角膜胶原交联方法联合那他霉素抗真菌效果研究

目的:研究角膜胶原交联方法联合那他霉素应用时的体内外抗真菌效果,为临床真菌性角膜炎的治疗提供治疗方法及实验基础。方法:采用黄曲霉菌、茄病镰刀菌、白色念珠菌三种常见致病真菌,实验组分为交联联合那他霉素组、那他霉素联合核黄素组、那他霉素联合紫外照射组、交联组,并用那他霉素组作为对照。将药物涂到有1. 5麦氏浊度的真菌孢子悬液的沙堡弱琼脂培养皿的中心,10min后使用胶原交联仪照射10min,之后28℃培养36h,测量抑菌圈并进行统计学分析。制备兔眼茄病镰刀菌感染模型,按随机数字表法将模型兔随机分为模型对照组、交联治疗组、那他霉素治疗组、交联联合那他霉素治疗组,每组5只;另取5只正常兔按照角膜胶原交联疗法进行照射,5只正常对照。通过前节照相、角膜刮片、共焦显微镜等观察各组治疗结果,并在治疗结束后采用电镜观察角膜超微结构改变情况。结果:体外单独应用角膜胶原交联术,对三种真菌均无效;当交联与那他霉素联合应用时,抗真菌效果均优于对照组,且差异具有统计学意义(P<0. 05);那他霉素与核黄素、那他霉素与紫外线分别联合应用时,抗菌效果与对照组比较,差异均无统计学意义(P>0. 05)。针对兔真菌感染模型,那他霉素治疗组及交联联合那他霉素治疗组病程约14d,交联治疗组病程约21d;经治疗后,各治疗组均已愈合,各组角膜上皮均无缺损,新生血管较多,角膜内无菌丝;前节照相结果显示,交联联合那他霉素治疗组治疗结果优于其它各治疗组,瘢痕组织较少,角膜愈合较好,病程相对短。结论:角膜胶原交联方法联合那他霉素,可促进角膜愈合,缩短病程,增强抗真菌效果,有望为眼科临床真菌性角膜炎的治疗提供一种新的治疗技术。

Prevalence and risk factors of dry eye disease in young and middle-aged office employee:a Xi’an Study

AIM:To estimate the prevalence of and risk factors for dry eye disease(DED)in young and middle-aged office employee in Xi’an.METHODS:This cross-sectional study of the prevalence of and risk factors for DED investigated 486 young and middle-aged Chinese office employee in Xi’an.DED symptoms and potential risk factors were assessed using the ocular surface disease index combined with a risk factors questionnaire,and tear function was evaluated using the tear film break-up time and Schirmer’s test.Possible risk factors for DED were estimated by binary Logistic regression analysis.RESULTS:DED was diagnosed in 100 females and 96 males,giving a prevalence of 40.3%[95%confidence interval(CI)=36.0%-44.7%].The multivariate binary Logistic regression model indicated that the possible risk factors for DED were being female(OR=1.592,95%CI=1.034-2.451,P=0.035),being aged≥40 y(OR=1.593,95%CI=1.034-2.454,P=0.035),using a VDT daily for>6 h(OR=1.990,95%CI=1.334-2.971,P=0.001),the presence of central air conditioning(OR=1.548,95%CI=1.053-2.276,P=0.026),and self-reported dryness of the mouth and nose(OR=1.589,95%CI=1.071-2.357,P=0.021).CONCLUSION:There is a high prevalence of clinically diagnosed DED in young and middle-aged video displayterminal(VDT)users.Interventions against the modifiable risk factors should be taken to prevent the occurrence and development of DED in this population.

Acellular ostrich corneal stroma used as scaffold for construction of tissue-engineered cornea

AIM： To assess acellular ostrich corneal matrix used as a scaffold to reconstruct a damaged cornea. METHODS： A hypertonic saline solution combined with a digestion method was used to decellularize the ostrich cornea. The microstructure of the acellular corneal matrix was observed by transmission electron microscopy （TEM） and hematoxylin and eosin （H＆E） staining. The mechanical properties were detected by a rheometer and a tension machine. The acellular corneal matrix was also transplanted into a rabbit cornea and cytokeratin 3 was used to check the immune phenotype, RESULTS： The microstructure and mechanical properties of the ostrich cornea were well preserved after the decellularization process, in vitro, the methyl thiazolyl tetrazoUum results revealed that extracts of the acellular ostrich corneas （AOCs） had no inhibitory effects on the proliferation of the corneal epithelial or endothelial cells or on the keratocytes, The rabbit lamellar keratoplasty showed that the transplanted AOCs were transparent and completely incorporated into the host cornea while corneal turbidity and graft dissolution occurred in the acellular porcine cornea （APC） transplantation, The phenotype of the reconstructed cornea was similar to a normal rabbit cornea with a high expression of cytokeratin 3 in the superficial epithelial cell layer, CONCLUSION： We first used AOCs as scaffolds to reconstruct damaged corneas. Compared with porcine corneas, the anatomical structures of ostrich corneas are closer to those of human corneas. In accordance with the principle that structure determines function, a xenograft lamellar keratoplasty also confirmed that the AOC transplantation generated a superior outcome compared to that of the APC graft.

Expression of visual system homeobox 1 in human keratoconus

AIM: To investigate the expression of visual system homeobox 1(VSX1) and myofibroblast marker alpha smooth muscle actin(α-SMA) in keratoconus(KC). METHODS: Thirty corneal tissue were collected from KC patients after corneal transplantation and 15 normal donor corneas were obtained. All corneal tissues divided into 4 parts for different detections. Scanning electron microscopy was used to observe the ultrastructure of the specimens. VSX1 and α-SMA localization in cornea tissues was detected using immunofluorescence histochemistry. Reverse transcription-quantitative polymerase chain reaction(RT-qPCR) and Western blot were performed to analyze the expression level of VSX1 and α-SMA. RESULTS: Compared to normal cornea tissue, the collagen fibers in KC stroma were distortional and attenuated and keratocytes were abnormally changed. VSX1 and α-SMA located in the corneal stroma. The mRNA and protein expression level of VSX1 in KC were about 3 times as high as that of normal tissue(P<0.001). α-SMA was hardly expressed in the normal corneas, however, its expression in the KC was about 1.5 times higher than that of the normal corneas(P<0.0001). CONCLUSION: Compared with normal corneal the expression of VSX1 and α-SMA in KC both increased. VSX1 is related to the activation of keratocytes and involved in the pathogenesis of keratoconus.

Comparative study of oxidation ability between boron-doped diamond (BDD) and lead oxide (PbO_2) electrodes

The electrochemical oxidation capabilities of two high-performance electrodes,the boron-doped diamond film on Ti （Ti/BDD） and the lead oxide film on Ti （Ti/PbO2）,were discussed.Hydroxyl radicals （·HO） generated on the electrode surface were detected by using p-nitrosodimethylaniline （RNO） as the trapping reagent.Electrochemical oxidation measurements,including the chemical oxygen demand （COD） removal and the current efficiency （CE）,were carried out via the degradation of p-nitrophenol （PNP） under the galvanostatic condition.The results indicate that an indirect reaction,which is attributed to free hydroxyl radicals with high activation,conducts on the Ti/BDD electrode,while the absorbed hydroxyl radicals generated at the Ti/PbO2 surface results in low degradation efficiency.Due to quick mineralization which combusts PNP to CO2 and H2O absolutely by the active hydroxyl radical directly,the CE obtained on the Ti/BDD electrode is much higher than that on the Ti/PbO2 electrode,notwithstanding the number of hydroxyl radicals produced on PbO2 is higher than that on the BDD surface.

The pathogenic spectrum of fungal keratitis in northwestern China

I am Na An, from the Shaanxi Key Lab of Ophthalmology, Shaanxi Institute of Ophthalmology,Xi＇an City First Hospital, Xi＇an, Shaanxi Province, China. Fungal keratitis is a severe problem in most developing countries.

Short-term effect of 0.01% atropine sulphate eye gel on myopia progression in children

AIM: To investigate the effect of 0.01% atropine sulphate eye gel on myopia progression and axial elongation in a 6-month treatment in children.METHODS: Totally 185 children aged 6-12 y with binocular myopia of 3.0 D or less in both eyes were enrolled in this prospective cohort study. The atropine group(n=125) received one drop of 0.01% atropine sulphate eye gel in each eye before bedtime daily. The control group included 60 matched children without drug intervention during the same period. The spherical equivalent and axial length was recorded at baseline and the sixth month of treatment. The efficacy was evaluated by the change of the spherical equivalent and axial length. Adverse events were also recorded.RESULTS: The average spherical equivalent and axial length at baseline were not statistically significant between the atropine group(-1.64±0.80 D, 24.13±0.76 mm) and the control group(-1.59±0.94 D, 24.06±0.77 mm, P>0.05). After 6 mo, there was significantly difference in the spherical equivalent progression between the atropine and the control group(-0.27±0.33 vs-0.60±0.35 D, P<0.001),with a relative reduction of 55.0% in myopia progression. The increase in axial elongation in the atropine group was significantly less than control group(0.19±0.14 vs 0.26±0.14 mm, P<0.001), with a relative reduction of 26.9% in axial length. The 84.4% and 38.4% of the eyes progressed by less than 0.50 D and remained stable in the atropine group, compared with 51.7% and 4.2% in the control group. No adverse events were observed.CONCLUSION: Atropine sulphate eye gel 0.01% can slow down myopia progression and axial elongation in children with a 6-month treatment.