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Sample records for anterior segment optical

  1. Automatic segmentation of anterior segment optical coherence tomography images

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    Williams, Dominic; Zheng, Yalin; Bao, Fangjun; Elsheikh, Ahmed

    2013-05-01

    Optical coherence tomography (OCT) images can provide quantitative measurements of the eye's entire anterior segment. A new technique founded on a newly proposed level set-based shape prior segmentation model has been developed for automatic segmentation of the cornea's anterior and posterior boundaries. This technique comprises three major steps: removal of regions containing irrelevant structures and artifacts, estimation of the cornea's location using a thresholding technique, and application of the new level set-based shape prior segmentation model to improve segmentation. The performance of our technique is compared to previously developed methods for analysis of the cornea in 33 OCT images of normal eyes, whereby manual annotations are used as a reference standard. The new technique achieves much improved concordance than previous methods, with a mean Dice's similarity coefficient of >0.92. This demonstrates the technique's potential to provide accurate and reliable measurements of the anterior segment geometry, which is important for many applications, including the construction of representative numerical simulations of the eye's mechanical behavior.

  2. Anterior segment spectral domain optical coherence tomography imaging of patients with anterior scleritis.

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    Levison, Ashleigh L; Lowder, Careen Y; Baynes, Kimberly M; Kaiser, Peter K; Srivastava, Sunil K

    2016-08-01

    The purpose of the study was to describe the findings seen on anterior segment spectral domain optical coherence tomography (SD-OCT) in patients with anterior scleritis and determine the feasibility of using SD-OCT to image and grade the degree of scleral inflammation and monitor response to treatment. All patients underwent slit lamp examination by a uveitis specialist, and the degree of scleral inflammation was recorded. Spectral domain OCT imaging was then performed of the conjunctiva and scleral tissue using a standardized acquisition protocol. The scans were graded and compared to clinical findings. Twenty-eight patients with anterior scleritis and ten patients without ocular disease were included in the study. Seventeen of the scleritis patients were followed longitudinally. Common findings on SD-OCT in patients with active scleritis included changes in hyporeflectivity within the sclera, nodules, and visible vessels within the sclera. There was significant variation in findings on SD-OCT within each clinical grade of active scleritis. These changes on SD-OCT improved with treatment and clinical improvement. SD-OCT imaging provided various objective measures that could be used in the future to grade inflammatory activity in patients with anterior scleritis. Longitudinal imaging of patients with active scleritis demonstrated that SD-OCT may have great utility in monitoring response to treatment.

  3. Anterior Segment Tomography with the Cirrus Optical Coherence Tomography

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    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.

  4. 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.

  5. Pupil Tracking for Real-Time Motion Corrected Anterior Segment Optical Coherence Tomography

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    Carrasco-Zevallos, Oscar M.; Nankivil, Derek; Viehland, Christian; Keller, Brenton; Izatt, Joseph A.

    2016-01-01

    Volumetric acquisition with anterior segment optical coherence tomography (ASOCT) is necessary to obtain accurate representations of the tissue structure and to account for asymmetries of the anterior eye anatomy. Additionally, recent interest in imaging of anterior segment vasculature and aqueous humor flow resulted in application of OCT angiography techniques to generate en face and 3D micro-vasculature maps of the anterior segment. Unfortunately, ASOCT structural and vasculature imaging systems do not capture volumes instantaneously and are subject to motion artifacts due to involuntary eye motion that may hinder their accuracy and repeatability. Several groups have demonstrated real-time tracking for motion-compensated in vivo OCT retinal imaging, but these techniques are not applicable in the anterior segment. In this work, we demonstrate a simple and low-cost pupil tracking system integrated into a custom swept-source OCT system for real-time motion-compensated anterior segment volumetric imaging. Pupil oculography hardware coaxial with the swept-source OCT system enabled fast detection and tracking of the pupil centroid. The pupil tracking ASOCT system with a field of view of 15 x 15 mm achieved diffraction-limited imaging over a lateral tracking range of +/- 2.5 mm and was able to correct eye motion at up to 22 Hz. Pupil tracking ASOCT offers a novel real-time motion compensation approach that may facilitate accurate and reproducible anterior segment imaging. PMID:27574800

  6. 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,...

  7. 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.

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

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    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.

  9. In Vivo Confocal Microscopy and Anterior Segment Optic Coherence Tomography Findings in Ocular Ochronosis

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    Elif Demirkilinc Biler

    2015-01-01

    Full Text Available Purpose. To report clinical and in vivo confocal microscopy (IVCM findings of two patients with ocular ochronosis secondary due to alkaptonuria. Materials and Methods. Complete ophthalmologic examinations, including IVCM (HRT II/Rostock Cornea Module, Heidelberg, Germany, anterior segment optical coherence tomography (AS-OCT (Topcon 3D spectral-domain OCT 2000, Topcon Medical Systems, Paramus, NJ, USA, corneal topography (Pentacam, OCULUS Optikgeräte GmbH, Wetzlar, Germany, and anterior segment photography, were performed. Results. Biomicroscopic examination showed bilateral darkly pigmented lesions of the nasal and temporal conjunctiva and episclera in both patients. In vivo confocal microscopy of the lesions revealed prominent degenerative changes, including vacuoles and fragmentation of collagen fibers in the affected conjunctival lamina propria and episclera. Hyperreflective pigment granules in different shapes were demonstrated in the substantia propria beneath the basement membrane. AS-OCT of Case 1 demonstrated hyporeflective areas. Fundus examination was within normal limits in both patients, except tilted optic discs with peripapillary atrophy in one of the patients. Corneal topography, thickness, and macular OCT were normal bilaterally in both cases. Conclusion. The degenerative and anatomic changes due to ochronotic pigment deposition in alkaptonuria can be demonstrated in detail with IVCM and AS-OCT. Confocal microscopic analysis in ocular ochronosis may serve as a useful adjunct in diagnosis and monitoring of the disease progression.

  10. Role of anterior segment optical coherence tomogram in Descemet′s membrane detachment

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    Sonia Kothari

    2011-01-01

    Full Text Available Descemet′s membrane detachment (DD is a rare but serious complication of intraocular surgery. In rare cases where corneal edema is severe and we may not be able to visualize DD on slit-lamp examination, anterior segment optical coherence tomogram (AS-OCT would be helpful. We describe two patients with DD, highlighting the role of AS-OCT in early diagnosis and management of patients with DD. One of the patients had DD with rolled in edge, which could only be visualized with AS-OCT. In such a situation, AS-OCT can identify the edge of detachment and show the exact position of the rolled edge, which can allow us to plan the surgical strategy to unroll the DD.

  11. Evaluation of Descemet’s Membrane Detachment Using Anterior Segment Optical Coherence Tomography

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    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

  12. A case of optic-nerve hypoplasia and anterior segment abnormality associated with facial cleft

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    Miyake T

    2016-07-01

    Full Text Available Tomoko Miyake,1 Shota Kojima,1 Tetsuya Sugiyama,2 Mari Ueki,1 Jun Sugasawa,1 Hidehiro Oku,1 Kensuke Tajiri,1 Yuka Shigemura,3 Koichi Ueda,3 Atsuko Harada,4 Mami Yamasaki,4 Takumi Yamanaka,4 Hidetsuna Utsunomiya,5 Tsunehiko Ikeda1 1Department of Ophthalmology, Osaka Medical College, Takatsuki City, 2Nakano Eye Clinic of Kyoto Medical Co-operative, Kyoto, 3Department of Plastic and Reconstructive Surgery, Osaka Medical College, Takatsuki City, 4Department of Pediatric Neurosurgery, Takatsuki General Hospital, Takatsuki City, 5Department of Radiological Science, International University of Health and Welfare, Graduate School, Fukuoka, Japan Introduction: The incidence of facial cleft is rare and ranges between 1.43 and 4.85 per 100,000 births. To date, there have been few reports of detailed ophthalmologic examinations performed in cases of facial cleft. Here, we report a case of optic-nerve hypoplasia and anterior segment abnormality associated with facial cleft. Case report: A 9-day-old female infant was delivered by cesarian section at 34 weeks of gestational age (the second baby of twins and weighed 2,276 g upon presentation. She had a facial cleft and ectrodactyly at birth. Right eye-dominant blepharophimosis was obvious. Examination of the right eye revealed inferior corneal opacity with vascularization, downward corectopia, and optic-nerve hypoplasia. The corneal diameter was 8 mm in both eyes, and tonometry by use of a Tono-Pen® XL (Reichert Technologies, Depew, NY, USA handheld applanation tonometer revealed that her intraocular pressure was 11–22 mmHg (Oculus Dexter and 8 mmHg (Oculus Sinister. B-mode echo revealed no differences in axial length between her right and left eyes. When she was 15–16 months old, we attempted to examine her eyes before she underwent plastic surgery under general anesthesia. She had a small optic disc in both eyes and the right-eye disc was tilted. After undergoing canthotomy, gonioscopy and ultrasound

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

    OpenAIRE

    Maruyama Y; Mori K; Ikeda Y; Ueno M; Kinoshita S

    2013-01-01

    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 s...

  14. Morphology of functioning trabeculectomy blebs using anterior segment optical coherence tomography

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    Mayuri B Khamar

    2014-01-01

    Full Text Available Purpose: To image trabeculectomy blebs using anterior segment optical coherence tomography (AS-OCT, and to correlate the bleb morphologic features at one month postoperatively with bleb function at six months. Materials and Methods: This prospective, observational study included 56 eyes undergoing trabeculectomy with MMC, followed up for minimum of six months. Postoperatively, bleb imaging was done using AS-OCT at one and six month. Bleb morphology was assessed for bleb wall reflectivity, bleb pattern in multiform reflectivity, visibility of drainage route and presence of hyper-reflectivity area. Bleb function was considered successful if IOP was <18 mmHg without medication at six month. Bleb morphology one month postoperatively was correlated with bleb function at six months. Results: At six months successful bleb function was noted in 44 (81.5% eyes. Morphology of bleb at one month showed uniform bleb wall reflectivity in 6 eyes (11% and multiform wall reflectivity in 48 eyes (89%. In eyes with multiform wall reflectivity, microcysts with multiple layers was seen in 26 eyes (48%, microcysts with subconjunctival separation in 12 eyes (22% and only microcyst in 10 eyes (19%. When bleb features at one month were correlated with the bleb function at six months, logistic regression analysis revealed that blebs with multiform reflectivity with multiple internal layers with microcysts were associated with higher chances of success (P < 0.001. Conclusion : AS-OCT demonstrated early bleb morphological features that may be used to predict the functioning of a bleb. Multiform bleb wall reflectivity with a pattern of multiple internal layers and microcysts was associated with increased chances of success of a bleb.

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

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    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.

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

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    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

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

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    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

  18. Full anterior segment biometry with extended imaging range spectral domain optical coherence tomography at 1340 nm

    OpenAIRE

    Li, Peng; Johnstone, Murray; Ruikang K Wang

    2014-01-01

    Abstract. We demonstrate an extended-imaging-range anterior-segment optical coherence tomography (eAS-OCT) system for the biometric assessment of full AS in human eye. This newly developed eAS-OCT operating at 1340-nm wavelength band is simultaneously capable of an imaging speed of 120 kHz A-line scan rate, an axial resolution of 7.2 μm, and an extended imaging range of up to 16 mm in air. Imaging results from three healthy subjects and one subject with a narrow-angle demonstrate the instrume...

  19. Comparison of immersion ultrasonography, ultrasound biomicroscopy and anterior segment optical coherence tomography in the evaluation of traumatic phacoceles

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    Harikrishna Vodapalli

    2012-01-01

    Full Text Available Blunt ocular trauma in the elderly can result in anterior dislocation of the crystalline lens into the subconjunctival space (phacocele. Although rare, this presentation can be missed, especially if the patient presents several days after the injury and if the lid is not everted on examination. While a careful clinical examination is adequate in the diagnosis, imaging techniques can be put to use for the accurate location of the associated sclera rupture. We report three cases of post-traumatic phacocele wherein ultrasound biomicroscopy (UBM was compared to the anterior segment optical coherence tomography (AS-OCT and B-scan ultrasonography (B-scan, in order to establish the best imaging tool for this condition. We concluded, based on image quality, that UBM could be the imaging modality of choice to aid in the diagnosis of phacocele.

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

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    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

  1. Agreement of angle closure assessments between gonioscopy, anterior segment optical coherence tomography and spectral domain optical coherence tomography

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    Elton; Lik; Tong; Tay; Vernon; Khet; Yau; Yong; Boon; Ang; Lim; Stelson; Sia; Elizabeth; Poh; Ying; Wong; Leonard; Wei; Leon; Yip

    2015-01-01

    AIM: To determine angle closure agreements between gonioscopy and anterior segment optical coherence tomography(AS-OCT), as well as gonioscopy and spectral domain OCT(SD-OCT). A secondary objective was to quantify inter-observer agreements of AS-OCT and SD-OCT assessments.METHODS: Seventeen consecutive subjects(33 eyes)were recruited from the study hospital’s Glaucoma clinic.Gonioscopy was performed by a glaucomatologist masked to OCT results. OCT images were read independently by 2 other glaucomatologists masked to gonioscopy findings as well as each other’s analyses of OCT images.RESULTS: Totally 84.8% and 45.5% of scleral spurs were visualized in AS-OCT and SD-OCT images respectively(P <0.01). The agreement for angle closure between AS-OCT and gonioscopy was fair at k =0.31(95% confidence interval, CI: 0.03-0.59) and k =0.35(95%CI: 0.07-0.63) for reader 1 and 2 respectively. The agreement for angle closure between SD-OCT and gonioscopy was fair at k =0.21(95% CI: 0.07-0.49) and slight at k =0.17(95% CI: 0.08-0.42) for reader 1 and 2 respectively. The inter-reader agreement for angle closure in AS-OCT images was moderate at 0.51(95% CI: 0.13-0.88). The inter-reader agreement for angle closure in SD-OCT images was slight at 0.18(95% CI: 0.08-0.45).CONCLUSION: Significant proportion of scleral spurs were not visualised with SD-OCT imaging resulting in weaker inter-reader agreements. Identifying other angle landmarks in SD-OCT images will allow more consistent angle closure assessments. Gonioscopy and OCT imaging do not always agree in angle closure assessments but have their own advantages, and should be used together and not exclusively.

  2. Trabecular-iris circumference volume in open angle eyes using swept-source fourier domain anterior segment optical coherence tomography.

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    Rigi, Mohammed; Blieden, Lauren S; Nguyen, Donna; Chuang, Alice Z; Baker, Laura A; Bell, Nicholas P; Lee, David A; Mankiewicz, Kimberly A; Feldman, Robert M

    2014-01-01

    Purpose. To introduce a new anterior segment optical coherence tomography parameter, trabecular-iris circumference volume (TICV), which measures the integrated volume of the peripheral angle, and establish a reference range in normal, open angle eyes. Methods. One eye of each participant with open angles and a normal anterior segment was imaged using 3D mode by the CASIA SS-1000 (Tomey, Nagoya, Japan). Trabecular-iris space area (TISA) and TICV at 500 and 750 µm were calculated. Analysis of covariance was performed to examine the effect of age and its interaction with spherical equivalent. Results. The study included 100 participants with a mean age of 50 (±15) years (range 20-79). TICV showed a normal distribution with a mean (±SD) value of 4.75 µL (±2.30) for TICV500 and a mean (±SD) value of 8.90 µL (±3.88) for TICV750. Overall, TICV showed an age-related reduction (P = 0.035). In addition, angle volume increased with increased myopia for all age groups, except for those older than 65 years. Conclusions. This study introduces a new parameter to measure peripheral angle volume, TICV, with age-adjusted normal ranges for open angle eyes. Further investigation is warranted to determine the clinical utility of this new parameter. PMID:25210623

  3. Trabecular-Iris Circumference Volume in Open Angle Eyes Using Swept-Source Fourier Domain Anterior Segment Optical Coherence Tomography

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    Mohammed Rigi

    2014-01-01

    Full Text Available Purpose. To introduce a new anterior segment optical coherence tomography parameter, trabecular-iris circumference volume (TICV, which measures the integrated volume of the peripheral angle, and establish a reference range in normal, open angle eyes. Methods. One eye of each participant with open angles and a normal anterior segment was imaged using 3D mode by the CASIA SS-1000 (Tomey, Nagoya, Japan. Trabecular-iris space area (TISA and TICV at 500 and 750 µm were calculated. Analysis of covariance was performed to examine the effect of age and its interaction with spherical equivalent. Results. The study included 100 participants with a mean age of 50 (±15 years (range 20–79. TICV showed a normal distribution with a mean (±SD value of 4.75 µL (±2.30 for TICV500 and a mean (±SD value of 8.90 µL (±3.88 for TICV750. Overall, TICV showed an age-related reduction (P=0.035. In addition, angle volume increased with increased myopia for all age groups, except for those older than 65 years. Conclusions. This study introduces a new parameter to measure peripheral angle volume, TICV, with age-adjusted normal ranges for open angle eyes. Further investigation is warranted to determine the clinical utility of this new parameter.

  4. Imaging of a Severe Case of Acute Hydrops in a Patient with Keratoconus Using Anterior Segment Optical Coherence Tomography

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    Hiroki Ueno

    2012-09-01

    Full Text Available Aim: To investigate the clinical and diagnostic findings of a patient with acute hydrops using anterior segment optical coherence tomography (AS-OCT. Methods: The AS-OCT findings of a 43-year-old patient with acute hydrops associated with keratoconus were examined. At the initial examination and during follow-up, evaluation of the anterior segment was performed. Results: The patient presented with decreased visual acuity, pain, and redness in the right eye. The symptoms, clinical presentation, and topographical findings of the right eye confirmed the diagnosis of acute corneal hydrops. Changes in the stroma and Descemet’s membrane during the healing process of acute hydrops could be demonstrated by high-resolution AS-OCT. The use of contact lenses was improved at the last follow-up visit after 8 months and increased visual acuity to 20/20 with correction. Conclusions: AS-OCT is a useful tool for studying the morphologic features of acute hydrops.

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

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    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

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

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    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.

  7. Toxic Anterior Segment Syndrome (TASS

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    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

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

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    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.

  9. 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.

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

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    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

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

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    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.

  12. 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.

  13. Establishing Age-Adjusted Reference Ranges for Iris-Related Parameters in Open Angle Eyes with Anterior Segment Optical Coherence Tomography.

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    Jeffrey R Peterson

    Full Text Available Define criteria for iris-related parameters in an adult open angle population as measured with swept source Fourier domain anterior segment optical coherence tomography (ASOCT.Ninety-eight eyes of 98 participants with open angles were included and stratified into 5 age groups (18-35, 36-45, 46-55, 56-65, and 66-79 years. ASOCT scans with 3D mode angle analysis were taken with the CASIA SS-1000 (Tomey Corporation, Nagoya, Japan and analyzed using the Anterior Chamber Analysis and Interpretation software. Anterior iris surface length (AISL, length of scleral spur landmark (SSL to pupillary margin (SSL-to-PM, iris contour ratio (ICR = AISL/SSL-to-PM, pupil radius, radius of iris centroid (RICe, and iris volume were measured. Outcome variables were summarized for all eyes and age groups, and mean values among age groups were compared using one-way analysis of variance. Stepwise regression analysis was used to investigate demographic and ocular characteristic factors that affected each iris-related parameter.Mean (±SD values were 2.24 mm (±0.46, 4.06 mm (±0.27, 3.65 mm (±0.48, 4.16 mm (±0.47, 1.14 (±0.04, 1.51 mm2 (±0.23, and 38.42 μL (±4.91 for pupillary radius, RICe, SSL-to-PM, AISL, ICR, iris cross-sectional area, and iris volume, respectively. Both pupillary radius (P = 0.002 and RICe (P = 0.027 decreased with age, while SSL-to-PM (P = 0.002 and AISL increased with age (P = 0.001. ICR (P = 0.54 and iris volume (P = 0.49 were not affected by age.This study establishes reference values for iris-related parameters in an adult open angle population, which will be useful for future studies examining the role of iris changes in pathologic states.

  14. Toxic anterior-segment syndrome (TASS

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    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

  15. Refraction and eye anterior segment parameters in schizophrenic patients

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    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. Adjacent Segment Pathology after Anterior Cervical Fusion.

    Science.gov (United States)

    Chung, Jae Yoon; Park, Jong-Beom; Seo, Hyoung-Yeon; Kim, Sung Kyu

    2016-06-01

    Anterior cervical fusion has become a standard of care for numerous pathologic conditions of the cervical spine. However, subsequent development of clinically significant disc disease at levels adjacent to fused discs is a serious long-term complication of this procedure. As more patients live longer after surgery, it is foreseeable that adjacent segment pathology (ASP) will develop in increasing numbers of patients. Also, ASP has been studied more intensively with the recent popularity of motion preservation technologies like total disc arthroplasty. The true nature and scope of ASP remains poorly understood. The etiology of ASP is most likely multifactorial. Various factors including altered biomechanical stresses, surgical disruption of soft tissue and the natural history of cervical disc disease contribute to the development of ASP. General factors associated with disc degeneration including gender, age, smoking and sports may play a role in the development of ASP. Postoperative sagittal alignment and type of surgery are also considered potential causes of ASP. Therefore, a spine surgeon must be particularly careful to avoid unnecessary disruption of the musculoligamentous structures, reduced risk of direct injury to the disc during dissection and maintain a safe margin between the plate edge and adjacent vertebrae during anterior cervical fusion.

  17. 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

  18. Comparison of Central Corneal Thickness Measurements Obtained with Ultrasonic Pachymetry and Spectral Domain Anterior Segment OCT

    OpenAIRE

    Kirikkaya, Esin Tunca; Akyuz Unsal, Ayşe İpek; Dogramaci, Mahmut

    2014-01-01

    Aim: To compare central corneal thickness (CCT) measurements obtained with Ultrasonic Pachymetry (USP) and Anterior Segment Optical Coherence Tomography (AS-OCT).Methods: Seventy eight eyes of thirty nine volunteers between 40-60 ages were recruited in this study. Best corrected visual acuity (BCVA), intraocular pressure (IOP) measurements, anterior and posterior segment biomicroscopic examinations of all volunteers were performed. CCT measurements were evaluated with Nidek  UP and Zeiss Cirr...

  19. Evaluation of Filtering Bleb Function after Trabeculectomy with Mitomycin C Using Biomicroscopy, Anterior Segment Optical Coherence Tomography and In Vivo Confocal Microscopy

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    Suzan Güven Yılmaz

    2015-08-01

    Full Text Available Objectives: To analyze and assess compatibility of trabeculectomy filtering bleb characteristics and appearances using biomicroscopy, anterior segment optical coherence tomography (AS-OCT and in vivo confocal microscopy (IVCM. Materials and Methods: Twenty-eight eyes of 28 patients who underwent glaucoma filtering surgery with mitomycin C in our clinic between 2009 and 2013 were evaluated. Morphological appearances of the blebs on slit-lamp biomicroscopy were defined according to the Moorfields bleb classification system. For the internal tissue assessment of blebs, AS-OCT and IVCM were performed. Bleb biometric parameters such as length, height and bleb wall thickness were assessed by AS-OCT; conjunctival epithelial-stromal cyst, structural network of conjunctival stroma and vascularisation were examined with IVCM. The relation between biomicroscopic morphological staging and bleb characteristics detected on AS-OCT and IVCM were assessed. Results: The mean age of the 28 patients (16 male, 12 female was 57.2±15.9 (19 to 79 years. The mean time elapsed between surgery and examination was 29.2±19.2 (6 to 68 months. According to biomicroscopic appearance, 17 (60.7% blebs were functional (13 diffuse, 4 microcystic, whereas 11 (39.3% blebs were non-functional (9 flat, 2 encapsulated. In the comparison of non-functional and functional blebs, functional blebs were found to be superior in terms of biometric parameters on AS-OCT assessment (p<0.05. Higher number of epithelial and stromal cysts and less vascularisation were detected by IVCM in functional blebs when compared with non-functional blebs (p<0.05. Conclusion: Biomicroscopic appearances and characteristics on AS-OCT and IVCM of filtration blebs are consistent with each other. Besides biomicroscopic examination, which is an easy and practical method for determining bleb morphology, cross-sectional images obtained by AS-OCT and IVCM provide objective data regarding internal structure and

  20. Comparison of Hanna and Hessburg-Barron trephine and punch systems using histological, anterior segment optical coherence tomography, and elliptical curve fitting models

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    Moshirfar M

    2011-08-01

    Full Text Available Majid Moshirfar1, Charles M Calvo2, Krista I Kinard1, Lloyd B Williams1, Shameema Sikder3, Marcus C Neuffer11University of Utah, Department of Ophthalmology and Visual Sciences, Salt Lake City, UT, USA; 2University of Nevada, School of Medicine, Las Vegas, NV, USA; 3Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USABackground: This study analyzes the characteristics of donor and recipient tissue preparation between the Hessburg-Barron and Hanna punch and trephine systems by using elliptical curve fitting models, light microscopy, and anterior segment optical coherence tomography (AS-OCT.Methods: Eight millimeter Hessburg-Barron and Hanna vacuum trephines and punches were used on six cadaver globes and six corneal-scleral rims, respectively. Eccentricity data were generated using measurements from photographs of the corneal buttons and were used to generate an elliptical curve fit to calculate properties of the corneal button. The trephination angle and punch angle were measured by digital protractor software from light microscopy and AS-OCT images to evaluate the consistency with which each device cuts the cornea.Results: The Hanna trephine showed a trend towards producing a more circular recipient button than the Barron trephine (ratio of major axis to minor axis, ie, 1.059 ± 0.041 versus 1.110 ± 0.027 (P = 0.147 and the Hanna punch showed a trend towards producing a more circular donor cut than the Barron punch, ie, 1.021 ± 0.022 versus 1.046 ± 0.039 (P = 0.445. The Hanna trephine was demonstrated to have a more consistent trephination angle than the Barron trephine when assessing light microscopy images, ie, ±14.39° (95% confidence interval [CI] 111.9–157.7 versus ±19.38° (95% CI 101.9–150.2, P = 0.492 and OCT images, ie, ± 8.08° (95% CI 106.2–123.3 versus ± 11.16° (95% CI 109.3–132.6, P = 0.306. The angle created by the Hanna punch had less variability than the Barron punch from both the light microscopy

  1. Clinical applications and limitations of anterior segment optical coherence tomography%眼前节相干光断层扫描技术的临床应用进展

    Institute of Scientific and Technical Information of China (English)

    洪佳旭; 孙兴怀

    2010-01-01

    Optical coherence tomography (OCT) is being employed more and more often to facilitate the diagnosis and management of the anterior eye segment diseases. The cross-sectional imaging capability of its higher resolution allows OCT to measure and visualize clear anatomic structures, specifically in anterior chamber biometry, corneal pachymetric mapping, and anterior chamber angle. Fourier-domain OCT technique which achieves higher speed and higher resolution and time-domain OCT technique have driven their further application in ophthalmological practice. In this review, we describe the principles and characteristics of OCT, summarize the recent utility and the limitations of anterior segment OCT in the pathologies and surgical planning of anterior chamber, cornea and surrounding areas, and prospect its future development.%近年来,相干光断层扫描(OCT)技术在眼前节疾病诊治中的应用飞速发展.由于OCT的分辨率更高、成像效果更好且为无创的非接触测量,所以它在前房参数测量、角膜地形测量及房角测量等方面具有明显的优势.高速、高分辨率的傅立叶OCT技术与传统的时域OCT技术相辅相成,推动和发展OCT在眼科临床中的应用.本文介绍了眼前节OCT的成像原理,结合相应的临床应用展示了OCT在眼前节疾病发病机制研究及诊疗中的价值与局限,并对OCT技术未来的发展进行展望.

  2. 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

  3. Application of Fourier Domain OCT Imaging Technology to the Anterior Segment of the Human Eye

    Science.gov (United States)

    Wojtkowski, Maciej; Marcos, Susana; Ortiz, Sergio; Grulkowski, Ireneusz

    The anterior segment is the front part of the human eye, which forms the optical system and hence directly impacts vision. Traumatic or pathological changes in the anterior segment may lead to vision loss and, in some cases, even blindness. Since the eighteenth century, optical instrumentation for measuring and imaging the anterior segment of the human eye has been developing along with modern ophthalmology. The application of OCT to the anterior segment imaging is particularly of interest, since this could potentially provide substantial complementary information regarding the large-scale architecture of the cornea and the crystalline lens, or on small portions of tissue imaged with high spatial resolutions comparable to regular microscopy. Especially an introduction of Fourier domain detection in OCT has opened new frontiers in OCT ophthalmic applications. The resultant substantial speed improvement enables rapid image acquisition, helping to reduce artifacts due to patient motion. Thus, it is currently possible to perform high-speed, in vivo, three-dimensional volumetric imaging over large scales within a reasonable time limit and without reducing system sensitivity. This chapter describes the state-of the art OCT technology dedicated to anterior segment imaging and indicates all important parameters which are required for optimization of the performance of OCT instrument.

  4. 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.
...

  5. 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

  6. Genetics in Ophthalmology II–Anterior Segment Diseases

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    Canan Aslı Utine

    2012-10-01

    Full Text Available Genetic diseases are congenital or acquired hereditary diseases that result from structural/functional disorders of the human genome. Today, the genetic factors that play a role in many diseases are being highlighted with the rapid progress in the field of genetics science. It becomes increasingly important that physicians from all disciplines have knowledge about the basic principles of genetics, patterns of inheritance, etc., so that they can follow the new developments. In genetic eye diseases, ophthalmologists should know the basic clinical and recently rapidly developing genetic characteristics of these diseases in order to properly approach the diagnosis and treatment and to provide genetic counseling. In this paper, anterior segment eye diseases of genetic origin are reviewed, and aniridia, anterior segment dysgenesis, glaucoma, corneal dystrophies, cataract, ectopia lentis, myopia, and other refractive errors are covered. (Turk J Ophthalmol 2012; 42: 378-85

  7. Leech segmental repeats develop normally in the absence of signals from either anterior or posterior segments

    Science.gov (United States)

    Seaver, E. C.; Shankland, M.

    2000-01-01

    We have investigated whether the development of segmental repeats is autonomous in the embryo of the leech Helobdella robusta. The segmental tissues of the germinal band arise from progeny of five stem cells called teloblasts. Asymmetric divisions of the teloblasts form chains of segment founder cells (called primary blast cells) that divide in a stereotypical manner to produce differentiated descendants. Using two distinct techniques, we have looked for potential interactions between neighboring blast cell clones along the anterior-posterior axis. In one technique, we prevented the birth of primary blast cells by injection of DNase I into the teloblast, thereby depriving the last blast cell produced before the ablation of its normal posterior neighbors. We also ablated single blast cells with a laser microbeam, which allowed us to assess potential signals acting on either more anterior or more posterior primary blast cell clones. Our results suggest that interactions along the anterior-posterior axis between neighboring primary blast cell clones are not required for development of normal segmental organization within the blast cell clone. We also examined the possibility that blast cells receive redundant signals from both anterior and posterior neighboring clones and that either is sufficient for normal development. Using double blast cell laser ablations to isolate a primary blast cell clone by removal of both its anterior and its posterior neighbor, we found that the isolated clone still develops normally. These results reveal that the fundamental segmental repeat in the leech embryo, the primary blast cell clone, can develop normally in the apparent absence of signals from adjacent repeats along the anterior-posterior axis.

  8. Novel mutations in PXDN cause microphthalmia and anterior segment dysgenesis.

    Science.gov (United States)

    Choi, Alex; Lao, Richard; Ling-Fung Tang, Paul; Wan, Eunice; Mayer, Wasima; Bardakjian, Tanya; Shaw, Gary M; Kwok, Pui-Yan; Schneider, Adele; Slavotinek, Anne

    2015-03-01

    We used exome sequencing to study a non-consanguineous family with two children who had anterior segment dysgenesis, sclerocornea, microphthalmia, hypotonia and developmental delays. Sanger sequencing verified two Peroxidasin (PXDN) mutations in both sibs--a maternally inherited, nonsense mutation, c.1021C>T predicting p.(Arg341*), and a paternally inherited, 23-basepair deletion causing a frameshift and premature protein truncation, c.2375_2397del23, predicting p.(Leu792Hisfs*67). We re-examined exome data from 20 other patients with structural eye defects and identified two additional PXDN mutations in a sporadic male with bilateral microphthalmia, cataracts and anterior segment dysgenesis--a maternally inherited, frameshift mutation, c.1192delT, predicting p.(Tyr398Thrfs*40) and a paternally inherited, missense substitution that was predicted to be deleterious, c.947 A>C, predicting p.(Gln316Pro). Mutations in PXDN were previously reported in three families with congenital cataracts, microcornea, sclerocornea and developmental glaucoma. The gene is expressed in corneal epithelium and is secreted into the extracellular matrix. Defective peroxidasin has been shown to impair sulfilimine bond formation in collagen IV, a constituent of the basement membrane, implying that the eye defects result because of loss of basement membrane integrity in the developing eye. Our finding of a broader phenotype than previously appreciated for PXDN mutations is typical for exome-sequencing studies, which have proven to be highly effective for mutation detection in patients with atypical presentations. We conclude that PXDN sequencing should be considered in microphthalmia with anterior segment dysgenesis.

  9. Síndrome tóxica do segmento anterior Toxic anterior segment syndrome

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    Luiz Filipe de Albuquerque Alves

    2013-02-01

    Full Text Available A síndrome tóxica do segmento anterior (STSA é uma severa reação inflamatória aguda causada por agente não infeccioso que entra no segmento anterior, resultando em lesão celular tóxica com necrose e apoptose mediado por resposta imunológica. Neste relato de caso de STSA são enfatizadas as causas mais comuns para o aparecimento da síndrome, apontam para os cuidados que devem ser tomados no processo de esterilização do material cirúrgico além de revisar a melhor conduta diante desses casos. Em conclusão notou-se que o foco principal deve ser a prevenção, pois o tratamento busca apenas suprimir a resposta inflamatória secundária. O tratamento nos casos de STSA consiste em intensa instilação de esteróides tópicos com seguimento rigoroso e controle de complicações tardias como o glaucoma.Toxic anterior segment syndrome is acute inflammatory reaction caused by a noninfectious substance that enters the anterior segment, resulting in extracellular damage with necrosis and apoptosis during an immune response. We have the report of a case of toxic anterior segment syndrome (TASS, in which the authors seek to emphasize the most common causes of the appearance of these syndrome. They point out the care that must be taken in the process of sterilization of surgical material, in addition to reviewing the best conduct when faced with these cases. In conclusion, it was noted that the main focus should be on prevention, as treatment only seeks to suppress the secondary inflammatory response. Treatment in cases of toxic anterior segment syndrome (TASS consists of intense instillation of topical steroids with strict follow-up and control of late complications such as glaucoma.

  10. Optical Ground Segment Performance Summary

    Science.gov (United States)

    Breidenthal, J.; Xie, H.; Clare, L.

    2016-05-01

    The performance of candidate optical communication systems for deep space that would use a single optical ground station in conjunction with various space terminals is reported here. We considered three potential diameters of ground receive terminals (4, 8, and 12 m) and three potential ground transmit powers (1, 5, and 10 kW). Combinations of ground receive terminals, ground transmit terminals, and spacecraft terminals were assessed for data rate and volume (both uplink and downlink), and for uplink irradiance needed to enable downlink pointing, in the context of a set of 12 design reference missions. Raw physical link performance was assessed assuming clear weather conditions with conservative desert daytime turbulence, using communication link parameters that were optimized according to previously reported methods using the Strategic Optical Link Tool (SOLT). Also, realistic bad weather conditions were considered, assuming a random process that could at any time make transitions between two states: a cloud-free state and a cloudy state that completely interrupts data transmission. We compared the link performance achievable under our assumptions to the anticipated requirements associated with the design reference missions to determine the degree of satisfaction possible with various optical segments. Nine potential operating concepts for an optical communication system were described, and two were evaluated in detail for the Mars 2022 mission opportunity: raw data delivery and automatic repeat request for complete data delivery.

  11. Anterior Cervical Corpectomy and Fusion Accelerates Degenerative Disease at Adjacent Vertebral Segments

    OpenAIRE

    Pickett, Gwynedd E.; Duggal, Neil; Theodore, Nicholas; Sonntag, Volker K.H.

    2008-01-01

    Background Anterior cervical corpectomy provides the most direct and thorough surgical approach for anterior decompression when spinal cord compression is found directly behind the vertebral body. However, anterior cervical fusion has been shown to be associated with the development of new degenerative changes at levels immediately adjacent to the fused segments. Th e incidence of adjacent segment disease (ASD) following anterior cervical corpectomy has not been widely reported. We set out to...

  12. Diagnostics of anterior eye segment in cats and dogs

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    Hadži-Milić Milan

    2006-01-01

    Full Text Available Diagnostics of the anterior segment of the eye present the most frequent diagnostics implemented in ophthalmology and by most veterinary practicians as well. This paper presents the complete diagnostics in the most concise form possible. The procedure with animals is presented first, followed by the equipment, and then anamnesis. The following diagnostic methods are presented: examination in a lighted room which include an examination from a distance, taking a smear, the Schirmer tear test (STT, an examination from close by, examination in a dark room which comprises the elementary examinations, such as the use of focal lighting and examination using a direct ophthalmoscope, and special examination in a dark room, such as biomicroscopy, gonioscopy and keratoscopy. Additional examination methods are also included.

  13. The relationship between the morphological features of A1 segment of anterior cerebral artery and anterior communicating artery aneurysms

    Institute of Scientific and Technical Information of China (English)

    冯文峰

    2013-01-01

    Objective To improve the predictability of surgical clipping and guide the steam shaping of microcatheters in endovascular embolization by analyzing the association of morphological features of A1 segment of anterior cerebral artery(ACA) with formation and classification of anterior

  14. Deep Learning Guided Partitioned Shape Model for Anterior Visual Pathway Segmentation.

    Science.gov (United States)

    Mansoor, Awais; Cerrolaza, Juan J; Idrees, Rabia; Biggs, Elijah; Alsharid, Mohammad A; Avery, Robert A; Linguraru, Marius George

    2016-08-01

    Analysis of cranial nerve systems, such as the anterior visual pathway (AVP), from MRI sequences is challenging due to their thin long architecture, structural variations along the path, and low contrast with adjacent anatomic structures. Segmentation of a pathologic AVP (e.g., with low-grade gliomas) poses additional challenges. In this work, we propose a fully automated partitioned shape model segmentation mechanism for AVP steered by multiple MRI sequences and deep learning features. Employing deep learning feature representation, this framework presents a joint partitioned statistical shape model able to deal with healthy and pathological AVP. The deep learning assistance is particularly useful in the poor contrast regions, such as optic tracts and pathological areas. Our main contributions are: 1) a fast and robust shape localization method using conditional space deep learning, 2) a volumetric multiscale curvelet transform-based intensity normalization method for robust statistical model, and 3) optimally partitioned statistical shape and appearance models based on regional shape variations for greater local flexibility. Our method was evaluated on MRI sequences obtained from 165 pediatric subjects. A mean Dice similarity coefficient of 0.779 was obtained for the segmentation of the entire AVP (optic nerve only =0.791 ) using the leave-one-out validation. Results demonstrated that the proposed localized shape and sparse appearance-based learning approach significantly outperforms current state-of-the-art segmentation approaches and is as robust as the manual segmentation.

  15. Deep Learning Guided Partitioned Shape Model for Anterior Visual Pathway Segmentation.

    Science.gov (United States)

    Mansoor, Awais; Cerrolaza, Juan J; Idrees, Rabia; Biggs, Elijah; Alsharid, Mohammad A; Avery, Robert A; Linguraru, Marius George

    2016-08-01

    Analysis of cranial nerve systems, such as the anterior visual pathway (AVP), from MRI sequences is challenging due to their thin long architecture, structural variations along the path, and low contrast with adjacent anatomic structures. Segmentation of a pathologic AVP (e.g., with low-grade gliomas) poses additional challenges. In this work, we propose a fully automated partitioned shape model segmentation mechanism for AVP steered by multiple MRI sequences and deep learning features. Employing deep learning feature representation, this framework presents a joint partitioned statistical shape model able to deal with healthy and pathological AVP. The deep learning assistance is particularly useful in the poor contrast regions, such as optic tracts and pathological areas. Our main contributions are: 1) a fast and robust shape localization method using conditional space deep learning, 2) a volumetric multiscale curvelet transform-based intensity normalization method for robust statistical model, and 3) optimally partitioned statistical shape and appearance models based on regional shape variations for greater local flexibility. Our method was evaluated on MRI sequences obtained from 165 pediatric subjects. A mean Dice similarity coefficient of 0.779 was obtained for the segmentation of the entire AVP (optic nerve only =0.791 ) using the leave-one-out validation. Results demonstrated that the proposed localized shape and sparse appearance-based learning approach significantly outperforms current state-of-the-art segmentation approaches and is as robust as the manual segmentation. PMID:26930677

  16. The Effects of Smoking on Anterior Segment Parameters, Retinal Nerve Fiber Layer, and Pupillary Functions

    Directory of Open Access Journals (Sweden)

    Bengü Ekinci Köktekir

    2014-01-01

    Full Text Available Objectives: To evaluate the alterations in the anterior segment parameters, retinal nerve fiber layer, and pupillary functions in smokers. Materials and Methods: In this case-control study, 45 eyes of 45 smokers and 45 eyes of 45 non-smoker control subjects were evaluated. All patients underwent measurement of anterior segment parameters with optical low coherence reflectometry (OLCR, mesopic and photopic pupillary diameter with an aberrometer device, retinal nerve fiber layer thickness with optical coherence tomography, and dry-eye assessment with Schirmer’s test. The results were compared with independent t-test by SPSS 16.0 Inc., and a p-value lower than 0.05 was determined as significant. Results: There was a significant difference between both groups in terms of mesopic pupil diameters that were measured with both OLCR and aberrometer device (p=0.03 and 0.02, respectively. Schirmer scores were also significantly decreased in smokers (p=0.001. The other measured parameters demonstrated no difference between smokers and non-smokers (p>0.05 for all. Conclusion: Smoking may affect pupillary functions, especially the mesopic pupillary diameter, and may cause a deficiency in pupil response under dark circumstances. (Turk J Ophthalmol 2014; 44: 11-4

  17. Anterior-segment morphology and corneal biomechanical characteristics in pigmentary glaucoma

    Directory of Open Access Journals (Sweden)

    Klingenstein A

    2013-12-01

    Full Text Available Annemarie Klingenstein, Marcus Kernt, Florian Seidensticker, Anselm Kampik, Christoph HirneissDepartment of Ophthalmology, University of Munich Hospital, Ludwig-Maximilians University, Munich, GermanyPurpose: The aim of the study reported here was to evaluate characteristics of the anterior-segment via anterior-segment optical coherence tomography (AS-OCT and corneal biomechanical properties using an ocular response analyzer and their changes by peripheral laser iridotomy (PI in patients with pigmentary glaucoma (PG.Materials and methods: Seventeen eyes with PG were included consecutively. AS-OCT and ocular response analyzer measurements were taken before and 3 months after PI. Baseline morphology and change in morphology were analyzed by correlation and multiple linear regression analysis. The main parameters assessed were anterior-chamber (AC angles and volume as well as corneal hysteresis (CH and corneal resistance factor.Results: AC angles were found to have decreased significantly in each quadrant after PI (P<0.001, with the highest effect seen in the temporal quadrant, which decreased from 57.0°±9.6° to 44.1°±5.2° (± standard deviation. Mean AC volume decreased significantly from 213.1±36.4 to 187.0±23.4 mm3 (P<0.001. CH and corneal resistance factor did not change after PI. CH was found to correlate with the preoperative superior and inferior angle width (Spearman's rho 0.553 and 0.615, respectively, P<0.05. Biomechanical parameters showed no predictive value on the change of AC angles or volume.Conclusion: PI in eyes with PG results in a highly significant reduction in the AC angles and volume as visualized by AS-OCT, with the largest effect seen in the temporal quadrant. CH is strongly positively correlated with the superior and inferior preoperative AC angles, emphasizing the importance of the biomechanical properties of the cornea for glaucoma pathogenesis in PG, but corneal biomechanical properties cannot predict PI

  18. Observation of posterior corneal vesicles with in vivo confocal microscopy and anterior segment OCT

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    Ryou Watanabe

    2010-10-01

    Full Text Available Ryou Watanabe, Toru Nakazawa, Nobuo FuseDepartment of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, JapanAbstract: The histopathology of posterior corneal vesicles (PCV has not yet been revealed. A 15-year-old girl, who was diagnosed by slit-lamp microscopy as PCV, was examined using specular microscopy, in vivo confocal microscopy, and anterior segment OCT (optical coherence tomography. Anterior segment OCT showed that the thickness of both corneas was within normal limits. At the same time, in vivo confocal microscopy revealed endothelial cells in the rounded dark areas, acellular hyporeflective layers on the Descemet’s membrane, and hyperreflective linear lesions. These findings were not reported previously by slit-lamp and specular microscopy. The abnormal findings only existed at the Descemet’s membrane and corneal endothelial layer. Previous reports dealing with posterior polymorphous dystrophy (PPMD examined using in vivo confocal microscopy reported almost the same findings, suggesting that PCV and PPMD may be the same at the microstructural level.Keywords: cornea, Descemet’s membrane, imaging

  19. Anterior segment and retinal OCT imaging with simplified sample arm using focus tunable lens technology (Conference Presentation)

    Science.gov (United States)

    Grulkowski, Ireneusz; Karnowski, Karol; Ruminski, Daniel; Wojtkowski, Maciej

    2016-03-01

    Availability of the long-depth-range OCT systems enables comprehensive structural imaging of the eye and extraction of biometric parameters characterizing the entire eye. Several approaches have been developed to perform OCT imaging with extended depth ranges. In particular, current SS-OCT technology seems to be suited to visualize both anterior and posterior eye in a single measurement. The aim of this study is to demonstrate integrated anterior segment and retinal SS-OCT imaging using a single instrument, in which the sample arm is equipped with the electrically tunable lens (ETL). ETL is composed of the optical liquid confined in the space by an elastic polymer membrane. The shape of the membrane, electrically controlled by a specific ring, defines the radius of curvature of the lens surface, thus it regulates the power of the lens. ETL can be also equipped with additional offset lens to adjust the tuning range of the optical power. We characterize the operation of the tunable lens using wavefront sensing. We develop the optimized optical set-up with two adaptive operational states of the ETL in order to focus the light either on the retina or on the anterior segment of the eye. We test the performance of the set-up by utilizing whole eye phantom as the object. Finally, we perform human eye in vivo imaging using the SS-OCT instrument with versatile imaging functionality that accounts for the optics of the eye and enables dynamic control of the optical beam focus.

  20. Extended coherence length megahertz FDML and its application for anterior segment imaging.

    Science.gov (United States)

    Wieser, Wolfgang; Klein, Thomas; Adler, Desmond C; Trépanier, Francois; Eigenwillig, Christoph M; Karpf, Sebastian; Schmitt, Joseph M; Huber, Robert

    2012-10-01

    We present a 1300 nm Fourier domain mode locked (FDML) laser for optical coherence tomography (OCT) that combines both, a high 1.6 MHz wavelength sweep rate and an ultra-long instantaneous coherence length for rapid volumetric deep field imaging. By reducing the dispersion in the fiber delay line of the FDML laser, the instantaneous coherence length and hence the available imaging range is approximately quadrupled compared to previously published MHz-FDML setups, the imaging speed is increased by a factor of 16 compared to previous extended coherence length results. We present a detailed characterization of the FDML laser performance. We demonstrate for the first time MHz-OCT imaging of the anterior segment of the human eye. The OCT system provides enough imaging depth to cover the whole range from the top surface of the cornea down to the crystalline lens. PMID:23082303

  1. Anterior ischemic optic neuropathy in association with optic nervehead drusen

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    Bharathi Megur

    2014-01-01

    Full Text Available Optic nerve head drusen (ONHD are incidental ophthalmologic finding in the optic nerve. Patients with ONHD are often asymptomatic, but sometimes present with transient visual obscuration′s (TVO, the reported incidence of which is 8.6%. Optic nerve head drusen are of two types: Superficial; visible and deep. The deep-buried drusen mimic papilledema. Because of the varied presentation deep-buried drusen pose a diagnostic challenge to the ophthalmologists. In young patients, they are mistaken for papilledema as it is clinically difficult to detect a buried drusen in the optic nerve head, but are seen on the surface with aging as the retinal nerve fiber layer thins out. They are observed as pale yellow lesions more often located towards the poles. Clinical examination aided with diagnostic tests like computed tomography (CT orbits and ultrasound B scan can help establish the diagnosis. Herein, we report a rare case of optic nerve head drusen in a young lady, who presented with loss of vision and clinical evaluation and investigations suggested ONHD with anterior ischemic optic neuropathy.

  2. Gluteus minimus: an intramuscular EMG investigation of anterior and posterior segments during gait.

    Science.gov (United States)

    Semciw, Adam I; Green, Rodney A; Murley, George S; Pizzari, Tania

    2014-02-01

    Gluteus minimus is believed to consist of two structurally and functionally unique segments (anterior and posterior); however there is a lack of electromyography (EMG) research that attempts to verify current theoretical knowledge of this muscle. The purpose of this study was therefore to evaluate the function of gluteus minimus during gait, and to determine whether anterior and posterior segments are functionally independent. Bipolar fine wire intramuscular EMG electrodes were inserted into anterior and posterior gluteus minimus segments of fifteen healthy volunteers (9 males) according to previously verified guidelines. Participants completed a series of four walking trials, followed by maximum voluntary isometric contractions in five different positions. Temporal and amplitude variables for each segment were compared across the gait cycle with independent t-tests. The relative contribution of each segment to the maximum resisted trials was compared with Mann-Whitney U tests (α = 0.05). Anterior and posterior segments were contracting at different relative intensities for three of the five maximum resisted trials (effect size = 0.39 to 0.62, P gait cycle (effect size = 0.96 to 1.03, P phase (effect size = 0.83, P = 0.034). Gluteus minimus is therefore composed of functionally independent segments. These results build on contemporary theoretical knowledge and may signify hip stabilising roles for each segment across different phases of the gait cycle.

  3. Gluteus medius: an intramuscular EMG investigation of anterior, middle and posterior segments during gait.

    Science.gov (United States)

    Semciw, Adam I; Pizzari, Tania; Murley, George S; Green, Rodney A

    2013-08-01

    Previous electromyographic (EMG) studies of gluteus medius (GMed) have not accurately quantified the function of the three proposed structurally and functionally unique segments (anterior, middle and posterior). Therefore this study used anatomically verified locations for intramuscular electrode recordings in three segments of GMed to determine whether the segments are functionally independent. Bipolar fine wire electrodes were inserted into each segment of GMed in 15 healthy individuals. Participants completed a series of four walking trials, followed by maximum voluntary isometric contractions (MVICs) in five different positions. Temporal and amplitude variables for each segment were compared across the gait cycle using ANOVA. The relative contributions of each segment to the MVIC trials were compared with non-parametric tests. All segments showed a biphasic response during the stance phase of gait. There were no differences in amplitude variables (% MVIC) between segments, but the anterior segment had a later peak during both the first and second bursts.For the MVIC trials, there were significant differences in amplitude between segments in four of the five test positions. These data indicate that GMed is composed of three functionally independent segments. This study contributes to the theoretical understanding of the role of GMed.

  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. Risk Factors for the Development of Adjacent Segment Disease Following Anterior Cervical Arthrodesis

    OpenAIRE

    Ezgi Akar; Mehmet Ufuk Akmil; Merih İş

    2015-01-01

    Aim: The aim of this study was to clinically and radiologically evaluate the efficacy of anterior cervical discectomy and fusion (ACDF) in the treatment of adjacent level degeneration. Methods: We retrospectively evaluated 89 patients (55 females, 34 males) who underwent ACDF. Adjacent segment degeneration findings were evaluated by investigating new osteophyte formation, growth of existing osteophytes, ossification of the anterior longitudinal ligament, presence of inter...

  6. Anterior Segmental Distraction Osteogenesis in the Hypoplastic Cleft Maxilla: Report of five cases

    OpenAIRE

    Sruthi Rao (Janardhan); Kotrashetti, S. M.; J. B. Lingaraj; Pinto, P. X.; Keluskar, K. M.; Siddharth Jain; Piyush Sone; Santhosh Rao

    2013-01-01

    Orthognathic surgery and distraction osteogenesis play a prime role in the correction of maxillary hypoplasia in patients with cleft lip and palate (CLP). Advancement of the anterior maxilla alone without interfering with the velopharyngeal sphincter may be advantageous in cleft patients, who more commonly have speech deficits and dental crowding. We present a case series of anterior maxillary segmental distraction for maxillary hypoplasia in 5 CLP patients with a one-year follow-up. A custom...

  7. Anterior ischemic optic neuropathy in patients undergoing hemodialysis

    NARCIS (Netherlands)

    DoorenbosBot, ACC; Geerlings, W; Houtman, IA

    1996-01-01

    Four patients are discussed who underwent hemodialysis and developed anterior ischemic optic neuropathy (AION). Three patients had been treated by hemodialysis for several years. One patient developed bilateral optic neuropathy after the first hemodialysis session, So far, only four hemodialysis pat

  8. 7.1 T MRI to Assess the Anterior Segment of the Eye

    NARCIS (Netherlands)

    Langner, Soenke; Martin, Heiner; Terwee, Thom; Koopmans, Steven A.; Krueger, Paul C.; Hosten, Norbert; Schmitz, Klaus-Peter; Guthoff, Rudolf F.; Stachs, Oliver

    2010-01-01

    PURPOSE. Visualization of the anterior segment and biometric evaluation of the entire crystalline lens pose significant challenges for imaging techniques because of tissue-induced distortion artifacts. The present study was conducted to demonstrate the advantages of high-resolution magnetic resonanc

  9. TOXIC ANTERIOR SEGMENT SYNDROME (TASS WITH SEVERE PIGMENT DISPERSION

    Directory of Open Access Journals (Sweden)

    Stephen Sudhakar

    2014-09-01

    Full Text Available AIM: To clinically analyze the cases of TASS with severe pigment dispersion following uncomplicated cataract surgery in a tertiary care teaching hospital from January 2011 to January 2013. DESIGN: Retrospective case series study. MATERIALS AND METHODS: The records of all eyes developing TASS with severe pigment dispersion following uncomplicated Cataract surgery were retrospectively reviewed. Clinical outcomes including visual acuity, intraocular pressure and complications were recorded at 1st post-operative day, 7th post-operative day and after six weeks of follow up visits. RESULTS: TASS with severe pigment dis pension was recorded in five out of 1060 patients. All cases were females. Phacoemulsification with foldable IOL was done in 2 patients and Small Incision Cataract Surgery (SICS with in bag posterior chamber IOL was done in three patients. All patients had pain which was less severe when compared to the amount of inflammation. Visual acuity ranged from 6/36 to perception of light. All the five patients had rim to rim corneal edema which was seen from the first post-operative day and persisted at six weeks follow up. Pupils were dilated and fixed in all patients. Intraocular pressure was raised in four out of five patients who poorly responded to medical treatment. Dense pigment clumps were seen in the corneal endothelium and on the surgical wound site after one week in three out of five patients and increased at 6 weeks of follow up. Visual acuity did not improve in any of the patient even with treatment. The reduced visual acuity was due to worsening corneal edema and dense pigment clumping in corneal endothelium. CONCLUSION: TASS with severe pigment dispersion has more complication than routine TASS. The complication are due to dense pigment clumping in cornea and angle of anterior chamber causing corneal endothelial de-compensation and raised Intraocular pressure, which persisted even after the inflammation subsided. Although the

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

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    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.

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

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    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.

  12. Anterior Overgrowth in Primary Curves, Compensatory Curves and Junctional Segments in Adolescent Idiopathic Scoliosis

    Science.gov (United States)

    van Stralen, Marijn; Chu, Winnie C. W.; Lam, Tsz-Ping; Ng, Bobby K. W.; Vincken, Koen L.; Cheng, Jack C. Y.; Castelein, René M.

    2016-01-01

    Introduction Although much attention has been given to the global three-dimensional aspect of adolescent idiopathic scoliosis (AIS), the accurate three-dimensional morphology of the primary and compensatory curves, as well as the intervening junctional segments, in the scoliotic spine has not been described before. Methods A unique series of 77 AIS patients with high-resolution CT scans of the spine, acquired for surgical planning purposes, were included and compared to 22 healthy controls. Non-idiopathic curves were excluded. Endplate segmentation and local longitudinal axis in endplate plane enabled semi-automatic geometric analysis of the complete three-dimensional morphology of the spine, taking inter-vertebral rotation, intra-vertebral torsion and coronal and sagittal tilt into account. Intraclass correlation coefficients for interobserver reliability were 0.98–1.00. Coronal deviation, axial rotation and the exact length discrepancies in the reconstructed sagittal plane, as defined per vertebra and disc, were analyzed for each primary and compensatory curve as well as for the junctional segments in-between. Results The anterior-posterior difference of spinal length, based on “true” anterior and posterior points on endplates, was +3.8% for thoracic and +9.4% for (thoraco)lumbar curves, while the junctional segments were almost straight. This differed significantly from control group thoracic kyphosis (-4.1%; Plumbar lordosis (+7.8%; Plumbar curves). Conclusions Excess anterior length of the spine in AIS has been described as a generalized growth disturbance, causing relative anterior spinal overgrowth. This study is the first to demonstrate that this anterior overgrowth is not a generalized phenomenon. It is confined to the primary as well as the compensatory curves, the junctional zones do not exhibit this growth discrepancy, however, they are straight. PMID:27467745

  13. Identification of the segmental artery feeding the anterior spinal artery. Correlation between helical CT and angiography

    International Nuclear Information System (INIS)

    We investigated whether identification of the segmental artery feeding the anterior spinal artery (ASA) is possible by single-slice helical CT. Enhanced CT and angiography were performed in 14 patients with retroperitoneal, liver, or bone tumor. A single-slice helical CT scanner with 7 mm collimation and a 1.0 helical pitch was used. Scanning was started 25 to 30 sec after an intravenous injection of 100 ml of contrast medium at a rate of 3.0 ml/sec. We predicted the segmental artery feeding the ASA in all 14 patients using enhanced CT images. In 12 of the 14 patients, the segmental artery feeding the ASA was angiographically identified. In 7 of these 12 patients, the level of the segmental artery feeding the ASA identified on segmental arteriogram was the same level as that predicted by enhanced CT. In the remaining 5 patients, the level of the segmental artery feeding the ASA identified on segmental arteriogram was one level higher or lower than the predicted spinal level. We could identify the segmental artery feeding the ASA by detailed examination and interpretation of single-slice helical CT images. (author)

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

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    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

  15. Risk Factors for the Development of Adjacent Segment Disease Following Anterior Cervical Arthrodesis

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    Ezgi Akar

    2015-06-01

    Full Text Available Aim: The aim of this study was to clinically and radiologically evaluate the efficacy of anterior cervical discectomy and fusion (ACDF in the treatment of adjacent level degeneration. Methods: We retrospectively evaluated 89 patients (55 females, 34 males who underwent ACDF. Adjacent segment degeneration findings were evaluated by investigating new osteophyte formation, growth of existing osteophytes, ossification of the anterior longitudinal ligament, presence of intervertebral disc space narrowing, sagittal alignment and range of motion (ROM using serial radiographs and magnetic resonance imaging. Results: The mean age of the 89 patients was 41.3 (24-76 years. The mean follow-up duration was 34.3 (12-64 months. Radiographic evidence of adjacent segment degeneration was observed in 12 patients (13.4%. Nine (75% patients had new complaints. Of the patients who had degenerative changes, 7 were (58% were male, 5 (42% were female; the mean age was 46 (30- 62 years. It was observed that the level of fusion and the number of fusion did not increase the adjacent segment degeneration. All of 12 patients were observed to have a non lordotic cervical spine and increased ROM. Conclusion: Development of degeneration at the level adjacent to region anterior cervical discectomy and fusion performed is higher compared to non-adjacent levels. The level of fusion and the number of fusion levels have no effect on the development of degeneration. (The Medical Bulletin of Haseki 2015; 53:120-3

  16. Graves' disease presenting as unilateral anterior ischaemic optic neuropathy.

    Science.gov (United States)

    Monigari, Naresh; Deshpande, Anirudda; Nalabothu, Murali; Rao, Shilpa

    2014-03-19

    We report a case of a 28-year-old man who presented with 1-day history of sudden diminution of vision in the right eye. Examination showed unilateral exophthalmos with restricted eyeball movement on upward gaze in the right eye. MRI of the orbit showed no evidence of compression of the optic nerve on the right side. Visual-evoked potential showed prolonged P100 in the right eye. Fundus examination revealed swollen optic disc and para papillary nerve fibre layer splinter haemorrhages with corresponding altitudinal field defect on perimetry suggestive of anterior ischaemic optic neuropathy.

  17. Ceratoconjuntivite alérgica e complicações no segmento ocular anterior de pacientes Evaluation of anterior ocular segment complications in patients with allergic keratoconjunctivitis

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    Patrícia Bezerra de Menezes Botelho

    2003-01-01

    with secondary anterior segment alterations. Data collected from the charts were: age, gender, kind of allergy, time of disease, time that complication appeared after treatment in our Service, side effects and ocular complications. RESULTS: Complications of anterior segment that caused reduction in visual acuity were: shield ulcers, 5 cases; cataract, 3 cases; corneal opacity, 6 cases; ocular perforation, 2 cases and keratoconus 13 cases. There were 7 surgeries: 2 tectonic penetrating keratoplasty, 4 optic keratoplasty, 4 optic penetrating keratoplasty and one superficial keratectomy. CONCLUSION: Patients with allergic keratoconjunctivitis should be treated in order to prevent ocular complications like keratitis, keratoconus, opacities and cataract.

  18. Failure of the human lumbar motion-segments resulting from anterior shear fatigue loading.

    Science.gov (United States)

    Skrzypiec, Daniel M; Nagel, Katrin; Sellenschloh, Kay; Klein, Anke; Püschel, Klaus; Morlock, Michael M; Huber, Gerd

    2016-08-01

    An in-vitro experiment was designed to investigate the mode of failure following shear fatigue loading of lumbar motion-segments. Human male lumbar motion-segments (age 32-42 years, n=6) were immersed in Ringer solution at 37°C and repeatedly loaded, using a modified materials testing machine. Fatigue loading consisted of a sinusoidal shear load from 0 N to 1,500 N (750 N±750 N) applied to the upper vertebra of the motion-segment, at a frequency of 5 Hz. During fatigue experiments, several failure events were observed in the dynamic creep curves. Post-test x-ray, CT and dissection revealed that all specimens had delamination of the intervertebral disc. Anterior shear fatigue predominantly resulted in fracture of the apophyseal processes of the upper vertebrae (n=4). Exposure to the anterior shear fatigue loading caused motion-segment instability and resulted in vertebral slip corresponding to grade I and 'mild' grade II spondylolisthesis, as observed clinically. PMID:26829975

  19. Failure of the human lumbar motion-segments resulting from anterior shear fatigue loading

    Science.gov (United States)

    SKRZYPIEC, Daniel M.; NAGEL, Katrin; SELLENSCHLOH, Kay; KLEIN, Anke; PÜSCHEL, Klaus; MORLOCK, Michael M.; HUBER, Gerd

    2016-01-01

    An in-vitro experiment was designed to investigate the mode of failure following shear fatigue loading of lumbar motion-segments. Human male lumbar motion-segments (age 32–42 years, n=6) were immersed in Ringer solution at 37°C and repeatedly loaded, using a modified materials testing machine. Fatigue loading consisted of a sinusoidal shear load from 0 N to 1,500 N (750 N±750 N) applied to the upper vertebra of the motion-segment, at a frequency of 5 Hz. During fatigue experiments, several failure events were observed in the dynamic creep curves. Post-test x-ray, CT and dissection revealed that all specimens had delamination of the intervertebral disc. Anterior shear fatigue predominantly resulted in fracture of the apophyseal processes of the upper vertebrae (n=4). Exposure to the anterior shear fatigue loading caused motion-segment instability and resulted in vertebral slip corresponding to grade I and ‘mild’ grade II spondylolisthesis, as observed clinically. PMID:26829975

  20. The changes of inflammatory cytokines and their clinical significance in patients of inferior ST-segment elevation acute myocardial infarction with anterior ST-segment depression

    Institute of Scientific and Technical Information of China (English)

    叶明

    2014-01-01

    Objective To investigate the level of Hs-CRP,Fib,IL-6,TNF-α,MDA,SOD,and analyze the correlation between the level of plasma inflammatory cytokines and clinical significance in patients with anterior ST-segment depression.Methods We chose 360 patients with inferior ST Segment elavation acute myocardial infarction from May 2007 to Sep 2012 in emergency department of

  1. Anterior maxillary osteotomy: A technical note for superior repositioning: A bird wing segment

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    V Sadesh Kannan

    2014-01-01

    Full Text Available Aim: The aim of this study is to evaluate the efficacy of a single piece bird wing osteotectomy segment during anterior maxillary osteotomy (AMO markedly reduces the duration of the surgery by nearly one-half of the time during bone removal with the conventional method thereby reducing the kinking effect to the palatal pedicle and gives good perfusion to the anterior segment. Materials and Methods: This study was conducted at Karpaga Vinayaga Institute of Dental Sciences composing of 20 patients in which male: female ratio was 8:12, with a mean age of 25-30 years. This bird wing segment technique is performed following presurgical orthodontics under the guidance of clinical assessment of the gummy smile with an incisal show when the lip is at repose (vertical maxillary excess, especially for the calculated amount of superior repositioning. It is calculated by subtracting 2 mm from the total amount of an incisor show when the lip is at repose. The normal incisal show when the lip is at repose is 2 mm. After conventional primary AMO cut was performed, the precise calculated. Results: All our cases were tested positive for pulp vitality, no relapse, and minimal edema and with no changes in the bite or dentoalveolar relation followed until 1 year postoperatively indicating a good perfusion to the anterior segment and all the patients were satisfied esthetically and free of complaints. Conclusion: This simple technique allows the precise amount of calculated bone removal in a single piece from the nasal floor markedly reduces the duration of the surgery by nearly one-half of the time during bone removal with the conventional method there by reducing the kinking effect to the palatal pedicle and maintains good perfusion.

  2. 超声乳化白内障吸除联合人工晶状体植入术后眼前节相干光断层扫描观察%Slit lamp optical coherence tomography study of anterior segment changes after phacoemulsification and foldable intraocular lens implantation

    Institute of Scientific and Technical Information of China (English)

    晏丕松; 张振平; 林浩添; 吴文捷; 柏凌

    2009-01-01

    目的 应用裂隙灯显微镜眼前节相干光断层扫描(OCT)观察超声乳化白内障吸除联合人工晶状体(IOL)植入术后眼前节组织的变化情况,探讨手术对眼前节结构的影响.方法 前瞻性系列病例研究.使用海德堡公司裂隙灯显微镜眼前节OCT观察40例(44只眼)行超声乳化白内障吸除联合IOL植入术患者术前和术后1 d、1周、2周及1个月的眼前节组织变化情况.对所测量的数据进行重复测量设计资料的方差分析,用LSD法进行两两比较.结果 中央及切口处角膜在术后第1天全部患者均明显增厚(与术前相比增厚分别为99.59μm,234.57μm;P=0.490),中央角膜厚度至术后1个月可恢复术前水平,而切口处角膜厚度还较术前厚约19.25μm(P=0.001);前房深度(ACD)和各项反映前房角宽度的指标(AOD500、AOD750、TISA500、TISA750)在术后各观察时间点,均较术前明显加深和加宽(均P0.05).结论 裂隙灯显微镜眼前节OCT可客观、定量评价白内障手术对眼前节形态特征的影响.%Objective To investigate quantitative changes of the anterior segment configuration after clear corneal incision phacoemulsification and foldable intraocular lens (IOL) implantation with slit-lamp-adapted optical coherence tomography (SL-OCT). Methods In prospective consecutive case series, clear corneal incision phacoemulsification and foldable intraocular lens implantation were performed in 44 eyes of 40 patients. The changes of the anterior segment configuration were performed by SL-OCT before and 1 day, 1 week, 2 weeks and 1 month after surgery. SPSS 16.0 software was used to analyze statistical difference. Results For all patients, the central corneal thickness (CCT) and the incisional corneal thickness (ICT) increased significantly 1 day after surgery ( CCT increased 99. 59 μm, ICT increased 234. 57 μm;P = O. 490). At 1 month, the CCT almost had returned to baseline, but the ICT had been ticker about 19. 25 μm than

  3. Descemet’s scroll in syphilitic interstitial keratitis: a case report with anterior segment evaluation and a literature review

    Directory of Open Access Journals (Sweden)

    Kasetsuwan N

    2015-09-01

    Full Text Available Ngamjit Kasetsuwan,1,2 Usanee Reinprayoon,1,2 Patchima Chantaren2 1Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University, 2Ophthalmology Department, King Chulalongkorn Memorial Hospital, Bangkok, Thailand Purpose: To present a case of syphilitic interstitial keratitis with Descemet’s scrolls, as well as its characteristic findings in an anterior segment investigation in relation to the histopathologic findings from a literature review. Case presentation: A case report of a 64-year-old woman with syphilitic infection presented with band keratopathy and retrocorneal scrolls. Slit-lamp photography, confocal microscopy, anterior segment optical coherence tomography (AS-OCT, and ultrasound biomicroscopy were performed. Four previous reports were reviewed to describe the pathogenesis, natural history, and histopathologic and immunohistologic findings of the Descemet’s scroll. Results: The spectacle-corrected visual acuity was 20/50 and 20/30 in the right and left eyes, respectively. The scrolls appeared as a translucent web extending from Descemet’s membrane into the anterior chamber. Confocal microscopy showed decreased endothelial cell density, pleomorphism, polymegathism, and hyperreflective fibrocellular rods with central hollow. The AS-OCT and ultrasound biomicroscopy showed rod-shaped retrocorneal scrolls. The corneal thickness was 494 microns, as measured by AS-OCT. The corneal lesion remained stable during the 6-year follow-up period without the need for keratoplasty, while the previous literature reported spontaneous and postoperative corneal decompensation. Conclusion: We present a case of syphilitic interstitial keratitis with rare Descemet’s scrolls featuring relatively good visual acuity. Although we did not obtain the corneal tissue for examination, the anterior segment investigation provides insight into the underlying histopathology and natural disease history. The central hollow and cellular component seen

  4. 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

  5. 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.

  6. Toxic Anterior Segment Syndrome after Foldable Artiflex Iris-Fixated Phakic Intraocular Lens Implantation

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    Lucien A. M. van Philips

    2011-01-01

    Full Text Available Toxic anterior segment syndrome (TASS developed in four cases after uneventful implantation of a foldable iris-fixated phakic intraocular lens (pIOL. Two cases occurred sequentially in one patient. The TASS subsided without complications in all cases after intensive topical steroid treatment. A multitude of possible causes is considered for the occurrence of these TASS cases. From the sterilization and cleaning of surgical instruments to the possibility of endotoxines in ophthalmic viscosurgical devices (OVD. These rare cases should alert the surgeon to the possibility of TASS after pIOL implantation.

  7. Adjustable muscle plication: a new surgical technique for strabismic patients with high risk for anterior segment ischemia

    Institute of Scientific and Technical Information of China (English)

    Carlos; Laria; David; P.Pi?ero

    2015-01-01

    <正>INTRODUCTION Anterior ciliary arteries provide 70%of the vascular supply of the anterior segment.A significant interruption of the vascular flow of these arteries increases the risk for anterior ischemia.Although the frequency of this special condition is low after strabismus surgery(1:13 000)[1],its effects may involve substantial visual problems[2].We report the successful outcome of a new surgical approach for strabismus management in a case of high risk for anterior ischemia.Specifically,we show the correction of the horizontal ocular deviation by means of an adjustable muscle

  8. Ultraviolet absorption by contact lenses and the significance on the ocular anterior segment.

    Science.gov (United States)

    Chandler, Heather

    2011-07-01

    It is well established that both acute and chronic ultraviolet (UV) exposure can lead to various ophthalmic pathologic conditions in the anterior segment. Several scientific studies have demonstrated that after UV exposure, the unprotected cornea is vulnerable to damage in the epithelial, stromal, and endothelial cellular layers. DNA damage, apoptosis, and altered protease expression are all examples of harmful changes that can occur within the cornea after irradiation. Beyond the cornea, damage associated with UV exposure, such as decreased antioxidant levels and increased reactive oxygen species production, has been noted in the aqueous humor and crystalline lens. Ultraviolet-blocking contact lenses have the potential to provide protection against such exposure to harmful UV radiation. Experimental use of UV-absorbing contact lenses prevented detrimental cellular changes to the cornea and maintained corneal clarity after UV exposure. Additionally, studies suggest that shielding the aqueous humor and crystalline lens from irradiation with UV-absorbing contact lenses aids in protection against precataractous changes. Despite ongoing research, to date, neither chronic nor clinical studies have been performed in humans to demonstrate that wearing UV-blocking contact lenses reduces the risk of developing cataracts or other ocular disorders within the anterior segment. This article will discuss the impact of UV exposure on ocular tissue and the need for adequate UV protection, with particular emphasis on UV-blocking contact lenses.

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

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    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

  10. 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.

  11. Coil embolization in precommunicating (A1) segment aneurysms of anterior cerebral artery

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Dae; Ahn, Jun Hyong; Jung, Seung Chai; Kim, Chang Hun [Seoul National University Hospital, Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Kang, Hyun-Seung; Kim, Jeong Eun [Seoul National University Hospital, Seoul National University College of Medicine, Department of Neurosurgery, 28 Yongon-dong, Jongno-gu, Seoul (Korea, Republic of); Son, Young Je [Seoul National University Boramae Hospital, Seoul National University College of Medicine, Department of Neurosurgery, Seoul (Korea, Republic of); Han, Moon Hee [Seoul National University Hospital, Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Hospital, Seoul National University College of Medicine, Department of Neurosurgery, 28 Yongon-dong, Jongno-gu, Seoul (Korea, Republic of)

    2014-03-15

    Precommunicating (A1) segment aneurysms of the anterior cerebral artery are rare and often pose technical challenges for coil embolization due to their distinctive configurations. Clinical and radiologic outcomes of treating such aneurysms through endovascular coil embolization are presented herein. Data accruing prospectively from May 2002 to August 2013 yielded 48 patients harboring 50 A1 segment aneurysms, each classified as proximal, middle, or distal by location. Clinical outcome of the patients and morphological outcome of the aneurysms were assessed, with emphasis on technical aspects of treatment. The aneurysms studied occupied either proximal (n = 39), middle (n = 6), or distal (n = 5). Proximal aneurysms were largely directed posteriorly (80 %), and most (97 %) were devoid of branches. Middle and distal aneurysms were associated with the medial lenticulostriate artery, cortical branches, or fenestrations. The preshaped ''S'' and steam-shaped ''S'' microcatheters facilitated aneurysm selection in 60 % of lesions. Single-microcatheter technique was most commonly applied for coil embolization (62 %), followed by balloon protection (16 %). Successful aneurysmal occlusion could be achieved in 76 % of the patients, with no procedure-related morbidity and mortality. At final follow-up (mean interval, 29.9 months), stable aneurysmal occlusion was sustained in 93 % of the patients (40/43). A1 segment aneurysms are amenable to safe and efficacious endovascular coil embolization by adjusting procedural strategy to accommodate distinctive anatomic configurations. (orig.)

  12. Improved Large Segmented Optics Fabrication Using Magnetorheological Finishing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Primary mirrors for large aperture telescopes (> 10 m) are collections of smaller (1-2 m), typically hexagonal, often aspheric, optical segments. NASA's next...

  13. Improved Large Segmented Optics Fabrication Using Magnetorheological Finishing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Primary mirrors for large aperture telescopes (>10m) are collections of smaller (1-2m), typically hexagonal, often aspheric, optical segments. NASA?s next...

  14. Advanced Lightweight Metal Matrix Composite Segmented Optic Manufacture Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Design, manufacture and test a flat segmented mirror made of optical grade AlBeMet 162 material and fusion bonded through the use of E Beam welding to demonstrate...

  15. 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.

  16. A New Potential Cause in the Development of Toxic Anterior Segment Syndrome: Fibrin Glue

    Directory of Open Access Journals (Sweden)

    Selçuk Sızmaz

    2014-08-01

    Full Text Available Objectives: To present a potential cause for toxic anterior segment syndrome (TASS. Materials and Methods: We report 4 cases of TASS that occurred following uneventful phacoemulsification and intraocular lens implantation. Results: The 4 cases were the first consecutive 2 cases of 2 different surgery days, 5 months apart. The most prominent sign of TASS was limbus-to-limbus corneal edema. Pain and/or intraocular pressure rise were also common. All surgical and presurgical procedures were checked after the first outbreak, whereas the second outbreak required further investigation. Fibrin glue remnants from preceding pterygium surgery with conjunctival autografting were found to be the potential cause. Despite intensive corticosteroid therapy, corneal edema did not resolve in 2 patients who underwent keratoplasty. Conclusion: TASS is a sight-threatening condition which requires thorough investigation for prevention of new cases. All steps must be carefully revised. (Turk J Ophthalmol 2014; 44: 280-3

  17. Comparative study on the effect of anterior and posterior decompression in the treatment of multi-segmental cervical spondylotic myelopathy

    Institute of Scientific and Technical Information of China (English)

    Liang Li; Mei-Lin Jiang; Xiao-Jun Yang

    2016-01-01

    Objective: To analyze and compare the clinical efficacy of anterior and posterior decompression in the treatment of multi-segmental cervical spondylotic myelopathy (MCSM), providing certain guidance for the clinical treatment. Methods:A total of 72 patients with MCSM who were admitted in our hospital from September, 2012 to October, 2014 were included in the study and divided into the anterior group (n=37) and the posterior group (n=35) according to different surgical methods. The patients in the anterior group were given anterior cervical discectomy fusion (ACDF) and anterior cervical corpectomy fusion (ACCF), while the patients in the posterior group were given laminoplasty (LP). The general materials, surgical materials, and postoperative functional recovery in the two groups were compared. Results:The comparison of gender, age, course, preoperative JOA score, follow-up time, and affected segment between the two groups was not statistically significant. The operation time in the anterior group was significantly longer than that in the posterior group, but the intraoperative amount of bleeding was significantly less than that in the posterior group. The postoperative spinal cord function in the two groups was significantly improved when compared with before operation;moreover, the improved degree in the anterior group was more obvious. The postoperative cervical physiological curvature in the anterior group was significantly increased, but in the posterior group was significantly reduced. The comparison of the occurrence rate of postoperative complications between the two groups was not statistically significant. Conclusions:The anterior and posterior surgeries in the treatment of MCSM can significantly improve the postoperative spinal cord function, among which the anterior surgery can effectively recover the cervical physiological curvature. It is recommended that an appropriate surgical method should be reasonably selected by comprehensively considering the

  18. MPLS over Segmented WDM Optical Packet Switching Networks

    Directory of Open Access Journals (Sweden)

    Hakim Mellah

    2006-01-01

    Full Text Available Wavelength Division Multiplexing (WDM is a promising solution for data transport in future all-optical wide area networks. Such networks consist of fibers joined by dynamically controllable cross-connects which provide purely optical transport between pairs of network access stations. Optical packet switching (OPS is optical switching with the finest granularity. Incoming packets are switched all-optically without being converted to electrical signal. There are two categories of OPS networks. Slotted (synchronous OPS networks, in which all the packets have the same size and unslotted (asynchronous OPS networks, where packets may or may not have the same size. In this study we propose to integrate MPLS over slotted OPS networks by aggregating optical packets into a labeled optical burst. The burst has a fixed number of packets (segments. The number of segments in each burst is encoded in the experimental field of the MPLS header.

  19. 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

  20. 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

    noncontact, noninvasive, and comfortable system for patients that is highly reliable and repeatable for anterior segment measurements. PMID:27478351

  1. 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

  2. Interactive cell segmentation based on phase contrast optics.

    Science.gov (United States)

    Su, Hang; Su, Zhou; Zheng, Shibao; Yang, Hua; Wei, Sha

    2014-01-01

    Cell segmentation in phase contrast microscopy images lays a crucial foundation for numerous subsequent computer-aided cell image analysis, but it encounters many unsolved challenges due to image qualities and artifacts caused by phase contrast optics. Addressing the unsolved challenges, the authors propose an interactive cell segmentation scheme over phase retardation features. After partitioning the images into phase homogeneous atoms, human annotations are propagated to unlabeled atoms over an affinity graph that is learned based on discrimination analysis. Then, an active query strategy is proposed for which the most informative unlabeled atom is selected for annotation, which is also propagated to the other unlabeled atoms. Cell segmentation converges to quality results after several rounds of interactions involving both the user's intentions and characteristics of image features. Experimental results demonstrate that cells with different optical properties are well segmented via the proposed approach.

  3. Imaging the anterior eye with dynamic-focus swept-source optical coherence tomography

    Science.gov (United States)

    Su, Johnny P.; Li, Yan; Tang, Maolong; Liu, Liang; Pechauer, Alex D.; Huang, David; Liu, Gangjun

    2015-12-01

    A custom-built dynamic-focus swept-source optical coherence tomography (SS-OCT) system with a central wavelength of 1310 nm was used to image the anterior eye from the cornea to the lens. An electrically tunable lens was utilized to dynamically control the positions of focusing planes over the imaging range of 10 mm. The B-scan images were acquired consecutively at the same position but with different focus settings. The B-scan images were then registered and averaged after filtering the out-of-focus regions using a Gaussian window. By fusing images obtained at different depth focus locations, high-resolution and high signal-strength images were obtained over the entire imaging depth. In vivo imaging of human anterior segment was demonstrated. The performance of the system was compared with two commercial OCT systems. The human eye ciliary body was better visualized with the dynamic-focusing SS-OCT system than using the commercial 840 and 1310 nm OCT systems. The sulcus-to-sulcus distance was measured, and the result agreed with that acquired with ultrasound biomicroscopy.

  4. 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.

  5. Image segmentation by nonlinear filtering of optical Hough transform.

    Science.gov (United States)

    Fernández, Ariel; Flores, Jorge L; Alonso, Julia R; Ferrari, José A

    2016-05-01

    The identification and extraction (i.e., segmentation) of geometrical features is crucial in many tasks requiring image analysis. We present a method for the optical segmentation of features of interest from an edge enhanced image. The proposed method is based on the nonlinear filtering (implemented by the use of a spatial light modulator) of the generalized optical Hough transform and is capable of discriminating features by shape and by size. The robustness of the method against noise in the input, low contrast, or overlapping of geometrical features is assessed, and experimental validation of the working principle is presented. PMID:27140381

  6. Ocular Drug Delivery - New Strategies for Targeting Anterior and Posterior Segments of the Eye.

    Science.gov (United States)

    Fangueiro, Joana F; Veiga, Francisco; Silva, Amelia M; Souto, Eliana B

    2016-01-01

    The ocular delivery of drugs encounters several limitations because of the dynamic and static barriers of the human's eye anatomy and physiology. The poor bioavailability of drugs are mainly related to the topical administration, i.e. eye drops which is the most common drug dosage form for the treatment of eye pathologies. Precorneal factors and drug limitations related to its solubility and susceptibility for physicochemical degradation could be the main reasons for the poor permeation and uptake in the ocular mucosa. Pathologies affecting the anterior and posterior segment of the eye are thereafter difficult to be treated and, given the chronic and degenerative nature of some of these injuries, it is crucial to improve drugs therapeutic effect. Nanotechnology-based delivery systems could be a suitable approach to overcome these limitations. Some of the most important colloidal systems are highlighted in this review, such as the use of mucoadhesive polymers, prodrugs, nanogels, liposomes, microemulsions, lipid and polymeric nanoparticles, cyclodextrins, dendrimers and nanocrystals, along with their clinical and therapeutic relevance for the administration of drugs for ocular delivery. PMID:26675225

  7. Robust optic nerve segmentation on clinically acquired CT

    Science.gov (United States)

    Panda, Swetasudha; Asman, Andrew J.; DeLisi, Michael P.; Mawn, Louise A.; Galloway, Robert L.; Landman, Bennett A.

    2014-03-01

    The optic nerve is a sensitive central nervous system structure, which plays a critical role in many devastating pathological conditions. Several methods have been proposed in recent years to segment the optic nerve automatically, but progress toward full automation has been limited. Multi-atlas methods have been successful for brain segmentation, but their application to smaller anatomies remains relatively unexplored. Herein we evaluate a framework for robust and fully automated segmentation of the optic nerves, eye globes and muscles. We employ a robust registration procedure for accurate registrations, variable voxel resolution and image fieldof- view. We demonstrate the efficacy of an optimal combination of SyN registration and a recently proposed label fusion algorithm (Non-local Spatial STAPLE) that accounts for small-scale errors in registration correspondence. On a dataset containing 30 highly varying computed tomography (CT) images of the human brain, the optimal registration and label fusion pipeline resulted in a median Dice similarity coefficient of 0.77, symmetric mean surface distance error of 0.55 mm, symmetric Hausdorff distance error of 3.33 mm for the optic nerves. Simultaneously, we demonstrate the robustness of the optimal algorithm by segmenting the optic nerve structure in 316 CT scans obtained from 182 subjects from a thyroid eye disease (TED) patient population.

  8. 前节OCT与超声角膜测厚仪在角膜内皮移植术后测量中央角膜厚度的比较%Comparison of central corneal thickness measurements between anterior segment optical coherence tomography and ultrasonic pachymeter after DSAEK

    Institute of Scientific and Technical Information of China (English)

    李炳震; 彭荣梅; 任婧; 刘峰; 吴玲玲; 洪晶

    2011-01-01

    Objective To assess the agreement of central corneal thickness ( CCT) measured by anterior segment-optical tomography (AS-OCT) and ultrasonic pachymeter after Descemet's Stripping with Automated Endothelium Keratoplasty (DSAEK) and provide objective basis for clinical application of AS-OCT. Methods Forty-one eyes of 38 patients after Descemet's Stripping with Automated Endothelium Keratoplasty (DSAEK) underwent CCT measurement by AS-OCT and ultrasonic pachymeter.The data was analyzed by paired-t test and Pearson correlation analysis. Bland-Altman plot was used to assess the agreement.Results The mean CCT values were(728.73±1 38.39)μ m measured by AS-OCT and (718.56+131.37)μ m measured by ultrasonic pachymeter,and there was no significant difference between the two methods. Regression analysis showed a high correlation between the values obtained by both devices (r =0.916, P<0.01). AS-OCT and ultrasonic pachymeter showed a less a-greernent in CCT measurement after DSAEK. Conclusions After DSAEK, there is a reasonable agreement between two techniques, AS-OCT and ultrasonic pachymeter of CCT measurements. Considering the special advantages, AS-OCT is an effective method to observe the changes of the corneal thickness in the long term.%目的 比较角膜内皮移植(DSAEK)术后后眼前节相干光断层扫描(AS-OCT)与超声角膜测厚仪测量的中央角膜厚度(CCT),评估两种方法的一致性,为AS-OCT的临床应用提供客观依据.方法 分别应用AS-OCT与超声角膜测厚仪测量DSAEK后患者38例(41只眼)的CCT,对两种方法所得的测量值进行配对t检验及Pearson相关分析,并采用Bland-Altman plot进行一致性评价.结果 AS-OCT与超声角膜测厚仪测量CCT的平均值分别为(728.73±138.39)μm和(718.56±131.37)μm;两组数据差异无统计学意义(t=-1.170;P=0.249).通过Pearson相关性分析,这两种方法的测量值成正相关(r=0.916,P <0.01).AS-OCT与超声角膜测厚测量

  9. Extensive molecular differences between anterior- and posterior-half-sclerotomes underlie somite polarity and spinal nerve segmentation

    Directory of Open Access Journals (Sweden)

    Keynes Roger J

    2009-05-01

    Full Text Available Abstract Background The polarization of somite-derived sclerotomes into anterior and posterior halves underlies vertebral morphogenesis and spinal nerve segmentation. To characterize the full extent of molecular differences that underlie this polarity, we have undertaken a systematic comparison of gene expression between the two sclerotome halves in the mouse embryo. Results Several hundred genes are differentially-expressed between the two sclerotome halves, showing that a marked degree of molecular heterogeneity underpins the development of somite polarity. Conclusion We have identified a set of genes that warrant further investigation as regulators of somite polarity and vertebral morphogenesis, as well as repellents of spinal axon growth. Moreover the results indicate that, unlike the posterior half-sclerotome, the central region of the anterior-half-sclerotome does not contribute bone and cartilage to the vertebral column, being associated instead with the development of the segmented spinal nerves.

  10. Unilateral Acute Anterior Ischemic Optic Neuropathy in a Patient with an Already Established Diagnosis of Bilateral Optic Disc Drusen

    Directory of Open Access Journals (Sweden)

    Ziya Ayhan

    2015-01-01

    Full Text Available Optic disc drusen (ODD are calcific deposits that form in the optic nerve head secondary to abnormalities in axonal metabolism and degeneration. Anterior ischemic optic neuropathy, central retinal artery, and vein occlusion are among the rare vascular complications of disc drusen. We reported the clinical course of a 51-year-old patient with a unilateral acute nonarteritic anterior ischemic optic neuropathy (NAION who received the diagnosis of bilateral optic disc drusen five years earlier and thereby reiterated the association of ODD and acute NAION.

  11. Unilateral Acute Anterior Ischemic Optic Neuropathy in a Patient with an Already Established Diagnosis of Bilateral Optic Disc Drusen

    Science.gov (United States)

    Ayhan, Ziya; Yaman, Aylin; Söylev Bajin, Meltem; Saatci, A. Osman

    2015-01-01

    Optic disc drusen (ODD) are calcific deposits that form in the optic nerve head secondary to abnormalities in axonal metabolism and degeneration. Anterior ischemic optic neuropathy, central retinal artery, and vein occlusion are among the rare vascular complications of disc drusen. We reported the clinical course of a 51-year-old patient with a unilateral acute nonarteritic anterior ischemic optic neuropathy (NAION) who received the diagnosis of bilateral optic disc drusen five years earlier and thereby reiterated the association of ODD and acute NAION. PMID:26550507

  12. Ocular anterior segment pathologies and tear film changes in patients with psoriasis vulgaris.

    Directory of Open Access Journals (Sweden)

    Erbagci I

    2003-12-01

    Full Text Available Ocular manifestations in patients with psoriasis vulgaris have been investigated in only a small number of studies. Our purpose was to identify tear film function and ocular pathologies associated with psoriasis vulgaris in patients who had received neither oral retinoids nor phototherapy. We examined 62 eyes of 31 patients with psoriasis and 60 eyes of 30 age-and-sex matched healthy volunteers. In addition to complete ocular and dermatological examination, tear film function (i.e., tear secretion and tear film stability were assessed by the Schirmer-I test, as well as by tear film break-up time. None of the controls had any ocular abnormalities, whereas 67.74% of patients with psoriasis had various anterior segment pathologies (P<0.00009. The most prevalent finding was chronic blepharoconjunctivitis (64.5%, as the only pathology (n=9 or in association with other findings, including nonspecific corneal opacities (n=4, cataract (n=3, both corneal opacities and cataract (n=2, and corneal pigment dispersion (n=2. The Schirmer-I test results revealed comparable mean values in the patient group (9.8+-4.2 mm and in the controls (11.2+-3.7 mm; P=0.078. However, mean tear film break-up time was significantly shorter in the patients (7.2+-2.5 sec than in the healthy persons (11.7+-3.1 sec; P=0.001. In agreement with some previous reports, our findings clearly demonstrated that early ocular involvement occurs in patients with psoriasis vulgaris, irrespective of the history of previous therapeutic modalities (e.g., retinoid therapy and phototherapy. Thus, the present findings are suggestive of the contributory role of primary etiologic factors of psoriasis in the pathogenesis of ocular changes in patients with psoriasis vulgaris.

  13. From acoustic segmentation to language processing: evidence from optical imaging.

    Science.gov (United States)

    Obrig, Hellmuth; Rossi, Sonja; Telkemeyer, Silke; Wartenburger, Isabell

    2010-01-01

    During language acquisition in infancy and when learning a foreign language, the segmentation of the auditory stream into words and phrases is a complex process. Intuitively, learners use "anchors" to segment the acoustic speech stream into meaningful units like words and phrases. Regularities on a segmental (e.g., phonological) or suprasegmental (e.g., prosodic) level can provide such anchors. Regarding the neuronal processing of these two kinds of linguistic cues a left-hemispheric dominance for segmental and a right-hemispheric bias for suprasegmental information has been reported in adults. Though lateralization is common in a number of higher cognitive functions, its prominence in language may also be a key to understanding the rapid emergence of the language network in infants and the ease at which we master our language in adulthood. One question here is whether the hemispheric lateralization is driven by linguistic input per se or whether non-linguistic, especially acoustic factors, "guide" the lateralization process. Methodologically, functional magnetic resonance imaging provides unsurpassed anatomical detail for such an enquiry. However, instrumental noise, experimental constraints and interference with EEG assessment limit its applicability, pointedly in infants and also when investigating the link between auditory and linguistic processing. Optical methods have the potential to fill this gap. Here we review a number of recent studies using optical imaging to investigate hemispheric differences during segmentation and basic auditory feature analysis in language development.

  14. From acoustic segmentation to language processing: evidence from optical imaging

    Directory of Open Access Journals (Sweden)

    Hellmuth Obrig

    2010-06-01

    Full Text Available During language acquisition in infancy and when learning a foreign language, the segmentation of the auditory stream into words and phrases is a complex process. Intuitively, learners use ‘anchors’ to segment the acoustic speech stream into meaningful units like words and phrases. Regularities on a segmental (e.g., phonological or suprasegmental (e.g., prosodic level can provide such anchors. Regarding the neuronal processing of these two kinds of linguistic cues a left hemispheric dominance for segmental and a right hemispheric bias for suprasegmental information has been reported in adults. Though lateralization is common in a number of higher cognitive functions, its prominence in language may also be a key to understanding the rapid emergence of the language network in infants and the ease at which we master our language in adulthood. One question here is whether the hemispheric lateralization is driven by linguistic input per se or whether non-linguistic, especially acoustic factors, ‘guide’ the lateralization process. Methodologically, fMRI provides unsurpassed anatomical detail for such an enquiry. However, instrumental noise, experimental constraints and interference with EEG assessment limit its applicability, pointedly in infants and also when investigating the link between auditory and linguistic processing. Optical methods have the potential to fill this gap. Here we review a number of recent studies using optical imaging to investigate hemispheric differences during segmentation and basic auditory feature analysis in language development.

  15. A case of superior segmental optic hypoplasia accompanied by a glaucomatous optic neuropathy

    OpenAIRE

    Ohguro, Hiroshi

    2008-01-01

    Ikuyo Ohguro, Hiroshi OhguroDepartment of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, JapanAbstract: This is the first case report of a bilateral superior segmental optic hypoplasia (SSOH) accompanied by a glaucomatous optic neuropathy (GON). A 47-year-old man incidentally diagnosed as having bilateral SSOH, simultaneously disclosed glaucomatous optic disc appearances, including enlargements of the cup of the optic nerve heads and a thinning of the infero-...

  16. Understanding the optics to aid microscopy image segmentation.

    Science.gov (United States)

    Yin, Zhaozheng; Li, Kang; Kanade, Takeo; Chen, Mei

    2010-01-01

    Image segmentation is essential for many automated microscopy image analysis systems. Rather than treating microscopy images as general natural images and rushing into the image processing warehouse for solutions, we propose to study a microscope's optical properties to model its image formation process first using phase contrast microscopy as an exemplar. It turns out that the phase contrast imaging system can be relatively well explained by a linear imaging model. Using this model, we formulate a quadratic optimization function with sparseness and smoothness regularizations to restore the "authentic" phase contrast images that directly correspond to specimen's optical path length without phase contrast artifacts such as halo and shade-off. With artifacts removed, high quality segmentation can be achieved by simply thresholding the restored images. The imaging model and restoration method are quantitatively evaluated on two sequences with thousands of cells captured over several days. PMID:20879233

  17. Technical note: Endoscopic resection of a dermoid cyst anchored to the anterior optic chiasm

    Directory of Open Access Journals (Sweden)

    Yuichiro Yoneoka, MD, PhD

    2014-06-01

    Conclusion: To the best of our knowledge, ours is the only case of a dermoid cyst anchored to the anterior optic chiasma, which was visually confirmed under endoscopic observation. After surgery, the patient presented a transient impairment of the visual field, which was not evident at four month follow-up. It will contribute to a similar case, in which surgeons hesitate to make an incision in the optic chiasm. A subtotal excision should be considered in cases of dermoid cysts anchored to the anterior optic chiasm, because all the previously reported cases of suprasellar dermoid cysts are young people or those who have a relatively long life expectancy.

  18. Doenças do segmento anterior ocular associadas a lentes de contato Contact lens-associated ocular anterior segment diseases

    Directory of Open Access Journals (Sweden)

    Murilo Barreto Souza

    2008-12-01

    Full Text Available A disponibilidade de lentes de contato cada vez mais confortáveis e toleráveis favoreceu não só a ampliação das indicações, mas também o aumento do número de seus usuários. Como conseqüência deste fato as complicações associadas ao uso de lentes de contato são cada vez mais comuns, e representam um problema de grande prevalência na prática clínica. O objetivo deste estudo é revisar as principais doenças e alterações do segmento anterior e superfície ocular associadas ao uso de lentes de contato.Nowadays, contact lenses have shown a larger variety of options in order to meet the needs of different patients. They have become more frequent in the clinical practice and, consequently, the complications related to contact lenses have been more common. This review attempted to describe the main alterations and diseases of the cornea and anterior segment associated with contact lens wearers.

  19. Anterior Segment Alterations and Comparative Aqueous Humor Proteomics in the Buphthalmic Rabbit (An American Ophthalmological Society Thesis)

    Science.gov (United States)

    Edward, Deepak P.; Bouhenni, Rachida

    2011-01-01

    Purpose To use an integrated proteohistologic approach to gain insight into the anterior segment alterations in the buphthalmic rabbit. Methods Eyes from 2- and 5-year-old buphthalmic and normal rabbits (n=20) were studied histologically. Liquid chromatography–tandem mass spectrometry (LC-MS/MS) of aqueous humor (AH) was used to determine differential protein expression between animal groups. Western blot and immunohistochemistry were performed on selected differentially expressed proteins identified by LC-MS/MS. Results The buphthalmic rabbits manifested a mild clinical phenotype with typical angle anomalies that appeared progressive by histology. Significantly thickened Descemet’s membrane (DM) and anterior lens capsule in all buphthalmic rabbits showed increased fibronectin and collagen-IV immunolabeling. LC-MS/MS applying stringent filtering criteria revealed significant differential expression of several AH proteins in these rabbits. The protein of interest in the 2-year-old group was histidine-rich glycoprotein, and those in the 5-year-old group included alpha-2-HS-glycoprotein, clusterin, apolipoprotein E, interphotoreceptor retinoid-binding protein, transthyretin, cochlin, gelsolin, haptoglobin, hemopexin, and beta-2 microglobulin. The proteomic data for selected proteins was validated by Western blot and immunohistochemistry. A wide range of functional groups were affected by the altered AH proteins. These included extracellular matrix modulation, regulation of apoptosis, oxidative stress, and protein transport. Conclusions Multiple anterior segment alterations were histologically identified in the buphthalmic rabbits that showed progressive changes with age. The differentially expressed AH proteins in these rabbits suggest a multifunctional role for AH in modulating pathologic changes in DM, anterior lens capsule, and the angular meshwork in these animals. PMID:22253484

  20. Biomechanical effects of polyaxial pedicle screw fixation on the lumbosacral segments with an anterior interbody cage support

    Directory of Open Access Journals (Sweden)

    Chen Hsiang-Ho

    2007-03-01

    Full Text Available Abstract Background Lumbosacral fusion is a relatively common procedure that is used in the management of an unstable spine. The anterior interbody cage has been involved to enhance the stability of a pedicle screw construct used at the lumbosacral junction. Biomechanical differences between polyaxial and monoaxial pedicle screws linked with various rod contours were investigated to analyze the respective effects on overall construct stiffness, cage strain, rod strain, and contact ratios at the vertebra-cage junction. Methods A synthetic model composed of two ultrahigh molecular weight polyethylene blocks was used with four titanium pedicle screws (two in each block and two rods fixation to build the spinal construct along with an anterior interbody cage support. For each pair of the construct fixed with polyaxial or monoaxial screws, the linked rods were set at four configurations to simulate 0°, 7°, 14°, and 21° lordosis on the sagittal plane, and a compressive load of 300 N was applied. Strain gauges were attached to the posterior surface of the cage and to the central area of the left connecting rod. Also, the contact area between the block and the cage was measured using prescale Fuji super low pressure film for compression, flexion, lateral bending and torsion tests. Results Our main findings in the experiments with an anterior interbody cage support are as follows: 1 large segmental lordosis can decrease the stiffness of monoaxial pedicle screws constructs; 2 polyaxial screws rather than monoaxial screws combined with the cage fixation provide higher compression and flexion stiffness in 21° segmental lordosis; 3 polyaxial screws enhance the contact surface of the cage in 21° segmental lordosis. Conclusion Polyaxial screws system used in conjunction with anterior cage support yields higher contact ratio, compression and flexion stiffness of spinal constructs than monoaxial screws system does in the same model when the spinal segment

  1. Recurrent progressive anterior segment fibrosis syndrome following a descemet-stripping endothelial keratoplasty in an infant with congenital aniridia

    Directory of Open Access Journals (Sweden)

    Mihir Kothari

    2014-01-01

    Full Text Available Progressive anterior segment fibrosis syndrome (ASFS, after intraocular surgery in older children (≥9 years and adults with congenital aniridia, is described in the literature. In this report, we describe an unique case of ASFS in an infant with congenital aniridia following a combined trabeculotomy-ectomy and its recurrence after a descemet stripping endothelial keratoplasty. The ophthalmologists should be well aware of this entity and warn the parents about its possibilities. Use of immunomodulators or prolonged anti-inflammatory therapy may be considered to prevent its occurrence.

  2. 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

  3. The spinal nail: a new implant for short-segment anterior instrumentation of the thoracolumbar spine.

    Science.gov (United States)

    Dawson, J M; DeBoer, D K; Spengler, D M; Schwartz, H S

    1996-08-01

    The biomechanics of a new spinal implant were evaluated and its dependence on an anterior strut graft was determined. Six fresh-frozen adult porcine spines were used. An L3 corpectomy was created. The spinal nail was inserted intraosseously into the middle column of the L2-L4 vertebral bodies in a trough. Implant drill holes were made for proximal and distal locking bolts in L2 and L4. A locking plate bridged the L2 and L4 trough and anchored the exposed ends of the locking bolts. Testing was performed in axial compression, torsion, and flexion. The axial and torsional stability of the spine instrumented with the spinal nail are similar to results with other devices when used with anterior strut grafting. The axial and flexural stiffnesses of the instrumented spine are independent of strut grafting. This study suggests that this device may be useful for reconstruction of the anterior spine because of instability. PMID:8877956

  4. 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.

  5. Advancement of maxillary anterior segment by distraction osteogenesis for severe maxillary retrusion in cleft lip and palate

    Institute of Scientific and Technical Information of China (English)

    Gao Feng; Yang Minlie; Zhao Zhenmin; Sun Xiaomei; Yin Ningbei; Wang Yongqian; Song Tao

    2014-01-01

    Background Maxillary anterior segmental distraction osteogenesis (MASDO) is a recently used method for correction of severe maxillary retrusion in cleft lip and palate (CLP) patients.In this article,we evaluated the feasibility of MASDO using rigid external distraction (RED) and rapid orthodontic tooth movement to correct severe maxillary retrusion in CLP patients.Methods Fourteen male and five female complete CLP patients between the ages of 18 and 22 years (mean age 19.7 years) at the time of distraction,with severe maxillary retrusion,were treated with the rigid external distraction (RED) device after maxillary anterior osteotomy.Rapid orthodontic tooth movement was started one week after the MASDO.Standard profile photographic,cephalometric films were obtained preoperatively and after therapy.Sella-nasion-point A (SNA) and Sella-nasion-point B (SNB) angles were measured to reflect changes in maxillary and mandibular position,and the distance between anterior nasal spine and posterior nasal spine (ANS-PNS) was measured to represent the maxillary dental arch length.Results The SNA angle increased from an average of 74.6° (range 73.0°-78.0°),preoperatively,to 83.4° (range 78.6°-88.0°) after the RED was removed (P <0.01).All cases of severe maxillary retrusion were improved.Nine patients' profiles became harmonious after therapy.One patient had a bimaxillary protrusion deformity and needed further surgery.The regenerate alveolar crest and edentulous space on both segments was almost completely eliminated after rapid orthodontic tooth movement.Conclusion MASDO with the RED system and rapid orthodontic tooth movement is a successful way of correcting severe maxillary retrusion in CLP patients.

  6. Retinal Blood Vessel Segmentation with Optic Disc Pixels Exclusion

    Directory of Open Access Journals (Sweden)

    Randy Cahya Wihandika

    2013-06-01

    Full Text Available The morphological changes of retinal blood vessels are important indicators used to diagnose and monitor the progression of various diseases. A number of retinal blood vessel segmentation methods have been introduced, including the line operator based methods, which have shown satisfactory results. However, the basic line operator method cannot discriminate the pixels around the retinal optic disc, resulting in false classification of those pixels. In this paper, we integrate the detection of pixels around the retinal optic disc to the line operator method so that those pixels can be excluded from the vessel pixels. The method is evaluated on the widely used retinal dataset, the DRIVE dataset. The results demonstrate that the proposed method has made improvements over the basic and the multi-scale line detector with accuracy and area under curve of 0.942 and 0.9521, respectively.

  7. 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...

  8. Analysis of Fundus Photography and Fluorescein Angiography in Nonarteritic Anterior Ischemic Optic Neuropathy and Optic Neuritis

    Science.gov (United States)

    Kim, Min Kyung

    2016-01-01

    Purpose We evaluated fundus and fluorescein angiography (FAG) findings and characteristics that can help distinguish nonarteritic anterior ischemic optic neuropathy (NAION) from optic neuritis (ON). Methods Twenty-three NAION patients and 17 ON with disc swelling patients were enrolled in this study. We performed fundus photography and FAG. The disc-swelling pattern, hyperemia grade, presence of splinter hemorrhages, cotton-wool spots, artery/vein ratio and degree of focal telangiectasia were investigated. The FAG findings for each patient were compared with respect to the following features: the pattern of disc leakage in the early phase, arteriovenous (artery/vein) transit time (second), and the presence and pattern of the filling delay. Results Cotton-wool spots, focal telangiectasia, and venous congestion were more common in the affected eyes of NAION patients. Upon FAG, 76.5% of the patients in the ON group exhibited normal choroidal circulation. However, 56.5% of patients in the NAION group demonstrated abnormal filling defects, such as peripapillary, generalized, or watershed zone filling delays. Conclusions Fundus findings, including cotton-wool spots, focal telangiectasia, and venous congestion in the affected eye, may be clues that can be used to diagnose NAION. In addition, choroidal insufficiencies on FAG could be also helpful in differentiating NAION from ON. PMID:27478356

  9. Consideration of QRS complex in addition to ST-segment abnormalities in the estimated "risk region" during acute anterior myocardial infarction

    DEFF Research Database (Denmark)

    van Hellemond, Irene E. G.; Bouwmeester, Sjoerd; Olson, Charles W.;

    2011-01-01

    The myocardial area at risk (MaR) has been estimated in patients with acute myocardial infarction (AMI) by using ST segment-based electrocardiographic (ECG) methods. As the process from ischemia to infarction progresses, the ST-segment deviation is typically replaced by QRS abnormalities causing...... a falsely low estimated total MaR if determined by using ST segment-based methods. The purpose of this study was to investigate if consideration of the abnormalities in the QRS complex, in addition to those in the ST segment, provides a more accurate estimated total MaR during anterior AMI than...

  10. 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...

  11. Should steroids be offered to patients with nonarteritic anterior ischemic optic neuropathy (NAION)?

    OpenAIRE

    Lee, Andrew G.; Biousse, Valérie

    2010-01-01

    The treatment of nonarteritic anterior optic neuropathy remains very limited and disappointing. Recent publications have suggested that oral steroids as well as intravitreal injections of steroids might be helpful to accelerate resolution of disc edema and improve visual outcome. However, the use of steroids to treat acute NAION remains largely debated.

  12. Neuropatia óptica isquêmica anterior e poliarterite nodosa: relato de caso Anterior ischemic optic neuropathy and polyarteritis nodosa: case report

    OpenAIRE

    Christie Michelle Graf; Thelma Larocca Skare; Carlos Augusto Moreira

    2006-01-01

    Descreve-se uma paciente com diagnóstico de poliarterite nodosa, em tratamento com citostáticos e corticosteróides que desenvolveu neuropatia óptica isquêmica anterior, uma manifestação considerada bastante rara para esta doença.We describe a patient with polyarteritis nodosa being treated with cytostatics and corticosteroids who developed an anterior ischemic optic neuropathy, a rare manifestation of this pathology.

  13. Neuropatia óptica isquêmica anterior e poliarterite nodosa: relato de caso Anterior ischemic optic neuropathy and polyarteritis nodosa: case report

    Directory of Open Access Journals (Sweden)

    Christie Michelle Graf

    2006-02-01

    Full Text Available Descreve-se uma paciente com diagnóstico de poliarterite nodosa, em tratamento com citostáticos e corticosteróides que desenvolveu neuropatia óptica isquêmica anterior, uma manifestação considerada bastante rara para esta doença.We describe a patient with polyarteritis nodosa being treated with cytostatics and corticosteroids who developed an anterior ischemic optic neuropathy, a rare manifestation of this pathology.

  14. Conservation, Innovation, and Bias: Embryonic Segment Boundaries Position Posterior, but Not Anterior, Head Horns in Adult Beetles.

    Science.gov (United States)

    Busey, Hannah A; Zattara, Eduardo E; Moczek, Armin P

    2016-07-01

    The integration of form and function of novel traits is a fundamental process during the developmental evolution of complex organisms, yet how novel traits and trait functions integrate into preexisting contexts remains poorly understood. Here, we explore the mechanisms by which the adult insect head has been able to integrate novel traits and features during its ontogeny, focusing on the cephalic horns of Onthophagus beetles. Specifically, using a microablation approach we investigate how different regions of the dorsal head of adult horned beetles relate to their larval and embryonic counterparts and test whether deeply conserved regional boundaries that establish the embryonic head might also facilitate or bias the positioning of cephalic horns along the dorsal adult head. We find that paired posterior horns-the most widespread horn type within the genus-are positioned along a border homologous to the embryonic clypeolabral (CL)-ocular boundary, and that this placement constitutes the ancestral form of horn positioning. In contrast, we observed that the phylogenetically much rarer anterior horns are positioned by larval head regions contained firmly within the CL segment and away from any major preexisting larval head landmarks or boundaries. Lastly, we describe the unexpected finding that ablations at medial head regions can result in ectopic outgrowths bearing terminal structures resembling the more anterior clypeal ridge. We discuss our results in the light of the developmental genetic mechanisms of head formation in holometabolous insects and the role of co-option in innovation and bias in developmental evolution.

  15. 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.

  16. Texture analysis improves level set segmentation of the anterior abdominal wall

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhoubing [Electrical Engineering, Vanderbilt University, Nashville, Tennessee 37235 (United States); Allen, Wade M. [Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37235 (United States); Baucom, Rebeccah B.; Poulose, Benjamin K. [General Surgery, Vanderbilt University Medical Center, Nashville, Tennessee 37235 (United States); Landman, Bennett A. [Electrical Engineering, Vanderbilt University, Nashville, Tennessee 37235 and Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee 37235 (United States)

    2013-12-15

    Purpose: The treatment of ventral hernias (VH) has been a challenging problem for medical care. Repair of these hernias is fraught with failure; recurrence rates ranging from 24% to 43% have been reported, even with the use of biocompatible mesh. Currently, computed tomography (CT) is used to guide intervention through expert, but qualitative, clinical judgments, notably, quantitative metrics based on image-processing are not used. The authors propose that image segmentation methods to capture the three-dimensional structure of the abdominal wall and its abnormalities will provide a foundation on which to measure geometric properties of hernias and surrounding tissues and, therefore, to optimize intervention.Methods: In this study with 20 clinically acquired CT scans on postoperative patients, the authors demonstrated a novel approach to geometric classification of the abdominal. The authors’ approach uses a texture analysis based on Gabor filters to extract feature vectors and follows a fuzzy c-means clustering method to estimate voxelwise probability memberships for eight clusters. The memberships estimated from the texture analysis are helpful to identify anatomical structures with inhomogeneous intensities. The membership was used to guide the level set evolution, as well as to derive an initial start close to the abdominal wall.Results: Segmentation results on abdominal walls were both quantitatively and qualitatively validated with surface errors based on manually labeled ground truth. Using texture, mean surface errors for the outer surface of the abdominal wall were less than 2 mm, with 91% of the outer surface less than 5 mm away from the manual tracings; errors were significantly greater (2–5 mm) for methods that did not use the texture.Conclusions: The authors’ approach establishes a baseline for characterizing the abdominal wall for improving VH care. Inherent texture patterns in CT scans are helpful to the tissue classification, and texture

  17. Combined anterior and posterior decompression and short segment fixation for unstable burst fractures in the dorso lumbar region.

    Directory of Open Access Journals (Sweden)

    Ramani P

    2002-07-01

    Full Text Available The dorso lumbar segment of spine (D10 to L2 is an unstable zone between fixed dorsal and mobile lumbar spine. A combined anterior and posterior approach with short segment stabilization was found most appropriate. Thirty cases were treated over a period of 4 years and 6 months. There were 26 male and 4 female patients with mean age of 32.6 years. L1 vertebra was fractured in 17 cases, D1 in 8 cases, D11 in 4 cases and D10 in one case. 14 cases had total neurological deficit, 9 cases had partial and 7 had no neurological deficit. We have used three column classification of Denis to assess the cases. Seven patients returned to regular physical work, 5 had restricted physical work, 5 remained in full time light job and 9 patients were unable to return to original job but did some work. Most had flaccid paraplegia but 4 patients were completely disabled due to spastic paraplegia. Neurological recovery occurred in all the patients with partial paralysis, and appeared to be dependent on initial kyphosis. The overall recovery rate varied from 50% to 90%. There is no correlation between canal compromise and severity of injury. Neurological injury occured at the time of trauma, rather than as a result of pressure of fragment in the canal. No strong conclusion could be drawn to say that the results of surgery were superior to non-operative treatment.

  18. Coating Thin Mirror Segments for Lightweight X-ray Optics

    Science.gov (United States)

    Chan, Kai-Wing; Sharpe, Marton V.; Zhang, William; Kolosc, Linette; Hong, Melinda; McClelland, Ryan; Hohl, Bruce R.; Saha, Timo; Mazzarellam, James

    2013-01-01

    Next generations lightweight, high resolution, high throughput optics for x-ray astronomy requires integration of very thin mirror segments into a lightweight telescope housing without distortion. Thin glass substrates with linear dimension of 200 mm and thickness as small as 0.4 mm can now be fabricated to a precision of a few arc-seconds for grazing incidence optics. Subsequent implementation requires a distortion-free deposition of metals such as iridium or platinum. These depositions, however, generally have high coating stresses that cause mirror distortion. In this paper, we discuss the coating stress on these thin glass mirrors and the effort to eliminate their induced distortion. It is shown that balancing the coating distortion either by coating films with tensile and compressive stresses, or on both sides of the mirrors is not sufficient. Heating the mirror in a moderately high temperature turns out to relax the coated films reasonably well to a precision of about a second of arc and therefore provide a practical solution to the coating problem.

  19. Large-scale segmentation errors in optical gratings and their unique effect onto optical scattering spectra

    Science.gov (United States)

    Heusinger, Martin; Flügel-Paul, Thomas; Zeitner, Uwe-Detlef

    2016-08-01

    In this paper, we analyze the influence of large-scale segmentation errors in the morphology of high-performance optical gratings. It is thus assumed that the optical grating under consideration (typical lateral extends S are 10-1000 mm) can be spatially decomposed into a great many but unique sub-segments (≪ S; typical extends are 10-100 μm). Any violation of the perfect periodicity will result in the generation of stray light, especially Rowland ghosts, which radiate into a small angular region around the grating's diffraction orders. In this paper, we focus on three different kinds of segmentation errors. On the one hand, there are statistic as well as deterministic alignment errors between otherwise perfect sub-segments. On the other hand, we analyze the effect of chirping of geometrical parameters, i.e., the groove width, within every sub-segment. Most importantly, we find that the particular type of imperfection results in a unique characteristic of the according stray light spectrum which thus acts as a fingerprint. We come to this conclusion on three different ways. First, we rely on a simple theoretical model that is based on scalar diffraction theory. Second, we have performed rigorous numerical simulations for a high aspect ratio purely dielectric spectrometer grating (period = {667} nm). Third, the very same grating was then fabricated by e-beam lithography and its stray light spectrum was measured with a purposely designed optical setup. Eventually, all different routes to analyze the problem turn out to be in very good agreement, and we are confident that stray light measurements can be used as an important tool in the detection of fabrication imperfections.

  20. Extended coherence length megahertz FDML and its application for anterior segment imaging

    OpenAIRE

    Wieser, Wolfgang; Klein, Thomas; Adler, Desmond C.; Trépanier, Francois; Eigenwillig, Christoph M.; Karpf, Sebastian; Schmitt, Joseph M.; Huber, Robert

    2012-01-01

    We present a 1300 nm Fourier domain mode locked (FDML) laser for optical coherence tomography (OCT) that combines both, a high 1.6 MHz wavelength sweep rate and an ultra-long instantaneous coherence length for rapid volumetric deep field imaging. By reducing the dispersion in the fiber delay line of the FDML laser, the instantaneous coherence length and hence the available imaging range is approximately quadrupled compared to previously published MHz-FDML setups, the imaging speed is increase...

  1. A real-time technique for optical alignment of telescopes with segmented optics

    Science.gov (United States)

    DiVittorio, Michael; Gathright, John

    2003-02-01

    While telescopes with segmented optics (currently Keck and HET and in the future GTC, CELT, GSMT, NGST, etc) present extra challenges in terms of optical alignment, they also present the opportunity for using an alignment technique not available to telescopes with monolithic optics. We present a technique for aligning telescope secondary mirrors utilizing the segmented nature of the primary. The data required is gathered in direct image mode and can be collected from science instrument detectors (as compared to a wavefront sensor). From this data aberrations (focus and coma) are calculated from which secondary piston and tip/tilt (or decenter) corrections are determined. In addition, tip/tilt corrections for each of the primary mirror segments can also be calculated. Furthermore, other aberrations are available to determine other alignment or support issues including differentiating secondary tip/tilt from decenter, focal surface tilt, and instrument aberrations. This technique has been used nightly on the Keck I and II telescopes over the last 8 years and has made a significant improvement in image quality.

  2. Anterior Ischaemic Optic Neuropathy in Patient with Rheumatoid Arthritis – Case Report

    OpenAIRE

    Perić, S; Cerovski, B.; Perić, P.

    2001-01-01

    This case report presents a patient with long-lasting rheumatoid arthritis (RA) of fourth clinical grade, having ocular complications. RA was diagnosed according to current modified ARA criteria from 1987. Upon admission to the Department of Ophthalmology clinical examination revealed anterior ischaemic optic neuropathy (AION), which is not characteristic manifestation of RA in the eye. The occurrence of AION in patients with RA has been explained in literature as a secondary m...

  3. Efficacy of Optical Internal Urethrotomy and Intralesional Injection of Vatsala-Santosh PGI Tri-Inject (Triamcinolone, Mitomycin C, and Hyaluronidase in the Treatment of Anterior Urethral Stricture

    Directory of Open Access Journals (Sweden)

    Santosh Kumar

    2014-01-01

    Full Text Available Purpose. To study the efficacy of optical internal urethrotomy with intralesional injection of Vatsala-Santosh PGI tri-inject (triamcinolone, mitomycin C, and hyaluronidase in the treatment of anterior urethral stricture. Material and Methods. A total of 103 patients with symptomatic anterior urethral stricture were evaluated on the basis of clinical history, physical examination, uroflowmetry, and retrograde urethrogram preoperatively. All patients were treated with optical internal urethrotomy followed by injection of tri-inject at the urethrotomy site. Tri-inject was prepared by diluting the combination of triamcinolone 40 mg, mitomycin C 2 mg, and hyaluronidase 3000 in 5–10 mL of saline according to length of stricture. An indwelling 18 Fr silicone catheter was left in place for a period of 7–21 days. All patients were followed up for 6–18 months postoperatively on the basis of history, uroflowmetry, and, if required, retrograde urethrogram and micturating urethrogram every 3 months. Results. The overall recurrence rate after first OIU is 19.4% (20 out of 103 patients, that is, a success rate of 80.6%. Overall recurrence rate after second procedure was 5.8% (6 out of 103 patients, that is, a success rate of 94.2%. Conclusion. Optical internal urethrotomy with intralesional injection of Vatsala-Santosh PGI tri-inject (triamcinolone, mitomycin C, and hyaluronidase is a safe and effective minimally invasive therapeutic modality for short segment anterior urethral strictures.

  4. 角膜塑形术后眼前节形态及调节功能%Anterior segment biometry and accommodative function after orthokeratology

    Institute of Scientific and Technical Information of China (English)

    朱伟根; 张莎莎; 邵一磊; 袁一民; 沈梅晓; 瞿佳

    2016-01-01

    Objective To investigate the changes in accommodative response and anterior segment biometry during accommodation in young progressive myopes who wear overnight orthokeratology lenses.Methods Eighteen children (age:14.4±2.6 years) were enrolled in this prospective experimental study and were tested before wearing orthokeratology (OK) lenses and after wearing them for three months.Using a Badal optical system,the refractive error of each subject was corrected before and after lens wear,and then accommodative stimuli of 3 D and 5 D were presented.A custom-built optical coherence tomographer (OCT) with a long scan depth was used to image the entire anterior segment through the pupil,and to obtain the anterior segment biometry including pupil diameter (PD),anterior chamber depth (ACD),lens thickness (LT) and the lens anterior surface's radius of curvature (LAC).An auto-refractometer (WAM-5500) was used to measure ocular refraction during accommodation,which was used to calculate the accommodative response.The measurements of anterior segment biometry and accommodative response were repeated twice under each accommodative state.Results After wearing orthokeratology lenses for one to three months,an improvement in the accommodative response was evident under both the 3 D (1.72±0.59 D vs.2.42±0.84 D) and 5 D (3.09±0.63 D vs.3.61±0.86 D) accommodative states (paired t-test,t=2.84,2.12,P<0.05).During accommodation,△PD,△ACD,△LT,and △LAC changed obviously.Compared with baseline (before wearing OK lenses),accommodation-related changes in △ACD (3 D:-0.11±0.04 mm vs.-0.16±0.06 mm,t=3.88,P<0.01;5 D:-0.15±0.05 mm vs.-0.20±0.07 mm,t=2.37,P<0.05),△LAC (3 D:-2.60±0.79 mm vs.-3.81±1.08 mm,t=3.96,P<0.01;5 D:-3.57±1.14 mm vs.-4.32±1.36 mm,t=2.08,P<0.05) and △LT (3 D:0.22±0.13 mm vs.0.27±0.06 mm,t=-1.94,P<0.05;5 D:0.26± 0.09 mm vs.0.30±0.10 mm,t=-1.99,P<0.05) showed statistically significant increases.Conclusion After wearing orthokeratology

  5. 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.

  6. Anterior maxillary segmental distraction in the treatment of severe maxillary hypoplasia secondary to cleft lip and palate

    Science.gov (United States)

    Li, Hongliang; Dai, Jiewen; Si, Jiawen; Zhang, Jianfei; Wang, Minjiao; Shen, Steve Guofang; Yu, Hongbo

    2015-01-01

    Anterior maxillary segmental distraction (AMSD) is an effective surgical procedure in the treatment of maxillary hypoplasia secondary to cleft lip and palate. Its unique advantage of preserving velopharyngeal function makes this procedure widely applied. In this study, the application of AMSD was described and its long-term stability was explored. Eight patients with severe maxillary hypoplasia secondary to CLP were included in this study. They were treated with AMSD using rigid external distraction (RED) device. Cephalometric analysis was performed twice at three time points for evaluation: before surgery (T1), after distraction (T2), and 2 years after treatment (T3). One-way analysis of variance was used to assess the differences statistically. All the distractions completed smoothly, and maxilla was distracted efficiently. The value of SNA, NA-FH, Ptm-A, U1-PP, overjet and PP (ANS-PNS) increased significantly after the AMSD procedure (P 0.05). Changes of palatopharyngeal depth and soft palatal length were insignificant. AMSD with RED device provided an effective way to correct maxillary hypoplasia secondary to CLP, extended the palatal and arch length, avoided damage on velopharyngeal closure function and reduced the relapse rate. It is a promising and valuable technique in this potentially complicated procedure. PMID:26629107

  7. Application of a stand-alone anchored spacer in noncontiguous anterior cervical arthrodesis with radiologic analysis of the intermediate segment.

    Science.gov (United States)

    Shi, Sheng; Liu, Zu-De; You, Wen-Jie; Ouyang, Yue-Ping; Li, Xin-Feng; Qian, Lie; Zhong, Gui-Bin

    2016-03-01

    The purpose of this study was to describe the clinical features of noncontiguous cervical degenerative disc disease (cDDD), investigate the efficacy and complications of a stand-alone anchored spacer (SAAS) for patients with noncontiguous cDDD, and present radiologic analysis of the intermediate segment (IS) after skip-level fusion. Nineteen consecutive patients with noncontiguous cDDD who underwent skip-level anterior cervical discectomy and fusion (ACDF) with SAAS from January 2010 to December 2012 were enrolled in this study. Clinical outcomes were assessed preoperatively and at 24 months postoperatively using the Japanese Orthopaedic Association score, Neck Disability Index, and Visual Analog Scale. Overall cervical alignment (OCA) of the cervical spine, and the range of motion (ROM), intervertebral disc height (IDH), disc signal intensity and disc protrusion of IS were measured and compared before and after surgery. Clinical outcomes significantly improved compared to preoperative scores. The OCA was corrected and maintained at 24 months postoperatively compared with preoperative values (p0.05). However, decreased signal intensity on T2-weighted MRI was evidenced in three mobile IS at final follow-up (20.0%). Skip-level ACDF with SAAS may be an efficacious option for the treatment of noncontiguous cDDD. PMID:26597607

  8. Optic nerve head analysis of superior segmental optic hypoplasia using Heidelberg retina tomography

    Directory of Open Access Journals (Sweden)

    Atsushi Miki

    2010-10-01

    Full Text Available Atsushi Miki1,2, Motohiro Shirakashi1, Kiyoshi Yaoeda1, Atsushi Fukushima1, Mineo Takagi1, Haruki Abe11Division of Ophthalmology and Visual Sciences, Niigata University Graduate School of Medical and Dental Sciences, Niigata, 2Department of Ophthalmology, Kawasaki Medical School, Okayama, JapanPurpose: To evaluate the optic disc characteristics of eyes with superior segmental optic hypoplasia (SSOH using the Heidelberg retina tomograph (HRT.Patients and methods: Thirteen eyes of 13 Japanese patients with SSOH were studied with the HRT (software version: 3.0. The group included six males and seven females, with a mean age of 34.7 years. Six optic disc parameters in the six sectors derived from the patients with SSOH were compared with those of 13 eyes of 13 normal controls. In addition, the diagnostic classification performance of the Frederick S Mikelberg (FSM discriminant function, glaucoma probability score (GPS, and Moorfields regression analysis (MRA were assessed.Results: When compared with normal subjects, many of the optic disc parameters were significantly altered in SSOH in the superior sectors. The area under the curve (AUC for the receiver operating characteristic was 0.932 for the rim area, 0.926 for the cup-to-disc area ratio, and 0.882 for the cup shape measure. Among the HRT parameters, the largest AUC (0.988 was found for the cup shape measure in the nasal superior segment. The proportion classified as outside normal limits by the FSM discriminant function was 92.3% (12 eyes. For GPS, six eyes (46.2% were classified as outside normal limits. For MRA, when borderline cases were considered test-negative or test-positive, 10 eyes (76.9% or 11 eyes (84.6% were classified as outside normal limits, respectively. The AUCs were 0.976 for the FSM discriminant function, 0.914 for the MRA overall classification, and 0.710 for the GPS overall classification.Conclusions: In eyes with SSOH, there is a significant thinning of the rim

  9. Strain gauge ambiguity sensor for segmented mirror active optical system

    Science.gov (United States)

    Wyman, C. L.; Howe, T. L. (Inventor)

    1974-01-01

    A system is described to measure alignment between interfacing edges of mirror segments positioned to form a segmented mirror surface. It serves as a gauge having a bending beam with four piezoresistive elements coupled across the interfaces of the edges of adjacent mirror segments. The bending beam has a first position corresponding to alignment of the edges of adjacent mirror segments, and it is bendable from the first position in a direction and to a degree dependent upon the relative misalignment between the edges of adjacent mirror segments to correspondingly vary the resistance of the strain guage. A source of power and an amplifier are connected in circuit with the strain gauge whereby the output of the amplifier varies according to the misalignment of the edges of adjacent mirror segments.

  10. Anterior ischemic optic neuropathy after conventional coronary artery bypass graft surgery

    Science.gov (United States)

    Dorecka, Mariola; Miniewicz-Kurkowska, Joanna; Romaniuk, Dorota; Gajdzik-Gajdecka, Urszula; Wójcik-Niklewska, Bogumiła

    2011-01-01

    Summary Background Perioperative optic neuropathy is a disease which can lead to serious, irreversible damage of vision. This complication could be the result of non-ocular surgery, for example, cardiac or spinal procedures. We present a case of anterior ischemic neuropathy (AION) which occurred following a conventional coronary artery bypass graft procedure. Case Report A 57-year-old man, 4 days after Conventional Coronary Artery Bypass Graft surgery as result of multi-vessel stabile coronary artery disease and history of anterolateral wall myocardial infarction, was admitted to the Eye Clinic due to significant loss of vision in his right eye. The patient had hypertension and was a heavy smoker. On admission, the slit lamp examination revealed a relative afferent pupillary defect in the right eye. The fundus examination showed optic disc edema with the presence of flame hemorrhages. Best corrected visual acuity (BCVA) was 0.02. The results of eye examination and fluorescein angiography confirmed the diagnosis of AION. Anti-aggregation and antithrombotic treatment was continued with steroids and vasodilators. After 7 days of this treatment we noticed the improvement of BCVA to 0.2. At 6-month follow-up, the vision was stable, and fundus examination revealed optic disc atrophy. Conclusions After cardiac surgical operations, such as coronary artery bypass graft procedures, anterior ischemic optic neuropathy may occur. In those cases, close cooperation between the various specialists is necessary. PMID:21629193

  11. Comparison of the Deep Optic Nerve Head Structure between Normal-Tension Glaucoma and Nonarteritic Anterior Ischemic Optic Neuropathy.

    Directory of Open Access Journals (Sweden)

    Eun Ji Lee

    Full Text Available To compare the deep optic nerve head (ONH structure between normal-tension glaucoma (NTG and nonarteritic anterior ischemic optic neuropathy (NAION and also in healthy subjects as a control using enhanced depth imaging (EDI spectral-domain optical coherence tomography (SD-OCT.This prospective cross-sectional study included 21 NAION patients who had been diagnosed as NAION at least 6 months prior to study entry, and 42 NTG patients and 42 healthy controls who were matched with NAION patients in terms of age, intraocular pressure (IOP, and optic disc area. The retinal nerve fiber layer (RNFL thickness in the affected sector was also matched between NAION and NTG patients. The ONH was imaged using SD-OCT with the EDI technique. The anterior lamina cribrosa surface depth (LCD and average prelaminar tissue (PT thickness were measured in a sector of interest in each eye and compared among the three groups.In the sector-matched comparison, LCD was largest in NTG patients, followed by NAION patients, while PT was thinner in NTG patients than in NAION patients (all P < 0.001. NAION patients had a comparable LCD and a thinner PT relative to normal controls (P = 0.170 and < 0.001, respectively.The deep ONH configuration is strikingly different between NTG and NAION. The differing features provide comparative insight into the pathophysiology of the two diseases, and may be useful for differential diagnosis.

  12. 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

  13. 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.

  14. Region-based multi-step optic disk and cup segmentation from color fundus image

    Science.gov (United States)

    Xiao, Di; Lock, Jane; Manresa, Javier Moreno; Vignarajan, Janardhan; Tay-Kearney, Mei-Ling; Kanagasingam, Yogesan

    2013-02-01

    Retinal optic cup-disk-ratio (CDR) is a one of important indicators of glaucomatous neuropathy. In this paper, we propose a novel multi-step 4-quadrant thresholding method for optic disk segmentation and a multi-step temporal-nasal segmenting method for optic cup segmentation based on blood vessel inpainted HSL lightness images and green images. The performance of the proposed methods was evaluated on a group of color fundus images and compared with the manual outlining results from two experts. Dice scores of detected disk and cup regions between the auto and manual results were computed and compared. Vertical CDRs were also compared among the three results. The preliminary experiment has demonstrated the robustness of the method for automatic optic disk and cup segmentation and its potential value for clinical application.

  15. Automated segmentation of the optic disc from stereo color photographs using physiologically plausible features

    NARCIS (Netherlands)

    Abramoff, M.D.; Alward, W.L.M.; Greenlee, E.C.; Shuba, L.; Kim, Chan Y.; Fingert, J.H.; Kwon, Y.H.

    2007-01-01

    PURPOSE. To evaluate a novel automated segmentation algorithm for cup-to-disc segmentation from stereo color photographs of patients with glaucoma for the measurement of glaucoma progression. METHODS. Stereo color photographs of the optic disc were obtained by using a fixed stereo-base fundus camera

  16. Mutation analysis of the genes associated with anterior segment dysgenesis, microcornea and microphthalmia in 257 patients with glaucoma.

    Science.gov (United States)

    Huang, Xiaobo; Xiao, Xueshan; Jia, Xiaoyun; Li, Shiqiang; Li, Miaoling; Guo, Xiangming; Liu, Xing; Zhang, Qingjiong

    2015-10-01

    Genetic factors have an important role in the development of glaucoma; however, the exact genetic defects remain to be identified in the majority of patients. Glaucoma is frequently observed in patients with anterior segment dysgenesis (ASD), microcornea or microphthalmia. The present study aimed to detect the potential mutations in the genes associated with ASD, microcornea and microphthalmia in 257 patients with glaucoma. Variants in 43 of the 46 genes, which are associated with ASD, microcornea or microphthalmia, were available in whole‑exome sequencing. Candidate variants in the 43 genes were selected following multi‑step bioinformatic analysis and were subsequently confirmed by Sanger sequencing. Confirmed variants were further validated by segregation analysis and analysis of controls. Overall, 70 candidate variants were selected from whole‑exome sequencing, of which 53 (75.7%) were confirmed by Sanger sequencing. In total, 27 of the 53 were considered potentially pathogenic based on bioinformatic analysis and analysis of controls. Of the 27, 6 were identified in BEST1, 4 in EYA1, 3 in GDF6, 2 in BMP4, 2 in CRYBA4, 2 in HCCS, and 1 in each of CRYAA, CRYGC, CRYGD, COL4A1, FOXC1, GJA8, PITX2 and SHH. The 27 variants were detected in 28 of 257 (10.9%) patients, including 11 of 125 patients with primary open‑angle glaucoma and 17 of 132 patients with primary angle‑closure glaucoma. Variants in these genes may be a potential risk factor for primary glaucoma. Careful clinical observation and analysis of additional patients in different populations are expected to further these findings.

  17. 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...

  18. The segmentation of the HMD market: optics for smart glasses, smart eyewear, AR and VR headsets

    Science.gov (United States)

    Kress, Bernard; Saeedi, Ehsan; Brac-de-la-Perriere, Vincent

    2014-09-01

    This paper reviews the various optical technologies that have been developed to implement HMDs (Head Mounted Displays), both as AR (Augmented Reality) devices, VR (Virtual Reality) devices and more recently as smart glasses, smart eyewear or connected glasses. We review the typical requirements and optical performances of such devices and categorize them into distinct groups, which are suited for different (and constantly evolving) market segments, and analyze such market segmentation.

  19. 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.

  20. Length-adaptive graph search for automatic segmentation of pathological features in optical coherence tomography images

    Science.gov (United States)

    Keller, Brenton; Cunefare, David; Grewal, Dilraj S.; Mahmoud, Tamer H.; Izatt, Joseph A.; Farsiu, Sina

    2016-07-01

    We introduce a metric in graph search and demonstrate its application for segmenting retinal optical coherence tomography (OCT) images of macular pathology. Our proposed "adjusted mean arc length" (AMAL) metric is an adaptation of the lowest mean arc length search technique for automated OCT segmentation. We compare this method to Dijkstra's shortest path algorithm, which we utilized previously in our popular graph theory and dynamic programming segmentation technique. As an illustrative example, we show that AMAL-based length-adaptive segmentation outperforms the shortest path in delineating the retina/vitreous boundary of patients with full-thickness macular holes when compared with expert manual grading.

  1. Fusion of Adjacent Segment Degeneration after Anterior Portion Cervical Decompression%颈前路融合术后相邻节段退变120例

    Institute of Scientific and Technical Information of China (English)

    占蓓蕾; 叶舟

    2014-01-01

    目的:探讨颈椎前路减压融合术后相邻节段退变的因果关系。方法:对237例患者行前路椎间节段减压植骨融合术(87例),椎体次全切除减压植骨融合术(109例),椎间节段减压、椎体次全切除减压植骨融合术(41例)。通过影像学检查,观察不同手术方法术后相邻节段退变发生情况。结果:术后随访时间2.6~13年,平均6.8年;发生相邻节段明显退变的120例(50.6%),头侧相邻节段退变发生率明显高于尾侧邻近节段(P<0.05),其中27例(22.2%)需2次翻修手术。结论:颈椎前路融合术后可导致颈椎相邻节段的退变。%Objective To investigate the result of anterior cervical decompression and fusion of adjacent segment degeneration after causality. Methods among 237 patients(87 cases) weretreated with anterior decom-pression and interbody fusion intervertebral segments, 109cases with subtotal excision of the vertebral body with decompression and interbody fusion,and 41 cases with intervertebral segmental decompression, vertebral body subtotal resection decompression and interbody fusion.By imaging examination, different surgical methods and postoperative adjacent segment degeneration were observed. Results Postoperative follow-up at time of 2.6~13 years, averaging 6.8 years; showed significantly degeneration of adjacent segments in 120 cases (50.6%), the cranial adjacent segment degeneration rate significantly higher than that of the caudal adjacent segment (P<0.05), among them,27 cases (22.2%)needed 2 times of revision surgery. Conclusion The anterior cervical fu-sion surgery can lead to cervical vertebral adjacent segment degeneration.

  2. Optical Design of Segmented Hexagon Array Solar Mirror

    Science.gov (United States)

    Huegele, Vince

    2000-01-01

    A segmented array of mirrors was designed for a solar concentrator test stand at MSFC for firing solar thermal propulsion engines. The 144 mirrors each have a spherical surface to approximate a parabolic concentrator when combined into the entire 18-foot diameter array. The mirror segments are aluminum hexagons that had the surface diamond turned and quartz coated. The array focuses sunlight reflected from a heliostat to a 4 inch diameter spot containing 10 kw of power at the 15-foot focal point. The derivation of the surface figure for the respective mirror elements is shown. The alignment process of the array is discussed and test results of the system's performance is given.

  3. THE RHEO-OPTICAL FTIR STUDY OF POLYESTER-POLYETHER SEGMENTED COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    WEN Zaiqing; SHEN Deyan; ZHAO Hengqi

    1988-01-01

    The polyester-polyether segmented copolymer has been investigated by rheo-optical FTIR during stretching for the information on strain induced crystallization of soft segment chains, hard and soft chain orientation.At room temperature 15℃, the soft segment chains of polyester-polyether being to crystallize at 220% strain and the degree of crystallization increase with draw ratio, but there will not be any soft segment chains crystallization above 21℃ even at higher strain. The average orientation of hard segment chains are higher than that of the soft chain at high strain level, both are positive oriented into the stretching direction at allover strain level. This indicates that the hard segment chains are dispersed into the elastomeric phase and without forming spherulite.

  4. A NEW DECODER OF SYNCHRONOUS OPTICAL CODE DIVISION MULTIPLE ACCESS SYSTEMS USING SEGMENTED CORRELATION

    Institute of Scientific and Technical Information of China (English)

    Li Ou; Wu Jiangxing; Lan Julong

    2001-01-01

    A new segmented correlating decoder of synchronous optical CDMA using modified prime sequence codes is proposed. The performance of the proposed system is analyzed under the assumption of Poisson shot noise model for the receiver photodetector. The decoder technique is shown to be more effective to improve the bit error probability performance than the method using an optical hard-limiter.

  5. 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

  6. Impact of Indocyanine Green Concentration, Exposure Time, and Degree of Dissolution in Creating Toxic Anterior Segment Syndrome: Evaluation in a Rabbit Model

    Science.gov (United States)

    Khoramnia, Ramin; Uwe Auffarth, Gerd

    2016-01-01

    Purpose. To investigate the role of indocyanine green (ICG) dye as a causative material of toxic anterior segment syndrome (TASS) in an experimental rabbit model. Method. Eight eyes of four rabbits were allocated to this study. Capsular staining was performed using ICG dye, after which the anterior chamber was irrigated with a balanced salt solution. The effects of different concentrations (control, 0.25, 0.5, and 1.0%), exposure times (10 and 60 seconds), and the degree of dissolution (differently vortexed) were investigated. The analysis involved anterior segment photography, ultrasound pachymetry, prostaglandin assay (PGE2 Parameter Assay, R&D systems, Inc.), and scanning electron microscopy of each iris. Result. There was no reaction in the control eye. A higher aqueous level of PGE2 and more severe inflammatory reaction were observed in cases of eyes with higher concentration, longer exposure time, and poorly dissolved dye. Additionally, scanning electron microscopy revealed larger and coarser ICG particles. Conclusion. TASS occurrence may be associated with the concentration, exposure time, and degree of dissolution of ICG dye during cataract surgery. PMID:27478634

  7. 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

  8. 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.

  9. The Retinal Nerve Fiber Layer Defects in Patients with Anterior Ischemic Optic Neuropathy

    Institute of Scientific and Technical Information of China (English)

    HaiLu; QiZang

    1995-01-01

    Purpose:To demonstrate the effects of optic nerve ischemia on retinal nerve fiber layer(RNFL)and the associated visual dysfunction.Methods:23patients(25eyes)wits anterior ischemic optic neuropathy(AION)un derwent fundus fluorescein angiography(FFA),and then red-foree light pic-tures were taken via SE-40exceiter filter.All pictures were printed for RNAFL analysis,Humphrey central field analysis was conducted.All dataobtained fromFFA and visual field defects were analysed statistically.Results:The RNFL defects and the corresponding visual field edfects were pre-sented in 23of 25eyes(92%),The optic disc filling defects,RNAL edfects and visual field defects were found to be highly correspondent to each other.The RNFL defects were mainly the local losses of RNFL which were correspondent to the ischemic regions.Conclusion:The poor optic disc filling or ischemia can result in the RNFL defects which cause the associated visual dysfunction.Because RNFLdefects are irrever-siable changes,the potential values in predicting the prognosis of visual field de-fects caused by RNFL damages were suggested.Eye Science1995;11:165-167.

  10. Prevalence of adjacent segment disc degeneration in patients undergoing anterior cervical discectomy and fusion based on pre-operative MRI findings.

    Science.gov (United States)

    Lundine, Kristopher M; Davis, Gavin; Rogers, Myron; Staples, Margaret; Quan, Gerald

    2014-01-01

    Anterior cervical discectomy and fusion (ACDF) is a widely accepted surgical treatment for symptomatic cervical spondylosis. Some patients develop symptomatic adjacent segment degeneration, occasionally requiring further treatment. The cause and prevalence of adjacent segment degeneration and disease is unclear at present. Proponents for motion preserving surgery such as disc arthroplasty argue that this technique may decrease the "strain" on adjacent discs and thus decrease the incidence of symptomatic adjacent segment degeneration. The purpose of this study was to assess the pre-operative prevalence of adjacent segment degeneration in patients undergoing ACDF. A database review of three surgeons' practice was carried out to identify patients who had undergone a one- or two-level ACDF for degenerative disc disease. Patients were excluded if they were operated on for recent trauma, had an inflammatory arthropathy (for example, rheumatoid arthritis), or had previous spine surgery. The pre-operative MRI of each patient was reviewed and graded using a standardised methodology. One hundred and six patient MRI studies were reviewed. All patients showed some evidence of intervertebral disc degeneration adjacent to the planned operative segment(s). Increased severity of disc degeneration was associated with increased age and operative level, but was not associated with sagittal alignment. Disc degeneration was more common at levels adjacent to the surgical level than at non-adjacent segments, and was more severe at the superior adjacent level compared with the inferior adjacent level. These findings support the theory that adjacent segment degeneration following ACDF is due in part to the natural history of cervical spondylosis.

  11. A Case of Schizencephaly and Septo-Optic Dysplasia Presenting with Anterior Encephalocele

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    Kaveh FADAKAR

    2013-01-01

    Full Text Available How to cite this article: Fadakar K, Dadkhahfar S, Esmaeili A, Keyhanidoust Z. A Case of Schizencephaly and Septo-Optic Dysplasia Presenting with Anterior Encephalocele. Iran J Child Neurol Autumn 2012; 6(4:47-50. AbstractSchizencephaly is a rare central nervous system disorder with variable presentations. Here we report a patient with a huge bilateral schizencephaly and septo-optic dysplasia presenting with anterior encephalocele. References:Yakovlev PI, Wadsworth RC. Schizencephalies; a study of the congenital clefts in the cerebral mantle; clefts with hydrocephalus and lips separated. J Neuropathol Exp Neurol. 1946 Jul;5(3:169-206.Yakovlev PI, Wadsworth RC. Schizencephalies; a study of the congenital clefts in the cerebral mantle; clefts with fused lips. J Neuropathol Exp Neurol. 1946 Apr;5:116-30.Brunelli S, Faiella A, Capra V, Nigro V, Simeone A,Cama A et al. Germline mutations in the homeobox gene EMX2 in patients with severe schizencephaly. Nat Genet. 1996 Jan;12(1:94-6.Montenegro MA, Guerreiro MM, Lopes-Cendes I,Guerreiro CA, Cendes F. Interrelationship of genetics and prenatal injury in the genesis of malformations of cortical development. Arch Neurol. 2002 Jul;59(7:1147-53.Granata T, Freri E, Caccia C, Setola V, Taroni F,Battaglia G. Schizencephaly: clinical spectrum, epilepsy, and pathogenesis. J Child Neurol. 2005 Apr;20(4:313-8.Lee HK, Kim JS, Hwang YM, Lee MJ, Choi CG, Suh DC et al. Location of the primary motor cortex in schizencephaly. AJNR Am J Neuroradiol. 1999 Jan;20(1:163-6.De Morsier G. [Studies on malformation of cranio-encephalic sutures. III. Agenesis of the septum lucidum with malformation of the optic tract]. Schweiz Arch Neurol Psychiatr. 1956;77(1:267-92.Hoyt WF, Kaplan SL, Grumbach MM, Glaser JS. Septo-optic dysplasia and pituitary dwarfism. Lancet. 1970 Apr;1(7652:893-4.Webb EA, Dattani MT. Septo-optic dysplasia. Eur J Hum Genet. 2010 Apr;18(4:393-7.Ellenberger C Jr, Runyan TE

  12. Adjacent segment disease after anterior cervical discectomy and fusion: Incidence and clinical outcomes of patients requiring anterior versus posterior repeat cervical fusion

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    Mohamad Bydon

    2014-01-01

    Conclusions : Patients undergoing an anterior revision surgery for ASD after ACDF have higher rates of postoperative radiculopathy and redevelopment of ASD when compared with posteriorly approached patients. Patients receiving posterior revision surgery had higher intraoperative blood loss, hospitalizations, and postoperative complications such as wound infections and discharge to rehabilitation, but had a statistically lower chance of redevelopment of ASD requiring secondary revision surgery. This may be due to the fact that posterior revision surgeries involved more levels fused. This study provides one of the longest and most comprehensive follow-ups of this challenging patient population. Prospective studies comparing surgical approaches and techniques are needed to corroborate our findings.

  13. Three-dimensional choroidal segmentation in spectral OCT volumes using optic disc prior information

    Science.gov (United States)

    Hu, Zhihong; Girkin, Christopher A.; Hariri, Amirhossein; Sadda, SriniVas R.

    2016-03-01

    Recently, much attention has been focused on determining the role of the peripapillary choroid - the layer between the outer retinal pigment epithelium (RPE)/Bruchs membrane (BM) and choroid-sclera (C-S) junction, whether primary or secondary in the pathogenesis of glaucoma. However, the automated choroidal segmentation in spectral-domain optical coherence tomography (SD-OCT) images of optic nerve head (ONH) has not been reported probably due to the fact that the presence of the BM opening (BMO, corresponding to the optic disc) can deflect the choroidal segmentation from its correct position. The purpose of this study is to develop a 3D graph-based approach to identify the 3D choroidal layer in ONH-centered SD-OCT images using the BMO prior information. More specifically, an initial 3D choroidal segmentation was first performed using the 3D graph search algorithm. Note that varying surface interaction constraints based on the choroidal morphological model were applied. To assist the choroidal segmentation, two other surfaces of internal limiting membrane and innerouter segment junction were also segmented. Based on the segmented layer between the RPE/BM and C-S junction, a 2D projection map was created. The BMO in the projection map was detected by a 2D graph search. The pre-defined BMO information was then incorporated into the surface interaction constraints of the 3D graph search to obtain more accurate choroidal segmentation. Twenty SD-OCT images from 20 healthy subjects were used. The mean differences of the choroidal borders between the algorithm and manual segmentation were at a sub-voxel level, indicating a high level segmentation accuracy.

  14. Significant relationship between local angle at fused segments and C2-7 angle: Average duration of longer than 20 years after anterior cervical discectomy and fusion

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    T Nagata

    2011-01-01

    Full Text Available Background : The authors have focused their attention to the radiological durability of cervical sagittal alignment after anterior cervical discectomy and fusion (ACDF using autologous bone grafting. Materials and Methods : Among the patients who underwent ACDF with trans-unco-discal (TUD approach between 1976 and 1997, 22 patients (16 males and 6 females made return visits for a clinical evaluation. Patients with trauma or previously treated by anterior cervical fusion or by posterior decompression were excluded from the present study. Clinical evaluation included adjacent segment degeneration (ASD, osseous fusion, local angle at the fused segments and C2-7 angle of cervical spine. Results : The duration after ACDF ranged from 13 to 34 years with an average of 21.3 ± 7.0 years. A single level fusion was done on 8 patients, 2 levels on 11 patients, 3 levels on 2 patients, and 4 levels on 1 patient. Imaging studies indicated that 12 of the 22 patients (54.5% were graded as having symptomatic ASD. Osseous bony fusion at ACDF was recognized in all cases. None of the patients demonstrated kyphotic malalignment of the cervical spine. Average degrees of local angle at the fused segments and the C2-7 angle were 7.06 and 17.6, respectively. Statistical analysis indicated a significant relationship between the local at the fused segments and C2-7 angles. Conclusions : Sagittal alignment of the cervical spine was durable long after ACDF when the local angle at the fused segments was well stabilized.

  15. Segmentation of anterior cruciate ligament in knee MR images using graph cuts with patient-specific shape constraints and label refinement.

    Science.gov (United States)

    Lee, Hansang; Hong, Helen; Kim, Junmo

    2014-12-01

    We propose a graph-cut-based segmentation method for the anterior cruciate ligament (ACL) in knee MRI with a novel shape prior and label refinement. As the initial seeds for graph cuts, candidates for the ACL and the background are extracted from knee MRI roughly by means of adaptive thresholding with Gaussian mixture model fitting. The extracted ACL candidate is segmented iteratively by graph cuts with patient-specific shape constraints. Two shape constraints termed fence and neighbor costs are suggested such that the graph cuts prevent any leakage into adjacent regions with similar intensity. The segmented ACL label is refined by means of superpixel classification. Superpixel classification makes the segmented label propagate into missing inhomogeneous regions inside the ACL. In the experiments, the proposed method segmented the ACL with Dice similarity coefficient of 66.47±7.97%, average surface distance of 2.247±0.869, and root mean squared error of 3.538±1.633, which increased the accuracy by 14.8%, 40.3%, and 37.6% from the Boykov model, respectively. PMID:25305694

  16. The Role of the Reactive Oxygen Species and Oxidative Stress in the Pathomechanism of the Age-Related Ocular Diseases and Other Pathologies of the Anterior and Posterior Eye Segments in Adults

    Science.gov (United States)

    Nita, Małgorzata; Grzybowski, Andrzej

    2016-01-01

    The reactive oxygen species (ROS) form under normal physiological conditions and may have both beneficial and harmful role. We search the literature and current knowledge in the aspect of ROS participation in the pathogenesis of anterior and posterior eye segment diseases in adults. ROS take part in the pathogenesis of keratoconus, Fuchs endothelial corneal dystrophy, and granular corneal dystrophy type 2, stimulating apoptosis of corneal cells. ROS play a role in the pathogenesis of glaucoma stimulating apoptotic and inflammatory pathways on the level of the trabecular meshwork and promoting retinal ganglion cells apoptosis and glial dysfunction in the posterior eye segment. ROS play a role in the pathogenesis of Leber's hereditary optic neuropathy and traumatic optic neuropathy. ROS induce apoptosis of human lens epithelial cells. ROS promote apoptosis of vascular and neuronal cells and stimulate inflammation and pathological angiogenesis in the course of diabetic retinopathy. ROS are associated with the pathophysiological parainflammation and autophagy process in the course of the age-related macular degeneration. PMID:26881021

  17. Image-guided modified deep anterior lamellar keratoplasty (DALK) corneal transplant using intraoperative optical coherence tomography

    Science.gov (United States)

    Tao, Yuankai K.; LaBarbera, Michael; Ehlers, Justis P.; Srivastava, Sunil K.; Dupps, William J.

    2015-03-01

    Deep anterior lamellar keratoplasty (DALK) is an alternative to full-thickness corneal transplant and has advantages including the absence of allograft rejection; shortened duration of topical corticosteroid treatment and reduced associated risk of glaucoma, cataract, or infection; and enables use of grafts with poor endothelial quality. DALK begins by performing a trephination of approximately 80% stromal thickness, as measured by pachymetry. After removal of the anterior stoma, a needle is inserted into the residual stroma to inject air or viscoelastic to dissect Descemet's membrane. These procedures are inherently difficult and intraoperative rates of Descemet's membrane perforation between 4-39% have been reported. Optical coherence tomography (OCT) provides high-resolution images of tissue microstructures in the cornea, including Descemet's membrane, and allows quantitation of corneal layer thicknesses. Here, we use crosssectional intraoperative OCT (iOCT) measurements of corneal thickness during surgery and a novel micrometeradjustable biopsy punch to precision-cut the stroma down to Descemet's membrane. Our prototype cutting tool allows us to establish a dissection plane at the corneal endothelium interface, mitigates variability in cut-depths as a result of tremor, reduces procedure complexity, and reduces complication rates. iOCT-guided modified DALK procedures were performed on 47 cadaveric porcine eyes by non-experts and achieved a perforation rate of ~5% with a mean corneal dissection time care.

  18. 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.

  19. An optical approach to validate ultrasound surface segmentation of the heart

    Science.gov (United States)

    Wang, Bo; Schlaefer, Alexander; Zhang, Zhenxi

    2014-09-01

    The patient specific geometry of the heart is of interest for a number of diagnostic methods, e.g., when modeling the inverse electrocardiography (ECG) problem. One approach to get images of the heart is three-dimensional ultrasound. However, segmentation of the surface is complicated and segmentation methods are typically validated against manually drawn contours. This requires considerable expert knowledge. Hence, we have developed a setup that allows studying the accuracy of image segmentation from cardiac ultrasound. Using an optical tracking system, we have measured the three-dimensional surface of an isolated porcine heart. We studied whether the actual geometry can be reconstructed from both optical and ultrasound images. We illustrate the use of our approach in quantifying the segmentation result for a three-dimensional region-based active contour algorithm.

  20. Anterior ischaemic optic neuropathy in patient with rheumatoid arthritis--case report.

    Science.gov (United States)

    Perić, S; Cerovski, B; Perić, P

    2001-01-01

    This case report presents a patient with long-lasting rheumatoid arthritis (RA) of fourth clinical grade, having ocular complications. RA was diagnosed according to current modified ARA criteria from 1987. Upon admission to the Department of Ophthalmology clinical examination revealed anterior ischaemic optic neuropathy (AION), which is not characteristic manifestation of RA in the eye. The occurrence of AION in patients with RA has been explained in literature as a secondary manifestation of hypertension in these patients or, by the presence of other connective tissue disease apart from RA (for example, MCTD--mixed connective tissue disease). Both mentioned causes were excluded in our case, as well as any other condition that could lead to AION. Therefore, we had concluded that AION presented a late complication of RA.

  1. Could Topical Minoxidil Cause Non-Arteritic Anterior Ischemic Optic Neuropathy?

    Science.gov (United States)

    Aktas, Habibullah; Alan, Sevil; Türkoglu, Elif Betül; Sevik, Özge

    2016-08-01

    Minoxidil hair formulation is commonly used for the treatment of male or female androgenic alopecia. Minoxidil is a Health Canada and US FDA-approved medication for hair loss in men and women. The drug is marketed as 2% and 5% topical solutions. This over-the-counter product is considered safe, but should be used with caution. Furthermore, minoxidil is an orally active vasodilator for treatment of severe hypertension. Typical side effects of minoxidil are faster heart rate, augmented heart function and stroke volume (which can be associated with reduced vascular resistance upon baroflex stimulus), retained sodium and water and abnormal hair growth. The most common adverse reactions of the topical formulation are limited to irritant and allergic contact dermatitis on the scalp. Herein, we report a non-arteritic anterior ischemic optic neuropathy caused by topical 5% minoxidil treatment that was resolved after discontinuation of minoxidil. PMID:27656541

  2. Bilateral Simultaneous Nonarteritic Anterior Ischemic Optic Neuropathy after Ingestion of Sildenafil for Erectile Dysfunction

    Directory of Open Access Journals (Sweden)

    Anna Tarantini

    2012-01-01

    Full Text Available Purpose. To describe a patient who developed bilateral, simultaneous nonarteritic anterior ischemic optic neuropathy (NAION after ingestion of Sildenafil citrate (Viagra for erectile dysfunction. Methods. Observational case report. Results. A 60-year-old diabetic man noted sudden decrease of vision in both eyes 16 hours after his third consecutive 50 mg daily Sildenafil ingestion. A diagnosis of bilateral NAION was made and he was treated for three days with methylprednisolone 1 g/d intravenously, followed by oral prednisone 75 mg/d. Final visual acuity was 20/50 right eye (OD and 20/20 left eye (OS. He had preexisting diabetes. Conclusion. This is the first reported case of simultaneous bilateral NAION occurred in a diabetic patient early after Sildenafil intake. Patients with predisposing conditions such as diabetes have to be warned against the use of PDE inhibitors.

  3. 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

  4. Segmented X-ray optics for future space telescopes

    Science.gov (United States)

    McClelland, R. S.

    Lightweight and high resolution mirrors are needed for future space-based X-ray telescopes to achieve advances in high-energy astrophysics. The slumped glass mirror technology in development at NASA GSFC aims to build X-ray mirror modules with an area to mass ratio of ~17 cm2/kg at 1 keV and a resolution of 10 arc-sec Half Power Diameter (HPD) or better at an affordable cost. As the technology nears the performance requirements, additional engineering effort is needed to ensure the modules are compatible with space-flight. This paper describes Flight Mirror Assembly (FMA) designs for several X-ray astrophysics missions studied by NASA and defines generic driving requirements and subsequent verification tests necessary to advance technology readiness for mission implementation. The requirement to perform X-ray testing in a horizontal beam, based on the orientation of existing facilities, is particularly burdensome on the mirror technology, necessitating mechanical over-constraint of the mirror segments and stiffening of the modules in order to prevent self-weight deformation errors from dominating the measured performance. This requirement, in turn, drives the mass and complexity of the system while limiting the testable angular resolution. Design options for a vertical X-ray test facility alleviating these issues are explored. An alternate mirror and module design using kinematic constraint of the mirror segments, enabled by a vertical test facility, is proposed. The kinematic mounting concept has significant advantages including potential for higher angular resolution, simplified mirror integration, and relaxed thermal requirements. However, it presents new challenges including low vibration modes and imperfections in kinematic constraint. Implementation concepts overcoming these challenges are described along with preliminary test and analysis results demonstrating the feasibility of kinematically mounting slumped glass mirror segments.

  5. Segmented X-Ray Optics for Future Space Telescopes

    Science.gov (United States)

    McClelland, Ryan S.

    2013-01-01

    Lightweight and high resolution mirrors are needed for future space-based X-ray telescopes to achieve advances in high-energy astrophysics. The slumped glass mirror technology in development at NASA GSFC aims to build X-ray mirror modules with an area to mass ratio of approx.17 sq cm/kg at 1 keV and a resolution of 10 arc-sec Half Power Diameter (HPD) or better at an affordable cost. As the technology nears the performance requirements, additional engineering effort is needed to ensure the modules are compatible with space-flight. This paper describes Flight Mirror Assembly (FMA) designs for several X-ray astrophysics missions studied by NASA and defines generic driving requirements and subsequent verification tests necessary to advance technology readiness for mission implementation. The requirement to perform X-ray testing in a horizontal beam, based on the orientation of existing facilities, is particularly burdensome on the mirror technology, necessitating mechanical over-constraint of the mirror segments and stiffening of the modules in order to prevent self-weight deformation errors from dominating the measured performance. This requirement, in turn, drives the mass and complexity of the system while limiting the testable angular resolution. Design options for a vertical X-ray test facility alleviating these issues are explored. An alternate mirror and module design using kinematic constraint of the mirror segments, enabled by a vertical test facility, is proposed. The kinematic mounting concept has significant advantages including potential for higher angular resolution, simplified mirror integration, and relaxed thermal requirements. However, it presents new challenges including low vibration modes and imperfections in kinematic constraint. Implementation concepts overcoming these challenges are described along with preliminary test and analysis results demonstrating the feasibility of kinematically mounting slumped glass mirror segments.

  6. End-to-End Assessment of a Large Aperture Segmented Ultraviolet Optical Infrared (UVOIR) Telescope Architecture

    Science.gov (United States)

    Feinberg, Lee; Bolcar, Matt; Liu, Alice; Guyon, Olivier; Stark,Chris; Arenberg, Jon

    2016-01-01

    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10-10 contrast measurements and sufficient throughput and sensitivity for high yield Exo-Earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an Exo-Earth yield assessment to evaluate potential performance.

  7. Bilateral simultaneous anterior ischemic optic neuropathy, an extrahepatic manifestation of hepatitis C cured with direct acting antivirals

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    Prud’homme, Sylvie

    2016-04-01

    Full Text Available We report a patient with a bilateral optic anterior ischemic neuropathy as an extrahepatic complication of a chronic hepatitis C (HCV infection. The patient presented with a bilateral visual acuity loss and bilateral optic disc oedema. The optic neuropathy was associated with a sudden increase in the viral HCV load after a recent liver transplantation. The stop of the calcineurin inhibitor had no effect on the course of the optic neuropathy. Visual improvement and normalization of HCV viraemia occurred after treatment with sofosbuvir and daclatasvir, which are direct acting antivirals.

  8. Inter-Segmental Coordination Pattern in Patients with Anterior Cruciate Ligament Deficiency during a Single-Step Descent.

    Science.gov (United States)

    Nematollahi, Mohammadreza; Razeghi, Mohsen; Mehdizadeh, Sina; Tabatabaee, Hamidreza; Piroozi, Soraya; Rojhani Shirazi, Zahra; Rafiee, Ali

    2016-01-01

    Anterior cruciate ligament injury is a debilitating pathology which may alter lower limb coordination pattern in both intact and affected lower extremities during activities of daily living. Emerging evidence supports the notion that kinematic variables may not be a good indicator to differentiate patients with anterior cruciate ligament deficiency during step descent task. The aim of the present study was to examine alterations in kinematics as well as coordination patterns and coordination variability of both limbs of these patients during a single step descent task. Continuous relative phase technique was used to measure coordination pattern and coordination variability between a group of anterior cruciate ligament deficient (n = 23) and a healthy control group (n = 23). A third order polynomial Curve fitting was utilized to provide a curve that best fitted to the data points of coordination pattern and coordination variability of the healthy control group. This was considered as a reference to compare to that of patient group using nonlinear regression analysis. The results of the present study demonstrated an altered coordination pattern of the supporting shank-thigh and the stepping foot-shank couplings in anterior cruciate ligament deficient subjects. It was further noticed that there was an increased coordination variability in foot-shank and shank-thigh couplings of both supporting and stepping legs. There was no significant difference in the hip, knee and ankle joints kinematics in either side of these patients. Anterior cruciate ligament deficient individuals showed altered strategies in both intact and affected legs, with increased coordination variability. Kinematic data did not indicate any significant difference between the two groups. It could be concluded that more sophisticated dynamic approach such as continuous relative phase would uncover discrepancies between the healthy and anterior cruciate ligament deficient individuals.

  9. Nonarteritic Anterior Ischemic Optic Neuropathy and Double Thrombophilic Defect: A New Observation

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    Eleni Papageorgiou

    2012-02-01

    Full Text Available We report the first case of nonarteritic anterior ischemic neuropathy (NAION associated with double thrombophilia: protein S deficiency and prothrombin G20210A mutation. A 58-year-old man is presented including the clinical and laboratory findings, cardiovascular profile and thrombophilia screening. The patient presented with 3/10 vision and an inferior altitudinal defect in the right eye. Funduscopic examination of the right eye revealed a hyperemic optic disk with blurred superior optic disk border and sectoral nerve fiber layer edema. Complete blood count, erythrocyte sedimentation rate and C-reactive protein were normal, suggesting a NAION. A workup of cardiovascular risk factors revealed hyperlipidemia, arterial hypertension and high-risk asymptomatic coronary artery disease. Due to the family history of deep vein thrombosis in the patient’s daughter, a thrombophilia screening was additionally performed. The results revealed a double thrombophilic defect, namely congenital protein S deficiency and heterozygosity for prothrombin G20210A mutation, which were also identified in the patient’s daughter. Anticoagulant warfarin therapy was initiated and the patient underwent a triple bypass surgery. At three-month follow-up, the right optic disk edema had resolved, leaving a pale superior optic nerve head. Visual acuity in the right eye had slightly improved to 4/10; however, the dense inferior altitudinal field defect had remained unchanged. The patient is currently treated with warfarin, atorvastatin, irbesartan and metoprolol. This case suggests that the first line of investigation in all patients with NAION involves assessment of cardiovascular risk factors. However, careful history taking will identify NAION patients who are eligible for additional thrombophilia screening: young patients without vasculopathic risk factors, bilateral or recurrent NAION, idiopathic or recurrent venous thromboembolism (VTE, positive family history of VTE

  10. Viewpoint-independent 3D object segmentation for randomly stacked objects using optical object detection

    International Nuclear Information System (INIS)

    This work proposes a novel approach to segmenting randomly stacked objects in unstructured 3D point clouds, which are acquired by a random-speckle 3D imaging system for the purpose of automated object detection and reconstruction. An innovative algorithm is proposed; it is based on a novel concept of 3D watershed segmentation and the strategies for resolving over-segmentation and under-segmentation problems. Acquired 3D point clouds are first transformed into a corresponding orthogonally projected depth map along the optical imaging axis of the 3D sensor. A 3D watershed algorithm based on the process of distance transformation is then performed to detect the boundary, called the edge dam, between stacked objects and thereby to segment point clouds individually belonging to two stacked objects. Most importantly, an object-matching algorithm is developed to solve the over- and under-segmentation problems that may arise during the watershed segmentation. The feasibility and effectiveness of the method are confirmed experimentally. The results reveal that the proposed method is a fast and effective scheme for the detection and reconstruction of a 3D object in a random stack of such objects. In the experiments, the precision of the segmentation exceeds 95% and the recall exceeds 80%. (paper)

  11. Central Corneal Thickness Measurements in Nonarteritic Anterior Ischemic Optic Neuropathy Patients: A Controlled Study

    Directory of Open Access Journals (Sweden)

    Haneen Jabaly-Habib

    2014-01-01

    Full Text Available Purpose. To measure central corneal thickness (CCT in patients with history of nonarteritic anterior ischemic optic neuropathy (NAION. Patients and Methods. Patients older than 40 years with a history of NAION (group 1 were prospectively evaluated including full eye examination and central corneal thickness (CCT pachymetry. Patients with a history of intraocular surgery, corneal disease, glaucoma, and contact lens wear were excluded. Measurements were also performed in a gender and age matched control group (group 2. Results. Thirty-one eyes of 31 NAION patients in group 1 were included and 30 eyes of 30 participants in group 2. There were 15 men in group 1 and 9 in group 2 P=0.141, and mean age of the patients was 59±10 years in group 1 versus 61±11 years in group 2 P=0.708. Mean CCT was 539±30 microns in group 1 and 550±33 microns in group 2 P=0.155. Conclusion. Patients with NAION have no special characteristic of CCT in contrast to the crowded optic disc known to be a significant anatomic risk factor for NAION. More studies should be carried out to investigate CCT and other structure related elements in NAION patients.

  12. Arteritic anterior ischemic optic neuropathy associated with chronic myelomonocytic leukemia (CMML: A case report

    Directory of Open Access Journals (Sweden)

    Miriam García Fernández

    2015-02-01

    Full Text Available Introduction: Ocular involvement in patients with CMML is rarely reported, owing in part to the fact that the severe illness faced by many of these patients limits the feasibility of ocular examinations. Nevertheless, post-mortem examination of the eyes of patients without ophthalmological symptoms and diagnosis of CMML, has revealed ocular infiltration of atypical cells. Case report: A 72-year-old man presented with two days of left-sided blurring of vision and an episode of transient visual obscuration associated to periorbitary pain. A relative afferent pupillary defect was present in the LE. Fundus examination revealed optic disc swelling in LE. The erythrocyte sedimentation rate (ESR was 120 mm (1st hour and C-reactive protein was 7.8. Complementary examinations yielded normal findings. A presumptive diagnosis of arteritic anterior ischemic optic neuropathy (AAION was made. Treatment with endovenous bolus of methylprednisolone, followed by slow-tapering of oral steroids, was started, without improvement. Temporal artery biopsy confirmed the diagnosis. Conclusions: To our knowledge, this is the second case in peer-reviewed literature reporting the association between AAION and CMML. A possible explanation is the fact that small vessel vasculitis, of unclear pathogenesis so far, complicates approximately 10% of CMML and presents as cutaneous vasculitis and lupus-like syndromes. Therefore, this may be in relation with the vasculitis of the short posterior ciliary arteries which happens in cases of AAION.

  13. Anterior ischemic optic neuropathy associated with metabolic syndrome Neuropatia óptica isquêmica anterior associada a síndrome metabólica

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    Natalija Kosanovic-Jakovic

    2008-02-01

    Full Text Available PURPOSE: Metabolic syndrome denotes a common cluster of naturally connected risk factors including obesity, elevated blood pressure, insulin resistance, dyslipidemia, proinflammatory state and prothrombotic state. Anterior ischemic optic neuropathy is an acute ischaemic disorder of the optic nerve head and may lead to severe visual loss. METHODS: We considered three patients with moderate degree of diabetic retinopathy and anterior ischemic optic neuropathy. They were submitted to endocrinological examination and the diagnosis of metabolic syndrome was established. RESULTS: Cardiological examination revealed that blood pressure control was not optimal. The signs of left ventricular hypertrophy and diastolic dysfunction were confirmed by echocardiography. They are possible markers of preclinical cardiovascular disease. CONCLUSION: We observed that a variety of well-known risk factors in metabolic syndrome may be involved in serious eye and cardiological complications. The early diagnosis and treatment of these patients can not only improve visual function but also prevent cardiovascular complications.OBJETIVO: A síndrome metabólica indica um grupo comum dos seguintes achados clinicos: obesidade, hipertensão arterial, variações nos níveis de glicemia, dislipidemia, estado proinflamatório e o estado protrombótico. Neuropatia óptica isquêmica anterior é um distúrbio agudo isquêmico da cabeça do nervo óptico que pode levar à perda de visão. MÉTODOS: Consideramos três pacientes com retinopatia diabética não proliferativa moderada e neuropatia óptica isquêmica anterior. Os pacientes foram examinados por endocrinologistas e o diagnóstico de síndrome metabólica foi confirmado. RESULTADOS: O exame cardiológico revelou que o controle da pressão sangüínea não era adequado e tal anormalidade foi corrigida. A ecocardiografia confirmou os indícios de hipertrofia ventricular esquerda e disfunção diastólica. Estes são os

  14. Clinical Research Progress of Toxic Anterior Segment Syndrome%眼前节毒性反应综合征的临床研究进展

    Institute of Scientific and Technical Information of China (English)

    刘昞莉

    2011-01-01

    Toxic anterior segment syndrome ( TASS ) is a rare and sterile postoperative inflammatory reaction, which is different from infectious inflammation.It is belong to particular postoperative inflammatory reaction, with typical clinical features and serious secondary complications.Its causes have been identified to relate to poisonous substance accessing the anterior chamber, such as intraocular irrigating solutions, preservative, disinfectant used in disinfecting equipment, bacterial endotoxin,metal ion on the surface of instrument,viscoelastic materials of denaturation, impurity in steam sterilization, antibiotic, anesthetic and intraocular lens etc.In recent years,with the improvement of anterior segment surgery,TASS has emerged in large numbers.This article reviewed the toxic anterior segment syndrome, including of the clinical manifestation, pathology characteristic, etiopathogenisis, diagnosis, differential diagnosis, treatment and prevention.%眼前节毒性反应综合征(TASS)是一种少见的、无菌性的术后炎性反应,属于特殊类型的术后炎症,具有典型的临床特征并可引起严重的继发性反应.TASS发生与多种进入眼前房物质的毒性作用有关,如眼内灌注液、防腐剂、消毒设备使用的消毒剂、细菌内毒素、器械表面的金属离子残渣、变性的黏弹剂、高压蒸气杂质、抗生素、麻醉药物以及使用的人工晶体等.近年来,随着眼前节手术的发展,本病有逐渐增加的趋势.现TASS的从临床表现、病理特征、病因、诊断和鉴别诊断、治疗及预防措施等方面对其予以综述.

  15. Consideration of QRS complex in addition to ST-segment abnormalities in the estimation of the "risk region" during acute anterior or inferior myocardial infarction.

    Science.gov (United States)

    Vervaat, F E; Bouwmeester, S; van Hellemond, I E G; Wagner, G S; Gorgels, A P M

    2014-01-01

    The myocardial area at risk (MaR) is an important aspect in acute ST-elevation myocardial infarction (STEMI). It represents the myocardium at the onset of the STEMI that is ischemic and could become infarcted if no reperfusion occurs. The MaR, therefore, has clinical value because it gives an indication of the amount of myocardium that could potentially be salvaged by rapid reperfusion therapy. The most validated method for measuring the MaR is (99m)Tc-sestamibi SPECT, but this technique is not easily applied in the clinical setting. Another method that can be used for measuring the MaR is the standard ECG-based scoring system, Aldrich ST score, which is more easily applied. This ECG-based scoring system can be used to estimate the extent of acute ischemia for anterior or inferior left ventricular locations, by considering quantitative changes in the ST-segment. Deviations in the ST-segment baseline that occur following an acute coronary occlusion represent the ischemic changes in the transmurally ischemic myocardium. In most instances however, the ECG is not available at the very first moments of STEMI and as times passes the ischemic myocardium becomes necrotic with regression of the ST-segment deviation along with progressive changes of the QRS complex. Thus over the time course of the acute event, the Aldrich ST score would be expected to progressively underestimate the MaR, as was seen in studies with SPECT as gold standard; anterior STEMI (r=0.21, p=0.32) and inferior STEMI (r=0.17, p=0.36). Another standard ECG-based scoring system is the Selvester QRS score, which can be used to estimate the final infarct size by considering the quantitative changes in the QRS complex. Therefore, additional consideration of the Selvester QRS score in the acute phase could potentially provide the "component" of infarcted myocardium that is missing when the Aldrich ST score alone is used to determine the MaR in the acute phase, as was seen in studies with SPECT as gold

  16. A Closed Form Solution to Segment 3D Motion Using Straight-line Optical Flow

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing; SHI Fan-huai; MA Wen-juan; LIU Yun-cai

    2008-01-01

    A closed form solution to the problem of segmenting multiple 3D motion models was proposed fromstraight-line optical flow. It introduced the multibody line optical flow constraint (MLOFC), a polynomial equation relating motion models and line parameters. The motion models can be obtained analytically as the derivative of the MLOFC at the corresponding line measurement, without knowing the motion model associated with that line. Experiments on real and synthetic sequences were also presented.

  17. 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.

  18. An Intelligent Segmented Burst Assembly Mechanism in Optical Burst Switching Networks

    Institute of Scientific and Technical Information of China (English)

    XIE Yi-Yuan; ZHANG Jian-Guo

    2008-01-01

    We focus on the burst assembly mechanism and propose a new intelligent method in which the burst is assembled from several internet protocol (IP) packets in which the number of IP packets is changed according to the traffic load and the burst is segmented into several parts, called the ISOBS mechanism. The average burst assembly time of the ISOBS mechanism decreases as compared with the fixed-assembly-time and fixed-assembly-time-and-length mechanisms. The loss ratio decreases 50% as compared with the general optical burst switching (OBS) mechanism. The last segment can carry high quality of service (QOS) information. We can achieve that the loss ratio of the last segment is almost zero when the traffic load is less than 0.05. When the traffic load is 0.9, the loss ratio of the last segment is 0.0041. The ISOBS can support to transmit different QOS data.

  19. An Intelligent Segmented Burst Assembly Mechanism in Optical Burst Switching Networks

    International Nuclear Information System (INIS)

    We focus on the burst assembly mechanism and propose a new intelligent method in which the burst is assembled from several internet protocol (IP) packets in which the number of IP packets is changed according to the traffic load and the burst is segmented into several parts, called the ISOBS mechanism. The average burst assembly time of the ISOBS mechanism decreases as compared with the fixed-assembly-time and fixed-assembly-time-and-length mechanisms. The loss ratio decreases 50% as compared with the general optical burst switching (OBS) mechanism. The last segment can carry high quality of service (QOS) information. We can achieve that the loss ratio of the last segment is almost zero when the traffic load is less than 0.05. When the traffic load is 0.9, the loss ratio of the last segment is 0.0041. The ISOBS can support to transmit different QOS data. (fundamental areas of phenomenology (including applications))

  20. Establishing an experimental model of photodynamic induced anterior ischemic optic neuropathy

    Institute of Scientific and Technical Information of China (English)

    Runsheng Wang; Xiaodi Wang; Peilin Lü; Jianwei Bai; Jianzhou Wang; Xiaoqin Lei; Xiaoliang Zhou; Hongfen Sun; Aizhu Pan

    2006-01-01

    BACKGROUND: Scholars have supposed to establish animal models of optic neuropathy by pressing and partially amputating optic nerve, increasing intraocular pressure and injecting vasoconstrictor, etc., but the models are greatly different from anterior ischemia optic neuropathy. Therefore, a more ideal method is needed to establish animal model of anterior ischemic optic neuropathy (AION).OBJECTIVE: To establish AION models in rats, observe the functional changes of fundus, fundus fluorescein angiography (FFA), optical coherence tomography (OCT), flash visual evoked potential (F-VEP), and histopathologically confirm its reliability.DESIGN: A randomized control trial.SETTINGS: Department of Ophthalmology, Xi'an Fourth Hospital; Xi'an Institute of Ocular Fundus Diseases.MATERIALS: The experiments were carried out in the research room of Xi'an Institute of Ocular Fundus Diseases from February 2005 to May 2006. Thirty healthy male SD rats of 4-5 weeks old, weighing 140-160 g,were provided by the animal experimental center of the Fourth Military Medical University of Chinese PLA [SCXK (Military)2002-005], and those without eye disease examined by slit lamp and direct ophthalmoscope after mydriasis were enrolled. The conditions for feeding mice without special pathogen were strictly followed.The rats were randomly divided into blank control group (n =5), laser group (n =5), hematoporphyrin derivative (HPD) group and AION group (n =15), each group was numbered randomly. For each rat, the right eye was taken as the experimental eye, and the left one as the control one.METHODS: In the AION group, the rats were injected with HPD (10 mg/kg) via caudal vein, and then the optic discs were exposed to krypton red (647 nm, 80 mV) for 120 s, and the rats were in avoidance of light for 2 weeks postoperatively. Rats in the laser group were only exposed to krypton red (647 nm, 80 mV) for 120 s, and in avoidance of light for 2 weeks postoperatively; Those in the HPD group were only

  1. Lumen Segmentation in Intravascular Optical Coherence Tomography Using Backscattering Tracked and Initialized Random Walks.

    Science.gov (United States)

    Guha Roy, Abhijit; Conjeti, Sailesh; Carlier, Stéphane G; Dutta, Pranab K; Kastrati, Adnan; Laine, Andrew F; Navab, Nassir; Katouzian, Amin; Sheet, Debdoot

    2016-03-01

    Intravascular imaging using ultrasound or optical coherence tomography (OCT) is predominantly used to adjunct clinical information in interventional cardiology. OCT provides high-resolution images for detailed investigation of atherosclerosis-induced thickening of the lumen wall resulting in arterial blockage and triggering acute coronary events. However, the stochastic uncertainty of speckles limits effective visual investigation over large volume of pullback data, and clinicians are challenged by their inability to investigate subtle variations in the lumen topology associated with plaque vulnerability and onset of necrosis. This paper presents a lumen segmentation method using OCT imaging physics-based graph representation of signals and random walks image segmentation approaches. The edge weights in the graph are assigned incorporating OCT signal attenuation physics models. Optical backscattering maxima is tracked along each A-scan of OCT and is subsequently refined using global graylevel statistics and used for initializing seeds for the random walks image segmentation. Accuracy of lumen versus tunica segmentation has been measured on 15 in vitro and 6 in vivo pullbacks, each with 150-200 frames using 1) Cohen's kappa coefficient (0.9786 ±0.0061) measured with respect to cardiologist's annotation and 2) divergence of histogram of the segments computed with Kullback-Leibler (5.17 ±2.39) and Bhattacharya measures (0.56 ±0.28). High segmentation accuracy and consistency substantiates the characteristics of this method to reliably segment lumen across pullbacks in the presence of vulnerability cues and necrotic pool and has a deterministic finite time-complexity. This paper in general also illustrates the development of methods and framework for tissue classification and segmentation incorporating cues of tissue-energy interaction physics in imaging. PMID:25700476

  2. Adjacent segment disease after anterior cervical decompression and fusion: analysis of risk factors on X-ray and magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Zhao Yanbin; Sun Yu; Zhou Feifei; Wang Shaobo; Zhang Fengshan; Pan Shengfa

    2014-01-01

    Background Adjacent segment disease (ASD) is common after cervical fusion.The aim of this study was to evaluate the risk factors for ASD on X-ray and magnetic resonance imaging (MRI).Methods Patients included in this study had received revision surgeries after developing symptomatic ASD following anterior decompression and fusion.A control group that had not developed ASD was matched 1:1 by follow-up time and fusion segments.Plate-to-disc distances (PDDs),developmental cervical canal stenosis on X-ray,cervical disc degeneration grading,and cervical disc bulge impingements on preoperative MRI were measured and compared between the ASD group and the control group.Results Thirty-four patients with complete radiographic data were included in the ASD group.The causative segments of ASD included nine cases of C3-4,18 cases of C4-5,three cases of C5-6,and four cases of C6-7.The ASD occurred at the upper adjacent segments in 26 patients and at the lower adjacent segments in eight patients.PDD distributions were similar between the ASD group and the control group.Developmental cervical canal stenosis was a risk factor for ASD,with an odd ratio value of 2.88.Preoperative cervical disc degenerations on MRI were similar between the ASD group and the control group.In the upper-level ASD group,the disc bulge impingement was (19.7±9.7)%,which was significantly higher than that of the control group of (11.8±4.8)%.Conclusions ASD was more likely to develop above the index level of fusion.Developmental cervical canal stenosis and greater disc bulge impingement may be risk factors for the development of ASD.

  3. The role of a high pull headgear in counteracting side effects from intrusion of the maxillary anterior segment.

    Science.gov (United States)

    van Steenbergen, E; Burstone, C J; Prahl-Andersen, B; Aartman, I H A

    2004-08-01

    Intrusion of incisors is often the preferred treatment of a deep overbite. This study focuses on deep overbite correction by intrusion of maxillary incisors. The purpose of this study is to determine whether high-pull headgear wear can prevent steepening of the buccal segment, extrusion of the buccal segment, maintain arch width, and increase the rate of incisor intrusion. The number of patients needed for this study was calculated to be 20. Patients were between nine and 14 years of age and assigned to one of two groups. In each group, intrusion of maxillary incisors was performed. Patients in one group wore a high-pull headgear at night, and patients in the other group did not. For each patient, a lateral head film, impressions with a wax bite in centric occlusion, and intraoral photographs were taken at the beginning and end of intrusion. This study demonstrated that high-pull headgear had no effect on steepening and extrusion of the buccal segments or on the rate of intrusion but did have an effect on narrowing of the buccal segments. By performing intrusion as described in this study, no statistically significant side effects were observed in the buccal segments, whereas a statistically significant amount of incisor intrusion of 2.24 mm in the no-headgear group and 2.37 mm in the headgear group was observed.

  4. Diode Laser 810 Nm as a Potential Treatment to Improve Visual Function in Nonarteritic Anterior Ischemic Optic Neuropathy (NAION

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    Mohammad Hossein Heidari

    2011-01-01

    Full Text Available Nonarteritic anterior ischemic optic neuropathy (NAION is one of the most widespread visually disabling diseases in the middle-aged and elderly population. The optic nerve damage appears to result from a perfusion insufficiency in the short posterior ciliary arteries leading to infarction of the retrolaminar portion of the optic disc. Induced Heat shock protein (Hsp is known to have neuroprotective effects against ischemic injury of the central nervous system in mammals. Transpupillary thermotherapy (TTT application to the optic nerve head induces Hsp70 expression. We hypothesize that Transpupillary thermotherapy (TTT could be a novel method for improving and preserving the function of the optic nerve fibers in the eye with NAION. An 810-nm diode laser beam is focused to the center of the optic nerve head to induce Hsp. Controlled prospective and randomized clinical trial is necessary to confirm conclusively the effectiveness of this method.

  5. Neural organization and visual processing in the anterior optic tubercle of the honeybee brain.

    Science.gov (United States)

    Mota, Theo; Yamagata, Nobuhiro; Giurfa, Martin; Gronenberg, Wulfila; Sandoz, Jean-Christophe

    2011-08-10

    The honeybee Apis mellifera represents a valuable model for studying the neural segregation and integration of visual information. Vision in honeybees has been extensively studied at the behavioral level and, to a lesser degree, at the physiological level using intracellular electrophysiological recordings of single neurons. However, our knowledge of visual processing in honeybees is still limited by the lack of functional studies of visual processing at the circuit level. Here we contribute to filling this gap by providing a neuroanatomical and neurophysiological characterization at the circuit level of a practically unstudied visual area of the bee brain, the anterior optic tubercle (AOTu). First, we analyzed the internal organization and neuronal connections of the AOTu. Second, we established a novel protocol for performing optophysiological recordings of visual circuit activity in the honeybee brain and studied the responses of AOTu interneurons during stimulation of distinct eye regions. Our neuroanatomical data show an intricate compartmentalization and connectivity of the AOTu, revealing a dorsoventral segregation of the visual input to the AOTu. Light stimuli presented in different parts of the visual field (dorsal, lateral, or ventral) induce distinct patterns of activation in AOTu output interneurons, retaining to some extent the dorsoventral input segregation revealed by our neuroanatomical data. In particular, activity patterns evoked by dorsal and ventral eye stimulation are clearly segregated into distinct AOTu subunits. Our results therefore suggest an involvement of the AOTu in the processing of dorsoventrally segregated visual information in the honeybee brain. PMID:21832175

  6. 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)

  7. Reattachment of a Fractured Anterior Tooth Segment With Pulp Exposure via Er:YAG and Nd:YAG Lasers

    Directory of Open Access Journals (Sweden)

    Fornaini

    2015-11-01

    Full Text Available Introduction The reattachment of a dental fragment may be performed for treatment of traumatized anterior teeth, both in cases of simple coronal fracture (enamel and superficial dentin and in those with complicated coronal fracture (deep dentin with pulp exposure. A major part of this procedure is the adhesion technique, which was described for the first time by Buonocore in 1955. This clinical case demonstrates the use of Er:YAG and Nd:YAG lasers in fragment reattachment of a traumatically fractured anterior tooth with pulp exposure, describes their advantages and highlights the steps involved in their use. Case Presentation A 14-year-old patient who came to our clinic with a traumatic crown fracture of the permanent, right central incisor is described. The patient had preserved the fragment that had broken off into his mouth and it was rebonded to the tooth using lasers (LightWalker device; Fotona, Ljubljana, Slovenia with the following parameters: Er:YAG, SSP mode; 200 mJ; 10 Hz; quasi-contact tipless handpiece; Nd:YAG, SP mode; 4 W; 40 Hz; 300 μm contact fiber. The whole procedure was performed without the need for anesthesia. Conclusions The patient reported that he did not feel pain or discomfort throughout the intervention. Follow-up visits performed after one, three, six, twelve, and sixteen months demonstrated vitality of the tooth the absence of complications, as well as good esthetic results. Laser technology may be used in the treatment of traumatic anterior teeth injury with advantages in terms of quality of the restoration, esthetic results, and patient comfort.

  8. An Automatic Optic Disk Detection and Segmentation System using Multi-level Thresholding

    OpenAIRE

    KARASULU, B.

    2014-01-01

    Optic disk (OD) boundary localization is a substantial problem in ophthalmic image processing research area. In order to segment the region of OD, we developed an automatic system which involves a multi-level thresholding. The OD segmentation results of the system in terms of average precision, recall and accuracy for DRIVE database are 98.88%, 99.91%, 98.83%, for STARE database are 98.62%, 97.38%, 96.11%, and for DIARETDB1 database are 99.29%, 99.90%, 99.20%, respectively. Th...

  9. Endovascular repair of ruptured aneurysm arising from fenestration of the horizontal segment of the anterior cerebral artery: case report.

    Science.gov (United States)

    Yoshida, Masahiro; Ezura, Masayuki; Sasaki, Kazuto; Chonan, Masashi; Mino, Masaki

    2012-01-01

    A 50-year-old man presented with an aneurysm arising from a fenestration of horizontal portion (A(1)) of the anterior cerebral artery manifesting as subarachnoid hemorrhage. Coil embolization was conducted and the aneurysm was occluded easily. Most reported cases of these types of aneurysms underwent direct surgery. Aneurysm arising from the A(1) fenestration is rare, but the present case shows that coil embolization can be an effective treatment modality. Three-dimensional rotational angiography and aneurysmography were helpful to characterize this complicated vascular structure.

  10. Impending anterior ischemic optic neuropathy with elements of retinal vein occlusion in a patient on interferon for polycythemia vera

    OpenAIRE

    Rue KS; Hirsch LK; Sadun AA

    2012-01-01

    Kelly S Rue, Louis K Hirsch, Alfredo A SadunDepartment of Neuro-Ophthalmology, Doheny Eye Institute and Keck School of Medicine, University of Southern California, Los Angeles, CA, USAAbstract: We describe the course and likely pathophysiology of impending anterior ischemic optic neuropathy (AION) and retinal vein occlusion in a 56-year-old man with polycythemia vera managed with interferon alpha for 2 years. Our patient presented with decreased vision, scintillating scotomata, and floaters. ...

  11. End-to-end assessment of a large aperture segmented ultraviolet optical infrared (UVOIR) telescope architecture

    Science.gov (United States)

    Feinberg, Lee; Rioux, Norman; Bolcar, Matthew; Liu, Alice; Guyon, Olivier; Stark, Chris; Arenberg, Jon

    2016-07-01

    Key challenges of a future large aperture, segmented Ultraviolet Optical Infrared (UVOIR) Telescope capable of performing a spectroscopic survey of hundreds of Exoplanets will be sufficient stability to achieve 10^-10 contrast measurements and sufficient throughput and sensitivity for high yield exo-earth spectroscopic detection. Our team has collectively assessed an optimized end to end architecture including a high throughput coronagraph capable of working with a segmented telescope, a cost-effective and heritage based stable segmented telescope, a control architecture that minimizes the amount of new technologies, and an exo-earth yield assessment to evaluate potential performance. These efforts are combined through integrated modeling, coronagraph evaluations, and exo-earth yield calculations to assess the potential performance of the selected architecture. In addition, we discusses the scalability of this architecture to larger apertures and the technological tall poles to enabling these missions.

  12. Optic atrophy, necrotizing anterior scleritis and keratitis presenting in association with Streptococcal Toxic Shock Syndrome: a case report

    Directory of Open Access Journals (Sweden)

    Papageorgiou Konstantinos I

    2008-02-01

    Full Text Available Abstract Introduction We report a case of optic atrophy, necrotizing anterior scleritis and keratitis presenting in a patient with Streptococcal Toxic Shock Syndrome. Case presentation A 43-year-old woman developed streptococcal toxic shock syndrome secondary to septic arthritis of her right ankle. Streptococcus pyogenes (b-haemolyticus Group A was isolated from blood cultures and joint aspirate. She was referred for ophthalmology review as her right eye became injected and the pupil had become unresponsive to light whilst she was in the Intensive Therapy Unit (ITU. The iris appeared atrophic and was mid-dilated with no direct or consensual response to light. Three zones of sub-epithelial opacification where noted in the cornea. There where extensive posterior synechiae. Indirect ophthalmoscopy showed a pale right disc. The vision was reduced to hand movements (HM. A diagnosis of optic atrophy was made secondary to post-streptococcal uveitis. She subsequently developed a necrotizing anterior scleritis. Conclusion This case illustrates a previously unreported association of optic atrophy, necrotizing anterior scleritis and keratitis in a patient with post-streptococcal uveitis. This patient had developed Streptococcal Toxic Shock Syndrome secondary to septic arthritis. We recommend increased awareness of the potential risks of these patients developing severe ocular involvement.

  13. Understanding the Phase Contrast Optics to Restore Artifact-free Microscopy Images for Segmentation

    OpenAIRE

    Yin, Zhaozheng; Kanade, Takeo; Chen, Mei

    2012-01-01

    Phase contrast, a noninvasive microscopy imaging technique, is widely used to capture time-lapse images to monitor the behavior of transparent cells without staining or altering them. Due to the optical principle, phase contrast microscopy images contain artifacts such as the halo and shade-off that hinder image segmentation, a critical step in automated microscopy image analysis. Rather than treating phase contrast microscopy images as general natural images and applying generic image proces...

  14. Signaling-based path-segment protection in mesh optical networks

    Institute of Scientific and Technical Information of China (English)

    Yueming Lu; Chao Zou; Qiushi Wang; Yuefeng Ji

    2011-01-01

    Path protections have become increasingly important for current mesh optical networks because fast restorations in generalized multiprotocol label switching (GMPLS) networks are uncertain. However, setting up additional disjoint paths to protect connections leads to more path setup blocking and signaling collisions. We analyze signaling collisions, path blocking and blocking probability, as well as calculate node-to-node blocking probabilities. A signaling-based path-segment protection (PSP) is proposed, which integrates segment protections and path protections as well as enhances the performance of path protections and ring protections. The setup of PSP connections causes less blocking probability than the setup of path protection connections in the simulations.%Path protections have become increasingly important for current mesh optical networks because fast restorations in generalized multiprotocol label switching (GMPLS) networks are uncertain.However,setting up additional disjoint paths to protect connections leads to more path setup blocking and signaling collisions.We analyze signaling collisions,path blocking and blocking probability,as well as calculate node-to-node blocking probabilities.A signaling-based path-segment protection (PSP) is proposed,which integrates segment protections and path protections as well as enhances the performance of path protections and ring protections.The setup of PSP connections causes less blocking probability than the setup of path protection connections in the simulations.Recently,with the emergence of new protection and restoration methods,mesh topologies have gradually replaced ring topologies,especially in optical transport networks (OTNs)[1],automatically switched optical networks (ASONs)[2],generalized multiprotocol label switching (GMPLS) protocol networks[3,4],and packet transport networks (PTNs)[5].However,fast restoration methods currently face some challenges in China.

  15. Adjacent segment degeneration after single-level anterior cervical decompression and fusion: disc space distraction and its impact on clinical outcomes.

    Science.gov (United States)

    Li, Jia; Li, Yongqian; Kong, Fanlong; Zhang, Di; Zhang, Yingze; Shen, Yong

    2015-03-01

    The purpose of this study was to find whether excessive distraction of the disc space for cage insertion was a risk factor for adjacent segment degeneration (ASD) after anterior cervical decompression and fusion (ACDF). One hundred and sixteen consecutive patients who underwent ACDF for single-level cervical disc herniation between June 2006 and November 2008 were retrospectively reviewed. Preoperative, postoperative and final follow-up disc height (DH), sagittal segmental alignment (SSA), and sagittal alignment of the cervical spine (SACS) were measured and compared between the ASD group and non-ASD group. In 116 patients, ASD was radiographically proven in 28 (24.1%) patients. The clinical outcomes were significantly improved compared to the preoperative scores in both groups. However, the postoperative and final follow-up DH of the ASD group were significantly higher than in the non-ASD group (p<0.05). In addition, the postoperative DH was significantly correlated with the postoperative or final follow-up SSA (p<0.05). However, postoperative DH was not found to significantly correlate with postoperative or final follow-up SACS (p=0.072 and p=0.096, respectively). Multivariate analysis showed that postoperative DH was the most significant risk factor for ASD. The clinical outcomes of ACDF for single-level degenerative cervical disc disease were satisfactory. Postoperative DH (the distracted distance) had the greatest impact on the incidence of ASD. Excessive disc space distraction is a considerable risk factor for the development of radiographic ASD.

  16. A fully automatic framework for cell segmentation on non-confocal adaptive optics images

    Science.gov (United States)

    Liu, Jianfei; Dubra, Alfredo; Tam, Johnny

    2016-03-01

    By the time most retinal diseases are diagnosed, macroscopic irreversible cellular loss has already occurred. Earlier detection of subtle structural changes at the single photoreceptor level is now possible, using the adaptive optics scanning light ophthalmoscope (AOSLO). This work aims to develop a fully automatic segmentation framework to extract cell boundaries from non-confocal split-detection AOSLO images of the cone photoreceptor mosaic in the living human eye. Significant challenges include anisotropy, heterogeneous cell regions arising from shading effects, and low contrast between cells and background. To overcome these challenges, we propose the use of: 1) multi-scale Hessian response to detect heterogeneous cell regions, 2) convex hulls to create boundary templates, and 3) circularlyconstrained geodesic active contours to refine cell boundaries. We acquired images from three healthy subjects at eccentric retinal regions and manually contoured cells to generate ground-truth for evaluating segmentation accuracy. Dice coefficient, relative absolute area difference, and average contour distance were 82±2%, 11±6%, and 2.0±0.2 pixels (Mean±SD), respectively. We find that strong shading effects from vessels are a main factor that causes cell oversegmentation and false segmentation of non-cell regions. Our segmentation algorithm can automatically and accurately segment photoreceptor cells on non-confocal AOSLO images, which is the first step in longitudinal tracking of cellular changes in the individual eye over the time course of disease progression.

  17. Accurate and reliable segmentation of the optic disc in digital fundus images.

    Science.gov (United States)

    Giachetti, Andrea; Ballerini, Lucia; Trucco, Emanuele

    2014-07-01

    We describe a complete pipeline for the detection and accurate automatic segmentation of the optic disc in digital fundus images. This procedure provides separation of vascular information and accurate inpainting of vessel-removed images, symmetry-based optic disc localization, and fitting of incrementally complex contour models at increasing resolutions using information related to inpainted images and vessel masks. Validation experiments, performed on a large dataset of images of healthy and pathological eyes, annotated by experts and partially graded with a quality label, demonstrate the good performances of the proposed approach. The method is able to detect the optic disc and trace its contours better than the other systems presented in the literature and tested on the same data. The average error in the obtained contour masks is reasonably close to the interoperator errors and suitable for practical applications. The optic disc segmentation pipeline is currently integrated in a complete software suite for the semiautomatic quantification of retinal vessel properties from fundus camera images (VAMPIRE). PMID:26158034

  18. Engrafted human induced pluripotent stem cell-derived anterior specified neural progenitors protect the rat crushed optic nerve.

    Directory of Open Access Journals (Sweden)

    Leila Satarian

    Full Text Available BACKGROUND: Degeneration of retinal ganglion cells (RGCs is a common occurrence in several eye diseases. This study examined the functional improvement and protection of host RGCs in addition to the survival, integration and neuronal differentiation capabilities of anterior specified neural progenitors (NPs following intravitreal transplantation. METHODOLOGY/PRINCIPAL FINDINGS: NPs were produced under defined conditions from human induced pluripotent stem cells (hiPSCs and transplanted into rats whose optic nerves have been crushed (ONC. hiPSCs were induced to differentiate into anterior specified NPs by the use of Noggin and retinoic acid. The hiPSC-NPs were labeled by green fluorescent protein or a fluorescent tracer 1,1' -dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI and injected two days after induction of ONC in hooded rats. Functional analysis according to visual evoked potential recordings showed significant amplitude recovery in animals transplanted with hiPSC-NPs. Retrograde labeling by an intra-collicular DiI injection showed significantly higher numbers of RGCs and spared axons in ONC rats treated with hiPSC-NPs or their conditioned medium (CM. The analysis of CM of hiPSC-NPs showed the secretion of ciliary neurotrophic factor, basic fibroblast growth factor, and insulin-like growth factor. Optic nerve of cell transplanted groups also had increased GAP43 immunoreactivity and myelin staining by FluoroMyelin™ which imply for protection of axons and myelin. At 60 days post-transplantation hiPSC-NPs were integrated into the ganglion cell layer of the retina and expressed neuronal markers. CONCLUSIONS/SIGNIFICANCE: The transplantation of anterior specified NPs may improve optic nerve injury through neuroprotection and differentiation into neuronal lineages. These NPs possibly provide a promising new therapeutic approach for traumatic optic nerve injuries and loss of RGCs caused by other diseases.

  19. Volume Averaging of Spectral-Domain Optical Coherence Tomography Impacts Retinal Segmentation in Children

    Science.gov (United States)

    Trimboli-Heidler, Carmelina; Vogt, Kelly; Avery, Robert A.

    2016-01-01

    Purpose To determine the influence of volume averaging on retinal layer thickness measures acquired with spectral-domain optical coherence tomography (SD-OCT) in children. Methods Macular SD-OCT images were acquired using three different volume settings (i.e., 1, 3, and 9 volumes) in children enrolled in a prospective OCT study. Total retinal thickness and five inner layers were measured around an Early Treatment Diabetic Retinopathy Scale (ETDRS) grid using beta version automated segmentation software for the Spectralis. The magnitude of manual segmentation required to correct the automated segmentation was classified as either minor (12 and 26 and 48 lines adjusted or could not adjust due to poor image quality). The frequency of each edit classification was assessed for each volume setting. Thickness, paired difference, and 95% limits of agreement of each anatomic quadrant were compared across volume density. Results Seventy-five subjects (median age 11.8 years, range 4.3–18.5 years) contributed 75 eyes. Less than 5% of the 9- and 3-volume scans required more than minor manual segmentation corrections, compared with 71% of 1-volume scans. The inner (3 mm) region demonstrated similar measures across all layers, regardless of volume number. The 1-volume scans demonstrated greater variability of the retinal nerve fiber layer (RNLF) thickness, compared with the other volumes in the outer (6 mm) region. Conclusions In children, volume averaging of SD-OCT acquisitions reduce retinal layer segmentation errors. Translational Relevance This study highlights the importance of volume averaging when acquiring macula volumes intended for multilayer segmentation.

  20. Individual tree segmentation over large areas using airborne LiDAR point cloud and very high resolution optical imagery

    OpenAIRE

    Qin, Y.; Ferraz, A.; C. Mallet; Iovan, Corina

    2015-01-01

    Timely and accurate measuremen ts of forest parameters are critical for ecosystem studies, sustainable forest resources management, monitoring and planning. This paper presents a processing chain for individual tree segmentation over large areas with airborne LiDAR 3D point cloud and very high resolution (VHR) optical imagery. The proposed processing chain consists of fo rest stand level delineation with optical imagery, individual tree segmentation with Canopy ...

  1. Accurate integration of segmented x-ray optics using interfacing ribs

    Science.gov (United States)

    Civitani, Marta Maria; Basso, Stefano; Citterio, Oberto; Conconi, Paolo; Ghigo, Mauro; Pareschi, Giovanni; Proserpio, Laura; Salmaso, Bianca; Sironi, Giorgia; Spiga, Daniele; Tagliaferri, Gianpiero; Zambra, Alberto; Martelli, Francesco; Parodi, Giancarlo; Fumi, Pierluigi; Gallieni, Daniele; Tintori, Matteo; Bavdaz, Marcos; Wille, Eric

    2013-09-01

    Future lightweight and long-focal-length x-ray telescopes must guarantee a good angular resolution (e.g., 5 arc sec HEW) and reach an unprecedented large effective area. This goal can be reached with the slumping of borosilicate glass sheets that allow the fabrication of lightweight and low-cost x-ray optical units (XOU). These XOUs, based on mirror segments, have to be assembled together to form complete multishell Wolter-I optics. The technology for the fabrication and the integration of these XOUs is under development in Europe, funded by European Space Agency, and led by the Brera Observatory (INAF-OAB). While the achievement of the required surface accuracy on the glass segments by means of a hot slumping technique is a challenging aspect, adequate attention must be given to the correct integration and coalignment of the mirror segments into the XOUs. To this aim, an innovative assembly concept has been investigated, based on glass reinforcing ribs. The ribs connect pairs of consecutive foils, stacked into a XOU, with both structural and functional roles, providing robust monolithic stacks of mirror plates. Moreover, this integration concept allows the correction of residual low-frequency errors still present on the mirror foil profile after slumping. We present the integration concept, the related error budget, and the results achieved so far with a semi-robotic integration machine especially designed and realized to assemble slumped glass foils into XOUs.

  2. Automatic Speech Segmentation Based On Audio and Optical Flow Visual Classification

    Directory of Open Access Journals (Sweden)

    Behnam Torabi

    2014-10-01

    Full Text Available Automatic speech segmentation as an important part of speech recognition system (ASR is highly noise dependent. Noise is made by changes in the communication channel, background, level of speaking etc. In recent years, many researchers have proposed noise cancelation techniques and have added visual features from speaker’s face to reduce the effect of noise on ASR systems. Removing noise from audio signals depends on the type of the noise; so it cannot be used as a general solution. Adding visual features improve this lack of efficiency, but advanced methods of this type need manual extraction of visual features. In this paper we propose a completely automatic system which uses optical flow vectors from speaker’s image sequence to obtain visual features. Then, Hidden Markov Models are trained to segment audio signals from image sequences and audio features based on extracted optical flow. The developed segmentation system based on such method acts totally automatic and become more robust to noise.

  3. Fibre segment interferometry using code-division multiplexed optical signal processing for strain sensing applications

    International Nuclear Information System (INIS)

    A novel optical signal processing scheme for multiplexing fibre segment interferometers is proposed. The continuous-wave, homodyne technique combines code-division multiplexing with single-sideband modulation. It uses only one electro-optic phase modulator to achieve both range separation and quadrature interferometric phase measurement. This scheme is applied to fibre segment interferometry, where a number of long-gauge length interferometric fibre sensors are formed by subtracting pairs of signals from equidistantly placed, weak back reflectors. In this work we give a detailed account of the signal processing involved and, in particular, explore aspects such as electronic bandwidth requirements, noise, crosstalk and linearity, which are important design considerations. A signal bandwidth of ±20 kHz permits the resolution of phase change rates of 2.5 × 104 rad s−1 for each of the four 16.5 m long segments in our setup. We show that dynamic strain resolutions below 0.2 nanostrain Hz−0.5 at 2 m sensor gauge length are achievable, even with an inexpensive diode laser. When used in applications that require only relative strain change measurements, this scheme compares well to more established techniques and can provide high-fidelity yet cost-effective measurements. (paper)

  4. Relation of Left Ventricular Mass and Infarct Size in Anterior Wall ST-Segment Elevation Acute Myocardial Infarction (from the EMBRACE STEMI Clinical Trial).

    Science.gov (United States)

    Daaboul, Yazan; Korjian, Serge; Weaver, W Douglas; Kloner, Robert A; Giugliano, Robert P; Carr, Jim; Neal, Brandon J; Chi, Gerald; Cochet, Madeleine; Goodell, Laura; Michalak, Nathan; Rusowicz-Orazem, Luke; Alkathery, Turky; Allaham, Haytham; Routray, Sujit; Szlosek, Donald; Jain, Purva; Gibson, C Michael

    2016-09-01

    Biomarker measures of infarct size and myocardial salvage index (MSI) are important surrogate measures of clinical outcomes after a myocardial infarction. However, there is variability in infarct size unaccounted for by conventional adjustment factors. This post hoc analysis of Evaluation of Myocardial Effects of Bendavia for Reducing Reperfusion Injury in Patients With Acute Coronary Events (EMBRACE) ST-Segment Elevation Myocardial Infarction (STEMI) trial evaluates the association between left ventricular (LV) mass and infarct size as assessed by areas under the curve for creatine kinase-MB (CK-MB) and troponin I release over the first 72 hours (CK-MB area under the curve [AUC] and troponin I [TnI] AUC) and the MSI. Patients with first anterior STEMI, occluded left anterior descending artery, and available LV mass measurement in EMBRACE STEMI trial were included (n = 100) (ClinicalTrials.govNCT01572909). MSI, end-diastolic LV mass on day 4 cardiac magnetic resonance, and CK-MB and troponin I concentrations were evaluated by a core laboratory. After saturated multivariate analysis, dominance analysis was performed to estimate the contribution of each independent variable to the predicted variance of each outcome. In multivariate models that included age, gender, body surface area, lesion location, smoking, and ischemia time, LV mass remained independently associated with biomarker measures of infarct size (CK-MB AUC p = 0.02, TnI AUC p = 0.03) and MSI (p = 0.003). Dominance analysis demonstrated that LV mass accounted for 58%, 47%, and 60% of the predicted variances for CK-MB AUC, TnI AUC, and MSI, respectively. In conclusion, LV mass accounts for approximately half of the predicted variance in biomarker measures of infarct size. It should be considered as an adjustment variable in studies evaluating infarct size. PMID:27392509

  5. An Automatic Optic Disk Detection and Segmentation System using Multi-level Thresholding

    Directory of Open Access Journals (Sweden)

    KARASULU, B.

    2014-05-01

    Full Text Available Optic disk (OD boundary localization is a substantial problem in ophthalmic image processing research area. In order to segment the region of OD, we developed an automatic system which involves a multi-level thresholding. The OD segmentation results of the system in terms of average precision, recall and accuracy for DRIVE database are 98.88%, 99.91%, 98.83%, for STARE database are 98.62%, 97.38%, 96.11%, and for DIARETDB1 database are 99.29%, 99.90%, 99.20%, respectively. The experimental results show that our system works properly on retinal image databases with diseased retinas, diabetic signs, and a large degree of quality variability.

  6. Extremely Lightweight Segmented Membrane Optical Shell Fabrication Technology for Future IR to Optical Telescope Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose that the Membrane Optical Shell Technology (MOST) substrate fabrication approach be extended with a specific focus on advanced off-axis very light...

  7. Understanding the phase contrast optics to restore artifact-free microscopy images for segmentation.

    Science.gov (United States)

    Yin, Zhaozheng; Kanade, Takeo; Chen, Mei

    2012-07-01

    Phase contrast, a noninvasive microscopy imaging technique, is widely used to capture time-lapse images to monitor the behavior of transparent cells without staining or altering them. Due to the optical principle, phase contrast microscopy images contain artifacts such as the halo and shade-off that hinder image segmentation, a critical step in automated microscopy image analysis. Rather than treating phase contrast microscopy images as general natural images and applying generic image processing techniques on them, we propose to study the optical properties of the phase contrast microscope to model its image formation process. The phase contrast imaging system can be approximated by a linear imaging model. Based on this model and input image properties, we formulate a regularized quadratic cost function to restore artifact-free phase contrast images that directly correspond to the specimen's optical path length. With artifacts removed, high quality segmentation can be achieved by simply thresholding the restored images. The imaging model and restoration method are quantitatively evaluated on microscopy image sequences with thousands of cells captured over several days. We also demonstrate that accurate restoration lays the foundation for high performance in cell detection and tracking. PMID:22386070

  8. An unusual variant of the common trunk of the fronto-orbital and frontopolar arteries associated with a ruptured aneurysm of the A1 segment of the anterior cerebral artery

    Directory of Open Access Journals (Sweden)

    Kenta Aso

    2015-01-01

    Full Text Available Background: The common trunk of the fronto-orbital artery (FOA and frontopolar artery (FPA arising from the A1 segment of the anterior cerebral artery (ACA associated with a ruptured aneurysm (AN, is rare. Case Description: The patient was a 52-year-old man who suffered from subarachnoid hemorrhage. Three-dimensional computed tomography angiography revealed an elongated and tortuous left A1 segment of the ACA and a saccular AN arising from the left A1 segment of the ACA at the origin of the cortical branch, defining its location just on the midline and behind the anterior communicating artery. This vessel had two branches. One branch ran along the inferior surface of the ipsilateral frontal lobe, and the other branch ran anteriorly and medially along the surface of the left hemisphere toward the frontal pole. The anomalous artery was interpreted as a common trunk of the FOA and FPA. Bifrontal craniotomy was performed. The anomalous artery arose from the A1 segment of the ACA at the origin of the AN, and the recurrent artery of Heubner branched off the anomalous artery. The AN was successfully obliterated, clipping with a bayonet-shaped Yasargil titanium clip. Complete AN occlusion and patency of both the A1 and the common trunk of the FOA and FPA, were confirmed intraoperatively by indocyanine green angiography. Conclusions: Recognizing this variant preoperatively, could be helpful in preventing the complications of surgery.

  9. New variational image decomposition model for simultaneously denoising and segmenting optical coherence tomography images

    Science.gov (United States)

    Duan, Jinming; Tench, Christopher; Gottlob, Irene; Proudlock, Frank; Bai, Li

    2015-11-01

    Optical coherence tomography (OCT) imaging plays an important role in clinical diagnosis and monitoring of diseases of the human retina. Automated analysis of optical coherence tomography images is a challenging task as the images are inherently noisy. In this paper, a novel variational image decomposition model is proposed to decompose an OCT image into three components: the first component is the original image but with the noise completely removed; the second contains the set of edges representing the retinal layer boundaries present in the image; and the third is an image of noise, or in image decomposition terms, the texture, or oscillatory patterns of the original image. In addition, a fast Fourier transform based split Bregman algorithm is developed to improve computational efficiency of solving the proposed model. Extensive experiments are conducted on both synthesised and real OCT images to demonstrate that the proposed model outperforms the state-of-the-art speckle noise reduction methods and leads to accurate retinal layer segmentation.

  10. Segmentation of optical coherence tomography images for differentiation of the cavernous nerves from the prostate gland

    Science.gov (United States)

    Chitchian, Shahab; Weldon, Thomas P.; Fried, Nathaniel M.

    2009-07-01

    The cavernous nerves course along the surface of the prostate and are responsible for erectile function. Improvements in identification, imaging, and visualization of the cavernous nerves during prostate cancer surgery may improve nerve preservation and postoperative sexual potency. Two-dimensional (2-D) optical coherence tomography (OCT) images of the rat prostate were segmented to differentiate the cavernous nerves from the prostate gland. To detect these nerves, three image features were employed: Gabor filter, Daubechies wavelet, and Laws filter. The Gabor feature was applied with different standard deviations in the x and y directions. In the Daubechies wavelet feature, an 8-tap Daubechies orthonormal wavelet was implemented, and the low-pass sub-band was chosen as the filtered image. Last, Laws feature extraction was applied to the images. The features were segmented using a nearest-neighbor classifier. N-ary morphological postprocessing was used to remove small voids. The cavernous nerves were differentiated from the prostate gland with a segmentation error rate of only 0.058+/-0.019. This algorithm may be useful for implementation in clinical endoscopic OCT systems currently being studied for potential intraoperative diagnostic use in laparoscopic and robotic nerve-sparing prostate cancer surgery.

  11. Spectral Clustering for Unsupervised Segmentation of Lower Extremity Wound Beds Using Optical Images.

    Science.gov (United States)

    Dhane, Dhiraj Manohar; Krishna, Vishal; Achar, Arun; Bar, Chittaranjan; Sanyal, Kunal; Chakraborty, Chandan

    2016-09-01

    Chronic lower extremity wound is a complicated disease condition of localized injury to skin and its tissues which have plagued many elders worldwide. The ulcer assessment and management is expensive and is burden on health establishment. Currently accurate wound evaluation remains a tedious task as it rely on visual inspection. This paper propose a new method for wound-area detection, using images digitally captured by a hand-held, optical camera. The strategy proposed involves spectral approach for clustering, based on the affinity matrix. The spectral clustering (SC) involves construction of similarity matrix of Laplacian based on Ng-Jorden-Weiss algorithm. Starting with a quadratic method, wound photographs were pre-processed for color homogenization. The first-order statistics filter was then applied to extract spurious regions. The filter was selected based on the performance, evaluated on four quality metrics. Then, the spectral method was used on the filtered images for effective segmentation. The segmented regions were post-processed using morphological operators. The performance of spectral segmentation was confirmed by ground-truth pictures labeled by dermatologists. The SC results were additionally compared with the results of k-means and Fuzzy C-Means (FCM) clustering algorithms. The SC approach on a set of 105 images, effectively delineated targeted wound beds yielding a segmentation accuracy of 86.73 %, positive predictive values of 91.80 %, and a sensitivity of 89.54 %. This approach shows the robustness of tool for ulcer perimeter measurement and healing progression. The article elucidates its potential to be incorporated in patient facing medical systems targeting a rapid clinical assistance. PMID:27520612

  12. 视神经颅内段受血管压迫的MRI诊断%The MRI Performance of the Optic Nerve Intracranial Segment Vascular Compression

    Institute of Scientific and Technical Information of China (English)

    陈丹; 瞿中威; 张亚林; 姚景江; 罗杰; 周理超

    2015-01-01

    目的:探讨视神经血管性卡压的MRI表现。方法回顾性分析18例视神经颅内段受邻近动脉卡压的MRI表现特点和临床资料。结果视神经受邻近动脉卡压情况包括:颈内动脉和大脑前动脉卡压同侧视神经交叉前段占多数,共15例(15/18),前交通动脉与大脑前动脉卡压、颈内动脉与眼动脉卡压及Heubner回返动脉各1例。MRI表现为:邻近血管与视神经接触,两者之间脑脊液间隙消失;视神经可见深浅不一压迹;极少病例出现视神经信号异常。结论 MRI对视神经血管性卡压的观察具有其他检查不具备的独特优势。只要我们平时在工作中给予足够重视,熟悉鞍区视神经及周围血管解剖结构,根据MRI直接或间接表现得出正确诊断并不难。%Objective To explore the MRI value in optic nerve vascular compression. Methods The MRI performance and clinical data of 18 cases which optic nerve intracranial segment compressed by adjacent arteries were analyzed retrospectively. Results Optic nerve compressed by adjacent arteries include: the compressed of the anterior cerebral artery and internal carotid artery were common with 15 cases (15/18), the compressed of arteriae communicans artery and anterior cerebral artery 1 case, the compressed of internal carotid artery and ophthalmic artery 1 case and Heubner artery 1 case. The optic nerve was contacted with nearby blood vessels on MRI imaging, and the cerebrospinal fluid between disappeared, the optic nerve impression could be seen. The abnormal optic signal could be seen in very few case. Conclusion MRI had unique advantages in observing the compress of optic nerve. As long as we pay attention to it during the work and be familiar with the anatomy of sellar region, we could make the correct diagnosis.

  13. Application of Multifractal Analysis to Segmentation of Water Bodies in Optical and Synthetic Aperture Radar Satellite Images

    OpenAIRE

    Martin, Victor Manuel San; Figliola, Alejandra

    2016-01-01

    A method for segmenting water bodies in optical and synthetic aperture radar (SAR) satellite images is proposed. It makes use of the textural features of the different regions in the image for segmentation. The method consists in a multiscale analysis of the images, which allows us to study the images regularity both, locally and globally. As results of the analysis, coarse multifractal spectra of studied images and a group of images that associates each position (pixel) with its correspondin...

  14. 颈椎间盘置换及前路椎间融合治疗单节段颈椎间盘突出症:谁更多影响邻近节段发生退变?%Anterior cervical disc replacement and anterior cervical decompression and fusion for treating single segment cervical disc herniation:which has greater effects on adjacent segment degeneration?

    Institute of Scientific and Technical Information of China (English)

    刘威; 盛伟斌; 张健; 邓强; 郭海龙

    2016-01-01

    背景:有研究表明,颈椎间盘置换及前路固定融合治疗颈椎病可以取得较好的临床效果,但是哪种术式在避免邻近节段退变方面更具优势尚无定论。目的:比较颈椎间盘置换与前路固定融合治疗单节段颈椎间盘突出症对邻近节段的近期影响。方法:收集2009年1月至2012年12月以“颈椎间盘突出症”为诊断收入院并行单节段颈椎间盘置换或颈前路椎间盘切除融合患者178例的临床资料,进行回顾性分析,其中前路固定融合组116例,颈椎间盘置换组62例。结果与结论:①评价:两组患者末次随访时目测类比评分、日本骨科协会评估治疗评分、颈椎功能障碍指数均较治疗前明显改善(P 0.05)。前路固定融合组术后3个月时手术节段基本融合,活动度丧失,末次随访时邻近上位节段活动度与邻近下位节段活动度明显增加,且上位节段活动度增加的度数较下位节段大(P 0.05). At 3 months after surgery, in the anterior cervical decompression and fusion group, surgical segment was confluent, and range of motion lost. During final fol ow-up, range of motion of adjacent upper segment and adjacent lower segment was significantly increased, and the increased range of motion in the upper segment was bigger than that of the lower segment (P < 0.05). (3) During final fol ow-up, X-ray films and MRI images revealed the number of degenerated adjacent segment was more in the anterior cervical decompression and fusion group than in the anterior cervical disc replacement group (P <0.05). The number of degenerated middle and upper segments was more than that of the lower segment in both groups (P < 0.05). (4) The findings confirmed that anterior cervical disc replacement or anterior cervical decompression and fusion for treating cervical disc herniation could effectively relieve nerve symptoms of patients. However, compared with the anterior cervical disc

  15. Automated segmentation and characterization of esophageal wall in vivo by tethered capsule optical coherence tomography endomicroscopy.

    Science.gov (United States)

    Ughi, Giovanni J; Gora, Michalina J; Swager, Anne-Fré; Soomro, Amna; Grant, Catriona; Tiernan, Aubrey; Rosenberg, Mireille; Sauk, Jenny S; Nishioka, Norman S; Tearney, Guillermo J

    2016-02-01

    Optical coherence tomography (OCT) is an optical diagnostic modality that can acquire cross-sectional images of the microscopic structure of the esophagus, including Barrett's esophagus (BE) and associated dysplasia. We developed a swallowable tethered capsule OCT endomicroscopy (TCE) device that acquires high-resolution images of entire gastrointestinal (GI) tract luminal organs. This device has a potential to become a screening method that identifies patients with an abnormal esophagus that should be further referred for upper endoscopy. Currently, the characterization of the OCT-TCE esophageal wall data set is performed manually, which is time-consuming and inefficient. Additionally, since the capsule optics optimally focus light approximately 500 µm outside the capsule wall and the best quality images are obtained when the tissue is in full contact with the capsule, it is crucial to provide feedback for the operator about tissue contact during the imaging procedure. In this study, we developed a fully automated algorithm for the segmentation of in vivo OCT-TCE data sets and characterization of the esophageal wall. The algorithm provides a two-dimensional representation of both the contact map from the data collected in human clinical studies as well as a tissue map depicting areas of BE with or without dysplasia. Results suggest that these techniques can potentially improve the current TCE data acquisition procedure and provide an efficient characterization of the diseased esophageal wall. PMID:26977350

  16. Impending anterior ischemic optic neuropathy with elements of retinal vein occlusion in a patient on interferon for polycythemia vera

    Directory of Open Access Journals (Sweden)

    Rue KS

    2012-10-01

    Full Text Available Kelly S Rue, Louis K Hirsch, Alfredo A SadunDepartment of Neuro-Ophthalmology, Doheny Eye Institute and Keck School of Medicine, University of Southern California, Los Angeles, CA, USAAbstract: We describe the course and likely pathophysiology of impending anterior ischemic optic neuropathy (AION and retinal vein occlusion in a 56-year-old man with polycythemia vera managed with interferon alpha for 2 years. Our patient presented with decreased vision, scintillating scotomata, and floaters. Fundus examination findings and results of a fluorescein angiogram led to the diagnosis of impending AION and retinal vein occlusion. Considering that both polycythemia vera and interferon have possible influences on vascular occlusion and optic disc edema, we stopped interferon treatment and immediately attempted to treat the polycythemia vera empirically with pentoxifylline and any interferon-associated inflammation with prednisone. Our patient experienced complete resolution of fundus abnormalities and return of normal vision within 3 weeks, which may be attributed to our successful treatment of both etiologies. Thus, further study is warranted to elucidate the treatment of both polycythemia vera and interferon-induced impending AION.Keywords: optic disc edema, interferon alpha, vascular occlusion, Roth spot, autoantibody, pentoxifylline

  17. Quantitative changes of anterior segment before and after implantable collamer lens implantation for high myopia with Pentacam anterior segment system%Pentacam评估高度近视有晶状体眼人工晶状体植入术前后眼前节形态的改变

    Institute of Scientific and Technical Information of China (English)

    周远香

    2015-01-01

    目的:通过眼前节全景分析仪( Pentacam)量化分析高度近视患者行ICL植入术手术前后眼前节形态的改变,评估手术的安全性、有效性。  方法:收集我院2011-09/2013-02高度近视眼行ICL植入手术的患者21例39眼,术后随访6~12mo。通过Pentacam分别测量术前;术后1wk;1,6mo的中央前房深度( ACD)、前房角度(ACA)、前房容积(ACV);记录术后1wk;1,6mo的ICL拱高(ICL-vault);记录术前裸眼视力(pre-UCVA)、最佳矫正视力( BCVA)、术后裸眼视力( post-UCVA)以及眼压值。使用SPSS18.0统计软件分析各项指标,术前、术后的资料均采用配对t检验进行统计学分析。  结果:术前;术后1wk;1,6mo 的ACD分别是3.27±0.22,3.02±0.33,2.98±0.31,2.98±0.32mm, ACA分别是(40.39±5.40)°,(26.70±4.47)°,(26.96±4.48)°,(26.95±4.45)°, ACV分别是207.74±25.43,122.87±17.58,128.05±17.84, ;128.64±17.50mm 3。术后1wk;1,6mo的拱高分别是0.49±0.13,0.46±0.13,0.46±0.14mm。术前与术后3个不同时段的ACD,ACA,ACV的值相比,其均存在统计学差异( P  结论:通过眼前节全景分析仪( Pentacam)分析发现ICL术后前房变浅,房角变窄,前房容积变小,但人工晶状体与透明晶状体之间仍拥有安全的间隙,ICL植入术治疗高度近视眼安全、有效,但远期疗效有待进一步观察。%•AlM: To analyze the quantitative changes of anterior segment by Pentacam anterior segment system and to evaluate the safety and effectiveness after implantable collamer lens ( lCL) implantation for high myopia. •METHODS:Twenty- one patients with 39 eyes were implanted lCL in our hospital from September 2011 to February 2013. The follow-up was 6 ~ 12mo. Central anterior chamber depth ( ACD ) , anterior chamber angle ( ACA) , anterior chamber volume ( ACV) were measured by Pentacam preoperatively, 1wk, 1 and 6mo postoperatively. The distance between crystal lens and lOL ( lCL- vault ) were measured at

  18. New variational image decomposition model for simultaneously denoising and segmenting optical coherence tomography images

    International Nuclear Information System (INIS)

    Optical coherence tomography (OCT) imaging plays an important role in clinical diagnosis and monitoring of diseases of the human retina. Automated analysis of optical coherence tomography images is a challenging task as the images are inherently noisy. In this paper, a novel variational image decomposition model is proposed to decompose an OCT image into three components: the first component is the original image but with the noise completely removed; the second contains the set of edges representing the retinal layer boundaries present in the image; and the third is an image of noise, or in image decomposition terms, the texture, or oscillatory patterns of the original image. In addition, a fast Fourier transform based split Bregman algorithm is developed to improve computational efficiency of solving the proposed model. Extensive experiments are conducted on both synthesised and real OCT images to demonstrate that the proposed model outperforms the state-of-the-art speckle noise reduction methods and leads to accurate retinal layer segmentation. (paper)

  19. Semi-Automatic Segmentation of Optic Radiations and LGN, and Their Relationship to EEG Alpha Waves

    Science.gov (United States)

    Descoteaux, Maxime; Bernier, Michaël; Garyfallidis, Eleftherios; Whittingstall, Kevin

    2016-01-01

    At rest, healthy human brain activity is characterized by large electroencephalography (EEG) fluctuations in the 8-13 Hz range, commonly referred to as the alpha band. Although it is well known that EEG alpha activity varies across individuals, few studies have investigated how this may be related to underlying morphological variations in brain structure. Specifically, it is generally believed that the lateral geniculate nucleus (LGN) and its efferent fibres (optic radiation, OR) play a key role in alpha activity, yet it is unclear whether their shape or size variations contribute to its inter-subject variability. Given the widespread use of EEG alpha in basic and clinical research, addressing this is important, though difficult given the problems associated with reliably segmenting the LGN and OR. For this, we employed a multi-modal approach and combined diffusion magnetic resonance imaging (dMRI), functional magnetic resonance imaging (fMRI) and EEG in 20 healthy subjects to measure structure and function, respectively. For the former, we developed a new, semi-automated approach for segmenting the OR and LGN, from which we extracted several structural metrics such as volume, position and diffusivity. Although these measures corresponded well with known morphology based on previous post-mortem studies, we nonetheless found that their inter-subject variability was not significantly correlated to alpha power or peak frequency (p >0.05). Our results therefore suggest that alpha variability may be mediated by an alternative structural source and our proposed methodology may in general help in better understanding the influence of anatomy on function such as measured by EEG or fMRI. PMID:27383146

  20. Semi-Automatic Segmentation of Optic Radiations and LGN, and Their Relationship to EEG Alpha Waves.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Renauld

    Full Text Available At rest, healthy human brain activity is characterized by large electroencephalography (EEG fluctuations in the 8-13 Hz range, commonly referred to as the alpha band. Although it is well known that EEG alpha activity varies across individuals, few studies have investigated how this may be related to underlying morphological variations in brain structure. Specifically, it is generally believed that the lateral geniculate nucleus (LGN and its efferent fibres (optic radiation, OR play a key role in alpha activity, yet it is unclear whether their shape or size variations contribute to its inter-subject variability. Given the widespread use of EEG alpha in basic and clinical research, addressing this is important, though difficult given the problems associated with reliably segmenting the LGN and OR. For this, we employed a multi-modal approach and combined diffusion magnetic resonance imaging (dMRI, functional magnetic resonance imaging (fMRI and EEG in 20 healthy subjects to measure structure and function, respectively. For the former, we developed a new, semi-automated approach for segmenting the OR and LGN, from which we extracted several structural metrics such as volume, position and diffusivity. Although these measures corresponded well with known morphology based on previous post-mortem studies, we nonetheless found that their inter-subject variability was not significantly correlated to alpha power or peak frequency (p >0.05. Our results therefore suggest that alpha variability may be mediated by an alternative structural source and our proposed methodology may in general help in better understanding the influence of anatomy on function such as measured by EEG or fMRI.

  1. Segment Orientation and Optical Birefringence of Amorphous Polymers Under Tensile Deformation: Novel Computational Method applied to Different Glassy Polycarbonates

    Science.gov (United States)

    Natarajan, Upendra; Sulatha, M. S.

    2005-03-01

    Orientation dependent optical properties of Bisphenol A polycarbonate and two aliphatic substituted polycarbonates in glassy phase have been studied by atomistic modeling using molecular mechanics simulations under tensile deformation. Probability distributions and orientation functions show that phenylene rings and carbonate groups vectors along the main chain orient towards stretching direction following deformation. Interchain packing of rings and carbonates become ordered with strain. Efficient computational approach for calculation of optical birefringence of amorphous polymers is presented and applied to the polycarbonates in detail. Polarizability anisotropy of the polymer segments and chain as a function of deformation is calculated by combining information on the conformations and group polarizabilities, and used to estimate birefringence during deformation. Simulated and experimental values for segment orientation and bulk birefringence are in very good agreement. Effect of the optical properties of atomic groups on bulk birefringence is brought forth for the first time by molecular simulation for polymers other than polyethylene.

  2. Efifcacy of granulocyte-colony stimulating factor treatment in a rat model of anterior ischemic optic neuropathy

    Institute of Scientific and Technical Information of China (English)

    Shun-Ping Huang; Rong-Kung Tsai

    2014-01-01

    Non-arteritic anterior ischemic optic neuropathy (NA-AION) is the most common cause of acute ischemic damage to the optic nerve (ON), and the leading cause of seriously impaired vision in people over 55 years of age. It demonstrated that subcutaneous administration of Granulocyte colony-stimulating factor (G-CSF) reduces RGC death in an ON crush model in rats, and that the neuroprotective effects may involve both anti-apoptotic and anti-inlfammatory processes. Our recent work shows that the protective actions of G-CSF in rAION models may involve both anti-apoptotic and anti-inlfammatory processes. However, the exact rescuing mech-anisms involved in the administration of G-CSF in rAION models need further investigation. In addition, further studies on the administration of G-CSF at different time intervals after the induction of rAION may be able to illustrate whether treatment given at a later time is still neu-roprotective. Further, it is unknown whether treatment using G-CSF combined with other drugs will result in a synergistic effect in a rAION model. Inlfammation induced by ischemia plays an essential role on the ON head in NA-AION, which can result in disc edema and compartment changes. Therefore, it is reasonable that adding an anti-inflammatory drug may enhance the therapeutic effects of G-CSF. An ongoing goal is to evaluate the novel sites of action of both G-CSF and other anti-inlfammatory drugs, and to identify the functionally protective pathways to enhance RGC survival. These investigations may open up new therapeutic avenues for the treatment of ischemic optic neuropathy.

  3. 3-D segmentation of retinal blood vessels in spectral-domain OCT volumes of the optic nerve head

    Science.gov (United States)

    Lee, Kyungmoo; Abràmoff, Michael D.; Niemeijer, Meindert; Garvin, Mona K.; Sonka, Milan

    2010-03-01

    Segmentation of retinal blood vessels can provide important information for detecting and tracking retinal vascular diseases including diabetic retinopathy, arterial hypertension, arteriosclerosis and retinopathy of prematurity (ROP). Many studies on 2-D segmentation of retinal blood vessels from a variety of medical images have been performed. However, 3-D segmentation of retinal blood vessels from spectral-domain optical coherence tomography (OCT) volumes, which is capable of providing geometrically accurate vessel models, to the best of our knowledge, has not been previously studied. The purpose of this study is to develop and evaluate a method that can automatically detect 3-D retinal blood vessels from spectral-domain OCT scans centered on the optic nerve head (ONH). The proposed method utilized a fast multiscale 3-D graph search to segment retinal surfaces as well as a triangular mesh-based 3-D graph search to detect retinal blood vessels. An experiment on 30 ONH-centered OCT scans (15 right eye scans and 15 left eye scans) from 15 subjects was performed, and the mean unsigned error in 3-D of the computer segmentations compared with the independent standard obtained from a retinal specialist was 3.4 +/- 2.5 voxels (0.10 +/- 0.07 mm).

  4. Object-Based Canopy Gap Segmentation and Classification: Quantifying the Pros and Cons of Integrating Optical and LiDAR Data

    Directory of Open Access Journals (Sweden)

    Jian Yang

    2015-11-01

    Full Text Available Delineating canopy gaps and quantifying gap characteristics (e.g., size, shape, and dynamics are essential for understanding regeneration dynamics and understory species diversity in structurally complex forests. Both high spatial resolution optical and light detection and ranging (LiDAR remote sensing data have been used to identify canopy gaps through object-based image analysis, but few studies have quantified the pros and cons of integrating optical and LiDAR for image segmentation and classification. In this study, we investigate whether the synergistic use of optical and LiDAR data improves segmentation quality and classification accuracy. The segmentation results indicate that the LiDAR-based segmentation best delineates canopy gaps, compared to segmentation with optical data alone, and even the integration of optical and LiDAR data. In contrast, the synergistic use of two datasets provides higher classification accuracy than the independent use of optical or LiDAR (overall accuracy of 80.28% ± 6.16% vs. 68.54% ± 9.03% and 64.51% ± 11.32%, separately. High correlations between segmentation quality and object-based classification accuracy indicate that classification accuracy is largely dependent on segmentation quality in the selected experimental area. The outcome of this study provides valuable insights of the usefulness of data integration into segmentation and classification not only for canopy gap identification but also for many other object-based applications.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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。

  11. 25G玻璃体切割系统在眼前节手术中的应用进展%25-gauge vitrectomy system for the surgery of eye anterior segment

    Institute of Scientific and Technical Information of China (English)

    张影影; 张立贵

    2012-01-01

    25 G经结膜无缝合玻璃体切割系统的出现,标志着微创玻璃体切割手术取得了突破性进展,该系统在一些眼底疾病的治疗中已取得令人满意的疗效,随着对其不断改进,目前已逐步应用到眼前节手术中,尤其在儿童白内障手术中经角巩膜缘或扁平部行后囊膜切开联合前段玻璃体切割术更突显其微创优势.本文就25 G玻璃体切割系统的工作原理和优点、在眼前节手术中的临床应用及其潜在并发症等作一综述.%One of the most revolutionary developments in vitreoretinal surgery is 25-gauge transconjunctival sutureless vitrectomy.Its use in the treatment of retina diseases has achieved signifcant effects.With the improvement of surgical technique,it has been developed for application to the operation of eye anterior segment,especially for pediatric cataract surgery,during which posterior capsulotomy and anterior vitrectomy are performed via a corneoscleral limbal or pars plana approach with it.This paper summaries the principle,advantages,indications and the potential accomplications of 25-gauge transconjunctival sutureless vitrectomy system for the surgery of eye anterior segment.

  12. Combined use of high-definition and volumetric optical coherence tomography for the segmentation of neural canal opening in cases of optic nerve edema

    Science.gov (United States)

    Wang, Jui-Kai; Kardon, Randy H.; Garvin, Mona K.

    2015-03-01

    In cases of optic-nerve-head edema, the presence of the swelling reduces the visibility of the underlying neural canal opening (NCO) within spectral-domain optical coherence tomography (SD-OCT) volumes. Consequently, traditional SD-OCT-based NCO segmentation methods often overestimate the size of the NCO. The visibility of the NCO can be improved using high-definition 2D raster scans, but such scans do not provide 3D contextual image information. In this work, we present a semi-automated approach for the segmentation of the NCO in cases of optic disc edema by combining image information from volumetric and high-definition raster SD-OCT image sequences. In particular, for each subject, five high-definition OCT B-scans and the OCT volume are first separately segmented, and then the five high-definition B-scans are automatically registered to the OCT volume. Next, six NCO points are placed (manually, in this work) in the central three high-definition OCT B-scans (two points for each central B-scans) and are automatically transferred into the OCT volume. Utilizing a combination of these mapped points and the 3D image information from the volumetric scans, a graph-based approach is used to identify the complete NCO on the OCT en-face image. The segmented NCO points using the new approach were significantly closer to expert-marked points than the segmented NCO points using a traditional approach (root mean square differences in pixels: 5.34 vs. 21.71, p < 0.001).

  13. Segmental anterior cervical decompression with fusion for treating multilevel cervical myelopathy%颈前路分节段减压融合治疗多节段颈椎病

    Institute of Scientific and Technical Information of China (English)

    林昊; 何仿; 李健; 崔庆元; 陈小强; 田纪伟

    2011-01-01

    Objective To evaluate the clinical value of the segmental anterior cervical decompression with fusion for treating multilevel cervical myelopathy.Methods 24 patients of multilevel cervical myelopathy with 3 or 4 consecutive segments were treated with segmental anterior cervical decompression with fusion.All patientst' cervical plain films,magnetic resonance imaging( MRI ) on preoperation and cervical plain films on postoperation were ohserved.The JOA scores of preoperation and 3 months postoperatively were collected.Results 24 cases were followed up from 3 months to 48 months, average 28 months.All patients improved their functional status in different degree.No complications such as graft nonunion and graft suhsidence occurred.The mean preoperative JOA score of all patients was ( 8.20 ±2.26 ),the postoperative of 3 months was ( 13.50 ± 1.28 ) , the average JOA recovery rate was 60.2%.Fusion rate was 100%.Conclusions The segmental anterior cervical decompression with fusion for treating multilevel cervical myelopathy appears to be effective in decompressing spinal cord, improving nerve functional status and restoring lordosis to the cervical spine with high fusion rate and fewer complications.%目的 评价颈前路分节段减压植骨融合术治疗多节段颈椎病的临床疗效.方法 对24例连续3或4个节段病变的颈椎病患者采用分节段减压融合术治疗.均行术前X线、MRI和术后X线片检查.均于术前及术后3个月进行JOA评分.结果 24例均获随访,时间3~48(28±20)个月.患者功能均有不同程度的改善.无植骨块不愈合、内置物下沉等并发症发生.JOA评分术前平均为(8.20±2.26)分,术后3个月平均为(13.50±1.28),改善率为60.2%,植骨融合率100%.结论 颈椎前路分节段减压融合术具有减压彻底、术后神经功能恢复好、恢复颈椎曲度、融合率高、并发症少等优点.

  14. The role of prosthesis design on segmental biomechanics: Semi-constrained versus unconstrained prostheses and anterior versus posterior centre of rotation

    OpenAIRE

    Wilke, Hans-Joachim; Schmidt, René; Richter, Marcus; Schmoelz, Werner; Reichel, Heiko; Cakir, Balkan

    2010-01-01

    The purpose of this study was to evaluate the influence of different implant designs of total lumbar disc replacements on the segmental biomechanics of the lumbar spine. The unconstrained Charité, the semi-constrained Prodisc and a semi-constrained Prototype with more posterior centre of rotation than the Prodisc were tested in vitro using six human, lumbar spines L2–L5. The segmental lordosis was measured on plain radiographs and the range of motion (ROM) for all six degrees of freedom with ...

  15. Comparative study of CT and ultrasound biomicroscope diagnosis of foreign body in anterior segment of eye%眼前段异物CT与超声生物显微镜的诊断对比

    Institute of Scientific and Technical Information of China (English)

    李纬; 李舒茵; 史大鹏; 朱绍成

    2011-01-01

    目的 探讨CT与超声生物显微镜(ultrasound biomicroscope,UBM)对眼前段异物诊断优缺点及联合应用价值.方法 对本院47例眶内异物者行CT和UBM检查,并与手术结果相对照.结果 47例眼前段异物中42例CT上显示为高密度影,手术取出物分别为金属碎片、铅笔芯、石块、玻璃等,3例呈稍高密度影,为塑料异物,2例无异常发现者分别为竹签和板栗刺.45例UBM检查均表现为强回声光斑伴声影,2例 CT检查发现异物后,再次行UBM检查找到异物.结论 眼前段异物诊断最佳方案应先行CT扫描确定异物方位及异物种类,再行UBM检查确定异物准确位置和并发症.%Objective To evaluate the advantages and disadvantages of CT and ultrasound biomicroscope ( UBM) in diagnosing foreign body in anterior segment of eye. Methods The findings of CT and UBM in 47 patients with foreign body at anterior segment of eye were retrospectively reviewed comparatively with operation results. Results The foreign bodys in 42/47 cases were hyperdensity on CT image, which were metal debris,hearts of pencil, stones and glasses, 3/47 were slightly high density on CT image, which were plastics and 2/47 were negative on CT images, which were bamboo stick and chestnuts thorns. The foreign bodys in 45/47 cases were hyperecho with acoustic shadow at UBM,2 cases of them, the foreign bodys were find out by UBM later after the discovery of foreign bodys by CT. Conclusion It is the best schedule in diagnosis of foreign body in anterior segment of eve to identifv its locations and kinds with CT, then describe its precise locations and complications with UBM.

  16. A new osteophyte segmentation method with applications to an anterior cruciate ligament transection rabbit femur model via micro-CT imaging

    Science.gov (United States)

    Liang, G.; Elkins, J. M.; Coimbra, A.; Duong, L. T.; Williams, D. S.; Sonka, M.; Saha, P. K.

    2010-03-01

    Osteophyte is an additional bony growth on a normal bone surface limiting or stopping motion in a deteriorating joint. Detection and quantification of osteophytes from CT images is helpful in assessing disease status as well as treatment and surgery planning. However, it is difficult to segment osteophytes from healthy bones using simple thresholding or edge/texture features in CT imaging. Here, we present a new method, based on active shape model (ASM), to solve this problem and evaluate its application to ex vivo μCT images in an ACLT rabbit femur model. The common idea behind most ASM based segmentation methods is to first build a parametric shape model from a training dataset and during application, find a shape instance from the model that optimally fits to target image. However, it poses a fundamental difficulty for the current application because a diseased bone shape is significantly altered at regions with osteophyte deposition misguiding an ASM method that eventually leads to suboptimum segmentation results. Here, we introduce a new partial ASM method that uses bone shape over healthy regions and extrapolate its shape over diseased region following the underlying shape model. Once the healthy bone region is detected, osteophyte is segmented by subtracting partial-ASM derived shape from the overall diseased shape. Also, a new semi-automatic method is presented in this paper for efficiently building a 3D shape model for rabbit femur. The method has been applied to μCT images of 2-, 4-, and 8-week post ACLT and sham-treated rabbit femurs and results of reproducibility and sensitivity analyses of the new osteophyte segmentation method are presented.

  17. Analysis of adjacent segment degeneration of patients with anterior cervical discectomy and fusion%颈椎前路减压植骨融合术后邻近节段退变情况分析

    Institute of Scientific and Technical Information of China (English)

    邓志龙; 张晓星; 王令; 李邦春

    2011-01-01

    目的 分析颈椎前路减压植骨融合术后融合椎体邻近节段退变的影响因素.方法 选取250例行颈椎前路减压植骨融合内固定手术治疗的患者作为研究对象,观察术后邻近节段退变的发生情况,对退变患者组与无退变患者组各项观察指标进行统计学比较.结果 共72例(75个节段)(28.8%)发生术后邻近节段退变,椎间盘退变程度按评分,1分48例,2分21例,3分3例;退变组术前D值(1.26±1.30)mm、术后D值(3.76±3.10)mm,明显小于无退变组的(1.90±1.30)mm与(5.85±3.04)mm(P0.05).结论 颈椎前路减压植骨融合术后融合椎体邻近节段退变发生率较高;颈椎前凸程度较小、且手术对颈椎前凸程度改善较小是导致邻近节段退变发生的重要影响因素.%Objective To analyze the influeneing factors of adjacent segment degeneration of patients with anterior cervical discectolny and fusion. Methods Totally 250 cases of anterior cervical discectolny and fusion were selected for study. The incidence of adjacent segment degeneration was observed and the indexes of degeneration group and non-degeneration group were compared statistically. Results There were 72 cases (75 segment) of adjacent segment degeneration( 28.8% ) ,including 48 cases of degradation score of 1, 21 cases of degradation score of 2,3 cases of degradation score of 3. The preoperative D value of degradation group was ( 1.26 ± 1.30 ) mm, while ( 3.76 + 3.10) mm after operation, indicating significantly lower than that of non-degradation group ( P < 0.05 ).The postoperative D value of degradation group increased by ( 2.5 + 3.21 ) mm,notably lower than that of non-degradation group (3.95 ± 3.13) mm ( P < 0.05 ) . The age, gender distribution, JOA score and Cobb' s angle of the two groups had no statistical difference( P < 0.05). Conclusion The incident rate of adjacent segment degeneration in patients with anterior cervical diseectolny and fusion is high. The small degree of

  18. Clinical observation and analysis of adjacent segment degeneration after anterior cervical fusion%颈椎前路融合术后相邻节段退变的临床观察与分析

    Institute of Scientific and Technical Information of China (English)

    王义生; 邓俊森

    2012-01-01

    [Objective] To study whether the anterior cervical fusion inevitably lead to the adjacent segment degeneration (ASD) . [Methods] From 1986.1 to 1999. 12, a total of 346 patients with cervical degenerative disease underwent the surgery of enlarged decompression with circular saw and auto iliac bone grafting. Among them there were 1 segment in 55 patients, 2 segments in 223 patients and 3 segments in 68 patients. The two motion segments adjacent to the fused segment and interval from the fused segment were evaluated respectively for imaging changes and divided the results into groups for statistical test. [Results] The patients were followed up for 13. 5 (4.1 ~ 18) years on average. Total 156 cases (45. 1% ) had obvious adjacent segment degeneration, 23 cases (6. 6% ) had obvious interval segment degeneration. The interval segment degeneration was less than that of adjacent segment degeneration, and the comparative differences had statistically significance (P 0.05 ) . [ Conclusion] The anterior cervical fusion accelerated the occurrence of ASD. The incidence of cephalic adjacent segment ASD was higher than that of tail side adjacent segments. The incidences of postoperative ASD in single segment and several segment fusion have no significant differences.%[目的]研究颈椎前路融合术是否必然导致邻近节段退变(adjacent segment degeneration,ASD).[方法]1986~1999年,共346例采用“环锯法前路扩大脊髓减压+椎体间植骨内固定术”治疗颈椎退变性疾病,其中,1个间隙55例,2个间隙223例,3个间隙68例.分别评定融合节段头、尾侧相邻间隙及间隔间隙的影像学表现,对结果分组进行统计学检验.[结果]术后随访13.5 (4.1 ~18)年,发生邻近节段明显退变的156例(45.1%),间隔节段明显退变的23例(6.6%).间隔节段退变明显少于邻近节段退变,两者比较差异有统计学意义(P<0.05).单纯头侧邻近节段发生ASD 84例,单纯尾侧邻近节段发生ASD 27例,头

  19. Application of Multifractal Analysis to Segmentation of Water Bodies in Optical and Synthetic Aperture Radar Satellite Images

    CERN Document Server

    Martin, Victor Manuel San

    2016-01-01

    A method for segmenting water bodies in optical and synthetic aperture radar (SAR) satellite images is proposed. It makes use of the textural features of the different regions in the image for segmentation. The method consists in a multiscale analysis of the images, which allows us to study the images regularity both, locally and globally. As results of the analysis, coarse multifractal spectra of studied images and a group of images that associates each position (pixel) with its corresponding value of local regularity (or singularity) spectrum are obtained. Thresholds are then applied to the multifractal spectra of the images for the classification. These thresholds are selected after studying the characteristics of the spectra under the assumption that water bodies have larger local regularity than other soil types. Classifications obtained by the multifractal method are compared quantitatively with those obtained by neural networks trained to classify the pixels of the images in covered against uncovered b...

  20. Segmentation and quantification of retinal lesions in age-related macular degeneration using polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Baumann, Bernhard; Götzinger, Erich; Pircher, Michael; Sattmann, Harald; Schütze, Christopher; Schlanitz, Ferdinand; Ahlers, Christian; Schmidt-Erfurth, Ursula; Hitzenberger, Christoph K.

    2010-11-01

    We present polarization-sensitive optical coherence tomography (PS-OCT) for quantitative assessment of retinal pathologies in age-related macular degeneration (AMD). On the basis of the polarization scrambling characteristics of the retinal pigment epithelium, novel segmentation algorithms were developed that allow one to segment pathologic features such as drusen and atrophic zones in dry AMD as well as to determine their dimensions. Results from measurements in the eyes of AMD patients prove the ability of PS-OCT for quantitative imaging based on the retinal features polarizing properties. Repeatability measurements were performed in retinas diagnosed with drusen and geographic atrophy in order to evaluate the performance of the described methods. PS-OCT appears as a promising imaging modality for three-dimensional retinal imaging and ranging with additional contrast based on the structures' tissue-inherent polarization properties.

  1. Non-fusion segment disease after the anterior cervical arthrodesis:a retrospective study%颈椎前路融合术后非融合节段退变性疾病的回顾性研究

    Institute of Scientific and Technical Information of China (English)

    郭炳路; 宋科冉; 陈巧灵; 陈增海; 王大鹏; 王慧; 金培; 唐家广

    2016-01-01

    Objective To investigate the incidence and causes of non-fusion segment disease ( NFSD ), both adjacent and non-adjacent to the fused segment, after the anterior cervical arthrodesis.Methods This is a retrospective cohort study. Between January 1998 and January 2011, 171 patients who had anterior cervical decompression and fusion for the intervertebral disc herniation and cervical spondylosis were followed clinically. There were 97 males and 74 females, and the average age at the operation was ( 51.90 ± 9.28 ) years ( range: 31 - 72 years ). We evaluated the correlation between the incidence of symptomatic non-fusion segment disease and the following clinical parameters ( age at the operation, fusion levels ) and radiological parameters ( preoperative and postoperative cervical spine alignment, Pavlov’s ratio at the C5 level, and preoperative existence of a non-fusion segment degeneration on magnetic resonance imaging ).Results Of the 171 patients reviewed, 16 patients had non-fusion segment disease ( 9.36% ), 12 patients had adjacent segment disease and 4 had non-adjacent segment disease. Postoperative cervical lordosis in the non-fusion segment disease group was signiifcantly smaller than that of the disease-free group [ ( 7.38 ± 12.37 ) ° vs. ( 17.26 ± 9.75 ) °,P < 0.001 ]. Fusion levels in the NFSD group were 1.63 whereas 2.27 in disease-free group (P = 0.002 ). The incidence of disc degeneration in non-fused segments was more severe in the NFSD group than in the disease-free group [ ( 2.63 ± 0.62 )vs. ( 1.62 ± 0.99 ), P = 0.008 ].Conclusions The incidence of symptomatic non-fusion segment disease after the anterior cervical arthrodesis has multifactorial causes. Postoperative cervical lordosis, disc degeneration in non-fusion segments, and the number of fusion levels are all factors in the incidence of NFSD.%目的:探讨颈椎前路减压融合术后非融合节段病变( non-fusion segment disease,NFSD )的发生率和

  2. Automatic Registration Method for Optical Remote Sensing Images with Large Background Variations Using Line Segments

    Directory of Open Access Journals (Sweden)

    Xiaolong Shi

    2016-05-01

    Full Text Available Image registration is an essential step in the process of image fusion, environment surveillance and change detection. Finding correct feature matches during the registration process proves to be difficult, especially for remote sensing images with large background variations (e.g., images taken pre and post an earthquake or flood. Traditional registration methods based on local intensity probably cannot maintain steady performances, as differences are significant in the same area of the corresponding images, and ground control points are not always available in many disaster images. In this paper, an automatic image registration method based on the line segments on the main shape contours (e.g., coastal lines, long roads and mountain ridges is proposed for remote sensing images with large background variations because the main shape contours can hold relatively more invariant information. First, a line segment detector called EDLines (Edge Drawing Lines, which was proposed by Akinlar et al. in 2011, is used to extract line segments from two corresponding images, and a line validation step is performed to remove meaningless and fragmented line segments. Then, a novel line segment descriptor with a new histogram binning strategy, which is robust to global geometrical distortions, is generated for each line segment based on the geometrical relationships,including both the locations and orientations of theremaining line segments relative to it. As a result of the invariance of the main shape contours, correct line segment matches will have similar descriptors and can be obtained by cross-matching among the descriptors. Finally, a spatial consistency measure is used to remove incorrect matches, and transformation parameters between the reference and sensed images can be figured out. Experiments with images from different types of satellite datasets, such as Landsat7, QuickBird, WorldView, and so on, demonstrate that the proposed algorithm is

  3. Performance evaluation of automated segmentation software on optical coherence tomography volume data.

    Science.gov (United States)

    Tian, Jing; Varga, Boglarka; Tatrai, Erika; Fanni, Palya; Somfai, Gabor Mark; Smiddy, William E; Debuc, Delia Cabrera

    2016-05-01

    Over the past two decades a significant number of OCT segmentation approaches have been proposed in the literature. Each methodology has been conceived for and/or evaluated using specific datasets that do not reflect the complexities of the majority of widely available retinal features observed in clinical settings. In addition, there does not exist an appropriate OCT dataset with ground truth that reflects the realities of everyday retinal features observed in clinical settings. While the need for unbiased performance evaluation of automated segmentation algorithms is obvious, the validation process of segmentation algorithms have been usually performed by comparing with manual labelings from each study and there has been a lack of common ground truth. Therefore, a performance comparison of different algorithms using the same ground truth has never been performed. This paper reviews research-oriented tools for automated segmentation of the retinal tissue on OCT images. It also evaluates and compares the performance of these software tools with a common ground truth.

  4. Image processing based automatic diagnosis of glaucoma using wavelet features of segmented optic disc from fundus image.

    Science.gov (United States)

    Singh, Anushikha; Dutta, Malay Kishore; ParthaSarathi, M; Uher, Vaclav; Burget, Radim

    2016-02-01

    Glaucoma is a disease of the retina which is one of the most common causes of permanent blindness worldwide. This paper presents an automatic image processing based method for glaucoma diagnosis from the digital fundus image. In this paper wavelet feature extraction has been followed by optimized genetic feature selection combined with several learning algorithms and various parameter settings. Unlike the existing research works where the features are considered from the complete fundus or a sub image of the fundus, this work is based on feature extraction from the segmented and blood vessel removed optic disc to improve the accuracy of identification. The experimental results presented in this paper indicate that the wavelet features of the segmented optic disc image are clinically more significant in comparison to features of the whole or sub fundus image in the detection of glaucoma from fundus image. Accuracy of glaucoma identification achieved in this work is 94.7% and a comparison with existing methods of glaucoma detection from fundus image indicates that the proposed approach has improved accuracy of classification.

  5. What is a segment?

    Science.gov (United States)

    Hannibal, Roberta L; Patel, Nipam H

    2013-12-17

    Animals have been described as segmented for more than 2,000 years, yet a precise definition of segmentation remains elusive. Here we give the history of the definition of segmentation, followed by a discussion on current controversies in defining a segment. While there is a general consensus that segmentation involves the repetition of units along the anterior-posterior (a-p) axis, long-running debates exist over whether a segment can be composed of only one tissue layer, whether the most anterior region of the arthropod head is considered segmented, and whether and how the vertebrate head is segmented. Additionally, we discuss whether a segment can be composed of a single cell in a column of cells, or a single row of cells within a grid of cells. We suggest that 'segmentation' be used in its more general sense, the repetition of units with a-p polarity along the a-p axis, to prevent artificial classification of animals. We further suggest that this general definition be combined with an exact description of what is being studied, as well as a clearly stated hypothesis concerning the specific nature of the potential homology of structures. These suggestions should facilitate dialogue among scientists who study vastly differing segmental structures.

  6. Edge Control in Large Segmented Optics Using Zeeko Polishing Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The fabrication of very large optical telescopes for space astronomy can be prohibitively costly due to the immense weight and size of monolithic primary mirrors....

  7. Label-free optical lymphangiography: development of an automatic segmentation method applied to optical coherence tomography to visualize lymphatic vessels using Hessian filters

    Science.gov (United States)

    Yousefi, Siavash; Qin, Jia; Zhi, Zhongwei; Wang, Ruikang K.

    2013-08-01

    Lymphatic vessels are a part of the circulatory system that collect plasma and other substances that have leaked from the capillaries into interstitial fluid (lymph) and transport lymph back to the circulatory system. Since lymph is transparent, lymphatic vessels appear as dark hallow vessel-like regions in optical coherence tomography (OCT) cross sectional images. We propose an automatic method to segment lymphatic vessel lumen from OCT structural cross sections using eigenvalues of Hessian filters. Compared to the existing method based on intensity threshold, Hessian filters are more selective on vessel shape and less sensitive to intensity variations and noise. Using this segmentation technique along with optical micro-angiography allows label-free noninvasive simultaneous visualization of blood and lymphatic vessels in vivo. Lymphatic vessels play an important role in cancer, immune system response, inflammatory disease, wound healing and tissue regeneration. Development of imaging techniques and visualization tools for lymphatic vessels is valuable in understanding the mechanisms and studying therapeutic methods in related disease and tissue response.

  8. 前路减压植骨融合术后颈椎相邻节段生物力学变化%Biomechanical changes of the adjacent segments after anterior cervical decompression and fusion

    Institute of Scientific and Technical Information of China (English)

    尹飞; 郭丽; 朱庆三; 赵东旭; 巩固; 李然; 赵昆池; 王迎智

    2013-01-01

    Objective To study the biomechanical changes of the adjacent segments after anterior cervical decompression and fusion (ACDF).Methods EB composite resin was used to mimic the fuion effect after anterior cervical decompression.The motion range and biomechanical changes of the adjacent segments were measured.Results Under the same torque of 2.0 Nm,the motion range of the adjacent segments was from 4.3 to 8.0 degrees,which was not significantly different from that before fusion (P >0.05).Increasing the torque gradually to let the samples reach their normal range of motion,the range of motion of the adjacent segments increased significantly.There are significant differences of them after and before fusion (P < 0.05).Conclusion If people keep the normal range of motion of cervical spine after ACDF,their adjacent segment's movement will increase significantly.This might be the main cause of the degeneration after fusion.By limiting the neck movement can reduce,or even avoid postoperative degeneration.%目的 观察颈椎前路减压植骨融合术后相邻节段生物力学变化.方法 采用EB复合树脂黏合的方法模拟颈椎前路减压植骨术后融合的效果,检测颈椎融合前、后相邻节段运动范围及生物力学的变化.结果 在2.0 Nm力矩不变的情况下,融合节段相邻间隙的运动范围为4.3°~8.0°,与融合前比较差异无统计学意义(P>0.05);加大力矩使融合后的颈椎尽量达到术前正常运动范围时融合节段相邻间隙运动范围明显增加,与融合前比较差异有统计学意义(P<0.05).结论 颈椎融合术后如果仍要达到术前正常的运动范围,其相邻节段的运动范围明显增加,这可能是造成其退变的主要原因.限制颈部术后活动可以减少、甚至避免术后退变的发生.

  9. 经前路颈椎椎体次全切除钛网置入融合后相邻节段的退变%Adjacent segment degeneration after anterior cervical corpectomy and fusion

    Institute of Scientific and Technical Information of China (English)

    翟鹏飞; 刘伟; 孙志明; 张学利

    2016-01-01

    BACKGROUND:In recent years, the researchers have studied the adjacent segment degeneration after cervical fusion. Several studies concerned the adjacent segment degeneration after anterior cervical corpectomy and fusion. OBJECTIVE:To evaluate the correlative factors of adjacent segment degeneration after anterior cervical corpectomy and fusion. METHODS:122 patients were included in the study from 126 patients who underwent anterior cervical corpectomy and fusion that operated by the same treatment team and involved a single vertebral body and the two plates between February 2009 and February 2012. The final fol ow-up period was 3 years. According to the degeneration progress of adjacent segment degeneration, these patients were divided into non-progression group and progression group. The gender, age, preoperative adjacent segment degeneration, cervical range of motion, upper and lower vertebral range of motion, surgical segment, titanium mesh subsidence, plate-to-disc distance, and cervical curvature index were compared between two groups. Logistic regression analysis was applied to analyze the correlative factors of adjacent segment degeneration. RESULTS AND CONCLUSION:(1) There were significant differences in preoperative adjacent segment degeneration, postoperative cervical range of motion, postoperative upper and lower vertebral range of motion, and postoperative cervical curvature index (P  目的:探讨经前路椎体次全切除钛网椎间置入融合后相邻节段退变的相关因素。  方法:纳入2009年2月至2012年2月行经前路椎体次全切除钛网椎间置入融合的患者共126例,其中资料完整的122例纳入研究。均由同一治疗组完成,且手术均涉及单个椎体及2个间盘。终末随访期为3年。根据术前及术后相邻节段退变程度,分为非相邻节段退变进展组和相邻节段退变进展组,比较2组患者的性别、年龄、术前相邻节段退变、颈椎活动度、术椎

  10. A dual purpose optical truss laser metrology system for a space-based far-IR segmented telescope: Figure maintenance and pointing control

    Science.gov (United States)

    Lau, Kenneth

    1992-01-01

    To obtain imaging performance as for monolithic mirrors, large segmented reflectors used for astronomy must be actively aligned and pointed to extreme levels of precision. A system concept for a dual purpose optical truss laser metrology system is described which is used for both figure and alignment maintenance and telescope pointing. A two-stage figure active control approach was developed for several proposed spaceborne far infrared segmented telescopes, one of which is the 10-20 meters Large Deployable Reflector (LDR). The first active control stage, the figure initialization control system, aligns the optical elements (i.e., the primary segments, secondary and focal plane assembly) based on images obtained. The second stage, the figure maintenance control system, maintains the alignment between re-initializations using measurements provided by laser interferometers arranged in an optical truss configuration. It measures the relative positions and alignments of the telescope segments so that a controller can reposition them appropriately. The application of this optical truss for figure maintenance control is the subject of the first part of this paper. The second portion of this paper discusses the application of the optical truss to telescope pointing. Here, the laser metrology system is used to transfer pointing information from an external fine guidance sensor (FGS) to the telescope optical boresight as defined by the primary mirror, secondary mirror, and focal plane assembly. Thus, any alignment variations between the two boresights can be observed and accounted for.

  11. Design and analysis of modules for segmented X-ray optics

    Science.gov (United States)

    McClelland, Ryan S.; Biskach, Michael P.; Chan, Kai-Wing; Saha, Timo T.; Zhang, William W.

    2012-09-01

    Lightweight and high resolution mirrors are needed for future space-based X-ray telescopes to achieve advances in high-energy astrophysics. The slumped glass mirror technology in development at NASA GSFC aims to build X-ray mirror modules with an area to mass ratio of ~17 cm2/kg at 1 keV and a resolution of 10 arc-sec Half Power Diameter (HPD) or better at an affordable cost. As the technology nears the performance requirements, additional engineering effort is needed to ensure the modules are compatible with space-flight. This paper describes Flight Mirror Assembly (FMA) designs for several X-ray astrophysics missions studied by NASA and defines generic driving requirements and subsequent verification tests necessary to advance technology readiness for mission implementation. The requirement to perform X-ray testing in a horizontal beam, based on the orientation of existing facilities, is particularly burdensome on the mirror technology, necessitating mechanical over-constraint of the mirror segments and stiffening of the modules in order to prevent self-weight deformation errors from dominating the measured performance. This requirement, in turn, drives the mass and complexity of the system while limiting the testable angular resolution. Design options for a vertical X-ray test facility alleviating these issues are explored. An alternate mirror and module design using kinematic constraint of the mirror segments, enabled by a vertical test facility, is proposed. The kinematic mounting concept has significant advantages including potential for higher angular resolution, simplified mirror integration, and relaxed thermal requirements. However, it presents new challenges including low vibration modes and imperfections in kinematic constraint. Implementation concepts overcoming these challenges are described along with preliminary test and analysis results demonstrating the feasibility of kinematically mounting slumped glass mirror segments.

  12. Active figure maintenance control using an optical truss laser metrology system for a space-based far-IR segmented telescope

    Science.gov (United States)

    Lau, Kenneth; Breckenridge, Bill; Nerheim, Noble; Redding, David

    1992-01-01

    A two-stage active control approach was developed addressing the figure control problem for a spaceborne FIR telescope, the Precision Segmented Reflectors Focus Moderate Mission Telescope (FMMT). The first active control stage aligns the optical segments based on images; attention is here given to the second stage, active figure maintenance control system, which maintains the alignment of the optical elements between initializations to hold the mirror figure steady while obtaining data and fixes translational and rotational changes of the optical segments induced by long-term thermal drifts of the support structure. Errors are expected to be 10-100 microns at the nodes of the primary backup structure over the course of an orbit. An rms performance of 0.8 microns of wavefront error can be expected during the maintenance function based on specified nominal sensor noises, actuator accuracies, and system environments. A performance of less than 0.3 microns rms can be expected, based on advanced components.

  13. 可植入胶原聚合透镜植入术后早期眼前段观察%Observation of anterior segment after implantation of implantable collamer lens in early stage

    Institute of Scientific and Technical Information of China (English)

    栗静; 刘磊; 李新宇; 王虎杰

    2014-01-01

    Objective To observe the anterior segment after implantation of implantable collamer lens (ICL) in early stage.Methods 65 eyes of 37 patients with high myopia who accepted ICL implantation were enrolled in this study.Anterior chamber volume (ACV),anterior chamber depth (ACD),iridocorneal angle,intraocular pressure (IOP) and endothelial cell density were measured at pre-operation,1 month and 6 months after surgery,and measurements were analyzed by statistical analysis.Results After surgeries,the ACD,iridocorneal angles and ACV decreased statistically significantly,and there were no statistical differences between measurements of 1 month and 6 months after surgery; the IOP measured at postoperative 1 month was lower than before and achieved stable state during postoperative 6 months; The endothelial cell density decreased about 4.75% and 6.87% respectively at postoperative 1 month and 6 months (P < 0.05) ; The mean central vault were (412.61 ± 192.94) μm and (365.69 ± 179.75) μm respectively at postoperative 1 month and 6 months,the ICLs had no contact with lens.Conclusion In the early period after implantation of ICL,the anterior segment morphology changed significantly,but these indexes were stable and no closure of iridocorneal angle or increasing of IOP were observed in the follow-up 6 months,therefore,long time follow-up is still required.%目的 观察有晶状体眼可植入胶原聚合透镜(ICL)植入术后早期的眼前段形态.方法 随机选取接受ICL植入术的高度近视37例(65只眼),测量患者术前、术后1个月和6个月的前房深度、前房角、前房容积、眼压和角膜内皮细胞密度,并对测量结果进行统计学分析.结果 术后前房深度、前房角和前房容积均较术前显著减小,术后1个月和术后6个月相比差异无统计学意义.术后1个月时眼压较术前稍有降低,术后6个月时恢复至术前水平;术后1个月和6个月患眼角膜内皮细胞密度较术前分别降低4

  14. Automated detection of kinks from blood vessels for optic cup segmentation in retinal images

    Science.gov (United States)

    Wong, D. W. K.; Liu, J.; Lim, J. H.; Li, H.; Wong, T. Y.

    2009-02-01

    The accurate localization of the optic cup in retinal images is important to assess the cup to disc ratio (CDR) for glaucoma screening and management. Glaucoma is physiologically assessed by the increased excavation of the optic cup within the optic nerve head, also known as the optic disc. The CDR is thus an important indicator of risk and severity of glaucoma. In this paper, we propose a method of determining the cup boundary using non-stereographic retinal images by the automatic detection of a morphological feature within the optic disc known as kinks. Kinks are defined as the bendings of small vessels as they traverse from the disc to the cup, providing physiological validation for the cup boundary. To detect kinks, localized patches are first generated from a preliminary cup boundary obtained via level set. Features obtained using edge detection and wavelet transform are combined using a statistical approach rule to identify likely vessel edges. The kinks are then obtained automatically by analyzing the detected vessel edges for angular changes, and these kinks are subsequently used to obtain the cup boundary. A set of retinal images from the Singapore Eye Research Institute was obtained to assess the performance of the method, with each image being clinically graded for the CDR. From experiments, when kinks were used, the error on the CDR was reduced to less than 0.1 CDR units relative to the clinical CDR, which is within the intra-observer variability of 0.2 CDR units.

  15. Nursing of slit-lamp anterior segment processing system in treatments of corneal foreign body%裂隙灯眼前段处理系统在角膜异物中的应用及护理

    Institute of Scientific and Technical Information of China (English)

    李伍英; 丛日昌

    2010-01-01

    目的 探讨裂隙灯眼前段处理系统在治疗角膜异物中的应用及护理.方法 将120例患者随机分为对照组(n=60)和实验组(n=60),对照组采用传统检查治疗方法 .实验组应用配置佳能PowerShotA720IS型数码照相机(1 200万像素)SLM型裂隙灯显微镜检查角膜异物的位置,并在不同角度下进行照相(放大倍率×10,×16,×20).结果 实验组患者对医护人员信任度和满意度高于对照组,差异有统计学意义(P<0.05).结论 裂隙灯眼前段处理系统的应用为角膜异物伤的患者提供直接定性依据,给患者了解自身病情带来便利,同时进行相关的护理,达到较理想的效果.%Objective To explore the application and nursing of slit-lamp anterior segment processing system in treatments of corneal foreign body. Methods Totally, 120 cases were divided into the control group and the experimental group randomly, the 60 cases of control group received the traditional treatment and the other 60 cases received the Canon PowerShotA720IS numerical code camera (12,000,000 picture elements)SLM slit lamp to show the position of corneal foreign body, and were carried on some photographs under different angles ( the enlargement ratio ×10, ×16, ×20). Results The rate of credibility and satisfaction to the medical care personnel in experimental group were higher than that in control group, the difference has statistical significance. Conclusions The application of slit-lamp anterior segment processing system provides the direct qualitative basis for the patients. It's convenient for patients to understand their state of the illness, and at the same time, it will achieve the ideal effect when carrying on the relative nursing.

  16. Hybrid Surgery术式治疗颈前路多节段脊髓型颈椎病的临床分析%Clinic analysis of Hybrid Surgery to treat multi segmental anterior cervical spondylotic myelopathy

    Institute of Scientific and Technical Information of China (English)

    福嘉欣; 江汉; 江毅; 肖联平; 田永刚

    2015-01-01

    Objective To investigate the effect of corpectomy decompression by subtotal vertebrectomy and fusion of adjacent segmental artificial disc replacement through anterior intervertenral spance (Hybrid Surgery) in the anteriorcervical spondylotic myelopathy treatment . Methods Hybrid Surgery were operated on 18 patients who suffered from anterior cervi⁃cal spondylotic myelopathy . Follow up of 1-50 months. Patient’s conditions were assessed according to the Japanese Associ⁃ation for Department of orthopedics assessment score (JOA score) before and after operation. Effects of Hybrid operation were assessed by the improvement of JOA score, Odom’s follow-up grade and cervical mobility . Results The JOA scores of all 18 operated patients were improved from 10.6 ± 1.7 before operation to 13.5 ± 2.4 after operation. And the difference is statistically significant (t=1.314, P 0.05). Conclusion Hybrid Surgery of anterior cervical decompression and fusion can both improve the nerve function and preserve cervical mobility.%目的:探讨颈椎前路经椎间隙或椎体次全切除减压植骨融合联合邻近节段人工间盘置换(Hybrid Surgery)在颈前路多节段脊髓型颈椎病治疗中的效果。方法应用Hybrid Surgery术式治疗颈前路多节段脊髓型颈椎病患者18例。随访1~50个月,手术前后根据日本骨科协会评估分数(JOA)进行评分。通过JOA评分的改善情况, Odom’s分级随访结果及颈椎活动度的变化评价Hybrid Surgery的效果。结果18例术后JOA评分(13.5±2.4)分高于术前(10.6±1.7)分,差异有统计学意义(t=1.314,P0.05)。结论 Hybrid Surgery术式颈前路充分减压融合,既可改善患者神经功能,又可保留一定程度上的颈椎活动度。

  17. Automated Retinal Layer Segmentation Using Spectral Domain Optical Coherence Tomography: Evaluation of Inter-Session Repeatability and Agreement between Devices.

    Science.gov (United States)

    Terry, Louise; Cassels, Nicola; Lu, Kelly; Acton, Jennifer H; Margrain, Tom H; North, Rachel V; Fergusson, James; White, Nick; Wood, Ashley

    2016-01-01

    Retinal and intra-retinal layer thicknesses are routinely generated from optical coherence tomography (OCT) images, but on-board software capabilities and image scaling assumptions are not consistent across devices. This study evaluates the device-independent Iowa Reference Algorithms (Iowa Institute for Biomedical Imaging) for automated intra-retinal layer segmentation and image scaling for three OCT systems. Healthy participants (n = 25) underwent macular volume scans using a Cirrus HD-OCT (Zeiss), 3D-OCT 1000 (Topcon), and a non-commercial long-wavelength (1040nm) OCT on two occasions. Mean thickness of 10 intra-retinal layers was measured in three ETDRS subfields (fovea, inner ring and outer ring) using the Iowa Reference Algorithms. Where available, total retinal thicknesses were measured using on-board software. Measured axial eye length (AEL)-dependent scaling was used throughout, with a comparison made to the system-specific fixed-AEL scaling. Inter-session repeatability and agreement between OCT systems and segmentation methods was assessed. Inter-session coefficient of repeatability (CoR) for the foveal subfield total retinal thickness was 3.43μm, 4.76μm, and 5.98μm for the Zeiss, Topcon, and long-wavelength images respectively. For the commercial software, CoR was 4.63μm (Zeiss) and 7.63μm (Topcon). The Iowa Reference Algorithms demonstrated higher repeatability than the on-board software and, in addition, reliably segmented all 10 intra-retinal layers. With fixed-AEL scaling, the algorithm produced significantly different thickness values for the three OCT devices (Pimaged with these devices, however ocular biometry is required for accurate quantification of OCT images. PMID:27588683

  18. Adjacent segment degeneration after anterior cervical discectomy and fusion follow-up%颈椎前路融合术后邻近节段退变情况的研究

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      目的通过观察分析前路颈椎间盘切除融合术(anterior cervical discectomy and fusion,ACDF)术后随访患者的影像学资料,探讨邻近节段病变的发生时间和发生率。方法分析2008年以来本科收治的94例施行 ACDF 手术并获得完整随访的患者,其中男性51例,女性43例;年龄28~70岁,平均50.5岁。融合节段:单节段42例,上节段30例,三节段22例。术前均常规行颈椎正、侧位 X 线、MRI 检查。术后评定患者神经功能恢复情况,根据 Kellgren 分级标准对临近节段颈椎间盘退变情况进行 X 线评价。结果94例患者随访时间12~45个月,平均随访时间为29.1月。术后患者神经功能改善明显,JOA 评分较术前提高5.8,改善率为64.3%,有效率为100%。临近节段颈椎间盘退变情况的 X 线评估显示,有19例发生临近节段的退变,其中12例有轻度退变表现,7例出现较严重退变表现,邻近节段退变发生率为20.2%。退变发生时间为术后5~40个月,平均为18.7±4.79个月。结论 ACDF 治疗颈椎间盘退行性疾病有良好的疗效,术后邻近节段发生退变时间为18.7±4.79月,随访29.1个月邻近节段退变发生率为20.2%。%Objective To study the clinical efficacy of anterior cervical discectomy and fusion(ACDF) for cervical spondylosis , also the rate and occurrence time of adjacent segment degeneration.Methods 94 cases (male: 51, female: 43, average age: 50.5, ranging from 28 to 70)of cervical spondylosis admitted to our department since 2008 were analyzed in this study.42 patients were performed with single-level ACDF, 30 patients with double-level ACDF,and 22 patients with three-level ACDF. The cervical anterior-posterior and lateral X-ray and MRI examination were performed before the operation.Neurological functional recovery was assessed after operation. X -ray was used to evaluate the degree of adjacent segment degeneration according to

  19. 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.

  20. Object-Based Canopy Gap Segmentation and Classification: Quantifying the Pros and Cons of Integrating Optical and LiDAR Data

    OpenAIRE

    Jian Yang; Trevor Jones; John Caspersen; Yuhong He

    2015-01-01

    Delineating canopy gaps and quantifying gap characteristics (e.g., size, shape, and dynamics) are essential for understanding regeneration dynamics and understory species diversity in structurally complex forests. Both high spatial resolution optical and light detection and ranging (LiDAR) remote sensing data have been used to identify canopy gaps through object-based image analysis, but few studies have quantified the pros and cons of integrating optical and LiDAR for image segmentation and ...

  1. 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.

  2. Optical measurements of phase steps in segmented mirrors - fundamental precision limits

    CERN Document Server

    Noethe, L

    2006-01-01

    Phase steps are an important type of wavefront aberrations generated by large telescopes with segmented mirrors. In a closed-loop correction cycle these phase steps have to be measured with the highest possible precision using natural reference stars, that is with a small number of photons. In this paper the classical Fisher information of statistics is used for calculating the Cramer-Rao bound, which determines the limit to the precision with which the height of the steps can be estimated in an unbiased fashion with a given number of photons and a given measuring device. Four types of measurement devices are discussed: a Shack-Hartmann sensor with one small cylindrical lenslet covering a sub-aperture centred over a border, a modified Mach-Zehnder interferometer, a Foucault test, and a curvature sensor. The Cramer-Rao bound is calculated for all sensors under ideal conditions, that is narrowband measurements without additional noise or disturbances apart from the photon shot noise. This limit is compared with...

  3. Multivendor Spectral-Domain Optical Coherence Tomography Dataset, Observer Annotation Performance Evaluation, and Standardized Evaluation Framework for Intraretinal Cystoid Fluid Segmentation.

    Science.gov (United States)

    Wu, Jing; Philip, Ana-Maria; Podkowinski, Dominika; Gerendas, Bianca S; Langs, Georg; Simader, Christian; Waldstein, Sebastian M; Schmidt-Erfurth, Ursula M

    2016-01-01

    Development of image analysis and machine learning methods for segmentation of clinically significant pathology in retinal spectral-domain optical coherence tomography (SD-OCT), used in disease detection and prediction, is limited due to the availability of expertly annotated reference data. Retinal segmentation methods use datasets that either are not publicly available, come from only one device, or use different evaluation methodologies making them difficult to compare. Thus we present and evaluate a multiple expert annotated reference dataset for the problem of intraretinal cystoid fluid (IRF) segmentation, a key indicator in exudative macular disease. In addition, a standardized framework for segmentation accuracy evaluation, applicable to other pathological structures, is presented. Integral to this work is the dataset used which must be fit for purpose for IRF segmentation algorithm training and testing. We describe here a multivendor dataset comprised of 30 scans. Each OCT scan for system training has been annotated by multiple graders using a proprietary system. Evaluation of the intergrader annotations shows a good correlation, thus making the reproducibly annotated scans suitable for the training and validation of image processing and machine learning based segmentation methods. The dataset will be made publicly available in the form of a segmentation Grand Challenge. PMID:27579177

  4. Optical granulometric analysis of sedimentary deposits by color segmentation-based software: OPTGRAN-CS

    Science.gov (United States)

    Chávez, G. Moreno; Sarocchi, D.; Santana, E. Arce; Borselli, L.

    2015-12-01

    The study of grain size distribution is fundamental for understanding sedimentological environments. Through these analyses, clast erosion, transport and deposition processes can be interpreted and modeled. However, grain size distribution analysis can be difficult in some outcrops due to the number and complexity of the arrangement of clasts and matrix and their physical size. Despite various technological advances, it is almost impossible to get the full grain size distribution (blocks to sand grain size) with a single method or instrument of analysis. For this reason development in this area continues to be fundamental. In recent years, various methods of particle size analysis by automatic image processing have been developed, due to their potential advantages with respect to classical ones; speed and final detailed content of information (virtually for each analyzed particle). In this framework, we have developed a novel algorithm and software for grain size distribution analysis, based on color image segmentation using an entropy-controlled quadratic Markov measure field algorithm and the Rosiwal method for counting intersections between clast and linear transects in the images. We test the novel algorithm in different sedimentary deposit types from 14 varieties of sedimentological environments. The results of the new algorithm were compared with grain counts performed manually by the same Rosiwal methods applied by experts. The new algorithm has the same accuracy as a classical manual count process, but the application of this innovative methodology is much easier and dramatically less time-consuming. The final productivity of the new software for analysis of clasts deposits after recording field outcrop images can be increased significantly.

  5. Anterior cervical discectomy combined with corpectomy treatment of multi-segmental cervical spondylotic myeiopathy%颈椎前路两种手术方式治疗多节段脊髓型颈椎病

    Institute of Scientific and Technical Information of China (English)

    巩陈; 申才良; 董福龙; 郑军; 汪卫兵

    2011-01-01

    Objective To evaluate of two different anterior cervical surgical treatment of multilevel cervical spondylotic myelopathy clinical efficacy. Methods Selected three or more segments accumulated of the spinal cord-type cervical spondylosis of 36 patients, of which 18 cases were treated with a single sub-segment corpectomy internal fixation + other disc excision alone bone graft and internal fixation( A group ), which was segmental decompression and bone graft fixation; 18 patients with two or more vertebral bodies and fusion with subtotal long segment plate fixation( B group ), which was long segment decompression and bone graft fixation. Two groups were compared with operative time , operative blood loss, hospital stay, fusion rate, neurological improvement rate and cervical physiological curvature of the situation. Results Operation time, blood loss, hospital stay in A group were lower than those in B group( P <0. 05 ). Internal fixations of both groups had not problem postoperative. Cobb’s angle compared with preoperative improvement between the two groups was statistically significant( P < 0. 05 ) ; B group anglec loss rate of postoperative follow-up was higher than that in A group( P <0. 05 ); Bone graft fusion occurred after 6 months in two groups, JOA scores had improvement in the two groups and there was no statistically significant ( P >0. 05 ). Conclusion Both methods attain good clinical results; Anterior cervical discectomy combined with corpectomy treatment of multi-segmental cervical spondylotic myeiopathy , with relatively less blood loss, shorter operative time,less trauma, retain more vertebral bone.which is a good operation method.%目的 评价颈椎前路分节段减压植骨内固定术和长节段减压植骨固定术治疗多节段脊髓型颈椎病的临床疗效.方法 选择累及≥3个节段的脊髓型颈椎病患者36例,其中18例采用分节段单个椎体次全切除植骨内固定+其它椎间盘单独切除植骨内固

  6. A segmented scintillator-lead photon calorimeter using a double wavelength shifter optical readout system

    International Nuclear Information System (INIS)

    The construction and performance of a prototype scintillator-lead photon calorimeter using a double wavelength shifter optical readout is described. The calorimeter is divided into four individual cells consisting of 44 layers of 3 mm lead plus 1 cm thick scintillator. The edges of each scintillator plate are covered by acrylic bars doped with a wavelength shifting material. The light produced in each scintillator plate is first converted in these bars, then converted a second time in a set of acrylic rods which run longitudinally through the calorimeter along the corners of each calorimeter cell. A photomultiplier is attached to each of these rods at the back end of the calorimeter. The energy resolution obtained with incident in the energy range 2-30 GeV is sigma/E = 0.12/√E. The uniformity of response across the front face of each cell was measured. Showers within each cell can be localised with an accuracy of better than sigma = 7 mm. (orig.)

  7. 应用25G玻璃体切除术治疗白内障术后眼前段拥挤征%25-Gauge transconjunctival sutureless vitrectomy for crowded anterior segment after cataract surgery.

    Institute of Scientific and Technical Information of China (English)

    李雯; 荣翱

    2012-01-01

    Objective To investigate the application of 25-gauge transconjunctival sutureless vitrectomy system(25GTSV)on the treatment of crowded anterior segment(CAS)after phacoemulsification and intraocular lens implantation.Methods 15 cases(15 eyes)of CAS after cataract surgery were treated with posterior capsulotomy and anterior segment vitrectomy with 25GTSV.The follow-up periods were 6 ~ 12months[(8.0 ± 1.5)months].The visual acuity,intraocular pressure(IOP)and the depth of anterior chamber were recorded,the condition of cornea,pupil,intraocular lens and complication were observed.Results All operations were successful.The visual acuity of all cases were improved in different degree after treatment.The best corrected visual acuity before treatment,1 week after treatment and at the end of the followup period was(0.05 ± 0.02),(0.2 ± 0.1)and(0.4 ± 0.1)respectively.There were significant difference before and after treatment(t =0.00,P =0.00).The mean IOP 1 week after treatment and at the end of the follow-up period was(17.3 ± 1.8)mmHg and(16.5 ± 1.3)mmHg respectively.They were lower obviously than the mean IOP before surgery which was(40.1 ± 7.5)mmHg.There were significant difference between them(t =0.00,P =0.00).The mean depth of anterior chamber before treatment,1 week after treatment and at the end of the follow-up period was(0.69 ±0.17)mm,(2.7 1 ±0.43)mm and(2.85 ±0.52)mm respectively.There were significant difference before and after treatment(t =0.00,P =0.00).After surgery,the edema of cornea disappeared,the pupil is round and a round hyalomere with diameter of 3.0 ~ 4.0 mmwas formed at the center of lens ' posterior capsule in all eyes.No obvious complications were observed intraoperatively and postoperatively.Conclusion 25GTSV with micro-incision can release and cure CAS after cataract surgery effectively and safely.%目的 评价25G经结膜无缝合玻璃体切除手术系统(25G TSV)在白内障行超声乳化联合人工晶状体植入术后眼前

  8. CASE OF BILATERAL ANTERIOR SEGMENT TUBERCULOSIS

    Directory of Open Access Journals (Sweden)

    Gopal Kishan

    2015-04-01

    Full Text Available Tuberculosis is an important cause of uveitis in our country. India has been declared the country with the highest tuberculosis burden with 25 % of the cases . (1 This is especially true in Andhra Pradesh and Telangana which have a high percentage of affected patients. However , tuberculous uveitis is usually a unilateral presen tation. We report a case of bilateral uveitis of tuberculous origin in a 55 year old woman. She presented with different tuberculous manifestations in the two eyes. While the RE showed non granulomatous uveitis with sclerosing keratitis , the LE showed gran ulomatous uveitis with mutton fat keratic precipitates. Systemic examination revealed an enlarged lymph node which was positive for tuberculosis on biopsy. She was hence diagnosed as extra pulmonary tuberculosis and was treated with ATT regimen. In this pa tient , uveitis was the initial manifestation and resulted in a systemic diagnosis.

  9. CTA study on relationship between dominant A1 segment and the anterior communicating artery aneurysm%大脑前动脉 A1段优势征与前交通动脉瘤关系的 CTA 研究

    Institute of Scientific and Technical Information of China (English)

    王洪生; 陈晓峰; 陈斌; 殷尚炯; 赵佩林; 王志明

    2015-01-01

    目的:探讨大脑前动脉水平段( A1段)优势征与前交通动脉瘤( ACoAA )形成的关系。方法分析173例患者的64排CT血管成像(CTA)检查资料,并按CTA结果分为ACoAA组(83例)与正常对照组(90例)。观察指标:有无动脉瘤,动脉瘤的部位、形态、大小和瘤颈宽度、瘤顶指向及瘤体与周围结构的关系等,判定结果与手术及DSA结果进行对照。同时观察大脑前动脉A1段是否发育不良或缺如,是否存在一侧大脑前动脉A1段优势征。结果 ACoAA组中显示一侧大脑前动脉A1段优势征者的比率达80.7%,明显高于正常对照组的16.7%(P<0.05)。结论一侧大脑前动脉A1段优势征,另一侧A1段发育不良或缺如与ACoAA的发生有密切关系。%Objective To investigate the relationship between the dominant A 1 segment and presence of the anterior communicating artery aneurysm .Methods The data of 64-slice computed tomography angiography ( CTA ) of 173 cases were analysed retrospectively .The 173 cases were divided into anterior communicating artery aneurysm (ACoAA) group(83 cases) and control group (90 cases).The observation items were the presence of aneurysm and the location , shape, size, neck, axis point of every one aneurysm and the relationship of aneurysms to parent vessels and other branches and bone structure .The results of aneurysms were compared with clipping or coiling , at the same time, to observe the A1 segment of anterior cerebral artery whether had dysplasia or absence , whether existed the dominance of A 1 segment of anterior cerebral artery .Results The rate of display the dominance of A1 segment of anterior cerebral artery (80.7%) in the ACoAA group was higher than that in the control group (16.7%) ( P <0.05 ).Conclusion The development of the anterior communicating artery aneurysm closely related with the the dominance of A 1 segment of anterior cerebral artery and the dysplasia or

  10. Sipunculans and segmentation

    DEFF Research Database (Denmark)

    Wanninger, Andreas; Kristof, Alen; Brinkmann, Nora

    2009-01-01

    Comparative molecular, developmental and morphogenetic analyses show that the three major segmented animal groups- Lophotrochozoa, Ecdysozoa and Vertebrata-use a wide range of ontogenetic pathways to establish metameric body organization. Even in the life history of a single specimen, different...... mechanisms may act on the level of gene expression, cell proliferation, tissue differentiation and organ system formation in individual segments. Accordingly, in some polychaete annelids the first three pairs of segmental peripheral neurons arise synchronously, while the metameric commissures of the ventral...... nervous system form in anterior-posterior progression. Contrary to traditional belief, loss of segmentation may have occurred more often than commonly assumed, as exemplified in the sipunculans, which show remnants of segmentation in larval stages but are unsegmented as adults. The developmental...

  11. The observation of anterior segment morphological changes in eyes with primary angle closure after LPI by using UBM%原发性前房角关闭行LPI后眼前节形态学的UBM观察

    Institute of Scientific and Technical Information of China (English)

    吴杨杨; 宋胜仿; 刘世纯; 李春华; 张永烨; 吕莎

    2014-01-01

    观察原发性前房角关闭(primary angle closure, PAC)行YAG激光周边虹膜切除术(laser peripheral iridotomy, LPI)后眼前节形态学的变化。方法:选择2012年3月至2013年3月在我院诊断为PAC并行LPI的患者28例(48眼)为研究对象,应用超声生物显微镜(ultrasound biomicroscopy, UBM),观察LPI术前及术后1天、1周、1个月及3个月各时间点颞上、正上、正下、颞侧、鼻侧共5个位点的房角开放距离(angle opening distance, AOD500)、小梁虹膜夹角(trabecu-lar-iris angle, TIA)、小梁睫状体距离(trabecular ciliary process distance, TCPD)、虹膜睫状体距离(iris ciliary process distance , ICPD)、虹膜晶体夹角(iris lens angle, ILA)、虹膜晶体接触距离(iris lens process distance, ILCD)、虹膜厚度1(iris thickness, ITl)、IT2、IT3以及中央前房深度(cental depth distance, ACD)的变化。结果:AOD500、TIA:术后较术前均增大(P<0.05);术后1周大于术后其余时间点(P>0.05)。TCPD:除个别位点较术前增加(P>0.05),其余时间点相应位点较术前增加(P<0.05);术后1周大于术后其余时间点(P>0.05)。ILA:术后较术前均减小(P<0.05);术后1天至术后3个月逐渐增大(P>0.05)。ILCD:术后较术前均增大(P<0.05),术后1天至术后3个月逐渐减小(P>0.05);IT1、IT2、IT3:术后较术前均减小(P<0.05);术后各时间点间比较(P>0.05)。ACD:术后较术前增加(P>0.05)。 LPI术前及术后各时间点平均ILA与平均ILCD的相关性显示二者呈高度负相关。结论:PAC患者行LPI术后周边前房明显加深,虹膜膨隆和瞳孔阻力减轻,但术后3个月内眼前节形态并不稳定,个别参考值有不同程度的回退,LPI术后有必要进行长期随访观察。%Objective To evaluate the changes in the anterior segment morphology by using ultrasound biomicroscopy (UBM) after YAG laser

  12. 原发性前房角关闭激光周边虹膜切除术后前房角的改变%Evaluation of changes in anterior segment morphology of primary angle closure after laser peripheral iridotomy

    Institute of Scientific and Technical Information of China (English)

    张英; 田祥; 潘乐

    2012-01-01

    Objective To discover primary angle closure (PAC) in eyes of anatomic narrow angle (ANA),evaluate quantify changes of the PAC in anterior segment morphology after laser iridotomy using ultrasound biomicroscopy (UBM) and explore the therapy of primary angle closure.Methods Prospective interventive observational case series.Twenty-eight eyes of patients presented PAC in the Department of Ophthalmology at Zunyi Medical College Hospital.PAC was presented on iris contacting with trabecular meshwork temporally in one UBM image.The PAC eyes were examined again by UBM in the both same light conditions and items at two weeks after laser peripheral iridotomy (LPI).Results The rate of PAC was significantly decreased after LPI in the same condition,the rate of PAC was 96.43% before LPI in dark condition,and it was significantly dropped down to 32.14% after LPI (x2 =14.45,P <0.05).In light condition,it was cut down from 67.86% to 7.14% after LPI (x2 =15.06,P <0.05).The AOD500 and TIA were increased after LPI (P <0.001),it indicated that the angle of PAC was widened after LPI.The ILCD of PAC was also added after LPI,but the ILA was decreased after LPI (P <0.001).This phenomenon suggested that the pupillary block was relieved after care of LPI.The IT1 was thinner in laser site quadrant in dark condition after LPI which combined Nd-YAG and green laser (P <0.05).There were no significant changes of the ACD (P >0.05).The ICPD was reduced in dark after LPI (t =2.519,P =0.012).The pupillary block was relieved; it leaded to iris caving backward.But the TCPD was added in light after LPI (t =-2.967,P =0.003).It suggested that the ciliary body removed towards the back after LPI.Conclusions LPI produces a significant widening of the peripheral anterior chamber angle and reducing the power of pupillary block for major PAC eyes,which have not peripheral anterior synechia,but not deeping the central anterior chamber distance.LPI can prevent most PAC from developing to PACG

  13. Structural Alterations of Segmented Macular Inner Layers in Aquaporin4-Antibody-Positive Optic Neuritis Patients in a Chinese Population.

    Directory of Open Access Journals (Sweden)

    Chunxia Peng

    Full Text Available This study aimed to analyse the structural injury of the peripapillary retinal nerve fibre layer (pRNFL and segmented macular layers in optic neuritis (ON in aquaporin4-antibody (AQP4-Ab seropositivity(AQP4-Ab-positiveON patients and in AQP4-Ab seronegativity (AQP4-Ab-negative ON patients in order to evaluate their correlations with the best-corrected visual acuity (BCVA and the value of the early diagnosis of neuromyelitis optica (NMO.This is a retrospective, cross-sectional and control observational study.In total, 213 ON patients (291 eyes and 50 healthy controls (HC (100 eyes were recruited in this study. According to a serum AQP4-Ab assay, 98 ON patients (132 eyes were grouped as AQP4-Ab-positive ON and 115 ON patients (159 eyes were grouped as AQP4-Ab-negative ON cohorts. All subjects underwent scanning with spectralis optical coherence tomography (OCT and BCVA tests. pRNFL and segmented macular layer measurements were analysed.The pRNFL thickness in AQP4-Ab-positive ON eyes showed a more serious loss during 0-2 months (-27.61μm versus -14.47 μm and ≥6 months (-57.91μm versus -47.19μm when compared with AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON preferentially damaged the nasal lateral pRNFL. The alterations in the macular ganglion cell layer plus the inner plexiform layer (GCIP in AQP4-Ab-positive ON eyes were similar to those in AQP4-Ab-negative ON eyes. AQP4-Ab-positive ON eyes had entirely different injury patterns in the inner nuclear layer (INL compared with AQP4-Ab-negative ON eyes during the first 6 months after the initial ON attack. These differences were as follows: the INL volume of AQP4-Ab-positive ON eyes had a gradual growing trend compared with AQP4-Ab-negative ON eyes, and it increased rapidly during 0-2 months, reached its peak during 2-4 months, and then decreased gradually. The pRNFL and GCIP in AQP4-Ab-positive ON eyes had positive correlations with BCVA. When the pRNFL thickness decreased to 95%CI (50.77

  14. 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.

  15. 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.

  16. 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

  17. Three-dimensional Segmentation of Retinal Cysts from Spectral-domain Optical Coherence Tomography Images by the Use of Three-dimensional Curvelet Based K-SVD.

    Science.gov (United States)

    Esmaeili, Mahdad; Dehnavi, Alireza Mehri; Rabbani, Hossein; Hajizadeh, Fedra

    2016-01-01

    This paper presents a new three-dimensional curvelet transform based dictionary learning for automatic segmentation of intraretinal cysts, most relevant prognostic biomarker in neovascular age-related macular degeneration, from 3D spectral-domain optical coherence tomography (SD-OCT) images. In particular, we focus on the Spectralis SD-OCT (Heidelberg Engineering, Heidelberg, Germany) system, and show the applicability of our algorithm in the segmentation of these features. For this purpose, we use recursive Gaussian filter and approximate the corrupted pixels from its surrounding, then in order to enhance the cystoid dark space regions and future noise suppression we introduce a new scheme in dictionary learning and take curvelet transform of filtered image then denoise and modify each noisy coefficients matrix in each scale with predefined initial 3D sparse dictionary. Dark pixels between retinal pigment epithelium and nerve fiber layer that were extracted with graph theory are considered as cystoid spaces. The average dice coefficient for the segmentation of cystoid regions in whole 3D volume and with-in central 3 mm diameter on the MICCAI 2015 OPTIMA Cyst Segmentation Challenge dataset were found to be 0.65 and 0.77, respectively. PMID:27563573

  18. Evaluation of Corneal Stromal Demarcation Line after Two Different Protocols of Accelerated Corneal Collagen Cross-Linking Procedures Using Anterior Segment Optical Coherence Tomography and Confocal Microscopy

    Directory of Open Access Journals (Sweden)

    Engin Bilge Ozgurhan

    2014-01-01

    Full Text Available Purpose. To evaluate the depth of corneal stromal demarcation line using AS-OCT and confocal microscopy after two different protocols of accelerated corneal collagen cross-linking procedures (CXL. Methods. Patients with keratoconus were divided into two groups. Peschke CXL device (Peschke CCL-VARIO Meditrade GmbH applied UVA light with an intended irradiance of 18.0 mW/cm2 for 5 minutes after applying riboflavin for 20 minutes (group 1 and 30 minutes (group 2. One month postoperatively, corneal stromal demarcation line was measured using AS-OCT and confocal microscopy. Results. This study enrolled 34 eyes of 34 patients (17 eyes in group 1 and 17 eyes in group 2. The mean depth of the corneal stromal demarcation line was 208.64±18.41 μm in group 1 and 240.37±18.89 μm in group 2 measured with AS OCT, while it was 210.29±18.66 μm in group 1 and 239.37±20.07 μm in group 2 measured with confocal microscopy. Corneal stromal demarcation line depth measured with AS OCT or confocal microscopy was significantly deeper in group 2 than group 1 (P<0.01. Conclusion. The group in which riboflavin was applied for 30 minutes showed significantly deeper corneal stromal demarcation line than the group in which riboflavin was applied for 20 minutes.

  19. 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.

  20. Cryogenic optical measurements of 12-segment-bonded carbon-fiber-reinforced silicon carbide composite mirror with support mechanism

    Science.gov (United States)

    Kaneda, Hidehiro; Nakagawa, Takao; Onaka, Takashi; Enya, Keigo; Makiuti, Sin'itirou; Takaki, Junji; Haruna, Masaki; Kume, Masami; Ozaki, Tsuyoshi

    2008-03-01

    A 720 mm diameter 12-segment-bonded carbon-fiber-reinforced silicon carbide (C/SiC) composite mirror has been fabricated and tested at cryogenic temperatures. Interferometric measurements show significant cryogenic deformation of the C/SiC composite mirror, which is well reproduced by a model analysis with measured properties of the bonded segments. It is concluded that the deformation is due mostly to variation in coefficients of thermal expansion among segments. In parallel, a 4-degree-of-freedom ball-bearing support mechanism has been developed for cryogenic applications. The C/SiC composite mirror was mounted on an aluminum base plate with the support mechanism and tested again. Cryogenic deformation of the mirror attributed to thermal contraction of the aluminum base plate via the support mechanism is highly reduced by the support, confirming that the newly developed support mechanism is promising for its future application to large-aperture cooled space telescopes.

  1. Application of Zero-P interbody fusion in degenerative disease at the adjacent segments after anterior cervical fusion%Zero-P椎间融合术在治疗颈前路融合术后相邻节段退变性疾病中的应用

    Institute of Scientific and Technical Information of China (English)

    程彩霞; 卢旭华; 谢宁; 郭翔; 郭群峰; 倪斌

    2012-01-01

    Objective To investigate the clinical outcomes of Zero-P interbody fusion in the treatment of degenerative disease at the adjacent segments after anterior cervical decompression and fusion with internal fixation. Methods Sixteen patients with degenerative diseases at adjacent segments after anterior cervical decompression and fusion with internal fixation received Zero-P anterior cervical interbody fusion. Japanese Orthopaedic Association ( JOA) scores were compared before and after the operation. Postoperative dysphagia and intervertebral fusion were observed. Results Postoperative JOA score was significantly increased as compared with preoperative score (P<0.05). No dysphagia occurred and all the patients obtained solid fusion. Conclusion The mid- and short-term curative effect is satisfactory for the Zero-P intervertebral fusion in the treatment of cervical degenerative disease in the adjacent segments after anterior cervical fusion.%目的 探讨采用Zero-P椎间融合术治疗颈前路减压融合内固定术后相邻节段退变性疾病的疗效.方法 对16例颈前路减压融合内固定术后发生相邻节段退变性疾病的患者采用Zero-P行颈前路椎间融合术,比较患者手术前后日本骨科学会(Japanese Orthopaedic Association,JOA)评分,观察患者术后吞咽困难发生情况及椎间融合情况.结果 患者术后JOA评分较术前提高,差异有统计学意义(P<0.05),未发生吞咽困难,所有患者均获得牢固融合.结论 采用Zero-P椎间融合术治疗颈前路融合术后相邻节段退变性疾病中短期疗效较好.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 颈椎前路融合致邻近节段椎间盘退变的原因探讨%Causes of adjacent segments disc degeneration caused by anterior cervical fusion

    Institute of Scientific and Technical Information of China (English)

    张克非; 刘伟; 于长水; 袁绍辉; 潘琦

    2011-01-01

    目的 探讨颈椎前路融合后邻近节段椎间盘退变的原因及其防治办法.方法 对实施颈椎前路融合术的126例颈椎间盘突出症患者进行回顾性分析,归纳可能导致颈椎前路融合术后临近椎间盘退变突出的原因.结果 随访时间最短10个月,最长10年,平均7.8年.37例颈椎间盘突出症患者发生临近节段椎间盘退变加重,其中7例患者再次手术.结论 颈椎前路融合后邻近节段椎间盘退变的原因可能为临近节段原有退变加重,椎间融合后生物力学改变,临近节段应力集中.%To investigate the causes of the adjacent intervertebral disc degeneration after anterior decompression and interbody fusion of C-spine and search for the way of prevention.Methods A retrospective study was given to 126 patients who underwent an anterior decompression and interbody fusion of C-spine, the causes of the adjacent intervertebral disc degeneration after anterior decompression and interbody fusion of C-spine were analyzed. Results The follow-up time was from 10 months to 10 years, average 7.8 years. Thirty-seven patients occurred the aggravation of adjacent intervertebral discs degeneration, in which 7 patients underwent reoperation. Conclusion The possible causes of the adjacent intervertebral disc degeneration after anterior decompression and interbody fusion of C-spine is that the aggravation of original degeneration of adjacent intervertebral disc, the alteration of biomechanics after anterior decompression and interbody fusion of C-spine induces the stress concentration of the adjacent intervertebral disc.

  7. Risk factors and treatment strategy for adjacent segment diseases after anterior cervical decompression and fusion%颈椎前路融合术后邻近节段退变性疾病的原因分析及治疗策略

    Institute of Scientific and Technical Information of China (English)

    王洪立; 姜建元; 吕飞舟; 马晓生; 夏新雷; 王立勋

    2014-01-01

    目的 探讨颈椎前路融合术后邻近节段退变性疾病的发生原因及治疗策略.方法 对2005年12月至2012年8月颈椎前路减压融合术后并发邻近节段退变性疾病的14例进行回顾性分析.男10例,女4例,初次手术年龄36~68岁,平均(52.0±11.0)岁.测量初次手术后颈椎整体曲度、手术节段局部曲度、钢板与上、下间隙的距离.二次手术时对节段数量≤2个且不伴严重后纵韧带或黄韧带骨化的9例采用颈椎前路减压融合内固定术,对节段数量≥3个且不伴明显后凸畸形、排列不稳及严重黄韧带骨化的3例采用颈椎后路减压椎管扩大成形术,对伴有明显后凸畸形、排列不稳且因技术原因无法行前路减压及合并严重黄韧带骨化的2例采用颈椎后路全椎板切除减压融合术.结果 初次术后邻近节段退变性疾病的发生时间为(9.3±4.4)年,二次手术时患者年龄(61.3±12.4)岁.初次术后颈椎整体曲度与手术节段局部曲度分别为12.4°±10.8°、1.5°±6.8°;钢板与上、下间隙的距离分别为(0.9±1.8)mm、(3.8±3.2) mm.二次术后平均随访(30.4±17.8)个月,末次随访时日本骨科学会颈椎病疗效评分改善率为73.9%±9.7%.结论 钢板与邻近间隙距离过小、手术节段局部曲度恢复不良可能是前路融合术后邻近节段退变性疾病的发生原因;二次手术方案的选择应根据病变累及节段、致压因素、颈椎曲度等因素进行综合分析.%Objective To investigate the risk factors and treatment strategy in treating adjacent segment diseases (ASD) after anterior cervical decompression and fusion.Methods Fourteen patients with ASD after anterior cervical decompression and fusion from December 2005 to August 2012 were analyzed.The overall curvature of the cervical spine,local curvature of surgical segments,and the distances between the plate and the upper and lower intervertebral space were measured and analyzed.10 males

  8. 大脑前动脉A1段的显微解剖与数字减影血管造影对照观测及临床意义%Microanatomy and digital subtraction angiography comparative observation of the A1 segment of anterior cerebral artery and its clinical significance

    Institute of Scientific and Technical Information of China (English)

    范锡印; 王怀彬; 付升旗; 赵东方; 苗莹莹

    2014-01-01

    目的 为临床选择颅内血管支架的类型和放置部位提供解剖学基础.方法 选取尸头标本20具,经双侧翼点入路显微解剖观测大脑前动脉A1段及其穿支血管.选取无病变的全脑DSA 100例,观测大脑前动脉A1段的走行及其穿支的开口部位.结果 显微解剖大脑前动脉A1段的长度和直径分别为(13.55±1.43) mm、(2.43±0.37) mm,DSA血管造影的长度和直径分别为(13.42±1.57) mm、(2.28 ±0.40) mm,显微解剖与DSA血管造影直径的差异有统计学意义(P<0.05).大脑前动脉A1段的穿支发自其后上壁,近侧段穿支数目(2.55±0.39)支,中间段(0.52±0.46)支,远侧段(1.12±0.11)支,近侧、中间、远侧段的穿支数目的差异均有统计学意义(P值均<0.05).男性较女性的大脑前动脉A1段长、直径粗,两者差异均有统计学意义(P值均<0.05).结论 大脑前动脉A1段的显微解剖与数字减影血管造影对照观测对临床选择颅内血管支架的类型和放置部位,避免血管支架阻塞穿支开口处,防止术后穿支供应区域缺血等具有重要的临床意义.%Objective To provide anatomical basis for selecting the types and placing parts of vascular stent.Methods Twenty head specimens were selected and the A1 segment of anterior cerebral artery and its perforators were measured by the pterion approach.One hundred digital subtraction angiography(DSA) images with no diseases of whole brain were selected,the course of the A1 segment of anterior cerebral artery and the opening parts of its perforators were observed.Results The length and external diameter of the microanatomy were (13.55 ± 1.43) mm and (2.43 ± 0.37) mm,respectively.The length and diameter of the DSA angiography of the A1 segment of anterior cerebral artery were (13.42 ± 1.57) mm and (2.28 ±0.40) mm respectively.There were significant differences in the diameter between the microanatomy and DSA angiography (P < 0.05).The perforators of the A1 segment of

  9. Clinical Effectiveness and Influence on Adjacent Segments Degeneration after Single-level Anterior Cervical Fusion%单节段颈椎前路减压融合术对邻近节段退变的影响及疗效观察

    Institute of Scientific and Technical Information of China (English)

    郑兆君; 邱玉金; 刘文华; 李军磊; 曹亮波

    2013-01-01

    Objective To evaluate the clinical effectiveness and influence on adjacent segments degenera-tion after single-level anterior cervical fusion.Methods A retrospective study was given to 40 patients who underwent single-level anterior cervical fusion from Aug.2007 to Dec.2010 and 40 patients with cervical spondylosis of the same age for the same period(imaging showed only a single segment lesions ) underwent conservative therapypatient .The disc degeneration were evaluated using intervertebral disc height and disc Pfirrmann MRI degeneration score .The clinical ef-fectiveness were evaluated using cervical JOA score ,the neck disability index(NDI) .Results The surgical group and conservative group had a statistically significant difference (P0.05) in cervi-cal JOA score and NDI than 1 week after that.Conclusion Anterior cervical discectomy and fusion can lead to degener-ation at the adjacent segment,but the clinical effectiveness are worthy of recognition .%  目的探讨单节段颈椎前路减压融合术对邻近节段退变的影响及手术疗效.方法回顾性分析2007年8月~2010年12月我科收治的40例行单节段颈椎前路减压融合术患者及同期同年龄段颈椎病(影像学显示仅单节段病变)且行保守治疗的患者资料.采用椎间隙高度及椎间盘Pfirrmann MRI退变评分作为评价椎间盘退变指标;采用颈椎JOA评分、颈椎功能障碍指数(NDI)作为手术疗效评价指标.结果术后24个月时,与对照组相比,手术组邻近节段椎间隙高度明显降低,差异有统计学意义(P0.05).结论颈椎前路减压融合术后邻近节段易发生退变,但疗效值得肯定.

  10. 前后段联合手术及硅油填充治疗高度近视黄斑孔视网膜脱离的疗效观察%The therapeutic effect of combined surgery of anterior and posterior segment and silicon oil tamponade on macular hole retinal detachment in eyes with high myopia

    Institute of Scientific and Technical Information of China (English)

    陈伟奇; 张责华; 胡一骏; 郑建龙

    2009-01-01

    Objective To observe the therapeutic effect of combined surgery of anterior and posterior segment and silicon oil tamponade on macular hole retinal detachment in eyes with high myopia. Methods The clinical data of 48 high myopia patients (48 eyes) with macular hole retinal detachment were retrospectively analyzed. Retinal detachment was mainly at the posterior pole; macular hole was confirmed by non-contact Hruby lens and optical coherence tomography (OCT). Phacoemulsification combined with pars plana vitrectomy and silicon oil tamponade were performed to all patients, of which 41 had undergone internal limiting membrane peeling, and 23 had intraocular lens implanting. The oil had been removed 3.5-48.0 months after the first surgery and OCT had been performed before the removal. The follow-up period after the removal of the silicon oil was more than 1 year. Results The edge of the macular hole could not be seen under the non-contact Hruby lens 1 week after the surgery in all but 5 patients, and the visual acuity improved. The silicon oil had been removed in all of the 48 patients; the OCT scan before the removal showed that the closed macular holes can be in U shape (8 eyes), V shape (6 eyes) or W shape (23 eyes). About 13-38 months after the oil removal, retinal detachment recurred in 2 patients with the W-shaped holes. At the end of the follow-up period, 16 patients (33.3%) had U or V-shaped macular holes, and 32 patients (66.7%) had W-shaped macular holes. The rate of retinal reattachment was 100%. Conclusion Combined surgery of anterior and posterior segment and silicon oil tamponade is effective on macular hole retinal detachment in eyes with high myopia.%目的 观察前后段联合手术及硅油充填治疗高度近视黄斑孔视网膜脱离临床疗效.方法 回顾分析前后段联合手术及硅油充填治疗高度近视黄斑孔视网膜脱离患者48例48只眼的临床资料.患者均有高度近视史,视网膜脱离以后极部为主.裂隙灯

  11. Clinical outcomes of selective anterior cervical corpectomy combined with segmental disectomy and fusion for treating three-level cervical myelopathy%前路选择性椎体切除结合单间隙减压植骨融合术治疗三节段脊髓型颈椎病的临床疗效

    Institute of Scientific and Technical Information of China (English)

    曹涌; 张烽; 陈向东; 姜星杰

    2011-01-01

    Objective To evaluate the clinical outcomes of selective anterior cervical corpectomy combined with segmental disectomy and fusion for treating three-level cervical myelopathy. Methods Thirtee patients of multilevel cervical myelopathy with 3 consecutive segments were treated with anterior cervical corpectomy combined with segmental disectomy and fusion. Study parameters included JOA score and grading the Odom criteria. The sagittal segmental alignment of fusion levels was measured using the Cobb method before and after surgery. Graft fusion rate was observed during final follow up. Results The patients were followed up for 12 to 39 months. The JOA score of 13 patients was higher three months after surgery than that before[(14. 6± 1.0) points vs. (11.1 ± 1.0) points] (P<0. 01). Surgical results of Odom criteria were excellent in 8 cases, good in 3 cases, fair in 2 cases. Graft fusion rate was 100%. Radiograph analysis indicated that the Cobb angle of mean segmental lordosis was 3.7 degrees before, 10.7 degrees one week later and 10.4 degrees during the final follow up. Conclusion Selective anterior cervical corpectomy combined with segmental disectomy and fusion results in high fusion rates with sufficient decompression in the treatment of three-level cervical myelopathy.%目的 分析颈前路选择性椎体次全切除十单间隙减压植骨融合术治疗三节段脊髓型颈椎病的临床疗效.方法 13例脊髓型颈椎病患者行颈前路选择性椎体次全切除十单间隙减压、自体髂骨植骨、钢板内固定术.分析术前及随访时的日本骨科协会(JOA)评分,记录术后Odom分级.测量术前、术后1周及末次随访时颈椎侧位X线片,观察术后颈椎植骨融合率、颈椎曲度(Cobb角)维持、症状及功能改善率.结果 13例患者随访12~39个月,术后3个月JOA评分为(14.6±1.0)分,明显高于术前的(11.1±1.0)分(P<0.01).术后Odom分级:优8例,良3例,一般2例,植骨融合率100%.

  12. Anterior ischemic optic neuropathy: a comparison of the optic disc area of patients with the arteritic and non-arteritic forms of the disease and that of normal controls Neuropatia óptica isquêmica anterior: estudo comparativo da área do disco óptico de pacientes com as formas arterítica e não-arterítica da doença e de controles normais

    Directory of Open Access Journals (Sweden)

    Mário Luiz Ribeiro Monteiro

    2006-12-01

    Full Text Available PURPOSE: To evaluate the optic disc area of patients with non-arteritic anterior ischemic optic neuropathy (NA-AION and arteritic anterior ischemic optic neuropathy (A-AION and compare the results between each other and with those from controls in order to verify the existence and the magnitude of anatomical factors predisposing to the development of anterior ischemic optic neuropathy. METHODS: This is a case-controlled study of the optic disc area of 24 consecutive patients affected with NA-AION, 13 patients with A-AION and 24 consecutive healthy normals, sex- and age-matched with the patients with the NA-AION group. Measurements of optic disc area were performed for each studied group using disc photographs projected, measured and corrected for the refractive error and the keratometric readings, according to Littmann's method in each studied group. The results were compared using variance analysis. RESULTS: The mean areas and standard deviations of the optic discs from patients with NA-AION, A-AION and normals were respectively 1.99 ± 0.35 mm², 2.29 ± 0.39 mm² and 2.49 ± 0.53 mm². The statistical analysis revealed that the mean areas of the optic disc of patients with NA-AION were significantly different from those of normal controls. No statistical difference was found between A-AION and normal controls. CONCLUSION: NA-AION occurs predominantly in small discs while the arteritic form of the disease shows no such preference. Factors related to optic disc structure play a role in the pathophysiology of NA-AION. The occurrence of AION in large optic optic discs should raise the suspicion of temporal arteritis. On the other hand, small optic disc areas do not rule out that vasculitis.OBJETIVO: Calcular a área do disco óptico de pacientes com neuropatia óptica isquêmica anterior não arterítica (NOIA-NA e com neuropatia óptica isquêmica anterior por arterite temporal (NOIA-A comparando os resultados entre si e com o grupos controle

  13. The sugery for adjacent segment degenerative disease after previous anterior cervical corpectomy and fusion%颈前路椎体次全切除融合术后邻近节段病的手术治疗

    Institute of Scientific and Technical Information of China (English)

    张海龙; 贺石生; 丁悦; 顾广飞; 李忠海; 溪铁胜

    2012-01-01

    颈前路椎体次全切除融合术(anterior cervical corpectomy and fusion,ACCF)是治疗神经根及脊髓型颈椎病的有效方法,但随之而来的邻近节段退变问题成为广泛关注的焦点.既往文献报告引起症状的邻近节段退变的发生率达7%~17%,部分患者需要手术干预[1].1997年8月~2007年8月对42例ACCF后邻近节段退变性疾病患者行再手术治疗,总结如下.

  14. 前部缺血性视神经病变并发视网膜分支动脉阻塞1例%A case of branch retinal artery obstruction complicated after anterior ischemic optic neuropathy

    Institute of Scientific and Technical Information of China (English)

    Ungsoo Samuel Kim; Hyoung-Seok Kim; Young Ju Lew

    2011-01-01

    AIM: To report a case of branch retinal artery obstruction (BRAO) complicated after anterior ischemic optic neuropathy (AION).METHODS: A 42-year-old woman who complained of visual disturbance was performed ophthalmological examinations such as fundus photography, fluorescent angiography (FAG) and visual field test. RESULTS: At first visit, disc swelling was noted and arterial circulation was intact, however, 1 week after onset, the inferior branch retinal artery began to shrink and the flame hemorrhage intensified. Sixteen months later, the optic disc evidenced an atrophic change; additionally, a ghost vessel in the inferior branch retinal artery was found.CONCLUSION: We report a case of complications of BRAO arising after AION which caused the mechanical compression on the arterial circulation.%目的:报告1例前部缺血性视神经病变(anterior ischemic optic neuropathy,AION)并发视网膜分支动脉阻塞(branch retinal artery obstruction,BRAO).方法:患者,女,42岁,因视力障碍进行如下眼科检查:眼底照相、荧光血管造影(fluorescent angiography,FAG)和视野测试.结果:第一次就诊时,患者视盘肿胀,动脉循环完整,发病1wk后,视网膜下支动脉开始萎缩并火焰状出血加剧.16mo后,视盘呈萎缩性改变,此外,发现视网膜下分支动脉血管影一条.结论:AION并发BRAO可造成动脉循环的机械性压迫.

  15. Segmental neurofibromatosis

    OpenAIRE

    Galhotra, Virat; Sheikh, Soheyl; Jindal, Sanjeev; Singla, Anshu

    2014-01-01

    Segmental neurofibromatosis is a rare disorder, characterized by neurofibromas or cafι-au-lait macules limited to one region of the body. Its occurrence on the face is extremely rare and only few cases of segmental neurofibromatosis over the face have been described so far. We present a case of segmental neurofibromatosis involving the buccal mucosa, tongue, cheek, ear, and neck on the right side of the face.

  16. Reactive histiocytosis of the orbit and posterior segment in a dog.

    Science.gov (United States)

    Pumphrey, Stephanie A; Pizzirani, Stefano; Pirie, Christopher G; Sato, Amy F; Buckley, Faith I

    2013-05-01

    We present a case of reactive histiocytic disease involving the orbit, optic nerve, retina, and choroid in a Border Collie dog initially presenting for vision loss. Long-term partial return of vision has been achieved with systemic immunosuppression. Anterior segment and ocular surface manifestations of reactive histiocytic disease in dogs are relatively common. Posterior segment and orbital involvement, however, are minimally documented in the existing literature. To the authors' knowledge, this is the first report of disease confined to the orbit and posterior segment as well as the first report of vision loss as a presenting complaint for reactive histiocytic disease. Clinical, magnetic resonance imaging, cytologic, and histopathologic findings are reviewed. PMID:22853429

  17. 节段型严重颈椎后纵韧带骨化症前路、后路手术的疗效比较与选择策略%Anterior or posterior approach for segmental severe ossification of posterior longitudinal ligament of the cervical spine: the efficacy and selection strategy

    Institute of Scientific and Technical Information of China (English)

    雷涛; 申勇; 王林峰; 丁文元; 张为; 张迪

    2013-01-01

    Objective To investigate the efficacy and selection of anterior and posterior approaches for segmental severe ossification of posterior longitudinal ligament (OPLL)of the cervical spine.Method From January 2007 to May 2011,59 patients with segmental severe OPLL underwent surgical treatment,including 41 males and 18 females,with an average age of 55.7 years.Among them,24 patients underwent anterior corpectomy and fusion,and 35 patients underwent laminectomy and lateral mass screw fixation.In two groups,the operation time,intraoperative blood loss,change of cervical curvature,neck axial symptoms,and JOA (Japanese Orthopaedic Association) score were recorded and compared.Result All patients were followed up for 12 to 18 months (average,15.4 months).The average JOA score in anterior approach group increased from preoperative 7.33 ± 1.09 to 13.63±0.82 at final follow-up,with an average improvement rate of 65.16% ±7.50%; the average JOA score in posterior approach group increased from preoperative 7.20 ± 1.05 to 12.23 ± 1.11 at final follow-up,with an improvement rate of 51.46%±9.64%; and the difference between two groups was statistically significant.Immediately after the operation,the segmental curvature of the operative site was 5.38°±1.14° in anterior approach group and 3.89°±1.65° in posterior approach group,and the difference was statistically significant.At final follow-up,the rate of neck axial symptoms was 20.83% in anterior approach group and 51.43% in posterior approach group,and the difference was also statistically significant.Conclusion For severe OPLL with not more than 3 segments of ossification,the anterior approach can remove the ossified mass directly,get a better neurological recovery,provide a good biomechanical alignment,and decrease the postoperative axial symptoms.However,posterior laminectomy and lateral mass screw fixation also can obtain enough decompression and maintain the segmental curvature.%目的 探讨前路和

  18. Segmental Neurofibromatosis

    Directory of Open Access Journals (Sweden)

    Yesudian Devakar

    1997-01-01

    Full Text Available Segmental neurofibromatosis is a rare variant of neurofibromatosis in which the lesions are confined to one segment or dermatome of the body. They resemble classical neurofibromas in their morphology, histopathology and electron microscopy. However, systemic associations are usually absent. We report one such case with these classical features.

  19. Segmentation: Identification of consumer segments

    DEFF Research Database (Denmark)

    Høg, Esben

    2005-01-01

    It is very common to categorise people, especially in the advertising business. Also traditional marketing theory has taken in consumer segments as a favorite topic. Segmentation is closely related to the broader concept of classification. From a historical point of view, classification has its...... a basic understanding of grouping people. Advertising agencies may use segmentation totarget advertisements, while food companies may usesegmentation to develop products to various groups of consumers. MAPP has for example investigated the positioning of fish in relation to other food products...... their evaluation of fish - for example by focusing on quality. Therefore, taking heterogeneity between segments into account makes a lot of difference, quantitatively as well as qualitatively....

  20. 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.

  1. 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...

  2. Anterior surgery for the treatment of acute single segment 30 cases of cervical disc%前路手术治疗急性单节段颈椎间盘突出30例

    Institute of Scientific and Technical Information of China (English)

    吴成如; 张诗虎

    2013-01-01

    目的 研究探讨前路颈椎间盘切除+椎间融合器+钛板内固定治疗急性颈椎间盘突出症的效果.方法 采用前路手术对我科2008-03-2011-03收治的30例急性颈椎间盘突出症患者进行治疗,所有患者均获得平均15个月的随访,根据术后摄片及JOA评分判断疗效.结果 在随访过程中,所有患者均未出现临床并发症,术后摄片显示均获得骨性融合,依据JOA评分标准:优(改善率大于75%)20例,良(改善率50~75%)8例,好转(改善率25~50%)2例.结论 该方法治疗急性颈椎间盘突出症可达到充分减压、重建颈椎生理曲度、恢复椎间隙高度、椎体间高融合率、颈椎牢固固定的作用.而且该术式操作简单,手术时间短、出血少、并发症少,是治疗急性颈椎间盘突出一种可靠方法.%Objective research and discuss the effect of the treatment of acute cervical disc herniation by using anterior cervical discectomy, Intervertebral fusion and Internal fixation with titanium plate. Methods 30 cases of patients with acute cervical disc herniation in our department in March 2008-March 2011 were treated by using anterior surgery,all patients received an average of 15 months of follow-up visit,then judge the curative effect according to postoperative radiography and JOA scores. Results In the process of follow-up, all patients did not show clinical complications, postoperative radiography showed bony fusion,according to JOA scoring criteria, optimal (improvement rate more than 75%) 20 cases, fine (improvement rate 50%~75%) 8 cases,improved (improvement rate 25%-50%) 2 cases. Conclusion the treatment of acute cervical disc herniation can achieve full decompression, reconstruction of cervical physiological curvature, restore interverte-bral disc height,high fusion rate between the vertebral bodies, cervical vertebra firmly fixed. And the operation is simple,short operation time,less bleeding,fewer complications,so the treatment of acute

  3. 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

  4. MARKET SEGMENTATION

    OpenAIRE

    Munaga Ramakrishna Mohan Rao

    2015-01-01

    Market segmentation is a marketing strategy that involves dividing a broad target market into subsets of consumers, businesses, or countries who have common needs and priorities, and then designing and implementing strategies to target them. Market segmentation strategies may be used to identify the target customers, and provide supporting data for positioning to achieve a marketing plan objective. Businesses may develop product differentiation strategies, or an undifferentiated approach, inv...

  5. Fingerprint Segmentation

    OpenAIRE

    Jomaa, Diala

    2009-01-01

    In this thesis, a new algorithm has been proposed to segment the foreground of the fingerprint from the image under consideration. The algorithm uses three features, mean, variance and coherence. Based on these features, a rule system is built to help the algorithm to efficiently segment the image. In addition, the proposed algorithm combine split and merge with modified Otsu. Both enhancements techniques such as Gaussian filter and histogram equalization are applied to enhance and improve th...

  6. Gene expression suggests double-segmental and single-segmental patterning mechanisms during posterior segment addition in the beetle Tribolium castaneum.

    Science.gov (United States)

    Janssen, Ralf

    2014-01-01

    In the model arthropod Drosophila, all segments are patterned simultaneously in the blastoderm. In most other arthropods, however, posterior segments are added sequentially from a posterior segment addition zone. Posterior addition of single segments likely represents the ancestral mode of arthropod segmentation, although in Drosophila, segments are patterned in pairs by the pair-rule genes. It has been shown that in the new model insect, the beetle Tribolium, a segmentation clock operates that apparently patterns all segments in pairs as well. Here, I report on the expression of the segment polarity gene H15/midline in Tribolium. In the anterior embryo, segmental stripes of H15 appear in pairs, but in the posterior of the embryo stripes appear in a single-segmental periodicity. This implies that either two completely different segmentation-mechanisms may act in the germ band of Tribolium, that the segmentation clock changes its periodicity during development, or that the speed in which posterior segments are patterned changes. In any case, the data suggest the presence of another (or modified), yet undiscovered, mechanism of posterior segment addition in one of the best-understood arthropod models. The finding of a hitherto unrecognized segmentation mechanism in Tribolium may have major implications for the understanding of the origin of segmentation mechanisms, including the origin of pair rule patterning. It also calls for (re)-investigation of posterior segment addition in Tribolium and other previously studied arthropod models.

  7. [Bilateral anterior uveiopapillitis, suspicious of Lyme disease--case report].

    Science.gov (United States)

    Nicula, Cristina; Nicula, D; Rusu, Ioana; Popescu, Raluca

    2013-01-01

    We present the case of a patient which associated bilateral anterior uveitis manifestations with those of bilateral anterior inflammatory optic neuropathy. We followed the evolution of the case under treatment and we discussed the differential diagnosis and the association of the two ocular pathologies.

  8. 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. ...

  9. 单侧A1优势前交通动脉瘤的栓塞治疗(附48例报告)%Embolization for the treatment of unilateral A1 segment anterior communicating artery aneurysm: a report of 48 cases

    Institute of Scientific and Technical Information of China (English)

    郭庆东; 刘伟; 付洛安; 张磊; 张学析; 胡晶; 费舟

    2011-01-01

    目的 总结使用可脱弹簧圈栓塞治疗48例单侧A1优势前交通动脉瘤的经验和方法.方法 2009年1月-2010年4月西京医院收治的单侧A1优势前交通动脉瘤患者48例,其中男23例,女25例,年龄32~72岁,平均53.4岁.全部动脉瘤均在术中应用旋转成像图像后处理技术,并采用弹簧圈进行动脉瘤内栓塞治疗,采用双侧颈动脉置管技术监测栓塞术中载瘤动脉通畅情况.对宽颈动脉瘤采用支架辅助技术,球囊辅助瘤颈重塑形技术,微导管、微导丝辅助技术保持载瘤动脉通畅.其中38例术后6个月复查全脑血管造影,了解已栓塞动脉瘤及前交通动脉通畅情况.结果 48例患者中动脉瘤致密栓塞39例(81.25%),90%以上栓塞6例(12.50%),90%以下栓塞3例(6.25%);术中出血 1例(2.08%),前交通动脉闭塞3例(6.25%),前交通动脉闭塞后对侧代偿2例(4.17%).随访均无再出血,38例复查全脑血管造影见动脉瘤栓塞致密、前交通动脉血流通畅.结论 单侧主供血前交通动脉瘤栓塞治疗术中应注意保持前交通动脉通畅,使用微导管或微导丝置于瘤颈处辅助栓塞有一定帮助.%Objective To summarize the experience and method of endovascular treatment of unilateral A1 segment anterior communicating artery aneurysm with detachable coils. Methods Forty-eight patients with unilateral Al anterior communicating artery aneurysm (23 males and 25 females, age ranged from 32 to 72 years with mean of 53.4, hospitalized in Xijing hospital from Jan. 2009 to Apr. 2010) were involved in present study. All of the aneurysms were measured with rotational digital subtraction angiography (RDSA) and image post-processing techniques, and they were embolized with Guglielmi detachable coils (GDCs). The patency of the parent arteries was monitored by catheterization in both carotid arteries in the process of treatment Stent-assisted, balloon remodeling, microcatheter and microwire assisted techniques were used

  10. Comparison of anterior cervical discectomy and fusion and anterior cervical corpectomy and fusion for the treatment of multi-segmental cervical spondylotic myelopathy%前路椎间盘切除减压融合与椎体次全切除减压融合治疗多节段颈椎病疗效比较

    Institute of Scientific and Technical Information of China (English)

    吴畏; 朱天亮

    2014-01-01

    目的:比较前路椎间盘减压融合( ACDF)与前路椎体次全切除减压融合( ACCF)治疗多节段颈椎病的效果。方法将138例多节段脊髓型颈椎病患者按照治疗方式的不同分为观察组(行ACDF治疗)和对照组(行ACCF治疗),比较两组手术时间、术中出血量、术后住院时间、术前与术后6个月颈椎总活动度、颈椎曲度、颈椎节段性高度及JOA评分。结果手术时间:观察组(128.3±32.4)min,对照组(163.2±43.6)min;术中出血量:观察组(161.4±122.5)ml,对照组(319.2±308.7)ml;以上指标观察组均少于对照组(P0.05)。术后颈椎曲度:观察组23.5°±7.4°,对照组16.1°±7.2°;椎间节段性高度:观察组5.6°±0.4°,对照组4.7°±0.8°;以上指标两组比较差异有统计学意义(P0. 05 ) . Postoperative cervical curvature: the observation group was 23. 5° ± 7. 4°, the control group was 16. 1° ± 7. 2°;intervertebral segmental height:observation group was 5. 6° ± 0. 4°, the control group was 4. 7° ± 0. 8°; between these indicators there were statistically significant differences between groups ( P <0. 05 ) . Conclusions Compared with ACCF, ACDF has shorter operative time, less blood loss, cervical physiological curvature and height of intervertebral segment recovered well, but there is no statistically significant differences on postoperative hospital stay time, postoperative JOA score and cervical total activity.

  11. Treatment of lumbosacral spinal tuberculosis by one-stage anterior debridement and fusion combined with dual screw-rod anterior instrumentation underneath the iliac vessel

    OpenAIRE

    Zhang, Ting; He, Xijing; Li, Haopeng; Xu, Siyue

    2016-01-01

    Background There has been no consensus regarding what is the optimal means of treating lumbosacral segment tuberculosis. The aim of this study was to evaluate the clinical outcomes of our newly developed one-stage anterior debridement and fusion combined with dual screw-rod construct anterior instrument underneath the iliac vessels for lumbosacral spinal tuberculosis. Methods We retrospectively reviewed 22 patients with lumbosacral spinal tuberculosis who underwent one-stage anterior debridem...

  12. Biological activity is the likely origin of the intersection between the photoreceptor inner and outer segments of the rat retina as determined by optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Yamauchi Y

    2011-11-01

    Full Text Available Yasuyuki Yamauchi, Hiromichi Yagi, Yoshihiko Usui, Keisuke Kimura, Tsuyoshi Agawa, Rintaro Tsukahara, Naoyuki Yamakawa, Hiroshi GotoDepartment of Ophthalmology, Tokyo Medical University Hospital, Tokyo, JapanBackground: Recent research on macular diseases has prompted investigations into the condition of the intersection between the photoreceptor inner and outer segments (IS/OS and the relationship with retinal photoreceptor abnormalities. Although the origin of the IS/OS in optical coherence tomography (OCT images is unclear, it may be related to either the cellular activity of the photoreceptors or the structure of the OS disks. To address this question, we compared the IS/OS status in OCT images of rat retinas before and after euthanasia.Methods: OCT images were taken before and after euthanasia in four eyes of two Brown Norway rats. After the OCT images were taken, the rats were used for histopathological studies to confirm that retinal structures were intact.Results: Before euthanasia, the IS/OS and external limiting membrane (ELM line were clearly identifiable on the OCT images. However, after euthanasia, neither the IS/OS nor the ELM line was evident in three out of four eyes, and a faint IS/OS and an ELM line were identified in one eye. Histopathological analysis did not show any abnormalities in the retina in any of the four eyes.Conclusion: The origin of the IS/OS identified in OCT images is likely related to the biological activities of the photoreceptor cells.Keywords: IS/OS, OCT, histopathology, biological activity

  13. Comparative analysis on biological measurement of anterior segment structure in some Fuzhou colleges and primary students%福州市部分大学生和小学生眼前节结构生物测量对比分析

    Institute of Scientific and Technical Information of China (English)

    孙堂胜; 过贵元; 吴生泉; 薛建设

    2012-01-01

    Objective To investigate relation between the part of the anatomy structure of the anterior segment and age in some Fuzhou students. Methods The ciliary body, iris, anterior chamber angle and other relevant data of 54 primary school students and 51 college students in Fuzhou were detected with an ultrasound biomicroseopy (UBM),and statistical analysis was underwent. Results The data in primary students group were CPD (160.53 ±17. 78),CT (90.01 ±34. 30),ICPD (23. 11 ±3. 33), IDt (35.95 ±6. 60),ID2 (52.81 ±9.94),θ3 (39.23 ±7.46) ,θ4 (56.02 ±6.75), and TCPD (151.27 ±23. 11) respectively. The data in college students group were CPD (214. 64 ± 15. 25), CT (99. 13 ±17. 80),ICPD (27.92 ±9.00),IDl (40.72±6.43),ID2 (56.57 ±9. 13),θ3 (43.73 ±6. 93),θ4 (60. 15 ±10.48),and TCPD (176.82 ± 28.06 ) respectively. There were highly significant differences in CPD, ID1,θ3, TCPD (P < 0. 01) between the primary and college students. Conclusion Significant changes occur in the development process of anterior segment and ciliary body structure,which closely related to the occurrence and development of myopia.%目的 探讨福州市部分大学生和小学生眼前节部分解剖结构随年龄增长的发展趋势.方法 采用美国产超声生物显微镜(ultrasound biomicroscopy,UBM)检测福州市54名小学生及51名大学生的睫状体、虹膜及房角等相关数据,并进行统计学分析.结果 小学生组:CPD值(160.53±17.78),CT值(90.01±34.30),ICPD值(23.11±3.33),ID1值(35.95±6.60),ID2值(52.81±9.94),θ3值(39.23±7.46),θ4值(56.02±6.75),TCPD值(151.27±23.11);大学生CPD值(214.64±15.25),CT值(99.13±17.80),ICPD值(27.92±9.00),ID1值(40.72±6.43),ID2值(56.57±9.13),θ3值(43.73±6.93),θ4值(60.15±10.48),TCPD值(176.82+28.06).其中在大学生和小学生之间,CPD、ID1、θ3、和TCPD指标均存在极显著性差异(P均<0.01).结论 在人体发育过程中,与睫状体相关的眼前节结构部分指标改变明显,这些指

  14. Clinical research on segmental invisible technique with mini-implant for en-masse retraction of maxillary anterior teeth%片段隐形矫治器结合微种植体内收上前牙的临床研究

    Institute of Scientific and Technical Information of China (English)

    金丽飞; 黄一慧; 弓国梁; 林新平

    2016-01-01

    Objective To evaluate the clinical efficiency of segmental invisible technique with mini-implant for en-masse retraction of maxillary anterior teeth on the aspect of vertical and torque in the treatment of bimaxillary protrusion. Methods Twelve subjects with upper dental alveolar bone protrusion were selected for this study. Arch-dimension variables were evaluated by cephalometric and dental models before and after orthodontic retraction. All data were analyzed by SPSS 20. 0 software. Results For vertical control, U1E-PP was increased by 0. 78 mm, U1AP-PP was decreased by 0. 29 mm, while the change of U1CR-PP showed no significant difference ( P>0. 05). For sagittal control, all the anterior teeth showed a decreased torque with canine displaying uprighting. Conclusion Segmen-tal invisible technique with mini-implant is efficient in the vertical and torque control of anterior teeth in the treatment of bimaxillary protrusion, and it can demonstrate invisible and aesthetic orthodontic effects.%目的:评估片段隐形矫治器结合微种植体矫治前突患者时对上前牙垂直向和转矩方面的控制效果。方法选取12例双牙槽前突患者,通过测量治疗前后X线头颅定位侧位片上颌前牙矢状向与垂直向的变化值,以及模型上的转矩变化值,使用SPSS 20.0软件进行统计分析。结果治疗后上切牙切缘至腭平面距离U1E-PP增加0.78 mm,上切牙根尖点至腭平面距离U1AP-PP减小0.29 mm,上切牙阻抗中心至腭平面距离U1CR-PP的变化无统计学差异(P>0.05),上切牙阻抗中心的位置基本不变;治疗后的上前牙转矩值减少,尖牙出现直立趋势。结论片段隐形矫治技术治疗前突患者对其上前牙的垂直向和转矩控制较好,总体获得了良好的治疗效果,并且在治疗期间充分发挥了隐形、美观的矫治效果。

  15. Diffusion MR Imaging of Postoperative Bilateral Acute Ischemic Optic Neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, Anusha; Srinivasan, Sivasubramanian [Khoo Teck Puat Hospital, Singapore (Singapore)

    2012-09-15

    We read with great interest, the case report on ischemic optic neuropathy (1). We would like to add a few points concerning the blood supply of the optic nerve and the correlation with the development of post-operative ischemic neuropathy. Actually, the perioperative or post-operative vision loss (postoperative ischemic neuropathy) is most likely due to ischemic optic neuropathy. Ischemic optic neuropathy (2) is classified as an anterior ischemic optic neuropathy (AION) and posterior ischemic optic neuropathy (PION). This classification is based on the fact that blood supply (2) to the anterior segment of the optic nerve (part of the optic nerve in the scleral canal and the optic disc) is supplied by short posterior ciliary vessels or anastamotic ring branches around the optic nerve. The posterior part of the optic canal is relatively less perfused, and is supplied by ophthalmic artery and central fibres are perfused by a central retinal artery. So, in the post-operative period, the posterior part of the optic nerve is more vulnerable for ischemia, especially, after major surgeries (3), one of the theories being hypotension or anaemia (2) and resultant decreased perfusion. The onset of PION is slower than the anterior ischemic optic neuropathy. AION on the other hand, is usually spontaneous (idiopathic) or due to arteritis, and is usually sudden in its onset. The reported case is most likely a case of PION. The role of imaging, especially the diffusion weighted magnetic resonance imaging, is very important because the ophthalmoscopic findings in early stages of PION is normal, and it may delay the diagnosis. On the other hand, edema of the disc is usually seen in the early stages of AION.

  16. 3D-CTA大脑前动脉A1-A2段夹角测量与前交通动脉瘤相关性研究%The Angles between A1 and A2 Segments of the Anterior Cerebral Artery Measured by Three-dimensional Computer Tomographic Angiography and The Relationship with Anterior Communication Artery Aneurysms

    Institute of Scientific and Technical Information of China (English)

    韦超; 邓克学; 韦炜; 赵英明

    2010-01-01

    目的:探讨大脑前动脉A1-A2段夹角与前交通动脉(anterior communicating arterv,ACoA)动脉瘤发生的关系.方法:回顾性分析32例前交通动脉瘤及随机选取的同期35例非前交通动脉瘤影像学资料,利用3D-CTA测量A1-A2段夹角(外侧夹角);同时探讨其对前交通动脉瘤形成的可能影响.结果:32例前交通动脉瘤中,有19例大脑前动脉为A1段优势型,13例表现为A1段均衡型.3D-CTA所测得前交通动脉瘤组A1-A2段夹角平均值为99.0°±18.8°,而非前交通动脉瘤组夹角平均值为118.1°±16.4°,两者间具有统计学差异(P<0.001).A1段均衡型动脉瘤侧A1-A2段平均夹角为96.3°±18.8°,较非动脉瘤侧平均夹角(115.2°±15.3°)小11.9°±3.3°(P<0.05);结论:较小的A1一A2交界处夹角更容易发生前交通动脉瘤,这可能与该处不恰当成角造成的血流动力学改变有关.

  17. 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.

  18. 人工椎间盘置换加颈前路椎体次全切减压植骨融合术治疗多节段颈椎病%Artificial Disc Replacement Combined with Anterior Cervical Decompression and Autograft Bone Fusion for the Treatment of Multi-segment Cervical Spondylosis

    Institute of Scientific and Technical Information of China (English)

    廖维峰; 肖晟; 黄象望; 刘向阳; 张毅; 向铁城

    2014-01-01

    [目的]探讨人工椎间盘置换加颈前路椎体次全切减压植骨融合术治疗多节段颈椎病的临床疗效。[方法]湖南省人民医院2008年2月至2012年6月收治的12例多节段颈椎病手术病例,均行人工椎间盘置换加颈前路椎体次全切减压植骨融合术,随访时间为12~18个月,平均随访15.5个月,均摄术前、术后及末次随访时的颈椎正侧位及颈椎过伸过屈位X线片及磁共振检查,观察植骨融合、内固定及人工椎间盘的情况,以JO A评分评价神经功能改善情况。[结果]所有病例内置物无松动、移位,植骨融合时间在3~6个月,平均4.9个月。置换间隙活动度术后1年时为12.5°±5.0°,与术前(12.3°±4.9°)比较无统计学差异(P>0.05)。术前JOA 评分平均为9.3分,术后6个月时平均为16.1分,平均改善率为91.2%。[结论]人工椎间盘置换加颈前路椎体次全切减压植骨融合术治疗多节段颈椎病近期疗效满意,是治疗多节段颈椎病的一种可行方法。%[Objective]To explore the clinical efficacy of cervical artificial disc replacement combined with anterior cervical decompression and autograft bone fusion for the treatment of multi -segment cervical spon-dylosis .[Methods]Twelve patients with multi- segment cervical spondylosis operated in Hunan provincial people's hospital from Feb .2008 to June 2012 underwent cervical artificial disc replacement combined with an-terior cervical decompression and autograft bone fusion .The follow up time was 12~18 months(average 15 .5 months) .Cervical MRI and X-ray films of cervical normal lateral position ,hyperextension and hyperflexion position were performed before and after operation and at the last time of follow up .Bone fusion ,internal fixa-tion and artificial disc were observed .JOA score was used to evaluate the improvement of neurological func-tion .[Results]No loosening and displacement of

  19. Donor disc attachment assessment with intraoperative spectral optical coherence tomography during descemet stripping automated endothelial keratoplasty

    Directory of Open Access Journals (Sweden)

    Edward Wylegala

    2013-01-01

    Full Text Available Optical coherence tomography has already been proven to be useful for pre- and post-surgical anterior eye segment assessment, especially in lamellar keratoplasty procedures. There is no evidence for intraoperative usefulness of optical coherence tomography (OCT. We present a case report of the intraoperative donor disc attachment assessment with spectral-domain optical coherence tomography in case of Descemet stripping automated endothelial keratoplasty (DSAEK surgery combined with corneal incisions. The effectiveness of the performed corneal stab incisions was visualized directly by OCT scan analysis. OCT assisted DSAEK allows the assessment of the accuracy of the Descemet stripping and donor disc attachment.

  20. UNSUPERVISED WOUND IMAGE SEGMENTATION

    Directory of Open Access Journals (Sweden)

    K. Sundeep Kumar

    2014-02-01

    Full Text Available The purpose of our research is to introduce two unique approaches for the unsupervised segmentation of wound images. The first method of segmentation is by using the texture of the image and is performed using the multi-channel filtering hypothesis for the processing of visual or optical data during the preliminary stages of the Human Visual System. We obtain the different channels from an image by filtering the image using a Gabor Filter Bank. The textural features are obtained from each filtered image and the final segmented image is acquired by reconstructing the original input image from these filtered images. The second method of segmentation was performed using parametric kernel graph cuts. Using a kernel function we transform the image data implicitly such that a piecewise constant model of the graph cut interpretation is now applicable. The objective function comprises of an original data term in order to assess the deviance of the transformed data from the initial input data within each partition. This method avoids sophisticated modelling of the input image data while availing of the computational advantages of graph cuts. By using a conventional kernel function, the energy minimization boils down to image partitioning via graph cut iterations and assessments of region parameters by means of fixed point calculations. The efficacy and flexibility of both the methods are established by carrying out investigations on real wound images.

  1. Segmental neurofibromatosis

    OpenAIRE

    Yesudian Devakar; Krishnan S. G. S; Jayaraman M; Janaki V R; Yesudian Patrick

    2014-01-01

    Segmental neurofibromatosis or type V neurofibromatosis is a rare genodermatosis characterized by neurofibromas, café-au-lait spots and neurofibromas limited to a circumscribed body region. The disease may be associated with systemic involvement and malignancies. The disorder has not been reported yet in the Polish medical literature. A 63-year-old Caucasian woman presented with a 20-year history of multiple, flesh colored, dome-shaped, soft to firm nodules situated in the right lumbar region...

  2. An Approach with Hybrid Segmental Mechanics.

    Science.gov (United States)

    Mishra, Harsh Ashok; Maurya, Raj Kumar

    2016-06-01

    Present case report provides an insight into the hybrid segmental mechanics with treatment of 13-year-old male, considering the side effects of sole continuous arch wire sliding mechanics. Patient was diagnosed as a case of skeletal class I jaw relationship, low mandibular plane angle, class II molar relation on right and class I molar relation on left side, anterior cross bite, crowding of 12mm in upper, 5mm in lower arch. He also had proclined upper and lower anteriors by 2mm, convex profile and incompetent lips. Total treatment duration was 20 months, during which segmental canine retraction was performed with TMA (Titanium, Molybdenum, Aluminum) 'T' loop retraction spring followed by consolidation of spaces with continuous arch mechanics. Most of the treatment objectives were met with good intraoral and facial results within reasonable framework of time. This approach used traditional twin brackets, which offered the versatility to use continuous arch-wire mechanics, segmental mechanics and hybrid sectional mechanics.

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

    Directory of Open Access Journals (Sweden)

    A. Rubin

    2010-12-01

    holistic and quantitative approach to ACA used here may be useful also in diabetic, neoplastic or other disease of the anterior segment of the eye.  This methodology could provide better understanding of the potential risk for acute or chronic angle-closure glaucoma through more complete evaluation of ACA.  The methods also could be usefully applied to measurement of ACA using techniques such as anterior segment optical coherence tomography or ultrasound biomicroscopy. (S Afr Optom 2010 69(1 35-47  

  4. Effect of tirofiban in acute anterior myocardial infarction patients without ST segment resolution after primary percutaneous coronary intervention%替罗非班对急诊冠状动脉介入治疗后ST段回落不良的急性前壁心肌梗死患者预后的影响

    Institute of Scientific and Technical Information of China (English)

    彭建军; 马志敏; 任利辉; 付桂琴; 贾凯英; 雷力成; 叶慧明

    2009-01-01

    Objective To observe the effect of glycoprotein receptor blockade tirofiban in acute anterior myocardial infarction patients without ST segment resolution after primary percutaneous coronary intervention (PCI). Methods From April 2006 to April 2008, 157 acute anterior myocardial infarction patients without ST segment resolution after PCI were randomly allocated to tirofiban (intravenous bolus 10 fig/kg followed by intravenous infusion of 0. 15 μg·kg-1·min-1 for 48 h, n =80) or equal volume saline (control group, n =77). Baseline characteristics, PCI features and clinical outcomes during hospitalization, left ventricular ejection fractions (LVEF) and major adverse cardiac events (MACE, including death, re-infarction and target vessel revascularization) at 30 and 180 days after discharge were compared between the two groups. Results The baseline clinical characteristics were comparable between the two groups. Compared to control group, the MACE rates and re-infarction rates at 30 days (6. 3% vs. 18. 2% , P < 0.05; 1.3% vs. 9. 1%, P<0.05, respectively) and 180 days (10.0% vs. 23. 4% , P<0.05; 2.5% vs. 10.4% , P < 0. 05, respectively ) were significantly reduced in tirofiban group. LVEF value was significantly higher in tirofiban group at 30 days and 180 days compared with those in control group [ (51 ± 6)% vs. (46±8)%, P<0.05; (57±7)% vs. (50±9)%, P<0.05]. Hemorrhagic complications were similar between the two groups. Conclusion Use of tirofiban for acute anterior myocardial infarction patients without ST segment resolution after PCI is safe and can significantly improve 30 and 180 days clinical outcomes after discharge.%目的 探讨血小板糖蛋白Ⅱb/Ⅲa受体拮抗剂替罗非班对直接经皮冠状动脉介入治疗后出现ST段回落不良的急性前壁心肌梗死患者预后的影响.方法 2006年4月至2008年4月共入选157例急性前壁心肌梗死患者,随机将患者分为两组.治疗组(80例)在术后1 h应用替罗非班(10

  5. 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

  6. Compartmentation of redox metabolites in the anterior eye segment?

    Science.gov (United States)

    Reim, M; Luthe, P

    1977-10-28

    In bovine corneal epithelium, stroma, and aqueous humor the levels of ascorbic acid (ASC) and dehydroascorbic acid (DHA) were investigated. Two methods were used, the photometric assay with 2,6-dichlorophenolindophenol and the formation of osazone by 2,4-dinitrophenylhydrazine. The ASC levels in the corneal epithelium and aqueous humor were found to be in the millimolar range, the ASC/DHA ratio being about 10. The stromal ASC and DHA levels were much lower, with a ratio of 0.7. ASC and DHA had similar levels and ratios to those of reduced and oxidized glutathione (GSH/GSSG) reported in the literature. In the corneal epithelium the redox ratio of glutathione was higher than that of ascorbic acid. Therefore, glutathione was supposed to reduce dehydroascorbic acid. PMID:303870

  7. 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.

  8. Segmental neurofibromatosis.

    Science.gov (United States)

    Sobjanek, Michał; Dobosz-Kawałko, Magdalena; Michajłowski, Igor; Pęksa, Rafał; Nowicki, Roman

    2014-12-01

    Segmental neurofibromatosis or type V neurofibromatosis is a rare genodermatosis characterized by neurofibromas, café-au-lait spots and neurofibromas limited to a circumscribed body region. The disease may be associated with systemic involvement and malignancies. The disorder has not been reported yet in the Polish medical literature. A 63-year-old Caucasian woman presented with a 20-year history of multiple, flesh colored, dome-shaped, soft to firm nodules situated in the right lumbar region. A histopathologic evaluation of three excised tumors revealed neurofibromas. No neurological and ophthalmologic symptoms of neurofibromatosis were diagnosed. PMID:25610358

  9. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  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. Quantitative assessment of rat corneal thickness and morphology during stem cell therapy by high-speed optical coherence tomography

    Science.gov (United States)

    Lal, Cerine; McGrath, James; Subhash, Hrebesh; Rani, Sweta; Ritter, Thomas; Leahy, Martin

    2016-03-01

    Optical Coherence Tomography (OCT) is a non-invasive 3 dimensional optical imaging modality that enables high resolution cross sectional imaging in biological tissues and materials. Its high axial and lateral resolution combined with high sensitivity, imaging depth and wide field of view makes it suitable for wide variety of high resolution medical imaging applications at clinically relevant speed. With the advent of swept source lasers, the imaging speed of OCT has increased considerably in recent years. OCT has been used in ophthalmology to study dynamic changes occurring in the cornea and iris, thereby providing physiological and pathological changes that occur within the anterior segment structures such as in glaucoma, during refractive surgery, lamellar keratoplasty and corneal diseases. In this study, we assess the changes in corneal thickness in the anterior segment of the eye during wound healing process in a rat corneal burn model following stem cell therapy using high speed swept source OCT.

  12. All-optical bit-pattern recognition in data segments using logic AND and XOR in a single all-active MZI wavelength converter

    DEFF Research Database (Denmark)

    Nielsen, Mads Lønstrup; Fjelde, T; Buron, J D;

    2002-01-01

    A novel and cost-effective scheme far comparing a segment of an incoming data stream to an expected sequence, using a single, all- active MZI is proposed. The comparator comprises the logic AND and XOR functions, and is demonstrated at 10 Gb/s......A novel and cost-effective scheme far comparing a segment of an incoming data stream to an expected sequence, using a single, all- active MZI is proposed. The comparator comprises the logic AND and XOR functions, and is demonstrated at 10 Gb/s...

  13. Biomarkers and special features of oxidative stress in the anterior segment of the eye linked to lens cataract and the trabecular meshwork injury in primary open-angle glaucoma: challenges of dual combination therapy with N-acetylcarnosine lubricant eye drops and oral formulation of nonhydrolyzed carnosine.

    Science.gov (United States)

    Babizhayev, Mark A

    2012-02-01

    The implication of oxidative stress associated with increased oxidant production in mammalian and human cells characterized by the release of free radicals, resulting in cellular degeneration, is involved in many ocular diseases, such as age-related macular degeneration, retinopathy of prematurity, retinal light damage, primary open-angle glaucoma (POAG), and cataract. Cataract is the leading cause of blindness, accounting for 50% of blindness worldwide. Glaucoma, the leading cause of irreversible blindness, is considered as a progressive optic neuropathy often caused by elevated intraocular pressure (IOP) consequent to abnormally high resistance to aqueous humor (AH) drainage via the trabecular meshwork (TM) and Schlemm's canal. Morphological and biochemical analyses of the TM of patients with POAG revealed the loss of cells, increased accumulation of extracellular matrix proteins (ECM), changes in the cytoskeleton, cellular senescence, and the process of subclinical inflammation. The TM is the target tissue of glaucoma in the anterior chamber, and the development and progression of glaucoma are accompanied by the accumulation of oxidative damage in this tissue. The separate studies were conducted to comparatively evaluate the sensitivity to oxidative stress and lipid peroxidation (LPO) of anterior chamber tissues including TM. Accumulation of the primary, secondary, and end products of LPO (diene and triene conjugates, Schiff's bases) was noted in the studied extracts. Significant differences in the levels of all mentioned LPO products in comparison with the control were observed. The data may be considered as an evidence of LPO participation in the destruction of the trabecule and Schlemm's canal in POAG. Treatment of TM cells with oxidative stress induced POAG-typical changes such as ECM accumulation, cell death, disarrangement of the cytoskeleton, advanced senescence, and the release of inflammatory markers. By pretreatment with antioxidants, prostaglandin

  14. Segmentation of knee injury swelling on infrared images

    Science.gov (United States)

    Puentes, John; Langet, Hélène; Herry, Christophe; Frize, Monique

    2011-03-01

    Interpretation of medical infrared images is complex due to thermal noise, absence of texture, and small temperature differences in pathological zones. Acute inflammatory response is a characteristic symptom of some knee injuries like anterior cruciate ligament sprains, muscle or tendons strains, and meniscus tear. Whereas artificial coloring of the original grey level images may allow to visually assess the extent inflammation in the area, their automated segmentation remains a challenging problem. This paper presents a hybrid segmentation algorithm to evaluate the extent of inflammation after knee injury, in terms of temperature variations and surface shape. It is based on the intersection of rapid color segmentation and homogeneous region segmentation, to which a Laplacian of a Gaussian filter is applied. While rapid color segmentation enables to properly detect the observed core of swollen area, homogeneous region segmentation identifies possible inflammation zones, combining homogeneous grey level and hue area segmentation. The hybrid segmentation algorithm compares the potential inflammation regions partially detected by each method to identify overlapping areas. Noise filtering and edge segmentation are then applied to common zones in order to segment the swelling surfaces of the injury. Experimental results on images of a patient with anterior cruciate ligament sprain show the improved performance of the hybrid algorithm with respect to its separated components. The main contribution of this work is a meaningful automatic segmentation of abnormal skin temperature variations on infrared thermography images of knee injury swelling.

  15. 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

  16. Optical coherence tomography and autofluorescence findings in chronic phototoxic maculopathy secondary to snow-reflected solar radiation

    Directory of Open Access Journals (Sweden)

    Dhananjay Shukla

    2015-01-01

    Full Text Available A professional mountain trekker presented with gradual, moderate visual decline in one eye. The subnormal vision could not be explained by the examination of anterior and posterior segment of either eye, which was unremarkable. Optical coherence tomography and autofluorescence imaging revealed subtle defects in the outer retina, which correlated with the extent of visual disturbance. A novel presentation of retinal phototoxicity due to indirect solar radiation reflected from snow in inadequately protected eyes of a chronically exposed subject is reported.

  17. Silent ST segment elevation myocardial infarction with multi-segmental renal infarction: an unusual presentation.

    Science.gov (United States)

    Chang, Hung-Yu; Yang, Yung-Nien

    2011-01-01

    A 36-year-old diabetic man came to our institution presenting with constant left flank pain. Left renal embolic infarction was found by abdominal computed tomography. Silent ST segment elevation myocardial infarction was noted on 12-lead electrocardiogram. Emergent coronary angiography revealed large thrombus burdens with complete occlusion at the left anterior descending artery ostium, which may be the embolic origin. Silent ST segment elevation myocardial infarction with acute flank pain and multiple segmental renal infarction is an unusual presentation. High vigilance may prevent delay of the "golden hour" to treat acute myocardial infarction.

  18. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  19. Artificial cervical disc replacement and anterior cervical decompression and fusion for the treatment of single segmental cervical disc herniation:a 3-year follow-up%颈椎人工间盘置换与前路减压融合修复单节段颈椎间盘突出症:3年随访

    Institute of Scientific and Technical Information of China (English)

    程俊杰; 眭江涛; 马原; 田慧中

    2015-01-01

    stages. Artificial disc replacement can not only play a role in mitigation of cervical disease neurological symptoms and signs, but also maintain stability and semental activity of cervical spine, and reduce secondary adjacent segmental degeneration. These two methods which applied in cervical degenerative intervertebral disc herniation stil remain controversial. OBJECTIVE:To investigate the short-term effect of artificial cervical disc replacement and anterior cervical decompression and fusion for the treatment of single segmental cervical disc herniation. METHODS:Total y 48 patients with single segment radiculopathy or myelopathy cervical diseases induced by cervical disc herniation that required surgery and received a three-month fol ow-up were included and retrospectively analyzed. These patients were divided into replacement group (n=21) and fusion group (n=27) according to the different repair programs. Patients in the replacement group were subjected to Prestige LP cervical artificial disc replacement, and patients in the fusion group were subjected to disc fusion using interbody fusion cage of Johnson or al ogeneic fibularing. They were fol owed up at 1 week, 3, 6, 12, 24, 36 months after treatment. Complications were recorded during the fol ow-up. The pain of patients was evaluated using neck and upper limb pain visual analogue scale scores. The therapeutic effect was evaluated using Japanese Orthopaedic Association (JOA) score. The clinical symptoms improvement and daily functional status of patients after treatment were evaluated using cervical disability index. RESULTS AND CONCLUSION:During the final fol ow-up, the fusion rate in fusion group was 93%(25/27). Comparisons between groups:at the 1 week and final fol ow-up after treatment, the visual analog scale scores of neck and upper limbs and cervical dysfunction indexes were al lower than those before treatment;the Japanese Orthopaedic Association scores were higher than those before treatment (P0.05). The

  20. Is it possible to differentiate between Takotsubo cardiomyopathy and acute anterior ST-elevation myocardial infarction?

    DEFF Research Database (Denmark)

    Vervaat, Fabienne E; Christensen, Thomas E; Smeijers, Loes;

    2015-01-01

    INTRODUCTION: Several studies have investigated the ability of the twelve-lead electrocardiogram (ECG) to reliably distinguish Takotsubo cardiomyopathy (TC) from an acute anterior ST-segment elevation myocardial infarction (STEMI). In these studies, only ECG changes were required - ST......-segment deviation and/or T-wave inversion - in TC whereas in acute anterior STEMI, ECGs had to meet STEMI criteria. In the majority of these studies, patients of both genders were used even though TC predominantly occurs in women. The aim of this study is to see whether TC can be distinguished from acute anterior...... STEMI in a predominantly female study population where all patients meet STEMI-criteria. METHODS: Retrospective analysis of the ST-segment changes was done on the triage ECGs of 37 patients with TC (34 female) and was compared to the triage ECGs of 103 female patients with acute anterior STEMI...

  1. Anterior Decompression and Anterior Instrumentation of Tuberculosis of Cervicothoracic Spine by Cervicomanubrial Approach

    Directory of Open Access Journals (Sweden)

    Anant Kumar Garg

    2012-04-01

    Full Text Available Background: Evaluation of result of anterior cervical approach with manubriotomy and anterior instrumentation in tuberculosis of cervicothoracic spine in terms of the neurological recovery, reconstruction of spine and prevention of deformity along with relief of pain. Materials and Methods: All five patients with cervicothoracic caries spine had surgery through anterior cervical approach with manubriotomy in our hospital and underwent excision of the involved vertebrae and intervertebral discs followed by anterior spinal reconstruction with titanium spacer cage filled with cancellous iliac crest bone graft and Orion plate with locking screw. Antitubercular drugs were administered for 12 months. The follow-up period ranged from 12 to 36 months. Results: Analysis of result was done on the basis of clinical and radiological criteria. Clinical assessment based on Frankel grade and modified JOA score showed significant improvement from preoperative findings. Radiological assessment showed osteointegration, no spinal instability and no progression of the deformity. The pain control, based on visual analog scale changed from a pre-operative average of 7.5 to 2 at the last follow-up thereby indicating significant improvement and all patients returned to preoperative functional status. One patient had transient hoarseness of voice. No other complication had been encountered in the immediate post operative and during the follow-up period. Conclusions: Our study showed that anterior cervical approach with manubriotomy and anterior insertion of titanium cage, filled with autogenous bone graft, secured with locking plate instrumentation has a successful role in the eradication of infection, neurological recovery, segmental spinal reconstruction and it also reduces surgical time, blood loss, and surgical complications and approach related comorbidity in follow up period. Level of Evidence- Level 4, Case series

  2. Segmental anterior cervical decompression with fusion for treating multilevel cervical myelopathy: Comparison of fusion rates among three methods%颈前路分节段减压植骨融合术治疗多节段颈椎病:3种方法移植骨融合率的比较

    Institute of Scientific and Technical Information of China (English)

    袁文; 徐盛明; 王新伟; 张涛; 刘百峰

    2007-01-01

    院时间均明显少于/短于长节段减压组(P<0.05),平均住院费用明显高于长节段减压组(P<0.05).分节段减压组、三间隙减压组和长节段减压组术后JOA评分提高分数和植骨融合率相近(P>0.05).结论:综合植骨融合率、神经功能恢复情况、手术时间、术中出血量、住院时间多种因素,3种术式中以颈前路分节段减压植骨融合术为治疗多节段颈椎病的手术方式较佳方案.%BACKGROUND:As a traditional treatment for multilevel cervical myelopathy,nterior long-segmental decompression has the shortcomings of great operative trauma,high difficulty,low fusion rate,etc.,which can affect the postoperative efficacy.OBJ ECTIVE:To evaluate the clinical effects of three different anterior surgeries on multilevel cervical myelopathy.DESIGN:A comparative observation.SETTING:Department of Orthopaedics,Changzheog Hospital,the Second Military Medical University of Chinese PLA.PARTICIPANTS:Thirty-six patients with multilevel cervical myelopathy of 3 consecutive segments,who were surgically treated,were selected from the Department of Orthopaedics,Changzheng Hospital,the Second Military Medical University of Chinese PLA from June 1999 to June 2003,including 25 males and 11 females,35-62 years of age,the disease course ranged from 3 to 26 months. According to the clinical manifestations and imaging esults,they were diagnosed as multilevel cervical myelopathy,and they were not suffering from consecutive ossification of posterior longitudinal ligament and ossification of ligamenta flava. Informed contents were obtained from all the patients and their relatives.METHODS:All the patients were grafted with utologous bone. Autologous ilium or cancellous bone excluding vertebral body was filled into titan net or Cage,which were made of titan and characterized by high intensity,tolerance to decay,good biocompatibility,etc. According to the operative manner,the patients were divided into 3 groups:① two

  3. Continuous intraoperative OCT guided management of post-deep anterior lamellar keratoplasty descemet’s membrane detachme

    Directory of Open Access Journals (Sweden)

    Namrata Sharma

    2016-04-01

    Full Text Available Continuous intraoperative optical coherence tomography (iOCT integrated into the operating microscope is a new modification in the current operating microscope to aid in the surgical procedures involving both the anterior and the posterior segment. This helps in intraoperative planning, modification of the surgical steps if required and confirmation of the surgical endpoint in the operating room itself. iOCT was used for the successful management of descemet’s membrane detachment (DMD following deep anterior lamellar keratoplasty (DALK with intracameral injection of 20% Sulphur hexafluoride. The gas was injected under direct visualization through the microscope with continuous real time monitoring of the change in height of the detached Descemet’s membrane (DM. Additionally stab incisions were given through the anterior cornea due to the presence of residual fluid above the DM which was visible on continuous iOCT images. This led to the successful apposition of the DM which otherwise would have remained detached due to the residual fluid. This highlights the importance of continuous iOCT monitoring of the ophthalmic surgical procedures in order to produce a successful anatomical outcome of the surgery without disruption of the surgical procedure.

  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. 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.

  6. 非动脉炎性前部缺血性视神经病变的电生理及临床特征分析%Electrophysiological and clinical characteristics of non-arteritic anterior ischemic optic neuropathy

    Institute of Scientific and Technical Information of China (English)

    王敏; 王刚; 李世迎; 刘勇; 孟晓红; 阴正勤

    2015-01-01

    目的 研究非动脉炎性前部缺血性视神经病变(NAION)的电生理及临床特征.方法 收集2013年3月至2014年3月我院确诊为NAION的17例患者28眼,分析其图形视觉诱发电位(PVEP)、荧光素眼底血管造影(FFA)、视野(VF)等临床检查特征.结果 28眼均行PVEP检查,其中21眼P100波幅值在1°或15′空间频率均出现不同程度降低.P100波峰时在1 °空间频率5眼中度延迟(> 15 ms),其余23眼未见明显延迟或者轻度延迟;15′空间频率时6眼中度延迟(>15 ms),其余22眼峰时未见明显延迟或者轻度延迟(< 15 ms).15患者23眼行FFA检查,其中6患者(40%)患者臂-视网膜循环时间(ART)大于15 s.7眼后期出现高荧光,其余后期呈低荧光.28眼均行视野检查,其中10眼正常,7眼视敏度降低或暗点(4眼集中在生理盲点附近),7眼呈现与生理盲点相连的缺损,4眼残存部分视野.对比分析PVEP和FFA,发现FFA后期高荧光的患眼P100波峰时呈中度以上延迟,后期低荧光患眼的峰时未见明显延迟或轻度延迟.对比分析PVEP和视野,发现14眼VF和PVEP均异常,7眼视野正常时PVEP异常,4眼PVEP正常时而VF异常.结论 NAION的PVEP的P100波峰时大多为正常或轻度延迟,当视乳头水肿、FFA后期视盘高荧光时P100波峰时明显延迟.FFA的ART延长不是NAION的敏感指标.PVEP对于视野正常的患眼有辅助诊断的价值.%Objective To investigate the electrophysiological and clinical characteristics of nonarteritic anterior ischemic optic neuropathy (NAION).Methods A total of 28 eyes of 17 patients with NAION from March 2013 to March 2014 were selected to analyze the clinical characteristics including pattern visual evoked potential (PVEP),fluorescein fundus angiography (FFA),and visual field (VF).Results Among the 28 eyes undergoing PVEP test,the amplitude of P100 wave was decreased differently to 1° or 15' temporal frequency stimuli.Latency of P100 wave to 1 temporal frequency

  7. Fabrication, performance, and figure metrology of epoxy-replicated aluminum foils for hard x-ray focusing multilayer-coated segmented conical optics

    Science.gov (United States)

    Jimenez-Garate, Mario A.; Craig, William W.; Hailey, Charles J.; Christensen, Finn E.; Hussain, Ahsen M.

    2000-11-01

    We fabricated x-ray mirrors for hard x-ray (>= 10 keV) telescopes using multilayer coatings and an improved epoxy- replicated aluminum foil (ERAF) nonvacuum technology. The ERAF optics have approximately 1 arcmin axial figure half- power diameter (HPD) and passed environmental testing. Reflectivity measurements at 8 keV on ERAFs with and without multilayer coatings show a 4.4 to 4.8 angstroms room mean square microroughness for correlation lengths EQ 15 micrometers . To reduce the dominant contribution of mirror assembly and large-scale distortion in the overall telescope HPD, we designed a figure metrology system and a new mounting technique. We describe a cylindrical metrology system built for fast axial and roundness figure measurement of hard x-ray conical optics. These developments lower cost and improve the optics performance of the HEFT (high-energy focusing telescope) and Constellation-X missions.

  8. Fabrication, performance, and figure metrology of epoxy-replicated aluminum foils for hard x-ray focusing multilayer-coated segmented conical optics

    DEFF Research Database (Denmark)

    Jimenez-Garate, M.A.; Craig, W.W.; Hailey, C.J.;

    2000-01-01

    We fabricated x-ray mirrors for hard x-ray (greater than or equal to 10 keV) telescopes using multilayer coatings and an improved epoxy-replicated aluminum foil (ERAF) nonvacuum technology. The ERAF optics have similar to1 arcmin axial figure half-power diameter (HPD) and passed environmental...... testing. Reflectivity measurements at 8 keV on ERAFs with and without multilayer coatings show a 4.4 to 4.8 A root mean square (rms) microroughness for correlation lengths less than or equal to 15 mum. To reduce the dominant contribution of mirror assembly and large-scale distortion in the overall...... telescope HPD, we designed a figure metrology system and a new mounting technique. We describe a cylindrical metrology system built for fast axial and roundness figure measurement of hard x-ray conical optics. These developments lower cost and improve the optics performance of the HEFT (high-energy focusing...

  9. Review of 31 cases of anterior thoracolumbar fixation with the anterior thoracolumbar locking plate system.

    Science.gov (United States)

    Wilson, J A; Bowen, S; Branch, C L; Meredith, J W

    1999-07-15

    Anterior fixation devices for the thoracolumbar spine have gained wide acceptance as viable alternatives to long-segment posterior fixation in cases of thoracolumbar spine trauma. This review was undertaken to evaluate the safety and efficacy of the Synthes anterior thoracolumbar locking plate (ATLP) system. Over a 3-year period, 31 patients with unstable traumatic fractures of the thoracolumbar spine underwent corpectomy, placement of a structural bone graft, and anterior fixation in which the Synthes ATLP system was used. Long-term follow-up data were obtained in 29 patients. Two patients were lost to follow up, one at 4 months and the other at 1 year. In the remaining patients, the average length of follow up was 20 months. In all patients radiographic evidence of solid bone fusion was demonstrated on follow-up plain x-ray films, and there were no signs or symptoms of pseudarthrosis. No patient suffered neurological deterioration as a result of surgery, and there was relatively little morbidity associated with this plating system. To date, none of the patients in this study has developed any delayed complications related to the fixation device. In one patient, who had sustained a severe flexion injury, loosening of the anterior fixation device occurred, and the patient developed progressive kyphosis, which required a posterior stabilization procedure. These results appear slightly better than those obtained in published studies in which other anterior plating systems were used, indicating that this system is safe and effective in the treatment of unstable fractures of the thoracolumbar spine. PMID:16918232

  10. Optical coherence tomography imaging of ocular and periocular tumours

    Science.gov (United States)

    Medina, Carlos A; Plesec, Thomas; Singh, Arun D

    2014-01-01

    Optical coherence tomography (OCT) has become pivotal in the practice of ophthalmology. Similar to other ophthalmic subspecialties, ophthalmic oncology has also incorporated OCT into practice. Anterior segment OCT (AS-OCT), ultra-high resolution OCT (UHR-OCT), spectral domain OCT (SD-OCT) and enhanced depth imaging OCT (EDI-OCT), have all been described to be helpful in the diagnosis, treatment planning and monitoring response of ocular and periocular tumours. Herein we discuss the role of OCT including the advantages and limitations of its use in the setting of common intraocular and adnexal tumours. PMID:24599420

  11. Expression of segment polarity genes in brachiopods supports a non-segmental ancestral role of engrailed for bilaterians.

    Science.gov (United States)

    Vellutini, Bruno C; Hejnol, Andreas

    2016-01-01

    The diverse and complex developmental mechanisms of segmentation have been more thoroughly studied in arthropods, vertebrates and annelids-distantly related animals considered to be segmented. Far less is known about the role of "segmentation genes" in organisms that lack a segmented body. Here we investigate the expression of the arthropod segment polarity genes engrailed, wnt1 and hedgehog in the development of brachiopods-marine invertebrates without a subdivided trunk but closely related to the segmented annelids. We found that a stripe of engrailed expression demarcates the ectodermal boundary that delimits the anterior region of Terebratalia transversa and Novocrania anomala embryos. In T. transversa, this engrailed domain is abutted by a stripe of wnt1 expression in a pattern similar to the parasegment boundaries of insects-except for the expression of hedgehog, which is restricted to endodermal tissues of the brachiopod embryos. We found that pax6 and pax2/5/8, putative regulators of engrailed, also demarcate the anterior boundary in the two species, indicating these genes might be involved in the anterior patterning of brachiopod larvae. In a comparative phylogenetic context, these findings suggest that bilaterians might share an ancestral, non-segmental domain of engrailed expression during early embryogenesis. PMID:27561213

  12. Segmentation of Offline Handwritten Bengali Script

    CERN Document Server

    Basu, Subhadip; Kundu, Mahantapas; Nasipuri, Mita; Basu, Dipak K

    2012-01-01

    Character segmentation has long been one of the most critical areas of optical character recognition process. Through this operation, an image of a sequence of characters, which may be connected in some cases, is decomposed into sub-images of individual alphabetic symbols. In this paper, segmentation of cursive handwritten script of world's fourth popular language, Bengali, is considered. Unlike English script, Bengali handwritten characters and its components often encircle the main character, making the conventional segmentation methodologies inapplicable. Experimental results, using the proposed segmentation technique, on sample cursive handwritten data containing 218 ideal segmentation points show a success rate of 97.7%. Further feature-analysis on these segments may lead to actual recognition of handwritten cursive Bengali script.

  13. Probabilistic retinal vessel segmentation

    Science.gov (United States)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  14. Optical Coherence Tomography Guided Percutaneous Coronary Intervention With Nobori Stent Implantation in Patients With Non-ST-Segment-Elevation Myocardial Infarction (OCTACS) Trial

    DEFF Research Database (Denmark)

    Antonsen, Lisbeth; Thayssen, Per; Maehara, Akiko;

    2015-01-01

    BACKGROUND: Incomplete strut coverage has been documented an important histopathologic morphometric predictor for later thrombotic events. This study sought to investigate whether optical coherence tomography (OCT)-guided percutaneous coronary intervention with Nobori biolimus-eluting stent impla...... 6-month follow-up in comparison with angiographic guidance alone. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02272283....

  15. 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.

  16. 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

  17. Amodal Instance Segmentation

    OpenAIRE

    Li, Ke; Malik, Jitendra

    2016-01-01

    We consider the problem of amodal instance segmentation, the objective of which is to predict the region encompassing both visible and occluded parts of each object. Thus far, the lack of publicly available amodal segmentation annotations has stymied the development of amodal segmentation methods. In this paper, we sidestep this issue by relying solely on standard modal instance segmentation annotations to train our model. The result is a new method for amodal instance segmentation, which rep...

  18. Visual outcome after fractionated stereotactic radiation therapy of benign anterior skull base tumors

    DEFF Research Database (Denmark)

    Astradsson, Arnar; Wiencke, Anne Katrine; Munck af Rosenschold, Per;

    2014-01-01

    To determine visual outcome including the occurrence of radiation induced optic neuropathy (RION) as well as tumor control after fractionated stereotactic radiation therapy (FSRT) of benign anterior skull base meningiomas or pituitary adenomas. Thirty-nine patients treated with FSRT for anterior ...

  19. Shape of the anterior cornea : Comparison of height data from 4 corneal topographers

    NARCIS (Netherlands)

    de Jong, Tim; Sheehan, Matthew T.; Dubbelman, Michiel; Koopmans, Steven A.; Jansonius, Nomdo M.

    2013-01-01

    PURPOSE: To compare the ability of clinical corneal topographers to describe the shape of the anterior cornea for optical modeling. SETTING: University Medical Center Groningen, Groningen, Netherlands. DESIGN: Cross-sectional study. METHODS: The anterior corneal shape of healthy subjects was assesse

  20. Endoscopic anterior decompression in cervical disc disease

    Directory of Open Access Journals (Sweden)

    Yad Ram Yadav

    2014-01-01

    Full Text Available Background: Although microscopic anterior cervical discectomy with or without fusion are common surgical procedures for treatment of cervical herniated discs, loss of disc height, pseudarthrosis, and adjacent disc degeneration are some of the problems associated with it. This study is aimed to evaluate results of endoscopic microforaminotomy in cervical disc diseases. Materials and Methods: A prospective study of 50 patients of mono segmental soft or hard disc causing myeloradiculopathy was undertaken. A visual analogue scale (VAS for neck and arm pain and functional outcomes using the Nurick grading system were assessed. There were 28, 12, 8, and 2 patients at C5-6, C6-7, C4-5, and C3-4 levels disc diseases, respectively. Patients with two or more level disc, instabilities, disc extending more than half vertebral body height, and previous operation at the same segment were excluded. Results: Age ranged from 21 to 67 years. Average postoperative reduction in disc height, operating time, and blood loss was 1.1 mm, 110 minutes, and 30 ml, respectively. Average pre-operative VAS score for arm pain and Nurick grading was 7.6 and 2.7, which improved to 1.9 and 0.82, respectively. All patients improved; 1, 2, 3 grade improvement was seen in 10, 27, and 10 patients, respectively. There was no significant complication or any mortality. Conclusion: Although longer follow up of large number of patients is required, endoscopic microforaminotomy is a safe and an effective alternative to microscopic anterior discectomy with or without fusion.

  1. Load Rate of Facet Joints at the Adjacent Segment Increased After Fusion

    Institute of Scientific and Technical Information of China (English)

    Hui Li; Bao-Qing Pei; Jin-Cai Yang; Yong Hai; De-Yu Li; Shu-Qin Wu

    2015-01-01

    Background:The cause of the adjacent segment degeneration (ASD) after fusion remains unknown.It is reported that adjacent facet joint stresses increase after anterior cervical discectomy and fusion.This increase of stress rate may lead to tissue injury.Thus far,the load rate of the adjacent segment facet joint after fusion remains unclear.Methods:Six C2-C7 cadaveric spine specimens were loaded under four motion modes:Flexion,extension,rotation,and lateral bending,with a pure moment using a 6° robot arm combined with an optical motion analysis system.The Tecscan pressure test system was used for testing facet joint pressure.Results:The contact mode of the facet joints and distributions of the force center during different motions were recorded.The adjacent segment facet joint forces increased faster after fusion,compared with intact conditions.While the magnitude of pressures increased,there was no difference in distribution modes before and after fusion.No pressures were detected during flexion.The average growth velocity during extension was the fastest and was significantly faster than lateral bending.Conclusions:One of the reasons for cartilage injury was the increasing stress rate of loading.This implies that ASD after fusion may be related to habitual movement before and after fusion.More and faster extension is disadvantageous for the facet joints and should be reduced as much as possible.

  2. Load Rate of Facet Joints at the Adjacent Segment Increased After Fusion

    Directory of Open Access Journals (Sweden)

    Hui Li

    2015-01-01

    Full Text Available Background: The cause of the adjacent segment degeneration (ASD after fusion remains unknown. It is reported that adjacent facet joint stresses increase after anterior cervical discectomy and fusion. This increase of stress rate may lead to tissue injury. Thus far, the load rate of the adjacent segment facet joint after fusion remains unclear. Methods: Six C2-C7 cadaveric spine specimens were loaded under four motion modes: Flexion, extension, rotation, and lateral bending, with a pure moment using a 6° robot arm combined with an optical motion analysis system. The Tecscan pressure test system was used for testing facet joint pressure. Results: The contact mode of the facet joints and distributions of the force center during different motions were recorded. The adjacent segment facet joint forces increased faster after fusion, compared with intact conditions. While the magnitude of pressures increased, there was no difference in distribution modes before and after fusion. No pressures were detected during flexion. The average growth velocity during extension was the fastest and was significantly faster than lateral bending. Conclusions: One of the reasons for cartilage injury was the increasing stress rate of loading. This implies that ASD after fusion may be related to habitual movement before and after fusion. More and faster extension is disadvantageous for the facet joints and should be reduced as much as possible.

  3. Pituitary Adenoma Segmentation

    CERN Document Server

    Egger, Jan; Kuhnt, Daniela; Freisleben, Bernd; Nimsky, Christopher

    2011-01-01

    Sellar tumors are approximately 10-15% among all intracranial neoplasms. The most common sellar lesion is the pituitary adenoma. Manual segmentation is a time-consuming process that can be shortened by using adequate algorithms. In this contribution, we present a segmentation method for pituitary adenoma. The method is based on an algorithm we developed recently in previous work where the novel segmentation scheme was successfully used for segmentation of glioblastoma multiforme and provided an average Dice Similarity Coefficient (DSC) of 77%. This scheme is used for automatic adenoma segmentation. In our experimental evaluation, neurosurgeons with strong experiences in the treatment of pituitary adenoma performed manual slice-by-slice segmentation of 10 magnetic resonance imaging (MRI) cases. Afterwards, the segmentations were compared with the segmentation results of the proposed method via the DSC. The average DSC for all data sets was 77.49% +/- 4.52%. Compared with a manual segmentation that took, on the...

  4. Abnormal origin of the ophthalmic artery from the anterior cerebral artery: Neuroradiological and intraoperative findings

    International Nuclear Information System (INIS)

    A 7-year old male child with an abnormal ophthalmic artery arising from the A1 segment of the anterior cerebral artery is described. The patient suffered growth inhibition which was thought to be caused by a craniobasal cystic lesion affecting the hypothalamus. Preoperative angiograms revealed no vascular abnormalities. The right ophthalmic artery, however, could not be identified. During resection of a large arachnoid cyst the ophthalmic artery was found to arise from the A1 segment of the anterior cerebral artery. To the best of our knowledge, this exact anomaly has not previously been reported. The clinical, neuroradiological and intraoperative findings are presented. (orig.)

  5. Study on the design and Zernike aberrations of a segmented mirror telescope

    Institute of Scientific and Technical Information of China (English)

    Jiang Zhen-Yu; Li Lin; Huang Yi-Fan

    2009-01-01

    The segmented mirror telescope is widely used. The aberrations of segmented mirror systems are different from single mirror systems. This paper uses the Fourier optics theory to analyse the Zernike aberrations of segmented mirror systems. It concludes that the Zernike aberrations of segmented mirror systems obey the linearity theorem. The design of a segmented space telescope and segmented schemes are discussed, and its optical model is constructed. The computer simulation experiment is performed with this optical model to verify the suppositions. The experimental results confirm the correctness of the model.

  6. Corticotomy and compression osteogenesis in the posterior maxilla for treating severe anterior open bite.

    Science.gov (United States)

    Kanno, T; Mitsugi, M; Furuki, Y; Kozato, S; Ayasaka, N; Mori, H

    2007-04-01

    A new technique is described for outpatient treatment of anterior open bite. The compression osteogenesis method with a two-stage corticotomy was used in the posterior maxilla to treat a woman with severe anterior open bite. Three-week post-surgical compression using anchor plates and elastics repositioned the posterior maxillary bone/teeth segments by 7 mm to the ideal superior position. The patient had a stable skeletal position of the maxilla at 14-month follow-up with satisfactory results and no complications after orthodontic treatment. This technique appears to be an efficient option for treating patients with anterior open bite. PMID:17110086

  7. Carotid-anterior cerebral artery anastomosis on MR angiography: a university hospital-based study

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, Akira; Saito, Naoko; Okada, Yoshitaka; Inoue, Kaiji [Saitama Medical University International Medical Center, Department of Diagnostic Radiology, Hidaka, Saitama (Japan)

    2012-01-15

    Rarely in the anterior circulation, an anastomosis of the carotid and anterior cerebral arteries occurs when an anomalous branch arises from the ophthalmic segment of the internal carotid artery and anastomoses with the A1-A2 junction of the anterior communicating artery. Right-side predominance is known. To our knowledge, the incidence of carotid-anterior cerebral artery anastomosis has not been reported, so we researched cases in our institution records to determine incidence and investigated characteristic features of the condition on magnetic resonance (MR) angiography. To isolate such cases, we retrospectively reviewed cranial MR angiographic images of 3,491 consecutive patients in our institution. We found three cases with carotid-anterior cerebral artery anastomosis (two men, one woman), representing an incidence of 0.086%. The anastomosis was on the right in all three cases. A normal A1 segment of the anterior cerebral artery (ACA) was present in two cases but could not be identified in the remaining case on MR angiographic images that included source images. Two of the three patients demonstrated associated arterial variations in their carotid systems. On MR angiography, we observed a 0.086% incidence of carotid-anterior cerebral artery anastomosis in our institution and reaffirmed the right-side predominance of this anomaly. We found a high frequency of other associated arterial variations in the carotid system. (orig.)

  8. 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...

  9. 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.)

  10. 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 ...

  11. 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 ...

  12. 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...

  13. Multi-segmental neurofibromatosis

    OpenAIRE

    Kumar Sudhir; Kumar Ravi

    2004-01-01

    Neurofibromatosis (NF), one of the commonest phakomatoses, is characterized by varied clinical manifestations. Segmental NF is one of the uncommon subtypes of NF. We report a young adult presenting with asymptomatic skin lesions- neurofibromas and café-au-lait macules- over localized areas of the lower back, affecting more than one segment. None of the family members were found to have features of segmental NF. Segmental NF may be misdiagnosed as a birthmark or remain undiagnosed for l...

  14. 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

  15. An Approach with Hybrid Segmental Mechanics.

    Science.gov (United States)

    Mishra, Harsh Ashok; Maurya, Raj Kumar

    2016-06-01

    Present case report provides an insight into the hybrid segmental mechanics with treatment of 13-year-old male, considering the side effects of sole continuous arch wire sliding mechanics. Patient was diagnosed as a case of skeletal class I jaw relationship, low mandibular plane angle, class II molar relation on right and class I molar relation on left side, anterior cross bite, crowding of 12mm in upper, 5mm in lower arch. He also had proclined upper and lower anteriors by 2mm, convex profile and incompetent lips. Total treatment duration was 20 months, during which segmental canine retraction was performed with TMA (Titanium, Molybdenum, Aluminum) 'T' loop retraction spring followed by consolidation of spaces with continuous arch mechanics. Most of the treatment objectives were met with good intraoral and facial results within reasonable framework of time. This approach used traditional twin brackets, which offered the versatility to use continuous arch-wire mechanics, segmental mechanics and hybrid sectional mechanics. PMID:27504427

  16. Automatic Melody Segmentation

    NARCIS (Netherlands)

    Rodríguez López, Marcelo

    2016-01-01

    The work presented in this dissertation investigates music segmentation. In the field of Musicology, segmentation refers to a score analysis technique, whereby notated pieces or passages of these pieces are divided into “units” referred to as sections, periods, phrases, and so on. Segmentation analy

  17. 非动脉炎性前部缺血性视神经病变的危险因素分析%Risk factors of non-arteritic anterior ischemic optic neuropathy

    Institute of Scientific and Technical Information of China (English)

    王淑静; 魏蕾; 鲍莹; 姜虎林

    2015-01-01

    Objective To investigate the risk factors of non-arteritic anterior ischemic optic neuropathy ( NAION) , and to provide the guidance for proper prevention and treatment.Methods Ahthor examined patients that were diagnosed with NAION and were treated in our hospital between 2009 to 2013.Medical and ophthalmic records, 24-hour blood pressure, and other laboratory tests were reviewed and compared to those of time-matched normal population, in order to find out the risk factors of the disease and its characteristic manifestations, and to optimize the treatments.Results Av-erage age of the patients was 57.89 ±10.32.There were 47.84%males and 52.16%females.Comorbidities are common among NAION patients, including hypertension (49.07%), hyperglycemia (33.02%), hypercholesteremia (23.53%), hypertriglyceridemia (29.90%), low hematocrit (8.25%), and abnormal carotid artery ultrasonography (59.73%).In contrast, these comorbidities were less common in normal population.Conclusion Systemic comorbidities are more com-mon in NAION patients, and more common in men than in women.Major risk factors include hypertension, hyperglycemia, dyslipidemia, abnormal carotid artery ultrasonography, and nocturnal hypotension.Therefore it is important to identify and treat these risk factors in NAION patients and to prevent NAION.%目的:观察非动脉炎性前部缺血性视神经病变( NAION)的危险因素,为该病提供防治措施。方法对我院2009年至2013年5年间住院的并确诊为NAION的患者和同期体健中心的体检人群的实验室检查、24 h血压、全身及一般情况、眼部检查等进行分析,籍以说明其患病的危险因素,深入研究各种因素与该病的相互关系及特点,并通过临床干预性治疗,显现出该研究对此类疾病预后的影响。结果病例组发病年龄(57.89±10.32)岁,男性占47.84%,女性占52.16%。病例组中高血压、高血糖、胆固醇、甘油三酯、红细胞压

  18. The Clinical Efficacy of Mouse Nerve Growth Factor for Treatment of Anterior Ischemic Optic ;Neuropathy%鼠神经生长因子治疗前部缺血性视神经病变的临床疗效

    Institute of Scientific and Technical Information of China (English)

    董洁玉

    2015-01-01

    Objective:To investigate the clinical efficacy of mouse nerve growth factor (NGF) for treatment of pa-tients with anterior ischemic optic neuropathy (AION). Methods: Sixty-eight patients (70 eyes) with AION were randomly divided into control group and NGF group. All patients received the conventional treatment for AION. The cases in the NGF group were daily given the mouse NGF intramuscular injection combined with conventional treatment. All patients have been treated for four weeks. The clinical efficacy, visual acuity, visual field and visual evoked potentials situation and the nerve fiber thickness surrounding papilla optica were observed and compared. Results: After 4 weeks’treatment, the clinical efficacy of NGF group was significantly better than that in the con-trol group (P<0.05). The acuity and visual field of cases in the both groups were improved compared with those be-fore treatment and the acuity in the NGF group showed greater improvement than that in the control group (P<0. 05). The P100 wave latency in the NGF group was shorter than that before treatment and that in the control group (P<0.05). Before treatment, the nerve fiber thickness surrounding papilla optica in the both groups was thicker than the normal value (98.25±8.49) μm (P<0.05). The thickness was decreased after treatment (P<0.05), the data of thickness in the NGF group was higher than that in the control group (P<0.05). The thickness in the control group was lower than the normal value (P<0.05). Conclusion: Mouse NGF is an effective way to treat AION, which can significantly improve the clinical efficacy, acuity, visual field, and visual evoked potential recovery and reduce the peripapillary nerve fiber atrophy.%目的:探讨鼠神经生长因子(NGF)治疗前部缺血性视神经病变(AION)的临床疗效。方法:AION 的患者68例(70眼),随机分为对照组及 NGF 组。2组均给予 AION 基础治疗,NGF 组在此基础上予以鼠 NGF

  19. The generation of vertebral segmental patterning in the chick embryo.

    Science.gov (United States)

    Senthinathan, Biruntha; Sousa, Cátia; Tannahill, David; Keynes, Roger

    2012-06-01

    We have carried out a series of experimental manipulations in the chick embryo to assess whether the notochord, neural tube and spinal nerves influence segmental patterning of the vertebral column. Using Pax1 expression in the somite-derived sclerotomes as a marker for segmentation of the developing intervertebral disc, our results exclude such an influence. In contrast to certain teleost species, where the notochord has been shown to generate segmentation of the vertebral bodies (chordacentra), these experiments indicate that segmental patterning of the avian vertebral column arises autonomously in the somite mesoderm. We suggest that in amniotes, the subdivision of each sclerotome into non-miscible anterior and posterior halves plays a critical role in establishing vertebral segmentation, and in maintaining left/right alignment of the developing vertebral elements at the body midline.

  20. Fenestration of the anterior cerebral artery detected by magnetic resonance angiography

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hong-wei; FU Jie; LU Zhong-lie; L(U) Hai-juan

    2009-01-01

    Background Fenestration of the proximal anterior cerebral artery (ACA) A1 segment is a rare anatomic variation. The purpose of the this study was to report the incidence of fenestration in the proximal segment of the anterior cerebral artery and to delineate its configurations on cranial MR angiography.Methods Magnetic resonance angiography (MRA) was performed in 762 patients using 1.5T imagers during the period July 2007 through September 2008. All images were obtained by the three-dimensional time-of-flight (3D TOF) technique.Volume rendering (VR) images in the horizontal rotation view were displayed stereoscopically. The presence of fenestration in the proximal segment of the anterior cerebral artery was identified and evaluated retrospectively by MRA.Results Six patients (four men and two women, 15 to 63 years of age, median age 50 years) had proximal ACA fenestration. The appearance rate of ACA fenestration was 0.8% (6/762). All 6 fenestrations were located at the A1 segment: three of them were with a slit-like shape and three were with a convex-lens-like shape, 5 of the right A1 segment, 1 of the leftA1 segment.Conclusion Recognizing ACA fenestration is important to interpret cranial MR angiographys and helpful to make a plan for neurosurgical procedures or neurological intervention.

  1. Color image segmentation

    Science.gov (United States)

    McCrae, Kimberley A.; Ruck, Dennis W.; Rogers, Steven K.; Oxley, Mark E.

    1994-03-01

    The most difficult stage of automated target recognition is segmentation. Current segmentation problems include faces and tactical targets; previous efforts to segment these objects have used intensity and motion cues. This paper develops a color preprocessing scheme to be used with the other segmentation techniques. A neural network is trained to identify the color of a desired object, eliminating all but that color from the scene. Gabor correlations and 2D wavelet transformations will be performed on stationary images; and 3D wavelet transforms on multispectral data will incorporate color and motion detection into the machine visual system. The paper will demonstrate that color and motion cues can enhance a computer segmentation system. Results from segmenting faces both from the AFIT data base and from video taped television are presented; results from tactical targets such as tanks and airplanes are also given. Color preprocessing is shown to greatly improve the segmentation in most cases.

  2. Myocardial Bridges and their Relationship to the Anterior Interventricular Branch of the Left Coronary Artery

    Directory of Open Access Journals (Sweden)

    Lima Vanildo Júnior de Melo

    2002-01-01

    Full Text Available OBJECTIVE: To analyze the relationship between myocardial bridges and the anterior interventricular branch (anterior descending of the left coronary artery. METHODS: The study was carried out with postmortem material, and methods of dissection and observation were used. We assessed the perimeter of the anterior interventricular branch of the left coronary artery using a pachymeter, calculated its proximal and distal diameters in relation to the myocardial bridge, and also its diameter under the myocardial bridge in 30 hearts. We also observed the position of the myocardial bridge in relation to the origin of the anterior interventricular branch. RESULTS: The diameters of the anterior interventricular branch were as follows: the mean proximal diameter was 2.76±0.76 mm; the mean diameter under the myocardial bridge was 2.08±0.54 mm; and the mean distal diameter was 1.98±0.59 mm. In 33.33% (10/30 of the cases, the diameter of the anterior interventricular branch under the myocardial bridge was lower than the diameter of the anterior interventricular branch distal to the myocardial bridge. In 3.33% (1/30 of the cases, an atherosclerotic plaque was found in the segment under the myocardial bridge. The myocardial bridge was located in the middle third of the anterior interventricular branch in 86.66% (26/30 of the cases. CONCLUSION: Myocardial bridges are more frequently found in the middle third of the anterior interventricular branch of the left coronary artery. The diameter of the anterior interventricular branch of the left coronary artery under the myocardial bridge may be smaller than after the bridge. Myocardial bridges may not provide protection against the formation of atherosclerotic plaque inside the anterior interventricular branch of the left coronary artery.

  3. 前节光学相干断层扫描仪观察原发性闭角型青光眼激光虹膜周边切除术后前房形态的改变%Anterior segment optical coherence tomography for detecting the morphological changes of anterior chamber in patients with primary angle closure glaucoma after laser peripheral iridotomy

    Institute of Scientific and Technical Information of China (English)

    史强; 谢安明; 张小玲

    2014-01-01

    目的 通过前节光学相干断层扫描仅(AS-OCT)观察原发性闭角型青光眼(PACG)激光虹膜周边切除术(LPI)后前房形态的改变.方法 30例(30只眼)PACG患者均行LPI,于行LPI前、后1周使用AS-OCT检查前房深度(ACD)、晶状体膨隆高度(CLR)、房角开放距离(AOD)、虹膜小梁空间面积(TISA)及瞳孔直径(PD),观察LPI前后前房形态的改变.结果 手术前眼压为(15.923±2.028)mmHg(1 mmHg =0.133 kPa),术后1周为(14.523±1.650)mmHg,术后1周眼压显著低于术前,差异有统计学意义(P<0.05).LPI前患者ACD、CLR、PD与手术后1周比较,差异均无统计学意义(P>0.05).LPI后1周患者鼻侧AOD500、颞侧AOD500、鼻侧AOD750、颞侧AOD750、鼻侧TISA500、颞侧TISA500、鼻侧TISA750、颞侧TISA750及双侧平均AOD500、AOD750、TISA500、TISA750均显著大于手术前,差异均有统计学意义(P<0.01).结论 LPI可以显著改善PACG患者眼前房结构,AS-OCT可以客观准确地观察PACG患者的前房形态.

  4. Anterior spinal artery syndrome of the cervical hemicord.

    Science.gov (United States)

    Baumgartner, R W; Waespe, W

    1992-01-01

    Three patients developed signs of a unilateral cervical cord lesion 6 to 36 h after the acute onset of severe cervico-brachial pain. The neurological deficit progressed over 6 to 18 h. On the painful side a central Horner's syndrome, a hemiparesis with plegia of the hand, and a slight pallhypaesthesia were found. On the opposite side thermhypaesthesia and hypalgesia were noted with a level at the dermatome C5 or C6. T2-weighted MR images revealed in one patient a small area of increased signal intensity restricted to one half of the cervical cord, and electromyography in another patient showed after 6 months evidence of segmental chronic denervation. Both abnormalities were found at the clinically expected level. The findings are consistent with a small infarction of the cervical cord in the perfusion territory of a central (sulco-commissural) artery, a duplicated anterior spinal artery or an anterior spinal branch of the vertebral artery. PMID:1315578

  5. Optical coherence tomography a clinical and technical update

    CERN Document Server

    Cunha-Vaz, José

    2012-01-01

    Optical Coherence Tomography represents the ultimate noninvasive  ocular imaging technique although being in the field for over two-decades. This book encompasses both medical and technical developments and recent achievements. Here, the authors cover the field of application from the anterior to the posterior ocular segments (Part I) and present a comprehensive review on the development of OCT. Important developments towards  clinical applications are covered in Part II, ranging from the adaptive optics to the integration on a slit-lamp, and passing through new structural  and functional information extraction from OCT data. The book is intended to be informative, coherent and comprehensive for both the medical and technical communities and aims at easing the communication between the two fields and bridging the gap between the two scientific communities.

  6. Quantitative Analysis of Lens Nuclear Density Using Optical Coherence Tomography (OCT) with a Liquid Optics Interface: Correlation between OCT Images and LOCS III Grading.

    Science.gov (United States)

    Kim, You Na; Park, Jin Hyoung; Tchah, Hungwon

    2016-01-01

    Purpose. To quantify whole lens and nuclear lens densities using anterior-segment optical coherence tomography (OCT) with a liquid optics interface and evaluate their correlation with Lens Opacities Classification System III (LOCS III) lens grading and corrected distance visual acuity (BCVA). Methods. OCT images of the whole lens and lens nucleus of eyes with age-related nuclear cataract were analyzed using ImageJ software. The lens grade and nuclear density were represented in pixel intensity units (PIU) and correlations between PIU, BCVA, and LOCS III were assessed. Results. Forty-seven eyes were analyzed. The mean whole lens and lens nuclear densities were 26.99 ± 5.23 and 19.43 ± 6.15 PIU, respectively. A positive linear correlation was observed between lens opacities (R (2) = 0.187, p optics interface is a potential quantitative method for lens grading and can aid in monitoring and managing age-related cataracts. PMID:27651952

  7. Microsurgical anatomy of the anterior cerebral artery in Indian cadavers

    Directory of Open Access Journals (Sweden)

    Shweta Kedia

    2013-01-01

    Full Text Available Background: The microanatomy features of cerebral arteries may be variable and may be different in different ethnic groups. Aim: To study the anterior cerebral artery (ACA anatomy in North-West Indian cadavers. Materials and Methods: Microanatomy features of the ACA were studied in 15 formalin fixed human cadaveric brains under microscope. The outer diameter, length, and number of perforating branches with respective anomalies were measured for each of the following vessels: ACA (proximal A1 segment to distal A2 segment, anterior communicating artery (ACoA, Recurrent artery of Heubner (RAH, and callosomarginal artery and photographed for documentation. Results: The mean length and external diameter of right and left A1 segment was 12.09 mm and 12.0 mm and 2.32 mm and 2.36 mm respectively. Narrowing, duplication, and median ACA were seen in 6.6%, 3.3% and 6.6% of the vessels respectively. Complex ACoA type was seen in 40% cadavers. RAH originated at an average point of 0.2 mm distal to ACoA, but in one cadaver it arose 5 mm proximal to ACoA. Double RAH was found in 26.6%. The course of RAH in relation to A1 was superiorly in 60%, in anteriorly 30% and posteriorly in 10% of cadavers. The orbitofrontal artery (OFA and frontopolar artery (FPA arose from A2 in 83.3% to 40% respectively. The mean distance of OFA and FPA from ACoA was 4.17 mm and 8.5 mm respectively. After giving rise to central, callosal and cortical branches, pericallosal artery terminated near the splenium of the corpus callosum or on the precuneus as the inferomedial parietal artery. Conclusion: Knowledge of the microvascular anatomy is indispensable and it is mandatory to be aware of the possible variations in the anomalies to minimize morbidity.

  8. Automatic Melody Segmentation

    OpenAIRE

    Rodríguez López, Marcelo

    2016-01-01

    The work presented in this dissertation investigates music segmentation. In the field of Musicology, segmentation refers to a score analysis technique, whereby notated pieces or passages of these pieces are divided into “units” referred to as sections, periods, phrases, and so on. Segmentation analysis is a widespread practice among musicians: performers use it to help them memorise pieces, music theorists and historians use it to compare works, music students use it to understand the composi...

  9. Spectral mesh segmentation

    OpenAIRE

    Liu, Rong

    2009-01-01

    Polygonal meshes are ubiquitous in geometric modeling. They are widely used in many applications, such as computer games, computer-aided design, animation, and visualization. One of the important problems in mesh processing and analysis is segmentation, where the goal is to partition a mesh into segments to suit the particular application at hand. In this thesis we study structural-level mesh segmentation, which seeks to decompose a given 3D shape into parts according to human intuition. We t...

  10. Universal Numeric Segmented Display

    CERN Document Server

    Azad, Md Abul kalam; Kamruzzaman, S M

    2010-01-01

    Segmentation display plays a vital role to display numerals. But in today's world matrix display is also used in displaying numerals. Because numerals has lots of curve edges which is better supported by matrix display. But as matrix display is costly and complex to implement and also needs more memory, segment display is generally used to display numerals. But as there is yet no proposed compact display architecture to display multiple language numerals at a time, this paper proposes uniform display architecture to display multiple language digits and general mathematical expressions with higher accuracy and simplicity by using a 18-segment display, which is an improvement over the 16 segment display.

  11. Synthetic cornea: biocompatibility and optics

    Science.gov (United States)

    Parel, Jean-Marie A.; Kaminski, Stefan; Fernandez, Viviana; Alfonso, E.; Lamar, Peggy; Lacombe, Emmanuel; Duchesne, Bernard; Dubovy, Sander; Manns, Fabrice; Rol, Pascal O.

    2002-06-01

    Purpose. Experimentally find a method to provide a safe surgical technique and an inexpensive and long lasting mesoplant for the restoration of vision in patients with bilateral corneal blindness due to ocular surface and stromal diseases. Methods. Identify the least invasive and the safest surgical technique for synthetic cornea implantation. Identify the most compatible biomaterials and the optimal shape a synthetic cornea must have to last a long time when implanted in vivo. Results. Penetrating procedures were deemed too invasive, time consuming, difficult and prone to long term complications. Therefore a non-penetrating delamination technique with central trephination was developed to preserve the integrity of Descemet's membrane and the anterior segment. Even though this approach limits the number of indications, it is acceptable since the majority of patients only have opacities in the stroma. The prosthesis was designed to fit in the removed tissue plane with its skirt fitted under the delaminated stroma. To improve retention, the trephination wall was made conical with the smallest opening on the anterior surface and a hat-shaped mesoplant was made to fit. The skirt was perforated in its perimeter to allow passage of nutrients and tissues ingrowths. To simplify the fabrication procedure, the haptic and optic were made of the same polymer. The intrastromal biocompatibility of several hydrogels was found superior to current clinically used PMMA and PTFE materials. Monobloc mesoplants made of 4 different materials were implanted in rabbits and followed weekly until extrusion occurred. Some remained optically clear allowing for fundus photography. Conclusions. Hydrogel synthetic corneas can be made to survive for periods longer than 1 year. ArF excimer laser photoablation studies are needed to determine the refractive correction potential of these mesoplants. A pilot FDA clinical trial is needed to assess the mesoplant efficacy and very long-term stability.

  12. Application of multiple intraoperative monitoring techniques in microsurgery for anterior communicating aneurysms

    Directory of Open Access Journals (Sweden)

    NI Wei

    2012-02-01

    Full Text Available Objective To evaluate the efficacy of combined multiple intraoperative monitoring techniques including transcranial Doppler (TCD, indocyanine green angiography (ICGA and neuroelectrophysiological monitoring consisting of somatosensory evoked potential (SEP and motor evoked potential (MEP in the surgical management of anterior communicating aneurysm. Methods Clinical data were analyzed for the 23 patients who underwent microsurgery for anterior communicating aneurysms with assistance of combined multiple intraoperative monitoring techniques. Twenty-three patients [12 males, 11 females; mean age 52 (range 44-63 years] underwent aneurysm clipping via modified pterional approach. Total vein anaesthesia was used for all patients. Propofol, fentanyl and scoline were administrated before intubation. Remifentanil and propofol were used throughout the procedure. Internal carotid artery and A1 segment of anterior cerebral artery were exposed successively. The parent artery, perforating artery and aneurysm were carefully recognized after the A1 segment was temporarily occluded. The temporary clip was removed after the aneurysm being clipped. Neuroelectrophysiological monitoring, ICGA and TCD were applied for intraoperative monitoring. Results All of the 23 aneurysms were successfully clipped. MEP changes were seen in 6 patients during the temporary occlusion of A1 segment, which directed neurosurgeon to pause for its recovery. TCD and ICGA detected A2 segment or anterior communicating artery stenosis in 2 patients and residual aneurysm in 1 patient during clipping procedure, which directed neurosurgeons to readjust aneurysmal clips. Postoperative transient hemiparalysis were observed in 1 patient with modified Rankin Scale level 1 at discharge. No hemorrhagic or ischemic events were observed in other 22 patients with modified Rankin Scale level 0 at discharge. Conclusion Combined multiple intraoperative monitoring techniques may provide important

  13. Comparison of adjacent segment degeneration five years after single level cervical fusion and cervical arthroplasty:a retrospective controlled study

    Institute of Scientific and Technical Information of China (English)

    SUN Yu; ZHAO Yan-bin; PAN Sheng-fa; ZHOU Fei-fei; CHEN Zhong-qiang; LIU Zhong-jun

    2012-01-01

    Background Cervical arthroplasty is indicated to preserve cervical motion and prevent accelerated adjacent segment degeneration.Whether accelerated adjacent segment degeneration is prevented in the long term is unclear.This trial compared adjacent segment degeneration in Bryan disc arthroplasty with that in anterior cervical decompression and fusion five years after the surgery.Methods We studied patients with single level degenerative cervical disc disease.The extent of adjacent segment degeneration was estimated from lateral X-rays.Results Twenty-six patients underwent single level Bryan disc arthroplasty and twenty-four patients underwent single level anterior cervical decompression and fusion.All patients were followed up for an average of sixty months.In the Bryan arthroplasty group,nine(17.6%)segments developed adjacent segment degeneration,which was significantly lower than that(60.4%)in the anterior cervical decompression and fusion group.Eleven segments in the Bryan arthroplasty group developed heterotopic ossification according to McAfee's classification and two segments had range of motion less than 2°.In the heterotopic ossification group,four(19.5%)segments developed adjacent segment degeneration,similar to the number in the non-heterotopic ossification group(16.7%).Adjacent segment degeneration rate was 50% in gradeⅣ?group but 11.8% in gradeⅡ?to Ⅲ.Conclusions Adjacent segment degeneration was accelerated after anterior cervical decompression and fusion.However,Bryan disc arthroplasty avoided accelerated adjacent segment degeneration by preserving motion.Patients with gradeⅣ?heterotopic ossification lost motion,and the rate of adjacent segment degeneration was higher than that in patients without heterotopic ossification.

  14. Segment lengths influence hill walking strategies.

    Science.gov (United States)

    Sheehan, Riley C; Gottschall, Jinger S

    2014-08-22

    Segment lengths are known to influence walking kinematics and muscle activity patterns. During level walking at the same speed, taller individuals take longer, slower strides than shorter individuals. Based on this, we sought to determine if segment lengths also influenced hill walking strategies. We hypothesized that individuals with longer segments would display more joint flexion going uphill and more extension going downhill as well as greater lateral gastrocnemius and vastus lateralis activity in both directions. Twenty young adults of varying heights (below 155 cm to above 188 cm) walked at 1.25 m/s on a level treadmill as well as 6° and 12° up and downhill slopes while we collected kinematic and muscle activity data. Subsequently, we ran linear regressions for each of the variables with height, leg, thigh, and shank length. Despite our population having twice the anthropometric variability, the level and hill walking patterns matched closely with previous studies. While there were significant differences between level and hill walking, there were few hill walking variables that were correlated with segment length. In support of our hypothesis, taller individuals had greater knee and ankle flexion during uphill walking. However, the majority of the correlations were between tibialis anterior and lateral gastrocnemius activities and shank length. Contrary to our hypothesis, relative step length and muscle activity decreased with segment length, specifically shank length. In summary, it appears that individuals with shorter segments require greater propulsion and toe clearance during uphill walking as well as greater braking and stability during downhill walking. PMID:24968942

  15. 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.

  16. 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

  17. 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.

  18. Segmentation, advertising and prices

    NARCIS (Netherlands)

    Galeotti, Andrea; Moraga González, José

    2008-01-01

    This paper explores the implications of market segmentation on firm competitiveness. In contrast to earlier work, here market segmentation is minimal in the sense that it is based on consumer attributes that are completely unrelated to tastes. We show that when the market is comprised by two consume

  19. Multi-segmental neurofibromatosis

    Directory of Open Access Journals (Sweden)

    Kumar Sudhir

    2004-11-01

    Full Text Available Neurofibromatosis (NF, one of the commonest phakomatoses, is characterized by varied clinical manifestations. Segmental NF is one of the uncommon subtypes of NF. We report a young adult presenting with asymptomatic skin lesions- neurofibromas and café-au-lait macules- over localized areas of the lower back, affecting more than one segment. None of the family members were found to have features of segmental NF. Segmental NF may be misdiagnosed as a birthmark or remain undiagnosed for long periods of time, as the patients are often asymptomatic. Moreover, the clinical features are highly variable and range from a small area of skin involvement to involvement over the entire half of the body. This variation is explained by the fact that segmental NF is thought to arise from a postzygotic NF1 gene mutation, leading to somatic mosaicism. We have also reviewed the relevant literature on this subject.

  20. Multi-segmental neurofibromatosis

    Directory of Open Access Journals (Sweden)

    Kumar Sudhir

    2004-01-01

    Full Text Available Neurofibromatosis (NF, one of the commonest phakomatoses, is characterized by varied clinical manifestations. Segmental NF is one of the uncommon subtypes of NF. We report a young adult presenting with asymptomatic skin lesions- neurofibromas and café-au-lait macules- over localized areas of the lower back, affecting more than one segment. None of the family members were found to have features of segmental NF. Segmental NF may be misdiagnosed as a birthmark or remain undiagnosed for long periods of time, as the patients are often asymptomatic. Moreover, the clinical features are highly variable and range from a small area of skin involvement to involvement over the entire half of the body. This variation is explained by the fact that segmental NF is thought to arise from a postzygotic NF1 gene mutation, leading to somatic mosaicism. We have also reviewed the relevant literature on this subject.

  1. 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.

  2. Optical coherence tomography based microangiography for quantitative monitoring of structural and vascular changes in a rat model of acute uveitis in vivo: a preliminary study

    Science.gov (United States)

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

    2015-01-01

    Uveitis models in rodents are important in the investigation of pathogenesis in human uveitis and the development of appropriate therapeutic strategies for treatment. Quantitative monitoring of ocular inflammation in small animal models provides an objective metric to assess uveitis progression and/or therapeutic effects. We present a new application of optical coherence tomography (OCT) and OCT-based microangiography (OMAG) to a rat model of acute anterior uveitis induced by intravitreal injection of a killed mycobacterial extract. OCT/OMAG is used to provide noninvasive three-dimensional imaging of the anterior segment of the eyes prior to injection (baseline) and two days post-injection (peak inflammation) in rats with and without steroid treatments. OCT imaging identifies characteristic structural and vascular changes in the anterior segment of the inflamed animals when compared to baseline images. Characteristics of inflammation identified include anterior chamber cells, corneal edema, pupillary membranes, and iris vasodilation. In contrast, no significant difference from the control is observed for the steroid-treated eye. These findings are compared with the histology assessment of the same eyes. In addition, quantitative measurements of central corneal thickness and iris vessel diameter are determined. This pilot study demonstrates that OCT-based microangiography promises to be a useful tool for the assessment and management of uveitis in vivo.

  3. 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...

  4. [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.

  5. Pancreas and cyst segmentation

    Science.gov (United States)

    Dmitriev, Konstantin; Gutenko, Ievgeniia; Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Accurate segmentation of abdominal organs from medical images is an essential part of surgical planning and computer-aided disease diagnosis. Many existing algorithms are specialized for the segmentation of healthy organs. Cystic pancreas segmentation is especially challenging due to its low contrast boundaries, variability in shape, location and the stage of the pancreatic cancer. We present a semi-automatic segmentation algorithm for pancreata with cysts. In contrast to existing automatic segmentation approaches for healthy pancreas segmentation which are amenable to atlas/statistical shape approaches, a pancreas with cysts can have even higher variability with respect to the shape of the pancreas due to the size and shape of the cyst(s). Hence, fine results are better attained with semi-automatic steerable approaches. We use a novel combination of random walker and region growing approaches to delineate the boundaries of the pancreas and cysts with respective best Dice coefficients of 85.1% and 86.7%, and respective best volumetric overlap errors of 26.0% and 23.5%. Results show that the proposed algorithm for pancreas and pancreatic cyst segmentation is accurate and stable.

  6. Segmentation of Color Images Based on Different Segmentation Techniques

    OpenAIRE

    Purnashti Bhosale; Aniket Gokhale

    2013-01-01

    In this paper, we propose an Color image segmentation algorithm based on different segmentation techniques. We recognize the background objects such as the sky, ground, and trees etc based on the color and texture information using various methods of segmentation. The study of segmentation techniques by using different threshold methods such as global and local techniques and they are compared with one another so as to choose the best technique for threshold segmentation. Further segmentation...

  7. Segmentation of consumer's markets and evaluation of market's segments

    OpenAIRE

    ŠVECOVÁ, Iveta

    2013-01-01

    The goal of this bachelor thesis was to explain a possibly segmentation of consumer´s markets for a chosen company, and to present a suitable goods offer, so it would be suitable to the needs of selected segments. The work is divided into theoretical and practical part. First part describes marketing, segmentation, segmentation of consumer's markets, consumer's market, market's segments a other terms. Second part describes an evaluation of questionnaire survey, discovering of market's segment...

  8. 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.

  9. MEDICAL IMAGE SEGMENTATION

    Directory of Open Access Journals (Sweden)

    Madhavi Latha

    2010-07-01

    Full Text Available Image segmentation is an essential but critical component in low level vision image analysis, pattern recognition, and in robotic systems. It is one of the most difficult and challenging tasks in image processing which determines the quality of the final result of the image analysis. Image segmentation is the process of dividing an image into different regions such that each region is homogeneous. Various image segmentation algorithms are discussed. Some examples in different image formats are presented and overall results discussed and compared considering different parameters.

  10. 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...

  11. Anatomic variations of anterior cerebral artery cortical branches.

    Science.gov (United States)

    Stefani, M A; Schneider, F L; Marrone, A C; Severino, A G; Jackowski, A P; Wallace, M C

    2000-01-01

    The anterior cerebral artery (ACA) is a major vessel responsible for the blood supply to the interhemispheric region. The ACA segment after the anterior communicating artery (AComA) origin is called the distal ACA and has central and cortical branches. The cortical branches are distributed in the different regions of the orbital and medial part of the brain. The objects of this study are the anatomical variations found in the distal ACA. In 76 hemispheres the ACA distal branches were injected with latex and dissected under microscope magnification. Vessel diameters and distances between vessel origins and anterior communicating artery were recorded and analyzed. Microsurgical dissection was carried out to demonstrate anatomic variations of these vessels. Average diameter of ACA at origin was 2.61 +/- 0.34 mm and average diameter of cortical branches diameter ranged from 0.79 +/- 0.27 mm to 1.84 +/- 0.3 mm. Distances between vessel origin and AComA ranged from 7.68 +/- 3.91 mm (orbitofrontal) to 112.6 +/- 11.63 mm (inferior internal parietal). This study found anatomical variations: a single (azygos) ACA was present in one case and three in three cases. Crossing branches of the distal ACA to the contralateral hemisphere were present in 26% of the cases. In some cases a single ACA may supply the posterior hemispheric region through crossing branches. This calls attention to potential bilateral brain infarcts due to a single unilateral ACA occlusion. PMID:10873213

  12. Segmentation of ribs in digital chest radiographs

    Science.gov (United States)

    Cong, Lin; Guo, Wei; Li, Qiang

    2016-03-01

    Ribs and clavicles in posterior-anterior (PA) digital chest radiographs often overlap with lung abnormalities such as nodules, and cause missing of these abnormalities, it is therefore necessary to remove or reduce the ribs in chest radiographs. The purpose of this study was to develop a fully automated algorithm to segment ribs within lung area in digital radiography (DR) for removal of the ribs. The rib segmentation algorithm consists of three steps. Firstly, a radiograph was pre-processed for contrast adjustment and noise removal; second, generalized Hough transform was employed to localize the lower boundary of the ribs. In the third step, a novel bilateral dynamic programming algorithm was used to accurately segment the upper and lower boundaries of ribs simultaneously. The width of the ribs and the smoothness of the rib boundaries were incorporated in the cost function of the bilateral dynamic programming for obtaining consistent results for the upper and lower boundaries. Our database consisted of 93 DR images, including, respectively, 23 and 70 images acquired with a DR system from Shanghai United-Imaging Healthcare Co. and from GE Healthcare Co. The rib localization algorithm achieved a sensitivity of 98.2% with 0.1 false positives per image. The accuracy of the detected ribs was further evaluated subjectively in 3 levels: "1", good; "2", acceptable; "3", poor. The percentages of good, acceptable, and poor segmentation results were 91.1%, 7.2%, and 1.7%, respectively. Our algorithm can obtain good segmentation results for ribs in chest radiography and would be useful for rib reduction in our future study.

  13. Segmentation of antiperspirants and deodorants

    OpenAIRE

    Král, Tomáš

    2009-01-01

    The goal of Master's Thesis on topic Segmentation of antiperspirants and deodorants is to discover differences in consumer's behaviour, determinate and describe segments of consumers based on these differences and propose marketing strategy for the most attractive segments. Theoretical part describes market segmentation in general, process of segmentation and segmentation criteria. Analytic part characterizes Czech market of antiperspirants and deodorants, analyzes ACNielsen market data and d...

  14. Optic disc oedema

    DEFF Research Database (Denmark)

    Nielsen, Marianne Kromann; Hamann, Steffen

    2014-01-01

    Optic disc oedema describes the nonspecific, localized swelling of the optic nerve head regardless of aetiology. Therefore, differentiating among the various aetiologies depends on a thorough history and knowledge of the clinical characteristics of the underlying conditions. Papilloedema strictly...... refers to optic disc oedema as a consequence of elevated intracranial pressure. It is usually a bilateral condition and visual function is preserved until late. Optic disc oedema caused by an anterior optic neuropathy is usually unilateral and accompanied by the loss of visual function....

  15. Segmentation of SAR images

    Science.gov (United States)

    Kwok, Ronald

    1989-01-01

    The statistical characteristics of image speckle are reviewed. Existing segmentation techniques that have been used for speckle filtering, edge detection, and texture extraction are sumamrized. The relative effectiveness of each technique is briefly discussed.

  16. International EUREKA: Initialization Segment

    International Nuclear Information System (INIS)

    The Initialization Segment creates the starting description of the uranium market. The starting description includes the international boundaries of trade, the geologic provinces, resources, reserves, production, uranium demand forecasts, and existing market transactions. The Initialization Segment is designed to accept information of various degrees of detail, depending on what is known about each region. It must transform this information into a specific data structure required by the Market Segment of the model, filling in gaps in the information through a predetermined sequence of defaults and built in assumptions. A principal function of the Initialization Segment is to create diagnostic messages indicating any inconsistencies in data and explaining which assumptions were used to organize the data base. This permits the user to manipulate the data base until such time the user is satisfied that all the assumptions used are reasonable and that any inconsistencies are resolved in a satisfactory manner

  17. Chromosome condensation and segmentation

    International Nuclear Information System (INIS)

    Some aspects of chromosome condensation in mammalians -humans especially- were studied by means of cytogenetic techniques of chromosome banding. Two further approaches were adopted: a study of normal condensation as early as prophase, and an analysis of chromosome segmentation induced by physical (temperature and γ-rays) or chemical agents (base analogues, antibiotics, ...) in order to show out the factors liable to affect condensation. Here 'segmentation' means an abnormal chromosome condensation appearing systematically and being reproducible. The study of normal condensation was made possible by the development of a technique based on cell synchronization by thymidine and giving prophasic and prometaphasic cells. Besides, the possibility of inducing R-banding segmentations on these cells by BrdU (5-bromodeoxyuridine) allowed a much finer analysis of karyotypes. Another technique was developed using 5-ACR (5-azacytidine), it allowed to induce a segmentation similar to the one obtained using BrdU and identify heterochromatic areas rich in G-C bases pairs

  18. Changes of ocular anterior segment on morphology after implantation of the implantable collamer lens for high myopia%有晶状体眼后房型人工晶状体植入术后眼前节形态学观察

    Institute of Scientific and Technical Information of China (English)

    容维宁; 孙燕; 郭慧青; 徐惠芳; 贾沁; 梁静; 殷莉; 周玲婕; 盛迅伦

    2015-01-01

    Objective To assess the effect on anterior chamber angle,corneal endothelial and adjacent tissue after implantation of phakic posterior chamber implantable collamer lens (PPC-ICL) for the correction of high myopia.Methods In this prospective,nonrandomized clinical study,106 consecutive eyes of 58 patients with high myopic received ICL implantation between January 2011 and June 2013 in the Ningxia Eye Hospital.Uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA),intraocular pressure,corneal endothelial cell count were measured preoperatively and at 1 month,6 months and 12 months postoperatively.The ultrasound biomicroscopy (UBM) was used to observe the depth of anterior chamber (ACD) vault,angle opening distance 500 microns from the scleral spur (AOD500),trabecular-iris angle (TIA) at point 2,4,8 and 10 respectively.The repeated measurement ANOVA was used to analyzed statistical data.Results The postoperative UCVA was equally or higher compare with preoperative BCVA in all patients.Intraocular pressure and corneal endothelial cell count were no statistically significant difference between pre-and postoperative (P>0.05).The postoperaive ACD,AOD500 and TIA value were decreased significantly than preoperative at 1 month (F=12.372,21.393,22.076,21.154,21.763,19.471,19.823,19.836,19.247,P<0.05).But there were no statistically significant difference of ACD,AOD500,vault and TIA between 1-month and 6-month,12-month postoperatively.No pupillary block glaucoma or anterior capsule opacification occurred during the follow-up.Conclusion The structure of anterior chamber angle was stable and corneal endothelial cell was no obvious decrease postoperatively during 1 year follow-up.%目的 观察有晶状体眼后房型人工晶状体(PPC-ICL)植入术治疗高度近视后眼前节形态学变化,探讨PPC-ICL植入术对前房角、角膜内皮以及邻近组织的影响.方法 前瞻性研究.收集2011年1月至2013年6月在宁夏眼科医院行PPC-ICL

  19. The Comparison between Cervical Artificial Disc Arthroplasty and Anterior Cervical Decompression and Fusion on the Influence of the Adjacent Segments Degeneration%颈椎间盘置换术与颈椎前路减压融合术对邻近节段退变情况影响的比较

    Institute of Scientific and Technical Information of China (English)

    王鲲鹏; 邱玉金; 王玉凤; 刘守勇; 吴磊磊

    2013-01-01

    Objective To compare CADR with ACDF on the influence of the adjacent segments degenera-tion.Methods From February 2008 to October 2010,a total of 62 cases of cervical spondylosis was retrospectively re-viewed.All the patients were divided into CADR group and ACDF group ,depending on different surgical methods .The symptoms and neurological function were evaluated by the cervical Japanese Orthopaedic Association ( JOA) Scores and neck disability index ( NDI ) .The Cobb angle of C 2~7 and the mobility of adjacent segments were valuated the cervical range of mobility and degeneration .Results Compared with the preoperation , the last follow-up neurological function significantly improved ,the difference was statistically significant ( P0 .05 ) .At last follow-up Cobb angle of C 2~7 and the mobility of adjacent upper and lower segments in CADR group were similar to the preoperative ,there was no significant difference statistically (P>0.05).And there was significant difference statistically in ACDF group and between the groups ( P<0.05) .Conclusion CADR is less influ-ential on the adjacent segments degeneration postoperative .%目的:比较分析颈椎间盘置换术( CADR )与颈椎前路减压融合术( ACDF )对邻近节段退变情况的影响。方法回顾性分析2008年2月~2011年10月手术治疗的62名患者,根据术式不同,分为CADR组与ACDF组。采用颈椎JOA、NDI评分评价症状及神经功能,C2~7 Cobb角和手术相邻节段活动度评价颈椎活动范围及退变情况。结果与术前比较,末次随访时两组患者神经功能明显改善,组内差异有显著性(P<0.05),但组间比较差异无显著性(P>0.05)。与术前相比,末次随访时CADR组C2~7 Cobb角和手术相邻上、下节段活动度相近,差异无显著性(P>0.05);ACDF组内比较与两组间末次随访时比较C2~7 Cobb角和手术相邻上、下节段活动度,差异有显著性( P<0.05

  20. Segmentation of industrial markets

    OpenAIRE

    Drugă, Petruţa

    2011-01-01

    The business marketing manager performs on a market consisting of many different types of industrial customers with different needs. Only when this aggregate market is split into meaningful categories, the business marketing strategist can react suitably and usefully to the unique needs. After the determination process of the segments has ended, then the marketer must estimate the demand for every segment. Accurate projections of future possible sales represent one of ...

  1. Beer Market Segmentation

    OpenAIRE

    Koulová, Tereza

    2012-01-01

    The goal of the master's thesis is to find out similarities or differences among consumers in the Czech beer market by using primary and secondary research and content analysis. The thesis contains two parts, the theoretical and the practical one. Market segmentation, marketing research and Czech beer market are described in the theoretical part. The practical part includes market segmentation by using secondary data (agency data MML-TGI with Data Analyzer software), primary data (own researc...

  2. Adjacent segment disease.

    Science.gov (United States)

    Virk, Sohrab S; Niedermeier, Steven; Yu, Elizabeth; Khan, Safdar N

    2014-08-01

    EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Understand the forces that predispose adjacent cervical segments to degeneration. 2. Understand the challenges of radiographic evaluation in the diagnosis of cervical and lumbar adjacent segment disease. 3. Describe the changes in biomechanical forces applied to adjacent segments of lumbar vertebrae with fusion. 4. Know the risk factors for adjacent segment disease in spinal fusion. Adjacent segment disease (ASD) is a broad term encompassing many complications of spinal fusion, including listhesis, instability, herniated nucleus pulposus, stenosis, hypertrophic facet arthritis, scoliosis, and vertebral compression fracture. The area of the cervical spine where most fusions occur (C3-C7) is adjacent to a highly mobile upper cervical region, and this contributes to the biomechanical stress put on the adjacent cervical segments postfusion. Studies have shown that after fusion surgery, there is increased load on adjacent segments. Definitive treatment of ASD is a topic of continuing research, but in general, treatment choices are dictated by patient age and degree of debilitation. Investigators have also studied the risk factors associated with spinal fusion that may predispose certain patients to ASD postfusion, and these data are invaluable for properly counseling patients considering spinal fusion surgery. Biomechanical studies have confirmed the added stress on adjacent segments in the cervical and lumbar spine. The diagnosis of cervical ASD is complicated given the imprecise correlation of radiographic and clinical findings. Although radiological and clinical diagnoses do not always correlate, radiographs and clinical examination dictate how a patient with prolonged pain is treated. Options for both cervical and lumbar spine ASD include fusion and/or decompression. Current studies are encouraging regarding the adoption of arthroplasty in spinal surgery, but more long

  3. Segmental Neurofibromatosis: Atypical Localisation

    OpenAIRE

    Filiz Topaloğlu Demir; Burçe Can; Berkant Oman; İlkin Zindancı; Tülay Zenginkinet; Mukaddes Kavala

    2015-01-01

    Neurofibromatosis (NF) is a genetic disease leading pathological findings in skin, soft tissue, bone and nervous system by affecting neural crest cells. Due to its heterogeneity neurofibromatosis was divided into eight different subgroups (NF-I NF-VIII) by Riccardi. Segmental neurofibromatosis (NF type V) is characterized by cutaneous neurofibromas and Café-au-lait spots limited with a segment of dermatome. Here we report this case with numerous, painless cutaneous nodules showing extension f...

  4. Dictionary Based Image Segmentation

    DEFF Research Database (Denmark)

    Dahl, Anders Bjorholm; Dahl, Vedrana Andersen

    2015-01-01

    We propose a method for weakly supervised segmentation of natural images, which may contain both textured or non-textured regions. Our texture representation is based on a dictionary of image patches. To divide an image into separated regions with similar texture we use an implicit level sets...... in an efficient implementation of our segmentation method. We experimentally validated our approach on a number of natural as well as composed images....

  5. Skin Images Segmentation

    Directory of Open Access Journals (Sweden)

    Ali E. Zaart

    2010-01-01

    Full Text Available Problem statement: Image segmentation is a fundamental step in many applications of image processing. Skin cancer has been the most common of all new cancers detected each year. At early stage detection of skin cancer, simple and economic treatment can cure it mostly. An accurate segmentation of skin images can help the diagnosis to define well the region of the cancer. The principal approach of segmentation is based on thresholding (classification that is lied to the problem of the thresholds estimation. Approach: The objective of this study is to develop a method to segment the skin images based on a mixture of Beta distributions. We assume that the data in skin images can be modeled by a mixture of Beta distributions. We used an unsupervised learning technique with Beta distribution to estimate the statistical parameters of the data in skin image and then estimate the thresholds for segmentation. Results: The proposed method of skin images segmentation was implemented and tested on different skin images. We obtained very good results in comparing with the same techniques with Gamma distribution. Conclusion: The experiment showed that the proposed method obtained very good results but it requires more testing on different types of skin images.

  6. Segmental neurofibromatosis and malignancy.

    Science.gov (United States)

    Dang, Julie D; Cohen, Philip R

    2010-01-01

    Segmental neurofibromatosis is an uncommon variant of neurofibromatosis type I characterized by neurofibromas and/or café-au-lait macules localized to one sector of the body. Although patients with neurofibromatosis type I have an associated increased risk of certain malignancies, malignancy has only occasionally been reported in patients with segmental neurofibromatosis. The published reports of patients with segmental neurofibromatosis who developed malignancy were reviewed and the characteristics of these patients and their cancers were summarized. Ten individuals (6 women and 4 men) with segmental neurofibromatosis and malignancy have been reported. The malignancies include malignant peripheral nerve sheath tumor (3), malignant melanoma (2), breast cancer (1), colon cancer (1), gastric cancer (1), lung cancer (1), and Hodgkin lymphoma (1). The most common malignancies in patients with segmental neurofibromatosis are derived from neural crest cells: malignant peripheral nerve sheath tumor and malignant melanoma. The incidence of malignancy in patients with segmental neurofibromatosis may approach that of patients with neurofibromatosis type I. PMID:21137621

  7. Intraocular lens alignment from an en face optical coherence tomography image Purkinje-like method

    Science.gov (United States)

    Sun, Mengchan; de Castro, Alberto; Ortiz, Sergio; Perez-Merino, Pablo; Birkenfeld, Judith; Marcos, Susana

    2014-06-01

    Measurement of intraocular lens (IOL) alignment implanted in patients in cataract surgery is important to understand their optical performance. We present a method to estimate tilt and decentration of IOLs based on optical coherence tomography (OCT) images. En face OCT images show Purkinje-like images that correspond to the specular reflections from the corneal and IOL surfaces. Unlike in standard Purkinje-imaging, the tomographic nature of OCT allows unequivocal association of the reflection with the corresponding surface. The locations of the Purkinje-like images are linear combinations of IOL tilt, IOL decentration, and eye rotation. The weighting coefficients depend on the individual anterior segment geometry, obtained from the same OCT datasets. The methodology was demonstrated on an artificial model eye with set amounts of lens tilt and decentration and five pseudophakic eyes. Measured tilt and decentration in the artificial eye differed by 3.7% and 0.9%, respectively, from nominal values. In patients, average IOL tilt and decentration from Purkinje were 3.30±4.68 deg and 0.16±0.16 mm, respectively, and differed on average by 0.5 deg and 0.09 mm, respectively, from direct measurements on distortion-corrected OCT images. Purkinje-based methodology from anterior segment en face OCT imaging provided, therefore, reliable measurements of IOL tilt and decentration.

  8. Automated segmentation of the human hippocampus along its longitudinal axis.

    Science.gov (United States)

    Lerma-Usabiaga, Garikoitz; Iglesias, Juan Eugenio; Insausti, Ricardo; Greve, Douglas N; Paz-Alonso, Pedro M

    2016-09-01

    The human hippocampal formation is a crucial brain structure for memory and cognitive function that is closely related to other subcortical and cortical brain regions. Recent neuroimaging studies have revealed differences along the hippocampal longitudinal axis in terms of structure, connectivity, and function, stressing the importance of improving the reliability of the available segmentation methods that are typically used to divide the hippocampus into its anterior and posterior parts. However, current segmentation conventions present two main sources of variability related to manual operations intended to correct in-scanner head position across subjects and the selection of dividing planes along the longitudinal axis. Here, our aim was twofold: (1) to characterize inter- and intra-rater variability associated with these manual operations and compare manual (landmark based) and automatic (percentage based) hippocampal anterior-posterior segmentation procedures; and (2) to propose and test automated rotation methods based on approximating the hippocampal longitudinal axis to a straight line (estimated with principal component analysis, PCA) or a quadratic Bézier curve (fitted with numerical methods); as well as an automated anterior-posterior hippocampal segmentation procedure based on the percentage-based method. Our results reveal that automated rotation and segmentation procedures, used in combination or independently, minimize inconsistencies generated by the accumulation of manual operations while providing higher statistical power to detect well-known effects. A Matlab-based implementation of these procedures is made publicly available to the research community. Hum Brain Mapp 37:3353-3367, 2016. © 2016 Wiley Periodicals, Inc. PMID:27159325

  9. Evolution of anterior Hox regulatory elements among chordates

    Directory of Open Access Journals (Sweden)

    Natale Alfonso

    2011-11-01

    Full Text Available Abstract Background The Hox family of transcription factors has a fundamental role in segmentation pathways and axial patterning of embryonic development and their clustered organization is linked with the regulatory mechanisms governing their coordinated expression along embryonic axes. Among chordates, of particular interest are the Hox paralogous genes in groups 1-4 since their expression is coupled to the control of regional identity in the anterior nervous system, where the highest structural diversity is observed. Results To investigate the degree of conservation in cis-regulatory components that form the basis of Hox expression in the anterior nervous system, we have used assays for transcriptional activity in ascidians and vertebrates to compare and contrast regulatory potential. We identified four regulatory sequences located near the CiHox1, CiHox2 and CiHox4 genes of the ascidian Ciona intestinalis which direct neural specific domains of expression. Using functional assays in Ciona and vertebrate embryos in combination with sequence analyses of enhancer fragments located in similar positions adjacent to Hox paralogy group genes, we compared the activity of these four Ciona cis-elements with a series of neural specific enhancers from the amphioxus Hox1-3 genes and from mouse Hox paralogous groups 1-4. Conclusions This analysis revealed that Kreisler and Krox20 dependent enhancers critical in segmental regulation of the hindbrain appear to be specific for the vertebrate lineage. In contrast, neural enhancers that function as Hox response elements through the action of Hox/Pbx binding motifs have been conserved during chordate evolution. The functional assays reveal that these Hox response cis-elements are recognized by the regulatory components of different and extant species. Together, our results indicate that during chordate evolution, cis-elements dependent upon Hox/Pbx regulatory complexes, are responsible for key aspects of

  10. Ocular perfusion pressure and hemodynamics analysis in non-arteritic anterior ischemic optic neuropathy and idiopathic optic neuritis%非炎性前部缺血性视神经病变和特发性视神经炎眼灌注压与眼部血流动力学研究

    Institute of Scientific and Technical Information of China (English)

    王欣玲; 李雪姣; 阎启昌

    2014-01-01

    Objective To compare the Ocular perfusion pressure (OPP) and ocular hemodynamics of patients with non-arteritic anterior ischemic optic neuropathy (NAION) and idiopathic optic neuritis (ION),and analyze their relationship with fixation features.Methods It was a retrospective case study.Data were collected in patients with NAION and ION who were treated in Department of Ophthalmology,the Fourth Affiliated Hospital,China Medical University from March 2011 to May 2013.OPP and ocular hemodynamics were analyzed,as well as the ages,gender,and systemic diseases after these patients were divided as the central fixation group and the extra-central fixation one on the basis of ocular fixation features.The reason making the differences were thought over.Results There were 21 NAION cases (21 eyes,14 for central fixation and 7 for extra-central fixation) and 21 ION ones (21 eyes,8 for central fixation and 13 for extra-central fixation).The peak systolic velocity (PSV) of posterior ciliary artery (PCA) and central retinal artery (CRA) were significantly decreased in the NAION group comparing with the ION group in central fixation eyes (t =12.49,P =0.00; t =14.25,P =0.00).In the extra-central fixation eyes,the sitting mean artery pressure (MAP) of brachial artery and OPP were significantly increased in the NAION group,and the PSV of PCA and CRA were significantly decreased in the NAION group (t =6.41,P =0.02; t =5.66,P =0.03; t =8.47,P =0.01; t =11.32,P =0.00).However,the PSV of PCA and CRA were significantly decreased in the NAION group when the fixation features were excluded from the classification criteria and all kinds of vision was regarded totally as central fixation vision (t =5.81,P =0.02; t =9.20,P =0.00).Conclusions The fixation features of NAION and ION eyes can be classified as central fixation and extra-central fixation.The comparisons of OPP and ocular hemodynamics should be classified according to the fixation features.%目的 比较非炎性前部缺血性视神

  11. Rediscovering market segmentation.

    Science.gov (United States)

    Yankelovich, Daniel; Meer, David

    2006-02-01

    In 1964, Daniel Yankelovich introduced in the pages of HBR the concept of nondemographic segmentation, by which he meant the classification of consumers according to criteria other than age, residence, income, and such. The predictive power of marketing studies based on demographics was no longer strong enough to serve as a basis for marketing strategy, he argued. Buying patterns had become far better guides to consumers' future purchases. In addition, properly constructed nondemographic segmentations could help companies determine which products to develop, which distribution channels to sell them in, how much to charge for them, and how to advertise them. But more than 40 years later, nondemographic segmentation has become just as unenlightening as demographic segmentation had been. Today, the technique is used almost exclusively to fulfill the needs of advertising, which it serves mainly by populating commercials with characters that viewers can identify with. It is true that psychographic types like "High-Tech Harry" and "Joe Six-Pack" may capture some truth about real people's lifestyles, attitudes, self-image, and aspirations. But they are no better than demographics at predicting purchase behavior. Thus they give corporate decision makers very little idea of how to keep customers or capture new ones. Now, Daniel Yankelovich returns to these pages, with consultant David Meer, to argue the case for a broad view of nondemographic segmentation. They describe the elements of a smart segmentation strategy, explaining how segmentations meant to strengthen brand identity differ from those capable of telling a company which markets it should enter and what goods to make. And they introduce their "gravity of decision spectrum", a tool that focuses on the form of consumer behavior that should be of the greatest interest to marketers--the importance that consumers place on a product or product category. PMID:16485810

  12. Rediscovering market segmentation.

    Science.gov (United States)

    Yankelovich, Daniel; Meer, David

    2006-02-01

    In 1964, Daniel Yankelovich introduced in the pages of HBR the concept of nondemographic segmentation, by which he meant the classification of consumers according to criteria other than age, residence, income, and such. The predictive power of marketing studies based on demographics was no longer strong enough to serve as a basis for marketing strategy, he argued. Buying patterns had become far better guides to consumers' future purchases. In addition, properly constructed nondemographic segmentations could help companies determine which products to develop, which distribution channels to sell them in, how much to charge for them, and how to advertise them. But more than 40 years later, nondemographic segmentation has become just as unenlightening as demographic segmentation had been. Today, the technique is used almost exclusively to fulfill the needs of advertising, which it serves mainly by populating commercials with characters that viewers can identify with. It is true that psychographic types like "High-Tech Harry" and "Joe Six-Pack" may capture some truth about real people's lifestyles, attitudes, self-image, and aspirations. But they are no better than demographics at predicting purchase behavior. Thus they give corporate decision makers very little idea of how to keep customers or capture new ones. Now, Daniel Yankelovich returns to these pages, with consultant David Meer, to argue the case for a broad view of nondemographic segmentation. They describe the elements of a smart segmentation strategy, explaining how segmentations meant to strengthen brand identity differ from those capable of telling a company which markets it should enter and what goods to make. And they introduce their "gravity of decision spectrum", a tool that focuses on the form of consumer behavior that should be of the greatest interest to marketers--the importance that consumers place on a product or product category.

  13. Unilateral ophthalmoplegia secondary to anterior clinoid process mucocele.

    Science.gov (United States)

    Forer, Boaz; Hui, Ng Yuk; Sethi, Dharmbir Singh

    2010-12-01

    A 50-year-old Chinese man presented with rapidly progressive unilateral ophthalmoplegia and then an ipsilateral afferent pupil defect. CT and MRI revealed a mass centered in the anterior clinoid process causing bone destruction and showing high T1 and T2 signal intensity indicative of mucosal protein secretion. These imaging features suggested a mucocele, which may have resulted from sequestration of a clinoidal extension of the sphenoid sinus. The sphenoid sinus was opened via an image-guided endoscopic approach, and the lesion incised. There were no complications. The ophthalmoplegia and afferent pupil defect had completely resolved within 1 week of surgery. This is the eighth reported case of anterior clinoidal mucocele, a rare cause of ophthalmoplegia or optic neuropathy. Advances in endoscopic instrumentation, navigation systems, and intraoperative imaging have reduced the operative risk and made the endoscopic approach a feasible and safer alternative to open surgery for this condition. PMID:20881616

  14. Active Optics in Modern, Large Optical Telescopes

    OpenAIRE

    Noethe, Lothar

    2001-01-01

    Active optics is defined as the control of the shape and the alignment of the components of an optical system at low temporal frequencies. For modern large telescopes with flexible monolithic or segmented primary mirrors and also flexible structures this technique is indispensable to reach a performance which is either diffraction limited for an operation in space or limited by the atmosphere for an operation on the ground. This article first describes the theory of active optics, both of the...

  15. Segmentation of the foveal microvasculature using deep learning networks

    Science.gov (United States)

    Prentašić, Pavle; Heisler, Morgan; Mammo, Zaid; Lee, Sieun; Merkur, Andrew; Navajas, Eduardo; Beg, Mirza Faisal; Šarunić, Marinko; Lončarić, Sven

    2016-07-01

    Accurate segmentation of the retinal microvasculature is a critical step in the quantitative analysis of the retinal circulation, which can be an important marker in evaluating the severity of retinal diseases. As manual segmentation remains the gold standard for segmentation of optical coherence tomography angiography (OCT-A) images, we present a method for automating the segmentation of OCT-A images using deep neural networks (DNNs). Eighty OCT-A images of the foveal region in 12 eyes from 6 healthy volunteers were acquired using a prototype OCT-A system and subsequently manually segmented. The automated segmentation of the blood vessels in the OCT-A images was then performed by classifying each pixel into vessel or nonvessel class using deep convolutional neural networks. When the automated results were compared against the manual segmentation results, a maximum mean accuracy of 0.83 was obtained. When the automated results were compared with inter and intrarater accuracies, the automated results were shown to be comparable to the human raters suggesting that segmentation using DNNs is comparable to a second manual rater. As manually segmenting the retinal microvasculature is a tedious task, having a reliable automated output such as automated segmentation by DNNs, is an important step in creating an automated output.

  16. Segmented conjugated polymers

    Indian Academy of Sciences (India)

    G Padmanaban; S Ramakrishnan

    2003-08-01

    Segmented conjugated polymers, wherein the conjugation is randomly truncated by varying lengths of non-conjugated segments, form an interesting class of polymers as they not only represent systems of varying stiffness, but also ones where the backbone can be construed as being made up of chromophores of varying excitation energies. The latter feature, especially when the chromophores are fluorescent, like in MEHPPV, makes these systems particularly interesting from the photophysics point of view. Segmented MEHPPV- samples, where x represents the mole fraction of conjugated segments, were prepared by a novel approach that utilizes a suitable precursor wherein selective elimination of one of the two eliminatable groups is affected; the uneliminated units serve as conjugation truncations. Control of the composition x of the precursor therefore permits one to prepare segmented MEHPPV- samples with varying levels of conjugation (elimination). Using fluorescence spectroscopy, we have seen that even in single isolated polymer chains, energy migration from the shorter (higher energy) chromophores to longer (lower energy) ones occurs – the extent of which depends on the level of conjugation. Further, by varying the solvent composition, it is seen that the extent of energy transfer and the formation of poorly emissive inter-chromophore excitons are greatly enhanced with increasing amounts of non-solvent. A typical S-shaped curve represents the variation of emission yields as a function of composition suggestive of a cooperative collapse of the polymer coil, reminiscent of conformational transitions seen in biological macromolecules.

  17. Bootstrapping structured page segmentation

    Science.gov (United States)

    Ma, Huanfeng; Doermann, David S.

    2003-01-01

    In this paper, we present an approach to the bootstrap learning of a page segmentation model. The idea evolves from attempts to segment dictionaries that often have a consistent page structure, and is extended to the segmentation of more general structured documents. In cases of highly regular structure, the layout can be learned from examples of only a few pages. The system is first trained using a small number of samples, and a larger test set is processed based on the training result. After making corrections to a selected subset of the test set, these corrected samples are combined with the original training samples to generate bootstrap samples. The newly created samples are used to retrain the system, refine the learned features and resegment the test samples. This procedure is applied iteratively until the learned parameters are stable. Using this approach, we do not need to initially provide a large set of training samples. We have applied this segmentation to many structured documents such as dictionaries, phone books, spoken language transcripts, and obtained satisfying segmentation performance.

  18. Annular beam with segmented phase gradients

    Directory of Open Access Journals (Sweden)

    Shubo Cheng

    2016-08-01

    Full Text Available An annular beam with a single uniform-intensity ring and multiple segments of phase gradients is proposed in this paper. Different from the conventional superposed vortices, such as the modulated optical vortices and the collinear superposition of multiple orbital angular momentum modes, the designed annular beam has a doughnut intensity distribution whose radius is independent of the phase distribution of the beam in the imaging plane. The phase distribution along the circumference of the doughnut beam can be segmented with different phase gradients. Similar to a vortex beam, the annular beam can also exert torques and rotate a trapped particle owing to the orbital angular momentum of the beam. As the beam possesses different phase gradients, the rotation velocity of the trapped particle can be varied along the circumference. The simulation and experimental results show that an annular beam with three segments of different phase gradients can rotate particles with controlled velocities. The beam has potential applications in optical trapping and optical information processing.

  19. Large Telescope Segmented Primary Mirror Alignment

    Science.gov (United States)

    Rud, Mayer

    2010-01-01

    A document discusses a broadband (white light) point source, located at the telescope Cassegrain focus, which generates a cone of light limited by the hole in the secondary mirror (SM). It propagates to the aspheric null-mirror, which is optimized to make all the reflected rays to be normal to the primary mirror (PM) upon reflection. PM retro-reflects the rays back through the system for wavefront analysis. The point source and the wavefront analysis subsystems are all located behind the PM. The PM phasing is absolute (white light) and does not involve the SM. A relatively small, aspheric null-mirror located near the PM center of curvature has been designed to deliver the high level of optical wavefront correction. The phasing of the segments is absolute due to the use of a broadband source. The segmented PM is optically aligned independently and separately from the SM alignment. The separation of the PM segments alignment from the PM to the SM, and other telescope optics alignments, may be a significant advantage, eliminating the errors coupling. The point source of this concept is fully cooperative, unlike a star or laser-generated guide-star, providing the necessary brightness for the optimal S/N ratio, the spectral content, and the stable on-axis position. This concept can be implemented in the lab for the PM initial alignment, or made to be a permanent feature of the space-based or groundbased telescope.

  20. Nasal palatal: segment complex

    Directory of Open Access Journals (Sweden)

    Lourdes Romera

    2015-10-01

    Full Text Available This paper focuses on the nature of a segment which is always problematical —the palatal nasal. Phonetic results found in the acoustic, perceptive and articulate spheres, showing the different features of this nasal with regards to others, are the point of departure for a brief reflection on the phonological nature of this segment, taking into account the feature geometry and the articulatory phonology. It concludes by considering the palatal nasal /?/ as a complex segment formed by /n+j/ and the imputation, to temporary effects, of a degree of major o minor assimilation and gestural overlapping during effective perception of /?/, of /n+j/ or of /n+i/.

  1. Microscopic Halftone Image Segmentation

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-gang; YANG Jie; DING Yong-sheng

    2004-01-01

    Microscopic halftone image recognition and analysis can provide quantitative evidence for printing quality control and fault diagnosis of printing devices, while halftone image segmentation is one of the significant steps during the procedure. Automatic segmentation on microscopic dots by the aid of the Fuzzy C-Means (FCM) method that takes account of the fuzziness of halftone image and utilizes its color information adequately is realized. Then some examples show the technique effective and simple with better performance of noise immunity than some usual methods. In addition, the segmentation results obtained by the FCM in different color spaces are compared, which indicates that the method using the FCM in the f1f2f3 color space is superior to the rest.

  2. Segmentation of complex document

    Directory of Open Access Journals (Sweden)

    Souad Oudjemia

    2014-06-01

    Full Text Available In this paper we present a method for segmentation of documents image with complex structure. This technique based on GLCM (Grey Level Co-occurrence Matrix used to segment this type of document in three regions namely, 'graphics', 'background' and 'text'. Very briefly, this method is to divide the document image, in block size chosen after a series of tests and then applying the co-occurrence matrix to each block in order to extract five textural parameters which are energy, entropy, the sum entropy, difference entropy and standard deviation. These parameters are then used to classify the image into three regions using the k-means algorithm; the last step of segmentation is obtained by grouping connected pixels. Two performance measurements are performed for both graphics and text zones; we have obtained a classification rate of 98.3% and a Misclassification rate of 1.79%.

  3. 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.

  4. Clinical observation of the effect of mouse nerve growth factor on anterior ischemic optic neuropathy%鼠神经生长因子治疗前部缺血性视神经病变疗效观察

    Institute of Scientific and Technical Information of China (English)

    焦毅; 杨光

    2015-01-01

    Objective To observe curative effect of the rat nerve growth factor (NGF) treatment on anterior ischemic op⁃tic neuropathy(AION). Methods Patients with AION (n=78) were randomly divided into mouse NGF treatment group (treatment group):39 cases (39 eyes) and conventional treatment group (control group):37 cases (37 eyes). Patients in control group were given Actovegin 1.2 g intravenously, once a day while patients in treatment group were given 18μg mouse NGF once a day. Milton insurable were given orally at 0.5 mg, 3 times per day at both groups. Dexamethasone of 3 mg were given retrobulbarly once a day upon onset of symptoms and the extend of edema for 3 to 5 days. Rat nerve growth factor were given for consecutive14 days as a period of treatment, and the curative effect was observed after 28 days of treatment. Results In the treatment group:treatments were obviously effective in 28 eyes (71.79%), effective in 7 eyes (17.95%) and ineffective in 4 eyes (10.26%), so the total effective rate was 89.74%; In control group: treatments were obviously effective in 11 eyes (29.73%), effective in 15 eyes (40.54%) and ineffective in 11 eyes (29.73%), so the total effective rate was 70.27%. Curative effects in these 2 groups were of statistical significance (Z=3.552, P<0.05). Vision acuity and average light sensitivity in vi⁃sual field are better in treatment group than those control group (P<0.05). Conclusion Mouse NGF is effective in the treat⁃ment of AION and can improve vision acuity and visual field, therefore is worth promoting.%目的:观察鼠神经生长因子(NGF)治疗前部缺血性视神经病变(AION)的临床疗效。方法将78例AION患者随机分为鼠NGF治疗组(治疗组)39例(39眼)和常规治疗组(对照组)37例(37眼)。对照组爱维治1.2 g静脉滴注,1次/d,治疗组加用肌内注射鼠NGF 18μg,1次/d,两组同时给予甲钴胺片口服0.5 mg,3次/d,并根据发病时间长短及视盘水肿情

  5. Statistical Images Segmentation

    Directory of Open Access Journals (Sweden)

    Corina Curilă

    2008-05-01

    Full Text Available This paper deals with fuzzy statistical imagesegmentation. We introduce a new hierarchicalMarkovian fuzzy hidden field model, which extends to thefuzzy case the classical Pérez and Heitz hard model. Twofuzzy statistical segmentation methods related with themodel proposed are defined in this paper and we show viasimulations that they are competitive with, in some casesthan, the classical Maximum Posterior Mode (MPMbased methods. Furthermore, they are faster, which willshould facilitate extensions to more than two hard classesin future work. In addition, the model proposed isapplicable to the multiscale segmentation andmultiresolution images fusion problems.

  6. Segmental Neurofibromatosis: Atypical Localisation

    Directory of Open Access Journals (Sweden)

    Filiz Topaloğlu Demir

    2015-06-01

    Full Text Available Neurofibromatosis (NF is a genetic disease leading pathological findings in skin, soft tissue, bone and nervous system by affecting neural crest cells. Due to its heterogeneity neurofibromatosis was divided into eight different subgroups (NF-I NF-VIII by Riccardi. Segmental neurofibromatosis (NF type V is characterized by cutaneous neurofibromas and Café-au-lait spots limited with a segment of dermatome. Here we report this case with numerous, painless cutaneous nodules showing extension from the shoulder to the dorsal aspect of the right hand, since it a rare case.

  7. 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

  8. 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...

  9. 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.

  10. Ocular Coherence Tomography in the Evaluation of Anterior Eye Injuries in Space Flight

    Science.gov (United States)

    Fer, Dan M.; Law, Jennifer; Wells, Julia

    2017-01-01

    While Ocular Coherence Tomography (OCT) is not a first-line modality to evaluate anterior eye structures terrestrially, it is a resource already available on the International Space Station (ISS) that can be used in medical contingencies that involve the anterior eye. With remote guidance and subject matter expert (SME) support from the ground, a minimally trained crewmember can now use OCT to evaluate anterior eye pathologies on orbit. OCT utilizes low-coherence interferometry to produce detailed cross-sectional and 3D images of the eye in real time. Terrestrially, it has been used to evaluate macular pathologies and glaucoma. Since 2013, OCT has been used onboard the ISS as one part of a suite of hardware to evaluate the Visual Impairment/Intracranial Pressure risk faced by astronauts, specifically assessing changes in the retina and choroid during space flight. The Anterior Segment Module (ASM), an add-on lens, was also flown for research studies, providing an opportunity to evaluate the anterior eye in real time if clinically indicated. Anterior eye pathologies that could be evaluated using OCT were identified. These included corneal abrasions and ulcers, scleritis, and acute angle closure glaucoma. A remote guider script was written to provide ground specialists with step-by-step instructions to guide ISS crewmembers, who do not get trained on the ASM, to evaluate the anterior eye. The instructions were tested on novice subjects and/or operators, whose feedback was incorporated iteratively. The final remote guider script was reviewed by SME optometrists and NASA flight surgeons. The novel application of OCT technology to space flight allows for the acquisition of objective data to diagnose anterior eye pathologies when other modalities are not available. This demonstrates the versatility of OCT and highlights the advantages of using existing hardware and remote guidance skills to expand clinical capabilities in space flight.

  11. 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.

  12. A multi-faceted treatment approach for anterior reconstructions using current ceramics, implants, and adhesive systems.

    Science.gov (United States)

    Hajtó, Jan; Gehringer, Uwe; Ozcan, Mutlu

    2010-01-01

    Of all developments in dental technology, fulfilling the esthetic and functional demands of the patient, especially regarding anterior reconstructions, is still a challenge for both dentists and dental technicians. This becomes more difficult for patients with a previous treatment history that is not ideal. This case presentation demonstrates reconstruction of an anterior zirconia resin-bonded fixed dental prosthesis (RBFDP) for the mandible with a combined approach utilizing veneers for harmonized space distribution on the abutment teeth and an implant-supported zirconia fixed dental prosthesis in the anterior segment of the maxilla. Adhesive cementation of the restorations is also presented in a step-by-step approach based on the current state of the art.

  13. 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...

  14. Multisegmental cervical ossification of the posterior longitudinal ligament: Anterior vs posterior approach

    OpenAIRE

    Jain Subodh; Salunke Pravin; Vyas K; Behari Sanjay; Banerji Deepu; Jain Vijendra

    2005-01-01

    Aims : To determine the surgical approach in patients with multisegmental (four or more segments) OPLL of the cervical spine. Methods and Materials : Data of 27 patients who had undergone either an anterior (corpectomy with excision of OPLL and interbody fusion=14 patients) or posterior approach (laminectomy=12, laminoplasty=1 patient) for the multisegmental cervical OPLL was analyzed retrospectively. The patients in each group were statistically similar in respect to preoperative factors su...

  15. Evolution of anterior Hox regulatory elements among chordates

    OpenAIRE

    Natale Alfonso; Sims Carrie; Chiusano Maria L; Amoroso Alessandro; D'Aniello Enrico; Fucci Laura; Krumlauf Robb; Branno Margherita; Locascio Annamaria

    2011-01-01

    Abstract Background The Hox family of transcription factors has a fundamental role in segmentation pathways and axial patterning of embryonic development and their clustered organization is linked with the regulatory mechanisms governing their coordinated expression along embryonic axes. Among chordates, of particular interest are the Hox paralogous genes in groups 1-4 since their expression is coupled to the control of regional identity in the anterior nervous system, where the highest struc...

  16. Anterior cerebral artery aneurysm associated with multiple intracranial aneurysms and abdominal aorta aneurysm

    OpenAIRE

    Lee, Yunghwan; Min, Hyung Ki; Yoon, Sang Pil

    2013-01-01

    We found multiple aneurysms in the intracranial arteries and abdominal aorta of an 87-year-old Korean female cadaver, whose cause of death was reported as "cholangiocarcinoma." An abdominal aortic aneurysm was observed in the infrarenal aorta, where the inferior mesenteric artery arose. The intracranial aneurysms were found in the A3 segment of the anterior cerebral artery and at the bifurcation of the middle cerebral artery. This case provides an example of the very rare association of perip...

  17. Speckle reduction in optical coherence tomography imaging by affine-motion image registration

    Science.gov (United States)

    Alonso-Caneiro, David; Read, Scott A.; Collins, Michael J.

    2011-11-01

    Signal-degrading speckle is one factor that can reduce the quality of optical coherence tomography images. We demonstrate the use of a hierarchical model-based motion estimation processing scheme based on an affine-motion model to reduce speckle in optical coherence tomography imaging, by image registration and the averaging of multiple B-scans. The proposed technique is evaluated against other methods available in the literature. The results from a set of retinal images show the benefit of the proposed technique, which provides an improvement in signal-to-noise ratio of the square root of the number of averaged images, leading to clearer visual information in the averaged image. The benefits of the proposed technique are also explored in the case of ocular anterior segment imaging.

  18. The LOFT Ground Segment

    DEFF Research Database (Denmark)

    Bozzo, E.; Antonelli, A.; Argan, A.;

    2014-01-01

    we summarize the planned organization of the LOFT ground segment (GS), as established in the mission Yellow Book 1 . We describe the expected GS contributions from ESA and the LOFT consortium. A review is provided of the planned LOFT data products and the details of the data flow, archiving and...

  19. Linear and nonlinear properties of segmented waveguides

    International Nuclear Information System (INIS)

    This dissertation deals with Periodically Segmented Waveguides (PSW), which are applied on KTiOP04 (KTP) crystals, by chemical ion-exchange process. In these waveguides, the crystal polarity and refractive index are periodically modulated to obtain Quasi Phase Matching (QPM) between the fundamental and second-harmonic waves. PSW is a relatively new optical device which exhibits unique optical properties in comparison with a continuous waveguide. The possibility of utilizing the KTP-PSW as a compact, cw, blue-violet, source by doubling infra-red light, is the main motivation for studying the optical properties of KTP segmented waveguides. Nevertheless, much attention in this work is also given to the study of linear optical properties of KTP-PSW, most of which, to my best knowledge, has not been studied yet. Controlling and understanding the linear optical properties of KTP-PSW, are required, for applying the PSW as an optical device by its own, and for control and characterization of the non-linear optical properties of the waveguide. In this work the dependence of the linear optical properties of KTP-PSW on geometrical parameters (period size, duty cycle and waveguide width) were studied. The experimental measured parameters include the PSW near field and the Bragg reflections, which appear due lo the grating structure of the waveguide. The possibility of controlling the wavelength and intensity, of the segmented waveguide Bragg reflections of regular period and super-period, is shown theoretically and experimentally. An unexpected dependence was found, by the experimental measurement, between the index profile and the ion-exchanged segment area,. The segmented waveguide dispersion curve, neff(λ) in the infra-red region was found, A main part of the research work is dedicated to the study of nonlinear characteristics of PSW. The different factors, which effect the Second Harmonic Generation (SHG), are measured experimentally and analyzed. The experimental results

  20. Tantalum trabecular metal implants in anterior cervical corpectomy and fusion: 2-year prospective analysis.

    Science.gov (United States)

    King, V; Swart, A; Winder, M J

    2016-10-01

    Anterior cervical decompression for two or more cervical spondylotic levels can be performed using either multiple anterior cervical discectomies and fusion or anterior cervical corpectomy and fusion (ACCF). A variety of options for ACCF implants exist but to our knowledge, there is no clinical data for the use of tantalum trabecular metal implants (TTMI) for ACCF. A retrospective review was performed of prospectively collected data for ten patients undergoing ACCF with TTMI between 2011 and 2012. Radiological outcome was assessed by measuring the change in cervical (C) lordosis (fusion Cobb and C2-C7 Cobb), graft subsidence (anterior/posterior, determined by the subsidence of anterior/posterior body height of fused segments; cranial/caudal, determined by the cranial/caudal plate-to-disc distances) and rate of fusion using lateral cervical X-rays of patients at 0, 6, 12 and 24months post-operatively. The Neck Disability Index (NDI) assessed clinical outcome pre-operatively and at 6, 12 and 24months post-operatively. Cervical lordosis (Cobb angle of fused segment) was 5.2° (± 4.2°) at 0months and 6.0° (± 5.7°) at 24months post-operatively. Graft subsidence was observed to occur at 6months post-operatively and continued throughout follow-up. Anterior, posterior and caudal subsidence occurred more in the first 12months post-operatively than in the following 12months (p<0.05). Average pre-operative NDI was 45%. Average NDIs were 18%, 13% and 10% at 6, 12 and 24months post-operatively, respectively. ACCF patients treated with TTMI demonstrated stable cervical lordosis over 2years of follow-up and 100% fusion rates after 2years. Measures of subsidence appeared to decrease with time. Patients experienced improved clinical outcomes over the 2-year period. PMID:27515543

  1. SEPTO-OPTICDYSPLASIA WITH AN ANTERIOR ENCEPHALOCELE AND INTACT SEPTUM PELLUCIDUM: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Z. Razavi

    2008-10-01

    Full Text Available ObjectiveThe diagnosis of de Morsier syndrome or septo-optic dysplasia is made on the basis of the diagnosis of optic nerve hypoplasia. Septo-optic dysplasia is defined by a variable combination of dysgenesis of midline brain structures including optic nerve hypoplasia and hypothalamic-pituitary dysfunction often associated with a wide variety of brain malformations of cortical development.The importance of direct ophthalmoscopy of optic nerve abnormalities is stressed, as well as of magnetic resonance imaging, which has become a guideline in the classification of  this syndrome This article reports a 19-year-old female with bilateral optic nerve  hypoplasia,anterior encephalocele and intact septum pellucidum. She was diagnosed withdiabetes insipidus, short stature and the history of seizure.Keywords: De morsier syndrome, Septo-optic dysplasia, Encephalocele, Short stature, Optic nerve hypoplasia

  2. Surface Figure Metrology for CELT Primary Mirror Segments

    Energy Technology Data Exchange (ETDEWEB)

    Sommargren, G; Phillion, D; Seppala, L; Lerner, S

    2001-02-27

    The University of California and California Institute of Technology are currently studying the feasibility of building a 30-m segmented ground based optical telescope called the California Extremely Large Telescope (CELT). The early ideas for this telescope were first described by Nelson and Mast and more recently refined by Nelson. In parallel, concepts for the fabrication of the primary segments were proposed by Mast, Nelson and Sommargren where high risk technologies were identified. One of these was the surface figure metrology needed for fabricating the aspheric mirror segments. This report addresses the advanced interferometry that will be needed to achieve 15nm rms accuracy for mirror segments with aspheric departures as large as 35mm peak-to-valley. For reasons of cost, size, measurement consistency and ease of operation we believe it is desirable to have a single interferometer that can be universally applied to each and every mirror segment. Such an instrument is described in this report.

  3. Multimodal Correlative Preclinical Whole Body Imaging and Segmentation.

    Science.gov (United States)

    Akselrod-Ballin, Ayelet; Dafni, Hagit; Addadi, Yoseph; Biton, Inbal; Avni, Reut; Brenner, Yafit; Neeman, Michal

    2016-01-01

    Segmentation of anatomical structures and particularly abdominal organs is a fundamental problem for quantitative image analysis in preclinical research. This paper presents a novel approach for whole body segmentation of small animals in a multimodal setting of MR, CT and optical imaging. The algorithm integrates multiple imaging sequences into a machine learning framework, which generates supervoxels by an efficient hierarchical agglomerative strategy and utilizes multiple SVM-kNN classifiers each constrained by a heatmap prior region to compose the segmentation. We demonstrate results showing segmentation of mice images into several structures including the heart, lungs, liver, kidneys, stomach, vena cava, bladder, tumor, and skeleton structures. Experimental validation on a large set of mice and organs, indicated that our system outperforms alternative state of the art approaches. The system proposed can be generalized to various tissues and imaging modalities to produce automatic atlas-free segmentation, thereby enabling a wide range of applications in preclinical studies of small animal imaging. PMID:27325178

  4. Pulse compression using segmented grating in Gekko MII system, ILE

    Energy Technology Data Exchange (ETDEWEB)

    Habara, H; Jitsuno, T; Kodama, R; Suzuki, K; Sawai, K; Kawasaki, T; Kitamura, H; Kondo, K; Mima, K; Miyanaga, N; Nakata, Y; Shiraga, H; Tanaka, K A; Tsubakimoto, K [Institute of Laser Engineering, Osaka University, 2-6, Yamada-oka, Suita, Osaka, 565-0871 (Japan); Xu, G [National laboratory on High Power Laser and Physics, Shaghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai 201800 (China); Barty, C P J; Rushford, M C [LLNL Livermore, CA (United States)], E-mail: habara@ile.osaka-u.ac.jp

    2008-05-15

    A segmented (tiled) grating array is now investigated as a new compressor system for the reason of manufacturing cost of large aperture single grating. However the considerable freedom of motion of segment arises new difficulties on pulse compression and focusing. We constructed a real compressor system using a segmented grating for 15cm aperture laser beam at Gekko MII 100TW laser system, ILE, for investigating several alignment techniques. In order to produce clean pulse shape and focused pattern generated by misalignments or line density mismatching between segment gratings, we applied the image rotation technique as a compressor arrangement. In addition to reduce uncertainness of motion of all optics, we introduced several sensor/detector such as laser level meter or position sensor. It is also shown that a capacitance detector can keep the perfect flatness of segmented grating surface. Using these techniques we demonstrated pulse compression close to Fourier transform limit.

  5. 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.

  6. 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.

  7. Judging the quality of customer segments: segmentation effectiveness

    OpenAIRE

    Dibb, Sally; Simkin, Lyndon

    2010-01-01

    Market segmentation is well established in marketing theory and applied by organisations from all industry sectors. Despite widespread use, developing and implementing segmentation schemes is rarely problem free. Testing the quality and robustness of segments is one of the difficulties which marketers face. The literature describes segment quality criteria which are intended to help with this task, yet there is little evidence of their deployment and efficacy in practice. Using a longitudinal...

  8. 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.

  9. 非动脉炎性前部缺血性视神经病变24h动态血压的初步分析%Preliminary analysis on 24-hour ambulatory blood pressure monitoring of 19 patients with non-arteritic anterior ischemic optic neuropathy

    Institute of Scientific and Technical Information of China (English)

    梅晓白; 范坷; 魏世辉

    2012-01-01

    OBJECTIVE To conduct the preliminary analysis of the characteristics of 24-hour ambulatory blood pressure monitoring (ABPM) of the 19 patients with non-arteritic anterior ischemic optic neuropathy (NAION).METHODS Chose 19 cases of NA10N group and normal control group respectively, and recorded its 24-hour systolic, diastolic and mean arterial pressure, then portrayed the curve and analyzed the morning blood pressure surge (MBPS). RESULTS The daytime systolic blood pressure of 19 cases with NAION was lower than the normal group(P<0.01); The diastolic blood pressure of the day and the night was higher than the normal group(P<0.01); The blood pressure curves concluded seven non-dippers and eleven reverse-dippers. MBPS values were measured (MBPS==35 mmHg, 3cases; 10 mmHg =MBPS<35 mmHg, llcases; 0=MBPS<10 mmHg, 2cases, MBPS<0, 3cases). CONCLUSIONS NAION patients with low systolic blood pressure in the daytime, high diastolic blood pressure in the day and the night, reverse-dippers and non-dippers of the blood pressure curve, low morning blood pressure surge were all the possible risk factors damaging target organ, and further researches are needed.%目的 初步分析非动脉炎性前部缺血性视神经病变(non-arteritic anterior ischaemic optic neuropathy,NAION)患者的24h动态血压(ambulatory blood pressure monitoring,ABPM)特点.方法 选取NAION患者19例作为病例组,同期健康体检者19例作为正常对照组,分别记录其24h的收缩压、舒张压和平均动脉压,描绘其动态曲线并分类,分析血压晨峰情况.结果 19例NAION患者日间收缩压低于正常对照组(P<0.01),昼夜的舒张压均高于正常组(P<0.01);血压变化曲线中有7例为非勺型,其余均为反勺型;血压晨峰(morning blood pressure surge,MBPS)值>35mmHg者3例,≥10mmHg~<35mmHg者11例,≥0mmHg~<10mmHg者2例,<0mmHg者3例.结论 NAION患者的日间低收缩压、昼夜高舒张压、反勺型和非勺型血压曲线、低血

  10. Curative effects of mouse nerve growth factor combined with compound anisodine on nonarteritic anterior ischemic optic neuropathy%鼠神经生长因子联合复方樟柳碱治疗非动脉炎性前部缺血性视神经病变

    Institute of Scientific and Technical Information of China (English)

    万贝贝; 徐军

    2015-01-01

    AIM:To evaluate the clinical efficacy of mouse nerve growth factor combined with compound anisodine on the treatment of nonarteritic anterior ischemic optic neuropathy ( NAION) . METHODS:Clinical case series study was applied. One hundred and twenty-two patients with monocular onset NAION were randomly divided into three groups. Routine treatment was given to all of patients. Control group A ( 40 patients with 40 eyes ) were undergone subcutaneous injection of compound anisodine besides superficial temporal artery, 2mL each time, twice per day; control group B ( 41 patients with 41 eyes ) were given intramuscular injection of mouse nerve growth factor, 30μg each time, once per day;and the combined group ( 41 patients with 41 eyes ) received compound anisodine and mouse nerve growth factor for four consecutive weeks. Visual acuity and fundus were observed every day during the treatment period. When the treatment finished, the best corrected visual acuity ( BCVA ) , visual field and OCT were checked and recorded. The results were analyzed. RESULTS:The recovery of visual acuity and visual field in the combined group was better than those of two control groups (P0. 05). The effective rates of the three groups were respectively 70% ( control group A ) , 65. 9% (control group B), 92. 7% (the combined group). The overall effective rate of patients in the combined group was significantly higher than that of two control groups ( P0. 05). CONCLUSION: Mouse nerve growth factor combined with compound anisodine has a remarkable effect on the treatment of NAION.%目的:评价鼠神经生长因子联合复方樟柳碱对非动脉炎性前部缺血性视神经病变( nonarteritic anterior ischemic optic neuropathy, NAION)的疗效。  方法:采用临床病例系列研究,将122例单眼发病NAION患者分为3组,所有患者均接受常规治疗。对照组A (40例40眼)给予复方樟柳碱注射液2 mL/次颞浅动脉旁皮下注射,2次/d;对照组 B (41例41

  11. Scintillation counter, segmented shield

    International Nuclear Information System (INIS)

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  12. Market segmentation: Venezuelan ADRs

    Directory of Open Access Journals (Sweden)

    Urbi Garay

    2012-12-01

    Full Text Available The control on foreign exchange imposed by Venezuela in 2003 constitute a natural experiment that allows researchers to observe the effects of exchange controls on stock market segmentation. This paper provides empirical evidence that although the Venezuelan capital market as a whole was highly segmented before the controls were imposed, the shares in the firm CANTV were, through their American Depositary Receipts (ADRs, partially integrated with the global market. Following the imposition of the exchange controls this integration was lost. Research also documents the spectacular and apparently contradictory rise experienced by the Caracas Stock Exchange during the serious economic crisis of 2003. It is argued that, as it happened in Argentina in 2002, the rise in share prices occurred because the depreciation of the Bolívar in the parallel currency market increased the local price of the stocks that had associated ADRs, which were negotiated in dollars.

  13. Optimizing Anterior En Masse Retraction with Miniscrew Anchorage

    Directory of Open Access Journals (Sweden)

    Pavankumar Janardan Vibhute

    2011-01-01

    Full Text Available In severely protrusive patients, skeletal anchorage from miniscrew is often used to avoid anchorage loss with preferred miniscrew location near centre of resistance (Cres of posterior teeth. Biomechanical requirement for directing retraction force towards Cres of posterior teeth demands the insertion of miniscrew in loose mucosa, where risk of infection and failure increases. In addition, undesirable biomechanical side effects on anterior and posterior segments may be possible in all three planes, when continuous arch sliding mechanics are installed with miniscrew anchorage. This paper describes technique of molar-stabilizing power arm (MSPA for simultaneous intrusion and retraction of anteriors with miniscrew placement at attached gingiva between 1st molar and 2nd premolar. Advantages of this technique include (i the need of miniscrews placement in loose mucosa apically near the Cres of the posterior teeth is eliminated, (ii the risk of infection and miniscrew failure is lowered since the miniscrew is placed in attached gingiva rather than the loose mucosa, and (iii by adjusting vertical length or replacing MSPA, alteration of the retraction force vector is possible in all three planes; thus, need of removal and repositioning of the miniscrew (e.g., in correction of occlusal cant can be eliminated.

  14. Optimizing anterior en masse retraction with miniscrew anchorage.

    Science.gov (United States)

    Vibhute, Pavankumar Janardan

    2011-01-01

    In severely protrusive patients, skeletal anchorage from miniscrew is often used to avoid anchorage loss with preferred miniscrew location near centre of resistance (Cres) of posterior teeth. Biomechanical requirement for directing retraction force towards Cres of posterior teeth demands the insertion of miniscrew in loose mucosa, where risk of infection and f