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。

复方倍他米松对异种角膜板层移植术后免疫排斥反应的影响

目的:观察结膜下注射复方倍他米松对鸵鸟-兔眼板层角膜移植术后免疫排斥反应的缓释治疗作用。方法:16只6周龄健康新西兰白兔角膜(单眼)行板层角膜移植术,植片应用鸵鸟脱细胞的角膜基质,术后分成两组,实验组术毕及术后结膜下注射复方倍他米松注射液(每隔7d一次),对照组术毕及术后结膜下注射地塞米松磷酸钠注射液(每隔7d一次)。分别于术后1、2wk,1、2mo取兔角膜组织做石蜡包埋切片,进行HE染色观察组织特点,同时进行间接免疫荧光法检测CD4^+、CD8^+T淋巴细胞的变化。结果:术后2mo,实验组角膜植片在位,并保持透明,新生血管极少,组织切片HE染色和间接免疫荧光染色结果显示,仅见少许中性粒细胞浸润,未见CD4^+、CD8^+T淋巴细胞;对照组炎症反应明显,角膜植片混浊,组织切片HE染色和间接免疫荧光染色结果显示,炎性反应以中性粒细胞浸润为主,可见CD4^+、CD8^+T淋巴细胞。结论:复方倍他米松作为长效缓释剂可有效抑制鸵鸟-兔板层角膜移植术后免疫排斥反应,延长植片的存活时间。

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.

Corneal collagen cross-linking and liposomal amphotericin B combination therapy for fungal keratitis in rabbits

AIM： To observe the therapeutic effect of corneal collagen cross-linking（CXL） in combination with liposomal amphotericin B in fungal corneal ulcers.METHODS： New Zealand rabbits were induced fungal corneal ulcers by scratching and randomly divided into 3groups, i.e. control, treated with CXL, and combined therapy of CXL with 0.25% liposomal amphotericin B（n =5 each）. The corneal lesions were documented with slit-lamp and confocal microscopy on 3, 7, 14, 21 and 28 d after treatment. The corneas were examined with transmission electron microscopy（TEM） at 4wk.RESULTS： A rabbit corneal ulcer model of Fusarium was successfully established. The corneal epithelium defect areas in the two treatment groups were smaller than that in the control group on 3, 7, 14 and 21d（P 〈0.05）. The corneal epithelium defect areas of the combined group was smaller than that of the CXL group（P 〈0.05） on 7 and 14 d, but there were no statistical differences on 3, 21 and 28 d. The corneal epithelium defects of the two treatment groups have been healed by day 21. The corneal epithelium defects of the control group were healed on 28 d. The diameters of the corneal collagen fiber bundles（42.960 ±7.383 nm in the CXL group and 37.040±4.160 nm in the combined group） were thicker than that of the control group（24.900±1.868 nm）,but there was no difference between the two treatment groups. Some corneal collagen fiber bundles were distorted and with irregular arrangement, a large number of fibroblasts could be seen among them but no inflammatory cells in both treatment groups. CONCLUSION： CXL combined with liposomal amphotericin B have beneficial effects on fungal corneal ulcers. The combined therapy could alleviate corneal inflammattions, accelerate corneal repair, and shorten the course of disease.

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.