Cross-linking of human amniotic membrane by ultraviolet A-riboflavin / 中华实验眼科杂志

BackgroundStudies confirmed that ultraviolet A (UVA)- riboflavin photodynamic therapy can control keratoconus progresses by altering the physicochemical property of cornea.The collagen components of amniotic membrane transplantation is similar to that of cornea and amniotic membrane transplantation has been widely used to ocular surface reconstruction.However,the study on UVA riboflavin-induced-collagen crosslinking for amniotic tissue is less now.ObjectiveThis study was to investigate the role of UVA-riboflavin on frozen-preserved human amniotic membrane.Methods Human amnions were obtained in informed consent and prepared into 2 mm×15 mm pieces and were then divided into 4 groups using lottery method and 6 pieces for each group.The first 3 groups were treated with the photosensitizer riboflavin and UVA-irradiation ( wavelength:370 nm ; irradiation energy:1,2 or 3 mW/cm2,distance:10 mm) for 30 minutes,and the untreated fourth group was as control group.Biomechanical stress-strain test was performed using a microcomputer-controlled biomaterial tester and the stress(mN) was recorded when the strains were set to 5％,10％ and 15％.The 7 mm diameter of human amniotic membrane pieces were trephined and divided into 4 groups(5 pieces for each group) with the treated method as mentioned above,and then the buttons were exposed to 0.1％ collagenase Ⅰ solution.The transparency was scored and the complete dissolving time was record.In histological evaluation,three groups (3 pieces for each group) of human amniotic membranes were treated using UVAriboflavin(3 mW/cm2),0.1％riboflavin,normal saline for 30 minutes respectively and examined under the transmission electron microscopy.This study was performed under the permission of the Ethic Commission of Beijing Tongren Hospital.ResultsWhenthestrainwas 5％,10％,15％,thestressof controlgroupand1,2,3 mW/cm2UVA group were statistically signifcantly different ( F =3.411,P =0.037; F =9.927,P =0.001;F=11.118,P=0.000).The tensile strength of human amniotic membrane cross-linked with UVA-riboflavin was statistically significantly increased in comparison to the control group (P＜0.05 ),and the tensile strength of human amniotic membrane became stronger as UVA power increased.The complete dissolve time was (8.6± 1.8 ) hours for the control group,(39.6± 2.3 ) hours for 1 mW/cm2 UVA group,(71.4±0.9 ) hours for 2 mW/cm2 UVA group,(78.8± 1.8 ) hours for 3 mW/cm2 UVA group,showing the enhanced anti-enzyme ability of human amniotic membrane after cross-linking(P＜0.01 ).The collagen density in the UVA-riboflavin treated group was increased,the connection among the collagen fibers as well as between the stroma and the epithelium became tighter than those of control group.ConclusionsCollagen cross-linking with UVA-riboflavin make the biomechanical strength and enzymatic resistance of human amniotic membrane enhance and ultrastructure change of human amniotic membrane.

Effect of topical application of terbinafine on fungal keratitis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Fungal keratitis is a rare but serious corneal disease that may result in loss of vision. The poor prognosis might be due to limited treatment option. This study aimed to evaluate the clinical efficacy of 0.25% terbinafine eye drops comparing with 5% natamycin suspension on fungal keratitis.</p><p><b>METHODS</b>A retrospective clinical trial was performed on 90 patients presenting with direct smear and/or culture positive fungal keratitis at Beijing Tongren Hospital, Beijing, China from January 2006 to May 2008. Corneal ulcers were categorized as mild or severe. Forty-five patients were treated with topical terbinafine and the next 45 cases received topical natamycin hourly.</p><p><b>RESULTS</b>Filamentous fungi were found in corneal scrapings among all 90 cases. Fungal cultures were positive in 64 patients (71%). Species of Fusarium and Aspergillus were the principal isolates. Forty (89%) patients showed favorable response to terbinafine, while forty-two (93%) patients exhibited favorable response to natamycin (P > 0.05). The mean course of treatment was significantly showed in the terbinafine treatment group than natamycin group ((26.5 +/- 11.2) days versus (19.3 +/- 6.4) days; P < 0.05). In terbinafine group, twenty patients with ulcers smaller than 4 mm had favorable outcome, while 20 of 25 patients with ulcers more than 4 mm in diameter had favorable response (P < 0.05). Twenty-seven patients with depth of infiltration less than half of stroma thickness had favorable response to terbinafine, while 13 of 18 patients with depth of infiltration more than half of stroma responded to terbinafine. This difference was statistically significant (P < 0.05).</p><p><b>CONCLUSIONS</b>Our findings suggest that topical terbinafine is an effective antifungal drug for the management of filamentous mycotic keratitis, particularly in cases with smaller and shallower ulcers. Its mean duration of treatment was longer than natamycin.</p>

Movement capture of knot-tying manipulation in microsurgeries / 中国医疗器械杂志

The surgical dexterous suturing and knotting movements are photographed with binocular stereo vision and the movements' locus is captured through identifying the RGB values in a series of key-frames. Then a normal movement path of knot-tying is obtained through curve-fitting and smoothing. And meanwhile, the workspace of knot-tying manipulation in microsurgeries is got. And thus, a good foundation is laid for the design of an automatic knotting mechanism and for the establishment of a virtual surgery training system.

Etiological analysis on ocular fungal infection in the period of 1989 - 2000 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>This study was to review the distribution and shifting trend of fungal of culture specimens isolated from eyes of patients at the Beijing Institute of Ophthalmology, Tongren Hospital, Beijing, China.</p><p><b>METHODS</b>The fungal culture-positive rate, the distribution and change of isolates of 2609 specimens collected in a 12-year period (1989 - 2000) were retrospectively analyzed.</p><p><b>RESULTS</b>In 775 positive cultures, 707 specimens (91.2%) were from the cornea, 22 (2.8%) from the conjunctiva, 15 (1.9%) from the anterior chamber, 9 (1.2%) from the vitreous body, 3 (0.4%) from the lacrimal sac, and 19 (2.5%) from other parts of the eye. The average culture-positive rate was 29.7%. The ratio of the positive cultures in the first half year (from January to June) to those in the second half (from July to December) was 1:2.1. The main genus cultured was Fusarium sp (58.7%), followed by Aspergirum sp (16.8%). The percentage of Fusarium sp was increased from 53.6% (1989 - 1994) to 60.2% (1995 - 2000), whereas the percentage of Aspergirum sp was decreased from 22.3% (1989 - 1994) to 15.1% (1995 - 2000).</p><p><b>CONCLUSIONS</b>Fusaruim sp is one of the most predominant pathogens of ocular fungal infection in northern China and its incidence tends to increase, but that of Aspergirum sp to decrease. It is very important to recognize the distribution and shifting trend of pathogenic fungi in the diagnosis, prevention and treatment of fungal keratitis.</p>

Analysis of human transforming growth factor beta-induced gene mutation in corneal dystrophy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Corneal dystrophy is a group of inherited blinding diseases of the cornea. This study was to identify the mutations of the keratoepithelin (KE) gene for proper diagnosis of corneal dystrophy.</p><p><b>METHODS</b>Three families with corneal dystrophy were analysed. Thirteen individuals at risk for corneal dystrophy in family A, the proband and her son in family B, and the proband in family C were examined after their blood samples were obtained. Mutation screening of human transforming growth factor beta-induced gene (BIGH3 gene) was performed.</p><p><b>RESULTS</b>Five individuals in family A were found by clinical evaluation to be affected with granular corneal dystrophy and carried the BIGH3 mutation W555R. However, both probands in families B and C, also diagnosed with granular corneal dystrophy, harboured the BIGH3 mutation R124H.</p><p><b>CONCLUSION</b>Molecular genetic analysis can improve accurate diagnosis of corneal dystrophy.</p>

Genetic typing and antibiotic susceptibility testing of strains from pseudomonas aeruginosa keratitis patients / 眼科

Objective To study the characteristics of Genetic typing and the antibiotic susceptibility testing of strains from Pseudomonas aeruginosa keratitis patients.Design Experimental study,Participants 23 eyes of 23 patients of Pseudomonas aeruginosa keratitis.Methods The genomic was extracted and amplified with PCR.The PCR products were purified and sequenced.The results were registered in MIST web Antibiotic susceptibility testing were performed in theses strains,Main Outcome Measures Sequence types and antibiotic susceptibility.Results The isolates were resolved into 20 STs.Two lineages were identified.MIC test showed that strains were more susceptible to aminoglycosides,The activity of quinolones and cephalosporin were higher than that of aminoglycosides.Conclusion MIST can determine homology of the strains from Pseudomonas aeruginosa keratitis by clustering results. There is no finding about relationship between Genetic typing and drug resistance.

Study on the clinic and laboratory diagnosis of patients with trachoma / 眼科

Objective To investigate the clinical manifestation of trachoma,and to select the appropriate laboratory test for clini- cal diagnosis.Design Retrospective case series.Participants Retrospective analysis of medical records from 61 patients with trachoma from Jan 2003 to Aug 2006 in Bejing Tongren Eye Center.Methods Grades of trachoma diagnosis were according to the criteria de- signed by Chinese Ophthalmological Society (1979).The general state of health,case history,and the laboratory investigations of pa- tients were recorded.Laboratory tests included the conjunctiva scraping for inclusions,C.trachomatis immune antigen test and PCR test.Main Outcome Measures Manifestation of corneal and conjunctiva,the results of laboratory tests of C.trachomatis.Results Out of sixty-one patients including 28 males and 33 females,the average old was (29.05?19.99) years.88.5% cases were inⅠstage of tra- choma,8.2% were inⅡstage,and 3.3% were inⅢstage.The C.trachomatis inclusions were found in 7 (11.5%) scraping smears.42 (68.9%) cases were positive in C.trachomatis antigen test.46 (75.4%) cases were positive in PCR tests.The positive rates of antigen and PCR test were significantly higher than that of scraping (P=0.00).Conclusions A majority of clinical patients were inⅠstage of trachoma.The degree of their distress was minimal.It is necessary to apply C.trachomatis,antigen test or PCR test to improve the clin- ical diagnosis.

Clinical analysis about 5 cases of actinomycete keratitis / 眼科

Objective To analyze clinical diagnosis and management of 5 patients with actinomycete keratitis.Design Retro- spective case series.Participants 5 patients (5 eyes) with actinomycete keratitis.Methods The clinical features and microbiologic da- ta of 5 culture-proven cases of actinomycete keratitis recorded between October 2004 to March 2006 were analyzed.Main Outcome Measures clinical characteristics,isolations identification,drug susceptibility test and treatments.Results All patients were males and farmers.Of the 5 cases presented in this study,4 cases were followed by minor trauma as a predominant risk factor,and were pre- sented by a chronic progressive corneal ulcer with a wreath pattern of infiltrate.The diagnosis of all cases was based on laboratory in- vestigations,by which 4 cases of nocardia and one case of streptomyce were identified.A variable drug sensitivities were presented in nocardia isolates,which including TMP-SMZ,amicasin,gentamicin and fluorine-quinolones.Conclusions Nocardia keratitis is mainly followed by a minor trauma.It is identified predominantly by laboratory investigations.Tropical and systemically sensitive biotic are the initial choice,while debridement and amnionic transplantation could be an effective alternative.