferatum and 1 strain of Fusarium incarnatum;group 3 represents 5 strains including 1 strain of Fusarium moniliformis and 4 unknown strains;group 4 represents 13 strains including 10 strains of Aspergillus spp.and 3 strains of Alternaria spp.Significant differences were found in the disease duration (P=0.00),inducing cause (P=0.03),ulcer grade (P=0.01)and outcome of the anti-fungal treatment (P=0.035)when compared between group 1 and 2 with group 3 and 4.Conclusion Filamentous fungi that cause keratitis could be correctly identified by sequencing the internal tanscribed spacer of rDNA.There are significant clinical differences among the groups classified by genotype.