WorldWideScience

Sample records for anterior chamber depth

  1. Anterior chamber depth during hemodialysis

    Directory of Open Access Journals (Sweden)

    Gracitelli CPB

    2013-08-01

    Full Text Available Carolina Pelegrini Barbosa Gracitelli,1 Francisco Rosa Stefanini,1 Fernando Penha,1 Miguel Ângelo Góes,2 Sérgio Antonio Draibe,2 Maria Eugênia Canziani,2 Augusto Paranhos Junior1 1Ophthalmology Department, 2Division of Nephrology, Federal University of São Paulo – UNIFESP, São Paulo, Brazil Background: Exacerbation of chronic glaucoma or acute glaucoma is occasionally observed in patients undergoing hemodialysis (HD because of anterior chamber depth changes during this therapy. Purpose: To evaluate anterior chamber depth and axial length in patients during HD sessions. Methods: A total of 67 eyes of 35 patients were prospectively enrolled. Axial length and anterior chamber depth were measured using ultrasonic biometry, and these measures were evaluated at three different times during HD sessions. Body weight and blood pressure pre- and post-HD were also measured. Results: There was no difference in the axial length between the three measurements (P = 0.241. We observed a significantly decreased anterior chamber depth (P = 0.002 during HD sessions. Conclusion: Our results support the idea that there is a change in anterior chamber depth in HD sessions. Keywords: anterior chamber, hemodialysis, axial length, acute angle-closure glaucoma

  2. Measurements of anterior chamber depth, white-to-white distance, anterior chamber angle, and pupil diameter using two Scheimpflug imaging devices

    Directory of Open Access Journals (Sweden)

    Alberto Domínguez-Vicent

    2014-08-01

    Full Text Available Purpose: To compare the ocular anterior chamber depth, white-to-white distance, anterior chamber angle, and pupil diameter, as measured with two different Scheimpflug imaging devices. Methods: This transversal study included 80 right eyes from 80 subjects aged from 20 to 40 years. Their spherical equivalents ranged from -4.25 to +1.00 diopters (D. Each eye's anterior chamber depth, white-to-white distance, anterior chamber angle, and pupil diameter, were measured for far vision using both the Galilei G4 (double Scheimpflug camera and the Pentacam HR (single Scheimpflug camera systems. Results: Mean anterior chamber depths were calculated as 3.12 ± 0.23 mm and 3.19 ± 0.24 mm when measured with the Galilei G4 and the Pentacam HR, respectively. The mean white-to-white distance measured was 11.84 ± 0.31 mm and 11.90 ± 0.43 mm when measured with the Galilei G4 and the Pentacam HR, respectively. Mean pupil diameters were measured as 3.22 ± 0.58 mm and 3.22 ± 0.52 mm when measured with the Galilei G4 and the Pentacam HR, respectively. Finally, the mean anterior chamber angle was 34.30 ± 2.86 degrees when it was measured with the Galilei G4, and 39.26 ± 2.85 degrees when measured with the Pentacam HR. A comparative analysis revealed that the Galilei G4 yielded a significantly lower (P0.05 for both devices were obtained for the white-to-white distance measurements. Conclusion: The Galilei G4 and Pentacam HR Scheimpflug systems cannot be used interchangeably because they produce significant measurement differences.

  3. Anterior chamber depth and primary angle-closure glaucoma. II. A genetic study.

    Science.gov (United States)

    Alsbirk, P H

    1975-06-01

    The genetics of primary angle-closure glaucome (a.c.g.) was studied: a) through the prevalence in sibs and children of a.c.g. probands, and b) through the family distribution of the closely correlated axial anterior chamber depth (ACD). The material emerged from an epidemiologic study in Greeland Eskimos. a) Compared with the general population, the observed prevalence of a.c.g. was increased in sibs of a.c.g. probands and the estimated, future prevalence was found to be the same in sibs and children. Age influence prevented a proper Mendelian analysis, but no simple monogenic inheritance seems probable. b) The biometric study showed a relatively shallow chamber in sibs, children, nephews, nieces and grandchildren of a.c.g. probands. Regression analyses revealed a corresponding pattern, also in control families of probands with shallow chambers and in general population families. A heritability of 70% was found, indicating that about two thirds of the age and sex independent variation in ACD seems to be genetic. PMID:1174403

  4. The correlation between variation of visual acuity and the anterior chamber depth in the early period after phacoemulsification

    Directory of Open Access Journals (Sweden)

    Kai-jian CHEN

    2011-04-01

    Full Text Available Objective To investigate the correlation between the visual acuity variation and the anterior chamber depth in the early period after phacoemulsification.Methods Thirty-six eyes of 32 patients with age-related cataract underwent 3.2mm clear corneal incision phacoemulsification and intraocular lens(IOL implantation.The visual acuity was examined and horizontal curvature(K1,vertical curvature(K2,corneal astigmatism,and anterior chamber depth were measured with IOL-master preoperatively and also on 1,3,7 and 15 postoperative days.The changes in parameters were compared,and the correlations among visual acuity,corneal astigmatism and anterior chamber depth were analyzed.Results Before operation and 1d,3d,7d and 15d after operation,the corneal astigmatism was-0.87±0.40D,-1.92±1.38D,-1.69±1.13D,-1.45±0.79D and-1.36±0.74D;the anterior chamber depth was 3.08±0.35mm,4.04±0.38mm,4.28±0.29mm,4.22±0.17mm and 4.22±0.16mm;the visual acuity was 0.18±0.10,0.44±0.14,0.59±0.12,0.61±0.11 and 0.62±0.14.Significant difference was found between pre-operative and postoperative visual acuity,corneal astigmatism and anterior chamber depth,and it was also found in corneal astigmatism between 1d and 15d post operation(P < 0.05,as well as in anterior chamber depth and visual acuity between 1d and 3d post operation(P < 0.05.A positive correlation was found between visual acuity and corneal astigmatism on 1d(r=0.42,P < 0.05,3d(r=0.35,P < 0.05 and 7d(r=0.35,P < 0.05 post operation;and a negative correlation was found between visual acuity and anterior chamber depth on 3d(r=-0.29,P < 0.05,7d(r=-0.43,P < 0.01 and 15d(r=-0.37,P < 0.05 post operation.Conclusion Both the corneal astigmatism and the anterior chamber depth are correlated with the visual acuity variation in the early period after phacoemulsification.

  5. The Effect of Phacoemulsification with Posterior Chamber Intraocular Lens Implantation on Intraocular Pressure and Anterior Chamber Depth

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Mohamadi

    2013-12-01

    Full Text Available Purpose: To evaluate intraocular pressure (IOP and anterior chamber depth (ACD change after phacoemulsification with posterior chamber intraocular lens implantation Methods: In this quasi-experimental study, 84 patients with senile cataract were included. All patients had normal IOP. Patients with traumatic and complicated cataract, any history of uveitis, glaucoma, or other ocular disease or surgery were excluded. Patients underwent phacoemulsification and intraocular lens implantation by the same surgeon. IOP, ACD, and lens thickness were measured and recorded before surgery. IOP was measured at 4, 8 and 12 postoperative weeks and ACD was measured 12 weeks after surgery. Results: The mean preoperative ACD significantly increased from 2.93 mm to 3.54 mm postoperatively (p<0.0001. Mean preoperative IOP was 16.06 mmHg which decreased to 12.01 IOP mmHg, 12.57 mmHg and 12.90 mmHg at 4 weeks, 8 weeks and 12 weeks postoperatively, respectively (all p-values<0.0001. There was a correlation between lens thickness and changes of and ACD after the surgery. There was also a positive correlation between preoperative IOP and IOP reduction after the surgery. Conclusion: Phacoemulsification decreases IOP specially in eyes with higher preoperative IOP and thicker lenses.

  6. Association of eNOS Polymorphisms with Anterior Chamber Depth in Han Chinese: Jiangsu Eye Study

    Directory of Open Access Journals (Sweden)

    Haihong Shi

    2014-01-01

    Full Text Available Recently, a study reported that single nucleotide polymorphisms (SNP in endothelial nitric oxide synthase (eNOS were associated with primary angle closure glaucoma (PACG in Australian cohort. In this study, we aimed to investigate whether those eNOS SNPs are associated with primary angle closure (PAC or ocular biometric characteristics such as axial length (AL, anterior chamber depth (ACD, and diopter of spherical power (DS in Han Chinese. The samples consisted of 232 PAC subjects and 306 controls collected from a population-based prevalence survey conducted in Funing County of Jiangsu, China. The rs3793342 and rs11771443 in eNOS were genotyped by TaqMan-MGB probe using the RT-PCR system. Our data did not identify any association of the eNOS SNPs with PAC. However, the analysis on the quantitative traits of ocular biometrics showed that the ACD of rs11771443 AA and GA carriers is significantly deeper than that of rs11771443 GG carriers (P=0.0025, even though the AL and DS are not associated with rs11771443 genotypes. Rs3793342 was not associated with any biometric parameters including ACD, AL and DS. In summary, our data indicates that eNOS rs11771443 is associated with ACD and its role in the pathogenesis of PACG warranted further study.

  7. A Novel Method of Quantitative Anterior Chamber Depth Estimation Using Temporal Perpendicular Digital Photography

    Science.gov (United States)

    Zamir, Ehud; Kong, George Y.X.; Kowalski, Tanya; Coote, Michael; Ang, Ghee Soon

    2016-01-01

    Purpose We hypothesize that: (1) Anterior chamber depth (ACD) is correlated with the relative anteroposterior position of the pupillary image, as viewed from the temporal side. (2) Such a correlation may be used as a simple quantitative tool for estimation of ACD. Methods Two hundred sixty-six phakic eyes had lateral digital photographs taken from the temporal side, perpendicular to the visual axis, and underwent optical biometry (Nidek AL scanner). The relative anteroposterior position of the pupillary image was expressed using the ratio between: (1) lateral photographic temporal limbus to pupil distance (“E”) and (2) lateral photographic temporal limbus to cornea distance (“Z”). In the first chronological half of patients (Correlation Series), E:Z ratio (EZR) was correlated with optical biometric ACD. The correlation equation was then used to predict ACD in the second half of patients (Prediction Series) and compared to their biometric ACD for agreement analysis. Results A strong linear correlation was found between EZR and ACD, R = −0.91, R2 = 0.81. Bland-Altman analysis showed good agreement between predicted ACD using this method and the optical biometric ACD. The mean error was −0.013 mm (range −0.377 to 0.336 mm), standard deviation 0.166 mm. The 95% limits of agreement were ±0.33 mm. Conclusions Lateral digital photography and EZR calculation is a novel method to quantitatively estimate ACD, requiring minimal equipment and training. Translational Relevance EZ ratio may be employed in screening for angle closure glaucoma. It may also be helpful in outpatient medical clinic settings, where doctors need to judge the safety of topical or systemic pupil-dilating medications versus their risk of triggering acute angle closure glaucoma. Similarly, non ophthalmologists may use it to estimate the likelihood of acute angle closure glaucoma in emergency presentations. PMID:27540496

  8. Central corneal thickness and anterior chamber depth measurement by Sirius® Scheimpflug tomography and ultrasound

    Directory of Open Access Journals (Sweden)

    Jorge J

    2013-02-01

    Full Text Available J Jorge,1 JL Rosado,2 JA Díaz-Rey,1 JM González-Méijome11Clinical and Experimental Optometry Research Laboratory, Center of Physics (Optometry, School of Sciences, University of Minho, Braga, 2Opticlinic, Lisboa, PortugalBackground: The purpose of this study was to compare the accuracy of the new Sirius® Scheimpflug anterior segment examination device for measurement of central corneal thickness (CCT and anterior chamber depth (ACD with that of CCT measurements obtained by ultrasound pachymetry and ACD measurements obtained by ultrasound biometry, respectively.Methods: CCT and ACD was measured in 50 right eyes from 50 healthy subjects using a Sirius Scheimpflug camera, SP100 ultrasound pachymetry, and US800 ultrasound biometry.Results: CCT measured with the Sirius was 546 ± 39 µm and 541 ± 35 µm with SP100 ultrasound pachymetry (P = 0.003. The difference was statistically significant (mean difference 4.68 ± 10.5 µm; limits of agreement −15.8 to 25.20 µm. ACD measured with the Sirius was 2.96 ± 0.3 mm compared with 3.36 ± 0.29 mm using US800 ultrasound biometry (P < 0.001. The difference was statistically significant (mean difference −0.40 ± 0.16 mm; limits of agreement −0.72 to 0.07 mm. When the ACD values obtained using ultrasound biometry were corrected according to the values for CCT measured by ultrasound, the agreement increased significantly between both technologies for ACD measurements (mean difference 0.15 ± 0.16 mm; limits of agreement −0.16 to 0.45 mm.Conclusion: CCT and ACD measured by Sirius and ultrasound methods showing good agreement between repeated measurements obtained in the same subjects (repeatability with either instrument. However, CCT and ACD values, even after correcting ultrasound ACD by subtracting the CCT value obtained with either technology should not be used interchangeably.Keywords: Scheimpflug corneal tomography, ultrasound biometry, ultrasound pachymetry, limits of agreement

  9. Is being female a risk factor for shallow anterior chamber? The associations between anterior chamber depth and age, sex, and body height

    Directory of Open Access Journals (Sweden)

    Wei-Cherng Hsu

    2014-01-01

    Full Text Available Aim of Study: To analyze the association between anterior chamber depth (ACD and age, sex, and body height (BH. Materials and Methods: One thousand four hundred eighty eyes of 1480 adults 40 years of age and older receiving preoperative evaluation for cataract surgery were recruited consecutively from June 1, 2006, to December 31, 2010. ACD was measured with the Zeiss IOLMaster. Univariate and multivariate linear regression models were used to analyze the correlations, and receiving operator characteristic (ROC curves and the area under the curve (AUC were used for evaluating the predictability of an ACD less than 2.70 mm. Results: ACD was negatively correlated with age and positively correlated with BH in both univariate and multivariate regression analysis (P < 0.001. Sex was associated with ACD in univariate analysis, but not after adjustment with age and BH. In predicting an ACD less than 2.70 mm, the AUCs of ROC curves for ′age and sex′, ′age and BH′, and ′age, sex, and BH′ were 0.687, 0.689, and 0.689, respectively. Conclusion: Age and BH were independent associating factors of ACD; however, sex was not. Older people and shorter ones likely had shallower ACD, and therefore were predisposed to Primary angle closure glaucoma (PACG. The predictability of ACD by age and BH solely was low, and adding sex did not increase it.

  10. Anterior chamber depth and lens thickness in primary angle-closure glaucoma : A case-control study

    Directory of Open Access Journals (Sweden)

    Saxena Sandeep

    1993-01-01

    Full Text Available Anterior chamber depth and lens thickness have been considered as important biometric determinants in primary angle-closure glaucoma (PACG. In a tertiary care centre-based case-control study, 70 patients and equal number of controls were investigated to analyse the strength of association and predictability of anterior chamber depth (ACD and lens thickness (LT in the disease. Mean (+/- S.D. ACD and LT in the cases and the controls were found to be 2.28 +/- 0.19, 2.87 +/- 0.10; 4.57 +/- 0.34 and 4.13 +/- 0.19 mm respectively. Two sample t test demonstrated statistically significant difference in the ACD and LT between the cases and the controls (Difference being -0.59, 0.44; 95% confidence interval of the difference: -0.64, -0.53 and 0.34, 0.53 respectively, P < 0.01. Logistic regression analysis demonstrated statistically significant protective effect of ACD over PACG (P < 0.01. The odds ratio corresponding to an increase of 0.01 mm in ACD and LT were computed as 0.83 and 1.11 respectively

  11. Effect of anterior chamber depth on the choice of intraocular lens calculation formula in patients with normal axial length

    Directory of Open Access Journals (Sweden)

    Mohammad Miraftab

    2014-01-01

    Full Text Available Purpose: To compare the accuracy of  Sanders-Retzlaff-Kraff II (SRK II and 3 rd and 4 th generation intraocular lens (IOL formulas and to compare the effect of different anterior chamber depths among the IOL formulas in cataract patients with normal axial length (AL; 22.0-24.5 millimeters, mm. Materials and Methods: A retrospective chart review was performed of patients with normal AL who underwent cataract surgery. The SRK II and 3 rd generation IOL formulas (Hoffer Q, SRK T, Holladay 1 were compared to the 4 th generation Haigis formula. For analysis, preoperative anterior chamber depth (ACD was divided into three subgroups: ≤3, 3-3.5, and ≥ 3.5 mm. The mean error (ME and mean absolute error (MAE of each formula was compared for each subgroup against the total. The difference between the ME and MAE of the formulas were compared for each ACD subgroup. P 0.05, all comparisons. Conclusion: The SRK II formula can predict refraction in patients with normal AL and ACD less than 3 mm with less error and is preferred over other formulas. The Haigis formula is the preferred choice in patients with a normal AL and ACD longer than 3.5 mm. The prediction accuracy of Hoffer Q, SRK T, and Holladay 1 is comparable in normal AL.

  12. ABCC5, a gene that influences the anterior chamber depth, is associated with primary angle closure glaucoma.

    Directory of Open Access Journals (Sweden)

    Monisha E Nongpiur

    2014-03-01

    Full Text Available Anterior chamber depth (ACD is a key anatomical risk factor for primary angle closure glaucoma (PACG. We conducted a genome-wide association study (GWAS on ACD to discover novel genes for PACG on a total of 5,308 population-based individuals of Asian descent. Genome-wide significant association was observed at a sequence variant within ABCC5 (rs1401999; per-allele effect size =  -0.045 mm, P = 8.17 × 10(-9. This locus was associated with an increase in risk of PACG in a separate case-control study of 4,276 PACG cases and 18,801 controls (per-allele OR = 1.13 [95% CI: 1.06-1.22], P = 0.00046. The association was strengthened when a sub-group of controls with open angles were included in the analysis (per-allele OR = 1.30, P = 7.45 × 10(-9; 3,458 cases vs. 3,831 controls. Our findings suggest that the increase in PACG risk could in part be mediated by genetic sequence variants influencing anterior chamber dimensions.

  13. Comparison between a New Optical Biometry Device and an Anterior Segment Optical Coherence Tomographer for Measuring Central Corneal Thickness and Anterior Chamber Depth

    Directory of Open Access Journals (Sweden)

    Jinhai Huang

    2016-01-01

    Full Text Available Purpose. To compare between a new optical biometer (AL-Scan, Nidek Co., Aichi, Japan and an anterior segment optical coherence tomographer (Visante AS-OCT, Carl Zeiss Meditec, Dublin, USA for measuring central corneal thickness (CCT, anterior chamber depth (ACD, and aqueous depth (AD. Methods. Sixty-three eyes of 63 normal subjects were examined with AL-Scan and Visante AS-OCT in this prospective study. One eye per subject was measured three times with both devices to record their CCT, ACD, and AD. All procedures were performed by the same operator. Agreement between the two devices was assessed using paired t-tests, Bland-Altman plots, and 95% limits of agreement (LoA. Results. The mean CCT, ACD, and AD measured by AL-Scan were 538.59±27.37 μm, 3.70±0.30 mm, and 3.16±0.30 mm, respectively. The mean values obtained by the Visante OCT were 536.14±26.61 μm for CCT, 3.71±0.29 mm for ACD, and 3.17±0.29 mm for AD. The mean CCT by the AL-Scan was higher than that obtained by the Visante AS-OCT (difference = 2.45±6.07 μm, P<0.05. The differences in ACD and AD measurements were not statistically significant. The 95% LoA of CCT, ACD, and AD were between −9.44 and 14.35 μm, −0.15 and 0.12 mm, and −0.15 and 0.12 mm, respectively. Conclusions. Since these two devices were comparable for measuring CCT, ACD, and AD, their results can be interchangeably used in the clinic.

  14. Comparison between a New Optical Biometry Device and an Anterior Segment Optical Coherence Tomographer for Measuring Central Corneal Thickness and Anterior Chamber Depth.

    Science.gov (United States)

    Huang, Jinhai; Lu, Weicong; Savini, Giacomo; Chen, Hao; Wang, Chengfang; Yu, Xinxin; Bao, Fangjun; Wang, Qinmei

    2016-01-01

    Purpose. To compare between a new optical biometer (AL-Scan, Nidek Co., Aichi, Japan) and an anterior segment optical coherence tomographer (Visante AS-OCT, Carl Zeiss Meditec, Dublin, USA) for measuring central corneal thickness (CCT), anterior chamber depth (ACD), and aqueous depth (AD). Methods. Sixty-three eyes of 63 normal subjects were examined with AL-Scan and Visante AS-OCT in this prospective study. One eye per subject was measured three times with both devices to record their CCT, ACD, and AD. All procedures were performed by the same operator. Agreement between the two devices was assessed using paired t-tests, Bland-Altman plots, and 95% limits of agreement (LoA). Results. The mean CCT, ACD, and AD measured by AL-Scan were 538.59 ± 27.37 μm, 3.70 ± 0.30 mm, and 3.16 ± 0.30 mm, respectively. The mean values obtained by the Visante OCT were 536.14 ± 26.61 μm for CCT, 3.71 ± 0.29 mm for ACD, and 3.17 ± 0.29 mm for AD. The mean CCT by the AL-Scan was higher than that obtained by the Visante AS-OCT (difference = 2.45 ± 6.07 μm, P LoA of CCT, ACD, and AD were between -9.44 and 14.35 μm, -0.15 and 0.12 mm, and -0.15 and 0.12 mm, respectively. Conclusions. Since these two devices were comparable for measuring CCT, ACD, and AD, their results can be interchangeably used in the clinic. PMID:27403339

  15. Pentacam could be a useful tool for evaluating and qualifying the anterior chamber morphology

    OpenAIRE

    Li, Xiaoyu; Wang, Zheng; Cao, Qun; Hu, Lei; Tian, Fang; Dai, Hong

    2014-01-01

    Objective: This study aims to investigate the changes of anterior chamber morphology after laser peripheral iridotomy (LPI) in primary angle-closure (PAC) patients using Pentacam. Methods: 35 normal persons and 35 patients of PAC before and 1 week after neodymium: yttrium: aluminum garnet (Nd: YAG) LPI were evaluated with Pentacam. We measured the anterior chamber angle (ACA), central anterior chamber depth (CACD), peripheral anterior chamber depth (PACD), anterior chamber volume (ACV) and pu...

  16. Short-term variation of central corneal thickness and axial anterior chamber depth of healthy eyes using Scheimpflug photography via the Oculus Pentacam*

    Directory of Open Access Journals (Sweden)

    S. D. Mathebula

    2009-12-01

    Full Text Available The purpose of this study was to investigate short-term variation and intra-subject repeatabil-ity of  human central corneal thickness (CCT and axial anterior chamber depth (AACD measure-ments obtained using the Oculus Pentacam. Forty consecutive images of the right eye of the anteriorsegment of 10 young and healthy individuals were measured with the Pentacam. Measurements of CCT and AACD were ob-tained from these images and means, standard deviations,variances and repeatability of the measurements were investigated. Both parameters (CCTand AACD showed small variation with good orexcellent repeatability for all eyes. The inter-subject or overall means and standard deviations for CCT and AACD of the 10 right eyes were 0.555 ±0.05 millimeters (or 555 ± 50 microns and 3.206± 0.04 millimeters, respectively. The individual or intra-subject averages for samples of CCT and AACD measurements are also provided in this paper. Univariate normality of the data was explored with Kolmogorov-Smirnov, Lilliefors and ShapiroWilks tests and we found that generally the data was normally distributed although there were some exceptions. Based on the results of this study, the Oculus Pentacam appears to provide repeatable and reliable measures for both CCT and AACD in young,normal eyes. Further research is, however, needed to determine short-term variation and repeatability of CCT and AACD with the Pentacam in more com-plicated eyes with, say, corneal scarring or ectasia or where refractive surgery may be an issue.

  17. Anterior Chamber Live Loa loa: Case Report.

    Science.gov (United States)

    Kagmeni, G; Cheuteu, R; Bilong, Y; Wiedemann, P

    2016-01-01

    We reported a case of unusual intraocular Loa loa in a 27-year-old patient who presented with painful red eye. Biomicroscopy revealed a living and active adult worm in the anterior chamber of the right eye. After surgical extraction under local anesthesia, parasitological identification confirmed L. loa filariasis. PMID:27441005

  18. Anterior Chamber Live Loa loa: Case Report

    Science.gov (United States)

    Kagmeni, G.; Cheuteu, R.; Bilong, Y.; Wiedemann, P.

    2016-01-01

    We reported a case of unusual intraocular Loa loa in a 27-year-old patient who presented with painful red eye. Biomicroscopy revealed a living and active adult worm in the anterior chamber of the right eye. After surgical extraction under local anesthesia, parasitological identification confirmed L. loa filariasis. PMID:27441005

  19. 角膜塑形镜对角膜前后表面曲率半径和前房深度的影响%The affect of orthokeratology lens to the anterior and posterior corneal surface and anterior chamber depth

    Institute of Scientific and Technical Information of China (English)

    陈蛟; 肖满意; 王华; 郭颖卓; 何书喜

    2013-01-01

      目的:探讨角膜塑形镜对角膜前后表面曲率半径和前房深度的影响。方法:用Orbscan-Ⅱ角膜地形图,检查17例31眼配戴角膜塑形镜3个月后角膜前后表面曲率半径和前房深度的变化。结果:配戴角膜塑形镜3个月后所有患者屈光度下降,裸眼视力上升(P0.05)。结论:角膜塑形镜主要通过改变角膜前表面的曲率,压平角膜前表面达到矫正近视的目的,对角膜后表面与前房深度无明显影响。%Objective To find out the affect of orthokeratology lens to the anterior and posterior corneal sur-face and anterior chamber depth.Methods 17 patients ,31eyes, after 3 months orthokeratology wearing, corneal topography examination with Orbscan-Ⅱ,record the changes of the anterior and posterior corneal surface radius and anterior chamber depth.Results After 3 months orthokeratology wearing, the refraction diopter decline, uncor-rected visual acuity increased (P0.05).Conclusion Orthokeratology lens mainly affects the shape of the anterior corneal surface , flatten the anteri-or corneal surface, rather than change of the posterior corneal surface radius and anterior chamber depth to achieve the effect of reducing refraction.

  20. Role of Optical Coherence Tomography in Assessing Anterior Chamber Angles

    Science.gov (United States)

    Kochupurakal, Reema Thomas; Jha, Kirti Nath; Rajalakshmi, A.R.; Nagarajan, Swathi; Ezhumalai, G.

    2016-01-01

    Introduction Gonioscopy is the gold standard in assessing anterior chamber angles. However, interobserver variations are common and there is a need for reliable objective method of assessment. Aim To compare the anterior chamber angle by gonioscopy and Spectral Domain Optical Coherence Tomography (SD-OCT) in individuals with shallow anterior chamber. Materials and Methods This comparative observational study was conducted in a rural tertiary multi-speciality teaching hospital. A total of 101 eyes of 54 patients with shallow anterior chamber on slit lamp evaluation were included. Anterior chamber angle was graded by gonioscopy using the shaffer grading system. Angles were also assessed by SD-OCT with Trabecular Iris Angle (TIA) and Angle Opening Distance (AOD). Chi-square test, sensitivity, specificity, positive and negative predictive value to find correlation between OCT parameters and gonioscopy grading. Results Females represented 72.7%. The mean age was 53.93 ±8.24 years and mean anterior chamber depth was 2.47 ± 0.152 mm. Shaffer grade ≤ 2 were identified in 95(94%) superior, 42(41.5%) inferior, 65(64.3%) nasal and 57(56.4%) temporal quadrants. Cut-off values of TIA ≤ 22° and AOD ≤ 290 μm were taken as narrow angles on SD-OCT. TIA of ≤ 22° were found in 88(92.6%) nasal and 87(87%) temporal angles. AOD of ≤ 290 μm was found in 73(76.8%) nasal and 83(83%) temporal quadrants. Sensitivity in detecting narrow angles was 90.7% and 82.2% for TIA and AOD, while specificity was 11.7% and 23.4%, respectively. Conclusion Individuals were found to have narrow angles more with SD-OCT. Sensitivity was high and specificity was low in detecting narrow angles compared to gonioscopy, making it an unreliable tool for screening. PMID:27190851

  1. Foreign Body Embedded in Anterior Chamber Angle

    OpenAIRE

    Shmuel Graffi; Beatrice Tiosano; Ran Ben Cnaan; Jonathan Bahir; Modi Naftali

    2012-01-01

    Introduction. We present a case of a metallic foreign body embedded in the anterior chamber angle. After standing in close proximity to a construction worker breaking a tile, a 26-year-old woman using soft contact lens for the correction of mild myopia presented to emergency department for evaluation of a foreign body sensation of her right eye. Methods and Results. Diagnosis was confirmed by gonioscopic examination and a noncontrast CT scan of head and orbits. The foreign body was removed by...

  2. Pupillary block glaucoma following implantation of a posterior chamber pseudophakos in the anterior chamber.

    Directory of Open Access Journals (Sweden)

    Mandal Anil

    2002-01-01

    Full Text Available Pupillary block glaucoma is a common complication of cataract surgery, especially following anterior chamber intraocular lens implantation. We report a case of pupillary block glaucoma with a posterior chamber IOL that was implanted in the anterior chamber following a complicated extracapsular cataract extraction. The case was successfully managed by explantation of the posterior chamber lens, anterior vitrectomy, peripheral iridectomy and secondary anterior chamber intraocular lens implantation. The intraocular pressure was controlled with a single topical antiglaucoma medication.

  3. Effect of primary iris and ciliary body cyst on anterior chamber angle in patients with shallow anterior chamber

    Institute of Scientific and Technical Information of China (English)

    Bing-hong WANG; Yu-feng YAO

    2012-01-01

    Objective:To evaluate the prevalence of primary iris and/or ciliary body cysts in eyes with shallow anterior chamber and their effect on the narrowing of the anterior chamber angle.Methods:Among the general physical check-up population,subjects with shallow anterior chambers,as judged by van Herick technique,were recruited for further investigation.Ultrasound biomicroscope (UBM) was used to detect and measure the cysts located in the iris and/or ciliary body,the anterior chamber depth (ACD),the angle opening distance at 500 μm (AOD500),and the trabecular-iris angle (TIA).A-scan ultrasonography was used to measure the ocular biometry,including lens thickness,axial length,lens/axial length factor (LAF),and relative lens position (RLP).The effect of the cyst on narrowing the corresponding anterior chamber angle and the entire angle was evaluated by the UBM images,ocular biometry,and gonioscopic grading.The eye with unilateral cyst was compared with the eye without the cyst for further analysis.Results:Among the 727 subjects with shallow anterior chamber,primary iris and ciliary body cysts were detected in 250 (34.4%) patients; among them 96 (38.4%) patients showed unilateral single cyst,21 (8.4%) patients had unilateral double cysts,and 42 (16.8%) patients manifested unilateral multiple and multi-quadrants cysts.Plateau iris configuration was found in 140 of 361 (38.8%) eyes with cysts.The mean size of total cysts was (0.6547±0.2319) mm.In evaluation of the effect of the cyst size and location on narrowing the corresponding angle to their position,the proportion of the cysts causing corresponding angle narrowing or closure among the cysts larger than 0.8 mm (113/121,93.4%) was found to be significantly higher than that of the cysts smaller than 0.8 mm (373/801,46.6%),and a significant higher proportion was also found in the cysts located at iridociliary sulcus (354/437,81.0%) than in that at the pars plicata (131/484,27.1%).In evaluating the effect

  4. Evaluation of the Effects of Menstrual Cycle on Anterior Chamber Parameters as Measured with Pentacam

    Directory of Open Access Journals (Sweden)

    Arzu Seyhan Karatepe

    2013-01-01

    Full Text Available Pur po se: To evaluate the effects of endogenous gonadotropic hormones (follicle-stimulating hormone, luteinizing hormone and sex steroids (progesterone, estrogen to anterior segment parameters. Ma te ri al and Met hod: Thirty healthy females who had a menstrual cycle of 28±1 day and with a mean age of 36.5±7.56 (range, 20 – 46 years were included in the study. Starting from the first day of their cycle, Pentacam Scheimpflug camera measurements were performed on the 1st, 3rd, 7th, 12th, 16th, 21st, 26th, and 28th days. The central corneal thickness, anterior chamber depth, anterior segment volume, keratometric values, anterior chamber angle value, and pupilla diameter of both eyes were evaluated. Repeated measures analysis of variance test was used for statistical analysis. Re sults: No difference that reaches statistical significance was found in the means of central corneal thickness, anterior chamber volume, keratometric values, anterior chamber angle, and pupilla diameter between the days. Mean anterior chamber depth measurement of the right eyes on the 1st day was 2.72±0.44 mm, whereas it was 2.77±0.46 mm on the 26th day. Mean anterior chamber depth measurement of the left eyes on the 1st day was 2.74±0.42 mm, whereas it was 2.80±0.43 mm on the 26th day. This increment of anterior chamber depth value from the 1st to the 26th days was found to be statistically significant (p≤0.05. Dis cus si on: Progesterone and estrogen that rise in the second half of the menstrual cycle might have a deepening effect on the anterior chamber. These findings should be further investigated with more profound studies that also evaluate the hormonal values and their correlations with anterior segment parameters. (Turk J Ophthalmol 2013; 43: 15-8

  5. Double anterior chamber in a patient with glaucoma and microspherophakia

    Directory of Open Access Journals (Sweden)

    Hamid Khakshoor

    2011-01-01

    Full Text Available We report the case of a 16-year-old woman with microspherophakia and secondary open angle glaucoma. The patient presented with a membrane dividing the anterior chamber into two segments without edema or Descemet′s membrane detachment. Slit lamp biomicroscopy, Pentacam, and specular microscopy images were obtained. Double anterior chamber is primarily found in patients with anterior chamber anomalies when there is no history of surgery or trauma.

  6. RETAINED STONE PIECE IN ANTERIOR CHAMBER

    Directory of Open Access Journals (Sweden)

    ZvornicaninJasmin, Nadarevic-VodencarevicAmra

    2015-04-01

    Full Text Available ABSTRACT We read with interest the article by Surekha et al. regarding the retained stone piece in anterior chamber. Similar to the results of previous studies, the authors found that delayed intraocular foreign body (IOFB management can result in good visual outcome without an apparent increased risk of endophthalmitis or other deleterious side effects. However, the authors failed to explain the exact reason for the diminution of vision in patients left eye. It is unclear what the uncorrected visual acuity was and what kind of correction was used, more precisely type and amount of cylinder, given the presence of the corneal opacity. Since the size of the IOFB is approximately 4x4x1mm, significant irido-corneal angle changes resulting in intraocular pressure raise and optic nerve head damage can be expected. Traumatic glaucoma following open globe injury can occur in 2.7 to 19% of cases, with several risk factors associated with glaucoma development (advanced age, poor visual acuity at presentation,perforating rather than penetrating ocular injury,lens injury, presence of vitreous hemorrhage and presence of an IOFB. Earlier reportsof latetraumaticoptic neuropathy onset, even after several years, indicate that this possibility cannot be completely ruled out too. Therefore, repeated intraocular pressure measurements, gonioscopy, pupillary reaction assessment, together with through posterior segment examination including visual field and optical coherence tomography examinations can be useful in determining the possible optic nerve damage as one of the possible reasons for visual acuity reduction. The authors did not suggest any operative treatment at this time. However, it should bear in mind that the inert anterior chamber IOFB could be a risk factor for non-infectious endophthalmitis development even after many years. Also, long term retained anterior chamber foreign body leads to permanent endothelial cell loss and can even result in a corneal

  7. Foreign Body Embedded in Anterior Chamber Angle

    Directory of Open Access Journals (Sweden)

    Shmuel Graffi

    2012-01-01

    Full Text Available Introduction. We present a case of a metallic foreign body embedded in the anterior chamber angle. After standing in close proximity to a construction worker breaking a tile, a 26-year-old woman using soft contact lens for the correction of mild myopia presented to emergency department for evaluation of a foreign body sensation of her right eye. Methods and Results. Diagnosis was confirmed by gonioscopic examination and a noncontrast CT scan of head and orbits. The foreign body was removed by an external approach without utilizing a magnet. The patient's final outcome was favorable. Discussion. The above is a rare clinical situation, which is impossible to detect on slit-lamp examination without a gonioscopic view. Proper imaging and a specific management are mandatory in order to achieve favorable outcome.

  8. Anterior chamber cholesterolosis in a patient with retinoblastoma.

    Science.gov (United States)

    Hong, Bryan K; Say, Emil Anthony T; Chévez-Barrios, Patricia; Lee, Thomas C; Kim, Jonathan W

    2016-01-01

    Anterior chamber cholesterolosis is a rare phenomenon typically associated with non-neoplastic conditions such as hyphema or Coats disease; it has never been reported to be associated with intraocular malignancy. We report a case of anterior chamber cholesterolosis presenting in the setting of retinoblastoma and discuss clinical features relevant for its differentiation from Coats disease. PMID:27330481

  9. Method for measuring anterior chamber volume by image analysis

    Science.gov (United States)

    Zhai, Gaoshou; Zhang, Junhong; Wang, Ruichang; Wang, Bingsong; Wang, Ningli

    2007-12-01

    Anterior chamber volume (ACV) is very important for an oculist to make rational pathological diagnosis as to patients who have some optic diseases such as glaucoma and etc., yet it is always difficult to be measured accurately. In this paper, a method is devised to measure anterior chamber volumes based on JPEG-formatted image files that have been transformed from medical images using the anterior-chamber optical coherence tomographer (AC-OCT) and corresponding image-processing software. The corresponding algorithms for image analysis and ACV calculation are implemented in VC++ and a series of anterior chamber images of typical patients are analyzed, while anterior chamber volumes are calculated and are verified that they are in accord with clinical observation. It shows that the measurement method is effective and feasible and it has potential to improve accuracy of ACV calculation. Meanwhile, some measures should be taken to simplify the handcraft preprocess working as to images.

  10. Dirofilaria in the anterior chamber: A rare occurrence

    Directory of Open Access Journals (Sweden)

    Rupali Chopra

    2012-01-01

    Full Text Available Dirofilariasis is a parasitic infection of the carvivores that may present as a zoonotic infestation in humans. Systemic involvement in man is subcutaneous, pulmonary, or ocular. We report a rare occurrence of ocular dirofilariasis in a 25-year-old male patient who presented with pain and redness in the eye. A live, white, coiled, and highly motile worm was present in the anterior chamber. The worm, however, could not be detected in the anterior chamber, posterior segment, or the angle of the anterior chamber when the patient was taken to the operating room for surgical removal of the worm. The patient was made to lie prone till the worm reappeared in the anterior chamber and was removed by paracentesis. The worm was identified as Dirofilaria repens on the basis of microscopic and histopathological examination.

  11. Anterior chamber flare after trabeculectomy and after phacoemulsification

    OpenAIRE

    Siriwardena, D; Kotecha, A; Minassian, D; Dart, J.; KHAW, P.

    2000-01-01

    AIMS—To evaluate and compare prospectively the anterior chamber inflammatory response after phacoemulsification cataract surgery and after trabeculectomy with peripheral iridectomy.
METHODS—Anterior chamber inflammation was measured using the Kowa FM-500 laser flare meter in 131 patients undergoing trabeculectomy and 148 patients undergoing phacoemulsification cataract extraction with intraocular lens implantation. Flare was measured before surgery and on each postoperative visit up to 12 mon...

  12. 三维眼前节分析系统与超声生物显微镜测量急性原发性闭角型青光眼前房深度的一致性分析%The anterior chamber depth measurement of acute primary angle-closure glaucoma with Sirius triaxial anterior system and ultrasound biomicroscopy

    Institute of Scientific and Technical Information of China (English)

    江媛; 陈伟; 陈增辉; 张伟刚

    2013-01-01

    目的 研究Sirius三维眼前节分析系统与超声生物显微镜(UBM)测量急性原发性闭角型青光眼(APACG)中央前房深度(CACD)及周边前房深度(PACD)的一致性.方法 前瞻性对照研究.分别采用Sirius三维眼前节分析系统和UBM测量40例(40眼)APACG患者的CACD和PACD,采用配对样本f检验及Pearson直线相关进行统计学分析,并应用Bland-Altman分析评价2种仪器测量结果的一致性.结果 Sirius三维眼前节分析系统和UBM测得的CACD值分别为(1.87±0.30) mm和(1.98±0.30)mm,PACD值为(0.61±0.21)mm和(0.56±0.21)mm,2种仪器测得CACD值及PACD值差异均有统计学意义(t=-6.533、2.432,P<0.05).2种仪器测得到CACD、PACD值均呈正相关(r=0.944、0.796,P<0.05).Sirius三维眼前节分析系统和UBM测得的CACD值、PACD值差值分别为(-0.10±0.l0)mm和(0.05±0.14)mm,95%一致性界限分别为(-0.30,0.09)mm和(-0.22,0.32)mm.结论 Sirius三维眼前节分析系统和UBM在测量APACG患眼的CACD及PACD时有较好的一致性,可相互替代使用.%Objective To explore the difference and agreement in the measurement of central anterior chamber depth (CACD) and peripheral anterior chamber depth (PACD) in the acute primary angle-closure glaucoma (APACG) between Sirius triaxial anterior system and ultrasound biomicroscopy (UBM).Methods Prospective control study.Forty eyes of 40 APACG patients were selected,respectively,using Sirius triaxial anterior system and UBM measuring CACD and PACD.Paired samples t-test and Pearson linear correlation for statistical analysis,and application of Bland-Altman analysis to evaluate the two methods of measurement consistency.Results The CACD values measured by Sirius triaxial anterior system and UBM were (1.87±0.30)mm and (1.98±0.30)mm,PACD values were (0.61±0.21)mm and (0.56±0.21)mm,respectively,indicating a significant difference (t=-6.533,2.432,P<0.05); and a significant linear correlation between them (r=0.944,0.796,P<0.05).Sirius

  13. Evaluation of Cornea and Anterior Chamber Using Pentacam in Pediatric Cases

    Directory of Open Access Journals (Sweden)

    Melis Palamar Onay

    2011-08-01

    Full Text Available Purpose: To evaluate the anterior segment structures using Pentacam in pediatric cases. Material and Method: One hundred sixty-two eyes (study group of 81 healthy children who attended our clinic were compared with 114 eyes (control group of 57 healthy adults. The central corneal thickness, anterior chamber volume, and anterior chamber depth of all cases were evaluated with Pentacam. Independent t-test and Pearson’s correlation analysis were used for statistics. Results: The mean age of the study group (40 male, 41 female was 9.99±2.80 (range: 6-16 years. The mean central corneal thickness in the right eyes was 580.74±42.04 (range: 492-669 micrometers and in the left eyes was 586.52±43.51 (range: 495-699 micrometers. The mean anterior chamber depth, volume, and anterior chamber angle were 3.02±0.29 (range: 2.39-3.9 mm, 176.43±31.77 (range: 117-272 mm3 and 36.23±5.41 (range: 25.8-50.7 degree, respectively. When the right and the left eyes were compared, significant differences were observed between central corneal thickness (p=0.001 and anterior chamber angles (p=0.05. The mean left eye keratometry was found to be significantly flatter in children (p=0.002. The mean anterior chamber depth, anterior chamber volume, and anterior chamber angle values were higher in children than in adults (p<0.001. Discussion: Pentacam is an easy-to-use and noninvasive technique that can be used for the evaluation of central corneal thickness and anterior chamber even in pediatric cases. Significant differences were detected in measurements with this device between adults and pediatric cases, and between the right and left eyes. Being aware of these differences in normal eyes will be a guide in correct evaluation of pathologic eyes. (Turk J Ophthalmol 2011; 41: 133-7

  14. Clearance from the anterior chamber of RBCs from human diabetics

    International Nuclear Information System (INIS)

    Erythrocytes from diabetic patients manifest decreased deformability and increased adherence. These abnormal membrane properties may diminish the ability of erythrocytes (RBCs) from diabetics to undergo deformation in passage through the trabecular meshwork. Using sodium chromate Cr 51-labeled RBCs from type I diabetic patients with proliferative retinopathy and normal control subjects, we studied RBC clearance from the rabbit anterior chamber. The mean time for 50% clearance (T50) of RBCs from diabetics (76 hours) was significantly longer than that for RBCs from normal subjects (19.5 hours). In this model, RBCs from diabetics have a slower clearance from the anterior chamber than do RBCs from normal subjects

  15. Predictive factors for anterior chamber fibrin formation after vitreoretinal surgery

    Directory of Open Access Journals (Sweden)

    Leonardo Provetti Cunha

    2014-04-01

    Full Text Available Purpose: The aim of this study was to investigate possible predictive factors related to anterior chamber fibrin formation after vitreoretinal surgery in a large series of patients. Methods: The data of 185 eyes of 185 patients submitted to vitreoretinal surgery was reviewed. The following variables were evaluated: the postoperatively presence of fibrin, age, diabetes mellitus, the vitrectomy system gauge (20, 23 or 25 gauge, the type of vitreous substitute, the influence of prior surgical procedures and the combination with cataract extraction. To evaluate predictive factors for anterior chamber fibrin formation, univariate analysis was performed. A multivariate stepwise logistic regression model was adjusted to investigate factors associated with fibrin formation (p<0.05. Results: Fibrinoid anterior chamber reaction was found in 12 (6.4% patients. For multivariate logistic regression analysis, balanced salt solution (BSS, the chance of fibrin occurrence was 5 times greater (odds ratio 4.83, CI 95% 1.302 - 17.892; p=0.019, while combination with phacoemulsification increased the chance of fibrin formation by 20 times (odds ratio 20, CI 95% 2.480 - 161.347; p=0.005. No significant difference was found regarding other variables. Conclusion: Anterior chamber fibrin formation is an unwanted complication after vitreoretinal surgery. Factors such as combined performance of phacoemulsification and the use of balanced salt solution as a vitreous substitute may predispose the occurrence of this complication.

  16. Spontaneous Scleral Perforation of an Anterior Chamber Intraocular Lens

    Science.gov (United States)

    Spierer, Oriel; O'Brien, Terrence P.

    2016-01-01

    A routine eye examination of a 69-year-old man revealed a scleral perforation of one of the haptics of the anterior chamber intraocular lens (AC IOL) which had been implanted many years ago. The patient was asymptomatic with good visual acuity. His history was negative for any trauma, eye rubbing, topical corticosteroid use, or autoimmune disease. The horizontal and vertical white-to-white diameters of the cornea in the right eye were 11.5 and 10.5 mm, respectively. Anterior segment optical coherence tomography showed the anterior chamber length to be 12.28 mm horizontally and 10.63 mm vertically. The patient underwent an IOL exchange, and the length of the explanted AC IOL was measured to be 12 mm. We speculate that the AC IOL, which was vertically aligned, was oversized. This case demonstrates the need for proper sizing and positioning of an AC IOL. In complex cases where AC IOL may be used, measuring the horizontal and vertical lengths of the anterior chamber by anterior segment optical coherence tomography prior to surgery may be useful.

  17. Spontaneous Scleral Perforation of an Anterior Chamber Intraocular Lens

    Directory of Open Access Journals (Sweden)

    Oriel Spierer

    2016-05-01

    Full Text Available A routine eye examination of a 69-year-old man revealed a scleral perforation of one of the haptics of the anterior chamber intraocular lens (AC IOL which had been implanted many years ago. The patient was asymptomatic with good visual acuity. His history was negative for any trauma, eye rubbing, topical corticosteroid use, or autoimmune disease. The horizontal and vertical white-to-white diameters of the cornea in the right eye were 11.5 and 10.5 mm, respectively. Anterior segment optical coherence tomography showed the anterior chamber length to be 12.28 mm horizontally and 10.63 mm vertically. The patient underwent an IOL exchange, and the length of the explanted AC IOL was measured to be 12 mm. We speculate that the AC IOL, which was vertically aligned, was oversized. This case demonstrates the need for proper sizing and positioning of an AC IOL. In complex cases where AC IOL may be used, measuring the horizontal and vertical lengths of the anterior chamber by anterior segment optical coherence tomography prior to surgery may be useful.

  18. Spontaneous Scleral Perforation of an Anterior Chamber Intraocular Lens

    Science.gov (United States)

    Spierer, Oriel; O'Brien, Terrence P.

    2016-01-01

    A routine eye examination of a 69-year-old man revealed a scleral perforation of one of the haptics of the anterior chamber intraocular lens (AC IOL) which had been implanted many years ago. The patient was asymptomatic with good visual acuity. His history was negative for any trauma, eye rubbing, topical corticosteroid use, or autoimmune disease. The horizontal and vertical white-to-white diameters of the cornea in the right eye were 11.5 and 10.5 mm, respectively. Anterior segment optical coherence tomography showed the anterior chamber length to be 12.28 mm horizontally and 10.63 mm vertically. The patient underwent an IOL exchange, and the length of the explanted AC IOL was measured to be 12 mm. We speculate that the AC IOL, which was vertically aligned, was oversized. This case demonstrates the need for proper sizing and positioning of an AC IOL. In complex cases where AC IOL may be used, measuring the horizontal and vertical lengths of the anterior chamber by anterior segment optical coherence tomography prior to surgery may be useful. PMID:27462251

  19. Spontaneous Scleral Perforation of an Anterior Chamber Intraocular Lens.

    Science.gov (United States)

    Spierer, Oriel; O'Brien, Terrence P

    2016-01-01

    A routine eye examination of a 69-year-old man revealed a scleral perforation of one of the haptics of the anterior chamber intraocular lens (AC IOL) which had been implanted many years ago. The patient was asymptomatic with good visual acuity. His history was negative for any trauma, eye rubbing, topical corticosteroid use, or autoimmune disease. The horizontal and vertical white-to-white diameters of the cornea in the right eye were 11.5 and 10.5 mm, respectively. Anterior segment optical coherence tomography showed the anterior chamber length to be 12.28 mm horizontally and 10.63 mm vertically. The patient underwent an IOL exchange, and the length of the explanted AC IOL was measured to be 12 mm. We speculate that the AC IOL, which was vertically aligned, was oversized. This case demonstrates the need for proper sizing and positioning of an AC IOL. In complex cases where AC IOL may be used, measuring the horizontal and vertical lengths of the anterior chamber by anterior segment optical coherence tomography prior to surgery may be useful.

  20. Microbiological profile of anterior chamber aspirates following uncomplicated cataract surgery

    Directory of Open Access Journals (Sweden)

    Prajna N

    1998-01-01

    Full Text Available Anterior chamber aspirate cultures were done for 66 patients who underwent either an uncomplicated intracapsular cataract extraction, extracapsular cataract extraction with posterior-chamber intraocular lens implantation, or phacoemulsification with posterior-chamber intraocular lens implantation. The aspirate was obtained at the time of wound closure. The aspirates were immediately transferred to the microbiology laboratory where one drop of the aspirate was placed on a glass slide for gram stain, and the remainder was unequally divided and inoculated into blood agar, chocolate agar and thioglycolate broth. The cultures were incubated at 37° C with 5% CO2 and held for 5 days. Of 66 patients 4 (6%, had smear-positive anterior chamber aspirates. None of the aspirates showed any growth on any of the 3 culture media used. None of the eyes in the study developed endophthalmitis. This study concludes that there is no contamination of the anterior chamber by viable bacteria after cataract surgery, irrespective of the mode of intervention.

  1. Pentacam、IOLMaster和A型超声测量近视患者前房深度的比较%Comparison of anterior chamber depth measured by Pentacam, IOLMaster and A-scan ultrasonography

    Institute of Scientific and Technical Information of China (English)

    张静; 张士胜; 于青; 姚文琴; 廖华萍; 戴南平; 刘春雷; 董世奇; 叶盛

    2013-01-01

    目的 对Pentacam、IOLMaster和A型超声测量仪测量前房深度(ACD)的准确性进行比较.方法 对69例(138眼)近视患者分别使用Pentacam、IOLMaster和A型超声测量仪进行ACD测量,对所得数据进行统计学处理与分析.结果 Pentacam、IOLMaster和A型超声的ACD测量值分别为(3.77±0.24)、(3.73±0.23)、(3.69±0.22) mm,3种方法测量结果差异有统计学意义(F=4.49,P=0.01).Pentacam测得的ACD值比A型超声大约(0.08±0.07) mm(t=13.25,P<0.001).3种仪器ACD测量值相互正相关(r=0.987、0.951、0.946,P<0.001),且变异系数很小(0.012±0.07).Bland-Altman分析结果显示,3种方法的ACD测量平均值一致性较好(Pentacam vs IOLMaster:CoA 0.04 mm,LoA 0.13~-0.05 mm;A型超声vs IOLMaster:CoA 0.04 mm,LoA 0.08~-0.17 mm;Pentacam vs A型超声:CoA 0.08 mm,LoA 0.22~-0.06 mm).结论 Pentacam、IOLMaster和A型超声测量ACD的可重复性均很好、变异小、高度相关.Pentacam测得的ACD值稍大于A型超声,但由于3组数据可重复性好,变异系数小,其差异没有重要的临床意义,临床上可相互代替使用.%Objective To investigate and compare the measuring outcomes of anterior chamber depth (ACD) measured with Pentacam,IOLMaster and A ultrasonography.Methods This was an observational study.ACD were measured in 138 eyes of 69 myopic patients with Pentacam,IOLMaster and A-scan ultrasonography by the same operator.Interdevice agreement was evaluated using paired two-tailed t-tests,Pearson correlation coefficient,and Bland-Altman analysis.Results Mean ± SD values for ACD using the Pentacam,IOLMaster and A-scan ultrasonography were 3.77±0.24 mm,3.73±0.23 mm,and 3.69±0.22 mm,respectively,and the differences were statistically significant (F=4.49,P=0.01).They were positively correlated with each other (r=0.987,0.951,0.946,P<0.001),and coefficient of variation was very small (0.012±0.07).Bland-Altman analysis showed that good agreement for ACD measures was observed between

  2. Anterior chamber gas bubbles in open globe injury.

    Science.gov (United States)

    Barnard, E B G; Baxter, D; Blanch, R

    2013-01-01

    We present a case of a 40-year-old soldier who was in close proximity to the detonation of an improvised explosive device (IED). Bubbles of gas were visible within the anterior chamber of his left eye. The authors propose that intraocular gas, present acutely after trauma, is diagnostic of open globe injury and is of particular importance in remote military environments. PMID:24079202

  3. Linguatula serrata in the anterior chamber of the eye

    Directory of Open Access Journals (Sweden)

    Muna Bhende

    2014-01-01

    Full Text Available We report a case of intraocular Linguatula in healthy young female who presented with a history of trivial trauma, dislocated lens, inflammation and secondary glaucoma. A mobile worm was seen in the anterior chamber. Pars plana lensectomy and vitrectomy was planned to remove both the cataractous lens and the parasite during which the worm disappeared from view but was later recovered from the cassette fluid. It was identified as the nymphal form of Linguatula serrata (tongue worm.

  4. AS-OCT与A超测量中央角膜厚度与前房深度的比较%Comparison of central corneal thickness and anterior chamber depth measurements using the Anterior Segment Optical Coherence Tomography and A-scan ultrasonography

    Institute of Scientific and Technical Information of China (English)

    曾阳发; 李彬彬; 黄国富; 李月桃; 何明光

    2009-01-01

    目的 探讨眼前段光学相干断层扫描技术(anteriorsegment optical coherence tomography,AS-OCT)和A型超声波生物测量技术(A超)测量,中央角膜厚度(central corneal thickness,CCT)和前房深度(anterior chamber depth,ACD)的异同.方法 分别采用AS-OCT和A超测量33名(54只眼)正常人的CCT和ACD,分别采用配对t检验、Pearson相关和Bland-Altman方法,分析两种仪器的测量值的差异、相关性和一致性.结果 A超与AS-OCT的CCT值分别为(524.41±23.24)μm、(513.37±22.71)μm,之间的差异有统计学意义(t=15.906,P=0.000),差值均数为(11.04±5.10)μm.两种仪器的CCT值正相关(r=0.976,P=0.000).95%LoA(95% Limts of Agreement)为(-21.03,-1.04)μm,95%LoA的区间范围为19.99μm,为A超CCT平均值的3.81%.A超与AS-OCT的ACD值分别为(2.89±0.29)mm、(3.18±0.26)mm,之间的差异有统计学意义(f=-12.052,P=0.000),差值的均数为(-0.29±0.17)mm.两种仪器的ACD值相关(r=0.803,P=0.000).95%LoA为(-0.63,-0.06)mm,95%LoA的区间范围为0.57mm,为A超ACD平均值的19.72%.结论 AS-OCT的CCT值和ACD值与A超的测量值相关.与A超相比,AS-OCT的CCT测量值更小,而ACD值更大.两种仪器测量CCT的一致性比ACD高.%Objective To assess central corneal thickness(CCT)and anterior chamber depth (ACD) measurements with anterior segment optical coherence tomography (AS-OCT)comparing with A-scan ultrasonography (A-scan US).Methods 54 eyes of 33 normal subjects were enrolled in the study.CCT and ACD were measured using AS-OCT and A-scan US.The measurements of two instruments were analyzed using paired t test,Pearson correlation and Bland-Altman plot,respectively.Results The CCT of AS-OCT and A-scan US were 524.41± 23.24 microm and 513.37± 22.7 microm,respectively.The CCT values measured by A-scan US were significantly greater than AS-OCT, paired difference was 11.04± 5.10 microm (t =15.906, P =0.000).There were a significantly correlation between CCTs value of two instruments (r =0

  5. Anterior chamber fixation of a posterior chamber intraocular lens: A novel technique

    Directory of Open Access Journals (Sweden)

    A Sahap Kükner

    2014-01-01

    Full Text Available We aimed to evaluate the implantation of a posterior chamber intraocular lens (IOL in the anterior chamber (AC with the haptics passing through two iridectomies to the posterior chamber. A total of 33 eyes of 33 patients with inadequate posterior capsular support due to either previous aphakia or posterior capsular rupture during cataract extraction were included in the study. A double iridectomy was performed on all patients using a vitrectomy probe on the midperiphery of the iris. IOLs were implanted in the AC, and the haptics were passed through the iridectomies to the posterior chamber. The mean follow-up time was 25.3 months. AC hemorrhage occurred in five patients during the iridectomy procedure. Corneal edema was detected in eight of 14 patients with primary IOL insertions. Haptic dislocation was detected in only one patient. This technique may be a good alternative to scleral-fixated IOL implantation in eyes with aphakia.

  6. 3D spectral imaging system for anterior chamber metrology

    Science.gov (United States)

    Anderson, Trevor; Segref, Armin; Frisken, Grant; Frisken, Steven

    2015-03-01

    Accurate metrology of the anterior chamber of the eye is useful for a number of diagnostic and clinical applications. In particular, accurate corneal topography and corneal thickness data is desirable for fitting contact lenses, screening for diseases and monitoring corneal changes. Anterior OCT systems can be used to measure anterior chamber surfaces, however accurate curvature measurements for single point scanning systems are known to be very sensitive to patient movement. To overcome this problem we have developed a parallel 3D spectral metrology system that captures simultaneous A-scans on a 2D lateral grid. This approach enables estimates of the elevation and curvature of anterior and posterior corneal surfaces that are robust to sample movement. Furthermore, multiple simultaneous surface measurements greatly improve the ability to register consecutive frames and enable aggregate measurements over a finer lateral grid. A key element of our approach has been to exploit standard low cost optical components including lenslet arrays and a 2D sensor to provide a path towards low cost implementation. We demonstrate first prototypes based on 6 Mpixel sensor using a 250 μm pitch lenslet array with 300 sample beams to achieve an RMS elevation accuracy of 1μm with 95 dB sensitivity and a 7.0 mm range. Initial tests on Porcine eyes, model eyes and calibration spheres demonstrate the validity of the concept. With the next iteration of designs we expect to be able to achieve over 1000 simultaneous A-scans in excess of 75 frames per second.

  7. Repeatability and reproducibility of scanning peripheral anterior chamber depth analyzer——the Handan Eye Study%周边前房深度扫描分析仪的可重复性及一致性研究——邯郸眼病研究

    Institute of Scientific and Technical Information of China (English)

    张烨; 李思珍; 王宁利

    2014-01-01

    致性;可关闭房角判断方面,SPAC在正常者具有良好的测量者间一致性,在浅前房者一致性为中度.%Background Early diagnosis of primary angle-closure glaucoma (PACG) and screening or case detection of high risk population have become a major challenge in the prevention and treatment of PACG.Commonly used methods for evaluation of anterior chamber depth (ACD) and anterior chamber angle nowadays have their shortcomings.Scanning peripheral anterior chamber depth analyzer (SPAC) measures ACD and evaluates the risk of angle closure.Also,SPAC is handy,objective and noninvasive.Objective This study was to evaluate the repeatability (within-rater differences) and reproducibility (between-rater differences) of SPAC to measure anterior chamber-related parameters and agreement of SPAC to estimate occludable angle between two operators.Methods A prospective cross-sectional study was designed.Thirty subjects with shallow ACD (modified van Herick grading≤ 3 and Shaffer grading≤2) aged 35 years and older,who met the inclusion criterion were enrolled as shallow anterior chamber group and 30 age-and gender-matched normal adults (modified van Herick grading≤3 and Shaffer grading≤2)from the follow-up research of the Handan Eye Study in February 2013.After an elementary eye examination,a randomly selected eye of each subject in both groups received three consecutive SPAC measurements by each of the two examiners,respectively to obtain ACD,central corneal thickness (CCT) and corneal radius of curvature (CRC).Meanwhile,the identity of occludable angle as the numerical grade was 5 or fewer and/or the categorical grade being S or P was also obtained.The repeatability of each examiner was evaluated by the repeatability limit (RL) and the reproducibility of the two examiners was evaluated by intraclass correlation coefficient (ICC).The agreement of occludable angle estimation between two operators was evaluated using Kappa coefficient.Results The RLs

  8. [Numerical Simulation of Heat Transfer in the Human Anterior Chamber at Different Corneal Temperatures].

    Science.gov (United States)

    Guo, Jingmin; Zhang, Hong; Wang, Junming

    2015-12-01

    A three-dimensional (3D) model of human anterior chamber is reconstructed to explore the effect of different corneal temperatures on the heat transfer in the chamber. Based on the optical coherence tomography imaging of the volunteers with normal anterior chamber, a 3D anterior chamber model was reconstructed by the method of UG parametric design. Numerical simulation of heat transfer and aqueous humor flow in the whole anterior chamber were analyzed by the finite volume methods at different corneal temperatures. The results showed that different corneal temperatures had obvious influence on the temperature distribution and the aqueous flow in the anterior chamber. The temperature distribution is linear and axial symmetrical around the pupillary axis. As the temperature difference increases, the symmetry becomes poorer. Aqueous floated along the warm side and sank along the cool side which forms a vortexing flow. Its velocity increased with the addition of temperature difference. Heat fluxes of cornea, lens and iris were mainly affected by the aqueous velocity. The higher the velocity, the bigger more absolute value of the above-mentioned heat fluxes became. It is practicable to perform the numerical simulation of anterior chamber by the optical coherence tomography imaging. The results are useful for studying the important effect of corneal temperature on the heat transfer and aqueous humor dynamics in the anterior chamber.

  9. Measurement of anterior chamber volume with rotating scheimpflug camera and anterior segment optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    FU Jing; LI Shu-ning; WANG Xiao-zhen; WU Ge-wei; MU Da-peng; WANG Jian; WANG Ning-li

    2010-01-01

    Background Measurement of anterior segment parameters plays an important role in diagnosis and treatment of glaucoma. The objective of this study was to evaluate the repeatability and reproducibility of anterior chamber volume (ACV) measurements with rotating scheimpflug camera (RSC) and to examine agreement with anterior segment optical coherence tomography (AS-OCT). Methods Thirty nine healthy normal subjects were recruited from the Eye Center of Tongren Hospital. ACV was measured using RSC and AS-OCT in a randomly selected eye for each subject. For RSC measurements, both automatic and manual ACV measurements and 2 independent operators' ACV measurements were obtained. All subjects were invited for 3 visits within a week to evaluate repeatability and reproducibility of ACV measurement by RSC. Agreement was evaluated between RSC and AS-OCT. Results Good repeatability and reproducibility were found for both automatic and manual ACV measurements obtained by RSC. For intrasession repeatability, coefficient of variation (CVw) and intraclass correlation coefficient (ICC) values for automatic were 3.52% and 0.98; the values for manual were 3.44% and 0.97, respectively. For intersession reproducibility, the respective CVw and ICC values were 3.96% and 0.96. Good agreement was also found in 2 operators for both automatic and manual ACV measurements; nevertheless, poor agreement was found between RSC and AS-OCT (95% confidence interval (CI) for agreement of automatic RSC measurement versus AS-OCT were -96.3 to 72.8 μl and 95% CI for agreement of manual RSC measurement versus AS-OCT were between -41.7 to 10.1 μl). Conclusions Both RSC automatic and manual ACV measurements showed good repeatability and reproducibility, and showed comparable agreement between 2 independent operators, but poor agreement was found between RSC and AS-OCT.

  10. Constructal approach to bio-engineering: the ocular anterior chamber temperature

    Science.gov (United States)

    Lucia, Umberto; Grisolia, Giulia; Dolcino, Daniela; Astori, Maria Rosa; Massa, Eugenio; Ponzetto, Antonio

    2016-08-01

    The aim of this work was to analyse the pressure inside the eyes anterior chamber, namedintraocular pressure (IOP), in relation to the biomechanical properties of corneas. The approach used was based on the constructal law, recently introduced in vision analysis. Results were expressed as the relation between the temperature of the ocular anterior chamber and the biomechanical properties of the cornea. The IOP, the elastic properties of the cornea, and the related refractive properties of the eye were demonstrated to be dependent on the temperature of the ocular anterior chamber. These results could lead to new perspectives for experimental analysis of the IOP in relation to the properties of the cornea.

  11. Anterior Chamber Iris Claw Lens for the Treatment of Aphakia in a Patient with Megalocornea

    Science.gov (United States)

    Saffra, Norman; Rakhamimov, Aleksandr; Masini, Robert; Rosenthal, Kenneth J.

    2015-01-01

    Megalocornea in isolation is a rare congenital enlargement of the cornea greater than 13 mm in diameter. Patients with megalocornea are prone to cataract formation, crystalline lens subluxation, zonular deficiencies and dislocation of the posterior chamber intraocular lens (PCIOL) within the capsular bag. A 55-year-old male with megalocornea in isolation developed subluxation of the capsular bag and PCIOL. The PCIOL and capsular bag were explanted, and the patient was subsequently implanted with an anterior chamber iris claw lens. An anterior chamber iris claw lens is an effective option for the correction of aphakia in patients with megalocornea. PMID:26120314

  12. Iris-fixated anterior chamber phakic intraocular lens for myopia moves posteriorly with mydriasis.

    NARCIS (Netherlands)

    Cruysberg, L.P.J.; Doors, M.; Berendschot, T.T.; Brabander, J. De; Webers, C.A.; Nuijts, R.M.

    2009-01-01

    PURPOSE: To elucidate the physiological characteristics of eyes implanted with iris-fixated anterior chamber phakic intraocular lenses (pIOLs), which are increasingly being used for the correction of higher myopic and hyperopic refractive errors. METHODS: In a case series of 20 patients (39 eyes), t

  13. Determination of relative ion chamber calibration coefficients from depth-ionization measurements in clinical electron beams

    Science.gov (United States)

    Muir, B. R.; McEwen, M. R.; Rogers, D. W. O.

    2014-10-01

    A method is presented to obtain ion chamber calibration coefficients relative to secondary standard reference chambers in electron beams using depth-ionization measurements. Results are obtained as a function of depth and average electron energy at depth in 4, 8, 12 and 18 MeV electron beams from the NRC Elekta Precise linac. The PTW Roos, Scanditronix NACP-02, PTW Advanced Markus and NE 2571 ion chambers are investigated. The challenges and limitations of the method are discussed. The proposed method produces useful data at shallow depths. At depths past the reference depth, small shifts in positioning or drifts in the incident beam energy affect the results, thereby providing a built-in test of incident electron energy drifts and/or chamber set-up. Polarity corrections for ion chambers as a function of average electron energy at depth agree with literature data. The proposed method produces results consistent with those obtained using the conventional calibration procedure while gaining much more information about the behavior of the ion chamber with similar data acquisition time. Measurement uncertainties in calibration coefficients obtained with this method are estimated to be less than 0.5%. These results open up the possibility of using depth-ionization measurements to yield chamber ratios which may be suitable for primary standards-level dissemination.

  14. Vascular Endothelial Growth Factor in Anterior Chamber Liquid Patients with Diabetic Retinopathy, Cataract and Neovascular Glaucoma

    OpenAIRE

    Kuzmin, Anatoly; Lipatov, Dmitry; Chistyakov, Timofei; Smirnova, Olga; Arbuzova, Margarita; Ilin, Alexander; Shestakova, Marina; Dedov, Ivan

    2013-01-01

    Introduction The aims of this study were: (1) to investigate the association of vascular endothelial growth factor isoform A (VEGF-A) concentration in the anterior chamber liquid (ACL) with vascular proliferation in patients with diabetic retinopathy (DR) who had undergone surgical treatment for cataract and neovascular glaucoma; (2) to analyze the association of VEGF-A level in ACL with the cataract surgery outcomes. Materials and Methods Undiluted aqueous fluid samples were obtained from 20...

  15. Laser Peripheral Iridotomy with Iridoplasty in Primary Angle Closure Suspect: Anterior Chamber Analysis by Pentacam

    OpenAIRE

    Lee, Jong Rak; Choi, Jin Young; Kim, Yeon-Deok; Choi, Jaewan

    2011-01-01

    Purpose To compare conventional laser peripheral iridotomy (LPI) and LPI combined with laser peripheral iridoplasty in eyes with primary angle closure suspect (PACS) by assessment of anterior chamber dimensional changes using a Pentacam. Methods Forty-eight eyes of 24 subjects with bilateral PACS were recruited consecutively. Each eye was randomly allocated to treatment with conventional LPI, argon LPI only, or LPI plus iridoplasty, which consisted of simultaneous argon LPI and peripheral iri...

  16. Ultrastructural Observations of The Anterior Chamber Angle Tissues in Congenital Glaucoma

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Eighteen trabeculectomy specimens of congenital glaucoma were examined by light and transimssion electron microscopy. The results showed that the primary anomalies in congenital glaucoma included the developmental defects of trabecular meshwork, excessive collagen fibrils in the trabecular matrix, shifting forward of ciliary muscle fibres and persistent mesenchymal tissues in the anterior-chamber angle. The authors also pointed out the importance of the secondary lesions of the trabecular meshwork in th...

  17. Inflammatory Response in the Anterior Chamber after Implantation of an Angle-Supported Lens in Phakic Myopic Eyes

    Directory of Open Access Journals (Sweden)

    Suphi Taneri

    2014-01-01

    Full Text Available Purpose. To evaluate the inflammatory reaction after implantation of an angle-supported foldable acrylic anterior chamber IOL for myopia correction over time. Methods. Adult individuals seeking vision correction with stable myopia >7.0 D were included. Exclusion criteria are anterior chamber depth <2.8 mm, insufficient endothelial cell density, other preexisting ocular conditions, and prior eye surgery. Laser flare photometry and slitlamp examination were performed before and up to 1 year after implantation of an AcrySof Cachet IOL (Alcon Laboratories, Forth Worth, TX, USA. Postoperative treatment comprised antibiotic eye-drops for 5 days and nonsteroidal anti-inflammatory eye-drops (NSAIDs for 4 weeks. Results. Average laser flare values of 15 consecutive eyes of 15 patients were 8.3±9.7 preoperatively and 19.0±24.2 (1 day, 24.0±27.5 (1 week, 17.6±13.4 (1 month, 14.9±15.4 (3 months, and 10.0±7.0 (1 year photon counts/ms after implantation, respectively. Slitlamp examination yielded 0 or 1+ cells (SUN classification in every one eye throughout the follow-up period. Conclusion. Results indicate a low maximum inflammatory response and a quick recovery to a long-term safe level. The use of NSAIDs seems sufficient in routine cases, thus avoiding potential drawbacks of using corticoids.

  18. Nitric oxide levels in the anterior chamber of vitrectomized eyes with silicon oil

    Directory of Open Access Journals (Sweden)

    Paulo Escarião

    2013-10-01

    Full Text Available PURPOSE: To investigate the nitric oxide levels in the anterior chamber of eyes who underwent pars plana vitrectomy (PPV with silicone oil. METHODS: Patients who underwent PPV with silicon oil injection, from february 2005 to august 2007, were selected. Nine patients (nine eyes participated in the study (five women and four men. Nitric oxide concentration was quantified after the aspiration of aqueous humor samples during the procedure of silicon oil removal. Data such as: oil emulsification; presence of oil in the anterior chamber; intraocular pressure and time with silicone oil were evaluated. Values of p <0.05 were considered to be statistically significant. RESULTS: A positive correlation between nitric oxide concentration and time with silicon oil in the vitreous cavity (r=0.799 was observed. The nitric oxide concentration was significantly higher (p=0.02 in patients with silicon oil more than 24 months (0.90µmol/ml ± 0.59, n=3 in the vitreous cavity comparing to patients with less than 24 months (0.19µmol/ml ± 0.10, n=6. CONCLUSION: A positive correlation linking silicone oil time in the vitreous cavity with the nitric oxide concentration in the anterior chamber was observed.

  19. Iris-claw intraocular lens implantation: Anterior chamber versus retropupillary implantation

    Science.gov (United States)

    Helvacı, Sezer; Demirdüzen, Selahaddin; Öksüz, Hüseyin

    2016-01-01

    Purpose: To compare the outcomes of anterior chamber and retropupillary implantation of iris-claw Artisan intraocular lenses (IOL). Design: Prospective, randomized, single-blinded study. Patients and Methods: Forty eyes of forty aphakic patients were enrolled. Patients were randomized into two groups. Each group includes twenty patients. Group 1 received anterior chamber Artisan IOL implantation. Group 2 received retropupillary Artisan IOL implantation. Preoperative and postoperative corrected distance visual acuity (CDVA), intraocular pressure (IOP), and all complications were noted and compared at 6 months follow-up. Results: Each two groups obtained a significant improvement in CDVA (P < 0.05). Four patients in Group 1 and five patients in Group 2 had significant but nonpermanent increase at IOP values. There were one and two pupillary irregularity in Group 1 and Group 2, respectively. In one patient, a shallow and inferior located retinal detachment were encountered in anterior chamber group. Conclusions: The results were not significantly different between the two fixation techniques for iris-claw lens. The surgery procedure is dependent to surgeon experience and eye's conditions. PMID:26953023

  20. Comparison of Biograph/Lenstar and IOL Master in the measurement of axial length, corneal curvature, and anterior chamber depth%Biograph/Lenstar与IOL Master测量眼轴、角膜曲率及前房深度的比较

    Institute of Scientific and Technical Information of China (English)

    黄锦海; 陈世豪; 温岱宗; 王勤美

    2011-01-01

    目的 比较两种光学相干生物测量仪Biograph/Lenstar和IOL Master测量眼轴(AL)、角膜曲率(K1、K2和Km)和前房深度(ACD)的差异,分析二者的一致性,为临床使用提供依据.方法 前瞻性临床研究.近视患者34例(68眼),等效球镜为-0.05~-10.00 D,平均(-4.11±2.31)D,分别应用Biograph/Lenstar和IOL Master进行AL、K1、K2、Km和ACD测量,两种仪器间以上指标的差异采用配对t检验,两种仪器间测量所得数据的相关性采用 Pearson相关分析,两种仪器间测量所得数据的一致性采用Bland-Altamn统计分析.结果 Biograph/Lenstar和IOL Master测量AL的平均值分别为(25.39±1.09)mm和(25.37±1.08)mm,差异具有统计学意义(t=8.855,P<0.01);两者间的K1、K2和Km差异均有统计学意义(t=2.511,P=0.014;t=-2.413,P=0.019;t=2.893,P=0.005);ACD值分别为(3.80±0.26)mm和(3.78±0.26)mm,差异无统计学意义.两种仪器间所有的测量参数均具有密切的线性相关(r均>0.9,P<0.01).两种方法测量AL和ACD一致性较好,而K1、K2和Km一致性较差.结论 Biograph/Lenstar测量眼部无明显器质性疾病人群的眼轴长度及前房深度与IOL Master具有良好的一致性.对角膜曲率的测量,两者测量一致性较差,使用中需结合临床意义进一步对仪器的适用范围加以判断.%Objective To assess the accuracy of axial length (AL), corneal curvature (K1, K2 and Km) and anterior chamber depth (ACD) measurements with the Biograph/Lenstar LS 900 biometer and the IOL Master. Methods In this prospective clinical study, 68 eyes of 34 myopes, whose spherical equivalent were -0.50-10.00 D, with an average of (-4.11±2.31)D. AL, K1, K2, Km and ACD of these myopes were measured with the Biograph/Lenstar and IOL Master biometer. Data were analyzed using a paired samples t test, linear regression and Bland-Altman plots. Results The mean AL and ACD measured by the Biograph/Lenstar and IOL Master were (25.39±1.09)mm, (25.37±1.08)mm, and (3

  1. The Relation of the Location of Haptics of Posterior Chamber Intraocular Lenses and Peripheral Anterior Synechia

    Institute of Scientific and Technical Information of China (English)

    RuiduanLiao; ShaozhenLi

    1995-01-01

    Purpose:To investigate the occurrence,outcome and influencial factors of the pe-ripheral anterior synechia(PAS)following implantation of posterior chamber in-traocular lenses for finding a way to reduce thePAS.Subjects;40 eyes of 38senile cataract patients with normal chamber angle and in-traocular pressue(IOP)preoperatively were examined.Methods:Extracapsular cataract extraction was performed under microscope with insertion of a posterior chamber lens implant vaulted anteriorly by 10°.Go-nioscopy and slit-lamp examination and photography of the operated eyes were performed 3to 6months postoperatively.Results:PAS were found in 20(50%)of the 40eyes.Among the 20eyes with PAS the locations of 23haptics in17eyes corresponded with those of the PAS.PAS were seen more frequently with vertically sulcus-fixated haptics than with the horizontally capsular-fixated haptics.showing a significant difference(P<0.05).88%of the eyes withPAS had pupillary edformation,but their visual acuities and IOP were not affected.Conclusions:PAS is more likely to occur with vertically sulcus-fixated IOL.Rotat-ing the capsular-fixated haptics to the horizontal position may reduce the inci-dence of PAS.Gonioscopy should be a routine follow-up examination.

  2. Catarata polar anterior piramidal deslocada para a câmara anterior causando edema de córnea: relato de caso Corneal edema caused by a pyramidal anterior polar cataract dislocated to the anterior chamber: case report

    Directory of Open Access Journals (Sweden)

    Ramon Coral Ghanem

    2004-08-01

    Full Text Available Cataratas polares anteriores piramidais são opacidades cônicas que se projetam para a câmara anterior a partir da cápsula anterior do cristalino. Na grande maioria dos pacientes a opacidade permanece aderida e estável durante toda a vida. O objetivo deste trabalho é documentar uma manifestação incomum desse tipo de catarata: a deiscência espontânea das pirâmides para a câmara anterior causando descompensação endotelial e edema corneal bilateral. Relatamos o caso de uma paciente feminina, de 66 anos, branca, que apresentava edema corneal localizado inferiormente no olho direito associado à lesão nodular branco-esclerótica compatível com a pirâmide anterior da catarata polar. O olho esquerdo apresentava edema corneal difuso intenso e presença de uma catarata polar anterior com a região piramidal deslocada para a câmara anterior. Sabe-se que a pirâmide anterior pode permanecer inabsorvida na câmara anterior por longo período, pois é composta de tecido colágeno denso. Isto causa perda endotelial progressiva e edema corneal e deve ser considerada indicação de remoção cirúrgica da catarata polar anterior e de seu fragmento. Ressalta-se, também, a importância do bom senso no julgamento das cataratas polares anteriores, considerando-se tamanho da opacidade, simetria das opacidades e componente cortical associado, na tentativa de se evitar ambliopia.Pyramidal anterior polar cataracts are conical opacities that project into the anterior chamber from the anterior capsule of the lens. In the vast majority of patients the opacity remains bound and stable throughout life. We report an unusual complication of this type of cataract: spontaneous dehiscence of the pyramids to the anterior chamber causing bilateral endothelial damage and corneal edema. 66-year-old white woman presented with inferior corneal edema in the right eye and diffuse corneal edema in the left eye. A white nodular lesion was observed in the inferior angle

  3. [Experimental hypertony caused by obstruction of the anterior chamber angle ab interno (author's transl)].

    Science.gov (United States)

    Maguritsas, N; Vikas, C; Theodossiadis, G; Vergados, I; Velissaropoulos, P

    1976-07-01

    In 30 rabbits, separated into 3 groups (A, B and C), the entire area (A), three quarters (B) half of the anterior chamber angle (C) was experimentally obstructed by means of a homologous scleral graft. In groups A and B a statistically significant change of the intraocular pressure and of the cornea diameter was shown as compared with the control eye and group C. This change is due to the obstructed area of the angle. The increased intraocular pressure lasted for some months. The graft was well tolerated by the tissue of the angle and the obstruction of the angle was total, as was confirmed by means of the histological preparations.

  4. Reproducibility and Agreement Between 2 Spectral Domain Optical Coherence Tomography Devices for Anterior Chamber Angle Measurements

    OpenAIRE

    Marion, Kenneth M.; Maram, Jyotsna; Pan, Xiaojing; Dastiridou, Anna; Zhang, ZhouYuan; Ho, Alex; Francis, Brian A; Sadda, Srinivas R.; Chopra, Vikas

    2015-01-01

    Purpose: To compare anterior chamber angle parameters based on the location of Schwalbe line (SL) from 2 spectral domain optical coherence tomography (SD-OCT) instruments and to measure their reproducibility. Methods: Forty-two eyes from 21 normal, healthy participants underwent imaging of the inferior irido-corneal angle with the Spectralis and Cirrus SD-OCT under tightly controlled low-light conditions. SL-angle opening distance (SL-AOD) and SL-trabecular iris space area (SL-TISA) were meas...

  5. Loa loa in the anterior chamber of the eye: A case report

    Directory of Open Access Journals (Sweden)

    Barua P

    2005-01-01

    Full Text Available An unusual case of loiasis from Assam is reported here. Loa loa is a subcutaneous filarial parasite of man and is transmitted to humans by chrysops flies. The patient presented with foreign body sensation and visual disturbances of the right eye. Examination revealed a white coiled structure in the cornea.. Routine blood and other investigations were within normal limits. A live adult worm was extracted and identity was confirmed by microscopy to be Loa loa. Patient was treated with diethylcarbamazine and steroid. We found this case interesting as the worm was present in the anterior chamber - an unusual site and there were no other positive findings besides the lone worm.

  6. GATA-3 expression in the development of anterior chamber associated immune deviation

    Institute of Scientific and Technical Information of China (English)

    FU Tao; YANG Pei-zeng; HUANG Xiang-kun; HUANG Qiang; ZHOU Hong-yan; LI Bing; ZHONG Hua-hong; CHEN Xuan

    2005-01-01

    Background Anterior chamber associated immune deviation (ACAID) is characterized by a Th2 cell response. GATA-3 has been shown to be necessary for the activation of Th2 cells. This study was designed to examine the expression of GATA-3 in the development of ACAID. Methods ACAID was induced by injection of 50 μg interphotoreceptor retinoid binding protein (IRBP) into the anterior chamber (AC) of Wistar rats. Delayed-type hypersensitivity (DTH) was evaluated on day 3, 7, 14, 21, 28 after IRBP inoculation. GATA-3 expression was detected using immunohistochemical staining. The expression of GATA-3 mRNA at different time points after AC injection of IRBP was assayed by reverse transcriptase polymerase chain reaction (RT-PCR). Results A significant DTH reaction was observed in Wistar rats on day 3 and 5 after IRBP inoculation. The DTH reaction was decreased 7 days after IRBP inoculation. GATA-3 expression was weak at both mRNA and protein levels in the normal spleen, but was significantly increased on day 5, 7, 14, and 21 after AC injection of IRBP. Conclusion The expression of GATA-3 is increased during ACAID, suggesting that GATA-3 may be involved in the development of ACAID.

  7. Fifty-year follow-up and Strampelli anterior chamber intraocular lens.

    Science.gov (United States)

    Oakley, Carmen L; Nigro, Matthew A; Vote, Brendan J

    2015-01-01

    The Strampelli anterior chamber intraocular lens was created in 1953, and was primarily used to treat myopia and aphakia. Due to the positioning of the lens, it was associated with a number of complications, and was later modified to decrease the rate of significant complications, including endothelial cell loss. This paper describes a 62-year-old man, who has had a Strampelli intraocular lens (IOL) in situ for 52 years, with relatively few complications. The case provides a framework for reflection on the significant advances in the development of IOLs since the Strampelli era. The Strampelli anterior chamber intraocular lens was created in 1953, and was primarily used to treat myopia and aphakia. Due to the positioning of the lens, it was associated with a number of complications, and was later modified to decrease the rate of significant complications, including endothelial cell loss. This paper describes a 62-year-old man, who has had a Strampelli intraocular lens (IOL) in situ for 52 years, with relatively few complications. The case provides a framework for reflection on the significant advances in the development of IOLs since the Strampelli era.

  8. Evaluation of Anterior Chamber Volume in Cataract Patients with Swept-Source Optical Coherence Tomography.

    Science.gov (United States)

    He, Wenwen; Zhu, Xiangjia; Wolff, Don; Zhao, Zhennan; Sun, Xinghuai; Lu, Yi

    2016-01-01

    Purpose. To evaluate the anterior chamber volume in cataract patients with Swept-Source Optical Coherence Tomography (SS-OCT) and its influencing factors. Methods. Anterior chamber volume of 92 cataract patients was evaluated with SS-OCT in this cross-sectional study. Univariate analyses and multiple linear regression were used to investigate gender, age, operated eye, posterior vitreous detachment, lens opacity grading, and axial length (AXL) related variables capable of influencing the ACV. Results. The average ACV was 139.80 ± 38.21 mm(3) (range 59.41 to 254.09 mm(3)). The average ACV was significantly larger in male patients than in female patients (P = 0.001). ACV was negatively correlated with age and LOCS III cortical (C) grading of the lens (Pearson's correlation analysis, r = -0.443, P ACV was also increased with AXL (Pearson's correlation analysis, r = 0.552, P ACV (F = 10.252  P ACV varied significantly among different subjects. Influencing factors that contribute to reduced ACV were female gender, increased age, LOCS III C grade, and shorter AXL.

  9. Evaluation of bacterial contamination rate of the anterior chamber during phacoemulsification surgery using an automated microbial detection system

    Institute of Scientific and Technical Information of China (English)

    Ibrahim; Kocak; Funda; Kocak; Bahri; Teker; Ali; Aydin; Faruk; Kaya; Hakan; Baybora

    2014-01-01

    ·AIM: To assess the incidence of anterior chamber bacterial contamination during phacoemulsification surgery using an automated microbial detection system(BacT/Alert).·METHODS: Sixty-nine eyes of 60 patients who had uneventful phacoemulsification surgery, enrolled in this prospective study. No prophylactic topical or systemic antibiotics were used before surgery. After antisepsis with povidone-iodine, two intraoperative anterior chamber aqueous samples were obtained, the first whilst entering anterior chamber, and the second at the end of surgery. BacT/Alert culture system was used to detect bacterial contamination in the aqueous samples.·RESULTS: Neither aqueous samples obtained at the beginning nor conclusion of the surgery was positive for microorganisms on BacT/Alert culture system. The rate of bacterial contamination during surgery was 0%. None of the eyes developed acute-onset endophthalmitis after surgery.· CONCLUSION: In this study, no bacterial contamination of anterior chamber was observed during cataract surgery. This result shows that meticulous surgical preparation and technique can prevent anterior chamber contamination during phacoemulsification cataract surgery.

  10. Extracting a large live freely floating cysticercosis cyst from the anterior chamber of the eye using visco expression technique: A case report.

    Science.gov (United States)

    Singh, Satya Prakash; Rana, Jagriti; Dukre, Jagdish; Singh, Premala Anthony

    2016-01-01

    Ocular involvement by cysticercosis is uncommon and rare in the anterior chamber. It can give rise to iridocyclitis which can be potentially blinding to the patient. The management is usually surgical. We report a case of 18-year-old girl with large cysticercosis cyst in the anterior chamber. The cyst was removed intact by viscoexpression technique from the anterior chamber of the eye and the patient achieved visual acuity of 6/9 post-operatively. PMID:26949361

  11. Short-term variation in ocular anterior chamber angle using Scheimpflug photography

    Directory of Open Access Journals (Sweden)

    A. Rubin

    2010-12-01

    Full Text Available Purpose: To investigate short-term variation of ocular Anterior Chamber Angle (ACA within and across the different meridians of young, healthy eyes.Method: Scheimpflug photography (via an  Oculus Pentacam was used to repeatedly measure the anterior segment of the right eyes of three young females, all aged 22 years.  For each individual, ten consecutive maps were determined over a short time period and each map contained information for the chamber angles of different meridians across the eye involved, roughly at 70 intervals.  Each meridian in an eye was thus measured 10 times in total permitting analysis of short-term variation both within and across the meridians concerned.  Parametric and non-parametric statistical methods used to understand short-term variation of ACA included meridional plots of medians andlower and upper quartiles (Q1 and Q3 and various polar plots (of raw observations, of means and 95%confidence regions, and of standard deviations.Results: Over, at least, short periods of time, Scheimpflug photography provided fairly repeatable results for ACA both within and across the meridians of the eyes involved.  However, occasionally outliers increased variability for some meridians.  While short-term variation within meridians was relatively small assuming exclusion of a limitednumber of outliers, variation across the meridians of specific eyes was greater (probably relating to the usual anatomical structure of eyes with ACA in the inferior quadrants being mostly larger than that for the superior quadrants.  Friedman ANOVA confirmed for each of the three eyes concerned thamedian ACA was significantly different across thvarious meridians.Conclusion: Scheimpflug photography allows for comprehensive, non-invasive and rapid measurement of ACA through 3600.  Repeatability of measurements appears satisfactory over the short-term, despite potential limitations relating to this photo-graphic method for measuring ACA.  The

  12. Sensitivity of laser flare photometry compared to slit-lamp cell evaluation in monitoring anterior chamber inflammation in uveitis.

    Science.gov (United States)

    Bernasconi, Ottavio; Papadia, Marina; Herbort, Carl P

    2010-10-01

    To study the sensitivity of laser flare photometry (LFP) in monitoring anterior chamber inflammation by correlating LFP measurements with slit-lamp evaluation of aqueous cells in HLA-B27-related uveitis in a prospective trial. Slit-lamp cell evaluation was correlated with LFP-measured flare in a masked fashion in HLA-B27-related uveitis patients receiving standard topical therapy. At the time of 50 and 90% LFP flare reduction, the corresponding reduction of cells was recorded and statistically compared using the sign test. Forty-three episodes (in 43 patients) of acute anterior HLA-B27-related uveitis were included. LFP flare reduction and slit-lamp cell reduction were strongly correlated. LFP was significantly more sensitive for both 50% (P = 0.001) and 90% (P = 0.02) LFP flare reduction in assessing the decrease of anterior chamber inflammation. LFP was superior to slit-lamp cell evaluation in monitoring anterior chamber inflammation in uveitis. Flare, becoming a quantitative parameter when measured by LFP, rather than cells, should be considered the gold standard to measure anterior chamber inflammation in uveitis. PMID:20686916

  13. The Management of a Patient with Elevated Intraocular Pressure Resistant to Medical Treatment: Anterior Chamber Irrigation

    Directory of Open Access Journals (Sweden)

    Abdullah Beyoğlu

    2014-10-01

    Full Text Available A 7-year-old male patient was medically treated in another center for hyphema which occurred after blunt trauma to his right eye. He was admitted to our clinic when his visual acuity decreased after being discharged. Biomicroscopic examination revealed total hyphema. Intraocular pressure (IOP was 48 mm Hg in the right eye with Goldmann applanation tonometry. Since IOP could not be managed by medical therapy and there was no regression in hyphema, anterior chamber was irrigated. As in our case, it should not be forgotten that re-hemorrhage may occur in the first week of hyphema during childhood. Moreover, surgical treatment should be considered when hemorrhage does not regress with medical treatment, increased IOP persists, and when there is a risk of corneal endothelial staining (corneal blood staining. (Turk J Ophthalmol 2014; 44: 400-2

  14. Ocular Toxicity after High-Dose Cefuroxime Injection into the Anterior Chamber

    Directory of Open Access Journals (Sweden)

    Harun Çakmak

    2016-08-01

    Full Text Available Cephalosporins are beta-lactam antibiotics and, like penicillin derivatives, they show bacteriostatic effect by disrupting bacterial cell wall synthesis. Cefuroxime is a second generation cephalosporin and the use of intracameral cefuroxime after cataract surgery has been widely used in the endophthalmitis prophylaxis. A 78-year-old male patient was operated for cataracts in both eyes about 8 years ago. Ocular trauma has occurred in the left eye nine months ago. Vitrectomy surgery combined with intraocular lens extraction was performed and the patient was left aphakic. Secondary intraocular lens implantation was performed. In this paper, we present postoperative ocular findings in a patient who was given cefuroxime into the anterior chamber 2.5 times higher than the recommended dose (25 mg/ml after secondary intraocular lens implantation.

  15. Evaluation of Anterior Chamber Volume in Cataract Patients with Swept-Source Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Wenwen He

    2016-01-01

    Full Text Available Purpose. To evaluate the anterior chamber volume in cataract patients with Swept-Source Optical Coherence Tomography (SS-OCT and its influencing factors. Methods. Anterior chamber volume of 92 cataract patients was evaluated with SS-OCT in this cross-sectional study. Univariate analyses and multiple linear regression were used to investigate gender, age, operated eye, posterior vitreous detachment, lens opacity grading, and axial length (AXL related variables capable of influencing the ACV. Results. The average ACV was 139.80 ± 38.21 mm3 (range 59.41 to 254.09 mm3. The average ACV was significantly larger in male patients than in female patients (P=0.001. ACV was negatively correlated with age and LOCS III cortical (C grading of the lens (Pearson’s correlation analysis, r=-0.443, P<0.001, and Spearman’s correlation analysis, ρ=-0.450, P<0.001. ACV was also increased with AXL (Pearson’s correlation analysis, r=0.552, P<0.001. Multiple linear regression showed that, with all of the covariates entered into the model, gender (P=0.002, age (P=0.015, LOCS III C grade (P=0.043, and AXL (P=0.001 were still associated with ACV (F=10.252  P<0.001  R2=0.498. Conclusion. With SS-OCT, we found that, in healthy cataract patients, ACV varied significantly among different subjects. Influencing factors that contribute to reduced ACV were female gender, increased age, LOCS III C grade, and shorter AXL.

  16. Effect of altered eating habits and periods during Ramadan fasting on intraocular pressure, tear secretion, corneal and anterior chamber parameters

    NARCIS (Netherlands)

    Kerimoglu, H.; Ozturk, B.; Gunduz, K.; Bozkurt, B.; Kamis, U.; Okka, M.

    2010-01-01

    Purpose To determine whether altered eating habits and periods, especially the pre-dawn meal, during Ramadan fasting have any significant effect on intraocular pressure (IOP), tear secretion, corneal and anterior chamber parameters. Methods IOP, basal tear secretion (BTS), reflex tear secretion (RTS

  17. Blunt needle revision with viscoelastic materials via the anterior chamber for early failed filtering blebs after trabeculectomy

    Directory of Open Access Journals (Sweden)

    Yamagami H

    2012-06-01

    Full Text Available Nozomi Kinoshita, Ayumi Ota, Fumihiko Toyoda, Hiroko Yamagami, Akihiro KakehashiDepartment of Ophthalmology, Saitama Medical Center, Jichi Medical University, Saitama, JapanPurpose: To report a new technique of blunt needle revision with viscoelastic materials via the anterior chamber for the treatment of early failed filtering blebs and elevated intraocular pressure after trabeculectomy, in which digital ocular massage and laser suture lysis have been ineffective.Methods: A 27-gauge blunt needle attached to a syringe containing viscoelastic material was inserted into the anterior chamber from the inferior paracentesis. The needle tip was inserted into the subscleral flap space from the filtering fistula at the anterior chamber side, and the scleral flap was lifted bluntly. The needle tip was then inserted into the subconjunctival space where the viscoelastic agent was injected and the adhesion between the sclera and conjunctiva was separated bluntly. Blunt needle revision via the anterior chamber was performed 14 times in six eyes of six patients at Saitama Medical Center, Jichi Medical University from January 2007 to May 2009. All procedures were performed within 1 month after trabeculectomy.Results: The intraocular pressure remained 21 mmHg or lower for more than 6 months in three of six eyes. Slight bleeding from the iris occurred in one of the 14 procedures, and hypotony (intraocular pressure below 5 mmHg occurred in one of the 14 procedures. No serious complications developed.Conclusion: Blunt needle revision via the anterior chamber for early failed filtering blebs is a new, simple, and safe procedure.Keywords: glaucoma, trabeculectomy, filtering bleb, needle revision, blunt needle

  18. Automated detection of inflammatory cells in whole anterior chamber of a uveitis mouse from swept-source optical coherence tomography images

    Science.gov (United States)

    Choi, Woo June; Pepple, Kathryn L.; Wang, Ruikang K.

    2016-03-01

    Cell grading in a rodent anterior chamber is essential for anterior inflammation evaluation in preclinical vision research. This paper describes a computerized method for detection and counting of the anterior chamber cells from swept-source optical coherence tomography (SS-OCT) images of a experimental rodent model of uveitis. The volumetric anterior segment OCT data is obtained from 100 kHz SS-OCT imaging of mouse eye in vivo. For the OCT cross-sections, each OCT structural image is de-speckled and binarized. After removal of cornea, iris, and crystalline lens structures connected to the binary image border, an area thresholding is then employed for each labeled region to isolate only celllike objects in the anterior chamber, followed by roundness estimation of the objects to identify potential cell candidates in the data. Eventually, the cell candidates are counted and graded as total number of cells in the anterior chamber.

  19. Corneal Immunosuppressive Mechanisms, Anterior Chamber-Associated Immune Deviation (ACAID) and Their Role in Allograft Rejection.

    Science.gov (United States)

    Treacy, Oliver; Fahy, Gerry; Ritter, Thomas; O'Flynn, Lisa

    2016-01-01

    Corneal transplantation is the most frequently performed transplant procedure in humans. Human leukocyte antigen matching, while imperative for other types of organ transplants, is usually not performed before cornea transplantation. With the use of topical steroid immunosuppressants, which are subsequently tailed off to almost zero, most corneal transplants will not be rejected in recipients with low risk of graft rejection. This phenomenon has been described as immune privilege by Medawar many years ago. However, this immune privilege is relative and can be easily eroded, e.g. by postoperative nonspecific inflammation or other causes of corneal or ocular inflammation. Interestingly, corneas that are at high risk of rejection have a higher failure rate than other organs. Considerable progress has been made in recent years to provide a better understanding of corneal immune privilege. This chapter will review current knowledge on ocular immunosuppressive mechanisms including anterior chamber-associated immune deviation and discuss their role(s) in corneal allograft rejection. Ultimately, this evolving information will be of benefit in developing therapeutic strategies to prevent corneal transplant rejection.

  20. Comparison of central corneal thickness measurements between anterior chamber-optical coherence tomography and ultrasonic pachymeter

    International Nuclear Information System (INIS)

    Objective: To assess the agreement of central corneal thickness (CCT) measured by anterior chamber-optical coherence tomography (AC-OCT) and ultrasonic pachymeter and provide an objective basis for clinical application of AC-OCT. Methods: CCT of 150 college student volunteers (300 eyes) measured by two devices were obtained. The data was analyzed by paired t test and Pearson correlation analysis. Bland-Altman plot and Mountain plot were used to assess the agreement. Results: The mean CCT values were (530.05 ± 33.611) μm measured by AC-OCT and (543.68 ± 35.088) μm measured by ultrasonic pachymeter. Regression analysis showed a high correlation between the values obtained by both devices (r=0.960, P<0.001). Compared with AC-OCT, ultrasonic pachymeter overestimated the CCT by a mean of 13.62 μm. The two modalities had incomparable results. Conclusion: It is important to be noted in clinical practice that the measurements acquired by these two modalities are not directly interchangeable. However, the CCT measurements by the AC-OCT and ultrasonic pachymeter are highly correlated. AC-OCT is an effective method to observe the changes of the corneal thickness in the long term. (authors)

  1. RANIBIZUMAB (LUCENTIS® INJECTION BY ANTERIOR CHAMBER IN APHAKIC EYES WITH MYOPIC CHOROIDAL NEOVASCULARIZATION

    Directory of Open Access Journals (Sweden)

    F. Petrarchini

    2012-05-01

    Full Text Available Purpose. macular choroidal neovascularization (CNV is one of the most vision-threatening complications of myopia, which can lead to severe vision loss. Our purpose was to evaluate the safety and efficacy of trans-corneal injection of ranibizumab in the treatment of myopic CNV in aphakic patients. Materials and Methods. ten eyes of 10 aphakic patients with CNV secondary to pathologic myopia treated with three trans- corneal injection of ranibizumab were evaluated. A complete ophthalmologic examination including best-corrected visual acuity (BCVA and fundus biomicroscopy, specular microscopy, fundus optical coherence tomography (OCT, fluorescein an- giography (FA were performed at baseline and monthly for all patients. Mean time of follow-up was 6 months. results. The mean axial length was 27,6 mm (range, 25.7-31.3 mm. The mean initial visual acuity (VA was 0.19 (decimal equivalent. A statistically significant improvement to a mean VA of 0.33 decimal equivalent (log-MAR:0.48 was demon- strated at the final follow-up. VA improved by a mean of 2.86 lines. Mean central macular thickness (CMT measured with OCT was 340 μm (range, 179-663 μm at the baseline, and was reduced significantly at the final follow-up to 212μm (range, 125-455 μm. No injection complications or drug-related side effects were noted during the follow-up period. Conclusions. in this small series of aphakic eyes with limited follow-up, ranibizumab by anterior chamber administration seems to be a safe and effective treatment for CNV secondary to pathologic myopia (PM, without any complications. Further studies to evaluate the safety and efficacy are justified.

  2. Predicting combined sewer overflows chamber depth using artificial neural networks with rainfall radar data.

    Science.gov (United States)

    Mounce, S R; Shepherd, W; Sailor, G; Shucksmith, J; Saul, A J

    2014-01-01

    Combined sewer overflows (CSOs) represent a common feature in combined urban drainage systems and are used to discharge excess water to the environment during heavy storms. To better understand the performance of CSOs, the UK water industry has installed a large number of monitoring systems that provide data for these assets. This paper presents research into the prediction of the hydraulic performance of CSOs using artificial neural networks (ANN) as an alternative to hydraulic models. Previous work has explored using an ANN model for the prediction of chamber depth using time series for depth and rain gauge data. Rainfall intensity data that can be provided by rainfall radar devices can be used to improve on this approach. Results are presented using real data from a CSO for a catchment in the North of England, UK. An ANN model trained with the pseudo-inverse rule was shown to be capable of predicting CSO depth with less than 5% error for predictions more than 1 hour ahead for unseen data. Such predictive approaches are important to the future management of combined sewer systems. PMID:24647201

  3. Mechanistic modeling of ophthalmic drug delivery to the anterior chamber by eye drops and contact lenses.

    Science.gov (United States)

    Gause, Samuel; Hsu, Kuan-Hui; Shafor, Chancellor; Dixon, Phillip; Powell, Kristin Conrad; Chauhan, Anuj

    2016-07-01

    Ophthalmic drug for the anterior chamber diseases are delivered into tears by either eye drops or by extended release devices placed in the eyes. The instilled drug exits the eye through various routes including tear drainage into the nose through the canaliculi and transport across various ocular membranes. Understanding the mechanisms relevant to each route can be useful in predicting the dependency of ocular bioavailability on various formulation parameters, such as drug concentration, salinity, viscosity, etc. Mathematical modeling has been developed for each of the routes and validated by comparison with experiments. The individual models can be combined into a system model to predict the fraction of the instilled drug that reaches the target. This review summarizes the individual models for the transport of drugs across the cornea and conjunctiva and the canaliculi tear drainage. It also summarizes the combined tear dynamics model that can predict the ocular bioavailability of drugs instilled as eye drops. The predictions from the individual models and the combined model are in good agreement with experimental data. Both experiments and models predict that the corneal bioavailability for drugs delivered through eye drops is less than 5% due to the small area of the cornea in comparison to the conjunctiva, and the rapid clearance of the instilled solution by tear drainage. A contact lens is a natural choice for delivering drugs to the cornea due to the placement of the contact in the immediate vicinity of the cornea. The drug released by the contact towards the cornea surface is trapped in the post lens tear film for extended duration of at least 30min allowing transport of a large portion into the cornea. The model predictions backed by in vivo animal and clinical data show that the bioavailability increases to about 50% with contact lenses. This realization has encouraged considerable research towards delivering ocular drugs by contact lenses. Commercial

  4. Mechanistic modeling of ophthalmic drug delivery to the anterior chamber by eye drops and contact lenses.

    Science.gov (United States)

    Gause, Samuel; Hsu, Kuan-Hui; Shafor, Chancellor; Dixon, Phillip; Powell, Kristin Conrad; Chauhan, Anuj

    2016-07-01

    Ophthalmic drug for the anterior chamber diseases are delivered into tears by either eye drops or by extended release devices placed in the eyes. The instilled drug exits the eye through various routes including tear drainage into the nose through the canaliculi and transport across various ocular membranes. Understanding the mechanisms relevant to each route can be useful in predicting the dependency of ocular bioavailability on various formulation parameters, such as drug concentration, salinity, viscosity, etc. Mathematical modeling has been developed for each of the routes and validated by comparison with experiments. The individual models can be combined into a system model to predict the fraction of the instilled drug that reaches the target. This review summarizes the individual models for the transport of drugs across the cornea and conjunctiva and the canaliculi tear drainage. It also summarizes the combined tear dynamics model that can predict the ocular bioavailability of drugs instilled as eye drops. The predictions from the individual models and the combined model are in good agreement with experimental data. Both experiments and models predict that the corneal bioavailability for drugs delivered through eye drops is less than 5% due to the small area of the cornea in comparison to the conjunctiva, and the rapid clearance of the instilled solution by tear drainage. A contact lens is a natural choice for delivering drugs to the cornea due to the placement of the contact in the immediate vicinity of the cornea. The drug released by the contact towards the cornea surface is trapped in the post lens tear film for extended duration of at least 30min allowing transport of a large portion into the cornea. The model predictions backed by in vivo animal and clinical data show that the bioavailability increases to about 50% with contact lenses. This realization has encouraged considerable research towards delivering ocular drugs by contact lenses. Commercial

  5. EarIy changes of anterior chamber parameters after FS-LASIK%飞秒 LASlK 术后早期前房参数的变化研究

    Institute of Scientific and Technical Information of China (English)

    程蕾; 朱冉; 王丹梅; 魏梅

    2015-01-01

      结论:飞秒LASIK术后早期引起前房参数变化,包括ACD变浅,ACV变小,但对周边前房角无明显影响,对屈光手术后行内眼手术患者有进一步指导作用。%· AlM: To investigate the changes of early anterior chamber parameters after femtosecond laser in -situ keratomileusis ( FS-LASlK) . ·METHODS:A total of 90 patients (90 eyes) in routine operation indications received FS-LASlK operation from January to June 2014 in our hospital were collected, including 47 males (47 eyes) , 43 females (43 eyes) , aged 18-33 years old (mean age 22.38±3.96 years).According to the diopter, the patients were divided into three groups:30 cases ( 30 eyes ) were in mild myopia group (group A) with diopter≤3D;30 cases (30 eyes) were in moderate myopia group ( group B) with diopter >3D and≤6D; 30 cases ( 30 eyes) were in high myopia group (group C) with diopter >6D.Pentacam measurements were used to measure the anterior chamber parameters including the changes of anterior chamber depth ( ACD) , anterior chamber volume ( ACV) , anterior chamber angle ( ACA ) before surgery and at 1, 3mo after surgery respectively. · RESULTS: All surgical procedures were performed successfully without complications. Compared with the value of ACD and ACV at pre-operation and 1, 3mo post-operation among groups A, B, C, there was statistically significant difference ( P0.05).However, in groups A, B and C, the value of ACA had no statistically significant difference ( P>0.05).Diopter had no obvious relevance with the changes of ACD, ACV, ACA values. · CONCLUSlON:The early changes of anterior chamber parameters after FS-LASlK, including that ACD become shallow, ACV become smaller, but there was no obvious effect on the peripheral anterior chamber angle.There will be a further instruction for those people who want to perform intraocular surgery after ocular refractive surgery.

  6. Surgical outcomes of 23-gauge transconjunctival pars plana vitrectomy combined with lensectomy for glaucomatous eyes with extremely shallow anterior chamber and cataract

    OpenAIRE

    Zhang, Zhaotian; Zhang, Shaochong; Jiang, Xintong; Qiu, Suo; Wei, Yantao

    2016-01-01

    Background Glaucoma combined with an extremely shallow anterior chamber and cataracts remains as a complex condition to deal with. And the emergence of microincision vitrectomy surgery (MIVS) system may provide an ideal option for the treatment of that. We report a clinical study of surgical outcomes of 23-gauge transconjunctival pars plana vitrectomy (PPV) combined with lensectomy in the treatment of glaucomatous eyes with extremely shallow anterior chamber and cataract. Methods Prospective,...

  7. Biometry of anterior segment of human eye on both horizontal and vertical meridians during accommodation imaged with extended scan depth optical coherence tomography.

    Directory of Open Access Journals (Sweden)

    Lin Leng

    Full Text Available To determine the biometry of anterior segment dimensions of the human eye on both horizontal and vertical meridians with extended scan depth optical coherence tomography (OCT during accommodation.Twenty pre-presbyopic volunteers, aged between 24 and 30, were recruited. The ocular anterior segment of each subject was imaged using an extended scan depth OCT under non- and 3.0 diopters (D of accommodative demands on both horizontal and vertical meridians. All the images were analyzed to yield the following parameters: pupil diameter (PD, anterior chamber depth (ACD, anterior and posterior surface curvatures of the crystalline lens (ASC and PSC and the lens thickness (LT. Two consecutive measurements were performed to assess the repeatability and reproducibility of this OCT. They were evaluated by calculating the within-subject standard deviation (SD, a paired t-test, intra-class correlation coefficients (ICC and the coefficient of repeatability/reproducibility (CoR.There were no significant differences between two consecutive measurements on either horizontal or vertical meridians under both two different accommodative statuses (P>0.05. The ICC for all parameters ranged from 0.775 to 0.998, except for the PSC (0.550 on the horizontal meridian under the non-accommodative status. In addition, the CoR for most of the parameters were excellent (0.004% to 4.89%. In all the parameters, only PD and PSC were found different between the horizontal and vertical meridians under both accommodative statuses (P<0.05. PD, ACD, ASC and PSC under accommodative status were significantly smaller than those under the non-accommodative status, except that the PSC at the vertical meridian did not change. In addition, LT was significantly increased when accommodation.The extended scan depth OCT successfully measured the dimensions of the anterior eye during accommodation with good repeatability and reproducibility on both horizontal and vertical meridians. The asymmetry

  8. Monte Carlo study of the depth-dependent fluence perturbation in parallel-plate ionization chambers in electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Zink, K., E-mail: klemens.zink@kmub.thm.de [Institute of Medical Physics and Radiation Protection (IMPS), University of Applied Sciences Giessen, Giessen D-35390, Germany and Department of Radiotherapy and Radiooncology, University Medical Center Giessen-Marburg, Marburg D-35043 (Germany); Czarnecki, D.; Voigts-Rhetz, P. von [Institute of Medical Physics and Radiation Protection (IMPS), University of Applied Sciences Giessen, Giessen D-35390 (Germany); Looe, H. K. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg D-26129, Germany and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg D-26129 (Germany); Harder, D. [Prof. em., Medical Physics and Biophysics, Georg August University, Göttingen D-37073 (Germany)

    2014-11-01

    Purpose: The electron fluence inside a parallel-plate ionization chamber positioned in a water phantom and exposed to a clinical electron beam deviates from the unperturbed fluence in water in absence of the chamber. One reason for the fluence perturbation is the well-known “inscattering effect,” whose physical cause is the lack of electron scattering in the gas-filled cavity. Correction factors determined to correct for this effect have long been recommended. However, more recent Monte Carlo calculations have led to some doubt about the range of validity of these corrections. Therefore, the aim of the present study is to reanalyze the development of the fluence perturbation with depth and to review the function of the guard rings. Methods: Spatially resolved Monte Carlo simulations of the dose profiles within gas-filled cavities with various radii in clinical electron beams have been performed in order to determine the radial variation of the fluence perturbation in a coin-shaped cavity, to study the influences of the radius of the collecting electrode and of the width of the guard ring upon the indicated value of the ionization chamber formed by the cavity, and to investigate the development of the perturbation as a function of the depth in an electron-irradiated phantom. The simulations were performed for a primary electron energy of 6 MeV. Results: The Monte Carlo simulations clearly demonstrated a surprisingly large in- and outward electron transport across the lateral cavity boundary. This results in a strong influence of the depth-dependent development of the electron field in the surrounding medium upon the chamber reading. In the buildup region of the depth-dose curve, the in–out balance of the electron fluence is positive and shows the well-known dose oscillation near the cavity/water boundary. At the depth of the dose maximum the in–out balance is equilibrated, and in the falling part of the depth-dose curve it is negative, as shown here the

  9. Effects of confined space and near vision stimulation on refractive status and vitreous chamber depth in adolescent rhesus monkeys

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This study aimed to investigate the effects of sustained near vision stimulation,on the refractive development and elongation of the vitreous chamber in adolescent rhesus monkeys.A total of 12 adolescent rhesus monkeys(1.5-2.0 years old) were randomly assigned to 3 groups.In groups A(n=4) and B(n=4),monkeys were reared in close-vision cages for 8 and 4 h d-1,respectively;tiny granules were added on the cage floor to avoid visual deprivation and to encourage near gaze.In group C(n=4),monkeys were reared in open-vision cages,with non-granule food as a control.Vitreous chamber depth,refractive status,and corneal refractive power were assessed over 18 months.Paired t-test was used to compare the differences and a P-value<0.05 was considered to be statistically significant.In group A,vitreous chamber depth and optical axis elongated significantly,and refractive error shifted towards myopia during the observation period.In group B,vitreous chambers and optical axis elongated but the refractive power did not show significant changes.In group C,there was no significant elongation in vitreous chambers and optical axis,and the refractive power changed slightly towards hypermetropia.There were no significant changes in corneal refractive power in each group.Sustained near vision can promote vitreous chamber growth and induce myopic shifts in refractive power in adolescent monkeys.Our results demonstrate the potential for a primate model of near-work-related myopia.

  10. The Injection of Air/Oxygen Bubble into the Anterior Chamber of Rabbits as a Treatment for Hyphema in Patients with Sickle Cell Disease

    Directory of Open Access Journals (Sweden)

    Emre Ayintap

    2014-01-01

    Full Text Available Purpose. To investigate the changes of partial oxygen pressure (PaO2 in aqueous humour after injecting air or oxygen bubble into the anterior chamber in sickle cell hyphema. Methods. Blood samples were taken from the same patient with sickle cell disease. Thirty-two rabbits were divided into 4 groups. In group 1 (n=8, there was no injection. Only blood injection constituted group 2 (n=8, both blood and air bubble injection constituted group 3 (n=8, and both blood and oxygen bubble injection constituted group 4 (n=8. Results. The PaO2 in the aqueous humour after 10 hours from the injections was 78.45 ± 9.9 mmHg (Mean ± SD for group 1, 73.97 ± 8.86 mmHg for group 2, 123.35 ± 13.6 mmHg for group 3, and 306.47 ± 16.5 mmHg for group 4. There was statistically significant difference between group 1 and group 2, when compared with group 3 and group 4. Conclusions. PaO2 in aqueous humour was increased after injecting air or oxygen bubble into the anterior chamber. We offer to leave an air bubble in the anterior chamber of patients with sickle cell hemoglobinopathies and hyphema undergoing an anterior chamber washout.

  11. Accuracy Evaluation of The Depth of Six Kinds of Sperm Counting Chambers for both Manual and Computer-Aided Semen Analyses

    Directory of Open Access Journals (Sweden)

    Jin-Chun Lu

    2016-12-01

    Full Text Available Background: Although the depth of the counting chamber is an important factor influencing sperm counting, no research has yet been reported on the measurement and comparison of the depth of the chamber. We measured the exact depths of six kinds of sperm counting chambers and evaluated their accuracy. Materials and Methods: In this prospective study, the depths of six kinds of sperm counting chambers for both manual and computer-aided semen analyses, including Makler (n=24, Macro (n=32, Geoffrey (n=34, GoldCyto (n=20, Leja (n=20 and Cell-VU (n=20, were measured with the Filmetrics F20 Spectral Reflectance Thin-Film Measurement System, then the mean depth, the range and the coefficient of variation (CV of each chamber, and the mean depth, relative deviation and acceptability of each kind of chamber were calculated by the closeness to the nominal value. Among the 24 Makler chambers, 5 were new and 19 were used, and the other five kinds were all new chambers. Results: The depths (mean ± SD, μm of Makler (new, Macro and Geoffrey chambers were 11.07 ± 0.41, 10.19 ± 0.48 and 10.00 ± 0.28, respectively, while those of GoldCyto, Leja and Cell-VU chambers were 23.76 ± 2.15, 20.49 ± 0.22 and 24.22 ± 2.58, respectively. The acceptability of Geoffrey chambers was the highest (94.12%, followed by Macro (65.63%, Leja (35% and Makler (20%, while that of the other two kinds and the used Makler chamber was zero. Conclusion: There existed some difference between the actual depth and the corresponding nominal value for sperm counting chambers, and the overall acceptability was very low. Moreover, the abrasion caused by the long use, as of Makler chamber, for example, may result in unacceptability of the chamber. In order to ensure the accuracy and repeatability of sperm concentration results, the depth of the sperm counting chamber must be checked regularly.

  12. COMPARISON OF ANTERIOR CHAMBER REACTION WITH SINGLE-PIECE AND THREE-PIECE INTRAOCULAR LENSES IN MANUAL SMALL INCISION CATARACT SURGERY

    Directory of Open Access Journals (Sweden)

    Usha

    2014-11-01

    Full Text Available OBJECTIVES: To study the anterior chamber reaction between single-piece and three-piece intraocular lenses in manual small incision cataract surgery. METHODS: Prospective study done at Mysore Race Club Charitable Eye Hospital. 140 Patients underwent suture less sclerocorneal tunnel cataract surgeries with single-piece or three-piece Polymethylmethacrylate (PMMA intra ocular lenses (3-piece IOL. Accurate Keratometry was done with the help of Bausch and Lomb Keratometer. IOL power was calculated by using SRK (Sanders-Retzlaff-Kraff II formula, with the help of non-immersion, contact type of A-Scan biometry. Single-piece IOLs were inserted in 70 patients. Three-piece IOL inserted in rest of 70 patients. Slit lamp examination for anterior chamber cells was graded according to Hogan system. Aqueous cells were measured by counting within the visible field under Slit lamp, keeping the beam at maximum intensity. Anterior chamber reaction (AC in 1stPostoperative week and at 8 weeks are compared and analyzed by ANOVA statistics. RESULTS: Single piece IOL group had anterior chamber reaction ranging from 1 to 2+ cells i.e., in 97%. In three-piece IOL group, 70%of eyes had 2+ cells and 12.8% had 3± cells. At 8 weeks, single- piece IOL showed either no cells or occasional cells in 98.6% of patients, compared to three –piece IOL group showing in 77%of cases. 23% had 1+ cells in later group. CONCLUSION: Single-piece implanted IOLs had significant less number of cells were seen in anterior chamber from 1 week to 8 weeks as compared to three-piece IOLs.

  13. Comparison of Physiologic versus Pharmacologic Mydriasis on Anterior Chamber Angle Measurements Using Spectral Domain Optical Coherence Tomography.

    Science.gov (United States)

    Dastiridou, Anna I; Pan, Xiaojing; Zhang, ZhouYuan; Marion, Kenneth M; Francis, Brian A; Sadda, Srinivas R; Chopra, Vikas

    2015-01-01

    Purpose. To compare the effects of physiologic versus pharmacologic pupil dilation on anterior chamber angle (ACA) measurements obtained with spectral domain optical coherence tomography (SD-OCT). Methods. Forty eyes from 20 healthy, phakic individuals with open angles underwent anterior segment OCT imaging under 3 pupillary states: (1) pupil constricted under standard room lighting, (2) physiologic mydriasis in a darkened room, and (3) postpharmacologic mydriasis. Inferior angle Schwalbe's line-angle opening distance (SL-AOD) and SL-trabecular-iris-space area (SL-TISA) were computed for each eye and pupillary condition by masked, certified Reading Center graders using customized grading software. Results. SL-AOD and SL-TISA under pupillary constriction to room light were 0.87 ± 0.31 mm and 0.33 ± 0.14 mm(2), respectively; decreased to 0.75 ± 0.29 mm (P < 0.01) and 0.29 ± 0.13 mm(2)  (P < 0.01), respectively, under physiologic mydriasis; and increased to 0.90 ± 0.38 mm (P < 0.01) and 0.34 ± 0.17 mm(2)  (P = 0.06) under pharmacologic mydriasis compared to baseline. Conclusions. Using SD-OCT imaging, pharmacologic mydriasis yielded the widest angle opening, whereas physiologic mydriasis yielded the most angle narrowing in normal individuals with open iridocorneal angles. Accounting for the state of the pupil and standardizing the lighting condition would appear to be of importance for future studies of the angle. PMID:25878896

  14. Comparison of Physiologic versus Pharmacologic Mydriasis on Anterior Chamber Angle Measurements Using Spectral Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Anna I. Dastiridou

    2015-01-01

    Full Text Available Purpose. To compare the effects of physiologic versus pharmacologic pupil dilation on anterior chamber angle (ACA measurements obtained with spectral domain optical coherence tomography (SD-OCT. Methods. Forty eyes from 20 healthy, phakic individuals with open angles underwent anterior segment OCT imaging under 3 pupillary states: (1 pupil constricted under standard room lighting, (2 physiologic mydriasis in a darkened room, and (3 postpharmacologic mydriasis. Inferior angle Schwalbe’s line-angle opening distance (SL-AOD and SL-trabecular-iris-space area (SL-TISA were computed for each eye and pupillary condition by masked, certified Reading Center graders using customized grading software. Results. SL-AOD and SL-TISA under pupillary constriction to room light were 0.87±0.31 mm and 0.33±0.14 mm2, respectively; decreased to 0.75±0.29 mm P<0.01 and 0.29±0.13 mm2  P<0.01, respectively, under physiologic mydriasis; and increased to 0.90±0.38 mm P<0.01 and 0.34±0.17 mm2  P=0.06 under pharmacologic mydriasis compared to baseline. Conclusions. Using SD-OCT imaging, pharmacologic mydriasis yielded the widest angle opening, whereas physiologic mydriasis yielded the most angle narrowing in normal individuals with open iridocorneal angles. Accounting for the state of the pupil and standardizing the lighting condition would appear to be of importance for future studies of the angle.

  15. Vascular endothelial growth factor in the fluid of the anterior chamber of the eye in patients with diabetic retinopathy, cataract andneovascular glaucoma

    OpenAIRE

    Anatoliy Gennad'evich Kuz'min; Dmitriy Valentinovich Lipatov; Timofey Aleksandrovich Chistyakov; Ol'ga Mikhaylovna Smirnova; Margarita Ivanovna Arbuzova; Aleksandr Viktorovich Il'in; Marina Vladimirovna Shestakova

    2010-01-01

    Aim. To study the role of vascular endothelial growth factor (VEGF-A) in the fluid of the anterior chamber of the eye (ACE) in the evolvement of diabetic retinopathy (DR) and the outcome of cataract surgery. Materials and methods. The study included 120 patients with diabetes mellitus (DM) operated for the removal of cataract. 16 patients received treatment for DR-related neovascular glaucoma (NG). The control group comprised 22 subjects without DM. VEGF-A and glucose levels were mea...

  16. Phakic anterior chamber intraocular lens (Verisyse™) implantation in children for treatment of severe ansiometropia myopia and amblyopia: Six-month pilot clincial trial and review of literature

    OpenAIRE

    Pirouzian, Amir; Ip, Kenneth C; O’Halloran, Henry S

    2009-01-01

    Purpose: The current study aims to evaluate both safety and efficacy of Verisyse™ (AMO, Irvine, CA) phakic anterior chamber intraocular lens (IOL) in the reduction of clinically significant (>−8 D) myopic anisometropia in children who are noncompliant to traditional medical treatment including spectacle correction or contact lenses. Design: Retrospective interventional case series. Methods: Six anisometropic myopic pediatric patients in one practice were identified through chart-review. None ...

  17. Anterior Lamina Cribrosa Surface Depth in Open-Angle Glaucoma: Relationship with the Position of the Central Retinal Vessel Trunk

    Science.gov (United States)

    Oh, Baek-Lok; Kim, Hyunjoong; Girard, Michaël J. A.; Mari, Jean Martial; Kim, Tae-Woo

    2016-01-01

    Purpose To determine the factors influencing the anterior lamina cribrosa (LC) surface depth (LCD) in patients with open-angle glaucoma (OAG), focusing on the association between LCD and the position of the central retinal vessel trunk (CRVT) at the anterior LC surface. Methods Optic nerve heads of 205 OAG eyes were scanned using swept-source optical coherence tomography (SS-OCT). After processing the images using adaptive compensation, the LCD was determined from 11 horizontal B-scan images that divided the optic disc vertically into 12 equal parts. Eyes were divided into two groups (central or peripheral) according to where the CRVT exits from the anterior LC surface. The influence of CRVT position on LCD was evaluated, taking into account age, gender, untreated intraocular pressure (IOP), IOP at optic-disc scanning, retinal nerve fiber layer (RNFL) thickness, visual-field mean deviation, central corneal thickness, and axial length. Results Patients in the peripheral CRVT group were younger and more myopic, and had a larger mean LCD and thinner global RNFL than those in the central CRVT group (all P≤0.023). On multivariate analysis, the peripheral CRVT location was significantly associated with a larger LCD (P = 0.002), together with the significant association of younger age (P<0.001), higher untreated IOP (P = 0.010), and thinner RNFL (P = 0.003) on the larger LCD. Conclusion In OAG, CRVT location was an independent factor influencing the LCD, together with age, untreated IOP, and global RNFL thickness. The data indicate that the CRVT may contribute to the resistance of the LC against deformation. A longitudinal prospective observation is required to clarify this relationship. PMID:27355646

  18. Depth

    NARCIS (Netherlands)

    Koenderink, J.J.; Van Doorn, A.J.; Wagemans, J.

    2011-01-01

    Depth is the feeling of remoteness, or separateness, that accompanies awareness in human modalities like vision and audition. In specific cases depths can be graded on an ordinal scale, or even measured quantitatively on an interval scale. In the case of pictorial vision this is complicated by the f

  19. 有晶状体眼后房型人工晶状体植入术后前房及前房角的超声活体显微镜观察%Observation on changes of anterior chamber and chamber angle structures after posterior chamber phakic intraocular lens implantation by ultrasound biomicroscopy

    Institute of Scientific and Technical Information of China (English)

    汪晓宇; 沈晔; 杜持新; 李毓敏; 董映

    2009-01-01

    Objective To study the changes of anterior chamber and chamber angle structures after implantable contact lens (ICL) implantation in high myopia by using ultrasound biomicroscopy (UBM).Methods A prospective series case study was conducted on 15 high myopia patients (30 eyes) treated with ICL implant.These patients were followed for one year postoperatively.Intraocular pressure (IOP) was measured by Goldmann applanation tonometer after surgery.All eyes were examined by UBM one year after the surgery.Central anterior chamber depth (ACD), trabecular-iris angle (TIA), the distance between the posterior surface of ICL and the lens and the distance between peripheral surface of ICL and the lens were measured.Nonparametric test was used to compare TIA.One-way ANOVA was used to assess the distance between peripheral surface of ICL and the lens.Repeated Measure ANOVA and Bonferroni test was performed to compare the IOP level before and after surgery.Paired t-test was used to compare ACD.Results Intraocular pressure changed from (13.75±2.27) mm Hg(1 mm Hg=0.133 kPa) preoperatively to (14.27±1.70), (14.70±2.07), (14.07±2.24), (14.00±2.69) and (13.97±2.95) mm Hg at 1 week, 1,3, 6 and 12 months after the surgery, respectively.There was a statistically significant increase of the IOP one month after the surgery, which was normalized completely at 3 months after surgery.The distances between central posterior surface of the cornea to the ICL and the lens were (2.24±0.21 ) and (2.97±0.11) mm, respectively.There was significant difference between these two data (t=20.63, P30°,ICL周边部与晶状体之间的距离在钟表位12:00、3:00、6:00、9:00位差异无统计学意义.ICL后表面与晶状体之间的距离为(0.63±0.16)mm,ICL与晶状体无接触.结论 ICL植入术后ICL位于晶状体前,致使术后中央ACD变浅、部分手术眼前房角宽度变窄.ICL与晶状体无接触,与虹膜后表面接触.

  20. SU-E-T-561: Development of Depth Dose Measurement Technique Using the Multilayer Ionization Chamber for Spot Scanning Method

    Energy Technology Data Exchange (ETDEWEB)

    Takayanagi, T; Fujitaka, S; Umezawa, M [Hitachi, Ltd., Hitachi Research Laboratory, Hitachi-shi, Ibaraki-ken (Japan); Ito, Y; Nakashima, C; Matsuda, K [Hitachi, Ltd., Hitachi Works, Hitachi-shi, Ibaraki-ken (Japan)

    2014-06-01

    Purpose: To develop a measurement technique which suppresses the difference between profiles obtained with a multilayer ionization chamber (MLIC) and with a water phantom. Methods: The developed technique multiplies the raw MLIC data by a correction factor that depends on the initial beam range and water equivalent depth. The correction factor is derived based on a Bragg curve calculation formula considering range straggling and fluence loss caused by nuclear reactions. Furthermore, the correction factor is adjusted based on several integrated depth doses measured with a water phantom and the MLIC. The measured depth dose profiles along the central axis of the proton field with a nominal field size of 10 by 10 cm were compared between the MLIC using the new technique and the water phantom. The spread out Bragg peak was 20 cm for fields with a range of 30.6 cm and 6.9 cm. Raw MLIC data were obtained with each energy layer, and integrated after multiplying by the correction factor. The measurements were performed by a spot scanning nozzle at Nagoya Proton Therapy Center, Japan. Results: The profile measured with the MLIC using the new technique is consistent with that of the water phantom. Moreover, 97% of the points passed the 1% dose /1mm distance agreement criterion of the gamma index. Conclusion: We have demonstrated that the new technique suppresses the difference between profiles obtained with the MLIC and with the water phantom. It was concluded that this technique is useful for depth dose measurement in proton spot scanning method.

  1. Allegro Oculyzer 眼前节诊断系统评估 ICL 术后眼前节参数变化与眼压相关性分析%Assessment on changes of anterior chamber parameters after ICL surgery with Allegro Oculyzer system and their correlation with IOP

    Institute of Scientific and Technical Information of China (English)

    陈庆; 余鹏; 赵雅丽; 郭晓枚

    2016-01-01

    Abstract? AIM: To investigate changes of anterior chamber parameters after posterior chamber phakic implantable collamer lens ( ICL ) surgery and its correlation with intraocular pressure ( IOP) .?METHODS: This was a retrospective case series study. Seventy four eyes in 43 myopia patients were examined by Allegro Oculyzer anterior segment tomography to obtain the changes of anterior chamber volume ( ACV ) , anterior chamber angle ( ACA) , central anterior chamber depth ( ACD) and vault, meanwhile, to measure the IOP to analyze the correlation with anterior chamber parameters.?RESULTS: Compared with preoperative, ACV, ACA, ACD all decreased apparently ( P 0.05).?CONCLUSION:For patients underwent ICL, the anterior chamber parameters all decreased which included ACV, ACA, ACD, and had stabilized since early postoperative period. Correspondingly, IOP was stable and had not correlate with ACV, ACA, ACD and vault, however the long-term observation is still necessary.%目的:研究有晶状体眼后房型人工晶状体植入术( posterior chamber phakic implantable collamer lens surgery ,ICL)后眼前节参数变化及各参数与眼内压( intraocular pressure , IOP)间相关性。方法:回顾性研究。2012/2014年于苏州理想眼科医院屈光手术中心行ICL患者43例74眼,应用Allegro Oculyzer眼前节诊断系统测量其术前、术后1、3、6 mo 前房容积( anterior chamber volume , ACV )、房角( anterior chamber angle,ACA )、中央前房深度( central anterior chamber depth,ACD)、拱高( vault)变化,并测量同一时期眼内压后进行统计学分析。结果:术前与术后1、3、6mo相比,术后较术前ACV,ACA, ACD均较显著减小(P<0.01)。术后ACV,ACA,ACD在各随访观测时间点均稳定,术后vault 在1mo与6mo间存在统计学差异( t=27.66, P=0.01)。而IOP术前与术后各测量点间无统计学差异( P>0.05)。各时期 IOP 与ACV

  2. Phakic anterior chamber intraocular lens (Verisyse™) implantation in children for treatment of severe ansiometropia myopia and amblyopia: Six-month pilot clincial trial and review of literature

    Science.gov (United States)

    Pirouzian, Amir; Ip, Kenneth C; O’Halloran, Henry S

    2009-01-01

    Purpose: The current study aims to evaluate both safety and efficacy of Verisyse™ (AMO, Irvine, CA) phakic anterior chamber intraocular lens (IOL) in the reduction of clinically significant (>−8 D) myopic anisometropia in children who are noncompliant to traditional medical treatment including spectacle correction or contact lenses. Design: Retrospective interventional case series. Methods: Six anisometropic myopic pediatric patients in one practice were identified through chart-review. None of the patients were compliant with specatacle correction or contact lens wear and as a result had dense amblyopia of less than 20/400 by Snellen or Allen visual acuity (mean 6 lines was achieved in four patients (mean visual acuity of 20/70 at six months). Improvement in stereoacuity was noted in all six patients (from total mean zero seconds-arc to six-months post-operative mean of 500 seconds-arc by randot stereoacuity testing). Improvement of >2 lines of visual acuity lines was achieved in the other two patients. No patient lost any lines of visual acuity. Enhanced physical activity, coordination, and improved social interaction were noted in patients and were reported by the parents. No intra/post-operative complications were noted. Discussion: Irreversible or intractable amblyopia secondary to severe anisometropic myopia is a serious medical concern in the pediatric population. Failure of compliance with contact lens therapy consistently leads to visual loss. Anterior chamber phakic IOLs may provide a safe alternative in treatment of noncompliant anisometropic myopic patients who do not accept spectacle wear or contact lens therapy. Conclusion: To reduce or eliminate highly significant anisometropic myopia in children who are noncompliant with traditional medical treatment, phakic anterior chamber IOL implantation may be considered as an alternative modality of treatment. PMID:19668592

  3. SU-E-T-562: Scanned Percent Depth Dose Curve Discrepancy for Photon Beams with Physical Wedge in Place (Varian IX) Using Different Sensitive Volume Ion Chambers

    International Nuclear Information System (INIS)

    Purpose: To investigate and report the discrepancy of scanned percent depth dose (PDD) for photon beams with physical wedge in place when using ion chambers with different sensitive volumes. Methods/Materials: PDD curves of open fields and physical wedged fields (15, 30, 45, and 60 degree wedge) were scanned for photon beams (6MV and 10MV, Varian iX) with field size of 5x5 and 10x10 cm using three common scanning chambers with different sensitive volumes - PTW30013 (0.6cm3), PTW23323 (0.1cm3) and Exradin A16 (0.007cm3). The scanning system software used was OmniPro version 6.2, and the scanning water tank was the Scanditronix Wellhoffer RFA 300.The PDD curves from the three chambers were compared. Results: Scanned PDD curves of the same energy beams for open fields were almost identical between three chambers, but the wedged fields showed non-trivial differences. The largest differences were observed between chamber PTW30013 and Exradin A16. The differences increased as physical wedge angle increased. The differences also increased with depth, and were more pronounced for 6MV beam. Similar patterns were shown for both 5x5 and 10x10 cm field sizes. For open fields, all PDD values agreed with each other within 1% at 10cm depth and within 1.62% at 20 cm depth. For wedged fields, the difference of PDD values between PTW30013 and A16 reached 4.09% at 10cm depth, and 5.97% at 20 cm depth for 6MV with 60 degree physical wedge. Conclusion: We observed a significant difference in scanned PDD curves of photon beams with physical wedge in place obtained when using different sensitive volume ion chambers. The PDD curves scanned with the smallest sensitive volume ion chamber showed significant difference from larger chamber results, beyond 10cm depth. We believe this to be caused by varying response to beam hardening by the wedges

  4. Comparison of corneal curvature and anterior chamber depth measurements using the manual keratometer, lenstar LS 900 and the pentacam

    Directory of Open Access Journals (Sweden)

    Ömür Ö Uçakhan

    2013-01-01

    Conclusions: The ACD measurements obtained using the Lenstar and the Pentacam seem to be interchangeable, whereas, the keratometry measurements obtained using the Lenstar, Pentacam, and MK differ considerably, and are not interchangeable.

  5. Capsid Mutated Adeno-Associated Virus Delivered to the Anterior Chamber Results in Efficient Transduction of Trabecular Meshwork in Mouse and Rat.

    Directory of Open Access Journals (Sweden)

    Barbara Bogner

    Full Text Available Adeno associated virus (AAV is well known for its ability to deliver transgenes to retina and to mediate improvements in animal models and patients with inherited retinal disease. Although the field is less advanced, there is growing interest in AAV's ability to target cells of the anterior segment. The purpose of our study was to fully articulate a reliable and reproducible method for injecting the anterior chamber (AC of mice and rats and to investigate the transduction profiles of AAV2- and AAV8-based capsid mutants containing self-complementary (sc genomes in the anterior segment of the eye.AC injections were performed in C57BL/6 mice and Sprague Dawley rats. The cornea was punctured anterior of the iridocorneal angle. To seal the puncture site and to prevent reflux an air bubble was created in the AC. scAAVs expressing GFP were injected and transduction was evaluated by immunohistochemistry. Both parent serotype and capsid modifications affected expression. scAAV2- based vectors mediated efficient GFP-signal in the corneal endothelium, ciliary non-pigmented epithelium (NPE, iris and chamber angle including trabecular meshwork, with scAAV2(Y444F and scAAV2(triple being the most efficient.This is the first study to semi quantitatively evaluate transduction of anterior segment tissues following injection of capsid-mutated AAV vectors. scAAV2- based vectors transduced corneal endothelium, ciliary NPE, iris and trabecular meshwork more effectively than scAAV8-based vectors. Mutagenesis of surface-exposed tyrosine residues greatly enhanced transduction efficiency of scAAV2 in these tissues. The number of Y-F mutations was not directly proportional to transduction efficiency, however, suggesting that proteosomal avoidance alone may not be sufficient. These results are applicable to the development of targeted, gene-based strategies to investigate pathological processes of the anterior segment and may be applied toward the development of gene

  6. Evaluation of the Effectiveness of Surgical Treatment of Malignant Glaucoma in Pseudophakic Eyes through Partial PPV with Establishment of Communication between the Anterior Chamber and the Vitreous Cavity

    Directory of Open Access Journals (Sweden)

    Marek Rękas

    2015-01-01

    Full Text Available Purpose. Determination of partial posterior vitrectomy (PPV in the proposed modification for treatment of malignant glaucoma. Methods. The prospective, consecutive, single-center case series study involved patients in whom symptoms of malignant glaucoma occurred after combined cataract and glaucoma surgery or after glaucoma surgery in pseudophakic eye. When medical and laser treatment were not successful, partial PPV with establishment of communication between the anterior chamber and the vitreous cavity was performed. Efficacy measures were intraocular pressure (IOP reduction, corrected distance visual acuity (CDVA, AND the number of antiglaucoma medications. Surgical success and occurring complications were also evaluated. Results. The study enrolled 20 eyes of 17 patients. Average IOP was reduced from 30.4 ± 14.2 (SD mmHg to 14.6 ± 3.2 (SD mmHg one year after surgery (P<0.00001. A statistically significant reduction of the number of antiglaucoma medications was obtained from 3.3 ± 1.1 (SD preoperatively to 1.2 ± 1.1 (SD at the end of follow-up. Statistically significant improvement of CDVA was observed 3, 6, and 12 months after surgery. Conclusions. Partial PPV with establishment of communication between the anterior chamber and the vitreous cavity enables effective IOP control over a 12-month observation; however, in most cases, it is necessary to use antiglaucoma medications for IOP control.

  7. Phakic anterior chamber intraocular lens (Verisyse™ implantation in children for treatment of severe ansiometropia myopia and amblyopia: Six-month pilot clincial trial and review of literature

    Directory of Open Access Journals (Sweden)

    Amir Pirouzian

    2009-06-01

    Full Text Available Amir Pirouzian1,3, Kenneth C Ip2, Henry S O’Halloran31The Permanente Medical Group, Santa Clara, CA, USA; 2The Permanente Medical Group, San Francisco, CA, USA; 3Rady’s Children’s Hospital of San Diego, San Diego, CA, USAPurpose: The current study aims to evaluate both safety and efficacy of Verisyse™ (AMO, Irvine, CA phakic anterior chamber intraocular lens (IOL in the reduction of clinically significant (>-8 D myopic anisometropia in children who are noncompliant to traditional medical treatment including spectacle correction or contact lenses.Design: Retrospective interventional case series.Methods: Six anisometropic myopic pediatric patients in one practice were identified through chart-review. None of the patients were compliant with specatacle correction or contact lens wear and as a result had dense amblyopia of less than 20/400 by Snellen or Allen visual acuity (mean <20/400. All patients underwent Verisyse™ phakic IOL implantation in the more myopic eye by one surgeon (AP. Pre- and post-operative visual acuity, anterior/posterior segment examination, stereoacuity, axial biometry measurements, cycloplegic refraction, and endothelial cell counts were performed in all patients whenever feasible.Results: The age of patients ranged from 5–11 years. The mean post-operative follow-up time was six months from the time of IOL insertion. Improvement in visual acuity >6 lines was achieved in four patients (mean visual acuity of 20/70 at six months. Improvement in stereoacuity was noted in all six patients (from total mean zero seconds-arc to six-months post-operative mean of 500 seconds-arc by randot stereoacuity testing. Improvement of >2 lines of visual acuity lines was achieved in the other two patients. No patient lost any lines of visual acuity. Enhanced physical activity, coordination, and improved social interaction were noted in patients and were reported by the parents. No intra/post-operative complications were noted

  8. Development of Extended-Depth Swept Source Optical Coherence Tomography for Applications in Ophthalmic Imaging of the Anterior and Posterior Eye

    Science.gov (United States)

    Dhalla, Al-Hafeez Zahir

    Optical coherence tomography (OCT) is a non-invasive optical imaging modality that provides micron-scale resolution of tissue micro-structure over depth ranges of several millimeters. This imaging technique has had a profound effect on the field of ophthalmology, wherein it has become the standard of care for the diagnosis of many retinal pathologies. Applications of OCT in the anterior eye, as well as for imaging of coronary arteries and the gastro-intestinal tract, have also shown promise, but have not yet achieved widespread clinical use. The usable imaging depth of OCT systems is most often limited by one of three factors: optical attenuation, inherent imaging range, or depth-of-focus. The first of these, optical attenuation, stems from the limitation that OCT only detects singly-scattered light. Thus, beyond a certain penetration depth into turbid media, essentially all of the incident light will have been multiply scattered, and can no longer be used for OCT imaging. For many applications (especially retinal imaging), optical attenuation is the most restrictive of the three imaging depth limitations. However, for some applications, especially anterior segment, cardiovascular (catheter-based) and GI (endoscopic) imaging, the usable imaging depth is often not limited by optical attenuation, but rather by the inherent imaging depth of the OCT systems. This inherent imaging depth, which is specific to only Fourier Domain OCT, arises due to two factors: sensitivity fall-off and the complex conjugate ambiguity. Finally, due to the trade-off between lateral resolution and axial depth-of-focus inherent in diffractive optical systems, additional depth limitations sometimes arises in either high lateral resolution or extended depth OCT imaging systems. The depth-of-focus limitation is most apparent in applications such as adaptive optics (AO-) OCT imaging of the retina, and extended depth imaging of the ocular anterior segment. In this dissertation, techniques for

  9. Comparison of depth-dose distributions of proton therapeutic beams calculated by means of logical detectors and ionization chamber modeled in Monte Carlo codes

    Science.gov (United States)

    Pietrzak, Robert; Konefał, Adam; Sokół, Maria; Orlef, Andrzej

    2016-08-01

    The success of proton therapy depends strongly on the precision of treatment planning. Dose distribution in biological tissue may be obtained from Monte Carlo simulations using various scientific codes making it possible to perform very accurate calculations. However, there are many factors affecting the accuracy of modeling. One of them is a structure of objects called bins registering a dose. In this work the influence of bin structure on the dose distributions was examined. The MCNPX code calculations of Bragg curve for the 60 MeV proton beam were done in two ways: using simple logical detectors being the volumes determined in water, and using a precise model of ionization chamber used in clinical dosimetry. The results of the simulations were verified experimentally in the water phantom with Marcus ionization chamber. The average local dose difference between the measured relative doses in the water phantom and those calculated by means of the logical detectors was 1.4% at first 25 mm, whereas in the full depth range this difference was 1.6% for the maximum uncertainty in the calculations less than 2.4% and for the maximum measuring error of 1%. In case of the relative doses calculated with the use of the ionization chamber model this average difference was somewhat greater, being 2.3% at depths up to 25 mm and 2.4% in the full range of depths for the maximum uncertainty in the calculations of 3%. In the dose calculations the ionization chamber model does not offer any additional advantages over the logical detectors. The results provided by both models are similar and in good agreement with the measurements, however, the logical detector approach is a more time-effective method.

  10. Correlation between trochlear groove depth and patellar position during open and closed kinetic chain exercises in subjects with anterior knee pain.

    Science.gov (United States)

    Felicio, Lílian Ramiro; Saad, Marcelo Camargo; Liporaci, Rogério Ferreira; Baffa, Augusto do Prado; dos Santos, Antônio Carlos; Bevilaqua-Grossi, Débora

    2012-07-01

    The purpose of this study was to correlate the trochlear shape and patellar tilt angle and lateral patellar displacement at rest and maximal voluntary isometric contraction (MVIC) exercises during open (OKC) and closed kinetic chain (CKC) in subjects with and without anterior knee pain. Subjects were all women, 20 who were clinically healthy and 19 diagnosed with anterior knee pain. All subjects were evaluated and subjected to magnetic resonance exams during OKC and CKC exercise with the knee placed at 15, 30, and 45 degrees of flexion. The parameters evaluated were sulcus angle, patellar tilt angle and patellar displacement using bisect offset. Pearson's r coefficient was used, with p < .05. Our results revealed in knee pain group during CKC and OKC at 15 degrees that the increase in the sulcus angle is associated with a tilt increase and patellar lateral displacement. Comparing sulcus angle, patellar tilt angle and bisect offset values between MVIC in OKC and CKC in the knee pain group, it was observed that patellar tilt angle increased in OKC only with the knee flexed at 30 degrees. Based on our results, we conclude that reduced trochlear depth is correlated with increased lateral patellar tilt and displacement during OKC and CKC at 15 degrees of flexion in people with anterior knee pain. By contrast, 30 degrees of knee flexion in CKC is more recommended in rehabilitation protocols because the patella was more stable than in other positions. PMID:22890436

  11. Efficacy of intacs intrastromal corneal ring segment relative to depth of insertion evaluated with anterior segment optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Hassan Hashemi

    2013-01-01

    Full Text Available Aim: To evaluate the effect of implantation depth of Intacs microthin prescription inserts (Addition Technology Inc, Fremont, California on visual and topographic outcomes in patients with post- laser-assisted in situ keratomileusis (LASIK ectasias. Settings and Design: Retrospective, observational case series. Materials and Methods: In this case series, 16 eyes of 12 patients were evaluated. All cases were post-LASIK ectasia that had undergone intrastromal corneal ring segment (ICRS implantation. The planned insertion depth was 70% of stromal thickness using a manual dissector. At least 12 months postoperatively, all eyes underwent Visante (Carl Zeiss Meditec AS-OCT to determine insertion depth. Cases were categorized into 3 groups based on the measured implantation depth: 40-59% thickness; 60-79% thickness; and ≥80% thickness. Visual, refractive and topographic outcomes were evaluated relative to implantation depth. Results: The lowest improvement in the study parameters ocurred when the implantation depth was ≥80%. In this group, uncorrected visual acuity (UCVA and best spectacle corrected VA (BSCVA improved less than 0.5 lines. Manifest refractive spherical equivalent (MRSE and mean keratometry (Km change was less than 0.5 diopters (D. The greatest improvements were observed with implantation depth of 60-79% where UCVA and BSCVA increased by 4.5 and 2.5 lines respectively, and MRSE and Km changed by approximately 2.00 D. Less improvement was found when ICRS were implanted between 40-59% of stromal thickness. Conclusion: Implantation of ICRS greater than 80% of stromal thickness may have no effect on visual and topographic status.

  12. Visualization of the ocular pulse in the anterior chamber of the mouse eye in vivo using phase-sensitive optical coherence tomography

    Science.gov (United States)

    Li, Peng; Ding, Zhihua; Ni, Yang; Xu, Baishen; Zhao, Chen; Shen, Yi; Du, Chixin; Jiang, Bo

    2014-09-01

    We report on a phase-based method for accurately measuring the ocular pulse in the anterior chamber in vivo. Using phase-sensitive optical coherence tomography with optimized scanning protocols and equations for compensating bulk motion and environmental vibrations, a high sensitivity of 0.9 μm/s minimal velocity is demonstrated at a wide detection band of 0 to 380 Hz. The pulsatile relative motion between cornea and crystalline lens in rodents is visualized and quantified. The relative motion is most likely caused by respiration (1.6 Hz) and heartbeat (6.6 Hz). The velocity amplitude of the relative motion is 10.3±2.4 μm/s. The displacement amplitudes at the respiratory and cardiac frequencies are 202.5±64.9 and 179.9±49.4 nm, respectively. The potential applications of the measurement technique can be found in the evaluation of intraocular pressure and the measurement of biomechanical properties of the ocular tissue, which are important in several ocular diseases.

  13. Comparison of different techniques of cataract surgery in bacterial contamination of the anterior chamber in diabetic and non-diabetic population

    Directory of Open Access Journals (Sweden)

    M Ashok Kumar

    2012-01-01

    Full Text Available Aim : To compare the bacterial contamination of the anterior chamber (AC between manual small incision cataract surgery (SICS and phacoemulsification (Phaco. To study the conjunctival flora and bacterial contamination of AC between well-controlled diabetics and non-diabetics. Materials and Methods : Three hundred and sixty-eight patients were randomized to manual SICS and Phaco. Sixty-eight patients were excluded for not completing follow-up or for intraoperative complications like posterior capsule rupture. One hundred and fifty patients in each group were finally analyzed. Conjunctival swabs were taken on admission, after one day of topical ofloxacin and 15 min after 5% Povidone Iodine (PI instillation. AC aspirate at the end of the surgery was also cultured. Results : Fifty-six (18.66% patients had positive conjunctival swab on admission which was reduced to 19 (6.33% with topical ofloxacin and to five (1.66% with instillation of 5% PI. AC contamination in both manual SICS and Phaco was 0.66%. The conjunctival flora in diabetics was similar to non-diabetics. None of the diabetics had AC contamination. Statistical analysis was performed by Chi-Square test (with Yates′ correction. Conclusion : Statistically significant reduction in conjunctival flora was achieved with topical ofloxacin and 5% PI instillation and AC contamination in both manual SICS and Phaco was minimal (0.66%. Well-controlled diabetics who underwent cataract surgery in this study had similar conjunctival flora and AC contamination as non-diabetics.

  14. 激光周边虹膜切除术后前房及房角形态评价方法的研究进展%Evaluation methods of anterior chamber and angle structures after laser peripheral iridotomy

    Institute of Scientific and Technical Information of China (English)

    林仲; 张袆草

    2011-01-01

    Laser peripheral iridotomy ( LPI) is one of the main therapy for glaucoma due to its reliable efficacy of widening peripheral angle and therefore decreasing intraocular pressure by partially relieving pupillary block. The parameters of the anterior chamber angle following the LPI are the main evaluation indexes. At present,the detecting and diagnosis technique for the anterior chamber angle is deeply advancing, including gonioscopy, ultrasound biomicroscopy, anterior segment optical coherence tomography and Pentacam. These methods offer some useful parameters and also present with some limits in the application respectively in the evaluation of anterior chamber and angle structure. This review focuses on the application of Methods mentioned above and morphologic changes of anterior chamber and angle structure following the LPI.%激光周边虹膜切除术(LPI)通过部分解除瞳孔阻滞,增宽周边前房角,降低眼压而成为青光眼治疗的重要手段之一.LPI术后前房角形态的检测参数是评价LPI治疗效果的主要指标.随着检测手段的进步,目前对LPI手术前后前房及房角形态的评价正在逐渐深入.已有的房角检查方法包括前房角镜、超声生物显微镜(UBM)、眼前节OCT(AS.OCT)以及Pentacam等,每种方法均可获得其各自的评价参数,但也存在一定限制.就LPI术后上述检查方法在评价前房及房角形态方面的应用价值进行总结,同时总结LPI术后前房和前房角结构的变化.

  15. 采用AS-OCT测量房角开放度数的一致性分析%Reproducibility of anterior chamber angle measurement with anterior segment optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    曾阳发; 刘杏; 王涛; 钟毅敏; 何明光

    2008-01-01

    目的 探讨采用眼前段光学相干断层扫描仪(AS-OCT)定量测量房角,并分析其测量一致性.方法 采用AS-OCT对23例受试者(30只眼)的房角进行扫描,分别由测量者甲和乙,以及测量者甲在两个不同的时间点对颞侧房角500μm(AA-500μm)和750μm(AA-750μm)的房角开放度数进行定量测量.采用类内相关系数ICC和95%LoA(95%Limts of Agreement,95% LoA)评价测量的一致性.结果 甲两次测量的AA-500μm和AA-750μm值比较差异均无统计学意义(均P>0.05);甲与乙测量的AA-500μm和AA-750μm值比较差异均无统计学意义(均P>0.05).AA-500μm和AA-750μm测量者内的95%LoA分别为(-5.441,5.281弧度和-7.313、6.020弧度);ICC分别为:0.933,0.907.AA-500μm和AA-750μm测量者间的95%LoA分别为:(-6.098,5.098弧度和-7.877、5.423弧度);ICC分别为0.925,0.887.结论 AS-OCT测量房角开放度数的一致性较好,可以用于定量测量房角开放度数.%Objective To assess reproducibility of anterior segment optical coherencetomography (AS-OCT)to quantify the anterior chamber angle(AA).Methods 23 eyes of 30 subjects were enrolled.Anterior champer angle was scanned using AS-OCT,and the 500μm(AA-500 μm)and 750μm(AA-750μm)temporal anterior champer angle were measured by two ophthalmologists,respectively.And one observer repeatedly measured its in two different times.Analyzing the reproducibility with intraclass correlation coefficient(ICC)and 95%Limts of Agreement(95%LoA).Results The difference in AA-500μm and AA-750μm measurements between two observers were not significant(all P>0.05),and its were also no significant difference between the first and the second measurement for same observer(all P>0.05).The 95%LoA of intraobserver of AA-500μm and AA-750μm were-5.441 to 5.281 degrees and-7.313 to 6.020 degrees,respectively.The ICC server of AA-500μm and AA-750μm were-6.098 to 5.098 degrees and-7.877 to 5.423 degrees,respectively.The ICC of interobserver of AA-500

  16. Phakic anterior chamber intraocular lens (Verisyse™) implantation in children for treatment of severe ansiometropia myopia and amblyopia: Six-month pilot clincial trial and review of literature

    OpenAIRE

    Pirouzian, Amir

    2009-01-01

    Amir Pirouzian1,3, Kenneth C Ip2, Henry S O’Halloran31The Permanente Medical Group, Santa Clara, CA, USA; 2The Permanente Medical Group, San Francisco, CA, USA; 3Rady’s Children’s Hospital of San Diego, San Diego, CA, USAPurpose: The current study aims to evaluate both safety and efficacy of Verisyse™ (AMO, Irvine, CA) phakic anterior chamber intraocular lens (IOL) in the reduction of clinically significant (>-8 D) myopic anisometropia in childre...

  17. The in vivo and in vitro induction of anterior chamber associated immune deviation to myelin antigens in C57BL/6 mice.

    Science.gov (United States)

    Farooq, Shukkur M; Elkhatib, Walid F; Ashour, Hossam M

    2014-11-01

    Introduction of antigens into the anterior chamber (AC) of the eye generates a specific systemic form of tolerance that is termed AC-associated immune deviation (ACAID). Experimental autoimmune encephalomyelitis (EAE) is an animal model of the human CNS demyelinating diseases, including multiple sclerosis (MS) and acute disseminated encephalomyelitis. We investigated whether the encephalitogenic antigens myelin oligodendrocyte glycoprotein (MOG35-55) or myelin basic protein (MBP) induce ACAID in the EAE-prone C57BL/6 mice. We hypothesized that injection of MOG35-55/MBP induces antigen-specific tolerance whether via the AC route, the adoptive transfer of in vitro-generated MOG35-55-specific/MBP-specific ACAID antigen presenting cells (APCs), or the adoptive transfer of MOG35-55-specific/MBP-specific ACAID T regulatory cells (Tregs). ACAID is characterized by the specific impairment of delayed-type hypersensitivity (DTH) responses. Thus, DTH assays were used to test for ACAID following the AC injection of MOG35-55/MBP, or the intravenous injection of MOG35-55-specific/MBP-specific ACAID APCs. The functional local adoptive transfer (LAT) assays were used to examine the putative regulatory functions of in vitro generated MOG35-55-specific/MBP-specific Tregs. This report is the first to demonstrate the in vivo and in vitro induction of MOG35-55-specific/MBP-specific ACAID-mediated tolerance in C57BL/6 mice. These findings highlight the need for novel immunotherapeutic strategies for MS and optic neuritis.

  18. Contaminação bacteriana da câmara anterior pós-facoemulsificação com implante de lente intra-ocular de polimetilmetacrilato ou silicone Bacterial anterior chamber contamination after phacoemulsification and polymethylmethacrylate or silicone intraocular lens implantation

    Directory of Open Access Journals (Sweden)

    Ricardo Antonio Pereira

    2004-12-01

    Full Text Available OBJETIVO: Avaliar a contaminação bacteriana da câmara anterior, após facoemulsificação não complicada, com tamanhos diferentes de incisões e lentes intra-oculares. MÉTODOS: Foi realizado estudo prospectivo randomizado, de 80 olhos de 80 pacientes, submetidos à facoemulsificação sob anestesia tópica, distribuídos aleatoriamente em dois grupos iguais. No grupo A foram alocados os pacientes submetidos à cirurgia com incisão de 3,0 mm, lente intra-ocular dobrável de silicone implantadas com injetor. No grupo B os pacientes foram submetidos à cirurgia com incisão de 5,8 mm e implante de lente intra-ocular de polimetilmetacrilato de peça única, com pinça. Ao final de cada cirurgia, uma amostra do líquido da câmara anterior foi colhida e semeada em meios de cultura para bactérias. RESULTADOS: A cultura do líquido da câmara anterior foi positiva em 2,5% dos casos do grupo A e em 5,0% do grupo B. Não houve diferença estatisticamente significante entre os dois grupos (chi2 = 0, 380, p> 0,05. CONCLUSÃO: O implante de lente intra-ocular através de incisão menor, não resultou em menor contaminação da câmara anterior na cirurgia de facoemulsificação.PURPOSE: To evaluate bacterial anterior chamber contamination following uncomplicated phacoemulsification with differents sizes of incisions. METHODS: Prospective randomized study, 80 eyes, 80 patients divided into two groups, were submitted to phacoemulsification with topical anaesthesia. In group A, with 40 patients, surgery was perfomed with 3.0 mm incision and silicone intraocular lens implant with injector. In group B the surgery was done with 5.8 mm incision and polymethylmethacrylate intraocular lens implant with forceps. Anterior chamber aspirate was taken for culture upon completion of surgery in each case. RESULTS: Anterior chamber cultures were positive in 2.5% of the cases in group A, and 5.0% in group B (chi-square test = 0.380, p>0.05, frequencies of

  19. 类风湿关节炎患者人工晶状体植入后前房反应%Anterior chamber inflammation after intraocular lens implantation in patients with rheumatoid arthritis

    Institute of Scientific and Technical Information of China (English)

    马伟华; 赵俊丽

    2013-01-01

    目的 观察类风湿关节炎患者白内障囊外摘出人工晶状体植入术(ECCE+ IOL)与超声乳化吸出人工晶状体植入术(Phaco+ IOL),比较其术后前房反应程度;探讨类风湿因子滴度与术后前房反应的关系.方法 类风湿关节炎患者11例(11眼)行ECCE+ IOL术;10例(12眼)行Phaco+ IOL术.术后复诊随访.结果 除1例(1眼)视神经萎缩,1例(1眼)老年黄斑变性外,其它均获得了0.6或以上的矫正视力,3个月后前房炎症消失,无手术并发症;行Phaco+ IOL术后前房反应较ECCE +IOL术后前房反应轻,术后3d两组间的差异具有统计学意义(mann-whitney u test分析P=0.0258).术后3d、1个月不同前房反应组的类风湿因子之间差异无统计学意义(mann-whitney utest分析,P>0.05).结论 类风湿性关节炎患者Phaco+ IOL术后前房反应较ECCE +IOL术后前房反应轻;术后前房反应的程度与术前类风湿因子滴度无关.%Objective To compare the postoperative anterior chamber inflammation between extracapsular cataract extraction with intraocular lens implantation (ECCE + IOL) and phacoemulsification with intraocular lens implantation (Phaco + IOL) on patients with rheumatoid arthritis,and to investigate the relation of rheumatoid factor and inflammation in anterior chamber.Methods The medical records of 23 eyes of 21patients with rheumatoid arthritis were reviewed,who underwent cataract extraction with intraocular lens implantation.ECCE + IOL was performed in 11 cases (11 eyes),and Phaco + IOL was performed in 10 cases (12 eyes).Patients had been followed up for 3 months.Results All the eyes,except for one case of optic atrophy and one case of age-related macular degeneration,acquired visual acuity of 0.6 or better.Inflammation in anterior chamber disappeared 3 months after surgery,and left no operative complication in any of the eyes.The inflammation in anterior chamber on patients who performed Phaco + IOL was lighter than patients who performed

  20. Surveying of Pressure in Posterior Chamber and Pressure Difference Between Anterior and Posterior Chambers of Rabbit Eye in Vivo%正常兔眼后房压强及前后房压强差值的在体监测

    Institute of Scientific and Technical Information of China (English)

    宋红芳; 杨红玉; 刘志成

    2011-01-01

    目的 寻求一种眼后房穿刺方法,并在体测量兔眼的前、后房压强差.方法 利用高精度压力传感器与空气差压传感器,采用"从角巩膜缘外周1~1.5mm处进针穿透巩膜,使针水平滑行于虹膜下而进入后房"的扎针方法,实现在体连续监测正常兔眼麻醉状态下的后房压强与前后房压强差值.结果 麻醉状态下兔眼后房压强的范围在839.93~2662.48Pa;前、后房压强差范围是46.15~85.52Pa,均值为59.73Pa,变化周期为11.17min.结论 扎针方法测量兔眼后房压强及前后房压强差值对眼球损伤较小,监测到的正常兔眼后房压强及前后房压强差值均在合理可信的范围内.监测方法的可行性为青光眼前后房压强差值的在体监测提供了新的思路.%Objective To find a proper method of puncturing into the posterior chamber of the rabbit eye and to measure the pressure in posterior chamber and the pressure difference between anterior and posterior chambers in vivo. Methods With the help of the high-accuracy pressure and pressure difference sensors, the pressure in posterior chamber and the pressure difference between anterior and posterior chambers were measured continuously in normal rabbit eyes with anesthesia in vivo. The needle directly punctured into the posterior chamber at 1 to 1.5 millimeters away from the cornea-sclera limbus, penetrated the sclera, and then slided horizontally the needle underneath the iris. Results The pressure value in posterior chamber was from 839. 93 Pa to 2662. 48 Pa, while the pressure difference between anterior and posterior chambers was from 46. 15 Pa to 85. 52 Pa with its average value 59. 73 Pa and the wave period was about 11. 17 min. Conclusions The puncture method for surveying the pressure of rabbit ' s chambers does less hurt to the eye-ball and the experimental data of the pressures in posterior chamber and pressure difference between anterior and posterior chambers. are authentic and

  1. Anterior segment parameters and eyelids in systemic sclerosis.

    Science.gov (United States)

    Sahin Atik, Sevinc; Koc, Feray; Akin Sari, Sirin; Sefi Yurdakul, Nazife; Ozmen, Mustafa; Akar, Servet

    2016-08-01

    To evaluate main numerical parameters of anterior segment and the effects of eyelid skin changes on these parameters in patients with systemic sclerosis (SSc). Thirty-four patients with SSc and 34 healthy individuals were enrolled. Besides full eye examination, anterior segment measurements including anterior chamber depth (ACD), anterior chamber volume, anterior chamber angle width, central corneal thickness, pupil size, corneal volume and keratometry were obtained using a Sirius Scheimpflug/Placido photography-based topography system. Eyelid thickness was evaluated using the scala of the modified Rodnan skin score and the patients were subgrouped with respect to these scores to evaluate the effect of eyelid thickening on the anterior segment parameters. Age and sex distributions of the groups were similar (p > 0.05). SSc patients had steeper and thinner corneas, smaller corneal volumes, narrower, shallower and smaller anterior segments but only the mean ACD value of right eyes was found significantly less than those of the controls (p = 0.047). The mean ACD values of SSc subgroup patients with moderate to severe eyelid thickening (50 %) had lower ACD measurements compared to those of control group. (p = 0.043 for the right eyes, p = 0.070 for the left eyes). However, SSc subgroup patients with none to mild eyelid thickening (50 %) had similar anterior segment parameters with control subjects (p > 0.05). Anterior chamber parameters of the SSc patients could show significant differences. These differences occur parallel to the eyelid changes but not secondary to it. PMID:26694912

  2. 超声生物显微镜观察弹性开放襻前房型人工晶状体对眼前段结构的影响%The influence of flexible open-loop anterior chamber intraocular lens on the structure of ocular anterior segment

    Institute of Scientific and Technical Information of China (English)

    陈伟蓉; 刘奕志; 陈秀琦; 程冰; 刘玉华

    2001-01-01

    Objective To evaluate the therapeutic effects and safety offlexible open-loop anterior chamber intraocular lens (FOAC-IOL). Methods By ultrasound biomicroscopy, the positions of the haptics of FOAC-IOL in 20 patients (20 eyes) and the relationships of the haptics with iris and anterior chamber angle structures were observed postoperatively to evaluate the impact of these lenses on the structures of ocular anterior segment. Follow-up duration was from 6 to 20 months. Results Among 40 IOL′s haptics, twenty-six haptics were fixed at the recess of the chamber angle ;and other fourteen haptics penetrated the iris and invaded into the ciliary stroma, which caused recurrent uveitis. There was 1 eye with eccentric lens. There were 8 eyes with anterior synechiae of iris, which were related to the haptics of intraocular lens. Conclusions Ultrasound biomicroscopy works well in dynamic observation of the influence of intraocular lens on ocular anterior segment. The haptics of flexible open-loop anterior chamber intraocular lens should be modified.%目的 评价弹性开放襻一体型前房型人工晶状体(anterchamberintraocularlens,AC-IOL)植入术的疗效及其安全性。方法 应用超声生物显微镜观察20例(20只眼)弹性开放襻一体型AC-IOL植入术后患者IOL襻的位置,以及其与虹膜及房角结构的关系,从而评价IOL对眼前段结构的影响。随访时间6~20个月。结果 40个IOL襻中,26个襻固定于房角隐窝;14个襻(8只眼)穿过虹膜侵入至睫状体实质内,并伴有反复发作的葡萄膜炎。术后8只眼虹膜前粘连与IOL襻有关。结论超声生物显微镜检查是动态了解IOL对眼前段结构影响的有效方法。AC-IOL襻的设计有待进一步改进。

  3. The effects of depth-dependent crustal viscosity variation on visco-elastic response to inflation/deflation of magma chamber

    Science.gov (United States)

    Yamasaki, Tadashi

    2016-04-01

    Development of the satellite observations (GPS and/or InSAR) has allowed us to precisely measure surface deformation. However any geodetic observation by itself does not tell us a mechanism of the deformation. All we can do the most is to compare such an observation to some quantitative predictions, only from which we can deduce a possible deformation mechanism. We therefore need to understand characteristic deformation pattern for a given source mechanism. This study particularly pays attention to magmatic activity in depth as the source, aiming to distinguish magma-induced crustal deformation by better knowing how the activity can be reflected in geodetically observable surface deformation. A parallelized 3-D finite element code, OREGANO_VE [e.g., Yamasaki and Houseman, 2015, J. Geodyn., 88, 80-89], is used to solve the linear Maxwell visco-elastic response to an applied internal inflation/deflation of magma chamber. The rectangular finite element model is composed with a visco-elastic layer overlaid by an elastic layer with thickness of H, and the visco-elastic layer extends over the rest of crust and the uppermost mantle. The visco-elastic crust has a depth-dependent viscosity (DDV) as an exponential function of depth due to temperature-dependent viscosity: hc = h0 exp[c(1 - z/L0)], where h0 is the viscosity at the bottom of the crust, c is a constant; c > 0 for DDV model and c = 0 for uniform viscosity (UNV) model, z is the depth, and L0 is a reference length-scale. The visco-elastic mantle has a spatially uniform viscosity hm. The inflation and/or deflation of sill-like magma chamber is implemented by using the split node method developed by Melosh and Raefsky [1981, Bull. Seism. Soc. Am., 71, 1391-1400]. UNV model with c = 0 employed in this study shows that the inflation-induced surface uplift would abate with time by visco-elastic relaxation. The post-inflation subsidence would erase the uplift in ~ 50 - 100 times Maxwell relaxation time of the crust

  4. A case involving an Ahmed™ glaucoma valve transferred from the vitreous into the anterior chamber of the eye with a silicone oil tamponade for the treatment of neovascular glaucoma

    Directory of Open Access Journals (Sweden)

    Miki M

    2013-02-01

    Full Text Available Michiko Miki, Mari Ueki, Tetsuya Sugiyama, Shota Kojima, Tsunehiko IkedaDepartment of Ophthalmology, Osaka Medical College, Takatsuki, JapanPurpose: To report the short-term efficacy and safety of the transfer of an Ahmed™ glaucoma valve (AGV™ tube from the vitreous into the anterior chamber, in a patient with neovascular glaucoma who had undergone pars plana AGV™ implantation and ultimately needed a silicone oil tamponade.Case: A 41-year-old male with proliferative diabetic retinopathy in both eyes was referred to us for treatment in December 2009. Although the patient previously underwent several surgeries, he ultimately lost vision in his right eye. His left eye suffered from neovascular glaucoma after undergoing a pars plana vitrectomy for tractional retinal detachment. After several vitreous and glaucoma surgeries, the patient underwent implantation of a pars plana AGV™. Postoperatively, although his intraocular pressure was stabilized at approximately 10 mmHg, he had repeated vitreous hemorrhage and hyphema without improvement. He ultimately underwent PPV with a silicone oil tamponade and at the same time, the AGV™ tube was pulled out from the vitreous and inserted into the anterior chamber in order to avoid complications caused by the silicone oil.Results: At 19 months postoperative, the patient’s intraocular pressure had stabilized at 10 mmHg with no recurrence of vitreous hemorrhage and hyphema. Eventually, he lost vision in his left eye because of cerebral hemorrhage.Conclusion: The findings show that insertion of a pars plana AGV™ tube into the anterior chamber in a patient undergoing a silicone oil tamponade is both effective and safe in the short-term.Keyword: tube implantation, glaucoma surgery, tube transfer, pars plana, proliferative diabetic retinopathy, intraocular pressure

  5. 全景超声生物显微镜对人眼睫状沟距离及前房直径的测量%Correlation between anterior chamber angle diameter and ciliary sulcus distance measured by Suowei panoramic 50-MHz digital ultrasound blomicroscopy

    Institute of Scientific and Technical Information of China (English)

    李德姣; 王宁利; 牟大鹏

    2011-01-01

    ciliary sulcus distance in different AC depth population and offer a clinical guide.Methods The anterior chamber angle diameter and ciliary sulcus distance were measured in 30 right eyes with shallow anterior chamber caused by suspect glaucoma and 30 right eyes with deep anterior chamber dut to the high myopia with Suowei panoramic 50-MHz digital ultrasound biomicroscopy.Three horizontal B-scans with the focal plane approximately at a depth corresponding to the iris plane were acquired for each eye.The differences of the anterior chamber angle diameter and ciliary sulcus distance were calculated and compared between the two groups.The correlation of the anterior chamber angle diameter and ciliary sulcus distance were evaluated in respective group.Results In shallow AC group,the mean angle diameter was(11.49+0.75)mm,the mean ciliary sulcus distance was (10.97±0.86)mm with the mean standard deviation of the difference of(-5.14± 0.55)mm,showing a statistically significant difference(t =-5.092,P =0.000).In shallow AC group,linear regression analysis showed a statistically significant correlation between ciliary sulcus distance and angle diameter(R2=0.593,P=0.000)and the Pearson's correlation coefficient was 0.767.In deep AC group,the angle diameter was(12.69±0.67)mm;while ciliary sulcus distance was(12.31 ± 0.61)mm with the mean slandard deviation(-0.38 ± 0.17)mm,which was statistically significantly different(t=-5.531,P=0.000).The ciliary sulcus distance was found to be linear correlation with the angle diameter(R2 =0.699,P=0.000)and Pearson' s correlation coefficient of 0.836.Conclusions Panoramic ultrasound biomicroscopy is an useful tool to the measurement of ciliary sulcus distance.This study exhibited that the ciliary sulcus distance is significant associated with the anterior chamber angle diameter,which may offer a guide for phakic intraocular lens implantation.

  6. Water table depth regulates evapotranspiration and methane flux of a near-pristine temperate lowland fen measured by eddy covariance and static chambers

    Science.gov (United States)

    Kaduk, Jörg; Pan, Gong; Cumming, Alex; Evans, Jon; Kelvin, Jon; Peacock, Mike; Gauci, Vincent; Hughes, John; Page, Susan; Balzter, Heiko

    2015-04-01

    Methane is the second most important greenhouse gas after carbon dioxide, although the current atmospheric concentration is only about two parts per million. This results from a radiative forcing of 0.48 +/-0.05 Wm-2, about 26 times that of carbon dioxide. Atmospheric concentrations as well as emissions to the atmosphere have been increasing strongly over the last decades. Emissions are to a large extent biogenic where the largest biogenic source, wetlands, has the largest uncertainty. This precludes the construction of a reliable global methane budget, as well as meaningful predictions, as results from wetland models are uncertain and there are insufficient data for model improvement. We measured evapotranspiration and methane flux of a near-pristine temperate lowland fen in East Anglia in the United Kingdom from July 2013 to June 2014 by eddy covariance, which represents the first annual cycle of eddy covariance measurements of methane flux in this category of wetland. Methane fluxes from vegetation and ditches were additionally measured separately with static chambers. Annual evapotranspiration was 720.4 to 732.6 mm yr-1. Annual methane release was 3.77 to 4.03 g CH4 m-2 yr-1. Water table and methane fluxes were very different in the two half years: an average of -0.63 nmol CH4 m-2s-1 (a net uptake) for July-December 2013 and 16.2 nmol CH4 m-2s-1 (a net release) for January-June 2014 with a data range of -99 to 410 nmol CH4 m-2s-1 over the full year. Water table has the dominant role in determining methane flux and, under a very low water table, methane uptake was observed. Temperature has a clear impact on fluxes at high water tables. Eddy covariance and chamber measurements show the same annual pattern flux magnitude throughout the year. The fen can switch from being a source to a sink if the water table changes over a small critical depth range. Our measurements have implications for large scale wetland restoration plans in the eastern UK and potential

  7. Long term refractive outcome in eyes of preterm infants with and without retinopathy of prematurity: comparison of keratometric value, axial length, anterior chamber depth, and lens thickness

    OpenAIRE

    Choi, M. Y.; Park, I.K.; Yu, Y S

    2000-01-01

    BACKGROUND/AIMS—A longitudinal study of premature infants was conducted to examine changes in refractive status and their relation with age and factors influencing the occurrence and degree of myopia. Identification of which of the various refractive factors play important parts in relation to myopia in premature infants was attempted.
METHODS—Under observation were 125 eyes in 65 patients who were found to demonstrate no signs of retinopathy of prematurity (ROP) or who had grade I or II ROP ...

  8. Avaliação da contaminação da câmara anterior na cirurgia de facoemulsificação com implante de lente intra-ocular Anterior chamber contamination in phacoemulsification surgery with intraocular lens implant

    Directory of Open Access Journals (Sweden)

    Cesar Nobuo Shiratori

    2002-06-01

    Full Text Available Objetivo: Avaliar a existência de contaminação da câmara anterior durante a facectomia por facoemulsificação com implante de lente intra-ocular. Método: Foi realizado estudo prospectivo, avaliando-se 30 pacientes submetidos a facectomia por facoemulsificação com implante de lente intra-ocular, colhendo-se duas amostras de humor aquoso, uma obtida no início e outra no final da cirurgia. As amostras foram semeadas em meio de cultura para germes aeróbios, anaeróbios e fungos. Resultado: Todas as amostras avaliadas resultaram negativas. Conclusão: A contaminação da câmara anterior na cirurgia de facoemulsificação com implante de lente intra-ocular, usando os cuidados necessários, é infreqüente.Purpose: To evaluate the frequency of anterior chamber contamination during phacoemulsification surgery with intraocular lens implant. Method: A prospective study was done with 30 patients submitted to phacoemulsification surgery with intraocular lens implant. Two samples of the aqueous humor were removed from the anterior chamber, one at the beginning and another one at the end of the surgery and were inoculated in culture plates for anaerobic and aerobic bacteria and fungi. Results: Intraocular aspirates yielded negative cultures. Conclusion: The absence of microorganisms in the samples evaluated allowed us to conclude that contamination during the phacoemulsification surgery with lens implant is unusual.

  9. Evaluation of Anterior Segment's Structures in Tilted Disc Syndrome

    Science.gov (United States)

    Ozsoy, Ercan; Demirel, Ersin Ersan; Cumurcu, Tongabay

    2016-01-01

    Purpose. To evaluate anterior segment's structures by Pentacam in patients with tilted disc syndrome (TDS). Methods. Group 1 included forty-six eyes of forty-six patients who have the TDS. Group 2 including forty-six eyes of forty-six cases was the control group which was equal to the study group in age, gender, and refraction. A complete ophthalmic examination was performed in both groups. All cases were evaluated by Pentacam. The axial length (AL) of eyes was measured by ultrasound. Quantitative data obtained from these measurements were compared between two groups. Results. There was no statistically significant difference for age, gender, axial length, and spherical equivalent measurements between two groups (p = 0.625, p = 0.830, p = 0.234, and p = 0.850). There was a statistically significant difference for central corneal thickness (CCT), corneal volume (CV), anterior chamber angle (ACA), and pupil size measurements between two groups (p = 0.001, p = 0.0001, p = 0.003, and p = 0.001). Also, there was no statistically significant difference for anterior chamber depth (ACD), anterior chamber volume (ACV), and lens thickness (LT) measurements between two groups (p = 0.130, p = 0.910, and p = 0.057). Conclusion. We determined that CCT was thinner, CV was less, and ACA was narrower in patients with TDS. There are some changes in the anterior segment of the eyes with tilted disc. PMID:27648303

  10. Importância da velocidade do movimento celular na câmara anterior, na avaliação clínica das uveítes Importance of the speed of the cellular movement in the anterior chamber in the clinical evaluation of uveitis

    Directory of Open Access Journals (Sweden)

    Fernando Antônio L. Mendes Furtado

    2000-08-01

    Full Text Available Objetivo: Acrescentar ao oftalmologista mais um dado para avaliação clínica das uveítes, que acometem o segmento anterior; seja contribuindo para revelar a intensidade do processo inflamatório, seja ajudando a nortear a conduta terapêutica. Métodos: Estudamos 46 pacientes portadores de uveíte e com reação celular na câmara anterior. Observamos a velocidade do deslocamento das células no humor aquoso e a relacionamos com a intensidade do processo inflamatório, comparando com a sintomatologia e principais sinais clínicos. Resultados: Os resultados nos mostram que existe uma correlação direta entre a velocidade das células na câmara anterior e o grau de inflamação. Quanto mais grave a inflamação, menor é o deslocamento das células. E podemos aplicar esse fato na abordagem clínica das uveítes. Em algumas situações é mais fácil perceber alterações na velocidade que na quantidade de células ou flare. Conclusões: Nosso estudo apresenta um elemento novo na semiologia das uveítes, já que não encontramos referências na literatura médica. Familiarizando-se com a velocidade dos movimentos celulares na câmara anterior, podemos dispor de uma valioso recurso que nos ajude no exame do paciente com uveíte. Há casos em que a mudança na velocidade é o único elemento a nos indicar uma piora ou melhora do quadro clínico.Purpose: To add for the ophthalmologist an element for clinical evaluation of uveitis, affecting the anterior segment; contributing both to reveal the intensity of the inflammatory process and helping to guide the therapeutic management conduct. Methods: We studied 46 uveitis patients with cellular reaction in the anterior chamber. We observed the speed of the displacement of the cells in the aqueous humor and related it to the intensity of the inflammatory process, in comparison with the symptomatology and main clinical signs. Results: The results showed that there is an inverse correlation between the

  11. Structural observation of the anterior chamber angle in CYP1B1-null mice%CYP1B1基因缺失小鼠眼前房角组织结构的观察

    Institute of Scientific and Technical Information of China (English)

    姜发纲; 崔凌; 刘晓文

    2008-01-01

    Objective To determine the effects of CYP1B1 gene on the structure of anterior chamber angle in mice. Methods It is experimental study. Adult CYP1BI-null mice were used, in comparison C57BL/6J mice was used as control. The mice eyes were enueleated and plastic-embedded and the anterior chamber angle were sagittally sectioned in 3 μm thickness. The morphology and structure of the eye tissues was studied by light microscopy and transmission electron microscopy. Results The anterior chamber angle in C57BL/6J mice were well developed. But in CYPIBI-null mice, a variety of anomalies were found in the these tissues, including hypoplastic and compressed trabecular meshwork, abnormal structure of trabecular cells, a basal lamina extending from cornea over the meshwork, small or absent Schlemm's canal, and long iris process extending from the iris root to the trabecular meshwork. These pathological changes was demonstrated focally and the rest of the angle in CYP1BI-null were normal.Conclusions CYP1B1 gene plays an important role in the development of the anterior chamber angle.Deletion of this gene leads to the abnormalities in trabecular meshwork, Schlemm's canal and iris process,which may have some influence on the metabolism and function of the outflow facilities.%目的 研究细胞色素P450 181(CYP1B1)基因对小鼠眼前房角组织结构的影响.方法 实验研究.采用成年CYP1B1基因缺失小鼠模型,以同龄C57BL/6J小鼠为对照.通过塑料包埋切片技术,用光学显微镜和透射电子显微镜观察两组小鼠眼前房角组织的形态和超微结构.结果 C57BL/6J小鼠眼前房角组织发育正常;CYP1B1因缺失小鼠存在不同程度的房水引流系统发育畸形,表现为小梁网发育不良,网眼狭窄,小梁细胞结构变异,有时可见小梁柱间有异常存在的均质膜,Schlemm管狭窄或缺失,虹膜突从虹膜根直达全部小梁网.这些异常改变在CYP1B1基因缺失小鼠眼前房角

  12. Evaluation of Changes in Anterior Segment Configuration by Ultrasound Biomicroscopy after Phacoemulsification and Foldable Intraocular Lens Implantation

    Directory of Open Access Journals (Sweden)

    ilhami Salcan

    2011-08-01

    Full Text Available Purpose: To quantify the configuration changes in anterior segment structures after cataract extraction using ultrasound biomicroscopy (UBM. Material and Method: 33 eyes of 33 patients (21 male, 12 female; mean age: 69.0±8.3 years with senile or presenile cataracts undergoing cataract surgery were prospectively studied. UBM was performed for each patient before and 1 month after surgery. At each UBM examination, axial images of the anterior chamber and radial sections of the angle in four quadrants were obtained. The measurements were performed by using the calipers included in the equipment software and UBM Pro2000® software. Results: After cataract surgery, we determined statistically significant increases in anterior chamber depth and angle parameters (p=0.001. We found that the postoperative increases in anterior chamber depth, angle recess area, angle opening distance 250 and angle opening distance 500 were 1.3, 1.4, 1.7 and 1.5 times, respectively, when compared with the preoperative levels. Decreases in acceleration and increases in y-intercept were determined in 4 quadrants postoperatively by of linear regression analysis of anterior chamber angle and these were also statistically significant (p=0.001. Discussion: UBM gives both qualitative and quantitative valuable information about anterior segment structures. We think that UBM may be a useful tool for evaluation of patients with cataract and occludable and/or narrow angles undergoing cataract surgery for therapeutic purpose. (Turk J Ophthalmol 2011; 41: 200-6

  13. Effects of age on ocular anterior segment dimensions measured by optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    QIN Bing; ZHOU Xing-tao; HUANG David; CHU Ren-yuan

    2011-01-01

    Background Older subjects tend to have smaller ocular anterior segment. The present study aimed to measure anterior segment dimensions with optical coherence tomography (OCT) and quantitatively assess the effect of age and other factors.Results Sixty-six eyes of 33 normal subjects (aged 22-65 years, 19 Asians, 14 Caucasians) were enrolled. For every 1 year of age, corneal diameter was 0.033 mm narrower (P <0.01), anterior chamber width was 0.031 mm narrower (P <0.01), corneal vault was 0.016 mm lower (P<0.01), and anterior chamber depth was 0.025 mm lower (P<0.01). Asian eyes had smaller corneal diameter (P=0.035) and anterior chamber width (P=0.015) compared with those of Caucasian eyes. Body height showed positive correlation with corneal diameter (0.039 mm per centimeter of height, P <0.01) and corneal vault (0.024 mm per centimetre of height, P <0.01). Gender did not have an independent effect on anterior segment dimensions.Conclusions Anterior segment dimensions were smaller in older subjects. Age-related changes may affect the tolerability of long-term implants such as phakic intraocular lens.

  14. Constraining Gas Diffusivity-Soil Water Content Relationships in Forest Soils Using Surface Chamber Fluxes and Depth Profiles of Multiple Trace Gases

    Science.gov (United States)

    Dore, J. E.; Kaiser, K.; Seybold, E. C.; McGlynn, B. L.

    2012-12-01

    Forest soils are sources of carbon dioxide (CO2) to the atmosphere and can act as either sources or sinks of methane (CH4) and nitrous oxide (N2O), depending on redox conditions and other factors. Soil moisture is an important control on microbial activity, redox conditions and gas diffusivity. Direct chamber measurements of soil-air CO2 fluxes are facilitated by the availability of sensitive, portable infrared sensors; however, corresponding CH4 and N2O fluxes typically require the collection of time-course physical samples from the chamber with subsequent analyses by gas chromatography (GC). Vertical profiles of soil gas concentrations may also be used to derive CH4 and N2O fluxes by the gradient method; this method requires much less time and many fewer GC samples than the direct chamber method, but requires that effective soil gas diffusivities are known. In practice, soil gas diffusivity is often difficult to accurately estimate using a modeling approach. In our study, we apply both the chamber and gradient methods to estimate soil trace gas fluxes across a complex Rocky Mountain forested watershed in central Montana. We combine chamber flux measurements of CO2 (by infrared sensor) and CH4 and N2O (by GC) with co-located soil gas profiles to determine effective diffusivity in soil for each gas simultaneously, over-determining the diffusion equations and providing constraints on both the chamber and gradient methodologies. We then relate these soil gas diffusivities to soil type and volumetric water content in an effort to arrive at empirical parameterizations that may be used to estimate gas diffusivities across the watershed, thereby facilitating more accurate, frequent and widespread gradient-based measurements of trace gas fluxes across our study system. Our empirical approach to constraining soil gas diffusivity is well suited for trace gas flux studies over complex landscapes in general.

  15. Refraction and eye anterior segment parameters in schizophrenic patients

    Directory of Open Access Journals (Sweden)

    Tongabay Cumurcu

    2015-06-01

    Full Text Available ABSTRACT Purpose: To evaluate the difference in terms of refractive errors and anterior segment parameters between schizophrenic patients and healthy volunteers. Methods: This study compared 70 patients (48 men who were diagnosed with schizophrenia with a control group of 60 (35 men who were similar in terms of age, gender, education, and socioeconomic level. Anterior segment examination was performed using a Scheimflug system. Axial length and lens thickness (LT were measured using optic biometry. The following tests were administered to the psychiatric patient group: Brief Psychiatric Rating Scale (BPRS, Scale for the Assessment of Negative Symptoms (SANS, and Scale for the Assessment of Positive Symptoms (SAPS. Results: Mild myopia was detected in both the schizophrenic and control groups, with no statistically significant difference (p>0.005. Corneal volume (CV, anterior chamber volume (ACV, anterior chamber depth (ACD, and central corneal thickness (CCT values were lower in the schizophrenic group, and there was a statistically significant between-group difference (p=0.026, p=0.014, p=0.048, and p=0.005, respectively. LT was greater in schizophrenics, and the difference was found to be statistically significant (p=0.006. A statistically significant negative correlation was found between SAPS and cylinder values (p=0.008. The axial eye length, cylinder value, pupil diameter, mean keratometric value, and anterior chamber angle revealed no statistically significant difference between the groups (p>0.05. Conclusion: No statistically significant difference was detected in terms of refraction disorders between schizophrenics and the healthy control group, while some differences in anterior chamber parameters were present. These results demonstrate that schizophrenics may exhibit clinical and structural differences in the eye.

  16. Changes of Anterior Chamber Angle and Intraocular Pressure after Implantation of Intraocular Lens through Small Incision in a Non-phacoemulsification Way%小切口非超声乳化人工晶状体植入术后房角及眼压变化的相关性研究

    Institute of Scientific and Technical Information of China (English)

    刘玉青; 冀向宁; 李坤; 戴冬姝

    2012-01-01

    Objective To explore the correlation between the anterior chamber angle and intraocular pressure after the implantation of intraocular lens ( iol) through small incision in a non - phacoemulsification way. Methods Totally 110 senile cataract patients admitted to our hospital in 2010 underwent implantation of iol with superficial anaesthesia through small incision. Among whom we chose 101 senile cataract patients ( 104 eyes ) as the research subjects whose operation process was smooth and the posterior capsulars remained complete and iol successfully being implanted into capsular bag. Relevant parameters of anterior chamber including anterior open distance at 500μm ( AOD500 ), trabeculum - tunica coerulea included angle ( TIA ), anterior chamber depth ( ACD ) were measured by ultrasonic biomicroscope ( UBM ) preoperatively. Intraocular pressures were measured by Goldmann ophthalmotonometer. All these parameters were re - measured by the same technician 2 weeks, 1 month, and 3 months postoperatively. Morphouses of the anterior chambers were recorded preoperatively and re - recorded 1 month postopera-tively through microgonioscope. Results Compared with the normal eyes, the intraocular pressure showed significant difference in these diseased eyes before surgery ( P < 0. 05 ). ACD, AOD 500, TIA, and intraocular pressure before surgery were also significantly different from thoese 2 weeks, 1 month, and 3 months after surgery ( P < 0. 05 ). In addition, AOD 500 and TIA had a negative correlation with intraocular pressure. Conclusion Small incision of non - phacoemulsification and intraocular lens ( iol) implantation might result in an enlargement of ACD and width of anterior chamber and a significant decrease of intraocular pressure. AOD500 and TIA are important factors that influence the intraocular pressure in the elderly.%目的 研究小切口非超声乳化人工晶状体植入术后前房角宽度及眼压变化的相关性.方法 选取2010年在我院就

  17. Agreement of anterior chamber angle examination by slit lamp optical coherence tomography and gonioscopy%裂隙灯前节OCT与房角镜检查前房角度数一致性分析

    Institute of Scientific and Technical Information of China (English)

    朱洪丽

    2013-01-01

    Objective To explore the agreement of anterior chamber angle examination by slit lamp optical coherence tomography (SL-OCT) and gonioscope.Methods Twenty-six patients with primary glaucoma (52 eyes) and 16 normal persons (32 eyes) were included.Anterior chamber angle was measured with SL-OCT and gonioscope in turns for temporal,nasal,superior and inferior quadrant.Results of two methods were analyzed and the data were analyzed with Pearson correlation coefficient and Kappa value.Results The Pearson Helation coefficient of the two methods was 0.86 (P =0.00) and the Kappa value was 0.75 (P=0.00).The specificity and sensitivity of detecting occludable angle were 94.7% and 89.4%.Conclusions Anterior chamber angle examination with SL-OCT and gonioscope are well consistent.The specificity and sensitivity for SL-OCT in detecting occludable angle is satisfying.SL-OCT can be regard as an objective assistant method for the diagnosis of angle closure glaucoma.%目的 探讨裂隙灯前节OCT与房角镜检查前房角的一致性,以便更准确地评价这一新的客观前节成像方法.方法 对2010年11月至2011年11月在沈阳市第四人民医院眼科选择原发性青光眼患者26例(52只眼)及正常人16名(32只眼).在同一暗室中依次对其双眼颞侧、鼻侧、上方、下方4个象限进行裂隙灯前节OCT和房角镜检查,采用Shaffer法与Scheie法结合的分级系统记录前房角度数,应用Pearson相关分析及Kappa值对两种检查结果进行一致性检验.结果 两种方法检查房角结果的Pearson相关系数为0.86 (P =0.00),Kappa值为0.75(P=0.00),检测可关闭房角(即房角镜检查Shaffer分级≤2级)的敏感性和特异性分别为94.7%和89.4%.结论 裂隙灯前节OCT与房角镜检查一致性好,检测可关闭房角的特异性和敏感性较高,可作为青光眼辅助诊断的客观检查手段.

  18. Comparison of Anterior Segment Measurements with Scheimpflug/Placido Photography-Based Topography System and IOLMaster Partial Coherence Interferometry in Patients with Cataracts

    OpenAIRE

    Jinhai Huang; Na Liao; Giacomo Savini; Fangjun Bao; Ye Yu; Weicong Lu; Qingjie Hu; Qinmei Wang

    2014-01-01

    Purpose. To assess the consistency of anterior segment measurements obtained using a Sirius Scheimpflug/Placido photography-based topography system (CSO, Italy) and IOLMaster partial coherence interferometry (Carl Zeiss Meditec, Germany) in eyes with cataracts. Methods. A total of 90 eyes of 90 patients were included in this prospective study. The anterior chamber depth (ACD), keratometry (K), corneal astigmatism axis, and white to white (WTW) values were randomly measured three times with Si...

  19. Cervicoplastia anterior Anterior cervicoplasty

    Directory of Open Access Journals (Sweden)

    Lucas Gomes Patrocínio

    2004-10-01

    Full Text Available Muitos pacientes buscam correção estética da frouxidão da pele do pescoço, depósito de gordura na região submentoneana ou bandas de platisma. Em grande parte dos casos a ação medial, via cervicoplastia anterior é necessária. OBJETIVO: Demonstrar a casuística e avaliar os resultados e complicações com a técnica de cervicoplastia anterior no Serviço de Otorrinolaringologia da Universidade Federal de Uberlândia. FORMA DE ESTUDO: Relato de série. PACIENTES E MÉTODOS: Quarenta e dois pacientes, entre 39 e 65 anos de idade, sendo 40 (95,2% do sexo feminino e 2 (4,8% do masculino, foram submetidos a cervicoplastia anterior. Retrospectivamente foram avaliados resultados e complicações. RESULTADOS: Destes, 34 apresentaram resultados satisfatórios, 4 apresentaram déficit estético notado somente pelo cirurgião, 3 apresentaram déficit estético notado somente pelo paciente e 1 apresentou déficit estético necessitando cirurgia revisional. Ao estudo fotográfico, todos os pacientes apresentaram melhora do perfil cervical, redução das bandas de platisma e da frouxidão da pele, estabilização da musculatura cervical e acentuação do ângulo cervicomental, em graus variados. Houve complicação em 2 casos (discreto serohematoma e cicatriz um pouco alargada. CONCLUSÃO: A cervicoplastia, associada ou não à tração lateral pela ritidoplastia, é uma técnica que produz resultados satisfatórios na grande maioria dos casos.Many patients look for aesthetic correction of the laxity of neck skin, submandibular fat deposit or platisma bands. In a large part of the cases, medial action, through anterior cervicoplasty is necessary. AIM: To demonstrate the casuistic and to evaluate the results and complications with anterior cervicoplasty technique in the Otorhinolaryngology Service of the Federal University of Uberlândia. STUDY DESIGN: Serie report. PATIENTS AND METHODS: Forty-two patients, between 39 and 65 years of age, being 40 (95

  20. 改良前房注射法移植血管内皮细胞替代角膜内皮细胞的实验观察%Transplanted vascular endothelial cells to replace corneal endothelial cells by improved anterior chamber injection

    Institute of Scientific and Technical Information of China (English)

    朱勤; 胡竹林; 孙晓梅; 胡敏; 刘海; 杨忠昆

    2014-01-01

    Objective To observe form and function changes of vascular endothelial cells (VEC) which were transplanted to the posterior surface of rhesus monkey cornea without Descemet's Membrane by anterior chamber injection,explore the feasibility of transplanting VEC to treat corneal endothelial injury,and find new method of corneal endothelial cell transplantation.Methods Cultured VEC to proliferate in vitro.Rhesus monkeys were randomly divided into two groups:Experimental group(6) and control group(6)according to a random number table.The experimental group:transplant the culured VEC to the posterior surface of rhesus monkey cornea without Descemet's membrane by anterior chamber injection.The control group:Tear out the Descemet's membrane by capsulotomy needle without VEC transplantation.A ultrasound apparatus was adopted to measure the postoperative thicknes of the cornea and Goldman intraocular pressure meter measuring intraocular pressure in the postoperative 7 days,14 days,30 days,60 days,90 days,organize the data and entered into the computer,applicated the software of SPSS 11.5 for data independent samples t-test and analysis of variance.The eyes were removed respectively in postoperative 30,60,90 days to do pathological HE dyeing and scanning electron microscopy (SEM) observation of VEC in the posterior surface of cornea graft.Results Corneal transpareney:In the experimental observation period (3 months),the experimental group had better transparency than the control group with normal anterior chamber depth and without bullous kerat-opathy.And the corneal neovascularization was exist in the cornea graft in experimental group in the third month.After 3 months,the corneal thickness of experimental group (500 ± 14) μm was significantly lower than the control group (618 ± 11) μm,Corneal thickness values between experimental and control groups were statistically significant differences in changes (all P < 0.05,t-values were-3.256,-4.419,-12.896 postoperative 1

  1. Evaluation of anterior segment parameters in patients with pseudoexfoliation syndrome using Scheimpflug imaging

    Directory of Open Access Journals (Sweden)

    Alime Gunes

    2016-06-01

    Full Text Available ABSTRACT Purpose: To evaluate anterior segment parameters in patients with pseudoexfoliation syndrome (PXS using Scheimpflug imaging. Methods: Forty-three PXS patients and 43 healthy control subjects were included in this cross-sectional study. All participants underwent a detailed ophthalmologic examination. Anterior segment parameters were measured using a Scheimpflug system. Results: Considering the PXS and control groups, the mean corneal thicknesses at the apex point (536 ± 31 and 560 ± 31 µm, respectively, p=0.001, at the center of the pupil (534 ± 31 and 558 ± 33 µm, respectively, p=0.001, and at the thinnest point (528 ± 30 and 546 ± 27 µm, respectively, p=0.005 were significantly thinner in PXS patients. Visual acuity was significantly lower (0.52 ± 0.37 versus 0.88 ± 0.23, p<0.001 and axial length was significantly longer (23.9 ± 0.70 mm versus 23.2 ± 0.90 mm, p=0.001 in the PXS eyes than in the control eyes. There were no statistically significant differences in the mean values of keratometry, anterior chamber angle, anterior chamber depth, corneal volume, and anterior chamber volume between the PXS and control eyes. Conclusions: The patients with PXS had thinner corneas, worse visual acuity, and longer axial length compared with those in the healthy controls.

  2. Effects of 1% cyclopentolate hydrochloride on anterior segment parameters obtained with Pentacam in young adults

    Directory of Open Access Journals (Sweden)

    Ceyhun Arici

    2014-08-01

    Full Text Available Purpose: To investigate the effects of topically applied 1% cyclopentolate hydrochloride on anterior segment parameters obtained with a Pentacam rotating Scheimpflug camera in healthy young adults. Methods: Anterior segment analyses of 25 eyes from 25 young adults (Group 1, before and after 45 min of 1% cyclopentolate hydrochloride application, were performed. For a control group (cycloplegia-free, Group 2, 24 eyes of 24 age- and sex-matched healthy cases were evaluated twice at 45 min intervals. The results obtained from the groups were compared statistically. Results: The mean ages of the groups were 23.04 ± 3.42 (range, 18-29 and 22.4 ± 2.05 (range, 18-27 years for Groups 1 and 2, respectively (p=0.259. In Group 1, measurements between the two analyses were significantly different for the values of anterior chamber depth (ACD, anterior chamber angle (ACA, and anterior chamber volume (ACV (p<0.05, whereas no statistical difference was found for the central corneal thickness (CCT and keratometry (K1, K2 measurements. In Group 2, none of these parameters were statistically different between the two analyses. Conclusions: Topically applied 1% cyclopentolate hydrochloride caused an increase in the ACD and ACV values, and a decrease in the ACA value. However, it had no significant effect on the CCT and keratometry measurements. It is important to consider these effects when using the Pentacam device on young adults with cycloplegia and when applying it for various reasons.

  3. 前房相关免疫偏离中调节性T细胞的变化%Variation of regulatory T cell during anterior chamber-associated immune deviation

    Institute of Scientific and Technical Information of China (English)

    张敏敏; 张晓敏; 赵少贞

    2011-01-01

    目的:探索前房相关免疫偏离(ACAID)机制中调节性T细胞的变化,为进一步研究其具体机制创造条件.方法:将C57BL/6小鼠分为ACAID实验组、阳性对照组和正常组.实验组将2μL卵白蛋白(OVA,50 mg/mL)前房注射,阳性对照组和正常组以2 μL PBS行前房注射,7d后实验组和阳性对照组足底皮下免疫OVA100μL(2.5 mg/mL OVA与CFA等体积充分乳化),正常对照组不予处理.14d后检测耳廓迟发型超教反应(DTH),流式分析脾细胞中CD4+CD25+Foxp3+T细胞以及CD8+Foxp3+T细胞的数量和比例.结果:DTH结果显示,实验组的耳廓肿胀值较阳性对照组明显减小.CD4+CD25+Foxp3+T细胞和CD8+Foxp3+T细胞比例较阳性对照组和正常组均升高.结论:CD4+CD25+Foxp3+T细胞和CD8+Foxp3+T细胞在ACAID机制中发挥重要作用.%Objective: To examine the variation of regulatory T cell during anterior chamber-associated immune deviation (ACAID), and determine the mechanism of ACAID. Methods: C57BLV6 mice were divided into 3 groups, ACAID group, positive control group and normal group. 2 H-L OVA {50 mg/Ml) were injected into the anterior chamber of ACAID group. Normal group and positive control group received AC injection of PBS. 7 d later, all the mice received subcutaneous injections of 100 Μl OVA ( 2.5 mg/Ml OVA emulsified 1:1 in complete Freuned adjuvant). 14 d later, DTH response was measured to evaluate the development of ACAID. Flow cytometry was used to assay the frequency of CD4+CD25+Fo+P3t cell and CD8+Foxp3T cell in the spleen of C57BL/6. Results: A significantly decreased DTH response was observed in the ACAID group, a high level of CD4+CD25+Foxp3T cell and CD8·Foxp3T cell were observed in ACAID group .compared with normal group and positive control group. Conclusion: CD4+CD25·Foxp3·T cell and CD8+Foxp3T cell play important roll in the mechanism of ACAID.

  4. Evaluation of ultrasonic biomicroscopy results in anterior eye segment before and after cataract surgery

    OpenAIRE

    Ciftci S.; Simsek A.

    2012-01-01

    Ali Simsek,1 Süleyman Ciftci21Department of Ophthalmology, Faculty of Medicine, Adiyaman University, Adiyaman, Turkey; 2Department of Ophthalmology, Diyarbakir Training and Research Hospital, Diyarbakir, TurkeyBackground: The aim of this study was to assess the value of ultrasonic biomicroscopy in reporting decreases in intraocular pressure resulting from changes in anterior chamber depth and angle after phacoemulsification and intracapsular lens implantation in patients with catarac...

  5. Pentacam对原发性闭角型青光眼激光周边虹膜切开术前后前房形态和参数的评估%The morphologic and quantitative evaluation of ocular anterior chamber parameters after laser peripheral iridotomy in primary angle-closure glaucoma eyes

    Institute of Scientific and Technical Information of China (English)

    刘晓丽; 刘丹岩; 张斌; 郭从容; 杜颖华; 段佳良

    2016-01-01

    in the quantitative evaluation of ocular anterior segment in primary angle-closure glaucoma (PACG) eyes than slit lamp microscope and ultrasound biomicroscope (UBM).However,its accuracy in the earlier stage of PACG before and after YAG laser peripheral iridotomy (LPI) is not fully elucidated.Objective This study was to assess the effect of YAG LPI in PACG patients with Pentacam.Methods A prospective self-controlled study was performed.Thirtyfive fellow eyes (pre-clinical stage of PACG) of acute PACG and 35 fellow eyes of chronic PACG were included in the Second Hospital of Hebei Medical University from July,2012 to December,2013.YAG LPI was performed on the eyes,and the parameters of ocular anterior segment including central anterior chamber depth (ACD),anterior chamber volume (ACV) and peripheral anterior chamber angle (ACA) were measured and compared by Pentacam before and 1 day,7 days,28 days after operation.This study was approved by the Ethic Committee of the Second Hospital of Hebei Medical University and informed consent was obtained from all subjects.Results In pre-clinical stage of PACG eyes,the postoperative ACD and ACV values were increased in comparison with preoperation,showing significant differences among various time points (ACD:F =6.783,P =0.004;ACV:F =19.090,P =0.000),and no significant difference was found in ACA among different time points (F =0.153,P =0.928).In the fellow eyes of chronic PACG,the postoperative ACD and ACV values were larger than those of preoperation,with significant differences among various time points (ACD:F =21.576,P =0.000;ACV:F =47.506,P =0.000),and no significant difference was found in ACA among different time points (F=0.581,P=0.629).The change values of ACD and ACV were (0.064±0.022) mm and (27.840±4.963) mm3 in the eyes of pre-clinical stage of PACG,and those in the fellow eyes of chronic PACG were (0.047-± 0.020) mm and (21.000 ± 3.278) mm3,showing significant differences between the two groups (ACD:t=2.783,P=0

  6. Establishment of chronic ocular hypertension model by anterior chamber injection of polystyrene microspheres in mouse%前房注射聚苯乙烯微球诱导小鼠慢性高眼压研究

    Institute of Scientific and Technical Information of China (English)

    沈策英; 陈兰兰; 姜利斌

    2014-01-01

    Background Many methods of ocular hypertension modeling have been used before,but these models remain short-duration ocular hypertension only.A new method of elevating intraocular pressure in mice by anterior chamber injection of polystyrene microspheres was reported abroad.However,this model is rarely used in China.Objective This study was to evaluate the application value of anterior chamber injection of polystyrene microspheres to establish glaucoma model in mice.Methods Forty-two SPF adult female C57BL/6L mice were divided into three groups according to random number table.Polystyrene microspheres (2 μl) were injected into the anterior chamber monocularly in the microspheres group,and the equal amount of PBS was used in the same way in the PBS group.No intervene was performed in the normal control group.The eyes of mice were examined by slit lamp microscope,and the intraocular pressure (IOP) was measured with TonoLab rebound tomometer in a 3-day interval after injection.Ocular histological sections were prepared 2 and 4 weeks after injection,and the anterior chamber angle was examined under the optical microscope.Neurons retrograde labeling was performed by 4% fluorogold to calculate the survival number of retinal ganglion cells (RGCs) and the nerve fiber density was detected to assess the degree of RGCs and axon damage in retinal flat mounts,and the β-Ⅲ-tubulin-positive cells in the RGCs layer were examined by immnofluorescence method.The use and care of the animals complied with the instruction of Association for Research in Vision Ophthalmology (ARVO).Results IOP was significantly higher in the mice of the microspheres group than that in the normal control group or PBS group 2 and 4 weeks (all at P<0.05).In the microspheres group,IOP reached peak in 2 weeks after injection and was significantly higher than that of 4 weeks after injection ([29.67±2.34] mmHg versus[15.71±1.23] mmHg) (all at P<0.05).In 2 and 4 weeks after the anterior chamber

  7. Ophthalmohelioses and peripheral light focusing by the anterior eye

    Science.gov (United States)

    Coroneo, Minas T.

    1994-07-01

    A coincidence of the locations of foci of scattered light in the anterior eye with the usual locations of common sun-related eye conditions has been observed. These phenomena may explain the pathogenesis of pterygium and the initial location of certain cortical lens opacities and eyelid malignancies. Human and bovine eyes were used to demonstrate that the anterior eye acts as a side-on lens system. Light incident at the temporal limbus can be concentrated at the nasal limbus or beyond or at the nasal crystalline lens equator. The main pathways of light are transcameral and this is demonstrated by the use of baffles. Although this phenomenon is obvious with visible light, focusing of light at 308nm can be demonstrated. Computer-assisted optical ray tracing in a standard human anterior segment model showed that the peak intensity at the distal limbus is approximately twenty times that of the incident light intensity. The degree of limbal focusing is determined by corneal shape and anterior chamber depth. Such light focusing may be particularly injurious to corneal and lenticular epithelial stem cells. These observations provide circumstantial evidence that peripheral refraction phenomena are involved in the pathogenesis of the anterior ophthalmohelioses. Adequate lateral protection of the eye from increasing ultraviolet insolation may be prudent.

  8. New Management of Malignant Glaucoma by Phacoemulsification with Posterior Chamber Foldable Intraocular Lens Implantation

    Institute of Scientific and Technical Information of China (English)

    GeJian; GuoY

    1999-01-01

    Objective:To investigate the feasibility of phacoemulsification with posterior chamber foldable intraocular lens implantation in the management of malignant glaucoma. Patients and Methods:Fourteen patients with malignant glaucoma diagnosed in the Department of Glaucoma were enrolled in the study.12 patients developed malignant glaucoma after filtration surgery.1 developed after peripheral iridectomy.1 patient developed malignant glaucoma without any clear cause.Cataract phacoemulsification was performed.Posterior chamber intraocular foldable lens was implanted in 10 cases of patients.Results:All 14 patients were cured wiht normal intraocular pressure,normal anterior chamber depth and increased visual acuity.Conclusion:Phacoemulsification with posterior chamber foldable intraocular lens implantation is a good alternative in treating malignant glaucoma.

  9. Quantitative observation on changes of anterior segment by ultrasound biomicroscopy after posterior chamber phakic intraocular lens implantation%UBM量化观察有晶状体眼后房型人工晶状体植入术前后眼前节形态的变化

    Institute of Scientific and Technical Information of China (English)

    王瑞娜; 郑广瑛; 王松田; 王洁; 赵建国; 郭红亮; 赵丽君

    2011-01-01

    ObjectiveThe objective is to study the safety and effectiveness of implantation of posterior chamber phakic intraocular contact lens (ICL) by observing the changes in anterior segment using ultrasound biomicroscopy (UBM). Methods It was a perspective study. The study sampled 30 high myopia patients (30 eyes) who were treated with posterior chamber phakic ICL implant. Central anterior chamber depth (ACD), trabecular-iris angle (TIA), angle opening distance (AOD500), trabecular-ciliary processes distance (TCPD) and iris-ciliary processes distance (ICPD) were measured using UBM preoperatively,3 months and 1 year postoperatively. The distance from ICL to the central surface of lens and peripheral lens and intra-ocular pressure were measured postoperatively and examined using slit-lamp biomicroscope. Oneway ANOVA was used to analyze the distance between peripheral surface of ICL and the lens. One-way repeated measures ANOVA and Bonferroni were conducted. Results Preoperatively, 3 months and 1 year postoperatively, ACD were(3. 16 ± 0. 08 ) mm, ( 2. 76 ± 0. 13 ) mm, (2. 74 ± 0. 14) mm; AOD500 were (0.45 + 0.04) mm, (0.41 ± 0.04) mm, (0.41 ±0.03) mm; TIA were (35.00 ±3. 24)°, (32.47 ±3.56) °, (32. 40 ± 3. 23 ) °, respectively. There were significant difference in TIA, ACD and AOD ( P <0. 05) between preoperative and postoperative data. There was no significant difference between the two postoperative periods tested. TCPD and ICPD showed no significant difference between various time points ( F =0. 49, F =0. 57 ; P > 0. 05 ). Conclusions The decrease in ACD depth and correction in TIA and AOD were the noticeable changes observed in morphological structure of the ocular anterior segment after the ICL treatment. The incidence of complication did not increase as the result of the minor changes in morph structure during the course of the study. However, the long-term effects would require further long-term observation.%目的 应用超声生物显微镜(UBM)对

  10. 有晶状体眼后房型人工晶状体植入术后前房角的变化及其相关因素%The change in anterior chamber angle and related factors in collamer lens implantation

    Institute of Scientific and Technical Information of China (English)

    朱浩斌; 贾琰; 周激波

    2014-01-01

    目的 研究高度近视眼植入有晶状体眼后房型人工晶状体(PPC-ICL)后前房角(ACA)的变化及其相关因素.方法 前瞻性研究.收集2013年3月至2014年4月在上海交通大学医学院附属第九人民医院行PPC-ICL植入手术的中高度近视患者26例(45眼).术后平均随访(4.3±3.2)个月.Pentacam测量术前及术后ACA、前房深度、角膜曲率、PPC-ICL拱高(vault).IOLMaster测量白到白距离和眼轴长度.同时记录术前及术后UCVA、等效球镜度及IOP.采用配对t检验、Wilcoxon符号秩和检验、Pearson相关、Spearman秩相关、多元回归分析进行数据分析.结果 3点方位术后ACA宽度为27.44°-±5.24°,与术前43.23°±5.72°比较,差异有统计学意义(Z=-5.841,P<0.01).3点方位ACA宽度的变化量与PPC-ICL拱高、同方位术前ACA宽度呈正相关(r=0.556、0.530,P<0.01),术后ACA宽度与拱高、术前ACA宽度回归方程为ACA术后=4.860-0.009 vault±0.621 ACA术前(F=20.032,P<0.01).9点方位ACA宽度术后为26.82°±4.73°,与术前42.40°±5.81°比较,差异有统计学意义(t=20.890,P<0.01);9点方位ACA宽度的变化量与PPC-ICL拱高、同方位术前ACA宽度呈正相关(r=0.581、0.626,P<0.01),术后ACA宽度和拱高、术前ACA宽度回归方程为ACA术后=5.767-0.008 vault±0.586 ACA术前(F=24.775,P<0.01).结论 PPC-ICL植入术后水平方向ACA宽度显著变小,变化量和术前ACA宽度、拱高均呈正相关.%Objective To investigate the change in the anterior chamber angle and to analyze its related factors of phakic posterior chamber implantable collamer lens (PPC-ICL) implantation.Methods Twenty-six moderate and high myopic patients (45 eyes) who received PPC-ICL implants from March 2013 to April 2014 were included in this prospective study.The mean follow-up time was 4.3±3.2 months.Anterior chamber angle (ACA),anterior chamber depth (ACD),corneal curvature,and vault were measured with a Pentacam preoperatively and

  11. spark chamber

    CERN Multimedia

    A few cosmic rays pass through your body every second of every day, no matter where you are. Look at the spark chamber to your right – every flash is the track made by a cosmic ray from outer space. The spark chamber is filled with a special gas mixture. Cosmic rays knock electrons out of the atoms in the gas. These electrons accelerate towards high voltage metal strips layered throughout the chamber, creating sparks like little bolts of lightning.

  12. spark chamber

    CERN Multimedia

    A few cosmic rays pass through your body every second of every day, no matter where you are. Look at the spark chamber to your right – every flash is the track made by a cosmic ray from outer space. The spark chamber is filled with a special gas mixture. Cosmic rays knock electrons out of the atoms in the gas. These electrons accelerate towards high voltage metal strips layered throughout the chamber, creating sparks like little bolts of lightning.

  13. Anterior Segment Eye Assessment of Refractive Surgery Candidates in the Southeast of Iran.

    Science.gov (United States)

    Nakhjavanpour, Neda; Payandeh, Abolfazl; Rajabi, Majid; Shoja, Vahid

    2016-01-01

    Anterior segment eye parameters are essential factors in diagnosis, screening and management of abnormal ocular conditions. Based on the previous studies, they might differ from one race or population to another. Sistan-and-Baluchestan province, the southeast of Iran, has special weather conditions and race, plus lack of research on these diagnostic factors. Hence, the objective of the present study was to assess anterior segment parameters using pentacam in this area. 800 eyes of subjects which had been referred to the Al-Zahra eye hospital of Zahedan, the capital city of the province, for corneal refractive surgery from October 2014 to March 2015 participated in this research. 95% confidence limits for mean of central corneal thickness, anterior chamber depth and volume were (536.02, 541.20), (3.13, 3.18) and (187.63, 192.58) respectively. Multiple linear regression models showed a lower mean central corneal thickness, and maximum/minimum of keratometry, for males than females, adjusting for age and spherical equivalent. Inversely, anterior chamber depth, and volume were more in males. In order to diagnosis and treating ocular diseases which have effect on retinal thickness, precisely specification of predictive factors is highly needed. PMID:27357884

  14. The effect of postoperative central vault on the anterior chamber after implantation of implantable contact lens V4c%有晶体眼后房型人工晶体 V4c 植入术后拱高对前房结构的影响

    Institute of Scientific and Technical Information of China (English)

    叶进; 袁长明; 王霁雪; 谢汉平

    2015-01-01

    目的:观察有晶体眼后房型人工晶体 V4c 植入术后拱高对前房结构的影响。方法对重庆普瑞眼科医院2014年11月2日至2015年2月5日开展的56眼有晶体眼后房型人工晶体 V4c 植入术进行回顾性研究。术前用房角镜检查房角并记录前房角色素分级,用 Pentacam 测量平均前房角宽度(ACA )、前房容积(ACV )。术后第1、3、6个月复诊时测量中央拱高和平均ACA 以及 ACV ,并记录前房角色素分级。对患者手术后3次复查的拱高与 ACA 减小的量、ACV 减小的量进行相关性分析。结果术后1个月56眼的拱高为250~765μm ,ACA 减小的量为(13.67±1.67)°,ACV 减小量为(94.23±17.02)mm3。术后第3个月55眼的拱高为239~761μm ,ACA 减小的量为(13.70±1.68)°,ACV 减小量为(93.6±17.48)mm3。术后第6个月51眼拱高为246~761μm ,ACA 减小的量为(13.60±1.69)°,ACV 减小量为(94.29±17.80)mm3。未发现色素为Ⅱ级的病例。将3次复查的中央拱高与 ACA 和 ACV 减小量进行相关性分析,呈正相关(P<0.05)。中央拱高越大,则 ACA 和 ACV 改变量越大。结论有晶体眼后房型人工晶体 V4c 植入术后前房角变窄,前房容积下降。中央拱高与 ACA 和 ACV 改变量呈正相关,合适的拱高对保持房角开放有积极的临床意义。%Objective To observe the effect of postoperative central vault on the anterior chamber after implantation of im-plantable contact lens V4c .Methods To carry out a retrospective study of 56 eyes with implantable contact lens V4c implantation in Chongqing Bright Eye Hospital from November 2 ,2014 to February 5 ,2015 ,examined anterior chamber angle before surgery ,the anterior chamber angular width (ACA) and anterior chamber volume (ACV) were measured by pentacam .the postoperative central vault and ACA and ACV during the first and third and sixth months after surgery

  15. Ussing Chamber

    NARCIS (Netherlands)

    Westerhout, J.; Wortelboer, H.; Verhoeckx, K.

    2015-01-01

    The Ussing chamber system is named after the Danish zoologist Hans Ussing, who invented the device in the 1950s to measure the short-circuit current as an indicator of net ion transport taking place across frog skin (Ussing and Zerahn, Acta Physiol Scand 23:110-127, 1951). Ussing chambers are increa

  16. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  17. Depth dose distribution in the water for clinical applicators of {sup 90}Sr + {sup 90}Y, with a extrapolation mini chamber; Distribuicao de dose em profundidade na agua para aplicadores clinicos de {sup 90}Sr + {sup 90}Y, com uma mini-camara de extrapolacao

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, Patricia de Lara; Caldas, Linda V.E., E-mail: patrilan@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Oliveira, Mercia L., E-mail: mercial@cnen.gov.b [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2009-07-01

    This work determines the depth dose in the water for clinical applicators of {sup 90}Sr + {sup 90}Y, using a extrapolation mini chamber developed at the IPEN, Sao Paulo, Brazil, and different thickness acrylic plates. The obtained results were compared with the international recommendations and were considered satisfactory

  18. wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  19. EFFECTS OF FLUNIXIN MEGLUMINE CONJUNCTIVAL SHOT OVER THE HUMOR AQUEOUS PROTEIN OF DOGS SUBMITTED TO THE PARACENTESIS OF THE ANTERIOR CHAMBER AVALIAÇÃO DOS EFEITOS DA FLUNIXINA MEGLUMINA, POR VIA SUBCONJUNTIVAL, SOBRE A CONCENTRAÇÃO E PADRÃO PROTEICO DO HUMOR AQUOSO DE CÃES SUBMETIDOS À PARACENTESE DA CÂMARA ANTERIOR

    Directory of Open Access Journals (Sweden)

    Paula Diniz Galera

    2009-12-01

    Full Text Available

    Flunixin meglumine effects, over aqueous humor proteins of eyes on dogs who were submitted to paracentesis of the anterior chamber, were evaluated. To ten adult dogs clinically healthy were given a subconjunctival shot with flunixin meglumine (1.1mg/Kg on the right eye and sterilized saline solution 0.9% on the left eye, with the same volume. After general anesthesia, were submitted to two paracentesis of the both eyes to collect 0.2mL of first and second aqueous. The samples were submitted to Bradford test, wich proteins concentrations were  15.98mg/dL ± 4.48 e 11.46mg/dL ± 2.72 for the right and the left eyes, respectively, on the first paracentesis and 119.8mg/dL ± 6.74 e 120.63mg/dL ± 22.4 for the right and the left eyes, on the second paracentesis. There was no significant statistically differences between the protein values of the treated eyes in comparison with the control one. When compared, the proteins concentrations between the first and second paracentesis of the right and left eyes, statistic differences were found between these two moments (p<0.001. SDS-PAGE showed differences in the protein patterns of aqueous humor in result of the paracentesis.

    KEY WORDS: Aqueous humor, eye, flunixin meglumine, paracentesis, proteíns.

    Avaliaram-se os efeitos da flunixina meglumina, pela via subconjuntival, sobre as proteínas do humor aquoso de olhos de cães submetidos à paracentese da câmara anterior. Dez animais adultos, clinicamente sadios, receberam, por aplicação subconjuntival, flunixina meglumina (1,1mg/kg no olho direito e solução salina estéril a 0,9% no olho esquerdo, em igual volume. Mediante anestesia geral, foram submetidos a duas paracenteses de ambos os olhos para coleta de 0,2mL de aquoso primário e secundário, respectivamente. As amostras foram submetidas ao Teste de Bradford, cujas concentrações proteicas (média e desvio-padrão obtidas foram de 15

  20. Analysis of low-energy and high-frequency femtosecond laser for the construction of deep anterior donor corneal lamellae

    Directory of Open Access Journals (Sweden)

    Gustavo Victor

    2014-04-01

    Full Text Available Purpose: To evaluate the efficacy and reliability of a low-energy femtosecond laser with a high repetition rate for construction of deep anterior donor corneal lamellae. Methods: This was a prospective laboratory investigation. Twenty-five human corneal buttons were femtosecond laser cut to create thick anterior lamellae (diameter, 10mm; thickness, 500µm. The laser cuts were made using an LDV® femtosecond laser in a Ziemer® anterior chamber. To obtain a better edge, the lamellae were trephined with an 8mm trephine (Katena®. The central corneal thickness and the anterior lamellae were measured using a Mitutoyo® thickness gauge with an accuracy of 0.001mm. Results: The central thickness of the 25 corneas ranged from 500 to 705µm (mean, 584 ± 51µm. The thickness of the anterior lamellae ranged from 420 to 480µm (mean, 455 ± 12.7µm. The anterior lamellae diameters were 7.90 ± 0.1mm, and all laser cuts were round. The lamellar interfaces appeared regular by surgical microscopy. There were no cases of inter-lamellar adhesion. Conclusion: The LDV® femtosecond laser appears to be a safe and reliable instrument for cutting deep anterior lamellae from donor corneoscleral buttons. Minimal variation in donor lamellar depth with the laser will be useful for creating donor corneal tissue for deeper anterior lamellar keratoplasty or endothelial keratoplasty surgery or both from a single donor cornea.

  1. Vacuum chamber

    International Nuclear Information System (INIS)

    A detailed description is given of the vacuum chamber of the so-called experimental equipment DEMAS (double-arm-time-of-flight spectrometer) at the heavy ion accelerator U-400 at the JINR-Dubna. (author)

  2. Assessment of Anterior Segment Measurements with Swept Source Optical Coherence Tomography before and after Ab Interno Trabeculotomy (Trabectome) Surgery

    Science.gov (United States)

    Huang, Ping

    2016-01-01

    Purpose. To compare the changes of anterior segment parameters, assessed by swept source anterior segment optical coherence tomography (AS-OCT) after combined Trabectome-cataract surgery and Trabectome-only surgery in open angle glaucoma patients. Methods. Thirty-eight eyes of 24 patients with open angle glaucoma were scanned with swept source AS-OCT before and 4 weeks after combined Trabectome-cataract or Trabectome-only surgery. Intraocular pressure, number of medications, and AS-OCT parameters, such as angle opening distance at 500 and 750 μm from the scleral spur (AOD500 and AOD750), trabecular-iris space area at 500 and 750 mm2 (TISA500, TISA750), angle recess area at 500 and 750 mm2 (ARA500, ARA750), trabecular iris angle (TIA), anterior chamber depth (ACD), anterior chamber width (ACW), and anterior chamber volume (ACV), were obtained before the surgery. These parameters were compared to evaluate whether the outcome of the surgery differed among the patients after the surgery. The width of the trabecular cleft was also measured for both groups. Results. The reduction of IOP and number of medications was found to be statistically significant in both groups (p ACV, and angle parameters such as AOD 500/750, TISA 500/750, ARA 500/750, and TIA500 showed significantly greater changes from the preoperative values to postoperative 1st month values in combined Trabectome-cataract surgery group (p 0.05). There was no statistically significant difference between two groups for the width of the trabecular cleft (p = 0.7). Conclusion. Anterior chamber angle parameters measured with swept source AS-OCT may be useful for evaluating glaucoma patients before and after Trabectome surgery with or without cataract surgery. PMID:27795855

  3. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  4. Robert Chambers

    NARCIS (Netherlands)

    K. Biekart (Kees); D.R. Gasper (Des)

    2013-01-01

    textabstractProfessor Robert Chambers is a Research Associate at the Institute of Development Studies (IDS), University of Sussex (Brighton, UK), where he has been based for the last 40 years, including as Professorial Research Fellow. He became involved in the field of development management in the

  5. Pentacam、IOLmaster和A型超声测量仪测量前房深度的比较%Comparison of anterior chamber depths measured using the Pentacam, the IOLMaster, and ultrasound pachymetry

    Institute of Scientific and Technical Information of China (English)

    张静; 张士胜; 于青; 吴江秀; 廉井财

    2015-01-01

      结果:Pentacam,IOLMaster和A型超声测量仪测得ACD值分别为(3.77±0.24)、(3.73±0.23)、(3.69±0.22) mm。Bland-Altman分析显示,3种方法测量ACD的平均值一致性较好(Pentacam vs IOLMaster:CoA 0.04mm,LoA-0.05~0.13mm;A 超 vs IOLMaster:CoA 0.04mm, LoA -0.17~0.08mm;Pentacam vs A 超:CoA 0.08mm, LoA -0.06~0.22mm)。组内标准差及计算重复性系数显示3种方法测量ACD 的重复性好( Sw=0.03、0.02、0.03;2.77 Sw=0.08、0 .06、0 .08)。3种仪器测量ACD值相互正相关( r=0.946,0.987,0.951,P  结论:Pentacam、IOLMaster和A型超声3种方法测量ACD 的可重复性均很好、变异小、高度相关。 Pentacam测得的ACD值稍大于A型超声,但由于3组数据可重复性好,变异系数小,故此差异没有重要的临床意义。

  6. New Management of Angle-closure Glaucoma by Phacoemulsification with Foldable Posterior Chamber Intraocular Lens Implantation

    Institute of Scientific and Technical Information of China (English)

    Jian Ge; Yan Guo; Yizhi Liu; Mingkai Lin; Yehong Zhuo; Bing Chen; Xiuqi Chen

    2000-01-01

    Objective: To investigate the management of angle-closure glaucoma by phacoemulsification with foldable posterior chamber intraocular lens (PC-IOL) implantation. Design: Retrospective, noncontrolled interventional case series.Participants: In 36 eyes with angle-closure glaucoma (ACG), there were 18 eyes with primary acute angle-closure glaucoma (PACG), 14 eyes with primary chronic angle-closure glaucoma (PCCG), 3 eyes with secondary acute angle-closure glaucoma (SACG) and 1 eye with secondary chronic angle-closure glaucoma (SCCG).Intervention: Phacoemulsification with posterior chamber intraocular lens implantation.Main Outcome Measures: Postoperative visual acuity, IOP, axial anterior chamber depth.Results: After a mean postoperative follow-up time of 8.81 ± 7.45 months, intraocular pressure was reduced from a preoperative mean of 23.81 ± 17.84 mmHg to a postoperative mean of 12.54 ± 4. 73 mmHg ( P = 0. 001 ). Mean anterior chamber depth was 1.75 ± 0.48 mm preoperatively and 2.29 ± 0.38 mm postoperatively ( P = 0. 000).Best spectacle-corrected visual acuity in 36 eyes ranged from 0. 01 to 0. 7 (20/200 to 20/30) postoperatively, which was better than preoperative VA ranging from hand movement to 0.4 (20/50) ( P= 0. 000).Conclusion: Phacoemulsification with posterior chamber foldable intraocular lens implantation can be a good alternative in treating angle-closure glaucoma. Eye Science 2000; 16:22 ~ 28.

  7. New Management of Angle-closure Glaucoma by Phacoemulsification with Folable Posterior Chamber Intraocular Lens Implantation

    Institute of Scientific and Technical Information of China (English)

    JianGE; YanGuo; 等

    2002-01-01

    Objective:To investigate the management of angle-closure glaucoma by phacoemulsification with foldable posterior chamber intraocular lens (PC-IOIL)implantation.Design:Retrospective,noncontrolled interventional case series.Participants:In 36 eyes with angle -closure glaucoma(ACG).there were 18eyes with primary acute angle-closure glaucoma(PACG),14 eyes with primary chonic angle -closure glaucoma(PCCG),3 eyes with secondary acute angle-closure glaucoma (SACG) and 1 eye with secondary chronic angle -closure glaucoma(SCCG).Intervention:Phacoemulsification with posterior chamber intraocular lens implantation.Main Outcome Measures:Postoperative visual acuity,IOP,axial anterior chamber depth.Results:After a mean postoperative follow -time of 8.81±7.45 months,intraocular pressure was reduced from a preoperative mean of 23.81±17.84 mmHg to a postoperative mean of 12.54±4.73mmHg(P=0.001).Mean anterior chamber depth was 1.75±0.48 mm preoiperatively and 2.29±0.38mm postoperatively(P-0.000).Best spectacle-corrected visual acuity in 36 eyes ranged from 0.01 to 0.7(20/200 to 20/30)postoperatively,which was better than preoperative VA ranging from hand movement to 0.4(20/50)(P=0.000).Conclusion:Phacoemulsification with posterior chamber foldable intraocular lens implantation can be a good alternative in treating angle-closure glaucoma.Eye Science2000;16:22-28.

  8. Changes in intraocular pressure and anterior segment morphometry after uneventful phacoemulsification cataract surgery.

    LENUS (Irish Health Repository)

    Dooley, I

    2012-02-01

    PURPOSE: To study changes in anterior segment morphometry after uneventful phacoemulsification cataract surgery, and to investigate whether there is a relationship between any observed changes and intraocular pressure (IOP) reduction after the procedure. METHODS: The anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), central corneal thickness (CCT), and IOP were measured in 101 non-glaucomatous eyes before and after uneventful phacoemulsification cataract surgery. RESULTS: After cataract surgery, the mean ACD, ACV, and ACA values increased by 1.08 mm, 54.4 mm(3), and 13.1 degrees , respectively, and the mean IOP (corrected for CCT) decreased by 3.2 mm Hg. The predictive value of a previously described index (preoperative ACD\\/preoperative IOP (corrected for CCT) or CPD ratio) for IOP (corrected for CCT) reduction after cataract surgery was confirmed, reflected in an r(2) value of 23.3% between these two parameters (P<0.001). Other indices predictive of IOP reduction after cataract surgery were also identified, including preoperative IOP\\/preoperative ACV and preoperative IOP\\/preoperative ACA, reflected in r(2) values of 13.7 and 13.7%, respectively (P<0.001 and P<0.001, respectively). CONCLUSIONS: Our study confirms the predictive value of the CPD ratio for IOP reduction after cataract surgery, and may contribute to the decision-making process in patients with glaucoma or ocular hypertension. Furthermore, two novel indices of preoperative parameters that are predictive for IOP reduction after cataract surgery were identified, and enhance our understanding of the mechanisms underlying IOP changes after this procedure.

  9. Uveítes anteriores associadas a doenças sistêmicas Anterior uveitis associated to systemic diseases

    Directory of Open Access Journals (Sweden)

    Maria Angélica Pavão Dimantas

    2003-01-01

    Full Text Available As uveítes anteriores são caracterizadas pela inflamação preponderante do segmento anterior do olho. Hiperemia conjuntival, reação de câmara anterior com células e "flare", precipitados ceráticos e sinéquias posteriores são sinais que compõem o quadro inflamatório. Aspectos clínicos de algumas doenças sistêmicas envolvidas na etiologia das uveítes anteriores serão abordados neste artigo.Anterior uveitis describes a disease predominantly limited to the anterior segment of the eye. Conjunctival hyperemia, anterior chamber cell and flare, keratic precipitates, and iris abnormalities including posterior synechiae characterize the inflammation. This article discusses clinical aspects of the systemic diseases that cause anterior uveitis with review of the literature.

  10. Under-air staining of the anterior capsule using Trypan blue with a 30 G needle

    Science.gov (United States)

    Giammaria, Daniele; Giannotti, Michele; Scopelliti, Angelo; Pellegrini, Giacomo; Giannotti, Bruno

    2013-01-01

    The original technique of staining the anterior capsule of the lens with Trypan blue involves the injection of an air bubble in the anterior chamber. A drawback of this technique is the possible instability of the anterior chamber caused by the sudden exit of air when the dye is injected with the cannula through the side-port incision. Other staining techniques that use viscoelastic substances to increase the stability of the anterior chamber and to dose the injected dye have been described. The authors present an under-air staining technique of the anterior capsule using one drop of Trypan blue injected with a 30 G needle through the peripheral cornea. This procedure prevents the air bubble from escaping the anterior chamber and allows fast and selective staining of the capsule. PMID:23386783

  11. Treatment for sudden attack of secondary glaucoma due to intumescent cataract by anterior chamber penetration using acupuncture knife%前房穿刺术治疗白内障膨胀期继发青光眼的临床分析

    Institute of Scientific and Technical Information of China (English)

    荆毓陶

    2013-01-01

    目的:探讨前房穿刺放液处理膨胀期白内障继发急性闭角型青光眼的急性发作的疗效及时机。方法:对30例30眼老年性白内障膨胀期引起的继发性急性闭角型青光眼患者的急性期,(术前眼压均在50mmHg以上,1kpa=7.5mmHg)在联合应用常规降眼压药物治疗未能有效降低眼压后,急诊采用15°穿刺刀在8倍放大倍率的手术显微镜下进行前房穿刺,轻压切口后唇缓慢放出房水。结果:所有患者经前房穿刺放液后高眼压及眼痛迅速缓解,其中25例眼压降至正常,术后眼压平均16mmHg,仅5例眼压偏高,维持在35mmHg左右,但视力提高不显著,其中3眼穿刺后5-8小时眼压再次升高遂再次放液。结论:15°穿刺刀在手术显微镜下前房穿刺放液比传统的注射针头穿刺放液损伤小反应轻,是治疗膨胀期白内障继发急性闭角型青光眼的急性发作辅助措施,可以缩短降眼压的时间以减轻患者痛苦,减轻因高眼压造成的视功能损害,避免了长时间大量应用常规降眼压药物可能引起的副作用,为白内障的进一步治疗创造了条件。%Objective To evaluate the clinical effects and opportunity of anterioi chamber penetration using acupuncture knife on treating the sudden attack of secondary glaucoma due to intumescent cataract. Methods anterior chamber penetration using 15° acupuncture knife was performed on thirty patients with the sudden attack of secondary glaucoma due to intumescent cataract. after topical anaestetic. Results The mean intralocular pressure was over 50mmHg(1Kp=7.5mmHg) before the penetration and reduced to16mmHg as soon as the penetration was finished. In 5 of the 30 cases , the mean postoperative intraocular pressure was 35mmHg.In 3 of the 30 case s, the postoperative intraocular pressure rised and performed anterior chamber penetration again.None of the patients fel painful during the opration and no

  12. Changes of anterior segment after early implantation of posterior chamber phakic intraocular lens for correction of high myopia%ICL植入术治疗高度近视术后早期眼前节形态的变化

    Institute of Scientific and Technical Information of China (English)

    黎冬平; 刘磊; 李新宇; 栗静; 王虎杰; 杨硕

    2014-01-01

    目的:我们应用眼前节全景分析仪( Pentacam)测量有晶状体眼后房型人工晶状体( ICL )植入术手术前后前节形态指标,评价有晶状体眼后房型人工晶状体植入术的安全性及稳定性。  方法:选取行有晶状体眼后房型人工晶状体植入术治疗的高度近视患者48例90眼,术后随访6mo。 Pentacam眼前节全景分析仪测量各时间点的中央前房深度( ACD)、3∶00位前房角( ICA)、角膜像差( CA)、角膜曲率( K)和角膜厚度(CCT)等指标。使用SPSS 19.0统计软件,描述术前术后各指标的分布特征,采用配对t检验对各指标进行手术前后的差异性比较。  结果:所有观察指标各时间点均呈正态分布。 ACD、3∶00位ICA较术前降低( P<0.05)。 CA中,总像差( CTA )及低阶像差( CLOA)较术前无统计差异( P>0.05),高阶像差(CHOA)则较术前有所增加(P<0.05);K略有减小(P<0.05)。 CCT较术前比较均无统计学差异( P>0.05)。对于术后有统计学意义变化的指标,均在术后1 mo时即达到稳定状态。  结论:应用眼前节全景分析仪( Pentacam )观察有晶状体眼后房型人工晶状体植入术眼前节形态的变化主要有ICA变窄, ACD变小, CHOA增加, K减小,尚在安全范围内,6 mo随访中各值均保持稳定,未出现并发症,但远期效果需进一步随访观察。%AIM:To evaluate safety and stability of ICL implantation treatment of high myopia through the observation of anterior segment parameters such as ACD and ICA over time pre-and post-operation changes by Pentacam. METHODS:According to the proposed inclusion criteria, 90 eyes (48 patients) with high myopia who accepted ICL implantation treatment were selected.The mean follow-ups are 6 months.Anterior segment parameters such as ACD, ICA ( 3'clock ) , corneal aberration ( CA ) , K-value and CCT were

  13. Coloboma típico associado à síndrome de clivagem de câmara anterior e microcórnea: descrição de um caso Typical coloboma associated with anterior chamber cleavage syndrome, and microcornea: description of one case

    OpenAIRE

    Ana Regina Cruz Vlainich; Norma Allemann; Isaac Neustein

    2004-01-01

    Os autores descrevem associação rara bilateral de coloboma da íris, coróide, retina e cabeça do nervo óptico, microcórnea e deficiência de clivagem de câmara anterior. Fazem também uma abordagem quanto à embriologia e à dificuldade de identificar se a causa da queda contínua e insidiosa da visão é devida ao próprio coloboma ou a outra doença associada, como o glaucoma. Os exames subsidiários disponíveis como campo visual, fundoscopia e tonometria, são de pouca confiabilidade devido ao nistagm...

  14. The application of binocular indirect ophthalmomicroscope combined with anterior chamber maintainer in vitrectomy for complicated vitreoretinopathy%非接触双目间接眼底显微镜联合前房灌注在复杂玻璃体视网膜病变术中的应用

    Institute of Scientific and Technical Information of China (English)

    王永梅; 王莹; 楚艳华; 韩泉洪

    2012-01-01

    目的 观察使用非接触双目间接眼底显微镜(BIOM)联合前房灌注系统(ACM)行玻璃体切割术处理复杂玻璃体视网膜病变的临床疗效.方法 6例(6只眼)复杂玻璃体视网膜病变行玻璃体切割术时,为了避免医源性的脉络膜视网膜损伤,采用前房灌注来维持眼压,晶状体摘除及前部玻璃体切割后,切换至BIOM行玻璃体视网膜手术.临床随访3~11月,评估手术疗效及并发症.结果 6例BIOM联合ACM的玻璃体切割术在操作中未见明显困难.术后5例视力提高,1例无变化.主要长期并发症为低眼压、前部PVR、视网膜前膜.4例行硅油取出术后,视网膜在位. 结论 采用BIOM联合ACM行玻璃体切割术治疗复杂玻璃体视网膜病变安全、有效,在实践中具有可行性.%Objective To evaluate the clinical results of vitrectomy by using binocular indirect ophthalmomicroscope (BIOM) combined with anterior chamber maintainer (ACM) for complicated vitreoretinopathy.Methods Six cases (6 eyes) of complicated vitreoretinopathy were undergone vitrectomy,during which ACM was used to maintain intraocular pressure and prevent from iatrogenic injury of choroid and retina.After lens and anterior vitreous removal,vitrectomy was completed through a BIOM observation system.The follow-up time ranged from 3 months to 11 months.The effects and complications were analyzed.Results No obvious drawback was noticed during the 6 cases vitrectomy by using BIOM and ACM combination.The visual acuities improved in 5 cases and remained stable in 1 case after operation.The major long-term complications were hypotony,epiretinal membrane,and anterior proliferative vitreoretinopathy.Retinal reattached in 4 cases after silicone oil removal.Conclusions The vitrectomy combined BIOM with ACM is effective and safe for complicated vitreoretinopathy,and clinical results ascertained the practical feasibility of it.

  15. Under-air staining of the anterior capsule using Trypan blue with a 30 G needle

    OpenAIRE

    Giammaria D; Giannotti M; Scopelliti A; Pellegrini G; Giannotti B

    2013-01-01

    Daniele Giammaria,1 Michele Giannotti,2 Angelo Scopelliti,1 Giacomo Pellegrini,1 Bruno Giannotti11Azienda Ospedaliera Ospedali Riuniti Marche Nord, Fano, Italy; 2Catholic University of Rome, Rome, ItalyAbstract: The original technique of staining the anterior capsule of the lens with Trypan blue involves the injection of an air bubble in the anterior chamber. A drawback of this technique is the possible instability of the anterior chamber caused by the sudden exit of air when the dye is injec...

  16. Anterior dislocation of an empty capsular bag in a pseudophakic eye: A rare case report

    Directory of Open Access Journals (Sweden)

    Hyung Bin Hwang

    2015-01-01

    Full Text Available Spontaneous intraocular lens (IOL dislocation is uncommon in the absence of any ocular areas with zonular weakness or trauma. There have been no reports of spontaneous capsular bag dislocation into the anterior chamber without an IOL. We report a rare, interesting case of spontaneous capsular bag anterior dislocation, without an IOL, into the anterior chamber with no history of genetic disease, ocular trauma, or pseudoexfoliation that might predispose to a zonular abnormality.

  17. Directed Energy Anechoic Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

  18. 孔源性视网膜脱离视网膜下液和前房液中VEGF及PDGF含量测定%Assays on VEGF and PDGF levels in the subretinal fluid and anterior chamber fluid of rhegmatogenous retinal detachment

    Institute of Scientific and Technical Information of China (English)

    王玲; 朱晓华; 张永红

    2006-01-01

    目的研究血管内皮生长因子(vascular endothelial growth factor,VEGF)和血小板源性生长因子(platelet-derived growth factor,PDGF)在视网膜下液(subretinal fluid,SRF)和前房液(anterior chamber fluid,ACF)中的含量,并观察其对增生性玻璃体视网膜病变(proliferative vitreo-retinopathy,PVR)形成的影响.方法用ELISA测定63例孔源性视网膜脱离患者SRF和ACF的VEGF和PDGF的含量.结果孔源性视网膜脱离患者SRF和ACF中含有VEGF和PDGF;其含量随患者眼部病情的加重而增加;VEGF和PDGF含量在SRF中成相关关系,在ACF中亦成相关关系;同一患者的VEGF在SRF和ACF中成相关关系,PDGF亦是.结论 VEGF和PDGF在PVR的发生发展过程中起了一定的作用,且VEGF和PDGF具有协同效应.

  19. Anterior iris-claw lens implantation with single paracentesis

    Directory of Open Access Journals (Sweden)

    Ahmet Özer

    2011-11-01

    Full Text Available In this study, the technique and results of iris-claw intraocular lens (IOL implantation with corneal incision and single paracentesis were presented. Eighteen eyes of 18 patients who underwent iris-claw implantation surgery with a single paracentesis were included in this prospective study. Iris-claw lens was grasped by its forceps and placed into the anterior chamber through superior corneal opening. While IOL was held by forceps, a blunt enclavation spatula was introduced through inferior paracentesis. Then the spatula was directed toward underneath of iris through pupil and toward sides where iris was entrapped into the claw by gentle push of iris through the slotted center of the lens haptics. Mean age of patients was 54.28±25.21 years (7-76 years. Mean anterior chamber depth was 4.07±0.32 mm and mean keratometric power was 43.01±2.73 D. Preoperative BCVA was 20/63 or better in 8 (44.4% patients. At the first postoperative month BCVA was 20/63 or better in 14 (77.8% patients. Preoperative mean spherical refraction was +11.05±2.62 D, preoperative astigmatism was 2.15±0.85. Postoperative mean spherical refraction was - 0.58±0.25 D and mean astigmatism was - 1.92±0.67 D. The most frequent postoperative complication was mild corneal edema seen in three patients that resolved completely during the first week with medical treatment. Irisclaw IOL implantation can be performed easily with corneal incision and single paracentesis. Single paracentesis does not increase surgical time or cause inconvenience during the procedure.

  20. Anterior Eye Imaging with Optical Coherence Tomography

    Science.gov (United States)

    Huang, David; Li, Yan; Tang, Maolong

    The development of corneal and anterior segment optical coherence tomography (OCT) technology has advanced rapidly in recently years. The scan geometry and imaging wavelength are both important choices to make in designing anterior segment OCT systems. Rectangular scan geometry offers the least image distortion and is now used in most anterior OCT systems. The wavelength of OCT light source affects resolution and penetration. An optimal choice of the OCT imaging wavelength (840, 1,050, or 1,310 nm) depends on the application of interest. Newer generation Fourier-domain OCT technology can provide scan speed 100-1000 times faster than the time-domain technology. Various commercial anterior OCT systems are available on the market. A wide spectrum of diagnostic and surgical applications using anterior segment OCT had been investigated, including mapping of corneal and epithelial thicknesses, keratoconus screening, measuring corneal refractive power, corneal surgery planning and evaluation in LASIK, intracorneal ring implantation, assessment of angle closure glaucoma, anterior chamber biometry and intraocular lens implants, intraocular lens power calculation, and eye bank donor cornea screening.

  1. Anterior segment dysgenesis in mosaic Turner syndrome

    OpenAIRE

    Lloyd, I; Haigh, P; Clayton-Smith, J.; Clayton, P.; Price, D.; Ridgway, A; Donnai, D

    1997-01-01

    AIMS/BACKGROUND—Females with Turner syndrome commonly exhibit ophthalmological abnormalities, although there is little information in the literature documenting findings specific to Turner syndrome mosaics. Ophthalmic findings are described in four patients with mosaic Turner syndrome. All had anterior chamber abnormalities and all four had karyotypic abnormalities with a 45, X cell line. The possible relation between the karyotypic and the phenotypic findings in these patients is discussed.
...

  2. Ciliary block (malignant) glaucoma after cataract extraction with lens implant treated with YAG laser capsulotomy and anterior hyaloidotomy.

    OpenAIRE

    Halkias, A; Magauran, D M; Joyce, M

    1992-01-01

    An 84-year-old woman developed high intraocular pressure with a shallow anterior chamber 2 months after an extracapsular cataract extraction with posterior chamber lens implant. The condition did not respond to peripheral iridectomy and removal of the implant but was treated successfully with YAG laser capsulotomy and anterior hyaloidotomy.

  3. 前房穿刺术联合激光周边虹膜切除术治疗急性原发性闭角型青光眼%Clinical effect of anterior chamber paracentesis combined with laser peripheral iridotomy on acute primary angle-closure glaucoma

    Institute of Scientific and Technical Information of China (English)

    李松峰; 常海敏

    2013-01-01

    目的 评价前房穿刺术联合激光周边虹膜切除术(laser peripheral iridotomy,LPI)治疗急性原发性闭角型青光眼(primary angle-closure glaucoma,PACG)的效果.方法 回顾性分析北京同仁医院2007年11月至2009年5月就诊的急性PACG患者16例(16眼),就诊时眼压≥50 mmHg(1 kPa =7.5 mmHg),均及时行前房穿刺术,并于术后12h内行LPI.用压平眼压计测量并记录前房穿刺术前、术后30 min、2h,LPI术前、术后24 h、7d、1个月、6个月和1 a的眼压,同时记录患者术后角膜水肿及瞳孔情况.结果 16例PACG患者随诊1 a,前房穿刺术后眼压由术前(63.13±7.94) mmHg降至术后30 min(15.47±7.67)mmHg,LPI术前眼压为(15.56±6.93) mmHg,LPI术后24 h眼压为(18.81±7.24) mmHg,其中14例患者术后1 a眼压为(12.79±1.72) mmHg,另2例患者因高眼压控制不良再行小梁切除术.LPI术后患者角膜水肿明显减轻,LPI术前瞳孔明显缩小,为(1.94±1.09)mm,有利于LPI的进行.结论 作为一种可行治疗方法,前房穿刺术联合LPI可安全有效地降低急性PACG患者眼压.%Objective To evaluate the clinical effects of anterior chamber paracentesis combined with laser peripheral iridotomy(LPI) on acute primary angle-closure glaucoma(PACG).Methods A total of 16 cases (16 eyes) with acute PACG and intraocular pressure(IOP) ≥50 mmHg(1 kPa =7.5 mmHg) in Beijing Tongren Hospital from November,2007 to May,2009 were retrospectively analyzed.They were all treated by anterior chamber paracentesis immediately and then LPI was performed on them within 12 hours after operation.The IOP was measured by applanation tonometry before paracentesis and 30 minutes and 2 hours after paracentesis,and before LPI and 24 hours,7 days,1 month,0.5 year,1 year after LPI.Results All patiens were followed up for 1 year.The IOP reduced from (63.13 ± 7.94) mmHg before paracentesis to (15.47 ± 7.67) mmHg 30 minutes after paracentesis,and then to (15.56 ± 6.93) mmHg before LPI and(18.81

  4. 眼外导光照明视网膜光凝联合前房注气在白内障玻璃体视网膜术中应用%Microscopically eye light illumination, retinal laser photocoagulation combined with gas anterior chamber tamponade in cataract joint vitreoretinal surgery

    Institute of Scientific and Technical Information of China (English)

    刘鹏飞

    2016-01-01

    目的 探讨显微镜下眼外导光照明、视网膜激光光凝联合前房注气在白内障联合玻璃体视网膜手术中的疗效及可行性.方法 回顾性分析2010年1月至2014年7月在唐山市眼科医院就治的47例(47只眼)合并晶状体后囊破裂的眼内异物患者实施白内障联合玻璃体视网膜手术.其中周边视网膜格子样变性39只眼,视网膜裂孔者7只眼,玻璃体积血30只眼,视网膜脱离7只眼,锯齿缘解离2只眼.实施白内障摘除、玻璃体切除、视网膜光凝、人工晶状体植入、眼内注气术,术中显微镜下眼外导光照明、视网膜激光光凝联合前房注气.术后观察视力、人工晶状体、视网膜情况及并发症.术后随访6~11个月,平均(6.14±2.15)月.结果 47例患者中,42只眼充填C3F8,5只眼充填硅油.44只眼视力不同程度改善.41只眼人工晶状体正位,1只眼人工晶状体略偏斜.3只眼发生孔源性视网膜脱离.8只眼继发性青光眼,药物治疗1周至2周眼压恢复正常.2只眼角膜内皮面增生膜生长.结论 显微镜下眼外导光照明、视网膜激光光凝联合前房注气在白内障联合玻璃体视网膜手术中操作方便,安全可靠,减少了手术并发症发生,有很好的实用价值.此术式是白内障玻璃体视网膜联合手术的有力补充.%Objective To study the clinical efficacy and feasibility associated with microscopically eye light illumination,retinal laser photocoagulation combined with gas anterior chamber tamponade in the cataract joint vitreoretinal surgery.Methods It was a retrospective analysis of 47 cases (47 eyes) with intraocular foreign bodies and lens capsule rupture was performed cataract joint vitreoretinal surgery.Among 47 cases,peripheral lattice retinal degeneration in 39 eyes,peripheral retinal tear in 7 eyes,vitreous hemorrhage in 30 eyes,retinal detachment in 7 eyes,retinal serrated edge disintegrate in 2 eyes.The patients were performed cataract

  5. Changes in anterior chamber flare and cells following cataract surgery.

    OpenAIRE

    Shah, S. M.; Spalton, D. J.

    1994-01-01

    The laser flare cell meter allows rapid non-invasive quantification of aqueous flare and cells. In this prospective study laser photometry was used to document the recovery of the blood-aqueous barrier in 27 normal eyes following cataract surgery. Aqueous flare and cells were highest on the first postoperative day, declining rapidly in the first week and returning to preoperative levels by 3 months. In six eyes (22.2%) there was an increase in either flare and cells or flare alone during the ...

  6. A tomografia de córnea e segmento anterior na propedêutica do exame complementar na avaliação de ectasia Simplifying ectasia screening with corneal and anterior segment tomography

    Directory of Open Access Journals (Sweden)

    Bruno de Freitas Valbon

    2013-02-01

    Full Text Available Descrevemos a importância da tomografia de córnea e segmento anterior na propedêutica do exame complementar na avaliação de ectasia. Esta descrição da interpretação clínica dos índices da tomografia de córnea e segmento anterior (Pentacam - Oculus, Wetzlar, Germany neste relato de caso, demonstra a relevância de uma nova tecnologia na avaliação da córnea e segmento anterior na suspeita de ceratocone. O diagnóstico de ceratocone foi excluído pela análise dos índices tomográficos de ectasia. Detectou-se assimetria entre os lados nasal e temporal por meio da avaliação do mapa de profundidade de câmara anterior. No exame biomicroscópico sob midríase foi constatado subluxação do cristalino, sendo assim devemos estar atentos não somente aos índices tomográficos corneanos na avaliação do exame complementar e sim analisarmos outros dados importantes oferecidos pela tomografia de córnea e segmento anterior.The methodology currently used for interpretation of the cornea and anterior segment tomography for the diagnosis of corneal ectasia. Description of the clinical interpretation of anterior segment tomography (Pentacam - Oculus, Wetzlar, Germany; case report of the ectopia lentis demonstrating the importance o evaluation of the cornea and anterior segment of the keratoconus. We excluded the disease, analyzing the tomographic analysis of rates of ectasia and observe an asymmetry between nasal and temporal sides in assessing the depth map of the anterior chamber. On the biomicroscopic examination in mydriasis, was found a ectopia lentis. We must be mindful not only to corneal tomography indices to evaluate a diagnostic test, but look at other important information provided by anterior segment tomography.

  7. Two chamber reaction furnace

    Science.gov (United States)

    Blaugher, Richard D.

    1998-05-05

    A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800.degree. to 950.degree. C. to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product.

  8. 应用锥形束CT探究上颌前牙区颌骨微种植支抗钉植入的安全区%Quantitative study of maxillary anterior bone depth and labial cortical bone thickness for micro- implant anchorage placement using cone beam CT

    Institute of Scientific and Technical Information of China (English)

    赵岩; 吴平

    2012-01-01

    目的:对上颌前牙区颌骨的骨量及唇侧骨皮质厚度进行测量分析,为正畸治疗植入微种植支抗钉的安全区提供参考.方法:对25例成人患者上颌前牙区行锥形束CT扫描及三维重建,测量距上颌牙槽嵴顶3、6、9、12mm水平上颌中切牙、侧切牙、尖牙根间区近远中向、唇腭向的距离以及唇侧骨皮质厚度.结果:在距上颌牙槽嵴顶3、6、9mm水平中切牙根间近远中向距离均最宽,唇侧骨皮质均最薄;在距牙槽嵴顶9mm水平中切牙与侧切牙根间近远中向距离最窄;在4个测量水平侧切牙与尖牙根间唇侧骨皮质均最厚;唇腭向在距牙槽嵴顶9mm及以上水平,中切牙根间骨厚度最薄,中切牙与侧切牙根间骨厚度最厚.25例中仅3例前牙区各牙根长度超过12mm,在距牙槽嵴顶12mm水平测出的根间近远中向距离均较宽.结论:通过对扫描后颌骨影像的分析,明确了前牙区颌骨的骨量及唇侧骨皮质厚度,为植入微种植支抗钉的安全区提供参考.%Objective: To investigate the bone depth and labial cortical bone thickness of maxillary anterior interdental area for orthodontic micro-implant anchorage. Methods; Maxillary anterior alveolar bone of 25 adults was scanned and reconstructed by cone beam CT, the mesio-distal interdental distance, labial-palatal bone depth and labial cortical bone thickness were measured at 3, 6, 9 and 12 mm from the alveolar crest between upper anterior dental roots. Results; The mesio-distal distance between central incisors was the widest in all measurement levels, while the labial cortical bone thickness was the thinnest. At the 9 mm-level, the shortest mesio-distal distance was between the roots of central and lateral incisors. The labial cortical bone thickness between lateral incisors and canines was the thickest in all measurement levels. At or above the 9 mm-level, the labial-palatal bone depth was the thinnest between central incisors, but the thickest

  9. CONGENITAL ANTERIOR TIBIOFEMURAL SUBLUXATION

    Directory of Open Access Journals (Sweden)

    A. Shahla

    2008-06-01

    Full Text Available Congenital anterior tibiofemoral subluxation is an extremely rare disorder. All reported cases accompanied by other abnormalities and syndromes. A 16-year-old high school girl referred to us with bilateral anterior tibiofemoral subluxation as the knees were extended and reduced at more than 30 degrees flexion. Deformities were due to tightness of the iliotibial band and biceps femuris muscles and corrected by surgical release. Associated disorders included bilateral anterior shoulders dislocation, short metacarpals and metatarsals, and right calcaneuvalgus deformity.

  10. Bilateral anterior shoulder dislocation

    OpenAIRE

    Meena, Sanjay; Saini, Pramod; Singh, Vivek; Kumar, Ramakant; Trikha, Vivek

    2013-01-01

    Shoulder dislocations are the most common major joint dislocations encountered in the emergency departments. Bilateral shoulder dislocations are rare and of these, bilateral posterior shoulder dislocations are more prevalent than bilateral anterior shoulder dislocations. Bilateral anterior shoulder dislocation is very rare. We present a case of 24-year-old male who sustained bilateral anterior shoulder dislocation following minor trauma, with associated greater tuberosity fracture on one side...

  11. Mush Column Magma Chambers

    Science.gov (United States)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  12. Evaluation of the Changes in Anterior Segment Morphology After Laser Peripheral Iridotomy Through One-Year Follow-Up

    Directory of Open Access Journals (Sweden)

    Ulviye Yiğit

    2014-01-01

    Full Text Available Objectives: To evaluate the long-term changes in anterior segment morphology after laser peripheral iridotomy (LPI in eyes with primary angle-closure suspect (PACS, primary angle closure (PAC, and primary angle-closure glaucoma (PACG using Scheimpflug camera (SC. Materials and Methods: Fifty-six eyes of 30 patients diagnosed as PACS, PAC, and PACG were included prospectively in this study. In addition to full ophthalmic examination and intraocular pressure (IOP assessment, anterior-posterior length (AxL values of the eyes were recorded. With use of SC, average anterior chamber angle (AACA, central anterior chamber depth (CACD, and anterior chamber volume (ACV were documented preoperatively and at 1 month, 3 months, 6 months, and 12 months after LPI. The results have been evaluated statistically. Results: There was no statistically significant difference between the groups in terms of mean age, gender, and AxL (p>0.05. AACA, CACD, and ACV measurements showed significant difference between baseline and months 1.3, 6, and 12 in all groups (p<0.05. AACA was statistically significantly decreased between months 6 and 12 in PACS group; between months 1 and 12, months 3 and 12, months 6 and 12 in PAC and PACG groups (p<0.05. CACD measurements demonstrated statistically significant decrease between months 6 and 12 in PAC group, between months 3 and 6, months 3 and 12 in PACG group (p<0.05. ACV was statistically significantly decreased between months 6 and 12 in PAC group, between months 1 and 12, months 3 and 12 in PACG group (p<0.05. Conclusion: LPI led to dramatic changes in anterior segment morphology. In our study, the course of the changes caused by LPI was observed through one-year follow-up with SC. In the early period, a positive effect on all parameters was detected. The trends in the course of measurements should be followed up for longer time in larger series to investigate whether the changes show continuity or not. (Turk J Ophthalmol 2014

  13. Fibrinous anterior uveitis following laser in situ keratomileusis

    Directory of Open Access Journals (Sweden)

    Parmar Pragya

    2009-01-01

    Full Text Available A 29-year-old woman who underwent laser in situ keratomileusis (LASIK for myopic astigmatism in both eyes presented with severe pain, photophobia and decreased visual acuity in the left eye eight days after surgery. Examination revealed severe anterior uveitis with fibrinous exudates in the anterior chamber, flap edema and epithelial bullae. Laboratory investigations for uveitis were negative and the patient required systemic and intensive topical steroids with cycloplegics to control the inflammation. This case demonstrates that severe anterior uveitis may develop after LASIK and needs prompt and vigorous management for resolution.

  14. The Bern Infinitesimal Bubble Chamber (BIBC)

    CERN Multimedia

    1977-01-01

    The chamber body was machined from a block of aluminium. The visible volume was cylindrical with 65 mm diameter and 35 mm depth. It was filled with propane or freon. It was meant as vertex detector in the search of short-lived particles. It was also used with in-line holography resulting in 8 µm bubble size and 9 cm depth of the field. See E. Ramseyer, B. Hahn and E. Hugentobler, Nucl. Instrum. Methods 201 (1982) 335.

  15. Evaluation of Anterior Segment Parameter Changes Using the Sirius after Uneventful Phacoemulsification

    Science.gov (United States)

    Şimşek, Ali; Çapkın, Musa; Bilak, Şemsettin; Güler, Mete; Reyhan, Ali Hakim

    2016-01-01

    Purpose To investigate changes in anterior chamber depth (ACD), corneal volume (CV), anterior chamber angle (ACA), anterior chamber volume (ACV), central corneal thickness (CCT), horizontal visible iris diameter (HVID), pupil diameter (PD), and intraocular pressure (IOP) after uneventful phacoemulsification cataract surgery with intraocular lens implantation. Methods A total of 132 eyes of 132 patients (87 men and 45 women) that underwent uneventful phacoemulsification cataract surgery and intraocular lens implantation were prospectively studied. The mean age of the patients was 63.68 ± 12.51 years. All patients were evaluated preoperatively and at 1 month postoperatively with the Sirius 3D Rotating Scheimpflug camera topography system. The ACD, CV, ACA, ACV, CCT, HVID, and PD measurements were recorded. IOP was measured using the Goldmann applanation tonometer, which was corrected for CCT of the Sirius device using Ehlers' formula. Results The preoperative mean ACD, ACV, ACA, CCT, CV, PD, HVID, and IOP were 2.79 ± 0.45 mm, 124.73 ± 25.72 mm3, 42.09 ± 7.490, 523.87 ± 41.97 microns, 55.37 ± 4.89 mm3, 3.98 ± 1.23 mm, 11.72 ± 0.67 mm, and 14.74 ± 2.59 mmHg, respectively. Three months postoperatively, the mean ACD, ACV, ACA, CCT, CV, PD, HVID, and IOP were 3.45 ± 0.6 mm, 162.52 ± 23.79 mm3, 51.46 ± 5.630, 526.21 ± 44.45 microns, 56.23 ± 5.12 mm3, 2.87 ± 0.45 mm, 11.91 ± 0.75 mm, and 12.02 ± 1.83 mmHg, respectively. There was a statistically significant increase in mean postoperative ACD, ACV, ACA, CV, and HVID compared with the corresponding preoperative values (p 3D Rotating Scheimpflug camera topography system might help surgeons to predict postoperative changes resulting from phacoemulsification and intraocular lens implantation. This is a noncontact, noninvasive, and comfortable system for patients that is highly reliable and repeatable for anterior segment measurements. PMID:27478351

  16. Evaluation of Anterior Segment Parameter Changes Using the Sirius after Uneventful Phacoemulsification

    Science.gov (United States)

    Şimşek, Ali; Çapkın, Musa; Bilak, Şemsettin; Güler, Mete; Reyhan, Ali Hakim

    2016-01-01

    Purpose To investigate changes in anterior chamber depth (ACD), corneal volume (CV), anterior chamber angle (ACA), anterior chamber volume (ACV), central corneal thickness (CCT), horizontal visible iris diameter (HVID), pupil diameter (PD), and intraocular pressure (IOP) after uneventful phacoemulsification cataract surgery with intraocular lens implantation. Methods A total of 132 eyes of 132 patients (87 men and 45 women) that underwent uneventful phacoemulsification cataract surgery and intraocular lens implantation were prospectively studied. The mean age of the patients was 63.68 ± 12.51 years. All patients were evaluated preoperatively and at 1 month postoperatively with the Sirius 3D Rotating Scheimpflug camera topography system. The ACD, CV, ACA, ACV, CCT, HVID, and PD measurements were recorded. IOP was measured using the Goldmann applanation tonometer, which was corrected for CCT of the Sirius device using Ehlers' formula. Results The preoperative mean ACD, ACV, ACA, CCT, CV, PD, HVID, and IOP were 2.79 ± 0.45 mm, 124.73 ± 25.72 mm3, 42.09 ± 7.490, 523.87 ± 41.97 microns, 55.37 ± 4.89 mm3, 3.98 ± 1.23 mm, 11.72 ± 0.67 mm, and 14.74 ± 2.59 mmHg, respectively. Three months postoperatively, the mean ACD, ACV, ACA, CCT, CV, PD, HVID, and IOP were 3.45 ± 0.6 mm, 162.52 ± 23.79 mm3, 51.46 ± 5.630, 526.21 ± 44.45 microns, 56.23 ± 5.12 mm3, 2.87 ± 0.45 mm, 11.91 ± 0.75 mm, and 12.02 ± 1.83 mmHg, respectively. There was a statistically significant increase in mean postoperative ACD, ACV, ACA, CV, and HVID compared with the corresponding preoperative values (p < 0.05). CCT remained stable after surgery. Postoperative PD and IOP were significantly decreased compared to corresponding preoperative values (p < 0.05). Conclusions Preoperative measurements by the Sirius 3D Rotating Scheimpflug camera topography system might help surgeons to predict postoperative changes resulting from phacoemulsification and intraocular lens implantation. This is a

  17. Prototype multiwire proportional chamber

    CERN Multimedia

    1975-01-01

    Chambers of this type were initially developed within the Alpha project (finally not approved). They were designed such to minimize the radiation length with a view to a mass spectrometer of high resolution meant to replace the Omega detector. The chambers were clearly forerunners for the (drift) chambers later built for R606 with the novel technique of crimping the wires. See also photo 7510039X.

  18. A model to forecast magma chamber rupture

    Science.gov (United States)

    Browning, John; Drymoni, Kyriaki; Gudmundsson, Agust

    2016-04-01

    An understanding of the amount of magma available to supply any given eruption is useful for determining the potential eruption magnitude and duration. Geodetic measurements and inversion techniques are often used to constrain volume changes within magma chambers, as well as constrain location and depth, but such models are incapable of calculating total magma storage. For example, during the 2012 unrest period at Santorini volcano, approximately 0.021 km3 of new magma entered a shallow chamber residing at around 4 km below the surface. This type of event is not unusual, and is in fact a necessary condition for the formation of a long-lived shallow chamber. The period of unrest ended without culminating in eruption, i.e the amount of magma which entered the chamber was insufficient to break the chamber and force magma further towards the surface. Using continuum-mechanics and fracture-mechanics principles, we present a model to calculate the amount of magma contained at shallow depth beneath active volcanoes. Here we discuss our model in the context of Santorini volcano, Greece. We demonstrate through structural analysis of dykes exposed within the Santorini caldera, previously published data on the volume of recent eruptions, and geodetic measurements of the 2011-2012 unrest period, that the measured 0.02% increase in volume of Santorini's shallow magma chamber was associated with magmatic excess pressure increase of around 1.1 MPa. This excess pressure was high enough to bring the chamber roof close to rupture and dyke injection. For volcanoes with known typical extrusion and intrusion (dyke) volumes, the new methodology presented here makes it possible to forecast the conditions for magma-chamber failure and dyke injection at any geodetically well-monitored volcano.

  19. Anterior cruciate ligament (ACL) injury

    Science.gov (United States)

    Cruciate ligament injury - anterior; ACL injury; Knee injury - anterior cruciate ligament (ACL) ... knee. It prevents the knee from bending out. Anterior cruciate ligament (ACL) is in the middle of the knee. ...

  20. Posterior Chamber Hemorrhage during Fluorescein Angiography

    Directory of Open Access Journals (Sweden)

    Manuel A. P. Vilela

    2015-01-01

    Full Text Available This paper provides the first reported case of acute posterior chamber hemorrhage during fluorescein angiography (FA. This is a case review with serial color photographs of the anterior segment. A 76-year-old male was referred for angiographic control of age-related macular degeneration. He was pseudophakic OU, BCVA 20/40 OU. He had mild hypertension, but not diabetes. He had had two previous angiograms without adverse effects. Difficulty was experienced in obtaining the images owing to a progressive reduction in the transparency of the media. A dense hemorrhage in the posterior chamber of the right eye was found, involving the visual axis. Thorough biomicroscopy, gonioscopy, and ultrasonic biomicroscopy showed that part of one of the haptics of the right intraocular lens (IOL was touching and tearing the posterior face of the iris, without any visible synechiae, iris, or angle neovascularization. Anterior segment FA and posterior ultrasonography were normal. No similar case has been described in the literature involving dense progressive bleeding located in the capsular bag and posterior chamber, without any detectable triggering ocular event other than mydriasis and fluorescein injection. Contact of the iris or sulcus with part of the intraocular lens, aggravated by the intense use of mydriatics during the FA procedure, probably caused bleeding to happen.

  1. Target chambers for gammashpere

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.P.; Falout, J.W.; Nardi, B.G. [and others

    1995-08-01

    One of our responsibilities for Gammasphere, was designing and constructing two target chambers and associated beamlines to be used with the spectrometer. The first chamber was used with the early implementation phase of Gammasphere, and consisted of two spun-Al hemispheres welded together giving a wall thickness of 0.063 inches and a diameter of 12 inches.

  2. High resolution drift chambers

    International Nuclear Information System (INIS)

    High precision drift chambers capable of achieving less than or equal to 50 μm resolutions are discussed. In particular, we compare so called cool and hot gases, various charge collection geometries, several timing techniques and we also discuss some systematic problems. We also present what we would consider an ''ultimate'' design of the vertex chamber. 50 refs., 36 figs., 6 tabs

  3. CHAMBER OF COMMERCE INFORMATION

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Experience Japan The Japanese Chamber of Commerce and Industry will further promote its Japan-experience program and seek cooperation with various Chinese institutions.Between early May and June 2007,the chamber organized a Chinese college student delegation to Japan with the support from its members in China.

  4. BEBC bubble chamber

    CERN Multimedia

    1972-01-01

    Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

  5. 前房放液治疗有晶状体眼后房型人工晶状体植入术后高眼压%Releasing aqueous humor of anterior chamber to treat early elevated lOP after lCL implantation

    Institute of Scientific and Technical Information of China (English)

    熊露; 易魁先; 邓一鹏; 彭晓琍

    2015-01-01

    目的::探讨前房放液法在有晶状体眼后房型人工晶状体植入术( implantable collamer lens,ICL)术后早期眼压升高治疗中的应用。方法:ICL植入术后早期高眼压患者,眼压>25 mmHg时,表面麻醉下,用一次性注射器针尖从角膜侧切口缓慢将房水放出,使眼压降至10~13 mmHg。术后每2 h测量眼压,如眼压再次升高,可反复放房水处理,直至眼压正常。结果:ICL植入术患者167例330眼,术后眼压>25 mmHg者32例62眼,其中部分房水可见黏弹剂。大多数患眼(48眼)通过1次放液治疗成功无复发。经过最多3次侧切口放液,所有患眼眼压均恢复正常。术后随访未见异常。结论:黏弹剂残留是导致ICL植入术后早期眼压升高的主要原因,侧切口前房放液法能有效、及时降低眼压。操作简单、安全、无痛,患者乐于接受,可反复进行。%To explore the effect of releasing aqueous humor of anterior chamber through lateral incision of cornea in treating early elevated intraocular pressure ( lOP ) after implantation of implantable collamer lens ( lCL) .METHODS: Patients with elevated lOP were analyzed after lCL implantation. When the lOP>25mmHg, aqueous humor was released slowly through lateral incision of cornea, and made the lOP reduce to 10 ~13mmHg. After operation, lOP was measured every 2h. The releasing of aqueous humor was repeated until the lOP was decreased to normal.RESULTS: One hundred sixty - seven patients ( 330 eyes) were implanted lCL, while the lOP of 32 patients (62 eyes) was higher than 25mmHg after lCL implantation. Viscoelastic material was found in aqueous humor of most of high lOP patients, and the lOP of 48 eyes did not increase again through releasing aqueous humor once. The lOP of all these eyes was decreased to normal through releasing aqueous humor in 3 times at most. There were no abnormal in postoperative follow-up.CONCLUSlON:The main reason of early elevated lOP after lCL implantation

  6. OPAL Jet Chamber Prototype

    CERN Multimedia

    OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

  7. Responses of the Ocular Anterior Segment and Refraction to 0.5% Tropicamide in Chinese School-Aged Children of Myopia, Emmetropia, and Hyperopia

    Directory of Open Access Journals (Sweden)

    Ying Yuan

    2015-01-01

    Full Text Available Purpose. To investigate the changes of anterior segment after cycloplegia and estimate the association of such changes with the changes of refraction in Chinese school-aged children of myopia, emmetropia, and hyperopia. Methods. 309 children were recruited and eligible subjects were assigned to three groups: hyperopia, emmetropia, or myopia. Cycloplegia was achieved with five cycles of 0.5% tropicamide. The Pentacam system was used to measure the parameters of interest before and after cycloplegia. Results. In the myopic group, the lenses were thinner and the lens position was significantly more posterior than that of the emmetropic and hyperopic groups in the cycloplegic status. The correlations between refraction and lens thickness (age adjusted; r=0.26, P<0.01, and lens position (age adjusted; r=-0.31, P<0.01 were found. After cycloplegia, ACD and ACV significantly increased, while ACA significantly decreased. Changes in refraction, ACD, ACV, and ACA were significantly different among the three groups (P<0.05, all. Changes of refraction were correlated with changes of ACD (r=0.41, P<0.01. Conclusions. Myopia presented thinner lenses and smaller changes of anterior segment and refraction after cycloplegia when compared to emmetropia and hyperopia. Changes of anterior chamber depth were correlated with refraction changes. This may contribute to a better understanding of the relationship between anterior segment and myopia.

  8. Numerical simulation of magma chamber dynamics.

    Science.gov (United States)

    Longo, Antonella; Papale, Paolo; Montagna, Chiara Paola; Vassalli, Melissa; Giudice, Salvatore; Cassioli, Andrea

    2010-05-01

    Magma chambers are characterized by periodic arrivals of deep magma batches that give origin to complex patterns of magma convection and mixing, and modify the distribution of physical quantities inside the chamber. We simulate the transient, 2D, multi-component homogeneous dynamics in geometrically complex dyke+chamber systems, by means of GALES, a finite element parallel C++ code solving mass, momentum and energy equations for multi-component homogeneous gas-liquid (± crystals) mixtures in compressible-to-incompressible flow conditions. Code validation analysis includes several cases from the classical engineering literature, corresponding to a variety of subsonic to supersonic gas-liquid flow regimes (see http://www.pi.ingv.it/~longo/gales/gales.html). The model allows specification of the composition of the different magmas in the domain, in terms of ten major oxides plus the two volatile species H2O and CO2. Gas-liquid thermodynamics are modeled by using the compositional dependent, non-ideal model in Papale et al. (Chem.. Geol., 2006). Magma properties are defined in terms of local pressure, temperature, and composition including volatiles. Several applications are performed within domains characterized by the presence of one or more magma chambers and one or more dykes, with different geometries and characteristic size from hundreds of m to several km. In most simulations an initial compositional interface is placed at the top of a feeding dyke, or at larger depth, with the deeper magma having a lower density as a consequence of larger volatile content. The numerical results show complex patterns of magma refilling in the chamber, with alternating phases of magma ingression and magma sinking from the chamber into the feeding dyke. Intense mixing takes place in feeding dykes, so that the new magma entering the chamber is always a mixture of the deep and the initially resident magma. Buoyant plume rise occurs through the formation of complex convective

  9. Toxic Test Chambers

    Data.gov (United States)

    Federal Laboratory Consortium — Description/History: Hazardous material test facility Both facilities have 16,000 cubic foot chambers, equipped with 5000 CFM CBR filter systems with an air change...

  10. ALICE Time Projection Chamber

    CERN Multimedia

    Lippmann, C

    2013-01-01

    The Time Projection Chamber (TPC) is the main device in the ALICE 'central barrel' for the tracking and identification (PID) of charged particles. It has to cope with unprecedented densities of charges particles.

  11. Calorimetry with flash chambers

    International Nuclear Information System (INIS)

    The flash chambers used in the Fermilab E594 neutrino experiment are described, and their use in a calorimeter discussed. Resolutions obtained with a calibration beam are presented, and comments made about the pattern recognition capabilities of the calorimeter

  12. Vacuum chamber 'bicone'

    CERN Multimedia

    1977-01-01

    This chamber is now in the National Museum of History and Technology, Smithsonian Institution, Washington, DC, USA, where it was exposed in an exhibit on the History of High Energy Accelerators (1977).

  13. Bubble chamber: antiproton annihilation

    CERN Multimedia

    1971-01-01

    These images show real particle tracks from the annihilation of an antiproton in the 80 cm Saclay liquid hydrogen bubble chamber. A negative kaon and a neutral kaon are produced in this process, as well as a positive pion. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  14. Congenital anterior urethral diverticulum.

    Science.gov (United States)

    Singh, Sanjeet Kumar; Ansari, Ms

    2014-09-01

    Congenital anterior urethral diverticulum (CAUD) may be found all along the anterior urethra and may present itself at any age, from infant to adult. Most children with this condition present with difficulty in initiating micturition, dribbling of urine, poor urinary stream, or urinary tract infection. A careful history will reveal that these children never had a good urinary stream since birth, and the telltale sign is a cystic swelling of the penile urethra. In this paper, we present two cases of CAUD that were managed by excision of the diverticulum with primary repair. PMID:26328174

  15. Pseudophakic hyperopia in nanophthalmic eyes managed by a posterior chamber implantable collamer lens

    Directory of Open Access Journals (Sweden)

    Kothari Kulin

    2011-01-01

    Full Text Available We report a case of a bilateral posterior chamber implantable collamer lens (ICL implantation post-clear lens extraction, to reduce the residual hyperopia, in a patient with nanophthalmic eyes. A 30-year-old female patient, keen to reduce her dependency on glasses and contact lenses, came to our refractive surgery department. Her refractive error was +12.0 and +12.5 diopters in the right and left eye, respectively, with steep corneas on keratometry and a shallow anterior chamber depth. She underwent clear lens extraction with implantation of +35.0 D and +40.0 D IOL in the right eye and left eye, respectively. Her post-operative best-corrected visual acuity was 20/30 with +8.5 D in the right eye and +6 D in the left. She underwent bilateral ICL implantation. Postoperatively after 6 months, her unaided visual acuity was 20/30 in both eyes. In conclusion, ICL implantation can be considered to correct residual hypermetropic ametropia in pseudophakic eyes when other options have limitations.

  16. Automated Electrostatics Environmental Chamber

    Science.gov (United States)

    Calle, Carlos; Lewis, Dean C.; Buchanan, Randy K.; Buchanan, Aubri

    2005-01-01

    The Mars Electrostatics Chamber (MEC) is an environmental chamber designed primarily to create atmospheric conditions like those at the surface of Mars to support experiments on electrostatic effects in the Martian environment. The chamber is equipped with a vacuum system, a cryogenic cooling system, an atmospheric-gas replenishing and analysis system, and a computerized control system that can be programmed by the user and that provides both automation and options for manual control. The control system can be set to maintain steady Mars-like conditions or to impose temperature and pressure variations of a Mars diurnal cycle at any given season and latitude. In addition, the MEC can be used in other areas of research because it can create steady or varying atmospheric conditions anywhere within the wide temperature, pressure, and composition ranges between the extremes of Mars-like and Earth-like conditions.

  17. Comparison of anterior segment parameters with pentacam according to age in emmetropic eyes

    Directory of Open Access Journals (Sweden)

    Yasin Çınar

    2013-12-01

    Full Text Available Objective: It was aimed to compare anterior segment parametersobtained by rotating Scheimpflug camera systemaccording to age groups.Methods: 290 eyes of 145 emmetropic subjects wereincluded in the study. Subjects were divided in threeage groups. Group 1 comprised the subjects age up to20 years, Group 2 comprised the subjects age between21 and 40 and Group 3 comprised the subjects between41 years and older. In all subjects, flat keratometry (K1,steep keratometry (K2, mean corneal power (Km,maximum keratometry (Kmax, central corneal thickness(CCT, apex corneal thickness (ACT, thinnest cornealthickness (TCT, anterior chamber volume (ACV and anteriorchamber depth (ACD were obtained by using rotatingScheimpflug camera system. To eliminate operatordependent variables, automatic release mode was used.All measurements were obtained by the same examiner.Results: The study included 72 female and 73 male subjects.The mean age of the subjects was 31.37±12.29years (range, 8-65. There were no significant differencesin keratometric values between age groups. Therewas significant difference between Groups 1 and 3 andGroups 2 and 3 in the mean CCT, ACT and TCT (p<0.05.There was significant difference between the groups inthe mean ACD and ACV. There significant positive correlationbetween age and CCT (r=0.181, p=0.001, ACT(r=0.161, p=0.006 and TCT (r=0.16, p=0.006. Therewere significant negative correlations between age andACD (r=-0.376, p<0.001 and ACV (r=-0.367, p<0.001.Conclusion: In the emmetropic eyes, significant reductionwas found in ACD and ACV, while there was significantincrease in CCT, ACT and TCT by age.Key words: Corneal topography, anterior segment, emetropic eyes, pentacam

  18. Under-air staining of the anterior capsule using Trypan blue with a 30 G needle

    Directory of Open Access Journals (Sweden)

    Giammaria D

    2013-01-01

    Full Text Available Daniele Giammaria,1 Michele Giannotti,2 Angelo Scopelliti,1 Giacomo Pellegrini,1 Bruno Giannotti11Azienda Ospedaliera Ospedali Riuniti Marche Nord, Fano, Italy; 2Catholic University of Rome, Rome, ItalyAbstract: The original technique of staining the anterior capsule of the lens with Trypan blue involves the injection of an air bubble in the anterior chamber. A drawback of this technique is the possible instability of the anterior chamber caused by the sudden exit of air when the dye is injected with the cannula through the side-port incision. Other staining techniques that use viscoelastic substances to increase the stability of the anterior chamber and to dose the injected dye have been described. The authors present an under-air staining technique of the anterior capsule using one drop of Trypan blue injected with a 30 G needle through the peripheral cornea. This procedure prevents the air bubble from escaping the anterior chamber and allows fast and selective staining of the capsule.Keywords: Trypan blue, staining technique, dye, cataract surgery, capsulorhexis

  19. micro strip gas chamber

    CERN Multimedia

    1998-01-01

    About 16 000 Micro Strip Gas Chambers like this one will be used in the CMS tracking detector. They will measure the tracks of charged particles to a hundredth of a millimetre precision in the region near the collision point where the density of particles is very high. Each chamber is filled with a gas mixture of argon and dimethyl ether. Charged particles passing through ionise the gas, knocking out electrons which are collected on the aluminium strips visible under the microscope. Such detectors are being used in radiography. They give higher resolution imaging and reduce the required dose of radiation.

  20. New development of holography in particle detectors: application to bubble chambers and streamer chambers

    International Nuclear Information System (INIS)

    This thesis describes the contribution of holography in two particle detectors well used in high energy physics. A first part presents the possibilities of a double beam holographic set up with diffuse illumination in the case of large scale bubble chamber (more than 1000 litres). The second part introduces the results obtained by the use of an in-line holographic recording in a streamer chamber (a streamer is the electroluminescent state of an electronic avalanche). In both cases, the new possibilities offered by these developments are discussed (resolution and depth of field of holographic images)

  1. Analysis of iris structure and iridocorneal angle parameters with anterior segment optical coherence tomography in Fuchs' uveitis syndrome.

    Science.gov (United States)

    Basarir, Berna; Altan, Cigdem; Pinarci, Eylem Yaman; Celik, Ugur; Satana, Banu; Demirok, Ahmet

    2013-06-01

    To evaluate the differences in the biometric parameters of iridocorneal angle and iris structure measured by anterior segment optical coherence tomography (AS-OCT) in Fuchs' uveitis syndrome (FUS). Seventy-six eyes of 38 consecutive patients with the diagnosis of unilateral FUS were recruited into this prospective, cross-sectional and comparative study. After a complete ocular examination, anterior segment biometric parameters were measured by Visante(®) AS-OCT. All parameters were compared between the two eyes of each patient statistically. The mean age of the 38 subjects was 32.5 ± 7.5 years (18 female and 20 male). The mean visual acuity was lower in eyes with FUS (0.55 ± 0.31) than in healthy eyes (0.93 ± 0.17). The central corneal thickness did not differ significantly between eyes. All iridocorneal angle parameters (angle-opening distance 500 and 750, scleral spur angle, trabecular-iris space (TISA) 500 and 750) except TISA 500 in temporal quadrant were significantly larger in eyes with FUS than in healthy eyes. Anterior chamber depth was deeper in the eyes with FUS than in the unaffected eyes. With regard to iris measurements, iris thickness in the thickest part, iris bowing and iris shape were all statistically different between the affected eye and the healthy eye in individual patients with FUS. However, no statistically significant differences were evident in iris thickness 500 μm, thickness in the middle and iris length. There were significant difference in iris shape between the two eyes of patients with glaucoma. AS-OCT as an imaging method provides us with many informative resultsin the analysis of anterior segment parameters in FUS. PMID:23277205

  2. Heavy liquid bubble chamber

    CERN Multimedia

    1965-01-01

    The CERN Heavy liquid bubble chamber being installed in the north experimental hall at the PS. On the left, the 1180 litre body; in the centre the magnet, which can produce a field of 26 800 gauss; on the right the expansion mechanism.

  3. Wire chamber conference

    International Nuclear Information System (INIS)

    This booklet contains program and the abstracts of the papers presented at the conference, most of them dealing with performance testing of various types of wire chambers. The publication of proceedings is planned as a special issue of 'Nuclear instruments and methods' later on. All abstracts are in English. An author index for the book of abstracts is given. (A.N.)

  4. Drift chamber detectors

    International Nuclear Information System (INIS)

    A review of High Energy Physics detectors based on drift chambers is presented. The ionization, drift diffusion, multiplication and detection principles are described. Most common drift media are analysied, and a classification of the detectors according to its geometry is done. Finally the standard read-out methods are displayed and the limits of the spatial resolution are discussed. (Author)

  5. LEP vacuum chamber, prototype

    CERN Multimedia

    1983-01-01

    Final prototype for the LEP vacuum chamber, see 8305170 for more details. Here we see the strips of the NEG pump, providing "distributed pumping". The strips are made from a Zr-Ti-Fe alloy. By passing an electrical current, they were heated to 700 deg C.

  6. OPAL Muon Chamber

    CERN Multimedia

    OPAL was one of the 4 experiments installed at the LEP particle accelerator from 1989 to 2000. This is a slice of the outermost layer of OPAL : the muon chambers. This outside layer detects particles which are not stopped by the previous layers. These are mostly muons.

  7. LEP Vacuum Chamber

    CERN Multimedia

    1983-01-01

    This is a cut-out of a LEP vacuum chamber for dipole magnets showing the beam channel and the pumping channel with the getter (NEG) strip and its insulating supports. A water pipe connected to the cooling channel can also be seen at the back.The lead radiation shield lining is also shown. See also 8305563X.

  8. Scanning bubble chamber pictures

    CERN Multimedia

    1974-01-01

    These were taken at the 2 m hydrogen bubble chamber. The photo shows an early Shiva system where the pre-measurements needed to qualify the event were done manually (cf photo 7408136X). The scanning tables were located in bld. 12. Gilberte Saulmier sits on foreground, Inge Arents at centre.

  9. Age-Related Change and Gender Difference in Ocular Anterior Segment Parameters%眼前段生物结构参数的年龄相关性改变与性别差异研究

    Institute of Scientific and Technical Information of China (English)

    苏鹏; 孔祥斌; 晏世刚; 黄玉娟

    2016-01-01

    目的:比较30岁以上正常人不同年龄段眼前段生物结构参数的变化及性别差异,为闭角型青光眼的发病机制提供证据。方法选择474例眼科门诊检查正常者为研究对象,均30岁以上,其中男213例,女261例。采用眼前段光学相干断层扫描仪,获取眼前段水平图像,用中山房角分析软件进行图片分析获得眼前段结构参数[包括房角宽度(angle open distance,AOD500)、虹膜面积、前房深度及前房容积],按年龄、性别进行分组,采用 stata12.0进行数据处理及分析。结果各年龄段 AOD500、前房深度、前房容积及虹膜面积比较差异均有统计学意义(P <0.001);男性 AOD500、前房深度、前房容积及虹膜面积均显著高于女性(P <0.001)。30~55岁年龄段,AOD500变化最大,而55岁后 AOD500变化相对平缓;男性前房容积在50岁前变化相对明显,50岁后变化相对平缓,而女性前房容积变化明显且均匀。结论30以上正常人 AOD500、前房深度、前房容积均随年龄增加呈递减趋势,而虹膜面积随年龄增加呈递增趋势;女性较男性更易患闭角型青光眼。%Objective To investigate the age-related change and gender difference in ocular an-terior segment parameters in persons older than 30 years,and to provide evidence for the patho-genesis of angle-closure glaucoma.Methods A total of 474 normal subjects older than 30 years (213 males and 261 females)were selected in this study.The anterior segment optical coherence tomography(AS-OCT)was performed to obtain the anterior segment images,and the Zhongshan Angle Assessment Program was used to obtain the ocular anterior segment parameters,including angle opening distance at 500 μm(AOD500),iris area,anterior chamber depth and anterior cham-ber volume.These subjects were divided into different age and gender groups.Data were analyzed using Stata12.0.Results There were significant

  10. Uveitis-glaucoma-hyphema syndrome caused by posterior chamber intraocular lens--a rare complication in pediatric cataract surgery.

    Science.gov (United States)

    Lin, Chun-Ju; Tan, Chau-Yi; Lin, Szu-Yuan; Jou, Jieh-Ren

    2008-01-01

    We report a case of postoperative uveitis-glaucome-hyphema (UGH) syndrome following pediatric cataract surgery due to posterior chamber intraocular lens (PC-IOL). Slit-lamp examination revealed the optic of PC-IOL migrated into anterior chamber. The PC-IOL explantation was performed and ocular inflammation subsided. PMID:19230361

  11. Misdiagnosis induced intraocular lens dislocation in anterior megalophthalmos

    Institute of Scientific and Technical Information of China (English)

    WANG Qi-wei; XU Wen; ZHU Ya-nan; LI Jin-yu; ZHANG Li; YAO Ke

    2012-01-01

    Anterior megalophthalmos (AM) is an uncommon developmental anomaly of the anterior segment of the eye with a constellation of findings that includes enlarged cornea,deep anterior chamber,posterior positioning of the iris and lens,iris stroma atrophy,hypoplasia of iris dilator,pupil displacement,large capsular bag,lens subluxation,prematurely cataract and the tendency to retinal detachment.AM,especially when symptoms are mild,is not an easy disease to diagnose.We present 3 AM cases that were misdiagnosed as congenital cataract with weak zonule and megalocornea.Intraocular lenses (IOLs) dislocated after standard cataract surgeries and subsequent surgery (replacing the dislocated IOLs with iris-claw intraocular lenses) achieved satisfactory outcome.Although rare,AM should be included in the differential diagnosis of enlarged cornea and we recommend implanting Artisan lens in AM patients.

  12. Effect of acupuncture depth on muscle pain

    Directory of Open Access Journals (Sweden)

    Kitakoji Hiroshi

    2011-06-01

    Full Text Available Abstract Background While evidence supports efficacy of acupuncture and/or dry needling in treating musculoskeletal pain, it is unclear which needling method is most effective. This study aims to determine the effects of depth of needle penetration on muscle pain. Methods A total of 22 healthy volunteers performed repeated eccentric contractions to induce muscle soreness in their extensor digital muscle. Subjects were assigned randomly to four groups, namely control group, skin group (depth of 3 mm: the extensor digital muscle, muscle group (depth of 10 mm: the extensor digital muscle and non-segmental group (depth of 10 mm: the anterior tibial muscle. Pressure pain threshold and electrical pain threshold of the skin, fascia and muscle were measured at a point 20 mm distal to the maximum tender point on the second day after the exercise. Results Pressure pain thresholds of skin group (depth of 3 mm: the extensor digital muscle and muscle group (depth of 10 mm: the extensor digital muscle were significantly higher than the control group, whereas the electrical pain threshold at fascia of muscle group (depth of 10 mm: the extensor digital muscle was a significantly higher than control group; however, there was no significant difference between the control and other groups. Conclusion The present study shows that acupuncture stimulation of muscle increases the PPT and EPT of fascia. The depth of needle penetration is important for the relief of muscle pain.

  13. Anterior migration of dexamethasone implant in a pseudophakic patient with intact posterior capsule

    OpenAIRE

    Nilufer Kocak; Taylan Ozturk; Eyyup Karahan; Suleyman Kaynak

    2014-01-01

    Intravitreal application of Ozurdex ® (Allergan, Inc., Irvine, CA, USA) which is a biodegradable, sustained-release dexamethasone implant has been reported to be effective in the treatment of macular edema. Migration of such implant into the anterior chamber has been recently described in cases without perfect zonular or the posterior capsular integrity. Herein, we report the first case with anterior migration of Ozurdex ® implant that mislocated just behind the intraocular lens (IOL) in an i...

  14. Reproducibility of Scleral Spur Identification and Angle Measurements Using Fourier Domain Anterior Segment Optical Coherence Tomography

    OpenAIRE

    Ricardo J. Cumba; Sunita Radhakrishnan; Nicholas P. Bell; Kundandeep S. Nagi; Alice Z. Chuang; Lin, Shan C.; Mankiewicz, Kimberly A.; Feldman, Robert M.

    2012-01-01

    Purpose. To evaluate intraobserver and interobserver agreement in locating the scleral spur landmark (SSL) and anterior chamber angle measurements obtained using Fourier Domain Anterior Segment Optical Coherence Tomography (ASOCT) images. Methods. Two independent, masked observers (SR and AZC) identified SSLs on ASOCT images from 31 eyes with open and nonopen angles. A third independent reader, NPB, adjudicated SSL placement if identifications differed by more than 80  μ m. Nine months later,...

  15. Comparison of Anterior Segment Measurements with Scheimpflug/Placido Photography-Based Topography System and IOLMaster Partial Coherence Interferometry in Patients with Cataracts.

    Science.gov (United States)

    Huang, Jinhai; Liao, Na; Savini, Giacomo; Bao, Fangjun; Yu, Ye; Lu, Weicong; Hu, Qingjie; Wang, Qinmei

    2014-01-01

    Purpose. To assess the consistency of anterior segment measurements obtained using a Sirius Scheimpflug/Placido photography-based topography system (CSO, Italy) and IOLMaster partial coherence interferometry (Carl Zeiss Meditec, Germany) in eyes with cataracts. Methods. A total of 90 eyes of 90 patients were included in this prospective study. The anterior chamber depth (ACD), keratometry (K), corneal astigmatism axis, and white to white (WTW) values were randomly measured three times with Sirius and IOLMaster. Concordance between them was assessed by calculating 95% limits of agreement (LoA). Results. The ACD and K taken with the Sirius were statistically significantly higher than that taken with the IOLMaster; however, the Sirius significantly underestimated the WTW values compared with the IOLMaster. Good agreement was found for Km and ACD measurements, with 95% LoA of -0.20 to 0.54 mm and -0.16 to 0.34 mm, respectively. Poor agreement was observed for astigmatism axis and WTW measurements, as the 95% LoA was -23.96 to 23.36° and -1.15 to 0.37 mm, respectively. Conclusion. With the exception of astigmatism axis and WTW, anterior segment measurements taken by Sirius and IOLMaster devices showed good agreement and may be used interchangeably in patients with cataracts. PMID:25400939

  16. Comparison of Anterior Segment Measurements with Scheimpflug/Placido Photography-Based Topography System and IOLMaster Partial Coherence Interferometry in Patients with Cataracts

    Directory of Open Access Journals (Sweden)

    Jinhai Huang

    2014-01-01

    Full Text Available Purpose. To assess the consistency of anterior segment measurements obtained using a Sirius Scheimpflug/Placido photography-based topography system (CSO, Italy and IOLMaster partial coherence interferometry (Carl Zeiss Meditec, Germany in eyes with cataracts. Methods. A total of 90 eyes of 90 patients were included in this prospective study. The anterior chamber depth (ACD, keratometry (K, corneal astigmatism axis, and white to white (WTW values were randomly measured three times with Sirius and IOLMaster. Concordance between them was assessed by calculating 95% limits of agreement (LoA. Results. The ACD and K taken with the Sirius were statistically significantly higher than that taken with the IOLMaster; however, the Sirius significantly underestimated the WTW values compared with the IOLMaster. Good agreement was found for Km and ACD measurements, with 95% LoA of −0.20 to 0.54 mm and −0.16 to 0.34 mm, respectively. Poor agreement was observed for astigmatism axis and WTW measurements, as the 95% LoA was −23.96 to 23.36° and −1.15 to 0.37 mm, respectively. Conclusion. With the exception of astigmatism axis and WTW, anterior segment measurements taken by Sirius and IOLMaster devices showed good agreement and may be used interchangeably in patients with cataracts.

  17. The anterior cingulate cortex

    Directory of Open Access Journals (Sweden)

    Pavlović D.M.

    2009-01-01

    Full Text Available The anterior cingulate cortex (ACC has a role in attention, analysis of sensory information, error recognition, problem solving, detection of novelty, behavior, emotions, social relations, cognitive control, and regulation of visceral functions. This area is active whenever the individual feels some emotions, solves a problem, or analyzes the pros and cons of an action (if it is a right decision. Analogous areas are also found in higher mammals, especially whales, and they contain spindle neurons that enable complex social interactions. Disturbance of ACC activity is found in dementias, schizophrenia, depression, the obsessive-compulsive syndrome, and other neuropsychiatric diseases.

  18. Anterior migration of dexamethasone implant in a pseudophakic patient with intact posterior capsule

    Directory of Open Access Journals (Sweden)

    Nilufer Kocak

    2014-01-01

    Full Text Available Intravitreal application of Ozurdex ® (Allergan, Inc., Irvine, CA, USA which is a biodegradable, sustained-release dexamethasone implant has been reported to be effective in the treatment of macular edema. Migration of such implant into the anterior chamber has been recently described in cases without perfect zonular or the posterior capsular integrity. Herein, we report the first case with anterior migration of Ozurdex ® implant that mislocated just behind the intraocular lens (IOL in an intact capsular bag. It is thought that such implant migrated anteriorly towards into the posterior chamber through weak zonules as the present case had a medical history of uneventful phacoemulsification surgery with the implantation of posterior chamber IOL. However, the migrated implant was well tolerated since there was no sign of the corneal complication, rise in intraocular pressure, and anterior chamber reaction. Close follow-up was scheduled to find out any signs of anterior segment pathology. Meanwhile dexamethasone implant completely degraded at the 4 th month of postoperative follow-up.

  19. Vertical two chamber reaction furnace

    Science.gov (United States)

    Blaugher, Richard D.

    1999-03-16

    A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800.degree. to 950.degree. C. to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product.

  20. Comment on 'Proton beam monitor chamber calibration'.

    Science.gov (United States)

    Palmans, Hugo; Vatnitsky, Stanislav M

    2016-09-01

    We comment on a recent article (Gomà et al 2014 Phys. Med. Biol. 59 4961-71) which compares different routes of reference dosimetry for the energy dependent beam monitor calibration in scanned proton beams. In this article, a 3% discrepancy is reported between a Faraday cup and a plane-parallel ionization chamber in the experimental determination of the number of protons per monitor unit. It is further claimed that similar discrepancies between calorimetry and ionization chamber based dosimetry indicate that [Formula: see text]-values tabulated for proton beams in IAEA TRS-398 might be overestimated. In this commentary we show, however, that this supporting argument misrepresents the evidence in the literature and that the results presented, together with published data, rather confirm that there exist unresolved problems with Faraday cup dosimetry. We also show that the comparison in terms of the number of protons gives a biased view on the uncertainty estimates for both detectors while the quantity of interest is absorbed dose to water or dose-area-product to water, even if a beam monitor is calibrated in terms of the number of protons. Gomà et al (2014 Phys. Med. Biol. 59 4961-71) also report on the discrepancy between cylindrical and plane-parallel ionization chambers and confirm experimentally that in the presence of a depth dose gradient, theoretical values of the effective point of measurement, or alternatively a gradient correction factor, account for the discrepancy. We believe this does not point to an error or shortcoming of IAEA TRS-398, which prescribes taking the centre of cylindrical ionization chambers as reference point, since it recommends reference dosimetry to be performed in the absence of a depth dose gradient. But these observations reveal that important aspects of beam monitor calibration in scanned proton beams are not addressed in IAEA TRS-398 given that those types of beams were not widely implemented at the time of its publication

  1. Multi-anode ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Bolotnikov, Aleksey E. (South Setauket, NY); Smith, Graham (Port Jefferson, NY); Mahler, George J. (Rocky Point, NY); Vanier, Peter E. (Setauket, NY)

    2010-12-28

    The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.

  2. Vacuum Chambers for LEP sections

    CERN Multimedia

    1983-01-01

    The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

  3. Bilateral spontaneous dislocation of posterior chamber intraocular lens in a patient with gyrate atrophy

    Directory of Open Access Journals (Sweden)

    Michael Kinori

    2012-01-01

    Full Text Available We report a patient with gyrate atrophy, a rare metabolic disease, who had bilateral late spontaneous posterior dislocation of in-the-bag posterior chamber intraocular lens (PCIOL. He underwent pars plana vitrectomy, PCIOL retrieval and anterior chamber intraocular lens implantation in both eyes. This report may imply that patients with gyrate atrophy are at risk for spontaneous dislocation of intraocular lenses.

  4. The APS ceramic chambers

    Energy Technology Data Exchange (ETDEWEB)

    Milton, S.; Warner, D.

    1994-07-01

    Ceramics chambers are used in the Advanced Photon Source (APS) machines at the locations of the pulsed kicker and bumper magnets. The ceramic will be coated internally with a resistive paste. The resistance is chosen to allow the low frequency pulsed magnet field to penetrate but not the high frequency components of the circulating beam. Another design goal was to keep the power density experienced by the resistive coating to a minimum. These ceramics, their associated hardware, the coating process, and our recent experiences with them are described.

  5. Review of wire chamber aging

    International Nuclear Information System (INIS)

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs

  6. Toxic anterior-segment syndrome (TASS

    Directory of Open Access Journals (Sweden)

    Cetinkaya S

    2014-10-01

    Full Text Available Servet Cetinkaya,1 Zeynep Dadaci,2 Hüsamettin Aksoy,3 Nursen Oncel Acir,2 Halil Ibrahim Yener,4 Ekrem Kadioglu5 1Ophthalmology Clinics, Turkish Red Crescent Hospital, Konya, 2Department of Ophthalmology, Faculty of Medicine, Mevlana University, Konya, 3Ophthalmology Clinics, Karaman State Hospital, Karaman, 4Konya Eye Center Hospital, Konya, 5Ophthalmology Clinics, Beyhekim State Hospital, Konya, Turkey Purpose: To evaluate the clinical findings and courses of five patients who developed toxic anterior-segment syndrome (TASS after cataract surgery and investigate the cause.Materials and methods: In May 2010, on the same day, ten patients were operated on by the same surgeon. Five of these patients developed TASS postoperatively.Results: Patients had blurred-vision complaints on the first day after the operation, but no pain. They had different degrees of diffuse corneal edema, anterior-chamber reaction, fibrin, hypopyon, iris atrophies, and dilated pupils. Their vision decreased significantly, and their intraocular pressures increased. Both anti-inflammatory and antiglaucomatous therapies were commenced. Corneal edema and inflammation resolved in three cases; however, penetrating keratoplasty was needed for two cases and additional trabeculectomy was needed for one case. Although full investigations were undertaken at all steps, we could not find the causative agent.Conclusion: TASS is a preventable complication of anterior-segment surgery. Recognition of TASS, differentiating it from endophthalmitis, and starting treatment immediately is important. Controlling all steps in surgery, cleaning and sterilization of the instruments, and training nurses and other operation teams will help us in the prevention of TASS. Keywords: cataract, phacoemulsification, TASS, corneal edema, inflammation

  7. Complications and Management of Deep Anterior Lamellar Keratoplasty

    Directory of Open Access Journals (Sweden)

    Banu Torun Acar

    2014-10-01

    Full Text Available Objectives: To report the intraoperative and postoperative follow-up complications and management of these in deep anterior lamellar keratoplasty (DALK surgery. Materials and Methods: Two hundred eighty-four eyes of 252 patients followed up in our cornea clinic who underwent DALK using Anwar’s big-bubble technique with healthy Descemet’s membrane and endothelium were included in this study. Intraoperative and postoperative complications as well as the management and treatment of these complications were evaluated. Results: Big bubble was created in 220 (77.5% eyes of 284 eyes, and lamellar dissection was performed in 64 (22.5% eyes. Perforation occurred during trephination in 4 eyes, and the procedure was accomplished by penetrating keratoplasty (PK. Intraoperative microperforation occurred in 44 eyes. Perforation enlarged in 4 eyes and PK was performed. Operation was continued in 40 eyes with air injection into the anterior chamber. In postopertive follow-up period, double anterior chamber (DAC occurred in 32 of 40 eyes. DAC spontaneously regressed in 8 eyes, and air was given into the anterior chamber with a second surgical intervention in 24 eyes. DAC improved in 20 eyes. Four eyes underwent PK. Fungal keratitis evolved at the interface in one eye, because of no healing during the follow-up period, this eye underwent PK under antifungal therapy. Eyes with interface haze and Descemet’s membrane folds were followed. Conclusion: DALK is a difficult technique with a steep learning curve. In addition to the complications seen in PK, specific complications can occur in lamellar surgery. (Turk J Ophthalmol 2014; 44: 337-40

  8. Morphometric changes of corneal endothelial cells following intracameral air for micro perforation of the Descemet Membrane during big-bubble deep anterior lamellar keratoplasty

    Directory of Open Access Journals (Sweden)

    Ashbala Khattak

    2016-04-01

    Conclusion: The presence of air inside the anterior chamber for a short term may not cause further endothelial cell loss and can be safely performed to prevent postoperative Descemet Membrane detachment in case of micro perforations.

  9. Council Chamber exhibition

    CERN Document Server

    CERN Bulletin

    2010-01-01

    To complete the revamp of CERN’s Council Chamber, a new exhibition is being installed just in time for the June Council meetings.   Panels will showcase highlights of CERN’s history, using some of the content prepared for the exhibitions marking 50 years of the PS, which were displayed in the main building last November. The previous photo exhibition in the Council Chamber stopped at the 1970s. To avoid the new panels becoming quickly out of date, photos are grouped together around specific infrastructures, rather than following a classic time-line. “We have put the focus on the accelerators – the world-class facilities that CERN has been offering researchers over the years, from the well-known large colliders to the lesser-known smaller facilities,” says Emma Sanders, who worked on the content. The new exhibition will be featured in a future issue of the Bulletin with photos and an interview with Fabienne Marcastel, designer of the exhibit...

  10. Anterior hip pain.

    Science.gov (United States)

    O'Kane, J W

    1999-10-15

    Anterior hip pain is a common complaint with many possible causes. Apophyseal avulsion and slipped capital femoral epiphysis should not be overlooked in adolescents. Muscle and tendon strains are common in adults. Subsequent to accurate diagnosis, strains should improve with rest and directed conservative treatment. Osteoarthritis, which is diagnosed radiographically, generally occurs in middle-aged and older adults. Arthritis in younger adults should prompt consideration of an inflammatory cause. A possible femoral neck stress fracture should be evaluated urgently to prevent the potentially significant complications associated with displacement. Patients with osteitis pubis should be educated about the natural history of the condition and should undergo physical therapy to correct abnormal pelvic mechanics. "Sports hernias," nerve entrapments and labral pathologic conditions should be considered in athletic adults with characteristic presentations and chronic symptoms. Surgical intervention may allow resumption of pain-free athletic activity. PMID:10537384

  11. On the acoustic wedge design and simulation of anechoic chamber

    Science.gov (United States)

    Jiang, Changyong; Zhang, Shangyu; Huang, Lixi

    2016-10-01

    This study proposes an alternative to the classic wedge design for anechoic chambers, which is the uniform-then-gradient, flat-wall (UGFW) structure. The working mechanisms of the proposed structure and the traditional wedge are analyzed. It is found that their absorption patterns are different. The parameters of both structures are optimized for achieving minimum absorber depth, under the condition of absorbing 99% of normal incident sound energy. It is found that, the UGFW structure achieves a smaller total depth for the cut-off frequencies ranging from 100 Hz to 250 Hz. This paper also proposes a modification for the complex source image (CSI) model for the empirical simulation of anechoic chambers, originally proposed by Bonfiglio et al. [J. Acoust. Soc. Am. 134 (1), 285-291 (2013)]. The modified CSI model considers the non-locally reactive effect of absorbers at oblique incidence, and the improvement is verified by a full, finite-element simulation of a small chamber. With the modified CSI model, the performance of both decorations with the optimized parameters in a large chamber is simulated. The simulation results are analyzed and checked against the tolerance of 1.5 dB deviation from the inverse square law, stipulated in the ISO standard 3745(2003). In terms of the total decoration depth and anechoic chamber performance, the UGFW structure is better than the classic wedge design.

  12. Multi-chamber ionization detector

    International Nuclear Information System (INIS)

    For the detector a single beta ionization source and a double- or three-chamber set-up is used, the chambers being designed in the shape of a truncated cone and facing each other with their bases. The source can be positioned with respect to the common center or modal electrode, the adjustment of the ionization in each chamber this becoming easier. The center or modal electrode also can be adjusted with respect to the source. (DG)

  13. Accuracy of corneal trephination depth using the Moria single-use adjustable depth vacuum trephine system

    Directory of Open Access Journals (Sweden)

    Fenzl CR

    2014-11-01

    Full Text Available Carlton R Fenzl,1 Adam J Gess,2 Majid Moshirfar31John A Moran Eye Center, University of Utah, Salt Lake City, UT, 2Eye Doctors of Washington, Washington, DC, 3Cornea and Refractive Surgery Division, Department of Ophthalmology, Francis I Proctor Foundation, University of California San Francisco, San Francisco, CA, USABackground: The Moria single-use adjustable depth trephine is a device that allows a goal trephination depth to be set prior to the surgical procedure.Methods: Eleven fresh human cadaveric eyes were trephined using 8.0 mm Moria single-use adjustable vacuum trephines. Prior to trephination, the average corneal pachymetry in the peripheral 7–10 mm range was obtained using anterior segment optical coherence tomography. The trephination depth was set to 80% of that value. Light microscopy was used to image anteroposterior cross-sections of each corneal specimen. Digital protractor software was used to evaluate the trephination angle, depth, and length. All adequately processed specimens were included in the analysis. In addition, trephination angle data from a previous publication by Moshirfar et al were used as a comparison with those of this study.Results: Trephination analysis of depth compared with pachymetry revealed a mean of 83.7%±6.53% (95% confidence interval 79.8–87.6. Maximum and minimum trephined depths were 95.35% and 71.3%, respectively. Trephination depth compared with angular corneal thickness yielded a mean of 66.2%±4.79% (95% confidence interval 63.0–69.4. Maximum and minimum depths were 73.7% and 59.7%, respectively. Analysis of trephination angle yielded a mean of 130.2±3.57 degrees (95% confidence interval 127.8–132.61. Maximum and minimum angles were 135.5 degrees and 126 degrees, respectively. The standard deviation of the trephination angle of the Moria trephine was found to be significantly less than that of Hessburg-Barron and Hanna trephines calculated in the previous study.Conclusion: The Moria

  14. Anterior segment study with the pentacam scheimpflug camera in refractive surgery candidates

    Directory of Open Access Journals (Sweden)

    Masih Hashemi

    2013-01-01

    Conclusions: Myopic eyes had steeper corneas than hyperopic eyes and anterior chamber measurements were significantly higher in the myopic eyes. In myopic eyes, AE max and PE max and K max measurements were higher, and ACD measurements were lower in the astigmatic groups.

  15. LET measurements with a liquid ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Tegami, Sara

    2013-02-08

    Deep-seated tumors can be efficiently treated with heavy charged particles. The characteristic depth dose profile inside the tissue (Bragg peak) allows to deliver a high dose inside the tumor, while sparing the neighboring healthy tissue. As compared to protons, heavy ions like carbon or oxygen produce a higher amount of ionization events along their track (and in particular at the end of the ion beam path), resulting in an irreparable damage to the DNA of the tumor cells. The density of such ionization events is described in terms of Linear Energy Transfer (LET), an important physical quantity, but difficult to be measured directly. The aim of this work is to determine LET of hadrontherapy beams by using Liquid Ionization Chambers (LIC). The ionization signal in LICs is affected by recombination effects that depend on the LET of the incident radiation. Differences in recombination effects in LICs and air-filled ionization chambers can be exploited to obtain the recombination index, which can be related to the LET, calculated by Monte Carlo methods. We thus developed a method to construct a calibration curve, which relates the recombination index with the LET at each depth in water. The result of this work can be used for online monitoring of the ion beam quality.

  16. Perforation forces of the intact porcine anterior lens capsule.

    Science.gov (United States)

    Ullrich, Franziska; Lussi, Jonas; Felekis, Dimitrios; Michels, Stephan; Petruska, Andrew J; Nelson, Bradley J

    2016-09-01

    During the first step of cataract surgery, the lens capsule is perforated and a circular hole is created with a sharp instrument, a procedure called capsulorhexis. To develop automated systems that can assist ophthalmologists during capsulorhexis, the forces required must be quantified. This study investigates perforation forces of the central anterior lens capsule in porcine eyes, which are used as a conservative model for the human eye. A micro-mechanical characterisation method is presented that measures capsular bag perforation forces with a high precision positioning and high-resolution force sensing system. The force during perforation of the anterior lens capsule was measured with various sized needles and indentation speeds and is found to be 15-35mN. A bio-mechanical model is identified that describes an exponential correlation between indentation force and depth, indicating strain hardening behaviour of the porcine anterior lens capsule. PMID:27254279

  17. Perforation forces of the intact porcine anterior lens capsule.

    Science.gov (United States)

    Ullrich, Franziska; Lussi, Jonas; Felekis, Dimitrios; Michels, Stephan; Petruska, Andrew J; Nelson, Bradley J

    2016-09-01

    During the first step of cataract surgery, the lens capsule is perforated and a circular hole is created with a sharp instrument, a procedure called capsulorhexis. To develop automated systems that can assist ophthalmologists during capsulorhexis, the forces required must be quantified. This study investigates perforation forces of the central anterior lens capsule in porcine eyes, which are used as a conservative model for the human eye. A micro-mechanical characterisation method is presented that measures capsular bag perforation forces with a high precision positioning and high-resolution force sensing system. The force during perforation of the anterior lens capsule was measured with various sized needles and indentation speeds and is found to be 15-35mN. A bio-mechanical model is identified that describes an exponential correlation between indentation force and depth, indicating strain hardening behaviour of the porcine anterior lens capsule.

  18. Development of Fission Chamber Assembly

    Institute of Scientific and Technical Information of China (English)

    YANGJinwei; ZHANGWei; SONGXianying; LIXu

    2003-01-01

    The fission chambers which are gas counters with fissile material inside chamber,provide essential information for plasma opcharacteristics. In conjunction with the neutron flux monitor system these provide time-resolved measurements of the global neutron source strength and fusion power from thermal nuclear fusion reactor as ITER for all plasma conditions for which neutrons are produced.

  19. The Big European Bubble Chamber

    CERN Document Server

    1977-01-01

    The 3.70 metre Big European Bubble Chamber (BEBC), dismantled on 9 August 1984. During operation it was one of the biggest detectors in the world, producing direct visual recordings of particle tracks. 6.3 million photos of interactions were taken with the chamber in the course of its existence.

  20. National Ignition Facility Target Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Wavrik, R W; Cox, J R; Fleming, P J

    2000-10-05

    On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This

  1. Ion chamber based neutron detectors

    Science.gov (United States)

    Derzon, Mark S; Galambos, Paul C; Renzi, Ronald F

    2014-12-16

    A neutron detector with monolithically integrated readout circuitry, including: a bonded semiconductor die; an ion chamber formed in the bonded semiconductor die; a first electrode and a second electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; and the readout circuitry which is electrically coupled to the first and second electrodes. The bonded semiconductor die includes an etched semiconductor substrate bonded to an active semiconductor substrate. The readout circuitry is formed in a portion of the active semiconductor substrate. The ion chamber has a substantially planar first surface on which the first electrode is formed and a substantially planar second surface, parallel to the first surface, on which the second electrode is formed. The distance between the first electrode and the second electrode may be equal to or less than the 50% attenuation length for neutrons in the neutron absorbing material filling the ion chamber.

  2. Forecasting magma-chamber rupture at Santorini volcano, Greece.

    Science.gov (United States)

    Browning, John; Drymoni, Kyriaki; Gudmundsson, Agust

    2015-01-01

    How much magma needs to be added to a shallow magma chamber to cause rupture, dyke injection, and a potential eruption? Models that yield reliable answers to this question are needed in order to facilitate eruption forecasting. Development of a long-lived shallow magma chamber requires periodic influx of magmas from a parental body at depth. This redistribution process does not necessarily cause an eruption but produces a net volume change that can be measured geodetically by inversion techniques. Using continuum-mechanics and fracture-mechanics principles, we calculate the amount of magma contained at shallow depth beneath Santorini volcano, Greece. We demonstrate through structural analysis of dykes exposed within the Santorini caldera, previously published data on the volume of recent eruptions, and geodetic measurements of the 2011-2012 unrest period, that the measured 0.02% increase in volume of Santorini's shallow magma chamber was associated with magmatic excess pressure increase of around 1.1 MPa. This excess pressure was high enough to bring the chamber roof close to rupture and dyke injection. For volcanoes with known typical extrusion and intrusion (dyke) volumes, the new methodology presented here makes it possible to forecast the conditions for magma-chamber failure and dyke injection at any geodetically well-monitored volcano. PMID:26507183

  3. Multidisciplinary management of anterior diastemata

    DEFF Research Database (Denmark)

    Furuse, Adilson Yoshio; Herkrath, Fernando José; Franco, Eduardo Jacomino;

    2007-01-01

    the aesthetic results when orthodontic therapy itself is not feasible. This article presents integrated orthodonticrestorative solutions of anterior diastemata, associated with the conditioning of the gingival tissue with composite resin, and discusses the most relevant aspects related to their etiology...

  4. Anterior approach for knee arthrography

    International Nuclear Information System (INIS)

    Objective. To develop a new method of magnetic resonance arthrography (MRA) of the knee using an anterior approach analogous to the portals used for knee arthroscopy.Design. An anterior approach to the knee joint was devised mimicking anterior portals used for knee arthroscopy. Seven patients scheduled for routine knee MRA were placed in a decubitus position and under fluoroscopic guidance a needle was advanced from a position adjacent to the patellar tendon into the knee joint. After confirmation of the needle tip location, a dilute gadolinium solution was injected.Results and conclusion. All the arthrograms were technically successful. The anterior approach to knee MRA has greater technical ease than the traditional approach with little patient discomfort. (orig.)

  5. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... Taperloc Microplasty stem and E-poly antioxidant-infused technology during a hip replacement through the anterior supine ... renewed interest at this time due to several advantages that it brings. The approach that is performed ...

  6. Anterior Approach Total Hip Replacement

    Medline Plus

    Full Text Available ... it to have any real negative or deleterious effect by removing the anterior capsule. Now I would ... is what happens with one of the competitive designs. Like I told you, I just take a ...

  7. Update on anterior ankle impingement

    OpenAIRE

    Vaseenon, Tanawat; Amendola, Annunziato

    2012-01-01

    Anterior ankle impingement results from an impingement of the ankle joint by a soft tissue or osteophyte formation at the anterior aspect of the distal tibia and talar neck. It often occurs secondary to direct trauma (impaction force) or repetitive ankle dorsiflexion (repetitive impaction and traction force). Chronic ankle pain, swelling, and limitation of ankle dorsiflexion are common complaints. Imaging is valuable for diagnosis of the bony impingement but not for the soft tissue impingemen...

  8. Anterior Segment Tomography with the Cirrus Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Eduardo B. Rodrigues

    2012-01-01

    Full Text Available Optical coherence tomography (OCT is an optical acquisition method to examine biological tissues. In recent years, OCT has become an important imaging technology used in diagnosing and following macular pathologies. Further development enabled application of optical coherence tomography in evaluation of the integrity of the nerve fiber layer, optic nerve cupping, anterior chamber angle, or corneal topography. In this manuscript we overview the use of OCT in the clinical practice to enable corneal, iris, ciliary body, and angle evaluation and diagnostics.

  9. Complexity and Dynamical Depth

    Directory of Open Access Journals (Sweden)

    Terrence Deacon

    2014-07-01

    Full Text Available We argue that a critical difference distinguishing machines from organisms and computers from brains is not complexity in a structural sense, but a difference in dynamical organization that is not well accounted for by current complexity measures. We propose a measure of the complexity of a system that is largely orthogonal to computational, information theoretic, or thermodynamic conceptions of structural complexity. What we call a system’s dynamical depth is a separate dimension of system complexity that measures the degree to which it exhibits discrete levels of nonlinear dynamical organization in which successive levels are distinguished by local entropy reduction and constraint generation. A system with greater dynamical depth than another consists of a greater number of such nested dynamical levels. Thus, a mechanical or linear thermodynamic system has less dynamical depth than an inorganic self-organized system, which has less dynamical depth than a living system. Including an assessment of dynamical depth can provide a more precise and systematic account of the fundamental difference between inorganic systems (low dynamical depth and living systems (high dynamical depth, irrespective of the number of their parts and the causal relations between them.

  10. Herds of methane chambers grazing bubbles

    Science.gov (United States)

    Grinham, Alistair; Dunbabin, Matthew

    2014-05-01

    Water to air methane emissions from freshwater reservoirs can be dominated by sediment bubbling (ebullitive) events. Previous work to quantify methane bubbling from a number of Australian sub-tropical reservoirs has shown that this can contribute as much as 95% of total emissions. These bubbling events are controlled by a variety of different factors including water depth, surface and internal waves, wind seiching, atmospheric pressure changes and water levels changes. Key to quantifying the magnitude of this emission pathway is estimating both the bubbling rate as well as the areal extent of bubbling. Both bubbling rate and areal extent are seldom constant and require persistent monitoring over extended time periods before true estimates can be generated. In this paper we present a novel system for persistent monitoring of both bubbling rate and areal extent using multiple robotic surface chambers and adaptive sampling (grazing) algorithms to automate the quantification process. Individual chambers are self-propelled and guided and communicate between each other without the need for supervised control. They can maintain station at a sampling site for a desired incubation period and continuously monitor, record and report fluxes during the incubation. To exploit the methane sensor detection capabilities, the chamber can be automatically lowered to decrease the head-space and increase concentration. The grazing algorithms assign a hierarchical order to chambers within a preselected zone. Chambers then converge on the individual recording the highest 15 minute bubbling rate. Individuals maintain a specified distance apart from each other during each sampling period before all individuals are then required to move to different locations based on a sampling algorithm (systematic or adaptive) exploiting prior measurements. This system has been field tested on a large-scale subtropical reservoir, Little Nerang Dam, and over monthly timescales. Using this technique

  11. Cyclically controlled welding purge chamber

    Science.gov (United States)

    Gallagher, Robert L. (Inventor)

    1996-01-01

    An arrangement for butt-welding cylindrical sections of large, thin-wall tanks includes a rotatable mandrel with side-by-side sets of radial position adjusters. Each set of adjusters bears on one of the tank sections adjacent the seam, to prevent the sections from sagging out-of-round. The mandrel rotates relative to the welder, so that a continuous seam is formed. A purge chamber is fixed in position behind the seam at the weld head, and is flushed with inert gas. The purge chamber includes a two-sided structure which is contiguous with the cylindrical sections and a circumferential vane to form an open-ended tube-like structure, through which the radial position adjusters pass as the mandrel and cylindrical workpiece sections rotate. The tube-like structure is formed into a chamber by a plurality of movable gates which are controlled to maintain a seal while allowing adjusters to progress through the purge chamber.

  12. The multigap resistive plate chamber

    Energy Technology Data Exchange (ETDEWEB)

    Zeballos, E. Cerron [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Crotty, I. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Hatzifotiadou, D. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Valverde, J. Lamas [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Univ. Louis Pasteur, Strasbourg (France); Neupane, S. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); World Lab., Lausanne (Switzerland); Williams, M. C. S. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Zichichi, A. [Univ. of Bologna, Bologna (Italy)

    2015-02-03

    The paper describes the multigap resistive plate chamber (RPC). This is a variant of the wide gap RPC. However it has much improved time resolution, while keeping all the other advantages of the wide gap RPC design.

  13. The HERMES Back Drift Chambers

    OpenAIRE

    al, S. Bernreuther et

    1998-01-01

    The tracking system of the HERMES spectrometer behind the bending magnet consists of two pairs of large planar 6-plane drift chambers. The design and performance of these chambers is described. This description comprises details on the mechanical and electronical design, information about the gas mixture used and its properties, results on alignment, calibration, resolution, and efficiencies, and a discussion of the experience gained through the first three years of operation.

  14. BEBC Big European Bubble Chamber

    CERN Multimedia

    1974-01-01

    A view of the dismantling of the magnet of BEBC, the 3.7 m European Bubble Chamber : iron magnetic shielding ; lower and upper parts of the vacuum enclosure of the magnet; turbo-molecular vacuum pumps for the "fish-eye" windows; the two superconducting coils; a handling platform; the two cryostats suspended from the bar of the travelling crane which has a 170 ton carrying capacity. The chamber proper, not dismantled, is inside the shielding.

  15. Comparative Study of Anterior Eye Segment Measurements with Spectral Swept-Source and Time-Domain Optical Coherence Tomography in Eyes with Corneal Dystrophies

    Directory of Open Access Journals (Sweden)

    Anna K. Nowinska

    2015-01-01

    Full Text Available Purpose. To compare anterior eye segment measurements and morphology obtained with two optical coherence tomography systems (TD OCT, SS OCT in eyes with corneal dystrophies (CDs. Methods. Fifty healthy volunteers (50 eyes and 54 patients (96 eyes diagnosed with CD (epithelial basement membrane dystrophy, EBMD = 12 eyes; Thiel-Behnke CD = 6 eyes; lattice CD TGFBI type = 15 eyes; granular CD type 1 = 7 eyes, granular CD type 2 = 2 eyes; macular CD = 23 eyes; and Fuchs endothelial CD = 31 eyes were recruited for the study. Automated and manual central corneal thickness (aCCT, mCCT, anterior chamber depth (ACD, and nasal and temporal trabecular iris angle (nTIA, tTIA were measured and compared with Bland-Altman plots. Results. Good agreement between the TD and SS OCT measurements was demonstrated for mCCT and aCCT in normal individuals and for mCCT in the CDs group. The ACD, nTIA, and tTIA measurements differed significantly in both groups. TBCD, LCD, and FECD caused increased CCT. MCD caused significant corneal thinning. FECD affected all analyzed parameters. Conclusions. Better agreement between SS OCT and TD OCT measurements was demonstrated in normal individuals compared to the CDs group. OCT provides comprehensive corneal deposits analysis and demonstrates the association of CD with CCT, ACD, and TIA measurements.

  16. Extreme skin depth waveguides

    CERN Document Server

    Jahani, Saman

    2014-01-01

    Recently, we introduced a paradigm shift in light confinement strategy and introduced a class of extreme skin depth (e-skid) photonic structures (S. Jahani and Z. Jacob, "Transparent sub-diffraction optics: nanoscale light confinement without metal," Optica 1, 96-100 (2014)). Here, we analytically establish that figures of merit related to light confinement in dielectric waveguides are fundamentally tied to the skin depth of waves in the cladding. We contrast the propagation characteristics of the fundamental mode of e-skid waveguides and conventional waveguides to show that the decay constant in the cladding is dramatically larger in e-skid waveguides, which is the origin of sub-diffraction confinement. Finally, we propose an approach to verify the reduced skin depth in experiment using the decrease in the Goos-H\\"anchen phase shift.

  17. Sexual dimorphism of the internal mandibular chamber in Fayum Pliohyracidae (Mammalia)

    Science.gov (United States)

    de Blieux, D.D.; Baumrind, M.R.; Simons, E.L.; Chatrath, P.S.; Meyer, G.E.; Attia, Y.S.

    2006-01-01

    An internal mandibular fenestra and chamber are found in many fossil hyracoids. The internal mandibular fenestra is located on the lingual surface of the mandibular corpus and opens into a chamber within the mandible. The mandibular chamber is maximally developed in late Eocene Thyrohyrax meyeri and early Oligocene Thyrohyrax domorictus from the Fayum Province of Egypt. The function of this chamber is unknown as it is not found in extant hyraxes, nor is it known to occur in any other mammal. In Thyrohyrax, this feature appears to be sexually dimorphic because it is confined to roughly one half of the specimens that otherwise cannot be separated by dental characteristics or measurements. It has been suggested that the chamber is found in females based on the presumed distribution of this character in other fossil hyracoids. Fossils from Fayum Quarry L-41, preserving the sexually dimorphic anterior dentition, show that, in Thyrohyrax meyeri and Thyrohyrax domorictus, the internal mandibular chamber is found in males. In Thyrohyrax litholagus, an internal mandibular fenestra and inflated mandibular chamber occurs in males whereas females show the variable presence of an internal mandibular fossa or fenestra but lack an expanded chamber. Other genera show differing patterns of sexual variation in which some Fayum hyracoids have an internal mandibular fenestra in both sexes but with the greatest development of the mandibular chamber occurring in males. We review functions proposed for the internal mandibular chamber and suggest that it housed a laryngeal air sac that may have had a vocal function by acting as a resonating chamber. ?? 2006 by the Society of Vertebrate Paleontology.

  18. Why bother about depth?

    DEFF Research Database (Denmark)

    Stæhr, Peter A.; Obrador, Biel; Christensen, Jesper Philip

    We present results from a newly developed method to determine depth specific rates of GPP, NEP and R using frequent automated profiles of DO and temperature. Metabolic rate calculations were made for three lakes of different trophic status using a diel DO methodology that integrates rates across ...

  19. Logging system depth recorder

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, C.L.; Harrell, J.W.

    1982-10-19

    A logging tool recording system counts and converts depth pulses into a digital coded format. Such digital coded format is converted to a serial digital word for recording on an analog recorder. During playback the digital serial word is converted back into a digital coded format for reproduction by means of a visual digital display.

  20. Plasma chemistry in wire chambers

    International Nuclear Information System (INIS)

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an 55Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed

  1. Emulsion Chamber Technology Experiment (ECT)

    Science.gov (United States)

    Gregory, John C.; Takahashi, Yoshiyuki

    1996-01-01

    The experimental objective of Emulsion Chamber Technology (ECT) was to develop space-borne emulsion chamber technology so that cosmic rays and nuclear interactions may subsequently be studied at extremely high energies with long exposures in space. A small emulsion chamber was built and flown on flight STS-62 of the Columbia in March 1994. Analysis of the several hundred layers of radiation-sensitive material has shown excellent post-flight condition and suitability for cosmic ray physics analysis at much longer exposures. Temperature control of the stack was 20 +/-1 C throughout the active control period and no significant deviations of temperature or pressure in the chamber were observed over the entire mission operations period. The unfortunate flight attitude of the orbiter (almost 90% Earth viewing) prevented any significant number of heavy particles (Z greater than or equal to 10) reaching the stack and the inverted flow of shower particles in the calorimeter has not allowed evaluation of absolute primary cosmic ray-detection efficiency nor of the practical time limits of useful exposure of these calorimeters in space to the level of detail originally planned. Nevertheless, analysis of the observed backgrounds and quality of the processed photographic and plastic materials after the flight show that productive exposures of emulsion chambers are feasible in low orbit for periods of up to one year or longer. The engineering approaches taken in the ECT program were proven effective and no major environmental obstacles to prolonged flight are evident.

  2. Anterior cruciate ligament - updating article.

    Science.gov (United States)

    Luzo, Marcus Vinicius Malheiros; Franciozi, Carlos Eduardo da Silveira; Rezende, Fernando Cury; Gracitelli, Guilherme Conforto; Debieux, Pedro; Cohen, Moisés

    2016-01-01

    This updating article on the anterior cruciate ligament (ACL) has the aim of addressing some of the most interesting current topics in this field. Within this stratified approach, it contains the following sections: ACL remnant; anterolateral ligament and combined intra and extra-articular reconstruction; fixation devices; and ACL femoral tunnel creation techniques.

  3. Anterior cruciate ligament - updating article.

    Science.gov (United States)

    Luzo, Marcus Vinicius Malheiros; Franciozi, Carlos Eduardo da Silveira; Rezende, Fernando Cury; Gracitelli, Guilherme Conforto; Debieux, Pedro; Cohen, Moisés

    2016-01-01

    This updating article on the anterior cruciate ligament (ACL) has the aim of addressing some of the most interesting current topics in this field. Within this stratified approach, it contains the following sections: ACL remnant; anterolateral ligament and combined intra and extra-articular reconstruction; fixation devices; and ACL femoral tunnel creation techniques. PMID:27517015

  4. Bluetooth Communication Interface for EEG Signal Recording in Hyperbaric Chambers.

    Science.gov (United States)

    Pastena, Lucio; Formaggio, Emanuela; Faralli, Fabio; Melucci, Massimo; Rossi, Marco; Gagliardi, Riccardo; Ricciardi, Lucio; Storti, Silvia F

    2015-07-01

    Recording biological signals inside a hyperbaric chamber poses technical challenges (the steel walls enclosing it greatly attenuate or completely block the signals as in a Faraday cage), practical (lengthy cables creating eddy currents), and safety (sparks hazard from power supply to the electronic apparatus inside the chamber) which can be overcome with new wireless technologies. In this technical report we present the design and implementation of a Bluetooth system for electroencephalographic (EEG) recording inside a hyperbaric chamber and describe the feasibility of EEG signal transmission outside the chamber. Differently from older systems, this technology allows the online recording of amplified signals, without interference from eddy currents. In an application of this technology, we measured EEG activity in professional divers under three experimental conditions in a hyperbaric chamber to determine how oxygen, assumed at a constant hyperbaric pressure of 2.8 ATA , affects the bioelectrical activity. The EEG spectral power estimated by fast Fourier transform and the cortical sources of the EEG rhythms estimated by low-resolution brain electromagnetic analysis were analyzed in three different EEG acquisitions: breathing air at sea level; breathing oxygen at a simulated depth of 18 msw, and breathing air at sea level after decompression. PMID:25608308

  5. Clinical outcomes of pars plicata anterior vitrectomy: 2-year results

    Directory of Open Access Journals (Sweden)

    Priya Narang

    2015-01-01

    Full Text Available Purpose: To demonstrate the safety and outcome of a surgical approach that uses pars plicata site for anterior vitrectomy during phacoemulsification procedure complicated by posterior capsule rupture and residual cortical matter. Design: Single center, retrospective, interventional, noncomparative study. Materials and Methods: Medical records of a consecutive series of 35 eyes of 35 patients who underwent pars plicata anterior vitrectomy (PPAV were reviewed. The main outcome measures were corrected and uncorrected distance visual acuity (CDVA, UDVA, early and late postoperative complications and intraocular pressure (IOP. Ultrasound biomicroscopic (UBM evaluation of sclerotomy site and spectral domain optical coherence tomography analysis for central macular thickness (CMT was performed. The final visual outcome at 2 years was evaluated. Results: At 2 years follow-up, the mean postoperative UDVA (logarithm of the minimum angle of resolution [logMAR] and CDVA (logMAR was 0.49 ± 0.26 and 0.19 ± 0.14, respectively. There was no significant change in the IOP (P = 0.061 and the mean CMT at 2 years was 192.5 ± 5.54 mm. The postoperative UBM image of the sclerotomy site at 8 weeks demonstrated a clear wound without any vitreous adhesion or incarceration. Intraoperative hyphema was seen in 1 (2.8% case and postoperative uveitis was seen in 2 (5.7% cases, which resolved with medications. No case of an iatrogenic retinal break or retinal detachment was reported. Conclusions: PPAV enables a closed chamber approach, allows thorough cleanup of vitreous in the pupillary plane and anterior chamber and affords better access to the subincisional and retropupillary cortical remnant with a significant visual outcome and an acceptable complication rate.

  6. Válvula de uretra anterior Anterior urethral valves

    Directory of Open Access Journals (Sweden)

    Silvio Tucci Jr.

    2003-02-01

    Full Text Available Objetivo: apresentar os aspectos clínicos, diagnósticos e terapêuticos de pacientes portadores de válvula da uretra anterior. Descrição: em dois neonatos, o diagnóstico presuntivo de patologia obstrutiva do trato urinário foi sugerido pela ultra-sonografia realizada no período pré-natal, confirmando-se o diagnóstico de válvula de uretra anterior pela avaliação pós-natal. Os pacientes foram submetidos a tratamento cirúrgico paliativo, com vesicostomia temporária e, posteriormente, definitivo, pela fulguração endoscópica das válvulas. Ambos evoluíram com função renal normal. Comentários: a válvula da uretra anterior é anomalia rara que deve ser considerada em meninos com quadro radiológico pré-natal sugestivo de obstrução infravesical, secundariamente à hipótese mais comum de válvula da uretra posterior. Ressaltamos a utilização da vesicostomia como derivação urinária temporária nestes casos, prevenindo potenciais complicações pela manipulação da uretra do recém-nascido.Objective: to discuss clinical signs, diagnostic tools and therapeutics of anterior urethral valves, an obstructive anomaly of the urinary system in males. Description: signs of urinary tract obstruction were identified on pre-natal ultrasound in two male fetuses and the diagnosis of anterior urethral valves was made through post-natal evaluation. As an initial treatment, vesicostomy was performed in both patients. Later, the valves were fulgurated using an endoscopic procedure. During the follow-up period both patients presented normal renal function. Comments: anterior urethral valves are a rare form of urethral anomaly that must be ruled out in boys with pre-natal ultrasound indicating infravesical obstruction. Vesicostomy used as an initial treatment rather than transurethral fulguration may prevent potential complications that can occur due to the small size of the neonatal urethra.

  7. Tohoku one meter bubble chamber

    International Nuclear Information System (INIS)

    At the request of Tohoku University and the National Laboratory for High Energy Physics, IHI has developed a complete freon bubble chamber system successfully, which is used for photo analysis of elementary particles physics. This system will be delivered to Fermi National Accelerator Laboratory (FNAL) in Illinois (U.S.A.) and will be coupled with the superconducting accelerator (TEVATRON) for the study of elementary particles. The total system of the freon bubble chamber is composed of a stainless steel casting spherical bubble chamber with a diameter of about one meter, an expansion system for freon pressure control, hydraulic system for driving an expansion piston, a freon feed system, a temperature control system, an overall control system as well as camera and flashlight for photograph. (author)

  8. The CLAS drift chamber system

    CERN Document Server

    Mestayer, M D; Asavapibhop, B; Barbosa, F J; Bonneau, P; Christo, S B; Dodge, G E; Dooling, T; Duncan, W S; Dytman, S A; Feuerbach, R; Gilfoyle, G P; Gyurjyan, V; Hicks, K H; Hicks, R S; Hyde-Wright, C E; Jacobs, G; Klein, A; Klein, F J; Kossov, M; Kuhn, S E; Magahiz, R A; Major, R W; Martin, C; McGuckin, T; McNabb, J; Miskimen, R A; Müller, J A; Niczyporuk, B B; O'Meara, J E; Qin, L M; Raue, B A; Robb, J; Roudot, F; Schumacher, R A; Tedeschi, D J; Thompson, R A; Tilles, D; Tuzel, W; Vansyoc, K; Vineyard, M F; Weinstein, L B; Wilkin, G R; Yegneswaran, A; Yun, J

    2000-01-01

    Experimental Hall B at Jefferson Laboratory houses the CEBAF Large Acceptance Spectrometer, the magnetic field of which is produced by a superconducting toroid. The six coils of this toroid divide the detector azimuthally into six sectors, each of which contains three large multi-layer drift chambers for tracking charged particles produced from a fixed target on the toroidal axis. Within the 18 drift chambers are a total of 35,148 individually instrumented hexagonal drift cells. The novel geometry of these chambers provides for good tracking resolution and efficiency, along with large acceptance. The design and construction challenges posed by these large-scale detectors are described, and detailed results are presented from in-beam measurements.

  9. The CLAS drift chamber system

    Energy Technology Data Exchange (ETDEWEB)

    Mestayer, M.D.; Carman, D.S.; Asavaphibhop, B. [and others

    1999-04-01

    Experimental Hall B at Jefferson Laboratory houses the CEBAF Large Acceptance Spectrometer, the magnetic field of which is produced by a superconducting toroid. The six coils of this toroid divide the detector azimuthally into six sectors, each of which contains three large multi-layer drift chambers for tracking charged particles produced from a fixed target on a toroidal axis. Within the 18 drift chambers are a total of 35,148 individually instrumented hexagonal drift cells. The novel geometry of these chambers provides for good tracking resolution and efficiency, along with large acceptance. The design and construction challenges posed by these large-scale detectors are described, and detailed results are presented from in-beam measurements.

  10. "Flat-Fish" Vacuum Chamber

    CERN Multimedia

    1978-01-01

    The picture shows a "Flat-Fish" vacuum chamber being prepared in the ISR workshop for testing prior to installation in the Split Field Magnet (SFM) at intersection I4. The two shells of each part were hydroformed from 0.15 mm thick inconel 718 sheet (with end parts in inconel 600 for easier manual welding to the arms) and welded toghether with two strips which were attached by means of thin stainless steel sheets to the Split Field Magnet poles in order to take the vertical component of the atmospheric pressure force. This was the thinnest vacuum chamber ever made for the ISR. Inconel material was chosen for its high elastic modulus and strenght at chamber bake-out temperature. In this picture the thin sheets transferring the vertical component of the atmosferic pressure force are attached to a support frame for testing. See also 7712182, 7712179.

  11. Impedances of Laminated Vacuum Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Burov, A.; Lebedev, V.; /Fermilab

    2011-06-22

    First publications on impedance of laminated vacuum chambers are related to early 70s: those are of S. C. Snowdon [1] and of A. G. Ruggiero [2]; fifteen years later, a revision paper of R. Gluckstern appeared [3]. All the publications were presented as Fermilab preprints, and there is no surprise in that: the Fermilab Booster has its laminated magnets open to the beam. Being in a reasonable mutual agreement, these publications were all devoted to the longitudinal impedance of round vacuum chambers. The transverse impedance and the flat geometry case were addressed in more recent paper of K. Y. Ng [4]. The latest calculations of A. Macridin et al. [5] revealed some disagreement with Ref. [4]; this fact stimulated us to get our own results on that matter. Longitudinal and transverse impendances are derived for round and flat laminated vacuum chambers. Results of this paper agree with Ref. [5].

  12. Evaluation of ion chamber dependent correction factors for ionisation chamber dosimetry in proton beams using a Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Palmans, H. [Ghent Univ. (Belgium). Dept. of Biomedical Physics; Verhaegen, F.

    1995-12-01

    In the last decade, several clinical proton beam therapy facilities have been developed. To satisfy the demand for uniformity in clinical (routine) proton beam dosimetry two dosimetry protocols (ECHED and AAPM) have been published. Both protocols neglect the influence of ion chamber dependent parameters on dose determination in proton beams because of the scatter properties of these beams, although the problem has not been studied thoroughly yet. A comparison between water calorimetry and ionisation chamber dosimetry showed a discrepancy of 2.6% between the former method and ionometry following the ECHED protocol. Possibly, a small part of this difference can be attributed to chamber dependent correction factors. Indications for this possibility are found in ionometry measurements. To allow the simulation of complex geometries with different media necessary for the study of those corrections, an existing proton Monte Carlo code (PTRAN, Berger) has been modified. The original code, that applies Mollire`s multiple scattering theory and Vavilov`s energy straggling theory, calculates depth dose profiles, energy distributions and radial distributions for pencil beams in water. Comparisons with measurements and calculations reported in the literature are done to test the program`s accuracy. Preliminary results of the influence of chamber design and chamber materials on dose to water determination are presented.

  13. Evaluation of ion chamber dependent correction factors for ionisation chamber dosimetry in proton beams using a Monte Carlo method

    International Nuclear Information System (INIS)

    In the last decade, several clinical proton beam therapy facilities have been developed. To satisfy the demand for uniformity in clinical (routine) proton beam dosimetry two dosimetry protocols (ECHED and AAPM) have been published. Both protocols neglect the influence of ion chamber dependent parameters on dose determination in proton beams because of the scatter properties of these beams, although the problem has not been studied thoroughly yet. A comparison between water calorimetry and ionisation chamber dosimetry showed a discrepancy of 2.6% between the former method and ionometry following the ECHED protocol. Possibly, a small part of this difference can be attributed to chamber dependent correction factors. Indications for this possibility are found in ionometry measurements. To allow the simulation of complex geometries with different media necessary for the study of those corrections, an existing proton Monte Carlo code (PTRAN, Berger) has been modified. The original code, that applies Mollire's multiple scattering theory and Vavilov's energy straggling theory, calculates depth dose profiles, energy distributions and radial distributions for pencil beams in water. Comparisons with measurements and calculations reported in the literature are done to test the program's accuracy. Preliminary results of the influence of chamber design and chamber materials on dose to water determination are presented

  14. Test chamber for alpha spectrometry

    Science.gov (United States)

    Larsen, Robert P.

    1977-01-01

    Alpha emitters for low-level radiochemical analysis by measurement of alpha spectra are positioned precisely with respect to the location of a surface-barrier detector by means of a chamber having a removable threaded planchet holder. A pedestal on the planchet holder holds a specimen in fixed engagement close to the detector. Insertion of the planchet holder establishes an O-ring seal that permits the chamber to be pumped to a desired vacuum. The detector is protected against accidental contact and resulting damage.

  15. The Clinical Analysis of Secondary Glaucoma Following Posterior Chamber Intraocular Lens Implantation

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    We present 14 patients with secondary gluacoma following the implantation of a posterior chamber intraocular lens (lOLs). All patients were u-nilateral gluacoma , which developed within 1 month following the IOL implantation in 10 cases, and from 1 to 3 years in 4 cases. The angle of anterior chamber was open in 8 patients, and close in 6 ones. Seven patients required treatment of antiglaucomatous medicine; 4 patients underwent laser indecto-my and 3 patients required antiglaucoma surgery. The results s...

  16. Complexity and Dynamical Depth

    OpenAIRE

    Terrence Deacon; Spyridon Koutroufinis

    2014-01-01

    We argue that a critical difference distinguishing machines from organisms and computers from brains is not complexity in a structural sense, but a difference in dynamical organization that is not well accounted for by current complexity measures. We propose a measure of the complexity of a system that is largely orthogonal to computational, information theoretic, or thermodynamic conceptions of structural complexity. What we call a system’s dynamical depth is a separate dimension of system c...

  17. Variable depth core sampler

    Science.gov (United States)

    Bourgeois, Peter M.; Reger, Robert J.

    1996-01-01

    A variable depth core sampler apparatus comprising a first circular hole saw member, having longitudinal sections that collapses to form a point and capture a sample, and a second circular hole saw member residing inside said first hole saw member to support the longitudinal sections of said first hole saw member and prevent them from collapsing to form a point. The second hole saw member may be raised and lowered inside said first hole saw member.

  18. MANIFEST OF DEPTH SOCIOPSYCHOLOGY

    OpenAIRE

    ZELITCHENKO ALEXANDER

    2013-01-01

    The observations of motives of activity of big groups (nations, confessions etc.) as a whole result in discovery of the part of unconscious mind that is common for all members of big group a collective unconscious. Two parts of collective unconscious may be determined: the collective superconscious known first as a group archetype and the collective subconscious, which manifest itself for example in phenomenon of collective trauma. Depth sociopsychology is a science about the collective uncon...

  19. Closed chamber globe stabilization and needle capsulorhexis using irrigation hand piece of bimanual irrigation and aspiration system

    Directory of Open Access Journals (Sweden)

    Rai Harminder K

    2005-08-01

    Full Text Available Abstract Background The prerequisites for a good capsulorhexis include a deep, well maintained anterior chamber, globe stabilization and globe manipulation. This helps to achieve a capsulorhexis of optimal size, shape and obtain the best possible position for a red glow under retroillumination. We report the use of irrigation handpiece of bimanual irrigation aspiration system to stabilize the globe, maintain a deep anterior chamber and manipulate the globe to a position of optimal red reflex during needle capsulorhexis in phacoemulsification. Methods Two side ports are made with 20 G MVR 'V' lance knife (Alcon, USA. The irrigation handpiece with irrigation on is introduced into the anterior chamber through one side port and the 26-G cystitome (made from 26-G needle is introduced through the other. The capsolurhexis is completed with the needle. Results Needle capsulorhexis with this technique was used in 30 cases of uncomplicated immature senile cataracts. 10 cases were done under peribulbar anaesthesia and 20 under topical anaesthesia. A complete capsulorhexis was achieved in all cases. Conclusion The irrigating handpiece maintains deep anterior chamber, stabilizes the globe, facilitates pupillary dilatation, and helps in maintaining the eye in the position with optimal red reflex during needle capsulorhexis. This technique is a safe and effective way to perform needle capsulorhexis.

  20. Posterior chamber phakic intraocular lens implantation for high myopia

    Institute of Scientific and Technical Information of China (English)

    沈晔; 杜持新; 顾扬顺; 王竞

    2003-01-01

    Objective To evaluate the efficacy, safety and stability of posterior chamber phakic intraocular lens (PIOLs) implantation for the correction of high myopia.Methods Thirty-nine eyes of twenty patients with high myopia (between-11.75 and-25.75 diopters) had a posterior chamber PIOL (Staar ICL) implanted. During 6-48 months' follow-up, visual acuity, refraction, intraocular pressure (IOP), corneal reaction and space between crystal lens and intraocular lens (IOLs) were tested.Results Successful implantation was achieved in all patients. Visual acuity without correction greater than 0.5 was found in 34 eyes at 1 day and 3 months postoperatively. Thirty-five eyes maintained a low negative power of refraction (-1.42±1.32 doipters), which did not prevent the patients from most of their daily activities. During 3-48 months' follow-up, refraction was stable and no cornea edema and glaucoma was found. Two eyes of one patient had corticosteroid glaucoma and another eye showed cataractogenesis under anterior capsular membrane.Conclusion Posterior chamber PIOL implantation is predictable, safe, and effective in the correction of high myopia, and its indications should be carefully selected.

  1. 38 CFR 3.379 - Anterior poliomyelitis.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Anterior poliomyelitis. 3... Specific Diseases § 3.379 Anterior poliomyelitis. If the first manifestations of acute anterior poliomyelitis present themselves in a veteran within 35 days of termination of active military service, it...

  2. DELPHI's Ring Imaging Cherenkov Chamber

    CERN Multimedia

    1989-01-01

    The hundreds of mirrors around this Ring Imaging Cherenkov Chamber reflect cones of light created by fast moving particles to a detector. The velocity of a particle can be measured by the size of the ring produced on the detector. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  3. Testing an hydrogen streamer chamber

    CERN Multimedia

    1975-01-01

    A 2x10 cm gap streamer chamber, 35x55 cm2 in surface, was built and tested at CERN. Good tracks of cosmic rays were obtained up to atmospheric pressure, see F. Rohrbach et al, CERN-LAL (Orsay) Collaboration, Nucl. Instr. Methods 141 (1977) 229. Michel Cathenoz stand on the center.

  4. Bubble chamber: colour enhanced tracks

    CERN Multimedia

    1998-01-01

    This artistically-enhanced image of real particle tracks was produced in the Big European Bubble Chamber (BEBC). Liquid hydrogen is used to create bubbles along the paths of the particles as a piston expands the medium. A magnetic field is produced in the detector causing the particles to travel in spirals, allowing charge and momentum to be measured.

  5. The TESLA Time Projection Chamber

    OpenAIRE

    Ghodbane, Nabil

    2002-01-01

    A large Time Projection Chamber is proposed as part of the tracking system for a detector at the TESLA electron positron linear collider. Different ongoing R&D studies are reviewed, stressing progress made on a new type readout technique based on Micro-Pattern Gas Detectors.

  6. Surgical Management of Significant Maxillary Anterior Vertical Ridge Defects.

    Science.gov (United States)

    Urban, Istvan A; Monje, Alberto; Nevins, Myron; Nevins, Marc L; Lozada, Jamie L; Wang, Hom-Lay

    2016-01-01

    Severe vertical ridge deficiency in the anterior maxilla represents one of the most challenging scenarios in bone regeneration. Under ideal circumstances, guided bone regeneration in combination with soft tissue management has shown predictable esthetic and functional outcomes. Success largely relies on primary wound closure during and after the surgical procedure. Surgical sites present different challenges that need to be considered when designing the flap. The goal of this article is to propose a classification of flap designs that considers vestibular depth and scar formation around the periosteum when performing vertical ridge augmentation in the atrophic anterior maxilla. The four clinical conditions proposed under this classification are (1) shallow vestibule with healthy periosteum, (2) deep vestibule with healthy periosteum, (3) shallow vestibule with scarred periosteum, and (4) deep vestibule with scarred periosteum. The classification will allow clinicians to achieve tension-free closure and more predictable vertical bone gain.

  7. Epidermoid cyst in Anterior, Middle

    Directory of Open Access Journals (Sweden)

    Kankane Vivek Kumar

    2016-09-01

    Full Text Available Epidermoid cysts are benign slow growing more often extra-axial tumors that insinuate between brain structures, we present the clinical, imaging, and pathological findings in 35 years old female patients with atypical epidermoid cysts which was situated anterior, middle & posterior cranial fossa. NCCT head revealed hypodense lesion over right temporal and perisylvian region with extension in prepontine cistern with mass effect & midline shift and MRI findings revealed a non-enhancing heterogeneous signal intensity cystic lesion in right frontal & temporal region extending into prepontine cistern with restricted diffusion. Patient was detoriated in night of same day of admission, emergency Fronto-temporal craniotomy with anterior peterousectomy and subtotal resection was done. The histological examination confirms the epidermoid cyst. The timing of ectodermal tissue sequestration during fetal development may account for the occurrence of atypical epidermoid cysts.

  8. Anterior impingement syndrome in dancers

    OpenAIRE

    O’Kane, John William; Kadel, Nancy

    2007-01-01

    Anterior impingement is a common problem in dancers occurring primarily secondary to the repetitive forced ankle dorsiflexion inherent in ballet. Symptoms generally occur progressively and may respond to conservative treatment including addressing biomechanical faults that contribute to the problem. As impingement progresses, movements essential to ballet may become impossible and arthroscopic ankle surgery is often effective for both diagnosis and treatment, allowing athletes to return to da...

  9. A CASE OF ANGLE - CLOSURE GLAUCOMA SECONDARY TO CHRONIC ANTERIOR UVEITIS

    Directory of Open Access Journals (Sweden)

    Pandu

    2015-05-01

    Full Text Available Elevation of intraocular pressure secondary to intraocular inflammation frequently presents a diagnostic & therapeutic challenge. Secondary glaucoma is more common in chronic anterior uveitis. We present a case of the same, a 25 years old female presented with headache and redness in right eye. She gives history of gradual loss of vision in both eyes 15 years back. On examination there was no perception of light in both eyes and pupillary reactions were absent in both eyes. Anterior segment of right eye showed circumciliary congestion, corneal edema, peripheral anterior synechiae, Aqueous flare of grade 1+, annular posterior synechiae with complicated cataract. Anterior segment of left eye showed shallow anterior chamber with closed angles and complicated cataract. A clinical diagnosis of secondary angle closure glaucoma was made. Once IOP was under control she underwent synechotomy and lens extraction in right eye and lens extraction in left eye. Post operatively corneal edema and congestion resolved. Fundus examination revealed glaucomatous optic atrophy. Thus, prompt and early treatment of anterior uveitis is needed to prevent secondary angle closure glaucoma. We report a case of secondary angle closure glaucoma in a young female patient.

  10. Coincidence of Varicella-Zoster Virus Anterior Uveitis in a Patient with Chandler's Syndrome

    Directory of Open Access Journals (Sweden)

    Takeshi Joko

    2013-11-01

    Full Text Available Purpose: We report a patient who, based on the clinical manifestations, was originally diagnosed as having Chandler's syndrome and later developed varicella-zoster virus (VZV DNA-positive anterior uveitis. Methods: The patient with Chandler's syndrome who manifested anterior uveitis underwent a complete ophthalmologic examination. Polymerase chain reaction (PCR was used to amplify the viral DNA in the aqueous humor to determine the cause of the intraocular inflammation. Results: Slit-lamp biomicroscopy showed focal iris atrophy and peripheral anterior synechiae (PAS; specular microscopy of the corneal endothelium disclosed the hammered-silver appearance. Based on these clinical findings, we diagnosed this patient as having Chandler's syndrome. During the follow-up period, however, the inflammatory cells suddenly appeared in the anterior chamber with formation of keratic precipitates and an increased intraocular pressure (IOP. VZV DNA was displayed in the aqueous humor by PCR. Based upon the diagnosis of VZV anterior uveitis, corticosteroids and acyclovir were given topically and systemically. The inflammation subsided with these medications; however, trabeculectomy was finally needed to control the IOP due to PAS progression. Conclusion: The coincidence of VZV anterior uveitis with Chandler's syndrome may constitute an implication for the possible viral etiology of iridocorneal endothelial syndrome.

  11. Selective importance of the rat anterior thalamic nuclei for configural learning involving distal spatial cues.

    Science.gov (United States)

    Dumont, Julie R; Amin, Eman; Aggleton, John P

    2014-01-01

    To test potential parallels between hippocampal and anterior thalamic function, rats with anterior thalamic lesions were trained on a series of biconditional learning tasks. The anterior thalamic lesions did not disrupt learning two biconditional associations in operant chambers where a specific auditory stimulus (tone or click) had a differential outcome depending on whether it was paired with a particular visual context (spot or checkered wall-paper) or a particular thermal context (warm or cool). Likewise, rats with anterior thalamic lesions successfully learnt a biconditional task when they were reinforced for digging in one of two distinct cups (containing either beads or shredded paper), depending on the particular appearance of the local context on which the cup was placed (one of two textured floors). In contrast, the same rats were severely impaired at learning the biconditional rule to select a specific cup when in a particular location within the test room. Place learning was then tested with a series of go/no-go discriminations. Rats with anterior thalamic nuclei lesions could learn to discriminate between two locations when they were approached from a constant direction. They could not, however, use this acquired location information to solve a subsequent spatial biconditional task where those same places dictated the correct choice of digging cup. Anterior thalamic lesions produced a selective, but severe, biconditional learning deficit when the task incorporated distal spatial cues. This deficit mirrors that seen in rats with hippocampal lesions, so extending potential interdependencies between the two sites.

  12. A new plant chamber facility PLUS coupled to the atmospheric simulation chamber SAPHIR

    OpenAIRE

    Hohaus, T.; Kuhn, U.; S. Andres; Kaminski, M.; Rohrer, F.; Tillmann, R.; A. Wahner; R. Wegener; Yu, Z.; Kiendler-Scharr, A.

    2015-01-01

    A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been build and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees are mixed with synthetic air and are transferred to the SAPHIR chamber ...

  13. Secondary signs of anterior cruciate ligament tear at MR imaging

    International Nuclear Information System (INIS)

    The value of secondary signs of anterior cruciate ligament (ACL) tear was evaluated. MR images of 47 knees, 15 with normal, 6 with acutely torn and 26 with chronically torn ACLs confirmed at arthroscopy, were reviewed. Lateral and medial anterior tibial translocations (ATT), posterior cruciate ligament (PCL) bowing ratio and depth of lateral femoral notch (LFN) were measured. The degrees of lateral and medial ATTs and the PCL bowing ratio of the chronically torn ACLs were significantly higher than those of normal ACLs. With cutoff values of 5-mm lateral ATT, 2.5-mm medial ATT and 0.35-PCL bowing ratio, torn ligaments were distinguished from intact ligaments with accuracies of over 80%. Depth of LFN was less sensitive and less accuracies. All knees with lateral ATT of 6.4 mm medial ATT of 3.5 mm, PCL bowing ratio of 0.43 and LFN depth of 1.5 mm or more had torn ACLs. Higher correlations were revealed between lateral ATT and medial ATT, and also between lateral ATT and PCL bowing ratio. Combined criteria of lateral ATT and PCL bowing ratio indicated the highest diagnostic value as a reliable secondary sign of torn ACLs. (author)

  14. Application of ultrasound biomicro-scopy in the planning of cataract surgery in anterior megalophthalmos

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Zare

    2011-01-01

    Full Text Available Anterior megalophthalmos, a rare hereditary disorder, is macrocornea (horizontal corneal diameter more than 13 mm in association with enlarged lens-iris diaphragm and ciliary ring. One of the major challenging issues in the cataract surgery of these patients is preventing intraocular lens (IOL malposition, because of probable large capsular bag. Several approaches have been selected by previous surgeons, such as, custom-made anterior chamber IOLs. In this study, we show a normal capsular bag diameter despite ciliary ring enlargement, with application of ultrasound biomicroscopy (UMB. We suggest that in cases of anterior megalophthalmos without phacodonesis, UBM could measure the actual size of the capsular bag and obviate the need for further procedures.

  15. MR determination of neonatal spinal canal depth

    Energy Technology Data Exchange (ETDEWEB)

    Arthurs, Owen, E-mail: owenarthurs@uk2.net [Centre for Cardiovascular MR, Great Ormond Street Hospital for Children, London WC1N 3JH (United Kingdom); Thayyil, Sudhin, E-mail: s.thayyil@ucl.ac.uk [Academic Neonatology, Institute for Women' s Health, London WC1E 6AU (United Kingdom); Wade, Angie, E-mail: a.wade@ucl.ac.uk [Centre for Paediatric Epidemiology and Biostatistics, UCL Institute of Child Health, London (United Kingdom); Chong, W.K., E-mail: Kling.Chong@gosh.nhs.uk [Paediatric Neuroradiology, Great Ormond Street Hospital for Children, London (United Kingdom); Sebire, Neil J., E-mail: Neil.Sebire@gosh.nhs.uk [Histopathology, Great Ormond Street Hospital for Children, London WC1E 6AU (United Kingdom); Taylor, Andrew M., E-mail: a.taylor76@ucl.ac.uk [Centre for Cardiovascular MR, Cardiorespiratory Unit, Great Ormond Street Hospital for Children and UCL Institute of Cardiovascular Science, London WC1E 6AU (United Kingdom)

    2012-08-15

    Objectives: Lumbar punctures (LPs) are frequently performed in neonates and often result in traumatic haemorrhagic taps. Knowledge of the distance from the skin to the middle of the spinal canal (mid-spinal canal depth - MSCD) may reduce the incidence of traumatic taps, but there is little data in extremely premature or low birth weight neonates. Here, we determined the spinal canal depth at post-mortem in perinatal deaths using magnetic resonance imaging (MRI). Patients and methods: Spinal canal depth was measured in 78 post-mortem foetuses and perinatal cases (mean gestation 26 weeks; mean weight 1.04 kg) at the L3/L4 inter-vertebral space at post-mortem MRI. Both anterior (ASCD) and posterior (PSCD) spinal canal depth were measured; MSCD was calculated and modelled against weight and gestational age. Results: ASCD and PSCD (mm) correlated significantly with weight and gestational age (all r > 0.8). A simple linear model MSCD (mm) = 3 Multiplication-Sign Weight (kg) + 5 was the best fit, identifying an SCD value within the correct range for 87.2% (68/78) (95% CI (78.0, 92.9%)) cases. Gestational age did not add significantly to the predictive value of the model. Conclusion: There is a significant correlation between MSCD and body weight at post-mortem MRI in foetuses and perinatal deaths. If this association holds in preterm neonates, use of the formula MSCD (mm) = 3 Multiplication-Sign Weight (kg) + 5 could result in fewer traumatic LPs in this population.

  16. Development of multiwire proportional chambers

    CERN Multimedia

    Charpak, G

    1969-01-01

    It has happened quite often in the history of science that theoreticians, confronted with some major difficulty, have successfully gone back thirty years to look at ideas that had then been thrown overboard. But it is rare that experimentalists go back thirty years to look again at equipment which had become out-dated. This is what Charpak and his colleagues did to emerge with the 'multiwire proportional chamber' which has several new features making it a very useful addition to the armoury of particle detectors. In the 1930s, ion-chambers, Geiger- Muller counters and proportional counters, were vital pieces of equipment in nuclear physics research. Other types of detectors have since largely replaced them but now the proportional counter, in new array, is making a comeback.

  17. LEP vacuum chamber, early prototype

    CERN Multimedia

    1978-01-01

    The structure of LEP, with long bending magnets and little access to the vacuum chamber between them, required distributed pumping. This is an early prototype for the LEP vacuum chamber, made from extruded aluminium. The main opening is for the beam. The small channel to the right is for cooling water, to carry away the heat deposited by the synchroton radiation from the beam. The 4 slots in the channel to the left house the strip-shaped ion-getter pumps (see 7810255). The ion-getter pumps depended on the magnetic field of the bending magnets, too low at injection energy for the pumps to function well. Also, a different design was required outside the bending magnets. This design was therefore abandoned, in favour of a thermal getter pump (see 8301153 and 8305170).

  18. Actuator System with Dual Chambers

    DEFF Research Database (Denmark)

    2015-01-01

    (8), the lid having a shaft opening (17) for a shaft (6) coupled to the magnetic rotor (5), wherein the magnetic rotor (5), when inserted in the translator cylinder (2), is arranged to translate a linear movement of the translator cylinder (2) into a rotational movement of the magnetic rotor by using...... magnetic flux (82) interacting between the magnetic stator and the magnetic rotor, said rotational movements is being transferred through a shaft (6), the lid (8) with a shaft opening (17) arranged for receiving the shaft (6), wherein the shaft is arranged to make both the linear and the rotational...... movement in the shaft opening (17), the lid (8) being arranged for confining the second end (15) of the translator cylinder (2), the translator cylinder confined by the lid (8) forms,when divided by the magnetic rotor (5), a first chamber (TC) with a first volume and a second chamber(BC) with a second...

  19. MPS II drift chamber system

    Energy Technology Data Exchange (ETDEWEB)

    Platner, E.D.

    1982-01-01

    The MPS II detectors are narrow drift space chambers designed for high position resolution in a magnetic field and in a very high particle flux environment. Central to this implementation was the development of 3 multi-channel custom IC's and one multi-channel hybrid. The system is deadtimeless and requires no corrections on an anode-to-anode basis. Operational experience and relevance to ISABELLE detectors is discussed.

  20. Morphological analysis of age-related iridocorneal angle changes in normal and glaucomatous cases using anterior segment optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Maruyama Y

    2013-12-01

    Full Text Available Yuko Maruyama, Kazuhiko Mori, Yoko Ikeda, Morio Ueno, Shigeru Kinoshita Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan Purpose: To analyze age-related morphological changes of the iridocorneal angle in normal subjects and glaucomatous cases, using anterior segment optical coherence tomography (AS-OCT. Methods: This study involved 58 eyes of 58 open-angle glaucoma cases and 72 eyes of 72 age-matched normal-open-angle control subjects. Iridocorneal angle structures in nasal and temporal regions and anterior chamber depth (ACD were measured using AS-OCT. Axial length and refractive error were measured by use of an ocular biometer and auto refractor keratometer. Angle opening distance (AOD, angle recess area (ARA, and trabecular-iris space area (TISA, measured at 500 µm (TISA500 and 750 µm (TISA750 distant from the scleral spur, were calculated, in the nasal and temporal regions. A new index, the peripheral angle frame index (PAFI, which represents the peripheral angle structure, was proposed, and was defined as (TISA750-TISA500/TISA500. Results: Refractive power in the glaucoma cases was less than in control cases (P<0.0001. Axial length (P<0.0001 and ACD (P=0.0004 were longer and deeper, respectively, in the glaucoma cases, compared with the control cases. In both control and glaucoma groups, ACD, AOD, ARA, and TISA decreased linearly in an age-dependent manner, while PAFI stayed at relatively constant values throughout the age distribution. AOD in the glaucoma group was longer than in the control group, in both the temporal and nasal regions; ARA and TISA were larger in the glaucoma than in the control group. However, no significant differences in nasal or temporal PAFI were found between the glaucoma and control groups. Conclusion: The findings of this study show that AS-OCT is useful for the quantitative evaluation of age-related changes in peripheral angle structure in glaucoma and control cases. Keywords

  1. The KEK 1 m hydrogen bubble chamber

    International Nuclear Information System (INIS)

    A medium size hydrogen bubble chamber has been constructed at the National Laboratory for High Energy Physics, KEK. The bubble chamber has been designed to be operated with a maximum rate of three times per half a second in every two second repetition time of the accelerator, by utilizing a hydraulic expansion system. The bubble chamber has a one meter diameter and a visible volume of about 280 l. A three-view stereo camera system is used for taking photographic pictures of the chamber. A 2 MW bubble chamber magnet is constructed. The main part of the bubble chamber vessel is supported by the magnet yoke. The magnet gives a maximum field of 18.4 kG at the centre of the fiducial volume of the chamber. The overall system of the KEK 1 m hydrogen bubble chamber facility is described in some detail. Some operational characteristics of the facility are also reported. (auth.)

  2. NRAO RF Anechoic Chamber & Antenna Range

    Data.gov (United States)

    Federal Laboratory Consortium — A shielded anechoic chamber measuring 15 by 15 by 37 feet is located in the Jansky Laboratory at Green Bank. This chamber has been outfitted as a far-field antenna...

  3. Growing and analyzing biofilms in flow chambers

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Sternberg, Claus

    2011-01-01

    This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic......, and disassembly and cleaning of the system. In addition, embedding and fluorescent in situ hybridization of flow chamber-grown biofilms are addressed....

  4. Frenectomy with anterior lingual sulcoplasty for an implant-supported overdenture: A clinical report.

    Science.gov (United States)

    Perri de Carvalho, Paulo Sergio; Janjacomo, Luiz Antonio; Ponzoni, Daniela

    2016-04-01

    This clinical report describes the deepening of a patient's anterior mandibular lingual sulcus in combination with frenectomy and the use of an acrylic resin guiding device fixed to an osseointegrated dental implant to maintain the patency of the new sulcular depth. PMID:26723097

  5. C1 anterior arch preservation in transnasal odontoidectomy using three-dimensional endoscope: A case report

    Directory of Open Access Journals (Sweden)

    Francesco Zenga

    2015-01-01

    Conclusions: The stereoscopic perception augmented the precision of the surgical gesture in the deep field. The importance of a 3D view relates to the depth of field, which a two-dimensional endoscopy cannot provide. This affects the preservation of the C1 anterior arch because of the presence of critical structures that are exposed to potential damage if not displayed.

  6. The Antiproton Depth-Dose Curve in Water

    DEFF Research Database (Denmark)

    Bassler, Niels; Holzscheiter, Michael; Jäkel, Oliver;

    2008-01-01

    We have measured the depth-dose curve of 126 MeV antiprotons in a water phantom using ionization chambers. Since the antiproton beam provided by CERN has a pulsed structure and possibly carries a high-LET component from the antiproton annihilation, it is necessary to correct the acquired charge...... for ion recombination effects. The results are compared with Monte Carlo calculations and were found to be in good agreement. Finally we compare the antiproton depth-dose curve with that of protons, and find a doubling of the physical dose in the peak region for antiprotons....

  7. LEP vacuum chamber cross-section

    CERN Multimedia

    1987-01-01

    This diagram shows the layout of the vacuum chambers used at LEP, which was in operation at CERN between 1989 and 2000. Vacuum chambers are necessary in accelerators to prevent unwanted interactions that can destabilise the beam. The pump on the right sucks air out of the chamber allowing the beam to progress with minimal interactions.

  8. A cryogenic chamber for scattering measurements

    OpenAIRE

    Lopes, M. I.; Chepel, V.; Kuchenkov, A.; Gonçalves, O. D.; Schechter, H.

    1999-01-01

    We have constructed a cryogenic chamber to measure scattering cross sections of photons in liquids of low-boiling point. The chamber was tested with liquid xenon using a 137Cs radioactive source emitting 662 keV photons. The spectra obtained are presented and analyzed, attesting the good performance of the chamber for the desired purposes.

  9. Subminiature fission chamber with gas tight penetration

    International Nuclear Information System (INIS)

    Fission chambers suffer from gas leaks at electric feed-trough. This micro chamber suppresses that defect thanks to an alumina plug and welded seal of the chamber sleeve. This device is easy to produce at industrial scale with reduced dimensions (1,5 mm diameter, 25 mm length). It can work with 30 m long feeding cables. (D.L.). 3 figs

  10. Vacuum chamber at intersection I-6

    CERN Multimedia

    1971-01-01

    The vacuum chamber at intersection region I-6, one of these where experiments in colliding-beam physics will be taking place. The "wheels" prevent the thin wall (1.5 mm) of the chamber from collapsing. The chamber is equipped with heating tapes and its wrapped in thermal insulation. Residual gas pressure at this and other similar regions is around 10_11.

  11. A Sensitive Cloud Chamber without Radioactive Sources

    Science.gov (United States)

    Zeze, Syoji; Itoh, Akio; Oyama, Ayu; Takahashi, Haruka

    2012-01-01

    We present a sensitive diffusion cloud chamber which does not require any radioactive sources. A major difference from commonly used chambers is the use of a heat sink as its bottom plate. The result of a performance test of the chamber is given. (Contains 8 figures.)

  12. Simple Cloud Chambers Using Gel Ice Packs

    Science.gov (United States)

    Kamata, Masahiro; Kubota, Miki

    2012-01-01

    Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

  13. Depth Echolocation Learnt by Novice Sighted People

    Science.gov (United States)

    Tonelli, Alessia; Brayda, Luca; Gori, Monica

    2016-01-01

    Some blind people have developed a unique technique, called echolocation, to orient themselves in unknown environments. More specifically, by self-generating a clicking noise with the tongue, echolocators gain knowledge about the external environment by perceiving more detailed object features. It is not clear to date whether sighted individuals can also develop such an extremely useful technique. To investigate this, here we test the ability of novice sighted participants to perform a depth echolocation task. Moreover, in order to evaluate whether the type of room (anechoic or reverberant) and the type of clicking sound (with the tongue or with the hands) influences the learning of this technique, we divided the entire sample into four groups. Half of the participants produced the clicking sound with their tongue, the other half with their hands. Half of the participants performed the task in an anechoic chamber, the other half in a reverberant room. Subjects stood in front of five bars, each of a different size, and at five different distances from the subject. The dimension of the bars ensured a constant subtended angle for the five distances considered. The task was to identify the correct distance of the bar. We found that, even by the second session, the participants were able to judge the correct depth of the bar at a rate greater than chance. Improvements in both precision and accuracy were observed in all experimental sessions. More interestingly, we found significantly better performance in the reverberant room than in the anechoic chamber. The type of clicking did not modulate our results. This suggests that the echolocation technique can also be learned by sighted individuals and that room reverberation can influence this learning process. More generally, this study shows that total loss of sight is not a prerequisite for echolocation skills this suggests important potential implications on rehabilitation settings for persons with residual vision. PMID

  14. Spontaneous fracture of an implanted posterior chamber polyimide intraocular lens haptic: A case report

    Directory of Open Access Journals (Sweden)

    Haemin Kang

    2014-01-01

    Full Text Available A 57-year-old male patient visited our clinic for decreased visual acuity in the right eye for 10 days. He denied any trauma history, but recalled that the symptom developed after straining. He had undergone uncomplicated phacoemulsification and posterior chamber intraocular lens (IOL implantation in the bag of the right eye 11 years ago. The IOL was a three-piece silicone polyimide-haptics design. On slit-lamp examination, the IOL optic and proximal part of nasal fractured haptic were found in the anterior chamber. The distal part of fractured haptic was observed in the capsular bag. He underwent IOL exchange. The fracture site of the haptic was near the optic-haptic junction. This is the unique case report of a spontaneous fracture of an implanted posterior chamber polyimide IOL haptic, which implies the possibility of IOL haptic fracture in various haptic materials.

  15. Offshore Wind Technology Depth Zones

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Coastal bathymetric depth, measured in meters at depth values of: -30, -60, -900 Shallow Zone (0-30m): Technology has been demonstrated on a commercial scale at...

  16. Time Evolution of Thermo-Mechanically and Chemically Coupled Magma Chambers

    Science.gov (United States)

    Ozimek, C.; Karlstrom, L.; Erickson, B. A.

    2015-12-01

    Complexity in the volcanic eruption cycle reflects time variation both of magma inputs to the crustal plumbing system and of crustal melt storage zones (magma chambers). These data include timing and volumes of eruptions, as well as erupted compositions. Thus models must take into account the coupled nature of physical attributes. Here we combine a thermo-mechanical model for magma chamber growth and pressurization with a chemical model for evolving chamber compositions, in the limit of rapid mixing, to study controls on eruption cycles and compositions through time. We solve for the mechanical evolution of a 1D magma chamber containing melt, crystals and bubbles, in a thermally evolving and viscoelastic crust. This pressure and temperature evolution constrains the input values of a chemical box model (Lee et al., 2013) that accounts for recharge, eruption, assimilation and fractional crystallization (REAFC) within the chamber. We plan to study the influence of melt supply, input composition, and chamber depth eruptive fluxes and compositions. Ultimately we will explore multiple chambers coupled by elastic-walled dikes. We expect that this framework will facilitate self-consistent inversion of long-term eruptive histories in terms of magma transport physics. Lee, C.-T. A., Lee, T.-C., Wu, C.-T., 2013. Modeling the compositional evolution of recharging, evacuating, and fractionating (REFC) magma chambers: Implications for differentiationof arc magmas. Geochemica Cosmochimica Acta, http://dx.doi.org/10.1016/j.gca.2013.08.009.

  17. Anterior chest wall examination reviewed

    Directory of Open Access Journals (Sweden)

    F. Trotta

    2011-09-01

    Full Text Available Anterior chest wall involvement is not infrequently observed within inflammatory arthropaties, particularly if one considers seronegative spondiloarthritides and SAPHO syndrome. Physical examination is unreliable and conventional X-rays analysis is an unsatisfactory tool during diagnostic work-up of this region. Scintigraphic techniques yield informations both on the activity and on the anatomical extent of the disease while computerized tomography visualize the elementary lesions, such as erosions, which characterize the process. Moreover, when available, magnetic resonance imaging couple the ability to finely visualize such lesions with the possibility to show early alterations and to characterize the “activity” of the disease, presenting itself as a powerful tool both for diagnosis and follow-up. This review briefly shows the applications of imaging techniques for the evaluation of the anterior chest wall focusing on what has been done in the SAPHO syndrome which can be considered prototypical for this regional involvement since it is the osteo-articular target mainly affected by the disease.

  18. Comment on ‘Proton beam monitor chamber calibration’

    Science.gov (United States)

    Palmans, Hugo; Vatnitsky, Stanislav M.

    2016-09-01

    We comment on a recent article (Gomà et al 2014 Phys. Med. Biol. 59 4961–71) which compares different routes of reference dosimetry for the energy dependent beam monitor calibration in scanned proton beams. In this article, a 3% discrepancy is reported between a Faraday cup and a plane-parallel ionization chamber in the experimental determination of the number of protons per monitor unit. It is further claimed that similar discrepancies between calorimetry and ionization chamber based dosimetry indicate that {{k}Q} -values tabulated for proton beams in IAEA TRS-398 might be overestimated. In this commentary we show, however, that this supporting argument misrepresents the evidence in the literature and that the results presented, together with published data, rather confirm that there exist unresolved problems with Faraday cup dosimetry. We also show that the comparison in terms of the number of protons gives a biased view on the uncertainty estimates for both detectors while the quantity of interest is absorbed dose to water or dose-area-product to water, even if a beam monitor is calibrated in terms of the number of protons. Gomà et al (2014 Phys. Med. Biol. 59 4961–71) also report on the discrepancy between cylindrical and plane-parallel ionization chambers and confirm experimentally that in the presence of a depth dose gradient, theoretical values of the effective point of measurement, or alternatively a gradient correction factor, account for the discrepancy. We believe this does not point to an error or shortcoming of IAEA TRS-398, which prescribes taking the centre of cylindrical ionization chambers as reference point, since it recommends reference dosimetry to be performed in the absence of a depth dose gradient. But these observations reveal that important aspects of beam monitor calibration in scanned proton beams are not addressed in IAEA TRS-398 given that those types of beams were not widely implemented at the time of its publication.

  19. Comment on ‘Proton beam monitor chamber calibration’

    Science.gov (United States)

    Palmans, Hugo; Vatnitsky, Stanislav M.

    2016-09-01

    We comment on a recent article (Gomà et al 2014 Phys. Med. Biol. 59 4961-71) which compares different routes of reference dosimetry for the energy dependent beam monitor calibration in scanned proton beams. In this article, a 3% discrepancy is reported between a Faraday cup and a plane-parallel ionization chamber in the experimental determination of the number of protons per monitor unit. It is further claimed that similar discrepancies between calorimetry and ionization chamber based dosimetry indicate that {{k}Q} -values tabulated for proton beams in IAEA TRS-398 might be overestimated. In this commentary we show, however, that this supporting argument misrepresents the evidence in the literature and that the results presented, together with published data, rather confirm that there exist unresolved problems with Faraday cup dosimetry. We also show that the comparison in terms of the number of protons gives a biased view on the uncertainty estimates for both detectors while the quantity of interest is absorbed dose to water or dose-area-product to water, even if a beam monitor is calibrated in terms of the number of protons. Gomà et al (2014 Phys. Med. Biol. 59 4961-71) also report on the discrepancy between cylindrical and plane-parallel ionization chambers and confirm experimentally that in the presence of a depth dose gradient, theoretical values of the effective point of measurement, or alternatively a gradient correction factor, account for the discrepancy. We believe this does not point to an error or shortcoming of IAEA TRS-398, which prescribes taking the centre of cylindrical ionization chambers as reference point, since it recommends reference dosimetry to be performed in the absence of a depth dose gradient. But these observations reveal that important aspects of beam monitor calibration in scanned proton beams are not addressed in IAEA TRS-398 given that those types of beams were not widely implemented at the time of its publication.

  20. Is biologic width of anterior and posterior teeth similar?

    Directory of Open Access Journals (Sweden)

    Amir Alireza Rasouli Ghahroudi

    2014-09-01

    Full Text Available The biologic width (BW includes attached epithelial cells and connective tissue attachment complex being very important in the periodontal health during prosthetic treatments as invading this zone can cause bone resorption and gingival recession. The present study investigated biologic width values in the normal periodontium in anterior and posterior teeth. 30 patients that referred from restorative department to periodontics department of Tehran University of medical sciences who need crown lengthening procedure on their teeth with no history of orthodontic, prosthodontic and periodontal treatment were randomly enrolled in this cross-sectional trial. Sulcus depths (SD as well as the distance between free gingival margin and the bone crest (FB of anterior and posterior teeth were measured by UNC-15 probe and compared. periodontium thickness was also assessed. The data were subjected to Student t test. Mean BW in the 43 anterior and 47 posterior teeth was measured and not significantly different (1.4651±0.39 mm vs. 1.6312±0.49 mm was observed; however, BW was significantly more in the teeth with thick periodontium compared to those with thin periodontium (1.703±0.5 vs. 1.408±0.35; P=0.002. BW not only is different in individuals but also could be dissimilar in different teeth and should be calculated independently prior to restorative treatments.

  1. Positioning of anterior teeth in removable dentures

    Directory of Open Access Journals (Sweden)

    Strajnić Ljiljana

    2002-01-01

    Full Text Available Introduction The aim of this paper was to present methods of placement of artificial anterior teeth in edentulous individuals. The following review takes account of the majority of papers published during the last 100 years. The review has been divided into sections regarding the method used to determine the position of artificial anterior teeth. Geometric aspect Gysi (1895-1920 produced the first scientific theory about the position of artificial anterior teeth. Physiognomic theory The aim of this theory is to find the most natural position for artificial anterior teeth for each individual. Camper's "face angle" as a physiognomic criterion, has been introduced in papers of Wehrli (1961, Marxhors (1966, Tanzer (1968, Lombardi (1973. Esthetic aspect Important names in the field of dental esthetics are: Schön and Singer (1961, Arnheim (1965, Krajiček (1969, Tanzer (1968, Lombardi (1973, Goldstein (1976. They have introduced principles of visual aspects for selection of contours, dimension and position of artificial anterior teeth. Constitution aspect Flagg (1880, Williams (1913 and Hrauf (1957, 1958, have considered body constitution and individual characteristics regarding position of artificial anterior teeth. Physiological theory In 1971, Marxhors pointed to the fact that the position of artificial teeth corresponds with the function of the surrounding soft tissue and from the aspect of physiognomy as well. Phonetic aspect According to Silverman (1962 artificial anterior teeth are nearest when we pronounce the sound "S". Cephalometrical research Rayson (1970, Watson (1989, Strajnić Lj. (1999, Bassi F. (2001 have presented cephalometric radiographic analyses of natural anterior teeth compared with cephalometric radiographic analyses of artificial anterior teeth. A review of dental literature shows several factors suggesting modalities which should determine the position of artificial anterior teeth. Numerous methods have been designed for

  2. Pharyngocutaneous fistula after anterior cervical spine surgery

    OpenAIRE

    Sansur, Charles A.; Early, Stephen; Reibel, James; Arlet, Vincent

    2009-01-01

    Pharyngocutaneous fistulae are rare complications of anterior spine surgery occurring in less than 0.1% of all anterior surgery cases. We report a case of a 19 year old female who sustained a C6 burst fracture with complete quadriplegia. She was treated urgently with a C6 corpectomy with anterior cage and plating followed by posterior cervical stabilization at another institution. Post operatively she developed a pharyngocutaneous fistula that failed to heal despite several attempts of closu...

  3. Incidental Anterior Cruciate Ligament Calcification: Case Report.

    Science.gov (United States)

    Hayashi, Hisami; Fischer, Hans

    2016-03-01

    The calcification of knee ligaments is a finding noted only in a handful of case reports. The finding of an anterior cruciate ligament calcification has been reported once in the literature. Comparable studies involving the posterior cruciate ligament, medial collateral ligament and an ossicle within the anterior cruciate ligament are likewise discussed in reports of symptomatic patients. We report a case of incidentally discovered anterior cruciate ligament calcification. We discuss the likely etiology and clinical implications of this finding.

  4. Efficiency improvements for ion chamber calculations in high energy photon beams.

    Science.gov (United States)

    Wulff, J; Zink, K; Kawrakow, I

    2008-04-01

    This article presents the implementation of several variance reduction techniques that dramatically improve the simulation efficiency of ion chamber dose and perturbation factor calculations. The cavity user code for the EGSnrc Monte Carlo code system is extended by photon cross-section enhancement (XCSE), an intermediate phase-space storage (IPSS) technique, and a correlated sampling (CS) scheme. XCSE increases the density of photon interaction sites inside and in the vicinity of the chamber and results-in combination with a Russian Roulette game for electrons that cannot reach the cavity volume-in an increased efficiency of up to a factor of 350 for calculating dose in a Farmer type chamber placed at 10 cm depth in a water phantom. In combination with the IPSS and CS techniques, the efficiency for the calculation of the central electrode perturbation factor Pcel can be increased by up to three orders of magnitude for a single chamber location and by nearly four orders of magnitude when considering the Pcel variation with depth or with distance from the central axis in a large field photon beam. The intermediate storage of the phase-space properties of particles entering a volume that contains many possible chamber locations leads to efficiency improvements by a factor larger than 500 when computing a profile of chamber doses in the field of a linear accelerator photon beam. All techniques are combined in a new EGSnrc user code egs_chamber. Optimum settings for the variance reduction parameters are investigated and are reported for a Farmer type ion chamber. A few example calculations illustrating the capabilities of the egs_chamber code are presented. PMID:18491527

  5. Herniation of the anterior lens capsule

    Directory of Open Access Journals (Sweden)

    Pereira Nolette

    2007-01-01

    Full Text Available Herniation of the anterior lens capsule is a rare abnormality in which the capsule bulges forward in the pupillary area. This herniation can be mistaken for an anterior lenticonus where both the capsule and the cortex bulge forward. The exact pathology behind this finding is still unclear. We report the clinical, ultrasound biomicroscopy (UBM and histopathological findings of a case of herniation of the anterior lens capsule. UBM helped to differentiate this entity from anterior lenticonus. Light microscopy revealed capsular splitting suggestive of capsular delamination and collection of fluid (aqueous in the area of herniation giving it a characteristic appearance.

  6. Experimental work on drift chambers

    International Nuclear Information System (INIS)

    An experimental work made on drift chambers is described in two chapters. In the firt chapter we present the description of the experimental installation used, as well as some details on the data adquisition systems and the characteristics on three ways used for calibration proposes (cosmic muons, β radiation and test beam using SPS at CERN facilities). The second chapter describes the defferent prototypes studied. The experimental set up and the analysis are given. Some results are discussed. The magnetic field effect is also studied. (Author)

  7. Severe anterior uveitis associated with idiopathic dacryoadenitis in diabetes mellitus patient

    Directory of Open Access Journals (Sweden)

    Takahashi YY

    2011-05-01

    Full Text Available Yasuhiro Takahashi¹, Hirohiko Kakizaki¹, Akihiro Ichinose², Masayoshi Iwaki¹¹Department of Ophthalmology, Aichi Medical University, Nagakute, Aichi, Japan; ²Department of Plastic Surgery, Kobe University, Kobe, Hyogo, JapanAbstract: A 38-year-old woman with diabetes mellitus complained of acute visual loss in the left eye (20/200 and swollen left upper eyelid. Slit lamp examination of the left eye revealed ciliary injection, posterior synechia iritis, numerous inflammatory cells, and fibrin exudates in the anterior chamber. T1-weighted enhanced magnetic resonance imaging demonstrated left lacrimal gland enhancement with inflammatory spread to the left anterior ocular segment. Blood examination showed increased blood sugar but the other components were within normal limits. The patient was treated with steroid pulse therapy (methylprednisolone 1 g/day × 3 days under a blood sugar control regimen in consultation with an endocrinologist, after which additional peribulbar injection of triamcinolone acetonide (40 mg was performed. Resolution of the anterior uveitis and the dacryoadenitis was obtained after 2 months and there was no recurrence 1 year after the therapy. This is a rare case of severe anterior uveitis caused by idiopathic dacryoadenitis in a patient with diabetes mellitus.Keywords: anterior uveitis, idiopathic dacryoadenitis, diabetes mellitus, magnetic resonance imaging, steroid

  8. Excitatory and inhibitory effects of prolactin release activated by nerve stimulation in rat anterior pituitary

    Directory of Open Access Journals (Sweden)

    Gao Li-Zhi

    2009-12-01

    Full Text Available Abstract Background A series of studies showed the presence of substantial amount of nerve fibers and their close relationship with the anterior pituitary gland cells. Our previous studies have suggested that aside from the classical theory of humoral regulation, the rat anterior pituitary has direct neural regulation on adrenocorticotropic hormone release. In rat anterior pituitary, typical synapses are found on every type of the hormone-secreting cells, many on lactotrophs. The present study was aimed at investigating the physiological significance of this synaptic relationship on prolactin release. Methods The anterior pituitary of rat was sliced and stimulated with electrical field in a self-designed perfusion chamber. The perfusate was continuously collected in aliquots and measured by radioimmunoassay for prolactin levels. After statistic analysis, differences of prolactin concentrations within and between groups were outlined. Results The results showed that stimulation at frequency of 2 Hz caused a quick enhancement of prolactin release, when stimulated at 10 Hz, prolactin release was found to be inhibited which came slower and lasted longer. The effect of nerve stimulation on prolactin release is diphasic and frequency dependent. Conclusions The present in vitro study offers the first physiological evidence that stimulation of nerve fibers can affect prolactin release in rat anterior pituitary. Low frequency stimulation enhances prolactin release and high frequency mainly inhibits it.

  9. Perawatan Gigitan Terbalik Anterior Dengan Menggunakan Inclined Plane

    OpenAIRE

    Siregar, Wilda A.

    2008-01-01

    Gigitan terbalik anterior adalah suatu anomali posisi gigi anterior atas yang lebih ke lingual dibandingkan gigi anterior bawah. Anomali gigitan terbalik anterior dapat ditemui pada periode gigi sulung, gigi bercampur, dan gigi permanen. Faktor etiologi gigitan terbalik anterior dibedakan atas dental, fungsional atau skeletal. Untuk menentukan etiologi dari anomali gigitan terbalik anterior perlu dilakukan diagnosa yang tepat. Perawatan gigitan terbalik anterior ini dapat dilakukan de...

  10. SU-D-19A-01: Can Farmer-Type Ionization Chambers Be Used to Improve the Accuracy of Low-Energy Electron Beam Reference Dosimetry?

    International Nuclear Information System (INIS)

    Purpose: To investigate the use of cylindrical Farmer-type ionization chambers to improve the accuracy of low-energy electron beam calibration. Historically, these chamber types have not been used in beams with incident energies less than 10 MeV (R50 < 4.3 cm) because early investigations suggested large (up to 5 %) fluence perturbation factors in these beams, implying that a significant component of uncertainty would be introduced if used for calibration. More recently, the assumptions used to determine perturbation corrections for cylindrical chambers have been questioned. Methods: Measurements are made with cylindrical chambers in Elekta Precise 4, 8 and 18 MeV electron beams. Several chamber types are investigated that employ graphite walls and aluminum electrodes with very similar specifications (NE2571, NE2505/3, FC65-G). Depth-ionization scans are measured in water in the 8 and 18 MeV beams. To reduce uncertainty from chamber positioning, measurements in the 4 MeV beam are made at the reference depth in Virtual Water™. The variability of perturbation factors is quantified by comparing normalized response of various chambers. Results: Normalized ion chamber response varies by less than 0.7 % for similar chambers at average electron energies corresponding to that at the reference depth from 4 or 6 MeV beams. Similarly, normalized measurements made with similar chambers at the reference depth in the 4 MeV beam vary by less than 0.4 %. Absorbed dose calibration coefficients derived from these results are stable within 0.1 % on average over a period of 6 years. Conclusion: These results indicate that the uncertainty associated with differences in fluence perturbations for cylindrical chambers with similar specifications is only 0.2 %. The excellent long-term stability of these chambers in both photon and electron beams suggests that these chambers might offer the best performance for all reference dosimetry applications

  11. SU-D-19A-01: Can Farmer-Type Ionization Chambers Be Used to Improve the Accuracy of Low-Energy Electron Beam Reference Dosimetry?

    Energy Technology Data Exchange (ETDEWEB)

    Muir, B R; McEwen, M R [Measurement Science and Standards, National Research Council, Ottawa, ON (Canada)

    2014-06-01

    Purpose: To investigate the use of cylindrical Farmer-type ionization chambers to improve the accuracy of low-energy electron beam calibration. Historically, these chamber types have not been used in beams with incident energies less than 10 MeV (R{sub 5} {sub 0} < 4.3 cm) because early investigations suggested large (up to 5 %) fluence perturbation factors in these beams, implying that a significant component of uncertainty would be introduced if used for calibration. More recently, the assumptions used to determine perturbation corrections for cylindrical chambers have been questioned. Methods: Measurements are made with cylindrical chambers in Elekta Precise 4, 8 and 18 MeV electron beams. Several chamber types are investigated that employ graphite walls and aluminum electrodes with very similar specifications (NE2571, NE2505/3, FC65-G). Depth-ionization scans are measured in water in the 8 and 18 MeV beams. To reduce uncertainty from chamber positioning, measurements in the 4 MeV beam are made at the reference depth in Virtual Water™. The variability of perturbation factors is quantified by comparing normalized response of various chambers. Results: Normalized ion chamber response varies by less than 0.7 % for similar chambers at average electron energies corresponding to that at the reference depth from 4 or 6 MeV beams. Similarly, normalized measurements made with similar chambers at the reference depth in the 4 MeV beam vary by less than 0.4 %. Absorbed dose calibration coefficients derived from these results are stable within 0.1 % on average over a period of 6 years. Conclusion: These results indicate that the uncertainty associated with differences in fluence perturbations for cylindrical chambers with similar specifications is only 0.2 %. The excellent long-term stability of these chambers in both photon and electron beams suggests that these chambers might offer the best performance for all reference dosimetry applications.

  12. Anterior-posterior asymmetry in iris mechanics measured by indentation.

    Science.gov (United States)

    Whitcomb, Julie E; Amini, Rouzbeh; Simha, Narendra K; Barocas, Victor H

    2011-10-01

    Indentation and histological analysis of the porcine iris were done to assess the relative stiffness of the anterior (stroma) and posterior (dilator and sphincter) layers. The dimensions of the constituent structures were documented histologically by staining with a monoclonal anti-human α-smooth muscle actin antibody to determine the location of the stroma, sphincter, and dilator. Intact porcine irides (4-8 h post-mortem) were bisected into two equal C-shaped halves to indent both surfaces. Indentation experiments were performed using a 1 mm cylindrical indenter tip. The load-displacement curve for each experiment was used to estimate effective instantaneous and equilibrium moduli for the anterior and posterior surfaces of the tissue. A total of 18 irides (9 pairs) with 3-5 indentations per iris surface was performed. The average thickness of the samples was 550 μm; the indentation depth was limited to 60-100 μm depending on the thickness of the sample at each point. Posterior surface indentation gave larger forces than anterior, with the resulting instantaneous modulus of 6.0 ± 0.6 kPa versus 4.0 ± 0.5 kPa (mean ± 95% CI, n = 45, p poroelasticity, we conclude that the posterior components of the iris - dilator, pigment epithelium, and sphincter - are on average stiffer than the stroma and anterior border layer. PMID:21787771

  13. Isotopic evidence for multiple contributions to felsic magma chambers

    DEFF Research Database (Denmark)

    Waight, Tod Earle; Wiebe, R.A.; Krogstad, E.J.

    2007-01-01

    by contemporaneous mafic magmas; the transition between the two now preserved as a zone of chilled mafic sheets and pillows in granite. Mafic components have highly variably isotopic compositions as a result of contamination either at depth or following injection into the magma chamber. Intermediate dikes...... exchange between the contemporaneous mafic magmas and the host granite to explain highly variable alkali contents. The felsic enclaves have relatively low Nd isotopic compositions (eNd=+2 - +1) indicative of the involvement of a third, lower eNd melt during granite petrogenesis, perhaps represented...

  14. Multiwire proportional chamber for Moessbauer spectroscopy: development and results

    International Nuclear Information System (INIS)

    A new Multiwere proportional Chamber designed for Moessbauer Spectroscopy is presented. This detector allows transmission backscattering experiments using either photons or electrons. The Moessbauer data acquisition system, partially developed for this work is described. A simple method for determining the frontier between true proportional and semi-proportional regions of operation in gaseous detectors is proposed. The study of the tertiary gas mixture He-Ar-CH4 leads to a straight forward way of energy calibration of the electron spectra. Moessbauer spectra using Fe-57 source are presented. In particular those obtained with backsattered electrons show the feasibility of depth selective analysis with gaseous proportional counters. (author)

  15. Physicist makes muon chamber sing

    CERN Multimedia

    2007-01-01

    This Monitored Drift Tube detector, consisting of argon-CO2-filled aluminium tubes with a wire down the centre of each, will track muons in ATLAS; Tiecke used a single tube from one of these detectors to create the pipes in his organ. Particle physicists can make good musicians; but did you know particle detectors can make good music? That's what NIKHEF physicist Henk Tiecke learned when he used pipes cut from the ATLAS Monitored Drift Tube detector (MDT) to build his own working Dutch-style barrel organ in the autumn of 2005. 'I like to work with my hands,' said Tiecke, who worked as a senior physicist at NIKHEF, Amsterdam, on ZEUS until his retirement last summer. Tiecke had already constructed his barrel organ when he visited some colleagues in the ATLAS muon chambers production area at Nikhef in 2005. He noticed that the aluminium tubes they were using to build the chambers were about three centimetres in diameter-just the right size for a pipe in a barrel organ. 'The sound is not as nice as from wooden...

  16. Limits to Drift Chamber Resolution

    CERN Document Server

    Riegler, Werner

    1998-01-01

    ATLAS (A Large Toroidal LHC Apparatus) will be a general-purpose experiment at the Large Hadron Collider that will be operational at CERN in the year 2004. The ATLAS muon spectrometer aims for a momentum resolution of 10% for a transverse momentum of pT=1TeV. The precision tracking devices in the muon system will be high pressure drift tubes (MDTs) with a single wire resolution of 1100 chambers covering an area of ≈ 2500m2. The high counting rates in the spectrometer as well as the aim for excellent spatial resolution and high efficiency put severe constraints on the MDT operating parameters. This work describes a detailed study of all the resolution limiting factors in the ATLAS environment. A ’full chain’ simulation of the MDT response to photons and charged particles as well as quantitative comparisons with measurements was performed. The good agreement between simulation and measurements resulted in a profound understanding of the drift chamber processes and the individual contributions to the spat...

  17. Anterior lamina cribrosa surface position in idiopathic intracranial hypertension and glaucoma

    DEFF Research Database (Denmark)

    Villarruel, Jenni Martinez; Li, Xiao Q; Bach-Holm, Daniella;

    2016-01-01

    PURPOSE: To compare the anterior lamina cribrosa (LC) surface position in patients with idiopathic intracranial hypertension (IIH), primary open-angle glaucoma (high-tension glaucoma [HTG] and normal-tension glaucoma [NTG]), and healthy controls using enhanced depth imaging spectral-domain optical...... coherence tomography (EDI-OCT). METHODS: This was a retrospective, cross-sectional observational study of 11 eyes with IIH, 20 eyes with HTG, 20 eyes with NTG, and 37 control eyes. Serial horizontal B-scans of the optic nerve head were obtained using EDI-OCT. The LC depth, defined as the distance from...... the Bruch membrane opening plane to the anterior LC surface, was manually measured on selected B-scans covering the central three-quarters of the optic nerve head in each eye. RESULTS: Mean LC depth in patients with IIH (325.2 ± 92.1 µm) was significantly (p<0.01) decreased compared to control subjects...

  18. Toxic Anterior Segment Syndrome (TASS

    Directory of Open Access Journals (Sweden)

    Özlem Öner

    2011-12-01

    Full Text Available Toxic anterior segment syndrome (TASS is a sterile intraocular inflammation caused by noninfectious substances, resulting in extensive toxic damage to the intraocular tissues. Possible etiologic factors of TASS include surgical trauma, bacterial endotoxin, intraocular solutions with inappropriate pH and osmolality, preservatives, denatured ophthalmic viscosurgical devices (OVD, inadequate sterilization, cleaning and rinsing of surgical devices, intraocular lenses, polishing and sterilizing compounds which are related to intraocular lenses. The characteristic signs and symptoms such as blurred vision, corneal edema, hypopyon and nonreactive pupil usually occur 24 hours after the cataract surgery. The differential diagnosis of TASS from infectious endophthalmitis is important. The main treatment for TASS formation is prevention. TASS is a cataract surgery complication that is more commonly seen nowadays. In this article, the possible underlying causes as well as treatment and prevention methods of TASS are summarized. (Turk J Oph thal mol 2011; 41: 407-13

  19. Mild toxic anterior segment syndrome mimicking delayed onset toxic anterior segment syndrome after cataract surgery

    Directory of Open Access Journals (Sweden)

    Su-Na Lee

    2014-01-01

    Full Text Available Toxic anterior segment syndrome (TASS is an acute sterile postoperative anterior segment inflammation that may occur after anterior segment surgery. I report herein a case that developed mild TASS in one eye after bilateral uneventful cataract surgery, which was masked during early postoperative period under steroid eye drop and mimicking delayed onset TASS after switching to weaker steroid eye drop.

  20. Impaired anterior swim bladder inflation following exposure to the thyroid peroxidase inhibitor 2-mercaptobenzothiazole part II: Zebrafish.

    Science.gov (United States)

    Stinckens, Evelyn; Vergauwen, Lucia; Schroeder, Anthony L; Maho, Walid; Blackwell, Brett R; Witters, Hilda; Blust, Ronny; Ankley, Gerald T; Covaci, Adrian; Villeneuve, Daniel L; Knapen, Dries

    2016-04-01

    Disruption of the thyroid hormone (TH) system, an important mode of action, can lead to ecologically relevant adverse outcomes, especially during embryonic development. The present study characterizes the effects of disruption of TH synthesis on swim bladder inflation during zebrafish early-life stages using 2-mercaptobenzothiazole (MBT), a thyroid peroxidase (TPO) inhibitor. Zebrafish were exposed to different MBT concentrations until 120/168h post fertilization (hpf) and 32days post fertilization (dpf), in two sets of experiments, to investigate the effects of TPO inhibition on posterior and anterior swim bladder inflation respectively, as well as whole body thyroid hormone concentrations (triiodothyronine (T3) and its prohormone, thyroxine (T4)). At 120hpf, MBT did not directly impair posterior chamber inflation or size, while anterior chamber inflation and size was impaired at 32dpf. As previously shown in amphibians and mammals, we confirmed that MBT inhibits TPO in fish. Whole-body T4 decreased after MBT exposure at both time points, while T3 levels were unaltered. There was a significant relationship between T4 levels and the anterior chamber surface at 32dpf. The absence of effects on posterior chamber inflation can possibly be explained by maternal transfer of T4 into the eggs. These maternally derived THs are depleted at 32dpf and cannot offset TPO inhibition, resulting in impaired anterior chamber inflation. Therefore, we hypothesize that TPO inhibition only inhibits swim bladder inflation during late development, after depletion of maternally derived T4. In a previous study, we showed that iodothyronine deiodinase (ID) knockdown impaired posterior chamber inflation during early development. Our findings, in parallel with similar effects observed in fathead minnow (see part I, this issue) suggest that thyroid disruption impacts swim bladder inflation, and imply an important distinction among specific subtypes of TH disrupting chemicals. However, the

  1. Anterior segment complications of retinal photocoagulation.

    Science.gov (United States)

    Kanski, J J

    1975-03-01

    Seven patients had anterior segment complications following xenon arc retinal photocoagulation. Irreversible keratopathy was induced in two cases; all patients showed evidence of iris injury. The absorption of radiation by the iris was considered the main factor in producing overheating of the anterior segment.

  2. Dentulous Appliance for Upper Anterior Edentulous Span

    OpenAIRE

    Chalakkal, Paul; Devi, Ramisetty Sabitha; Srinivas, G Vijay; Venkataramana, Pammi

    2013-01-01

    This article discusses about a fixed dentulous appliance that was constructed to replace the primary upper anterior edentulous span in a four year old girl. It constituted a design, whereby the maxillary primary second molars were used to support the appliance through bands and a wire that contained an acrylic flange bearing trimmed acrylic teeth, anteriorly. The appliance was functionally and aesthetically compliant.

  3. Totally thrombosed giant anterior communicating artery aneurysm

    Directory of Open Access Journals (Sweden)

    V R Roopesh Kumar

    2015-01-01

    Full Text Available Giant anterior communicating artery aneurysmsarerare. Apatient presented with visual dysfunction, gait ataxia and urinary incontinence. MRI showed a giant suprasellar mass.At surgery, the lesion was identified as being an aneurysm arising from the anterior communicating artery.The difficulty in preoperative diagnosis and relevant literature are reviewed.

  4. Chordal geometry determines the shape and extent of systolic anterior mitral motion: in vitro studies.

    Science.gov (United States)

    Cape, E G; Simons, D; Jimoh, A; Weyman, A E; Yoganathan, A P; Levine, R A

    1989-05-01

    In patients with hypertrophic cardiomyopathy, the mitral valve moves anteriorly and assumes a unique shape, with mitral-septal contact centrally and preserved valve orifice area laterally. This shape is not clearly predicted by the Venturi mechanism, which stresses flow above the valve as opposed to changes intrinsic to the valve. On the other hand, it has been suggested that displacement of the papillary muscles anteriorly and toward one another, as observed in this disease, can promote anterior mitral valve motion and produce this unusual shape. The purpose of this in vitro study was to test the hypotheses that anterior motion of a membrane in a flow field can be generated by altering the distribution or effectiveness of chordal tension tethering the membrane, and that the shape achieved by this membrane depends on the geometry of chordal tension. Accordingly, a horizontal leaflet mounted in a flow chamber was attached by chords at its distal end to a series of upstream screws. Chordal tension could be varied by turning the screws or redirected by shifting the screws anteriorly. Anterior leaflet motion having the same unusual configuration seen in patients was reproduced by decreasing central chordal restraint while tension on the leaflet edges was maintained. Directing chordal tension anteriorly caused greater degrees of anterior motion at earlier stages in the release of chordal restraint; increased flow rate had a similar but less marked effect. These studies suggest that primary geometric alterations in the papillary-mitral apparatus can play an important role in determining the presence and geometry of systolic anterior mitral motion. The nature of these alterations suggests a role for anterior and inward papillary muscle displacement in promoting such motion. The geometric factors embodied in this model can explain many observed features of this motion not adequately explained by the Venturi effect, such as early systolic onset and the importance of a

  5. Neutron-chamber detectors and applications

    International Nuclear Information System (INIS)

    Detector applications in Nuclear Safeguards and Waste Management have included measuring neutrons from fission and (alpha,n) reactions with well-moderated neutron proportional counters, often embedded in a slab of polyethylene. Other less-moderated geometries are useful for detecting both bare and moderated fission-source neutrons with good efficiency. The neutron chamber is an undermoderated detector design comprising a large, hollow, polyethylene-walled chamber containing one or more proportional counters. Neutron-chamber detectors are relatively inexpensive; can have large apertures, usually through a thin chamber wall; and offer very good detection efficiency per dollar. Neutron-chamber detectors have also been used for monitoring vehicles and for assaying large crates of transuranic waste. Our Monte Carlo calculations for a new application (monitoring low-density waste for concealed plutonium) illustrate the advantages of the hollow-chamber design for detecting moderated fission sources. 9 refs., 6 figs., 2 tabs

  6. A mathematical model of aerosol holding chambers

    DEFF Research Database (Denmark)

    Zak, M; Madsen, J; Berg, E;

    1999-01-01

    A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol...... in the chamber with time. Four different spacers were connected via filters to a mechanical lung model, and aerosol delivery during "breathing" was determined from drug recovery from the filters. The formula correctly predicted the delivery of budesonide aerosol from the AeroChamber (Trudell Medical, London......, Ontario, Canada), NebuChamber (Astra, Södirtälje, Sweden) and Nebuhaler (Astra) adapted for babies. The dose of fluticasone proportionate delivered by the Babyhaler (Glaxco Wellcome, Oxbridge, Middlesex, UK) was 80% of that predicted, probably because of incomplete priming of this spacer. Of the above...

  7. Repatriation of Gamma Chambers Exported by India

    International Nuclear Information System (INIS)

    The Board of Radiation and Isotope Technology (BRIT) is engaged in the production and supply of laboratory gamma chambers. The gamma chambers are self-shielded devices in which a number of 60Co source pencils placed in a cylindrical cage. The gamma chambers are type approved as a device and a transportation package separately by the Atomic Energy Regulatory Board. BRIT has exported number of such gamma chambers. For some of the gamma chambers, the type approval validity period is over and can no longer be transported. Hence, the radiation sources need to be transferred to a type approved package before transportation. BRIT has decommissioned five such gamma chambers so far and sources have been repatriated back to India. (author)

  8. Legacies of the bubble chamber

    International Nuclear Information System (INIS)

    Legacies are what we pass on to those who follow us, the foundations on which the next advances in our science are being made; the things by which we shall be remembered, recorded in learned journals, written in the text books -food for the historians of science. This is not a summary, and it will draw no conclusions. It is a personal view which will look a little wider than the main physics results to include a mention of one or two of the technologies and methods handed on to both particle physics and other branches of sciences, a brief reference to bubble chamber pictures as aids in teaching, and a comment on the challenge now increasingly applied in the UK - and perhaps elsewhere -as a criterion for funding research: will it contribute to ''wealth creation''? (orig.)

  9. A knotless, one-haptic fixation of posterior chamber intraocular lenses: one-year results

    Institute of Scientific and Technical Information of China (English)

    Pipat; Kongsap

    2015-01-01

    AIM: To assess the results of a modified technique for scleral fixation of a posterior chamber intraocular lens(IOL) in eyes which had deficient of posterior capsular support.METHODS: This retrospective study was comprised of ten patients with deficient posterior capsular support who underwent one-haptic fixation of posterior chamber IOLs, between February 2010 and October 2011. IOL as implanted with one haptic supported on the capsular remnant and the other haptic drawn into the sulcus by anchoring suture without a knot. All patients were evaluated for pre- and postoperative visual acuity, lens centration, intra-and postoperative complications.RESULTS: A knotless, one-haptic fixation of posterior chamber IOLs has successfully been performed on ten eyes. All cases had inadequate capsular support(i.e. a capsular tear ranged from 5 to 7 clock hours). The average age was 74.25 ±8.87y(SD). The average postoperative uncorrected visual acuity was 0.51 log MAR.Complications included hyphema in one eye, a mild inflammatory reaction in the anterior chamber in two eyes, and a transient rise in IOP in one eye. Neither IOL tilt nor dislocation was observed and there were no later complications.CONCLUSION: In the presence of insufficient capsular support, a knotless, one-haptic fixation of posterior chamber IOLs is a safe and viable option which reduces the operation time, and minimizes postoperative suture-related complications.

  10. Evaluation of Depth of Field for depth perception in DVR

    KAUST Repository

    Grosset, A.V.Pascal

    2013-02-01

    In this paper we present a user study on the use of Depth of Field for depth perception in Direct Volume Rendering. Direct Volume Rendering with Phong shading and perspective projection is used as the baseline. Depth of Field is then added to see its impact on the correct perception of ordinal depth. Accuracy and response time are used as the metrics to evaluate the usefulness of Depth of Field. The onsite user study has two parts: static and dynamic. Eye tracking is used to monitor the gaze of the subjects. From our results we see that though Depth of Field does not act as a proper depth cue in all conditions, it can be used to reinforce the perception of which feature is in front of the other. The best results (high accuracy & fast response time) for correct perception of ordinal depth occurs when the front feature (out of the two features users were to choose from) is in focus and perspective projection is used. © 2013 IEEE.

  11. Anterior Shoulder Instability with Concomitant Superior Labrum from Anterior to Posterior (SLAP) Lesion Compared to Anterior Instability without SLAP Lesion

    Science.gov (United States)

    Durban, Claire Marie C.; Kim, Je Kyun; Kim, Sae Hoon

    2016-01-01

    Background The aims of this study were to investigate the clinical characteristics of patients with combined anterior instability and superior labrum from anterior to posterior (SLAP) lesions, and to analyze the effect of concomitant SLAP repair on surgical outcomes. Methods We retrospectively reviewed patients who underwent arthroscopic stabilization for anterior shoulder instability between January 2004 and March 2013. A total of 120 patients were available for at least 1-year follow-up. Forty-four patients with reparable concomitant detached SLAP lesions (group I) underwent combined SLAP and anterior stabilization, and 76 patients without SLAP lesions (group II) underwent anterior stabilization alone. Patient characteristics, preoperative and postoperative pain scores, Rowe scores, and shoulder ranges of motion were compared between the 2 groups. Results Patients in group I had higher incidences of high-energy trauma (p = 0.03), worse preoperative pain visual analogue scale (VAS) (p = 0.02), and Rowe scores (p = 0.04). The postoperative pain VAS and Rowe scores improved equally in both groups without significant differences. Limitation in postoperative range of motion was similar between the groups (all p-value > 0.05). Conclusions Anterior instability with SLAP lesion may not be related to frequent episodes of dislocation but rather to a high-energy trauma. SLAP fixation with anterior stabilization procedures did not lead to poor functional outcomes if appropriate surgical techniques were followed. PMID:27247742

  12. Determination of transmission factors in tissue using a standard extrapolation chamber

    International Nuclear Information System (INIS)

    A commercial ionization chamber, Böhm extrapolation chamber, PTW, model 23392, recommended for measurements in low energy X-rays and beta radiation fields, was tested in three different 90Sr+90Y beams to verify its performance as a primary standard system for the calibration and dosimetry of beta radiation sources and detectors. Characterization tests were performed, as determination of the chamber null depth using two methods (the results presented a difference of only 0.9%), transmission factors in tissue, in comparison with those of the certificate (the maximum difference was 2.1%), and absorbed dose rates of the 90Sr+90Y sources, in comparison with the values provided by the calibration certificates (the maximum difference was 4.90%). The results obtained confirmed that this extrapolation chamber presents a very good behavior in beta radiation fields as a primary standard system. - Highlights: • Böhm extrapolation chamber was tested to be used as a primary standard system. • The chamber was exposed to the three 90Sr+90Y secondary standard sources. • Transmission factors were obtained. • Absorbed dose rates were determined using the sources at certificate conditions. • The results showed the good performance of the extrapolation chamber

  13. Drift chamber tracking with neural networks

    International Nuclear Information System (INIS)

    We discuss drift chamber tracking with a commercial log VLSI neural network chip. Voltages proportional to the drift times in a 4-layer drift chamber were presented to the Intel ETANN chip. The network was trained to provide the intercept and slope of straight tracks traversing the chamber. The outputs were recorded and later compared off line to conventional track fits. Two types of network architectures were studied. Applications of neural network tracking to high energy physics detector triggers is discussed

  14. Vacuum Chamber for the Booster Bending Magnets

    CERN Multimedia

    1974-01-01

    To minimize eddy currents, induced by the rising magnetic field, the chamber was made from thin stainless steel of high specific electric resistance. For mechanical stength, it was corrugated in a hydro-forming process. The chamber is curved, to follow the beam's orbital path. Under vacuum, the chamber tends to staighten, the ceramic spacer along half of its length keeps it in place (see also 7402458).

  15. Vapor wall deposition in Teflon chambers

    OpenAIRE

    Zhang, X; R. H. Schwantes; R. C. McVay; H Lignell; M. M. Coggon; Flagan, R C; Seinfeld, J.H.

    2014-01-01

    Teflon chambers are ubiquitous in studies of atmospheric chemistry. Secondary organic aerosol (SOA) formation can be substantially underestimated owing to deposition of SOA-forming compounds to chamber walls. We present here an experimental protocol to constrain the nature of wall deposition of organic vapors in Teflon chambers. We measured the wall deposition rates of 25 oxidized organic compounds generated from the photooxidation of isoprene, toluene, α-pinene, and dodecan...

  16. Bubble chamber: Omega production and decay

    CERN Multimedia

    1973-01-01

    This image is taken from one of CERN's bubble chambers and shows the decay of a positive kaon in flight. The decay products of this kaon can be seen spiraling in the magnetic field of the chamber. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that has been heated to boiling point.

  17. Drift chamber tracking with neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Lindsey, C.S.; Denby, B.; Haggerty, H.

    1992-10-01

    We discuss drift chamber tracking with a commercial log VLSI neural network chip. Voltages proportional to the drift times in a 4-layer drift chamber were presented to the Intel ETANN chip. The network was trained to provide the intercept and slope of straight tracks traversing the chamber. The outputs were recorded and later compared off line to conventional track fits. Two types of network architectures were studied. Applications of neural network tracking to high energy physics detector triggers is discussed.

  18. Laser Welding Test Results with Gas Atmospheres in Welding Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Joung, Chang-Young; Hong, Jin-Tae; Ahn, Sung-Ho; Heo, Sung-Ho; Jang, Seo-Yun; Yang, Tae-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The weld beads of specimens welded under identical conditions in the helium and argon gas were cleaner, more regular, and steadier than those in a vacuum. The penetration depth of the FZ in the vacuum was much deeper than those in the helium and argon gas. To measure the irradiation properties of nuclear fuel in a test reactor, a nuclear fuel test rod instrumented with various sensors must be fabricated with assembly processes. A laser welding system to assemble the nuclear fuel test rod was designed and fabricated to develop various welding technologies of the fuel test rods to joint between a cladding tube and end-caps. It is an air-cooling optical fiber type and its emission modes are a continuous (CW) mode of which the laser generates continuous emission, and pulse (QCW) mode in which the laser internally generates sequences of pulses. We considered the system welding a sample in a chamber that can weld a specimen in a vacuum and inert gas atmosphere, and the chamber was installed on the working plate of the laser welding system. In the chamber, the laser welding process should be conducted to have no defects on the sealing area between a cladding tube and an end-cap.

  19. D0 central tracking chamber performance studies

    Energy Technology Data Exchange (ETDEWEB)

    Pizzuto, D.

    1991-12-01

    The performance of the completed DO central tracking chamber was studied using cosmic rays at the State University of New York at Stony Brook. Also studied was a prototype tracking chamber identical in design to the completed DO tracking chamber. The prototype chamber was exposed to a collimated beam of 150 GeV pions at the Fermilab NWA test facility. Results indicate an R{Phi} tracking resolution compatible with the limitations imposed by physical considerations, excellent 2 track resolution, and a high track reconstruction efficiency along with a good rejection power against {gamma} {yields} e {sup +} e{sup {minus}} events.

  20. D0 central tracking chamber performance studies

    International Nuclear Information System (INIS)

    The performance of the completed DO central tracking chamber was studied using cosmic rays at the State University of New York at Stony Brook. Also studied was a prototype tracking chamber identical in design to the completed DO tracking chamber. The prototype chamber was exposed to a collimated beam of 150 GeV pions at the Fermilab NWA test facility. Results indicate an RΦ tracking resolution compatible with the limitations imposed by physical considerations, excellent 2 track resolution, and a high track reconstruction efficiency along with a good rejection power against γ → e + e- events

  1. Bicone vacuum chamber for ISR intersection

    CERN Multimedia

    1975-01-01

    This is one of the bicone chambers made of titanium for experiment R 702. The central corrugated part had a very thin titanium wall (0.28 mm). The first of these chambers collapsed in its central part when baked at 300 C (August 1975). After an intensive effort to develop better quality and reproducible welds for this special material, the ISR workshop was able to build two new chambers of this type. One of them was installed at I 7 for R 702 in 1976 and worked perfectly. It was at that time the most "transparent" intersection vacuum chamber. See also 7609219, 7609221.

  2. Precision Radio Frequency Anechoic Chamber Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Performs measurements and calibration of antennas for satellites and aircraft or groundbased systems. The chamber is primarily used for optimizing antenna...

  3. Neutron depth profiling at the University of Texas

    Science.gov (United States)

    Ünlü, Kenan; Wehring, Bernard W.

    1994-12-01

    A Neutron Depth Profiling (NDP) facility has been developed at The University of Texas at Austin (UT) Nuclear Engineering Teaching Laboratory. Thermal neutrons from the tangential beam port of the UT 1-MW TRIGA Mark II research reactor are utilized. The UT-NDP facility consists of a neutron beam collimator, target chamber, beam catcher, and necessary data acquisition and process electronics. The collimator was designed to achieve a high quality thermal neutron beam with good intensity and minimum contamination of neutrons above thermal energies. A target chamber for NDP was constructed from 40.6 cm diameter aluminum tubing. The chamber can accommodate several small samples as well as a single large sample with a diameter up to 30.5 cm. Depth profiles for borophosphosilicate glass films on silicon wafers were measured using the UT-NDP facility. Other potential applications of the UT-NDP facility include the study of implanted boron in semiconductor material; study of nitrogen in metals; and study of helium behavior in metals, and metallic and amorphous alloys.

  4. Effect of coronary occlusion during percutaneous transluminal angioplasty in humans on left ventricular chamber stiffness and regional diastolic pressure-radius relations

    NARCIS (Netherlands)

    W. Wijns (William); P.W.J.C. Serruys (Patrick); C.J. Slager (Cornelis); J. Grimm; H.P. Krayenbuehl; P.G. Hugenholtz (Paul); O.M. Hess (Otto)

    1986-01-01

    textabstractThe effect of repeated (3 to 10 second) and transient (15 to 75 second) abrupt coronary occlusion on the global and regional chamber stiffness was studied in nine patients undergoing angioplasty of a single proximal left anterior descending coronary artery stenosis. The left ventricular

  5. SU-E-T-443: Developmental Technique for Proton Pencil Beam Measurements: Depth Dose

    Energy Technology Data Exchange (ETDEWEB)

    Arjomandy, B; Lee, T; Schultz, T; Hsi, W; Park, S [McLaren Cancer Institute, Flint, MI (United States)

    2014-06-01

    Purpose: Measurements of depth dose distribution (DDD) of pencil beam in proton therapy can be challenging and time consuming. We have developed a technique that uses two Bragg peak chambers to expedite these measurements with a high accuracy. Methods and Material: We used a PTW water tank and two PTW 10.5 cm3 Bragg peak chambers; one as a field chamber and the other as a reference chamber to measure DDDs for 100–250 MeV proton pencil beams. The reference chamber was positioned outside of the water tank upstream with respect to field chamber. We used Geant4 Monte Carlo Simulation (MCS) to model the ProTom proton beam to generate DDDs. The MCS generated DDDs were used to account for halo effects of proton pencil beam that are not measureable with Bragg peak chambers. We also used PTW PEAKFINDER to measure DDDs for comparison purpose. Results: We compared measured and MCS DDDs with Continuous Slowing Down Approximation (CSDA) ranges to verify the range of proton beams that were supplied by the manufacturer. The agreements between all DDD with respect to CSDA were within ±0.5 mm. The WET for Bragg peak chamber for energies between 100–250 MeV was 12.7 ± 0.5 mm. The correction for halo effect was negligible below 150 MeV and was in order of ∼5-10% for 150–250 MeV. Conclusion: Use of Bragg Peak chamber as a reference chamber can facilitate DDD measurements in proton pencil beam with a high accuracy. Some corrections will be required to account for halo effect in case of high energy proton beams due to physical size of chamber.

  6. Estimation and relevance of depth correction in paediatric renal studies

    Energy Technology Data Exchange (ETDEWEB)

    Lythgoe, M.F.; Gradwell, M.J.; Evans, K.; Gordon, I. [Department of Radiology, Great Ormond Street Hospital for Children NHS Trust, London (United Kingdom)

    1998-02-01

    Measurement of absolute renal function by gamma camera techniques requires knowledge of kidney depth to correct for soft tissue attenuation, there is debate about the need to take depth into account when only relative renal function is estimated. The aim of this study was to derive a formula for renal depth in children and to assess the importance of depth correction when relative renal function is assessed with dimercaptosuccinic acid (DMSA) on the gamma camera. In this study, kidney depths were derived from measurements on abdominal computerised tomography (CT) images in 57 children in the supine position with two normally located kidneys. Using best-subset regression analysis, one formula for both left and right kidney depth (KD, cm) was developed based on the easily measured parameters of height (H, cm) and body weight (W, kg). The inclusion of extra variables was found to significantly improve the model compared with a model using weight alone (P<0.005). A second group of 19 children who underwent technetium-99m DMSA scans, had differential function estimated from both anterior and posterior views and the geometric mean method. The mean difference in differential renal function calculated by the geometric mean method versus the posterior image was only 1.2%. In conclusion, we present a new formula for the estimation of paediatric kidney depth for the absolute quantitation of kidney uptake. Further, for normally located kidneys it appears unnecessary to use the geometric mean method or to correct for individual renal depth when calculating differential function. (orig.) With 2 figs., 1 tab., 22 refs.

  7. Anterior retropharyngeal approach to the cervical spine.

    OpenAIRE

    Behari S; Banerji D; Trivedi P; Jain V; Chhabra D

    2001-01-01

    The anterior retropharyngeal approach (ARPA) accesses anteriorly situated lesions from the clivus to C3, in patients with a short neck, Klippel Feil anomaly or those in whom the C2-3 and C3-4 disc spaces are situated higher in relation to the hyoid bone and the angle of mandible where it is difficult to approach this region using the conventional anterior approach, due to the superomedial obliquity of the trajectory. The ARPA avoids the potentially contaminated oropharyngeal cavity providing ...

  8. Quadriceps muscle contraction protects the anterior cruciate ligament during anterior tibial translation.

    Science.gov (United States)

    Aune, A K; Cawley, P W; Ekeland, A

    1997-01-01

    The proposed skiing injury mechanism that suggests a quadriceps muscle contraction can contribute to anterior cruciate ligament rupture was biomechanically investigated. The effect of quadriceps muscle force on a knee specimen loaded to anterior cruciate ligament failure during anterior tibial translation was studied in a human cadaveric model. In both knees from six donors, average age 41 years (range, 31 to 65), the joint capsule and ligaments, except the anterior cruciate ligament, were cut. The quadriceps tendon, patella, patellar tendon, and menisci were left intact. One knee from each pair was randomly selected to undergo destructive testing of the anterior cruciate ligament by anterior tibial translation at a displacement rate of 30 mm/sec with a simultaneously applied 889 N quadriceps muscle force. The knee flexion during testing was 30 degrees. As a control, the contralateral knee was loaded correspondingly, but only 5 N of quadriceps muscle force was applied. The ultimate load for the knee to anterior cruciate ligament failure when tested with 889 N quadriceps muscle force was 22% +/- 18% higher than that of knees tested with 5 N of force. The linear stiffness increased by 43% +/- 30%. These results did not support the speculation that a quadriceps muscle contraction contributes to anterior cruciate ligament failure. In this model, the quadriceps muscle force protected the anterior cruciate ligament from injury during anterior tibial translation.

  9. Space Power Facility Reverberation Chamber Calibration Report

    Science.gov (United States)

    Lewis, Catherine C.; Dolesh, Robert J.; Garrett, Michael J.

    2014-01-01

    This document describes the process and results of calibrating the Space Environmental Test EMI Test facility at NASA Plum Brook Space Power Facility according to the specifications of IEC61000-4-21 for susceptibility testing from 100 MHz to 40 GHz. The chamber passed the field uniformity test, in both the empty and loaded conditions, making it the world's largest Reverberation Chamber.

  10. An ionization chamber with magnetic levitated electrodes

    CERN Document Server

    Kawaguchi, T

    1999-01-01

    A new type of ionization chamber which has magnetically levitated electrodes has been developed. The electrodes are supplied voltages for the repelling of ions by a battery which is also levitated with the electrodes. The characteristics of this ionization chamber are investigated in this paper.

  11. Supersonic Jet Interactions in a Plenum Chamber

    Directory of Open Access Journals (Sweden)

    K. M. Venugopal

    2004-07-01

    Full Text Available Understanding thè supersonic jet interactions in a plenum chamber is essential for thè design of hot launch systems. Static tests were conducted in a small-scale rocket motor ioaded with a typical nitramine propellaiit to produce a nozzle exit Mach number of 3. This supersonic jet is made to interact with plenum chambers having both open and closed sides. The distance between thè nozzle exit and thè back piate of plenum chamber are varied from 2. 5 to 7. 0 times thè nozzle exit diameter. The pressure rise in thè plenum chamber was measured using pressure transducers mounted at different locatìons. The pressure-time data were analysed to obtain an insight into thè flow field in thè plenum chamber. The maximum pressure exerted on thè back piate of plenum chamber is about 25-35 per cent. of thè maximum stagnation pressure developed in thè rocket motor. Ten static tests were carried out to obtain thè effect of axial distance between thè nozzle exit and thè plenum chamber back piate, and stagnation pressure in thè rocket motoron thè flow field in thè open-sided and closed-sided plenum chambers configurations.

  12. Chamber Music's Lesson in Performing Confidence.

    Science.gov (United States)

    Stubbs, Darrel W.

    1983-01-01

    Chamber music has the advantage of offering the student maximum exposure as an individual performer. The absence of a conductor means that the student assumes the role of interpreter, thereby gaining musical maturity. For these reasons, curriculum hours should be more evenly divided between chamber music and larger ensembles. (CS)

  13. Results from the MAC Vertex chamber

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, H.N.

    1987-05-01

    The design, construction, and performance characteristics of a high precision gaseous drift chamber made of thin walled proportional tubes are described. The device achieved an average spatial resolution of 45 ..mu..m in use for physics analysis with the MAC detector. The B-lifetime result obtained with this chamber is discussed.

  14. 21 CFR 866.2120 - Anaerobic chamber.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Anaerobic chamber. 866.2120 Section 866.2120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber....

  15. Resistive wall heating due to image current on the beam chamber for a superconducting undulator.

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. H. (Accelerator Systems Division (APS))

    2012-03-27

    The image-current heating on the resistive beam chamber of a superconducting undulator (SCU) was calculated based on the normal and anomalous skin effects. Using the bulk resistivity of copper for the beam chamber, the heat loads were calculated for the residual resistivity ratios (RRRs) of unity at room temperature to 100 K at a cryogenic temperature as the reference. Then, using the resistivity of the specific aluminum alloy 6053-T5, which will be used for the SCU beam chamber, the heat loads were calculated. An electron beam stored in a storage ring induces an image current on the inner conducting wall, mainly within a skin depth, of the beam chamber. The image current, with opposite charge to the electron beam, travels along the chamber wall in the same direction as the electron beam. The average current in the storage ring consists of a number of bunches. When the pattern of the bunched beam is repeated according to the rf frequency, the beam current may be expressed in terms of a Fourier series. The time structure of the image current is assumed to be the same as that of the beam current. For a given resistivity of the chamber inner wall, the application ofthe normal or anomalous skin effect will depend on the harmonic numbers of the Fourier series of the beam current and the temperature of the chamber. For a round beam chamber with a ratius r, much larger than the beam size, one can assume that the image current density as well as the density square, may be uniform around the perimeter 2{pi}r. For the SCU beam chamber, which has a relatively narrow vertical gap compared to the width, the effective perimeter was estimated since the heat load should be proportional to the inverse of the perimeter.

  16. Compact ion chamber based neutron detector

    Science.gov (United States)

    Derzon, Mark S.; Galambos, Paul C.; Renzi, Ronald F.

    2015-10-27

    A directional neutron detector has an ion chamber formed in a dielectric material; a signal electrode and a ground electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; readout circuitry which is electrically coupled to the signal and ground electrodes; and a signal processor electrically coupled to the readout circuitry. The ion chamber has a pair of substantially planar electrode surfaces. The chamber pressure of the neutron absorbing material is selected such that the reaction particle ion trail length for neutrons absorbed by the neutron absorbing material is equal to or less than the distance between the electrode surfaces. The signal processor is adapted to determine a path angle for each absorbed neutron based on the rise time of the corresponding pulse in a time-varying detector signal.

  17. Ionization-chamber smoke detector system

    Science.gov (United States)

    Roe, Robert F.

    1976-10-19

    This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system is designed to reduce false alarms caused by fluctuations in ambient temperature. Means are provided for periodically firing the gas discharge triode and each time recording the triggering voltage required. A computer compares each triggering voltage with its predecessor. The computer is programmed to energize an alarm if the difference between the two compared voltages is a relatively large value indicative of particulates in the measuring chamber and to disregard smaller differences typically resulting from changes in ambient temperature.

  18. Wet drift chambers for precise luminosity

    International Nuclear Information System (INIS)

    A set of high-precision compact drift chambers has been a vital component of the OPAL luminosity monitor since the start of data-taking at LEP. They were augmented in 1992 by the addition of Small Angle Reference Chambers with a very similar design to the original chamber. The performance of the chambers is reviewed, highlighting both the importance of using polyalkylene glycol (Breox) to maintain a uniform and parallel electric field and the construction techniques used to sustain the required field strength. We describe some of the operating problems, with their solutions, and show how the chambers have been used in achieving a systematic error of 0.41% on the luminosity measurement. ((orig.))

  19. Analyses of superficial and depth doses in intraoral radiology

    Energy Technology Data Exchange (ETDEWEB)

    Silva Santos de Oliveira, C.; Morais, R.P. de; Nascimento Souza, D. do [Universidade Federal de Sergipe - CCET - Dept. de Fisica, Sao Cristovao, SE (Brazil)

    2006-07-01

    In this work dosimetric analysis using thermoluminescence technique to study the beams characteristics of x-rays employed in dental radiology has been carried out. The obtained results with CaSO{sub 4}:Dy thermoluminescent dosimeters (TLD) were compared to the doses obtained with parallel-plates ionization chamber. Dosimetric evaluations were also done using radiographic films of large dimensions. The x-rays equipments analyzed were installed in the radiological services of Odontology Department of Sergipe Federal University (U.F.S.). Depending on the anatomical region to be examined the proper exposure time was select, for a fix voltage of 70 kV. The results with TLD and ionization chamber have been determined to female and male individuals. The intraoral regions analysed were the peri apical of the incisors, molar and pre-molar teeth and the occlusive region. These regions were simulated using acrylic plates absorbers installed on the film packet holder. The evaluation of the depth doses in the intraoral tissue was obtained using different acrylic plate thickness. The air kerma values have been evaluated with the ionization chamber located in the dental cone exit of the x-rays equipments. The integrated areas of the thermoluminescent glow curves showed coherent values when compared to the ones obtained with the ionization chamber and both methods presented a linear dependence with the exposition time. The analyses with films have allowed the evaluation of the beam scattering in the simulator apparatus. The studies had proven that the analysis of superficial dose and in depth used in dental radiology can be carried with thermoluminescent dosimeters. (authors)

  20. Analyses of superficial and depth doses in intraoral radiology

    International Nuclear Information System (INIS)

    In this work dosimetric analysis using thermoluminescence technique to study the beams characteristics of x-rays employed in dental radiology has been carried out. The obtained results with CaSO4:Dy thermoluminescent dosimeters (TLD) were compared to the doses obtained with parallel-plates ionization chamber. Dosimetric evaluations were also done using radiographic films of large dimensions. The x-rays equipments analyzed were installed in the radiological services of Odontology Department of Sergipe Federal University (U.F.S.). Depending on the anatomical region to be examined the proper exposure time was select, for a fix voltage of 70 kV. The results with TLD and ionization chamber have been determined to female and male individuals. The intraoral regions analysed were the peri apical of the incisors, molar and pre-molar teeth and the occlusive region. These regions were simulated using acrylic plates absorbers installed on the film packet holder. The evaluation of the depth doses in the intraoral tissue was obtained using different acrylic plate thickness. The air kerma values have been evaluated with the ionization chamber located in the dental cone exit of the x-rays equipments. The integrated areas of the thermoluminescent glow curves showed coherent values when compared to the ones obtained with the ionization chamber and both methods presented a linear dependence with the exposition time. The analyses with films have allowed the evaluation of the beam scattering in the simulator apparatus. The studies had proven that the analysis of superficial dose and in depth used in dental radiology can be carried with thermoluminescent dosimeters. (authors)

  1. On evaluation of depth accuracy in consumer depth sensors

    Science.gov (United States)

    Abd Aziz, Azim Zaliha; Wei, Hong; Ferryman, James

    2015-12-01

    This paper presents an experimental study of different depth sensors. The aim is to answer the question, whether these sensors give accurate data for general depth image analysis. The study examines the depth accuracy between three popularly used depth sensors; ASUS Xtion Prolive, Kinect Xbox 360 and Kinect for Windows v2. The main attention is to study on the stability of pixels in the depth image captured at several different sensor-object distances by measuring the depth returned by the sensors within specified time intervals. The experimental results show that the fluctuation (mm) of the random selected pixels within the target area, increases with increasing distance to the sensor, especially on the Kinect for Xbox 360 and the Asus Xtion Prolive. Both of these sensors provide pixels fluctuation between 20mm and 30mm at a sensor-object distance beyond 1500mm. However, the pixel's stability of the Kinect for Windows v2 not affected much with the distance between the sensor and the object. The maximum fluctuation for all the selected pixels of Kinect for Windows v2 is approximately 5mm at sensor-object distance of between 800mm and 3000mm. Therefore, in the optimal distance, the best stability achieved.

  2. Characterization of rat model of acute anterior uveitis using optical coherence tomography angiography

    Science.gov (United States)

    Choi, Woo June; Pepple, Kathryn L.; Zhi, Zhongwei; Wang, Ruikang K.

    2015-03-01

    Uveitis, or ocular inflammation, is a cause of severe visual impairment. Rodent models of uveitis are powerful tools used to investigate the pathological mechanisms of ocular inflammation and to study the efficacy of new therapies prior to human testing. In this paper, we report the utility of spectral-domain optical coherence tomography (SD-OCT) angiography in characterizing the inflammatory changes induced in the anterior segment of a rat model of uveitis. Acute anterior uveitis (AAU) was induced in two rats by intravitreal injection of a killed mycobacterial extract. One of them received a concurrent periocular injection of steroids to model a treatment effect. OCT imaging was performed prior to inflammation induction on day 0 (baseline), and 2 days post-injection (peak inflammation). Baseline and inflamed images were compared. OCT angiography identified swelling of the cornea, inflammatory cells in the anterior and posterior chambers, a fibrinous papillary membrane, and dilation of iris vessels in the inflamed eyes when compared to baseline images. Steroid treatment was shown to prevent the changes associated with inflammation. This is a novel application of anterior OCT imaging in animal models of uveitis, and provides a high resolution, in vivo assay for detecting and quantifying ocular inflammation and the response to new therapies.

  3. Clinical utility of anterior segment swept-source optical coherence tomography in glaucoma

    Directory of Open Access Journals (Sweden)

    Dewang Angmo

    2016-01-01

    Full Text Available Optical coherence tomography (OCT, a noninvasive imaging modality that uses low-coherence light to obtain a high-resolution cross-section of biological structures, has evolved dramatically over the years. The Swept-source OCT (SS-OCT makes use of a single detector with a rapidly tunable laser as a light source. The Casia SS-1000 OCT is a Fourier-domain, SS-OCT designed specifically for imaging the anterior segment. This system achieves high resolution imaging of 10΅m (Axial and 30΅m (Transverse and high speed scanning of 30,000 A-scans per second. With a substantial improvement in scan speed, the anterior chamber angles can be imaged 360 degrees in 128 cross sections (each with 512 A-scans in about 2.4 seconds. We summarize the clinical applications of anterior segment SS-OCT in Glaucoma. Literature search: We searched PubMed and included Medline using the phrases anterior segment optical coherence tomography in ophthalmology, swept-source OCT, use of AS-OCT in glaucoma, use of swept-source AS-OCT in glaucoma, quantitative assessment of angle, filtering bleb in AS-OCT, comparison of AS-OCT with gonioscopy and comparison of AS-OCT with UBM. Search was made for articles dating 1990 to August 2015.

  4. Results of cataract surgery and plasma ablation posterior capsulotomy in anterior persistent hyperplastic primary vitreous

    Directory of Open Access Journals (Sweden)

    Rajesh Sinha

    2013-01-01

    Full Text Available Purpose: To report the feasibility and outcome of lens aspiration, and Fugo blade-assisted capsulotomy and anterior vitrectomy in eyes with anterior persistent hyperplastic primary vitreous (PHPV. Materials and Methods: In this case series, 10 eyes of 10 patients with anterior PHPV underwent lens aspiration. The vascularized posterior capsule was cut with a Fugo blade (plasma knife and removed with a vitrector. A foldable posterior chamber intraocular lens (IOL was implanted in eight eyes and the outcomes were evaluated. Results: The mean age of patients was 16.8 ± 6.37 months (range: 5 to 28 months. The surgery was completed successfully in all eyes. There were no cases of intraocular hemorrhage intraoperatively. Foldable acrylic IOL was implanted in the bag in 3 eyes and in the sulcus in 5 eyes. Two eyes were microphthalmic and did no undergo IOL implantation (aphakic. None of the eyes had a significant reaction or elevated intraocular pressure postoperatively. The follow-up ranged from 4 to 21 months. All the pseudophakic eyes achieved a best corrected visual acuity of ≥20/200 with 50% (4/8 of these eyes with ≥20/60 vision. Conclusion: Lens aspiration followed by posterior capsulotomy with Fugo blade-assisted plasma ablation is a feasible technique for performing successful lens surgery in cases with florid anterior PHPV.

  5. Perturbation correction factors for the NACP-02 plane-parallel ionization chamber in water in high-energy electron beams

    International Nuclear Information System (INIS)

    Recent dosimetry protocols for clinical high-energy electron beams recommend measurements of absorbed dose-to-water with a plane-parallel or cylindrical ionization chamber. For well-guarded plane-parallel ionization chambers, the ionization chamber perturbation factor in water, pQ, has a recommended value of unity in all protocols. This assumption was investigated in detail in this study for one of the recommended ionization chambers in the protocols: the Scanditronix NACP-02 plane-parallel ionization chamber. Monte Carlo (MC) simulations of the NACP-02 ionization chamber with the EGSnrc code were validated against backscatter experiments. MC simulations were then used to calculate pwall, pcav and pQ perturbation factors and water-to-air Spencer-Attix stopping powers in 4-19 MeV electron beams of a calibration laboratory (NPL), and in 6-22 MeV clinical electron beams from a Varian CL2300 accelerator. Differences between calculated and the currently recommended (Burns et al 1996 Med. Phys. 23 383-8) stopping powers, water-to-air, were found to be limited to 0.9% at depths between the reference depth zref and the depth where the dose has decreased to 50% of the maximum dose, R50. pwall was found to exceed unity by 2.3% in the 4 MeV NPL calibration beam at zref. For higher energy electron beams pwall decreased to a value of about 1%. Combined with a pcav about 1% below unity for all energies at zref, this was found to cause pQ to exceed unity significantly for all energies. In clinical electron beams all three perturbation factors were found to increase with depth. Our findings indicate that the perturbation factors have to be taken into account in calibration procedures and for clinical depth dose measurements with the NACP-02 ionization chamber

  6. Care of children with anterior uveitis.

    Science.gov (United States)

    Kanski, J J

    1981-09-01

    The clinical features of 290 children with anterior uveitis are presented. The vast majority suffered from chronic uveitis. Specific uveitis entities in children include the syndrome of 'chronic iridocyclitis' in girls, heterochromic cyclitis, and pars planitis. Systemic associations include sarcoidosis, the Vogt-Harada-Koyanagi syndrome, and the seronegative arthritides (juvenile chronic arthritis, juvenile ankylosing spondylitis, psoriatic arthritis, and rarely Reiter's and Beçet's syndromes). Children with a pauciarticular onset of juvenile chronic arthritis, especially when combined with positive findings for antinuclear antibody, are at particular risk of developing chronic anterior uveitis. Most cases of chronic anterior uveitis can be controlled with topical corticosteroids. Those that are resistant to both topical and systemic corticosteroids may have to be treated with chlorambucil. The operation of lensectomy is a great advance in the management of complicated cataract. Secondary glaucoma is the most devastating complication of chronic anterior uveitis in children and responds poorly to therapy.

  7. Guideline on anterior cruciate ligament injury

    NARCIS (Netherlands)

    D.E. Meuffels (Duncan); M.T. Poldervaart (Michelle T.); R.L. Diercks (Ron L.); A.W.F.M. Fievez (Alex W.F.M.); T.W. Patt (Thomas W.); C.P. van der Hart (Cor P.); E.R. Hammacher (Eric); F. van der Meer (Fred); E.A. Goedhart (Edwin A.); A.F. Lenssen (Anton F); S.B. Muller-Ploeger (Sabrina B); M.A. Pols (Margreet); D.B.F. Saris (Daniel)

    2012-01-01

    textabstractThe Dutch Orthopaedic Association has a long tradition of development of practical clinical guidelines. Here we present the recommendations from the multidisciplinary clinical guideline working group for anterior cruciate ligament injury. The following 8 clinical questions were formulate

  8. Anterior Cervical Discectomy and Fusion with Plating

    Medline Plus

    Full Text Available Anterior Cervical Discectomy and Fusion with Plating Broward Health Medical Center Fort Lauderdale, FL November 17, 2011 I'm Dr. Matthew Moore, head of the Spine Care Center here at North Broward Medical Center. And ...

  9. Positioning of a plane-parallel ionization chamber in clinical electron beams and the impact on perturbation factors.

    Science.gov (United States)

    Zink, K; Wulff, J

    2009-04-21

    Current dosimetry protocols recommend the use of plane-parallel ionization chambers for the dosimetry of clinical electron beams. The necessary perturbation corrections p(wall) and p(cav) are assumed to be unity, independent of the depth of measurement and the energy of the primary electrons. To verify these assumptions detailed Monte Carlo studies of a Roos chamber in clinical electron beams with energies in the range of 6-21 MeV are performed at different depths in water and analyzed in terms of Spencer-Attix cavity theory. Separate simulations for the perturbation corrections p(wall) and p(cav) indicate quite different properties of both correction factors with depth. Dose as well as fluence calculations show a nearly depth-independent wall correction factor for a shift of the Roos chamber Deltaz = -0.017 cm toward the focus. This value is in good agreement with the positioning recommendation given in all dosimetry protocols. Regarding the fluence perturbation p(cav) the simulation of the electron fluence inside the air cavity in comparison to water unambiguously reveals an in-scattering of low energy electrons, despite the fact, that the cavity is 'well guarded'. For depths beyond the reference depth z(ref) this effect is superimposed by an increased loss of primary electrons from the beam resulting in p(cav) > 1. This effect is largest for low electron energies but present for all electron energies involved in this study. Based on the different depth dependences of p(wall) and p(cav) it is possible to choose a chamber shift Deltaz in a way to minimize the depth dependence of the overall perturbation factor p. For the Roos chamber this shift is Deltaz = -0.04 cm independent of electron energy.

  10. A novel micro liquid ionization chamber for clinical dosimetry

    International Nuclear Information System (INIS)

    Absorbed-dose-based protocols recommend calibration of clinical linear accelerators using airfilled ionization chambers for which an absorbed-dose to water calibration factor has been established in a 60Co beam. The factor kQ in these protocols involves the ratio of the mean restricted collision mass stopping power water-to-air, which is energy dependent. For high-energy clinical photon beams, the stopping power ratio water-to-air varies by up to 4%, whereas for electron beams the variation is even larger. For certain insulating liquids, however, the stopping power ratio water-to-liquid shows very little energy dependence, making a liquid-filled ionization chamber a potentially attractive dosimeter for clinical reference dosimetry. In this work some properties of two liquid-filled ionization chambers are investigated including ion recombination and variation of response as a function of energy for photon beams. In this work we used an Exradin A14P planar microchamber with chamber body and electrodes composed of C552 plastic. This chamber was modified, reducing the gap between the cap and collecting electrode to 0.5 mm. The diameter of the collecting electrode is 1.5 mm and the nominal sensitive volume of 1.12 mm3 was filled with isooctane. This chamber will be referred to as the MicroLIC. The energy response of the MicroLIC was compared to previous results measured using the LIC 9902-mix chamber, developed by G. Wickman of Umea University, Sweden. The sensitive volume of this chamber has a diameter of 2.5 mm, thickness of 0.35 mm and is filled with 60% isooctane, 40% tetramethylsilane by weight. The linear accelerator used was a Varian Clinac 21EX with nominal photon beam energies of 6 and 18 MV. Measurements were done in a 20x20x20 cm3 RMI Solid Water phantom at 10 cm depth with a 10x10 cm2 field at the phantom surface. Absorbed dose was determined using an Exradin A12 chamber with an absorbed-dose to water calibration factor for 60Co established at a primary

  11. Erlotinib-related bilateral anterior uveitis

    Science.gov (United States)

    Ali, Kashif; Kumar, Indu; Usman-Saeed, Muniba; Usman Saeed, Muhammad

    2011-01-01

    The authors report the case of a 68-year-old woman with secondary adenocarcinoma of the lungs from an unknown primary. Erlotinib was started which produced symptoms suggestive of uveitis. Erlotinib was stopped and restarted a month later at a lower dose, which resulted in severe bilateral anterior uveitis. The uveitis settled after stopping erlotinib and treatment with topical steroids and cycloplegics. To the best of the authors’ knowledge, this is the first case of erlotinib-related anterior uveitis. PMID:22694887

  12. Analysis of dose perturbation factors of a NACP-02 ionization chamber in clinical electron beams.

    Science.gov (United States)

    Chin, E; Palmans, H; Shipley, D; Bailey, M; Verhaegen, F

    2009-01-21

    For well-guarded plane-parallel ionization chambers, international dosimetry protocols recommend a value of unity for electron perturbation factors in water. However, recent data published by various groups have challenged this. Specifically for the NACP-02 chamber, non-unity electron perturbation factors have already been published by Verhaegen et al (2006 Phys. Med. Biol. 51 1221-35) and Buckley and Rogers (2006 Med. Phys. 33 1788-96). Recently it was found that the mass thickness of the front chamber window can be 35% greater than is listed in the IAEA's TRS-398 absorbed dose protocol (Chin et al 2008 Phys. Med. Biol. 53 N119-26). This study therefore recalculated NACP-02 electron perturbation correction factors for energies 4-18 MeV at depths z(ref) and R(50) to determine the effect of the chamber model change. Results showed that perturbation factors at z(ref) are fairly stable for similar chamber models but become highly sensitive to small changes at deeper depths. The results also showed some dependence on using 1 keV versus 10 keV for the transport cut-off. Additional investigations revealed that the wall perturbation factor, p(wall), is strongly influenced by the chamber back wall at z(ref) and at larger depths small changes in the positioning of the effective point of measurement cause large fluctuations in the final value. Finally, the cavity perturbation factor, p(cav), was found to be primarily influenced by electron backscatter.

  13. Evaluation of a novel reference chamber “stealth chamber” through Monte Carlo simulations and experimental data

    Directory of Open Access Journals (Sweden)

    Luis Vazquez Quino

    2015-01-01

    Full Text Available Purpose: To evaluate a novel reference chamber (Stealth Chamber by IBA through experimental data and Monte Carlo simulations for 6 and 15 MV photon energies. Methods: Monte Carlo simulations in a water phantom for field sizes ranging from 3×3 and 25×25 cm2 were performed for both energies with and without the Monte Carlo model of the Stealth Chamber in the beam path, and compared to commissioning beam data. Percent depth doses (PDDs, profiles, and gamma analysis of the simulations were performed along with an energy spectrum analysis of the phase-space files generated during the simulation. Experimental data were acquired in water with IBA three-dimensional (3D blue phantom in a set-up identical to the one used in the Monte Carlo simulations. PDD comparisons for fields ranging from 1×1 to 25×25 cm2 were performed for photon energies. Profile comparison for fields ranging from 1×1 to 25×25 cm2 were executed for the depths of dmax, 5, 10 and 20 cm. Criteria of 1%, 1 mm to compare PDDs and profiles were used. Transmission measurements with the Stealth Chamber and a Matrixx detector from IBA were investigated. Measurements for 6 and 15 MV with fields ranging from 3×3 to 25×25 cm2 dimensions were acquired in an open field with and without the Stealth Chamber in the path of the beam. Profiles and gamma analysis with a 1%, 1 mm gamma analysis criterion were performed. Results: Monte Carlo simulations of the PDDs and profiles demonstrate the agreement between both simulations. Furthermore, the gamma analysis (1%, 1 mm result of the comparison of both planes has 100% of the points passing the criteria. The spectral distribution analysis of the phase spaces for an open field with and without the chamber reveals the agreement between both simulations. Experimental measurements of PDDs and profiles have been conducted and reveal the comparability of relative dosimetric data acquired with the Stealth Chamber and our gold standard the CC13 chamber

  14. Formation depths of Fraunhofer lines

    CERN Document Server

    Gurtovenko, E A

    2015-01-01

    We have summed up our investigations performed in 1970--1993. The main task of this paper is clearly to show processes of formation of spectral lines as well as their distinction by validity and by location. For 503 photospheric lines of various chemical elements in the wavelength range 300--1000 nm we list in Table the average formation depths of the line depression and the line emission for the line centre and on the half-width of the line, the average formation depths of the continuum emission as well as the effective widths of the layer of the line depression formation. Dependence of average depths of line depression formation on excitation potential, equivalent widths, and central line depth are demonstrated by iron lines.

  15. Small-Field Dosimetry in A 6 MV Photon Beam Using Alanine and Liquid Ionisation Chamber

    DEFF Research Database (Denmark)

    Zimmermann, S.; Riis, H. L.; Hjelm-Hansen, M.;

    2012-01-01

    Purpose/Objective: Dosimetry of small field sizes in MV photon beams is an increasingly important subject, and a generally accepted guideline for clinical measurements is still lacking. The present comparative study was carried out to further investigate the use of alanine and the PTW microLion...... of each field and depth. This dose maximum was measured for each field using a Scanditronix Wellhöfer photon field diode. The same measurements were carried out using a liquid ionchamber, PTW microLion, irradiated by 500 MU. The output of the accelerator was controlled by a PTW semiflex ion chamber...

  16. Influence of the radioactive source position inside the well-type ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Kuahara, L.T.; Correa, E.L.; Potiens, M.P.A., E-mail: liliankuahara@usp.br [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The activimeter, instrument used in radionuclide activity measurement, consists primarily of a well type ionization chamber coupled to a special electronic device. Its response, after calibration, is shown in activity units (Becquerel or Curie). The goal of this study is to verify radioactive source position influence over activity measured by this instrument. Radioactive sources measurements were made at different depths inside the ionization chamber well. Results showed maximum variation of -23 %, -28 % and -15 % for {sup 57}Co, {sup 133}Ba and {sup 137}Cs, respectively. (author)

  17. Monitored Drift Chambers in the ATLAS Detector

    CERN Multimedia

    Herten, G

    Monitored Drift Chambers (MDT) are used in the ATLAS Detector to measure the momentum of high energy muons. They consist of drift tubes, which are filled with an Ar-CO2 gas mixture at 3 bar gas pressure. About 1200 drift chambers are required for ATLAS. They are up to 6 m long. Nevertheless the position of every wire needs to be known with a precision of 20 µm within a chamber. In addition, optical alignment sensors are required to measure the relative position of adjacent chambers with a precision of 30µm. This gigantic task seems impossible at first instance. Indeed it took many years of R&D to invent the right tools and methods before the first chamber could be built according to specifications. Today, at the time when 50% of the chambers have been produced, we are confident that the goal for ATLAS can be reached. The mechanical precision of the chambers could be verified with the x-ray tomograph at CERN. This ingenious device, developed for the MDT system, is able to measure the wire position insid...

  18. A prototype of an extrapolation chamber for beta radiation beams of 90Sr+90Y

    International Nuclear Information System (INIS)

    Extrapolation chamber is the only primary standard dosimeter for beta radiation. With the aim to test new configurations and materials using easily-available and low-cost materials and fulfill the need of a chamber for scientific metrological purposes, in this paper the prototype of an extrapolation chamber has been built and its performance has been investigated in the beta radiation field of 90Sr+90Y. The main differences between the chamber and commercially available chambers are the geometry, constituent material and configuration. The obtained results were compared with those of the calibration certificate of the source and an agreement within 4 % was verified. The depth-dose curve was also obtained and compared with the curve published in ISO 6980, showing a good agreement. Moreover, Monte Carlo simulation was undertaken using MCNP4C code and the relative difference of 0.3 % was observed compared to the experiment. All of the results proved the suitability of the chamber in the beta radiation field of 90Sr+90Y. (author)

  19. Making MUSIC: A multiple sampling ionization chamber

    International Nuclear Information System (INIS)

    A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the (α, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for (α, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only (α, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. x 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the (α, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the (α, p) reaction to reach the anode segment below the reaction

  20. Making MUSIC: A multiple sampling ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Shumard, B. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)]. E-mail: shumard@phy.anl.gov; Henderson, D.J. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Rehm, K.E. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Tang, X.D. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)

    2007-08-15

    A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the ({alpha}, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for ({alpha}, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only ({alpha}, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. x 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the ({alpha}, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the ({alpha}, p) reaction to reach the anode segment below the reaction.

  1. APS Storage Ring vacuum chamber fabrication

    International Nuclear Information System (INIS)

    The 1104-m circumference Advanced Photon Source Storage Ring Vacuum System is composed of 240 individual sections, which are fabricated from a combination of aluminum extrusions and machined components. The vacuum chambers will have 3800 weld joints, each subject to strict vacuum requirements, as well as a variety of related design criteria. The vacuum criteria and chamber design are reviewed, including a discussion of the weld joint geometries. The critical fabrication process parameters for meeting the design requirements are discussed. The experiences of the prototype chamber fabrication program are presented. Finally, the required facilities preparation for construction activity is briefly described. 6 refs., 6 figs., 1 tab

  2. Growing and Analyzing Biofilms in Flow Chambers

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim; Sternberg, Claus

    2011-01-01

    This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic......, and disassembly and cleaning of the system. In addition, embedding and fluorescent in situ hybridization of flow chamber–grown biofilms are addressed. Curr. Protoc. Microbiol. 21:1B.2.1-1B.2.17. © 2011 by John Wiley & Sons, Inc....

  3. Cloud chamber photographs of the cosmic radiation

    CERN Document Server

    Rochester, George Dixon

    1952-01-01

    Cloud Chamber Photographs of the Cosmic Radiation focuses on cloud chamber and photographic emulsion wherein the tracks of individual subatomic particles of high energy are studied. The publication first offers information on the technical features of operation and electrons and cascade showers. Discussions focus on the relationship in time and space of counter-controlled tracks; techniques of internal control of the cloud chamber; cascade processes with artificially-produced electrons and photons; and nuclear interaction associated with an extensive shower. The manuscript then elaborates on

  4. Bubble chamber: Omega production and decay

    CERN Multimedia

    1973-01-01

    This image is of real particle tracks taken from the CERN 2 m liquid hydrogen bubble chamber and shows the production and decay of a negative omega particle. A negative kaon enters the chamber which decays into many particles, including a negative omega that travels a short distance before decaying into more particles. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

  5. LEP vacuum chamber, cross-section

    CERN Multimedia

    1983-01-01

    Cross-section of the final prototype for the LEP vacuum chamber. The elliptic main-opening is for the beam. The small channel to the left is for the cooling water, to carry away the heat deposited by the synchrotron radiation. The square channel to the right houses the Non-Evaporable Getter (NEG) pump. The chamber is made from extruded aluminium. Its outside is clad with lead, to stop the synchrotron radiation emitted by the beam. For good adherence between Pb and Al, the Al chamber was coated with a thin layer of Ni. Ni being slightly magnetic, some resulting problems had to be overcome. See also 8301153.

  6. Use of Fourier-Domain Optical Coherence Tomography to Evaluate Anterior Stromal Opacities in Donor Corneas

    Directory of Open Access Journals (Sweden)

    Matthew R. Bald

    2013-01-01

    Full Text Available Purpose. To evaluate Fourier-domain optical coherence tomography (FD-OCT as an adjunct to traditional slit lamp examination of donor corneas with suspected Anterior Stromal Opacities. Methods. Seven corneas suspected of having anterior stromal opacities by slit lamp examination were evaluated with FD-OCT. Each cornea was evaluated to confirm the presence of opacity and, if present, the depth of opacity was measured. Results. The opacity depth ranged from 82 μm to 624 μm. The initial slit lamp impressions of five of the seven corneas were confirmed by OCT. In two corneas, the OCT findings were different from the initial slit lamp impressions. Slit lamp examination of the first cornea gave the impression of anterior stromal scarring, but OCT showed that the opacity was limited to the epithelium. Slit lamp examination of the second cornea suggested opacity limited to the epithelium, but OCT identified significant sub-Bowman's scarring. In all cases, the Eye Bank Technicians reported that the location and depth of corneal opacity were more sharply defined by OCT than by slit lamp. Conclusion. The high resolution of OCT makes it easier to determine the location of corneal opacities compared to slit lamp examinations. This enhanced visualization can improve decisions regarding transplant suitability of donor corneas.

  7. Magma Chambers, Thermal Energy, and the Unsuccessful Search for a Magma Chamber Thermostat

    Science.gov (United States)

    Glazner, A. F.

    2015-12-01

    Although the traditional concept that plutons are the frozen corpses of huge, highly liquid magma chambers ("big red blobs") is losing favor, the related notion that magma bodies can spend long periods of time (~106years) in a mushy, highly crystalline state is widely accepted. However, analysis of the thermal balance of magmatic systems indicates that it is difficult to maintain a significant portion in a simmering, mushy state, whether or not the system is eutectic-like. Magma bodies cool primarily by loss of heat to the Earth's surface. The balance between cooling via energy loss to the surface and heating via magma accretion can be denoted as M = ρLa/q, where ρ is magma density, L is latent heat of crystallization, a is the vertical rate of magma accretion, and q is surface heat flux. If M>1, then magma accretion outpaces cooling and a magma chamber forms. For reasonable values of ρ, L, and q, the rate of accretion amust be > ~15 mm/yr to form a persistent volume above the solidus. This rate is extremely high, an order of magnitude faster than estimated pluton-filling rates, and would produce a body 10 km thick in 700 ka, an order of magnitude faster than geochronology indicates. Regardless of the rate of magma supply, the proportion of crystals in the system must vary dramatically with depth at any given time owing to transfer of heat. Mechanical stirring (e.g., by convection) could serve to homogenize crystal content in a magma body, but this is unachievable in crystal-rich, locked-up magma. Without convection the lower part of the magma body becomes much hotter than the top—a process familiar to anyone who has scorched a pot of oatmeal. Thermal models that succeed in producing persistent, large bodies of magma rely on scenarios that are unrealistic (e.g., omitting heat loss to the planet's surface), self-fulfilling prophecies (e.g., setting unnaturally high temperatures as fixed boundary conditions), or physically unreasonable (e.g., magma is intruded

  8. Developing cloud chambers with high school students

    CERN Document Server

    Ishizuka, Ryo; Sato, Shoma; Zeze, Syoji

    2013-01-01

    The result and outcome of the cloud chamber project, which aims to develop a cloud chamber useful for science education is reported in detail. A project includes both three high school students and a teacher as a part of Super Science High School (SSH) program in our school. We develop a dry ice free cloud chamber using salt and ice (or snow). Technical detail of the chamber is presented. We also argue how the project affects student's cognition, motivation, academic skills and behavior. The research project had been done in very similar way to those of professional researchers, i.e., planning research, applying fund, writing a paper and giving a talk in conferences. From interviews with students, we learn that such style of scientific activity is very effective in promoting student's motivation for learning science.

  9. Developing Cloud Chambers with High School Students

    Science.gov (United States)

    Ishizuka, Ryo; Tan, Nobuaki; Sato, Shoma; Zeze, Syoji

    The result and outcome of the cloud chamber project, which aims to develop a cloud chamber useful for science education is reported in detail. A project includes both three high school students and a teacher as a part of Super Science High School (SSH) program in our school. We develop a dry-ice-free cloud chamber using salt and ice (or snow). Technical details of the chamber are described. We also argue how the project have affected student's cognition, motivation, academic skills and behavior. The research project has taken steps of professional researchers, i.e., in planning research, applying fund, writing a paper and giving a talk in conferences. From interviews with students, we have learnt that such style of scientific activity is very effective in promoting student's motivation for learning science.

  10. RADAR Anechoic Chamber/RCS Measurements Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The RF Anechoic Chamber is 56 feet long by 12 feet high by 13.5 feet wide, with an adjoining electronic computer control room. A double door entrance at one end of...

  11. High Performance Methane Thrust Chamber (HPMTC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop a High-Performance Methane Thrust Chamber (HPMRE) to meet the demands of advanced chemical propulsion systems for deep-space mission...

  12. MAN-IN-SIMULANT TEST (MIST) CHAMBER

    Data.gov (United States)

    Federal Laboratory Consortium — The MIST chamber uses methyl salicylate (oil of wintergreen) vapor as a simulant for HD agent to conduct system level evaluations of chemical protective ensembles....

  13. Using a ceramic chamber in kicker magnets

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S.

    1993-05-01

    A ceramic chamber inside kicker magnets can provide the relevant field risetime. On the other hand, some metallic coating inside has to prevent static charge buildup and shield the beam from ceramic and ferrite at high frequencies to avoid possible resonances. The issues concerning the metallized ceramic chamber, such as coupling impedances and requirements on the coating, are studied to find a compromise solution for kickers of the Medium Energy Booster at the Superconducting Super Collider.

  14. A very large multigap resistive plate chamber

    CERN Document Server

    Cerron-Zeballos, E; Hatzifotiadou, D; Kim, D W; Lamas-Valverde, J; Lee, S C; Platner, E D; Roberts, J; Williams, M C S; Zichichi, A

    1999-01-01

    We have built and tested a very large multigap resistive plate chamber (MRPC). We discuss the suitability of the multigap RPC for the construction of large area modules. We give details of the construction technique and results from a scan across the surface of the chamber. We also report on the implementation of `half-strip resolution', where we improve the spatial resolution by a factor 2 without increasing the number of read-out channels. (9 refs).

  15. Impact excited strain gage for multiwire chambers

    International Nuclear Information System (INIS)

    A method for measuring multiwire chamber tension by impact excitation of mechanical oscillations and measuring their periods is described. A flowsheet of an automated electron gaugeis presented; the gauge provides high efficiency and possibility for measurements under conditions of difficult availability of the multiwire chamber system. The range of tension measurements is 0.5-70 g for gilded tugsten wires of 20 μm in diameter and 60 cm length

  16. The world's largest time projection chamber

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    Peter Glassel, the technical coordinator for the ALICE time projection chamber, is seen sitting inside the detector; the largest in the world at nearly 100 cubic metres. Thousands of wires are connected to read out electronic data produced as particles are created in lead-lead collisions at the centre of the detector. These particles will cause the medium within the time projection chamber to ionise along their tracks allowing the particle paths to be recreated.

  17. Georges Charpak and his multiwire chamber

    CERN Multimedia

    1970-01-01

    In 1968, Georges Charpak developed the 'multiwire proportional chamber', a gas-filled box with a large number of parallel detector wires, each connected to individual amplifiers. Linked to a computer, it could achieve a counting rate a thousand times better than existing techniques - without a camera in sight. From left to right, Georges Charpak, Fabio Sauli and Jean-Claude Santiard working on a multiwire chamber in 1970.

  18. Tracking with wire chambers at high luminosities

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, G.G. (Indiana Univ., Bloomington, IN (USA) Stanford Linear Accelerator Center, Menlo Park, CA (USA))

    1989-12-01

    Radiation damage and rate limitations impose severe constraints on wire chambers at the SSC. Possible conceptual designs for wire chamber tracking systems that satisfy these constraints are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 11 refs., 10 figs.

  19. Virtual Calibration Chamber CPT on Ticino sand

    OpenAIRE

    Butlanska, Joanna; Arroyo Alvarez de Toledo, Marcos; Gens Solé, Antonio

    2010-01-01

    The following paper surnmarizes results of CPT's performed in virtual calibration chamber (VCC) built with a 3D model based on the distinct element method (DEM). A discrete material tailored to mimic Ticino sand is tested at different densities, stress and stress history. The limit cone tip resistance from the numerical experiments shows quantitative agreement with different empirical curves summarizing previous tests on Ticino sand in physical calibration chambers (ENEL and ISMES).

  20. The CDF vertex time projection chamber system

    International Nuclear Information System (INIS)

    The vertex time projection chamber (VTPC) system is one of the major components of the charged particle tracking system for the Collider Detector at Fermilab (CDF). The chambers cover about seven units of pseudorapidity (η) and must be capable of handling substantially more than the 30-35 charged particle tracks produced by typical anti pp collisions at center-of-mass energies of 1.8 TeV. The chambers are optimized to provide the good pattern recognition in the r-z view required to locate the event vertex, measure the overall event topology, and to complement the r-φ tracking in the large axial wire drift chamber that surrounds them. The chambers provide r-z information using TDC data from sense wire signals. Information on the φ of tracks is obtained from cathode pad signals on a subset of chambers read out by a FADC system. A similar system measures dE/dx of tracks in the forward cones surrounding the exiting beams. Because of the large number of photons that pass through the detector during each collision, novel techniques are required to reduce the amount of material in the chamber. These techniques include a custom surface mount integrated circuit preamplifier, epoxy-graphite and Kapton covered foam structural members, and miniature coaxial signal cables. The mechanical construction of the chamber, radiation length vs angle, and details of the electronics are described. The event reconstruction, corrections, and preliminary performance results for 1.8 TeV anti pp collisions are also discussed. (orig.)

  1. The Gargamelle heavy liquid bubble chamber

    CERN Multimedia

    1970-01-01

    This image shows the Gargamelle heavy liquid bubble chamber. It was used to detect particles in experiments at the PS between 1970 and 1976 before being moved to the SPS. In 1973, while working on the PS, it detected the first neutral current, an interaction vital to the electroweak theory. In 1978 a large fissure appeared in the body of the chamber and Gargamelle was stopped in 1979.

  2. Characteristic parameters of drift chambers calculation

    International Nuclear Information System (INIS)

    We present here the methods we used to analyse the characteristic parameters of drift chambers. The algorithms to calculate the electric potential in any point for any drift chamber geometry are presented. We include the description of the programs used to calculate the electric field, the drift paths, the drift velocity and the drift time. The results and the errors are discussed. (Author) 7 refs

  3. [Surgical anatomy of the anterior mediastinum].

    Science.gov (United States)

    Biondi, Alberto; Rausei, Stefano; Cananzi, Ferdinando C M; Zoccali, Marco; D'Ugo, Stefano; Persiani, Roberto

    2007-01-01

    The mediastinum is located from the thoracic inlet to the diaphragm between the left and right pleural cavities and contains vital structures of the circulatory, respiratory, digestive, and nervous system. Over the years, since there are no fascial or anatomic planes, anatomists and radiologists have suggested various schemes for subdividing the mediastinum and several anatomical and radiological classifications of the mediastinum are reported in the literature. The most popular of these scheme divides medistinum, for purposes of description, into two parts: an upper portion, above the upper level of the pericardium, which is named the superior mediastinum; and a lower portion, below the upper level of the pericardium. For clinical purposes, the mediastinum may be subdivided into three major areas, i.e. anterior, middle, and posterior compartments. The anterior mediastinum is defined as the region posterior to the sternum and anterior to the heart and brachiocephalic vessels. It extends from the thoracic inlet to the diaphragm and contains the thymus gland, fat, and lymph nodes. This article will review surgical anatomy of the anterior mediastinum and will focus on the surgical approch to anterior mediastinum and thymic diseases.

  4. Performance parameters of a liquid filled ionization chamber array

    Energy Technology Data Exchange (ETDEWEB)

    Poppe, B.; Stelljes, T. S.; Looe, H. K.; Chofor, N. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121, Germany and WG Medical Radiation Physics, Carl von Ossietzky University, Oldenburg 26121 (Germany); Harder, D. [Prof. em., Medical Physics and Biophysics, Georg August University, Göttingen 37073 (Germany); Willborn, K. [Clinic for Radiation Therapy, Pius-Hospital, Oldenburg 26121 (Germany)

    2013-08-15

    Purpose: In this work, the properties of the two-dimensional liquid filled ionization chamber array Octavius 1000SRS (PTW-Freiburg, Germany) for use in clinical photon-beam dosimetry are investigated.Methods: Measurements were carried out at an Elekta Synergy and Siemens Primus accelerator. For measurements of stability, linearity, and saturation effects of the 1000SRS array a Semiflex 31013 ionization chamber (PTW-Freiburg, Germany) was used as a reference. The effective point of measurement was determined by TPR measurements of the array in comparison with a Roos chamber (type 31004, PTW-Freiburg, Germany). The response of the array with varying field size and depth of measurement was evaluated using a Semiflex 31010 ionization chamber as a reference. Output factor measurements were carried out with a Semiflex 31010 ionization chamber, a diode (type 60012, PTW-Freiburg, Germany), and the detector array under investigation. The dose response function for a single detector of the array was determined by measuring 1 cm wide slit-beam dose profiles and comparing them against diode-measured profiles. Theoretical aspects of the low pass properties and of the sampling frequency of the detector array were evaluated. Dose profiles measured with the array and the diode detector were compared, and an intensity modulated radiation therapy (IMRT) field was verified using the Gamma-Index method and the visualization of line dose profiles.Results: The array showed a short and long term stability better than 0.1% and 0.2%, respectively. Fluctuations in linearity were found to be within ±0.2% for the vendor specified dose range. Saturation effects were found to be similar to those reported in other studies for liquid-filled ionization chambers. The detector's relative response varied with field size and depth of measurement, showing a small energy dependence accounting for maximum signal deviations of ±2.6% from the reference condition for the setup used. The σ-values of

  5. Flexible depth of field photography.

    Science.gov (United States)

    Kuthirummal, Sujit; Nagahara, Hajime; Zhou, Changyin; Nayar, Shree K

    2011-01-01

    The range of scene depths that appear focused in an image is known as the depth of field (DOF). Conventional cameras are limited by a fundamental trade-off between depth of field and signal-to-noise ratio (SNR). For a dark scene, the aperture of the lens must be opened up to maintain SNR, which causes the DOF to reduce. Also, today's cameras have DOFs that correspond to a single slab that is perpendicular to the optical axis. In this paper, we present an imaging system that enables one to control the DOF in new and powerful ways. Our approach is to vary the position and/or orientation of the image detector during the integration time of a single photograph. Even when the detector motion is very small (tens of microns), a large range of scene depths (several meters) is captured, both in and out of focus. Our prototype camera uses a micro-actuator to translate the detector along the optical axis during image integration. Using this device, we demonstrate four applications of flexible DOF. First, we describe extended DOF where a large depth range is captured with a very wide aperture (low noise) but with nearly depth-independent defocus blur. Deconvolving a captured image with a single blur kernel gives an image with extended DOF and high SNR. Next, we show the capture of images with discontinuous DOFs. For instance, near and far objects can be imaged with sharpness, while objects in between are severely blurred. Third, we show that our camera can capture images with tilted DOFs (Scheimpflug imaging) without tilting the image detector. Finally, we demonstrate how our camera can be used to realize nonplanar DOFs. We believe flexible DOF imaging can open a new creative dimension in photography and lead to new capabilities in scientific imaging, vision, and graphics. PMID:21088319

  6. The GODDESS ionization chamber: developing robust windows

    Science.gov (United States)

    Blanchard, Rose; Baugher, Travis; Cizewski, Jolie; Pain, Steven; Ratkiewicz, Andrew; Goddess Collaboration

    2015-10-01

    Reaction studies of nuclei far from stability require high-efficiency arrays of detectors and the ability to identify beam-like particles, especially when the beam is a cocktail beam. The Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies (GODDESS) is made up of the Oak Ridge-Rutgers University Barrel Array (ORRUBA) of silicon detectors for charged particles inside of the gamma-ray detector array Gammasphere. A high-rate ionization chamber is being developed to identify beam-like particles. Consisting of twenty-one alternating anode and cathode grids, the ionization chamber sits downstream of the target chamber and is used to measure the energy loss of recoiling ions. A critical component of the system is a thin and robust mylar window which serves to separate the gas-filled ionization chamber from the vacuum of the target chamber with minimal energy loss. After construction, windows were tested to assure that they would not break below the required pressure, causing harm to the wire grids. This presentation will summarize the status of the ionization chamber and the results of the first tests with beams. This work is supported in part by the U.S. Department of Energy and National Science Foundation.

  7. Quality control of ATLAS muon chambers

    CERN Document Server

    Fabich, Adrian

    ATLAS is a general-purpose experiment for the future Large Hadron Collider (LHC) at CERN. Its Muon Spectrometer will require ∼ 5500m2 of precision tracking chambers to measure the muon tracks along a spectrometer arm of 5m to 15m length, embedded in a magnetic field of ∼ 0.5T. The precision tracking devices in the Muon System will be high pressure drift tubes (MDTs). Approximately 370,000 MDTs will be assembled into ∼ 1200 drift chambers. The performance of the MDT chambers is very much dependent on the mechanical quality of the chambers. The uniformity and stability of the performance can only be assured providing very high quality control during production. Gas tightness, high-voltage behaviour and dark currents are global parameters which are common to gas detectors. For all chambers, they will be tested immediately after the chamber assembly at every production site. Functional tests, for example radioactive source scans and cosmic-ray runs, will be performed in order to establish detailed performan...

  8. In vitro penetration of bleaching agents into the pulp chamber

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Valera, M C; Mancini, M N G;

    2004-01-01

    To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures.......To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures....

  9. Bulkhead chamber ignition for internal combustion engines. Schottkammerzuendung fuer Verbrennungsmotore

    Energy Technology Data Exchange (ETDEWEB)

    Fox, G.

    1990-12-06

    Bulkhead chamber ignition makes for reliable ignition of different fuels (e.g. petrol or diesel) in internal combustion engines (multifuel engine) that can be operated with an extremely lean fuel-air mixture. This is realized by an open chamber (referred to as bulkhead chamber in the following) inside the combustion chamber which diverts a fraction of the compressed fuel-air mixture from the combustion chamber. After this the pressure in the bulkhead chamber is increased until the mixture ignites spontaneously. The combustion pressure drives back the piston and opens the bulkhead chamber. Then the compressed fuel-air mixture in the combustion chamber is ignited by the released combustion gas.

  10. Optimization of Variable-Depth Liner Configurations for Increased Broadband Noise Reduction

    Science.gov (United States)

    Jones, M. G.; Watson, W. R.; Nark, D. M.; Schiller, N. H.; Born, J. C.

    2016-01-01

    This paper employs three acoustic propagation codes to explore variable-depth liner configurations for the NASA Langley Grazing Flow Impedance Tube (GFIT). The initial study demonstrates that a variable impedance can acceptably be treated as a uniform impedance if the spatial extent over which this variable impedance occurs is less than one-third of a wavelength of the incident sound. A constrained optimization study is used to design a variable-depth liner and to select an optimization metric. It also provides insight regarding how much attenuation can be achieved with variable-depth liners. Another optimization study is used to design a liner with much finer chamber depth resolution for the Mach 0.0 and 0.3 test conditions. Two liners are designed based on spatial rearrangement of chambers from this liner to determine whether the order is critical. Propagation code predictions suggest this is not the case. Both liners are fabricated via additive manufacturing and tested in the GFIT for the Mach 0.0 condition. Predicted and measured attenuations compare favorably across the full frequency range. These results clearly suggest that the chambers can be arranged in any order, thus offering the potential for innovative liner designs to minimize depth and weight.

  11. Shallow magma chamber under the Wudalianchi Volcanic Field unveiled by seismic imaging with dense array

    Science.gov (United States)

    Li, Zhiwei; Ni, Sidao; Zhang, Baolong; Bao, Feng; Zhang, Senqi; Deng, Yang; Yuen, David A.

    2016-05-01

    The Wudalianchi Volcano Field (WDF) is a typical intraplate volcano in northeast China with generation mechanism not yet well understood. As its last eruption was around 300 years ago, the present risk for volcano eruption is of particular public interest. We have carried out a high-resolution ambient noise tomography to investigate the location of magma chambers beneath the volcanic cones with a dense seismic array of 43 seismometers and ~ 6 km spatial interval. Significant low-velocity anomalies up to 10% are found at 7-13 km depth under the Weishan volcano, consistent with the pronounced high electrical-conductivity anomalies from previous magnetotelluric survey. We propose these extremely low velocity anomalies can be interpreted as partial melting in a shallow magma chamber with volume at least 200 km3 which may be responsible for most of the recent volcanic eruptions in WDF. Therefore, this magma chamber may pose a serious hazard for northeast China.

  12. Esthetic crown lengthening for maxillary anterior teeth.

    Science.gov (United States)

    Sonick, M

    1997-08-01

    In the maxillary anterior region, the gingival labial margin position is an important parameter in the achievement of an ideal smile. The relationship between the periodontium and the restoration is critical if gingival health and esthetics are to be achieved. Periodontal therapy is a necessary and useful adjunct when any anterior restoration is undertaken. Anterior surgical crown lengthening may be undertaken to avoid restorative margin impingement on the biologic width. Crown lengthening is also used to alter the gingival labial profiles. This article discusses the esthetic parameters of ideal gingival labial positions and presents a classification of crown-lengthening procedures and the procedure for a two-stage crown-lengthening technique. The two-stage crown-lengthening technique is surgically precise because healing is predictable.

  13. THYMOLIPOMA: A RARE, LARGE ANTERIOR MEDIASTINAL MASS

    Directory of Open Access Journals (Sweden)

    Premananth

    2015-07-01

    Full Text Available Thymolipoma is a rare benign tumor of anterior mediastinum, described by Lange in 1916. 1 Less than 200 cases have been reported worldwide. 2 It accounts for 2% to 9% of thymic tumours. 3 We report a case of thymolipoma in a 37 year s old male patient, who pre sented with cough, dys p nea, chest pain for 2 months. CT THORAX revealed a large anterior mediastinal mass extending in to right hemithorax arising from thymus gland, with multiple areas of fat density, no significant mediastinal adenopathy, complete collap se of right middle and lower lobe suggestive of thymolipoma. CT guided biopsy suggestive of thymic neoplasm. The tumour was removed enbloc through surgery. Histopathological examination of large mass lesion confirmed thymolipoma. We report this case to emp hasize the importance of considering thymolipoma as a differential diagnosis of anterior mediastinal mass, although rare.

  14. Nonnecrotizing anterior scleritis mimicking orbital inflammatory disease

    Directory of Open Access Journals (Sweden)

    Lynch MC

    2013-08-01

    Full Text Available Michelle Chen Lynch,1 Andrew B Mick21Optometry Clinic, Ocala West Veterans Affairs Specialty Clinic, Ocala, FL, USA; 2Eye Clinic, San Francisco VA Medical Center, San Francisco, CA, USABackground: Anterior scleritis is an uncommon form of ocular inflammation, often associated with coexisting autoimmune disease. With early recognition and aggressive systemic therapy, prognosis for resolution is good. The diagnosis of underlying autoimmune disease involves a multidisciplinary approach.Case report: A 42-year-old African American female presented to the Eye Clinic at the San Francisco Veteran Affairs Medical Center, with a tremendously painful left eye, worse on eye movement, with marked injection of conjunctiva. There was mild swelling of the upper eyelid. Visual acuity was unaffected, but there was a mild red cap desaturation. The posterior segment was unremarkable. The initial differential diagnoses included anterior scleritis and orbital inflammatory disease. Oral steroid treatment was initiated with rapid resolution over a few days. Orbital imaging was unremarkable, and extensive laboratory work-up was positive only for antinuclear antibodies. The patient was diagnosed with idiopathic diffuse, nonnecrotizing anterior scleritis and has been followed for over 5 years without recurrence. The rheumatology clinic monitors the patient closely, as suspicion remains for potential arthralgias including human leukocyte antigen-B27-associated arthritis, lupus-associated arthritis, seronegative rheumatoid arthritis, recurrent juvenile idiopathic arthritis, and scleroderma, based on her constitutional symptoms and clinical presentation, along with a positive anti-nuclear antibody lab result.Conclusion: Untreated anterior scleritis can progress to formation of cataracts, glaucoma, uveitis, corneal melting, and posterior segment disease with significant risk of vision loss. Patients with anterior scleritis must be aggressively treated with systemic anti

  15. Dual (type IV left anterior descending artery

    Directory of Open Access Journals (Sweden)

    Ozdil Baskan

    2013-11-01

    Full Text Available Congenital coronary artery anomalies are uncommon. Dual left anterior descending coronary artery (LAD is defined as the presence of two LADs within the anterior interventricular sulcus (AIVS, and is classified into four types. Type IV is a rarely reported subtype and differs from the others, with a long LAD originating from the right coronary artery (RCA. Dual LAD is a benign coronary artery anomaly, but should be recognised especially before interventional procedures. With the increasing use of multidedector computed tomography (MDCT, it is essential for radiologists to be aware of this entity and the cross-sectional findings.

  16. ANTERIOR OSTEOPHYTE IDENTIFICATION IN CERVICAL VERTEBRAE

    Directory of Open Access Journals (Sweden)

    A. T. Chougale

    2011-06-01

    Full Text Available Radiologist always examines X-ray to determine abnormal changes in cervical, lumbar & thoracic vertebrae. Osteophyte (bony growth may appear at the corners of vertebrae so that vertebral shape becomes abnormal. This paper presents the idea from Image processing techniques such as customised Hough transform which will be used for segmentation which should be independent of rotation, scale, noise & shape. This segmented image will be then used for computing size invariant, convex hull based features to differentiate normal cervical vertebrae from cervical vertebrae containing anterior osteophyte. This approach effectively finds anterior osteophytes in cervical vertebrae.

  17. Evaluation of Descemet’s Membrane Detachment Using Anterior Segment Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Halil Hüseyin Çağatay

    2014-10-01

    Full Text Available We report the use of anterior segment optical coherence tomography (ASOCT in Descemet’s membrane detachment (DMD. A patient who developed DMD after uneventful cataract surgery with posterior chamber lens implantation is presented in this case report. At the follow-up examination after cataract surgery, slit-lamp evaluation showed stromal striae, but it was impossible to diagnose the DMD due to the corneal edema. ASOCT imaging of the cornea revealed a DMD, and the patient underwent intracameral air injection to the anterior chamber through the site which was identified as intact by ASOCT. Follow-up ASOCT imaging revealed the reattachment of the Descemet’s membrane and reduced corneal thickness. If DMD is suspected in any cases, ASOCT can be useful to document and follow the postsurgical detachment of DMD and also to determine the site, configuration, and extent of the DMD, thus guiding the treatment method and monitoring the treatment outcome. (Turk J Ophthalmol 2014; 44: 407-9

  18. Biomechanical Consequences of Anterior Femoral Notching in Cruciate-Retaining Versus Posterior-Stabilized Total Knee Arthroplasty.

    Science.gov (United States)

    Jethanandani, Rishabh; Patwary, Mahbubul B; Shellito, Adam D; Meehan, John P; Amanatullah, Derek F

    2016-01-01

    Anterior femoral notching during total knee arthroplasty is a potential risk factor for periprosthetic supracondylar femur fracture. We conducted a study to determine if the design of the femoral implant changes the risk for periprosthetic supracondylar femur fractures after anterior cortical notching. An anterior cortical defect was created in 12 femoral polyurethane models. Six femora were instrumented with cruciate-retaining implants and 6 with posterior-stabilized implants. Each femur was loaded in external rotation along the anatomical axis. Notch depth and distance from anterior cortical notch to implant were recorded before loading, and fracture pattern was recorded after failure. There were no statistically significant differences in notch depth, distance from notch to implant, torsional stiffness, torque at failure, final torque, or fracture pattern between cruciate-retaining and posterior-stabilized femoral component designs. Periprosthetic fracture after anterior femoral notching is independent of the bone removed from the intercondylar notch. After notching, there likely is no significant difference in femoral strength in torsion between cruciate-retaining and posterior-stabilized designs. PMID:27552464

  19. A novel method for measuring anterior segment area of the eye on ultrasound biomicroscopic images using photoshop.

    Directory of Open Access Journals (Sweden)

    Zhonghao Wang

    Full Text Available To describe a novel method for quantitative measurement of area parameters in ocular anterior segment ultrasound biomicroscopy (UBM images using Photoshop software and to assess its intraobserver and interobserver reproducibility.Twenty healthy volunteers with wide angles and twenty patients with narrow or closed angles were consecutively recruited. UBM images were obtained and analyzed using Photoshop software by two physicians with different-level training on two occasions. Borders of anterior segment structures including cornea, iris, lens, and zonules in the UBM image were semi-automatically defined by the Magnetic Lasso Tool in the Photoshop software according to the pixel contrast and modified by the observers. Anterior chamber area (ACA, posterior chamber area (PCA, iris cross-section area (ICA and angle recess area (ARA were drawn and measured. The intraobserver and interobserver reproducibilities of the anterior segment area parameters and scleral spur location were assessed by limits of agreement, coefficient of variation (CV, and intraclass correlation coefficient (ICC.All of the parameters were successfully measured by Photoshop. The intraobserver and interobserver reproducibilities of ACA, PCA, and ICA were good, with no more than 5% CV and more than 0.95 ICC, while the CVs of ARA were within 20%. The intraobserver and interobserver reproducibilities for defining the spur location were more than 0.97 ICCs. Although the operating times for both observers were less than 3 minutes per image, there was significant difference in the measuring time between two observers with different levels of training (p<0.001.Measurements of ocular anterior segment areas on UBM images by Photoshop showed good intraobserver and interobserver reproducibilties. The methodology was easy to adopt and effective in measuring.

  20. Investigation of Swirling Flows in Mixing Chambers

    Directory of Open Access Journals (Sweden)

    Jyh Jian Chen

    2011-01-01

    Full Text Available This investigation analyzed the three-dimensional momentum and mass transfer characteristics arising from multiple inlets and a single outlet in micromixing chamber. The chamber consists of a right square prism, an octagonal prism, or a cylinder. Numerical results which were presented in terms of velocity vector plots and concentration distributions indicated that the swirling flows inside the chamber dominate the mixing index. Particle trajectories were utilized to demonstrate the rotational and extensional local flows which produce steady stirring, and the configuration of colored particles at the outlet section expressed at different Re represented the mixing performance qualitatively. The combination of the Taylor dispersion and the vorticity was first introduced and made the mixing successful. The effects of various geometric parameters and Reynolds numbers on the mixing characteristics were investigated. An optimal design of the cylindrical chamber with 4 inlets can be found. At larger Reynolds number, Re>15, more inertia caused the powerful swirling flows in the chamber, and more damping effect on diffusion was diminished, which then increased the mixing performance.

  1. Study and analysis of drift chamber parameters

    International Nuclear Information System (INIS)

    The present work deals mainly with drift chambers. In the first chapter a summary of drift chamber properties is presented. The information has been collected from the extensive bibliography available in this field. A very simple calculation procedure of drift chamber parameters has been developed and is presented in detail in the second chapter. Some prototypes have been made following two geometries (multidrift chamber and Z-chambers). Several installations have been used for test and calibration of these prototypes. A complete description of these installations is given in the third chapter. Cosmic rays, beta particles from a Ru106 radiactive source and a test beam in the WA (West Area) of SPS at CERN have been used for experimental purposes. The analysis and the results are described for the different setups. The experimental measurements have been used to produce a complete cell parametrization (position as function of drift time) and to obtain spatial resolution values (in the range of 200-250 um). Experimental results are in good agreement with numerical calculations. (Author)

  2. Proportional chambers for the Σ installation

    International Nuclear Information System (INIS)

    Two types of proportional chambers used in experiments with SIGMA set are considered. The main parameters of detecting electronics, high-voltage, low-voltage and gas supplies are presented. The first type chambers consist of the round or square frames of sheet foiled glass-cloth-base laminate, on which surface electrode lands and joints between them are applied by photographic printing. The second type chamber electrodes are also made of the sheet foiled glass-cloth-base laminate as strips arranged at the ends of two rectangular metallic profiles. The chamber sensitive regions vary from 64x64 mm to 768x2500 mm. The chambers are used for more than 15 years in different experiments, such as determination of elastic scattering, study of J/ψ and ψ' particle production, search for charm particles in hadron interactions, measuring the change of π--meson polarizability, study of μ+μ-π- system production. The experience of past years manifested their high efficiency and reliability

  3. Tuned Chamber Core Panel Acoustic Test Results

    Science.gov (United States)

    Schiller, Noah H.; Allen, Albert R.

    2016-01-01

    This report documents acoustic testing of tuned chamber core panels, which can be used to supplement the low-frequency performance of conventional acoustic treatment. The tuned chamber core concept incorporates low-frequency noise control directly within the primary structure and is applicable to sandwich constructions with a directional core, including corrugated-, truss-, and fluted-core designs. These types of sandwich structures have long, hollow channels (or chambers) in the core. By adding small holes through one of the facesheets, the hollow chambers can be utilized as an array of low-frequency acoustic resonators. These resonators can then be used to attenuate low-frequency noise (below 400 Hz) inside a vehicle compartment without increasing the weight or size of the structure. The results of this test program demonstrate that the tuned chamber core concept is effective when used in isolation or combined with acoustic foam treatments. Specifically, an array of acoustic resonators integrated within the core of the panels was shown to improve both the low-frequency absorption and transmission loss of the structure in targeted one-third octave bands.

  4. Perawatan Ortodontik Gigi Anterior Berjejal dengan Tulang Alveolar yang Tipis

    Directory of Open Access Journals (Sweden)

    Miesje K. Purwanegara

    2015-09-01

    Full Text Available Anterior teeth movement in orthodontic treatment is limited to labiolingual direction by very thin alveolar bone. An uncontrolled anterior tooth movement to labiolingual direction can cause alveolar bone perforation at its root segment. This case report is to remind us that alveolar bone thickness limits orthodontc tooth movement. A case of crowded anterior teeth with thin alveolar bone in malocclusion I is reported. This case is treated using adgewise orthodontic appliance. Protraction of anterior teeth is anticipated due to thin alveolar bone on the anterior surface. The conclusion is although the alveolar bone surrounding the crowded anterior teeth is thin, by controlling the movement the teeth reposition is allowed.

  5. ANTERIOR COLUMN FRACTURES OF THE ACETABULUM

    NARCIS (Netherlands)

    HEEG, M; OTTER, N; KLASEN, HJ

    1992-01-01

    We retrospectively reviewed 20 patients at three to 19 years after displaced anterior fracture-dislocations of the hip. Eighteen of them were treated by traction, after ensuring that the femoral head was adequately reduced beneath the undisrupted part of the weight-bearing dome. Two required operati

  6. Anterior retropharyngeal approach to the cervical spine.

    Directory of Open Access Journals (Sweden)

    Behari S

    2001-10-01

    Full Text Available The anterior retropharyngeal approach (ARPA accesses anteriorly situated lesions from the clivus to C3, in patients with a short neck, Klippel Feil anomaly or those in whom the C2-3 and C3-4 disc spaces are situated higher in relation to the hyoid bone and the angle of mandible where it is difficult to approach this region using the conventional anterior approach, due to the superomedial obliquity of the trajectory. The ARPA avoids the potentially contaminated oropharyngeal cavity providing for a simultaneous arthrodesis and instrumentation during the primary surgical procedure. Experience of five patients with high cervical extradural compression, who underwent surgery using this approach between 1994 and 1999, is presented. The surgical procedures included excision of ossified posterior longitudinal ligament (n=2; excision of prolapsed disc and osteophytes (n=2; and excision of a vertebral body neoplasm (n=1. Following the procedure, vertebral arthrodesis was achieved using an iliac graft in all the patients. Only one patient with vertebral body neoplasm required an additional anterior cervical plating procedure for stabilisation the construct. The complications included transient respiratory insufficiency and neurological deterioration in two patients; and, pharyngeal fistula and donor site infection in one patient.

  7. Anterior process fractures of the calcaneus

    Energy Technology Data Exchange (ETDEWEB)

    Renfrew, D.L.; El-Khoury, G.Y.

    1985-07-01

    Fractures of the anterior process of the calcaneus are often missed. This error follows from the tendency to focus exclusively on the mortise and malleoli when a history of ankle trauma is supplied. Seven patients with this fracture are presented. The anatomy, mechanism of injury, clinical presentation, and the radiographic features of this injury are discussed.

  8. Anorgasmia in anterior spinal cord syndrome.

    OpenAIRE

    Berić, A; Light, J K

    1993-01-01

    Three male and two female patients with anorgasmia and dissociated sensory loss due to an anterior spinal cord syndrome are described. Clinical, neurophysiological and quantitative sensory evaluation revealed preservation of the large fibre dorsal column functions from the lumbosacral segments with concomitant severe dysfunction or absence of the small fibre neospinothalamic mediated functions. These findings indicate a role for the spinothalamic system in orgasm.

  9. Causes of anterior cruciate ligament injuries

    Directory of Open Access Journals (Sweden)

    Ristić Vladimir

    2010-01-01

    Full Text Available In order to prevent anterior cruciate ligament injuries it is necessary to define risk factors and to analyze the most frequent causes of injuries - that being the aim of this study. The study sample consisted of 451 surgically treated patients, including 400 sportsmen (65% of them being active and 35% recreational sportsmen, 29% female and 71% male; of whom 90% were younger than 35. Sports injuries, as the most frequent cause of anterior cruciate ligament injuries, were recorded in 88% of patients (non-contact ones in 78% and contact ones in 22%, injuries occurring in everyday activities in 11% and in traffic in 1%. Among sportsmen, reconstruction of the anterior cruciate ligament was most frequently performed in football players (48%, then in handball players (22%, basketball players (13%, volleyball players (8%, martial arts fighters (4%. However, the injury incidence was the highest among the active basketball players (1 injured among 91 active players. Type of footwear, warming up before the activity, genetic predisposition and everyday therapy did not have a significant influence on getting injured. Anterior cruciate ligament injuries happened three times more often during matches, in the middle and at the end of a match and training session (79%, at landing after the jump or when changing direction of movement (75% without a contact with other competitors, on dry surfaces (79%, among not so well prepared sportsmen.

  10. Treatment for acute anterior cruciate ligament tear

    DEFF Research Database (Denmark)

    Frobell, Richard B; Roos, Harald P; Roos, Ewa M;

    2013-01-01

    To compare, in young active adults with an acute anterior cruciate ligament (ACL) tear, the mid-term (five year) patient reported and radiographic outcomes between those treated with rehabilitation plus early ACL reconstruction and those treated with rehabilitation and optional delayed ACL...

  11. Tunnel widening in anterior cruciate ligament reconstruction

    DEFF Research Database (Denmark)

    Clatworthy, M G; Annear, P; Bulow, J U;

    1999-01-01

    We report a prospective series evaluating the incidence and degree of tunnel widening in a well-matched series of patients receiving a hamstring or patella tendon graft for anterior cruciate ligament (ACL) deficiency. We correlated tunnel widening with clinical factors, knee scores, KT-1000...

  12. Guideline on anterior cruciate ligament injury

    NARCIS (Netherlands)

    Meuffels, Duncan E; Poldervaart, Michelle T; Diercks, Ronald; Fievez, Alex W F M; Patt, Thomas W; Hart, Cor P van der; Hammacher, Eric R; Meer, Fred van der; Goedhart, Edwin A; Lenssen, Anton F; Muller-Ploeger, Sabrina B; Pols, Margreet A; Saris, Daniel B F

    2012-01-01

    The Dutch Orthopaedic Association has a long tradition of development of practical clinical guidelines. Here we present the recommendations from the multidisciplinary clinical guideline working group for anterior cruciate ligament injury. The following 8 clinical questions were formulated by a steer

  13. Novel Insights into Anterior Cruciate Ligament Injury

    NARCIS (Netherlands)

    D.E. Meuffels (Duncan)

    2011-01-01

    textabstractAnterior cruciate ligament (ACL) injury is one of the most common sports injuries of the knee. ACL reconstruction has become, standard orthopaedic practice worldwide with an estimated 175,000 reconstructions per year in the United States.6 The ACL remains the most frequently studied liga

  14. Treatment for acute anterior cruciate ligament tear

    DEFF Research Database (Denmark)

    Frobell, Richard B; Roos, Harald P; Roos, Ewa M;

    2015-01-01

    STUDY QUESTION: In young active adults with an acute anterior cruciate ligament (ACL) rupture, do patient reported or radiographic outcomes after five years differ between those treated with rehabilitation plus early ACL reconstruction and those treated with rehabilitation and optional delayed ACL...

  15. Dosimetric evaluation of a 2D pixel ionization chamber for implementation in clinical routine

    International Nuclear Information System (INIS)

    In this paper we present the results of a dosimetric evaluation of a 2D ionization chamber array with the objective of its implementation for quality assurance in clinical routine. The pixel ionization chamber MatriXX (Scanditronix Wellhofer, Germany) consists of 32 x 32 chambers with a distance of 7.6 mm between chamber centres. The effective depth of measurement under the surface of the detector was determined. The dose and energy dependence, the behaviour of the device during its initial phase and its time stability as well as the lateral response of a single chamber of the detector in cross-plane and diagonal directions were analysed. It could be shown, that the detector's response is linear with dose and energy independent. Taking the lateral response into account, two different dose profiles, for a pyramidal and an IMRT dose distribution, were applied to compare the data generated by a treatment planning system with measurements. From these investigations it can be concluded that the detector is a suitable device for quality assurance and 2D dose verifications

  16. Photon counting compressive depth mapping

    CERN Document Server

    Howland, Gregory A; Ware, Matthew R; Howell, John C

    2013-01-01

    We demonstrate a compressed sensing, photon counting lidar system based on the single-pixel camera. Our technique recovers both depth and intensity maps from a single under-sampled set of incoherent, linear projections of a scene of interest at ultra-low light levels around 0.5 picowatts. Only two-dimensional reconstructions are required to image a three-dimensional scene. We demonstrate intensity imaging and depth mapping at 256 x 256 pixel transverse resolution with acquisition times as short as 3 seconds. We also show novelty filtering, reconstructing only the difference between two instances of a scene. Finally, we acquire 32 x 32 pixel real-time video for three-dimensional object tracking at 14 frames-per-second.

  17. Periodicities in Aerosol Optical Depths

    CERN Document Server

    Ramachandran, S; Verma, Amit; Panigrahi, Prasanta K

    2011-01-01

    We investigate the temporal and spatial variability in aerosol optical depth (AOD) over different geographic locations in India due to their important role in the earth-atmosphere radiation budget. The use of continuous wavelet transform pinpoints the spatio-temporal non-stationarity of the periodic variations in the AOD depending on local factors. The optimal time-frequency localization ability of Morlet wavelet accurately isolates the periodic features in the different frequency domains, to study the variations in the dominant periods due to local effects. The origin of the effects on the periodic modulations is then related to physical phenomena of regional nature, which throws considerable light on the observed variations in aerosol optical depths. We also find the phase relationship between different locations and to identify the possible correlations between different geographic locations and related environmental variations.

  18. Applications of positron depth profiling

    Energy Technology Data Exchange (ETDEWEB)

    Hakvoort, R.A.

    1993-12-23

    In this thesis some contributions of the positron-depth profiling technique to materials science have been described. Following studies are carried out: Positron-annihilation measurements on neon-implanted steel; Void creation in silicon by helium implantation; Density of vacancy-type defects present in amorphous silicon prepared by ion implantation; Measurements of other types of amorphous silicon; Epitaxial cobalt disilicide prepared by cobalt outdiffusion. Positron-annihilation experiments on low-pressure CVD silicon-nitride films. (orig./MM).

  19. Change of Pressing Chamber Conicalness at Briquetting Process in Briquetting Machine Pressing Chamber

    Directory of Open Access Journals (Sweden)

    Peter Križan

    2012-01-01

    Full Text Available In this paper, we will present the impact of the conical shape of a pressing chamber, an important structural parameter. Besides the known impact of the technological parameters of pressing chambers, it is also very important to pay attention to their structural parameters. In the introduction, we present a theoretical analysis of pressing chamber conicalness. An experiment aimed at detecting this impact was performed at our institute, and it showed that increasing the conicalness of a pressing chamber improves the quality of the final briquettes. The conicalness of the pressing chamber has a significanteffect on the final briquette quality and on the construction of briquetting machines. The experimental findings presented here show the importance of this parameter in the briquetting process.

  20. Underwater camera with depth measurement

    Science.gov (United States)

    Wang, Wei-Chih; Lin, Keng-Ren; Tsui, Chi L.; Schipf, David; Leang, Jonathan

    2016-04-01

    The objective of this study is to develop an RGB-D (video + depth) camera that provides three-dimensional image data for use in the haptic feedback of a robotic underwater ordnance recovery system. Two camera systems were developed and studied. The first depth camera relies on structured light (as used by the Microsoft Kinect), where the displacement of an object is determined by variations of the geometry of a projected pattern. The other camera system is based on a Time of Flight (ToF) depth camera. The results of the structural light camera system shows that the camera system requires a stronger light source with a similar operating wavelength and bandwidth to achieve a desirable working distance in water. This approach might not be robust enough for our proposed underwater RGB-D camera system, as it will require a complete re-design of the light source component. The ToF camera system instead, allows an arbitrary placement of light source and camera. The intensity output of the broadband LED light source in the ToF camera system can be increased by putting them into an array configuration and the LEDs can be modulated comfortably with any waveform and frequencies required by the ToF camera. In this paper, both camera were evaluated and experiments were conducted to demonstrate the versatility of the ToF camera.

  1. Drift chamber tracking with neural networks

    International Nuclear Information System (INIS)

    With the very high event rates projected for experiments at the SSC and LHC, it is important to investigate new approaches to on line pattern recognition. The use of neural networks for pattern recognition. The use of neural networks for pattern recognition in high energy physics detectors has been an area of very active research. The authors discuss drift chamber tracking with a commercial analog VLSI neural network chip. Voltages proportional to the drift times in a 4-layer drift chamber were presented to the Intel ETANN chip. The network was trained to provide the intercept and slope of straight tracks traversing the chamber. The outputs were recorded and later compared off line to conventional track fits. Two types of network architectures were studied. Applications of neural network tracking to high energy physics detector triggers is discussed

  2. Classification of the LHC BLM Ionization Chamber

    CERN Document Server

    Stockner, M; Fabjan, Christian Wolfgang; Holzer, E B; Kramer, Daniel

    2008-01-01

    The LHC beam loss monitoring (BLM) system must prevent the super conducting magnets from quenching and protect the machine components from damage. The main monitor type is an ionization chamber. About 4000 of them will be installed around the ring. The lost beam particles initiate hadronic showers through the magnets and other machine components. These shower particles are measured by the monitors installed on the outside of the accelerator equipment. For the calibration of the BLM system the signal response of the ionization chamber is simulated in GEANT4 for all relevant particle types and energies (keV to TeV range). For validation, the simulations are compared to measurements using protons, neutrons, photons and mixed radiation fields at various energies and intensities. This paper will focus on the signal response of the ionization chamber to various particle types and energies including space charge effects at high ionization densities.

  3. Posing the first LEAR vacuum chamber

    CERN Multimedia

    1982-01-01

    The photo shows one of the four bending magnets of LEAR. They were of C-type with the opening ('mouth') to the outside of the ring (yoke to the inside). Last preparations are made before the vacuum chamber is slid through the mouth into the magnet. Stochastic cooling pickups/kickers were installed inside the chamber. One can distinguish a large number of feed-throughs on the chamber (leading to the pickup/kicker gaps). The free space in the middle of the block was left to offer room for an internal target in the magnet. This possibility was never exploited. Instead it is used here, to accommodate a pumping port for the high vacuum system. Michel Chanel (left) and Pierre Lefevre admire the mechanics at work.

  4. Rapid-Cycling Bubble-Chamber, details

    CERN Multimedia

    1980-01-01

    Parts of the hydraulic expansion system of the Rapid-Cycling Bubble-Chamber (RCBC). RCBC was the largest of 3 rapid-cycling bubble-chambers (the others were LEBC and HOLEBC), used as target- and vertex-detectors within the European Hybrid Spectrometer (EHS) in the SPS North Area (EHN1). RCBC contained 250 l of liquid hydrogen and was located inside a 3 T superconducting magnet. It was designed for 30 expansions/s (100 times faster than BEBC), the system shown here allowed 50 expansions/s. RCBC operated from 1981 to 1983 for experiments NA21, NA22 and NA23 at a rate of 15 expansions/s, clocking up a total of over 4 million. In the rear, at left, is bearded Lucien Veillet; Augustin Didona is at the right. See also 8001009. The installation of the piston assembly in the RCBC chamber body is shown in the Annual Report 1980, p.65.

  5. Thermal Vacuum Chamber Repressurization with Instrument Purging

    Science.gov (United States)

    Woronowicz, Michael

    2016-01-01

    At the end of James Webb Space Telescope (JWST) OTIS (Optical Telescope Element-OTE-Integrated Science Instrument Module-ISIM) cryogenic vacuum testing in NASA Johnson Space Centers (JSCs) thermal vacuum (TV) Chamber A, contamination control (CC) engineers are mooting the idea that chamber particulate material stirred up by the repressurization process may be kept from falling into the ISIM interior to some degree by activating instrument purge flows over some initial period before opening the chamber valves. This memo describes development of a series of models designed to describe this process. These are strung together in tandem to estimate overpressure evolution from which net outflow velocity behavior may be obtained. Creeping flow assumptions are then used to determine the maximum particle size that may be kept suspended above the ISIM aperture, keeping smaller particles from settling within the instrument module.

  6. Design of the CLIC Quadrupole Vacuum Chambers

    CERN Document Server

    Garion, C

    2010-01-01

    The Compact Linear Collider, under study, requires vacuum chambers with a very small aperture, of the order of 8 mm in diameter, and with a length up to around 2 m for the main beam quadrupoles. To keep the very tight geometrical tolerances on the quadrupoles, no bake out is allowed. The main issue is to reach UHV conditions (typically 10-9 mbar static pressure) in a system where the vacuum performance is driven by water outgassing. For this application, a thinwalled stainless steel vacuum chamber with two ante chambers equipped with NEG strips, is proposed. The mechanical design, especially the stability analysis, is shown. The key technologies of the prototype fabrication are given. Vacuum tests are carried out on the prototypes. The test set-up as well as the pumping system conditions are presented.

  7. A Positive GATA Element and a Negative Vitamin D Receptor-Like Element Control Atrial Chamber-Specific Expression of a Slow Myosin Heavy-Chain Gene during Cardiac Morphogenesis

    OpenAIRE

    Wang, Gang Feng; Nikovits, William; Schleinitz, Mark; Stockdale, Frank E.

    1998-01-01

    We have used the slow myosin heavy chain (MyHC) 3 gene to study the molecular mechanisms that control atrial chamber-specific gene expression. Initially, slow MyHC 3 is uniformly expressed throughout the tubular heart of the quail embryo. As cardiac development proceeds, an anterior-posterior gradient of slow MyHC 3 expression develops, culminating in atrial chamber-restricted expression of this gene following chamberization. Two cis elements within the slow MyHC 3 gene promoter, a GATA-bindi...

  8. SU-E-T-448: On the Perturbation Factor P-cav of the Markus Parallel Plate Ion Chambers in Clinical Electron Beams, Monte Carlo Based Reintegration of An Historical Experiment

    International Nuclear Information System (INIS)

    Purpose: All present dosimetry protocols recommend well-guarded parallel-plate ion chambers for electron dosimetry. For the guard-less Markus chamber an energy dependent fluence perturbation correction pcav is given. This perturbation correction was experimentally determined by van der Plaetsen by comparison of the read-out of a Markus and a NACP chamber, which was assumed to be “perturbation-free”. Aim of the present study is a Monte Carlo based reiteration of this experiment. Methods: Detailed models of four parallel-plate chambers (Roos, Markus, NACP and Advanced Markus) were designed using the Monte Carlo code EGSnrc and placed in a water phantom. For all chambers the dose to the active volume filled with low density water was calculated for 13 clinical electron spectra (E0=6-21 MeV) at the depth of maximum and at the reference depth under reference conditions. In all cases the chamber's reference point was positioned at the depth of measurement. Moreover, the dose to water DW was calculated in a small water voxel positioned at the same depth. Results: The calculated dose ratio DNACP/DMarkus, which according to van der Plaetsen reflects the fluence perturbation correction of the Markus chamber, deviates less from unity than the values given by van der Plaetsen's but exhibits a similar energy dependence. The same holds for the dose ratios of the other well guarded chambers. But, in comparison to water, the Markus chamber reveals the smallest overall perturbation correction which is nearly energy independent at both investigated depths. Conclusion: The simulations principally confirm the energy dependence of the dose ratio DNACP/DMarkus as published by van der Plaetsen. But, as shown by our simulations of the ratio DW/DMarkus, the conclusion drawn in all dosimetry protocols is questionable: in contrast to all well-guarded chambers the guard-less Markus chamber reveals the smallest overall perturbation correction and also the smallest energy

  9. A view inside the Gargamelle bubble chamber

    CERN Multimedia

    1970-01-01

    Gargamelle was the name given to a big bubble chamber built at the Saclay Laboratory in France during the late 1960s. It was designed principally for the detection at CERN of the elusive particles called neutrinos. A bubble chamber contains a liquid under pressure, which reveals the tracks of electrically charged particles as trails of tiny bubbles when the pressure is reduced. Neutrinos have no charge, and so leave no tracks, but the aim with Gargamelle was "see neutrinos" by making visible any charged particles set in motion by the interaction of neutrinos in the liquid

  10. Cosmic Muon Detector Using Proportional Chambers

    CERN Document Server

    Varga, Dezső; Hamar, Gergő; Molnár, Janka Sára; Oláh, Éva; Pázmándi, Péter

    2015-01-01

    A set of classical multi-wire proportional chambers were designed and constructed with the main purpose of efficient cosmic muon detection. These detectors are relatively simple to construct, and at the same time are low cost, making them ideal for educational purposes. The detector layers have efficiencies above 99% for minimum ionizing cosmic muons, and their position resolution is about 1 cm, that is, particle trajectories are clearly observable. Visualization of straight tracks is possible using an LED array, with the discriminated and latched signal driving the display. Due to the exceptional operating stability of the chambers, the design can also be used for cosmic muon telescopes.

  11. Quasi-Porous Plug With Vortex Chamber

    Science.gov (United States)

    Walsh, J. V.

    1985-01-01

    Pressure-letdown valve combines quasi-porous-plug and vortex-chamber in one controllable unit. Valve useful in fossil-energy plants for reducing pressures in such erosive two-phase process streams as steam/water, coal slurries, or combustion gases with entrained particles. Quasi-Porous Plug consists of plenums separated by perforated plates. Number or size of perforations increases with each succeeding stage to compensate for expansion. In Vortex Chamber, control flow varies to control swirl and therefore difference between inlet and outlet pressures.

  12. Anterior ethmoidal artery emerging anterior to bulla ethmoidalis: An abnormal anatomical variation in Waardenburg's syndrome

    OpenAIRE

    Wong, Danny K. C.; Shao, Angus; Campbell, Raewyn; Douglas, Richard

    2014-01-01

    In endoscopic sinus surgery, the anterior ethmoidal artery (AEA) is usually identified as it traverses obliquely across the fovea ethmoidalis, posterior to the bulla ethmoidalis and anterior to or within the ground lamella's attachment to the skull base. Injury to the AEA may result in hemorrhage, retraction of the AEA into the orbit, and a retrobulbar hematoma. The resulting increase in intraorbital pressure may threaten vision. Waardenburg's syndrome (WS) is a rare congenital, autosomal dom...

  13. Calibration of a pencil ionization chamber with and without preamplifier

    OpenAIRE

    Maia, Ana Figueiredo

    2004-01-01

    The pencil ionization chamber is a cylindrical dosimeter developed for computed tomography beams. Many kinds of ionization chambers have a preamplifier connected to the chamber to make it electrically more stable, specially for field instruments. In this study, the performance of a Victoreen pencil ionization chamber with the original preamplifier and after its removal was compared. The objective of the preamplifier removal was to enable connecting the chamber to other kinds of electromete...

  14. 30 CFR 77.305 - Access to drying chambers, hot gas inlet chambers and ductwork; installation and maintenance.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Access to drying chambers, hot gas inlet... drying chambers, hot gas inlet chambers and ductwork; installation and maintenance. Drying chambers, hot... dust and the loss of fluidizing air....

  15. Anterior capsule tear after laser iridotomy complicating phacoemulsification

    OpenAIRE

    Vivien Cherng Hui, Yip; Sanjay, Srinivasan; Benjamin Chong-Ming, Chang

    2011-01-01

    A 70-year-old Indian lady had a history of bilateral laser peripheral iridotomy (LPI) for primary angle closure. Subsequently she developed cataract in both the eyes. Right eye cataract surgery was complicated by an anterior capsule rupture, which was discovered intra-operatively at the site of the LPI. Trypan blue was used to stain the anterior capsule to delineate the anterior capsule defect. An attempt at continuous curvilinear capsulorhexis was unsuccessful, and the anterior capsulotomy w...

  16. Surgical treatment of anterior cruciate ligament injury in adults.

    Science.gov (United States)

    Alazzawi, Sulaiman; Sukeik, Mohamed; Ibrahim, Mazin; Haddad, Fares S

    2016-04-01

    Anterior cruciate ligament injury is among the most common soft tissue injuries of the knee joint and reconstruction of the anterior cruciate ligament is the gold standard treatment for young active symptomatic patients. This review summarizes the surgical treatment of anterior cruciate ligament injury.

  17. Pressurized ionization chamber detectors for industrial use

    International Nuclear Information System (INIS)

    The measurement of the thickness of the sheets made of different materials, e.g. metal, plastic, paper, cellulose, rubber, etc., is one of many industrial applications of nuclear techniques. The ionizing radiation detectors of ionization chamber type are based on measuring the variations in either exposure rate (for gamma radiation) or absorbed dose rate (for beta radiation) occurring in materials of different thickness, placed between the radiation source and the detector. The variations in exposure rate and absorbed dose rate can be traced by using radiation detectors of the ionization chamber type, which convert the exposure rate, X point, or the absorbed dose rate, D point, into a proportional electric current. The more stable the ionization current of the chambers (keeping a constant exposure rate or absorbed dose rate), the slighter the variations that can be detected in either exposure rate or absorbed dose rate, hence in the absorbing material placed between the radiation source and the detector. Based on these facts, several variants of such detectors, including the ionization chamber CIS-P5M-100Kr, CIS-P2M-1000Kr and CIS-P8M-70Kr, have been made. (author)

  18. The arrival of the CLOUD chamber

    CERN Multimedia

    CERN AVC

    2009-01-01

    The team from the CLOUD experiment - the world’s first experiment using a high-energy particle accelerator to study the climate - were on cloud nine after the arrival of their new three-metre diameter cloud chamber. This marks the end of three years’ R&D; and design, and the start of preparations for data taking later this year.

  19. Acoustical-Levitation Chamber for Metallurgy

    Science.gov (United States)

    Barmatz, M. B.; Trinh, E.; Wang, T. G.; Elleman, D. D.; Jacobi, N.

    1983-01-01

    Sample moved to different positions for heating and quenching. Acoustical levitation chamber selectively excited in fundamental and second-harmonic longitudinal modes to hold sample at one of three stable postions: A, B, or C. Levitated object quickly moved from one of these positions to another by changing modes. Object rapidly quenched at A or C after heating in furnace region at B.

  20. Vacuum chamber for intersection I-4

    CERN Multimedia

    1972-01-01

    Vacuum chamber for intersection I-4 of the ISR being assembled inside a wooden mock-up of the gap of the split-field magnet. The central round-cylinder section is provisional and is to be replaced by an elliptic-cylinder section to give more space vertically for installation of detectors. Supports for the central section are of carbon fibre composite.