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Sample records for anterior segment optical

  1. 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.

  2. 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.

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

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    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.

  4. 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

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

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    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.

  6. The complementary benefit of anterior segment optical coherence tomography in penetrating keratoplasty

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    Yenerel NM

    2013-07-01

    Full Text Available Nursal Melda Yenerel,1 Raciha Beril Kucumen,2 Ebru Gorgun3 1Haydarpasa Numune Research and Training Hospital, Istanbul, Turkey; 2Yeditepe University Medical Faculty, Department of Ophthalmology, Istanbul, Turkey; 3Dunya Goz Eye Hospital, Istanbul, Turkey Purpose: To evaluate the utility of anterior segment optical coherence tomography (AS-OCT assessment in the pre- and postsurgical management of full-thickness corneal grafts. Methods: Seventy eyes of 58 patients who had penetrating keratoplasty were included in the study. High resolution AS-OCT scans of the cornea and the anterior segment were performed before and after transplantation in 17 eyes with the VisanteTM optical coherence tomography. Fifty-three eyes were examined in the late postoperative period. Results: The mean follow-up was 4.3 years (range, 1–15 years. Six different graft–host junctions were identified. Three patients with graft rejection, four patients with anterior synechia, and three patients with corneal ulcer were evaluated. Preoperative evaluation of eyes with semiopaque and totally opaque corneas revealed important information about anterior segment structures additional to slit-lamp findings. Conclusion: AS-OCT is a useful complementary tool for the evaluation of penetrating corneal transplantation surgery and in the management of its postoperative complications. Keywords: anterior segment optical coherence tomography, imaging techniques, penetrating keratoplasty

  7. High-resolution spectral domain anterior segment optical coherence tomography in type 1 boston keratoprosthesis

    OpenAIRE

    2013-01-01

    Purpose: To report the results of imaging using high-resolution, Fourier domain anterior segment optical coherence tomography (AS-OCT) to evaluate patients with a type 1 Boston Keratoprosthesis (KPro). Methods: We performed a retrospective comparative study of patients in whom we implanted the Boston KPro. A total of 26 eyes of 23 patients from the Cornea Service at the University of California Davis Eye Center were included. Subjects were evaluated with the Spectralis AS-OCT (Heidelberg Engi...

  8. 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.

  9. Visualization of Tear Clearance Using Anterior Segment Optical Coherence Tomography and Polymethylmethacrylate Particles.

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    Zheng, Xiaodong; Yamaguchi, Masahiko; Kamao, Tomoyuki; Sakane, Yuri; Goto, Tomoko; Shiraishi, Atsushi; Ohashi, Yuichi

    2016-11-01

    We previously reported 2 new methods, anterior segment optical coherence tomography (AS-OCT) and polymethylmethacrylate particles suspended in fluorescein solution (PPF), for the evaluation of tear clearance and rapid tear flow after blinking (tear Krehbiel flow). Here, we investigated age-related OCT tear clearance and tear film thickness (TFT) and the potential correlation of OCT tear clearance and PPF velocity indicative of tear Krehbiel flow. Normal subjects separated into young and older groups received 5 μL of saline solution into the lower conjunctival sac, and an image of the central lower eyelid tear meniscus was captured by AS-OCT immediately and 30 seconds after natural blinking. Tear meniscus height (TMH) and tear meniscus area (TMA) were measured, and their percentage decrease was defined as OCT clearance rate. A Spectralis OCT Anterior Segment Module captured the central corneal tear film layer for TFT measurements. OCT clearance rates were significantly higher in young versus older subjects (P = 0.0002). When all subjects were analyzed, age was significantly and negatively correlated with TMH clearance rate (r = -0.4928, P = 0.0003) and TMA clearance rate (r = -0.4596, P = 0.0008). TFT values were significantly and negatively correlated with age (r = -0.6662, P clearance rates and PPF velocity (TMH rate: r = 0.2926, P = 0.0392; TMA rate: r = 0.3274, P = 0.0205). AS-OCT and PPF might be novel techniques for quantitative evaluation of tear clearance and Krehbiel flow.

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

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    Ricardo J. Cumba

    2012-01-01

    Full Text Available 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 μm. Nine months later, SR reidentified SSLs. Intraobserver and interobserver agreement in SSL placement, trabecular-iris space area (TISA750, and angle opening distance (AOD750 were calculated. Results. In 84% of quadrants, SR’s SSL placements during 2 sessions were within 80 μm in both the X- and Y-axes, and in 77% of quadrants, SR and AZC were within 80 μm in both axes. In adjudicated images, 90% of all quadrants were within 80 μm, 88% in nonopen-angle eyes, and 92% in open-angle eyes. The intraobserver and interobserver correlation coefficients (with and without adjudication were above 0.9 for TISA750 and AOD750 for all quadrants. Conclusions. Reproducible identification of the SSL from images obtained with FD-ASOCT is possible. The ability to identify the SSL allows reproducible measurement of the anterior chamber angle using TISA750 and AOD750.

  11. 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.

  12. Agreement between Gonioscopic Examination and Swept Source Fourier Domain Anterior Segment Optical Coherence Tomography Imaging

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    Mohammed Rigi

    2016-01-01

    Full Text Available Purpose. To evaluate interobserver, intervisit, and interinstrument agreements for gonioscopy and Fourier domain anterior segment optical coherence tomography (FD ASOCT for classifying open and narrow angle eyes. Methods. Eighty-six eyes with open or narrow anterior chamber angles were included. The superior angle was classified open or narrow by 2 of 5 glaucoma specialists using gonioscopy and imaged by FD ASOCT in the dark. The superior angle of each FD ASOCT image was graded as open or narrow by 2 masked readers. The same procedures were repeated within 6 months. Kappas for interobserver and intervisit agreements for each instrument and interinstrument agreements were calculated. Results. The mean age was 50.9 (±18.4 years. Interobserver agreements were moderate to good for both gonioscopy (0.57 and 0.69 and FD ASOCT (0.58 and 0.75. Intervisit agreements were moderate to excellent for both gonioscopy (0.53 to 0.86 and FD ASOCT (0.57 and 0.85. Interinstrument agreements were fair to good (0.34 to 0.63, with FD ASOCT classifying more angles as narrow than gonioscopy. Conclusions. Both gonioscopy and FD ASOCT examiners were internally consistent with similar interobserver and intervisit agreements for angle classification. Agreement between instruments was fair to good, with FD ASOCT classifying more angles as narrow than gonioscopy.

  13. 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

  14. 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

  15. Measurement of Scleral Thickness in Humans Using Anterior Segment Optical Coherent Tomography.

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    Hetal D Buckhurst

    Full Text Available Anterior segment optical coherent tomography (AS-OCT, Visante; Zeiss is used to examine meridional variation in anterior scleral thickness (AST and its association with refractive error, ethnicity and gender. Scleral cross-sections of 74 individuals (28 males; 46 females; aged between 18-40 years (27.7±5.3 were sampled twice in random order in 8 meridians: [superior (S, inferior (I, nasal (N, temporal (T, superior-temporal (ST, superior-nasal (SN, inferior-temporal (IT and inferior-nasal (IN]. AST was measured in 1mm anterior-to-posterior increments (designated the A-P distance from the scleral spur (SS over a 6mm distance. Axial length and refractive error were measured with a Zeiss IOLMaster biometer and an open-view binocular Shin-Nippon autorefractor. Intra- and inter-observer variability of AST was assessed for each of the 8 meridians. Mixed repeated measures ANOVAs tested meridional and A-P distance differences in AST with refractive error, gender and ethnicity. Only right eye data were analysed. AST (mean±SD across all meridians and A-P distances was 725±46 μm. Meridian SN was the thinnest (662±57 μm and I the thickest (806±60 μm. Significant differences were found between all meridians (p<0.001, except S:ST, IT:IN, IT:N and IN:N. Significant differences between A-P distances were found except between SS and 6 mm and between 2 and 4 mm. AST measurements at 1mm (682±48 μm were the thinnest and at 6mm (818±49 μm the thickest (p<0.001; a significant interaction occurred between meridians and A-P distances (p<0.001. AST was significantly greater (p<0.001 in male subjects but no significant differences were found between refractive error or ethnicity. Significant variations in AST occur with regard to meridian and distance from the SS and may have utility in selecting optimum sites for pharmaceutical or surgical intervention.

  16. 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.

  17. 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 < 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. PMID:27403339

  18. 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.

  19. 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

  20. 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.

  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. 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.

  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. Anterior Segment OpticalCoherence Tomography: Assisted Topographic Corneal Epithelial Thickness Distribution Imaging of a Keratoconus Patient

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    A. John Kanellopoulos

    2013-04-01

    Full Text Available Purpose: To evaluate safety, efficacy and ease of measurement of epithelial thickness in a keratoconic patient based on anterior segment optical coherence tomography (AS-OCT. Methods: A 25-year-old male patient, previously diagnosed with keratoconus, with highly asymmetric manifestation among the two eyes, was subjected to AS-OCT corneal epithelial imaging. We investigated epithelial thickness and epithelial topographic thickness distribution. Results: Mean epithelial thickness was 51.97 ± 0.70 for the less affected right eye (OD, and 55.65 ± 1.22 for the more affected left eye (OS. Topographic epithelial thickness variability for the OD was 1.53 ± 0.21 μm, while for the OS it was 9.80 ± 0.41 μm. Conclusions: This case further supports our previous findings with high-frequency ultrasound measurements of the increase in overall epithelial thickness in keratoconic eyes in comparison with normal eyes. AS-OCT further offers ease of use and possibly higher predictability of measurement. This case report, based on AS-OCT imaging, verifies increased overall epithelial thickness in keratoconic eyes, as introduced by a previous study [Kanellopoulos et al.: Clin Ophthalmol 2012;6:789-800], based on high-frequency scanning ultrasound biomicroscopy imaging.

  5. 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

  6. 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.

  7. 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.

  8. Boston type I keratoprosthesis-donor cornea interface evaluated by high-definition spectral-domain anterior segment optical coherence tomography

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    Alzaga Fernandez AG

    2012-08-01

    Full Text Available Ana G Alzaga Fernandez,* Nathan M Radcliffe,* Kimberly C Sippel, Mark I Rosenblatt, Priyanka Sood, Christopher E Starr, Jessica B Ciralsky, Donald J D'Amico, Szilárd KissDepartment of Ophthalmology, Weill Cornell Medical College, New York-Presbyterian Hospital, New York, NY, USA*These authors contributed equally to this work and both are considered principal authorsBackground: The purpose of this study was to assess whether the resolution offered by two different, recently commercially available high-resolution, spectral-domain anterior segment optical coherence tomography (AS-OCT instruments allows for detailed anatomic characterization of the critical device-donor cornea interface in eyes implanted with the Boston type I permanent keratoprosthesis.Methods: Eighteen eyes of 17 patients implanted with the Boston type I keratoprosthesis were included in this retrospective case series. All eyes were quantitatively evaluated using the Cirrus HD-OCT while a subset (five eyes was also qualitatively imaged using the Spectralis Anterior Segment Module. Images from these instruments were analyzed for evidence of epithelial migration onto the anterior surface of the keratoprosthesis front plate, and presence of a vertical gap between the posterior surface of the front plate and the underlying carrier donor corneal tissue. Quantitative data was obtained utilizing the caliper function on the Cirrus HD-OCT.Results: The mean duration between AS-OCT imaging and keratoprosthesis placement was 29 months. As assessed by the Cirrus HD-OCT, 83% of eyes exhibited epithelial migration over the edge of the front plate. Fifty-six percent of the keratoprosthesis devices displayed good apposition of the device with the carrier corneal donor tissue. When a vertical gap was present (44% of eyes, the mean gap was 40 (range 8–104 microns. The Spectralis Anterior Segment Module also displayed sufficient resolution to allow for similar characterization of the device

  9. Applications of anterior segment optical coherence tomography in ophthalmology%眼前段相干光断层成像术在眼科的应用

    Institute of Scientific and Technical Information of China (English)

    王冰松; 王宁利

    2008-01-01

    The background,technical characteristics and operation procedures of anterior segment optical coherence tomography(OCT)are introduced.The ophthalmic applications of this technique are summarized.The initial studies showed that anterior segment OCT can be a promising tool for the observation of image and analysis of the cornea,the imaging and biological measuring of the anterior chamber,the observation of image and quantitative evaluation of the anterior chamber angle,the observation of image and assessment of phakic intraocular lenses,the observation of image and evaluation of trabeculectomy blebs as well as the observation of ocular accommodation.%本文介绍了眼前段相干光断层成像术(OCT)产生的背景、技术特点及测量方法,并对其在眼科的应用进行综述.初步的研究结果显示眼前段OCT在角膜成像和分析、前房成像和活体测量、前房角成像和定量分析、有晶状体眼人工晶状体成像和位置测量、小梁切除术后滤过泡的成像和分析以及眼的调节观察等方面均具有良好的应用前景.

  10. Anterior Segment Imaging in Ocular Surface Squamous Neoplasia

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    Sally S. Ong

    2016-01-01

    Full Text Available Recent advances in anterior segment imaging have transformed the way ocular surface squamous neoplasia (OSSN is diagnosed and monitored. Ultrasound biomicroscopy (UBM has been reported to be useful primarily in the assessment of intraocular invasion and metastasis. In vivo confocal microscopy (IVCM shows enlarged and irregular nuclei with hyperreflective cells in OSSN lesions and this has been found to correlate with histopathology findings. Anterior segment optical coherence tomography (AS-OCT demonstrates thickened hyperreflective epithelium with an abrupt transition between abnormal and normal epithelium in OSSN lesions and this has also been shown to mimic histopathology findings. Although there are limitations to each of these imaging modalities, they can be useful adjunctive tools in the diagnosis of OSSN and could greatly assist the clinician in the management of OSSN patients. Nevertheless, anterior segment imaging has not replaced histopathology’s role as the gold standard in confirming diagnosis.

  11. 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

  12. 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.

  13. 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.

  14. Unilateral persistent fetal vasculature coexisting with anterior segment dysgenesis.

    Science.gov (United States)

    Khokhar, Sudarshan; Gupta, Shikha; Arora, Tarun; Gogia, Varun; Dada, Tanuj

    2013-08-01

    Persistent fetal vasculature (PFV) is a common congenital developmental anomaly of the eye which results from failure of the embryological primary vitreous and hyaloid vasculature to regress by the time of birth (Int Ophthalmol Clin 48: 53-62, 2008). Typically, it is divided into anterior, posterior or combined types and is characterized by the presence of a vascular stalk located between the optic disc and the posterior lens capsule (Int Ophthalmol Clin 48: 53-62, 2008). Although it has been reported to manifest itself differently, in our case it presented in a microphthalmic eye as anterior segment dysgenesis with broad-based mid-peripheral synechiae, posterior embryotoxon, iridoschisis, ectropion uveae, hypotony and subluxated cataractous lens with a taut anterior hyaloid face which are rare associations with PFV.

  15. 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.

  16. 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

  17. 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.

  18. Morphogenesis of the anterior segment in the zebrafish eye

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    Link Brian A

    2005-06-01

    Full Text Available Abstract Background The ocular anterior segment is critical for focusing incoming light onto the neural retina and for regulating intraocular pressure. It is comprised of the cornea, lens, iris, ciliary body, and highly specialized tissue at the iridocorneal angle. During development, cells from diverse embryonic lineages interact to form the anterior segment. Abnormal migration, proliferation, differentiation, or survival of these cells contribute to diseases of the anterior segment such as corneal dystrophy, lens cataract, and glaucoma. Zebrafish represent a powerful model organism for investigating the genetics and cell biology of development and disease. To lay the foundation for genetic studies of anterior segment development, we have described the morphogenesis of this structure in zebrafish. Results As in other vertebrates, the zebrafish anterior segment derives from diverse origins including surface ectoderm, periocular mesenchyme, and neuroepithelium. Similarly, the relative timing of tissue differentiation in the anterior segment is also conserved with other vertebrates. However, several morphogenic features of the zebrafish anterior segment differ with those of higher vertebrates. These include lens delamination as opposed to invagination, lack of iris muscles and ciliary folds, and altered organization in the iridocorneal angle. In addition, substantial dorsal-ventral differences exist within the zebrafish anterior segment. Conclusion Cumulatively, our anatomical findings provide a reference point to utilize zebrafish for genetic studies into the mechanisms of development and maintenance of the anterior segment.

  19. 前节OCT在瞳孔残膜诊治中的应用%The Value of Anterior Segment Optical Coherence Tomography in Persistent Pupillary Membrane

    Institute of Scientific and Technical Information of China (English)

    玛琮

    2013-01-01

    Objective:To analyze the value of anterior segment optical coherence tomography when diagnose and treat persistent pupillary membrane.Method:12 cases(24 eyes)of persistent pupillary membrane were underwent anterior segment optical coherence tomography examination both with or without the irradiation of light.Summarize the character of all the result.Design the treatment for the patients according to the results of examination as well as patient's age,visual acuity and the character of the membrane.Result:It showed a active reflect signal of the patients underwent the AS-OCT examination. It could detect the changes of the membrane under the condition of dark and light. The membranes showed no interfere effect on the movement of the pupils and no contact to the surface of lens. 8 cases(16 eyes)were treated of membrane resection,and 4 cases(8 eyes)underwent radiation treatment. Most of the patients received a better acuity or quantity of visual.Conclusion:AS-OCT can detect the shape of the membranes under the condition of dark and light,and provides information to determine the best chose for the patients in clinical practice.%  目的:探讨前节 OCT 在瞳孔残膜诊治中的应用价值。方法:采用光照射与暗光下对12例(24只眼)瞳孔残膜患者进行前节OCT 检查,总结其特点,根据检查结果,结合患者年龄、视力、残膜致密形态及致密程度制定治疗方案。结果:瞳孔残膜在 OCT 检查中表现为高信号,通过光照射与暗光下 OCT 检查结果的对比,12例(24只眼)瞳孔残膜与晶状体表面均无粘连,8例(16只眼)采用手术切除,4例(8只眼)行激光治疗,治疗后大部分患者视力或视觉质量有不同程度提高。结论:前节 OCT 能清楚显示瞳孔残膜,根据光照射与暗光下 OCT 检查可以进一步了解残膜与晶状体表面有无粘连,为治疗方案的选择提供依据,具有一定的临床实用价值。

  20. 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.

  1. 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

  2. Research progress on anterior segment optical coherence tomography in glaucoma%眼前节相干光断层扫描在青光眼中的研究进展

    Institute of Scientific and Technical Information of China (English)

    赵黎; 李青松; 柯梅青; 张兴儒

    2014-01-01

    Glaucoma is the second blindness disease in the world, and there are more primary angle closed glaucoma in China.The anatomy changes of the anterior chamber have close relationships with the development of glaucoma. Anterior segment optical coherence tomography ( AS-OCT) has the advantages of fast, non-contact, high resolution and accurate quantitative measurement, which provides a kind of important method for finding the pathogenesis of primary angle closed glaucoma, for early diagnosis and treatment of glaucoma, and for the postoperative evaluation of glaucoma.%青光眼是世界第二位致盲性眼病,我国以原发性闭角型青光眼较多。前房解剖结构的改变与青光眼的发展有密切的关系。眼前段光学相干断层成像技术( anterior segment optical coherence tomography , AS-OCT )具有检查快速、非接触、高分辨率、精确定量化测量等特点,为原发闭角型青光眼房角关闭的发病机制、早期诊断和治疗、青光眼术后评价等方面提供了一种重要的方法。

  3. AS-OCT测量眼前节虹膜参数可重复性研究%Reproducibility of iris parameters measurements with anterior segment optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    郑策; 谢晓玲; 陈文霞; 张铭志

    2015-01-01

    Objective To determine the repeatability and reproducibility of anterior segment optical coherence tomography (AS-OCT) on the measurement of iris parameters.Methods In this cross-sectional study,105 consecutive subjects,mean age was 48.5 years (range:24-67),(50 normal open angle subjects and 55 angle-closure subjects) were recruited.One eye from each subject was randomly selected for imaging by AS-OCT using anterior segment single protocol.For intraobserver and interobserver reproducibility,a single observer acquired two sets of images followed by a third set of images acquired by a second observer.AS-OCT images were measured using custom software to determine iris parameters,including iris thickness,iris area and iris curvature.The intraclass correlation coefficient (ICC),limits of agreement (LOA;mean of differences± 1.96SD of differences),and coefficient of variation (CV) were calculated as items of intraobserver and interobserver reproducibility.Results The mean and standard deviation of iris thickness,iris area and iris curvature,in open angle group,were 0.40±0.05mm,1.67±0.24 mm2 and 0.18±0.12 mm,respectively;and in angle-closure group,were 0.42±0.04 mm,1.62±0.25 mm2 and 0.25±0.11 mm,respectively.In open angle group,ICC of intraobserver and interobserver measurement was from 0.865 to 0.982.In angle-closure group,the range of ICC was from 0.875 to 0.948.Conclusions The reproducibility of iris parameters measurements with the AS-OCT is good in both open angle and angle closure eyes.%目的 评估使用眼前节光学相干断层成像术(AS-OCT)定量测量虹膜参数的可重复性.方法 横断面研究.对2013年1月至2015年1月在汕头国际眼科中心共纳入受试者105名,平均年龄48.5岁(24~67岁).分为房角开放(50名受试者)和房角关闭(55名受试者)两组.采用AS-OCT的眼前节单线扫描模式,使用自编程图像处理软件定量测量AS-OCT影像的虹膜参数,包括虹膜厚度,虹膜体积和虹膜曲度.先由

  4. Swept source OCT imaging of human anterior segment at 200 kHz

    Science.gov (United States)

    Karnowski, Karol; Gora, Michalina; Kaluzny, Bartlomiej; Huber, Robert; Szkulmowski, Maciej; Kowalczyk, Andrzej; Wojtkowski, Maciej

    2009-02-01

    We present applicability of the high speed swept-source optical coherence tomography for in vivo imaging of the anterior segment of the human eye. Three dimensional imaging of the cornea with reduced motion artifacts is possible by using swept source with Fourier domain mode locking operating at 200kHz with 1300nm central wavelength. High imaging speeds allow for assessment of anterior and posterior corneal topography and generation of thickness and elevation maps.

  5. 采用眼前段光学相干断层扫描仪检测的健康人眼前段结构相关参数间的关系%Relationship among related parameters of healthy human eye anterior segment structure detected by anterior segment optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    曾阳发; 刘杏; 王涛; 钟毅敏; 李媚; 何明光

    2009-01-01

    Objective To analyze the relationship among parameters of healthy human eye anterior segment structure detected by anterior segment optical coherence tomography (AS-OCT), and to explore the effect of age on these parameters. Methods AS-OCT was performed in 211 healthy people (211 eyes) to measure the parameters of anterior segment structure, including anterior chamber depth (ACD), anterior chamber horizontal diameter (ACHD), anatomy anterior chamber depth (AACD), lens thickness (LT), ciliary band length (CBL) , lens position (LP) and iris thickness (IT). These parameters were compared between men and women. Relationship among the parameters was analyzed, and effect of age on anterior segment structure biometric values was evaluated. Results The values of ACD, ACHD, AACD, CBL, IT and LP were significantly higher in male than those in female[ACD: (2.87±0.38) mm vs (2.66±0.40) mm; ACHD: (11.73±0.43) mm vs (11.53±0.36) mm;AACD: (3.09±0.19) mm vs (3.00±0.19) mm;CBL: (0.20± 0.09) mm vs (0.17±0.09) mm;iT: (0.36±0.08) mm vs (0.34±0.08) mm; LP: (5.11±0.26) mm vs (4.91± 0.28) ram; all P0.05). ACHD was negatively correlated with age (r=-0.148, P=0.032). LT was positively correlated with age (r=0.646, P=0.000). LT was negatively correlated with ACD (r=-0.714, P=0.000). LT had no significant effect on LP using regression analysis. Conclusions The anterior segments biometric structure of female is narrower than that of male. With aging, the narrowing of ACD is resulted from LT increment. And LP of healthy eyes does not change with aging and LT increment.%目的 采用眼前段光学相干断层扫描仪(AS-OCT)测量健康人的眼前段各参数,并分析参数间的关系以及年龄对其的影响.方法 采用AS-OCT扫描211例健康人(211只眼)眼前段结构,并测量前房深度(ACD)、前房横径(ACHD)、解剖前房深度(AACD)、晶状体厚度(LT)、睫状体带长度(CBL)、晶状体位置(LP)和虹膜厚度(IT).对各参数进行性别间的比较,

  6. 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.

  7. 眼前节相干光断层扫描在原发性闭角型青光眼诊治中的应用%Anterior segment optical coherence tomography for the evaluation of primary angle closure glaucoma

    Institute of Scientific and Technical Information of China (English)

    刘杏; 李媚

    2013-01-01

    眼前节相干光断层扫描(AS-OCT)是继超声生物显微镜(UBM)后又一种眼前段成像检测手段,其为无创性、非接触性,分辨率较UBM高.可测量包括角膜、前房、前房角、虹膜、晶状体等多个眼前段结构参数.本文评价了AS-OCT在原发性闭角型青光眼(PACG)诊治中利用AS-OCT了解PACG和正常人眼前段生物学参数的差异,了解周边虹膜切开(或切除)术后、小梁切除术后、白内障手术后PACG的眼前段结构性参数的变化,以及对小梁切除术后滤过泡功能进行评估等,强调AS-OCT在PACG的诊断、发病机制、治疗观察中具有重要的临床应用价值.%Anterior segment optical coherence tomography (AS-OCT) is an imaging instrument developped after ultrasound biomi-croscopy (UBM). Moreover, AS-OCT is a non-invasive and non-contact instrument with a higher resolution than UBM. AS-OCT offers anterior segment images of the cornea, anterior chamber, anterior chamber angle, iris and lens. In this article, the value of AS-OCT is e-valuated in the diagnosis and treatment of primary angle closure glaucoma (PACG), including the application of AS-OCT in observing the differences between PACG and normal controls, the changes in anterior segment configuration after peripheral iridectomy/trabeculec-tomy/ cataract surgery in PACG, and the morphology of filtering blebs after trabeculectomy. The present study showed that AS-OCT would play an important role in the diagnosis, treatment choice and pathogenesis study of PACG.

  8. Anterior ischemic optic neuropathy following dengue fever.

    Science.gov (United States)

    Ramakrishnan, Reshma; Shrivastava, Saurabh; Deshpande, Shrikant; Patkar, Priyanka

    2016-01-01

    Dengue fever is caused by a flavivirus. This infection is endemic in the tropics and warm temperate regions of the world. Ocular manifestations of dengue fever include subconjunctival, vitreous, and retinal haemorrhages; posterior uveitis; optic neuritis; and maculopathies, haemorrhage, and oedema. However anterior ischemic optic neuropathy is a rare presentation. Optic nerve ischemia most frequently occurs at the optic nerve head, where structural crowding of nerve fibers and reduction of the vascular supply may combine to impair perfusion to a critical degree and produce optic disc oedema. Here we present a case of anterior ischemic optic neurapathy associated with dengue fever.

  9. Anterior and posterior centers jointly regulate Bombyx embryo body segmentation.

    Science.gov (United States)

    Nakao, Hajime

    2012-11-15

    Insect embryo segmentation is largely divided into long and short germ types. In the long germ type, each segment primordium is represented on a large embryonic rudiment of the blastoderm, and segmental patterning occurs nearly simultaneously in the syncytium. In the short germ type, however, only anterior segments are represented in the small embryonic rudiment, usually located on the egg posterior, and the rest of the segments are added sequentially from the posterior growth zone in a cellular context. The long germ type is thought to have evolved from the short germ type. It is proposed that this transition, which appears to have occurred multiple times over the course of evolution, was realized through the acquisition of a localized anterior instruction center. Here, I examined the early segmentation process in the silkmoth Bombyx mori, a lepidopteran insect, in which the mechanisms of anterior-posterior (AP) axis formation have not been well analyzed. In this insect, both the long germ and short germ features have been reported. The mRNAs for two key genes involved in insect AP axis formation, orthodenticle (Bm-otd) and caudal (Bm-cad), are localized maternally in the germ anlage, where they act as anterior and posterior instruction centers, respectively. RNAi studies indicate that, while Bm-cad affects the formation of all the even skipped (Bm-eve) stripes, there is also anterior Bm-eve stripe formation activity that involves Bm-otd. Thus, there is redundancy in Bm-eve stripe formation activity that must be coordinated. Some genetic interactions, identified either experimentally or hypothetically, are also introduced, which might enable robust AP formation in this organism.

  10. The application of ocular anterior segment optical coherence tomography after operation of ocular penetraing injury%眼前段OCT在眼球穿孔伤术后的运用

    Institute of Scientific and Technical Information of China (English)

    李娟娟; 盛智超; 胡竹林

    2011-01-01

    Objective To evaluat the application of anterior segment optical coherence tomography (ASOCT) in the imaging of postoperative ocular penetrating injuries. Methods Thirty-six successive cases (36 eyes) with ocular penetrating injury in our hospital were examined by ASOCT after surgery to observe and analyze stuctural changes of cornea and anterior chamber angle by anterior segment biomicroscopy. Results The results of ASOCT showed that swollen and cloudy corneas with disordered stroma and irregular surfaces in 21 eyes, lacerated chamber angles in 5 eyes, synechial and closed chamber angles in 12 eyes, iris adhered to the wounds in 8 eyes, broken anterior lens capsules and overflowed cortices in 12 eyes and shallow cyclodialyses in 3 eyes. Conclusion ASOCT has good clinical value in evaluating injury degree in postoperative penetrating injury eyeballs and predicating the prognosis for recovery.%目的 评估眼前段OCT在眼球穿孔伤术后的应用价值.方法 连续收集我院所收治的眼球穿孔伤36例(36眼),术后进行眼前段裂隙灯显微镜检查,观察分析角膜,前房角等组织结构的变化.结果 眼前段OCT显示出:21眼角膜水肿浑浊,实质层结构紊乱,表面不规则;5眼房角撕裂,12眼房角粘连关闭;8眼虹膜粘连于伤口;2眼晶状体前囊破裂,皮质溢出;3眼睫状体浅脱离.结论 眼前段OCT对眼球穿孔伤术后评估眼球损伤程度,预后恢复等有较好的临床应用价值.

  11. 光学相干断层扫描技术在眼前节结构应用的新进展%Progression in application of optical coherence tomography in ocular anterior segment examination

    Institute of Scientific and Technical Information of China (English)

    张鹏

    2014-01-01

    光学相干断层扫描技术(OCT)是一种利用光的干涉原理来成像眼部结构的方法,最初用于眼后节的测量和检查,但随着OCT技术的进展,目前已广泛用于眼前节各组织的测量和检查.眼前节光学相干断层扫描技术(AS-OCT)可将角膜、前房、瞳孔、虹膜等眼前节组织结构显示于一张图像上,并可用于准分子激光角膜原位磨镶术术后角膜前后表面情况和角膜曲率的测定,青光眼患者房角、虹膜、睫状体的观察,抗青光眼术后功能性滤过泡的动态变化以及眼外伤患者的眼前节组织结构变化等.AS-OCT检测具有非接触、分辨率高、检测快捷、可定量分析等特点,因此是眼前节组织的检测的有力工具.就AS-OCT技术在眼科的临床应用、优缺点及展望进行综述.%Optical coherence tomography (OCT) is a technology that imaging the ocular structure by the interference of light.OCT is invented and applied in the examine and measure of the retina and choroid.However,the development of spectrum domain make the study of ocular anterior segment structure possible.Anterior segment OCT (AS-OCT) can image the tissue structures of the cornea,anterior chamber,pupil,iris,etc.on the same picture.Also,AS-OCT can be used to measure the corneal surface and curvature after excimer laser in situ keratomileusis,the examination of the angle,iris,ciliary body in glaumatous eyes,the observation of dynamic alteration of the filtering bleb following antiglaucoma surgery and the evaluation of ocular anterior segment tissue after eye trauma.AS-OCT examined at a non-contact,non-invasive way with higher resolution and higher speed.In addition,AS-OCT offers the quantitative analysis of the ocular anterior segment.The clinical application,advantages and disadvantages,prospect of AS-OCT in ophthalmology were reviewed in this paper.

  12. 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

  13. 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

  14. Discussion on application of optical coherence tomography for anterior segment imaging%光学相干断层扫描技术眼前节成像的应用探讨

    Institute of Scientific and Technical Information of China (English)

    董静; 吴强; 王晓刚

    2015-01-01

    It is very important for ophthalmic clinical diagnosis and research to obtain anterior segment information by non-invasive means. With the progress of science and technology, the application of optical coherence tomography ( OCT ) on clinical practice and scientific research of ophthalmology has been widely accepted . It not only can achieve precise imaging of an organization structure, but also can do some quantitative analysis for the assessment of clinical treatment and follow-up as an irreplaceable information.%通过无创性手段获得眼前节组织结构信息,对于眼科临床诊断及科研尤为重要。随着科技的进步,光学相干断层扫描技术( optical coherence tomography,OCT)在眼科临床及科研的应用已经得到广泛认可。目前不仅可以实现组织结构的精细成像,并可以进行对应的量化分析,为临床治疗的评估、随访观察提供不可替代的信息。

  15. Haploinsufficient Bmp4 ocular phenotypes include anterior segment dysgenesis with elevated intraocular pressure

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    Nusinowitz Steven

    2001-11-01

    Full Text Available Abstract Background Glaucoma is a blinding disease usually associated with high intraocular pressure (IOP. In some families, abnormal anterior segment development contributes to glaucoma. The genes causing anterior segment dysgenesis and glaucoma in most of these families are not identified and the affected developmental processes are poorly understood. Bone morphogenetic proteins (BMPs participate in various developmental processes. We tested the importance of Bmp4 gene dosage for ocular development and developmental glaucoma. Results Bmp4+/- mice have anterior segment abnormalities including malformed, absent or blocked trabecular meshwork and Schlemm's canal drainage structures. Mice with severe drainage structure abnormalities, over 80% or more of their angle's extent, have elevated IOP. The penetrance and severity of abnormalities is strongly influenced by genetic background, being most severe on the C57BL/6J background and absent on some other backgrounds. On the C57BL/6J background there is also persistence of the hyaloid vasculature, diminished numbers of inner retinal cells, and absence of the optic nerve. Conclusions We demonstrate that heterozygous deficiency of BMP4 results in anterior segment dysgenesis and elevated IOP. The abnormalities are similar to those in human patients with developmental glaucoma. Thus, BMP4 is a strong candidate to contribute to Axenfeld-Rieger anomaly and other developmental conditions associated with human glaucoma. BMP4 also participates in posterior segment development and wild-type levels are usually critical for optic nerve development on the C57BL/6J background. Bmp4+/- mice are useful for studying various components of ocular development, and may allow identification of strain specific modifiers affecting a variety of ocular phenotypes.

  16. 基于谱域OCT图像的人眼前节生物学参数自动测量%Automated biometry of human ocular anterior segment based on spectral domain optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    陈思思; 朱德喜; 马庆凯; 沈梅晓

    2016-01-01

    ocular anterior segment.However,the measurement of the dimension of anterior segment from the OCT image with high speed and precision is a challenge at present.The software of automatic data processing is still lack in analyzing spectral domain OCT.Objective This study was to perform the automatic biometry and data processing of human ocular anterior segment OCT image by using self-developed automatic detection software and evaluate the accuracy and repeatability of this method.Methods Twenty eyes of 10 normal subjects were included in Eye Hospital of Wenzhou Medical University from June to July 2013.The OCT image of anterior eye segments were obtained with custom-made ultra-long scan depth OCT under the informed consent.Anautomatic software algorithm was developed for the biometric measurement on these OCT images,including boundary segmentation,image registration and optical correction of OCT images.The boundary segmentation algorithm utilized the axial gradient information of OCT images and the shortest path search principal based on the dynamic programming to optimize edge finding.Central corneal thickness (CCT),anterior chamber depth (ACD),pupil diameter (PD),lens thickness (LT),radius of lens anterior curvatures (LAC) and radius of lens of posterior curvatures (LPC) were automatically and manually measured,and the validity of automatic detection algorithm was assessed by calculating the intraclass correlation coefficient (ICC) between the automatic and manual measurements,and the repeatability was validated by calculating the coefficient of repeatability (COR) between repeated measurement.This study was approved by the Ethic Committee of Wenzhou Medical University and informed consent was obtained from all subjects.Results There were no significant differences in the results of CCT,ACD,PD,LT,LAC and LPC between the automatic and manual measurements (P =0.205,0.167,0.285,0.127,0.102,0.074).The results were consistent between automatic and manual measurements (all at

  17. 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.

  18. 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.

  19. Experimental Study on the Prevention of Anterior Segment Ischemia by Preservation of Anterior Ciliary Vessels

    Institute of Scientific and Technical Information of China (English)

    Yanna Li; Guanghuan Mai; Zhijian Wang; Xinping Yu; Huanyun Yu; Yan Guo; Xiaoming Lin; Daming Deng; Ying Kang

    2003-01-01

    Purpose: To observe the effect of preserving anterior ciliary vessels (ACVs) on anteriorsegments of rabbit eyes undergoing tenotomy of extraocular muscles.Methods: Thirty-two adult New Zealand white rabbits were divided into four groups.Same procedures were done in both eyes in each group except that left eyes underwentpreservation of ACVs. In the first group medial and lateral recti, in the second group,superior and inferior recti, in the third group, medial, lateral and superior or inferior rectiand in the fourth group, all four recti, underwent tenotomy. Slit-lamp examination,intraocular pressure (IOP) measurement, total protein and lactic acid quantification inaqueous humor were done in all eyes pre- and post-operatively. By four weeks afteroperation, the eyes were enucleated for histological examination and electron microscopy.All data were analyzed using SPSS version 10.Results: In the left eyes of both group 1 and group 2, no inflammatory response wasobserved. In the left eyes of group 3 and 4, we observed mild inflammatory response withslit-lamp examination, which disappeared in one wk. However, we did not findsignificant changes in IOP, total protein and lactic acid of aqueous humor, histology andelectron microscopic examination in these groups. In the right eyes in group 2, 3 and 4,we observed moderate to severe inflammatory changes, a few even developed anteriorsegment ischemia, appeared as decreased IOP, increased total protein and lactic acid inaqueous humor, along with pathological and electron-microscopic changes.Conclusion: Simultaneous tenotomy of three or four recti or two vertical recti on one eyemay decrease anterior segment blood flow even lead to ischemia. ACVs preservation mayprotect the blood circulation in anterior segment. Our study suggests that ACVspreservation in strabismus surgeries especially those involving multi-recti tenotomies mayprevent potential anterior segment ischemia.

  20. The morphology of corneal cap and its relation to refractive outcomes in femtosecond laser small incision lenticule extraction (SMILE with anterior segment optical coherence tomography observation.

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    Full Text Available PURPOSE: To investigate the morphology of corneal caps in femtosecond laser small incision lenticule extraction (SMILE and its relation to the refractive outcomes. METHODS: A prospective study of fifty-four corneal caps created with VisuMax femtosecond laser were examined using an Fourier-domain optical coherence tomography at 1 day, 1 week, 1 month and 6 months after SMILE. The cap thickness at nine points on each of the four meridians (0°, 45°, 90°, 135° and the diameter were measured. Cap morphology, changes over time and its correlation with refractive outcomes were assessed. RESULTS: The mean achieved central cap thickness were (108.74±5.06 µm at 6 months and (107.32±4.81 µm at 1 month postoperatively, significantly thinner than that at 1 day (110.81±7.95 µm and 1 week (109.58±7.48 µm (P<0.05. The mean diameter on 0° meridian was (7.61±0.07 mm, significantly larger than that on 90° meridian (7.57±0.06 mm (P = 0.001. Cap morphology showed good regularity, except that the differences of points in two pairs were significant at 1 day postoperatively. The uniformity was consistent over time and the central cap thickness was thinner than those in the paracentral and peripheral areas. The refractive outcomes stabilized within 1 month. Uncorrected distance visual acuity (UDVA was correlated to the central cap thickness at 1 day and 1 week (both rs  = 0.33, p<0.05. The uniformity index was correlated with UDVA (rs  = 0.34, p<0.05 and corrected distance visual acuity (rs  = 0.32, p<0.05 at 1 week postoperatively. CONCLUSIONS: Corneal caps of SMILE are predictable with good reproducibility, regularity and uniformity. Cap morphology might have a mild effect on refractive outcomes in the early stage. Further study should focus on the impact on the visual quality.

  1. 频域眼前段光学相干断层扫描对周边虹膜切除术前后前房角的研究%Evaluation of the anterior chamber angle before and after iridectomy by spectral domain-anterior segment optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    袁永刚; 梁纳; 马胜生; 郑东健

    2014-01-01

    目的 应用频域眼前段光学相干断层扫描(OCT)分析周边虹膜切除术前后前房角的变化.方法 原发性前房角关闭者32例(40只眼)行周边虹膜切除术,术前、术后2d、2个月使用频域眼前段OCT进行前房角测量,比较500 μm/750 μm前房角角度(ACA500/ACA750)和500 μm/750μm前房角开放距离(AOD500/AOD750)等指标.结果 各指标在术前、术后差异有统计学意义,术后2d、2个月相应指标差异无统计学意义.结论 原发性前房角关闭行周边虹膜切除术后前房角增宽,可缓解瞳孔阻滞,预防前房角进一步关闭,频域眼前段OCT可进行术前术后的非接触检查,实现前房的生物统计学测量.%Objective To evaluate the change of the anterior chamber angle before and after iridectomy by spectral domain-anterior segment optical coherence tomography(SD-AS OCT).Methods The clinical trial was carried out in 40 eyes of 32 cases with primary angle closure(PAC).500μm/750μm anterior chamber angle (ACA500/ACA750) and 500μm/750μm angle opening distance (AOD500/AOD750) were imaged with SD-AS OCT before and after iridectomy.Results There were statistical significant differences between preoperation and post-operation in ACAS00/ACA750 and AODS00/AOD750.No significant differences of above indexes were found between 2 days and 2 months after surgery.Conclusion The anterior chamber angle becomes wider in PAC patient after iridectomy.This improvement can relieve pupil block and prevent further chamber angle closure.SD-AS OCT can be used to carry out a noncontact biometrical measurement of anterior chamber before and after surgery.

  2. 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.

  3. 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.

  4. 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

  5. Optical Coherence Tomography Findings in Anterior Chamber Ointment Globule after Phacoemulsification

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    Ahmad M. Mansour

    2015-12-01

    Full Text Available We present 2 cases of anterior chamber ointment with evidence of progressive endothelial cell loss. In both cases, an anterior segment optical coherence tomography (OCT was similar to an OCT of a tobramycin-dexamethasone ointment placed on a pen tip. An anterior segment OCT also demonstrated the direct contact of the globule with the corneal endothelium. A gas chromatography/mass spectrometry analysis documented the similarity to tobramycin-dexamethasone ointment in 1 case. Anterior segment OCT can help in confirming the diagnosis. Corneal endothelial injury is a continuous process, and its clinical manifestation is related to the size of the globule, the initial endothelium count, and the duration of ointment contact, which is related to supine positioning. It is advisable to avoid ointments in the immediate postoperative period, especially in corneal wounds larger than 3 mm.

  6. Automatic Measurement of Central Cornea Thickness of Eye Anterior Segment Optical Coherence Tomography Image%眼前节光学相干层析图像中央角膜厚度自动测量

    Institute of Scientific and Technical Information of China (English)

    舒鹏; 孙延奎; 田小林

    2012-01-01

    为了自动获取所需医学参数,辅助医生诊断,提出了一种基于边缘检测和随机抽样一致性的中央角膜厚度自动测量方法.采用边缘检测算子获得眼前节组织光学相干层析图像中的初始边缘,然后利用随机抽样一致性算法对初始中央角膜上边缘进行圆弧拟合,进一步提取中央角膜下边缘并采用相同方法进行圆弧拟合,根据得到的中央角膜上下边缘计算中央角膜厚度.实验结果表明,该算法能排除图像中时常出现的中央亮线干扰,实时而准确地提取中央角膜上下边缘,得到的中央角膜厚度计算结果与人工分析基本一致,具有良好的应用价值和商业前景.%To obtain quantitative parameters automatically and help medical diagnosis, automatic measurement of central cornea thickness based on edge detection and random sample consensus (RANSAC) is employed. The initial edge in the eye anterior segment optical coherence tomography (OCT) image is obtained with an edge detector. Upper and lower edges of the central cornea are extraxted using the RANSAC circle fitting method. The central cornea thickness is then computed based on the edges. Experiments show that the proposed method can avoid the effect of light beam crossing, and good results comparable to manual analysis can be obtained in real time, indicating that the method has potential applications in the future.

  7. Spectral domain optical coherence tomography study of pearl-like lesions in the anterior chamber

    Directory of Open Access Journals (Sweden)

    Soliman W

    2012-06-01

    Full Text Available Wael Soliman*, Ehab I Wasfi*, Omar M AliDepartment of Ophthalmology, Assiut University Hospital, Assiut University, Assiut, Egypt*These authors contributed equally to this workAim: To study the morphological pattern of pearl-like lesions in the anterior chambers of children before and after management using anterior segment spectral domain optical coherence tomography (SD-OCT.Patients and methods: This was a prospective, observational cross-sectional study of patients presenting with peculiar pearl-like lesions in the anterior chamber of their eyes. 1 mL of betamethasone sodium phosphate (2 mg/mL and betamethasone dipropionate (5 mg/mL was injected subconjunctivally. Follow-ups of all patients were conducted for a period of 6 weeks. Anterior segment imaging was done using SD-OCT and also photo slit lamp before and after management.Results: Twelve eyes of 12 patients were included in this study. These patients presented with pearl-like lesions in the anterior chamber with signs of anterior uveitis. There was no history of ocular injury or tuberculosis in any patients. Six weeks after subconjunctival steroid injection, all patients achieved mean best-corrected visual acuity, which changed from 0.2 (range 0.1–0.4 to 0.5 (range 0.4–0.8, and the severity of iritis decreased. SD-OCT showed that the lesions at presentation appeared as a globular noncystic mass attached to the back of the cornea, encroaching on the angle of the eye, and attached to the anterior surface of the iris at some points.Conclusion: SD-OCT for imaging the anterior segment allowed us to exclude the cystic nature of this pearly lesion. Some similarities may exist between these pearly lesions and superficial phlyctenular keratitis, which may support the immunological and inflammatory origin of these lesions.Keywords: pearl-like lesions, anterior chamber, phlycten, anterior segment OCT

  8. Anterior Segment Findings in Women with Polycystic Ovary Syndrome

    Science.gov (United States)

    Karaca Adıyeke, Seda; Karaca, Ibrahim; Yıldırım, Suna; Adıyeke, Mehmet; Uyar, İbrahim; Türe, Gamze

    2017-01-01

    Objectives: This study aimed to investigate the anterior segment in women with polycystic ovary syndrome (PCOS) and to compare them with those of healthy reproductive-age female volunteers. Materials and Methods: The study included 50 right eyes of 50 women with PCOS (group 1) and 50 right eyes of 50 healthy women (group 2). Intraocular pressure, Schirmer’s test, tear film break-up time and central corneal thickness were evaluated in all subjects. Correlations between serum hormone (estradiol and testosterone) levels and observed findings were also investigated. Results: Mean central corneal thickness values were significantly higher in the PCOS group (p=0.001). The mean intraocular pressures values were similar between the two groups (p=0.560). Schirmer’s test results and tear film break-up time values were significantly lower in the PCOS group (p=0.001 and p=0.001 respectively). Serum estradiol levels were moderately positively correlated with mean central corneal thickness (r=0.552), weakly positively correlated with intraocular pressure (r=0.351) and weakly negatively correlated with tear film break-up time (r=-0.393). Serum free testosterone levels were weakly correlated with intraocular pressure (r=0.342) and central corneal thickness (r=0.303), and showed weak negative correlations with Schirmer’s test results (r=-0.562) and tear film break-up time (r=-0.502). Conclusion: PCOS leads to physiological and structural changes in the eye. Dry eye symptoms were more severe and central corneal thickness measurements were greater in patients with PCOS. Those are correlated serum testosterone and estradiol levels. PMID:28182154

  9. Anterior Segment Findings in Women with Polycystic Ovary Syndrome

    Directory of Open Access Journals (Sweden)

    Seda Karaca Adıyeke

    2017-01-01

    Full Text Available Objectives: This study aimed to investigate the anterior segment in women with polycystic ovary syndrome (PCOS and to compare them with those of healthy reproductive-age female volunteers. Materials and Methods: The study included 50 right eyes of 50 women with PCOS (group 1 and 50 right eyes of 50 healthy women (group 2. Intraocular pressure, Schirmer’s test, tear film break-up time and central corneal thickness were evaluated in all subjects. Correlations between serum hormone (estradiol and testosterone levels and observed findings were also investigated. Results: Mean central corneal thickness values were significantly higher in the PCOS group (p=0.001. The mean intraocular pressures values were similar between the two groups (p=0.560. Schirmer’s test results and tear film break-up time values were significantly lower in the PCOS group (p=0.001 and p=0.001 respectively. Serum estradiol levels were moderately positively correlated with mean central corneal thickness (r=0.552, weakly positively correlated with intraocular pressure (r=0.351 and weakly negatively correlated with tear film break-up time (r=-0.393. Serum free testosterone levels were weakly correlated with intraocular pressure (r=0.342 and central corneal thickness (r=0.303, and showed weak negative correlations with Schirmer’s test results (r=-0.562 and tear film break-up time (r=-0.502. Conclusion: PCOS leads to physiological and structural changes in the eye. Dry eye symptoms were more severe and central corneal thickness measurements were greater in patients with PCOS. Those are correlated serum testosterone and estradiol levels.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Toxic Anterior Segment Syndrome following Phacoemulsification Secondary to Overdose of Intracameral Gentamicin

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    Yaran Koban

    2014-01-01

    Full Text Available Objective. To report a case of toxic anterior segment syndrome (TASS that was caused by inadvertent anterior chamber and cornea stromal injection with high dose gentamicin following cataract surgery. Methods. Case report. Results. We report a 72-year-old female patient who developed TASS that was caused by high dose gentamicin (20 mg/0.5 mL, which was inadvertently used during the formation of the anterior chamber and hydration of the corneal incision. Unlike previous cases, hyphema and hemorrhagic fibrinous reaction were seen in the anterior chamber. Despite treatment, bullous keratopathy developed and penetrating keratoplasty was performed. The excised corneal button was sent for histopathological examination. Conclusions. Subconjunctival gentamicin is highly toxic to the corneal endothelium and anterior chamber structures. Including it on the surgical table carries a potentially serious risk for contamination of the anterior chamber.

  15. Toxic Anterior Segment Syndrome following Phacoemulsification Secondary to Overdose of Intracameral Gentamicin

    Science.gov (United States)

    Koban, Yaran; Genc, Selim; Cagatay, Halil Huseyin; Ekinci, Metin; Gecer, Melin; Yazar, Zeliha

    2014-01-01

    Objective. To report a case of toxic anterior segment syndrome (TASS) that was caused by inadvertent anterior chamber and cornea stromal injection with high dose gentamicin following cataract surgery. Methods. Case report. Results. We report a 72-year-old female patient who developed TASS that was caused by high dose gentamicin (20 mg/0.5 mL), which was inadvertently used during the formation of the anterior chamber and hydration of the corneal incision. Unlike previous cases, hyphema and hemorrhagic fibrinous reaction were seen in the anterior chamber. Despite treatment, bullous keratopathy developed and penetrating keratoplasty was performed. The excised corneal button was sent for histopathological examination. Conclusions. Subconjunctival gentamicin is highly toxic to the corneal endothelium and anterior chamber structures. Including it on the surgical table carries a potentially serious risk for contamination of the anterior chamber. PMID:25574173

  16. Anterior segment intraocular metallic foreign body causing chronic hypopyon uveitis

    OpenAIRE

    Mete, Güler; Turgut, Yılmaz; Osman, Arslanhan; Gülşen, Ülkü; Hakan, Artaş

    2010-01-01

    Intraocular foreign body (IOFB) is a common association of penetrating ocular trauma. Early diagnosis and removal of IOFBs especially if they are metallic is very important to determine further management and the final result of treatment. Missed IOFB may present in different clinical aspects that may limit its detection and symptoms may only become apparent after a prolonged period of time. We report a case of a missed metallic intraocular foreign body in the anterior chamber over a 2-year p...

  17. Spherical primary optical telescope (SPOT) segments

    Science.gov (United States)

    Hall, Christopher; Hagopian, John; DeMarco, Michael

    2012-09-01

    The spherical primary optical telescope (SPOT) project is an internal research and development program at NASA Goddard Space Flight Center. The goals of the program are to develop a robust and cost effective way to manufacture spherical mirror segments and demonstrate a new wavefront sensing approach for continuous phasing across the segmented primary. This paper focuses on the fabrication of the mirror segments. Significant cost savings were achieved through the design, since it allowed the mirror segments to be cast rather than machined from a glass blank. Casting was followed by conventional figuring at Goddard Space Flight Center. After polishing, the mirror segments were mounted to their composite assemblies. QED Technologies used magnetorheological finishing (MRF®) for the final figuring. The MRF process polished the mirrors while they were mounted to their composite assemblies. Each assembly included several magnetic invar plugs that extended to within an inch of the face of the mirror. As part of this project, the interaction between the MRF magnetic field and invar plugs was evaluated. By properly selecting the polishing conditions, MRF was able to significantly improve the figure of the mounted segments. The final MRF figuring demonstrates that mirrors, in the mounted configuration, can be polished and tested to specification. There are significant process capability advantes due to polishing and testing the optics in their final, end-use assembled state.

  18. 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...

  19. Changes of the vasculature and innervation in the anterior segment of the RCS rat eye.

    Science.gov (United States)

    May, Christian Albrecht

    2011-12-01

    Investigating the anterior eye segment vasculature and innervation of dystrophic RCS rats, two major unique findings were observed: in the iris, young adult animals with retinal dystrophy showed an increase in substance P nerve fibres and a dilation of arterioles and capillaries. This finding continued during ageing. In the pars plana region, the surface covered by venules decreased continuously with age. In older animals, this decrease was parallelled by a local decrease of sympathetic TH-positive nerve fibres supplying these venules. For both conditions, no comparable data exists so far in the literature. They might point to a unique situation in the anterior eye segment of the dystrophic RCS rat.

  20. 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

  1. Depth evaluation of intended vs actual intacs intrastromal ring segments using optical coherence tomography.

    Science.gov (United States)

    Barbara, R; Barbara, A; Naftali, M

    2016-01-01

    PurposeEvaluation of actual vs intended intrastromal corneal ring segments (ICRS) implantation depth as measured by anterior segment optical coherence tomography (OCT)MethodsProspective study evaluating 30 Intacs segments implanted manually in 19 eyes of 15 patients suffering from keratoconus. Segment depth evaluation was performed using anterior segment OCT. Measurements were performed above and below the segment at 3 points in relation to the incision site. Statistical analysis was performed using the SAS software for ANOVA, matched t-test, and GLIMMIX procedure.ResultsIntacs segment depth was 153-μm shallower than intended (58% vs 80%). Segment layout demonstrated the proximal and distal portions to be 13-μm shallower and 12-μm deeper (on average), respectively. Intacs segment thickness does not influence implantation depth. Intacs segments implanted in the same eye do not share similar implantation depths. Stromal compression is likely to occur.ConclusionIntacs are implanted at a shallower depth than intended. The 'pocketing' stage prior to implantation most likely has a stronger effect on the segment's final implantation depth than does the incisions' depth.

  2. 原发性急性闭角型青光眼周边虹膜切除和滤过性手术前后眼前段结构参数对比分析%Anterior segment optical coherence tomography changes after iridectomy or trabeculectomy in angle-closure glaucoma

    Institute of Scientific and Technical Information of China (English)

    李媚; 刘杏; 钟毅敏; 曹丹; 杨晔; 曾阳发

    2011-01-01

    Objective To evaluate the changes in antenor segment configuration after peripheral iridectomy (PD or trabeculectomy (Trab) in acute primary angle closure glaucoma (APACG). Methods FiRy-seven eyes of 57 patients with APACG were successive collected. PI was performed to those patients with the clock hours of peripheral anterior synechiae (PAS) 6, while Trab was performed to those patients with the clock hours of PAS >6. Anterior segment optical coherence tomography (AS-OCT) examination was performed before and 3 months after PI/Trab to compare central anterior chamber depth (ACD), angle opening distance (AOD), trabecular iris area (TISA), angle recess area (ARA), anterior chamber width (ACW), anterior chamber volume (ACV) and crystalline lens rise (CLR). Results There were no differences in mean age (P 0.862) and male/female ratio (P=0.380) between the 2 groups. After surgery, AOD, TISA, ARA, ACA and ACV increased significantly (P <0.001~0.044), while no changes were found in ACD, ACW and CLR (P=0.102~0.609) in PI group. In Trab group, ACV increased significantly postoperation (P <0.001) while other parameters shown no changes. Conclusions Both surgery of PI and Trab can increase ACV; PI can improve the anterior angle parameters in APACG, but Trab surgery shows no changes of those parameters.%目的 观察原发性急性闭角型青光眼(acute primary angle closure glaucoma,APACG)周边虹膜切除(peripheral iridectomy,PI)和小梁切除术(Trabeculectomy,Trab)手术前后眼前段结构参数的改变.方法 临床病例对照研究.对2009年6~12月在中山大学眼科中心连续性收集57例57只眼APACG患者,周边虹膜粘连(peripheral anterior synechiae,PAS)范围≤6个钟点者行PI术,PAS范围>6个钟点者行小梁切除术,术前及术后3月行眼前段光学相干断层扫描仪(anterior segment optical coherence tomograph,AS-OCT)眼前段扫描.比较两组组内及组间术前及术后的中央前房深度(central anterior chamber

  3. 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

  4. Anterior ischemic optic neuropathy precipitated by acute primary angle closure

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    Choudhari Nikhil

    2010-01-01

    Full Text Available A 59-year-old man with a history of longstanding systemic hypotension developed asymmetric non-arteritic anterior ischemic optic neuropathy (NAION apparently precipitated by bilateral sequential acute primary angle closure. NAION is very rarely reported in association with raised intraocular pressure. In contrast to optical coherence tomography, the failure of scanning laser polarimetry to detect axonal swelling was another interesting finding. Possible reasoning for these observations is discussed.

  5. A case of anterior ischemic optic neuropathy associated with uveitis

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    Sugahara M

    2013-05-01

    Full Text Available Michitaka Sugahara, Takayuki Fujimoto, Kyoko Shidara, Kenji Inoue, Masato Wakakura Inouye Eye Hospital, Tokyo, Japan Introduction: Here, we describe a patient who presented with anterior ischemic optic neuropathy (AION and subsequently developed uveitis. Case: A 69-year-old man was referred to our hospital and initially presented with best-corrected visual acuities (BCVA of 20/40 (right eye and 20/1000 (left eye and relative afferent pupillary defect. Slit-lamp examination revealed no signs of ocular inflammation in either eye. Fundus examination revealed left-eye swelling and a pale superior optic disc, and Goldmann perimetry revealed left-eye inferior hemianopia. The patient was diagnosed with nonarteritic AION in the left eye. One week later, the patient returned to the hospital because of vision loss. The BCVA of the left eye was so poor that the patient could only count fingers. Slit-lamp examination revealed 1+ cells in the anterior chamber and the anterior vitreous in both eyes. Funduscopic examination revealed vasculitis and exudates in both eyes. The patient was diagnosed with bilateral panuveitis, and treatment with topical betamethasone was started. No other physical findings resulting from other autoimmune or infectious diseases were found. No additional treatments were administered, and optic disc edema in the left eye improved, and the retinal exudates disappeared in 3 months. The patient's BCVA improved after cataract surgery was performed. Conclusion: Panuveitis most likely manifests after the development of AION. Keywords: anterior ischemic optic neuropathy, uveitis

  6. Curcumin, A Potential Therapeutic Candidate for Anterior Segment Eye Diseases: A Review.

    Science.gov (United States)

    Liu, Xiu-Fen; Hao, Ji-Long; Xie, Tian; Mukhtar, Nour Jama; Zhang, Wiley; Malik, Tayyab Hamid; Lu, Cheng-Wei; Zhou, Dan-Dan

    2017-01-01

    Curcumin, the major curcuminoid of the turmeric, has been extensively used in many countries since ancient time for preventing and/or treating a multitude of diseases. This review is to illustrate the researches on the properties of curcumin and its potential therapeutic efficacy in major anterior segment eye diseases. The bio-medical potential of curcumin is restricted because of its low solubility and digestive bioavailability. This review will discuss promising research in improving curcumin bioavailability through structural modification. In vitro and in vivo research made progress in studying the beneficial effects of curcumin on major anterior segment eye diseases, including anti-angiogenesis effect in corneal diseases; anti-inflammation or anti-allergy effects in dry eye disease, conjunctivitis, anterior uveitis; anti-proliferation and pro-apoptosis effects in pterygium; anti-oxidative stress, anti-osmotic stress, anti-lipid peroxidation, pro-apoptosis, regulating calcium homeostasis, sequestrating free radicals, protein modification and degradation effects in cataracts; neuroprotective effects in glaucoma. Curcumin exhibited to be a potent therapeutic candidate for treating those anterior segment eye diseases.

  7. Curcumin, A Potential Therapeutic Candidate for Anterior Segment Eye Diseases: A Review

    Science.gov (United States)

    Liu, Xiu-Fen; Hao, Ji-Long; Xie, Tian; Mukhtar, Nour Jama; Zhang, Wiley; Malik, Tayyab Hamid; Lu, Cheng-Wei; Zhou, Dan-Dan

    2017-01-01

    Curcumin, the major curcuminoid of the turmeric, has been extensively used in many countries since ancient time for preventing and/or treating a multitude of diseases. This review is to illustrate the researches on the properties of curcumin and its potential therapeutic efficacy in major anterior segment eye diseases. The bio-medical potential of curcumin is restricted because of its low solubility and digestive bioavailability. This review will discuss promising research in improving curcumin bioavailability through structural modification. In vitro and in vivo research made progress in studying the beneficial effects of curcumin on major anterior segment eye diseases, including anti-angiogenesis effect in corneal diseases; anti-inflammation or anti-allergy effects in dry eye disease, conjunctivitis, anterior uveitis; anti-proliferation and pro-apoptosis effects in pterygium; anti-oxidative stress, anti-osmotic stress, anti-lipid peroxidation, pro-apoptosis, regulating calcium homeostasis, sequestrating free radicals, protein modification and degradation effects in cataracts; neuroprotective effects in glaucoma. Curcumin exhibited to be a potent therapeutic candidate for treating those anterior segment eye diseases. PMID:28261099

  8. 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.

  9. 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.

  10. The muscle pattern of the Drosophila abdomen depends on a subdivision of the anterior compartment of each segment

    OpenAIRE

    Krzemień, Joanna; Fabre, Caroline C. G.; Casal, José; Lawrence, Peter A

    2012-01-01

    In the past, segments were defined by landmarks such as muscle attachments, notably by Snodgrass, the king of insect anatomists. Here, we show how an objective definition of a segment, based on developmental compartments, can help explain the dorsal abdomen of adult Drosophila. The anterior (A) compartment of each segment is subdivided into two domains of cells, each responding differently to Hedgehog. The anterior of these domains is non-neurogenic and clones lacking Notch develop normally; ...

  11. 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.

  12. Right anterior segmental hepatic duct emptying directly into the cystic duct in a living donor

    Institute of Scientific and Technical Information of China (English)

    Yasunao; Ishiguro; Masanobu; Hyodo; Takehito; Fujiwara; Yasunaru; Sakuma; Nobuyuki; Hojo; Koichi; Mizuta; Hideo; Kawarasaki; Alan; T; Lefor; Yoshikazu; Yasuda

    2010-01-01

    A 35-year-old mother was scheduled to be the living donor for liver transplantation to her second son,who suffered from biliary atresia complicated with biliary cirrhosis at the age of 2 years.The operative plan was to recover the left lateral segment of the mother's liver for living donor transplantation.With the use of cholangiography at the time of surgery,we found the right anterior segmental duct(RASD) emptying directly into the cystic duct,and the catheter passed into the RASD.After repairing the inci...

  13. Corneal sensitivity and correlations between decreased sensitivity and anterior segment pathology in ocular leprosy.

    OpenAIRE

    Karaçorlu, M A; Cakiner, T; Saylan, T

    1991-01-01

    Leprosy is one of the leading causes of corneal hyposensitivity. In this article the corneal sensitivity of 143 leprosy patients was examined, and correlations between corneal hyposensitivity and anterior segment pathology were detected. Twenty four healthy volunteers were examined as controls. Various degrees of corneal loss of sensitivity were found in 46.2% of leprosy patients. Lagophthalmos, chronic lepromatous granulomatous uveitis, iris atrophy, and social blindness were found 4.5-16.6 ...

  14. Effect of Intracameral Lidocaine Anesthesia on the Anterior Segment of Rabbit Eyes

    Institute of Scientific and Technical Information of China (English)

    Hui Yang; Danying Zheng; Zhenping Zhang

    2002-01-01

    Purpose: To evaluate the effect of intracameral anesthesia on the anterior segment ofrabbit eyes using chinese-made lidocaine.Method: The study comprised eight eyes of four white rabbits which were divided intothree groups according to the concentration of the lidocaine given. They are 0.5%, 1%,2% lidocaine groups and balanced salt solution(BSS)control group. Each groupcontained two eyes.After 0.5 ml of the anesthetic agent was injected into the anteriorchamber and retainedthere for ten minutes, the rabbits were executed and the eye balls wereenucleated. Pathological examinations of the anterior segment, including cornea, iris andcilliary body, were carried out immediately.Result:The pathological study revealed no abnormal findings in lidocaine 0. 5% and 1%groups compared with the control group, where as in the lidocaine 2% group, muchabnormal pathological change was found, including the shrinkage of corneal endothelium,stroma edema of iris and cilliary body.Conclusion: Using intracameral anesthesia of high concentration of chinese-made lidocainewould run a risk of damaging the anterior segment of rabbit eye. But at the low concentrationusually usedin cataract surgery, no adverse effect was found.

  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. 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.

  17. [Compressive optic neuropathy related to an anterior clinoid mucocele].

    Science.gov (United States)

    Arnavielle, S; Vignal-Clermont, C; Galatoire, O; Jacomet, P-V; Klap, P; Boissonnet, H; Berges, O; Morax, S

    2010-03-01

    Nasal sinus mucoceles are an uncommon cause of painful optic neuropathy. We report the case of a patient presenting an acute compressive optic neuropathy related to an anterior clinoid mucocele. The diagnosis was mainly made with CT and MRI, and the patient was treated with endoscopic endonasal transseptal surgery 10 days after the beginning of the disorder. Visual recovery was complete 3 days later. We review the literature on the etiologies of this type of pathology, the work-up, and the possible treatments.

  18. 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

  19. 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.

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

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    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

  2. Stability of the anterior maxillary segment and teeth after segmental Le Fort I osteotomy and postoperative skeletal elastic fixation with or without occlusal splint

    OpenAIRE

    2015-01-01

    ABSTRACT Objectives To assess the short term dental and skeletal stability of the anterior maxillary segment after segmental Le Fort I osteotomy with postoperative skeletal elastic fixation with or without occlusal splint. Material and Methods 29 consecutive patients underwent segmental Le Fort I osteotomy and elastic skeletal fixation was applied. Patients were divided into two groups according to whether a fixed occlusal splint was used for six weeks (group A) or dismounted perioperatively ...

  3. Magnetic resonance imaging of luxury perfusion of the optic nerve head in anterior ischemic optic neuropathy.

    Science.gov (United States)

    Yovel, Oren S; Katz, Miriam; Leiba, Hana

    2012-09-01

    A 49-year-old woman with painless reduction in visual acuity in her left eye was found to have nonarteritic anterior ischemic optic neuropathy (NAION). Fluorescein angiography revealed optic disc capillary leakage consistent with "luxury perfusion." Contrast-enhanced FLAIR magnetic resonance imaging (MRI) showed marked enhancement of the left optic disc. Resolution of the optic disc edema and the MRI abnormalities followed a similar time course. This report appears unique in documenting the MRI findings of luxury perfusion in NAION.

  4. Stability of the anterior maxillary segment and teeth after segmental le fort I osteotomy and postoperative skeletal elastic fixation with or without occlusal splint

    DEFF Research Database (Denmark)

    Blæhr, Tue Lindberg; Jensen, Thomas; Due, Karen Margrethe;

    2014-01-01

    OBJECTIVES: To assess the short term dental and skeletal stability of the anterior maxillary segment after segmental Le Fort I osteotomy with postoperative skeletal elastic fixation with or without occlusal splint. MATERIAL AND METHODS: 29 consecutive patients underwent segmental Le Fort I.......83 to 1.69°). There was no statistically significant difference in stability between the two groups at the P value 0.05. CONCLUSIONS: The skeletal anterior fixation with postoperative elastics for eight weeks may not compromise the early postoperative dental and skeletal stability of the anterior segment...... osteotomy and elastic skeletal fixation was applied. Patients were divided into two groups according to whether a fixed occlusal splint was used for six weeks (group A) or dismounted perioperatively (group B). Changes in landmarks and reference planes between the two timepoints were estimated on lateral...

  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. Corneal sensitivity and correlations between decreased sensitivity and anterior segment pathology in ocular leprosy.

    Science.gov (United States)

    Karaçorlu, M A; Cakiner, T; Saylan, T

    1991-02-01

    Leprosy is one of the leading causes of corneal hyposensitivity. In this article the corneal sensitivity of 143 leprosy patients was examined, and correlations between corneal hyposensitivity and anterior segment pathology were detected. Twenty four healthy volunteers were examined as controls. Various degrees of corneal loss of sensitivity were found in 46.2% of leprosy patients. Lagophthalmos, chronic lepromatous granulomatous uveitis, iris atrophy, and social blindness were found 4.5-16.6 times more frequently in eyes which developed severe corneal hyposensitivity.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Anterior segment dysgenesis (Peters' anomaly) in two snow leopard (Panthera uncia) cubs

    DEFF Research Database (Denmark)

    Hamoudi, Hassan; Rudnick, Jens-Christian; Prause, Jan Ulrik

    2013-01-01

    Two sibling snow leopards, a male and a female, with bilateral anterior segment dysgenesis (ASD), are reported. Both snow leopards also had colobomas of both upper eyelids. All eyes exhibited a central corneal opacity associated with a defect in posterior corneal stroma, endothelium and Descemet...... remnant of the hyaloid artery. The male had hydrocephalus and thus some of the features of Peters' plus syndrome (Peters' anomaly in addition to systemic malformations). The histological findings in the eyes of these snow leopard siblings are identical with those described in humans with Peters' anomaly....

  9. 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

  10. Anterior Ischemic Optic Neuropathy as a Manifestation of HELLP Syndrome

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    Boby Varkey Maramattom

    2014-01-01

    Full Text Available Thrombotic microangiopathies (TMAs are a group of disorders characterized by occurrence of thrombi of fibrin and/or platelets with microvascular occlusion and organ ischemia especially the kidney and brain. Hemolysis with a microangiopathic blood smear, elevated liver enzymes, and low platelet count (HELLP syndrome is a type of TMA peculiar to pregnancy and may be associated with neurological complications. Visual complications in HELLP are usually related to cortical blindness. We present the first case of HELLP associated with bilateral anterior ischemic optic neuropathy (AION and blindness which resolved with plasma exchange.

  11. The reproducibility of mechanism categories of angle closure using ultrasound biomicroscopy and anterior segment optical coherence tomography%根据超声生物显微镜和眼前节OCT图像对房角关闭机制进行分型的一致性研究

    Institute of Scientific and Technical Information of China (English)

    张烨; 唐炘; 王宁利

    2016-01-01

    Background Angle closure is the pathological basis of primary angle-closure disease (PACD).Understanding different types of angle closure mechanisms is significant for evaluation of risk factors,prevention,diagnosis and treatment of PACD.Ultrasound biomicroscopy (UBM) is commonly used for investigating the types of angle closure mechanisms in clinical works.However,UBM is a contact examination,which limits its application.Anterior segment optical coherence tomography (AS-OCT) is a non-contact examination of anterior segment imaging,through which qualitative and quantitative evaluations of the anterior chamber angle can be made.Objective This study was to investigate the reproducibility of mechanism categories of angle closure based on AS-OCT images and UBM images.Methods Cross-sectional study was performed.PACD outpatients from September to October in 2013 in Beijing Tongren Hospital were enrolled and received both UBM and AS-OCT examinations.UBM images were obtained in superior,inferior,nasal and temporal quadrants of the anterior chamber.AS-OCT images were obtained in the "anterior segment quadrant" mode at 0-180,45-225,90-270,and 135-315 degree meridians.UBM and ASOCT images were categorized into three dominant angle closure mechanisms:pupil block,anterior located ciliary body and thick peripheral iris roll,separately.And the same mechanism of at least two UBM/AS-OCT images of one eye was defined as the angle closure mechanism of this eye.If both eyes of one PACD patient were eligible for inclusion,the right eye was selected for analysis.The reproducibility of two examinations was evaluated by Kappa coefficients.Results Finally 40 PACD patients (40 eyes,27 right eyes and 13 left eyes) were enrolled for analysis.Based on UBM images,12 eyes (30.0%) were classified as pupil block,23 eyes (57.5%) as anterior located ciliary body and 5 eyes (12.5%) as thick peripheral iris roll.Based on AS-OCT,12 eyes (30.0%) were classified as pupil block,21 eyes (52.5

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    Yasin Çınar

    2013-12-01

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

  14. Segmented bimorph mirrors for adaptive optics: morphing strategy.

    Science.gov (United States)

    Bastaits, Renaud; Alaluf, David; Belloni, Edoardo; Rodrigues, Gonçalo; Preumont, André

    2014-08-01

    This paper discusses the concept of a light weight segmented bimorph mirror for adaptive optics. It focuses on the morphing strategy and addresses the ill-conditioning of the Jacobian of the segments, which are partly outside the optical pupil. Two options are discussed, one based on truncating the singular values and one called damped least squares, which minimizes a combined measure of the sensor error and the voltage vector. A comparison of various configurations of segmented mirrors was conducted; it is shown that segmentation sharply increases the natural frequency of the system with limited deterioration of the image quality.

  15. 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.

  16. 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.

  17. 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...

  18. 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...

  19. 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...

  20. [Drug delivery systems to target the anterior segment of the eye: fundamental bases and clinical applications].

    Science.gov (United States)

    Behar-Cohen, F

    2002-05-01

    The development of new drug delivery systems to target the anterior segment of the eye may offer many advantages: to increase the biodisponibility of the drug, to allow the penetration of drug that cannot be formulated as solutions, to obtain constant and sustained drug release, to achieve higher local concentrations without systemic effects, to target more specifically one tissue or cell type, to reduce the frequency of instillation and therefore increase the observance and comfort of the patient while reducing side effects of frequent instillation. Several approaches are developed, aiming to increase the corneal contact time by modified formulation or reservoir systems, or by increasing the tissue permeability using iontophoresis. To date, no ocular drug delivery system is ideal for all purposes. To maximize treatment efficacy, careful evaluation of the specific pathological condition, the targeted Intraocular tissue and the location of the most severe pathology must be made before selecting the method of delivery most suitable for each individual patient.

  1. 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

  2. Anterior segment changes following intravitreal bevacizumab injection for treatment of neovascular glaucoma

    Directory of Open Access Journals (Sweden)

    Canut MI

    2011-05-01

    Full Text Available MI Canut1, A Alvarez2, J Nadal3, R Abreu4, JA Abreu5, JS Pulido61Glaucoma Section, 2Barraquer Ophthalmology Centre, 3Retina and Vitreous Unit, Macula Section, Institut Universitari Barraquer, Universidad Autonoma de Barcelona, Barcelona, Spain; 4Retina and Vitreous Unit, University Hospital of La Candelaria, Tenerife 5Glaucoma Section, University Hospital of the Canary Islands, Tenerife, Spain; 6Retina and Vitreous Unit, Ophthalmology Department, Mayo Clinic, Rochester, MN, USABackground: The purpose of this study was to describe anterior segment changes in a prospective, interventional, noncomparative case series of patients with neovascular glaucoma secondary to proliferative diabetic retinopathy treated with intravitreal bevacizumab.Methods: Five consecutive patients with neovascular glaucoma and a refractory, symptomatic elevation of intraocular pressure and pronounced anterior segment congestion received intravitreal bevacizumab 1.25 mg/0.05 mL. Follow-up examinations were performed at 4–16 weeks by the same specialists, with testing performed at hour 48, week 1, and months 1, 3, and 6 after intravitreal bevacizumab.Results: We observed a significant difference (P = 0.021 between initial and mean neovascularization at three months in all the quadrants. At three months, median intraocular pressure was 19 ± 5.38 (range 12–26 mmHg. In three of the five cases, diode laser cyclophotocoagulation was required, and in one case a trabeculectomy was performed. One patient showed complete synechial angle closure 48 hours after treatment which required cyclodestructive procedures to normalize intraocular pressure.Conclusion: Intravitreal bevacizumab achieves complete regression of neovascularization in neovascular glaucoma secondary to proliferative diabetic retinopathy, and this regression is stable when associated with treatment of the underlying disease and should be investigated more thoroughly as an adjunct in the management of neovascular

  3. Prevalence of Corneal Astigmatism and Anterior Segmental Biometry Characteristics Before Surgery in Chinese Congenital Cataract Patients.

    Science.gov (United States)

    Lin, Duoru; Chen, Jingjing; Liu, Zhenzhen; Wu, Xiaohang; Long, Erping; Luo, Lixia; Lin, Zhuoling; Li, Xiaoyan; Zhang, Li; Chen, Hui; Liu, Jinchao; Chen, Weirong; Lin, Haotian; Liu, Yizhi

    2016-02-25

    The prevalence and the distribution characteristics of corneal astigmatism (CA) and anterior segment biometry before surgery in Chinese congenital cataract (CC) patients are not completely understood. This study involved 400 CC patients from the Zhongshan Ophthalmic Center enrolled from February 2011 to August 2015. Data on CA, keratometry, central corneal thickness (CCT) and anterior chamber depth (ACD) were measured by the Pentacam Scheimpflug System. The mean age of patients was 54.27 months, and the ratio of boys to girls was 1.53:1. The mean CA was 2.03 diopters (D), and 39.25% of subjects had CA values ≥2 D. The most frequent (71.8%) diagnosis was with-the-rule astigmatism. Oblique astigmatism was present in 16.2% of cases, and 12% of cases had against-the-rule astigmatism. The mean keratometry measurement of cataractous eyes in bilateral patients was significantly larger than that in unilateral patients. Girls had a larger mean keratometry but a thinner CCT than did boys. The CA, CCT, and ACD of cataractous eyes were significantly larger than those of non-cataractous eyes in unilateral patients. The CA, mean keratometry, CCT, and ACD in CC patients varied with age, gender, and laterality. Fully understanding these characteristics may help inform guidelines and treatment decisions in CC patients.

  4. Right anterior segmental hepatic duct emptying directly into the cystic duct in a living donor.

    Science.gov (United States)

    Ishiguro, Yasunao; Hyodo, Masanobu; Fujiwara, Takehito; Sakuma, Yasunaru; Hojo, Nobuyuki; Mizuta, Koichi; Kawarasaki, Hideo; Lefor, Alan T; Yasuda, Yoshikazu

    2010-08-07

    A 35-year-old mother was scheduled to be the living donor for liver transplantation to her second son, who suffered from biliary atresia complicated with biliary cirrhosis at the age of 2 years. The operative plan was to recover the left lateral segment of the mother's liver for living donor transplantation. With the use of cholangiography at the time of surgery, we found the right anterior segmental duct (RASD) emptying directly into the cystic duct, and the catheter passed into the RASD. After repairing the incision in the cystic duct, transplantation was successfully performed. Her postoperative course was uneventful. Biliary anatomical variations were frequently encountered, however, this variation has very rarely been reported. If the RASD was divided, the repair would be very difficult because the duct will not dilate sufficiently in an otherwise healthy donor. Meticulous preoperative evaluation of the living donor's biliary anatomy, especially using magnetic resonance cholangiography and careful intraoperative techniques, is important to prevent bile duct injury and avoid the risk to the healthy donor.

  5. 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

  6. 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

  7. Stability of the Anterior Maxillary Segment and Teeth after Segmental Le Fort I Osteotomy and Postoperative Skeletal Elastic Fixation With or Without Occlusal Splint

    Directory of Open Access Journals (Sweden)

    Tue Lindberg

    2014-10-01

    Full Text Available Objectives: To assess the short term dental and skeletal stability of the anterior maxillary segment after segmental Le Fort I osteotomy with postoperative skeletal elastic fixation with or without occlusal splint. Material and Methods: 29 consecutive patients underwent segmental Le Fort I osteotomy and elastic skeletal fixation was applied. Patients were divided into two groups according to whether a fixed occlusal splint was used for six weeks (group A or dismounted perioperatively (group B. Changes in landmarks and reference planes between the two timepoints were estimated on lateral cephalometric radiographs. Results: Group A: The upper incisor had a mean intrusion of -0.56 mm (SD 0.77; range -2.04 to 1.08 mm and a mean posterior movement of -0.93 mm (SD 1.03; range -2.52 to 0.96 mm. The mean change in the axial inclination of the upper incisor was -0.33° (SD 2.56; range -6° to 4° (95% CI: -1.75 to 1.08°. Group B: The upper incisor had a mean intrusion of -0.13 mm (SD 1.36; range -1.92 to 3.6 mm and a mean anterior movement of 0.11 mm (SD 1.78; range -2.88 to 3.84 mm. The mean change in the axial inclination of the upper incisor was -0.07° (SD 3.05; range -5° to 5° (95% CI: -1.83 to 1.69°. There was no statistically significant difference in stability between the two groups at the P value 0.05. Conclusions: The skeletal anterior fixation with postoperative elastics for eight weeks may not compromise the early postoperative dental and skeletal stability of the anterior segment in segmental Le Fort I osteotomy.

  8. 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.

  9. 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.

  10. 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.

  11. Evaluation of anterior segment parameters using pentacam in silicone oil-injected patients after pars plana vitrectomy

    Directory of Open Access Journals (Sweden)

    Burcu Çalik

    2013-01-01

    Full Text Available Background: The aim of this study is to evaluate anterior segment changes with Pentacam Scheimpflug camera after pars plana vitrectomy (PPV and silicone oil injection. Materials and Methods: In all, 44 eyes of 44 patients who underwent PPV by one surgeon were evaluated with Pentacam preoperatively, first week, and first month after surgery. The patients were divided into two groups, eyes with silicone injection after PPV and eyes with PPV and no endotamponade. Main outcome measures were preoperative and postoperative anterior chamber volume (ACV, anterior chamber depth (ACD, anterior chamber angle (ACA, and central corneal thickness (CCT obtained with pentacam. Results: Each group consisted of 22 patients. In both groups no significant difference was detected among preop and postop changes in ACV and ACA values ( p > 0.05. The increase in ACD in silicone oil-injected group and the decrease in ACD in PPV group at postop 1 week were statistically significant ( p < 0.05. The increase in CCT in silicone oil-injected group at postop 1 week and then decrease in postop 1 month were also significant ( p < 0.05. Surgically induced astigmatism (SIA was 3.7 Dioptry (D in silicone oil-injected group and 2.4 D in PPV group at postop 1 week. SIA decreased to 1.7 D and 1.5 D, respectively, at postop 1 month. Changes in SIA were significant ( p < 0.05. Conclusion: PPV effects cornea and anterior segment. Changes in cornea and anterior segment after PPV seem to return to preoperative values among 1 month after surgery.

  12. The muscle pattern of the Drosophila abdomen depends on a subdivision of the anterior compartment of each segment.

    Science.gov (United States)

    Krzemien, Joanna; Fabre, Caroline C G; Casal, José; Lawrence, Peter A

    2012-01-01

    In the past, segments were defined by landmarks such as muscle attachments, notably by Snodgrass, the king of insect anatomists. Here, we show how an objective definition of a segment, based on developmental compartments, can help explain the dorsal abdomen of adult Drosophila. The anterior (A) compartment of each segment is subdivided into two domains of cells, each responding differently to Hedgehog. The anterior of these domains is non-neurogenic and clones lacking Notch develop normally; this domain can express stripe and form muscle attachments. The posterior domain is neurogenic and clones lacking Notch do not form cuticle; this domain is unable to express stripe or form muscle attachments. The posterior (P) compartment does not form muscle attachments. Our in vivo films indicate that early in the pupa the anterior domain of the A compartment expresses stripe in a narrowing zone that attracts the extending myotubes and resolves into the attachment sites for the dorsal abdominal muscles. We map the tendon cells precisely and show that all are confined to the anterior domain of A. It follows that the dorsal abdominal muscles are intersegmental, spanning from one anterior domain to the next. This view is tested and supported by clones that change cell identity or express stripe ectopically. It seems that growing myotubes originate in posterior A and extend forwards and backwards until they encounter and attach to anterior A cells. The dorsal adult muscles are polarised in the anteroposterior axis: we disprove the hypothesis that muscle orientation depends on genes that define planar cell polarity in the epidermis.

  13. Embolization for the treatment of unilateral A1 segment anterior communicating artery aneurysm: a report of 48 cases

    OpenAIRE

    Qing-dong GUO; Liu, Wei; Fu, Luo-An; Zhang, Lei; Zhang, Xue-Xi; Jing HU; Fei, Zhou

    2011-01-01

    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 A1 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(RDS...

  14. 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

    2014-03-21

    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 field-of-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.

  15. Relationship of A1 segment hypoplasia to anterior communicating artery aneurysm morphology and risk factors for aneurysm formation.

    Science.gov (United States)

    Rinaldo, Lorenzo; McCutcheon, Brandon A; Murphy, Meghan E; Bydon, Mohamad; Rabinstein, Alejandro A; Lanzino, Giuseppe

    2016-09-30

    OBJECTIVE Hypoplasia of the A1 segment of the anterior cerebral artery is frequently observed in patients with anterior communicating artery (ACoA) aneurysms. The effect of this anatomical variant on ACoA aneurysm morphology is not well understood. METHODS Digital subtraction angiography images were reviewed for 204 patients presenting to the authors' institution with either a ruptured or an unruptured ACoA aneurysm. The ratio of the width of the larger A1 segment to the smaller A1 segment was calculated. Patients with an A1 ratio greater than 2 were categorized as having A1 segment hypoplasia. The relationship of A1 segment hypoplasia to both patient and aneurysm characteristics was then assessed. RESULTS Of 204 patients that presented with an ACoA aneurysm, 34 (16.7%) were found to have a hypoplastic A1. Patients with A1 segment hypoplasia were less likely to have a history of smoking (44.1% vs 62.9%, p = 0.0410). ACoA aneurysms occurring in the setting of a hypoplastic A1 were also found to have a larger maximum diameter (mean 7.7 vs 6.0 mm, p = 0.0084). When considered as a continuous variable, increasing A1 ratio was associated with decreasing aneurysm dome-to-neck ratio (p = 0.0289). There was no significant difference in the prevalence of A1 segment hypoplasia between ruptured and unruptured aneurysms (18.9% vs 10.7%; p = 0.1605). CONCLUSIONS Our results suggest that a hypoplastic A1 may affect the morphology of ACoA aneurysms. In addition, the relative lack of traditional risk factors for aneurysm formation in patients with A1 segment hypoplasia argues for the importance of hemodynamic factors in the formation of ACoA aneurysms in this anatomical setting.

  16. 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.

  17. 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

  18. 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.

  19. Biomechanical Evaluation of Different Fixation Methods for Mandibular Anterior Segmental Osteotomy Using Finite Element Analysis, Part One: Superior Repositioning Surgery.

    Science.gov (United States)

    Kilinç, Yeliz; Erkmen, Erkan; Kurt, Ahmet

    2016-01-01

    The aim of the current study was to comparatively evaluate the mechanical behavior of 3 different fixation methods following various amounts of superior repositioning of mandibular anterior segment. In this study, 3 different rigid fixation configurations comprising double right L, double left L, or double I miniplates with monocortical screws were compared under vertical, horizontal, and oblique load conditions by means of finite element analysis. A three-dimensional finite element model of a fully dentate mandible was generated. A 3 and 5 mm superior repositioning of mandibular anterior segmental osteotomy were simulated. Three different finite element models corresponding to different fixation configurations were created for each superior repositioning. The von Mises stress values on fixation appliances and principal maximum stresses (Pmax) on bony structures were predicted by finite element analysis. The results have demonstrated that double right L configuration provides better stability with less stress fields in comparison with other fixation configurations used in this study.

  20. Embolization for the treatment of unilateral A1 segment anterior communicating artery aneurysm: a report of 48 cases

    Directory of Open Access Journals (Sweden)

    Qing-dong GUO

    2011-10-01

    Full Text Available 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 A1 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 in the treatment of wide-necked aneurysm to keep patency of parent arteries.Cerebral angiography was performed in 38 cases 6 months after the operation to observe the patency of embolized aneurysms and anterior communicating arteries.Results Of the 48 cases,total occlusion was achieved in 39(81.3%,more than 90% occlusion was achieved in 6(12.5%,and 3(6.3% with less than 90% occlusion;1 had hemorrhage during embolization,3 had anterior communicating artery occlusion,and 2 had contralateral internal carotid artery compensation after anterior communicating artery occlusion.No re-bleeding was found during the 6 months follow-up period.Cerebral angiography showed total occlusion of aneurysms and patency of anterior communicating arteries in 38 cases during re-examination.Conclusion The anterior communicating arteries should be kept patent in embolization treatment of the major unilateral blood supply anterior communicating artery aneurysms,and it is helpful to use microcatheter or microwire assisted techniques.

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

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    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.

  2. 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.

  3. Epidermal segmentation in high-definition optical coherence tomography.

    Science.gov (United States)

    Li, Annan; Cheng, Jun; Yow, Ai Ping; Wall, Carolin; Wong, Damon Wing Kee; Tey, Hong Liang; Liu, Jiang

    2015-01-01

    Epidermis segmentation is a crucial step in many dermatological applications. Recently, high-definition optical coherence tomography (HD-OCT) has been developed and applied to imaging subsurface skin tissues. In this paper, a novel epidermis segmentation method using HD-OCT is proposed in which the epidermis is segmented by 3 steps: the weighted least square-based pre-processing, the graph-based skin surface detection and the local integral projection-based dermal-epidermal junction detection respectively. Using a dataset of five 3D volumes, we found that this method correlates well with the conventional method of manually marking out the epidermis. This method can therefore serve to effectively and rapidly delineate the epidermis for study and clinical management of skin diseases.

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

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    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.

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

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    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.

  6. Evaluation of anterior segment parameters and possible influencing factors in normal subjects using a dual Scheimpflug analyzer.

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    Xiaogang Wang

    Full Text Available PURPOSE: To investigate normal anterior segment parameters and analyze the possible influencing factors using a dual Scheimpflug system. SETTING: Department of Ophthalmology, Affiliated Sixth People's Hospital Shanghai Jiao Tong University, Shanghai, China. DESIGN: A prospective observational case series. METHODS: A total of 153 normal subjects (153 eyes were studied. The anterior segment parameters, including the central corneal thickness (CCT, anterior chamber depth (ACD, pupil diameter (PD, keratoconus prediction index (KPI, simulated keratometry (SimK values, anterior instantaneous curvature (AIC, posterior axial curvature (PAC, corneal eccentricity, total corneal power (TCP, axial curvature (AC, total corneal wavefront (TCW, high order aberration (HOA, and spherical aberration (SA, were determined using a dual Scheimpflug analyzer. RESULTS: The CCT and ACD were both negatively correlated with age (r = -0.203, p = 0.012; r = -0.589, p<0.001. There was no significant difference in the refractive indices of AIC and SimK. Compared with the negative correlation of HOA and SA (r = -0.358, p<0.001, a positive correlation was found between TCW and HOA (r = 0.561, p<0.001. Unlike the decreased tendency of AC, the TCP increased gradually from the center to the periphery in the central 8 mm diameter. TCP showed a significant correlation with AC in the analyzed area. CONCLUSIONS: AIC and SimK provide different information in clinic, but the refractive indices of them showed no difference in this healthy study population, and age should be considered when using CCT and ACD values.

  7. 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

  8. 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

    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...

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

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    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

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

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    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.

  11. 白内障超声乳化摘出术后OCT测量的眼前节结构改变%The changes of ocular anterior segment configuration following phacoemulsification determined by anterior segment OCT

    Institute of Scientific and Technical Information of China (English)

    郑虔

    2016-01-01

    Cataract is a main blinding eye disease worldwide,follwed by glaucoma.Expension of lens volume occurs in early stage of age-related cataractous eyes,which is a risk factor of Primary angle-closure glaucoma,and phacoemulsification is a feasible approach to remove it.However,how to select the timing of operation and determine the prognosis is the major challenge for ophthalmologists.In order to evaluate the influence of phacoemulsification on ocular anterior segment configuration,we collected the information of 17 articles that quantitatively analyzed the ocular anterior segment parameter changes after phacoemulsification,determined by anterior segment OCT (AS-OCT).Total 866 eyes that received phacoemulsification for age-related cataract were included in the following-up duration for 6 months,and the results showed that the mean anterior chamber depth (ACD),anterior chamber volume (ACV),anterior chamber angle (ACA),angle opening distance 500 μm anterior to the scleral spur (AODS00),angle opening distance 750 μm anterior to the scleral spur (AOD750),trabecular-iris space area 500 μm from scleral spur (TISA500),trabecular-iris space area 750 μm from scleral spur(TISA750),and angle recess area 750 μm anterior to the scleral spur (ARA 750) were increased,but the mean anterior chamber width (ACW) and iris thickness measured at 750 μm (IT750) were not significantly changed,while the postoperative iris curvature (I-Curv),iris cross-sectional area and convex hull of iris segments were decreased after phacoemulsification.In addition,the postoperative ACD,TISA500 showed positive correlations to preoperative lens thickness,and the ACD and AOD500 in 3 months after operation were positively correlated to the preoperative lens value (LV).This systematic review concluded that phacoemulsification could be used for the treatment of glaucoma by relieving pupillary block,reducing the iris oppression,deepening the anterior chamber and opening anterior chamber angle.%目前,白内

  12. 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.

  13. Segmentation of 830- and 1310-nm LASIK corneal optical coherence tomography images

    Science.gov (United States)

    Li, Yan; Shekhar, Raj; Huang, David

    2002-05-01

    Optical coherence tomography (OCT) provides a non-contact and non-invasive means to visualize the corneal anatomy at micron scale resolution. We obtained corneal images from an arc-scanning (converging) OCT system operating at a wavelength of 830nm and a fan-shaped-scanning high-speed OCT system with an operating wavelength of 1310nm. Different scan protocols (arc/fan) and data acquisition rates, as well as wavelength dependent bio-tissue backscatter contrast and optical absorption, make the images acquired using the two systems different. We developed image-processing algorithms to automatically detect the air-tear interface, epithelium-Bowman's layer interface, laser in-situ keratomileusis (LASIK) flap interface, and the cornea-aqueous interface in both kinds of images. The overall segmentation scheme for 830nm and 1310nm OCT images was similar, although different strategies were adopted for specific processing approaches. Ultrasound pachymetry measurements of the corneal thickness and Placido-ring based corneal topography measurements of the corneal curvature were made on the same day as the OCT examination. Anterior/posterior corneal surface curvature measurement with OCT was also investigated. Results showed that automated segmentation of OCT images could evaluate anatomic outcome of LASIK surgery.

  14. The long-term anterior segment configuration after pediatric cataract surgery and the association with secondary glaucoma

    Science.gov (United States)

    Chen, Ding; Gong, Xian-hui; Xie, He; Zhu, Xue-ning; Li, Jin; Zhao, Yun-e

    2017-01-01

    Secondary glaucoma constitutes major sight-threatening complication of pediatric cataract surgery, yet the etiology remains unclear. The purpose of this study was to investigate the long-term anterior segment configuration and the association with secondary glaucoma in pediatric pseudophakia. Ultrasound biomicroscopy (UBM) was performed on 40 eyes of 26 children underwent pediatric cataract surgery and intraocular lens (IOL) implantation. The anterior chamber depth (ACD), angle-opening distance at 500 μm (AOD500), trabecular-iris angle (TIA), central corneal thickness (CCT), structural abnormities, IOL position, IOP, and incidence of glaucoma were evaluated. High insertion of iris, in which the iris root is attached more anteriorly than normal, was seen in 13 eyes (32.50%). IOL was located in the capsular bag in 19 eyes and in the ciliary sulcus in 21 eyes. Logistic regression analysis identified high insertion of iris (OR 3.40, 95% CI 1.03–11.17, p = 0.03) and IOL implantation in sulcus (OR 1.39, 95% CI 1.07–4.85, p = 0.04) as independent risk factors for glaucoma. The presence of high insertion of iris and IOL implantation in ciliary sulcus may increase the long-term risk of the development of secondary glaucoma after pediatric cataract surgery. PMID:28220849

  15. Automatic segmentation of choroidal thickness in optical coherence tomography.

    Science.gov (United States)

    Alonso-Caneiro, David; Read, Scott A; Collins, Michael J

    2013-01-01

    The assessment of choroidal thickness from optical coherence tomography (OCT) images of the human choroid is an important clinical and research task, since it provides valuable information regarding the eye's normal anatomy and physiology, and changes associated with various eye diseases and the development of refractive error. Due to the time consuming and subjective nature of manual image analysis, there is a need for the development of reliable objective automated methods of image segmentation to derive choroidal thickness measures. However, the detection of the two boundaries which delineate the choroid is a complicated and challenging task, in particular the detection of the outer choroidal boundary, due to a number of issues including: (i) the vascular ocular tissue is non-uniform and rich in non-homogeneous features, and (ii) the boundary can have a low contrast. In this paper, an automatic segmentation technique based on graph-search theory is presented to segment the inner choroidal boundary (ICB) and the outer choroidal boundary (OCB) to obtain the choroid thickness profile from OCT images. Before the segmentation, the B-scan is pre-processed to enhance the two boundaries of interest and to minimize the artifacts produced by surrounding features. The algorithm to detect the ICB is based on a simple edge filter and a directional weighted map penalty, while the algorithm to detect the OCB is based on OCT image enhancement and a dual brightness probability gradient. The method was tested on a large data set of images from a pediatric (1083 B-scans) and an adult (90 B-scans) population, which were previously manually segmented by an experienced observer. The results demonstrate the proposed method provides robust detection of the boundaries of interest and is a useful tool to extract clinical data.

  16. 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.

  17. Optical coherence tomography plaque characterization in a patient with ST segment elevation myocardial infarction after cocaine intake

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Morten Steen Svarer, E-mail: morten.steen.hansen2@rsyd.dk [Emergency Department, Kolding Hospital, Skovvangen 2-8, DK-6000 Kolding (Denmark); Antonsen, Lisbeth; Jensen, Lisette Okkels [Department of Cardiology, Odense University Hospital, Sdr. Boulevard 29, DK-5000 Odense (Denmark)

    2016-04-15

    A 28-year old man presented to the Emergency Department with malaise after cocaine intake. After arrival he developed retrosternal chest pain and the electrocardiogram showed ST segment elevations in V1-V2 and ST segment depressions in V5-V6. An acute coronary angiogram revealed a focal non-occlusive lesion with thrombus in the left anterior descending artery. Supplementary optical coherence tomography (OCT) detected plaque erosion with adherent thrombus to be the responsible underlying pathophysiological mechanism. The patient received an effective antithrombotic regimen. Repeat angiogram with additional OCT one month later documented thrombus resolution and complete restoration of the previously eroded coronary vascular surface area. - Highlights: • Optical coherence tomography (OCT) was used to characterize a coronary artery plaque. • OCT detected coronary plaque erosion in a young male with MI due to cocaine abuse. • OCT was used to document thrombus resolution.

  18. Morphological expression of the anterior spinal artery and the intracranial segment of the vertebral artery: a direct anatomic study.

    Science.gov (United States)

    Ballesteros, L; Forero, P; Quintero, I

    2013-01-01

    Given its importance for clinical diagnosis and management, the purpose of this study was to determine the morphological expression of the intracranial segment of both vertebral and spinal arteries. Ninety-five fresh cadaveric specimens autopsied at the Instituto de Medicina Legal of Bucaramanga (Colombia) were perfused with polyester resins at the vertebrobasilar vascular bed, by canalizing the proximal segment of the internal carotids and vertebral arteries. The intracranial segment of the vertebral arteries (VA) had a length of 33.2±5.2 mm and a caliber of 3.03±0.81 mm. The left vertebral artery had a caliber of 3.12±0.85 mm, this being greater than the caliber of the right artery in 59.6% of the cases. The VA junction was seen at the level of the ponto-medullary sulcus in 44.2%, above this level in 30.5%, and below it in 25.3%. The distance from the origin of the anterior spinal branches (ASBs) to the VA junction was 7.34±2.71 mm, with a greater distance corresponding to the right ASBs, a difference that did not reach statistical significance (p=0.32). The anterior spinal arteries (ASA) had a bilateral origin in 65.3% of the cases, with the caliber being balanced in 37 (39%) and dominant at the right side in 15.8%. A right unilateral origin of the ASA was observed in 13.7% and a left unilateral origin in 9.5% of the specimens. There is disagreement in the literature as to the level of the junction of the two vertebral arteries. The unilateral origin of the spinal arteries is more frequent than most prior studies have indicated.

  19. Automated seeding-based nuclei segmentation in nonlinear optical microscopy.

    Science.gov (United States)

    Medyukhina, Anna; Meyer, Tobias; Heuke, Sandro; Vogler, Nadine; Dietzek, Benjamin; Popp, Jürgen

    2013-10-01

    Nonlinear optical (NLO) microscopy based, e.g., on coherent anti-Stokes Raman scattering (CARS) or two-photon-excited fluorescence (TPEF) is a fast label-free imaging technique, with a great potential for biomedical applications. However, NLO microscopy as a diagnostic tool is still in its infancy; there is a lack of robust and durable nuclei segmentation methods capable of accurate image processing in cases of variable image contrast, nuclear density, and type of investigated tissue. Nonetheless, such algorithms specifically adapted to NLO microscopy present one prerequisite for the technology to be routinely used, e.g., in pathology or intraoperatively for surgical guidance. In this paper, we compare the applicability of different seeding and boundary detection methods to NLO microscopic images in order to develop an optimal seeding-based approach capable of accurate segmentation of both TPEF and CARS images. Among different methods, the Laplacian of Gaussian filter showed the best accuracy for the seeding of the image, while a modified seeded watershed segmentation was the most accurate in the task of boundary detection. The resulting combination of these methods followed by the verification of the detected nuclei performs high average sensitivity and specificity when applied to various types of NLO microscopy images.

  20. MRI of the anterior optic pathways following enucleation

    Energy Technology Data Exchange (ETDEWEB)

    Hardman, J.; Halpin, S.F.S.; Hourihan, M.D. [Department of Neuroradiology, University Hospital of Wales, Cardiff (United Kingdom); Mars, S.; Lane, C. [Department of Opthalmology, University Hospital of Wales, Cardiff (United Kingdom)

    1997-11-01

    We examined five patients who had enucleation of one eye for inflammatory or neoplastic disease, using MRI at 1.5 Tesla. None had symptoms referable to the enucleated orbit. In addition, age- and-sex matched individuals were imaged as control subjects, and a further 15 subjects, referred for other than orbital disease, were reviewed. Measurements were made retrospectively of the dimensions of the optic chiasm to establish normal values. All five patients showed abnormalities on MRI following enucleation: abnormal signal within the optic nerve remnant on short {tau} inversion recovery (STIR) images, and atrophy of the nerve remnant and the chiasm. These findings were not apparent in the control or normal subjects. Such findings are to be expected following enucleation and should not be interpreted as indicating active pathology. (orig.) With 3 figs., 2 tabs., 6 refs.

  1. Optic neuritis and acute anterior uveitis associated with influenza A infection: a case report

    Directory of Open Access Journals (Sweden)

    Nakagawa H

    2017-01-01

    Full Text Available Hayate Nakagawa, Hidetaka Noma, Osamu Kotake, Ryosuke Motohashi, Kanako Yasuda, Masahiko Shimura Department of Ophthalmology, Tokyo Medical University Hachioji Medical Center, Tokyo, Japan Background: A few reports have described ocular complications of influenza A infection, such as impaired ocular movement, parasympathetic ocular nerve, keratitis, macular lesion, and frosted branch angiitis. We encountered a rare case of acute anterior uveitis and optic neuritis associated with influenza A infection. Case presentation: A 70-year-old man presented with symptoms of upper respiratory tract infection. A rapid diagnostic test showed a positive result for influenza A. At the same time, he developed ocular symptoms including blurred vision with optic disk edema and hemorrhage in the left eye, and bilateral red eyes. Multiplex polymerase chain reaction performed on aqueous humor sample detected no viral infection. Visual field testing with a Goldmann perimeter showed central and paracentral scotomas in the left eye. In addition to antiviral agent (oseltamivir phosphate 75 mg, the patient was prescribed topical prednisolone acetate ophthalmic suspension eye drops every 5 hours and high-dose intravenous methylprednisolone 1,000 mg daily for 3 days. Two months later, his best-corrected visual acuity improved to 20/50 with regression of visual field defects in his left eye. Conclusion: We report a case of bilateral acute anterior uveitis and unilateral optic neuritis concomitant with influenza A infection. Topical and systemic corticosteroids were effective to resolve acute anterior uveitis and neuritis. Analysis of aqueous humor sample suggested that acute anterior uveitis and optic neuritis in this case were not caused by influenza A virus infection per se but by autoimmune mechanism. Keywords: optic neuritis, anterior uveitis, influenza virus, multiplex polymerase chain reaction

  2. Evaluation of anterior ocular segment complications in patients with allergic keratoconjunctivitis

    OpenAIRE

    Patrícia Bezerra de Menezes Botelho; Patrícia Marback; Luciene Barbosa de Sousa; Mauro Campos; Luiz Antonio Vieira

    2003-01-01

    INTRODUÇÃO: A alergia ocular é condição que pode ocasionar sintomas de coceira, ardor e lacrimejamento, podendo também ser ameaçadora para visão. A fisiopatologia envolve mecanismos de hipersensibilidade imunológica. Devido a fatores imunológicos, o segmento anterior destes pacientes está mais suscetível a alterações que ameaçam a acuidade visual, tais como: opacidades corneanas, ceratocone e catarata. MÉTODOS: Foram revistos, retrospectivamente, 186 pacientes com ceratoconjuntivite alérgica ...

  3. Anterior segment biometry using ultrasound biomicroscopy and the Artemis-2 very high frequency ultrasound scanner

    Directory of Open Access Journals (Sweden)

    Al-Farhan HM

    2013-01-01

    Full Text Available Haya M Al-Farhan, Reem N AlMutairiKing Saud University, College of Applied Medical Sciences, Department of Optometry and Vision Sciences, Riyadh, Kingdom of Saudi ArabiaPurpose: To compare the precision of anterior chamber angle (ACA and anterior chamber depth (ACD measurements taken with ultrasound biomicroscopy (UBM and the Artemis-2 Very High Frequency Ultrasound Scanner (VHFUS in normal subjects.Design: Prospective study.Methods: We randomly selected one eye from each of 59 normal subjects in this study. Two subjects dropped out of the study; the associated data were excluded from analysis. ACA and ACD measurements were obtained using the VHFUS and the UBM. The results were compared statistically using repeated-measures analysis of variance for the intraobserver repeatability, unpaired t-test, and limits of agreement.Results: The average ACA values for the UBM and the VHFUS (±standard deviation were 41.83° ± 5.03° and 33.36° ± 6.03°, respectively. The average ACD values were 2.96 ± 0.34 mm and 2.87 ± 0.31 mm. The intraobserver repeatability analysis of variance P-values for ACA and ACD measurements using UBM were 0.10 and 0.68, respectively; for the Artemis-2 VHFUS, the respective values were 0.68 and 0.09. The difference in ACA measurements was statistically significant (t = 8.41; P < 0.0001, while the difference in ACD values was not (t = 1.51; P < 0.13. The mean ACA difference was 8.50° ± 2.50°, and the limits of agreement were +13.30° to −3.60°. The mean ACD difference was 0.09 ± 0.27 mm, and the limits of agreement ranged from 0.61 mm to −0.43 mm. The mean difference percentage of ACD was 3.1% for both instruments.Conclusion: In case of the ACD, both instruments can be used interchangeably; however, with the ACA instruments, they cannot be used interchangeably.Keywords: anterior chamber angle, anterior chamber depth, Artemis-2 VHF scanner, ultrasound biomicroscope, normal eyes

  4. 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.

  5. 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

  6. 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.

  7. Combined brain and anterior visual pathways' MRIs assist in early identification of neuromyelitis optica spectrum disorder at onset of optic neuritis.

    Science.gov (United States)

    Buch, D; Savatovsky, J; Gout, O; Vignal, C; Deschamps, R

    2017-03-01

    Acute optic neuritis (ON) is the initial presentation in half of neuromyelitis optica spectrum disorder (NMO-SD) cases. Our objective was to evaluate accuracy of combined MRIs of the anterior visual pathways and of the brain to correctly identify NMO-SD among patients with acute ON. We performed a retrospective study on patients with acute ON in NMO-SD (16 episodes) and first-event non-NMO-SD (32 episodes). All MRIs included exams of the brain and anterior visual pathways using T2-weighted and post-gadolinium T1-weighted coronal thin slices. Images were reviewed by a neuroradiologist who was blinded to the final diagnosis. There were no multiple sclerosis (MS)-like lesions with dissemination in space (DIS) with NMO-SD (0 vs. 53%, p < 0.01). Non-NMO-SD ON usually spared the chiasma (3 vs. 44%, p < 0.01) and the optic tracts (0 vs. 19%, p < 0.01). Optic nerve lesions were longer [median (range) 26 mm (14-64) vs. 13 mm [8-36], p < 0.01] and the number of segments involved higher (3 [1-8] vs. 1 [1-4], p < 0.01) in NMO-SD. Bilateral optic nerve involvement, or involvement of ≥3 segments, or involvement of the chiasma, or optic tracts in the absence of MS-like lesions with DIS were suggestive of NMO-SD with a sensitivity of 69% (CI 95% 41-89) and a specificity of 97% (CI 95% 84-99) (p < 0.01). Combining brain and anterior visual pathways' MRIs seems efficient for detecting acute ON patients who are at high risk for NMO-SD.

  8. Infra-optic Course of Both Anterior Cerebral Arteries Associated with a Middle Cerebral Artery Aneurysm and an Aortic Coarctation

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Cheol; Ahn, Jae Geun; Cho, Song Mee [Catholic University, St. Paul' s Hospital, Seoul (Korea, Republic of)

    2009-06-15

    A ruptured aneurysm at the bifurcation of the left middle cerebral artery with an infra- optic course of the bilateral anterior cerebral arteries was found in a 28-year-old woman. Both abnormal anterior cerebral arteries arose from the ipsilateral internal carotid arteries, at the level of the origin of ophthalmic arteries, passed underneath the ipsilateral optic nerves and turned upward at the ventral portion of the optic chiasm. In addition, an aortic coarctation was found with the use of thoracic aortography. An infra-optic course of the bilateral anterior cerebral arteries is an extremely rare anomaly. An infra-optic course of the bilateral anterior cerebral arteries is frequently associated with cerebral aneurysms and possibly with a coarctation aorta. The clinical features, radiological findings and possible genesis of this anomaly are presented.

  9. Optical coherence tomography segmentation reveals ganglion cell layer pathology after optic neuritis.

    Science.gov (United States)

    Syc, Stephanie B; Saidha, Shiv; Newsome, Scott D; Ratchford, John N; Levy, Michael; Ford, E'tona; Crainiceanu, Ciprian M; Durbin, Mary K; Oakley, Jonathan D; Meyer, Scott A; Frohman, Elliot M; Calabresi, Peter A

    2012-02-01

    Post-mortem ganglion cell dropout has been observed in multiple sclerosis; however, longitudinal in vivo assessment of retinal neuronal layers following acute optic neuritis remains largely unexplored. Peripapillary retinal nerve fibre layer thickness, measured by optical coherence tomography, has been proposed as an outcome measure in studies of neuroprotective agents in multiple sclerosis, yet potential swelling during the acute stages of optic neuritis may confound baseline measurements. The objective of this study was to ascertain whether patients with multiple sclerosis or neuromyelitis optica develop retinal neuronal layer pathology following acute optic neuritis, and to systematically characterize such changes in vivo over time. Spectral domain optical coherence tomography imaging, including automated retinal layer segmentation, was performed serially in 20 participants during the acute phase of optic neuritis, and again 3 and 6 months later. Imaging was performed cross-sectionally in 98 multiple sclerosis participants, 22 neuromyelitis optica participants and 72 healthy controls. Neuronal thinning was observed in the ganglion cell layer of eyes affected by acute optic neuritis 3 and 6 months after onset (P optica, with and without a history of optic neuritis, when compared with healthy controls (P optica and a history of optic neuritis exhibited the greatest reduction in ganglion cell layer thickness. Results from our in vivo longitudinal study demonstrate retinal neuronal layer thinning following acute optic neuritis, corroborating the hypothesis that axonal injury may cause neuronal pathology in multiple sclerosis. Further, these data provide evidence of subclinical disease activity, in both participants with multiple sclerosis and with neuromyelitis optica without a history of optic neuritis, a disease in which subclinical disease activity has not been widely appreciated. No pathology was seen in the inner or outer nuclear layers of eyes with optic

  10. 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.

  11. Review of integrated neuromusculoskeletal release and the novel application of a segmental anterior/posterior approach in the thoracic, lumbar, and sacral regions.

    Science.gov (United States)

    Danto, Jay B

    2003-12-01

    Integrated neuromusculoskeletal release (INR) using a segmental anterior/posterior approach is an osteopathic manipulative treatment technique that is easily learned and applied. The segmental anterior/posterior approach to INR was developed as a practical osteopathic manipulative treatment procedure for the inpatient setting, but also has equal efficacy in the outpatient setting. It builds on the principles of INR and myofascial release techniques, as well as other techniques. This approach focuses on both the anterior and posterior connectivity of the body through the neuromusculoskeletal system and uses this connectivity to effectively treat somatic dysfunctions. The principles of INR are discussed, as well as the role of INR in the diagnosis and treatment of somatic dysfunctions in the thoracic, lumbar, and sacral regions.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. Analysis of offset error for segmented micro-structure optical element based on optical diffraction theory

    Science.gov (United States)

    Su, Jinyan; Wu, Shibin; Yang, Wei; Wang, Lihua

    2016-10-01

    Micro-structure optical elements are gradually applied in modern optical system due to their characters such as light weight, replicating easily, high diffraction efficiency and many design variables. Fresnel lens is a typical micro-structure optical element. So in this paper we take Fresnel lens as base of research. Analytic solution to the Point Spread Function (PSF) of the segmented Fresnel lens is derived based on the theory of optical diffraction, and the mathematical simulation model is established. Then we take segmented Fresnel lens with 5 pieces of sub-mirror as an example. In order to analyze the influence of different offset errors on the system's far-field image quality, we obtain the analytic solution to PSF of the system under the condition of different offset errors by using Fourier-transform. The result shows the translation error along XYZ axis and tilt error around XY axis will introduce phase errors which affect the imaging quality of system. The translation errors along XYZ axis constitute linear relationship with corresponding phase errors and the tilt errors around XY axis constitute trigonometric function relationship with corresponding phase errors. In addition, the standard deviations of translation errors along XY axis constitute quadratic nonlinear relationship with system's Strehl ratio. Finally, the tolerances of different offset errors are obtained according to Strehl Criteria.

  17. 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

  18. Keraring Intrastromal Segment Depth Measured by Spectral-Domain Optical Coherence Tomography in Eyes with Keratoconus

    Science.gov (United States)

    Lavia, Carlo; D'Amelio, Savino

    2017-01-01

    Purpose. To evaluate agreement between measured and intended distance of Keraring (Mediphacos, Belo Horizonte, Brazil) intracorneal ring segments from the anterior and posterior corneal surfaces. Methods. Twenty-six Keraring ICRS implanted in 24 keratoconic eyes were examined. The distance from the Keraring apex to the anterior corneal surface and the distance from the inner and the outer corners to the posterior corneal surface were measured 3 months postoperatively using spectral-domain optical coherence tomography. Agreement between measured distance and intended distance was assessed by calculating the absolute differences and 95% limits of agreement (95% LoA). Results. The mean absolute difference was significantly lower (p < 0.001) for the measurements taken at the inner corner (23.54 ± 15.90 μm) than that for those taken at the apex (108.92 ± 62.72 μm) and the outer corner (108.35 ± 56.99 μm). The measurements taken at the inner corner were within ±25 and ±50 μm of the intended distance in 15/26 (57.7%) and 24/26 (92.3%) cases, respectively, and showed the narrowest 95% LoA with the intended distance (−57.61 to 55.15 μm). Conclusions. The distance of the inner corner from the posterior corneal surface showed the best agreement with the intended distance. This measurement is suitable for determining whether the actual Keraring depth matches the intended depth. PMID:28261495

  19. 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.

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

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    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

  1. Dynamic changes in optic disc morphology, choroidal thickness, anterior chamber parameters, and intraocular pressure during Valsalva maneuver

    Directory of Open Access Journals (Sweden)

    Alper Mete

    Full Text Available ABSTRACT Purpose: To investigate the effects of the Valsalva maneuver (VM on optic disc morphology, choroidal thickness, and anterior chamber parameters. Methods: This prospective observational study included 60 eyes of 60 healthy subjects. The anterior chamber parameters, including central corneal thickness (CCT, anterior chamber depth (ACD, anterior chamber angle (ACA, anterior chamber volume (ACV, pupil diameter (PD, axial length (AL, subfoveal and peripapillary choroidal thickness, optic disc parameters, and intraocular pressure (IOP, were measured at rest and during VM. Results: VM did not have any significant influence on AL, subfoveal and peripapillary choroidal thickness, optic disc area, rim area, cup area, cup-to-disc area ratio, vertical cup-to-disc ratio, rim volume, cup volume, and nerve head volume measurements (for all; p >0.05. IOP and PD significantly increased during VM (for both; p <0.001. VM significantly decreased CCT, ACD, ACA, and ACV values (for all; p <0.001. Moreover, the optic nerve cup volume decreased and the horizontal cup-to-disc ratio significantly increased during VM (for both; p <0.05. Conclusions: VM may cause transient changes in IOP, optic disc morphology, and anterior chamber parameters.

  2. Efficacy and safety of out-of-hospital intravenous metoprolol administration in anterior ST-segment elevation acute myocardial infarction: insights from the METOCARD-CNIC trial

    OpenAIRE

    Mateos, Alonso; García Lunar, Inés; García Ruiz, José María; Pizarro, Gonzalo; Fernández Jiménez, Rodrigo; Huertas, Pilar; García Álvarez, Ana; Fernández-Friera, Leticia; Bravo, Jesús; Flores Arias, José; Barreiro, María V.; Chayán Zas, Luisa; Corral, Ervigio; Fuster, Valentín; Sánchez Brunete, Vicente

    2015-01-01

    We seek to examine the efficacy and safety of prereperfusion emergency medical services (EMS)–administered intravenous metoprolol in anterior ST-segment elevation myocardial infarction patients undergoing eventual primary angioplasty. This is a prespecified subgroup analysis of the Effect of Metoprolol in Cardioprotection During an Acute Myocardial Infarction trial population, who all eventually received oral metoprolol within 12 to 24 hours. We studied patients receiving intravenous metoprol...

  3. Assessment of Anterior Segment Changes in Pseudophakic Eyes, Using Ultrasonic Biomicroscopic Imaging, after Pars Plana Vitrectomy with Silicone Oil or Gas Tamponade

    OpenAIRE

    Erkan Ünsal; Kadir Eltutar; Belma Karini; Osman Kızılay

    2016-01-01

    Objective. To evaluate the morphological changes of the anterior segment using ultrasonic biomicroscopy (UBM) imaging in pseudophakic patients who underwent pars plana vitrectomy (PPV) with silicone oil or gas (C3F8) internal tamponade agent injection. Method. This prospective study included pseudophakic patients with planned PPV, divided into two groups according to internal tamponade agent: those in which silicone oil was used (n = 27, Group 1) and those in which gas (C3F8) was used (n = 24...

  4. Application of Pentacam Anterior Segment Analysis System on diagnosis of keratoconus%Pentacam眼前节分析在圆锥角膜诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    徐漫; 孙荔; 刘永珍; 卢迪; 徐艳春; 陈蕾

    2015-01-01

    Pentacam三维眼前节分析系统可合成眼前节从角膜前表面到晶状体后表面的三维图像,通过测量分析系统检测的角膜前后表面曲率、角膜前后表面高度、后表面屈光度、角膜厚度、角膜体积、角膜散光度等,在圆锥角膜,特别是早期圆锥角膜的诊断中有重要作用.%Pentacam Anterior Segment Analysis System shows a 3D image which synthesize from the front surface of the cornea to the post surface of the lens.Anterior and posterior corneal curvature, anterior and posterior corneal elevation, posterior refractive power, corneal astigmatism, corneal volume and corneal thickness measured by the Pentacam Anterior Segment Analysis System play the important roles in diagnosing keratoconus, particular in diagnosing early keratoconus.

  5. 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.

  6. 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.

  7. 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.

  8. Optical single-sideband OFDM transmission based on a two-segment EAM.

    Science.gov (United States)

    Cheng, Hsuan-Lin; Chen, Wei-Hung; Wei, Chia-Chien; Chiu, Yi-Jen

    2015-01-26

    This paper presents a novel optical single-sideband (SSB) OFDM modulation scheme using a two-segment electro-absorption modulator (EAM). Differences in the chirp characteristics of two segments of the EAM make it possible to design driving signals capable of suppressing one of the optical sidebands, such that the optical OFDM signal does not suffer from frequency-selective power fading following dispersive fiber transmission. Our experiment results demonstrate optical OFDM transmissions at 13.5-Gbps over a 0 ∼ 200-km IM/DD system without the need for dispersion compensation and distance-dependent bit- and power-loading.

  9. 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.

  10. Nonarteritic anterior ischemic optic neuropathy following pars plana vitrectomy for macular hole treatment: case report

    Directory of Open Access Journals (Sweden)

    Leonardo Provetti Cunha

    Full Text Available ABSTRACT Herein, we report a case of nonarteritic anterior ischemic optic neuropathy (NAION following uneventful pars plana vitrectomy for macular hole treatment. A 56-year-old previously healthy woman presented with a full-thickness macular hole in right eye (OD and small cup-to-disc ratios in both eyes. Five days after surgery, she noticed sudden painless loss of vision in OD and was found to have an afferent pupillary defect and intraocular pressure of 29 mmHg. Fundus examination showed right optic disc edema and the resolution of a macular hole with an inferior altitudinal visual field defect. Erythrocyte sedimentation rate, C-reactive protein levels, and general physical examination findings were normal. She was treated with hypotensive eyedrops and oral prednisone, resulting in mild visual improvement and a pale optic disc. A combination of face-down position and increased intraocular pressure due to a small optic disc cup were considered as potential mechanisms underlying NAION in the present case. Vitreoretinal surgeons should be aware of NAION as a potentially serious complication and be able to recognize associated risk factors and clinical findings.

  11. 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.

  12. 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

  13. 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.

  14. Assessment of Anterior Segment Changes in Pseudophakic Eyes, Using Ultrasonic Biomicroscopic Imaging, after Pars Plana Vitrectomy with Silicone Oil or Gas Tamponade.

    Science.gov (United States)

    Ünsal, Erkan; Eltutar, Kadir; Karini, Belma; Kızılay, Osman

    2016-01-01

    Objective. To evaluate the morphological changes of the anterior segment using ultrasonic biomicroscopy (UBM) imaging in pseudophakic patients who underwent pars plana vitrectomy (PPV) with silicone oil or gas (C3F8) internal tamponade agent injection. Method. This prospective study included pseudophakic patients with planned PPV, divided into two groups according to internal tamponade agent: those in which silicone oil was used (n = 27, Group 1) and those in which gas (C3F8) was used (n = 24, Group 2). UBM measurements were performed in the supine position before and one week after surgery. Results. In patients of Group 1, postoperative trabecular meshwork-ciliary process distance (T-CPD) and iris-ciliary process distance (I-CPD), according to preoperative values, were found to be statistically significantly reduced, and postoperative mean value of scleral thickness (ST) and intraocular pressure (IOP), according to preoperative value, was found to be statistically significantly increased. In patients of Group 2, postoperative mean values of anterior chamber depth (ACD), ciliary body thickness (CBT), T-CPD, I-CPD, and IOP, according to preoperative values, were found to be statistically significantly reduced. Preoperatively, in Group 2 patients, according to Group 1 patients, TIA and IOP were found to be statistically significantly increased. Preoperative and postoperative IOP between the measured parameters with UBM showed no statistically significant correlation. Conclusions. Gases cause more morphological changes in the anterior segment structures. It is thought that complications such as increased intraocular pressure can be seen more frequently for this reason.

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

    Directory of Open Access Journals (Sweden)

    Tamer Tandogan

    2016-01-01

    Full Text Available 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.

  16. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  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. 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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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.

  1. 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.

  2. 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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  6. Changes in segmentation and setation along the anterior/posterior axis of the homonomous trunk limbs of a remipede (Crustacea, Arthropoda

    Directory of Open Access Journals (Sweden)

    Viacheslav N. Ivanenko

    2016-08-01

    Full Text Available This study describes the segmentation and setation at different developmental stages of the homonomous trunk limbs of the remipede Speleonectes tulumensis Yager, 1987 collected in anchialine caves of the Yucatan Peninsula. Most homonomous trunk limbs originate ventrolaterally and are composed of two protopodal segments, three exopodal segments and four endopodal segments; contralateral limb pairs are united by a sternal bar. However, the last few posterior limbs originate ventrally, are smaller sized, and have regressively fewer segments, suggesting that limb development passes through several intermediate steps beginning with a limb bud. A terminal stage of development is proposed for specimens on which the posterior somite bears a simple bilobate limb bud, and the adjacent somite bears a limb with a protopod comprised of a coxapod and basipod, and with three exopodal and four endopodal segments. On each trunk limb there are 20 serially homologous groups of setae, and the numbers of setae on different limbs usually varies. These groups of setae are arranged linearly and are identified based on the morphology of the setae and their position on the segments. The number of setae in these groups increases gradually from the anterior homonomous limb to a maximum between limbs 8–12; the number then decreases sharply on the more posterior limbs. Changes in the number of setae, which reach a maximum between trunk limbs 8–12, differ from changes in segmentation which vary only over the last few posterior trunk limbs. Following a vector analysis that identified a spatial pattern for these 20 groups of setae among the different homonomous limbs, the hypothesis was confirmed that the number of setae in any given group and any given limb is correlated with the group, with the position of the somite along the body axis, and with the number of somites present on the specimens. This is the first vector analysis used to analyze a pattern of developmental

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  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. Ultrasund biomicroscopy diagnosis of anterior segment tumors%超声生物显微镜诊断眼前节肿瘤

    Institute of Scientific and Technical Information of China (English)

    杨文利; 胡士敏; 朱晓青; 王兰; 郑邦和

    2000-01-01

    目的 了解跟前节常见肿瘤的超声生物显微镜表现特点.方法 应用超声生物显微镜对55例常见眼前节肿瘤~虹膜囊、虹膜色素痣、睫状体肿瘤进行观察.结果 超块生物显微镜表现:虹膜囊肿为边界清晰的圆形或椭圆形囊样病变,内部为无回声区;虹膜色不痣为边界清晰的局限隆起,可为梭形、半球形等,内部回声均匀且与虹膜组织基本相同;睫状体肿瘤表现为睫状体局限隆起,可为半球形或蘑茹显微镜对虹膜肿瘤可明确鉴别实性或囊性,睫状体肿瘤的基底中亦可详尽观察,超声生物显微镜是一种新的无创评估眼前节肿瘤的诊断方法.%Objective To investigate the character of anterior segment tumor by ultrasound biomicroscopy (UBM).Methods UBM was used to diagnose 55 patients of anterior segment tumors,such as iris cyst ,iris nevi and ciliary bdy tumors.Results UBM showed iris cyst was circular or ellipse with Smooth surface and thin wall,but no renectivify.iris nevus was of anteriorly convex shape in fusifarm or semicircles ,its superficaial layer can rcoeCtS as Snne 3s ihs.Ciliary body tumors was of anteriorly convex shape in semircle or mushroom,its renectivlty was not even,namely the reflectivity gets stronger near the probeand nice versa, and may be associated with iris cyst and supcraciliary cffusion.Conclusions Diffexentiation between solid and cystic lesion was easily achicvcd by UBM,the margins of ciliary body tumors could be roofe accurately defined UBN, proved a new noninvasive technique in the evaluation of anterior tumors.

  16. Assessment of Anterior Segment Changes in Pseudophakic Eyes, Using Ultrasonic Biomicroscopic Imaging, after Pars Plana Vitrectomy with Silicone Oil or Gas Tamponade

    Directory of Open Access Journals (Sweden)

    Erkan Ünsal

    2016-01-01

    Full Text Available Objective. To evaluate the morphological changes of the anterior segment using ultrasonic biomicroscopy (UBM imaging in pseudophakic patients who underwent pars plana vitrectomy (PPV with silicone oil or gas (C3F8 internal tamponade agent injection. Method. This prospective study included pseudophakic patients with planned PPV, divided into two groups according to internal tamponade agent: those in which silicone oil was used (n=27, Group 1 and those in which gas (C3F8 was used (n=24, Group 2. UBM measurements were performed in the supine position before and one week after surgery. Results. In patients of Group 1, postoperative trabecular meshwork-ciliary process distance (T-CPD and iris-ciliary process distance (I-CPD, according to preoperative values, were found to be statistically significantly reduced, and postoperative mean value of scleral thickness (ST and intraocular pressure (IOP, according to preoperative value, was found to be statistically significantly increased. In patients of Group 2, postoperative mean values of anterior chamber depth (ACD, ciliary body thickness (CBT, T-CPD, I-CPD, and IOP, according to preoperative values, were found to be statistically significantly reduced. Preoperatively, in Group 2 patients, according to Group 1 patients, TIA and IOP were found to be statistically significantly increased. Preoperative and postoperative IOP between the measured parameters with UBM showed no statistically significant correlation. Conclusions. Gases cause more morphological changes in the anterior segment structures. It is thought that complications such as increased intraocular pressure can be seen more frequently for this reason.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. 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.

  20. Overview of segmented glass optics development for the Constellation-X hard X-ray telescope

    DEFF Research Database (Denmark)

    Hailey, C.J; Christensen, Finn Erland; Craig, W.W.;

    2002-01-01

    We report recent work on segmented glass optics for the Constellation-H hard x-ray telescope. This effort seeks to both improve the figure of the free-standing glass substrates, and to refine a newly-developed mounting technology for the substrates. We discuss metrology on recently characterized...

  1. 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.

  2. Segmentation of the Optic Disc and Optic Cup Using Histogram Feature-Based Adaptive Threshold for Cup to Disk Ratio

    Directory of Open Access Journals (Sweden)

    Nugraha Gibran Satya

    2016-01-01

    Full Text Available Glaucoma is a condition of increased intraocular pressure within the eyes. Such increase then causes the damage on optic nerves as the organ bringing information to be processed in brain. One of the parameters to detect the glaucoma is the ratio between the optic cup and optic disc that can be identified through an examination towards the retinal fundus image of the patient. The ratio is obtained by firstly calculating the width of the area of the optic cup and the optic disc. This research was aimed to propose a method of the segmentation of the optic cup and optic disc with the adaptive threshold. The value of the adaptive threshold was obtained once calculating the mean value and standard deviation on the retinal fundus image of the patient. Before conducting the segmentation, the red component of the image would firstly be extracted followed by doing the contrast stretching. The last one was to perform the morphological operation such as closing and opening to remove the blood vessel to make the ratio calculation more accurate. This method has been tested in a number of retinal fundus images coming from DRISTHI-GS and RIM-ONE.

  3. Bilateral Anterior Ischaemic Optic Neuropathy in a Child on Continuous Peritoneal Dialysis

    Science.gov (United States)

    Al-Kaabi, Abdullah; Haider, Agha S.; Shafeeq, Mohammed O.; El-Naggari, Mohammed A.; El-Nour, Ibtisam; Ganesh, Anuradha

    2016-01-01

    Non-arteritic anterior ischaemic optic neuropathy (NAION) is a serious complication of continuous peritoneal dialysis (CPD) which can lead to poor vision and blindness. We report a five-year-old girl who had undergone a bilateral nephrectomy at the age of one year and was on home CPD. She was referred to the Paediatric Ophthalmology Unit of Sultan Qaboos University Hospital, Muscat, Oman, in 2013 with acute bilateral vision loss, preceded by a three-day history of poor oral intake. At presentation, the patient had severe systemic hypotension. An ophthalmological examination revealed severe bilateral visual impairment and NAION. She was treated with intravenous methylprednisolone and normal saline boluses. At a five-month follow-up, the visual acuity of the right eye had improved but vision in the left eye remained the same. Acute bilateral blindness due to NAION while on CPD is a rare condition in childhood. Paediatricians should be aware of this complication in order to ensure prompt management. PMID:28003901

  4. Chromatic processing in the anterior optic tubercle of the honey bee brain.

    Science.gov (United States)

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

    2013-01-02

    Color vision in honey bees (Apis mellifera) has been extensively studied at the behavioral level and, to a lesser degree, at the physiological level by means of electrophysiological intracellular recordings of single neurons. Few visual neurons have been so far characterized in the lateral protocerebrum of bees. Therefore, the possible implication of this region in chromatic processing remains unknown. We performed in vivo calcium imaging of interneurons in the anterior optic tubercle (AOTu) of honey bees upon visual stimulation of the compound eye to analyze chromatic response properties. Stimulation with distinct monochromatic lights (ultraviolet [UV], blue, and green) matching the sensitivity of the three photoreceptor types of the bee retina induced different signal amplitudes, temporal dynamics, and spatial activity patterns in the AOTu intertubercle network, thus revealing intricate chromatic processing properties. Green light strongly activated both the dorsal and ventral lobes of the AOTu's major unit; blue light activated the dorsal lobe more while UV light activated the ventral lobe more. Eye stimulation with mixtures of blue and green light induced suppression phenomena in which responses to the mixture were lower than those to the color components, thus concurring with color-opponent processing. These data provide evidence for a spatial segregation of color processing in the AOTu, which may serve for navigation purposes.

  5. 3D Curvelet-Based Segmentation and Quantification of Drusen in Optical Coherence Tomography Images

    Directory of Open Access Journals (Sweden)

    M. Esmaeili

    2017-01-01

    Full Text Available Spectral-Domain Optical Coherence Tomography (SD-OCT is a widely used interferometric diagnostic technique in ophthalmology that provides novel in vivo information of depth-resolved inner and outer retinal structures. This imaging modality can assist clinicians in monitoring the progression of Age-related Macular Degeneration (AMD by providing high-resolution visualization of drusen. Quantitative tools for assessing drusen volume that are indicative of AMD progression may lead to appropriate metrics for selecting treatment protocols. To address this need, a fully automated algorithm was developed to segment drusen area and volume from SD-OCT images. The proposed algorithm consists of three parts: (1 preprocessing, which includes creating binary mask and removing possible highly reflective posterior hyaloid that is used in accurate detection of inner segment/outer segment (IS/OS junction layer and Bruch’s membrane (BM retinal layers; (2 coarse segmentation, in which 3D curvelet transform and graph theory are employed to get the possible candidate drusenoid regions; (3 fine segmentation, in which morphological operators are used to remove falsely extracted elongated structures and get the refined segmentation results. The proposed method was evaluated in 20 publically available volumetric scans acquired by using Bioptigen spectral-domain ophthalmic imaging system. The average true positive and false positive volume fractions (TPVF and FPVF for the segmentation of drusenoid regions were found to be 89.15% ± 3.76 and 0.17% ± .18%, respectively.

  6. Biomechanical Evaluation of Different Fixation Methods for Mandibular Anterior Segmental Osteotomy Using Finite Element Analysis, Part Two: Superior Repositioning Surgery With Bone Allograft.

    Science.gov (United States)

    Kilinç, Yeliz; Erkmen, Erkan; Kurt, Ahmet

    2016-01-01

    In this study, the biomechanical behavior of different fixation methods used to fix the mandibular anterior segment following various amounts of superior repositioning was evaluated by using Finite Element Analysis (FEA). The three-dimensional finite element models representing 3 and 5 mm superior repositioning were generated. The gap in between segments was assumed to be filled by block bone allograft and resignated to be in perfect contact with the mandible and segmented bone. Six different finite element models with 2 distinct mobilization rate including 3 different fixation configurations, double right L (DRL), double left L (DLL), or double I (DI) miniplates with monocortical screws, correspondingly were created. A comparative evaluation has been made under vertical, horizontal and oblique loads. The von Mises and principal maximum stress (Pmax) values were calculated by finite element solver programme. The first part of our ongoing Finite Element Analysis research has been addressed to the mechanical behavior of the same fixation configurations in nongrafted models. In comparison with the findings of the first part of the study, it was concluded that bone graft offers superior mechanical stability without any limitation of mobilization and less stress on the fixative appliances as well as in the bone.

  7. Anterior segment changes during accommodation in myopia with OCT%OCT测量近视眼在不同调节状态下眼前段结构变化

    Institute of Scientific and Technical Information of China (English)

    周少博; 李辉; 谭娟; 洪海峰

    2013-01-01

    AIM: To evaluate anterior segment changes during accommodation in different degree of myopia with OCT.METHODS: Sixty myopes with the age from 18 to 39 years were enrolled in this study and were divided into two groups: low to moderate myopia group (>-6. 0D), and high myopia group (≤-6. OD). Anterior segment measurements were performed by anterior segment optic coherence tomography ( OCT) under three different accommodative state of relax (0.0 D), 3. 00D and 5. 00D. The posterior corneal curvature (PCC), anterior chamber depth (ACD), lens thickness (LT), pupil diameter (PD) were compared at different accommodative state using repeated measures ANOVA.RESULTS:Low to moderate myopia group comprised 32 myopes with the mean age 29. 34 ± 4. 65 years, mean spherical equivalent -3. 72± 1. 05D; High myopia group comprised 28 myopes with the mean age 29. 57 ± 5. 89 years, mean spherical equivalent -7.05±0.85D; With the accommodation relaxed (0D), there was no difference between the low to moderate myopia group and high myopia group both in PCC and LT, ACD was 2. 92 ± 0.23mm in high myoia and 2. 67 ± 0. 19mm in low to moderate myopia (t=-4. 637, P=0.000). Pupil diameter was 6.21 ±0. 56mm in low to moderate myopia and 5.95± 0.42mm in high myopia (t= 2. 011, P= 0. 049). With the accommodation increased, ACD decreased significantly,LT increased significantly, and PD decreased significantly in both groups(all P 0.05).CONCLUSION: Anterior segment OCT can find the alteration of ACD, LT and PD with accommodation. During accommodation, the cornea is stable. However, with the accommodation increased, ACD, greater changes happened in LT and PD using anterior segment OCT.%目的:探讨不同程度近视眼在不同调节状态下OCT(optic coherence tomography,OCT)测量的眼前段结构的变化.方法:招募60例近视患者,年龄:18~39岁,按近视程度分为轻中度近视组和高度近视组,用眼前段OCT对测试眼分别在调节放松(0D)、诱发3.00D和5.00D

  8. A case of nonarteritic anterior ischemic optic neuropathy of a male with family history of the disease after receiving sildenafil

    Directory of Open Access Journals (Sweden)

    Felekis T

    2011-10-01

    Full Text Available T Felekis1, I Asproudis1, K Katsanos2, EV Tsianos21University Eye Clinic of Ioannina, Ioannina, Greece; 2First Department of Internal Medicine, University Hospital of Ioannina, Ioannina, GreeceAbstract: A 51-year-old male was referred to the University Eye Clinic of Ioannina with nonarteritic anterior ischemic optic neuropathy (NAION 12 hours after receiving sildenafil citrate (Viagra®. Examination for possible risk factors revealed mild hypercholesterolemia. Family history showed that his father had suffered from bilateral NAION. Although a cause-and-effect relationship is difficult to prove, there are reports indicating an association between the use of erectile dysfunction agents and the development of NAION. Physicians might need to investigate the presence of family history of NAION among systemic or vascular predisposing risk factors before prescribing erectile dysfunction drugs.Keywords: sildenafil, nonarteritic anterior ischemic optic neuropathy, erectile dysfunction drugs, family history

  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. Comparison of anterior segment parameters with Lenstar 900 and Sirius system%Sirius系统与Lenstar 900测量眼前节参数的比较研究

    Institute of Scientific and Technical Information of China (English)

    赵艳; 韦伟; 张长宁

    2014-01-01

    目的:比较两种非接触眼生物测量仪Lenstar 900( LS900)和Sirius眼前节分析系统测量眼前节有关参数的异同。  方法:对近视患者54例87眼分别采用LS900及Sirius系统测量角膜中央厚度( central corneal thickness, CCT)、前房深度(aqueous depth, ACD)、角膜平K(flat keratometry, FK)、角膜陡 K(steep keratometry,SK)、白到白(white to white, WTW)。采用配对 t 检验、Pearson 相关和 Bland-Altman图分析和评估。  结果:Sirius系统检测的CCT和ACD大于LS900,而FK、SK和 WTW 小于 LS900,差值的均值分别为-6.11±6.32μm;-0.09±0.07 mm;0.18±0.25 D;0.21±0.36 D 和0.25±0.39mm,差异有统计学意义(P  结论:LS900和Sirius系统对眼前节参数的检测具有良好的相关性和一致性,但也存在一定差异。这可能与Lenstar和Sirius测量方式并不一致有关,因此还有待进一步研究。%AlM: To compare the anterior segment measurements derived from optical low coherence reflectometer ( Lenstar LS900 ) and combined Scheimpflug - Placido disk topographer ( Sirius) . METHODS: ln this study, we enrolled healthy myopic subjects 54 ( 87 eyes ) . The central corneal thickness (CCT), anterior chamber depth (ACD), flat keratometry ( FK) readings , steep keratometry ( SK ) readings and white to white ( WTW ) were measured by LS900 and Sirius. Evaluation and analysis were performed using paired t tests, the Pearson correlation, and Bland-Altman analyses. RESULTS: The CCT and ACD measurements were significantly lower whereas FK, SK and WTW measurements were higher with LS900 (P CONCLUSlON: Anterior segment parameters evaluated with LS900 and Sirius systemare correlated well and achieve good agreement. However, there are significantly statistical differences which may be caused by the different measurement modes, so they may not be interchangeable use under certain clinical circumstances.

  11. 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.

  12. Feature extraction for magnetic domain images of magneto-optical recording films using gradient feature segmentation

    Science.gov (United States)

    Quanqing, Zhu; Xinsai, Wang; Xuecheng, Zou; Haihua, Li; Xiaofei, Yang

    2002-07-01

    In this paper, we present a method to realize feature extraction on low contrast magnetic domain images of magneto-optical recording films. The method is based on the following three steps: first, Lee-filtering method is adopted to realize pre-filtering and noise reduction; this is followed by gradient feature segmentation, which separates the object area from the background area; finally the common linking method is adopted and the characteristic parameters of magnetic domain are calculated. We describe these steps with particular emphasis on the gradient feature segmentation. The results show that this method has advantages over other traditional ones for feature extraction of low contrast images.

  13. 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.

  14. Automated detection of optic disk in retinal fundus images using intuitionistic fuzzy histon segmentation.

    Science.gov (United States)

    Mookiah, Muthu Rama Krishnan; Acharya, U Rajendra; Chua, Chua Kuang; Min, Lim Choo; Ng, E Y K; Mushrif, Milind M; Laude, Augustinus

    2013-01-01

    The human eye is one of the most sophisticated organs, with perfectly interrelated retina, pupil, iris cornea, lens, and optic nerve. Automatic retinal image analysis is emerging as an important screening tool for early detection of eye diseases. Uncontrolled diabetic retinopathy (DR) and glaucoma may lead to blindness. The identification of retinal anatomical regions is a prerequisite for the computer-aided diagnosis of several retinal diseases. The manual examination of optic disk (OD) is a standard procedure used for detecting different stages of DR and glaucoma. In this article, a novel automated, reliable, and efficient OD localization and segmentation method using digital fundus images is proposed. General-purpose edge detection algorithms often fail to segment the OD due to fuzzy boundaries, inconsistent image contrast, or missing edge features. This article proposes a novel and probably the first method using the Attanassov intuitionistic fuzzy histon (A-IFSH)-based segmentation to detect OD in retinal fundus images. OD pixel intensity and column-wise neighborhood operation are employed to locate and isolate the OD. The method has been evaluated on 100 images comprising 30 normal, 39 glaucomatous, and 31 DR images. Our proposed method has yielded precision of 0.93, recall of 0.91, F-score of 0.92, and mean segmentation accuracy of 93.4%. We have also compared the performance of our proposed method with the Otsu and gradient vector flow (GVF) snake methods. Overall, our result shows the superiority of proposed fuzzy segmentation technique over other two segmentation methods.

  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. Automatic airway wall segmentation and thickness measurement for long-range optical coherence tomography images.

    Science.gov (United States)

    Qi, Li; Huang, Shenghai; Heidari, Andrew E; Dai, Cuixia; Zhu, Jiang; Zhang, Xuping; Chen, Zhongping

    2015-12-28

    We present an automatic segmentation method for the delineation and quantitative thickness measurement of multiple layers in endoscopic airway optical coherence tomography (OCT) images. The boundaries of the mucosa and the sub-mucosa layers are accurately extracted using a graph-theory-based dynamic programming algorithm. The algorithm was tested with sheep airway OCT images. Quantitative thicknesses of the mucosal layers are obtained automatically for smoke inhalation injury experiments.

  17. 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.

  18. 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.

  19. 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.

  20. Pentacam System for the Measurement of the Anterior Segment of Myopia Eye%Pentacam系统对近视人群眼部前节的测量

    Institute of Scientific and Technical Information of China (English)

    盛豫; 黄一飞; 关娟; 王大江

    2012-01-01

    [Objective] To analyze the data of ocular anterior segment of myopia eye obtained by Pentacam system. [Methods]The anterior segment of 436 myopia eyes were measured by Pentacam system and the data were obtained. The coefficient of variation(CV) was calculated. According to the data of spherical equivalent(SE) , the subjects were divided into super-high myopia group, high myopia group, moderate myopia group and mild myopia group. One-way ANOVA was used to analyze the data. The data from the groups with different sex or different side of eyes were analyzed by using 2 independent samples tests (rank test). [Results] The change of the data from anterior tissues and eye tissues near the axis was little, While the change of the data from posterior and periphery tissues was larger. The anterior angle in the super-high myopia group was narrower than that in other groups, and there was significant difference ( P <0. 05=. There was no significant difference in thinnest corneal thickness, corneal volume and the diameter of pupil between male data and female data( P >0. 05). There was no significant difference in the data between left side and right side of eyes( P >0. 05). [Conclusion] Pentacam system for the examination of eyes is fast, useful and easy to operate, and can obtain the data at the first time. The result of the data accords with the characteristics of human anatomy and physiological change. Therefore, Pentacam system has better clinical application value.%[目的]对Pentacam系统获得的近视眼的前节各部位数据进行分析.[方法]应用Pentacam系统对436只近视眼球进行检测并获取数据,计算各部位数据的变异系数(Coefficient of variation,CV).按等效球镜数据,将人群分为超高近视组、高度近视组、中度近视组和低度近视组,数据采用单因素方差分析法(One-way ANOVA)进行分析.按性别分组及眼别分组的数据,采用两独立样本非参数检验法分析(秩和检验).[结果]眼前

  1. Adaptive optics via pupil segmentation for high-resolution imaging in biological tissues.

    Science.gov (United States)

    Ji, Na; Milkie, Daniel E; Betzig, Eric

    2010-02-01

    Biological specimens are rife with optical inhomogeneities that seriously degrade imaging performance under all but the most ideal conditions. Measuring and then correcting for these inhomogeneities is the province of adaptive optics. Here we introduce an approach to adaptive optics in microscopy wherein the rear pupil of an objective lens is segmented into subregions, and light is directed individually to each subregion to measure, by image shift, the deflection faced by each group of rays as they emerge from the objective and travel through the specimen toward the focus. Applying our method to two-photon microscopy, we could recover near-diffraction-limited performance from a variety of biological and nonbiological samples exhibiting aberrations large or small and smoothly varying or abruptly changing. In particular, results from fixed mouse cortical slices illustrate our ability to improve signal and resolution to depths of 400 microm.

  2. 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.

  3. 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.

  4. 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.

  5. 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 weight,...

  6. 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.

  7. Comparison of anterior segment changes resulted from accommodation before and after LASIK in myopia%近视眼LASIK手术前后调节所致眼前段结构变化的比较

    Institute of Scientific and Technical Information of China (English)

    周少博; 李辉; 洪海峰; 谭娟

    2014-01-01

    divided into two groups:low to moderate myopic group (>-6.0D),and high myopic group (≤-6.0D).Anterior segment measurements were performed by anterior segment optic coherence tomography (OCT) in undominant eye under three different accommodative state of relax (0.0 D) and 3.0 D before LASIK and one week,one month,and 3 months after LASIK.The changes in posterior corneal curvature (PCC),anterior chamber depth (ACD),lens thickness (LT),pupil diameter (PD) with accommodation at different time after LASIK were compared with those measured before LASIK.Results There were no significant differences between preoperative PCC,ACD,LT,PD and those of post-operation at the state of non-accommodated in both groups (all P >0.05).Compared with pre-operation,the mean changes of LT induced by 3.0D accommodation were significantly decreased in both groups at 1 week postoperatively (all P <0.05).There were no significant differences between preoperative alteration in anterior segment induced by accommodation and 1-month postoperative alteration in both groups (all P >0.05).Changes of LT were significantly increased in 3 months after surgery in high myopia.Conclusions The changes of LT induced by accommodation in myopia seem to be decreased in the early days after LASIK and may recover or even increase at one to three months,which may be the mechanism that accommodative function changes after LASIK.

  8. 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

    2015-11-21

    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.

  9. Optical design for ATHENA X-ray telescope based on slumped mirror segments

    Science.gov (United States)

    Proserpio, Laura; Breunig, Elias; Friedrich, Peter; Winter, Anita

    2014-07-01

    The Hot and Energetic Universe will be the focus of future ESA missions: in late 2013 the theme was selected for the second large-class mission in the Cosmic Vision science program. Fundamental questions on how and why ordinary matter assemble into galaxies and clusters, and how black holes grow and influence their surroundings can be addressed with an advanced X-ray observatory. The currently proposed ATHENA mission presents all the potentiality to answer the outstanding questions. It is based on the heritage of XMM-Newton and on the previous studies for IXO mission. The scientific payload will require state of the art instrumentations. In particular, the baseline for the X-ray optical system, delivering a combination of large area, high angular resolution, and large field of view, is the Silicon Pore Optics technology (SPO) developed by ESA in conjunction with the Cosine Measurement Systems. The slumping technology is also under development for the manufacturing of future X-ray telescopes: for several years the Max Planck Institute for Extraterrestrial physics (MPE) has been involved in the analysis of the indirect slumping approach, which foresees the manufacturing of segmented X-ray shells by shaping thin glass foils at high temperatures over concave moulds so to avoid any contact of the optical surface with other materials during the process, preserving in this way the original X-ray quality of the glass surface. The paper presents an alternative optical design for ATHENA based on the use of thin glass mirror segments obtained through slumping.

  10. 正常人眼前段组织与房角开放度数的关系%Relationship between Structure of Anterior Segment Tissue and Open Angle in Normal Subjects

    Institute of Scientific and Technical Information of China (English)

    曾阳发; 刘杏; 王涛; 李媚; 李彬彬; 何明光

    2009-01-01

    [Objective] To study the relationship between structure of anterior segment tissues and open angle(AA) in normal subjects.[Methods] A total of 211 eyes from 211 normal subjects were enrolled,whose anterior chambers and lens were scanned using anterior segment optical coherence tomography (AS-OCT).The measuring items included AA,anterior chamber depth (ACD),anterior chamber horizontal diameter (ACHD),anatomical anterior chamber depth (AACD),ciliary band length (CBL),iris thickness (IT),lens thickness (LT),lens position (LP) and lens anterior apex position (LAAP).The relationship between the 8 biometric parameters and AA was analyzed using linear correlation,respectively.[Results] The mean of AA was (40 ± 17)°,with (44 ± 18)° in male,and (37 ± 16)° in female.The difference of AA between male and female was statistically significant (t = 2.893,P = 0.004).There was significant correlation between AA and ACD (r = 0.721,P = 0.000),LT (r = -0.545,P = 0.000),CBL (r = 0.615,P = 0.000),LAAP (r = -0.717,P = 0.000),LP (r = 0.557,P = 0.000),and ACHD (r = 0.175,P = 0.011).There was no significant correlation between AA and AACD (r = 0.130,P = 0.059),IT (r = 0.129,P = 0.061).[Conclusion] The AA of females was narrower than that of males.In normal subjects,the most important factors which determine AA are the lens,the location of the peripheral iris and ciliary body.%[目的] 分析正常人房角开放度数(AA)与眼前段结构的关系. [方法] 收集211例(211只眼)正常人,采用眼前段光学相干断层扫描仪(AS-OCT)扫描其前房和晶状体,并测量前房深度(ACD)、前房横径(ACHD)、解剖前房深度(AACD)、睫状体带长度(CBL)、虹膜厚度(IT)、晶状体厚度(LT)、晶状体位置(LP)以及晶状体前极的位置(LAAP).采用直线相关分析这8个参数与AA的关系. [结果] AA的均值为(40 ± 17)°,男性(44 ± 18)°,女性(37 ± 16)°,比较差异有统计学意义(t = 2.893,P = 0.004).AA

  11. Kernel regression based segmentation of optical coherence tomography images with diabetic macular edema.

    Science.gov (United States)

    Chiu, Stephanie J; Allingham, Michael J; Mettu, Priyatham S; Cousins, Scott W; Izatt, Joseph A; Farsiu, Sina

    2015-04-01

    We present a fully automatic algorithm to identify fluid-filled regions and seven retinal layers on spectral domain optical coherence tomography images of eyes with diabetic macular edema (DME). To achieve this, we developed a kernel regression (KR)-based classification method to estimate fluid and retinal layer positions. We then used these classification estimates as a guide to more accurately segment the retinal layer boundaries using our previously described graph theory and dynamic programming (GTDP) framework. We validated our algorithm on 110 B-scans from ten patients with severe DME pathology, showing an overall mean Dice coefficient of 0.78 when comparing our KR + GTDP algorithm to an expert grader. This is comparable to the inter-observer Dice coefficient of 0.79. The entire data set is available online, including our automatic and manual segmentation results. To the best of our knowledge, this is the first validated, fully-automated, seven-layer and fluid segmentation method which has been applied to real-world images containing severe DME.

  12. Automatic segmentation of the choroid in enhanced depth imaging optical coherence tomography images.

    Science.gov (United States)

    Tian, Jing; Marziliano, Pina; Baskaran, Mani; Tun, Tin Aung; Aung, Tin

    2013-03-01

    Enhanced Depth Imaging (EDI) optical coherence tomography (OCT) provides high-definition cross-sectional images of the choroid in vivo, and hence is used in many clinical studies. However, the quantification of the choroid depends on the manual labelings of two boundaries, Bruch's membrane and the choroidal-scleral interface. This labeling process is tedious and subjective of inter-observer differences, hence, automatic segmentation of the choroid layer is highly desirable. In this paper, we present a fast and accurate algorithm that could segment the choroid automatically. Bruch's membrane is detected by searching the pixel with the biggest gradient value above the retinal pigment epithelium (RPE) and the choroidal-scleral interface is delineated by finding the shortest path of the graph formed by valley pixels using Dijkstra's algorithm. The experiments comparing automatic segmentation results with the manual labelings are conducted on 45 EDI-OCT images and the average of Dice's Coefficient is 90.5%, which shows good consistency of the algorithm with the manual labelings. The processing time for each image is about 1.25 seconds.

  13. James Webb Space Telescope segment phasing using differential optical transfer functions

    Science.gov (United States)

    Codona, Johanan L.; Doble, Nathan

    2015-04-01

    Differential optical transfer function (dOTF) is an image-based, noniterative wavefront sensing method that uses two star images with a single small change in the pupil. We describe two possible methods for introducing the required pupil modification to the James Webb Space Telescope, one using a small (segment's actuator and another that uses small misalignments of the NIRCam's filter wheel. While both methods should work with NIRCam, the actuator method will allow both MIRI and NIRISS to be used for segment phasing, which is a new functionality. Since the actuator method requires only small displacements, it should provide a fast and safe phasing alternative that reduces the mission risk and can be performed frequently for alignment monitoring and maintenance. Since a single actuator modification can be seen by all three cameras, it should be possible to calibrate the non-common-path aberrations between them. Large segment discontinuities can be measured using dOTFs in two filter bands. Using two images of a star field, aberrations along multiple lines of sight through the telescope can be measured simultaneously. Also, since dOTF gives the pupil field amplitude as well as the phase, it could provide a first approximation or constraint to the planned iterative phase retrieval algorithms.

  14. James Webb Space Telescope segment phasing using differential optical transfer functions

    CERN Document Server

    Codona, Johanan L

    2015-01-01

    Differential Optical Transfer Function (dOTF) is an image-based, non-iterative wavefront sensing method that uses two star images with a single small change in the pupil. We describe two possible methods for introducing the required pupil modification to the JWST, one using a small (segment's actuator and another that uses small misalignments of NIRCam's filter wheel. While both methods should work with NIRCam, the actuator method will allow both MIRI and NIRISS to be used for segment phasing, which is new functionality. Since the actuator method requires only small displacements, it should provide a fast and safe phasing alternative that reduces mission risk and can be performed frequently for alignment monitoring and maintenance. Since a single actuator modification can be seen by all three cameras, it should be possible to calibrate the non-common-path aberrations between them. Large segment discontinuities can be measured using dOTFs in two filter bands. Using two im...

  15. Automated segmentation of lung airway wall area measurements from bronchoscopic optical coherence tomography imaging

    Science.gov (United States)

    Heydarian, Mohammadreza; Choy, Stephen; Wheatley, Andrew; McCormack, David; Coxson, Harvey O.; Lam, Stephen; Parraga, Grace

    2011-03-01

    Chronic Obstructive Pulmonary Disease (COPD) affects almost 600 million people and is currently the fourth leading cause of death worldwide. COPD is an umbrella term for respiratory symptoms that accompany destruction of the lung parenchyma and/or remodeling of the airway wall, the sum of which result in decreased expiratory flow, dyspnea and gas trapping. Currently, x-ray computed tomography (CT) is the main clinical method used for COPD imaging, providing excellent spatial resolution for quantitative tissue measurements although dose limitations and the fundamental spatial resolution of CT limit the measurement of airway dimensions beyond the 5th generation. To address this limitation, we are piloting the use of bronchoscopic Optical Coherence Tomography (OCT), by exploiting its superior spatial resolution of 5-15 micrometers for in vivo airway imaging. Currently, only manual segmentation of OCT airway lumen and wall have been reported but manual methods are time consuming and prone to observer variability. To expand the utility of bronchoscopic OCT, automatic and robust measurement methods are required. Therefore, our objective was to develop a fully automated method for segmenting OCT airway wall dimensions and here we explore several different methods of image-regeneration, voxel clustering and post-processing. Our resultant automated method used K-means or Fuzzy c-means to cluster pixel intensity and then a series of algorithms (i.e. cluster selection, artifact removal, de-noising) was applied to process the clustering results and segment airway wall dimensions. This approach provides a way to automatically and rapidly segment and reproducibly measure airway lumen and wall area.

  16. 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.

  17. 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

  18. Pentacam of the anterior segment after implantation of iris-fixated lens%应用Pentacam三维眼前段分析仪对虹膜夹型人工晶状体植入术后的研究

    Institute of Scientific and Technical Information of China (English)

    汤欣; 邢晓杰

    2008-01-01

    目的 应用Pentacam术后追踪测量虹膜夹型有晶状体眼人工晶状体(PIOL)中央和周边部与角膜内皮和自然晶体之间的距离,倾斜度、偏心值以及前房深度的变化,评价其在前房的位置.方法 收集自2006年1月以来接受虹膜夹型人晶状体植入术的22例33只眼.术后6个月全部患者行Pentacam检查,测量VRSM50和VRSM60两组不同类型虹膜夹型PIOL中央和周边部与角膜内皮和自然晶体之间的距离,并测量术后1d、1、3及6个月人工晶状体的偏心量、倾斜度及前房深度值.结果 角膜内皮至PIOL光学部前表面距离为(1.94±0.36)mm.PIOL后表面与自然晶状体间的距离为(0.76±0.12)mm.分别比较各组在不同时期的平均偏心量与平均倾斜度,差异无统计学意义(P>0.05).在术后1d、1、3及6个月,比较2组的平均偏心量与平均倾斜度,差异无统计学意义(P>0.05).结论 Pentacam三维眼前段分析仪为PIOL植入术后提供高质量的Scheimpflug摄像,可以为有晶状体眼前房型人工晶状体提供精确的眼内定位,在这一方面具有重要的临床应用价值.%Objective To evaluate intraocular dimensions of the anterior segment and examine decentration,tilt and anterior chamber depth (ACD)of myopic phakic eyes after implantation of iris-fixated lenses.Methods Thirty-three myopic eyes that received a iris-fixated phakic intraocular lens (PIOL) were assessed.The eyes were randomized into VRSM50 and VRSM60 2 groups based on PIOL type.Distances between the cornea and the PIOL-optic edge and between the PIOL optic and the crystalline lens were evaluated using Scheimpflug photography 6 months postoperatively.The degree of IOL decentration, tilt and ACD was measured 1 day and 1,3and 6 months after surgery.Results The average postoperative distance between the central corneal endothelium and the anterior surface of the PIOL wasl.94±0.36 mm.The distance between the crystalline lens and posterior surface of the PIOL

  19. 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

  20. High-dose intravenous pulse steroid therapy for optic disc swelling and subretinal fluid in non-arteritic anterior ischemic optic neuropathy

    Science.gov (United States)

    Takayama, Kei; Kaneko, Hiroki; Kachi, Shu; Ra, Eimei; Ito, Yasuki; Terasaki, Hiroko

    2017-01-01

    ABSTRACT Non-arteritic anterior ischemic optic neuropathy (NAION) is a disease with microvascular abnormality that causes acute optic disc swelling (ODS) and, in severe cases, subretinal fluid (SRF) accumulation. ODS causes compartment syndrome and subsequent axonal degeneration and loss of retinal ganglion cells by apoptosis. No treatment modalities have been effective, although some cases improved after the intake of oral systemic steroids. We reported a case of a 72-year-old man who was referred due to a visual defect in the right eye. At first presentation, visual acuity and visual field were disturbed; critical flicker frequency (CFF) was decreased; and optic coherence tomography (OCT) showed ODS and SRF. Microscopic examination revealed parapapillary hemorrhage and fluorescence angiography showed non-filling, temporal-superior choroidal lesion adjacent to the optic disc at an early phase. After high-dose intravenous steroid treatment, SRF and ODS were decreased, and completely resolved after 30 days. Visual acuity and CFF were improved, and visual field was enlarged. High-dose intravenous steroids could possibly resolve SRF and ODS and improve visual function of patients with NAION. Some cases in NAION improved visual acuity and visual function in natural course, more cases were needed to evaluate the efficiency.

  1. Simultaneous macula detection and optic disc boundary segmentation in retinal fundus images

    Science.gov (United States)

    Girard, Fantin; Kavalec, Conrad; Grenier, Sébastien; Ben Tahar, Houssem; Cheriet, Farida

    2016-03-01

    The optic disc (OD) and the macula are important structures in automatic diagnosis of most retinal diseases inducing vision defects such as glaucoma, diabetic or hypertensive retinopathy and age-related macular degeneration. We propose a new method to detect simultaneously the macula and the OD boundary. First, the color fundus images are processed to compute several maps highlighting the different anatomical structures such as vessels, the macula and the OD. Then, macula candidates and OD candidates are found simultaneously and independently using seed detectors identified on the corresponding maps. After selecting a set of macula/OD pairs, the top candidates are sent to the OD segmentation method. The segmentation method is based on local K-means applied to color coordinates in polar space followed by a polynomial fitting regularization step. Pair scores are updated, resulting in the final best macula/OD pair. The method was evaluated on two public image databases: ONHSD and MESSIDOR. The results show an overlapping area of 0.84 on ONHSD and 0.90 on MESSIDOR, which is better than recent state of the art methods. Our segmentation method is robust to contrast and illumination problems and outputs the exact boundary of the OD, not just a circular or elliptical model. The macula detection has an accuracy of 94%, which again outperforms other macula detection methods. This shows that combining the OD and macula detections improves the overall accuracy. The computation time for the whole process is 6.4 seconds, which is faster than other methods in the literature.

  2. Real-Time Automatic Segmentation of Optical Coherence Tomography Volume Data of the Macular Region.

    Directory of Open Access Journals (Sweden)

    Jing Tian

    Full Text Available Optical coherence tomography (OCT is a high speed, high resolution and non-invasive imaging modality that enables the capturing of the 3D structure of the retina. The fast and automatic analysis of 3D volume OCT data is crucial taking into account the increased amount of patient-specific 3D imaging data. In this work, we have developed an automatic algorithm, OCTRIMA 3D (OCT Retinal IMage Analysis 3D, that could segment OCT volume data in the macular region fast and accurately. The proposed method is implemented using the shortest-path based graph search, which detects the retinal boundaries by searching the shortest-path between two end nodes using Dijkstra's algorithm. Additional techniques, such as inter-frame flattening, inter-frame search region refinement, masking and biasing were introduced to exploit the spatial dependency between adjacent frames for the reduction of the processing time. Our segmentation algorithm was evaluated by comparing with the manual labelings and three state of the art graph-based segmentation methods. The processing time for the whole OCT volume of 496×644×51 voxels (captured by Spectralis SD-OCT was 26.15 seconds which is at least a 2-8-fold increase in speed compared to other, similar reference algorithms used in the comparisons. The average unsigned error was about 1 pixel (∼ 4 microns, which was also lower compared to the reference algorithms. We believe that OCTRIMA 3D is a leap forward towards achieving reliable, real-time analysis of 3D OCT retinal data.

  3. Aeroelastic Control of a Segmented Trailing Edge Using Fiber Optic Strain Sensing Technology

    Science.gov (United States)

    Graham, Corbin Jay; Martins, Benjamin; Suppanade, Nathan

    2014-01-01

    Currently, design of aircraft structures incorporate a safety factor which is essentially an over design to mitigate the risk of structure failure during operation. Typically this safety factor is to design the structure to withstand loads much greater than what is expected to be experienced during flight. NASA Dryden Flight Research Centers has developed a Fiber Optic Strain Sensing (FOSS) system which can measure strain values in real-time. The Aeroelastics Lab at the AERO Institute is developing a segmented trailing edged wing with multiple control surfaces that can utilize the data from the FOSS system, in conjunction with an adaptive controller to redistribute the lift across a wing. This redistribution can decrease the amount of strain experienced by the wing as well as be used to dampen vibration and reduce flutter.

  4. Towards automated segmentation of cells and cell nuclei in nonlinear optical microscopy.

    Science.gov (United States)

    Medyukhina, Anna; Meyer, Tobias; Schmitt, Michael; Romeike, Bernd F M; Dietzek, Benjamin; Popp, Jürgen

    2012-11-01

    Nonlinear optical (NLO) imaging techniques based e.g. on coherent anti-Stokes Raman scattering (CARS) or two photon excited fluorescence (TPEF) show great potential for biomedical imaging. In order to facilitate the diagnostic process based on NLO imaging, there is need for an automated calculation of quantitative values such as cell density, nucleus-to-cytoplasm ratio, average nuclear size. Extraction of these parameters is helpful for the histological assessment in general and specifically e.g. for the determination of tumor grades. This requires an accurate image segmentation and detection of locations and boundaries of cells and nuclei. Here we present an image processing approach for the detection of nuclei and cells in co-registered TPEF and CARS images. The algorithm developed utilizes the gray-scale information for the detection of the nuclei locations and the gradient information for the delineation of the nuclear and cellular boundaries. The approach reported is capable for an automated segmentation of cells and nuclei in multimodal TPEF-CARS images of human brain tumor samples. The results are important for the development of NLO microscopy into a clinically relevant diagnostic tool.

  5. Optical design and performance analysis of a 25 m class telescope with a segmented spherical primary

    DEFF Research Database (Denmark)

    Owner-Petersen, Mette

    1996-01-01

    The basic design and an analysis of the performance possibilities of a 25 m class optical telescope are presented here. The configuration consists of a 28 m segmented spherical primary M1 followed by three highly aspherical corrective mirrors M2, M3 and M4 which also deviate from cartesian shape....... The construction is axially folded. The combination M1-M2 forms a focus in a coupling aperture in M4, and the combination M3-M4 relays this focus to the final focus behind M1 and M3. The combination M2-M3 images M1 on the segmented M4 to be used for correction of wavefront errors induced by M1 due to gravitational...... sag and windbuffeting. Several types of aspherical figuring of M2, M3 and M4 all resulting in a field performance better than characterized by a RMS spotradius smaller than 0.1 arcseconds within a full FOV of 21 arcminutes are presented....

  6. 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

  7. Zebrafish-a new animal models of anterior segment embryonic development and diseases basic reserch%斑马鱼在眼前节胚胎发育和疾病研究中的应用进展

    Institute of Scientific and Technical Information of China (English)

    郝永娜; 魏瑞华; 赵少贞

    2012-01-01

    In recent years,zebrafish has become ideall animal models of human disease with its unique characteristics,such as small body,fecundity,fast development and growth,embryo transparency,and so on.Furthermore,the structure and gene of zebrafish eye are highly conservative with human eye,which make ophthalmologists to pay close attention to zebrafish.This review focus on the studies and applications on zebrafish embryonic development of anterior segment,including the morphogenesis of cornea,lens and anterior chamber,and diseases of anterior segment (corneal diseases,cataract,glaucoma).%近年来,斑马鱼凭借其体型小、繁殖力强、生长发育快、胚胎透明等独特的生物学特性,成为人类疾病动物模型的理想选择,加之与人类眼部结构和基因的高度保守性,使斑马鱼受到眼科学领域工作者的关注.本文主要对斑马鱼在眼前节胚胎发育,包括角膜、晶状体和前房的形态发生,以及眼前节疾病(角膜病、白内障、青光眼等)方面的研究和应用作一综述.

  8. Astrocytes phagocytose focal dystrophies from shortening myelin segments in the optic nerve of Xenopus laevis at metamorphosis.

    Science.gov (United States)

    Mills, Elizabeth A; Davis, Chung-ha O; Bushong, Eric A; Boassa, Daniela; Kim, Keun-Young; Ellisman, Mark H; Marsh-Armstrong, Nicholas

    2015-08-18

    Oligodendrocytes can adapt to increases in axon diameter through the addition of membrane wraps to myelin segments. Here, we report that myelin segments can also decrease their length in response to optic nerve (ON) shortening during Xenopus laevis metamorphic remodeling. EM-based analyses revealed that myelin segment shortening is accomplished by focal myelin-axon detachments and protrusions from otherwise intact myelin segments. Astrocyte processes remove these focal myelin dystrophies using known phagocytic machinery, including the opsonin milk fat globule-EGF factor 8 (Mfge8) and the downstream effector ras-related C3 botulinum toxin substrate 1 (Rac1). By the end of metamorphic nerve shortening, one-quarter of all myelin in the ON is enwrapped or internalized by astrocytes. As opposed to the removal of degenerating myelin by macrophages, which is usually associated with axonal pathologies, astrocytes selectively remove large amounts of myelin without damaging axons during this developmental remodeling event.

  9. 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

    OpenAIRE

    Bruno de Freitas Valbon; Rodrigo Teixeira Santos; Isaac Ramos; Ana Laura Canedo; Leonardo Nogueira; Renato Ambrósio Jr

    2013-01-01

    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. D...

  10. The imaging characteristics and comparative analysis of 1310 nm study of real-time Fourier-domain anterior segment OCT%1310 nm傅里叶域眼前节OCT的成像特点及与其他两种OCT的对比分析

    Institute of Scientific and Technical Information of China (English)

    王飞; 赵镇南; 李喜琪; 姜春晖; 孙兴怀; 史国华; 钱韶红

    2012-01-01

    Objective To discuss the imaging ability of different anterior optical coherence tomography (OCT) systems.Methods It was a cross-sectional study.Six normal volunteers (12 eyes,24 directions) were involved in this cross-sectional study.Three different OCT systems were used to acquire images of their eyes.The important structures:scleral spur,Schlemm's canal,anterior segment angle recess and Schwalbe line were defined.The trabecular-iris angle (TIA500),angle opening distance at 500 μm (AOD500),the area of the trabeculo-iris space at 500 μm (TISA500),the widest diameter of Schlemm's canal,and the area and circumference of Schlemm's canal were measured if possible.Results Using real-time Fourier-domain anterior segment OCT,the scleral spur,Schlemm's canal,anterior segment angle recess and the Schwalbe line were defined in 8 eyes (67%) 13 positions (54%),12 eyes (100%) 22 positions (92%),12 eyes (100%) 24 positions (100%),and 6 eyes (50%) 9 positions (38%),respectively.Using RTV-ue 100 OCT,Schlemm's canal and the Schwalbe line could be defined in 8 eyes (67%) 8 positions (33%) and 10 eyes (83%) 19 positions (79%),respectively.The scleral spur and anterior segment angle recess could not be seen.The scleral spur and anterior segment angle recess were defined in 12 eyes (100%) 21 positions (88%) and 12 eyes (100%) 24positions (100%),respectively using Visante OCT,but Schwalbe's line and Schlemm's canal could not be defined.There was a significant difference in their ability to define important structures (scleral spur,P<0.01; Schlemm's canal,P<0.01; anterior segment angle recess,P<0.01; and Schwalbe line,P<0.01).The TIA500,AOD500 and TISA500 measured by Real-time Fourier-domain anterior segment OCT and Visante OCT were similar,and the area and widest diameter of Schlemm's canal measured by Real-time Fourier-domain anterior segment OCT and RTV-ue 100 OCT were also similar.The differences were not significant.Conclusion All three

  11. A morphological study of retinal changes in unilateral amblyopia using optical coherence tomography image segmentation.

    Directory of Open Access Journals (Sweden)

    Andrea Szigeti

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate the possible structural changes of the macula in patients with unilateral amblyopia using optical coherence tomography (OCT image segmentation. PATIENTS AND METHODS: 38 consecutive patients (16 male; mean age 32.4±17.6 years; range 6-67 years with unilateral amblyopia were involved in this study. OCT examinations were performed with a time-domain OCT device, and a custom-built OCT image analysis software (OCTRIMA was used for OCT image segmentation. The axial length (AL was measured by a LenStar LS 900 device. Macular layer thickness, AL and manifest spherical equivalent refraction (MRSE of the amblyopic eye were compared to that of the fellow eye. We studied if the type of amblyopia (strabismus without anisometropia, anisometropia without strabismus, strabismus with anisometropia had any influence on macular layer thickness values. RESULTS: There was significant difference between the amblyopic and fellow eyes in MRSE and AL in all subgroups. Comparing the amblyopic and fellow eyes, we found a statistically significant difference only in the thickness of the outer nuclear layer in the central region using linear mixed model analysis keeping AL and age under control (p = 0.032. There was no significant difference in interocular difference in the thickness of any macular layers between the subgroups with one-way between-groups ANCOVA while statistically controlling for interocular difference in AL and age. CONCLUSIONS: According to our results there are subtle changes in amblyopic eyes affecting the outer nuclear layer of the fovea suggesting the possible involvement of the photoreceptors. However, further studies are warranted to support this hypothesis.

  12. 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

  13. Comparison of ultrasound biomicroscopy and CT in diagnosis of anterior segment intraocular foreign body%超声活体显微镜和CT诊断眼前段异物的对比分析

    Institute of Scientific and Technical Information of China (English)

    李舒茵; 史大鹏

    2008-01-01

    Objective To report the appearance of anterior segment intraocular foreign body in ultrasound biomicroscopy(UBM)and CT. To investigate the advantage and disadvantage of these two imaging methods and to evaluate the value of combining application of these methods in the diagnosis of anterior segment intraocular foreign body. Methods It was a comparative study. Forty-four cases of suspected anterior segment intraoeular foreign body were simultaneously examined by UBM and CT from July 2000 to Mav 2007,the results were compared with the operation results.Results In 44 cases examined by CT,foreign bodies in 40 cases showed high density shadows,including iron,copper,stone and other foreign bodies:2 cases showed slightly high density shadow,which were identified as plastics;in 2 cases,the foreign bodies could not be detected by CT,which were bamboo pick and Chinese chestnut sting. It wasdifficuItv to locate the foreign body exactly and to detect the complications of anterior segment intraocular foreign body by using CT.All 44 cases of anterior segment intraocular foreign body showed strong echo spot with acoustic shadow in the UBM.UBM could provide the exact location of foreign body and could detect all complications. But the examining procedure of UBM was complicated,the examining screen was relativelynarrow and the examination was time-consuming. Condusion In suspected anterior segment intraocular foreign body,CT examination should be performed first to detect the position and the nature of foreign body,then UBM could be used to obtain the exact position of foreign body and to detect the complications.(Chin J Ophthalmol,2008,44:229-232)%目的 探讨超声活体显微镜(UBM)和CT两种不同成像方法 对眼前段异物诊断的优缺点及联合应用的价值.方法 为比较研究,收集2000年7月至2007年5月共44例疑诊为眼前段异物的患者同时行UBM和CT检查的资料,并与其手术结果 相对照.结果 CT扫描发现其中40例表现为高密

  14. 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.

  15. Multi-surface and multi-field co-segmentation of 3-D retinal optical coherence tomography.

    Science.gov (United States)

    Bogunovic, Hrvoje; Sonka, Milan; Kwon, Young H; Kemp, Pavlina; Abramoff, Michael D; Wu, Xiaodong

    2014-12-01

    When segmenting intraretinal layers from multiple optical coherence tomography (OCT) images forming a mosaic or a set of repeated scans, it is attractive to exploit the additional information from the overlapping areas rather than discarding it as redundant, especially in low contrast and noisy images. However, it is currently not clear how to effectively combine the multiple information sources available in the areas of overlap. In this paper, we propose a novel graph-theoretic method for multi-surface multi-field co-segmentation of intraretinal layers, assuring consistent segmentation of the fields across the overlapped areas. After 2-D en-face alignment, all the fields are segmented simultaneously, imposing a priori soft interfield-intrasurface constraints for each pair of overlapping fields. The constraints penalize deviations from the expected surface height differences, taken to be the depth-axis shifts that produce the maximum cross-correlation of pairwise-overlapped areas. The method's accuracy and reproducibility are evaluated qualitatively and quantitatively on 212 OCT images (20 nine-field, 32 single-field acquisitions) from 26 patients with glaucoma. Qualitatively, the obtained thickness maps show no stitching artifacts, compared to pronounced stitches when the fields are segmented independently. Quantitatively, two ophthalmologists manually traced four intraretinal layers on 10 patients, and the average error ( 4.58 ±1.46 μm) was comparable to the average difference between the observers ( 5.86±1.72 μm). Furthermore, we show the benefit of the proposed approach in co-segmenting longitudinal scans. As opposed to segmenting layers in each of the fields independently, the proposed co-segmentation method obtains consistent segmentations across the overlapped areas, producing accurate, reproducible, and artifact-free results.

  16. 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).

  17. Lenstar LS900与IOLMaster测量眼前节生物参数及人工晶状体度数的比较%Comparison of anterior segment biometry and intraocular lens power measured by Lenstar LS900 and IOLMaster

    Institute of Scientific and Technical Information of China (English)

    叶向彧; 纪建丽; 张广斌; 王乐; 毛益辉; 何雪洪

    2011-01-01

    目的 精确的眼生物测量对人工晶状体(intraocular lens,IOL)度数计算至关重要,尤其是眼轴及角膜曲率的测量.本研究将对比新一代光学低相干反射生物测量仪Lenstar LS900 (Haag-Streit)与IOLMaster对眼前节参数及IOL测算的差异.方法 应用Lenstar LS900和IOLMaster分别对30例(60眼)老年性白内障患者进行眼轴长度、前房深度、角膜曲率和散光轴方面的测量比较;分别利用2种设备计算IOL度数,均选用SRK/T计算公式和SA60AT(Alcon)IOL,在确定同一度数的前提下比较目标屈光度的差异.结果 Lenstar LS900和IOLMaster测量眼轴长度、前房深度、平均角膜曲率、陡峭轴角膜曲率之间差异均无统计学意义(均为P>0.05),且均具有良好的相关性(相关系数分别为0.999、0.955、0.936、0.845),而两种设备测得陡峭轴之间相关欠佳(r =0.579).Lenstar LS900和IOLMaster所获得的术后目标屈光度值分别为(-0.02±0.17)D和(-0.07±0.23)D,差异无统计学意义(P>0.05).Bland-Altman分析显示,2种设备获得的目标屈光值具有良好的一致性.结论 Lenstar LS900和IOLMaster两种设备测量眼前节参数及IOL度数具有良好的一致性.同时,Lenstar LS900还可以快速、准确的为白内障患者和屈光医师提供更多的眼生物参数.%Objective To compare the difference of anterior segment biometry and intraocular lens (IOL) power measured by a new noncontact optical biometer Lenstar LS9O0 (Haag-Streit) using optical low-coherence reflectometry and IOLMaster. Methods Biometry measurements in 60 eyes of 30 patients scheduled for cataract surgery by the same examiner with Lenstar LS900 and IOLMaster, the axial length (AL) .anterior chamber depth (ACD) and keratometric (K) were compared,IOL power for AcrySof SA60AT( Alcon) measure by two devices using SRK/T formulas was calculated, and the difference of targeted diopter under same IOL power was compared. Results There was no statistical

  18. Bilateral Anterior Ischaemic Optic Neuropathy in a Child on Continuous Peritoneal Dialysis; Case report and literature review

    Directory of Open Access Journals (Sweden)

    Abdullah Al-Kaabi

    2016-11-01

    Full Text Available Non-arteritic anterior ischaemic optic neuropathy (NAION is a serious complication of continuous peritoneal dialysis (CPD which can lead to poor vision and blindness. We report a five-year-old girl who had undergone a bilateral nephrectomy at the age of one year and was on home CPD. She was referred to the Paediatric Ophthalmology Unit of Sultan Qaboos University Hospital, Muscat, Oman, in 2013 with acute bilateral vision loss, preceded by a three-day history of poor oral intake. At presentation, the patient had severe systemic hypotension. An ophthalmological examination revealed severe bilateral visual impairment and NAION. She was treated with intravenous methylprednisolone and normal saline boluses. At a five-month follow-up, the visual acuity of the right eye had improved but vision in the left eye remained the same. Acute bilateral blindness due to NAION while on CPD is a rare condition in childhood. Paediatricians should be aware of this complication in order to ensure prompt management.

  19. Intra-retinal layer segmentation of 3D optical coherence tomography using coarse grained diffusion map.

    Science.gov (United States)

    Kafieh, Raheleh; Rabbani, Hossein; Abramoff, Michael D; Sonka, Milan

    2013-12-01

    Optical coherence tomography (OCT) is a powerful and noninvasive method for retinal imaging. In this paper, we introduce a fast segmentation method based on a new variant of spectral graph theory named diffusion maps. The research is performed on spectral domain (SD) OCT images depicting macular and optic nerve head appearance. The presented approach does not require edge-based image information in localizing most of boundaries and relies on regional image texture. Consequently, the proposed method demonstrates robustness in situations of low image contrast or poor layer-to-layer image gradients. Diffusion mapping applied to 2D and 3D OCT datasets is composed of two steps, one for partitioning the data into important and less important sections, and another one for localization of internal layers. In the first step, the pixels/voxels are grouped in rectangular/cubic sets to form a graph node. The weights of the graph are calculated based on geometric distances between pixels/voxels and differences of their mean intensity. The first diffusion map clusters the data into three parts, the second of which is the area of interest. The other two sections are eliminated from the remaining calculations. In the second step, the remaining area is subjected to another diffusion map assessment and the internal layers are localized based on their textural similarities. The proposed method was tested on 23 datasets from two patient groups (glaucoma and normals). The mean unsigned border positioning errors (mean ± SD) was 8.52 ± 3.13 and 7.56 ± 2.95 μm for the 2D and 3D methods, respectively.

  20. 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.

  1. 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

  2. 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.

  3. Methodology for fully automated segmentation and plaque characterization in intracoronary optical coherence tomography images.

    Science.gov (United States)

    Athanasiou, Lambros S; Bourantas, Christos V; Rigas, George; Sakellarios, Antonis I; Exarchos, Themis P; Siogkas, Panagiotis K; Ricciardi, Andrea; Naka, Katerina K; Papafaklis, Michail I; Michalis, Lampros K; Prati, Francesco; Fotiadis, Dimitrios I

    2014-02-01

    Optical coherence tomography (OCT) is a light-based intracoronary imaging modality that provides high-resolution cross-sectional images of the luminal and plaque morphology. Currently, the segmentation of OCT images and identification of the composition of plaque are mainly performed manually by expert observers. However, this process is laborious and time consuming and its accuracy relies on the expertise of the observer. To address these limitations, we present a methodology that is able to process the OCT data in a fully automated fashion. The proposed methodology is able to detect the lumen borders in the OCT frames, identify the plaque region, and detect four tissue types: calcium (CA), lipid tissue (LT), fibrous tissue (FT), and mixed tissue (MT). The efficiency of the developed methodology was evaluated using annotations from 27 OCT pullbacks acquired from 22 patients. High Pearson's correlation coefficients were obtained between the output of the developed methodology and the manual annotations (from 0.96 to 0.99), while no significant bias with good limits of agreement was shown in the Bland-Altman analysis. The overlapping areas ratio between experts' annotations and methodology in detecting CA, LT, FT, and MT was 0.81, 0.71, 0.87, and 0.81, respectively.

  4. 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

  5. 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.

  6. Robust automatic segmentation of corneal layer boundaries in SDOCT images using graph theory and dynamic programming.

    Science.gov (United States)

    Larocca, Francesco; Chiu, Stephanie J; McNabb, Ryan P; Kuo, Anthony N; Izatt, Joseph A; Farsiu, Sina

    2011-06-01

    Segmentation of anatomical structures in corneal images is crucial for the diagnosis and study of anterior segment diseases. However, manual segmentation is a time-consuming and subjective process. This paper presents an automatic approach for segmenting corneal layer boundaries in Spectral Domain Optical Coherence Tomography images using graph theory and dynamic programming. Our approach is robust to the low-SNR and different artifact types that can appear in clinical corneal images. We show that our method segments three corneal layer boundaries in normal adult eyes more accurately compared to an expert grader than a second grader-even in the presence of significant imaging outliers.

  7. 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。

  8. Combined anterior and posterior segment surgery in the treatment of penetrating eye injuries with small intraocular foreign body%眼球穿孔伤并眼内小异物眼前后段联合手术

    Institute of Scientific and Technical Information of China (English)

    石芊; 彭秀军; 刘百臣; 王桂琴

    2015-01-01

    目的:探讨眼球穿孔伤并眼内小异物早期行眼前后段联合手术治疗的临床效果。方法22例(22眼)眼球穿孔伤并眼内小异物,清创缝合术后2~4 d行前后段联合手术,根据病情,选择不同术式。前段手术:前房成形、虹膜裂伤缝合、白内障摘出、人工晶状体植入;后段手术:玻璃体切除术、异物摘出、视网膜损伤部位周围激光光凝、玻璃体腔C3 F8气体或硅油填充。术后随访3~12个月。其中硅油填充眼于术后4~5个月取出硅油,观察手术效果及并发症。结果所有患者均一次手术摘出了眼内异物,一期植入人工晶状体,未发生感染性眼内炎、人工晶状体移位、葡萄膜炎、视网膜脱离、脉络膜脱离或继发性青光眼等并发症。手术前最佳矫正视力为光感~0.1,术后随访最佳矫正视力为0.05~0.8,全组22眼视力均有不同程度提高。结论眼球穿孔伤并眼内小异物早期行眼前后段联合手术治疗可取得良好的临床效果。%Objective To investigate the clinical efficacy of combined anterior and posterior segment surgery in early treatment of penetrating eye injuries with small intraocular foreign body. Methods Twenty-two eyes of 22 patients suffered penetrating eye injuries with small intraocular foreign bodies underwent the combined operations of anterior and posterior eye segment 2-4 days after emergent debridement and suturing and according to their conditions different surgical procedures were preformed. Anterior segment surgery included anterior chamber forming, iris suture laceration, cataract extraction and intraocular lens implantation and posterior segment surgery included vitrectomy, foreign body removal, retinal laser photocoagulation around the injury site and C3 F8 gas or silicone oil tamponade. The surgery efficacy and the complications were analyzed from 3months to 12 months. Silicone oil was removed 4-5month after operation. Results Intraocular foreign

  9. En face optical coherence tomography of transient light response at photoreceptor outer segments in living frog eyecup.

    Science.gov (United States)

    Wang, Benquan; Lu, Rongwen; Zhang, Qiuxiang; Jiang, Yuqiang; Yao, Xincheng

    2013-11-15

    This study was designed to test the feasibility of en face mapping of the transient intrinsic optical signal (IOS) response at photoreceptor outer segments and to assess the effect of spatial resolution on functional IOS imaging of retinal photoreceptors. A line-scan optical coherence tomography (LS-OCT) was constructed to achieve depth-resolved functional IOS imaging of living frog eyecups. Rapid en face OCT revealed transient IOS almost immediately (IOS kinetics may reflect dynamics of G-protein binding and releasing in early phases of visual transduction, and high resolution is essential to differentiate positive and negative IOS changes in adjacent locations.

  10. 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.

  11. 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).

  12. Activities at Los Alamos for the optical model segment of the RIPL CRP

    Energy Technology Data Exchange (ETDEWEB)

    Young, P.G.

    1997-05-10

    This report discusses activity at Los Alamos on the nuclear optical model. In particular, the following topics are discussed: format of the optical model parameter library; contents of the library; validation of the optical model library; and conclusions and recommendations.

  13. Subluxed traumatic cataract: optical coherence tomography findings and clinical management

    Directory of Open Access Journals (Sweden)

    Kuriyan AE

    2012-12-01

    Full Text Available Ajay E Kuriyan, Harry W Flynn Jr, Sonia H YooDepartment of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, FLAbstract: This case report describes the optical coherence tomography (OCT findings and clinical management of a patient with traumatic subluxed cataract. The patient presented with a traumatic subluxed cataract and vitreous prolapse into the anterior chamber. The anterior segment OCT showed vacuoles in the anterior subcapsular regions of the crystalline lens. The patient was treated with pars plana lensectomy, vitrectomy, and placement of an anterior chamber intraocular lens. The patient's best corrected visual acuity improved from hand motion at presentation to 20/25 during 3 years of follow-up. Anterior segment OCT demonstrates that the clinically visible vacuoles in traumatic cataract are located in the anterior subcapsular part of the lens. This is the first report in the literature using anterior segment OCT to visualize the subcapsular vacuolar changes in a traumatic cataract.Keywords: traumatic cataract, subluxed lens, vacuoles, anterior chamber intraocular lens, anterior segment optical coherence tomography

  14. Fenestration of the anterior cerebral artery

    Energy Technology Data Exchange (ETDEWEB)

    Ito, J.; Washiyama, K.; Hong, K.C.; Ibuchi, Y.

    1981-08-01

    Three cases of angiographically demonstrated fenestration of the anterior cerebral artery are reported. Fenestration occurred at the medial half of the horizontal segment of the anterior cerebral artery in all cases. Its embryology and clinical significance are briefly discussed, and the anatomical and radiological literature on fenestration of the anterior cerebral artery is reviewed.

  15. The application of AS-OCT in the quantification study of anterior segment changes in patients with early stage PACG following LPI%原发性闭角型青光眼早期干预后眼前段结构改变定量研究

    Institute of Scientific and Technical Information of China (English)

    方敏; 葛坚; 王梅; 林明楷; 卓业鸿; 凌运兰; 张秀兰; 蔡小于; 金陈进

    2009-01-01

    目的 应用光学成像系统一前段OCT(Anterior Segment Optical Coherence Tomographv.AS-OCT)量化评价原发性闭角犁青光眼患者(Primary Angle Closure Glaucoma,PACG)早期干预后眼前段结构的改变.方法 对确诊的早期PACG患者36例(60只眼)予以激光周边虹膜切开术(Laser Peripheral Iri-dotomy,LPI)进行早期干预;采用AS-OCT量化评价干预后眼前段结构的改变.对视力、眼压、房角开放情况及眼前段结构包括AOD500(巩膜突前500μm的房角开放距离)、前房轴深、晶状体厚度等进行观察,随访时间3个月.结果 术后视力无明显变化,术后眼压较术前下降,差异有统计学意义(t=3.506,P<0.01).术后房角增宽,AOD500增加,差异有统计学意义(t=-8.34,P<0.01),术后前房轴深加深,差异有统计学意义,(t-2.909,P<0.01),术后晶状体厚度增加,差异有统计学意义(t-3.701,P<0.01 o结论AS-OCT的精确定量能够发现LPI术后眼前段结构的细微改变,是研究原发性闭角型青光眼早期于预的有力辅助工具.%Objeetive To quantify the clinical features and the anatomical changes following laser pe-ripheral iridotomy(LPI)in early stage PACG with AS-OCT.Methods 36 early stage PACG patients(60 eyes) were evaluated using gonioscopy and AS-OCT.Anterior segment configuration including angle opening dis-tance at 500 micron anterior to the scleral spur, AOD500,anterior chamber depth,ACD,lens thickness, LT were determined.The following-up was 3 months.Results After LPI, visual acuity changed little after LPI, in-traocular pressure reduced(t =3.506, P <0.01 ), AODS00 became wider(t =-8.34, P <0.01 ), ACD deepened(t =-2.909,P <0.01 )and the lens became thicker(t =-3.701 ,P <0.01 ).Conclusions AS-OCT can make precise quantifying discriminations in the anterior segment changes in early stage PACG patients following LPI, AS-OCT can be a useful high quality instrument in PACG study.

  16. 抗VEGF药物在眼前节疾病围手术期研究及应用%Anti VEGF drugs for Eye anterior segment disease in perioperative research and application

    Institute of Scientific and Technical Information of China (English)

    郭红林

    2015-01-01

    Objective: To investigate the effect of anti VEGF drugs in the perioperative period of the patients with anterior segment disease.Methods: According to different treatment methods, 90 patients with anterior segment disease were divided into observation group and control group (45 cases). The patients in the two groups were treated by operation, and the observation group was treated with anti VEGF drugs, and the clinical efficacy of the two groups were compared.Results: After treatment, the two groups of IOP were significantly lower than before treatment, and the observation group after treatment, 30d, 90d, 7d were significantly lower than the control group,P<0.05. The effective rate of the observation group was 98%, significantly higher than the control group of 88.46%, P<0.05.Conclusion: The use of anti VEGF drugs in the treatment of patients with anterior segment disease can effectively inhibit the generation and proliferation of new blood vessels in the retina and iris.%目的:探讨抗VEGF药物在眼前节疾病围术期中的应用效果。方法根据治疗方法的不同,将90例眼前节疾病患者分为观察组和对照组(每组45例),两组患者均行手术治疗,观察组在此基础上加用抗VEGF药物,比较两组患者的临床疗效。结果治疗后,两组的眼压水平均较治疗前显著降低,且观察组治疗后7d、30d、90d的眼压水平均显著低于对照组,P<0.05。观察组治疗有效率为98.0%,显著高于对照组的88.46%,P<0.05。结论对行手术治疗的眼前节疾病患者应用抗VEGF药物,能够有效抑制视网膜及虹膜上新生血管的生成与增殖,提高手术疗效。

  17. 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.

  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. 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

  20. Improving the segmentation for weed recognition applications based on standard RGB cameras using optical filters

    DEFF Research Database (Denmark)

    Stigaard Laursen, Morten; Jørgensen, Rasmus Nyholm; Midtiby, Henrik

    diseases, weeds and fungus. A common method for interpretation is based on the leaf shape. However in order to reliably achieve a good description of the shape a good segmentation is required. The excess green index is one of the most common methods for green vegetation segmentation within agriculture....... This method utilizes that most vegetation reflects more green light than blue and red. As silicon based image sensors is also sensitive to near-infrared light a typical rgb-camera will have a filter in place to block the near-infrared light. When using excess green the ideal filter would be a sinc...... for green vegetation segmentation we are able to attain a significantly improved segmentation under controlled illumination....

  1. The preliminary research of normal structure of ocular anterior segment with 20.0 MHz ultrasound%20.0 MHz超声对正常活体眼前节结构检测的初步研究

    Institute of Scientific and Technical Information of China (English)

    陈琴; 刘薇; 成仲夏

    2000-01-01

    目的 探讨高频超声对眼前节结构的检测价值,为进一步研究眼前节组织疾病奠定基础.方法 用20.0 MHz高频探头对30例正常人眼的眼前节结构进行测量.结果 20.0 MHz高频超声能清楚地观察角膜、虹膜、晶状体、睫状体、前房等结构.角膜呈一条弧形的高回声,中央厚度为(O·383±O.031)mm:前房为无回声,前房深度为(2.241±0.256)mm;虹膜呈短条状高回声,厚度为(O.419±O.044)mm;晶状体前囊膜呈弧形高回声,晶状体内部为无回声,晶状体厚度为(3.533±0.185)mm;睫状体为类似三角形的中高回声,最厚处厚度为(1.131±0.094)mm.结论 20.0 MHz高频超声可无创性、清晰地观察正常眼的眼前节结构,对青光眼、角膜、巩膜、虹膜、晶状体、睫状体疾病的诊断有较大价值.%Objective To investigate the normal structure of ocular anterior segment with 20.0MHz ultrasound.Methods The structres of ocular anterior segment in thirty normal humen were measured with 20.0MHz high frequency ultrasound probe.Results The conea,iris,lens,ciliary body, and the anterior chambet was clearly viewed and measured with 20.0 MHz high frequency ultrasound.An intense curving echo was seen in the conea, which central thickness was(0.383±0.031)mm. No echo was seen in the anterior chamber, which death was(2.241±0.256)mm.A short strip echo was seen in the iris, which thickness was(0.419±O.044) mm.The intense curving echo was seen in the whole lens.No echo was seen in the interior part of the lens. The thickness of the 1ens was(3.533±0.185)mm. A medium triangularlike echo was seen in the ciliary body. The most thickest pan was(1.131±0.094)mm. Conclusions The normal structure of ocular anterior segment can be clearly Observed by 20.0 MHz high frequency ultrasound without injury.The method is very valuable in the diagnosis of diseases ocular diseases, such as glaucoma, conea, sclera, iris, lense and the ciliary body.

  2. 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...

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

    Science.gov (United States)

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

    2010-01-01

    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.

  4. 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.

  5. 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

  6. Co-phasing primary mirror segments of an optical space telescope using a long stroke Zernike WFS

    Science.gov (United States)

    Jackson, Kate; Wallace, J. K.; Pellegrino, Sergio

    2016-07-01

    Static Zernike phase-contrast plates have been used extensively in microscopy for half a century and, more recently, in optical telescopes for wavefront sensing. A dynamic Zernike wavefront sensor (WFS) with four phase shifts, for reducing error due to spurious light and eliminating other asynchronous noise, has been proposed for use in adaptive optics. Here, we propose adapting this method for co-phasing the primary mirror of a segmented space telescope. In order to extend the dynamic range of the WFS, which has a maximum range of +/ - λ/2, a phase- contrast plate with multiple steps, both positive and negative, has been developed such that errors as large as +/ - 10λ can be sensed. The manufacturing tolerances have been incorporated into simulations, which demonstrate that performance impacts are minimal. We show that the addition of this small optical plate along with a high precision linear translation stage at the prime focus of a telescope and pupil viewing capability can provide extremely accurate segment phasing with a simple white-light fringe fitting algorithm and a closed-loop controller. The original focal-plane geometry of a centro-symmetric phase shifting element is replaced with a much less constrained shape, such as a slot. Also, a dedicated pupil imager is not strictly required; an existing pupil sampler such as a Shack-Hartmann (SH) WFS can be used just as effectively, allowing simultaneous detection of wavefront errors using both intensity and spot positions on the SH-WFS. This could lead to an efficient synergy between Zernike and SH-WFS, enabling segment phasing in conjunction with high-dynamic range sensing.

  7. 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

  8. 大脑前动脉A1段形态学特点与前交通动脉瘤的关系%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; 张龙; 李伟光; 张国忠; 何小艳; 王刚; 李明洲; 漆松涛

    2012-01-01

    Objective To improve the predictability of surgical clipping and guide the steam shaping of mi-crocatheters in endovascular embolization by analyzing the association of morphological features of A1 segment of anterior cerebral artery (ACA) with formation and classification of anterior communicating artery aneurysms (ACoAA). Methods Digital subtraction angiography data of 264 cases of ACoAA and 296 cases of other cerebral vascular diseases were analyzed retrospectively. The morphology of A1 segment of ACA was divided into four different patterns including "arc" pattern (type Ⅰ a; convex shape, type Ⅰ b: concave shape), "S" pattern (type Ⅱ a: inverse lateral "s" shape, type Ⅱ b: lateral "s" shape), approximate straight-line shape (type Ⅲ ) and non-development. According to the direction of aneurysm protrusion, the ACoAA were divided into 5 types including anterior-inferior type, anterior-superior type, posterior-superior type, posterior-inferior type and complicated type. Results Among 264 ACoAA patients, the morphology of A1 segment of ACA was type I a in 158 sides, type Ⅰ b in 11, type Ⅱ a in 35, type lib in 87, type Ⅲ in 171 and absence in 66. The morphology of A1 segment of ACA in 296 patients with other cerebral vascular diseases was type Ⅰ a in 195 sides, type Ⅰ b in 20, type Ⅱ a in 47, type Ⅱ b in 74, type Ⅲ in 217 and absence in 39. The no-visualization of Al segment of ACA occurred was more frequent in the ACoAA group than in control group (x2 = 11.482, P = 0.001). The direction of ACoAA in 264 patients were anterior-superior type in 121 cases, anterior-inferior type in 105, complicated type in 16, posterior-inferior type in 12 and posterior-superior type in 10. The correlation between the morphology of dominant A1 segment of ACA and direction of ACoAA was significant x2 = 221.859, P = 0.000; C - 0.619, P = 0.000). The direction of ACoAA was downward at the type Ⅰ a/ type Ⅱ a, upward at type Ⅰ b/ type Ⅱ b, upward or downward

  9. 高速枪击伤后兔眼前节组织结构改变%Morpholoigical changes in the anterior segment of rabbits' eyes injured by high-speed bullets

    Institute of Scientific and Technical Information of China (English)

    聂闯; 陈穗桦; 李俊杰; 杨丽萍

    2011-01-01

    目的 研究眼钝挫伤的损伤机制的实验动物模中多以重力为主要致伤因素,文中以高速枪弹击伤制作兔眼眼前节动物损伤模型,探讨高速枪弹钝挫伤损伤机制. 方法 实验组12只新西兰兔用汽步枪以90m/s的速度射发TB弹(平均质量0.20122g)击中左眼角膜中央区,对照组2只新西兰兔不致伤(单眼处理).裂隙灯下观察伤后3h、6h、1d、3d、7d、14d6个时相点眼前节组织的病理改变. 结果 致伤后球结膜水肿逐渐加重,第3天开始缓解;角膜损伤严重,雾状混浊2周后才稍有好转,同时,周边可见大量新生血管长入;前房可见大量新鲜出血,实验结束时仍未吸收;瞳孔呈外伤性散大,10只实验兔眼出现不可逆的瞳孔变形;晶体浑浊. 结论 高速枪弹钝挫伤可对眼前节造成严重的损伤.%Objective Most researchers study the mechanism of contusion injury by building animal trial models, particularly the gravity-injury animal model. Clinical samples show that the gravity of projection is not the most critical factor of injury. Thus, we built an animal model of high-speed bullet injury in rabbits to observe the damage and changes in the anterior segment and investigate the mechanism of high-speed contusion injury. Methods A total of 14 eyes of 14 healthy New Zealand rabbits weighing 2.0 - 3.0 kg were included in this study. Contusion injury was inflicted upon 12 left eyes of the rabbits with plastic bullets (mean weight 0.20122 g) from an air rifle at a speed of 90 m/s. The other 2 of the control group were not injured and received unilateral treatment. Pathological changes in the anterior segment were observed under the slit-lamp at 3h,6h, 1 d, 3 d, 7 d, and 14 d after the injury. Results Gradual deterioration of bulbar conjunctiva edema was observed after the injury, and alleviation began at 3 d. The corneal was damaged seriously and improved slightly only at 14 d, with obvious peripheral neovascularization

  10. 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.

  11. Ultrasound biomicroscopy in the comparison of the anterior segment morphometry before and after pars plana vitrectomy Biomicroscopia ultra-sônica na comparação da morfometria do segmento anterior antes e após vitrectomia "pars plana"

    Directory of Open Access Journals (Sweden)

    Flavio de Andrade Marigo

    2006-12-01

    Full Text Available PURPOSE: To determine if pars plana vitrectomy induces long-term changes in the anterior segment anatomy by means of ultrasound biomicroscopy. METHODS: A prospective case series study was undertaken of consecutive patients referred to a tertiary eye care centre for pars plana vitrectomy as the only procedure. Twenty eyes of 20 patients undergoing pars plana vitrectomy alone were studied by ultrasound biomicroscopy. Silicone oil or scleral buckle was not used in any of the included cases. The following morphometric parameters were compared before and after 3 months of surgery: anterior chamber depth, angle-opening distance at 500 µm from the scleral spur, trabecular-ciliary process distance, ciliary body thickness at 1, 2 and 3 millimeters from the scleral spur and measurement of the supraciliary space thickness, when fluid was detected. RESULTS: No statistically significant differences were found between the preoperative and the postoperative morphometric parameters. CONCLUSION: Uncomplicated pars plana vitrectomy does not induce any long-term change on anterior segment morphometry. Based on these findings, the normal long-term pattern to be expected after pars plana vitrectomy is the conservation of the preoperative morphometry.OBJETIVOS: O objetivo do presente estudo foi determinar, por meio da biometria ultra-sônica (UBM, se a vitrectomia via "pars plana" pode induzir alterações permanentes na anatomia do segmento anterior. MÉTODOS: Foi realizado estudo prospectivo, analisando-se uma série consecutiva de pacientes, encaminhados para um centro de referência terciário para serem submetidos a vitrectomia via "pars plana" como único procedimento. Vinte olhos de 20 pacientes a serem submetidos a vitrectomia como único procedimento foram estudados pela biomicroscopia ultra-sônica. Óleo de silicone ou introflexão escleral não foram usados em nenhum dos casos incluídos. Os seguintes parâmetros morfométricos foram comparados antes e

  12. 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.

  13. The clinical practice of pars plana anterior vitreous aspiration in sundenly positive vitreous pressure during intraocular operation of ocular anterior segment%经睫状体平坦部穿刺抽吸玻璃体液在眼前节内眼术中突发玻璃体正性压力下应用

    Institute of Scientific and Technical Information of China (English)

    李兴育; 马千丽; 杨新光; 张璐; 陈曦

    2013-01-01

    Objective To summary the clinical practice experience of pars plana anterior vitreous aspiration during intraocular operation of ocular anterior segment,to give suggestion to ophthalmologist in front of positive vitreous pressure.Methods A retrospective clinical study.The data of 24 patients (25 cases) who received pars plana anterior vitreous aspiration during intraocular operation of ocular anterior segment from December 2010 to March 2012 in Xi' an NO.4 hospital were collected.One of them had this practice in two time operations.Analysis the patients' sex,average age,preoperative diagnosis,operation mode,preoperative and postoperative intraocular pressure,puncture time,puncture related complications.Results The ratio of male and female was 1:2; average age was 60.0±10.4; in all cases,the first diagnosis was glaucoma in 21 cases,4 cases was cataract;the operation mode included:14 cases with glaucoma surgery,3 cases underwent phacoemulsification,4 cases underwent phacoemulsification combined with anterior vitrectomy,1 case underwent phacoemulsification combined with pars plana vitretomy,3 cases underwent anti-glaucoma and phacoemulsification combined with anterior vitrectomy; the average intraocular pressure of those cases with maximum drugs was 32.50±13.41mmHg,average intraocular pressure was 21.95±10.69 mmHg within the first day of postoperative; par plana anterior vitreous aspiration was likely to practice in any operation steps; two cases had complication,one was little vitreous hemorrhage,one was posterior capsular rupture.Conclusions Positive vitreous pressure is an occasionally thorny issue during intraocular operation in ocular anterior segment.Pars plana anterior vitreous aspiration can be quickly relieved clinical symptoms,make operation turn the comer.The clinical practice have some risk,ophthalmic should pay attention to operation and reduce complications.%目的 研究总结经睫状体平坦部穿刺抽吸玻璃体液在眼前节内眼手术中

  14. 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.

  15. 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

  16. 青光眼暗室激发试验的眼前节相关因素分析%The correlative factors of darkroom provocative test in anterior segment parameters

    Institute of Scientific and Technical Information of China (English)

    王忠浩; 李媚; 蔡小于; 梁轩伟; 刘杏

    2013-01-01

    目的 分析房角狭窄患者暗室激发试验阳性者的相关眼前节结构参数.方法 回顾性系列病例研究.分析260例房角狭窄患者的暗室试验结果和超声生物显微镜(UBM)眼前节结构参数.其中男性36例,女性224例,平均年龄(59.6±9.3)岁.眼前节结构参数包括前房深度(ACD)、瞳孔直径(PD)、晶状体矢高(LV)、周边虹膜厚度(IT)、虹膜膨隆度(IC)、房角开放距离(AOD)、小梁网睫状突夹角(TCPA)及房角接触性关闭的象限数(NPAC).用单因素和多因素Logistic回归分析青光眼暗室激发试验阳性的相关因素.结果 260例房角狭窄者青光眼暗室激发试验的阳性率为27.3% (71/206),男性阳性率(41.7%,15/36)大于女性(25.0%,56/224),差异有统计学意义(x2=4.340,P=0.037).单因素分析表明,男性(OR =2.14)、AOD(OR=0.98)、IT(OR=1.68)、NPAC(OR=2.24)是暗室试验阳性的相关因素;多因素Logistic回归分析表明,IT(OR=1.47)、NPAC(OR=1.70)是暗室试验阳性的独立相关因素.结论 房角和虹膜参数与房角狭窄者的青光眼暗室激发试验阳性结果相关,IT和NPAC是暗室激发试验阳性的独立相关因素.%Objective To investigate the correlative anterior segment parameters of positive darkroom provocative test in patients with narrow anterior chamber angles.Methods It was a retrospective case series study.Two hundred and sixty patients [36 males and 224 females,mean age (59.6 ± 9.3) years] with narrow anterior chamber angles underwent darkroom provocative test and UBM scan were analyzed retrospectively.Anterior segment parameters including anterior chamber depth (ACD),pupil diameter (PD),lens vault (LV),peripheral iris thickness (IT),iris convex (IC),anterior chamber angle open distance (AOD),trabecular-meshwork ciliary process angle (TCPA) and the number of appositional angle closure (NPAC) were quantitatively analyzed.Correlative factors of positive results were analysis by both single factor and multiple

  17. 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....

  18. 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.

  19. 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

  20. 20G 23G玻璃体切除术后眼前节形态学变化临床研究%Morphologic changes in the anterior segment after 20-, 23-G pars plana vitrectomy

    Institute of Scientific and Technical Information of China (English)

    禹海; 王颖; 李鹤一; 曹蕾; 张沈夏; 高明宏

    2015-01-01

    Objective To evaluate morphologic changes in anterior segment and the influencing factors for the changes after 20-, 23-G pars plana vitrectomy (PPV) by Ultrasound biomicroscope (UBM).Methods One hundred and thirty-one patients (133 eyes) who underwent primary PPV and 3 months follow-up after surgery in our hospital from January 2013 to February 2014 were enrolled in this prospective study.The patients were divided in 20-G group and 23-G group.UBM was applied to determine the tomographic features of anterior segment before and 1 week and 3 months after the surgery.The pre-and postoperative intraocular pressure (IOP), anterior chamber depth (ACD),parameters of anterior chamber angle, iris and ciliary body in 2 groups were assessed.Results The morphologic changes in anterior segment after surgery included: (1) ciliary body detachment (CBD) (2) anterior chamber angle closure (3) vitreous incarceration (4) anterior hyaloids proliferation (5) ciliary body atrophy.Forty-six of 86 eyes in 20G group presented morphologic changes after surgery compared with 22 of 47 eyes in 23G group.Vitreous incarceration was significantly higher in 23Ggroup (P =0.003).The proportion of CBD in 23G group was also higher than that in 20G, but there are no statistical significance within two groups (P =0.062).The other morphologic changes between 2 group were not statistical difference (P =0.098, 0.172, 1.000).The postoperative ACD of 20G group were deeper than that of 23G group, but the statistical difference were not significant (P =0.162, 0.301).The postoperative IOP of 20G group were significantly higher than that of 23G group in lweek (P =0.05) and sustained higher till 3 months after surgery.The incidence of CBD was significant difference among different diseases (P =0.041), CBD most frequently occurred in eyes of patients with proliferation diabetic retinopathy (PDR) or retinal vascular obstructive diseases (RVO).PDR was an influencing factor for postoperative CBD (Spearman analysis, r

  1. 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.

  2. 改进的上颌前部骨切开术矫治上颌前突及其术后的美学评价%Esthetic evaluation after modified anterior segmental osteotomy on maxillary protrusion

    Institute of Scientific and Technical Information of China (English)

    吴中兴; 李祖兵; 东耀峻; 叶翁三杰; 杨学文; 李智

    2009-01-01

    Objective The main goals of orthognathic surgery are to achieve funetional occlusion and improve patient's profile.The unintended nasal change in association with anterior maxillary osteotomy is always a challenging.The purpose of this study was to improve the anterior maxillary segmental osteotomy resulting in less post-operative unintended nasal change.Methods Thirty-two patients with maxillary protrusion underwent modified anterior subapical maxillary osteotomy.The design of the modified approach was based on the anterior mandibular subapical osteotomy.The horizontal osteotomy connecting the vertical osteotomy lines on both right and left sides was performed inferior to the piriform aperture and 3 mm over the apex.The integrity of piriform aperture was maximally preserved.Lateral cephalograms,lateral and frontal photographs taken pre-and post-operatively were analyzed.All the patients were followed up for at least 6 months.Results All thirty-two patients were satisfied with esthetic outcome.The upper lip protrusions and tooth exposure improved significantly.Cephalometric and photograph analysis showed that the ratio of upper lip to maxillary ineisor retractionwas 0.64:1.00,and the nasolabial angle and philtrum length were significantly increased(P<0.05)while vermilion length was decreased.The height of nasal tip and nasal width(alarbase to alarbase)were not significantly changed.Conclusion The modified anterior subapical maxillary osteotomy is a simple procedure leading to no significant postoperative nasal change.It provides a promising alternative in the treatment of maxillary protrusion.%目的 探讨矫治上颌前突的改进术式,以避免传统术式往往发生的继发鼻部形态改变,并可保证美容效果.方法 改进方式是根据下颌前部根尖下骨切开术的原则,在梨状孔下缘下方的前颌骨面、沿各上前牙根尖上3 mm做切骨标志点,将其相连即水平骨切开线,线两端与左右垂直骨切开线相连,呈"

  3. Wavefront alignment research of segmented mirror synthetic aperture optical (SAO) system

    Science.gov (United States)

    Deng, Jian; An, Xiaoqiang; Tian, Hao

    2010-05-01

    Wavefront control technology and imaging experiment are introduced for a segmented mirror SAO system with deformable sub-mirrors. This system is a RC style with 300mm aperture, 4.5 F#, +/-0.4°FOV, 0.45~0.75μm wave band, and diffraction-limit design MTF. The primary mirror is composed by three sub-mirrors, with parabolic shape, and each deformable sub-mirror has 19 actuators to control and keep the surface shape, and 5 actuators to align sub-mirrors location in 5 degree of freedom. Interferometer is used to feed back and control exit wavefront error, and base on measurement and finite element analysis, location and quanitity of actuators are optimized, making the surface shape and misadjustment errors interact and compensate each other, and the synthetic system exit pupil wavefront error is controlled. The integrated exit pupil wavefront errors are gotten by ZYGO interferometer, and central FOV is 0.077λRMS, and edge FOV is 0.093λRMS. At the end, an imaging experiment is executed, and good results are obtained, which proves, the deformable sub-mirrors have the ability to meliorate alignment and the latter can retroact the former, and this relationship iterate make system exit pupil wavefront error convergence and improve segmented mirror SAO system imaging ability.

  4. 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

  5. In vivo application of an optical segment tracking approach for bone loading regimes recording in humans: a reliability study.

    Science.gov (United States)

    Yang, Peng-Fei; Sanno, Maximilian; Ganse, Bergita; Koy, Timmo; Brüggemann, Gert-Peter; Müller, Lars Peter; Rittweger, Jörn

    2014-08-01

    This paper demonstrates an optical segment tracking (OST) approach for assessing the in vivo bone loading regimes in humans. The relative movement between retro-reflective marker clusters affixed to the tibia cortex by bone screws was tracked and expressed as tibia loading regimes in terms of segment deformation. Stable in vivo fixation of bone screws was tested by assessing the resonance frequency of the screw-marker structure and the relative marker position changes after hopping and jumping. Tibia deformation was recorded during squatting exercises to demonstrate the reliability of the OST approach. Results indicated that the resonance frequencies remain unchanged prior to and after all exercises. The changes of Cardan angle between marker clusters induced by the exercises were rather minor, maximally 0.06°. The reproducibility of the deformation angles during squatting remained small (0.04°/m-0.65°/m). Most importantly, all surgical and testing procedures were well tolerated. The OST method promises to bring more insights of the mechanical loading acting on bone than in the past.

  6. 超声乳化白内障吸出术对急性原发性闭角型青光眼眼前段的影响%Effects of anterior segment after phacoemulsification in patients with acute primary angle closure glaucoma

    Institute of Scientific and Technical Information of China (English)

    李乃洋; 赵岐; 钟兴武

    2011-01-01

    目的 使用Pentacam三维前房分析仪和眼前段光学相干断层扫描仪(AS-OCT)观察超声乳化白内障吸出术对急性原发性闭角型青光眼(APACG)患者眼前段的影响.方法 收集2010年7月至12月于中山大学附属中山医院眼科就诊的伴有白内障APACG的病例共39例(39眼).常规行超声乳化白内障吸出联合人工晶体(IOL)植入术.术前和术后3个月使用Pentacam和AS-OCT测量眼前段参数.结果 术后3个月,APACG患者眼压由术前(33.08±5.21)mm Hg降至(16.36±3.44)mm Hg(1mm Hg=0.133 kPa,t=20.644,P=0.000),中央前房深度由(1.79±0.20)mm增至(3.41±0.38) mm (t=36.191,P=0.000),周边前房深度由(0.82±0.12) mm加深至(1.81 ±0.20) mm (t=40.732,P=0.000),前房容积自(74.10±9.94) mm增加至(149.72± 17.12) mm (t=54.921,P=0.000),下方前房角自(24.03±3.50).加宽至( 43.29±3.92).(t=55.489,P=0.000),鼻侧前房角自(23.02±2.96)°加宽至(42.36±4.61).(t=43.291,P=0.000),上方前房角自(21.62±3.04).加宽至(39.66±3.53).( t=43.511,P=0.000),颞侧前房角自(22.88±2.87).加宽至(41.21±3.81).(t=44.930,P=0.000).瞳孔直径由术前(3.06±1.32)mm缩小至术后的(3.00±1.21)mm,但差异无统计学意义(t=1.177,P=0.247).结论 超声乳化白内障吸出术可改善APACG患者眼前段结构的狭窄.Pentacam和AS-OCT可简便快捷和非接触地观察眼前段,有良好的应用前景.%Objective To investigate the morphological changes of anterior segment in patients with acute primary angle closure glaucoma (APACG) after phacoemulsification using the Pentacam three-dimension anterior chamber analysis system and anterior segment optical coherence tomography (AS-OCT).Methods Thirty- nine APACG patients (39 eyes) accompanied with cataract were treated with phacoemulsification from July 2010 to December 2010 in Zhongshan Hospital.All the patients were examined by Pentacam and AS-OCT preoperation and 3 months postoperation.Outcomes included intraocular pressure (IOP

  7. 飞秒激光制瓣LASIK术后眼前节参数的变化%Changes of the parameters of anterior segment of eyes after femtosecond laser LASIK

    Institute of Scientific and Technical Information of China (English)

    胡正再; 张薇; 王志军

    2016-01-01

    Objective To analyze the changes of the parameters of anterior segment of eyes after femtosecond laser LASIK.Methods In this prospective clinic study,50 eyes of 25 patients who underwent femtosecond laser laser in situ keratomileusis (LASIK) were included.The corneal endothelium density,anterior chamber depth,anterior chamber angle width,posterior corneal surface height (4 mm diameter),distance between pupil center and corneal vertex,pupil diameter under light and dark environment were compared before and 6 months or more after surgery.Distance between pupil center and corneal vertex using absolute value.Data were analyzed using paired t test.Results After surgery,comeal endothelium density (2 829.7±227.2 cells/mm2 vs.2 716.4±255.2 cells/mm2),anterior chamber depth(3.18±0.19 mm vs.3.08±0.21 mm),anterior chamber angle width (39.39°±3.90°,37.92° ±3.76°) decreased (t=3.077,11.079,5.241,P<0.01).The differences of posterior corneal surface height (4 mm diameter),pupil diameter under light and dark environment before and after surgery were insignificant.The distance between pupil center and corneal vertex on X axis increased (0.11±0.10 mm vs.0.14±0.12 mm,t=-3.318,P<0.01).The distance between pupil center and corneal vertex on Y axis increase (0.11±0.08 mm vs.0.15±0.11 mm,t=-4.157,P<0.01).Conclusion The parameters of anterior segment of eyes after femtosecond laser LASIK changed obviously,especially for the distance between pupil center and corneal vertex.Maybe this change is important in guiding the following surgery.%目的 分析飞秒激光制瓣LASIK术后眼前节各参数(前房深度、前房角宽度、4 mm范围角膜后表面最高值、瞳孔中心与角膜顶点距离)的变化.方法 前瞻性临床研究.接受飞秒制瓣LASIK手术的患者25例(50眼),记录并分析术前和术后6个月以上中央角膜内皮细胞计数、前房深度、前房角宽度、4 mm范围角膜后表面最高值、瞳孔中心与角膜顶点距离、明

  8. The changes of inflammatory cytokines and their clinical significance in patients of inferior ST-segment elevation acute myocardial infarction with anterior ST-segment depression%急性下壁ST段抬高性心肌梗死合并前壁导联ST段压低患者炎性因子改变及临床意义

    Institute of Scientific and Technical Information of China (English)

    叶明; 曾玉杰

    2014-01-01

    目的 分析炎性因子水平与急性下壁心肌梗死有无前壁导联ST段压低之间的相关性及其临床意义.方法 选取北京安贞医院2007年5月至2012年9月急诊危重症中心因急性下壁ST段抬高性心肌梗死入院的患者360例,所有患者均急诊行PCI治疗,并观察罪犯血管以外冠脉病变的情况.所有患者根据有无前壁导联ST压低分为对照组180例和前壁ST段压低组180例.所有患者均于入院即刻取静脉血8ml,分离血浆,通过生物化学和ELISA方法检测血浆超敏C反应蛋白(Hs-CRP)、纤维蛋白原(Fib)、白细胞介素6(IL-6)、肿瘤坏死因子(TNF-α)、丙二醛(MDA)、过氧化物岐化酶(SOD)的变化,并分析血浆炎性因子水平与有无前壁ST段压低急性下壁心肌梗死相关性.结果 与对照组比较,前壁导联ST段压低患者双支病变、3支病变的比例更高(P<0.01);血浆Hs-CRP、Fib、IL-6、TNF-α水平升高更显著(P<0.01),脂质过氧化产物MDA含量更高(P<0.01),抗氧化物质SOD含量更低(P<0.01).结论 血浆炎症因子及脂质过氧化程度可在一定程度上反映冠脉病变的程度,对疾病的严重程度具有一定的预测价值.%Objective To investigate the level of Hs-CRP,Fib,IL-6,TNF-α,MDA,SOD,and analyse the correlation between the level of plasma inflammatory cytokines and clinical significance in patients with anterior ST-segment depression.Methods We choosed 360 patients with inferior ST Segment elavation acute myocardial infarction from May 2007 to Sep 2012 in rescue Center of Anzhen Hospital,in Anzhen Hospital,and all the patients received percutaneous coronary intervention treatment and the vascular lesions besides culprit vessel were observed.All the patients were divided into two groups:control group(n =180) and anterior ST-segment depression group (n =180).8ml venous blood was obtained from all the patients,and then plasma were separated.The level of plasma Hs-CRP,Fib,IL-6,TNF

  9. 急性闭角型青光眼对侧眼与可疑原发房角关闭眼的前节参数比较%Comparison of anterior segment parameters between fellow eyes of unilateral acute angle closure glaucoma and primary angle closure suspects

    Institute of Scientific and Technical Information of China (English)

    郭竞敏; 许小兰; 张虹; 王军明

    2015-01-01

    目的:探讨原发闭角型青光眼单侧急性发作( acute angle closure glaucoma,AACG)的对侧眼、可疑原发房角关闭眼(primary angle closure suspects,PACS)和正常眼的前节生物学参数差异。  方法:采用光学相干断层扫描( optical coherence tomography,OCT)和 Pentacam 三维眼前节分析诊断系统(pentacam scheimpflug system,Pentacam)完成26例26眼AACG对侧眼及与之年龄、性别匹配的28例28眼PACS和34例34眼正常眼的前节扫描。采用Pentacam获得以下参数:中央角膜厚度( CCT)、角膜容积( CV)、瞳孔直径( PD)、中央前房深度( CACD)、周边前房深度( PACD)、前房容积( CV )和房角度数( ACA )。应用图像处理软件和OCT测量虹膜厚度(IT750,IT2000),面积(IS)、体积(IV)和房角开放距离500( AOD500)进行。  结果:角膜参数(CCT,CV),PD、虹膜参数(IT750,IT2000, IS,IV)无统计学差异( P>0.05)。与 AACG 对侧眼和PACS比较,正常人CACD和PACD更深, ACV更大, ACA和AOD500更宽敞( P0.05)。以AACG对侧眼作为房角关闭好发的诊断标准,上述前房参数的受试者工作特征曲线下面积均小于0.7。  结论:AACG对侧眼和PACS的前节生物学参数无显著差异,以此作为房角关闭好发的诊断精准度较低。%AIM: To explore the differences of anterior segment parameters in the patients with fellow eyes of unilateral acute angle-closure glaucoma ( AACG ) , primary angle-closure suspects ( PACS) and normal group. METHODS: Twenty-six eyes of 26 patients with fellow eyes of AACG, 28 eyes of 28 age- and gender-matched PACS and 34 normal eyes were imaged using optical coherence tomography ( OCT) and pentacam scheimpflug system ( Pentacam ) . Anatomical parameters including central corneal thickness ( CCT ) , corneal volume ( CV ) , pupillary diameter ( PD ) , central anterior chamber depth ( CACD ) , peripheral anterior chamber depth ( PACD ) , anterior chamber volume ( ACV ) and anterior chamber angle

  10. 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...

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

    Directory of Open Access Journals (Sweden)

    Jing Wu

    2016-01-01

    Full Text Available 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.

  12. 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

  13. 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.

  14. Effect of phacoemulsification on drainage angle status in angle closure eyes with or without extensive peripheral anterior synechiae.

    Science.gov (United States)

    Latifi, Golshan; Moghimi, Sasan; Eslami, Yadollah; Fakhraie, Ghasem; Zarei, Reza; Lin, Shan

    2013-01-21

    Purpose. To evaluate the anatomic effects of phacoemulsification on drainage angle status in primary angle closure glaucoma (PACG) using anterior segment optical coherence tomography (AS-OCT). Methods. A total of 62 eyes of 58 patients underwent cataract surgery in Farabi Rye Hospital, Tehran, Iran. Patients were examined postoperatively on day 1, week 1, and week 6. Indentation gonioscopy and AS-OCT were performed preoperatively and at 6 weeks after surgery. Main outcome measures were angle and anterior segment parameters by AS-OCT and amount of peripheral anterior synechiae (PAS) by gonioscopy. Thirty-five eyes had PAS =180 degrees (group 1) and 27 eyes had >180-degree synechial closure (group 2). Results. Mean age of the patients was 64.3±9.0 years. The mean extent of PAS was significantly reduced from 45.9 to 32.2 degrees (p180 degrees.

  15. 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

  16. 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.

  17. In-vivo segmentation and quantification of coronary lesions by optical coherence tomography images for a lesion type definition and stenosis grading.

    Science.gov (United States)

    Celi, Simona; Berti, Sergio

    2014-10-01

    Optical coherence tomography (OCT) is a catheter-based medical imaging technique that produces cross-sectional images of blood vessels. This technique is particularly useful for studying coronary atherosclerosis. In this paper, we present a new framework that allows a segmentation and quantification of OCT images of coronary arteries to define the plaque type and stenosis grading. These analyses are usually carried out on-line on the OCT-workstation where measuring is mainly operator-dependent and mouse-based. The aim of this program is to simplify and improve the processing of OCT images for morphometric investigations and to present a fast procedure to obtain 3D geometrical models that can also be used for external purposes such as for finite element simulations. The main phases of our toolbox are the lumen segmentation and the identification of the main tissues in the artery wall. We validated the proposed method with identification and segmentation manually performed by expert OCT readers. The method was evaluated on ten datasets from clinical routine and the validation was performed on 210 images randomly extracted from the pullbacks. Our results show that automated segmentation of the vessel and of the tissue components are possible off-line with a precision that is comparable to manual segmentation for the tissue component and to the proprietary-OCT-console for the lumen segmentation. Several OCT sections have been processed to provide clinical outcome.

  18. 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

  19. 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.

  20. Microglomerular synaptic complexes in the sky-compass network of the honeybee connect parallel pathways from the anterior optic tubercle to the central complex

    Directory of Open Access Journals (Sweden)

    Martina Held

    2016-10-01

    Full Text Available While the ability of honeybees to navigate relying on sky-compass information has been investigated in a large number of behavioral studies, the underlying neuronal system has so far received less attention. The sky-compass pathway has recently been described from its input region, the dorsal rim area of the compound eye, to the anterior optic tubercle (AOTU. The aim of this study is to reveal the connection from the AOTU to the central complex. For this purpose we investigated the anatomy of large microglomerular synaptic complexes in the medial and lateral bulbs of the lateral complex. The synaptic complexes are formed by TuLAL1 neurons of the AOTU and GABAergic tangential neurons of the central body’s lower division (TL neurons. Both TuLAL1 and TL neurons strongly resemble neurons forming these complexes in other insect species. We further investigated the ultrastructure of these synaptic complexes using transmission electron microscopy. We found that single large presynaptic terminals of TuLAL1 neurons enclose many small profiles of TL neurons. The synaptic connections between these neurons are established by two types of synapses: divergent dyads and divergent tetrads. Our data support the assumption that these complexes are a highly conserved feature in the insect brain and play an important role in reliable signal transmission within the sky-compass pathway.

  1. 颈前路螺钉矢状角对相邻节段影响的生物力学研究%A biomechanical study of effects of anterior cervical screw sagittal angle on adjacent segments

    Institute of Scientific and Technical Information of China (English)

    陆兆华; 赵峰; 苏维成; 赵晓勇; 赵彦涛; 李忠海

    2015-01-01

    目的:采用三维有限元方法分析颈前路螺钉矢状角( sagittal screw angle,SSA )对相邻节段生物力学的影响,判断 SSA 是否是引起邻近节段病的危险因素。方法基于健康成年男性 C3~7节段 CT 图像建立颈椎有限元模型。模拟颈前路 C5椎体次全切除、C4~6钢板内固定术,按照 SSA (0°,0°)(5°,5°)(10°,10°)分别建模,计算在不同的 SSA 下,C4上终板、C6下终板以及钢板的应力变化情况。结果 C4上终板在前屈时前方区域所受应力最大,随着 SSA 的增加,C4上终板整体所受的最大应力逐渐减小,SSA 增大10°后,C4上终板前方区域的最大应力减小12.67%。C6下终板在前屈时前方区域所受应力最大,随着 SSA 的增加,C6下终板整体所受的最大应力逐渐减小,SSA 增大10°后,C6下终板前方区域的最大应力减小7.99%。钢板在前屈和后伸时其最大应力均较集中于中部区域,并且显著高于上部及下部区域,随着 SSA 的增加,钢板受到的应力会逐渐增加。结论在颈椎前路融合内固定手术中,增大 SSA,可增加钢板承受的应力,同时降低邻近节段终板的应力,从而减少邻近节段病的发生。%Objective To analyze effects of different screw sagittal angles ( SSA ) on the stress of adjacent levels, and determine whether SSA is a risk factor of adjacent segment disease ( ASD ).Methods A three-dimensional ifnite element ( FE ) model of intact C3-7 segments was developed and validated based on healthy males. C5 anterior corpectomy and allograft interbody fusion with a rigid anterior screw-plate construction was created from C4 to C6. Three additional FE models were developed from the fusion model corresponding to 3 different combinations of SSA: ( 0°, 0° ), ( 5°, 5° ), and ( 10°, 10° ). Von Mises stress on the C4 superior end-plate, C6 inferior end-plate and screw-plate were analyzed.Results The largest stress

  2. Topiramate-induced angle-closure glaucoma: cross-sensitivity with other sulphonamide derivatives causing anterior uveitis.

    Science.gov (United States)

    Kamal, Saurabh; Yadava, Usha; Kumar, Sushil; Goel, Ruchi

    2014-04-01

    Topiramate is a recognized cause of drug-induced acute angle-closure glaucoma. We describe a case presenting with bilateral acute angle-closure glaucoma caused by topiramate intake. Patient subsequently developed severe anterior uveitis caused by sulphonamide derivatives (acetazolamide and co-trimoxazole) due to cross-sensitivity, on two separate occasions. The present case also highlights the role of anterior segment optical tomography in diagnosis and follow-up. In a patient with known drug allergy to topiramate, other sulphonamide derivatives should be avoided to limit the ocular morbidity.

  3. Intraocular lens movement in anterior segment imaging system and pseudoaccommodation in eyes after phacoemulcification%人工晶体在前节OCT中的位移表现与伪调节力的研究

    Institute of Scientific and Technical Information of China (English)

    王飞; 卢奕; 汪琳

    2008-01-01

    目的 分析人工晶状体植入后生理状态下,在眼内的前后位移度及其和伪凋节力的关系.方法 选择病人46例(46只眼)行白内障超声乳化联合单焦点一体式折叠人工晶状体植入术,检测和分析术后人工晶状体在眼前节OCT图像中的位移表现,记录不同度数镜片附加时的前房深度和瞳孔直径变化值,测量患者术眼的伪凋节力,并进行相关性分析.平均随访(5.2±1.6)个月.结果 78.26%(36/46)术眼屈光矫正后近视力≥Jr5;患者术眼术后平均伪凋节力为(1.08±0.71)D.眼前节OCT图像显示附加负值镜片时人工晶状体向前位移,前房变浅,附加正值镜片时人工晶状体向后位移,前房变深,前房深度变化值为(0.26±0.09)mm;不同度数镜片附加时瞳孔直径变化值为(0.58±0.28)mm.伪凋节力与前房深度变化呈正相关(r=0.8267,P<0.01),与瞳孔直径变化亦呈正相关(r=0.6724,P<0.01).结论 白内障术后人工晶状体在生理状态下位置可前后移动,视近时睫状肌收缩、人工晶状体向前移动,是IOL眼产生伪凋节力的重要机制之一;瞳孔收缩也可部分补偿调节力.%Objective To evaluate the relationship between the position shift of posterior chamber in traocular lenses (PC IOLs) in physical condition and the amplitude of pseudoaccommodation in eyes after pacoemulcification.Methods This study analyzed 46 eyes of 46 patients after cataract surgery and PC IOLs implantation 3 months after surgery. The position shift of the IOL and radius of pupil were measured by anterior segment imaging system with different diopter spectacle plus. Pseudoaccommodation amplitude was also calculated. The relationship among pseudoaccommodation.IOL movement and pupil radius was analyzed. Results There were 78.26%(36/46 ) patients whose near visual acuity with best distance correction ≥ Jr5.With negative spectacles, IOLs moved forwards, with positive spectacles, IOLs moved backwards. The mean ACD

  4. 眼前节内眼模拟手术诱发血眼屏障破坏的大鼠动物模型%Rat model of blood-ocular barrier breakdown induced by anterior segment intraocular analogic surgery

    Institute of Scientific and Technical Information of China (English)

    谢茂松; 郑永征; 徐国兴

    2012-01-01

    目的 建立眼前节内眼模拟手术诱发血眼屏障破坏的大鼠动物模型.方法 清洁级健康成年雄性Sprague-Dawley大鼠150只,随机分为对照组和模型组,每组75只.按1 ml/kg的剂量腹腔注射盐酸氯胺酮-盐酸甲苯噻嗪混合液麻醉大鼠.磷酸盐缓冲液灌注袋连接三通管.三通管一端连接24G静脉留置针,手术显微镜下在3点时钟位从角巩缘前透明角膜30°斜行穿刺入前房,退出针头,留置套管;另一端连接24G静脉留置针套管,与测压计相连测量大鼠眼压.大鼠眼压波动于0~12 mm Hg(1 mm Hg=0.133 kPa)之间,波动30次/min,重复60次.采用氧氟沙星滴眼液滴眼.建模后第1、2、3、5、7天,采用免疫组织化学法检测大鼠白蛋白;定量检测大鼠房水、视网膜中伊凡思蓝(EB)浓度.结果 免疫组织化学染色结果显示,建模后第1、2、3、5、7天对照组白蛋白阳性染色均局限于虹膜和视网膜血管内,脉络膜弥漫性着色.建模后第1天,模型组白蛋白阳性染色主要位于虹膜和视网膜神经层血管周围;建模后第2、3天,阳性染色扩散到虹膜和视网膜全层;建模后第5、7天,阳性染色主要局限于虹膜和视网膜血管内.模型组房水中EB浓度在建模后第1、2、3、5天,均较对照组高(t=25.781,37.433,25.150,19.171;P<0.01);建模后第7天,与对照组接近(t=1.303,P=0.209).模型组视网膜EB浓度在建模后第1、2、3天,均较对照组高(t=11.997,14.622,23.014;P<0.01);建模后第5、7天,与对照组接近(t=2.027,0.756; P=0.058,0.459).结论 通过模拟眼前节内眼手术损伤因素,可建立内眼手术诱发的血眼屏障破坏的大鼠动物模型.%Objective To establish a rat model of blood ocular barrier breakdown induced by anterior segment intraocular analogic surgery. Methods One hundred and fifty healthy adult male rats were randomly divided into control group and model group,75 rats in each group.The rats were

  5. 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

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

    Science.gov (United States)

    Peng, Chunxia; Wang, Wei; Xu, Quangang; Zhao, Shuo; Li, Hongyang; Yang, Mo; Cao, Shanshan; Zhou, Huanfen; Wei, Shihui

    2016-01-01

    Objectives 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). Design This is a retrospective, cross-sectional and control observational study. Methods 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. Results 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 p

  7. Perawatan Ortodontik Gigi Anterior Berjejal dengan Tulang Alveolar yang Tipis

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    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.

  8. Visual perception changes and optical stability after intracorneal ring segment implantation: comparison between 3 months and 1 year after surgery

    Directory of Open Access Journals (Sweden)

    Paranhos JFS

    2011-07-01

    Full Text Available Juliane de Freitas Santos Paranhos, Marcos Pereira Ávila, Augusto Paranhos Jr, Paulo SchorFederal University of São Paulo, São Paulo, BrazilPurpose: To prospectively evaluate intracorneal ring segment (ICRS implantation on quality of life (QoL of patients with keratoconus changes and identify factors responsible.Methods: Sixty-nine eyes of 42 keratoconus patients were implanted with the Keraring (Mediphacos, Belo Horizonte, Brazil. Best corrected visual acuity (BCVA, refraction, and steep keratometry were analyzed 3 months and 1 year after surgery. All patients self-administered the National Eye Institute Refractive Error Quality of life instrument at 2 time points: after having worn best correction for at least 30 days since evaluation (mean 4 months after surgery and 1 year after surgery. To analyze if the use of the appropriate correction at 1 year follow up had any impact on visual acuity and V-QoL, patients were divided into 2 groups: group A (appropriate correction and B (not appropriate correction.Results: After 1 year, QoL changes related to scales ‘clarity of vision’, ‘near vision’, and ‘far vision’. Keratometric values, sphere, and spherical equivalent did not differ significantly between 3 months and 1 year postoperative. Cylinder increase was statistically but not clinically significant. Binocular BCVA did not change 1 year after surgery in group A and showed a clinically significant impairment in group B. A year after surgery, 18 patients did not use correction suggested by a physician 3 months after surgery. QoL was not statistically different 1 year after surgery between group A and group B.Conclusion: Our findings show that the way keratoconic patients see is difficult to analyze using only quantitative and 1-visit metrics. They highlight the importance of patients’ self perception and performing longitudinal analysis to consider neural compensation to optical changes from surgery.Keywords: keratoconus, cornea

  9. Evaluation the value of Pentacam anterial segment analysis system in the study of anterior segment of the eye before and after laser periphery iridectomy%Pentacam眼前节分析系统在激光周边虹膜切除术前后眼前节结构评估中的应用

    Institute of Scientific and Technical Information of China (English)

    吴慧娟; 任泽钦; 鲍永珍; 侯宪如; 胡亦文

    2010-01-01

    Objective To evaluate the anterior segment parameters in early primary angle-closure glaucoma (PACG) and primary angle closure (PAC) eyes before and after neodymium: yttrium aluminum garnet (Nd:YAG) laser periphery iridectomy (LPI) by using Pentacam system. Methods Self-coutrol study. Sixty one eyes of 33 patients were recruited into this study. The images of the anterior segment of the eye were captured and the parameters[I.e. The anterior chamber ( AC ) volume, the central AC depth, the peripherial AC depth, the peripherial AC angle and the pupil size]were measured by the Pentaeam system pre-operatively and 1 week after laser treatment. Results The Pentacam system clearly showed the structure changes of the anterior segment after LPI ( I. E. The convex configuration of the iris was flattened and the peripherial AC depth was deepened). The average AC volume( t = 15. 928 ), the peripherial AC depth( t =- 17. 399, - 10. 629, - 12. 576, - 14. 474 ) and the peripherial AC angle( t = - 5. 087 ) were increased significantly (P <0. 01 ) after LPI. The AC volume was (74. 10 ± 16.35 ) mm3 before LPI and (94. 10 ±18.42) mm3 after LPI, and the increases of peripherial AC depth were 0. 17 mm (nasal) and 0. 29 mm (temporal). There was no statistical significant changes in the AC depth before and after LPI. Conclusion In patients with PACG and PAC, the changes of AC after LPI can be demonstrated by the Pentacam qualitatively and quantitatively.%目的 评价Pentacam 眼前节分析系统的临床应用价值.方法 自身对照研究.33例(61只眼)原发性闭角型青光眼和原发性房角关闭患者,在接受掺钕钇铝石榴石激光周边虹膜切除术前及术后,应用Pentacam眼前节分析系统进行眼前节摄像和图像分析,同时分别测定患者眼前房相关量化指标.激光周边虹膜切除术前后各检测参数的变化比较采用配对t检验.结果 Pentacam眼前节分析系统能够清晰显示激光治疗前后眼前节结构变化,如

  10. Optical coherence tomography plaque characterization in a patient with ST segment elevation myocardial infarction after cocaine intake

    DEFF Research Database (Denmark)

    Hansen, Morten; Antonsen, L.; Jensen, L. O.

    2016-01-01

    A 28-year old man presented to the Emergency Department with malaise after cocaine intake. After arrival he developed retrosternal chest pain and the electrocardiogram showed ST segment elevations in V1-V2 and ST segment depressions in V5-V6. An acute coronary angiogram revealed a focal non-occlu...

  11. 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

  12. Semiautomated segmentation and analysis of retinal layers in three-dimensional spectral-domain optical coherence tomography images of patients with atrophic age-related macular degeneration.

    Science.gov (United States)

    Hu, Zhihong; Shi, Yue; Nandanan, Kiran; Sadda, Srinivas R

    2017-01-01

    Historically, regular drusen and geographic atrophy (GA) have been recognized as the hallmarks of nonneovascular age-related macular degeneration (AMD). Recent imaging developments have revealed another distinct nonneovascular AMD phenotype, reticular pseudodrusen (RPD). We develop an approach to semiautomatically quantify retinal surfaces associated with various AMD lesions (i.e., regular drusen, RPD, and GA) in spectral domain (SD) optical coherence tomography (OCT) images. More specifically, a graph-based algorithm was used to segment multiple retinal layers in SD-OCT volumes. Varying surface feasibility constraints based on the presegmentation were applied on the double-surface graph search to refine the surface segmentation. The thicknesses of these layers and their correlation with retinal functional measurements, including microperimetry (MP) sensitivity and visual acuity (VA), were investigated. The photoreceptor outer segment layer demonstrated significant thinning with a reduction in MP sensitivity and VA score when atrophic AMD lesions were present. Regular drusen and RPD were separately segmented on SD-OCT images to allow their characteristics and distribution to be studied separately. The mean thickness of regular drusen was found to significantly correlate with the VA score. RPD appeared to be distributed evenly throughout the macula and regular drusen appeared to be more concentrated centrally.

  13. 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.

  14. 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

  15. Evaluation of holmium laser versus cold knife in optical internal urethrotomy for the management of short segment urethral stricture

    Directory of Open Access Journals (Sweden)

    Sudhir Kumar Jain

    2014-01-01

    Conclusion: Both modalities are effective in providing immediate relief to patients with single and short segment (<2 cm long urethral strictures but more sustained response was attained with Cold knife urethrotomy.

  16. Unilateral anterior ischemic optic neuropathy

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Lund-Andersen, Henrik;

    2013-01-01

    and red colors were significantly reduced in the NAION-affected eyes, compared with the fellow non-affected eyes. When comparing the affected eyes with the healthy control eyes, the post-illumination responses were not significantly different. In addition, the post-illumination pupil responses after blue...

  17. 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.

  18. 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.

  19. 应用临时人工角膜行前后节联合手术治疗严重眼外伤%Combined anterior and posterior segments surgery using temporary keratoprosthesis for severe ocular injuries

    Institute of Scientific and Technical Information of China (English)

    王兴荣; 温莹; 毕宏生

    2008-01-01

    Objective To compare the effectiveness of combined vitrectomy with penetrating keratoplasty using temporary keratoprosthesis for different types of severe ocular injuries. Method 20cases (21eyes) including 11 ocular explosive injuries and 9 ocular penetrating injuries were underwent combined surgery .The preoperative visual acuity was from light perception to hand movement. With temporary keratoprosthesis pars plana vitrectomy, cataract excision, foreign body removal ,reattachment of retina and partial penetrating keratoplasty was performed .The follow-up period was from 3~36 months, the mean follow-up time was 17 months. Analysis was focused on visual acuity (VA), intraocular pressure, anatomic results and complications. Result 19 eyes including 100% ocular explosive injuries and 78% ocular penetrating injuries retained anatomic integrity of eyeball. 11 cases (52%) got the final postoperative VA 0.05 or better, 9 eyes were explosive injuries, the other 2 eyes were penetrating injuries. The severe complications including intraocular hypotension and retinal redetachment were all occurred in the cases with ocular penetrating injuries. Conclusion Temporary keratoprosthesis used in the combined surgeries of anterior and posterior ocular segments is proved to be an unique effective method for treatment of severe ocular injuries.Prognosis of ocular explosive injuries is better than ocular penetrating injuries.%目的 比较应用临时人工角膜行玻璃体切割联合穿透性角膜移植术治疗不同类型严重眼外伤的临床效果.方法 对伴有严重角膜混浊的眼外伤患者20例(21只眼),包括爆炸伤11例(12只眼)、眼球穿通伤9例(9只眼).术前视力为光感~眼前手动,采用临时人工角膜代替病变角膜完成闭合式玻璃体切割、白内障切除、球内异物取出、视网膜复位等眼内操作后,再用新鲜供体角膜置换人工角膜.术后随访3~36个月,平均17月,随访视力、眼压、眼球解

  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. Comparatire study of anterior segment parameters measurement by OCT, Orbscan, and A-scan ultrasound%眼前节相干光断层扫描仪与Orbscan Ⅱ及超声法眼前节生物测量对比研究

    Institute of Scientific and Technical Information of China (English)

    庞辰久; 宋晓虹; 王丽娅

    2009-01-01

    Objective To compare the accuracy of anterior segment OCT with Orbscan and A ultra-sound in measuring anterior segment parameters.Methods Anterior segment parameters in 66 eyes of 33 my-opic patients were measured with OCT, Orbscan and A-scan ultrasound.The central corneal thickness (CCT), anterior chamber depth (ACD)were acquired by the three methods, corneal diameter( W to W ), anterior cham-ber width,pupil diameter,and anterior chamber angle were measured by OCT and Orbscan.Results The CCTs were (532.32±35.26)μm,(538.45±38.31 )μm,and (555.82±37.63)μm,measured by AS-OCT, Orbscan,and A-scan ultrasound.There were significant differences between each of them (P <0.01 ),and also positive correlations were found.The ACD were ( 3.19±0.21 )mm, ( 3.08±0.24 )mm, and( 3.27±0.23 )mm, re-spectively measured by OCT, Orbcan and ultrasound.There were significant differences between each of them. Pupil diameterwere(5.5±0.93)mm,and(4.5±0.75)mm measured by OCT and Orbscan, The difference was(-1.00±0.68)mm,asignificantdifferencewasfound(t=1195,P=0.000),95%CI(0.84,1.17). Thedifferenceofanteriorcham-beranglewere 1.58° inposition 180° (P=0.119)and 2.89° in position 0° (P<0.01)measure by OCT and Orbscan.Conclusion The CCT was thinner obtained by OCT than by Orbscan and A-scan ultrasound,ACD was deeper than by Orbscan and more close to A-scan ultrasound.The anterior chamber angle were similar in both instruments. AS-OCT provide noncontact,rapid,simple and accurate anterior segment parameters and furthermore a clear ante-rior segment image.It is a useful instrument in measuring anterior segment parameters.%目的 比较眼前节相干光断层扫描仪(AS-OCT)与Orbscan Ⅱ以及超声法眼的节生物测量结果,为临床应用提供参考:方法对33例(66只眼)近视眼患者分别行AS-OCT,Orbscan Ⅱ以及A型超声测量仪(DGH550和DGH4000)进行眼前节生物测量,获取角膜中央厚度(CCT),前房深度(ACD),角膜直径,瞳孔直径以及前房角

  2. 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

  3. 人工颈椎间盘置换与前路颈椎间盘切除融合后邻近节段椎间盘应力分布的有限元对比%Comparison of stress distribution of adjacent segments after artificial cervical disc replacement versus anterior cervical discectomy and fusion:a finite element analysis

    Institute of Scientific and Technical Information of China (English)

    刘雅普; 侯秀伟; 吴广良; 夏虹

    2016-01-01

    背景:通过前期的临床随访研究发现,前路颈椎融合后邻近节段椎间盘退变速度要快于人工颈椎间盘置换,人工颈椎间盘置换相较于前路颈椎融合可以保持良好的置换节段活动度,是否置换后邻近椎间盘的应力情况与融合之间存在着差异需要进一步研究。目的:对比人工颈椎间盘置换与前路颈椎间盘切除融合后邻近节段椎间盘的应力分布情况。方法:选择1名30岁健康男性志愿者,人工颈椎间盘和颈椎前路钢板实物进行薄层CT扫描,通过Mimics 10.01及Geomagic Studio.v11软件重建出三维图像,将以上三维数据导入Abaqus 6.9有限元分析软件中进行网格划分、赋值、应力分析。利用有限元方法分析模拟人工颈椎间盘置换及前路颈椎间盘切除融合后邻近节段椎间盘的应力变化。结果与结论:①在相同的预载荷条件下,前屈、后伸、侧屈等运动状态时前路颈椎间盘切除融合后邻近节段椎间盘的应力明显大于正常人相应节段椎间盘应力;而人工椎间盘植入后与正常人相比,在前屈、后伸、侧屈等运动状态时邻近节段椎间盘的应力差异无显著性意义;②前路颈椎间盘切除融合组与人工颈椎间盘置换组相比较,融合组术后邻近节段椎间盘的应力较置换组增大10.3%-51.6%;③有限元分析方法发现,前路颈椎间盘切除融合后邻近节段椎间盘应力大于人工颈椎间盘置换组,随着随访时间的延长,相较于传统前路减压融合,人工颈椎间盘置换可能将更好地发挥其对邻近节段椎间盘的保护作用。%BACKGROUND:Previous clinical fol ow-up study showed that disc degeneration of adjacent segment after anterior cervical discectomy and fusion was faster than that of artificial cervical disc replacement. Compared with the anterior cervical discectomy and fusion, artificial cervical disc replacement can maintain a

  4. Segmentation error and macular thickness measurements obtained with spectral-domain optical coherence tomography devices in neovascular age-related macular degeneration

    Directory of Open Access Journals (Sweden)

    Moosang Kim

    2013-01-01

    Full Text Available Purpose: To evaluate frequency and severity of segmentation errors of two spectral-domain optical coherence tomography (SD-OCT devices and error effect on central macular thickness (CMT measurements. Materials and Methods: Twenty-seven eyes of 25 patients with neovascular age-related macular degeneration, examined using the Cirrus HD-OCT and Spectralis HRA + OCT, were retrospectively reviewed. Macular cube 512 × 128 and 5-line raster scans were performed with the Cirrus and 512 × 25 volume scans with the Spectralis. Frequency and severity of segmentation errors were compared between scans. Results: Segmentation error frequency was 47.4% (baseline, 40.7% (1 month, 40.7% (2 months, and 48.1% (6 months for the Cirrus, and 59.3%, 62.2%, 57.8%, and 63.7%, respectively, for the Spectralis, differing significantly between devices at all examinations (P < 0.05, except at baseline. Average error score was 1.21 ± 1.65 (baseline, 0.79 ± 1.18 (1 month, 0.74 ± 1.12 (2 months, and 0.96 ± 1.11 (6 months for the Cirrus, and 1.73 ± 1.50, 1.54 ± 1.35, 1.38 ± 1.40, and 1.49 ± 1.30, respectively, for the Spectralis, differing significantly at 1 month and 2 months (P < 0.02. Automated and manual CMT measurements by the Spectralis were larger than those by the Cirrus. Conclusions: The Cirrus HD-OCT had a lower frequency and severity of segmentation error than the Spectralis HRA + OCT. SD-OCT error should be considered when evaluating retinal thickness.

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

    Directory of Open Access Journals (Sweden)

    Hamid Khakshoor

    2011-01-01

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

  6. 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. Early applications of granulocyte colony-stimulating factor (G-CSF) can stabilize the blood-optic-nerve barrier and ameliorate inflammation in a rat model of anterior ischemic optic neuropathy (rAION).

    Science.gov (United States)

    Wen, Yao-Tseng; Huang, Tzu-Lun; Huang, Sung-Ping; Chang, Chung-Hsing; Tsai, Rong-Kung

    2016-10-01

    Granulocyte colony-stimulating factor (G-CSF) was reported to have a neuroprotective effect in a rat model of anterior ischemic optic neuropathy (rAION model). However, the therapeutic window and anti-inflammatory effects of G-CSF in a rAION model have yet to be elucidated. Thus, this study aimed to determine the therapeutic window of G-CSF and investigate the mechanisms of G-CSF via regulation of optic nerve (ON) inflammation in a rAION model. Rats were treated with G-CSF on day 0, 1, 2 or 7 post-rAION induction for 5 consecutive days, and a control group were treated with phosphate-buffered saline (PBS). Visual function was assessed by flash visual evoked potentials at 4 weeks post-rAION induction. The survival rate and apoptosis of retinal ganglion cells were determined by FluoroGold labeling and TUNEL assay, respectively. ON inflammation was evaluated by staining of ED1 and Iba1, and ON vascular permeability was determined by Evans Blue extravasation. The type of macrophage polarization was evaluated using quantitative real-time PCR (qRT-PCR). The protein levels of TNF-α and IL-1β were analyzed by western blotting. A therapeutic window during which G-CSF could rescue visual function and retinal ganglion cell survival was demonstrated at day 0 and day 1 post-infarct. Macrophage infiltration was reduced by 3.1- and 1.6-fold by G-CSF treatment starting on day 0 and 1 post-rAION induction, respectively, compared with the PBS-treated group (PG-CSF treatment compared with PBS treatment (PG-CSF-treated group compared with the PBS-treated group (PG-CSF also induced M2 microglia/macrophage activation. The cytokine levels were lower in the group that received immediate G-CSF treatment compared to those in the later G-CSF treatment group (PG-CSF stabilized the blood-ON barrier to reduce macrophage infiltration and induced M2 microglia/macrophage polarization to decrease the expressions of pro-inflammatory cytokines in this rAION model.

  8. 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.

  9. Obtaining Thickness Maps of Corneal Layers Using the Optimal Algorithm for Intracorneal Layer Segmentation.

    Science.gov (United States)

    Rabbani, Hossein; Kafieh, Rahele; Kazemian Jahromi, Mahdi; Jorjandi, Sahar; Mehri Dehnavi, Alireza; Hajizadeh, Fedra; Peyman, Alireza

    2016-01-01

    Optical Coherence Tomography (OCT) is one of the most informative methodologies in ophthalmology and provides cross sectional images from anterior and posterior segments of the eye. Corneal diseases can be diagnosed by these images and corneal thickness maps can also assist in the treatment and diagnosis. The need for automatic segmentation of cross sectional images is inevitable since manual segmentation is time consuming and imprecise. In this paper, segmentation methods such as Gaussian Mixture Model (GMM), Graph Cut, and Level Set are used for automatic segmentation of three clinically important corneal layer boundaries on OCT images. Using the segmentation of the boundaries in three-dimensional corneal data, we obtained thickness maps of the layers which are created by these borders. Mean and standard deviation of the thickness values for normal subjects in epithelial, stromal, and whole cornea are calculated in central, superior, inferior, nasal, and temporal zones (centered on the center of pupil). To evaluate our approach, the automatic boundary results are compared with the boundaries segmented manually by two corneal specialists. The quantitative results show that GMM method segments the desired boundaries with the best accuracy.

  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. Measuring the In-Process Figure, Final Prescription, and System Alignment of Large Optics and Segmented Mirrors Using Lidar Metrology

    Science.gov (United States)

    Ohl, Raymond; Slotwinski, Anthony; Eegholm, Bente; Saif, Babak

    2011-01-01

    The fabrication of large optics is traditionally a slow process, and fabrication capability is often limited by measurement capability. W hile techniques exist to measure mirror figure with nanometer precis ion, measurements of large-mirror prescription are typically limited to submillimeter accuracy. Using a lidar instrument enables one to measure the optical surface rough figure and prescription in virtuall y all phases of fabrication without moving the mirror from its polis hing setup. This technology improves the uncertainty of mirror presc ription measurement to the micron-regime.

  12. 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.

  13. Segmentation: Identification of consumer segments

    DEFF Research Database (Denmark)

    Høg, Esben

    2005-01-01

    origin in other sciences as for example biology, anthropology etc. From an economic point of view, it is called segmentation when specific scientific techniques are used to classify consumers to different characteristic groupings. What is the purpose of segmentation? For example, to be able to obtain...... 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...... and analysed possible segments in the market. Results show that the statistical model used identified two segments - a segment of so-called "fish lovers" and another segment called "traditionalists". The "fish lovers" are very fond of eating fish and they actually prefer fish to other dishes...

  14. 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.

  15. An Efficient Optical Observation Ground Network is the Fundamental basis for any Space Based Debris Observation Segment

    Science.gov (United States)

    Cibin, L.; Chiarini, M.; Annoni, G.; Milani, A.; Bernardi, F.; Dimare, L.; Valsecchi, G.; Rossi, A.; Ragazzoni, R.; Salinari, P.

    2013-08-01

    A matter which is strongly debated in the SSA Community, concerns the observation of Space Debris from Space [1]. This topic has been preliminary studied by our Team for LEO, MEO and GEO orbital belts, allowing to remark a fundamental concept, residing in the fact that to be suitable to provide a functionality unavailable from ground in a cost to performance perspective, any Space Based System must operate in tight collaboration with an efficient Optical Ground Observation Network. In this work an analysis of the different functionalities which can be implemented with this approach for every orbital belt is illustrated, remarking the different achievable targets in terms of population size as a function of the observed orbits. Further, a preliminary definition of the most interesting missions scenarios, together with considerations and assessments on the observation strategy and P/L characteristics are presented.

  16. Lenstar、Pentacam与Sirius测量白内障患者眼前节生物参数的比较%Comparison of anterior ocular segment measurements for cataracts using Lenstar, Pentacam and Sirius

    Institute of Scientific and Technical Information of China (English)

    黄锦海; 李坚; 鲁伟聪; 程丹; 邓军; 王勤美

    2014-01-01

    Objective To assess the differences and agreements among measurements of cataractous eyes using Lenstar LS900 biometer,Pentacam rotating Scheimpflug photography and a Sirius Scheimpflug-Placido disc topographer.The following measurements were taken:central corneal thickness (CCT),anterior chamber depth from the corneal endothelium to the anterior lens capsule (ACDendo),anterior chamber depth from the corneal epithelium to the anterior lens capsule (ACDepi) and mean keratometry (Kin).Methods In this prospective clinical study,CCT,ACD (including ACDendo and ACDepi) and the Km of 40 eyes were randomly obtained by Lenstar,Pentacam and Sirius.All measurements included the 3 methods which were compared using a repeated-measures analysis of variance (ANOVA),with a Bonferroni multiple comparison correction.Bland-Altman analyses were used to evaluate the agreement between the devices.Results The mean CCTs obtained by Lenstar,Pentacam and Sirius were 528.18±29.12 μm,533.21±27.02 μm and 534.48±26.15 μm,respectively.The mean ACDendo obtained by Lenstar,Pentacam and Sirius were 2.54±0.41 mm,2.54±0.43 mm and 2.57±0.43 mm,respectively.The mean ACDepi obtained by Lenstar,Pentacam and Sirius were 3.07±0.41 mm,3.08±0.42 mm and 3.10±0.43 mm,respectively.The mean Km obtained by Lenstar,Pentacam and Sirius were 44.05±1.69 D,43.99±1.65 D and 43.93±1.63 D,respectively.There were significant differences among the results of these three methods in CCT (F=11.641,P<0.01),ACDendo (F=9.961,P<0.01),ACDepi (F=12.539,P<0.01),and Km (F=4.186,P<0.05).The Bland-Altman plot analyses showed that the three devices had comparable results for CCT,ACD and Km.For the maximum absolute values of 95% limits of agreement (LoA) were 26.41 μm,0.12 mm,0.12 mm and 0.61 D respectively.Conclusion Lenstar,Pentacam and Sirius demonstrated high agreement for CCT,ACD and corneal curvature measurements in cataractous eyes.%目的 评估新型光学低相干反射仪Lenstar、Pentacam眼前节

  17. 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

  18. Optic nerve vascular compression in a patient with a tuberculum sellae meningioma.

    Science.gov (United States)

    Mizrahi, Cezar José; Moscovici, Samuel; Dotan, Shlomo; Spektor, Sergey

    2015-01-01

    Background. Optic nerve vascular compression in patients with suprasellar tumor is a known entity but is rarely described in the literature. Case Description. We present a unique, well-documented case of optic nerve strangulation by the A1 segment of the anterior cerebral artery in a patient with a tuberculum sellae meningioma. The patient presented with pronounced progressive visual deterioration. Following surgery, there was immediate resolution of her visual deficit. Conclusion. Vascular strangulation of the optic nerve should be considered when facing progressive and/or severe visual field deterioration in patients with tumors proximal to the optic apparatus.

  19. The Primary Study of Changes of the Structure of Ocular Anterior Segment after Trabeculectomy with Ultrasound Biomicroscopy%超声生物显微镜对原发性闭角型青光眼小梁切除手术前后眼前节结构改变的初步研究

    Institute of Scientific and Technical Information of China (English)

    潘雪; 李平华

    2009-01-01

    目的 应用超声生物显微镜(UBM)分别观察急、慢性原发性闭角型青光眼小梁切除手术前后眼前节结构的改变.方法 对26例33眼急性闭角型青光眼和25例37眼慢性闭角型青光眼分别于小梁切除手术前和手术后1个月应用UBM进行眼前节结构的测量.结果 急性闭角型青光眼房角开放距离 (AOD)、房角开放度数 (AA)、虹膜晶状体接触距离(ILCD)、虹膜晶体夹角(θ2)、虹膜悬韧带距离(IZD)手术前后比较有统计学差异(P<0.05),术前3眼发现睫状体脱离.慢性闭角型青光眼ILCD、θ2、IZD手术前后比较有统计学差异(P<0.05).结论 UBM对原发性闭角型青光眼患者小梁切除手术后眼前节结构的改变能进行精确测量,对探讨青光眼发病机制、防止并发症发生、判断手术预后均有较大的实用价值.%Objective To observe the changes of the structure of ocular anterior segment after trabeculectomy with ultrasound biomicroscopy(UBM) in acute angle-closure glaucoma(ACAG) and chronic angle-closure glaucoma(CACG).Methods 26 patients(33 eyes)of acute angle-closure glaucoma and 25 patients(37 eyes)of chronic angle-closure glaucoma were underwent trabeculectomy.The structure of ocular anterior segment were separately observed and measured by using UBM before and after surgery.Results In ACAG patients,there were statistically significant differences between the preoperative and postoperative angle opening distance(AOD),open angle(AA),iris-lens contact distance(ILCD),iris-lens angle(θ2),iris-zonular distance(IZD) (P<0.05),and there were 3 eyes with ciliary body detachment before surgery.In CACG patients,there were statistically significant differences between the preoperative and postoperative ILCD,θ2,IZD(P<0.05).Conclusions UBM is an exactly tool to mea-sure the changes of the structure of ocular anterior segment after trabeculectomy.It posses higher diagnostic value in discussing mechanism of glaucoma

  20. [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.

  1. Anterior Cruciate Ligament (ACL) Injuries

    Science.gov (United States)

    ... Week of Healthy Breakfasts Shyness Anterior Cruciate Ligament (ACL) Injuries KidsHealth > For Teens > Anterior Cruciate Ligament (ACL) ... and Recovery Coping With an ACL Injury About ACL Injuries A torn anterior cruciate ligament (ACL) is ...

  2. 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.

  3. 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...

  4. 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.

  5. 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

  6. Anterior cervical plating

    Directory of Open Access Journals (Sweden)

    Gonugunta V

    2005-01-01

    Full Text Available Although anterior cervical instrumentation was initially used in cervical trauma, because of obvious benefits, indications for its use have been expanded over time to degenerative cases as well as tumor and infection of the cervical spine. Along with a threefold increase in incidence of cervical fusion surgery, implant designs have evolved over the last three decades. Observation of graft subsidence and phenomenon of stress shielding led to the development of the new generation dynamic anterior cervical plating systems. Anterior cervical plating does not conclusively improve clinical outcome of the patients, but certainly enhances the efficacy of autograft and allograft fusion and lessens the rate of pseudoarthrosis and kyphosis after multilevel discectomy and fusions. A review of biomechanics, surgical technique, indications, complications and results of various anterior cervical plating systems is presented here to enable clinicians to select the appropriate construct design.

  7. 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.

  8. 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

  9. 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。

  10. 闭角型青光眼合并白内障患者人工晶状体植入术后眼前节变化的观察%The change in the ocular anterior segment of patients with angle-closure glaucoma combined with cataract after IOL implantation

    Institute of Scientific and Technical Information of China (English)

    王泽飞; 何锐; 方爱武

    2013-01-01

    Objective To observe the changes in the anatomical structure of the ocular anterior segment in patients with primary angle-closure glaucoma (PACG) combined with cataract pre-and post-operatively using four different types of measurements,and to evaluate the clinical application value of the those equipments.Methods Thirty eyes of 26 patients that fit the inclusion criteria with typical PACG combined with cataract were selected.Cataract phacoemulsification with IOL implantation was performed.Measurements of the ocular anterior segment were taken pre-and 3 months post-operatively with UBM,Visante OCT,Pentacam and IOL-Master.The changes of the parameters of the anterior segment obtained by these types of instruments pre-and post-operatively were analyzed,and compared the differences among the four different measuring systems.The SPSS 16.0 statistical software was used for the data process and analysis,P <0.05 indicating statistical significance.Results 1.The four different types of measuring methods showed that all patients had a significant increase in the central anterior chamber depth (ACD) post-operatively compared with that pre-operatively (t =-29.583,t =-28.478,t =-27.588,t =-24.075,P <0.01); statistical significance also existed in the difference among the four types of methods (F =20.036,P <0.01; F =20.012,P <0.01).2.Statistically significant difference existed in the AOD500 (Angle Open Distance 500) preand 3 months post-operatively measured by UBM and Visante OCT (t =-17.781,P <0.01;t =-18.313,P <0.01),with no significant difference between the measurement of the two measuring system either per-or post-operatively (t =-1.252,P =0.221; t =-0.059,P =0.953).3.Statistically significant difference existed in the Trabecular-Iris Angle at 500μm (TIA500) pre-and post-operatively measured by UBM and Visante OCT (t =-17.623,P <0.01; t =-17.016,P <0.01; t =-14.688,P <0.01),the angle degree was also statistically significantly different pre-and post

  11. 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.

  12. Corneal Segmentation Analysis Increases Glaucoma Diagnostic Ability of Optic Nerve Head Examination, Heidelberg Retina Tomograph's Moorfield's Regression Analysis, and Glaucoma Probability Score.

    Science.gov (United States)

    Saenz-Frances, F; Jañez, L; Berrozpe-Villabona, C; Borrego-Sanz, L; Morales-Fernández, L; Acebal-Montero, A; Mendez-Hernandez, C D; Martinez-de-la-Casa, J M; Santos-Bueso, E; Garcia-Sanchez, J; Garcia-Feijoo, J

    2015-01-01

    Purpose. To study whether a corneal thickness segmentation model, consisting in a central circular zone of 1 mm radius centered at the corneal apex (zone I) and five concentric rings of 1 mm width (moving outwards: zones II to VI), could boost the diagnostic accuracy of Heidelberg Retina Tomograph's (HRT's) MRA and GPS. Material and Methods. Cross-sectional study. 121 healthy volunteers and 125 patients with primary open-angle glaucoma. Six binary multivariate logistic regression models were constructed (MOD-A1, MOD-A2, MOD-B1, MOD-B2, MOD-C1, and MOD-C2). The dependent variable was the presence of glaucoma. In MOD-A1, the predictor was the result (presence of glaucoma) of the analysis of the stereophotography of the optic nerve head (ONH). In MOD-B1 and MOD-C1, the predictor was the result of the MRA and GPS, respectively. In MOD-B2 and MOD-C2, the predictors were the same along with corneal variables: central, overall, and zones I to VI thicknesses. This scheme was reproduced for model MOD-A2 (stereophotography along with corneal variables). Models were compared using the area under the receiver operator characteristic curve (AUC). Results. MOD-A1-AUC: 0.771; MOD-A2-AUC: 0.88; MOD-B1-AUC: 0.736; MOD-B2-AUC: 0.845; MOD-C1-AUC: 0.712; MOD-C2-AUC: 0.838. Conclusion. Corneal thickness variables enhance ONH assessment and HRT's MRA and GPS diagnostic capacity.

  13. 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

  14. Posterior single segment anterolateral decompression and anterior column reconstruction for type Denis B thoracolumbar burst fractures%后路单节段侧前方减压前柱重建术治疗Denis B型胸腰椎爆裂骨折

    Institute of Scientific and Technical Information of China (English)

    高志朝; 王梅; 张妙林; 孟永俊; 祝卫民; 张春

    2011-01-01

    Objective To investigate the feasibility and clinical effect of the posterior single segment anterolateral decompression and anterior column reconstruction in the treatment of thoracolumbar burst fractures. Methods A retrospective study was done on 21 patients with type Denis B thorocalumbar burst fractures who were treated by posterior approach minimal incision pedicle SCreW fixation,single segment anterolateral decompression and titanium mesh and bone graft from August 2007 to August 2009.There were 15 males and six males at mean age of 35.6 years(range,23-50 years).The involved segments included T12 in six patients,L1 in 11,L2 in three,and L3 in one.The preoperative spinal canal enemachment rate was 62.5%and the anterior-middle vertebral compression of all patients was less than 50%.CT scanning showed normal vertebral body and inferior endplate structure.The fracture reduction,graft fusion,neurological function recovery,correction loss,lumbar activities and adjacent lumbar disc degeneration were observed through preoperative,immediate postoperative and final follow up X-ray,CT and neurological examinations. Results The operation duration was 1.5-3.2 hours(average 2.1hours),with the bleeding of 350-1 000 ml(average 580 ml).All the patients were followed up for 4-26months(average 10.3 months),which showed that the vertebral fusion time was 4-6 months,with no loss of the vertebral height,implant breakage,loosening or extrusion.The nerve function was improved for 1-2 grades. Conclusions With correct selection of the indications,the posterior single segment anterolateral decompression and anterior column reconstruction is a reliable fixation,for it takes advantages of simple operation,minor trauma,less fusion segments and fast recovery.%目的 探讨后路小切口单节段侧前方减压前柱重建术治疗Denis B犁胸腰椎爆裂骨折的可行性及临床疗效.方法 回顾性分析2007年8月-2009年8月采用经后路小切口椎弓根钉内同定、单间

  15. 颈椎前路减压人工颈椎间盘置换术与融合术治疗单节段颈椎间盘突出症的短期疗效比较%Clinical outcome of Discover artificial cervical disc replacement versus anterior cervical decompression and fusion for single segment cervical disc herniation

    Institute of Scientific and Technical Information of China (English)

    卡哈尔·艾肯木; 楚戈; 王振斌; 陈继征; 顾文飞; 胡雅斌; 涂来勇; 赵疆; 项泽文

    2014-01-01

    Background: The curative effect of anterior cervical discectomy and fusion (ACDF) is satisfactory for the patients with symptomatic cervical disc herniation. However, it can result in stress increase in adjacent segments and speed up the degen-eration of adjacent segments. Artificial cervical disc replacement (ACDR), a typical non-fusion surgical treatment, may be an alternative to ACDF for cervical disc herniation. Objective:To compare the clinical outcomes between ACDR and ACDF for single segmental cervical disc herniation. Methods:From January 2009 to February 2012, 61 patients with single segmental cervical disc herniation were treated in our hospital. Of them, 26 received Discover ACDF (arthroplasty group) and 35 underwent single-level ACDF (fusion group). Visual analogue scale (VAS) neck/arm pain score, Japanese Orthopedics Association (JOA) score and flexion-exten-sion range of motion of operative and adjacent segments were evaluated preoperatively and 1 week and 3, 6, 12, and 24 months postoperatively. Complications and secondary treatment were recorded. Results:A total of 52 patients (29 in arthroplasty group and 23 in fusion group) were followed up. The average follow-up pe-riod was 15.3 months (range, 12-24 months). The VAS scores of neck pain and upper limb pain and JOA score were signifi-cantly improved during follow up as compared with preoperative ones in all patients (P0.05). In arthroplasty group, there was no significant difference in range of motion of opera-tive and adjacent segments before and after treatment (P>0.05). The rate of fusion achievement was 90.5%. In arthroplasy group, prosthesis antedisplacement (<3 mm) in 2 patients at 6 months after surgery, and cerebrospinal fluid leakage oc-curred 1 patient. In fusion group, adjacent segment disease occurred in one patient who underwent secondary operation. Conclusions:Discover cervical disc replacement is a feasible alternative to ACDF for patients with persistent symptomatic cervical disc

  16. Evaluation the value of Pentacam segment analysis system in the study of eye anterior segment before and after prophylactic laser periphery iridotomy%Pentacam眼前节分析系统在预防性激光虹膜周边切除评估中的应用

    Institute of Scientific and Technical Information of China (English)

    章玉群; 田琳璐; 章翼; 赵东升

    2013-01-01

    目的:以首次发作急性闭角型青光眼的对侧眼为研究对象,采用Pentacam眼前节分析系统观察预防性激光虹膜周边切除(laser peripheral iridotomy,LPI)前后眼前节结构变化,评估LPI的有效性和安全性.方法:急性原发性闭角型青光眼50例50眼的对侧眼行氩激光联合Nd:YAG激光预防性激光周边虹膜切除,检查治疗前及治疗后1d;6mo的眼内压(intraocular pressure,IOP),以Pentacam测量中央角膜厚度(central corneal thickness,CCT)、中央前房深度(central anterior chamber depth,CACD)、周边前房深度(peripheral anterior chamber depth,PACD)、前房容积(anterior chamber volume,ACV)、前房角(anterior chamber angle,ACA)、瞳孔直径(pupil diameter,PD)、晶状体厚度(lens thickness,LT),IOL-Master测量眼轴长度(axial length,AL),并估算晶状体在眼内的相对位置(relative position of the lens,RPL).结果:Pentacam 图像清晰显示凸出的虹膜变平坦,前房角加深.治疗前与治疗后1d;6mo的眼压无显著变化.CCT值分别为548.02 ±20.22,549.32±21.78,551.34±26.37mm.CACD值分别为1.65±0.28,1.72±0.31,1.71±0.23mm.PD值分别为2.32±0.55,2.20±0.39,2.38±0.40mm.LT值分别为1.90±0.55,1.82±0.39,1.98±0.40mm.眼AL分别为23.08±1.05,22.91±1.12,22.94±0.96.RPL值分别为0.118±0.035,0.126±0.041,0.121±0.028.治疗前后均无统计学差异.PACD值分别为颞侧(0.88±0.31,1.19±0.25,1.17±0.30mm),上方(0.83±0.32,1.01±0.42,1.02±0.36mm),鼻侧(0.80±0.42,0.95±0.21,0.94±0.24mm),下方(0.83 ±0.34,1.13 ± 0.14,1.12± 0.25mm);ACV值分别为57.06±18.43,80.65±20.02,81.43 ±17.21mm3;ACA值分别为27.02° ±6.65°,30.41°±5.87°,31.52°±6.98°,治疗前与治疗后均有统计学差异,治疗后1d与6mo无统计学差异.结论:LPI能明显增加急性闭角型青光眼对侧眼的周边前房深度和前房容积.Pentacam眼前节分析系统能直观定量反映LPI对于急性闭角型青光眼对侧眼的眼前节三维结构变化.

  17. 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.

  18. 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  

  19. 玻璃体切割联合眼内全视网膜光凝对 PDR合并虹膜新生血管的视网膜供血影响%Retinal blood supply changes after vitrectomy combined with panretinal photocoagulation in PDR patients with anterior segment neovascularization

    Institute of Scientific and Technical Information of China (English)

    王勇; 石兴东; 胡博杰; 边领斋; 李筱荣

    2016-01-01

    AIM: To investigate hemodynamic alterations of retrobulbar vessels in proliferative diabetic retinopathy ( PDR) patients with anterior segment neovascularization, before and 3mo after vitrectomy combined with panretinal photocoagulation and to explore the clinical significance. ●METHODS: Color Doppler flow imaging ( CDFl ) was used for measurement of blood flow velocities and resistive indexes ( Rl ) of the ophthalmic artery ( OA ) , short posterior ciliary arteries ( sPCA ) and central retinal artery ( CRA ) in 21 eyes of 21 PDR patients with anterior segment neovascularization. CDFl parameters were obtained before and 3mo after vitrectomy combined with panretinal photocoagulation ( PRP) . ● RESULTS: Peak systolic velocity ( PSV ) and end diastolic velocity ( EVD ) of CRA were significantly increased after surgeries, Rl were decreased significantly (P0. 05). ●CONCLUSION: Vitrectomy combined with panretinal photocoagulation might increase the velocity of CRA, decrease Rl and improve ocular blood supply postoperatively. lt may delay or prevent the process of neovascular glaucoma.%目的:探讨玻璃体切割联合眼内全视网膜光凝对增殖性糖尿病视网膜病变( proliferative diabetic retinopathy,PDR)合并虹膜新生血管( iris neovascularization,NVI)患者视网膜供血的影响及其临床价值。  方法:采用彩色多普勒超声血流显像技术( color doppler flow imaging,CDFI)检测21例21眼PDR合并NVI患者行玻璃体切割联合眼内光凝术前、术后3 mo视网膜中央动脉( central retinal artery, CRA )、睫状后短动脉( shot posterior ciliary artery, sPCA )、眼动脉( ophthalmic artery, OA)的收缩期峰值流速( peak systolic velocity,PSV)、舒张末期血流速度( end diastolic velocity, EDV )、阻力指数( resistance index,RI)的变化。  结果:玻璃体切割联合眼内全视网膜光凝术后3 mo CRA的PSV、EDV较术前明显升高,而RI值下降,有统计学差异( P0.05)。  结

  20. Anterior Segment Findings in Vitamin A Deficiency: A Case Series

    Science.gov (United States)

    Rubino, Pierangela; Mora, Paolo; Ungaro, Nicola; Gandolfi, Stefano A.; Orsoni, Jelka G.

    2015-01-01

    Vitamin A deficiency is a rare but vision threatening disorder in the developed world, which can lead to blindness for severe keratomalacia with cornea scarring and perforation or night blindness due to impaired dark adaptation. Conversely, the disease is quite common in developing countries, as a consequence of chronic malnutrition. The correct diagnosis and therapy with prompt vitamin A supplementation avoid blindness. We report a series of 3 local cases with different age and causes for vitamin A deficiency. The diagnostic workup, therapy, and prognosis are discussed. PMID:26509090

  1. [Segmental neurofibromatosis].

    Science.gov (United States)

    Zulaica, A; Peteiro, C; Pereiro, M; Pereiro Ferreiros, M; Quintas, C; Toribio, J

    1989-01-01

    Four cases of segmental neurofibromatosis (SNF) are reported. It is a rare entity considered to be a localized variant of neurofibromatosis (NF)-Riccardi's type V. Two cases are male and two female. The lesions are located to the head in a patient and the other three cases in the trunk. No family history nor transmission to progeny were manifested. The rest of the organs are undamaged.

  2. Automatic segmentation of seven retinal layers in SDOCT images congruent with expert manual segmentation.

    Science.gov (United States)

    Chiu, Stephanie J; Li, Xiao T; Nicholas, Peter; Toth, Cynthia A; Izatt, Joseph A; Farsiu, Sina

    2010-08-30

    Segmentation of anatomical and pathological structures in ophthalmic images is crucial for the diagnosis and study of ocular diseases. However, manual segmentation is often a time-consuming and subjective process. This paper presents an automatic approach for segmenting retinal layers in Spectral Domain Optical Coherence Tomography images using graph theory and dynamic programming. Results show that this method accurately segments eight retinal layer boundaries in normal adult eyes more closely to an expert grader as compared to a second expert grader.

  3. 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

  4. 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.

  5. 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.

  6. Impact of graft height on zygapophyseal joint pressure and range of motion adjacent to segment following cervical anterior fusion%颈椎前路融合术中植骨块的高度对邻近节段关节突压力及椎间位移的影响

    Institute of Scientific and Technical Information of China (English)

    罗春山; 欧阳北平; 梁栋柱; 陆廷盛; 姚书耽; 赵国权

    2016-01-01

    Objective To discuss impact of graft height on zygapophyseal joint pressure and range of motion of adjacent segments following the cervical anterior fusion and to guide the choice of optimal graft height in clinic. Methods Eight fresh-frozen human cadaveric cervical spines were used in this series, specimens were tested in five conditions, normal(specimens with intact discs)and different graft height(120%, 140%,160%of mean height) after Smith-Robinson discectomy between the fifth and sixth cervical vertebrae. Each specimens were subjected to flexion-extension. Lateral bending and axial rotation in material test system (BOSE ELECTROFORCE) were adopted to measure zygapophyseal joint pressure and rotation of the fourth to fifth segments and the sixth to seventh segments. Finally, The data for each state was used to determine the statistical significance of differences. Results The height of bone graft had little effect on the zygapophysial joints pressure values in neutral position with no statistical significance noted among each groups(P>0.05); The zygapophysial joints pressure value was the highest increase in extension position,but 120%M increased minimum of zygapophysial joints pressure value, and statistical significance were noted among each groups(P0.05), and statistical significance were noted in others groups(P0.05). Conclusion The appropriate graft height after single discectomy may be 120%mean height.%目的:探讨颈椎前路融合术中植骨块的高度对邻近节段关节突压力及活动度的影响,为临床上选择适宜的植骨高度提供依据。方法采用8例新鲜成人尸体颈椎标本,对完整状态,C5/6节段椎间隙减压术后(100%M、120%M、140%M、160%M)5组,于BOSE机加载下行三维运动,并测量颈C4/5,C6/7关节突压力值及C4/5,C6/7三维运动范围;最后将结果行多重比较分析。结果中立位状态下,关节突压力值各组无显著差异,P>0.05;后伸状态下,关节突压力

  7. Anterior crucate ligament (ACL) injury

    Science.gov (United States)

    ... An anterior cruciate ligament injury is the over-stretching or tearing of the anterior cruciate ligament (ACL) ... may be injured. This is a medical emergency. Prevention Use proper techniques when playing sports or exercising. ...

  8. Facetas em dentes anteriores

    OpenAIRE

    Veloso, Helena Rafaela Lourenço Martins

    2015-01-01

    Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária A presente revisão bibliográfica aborda as facetas estéticas em dentes anteriores, pela crescente valorização de um sorriso esteticamente agradável, facto que faz com que as pessoas procurem cada vez mais alternativas de tratamento para melhorar a aparência do seu sorriso. Os dentes anteriores são decisivos na aparência estética e, c...

  9. 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...

  10. 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

  11. 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

  12. 经前路椎体次全切钛笼置入锁定钢板螺丝钉内固定治疗相邻两节段脊髓型颈椎病%Adjacent Two Segments Anterior Subtotal Titanium Cage into the ;Locking Plate Screw Fixation for the Treatment of Cervical Spondylotic Myelopathy

    Institute of Scientific and Technical Information of China (English)

    青祖宏; 刘明; 高巍; 何蔚; 刘杨; 李永焕

    2013-01-01

    Objective To summarize the clinical efficacy of the anterior corpectomy cut with titanium cage and locking plate screw fixation for the treatment of two adjacent cervical spondylotic myelopathy.Method August 2010~December 2012,Anterior corpectomy cut with titanium cage and locking plate screw fixation for the treatment of adjacent two segments cervical spondylotic myelopathy 25 cases,including 18 men and 7 women patients,aged 33~75 years,mean 56.5 years.In 25 patients with varying degrees of symptoms of spinal cord compression. There are 9 cases(C4/C5). There are 15 cases(C5/C6).There are 1 case(C6/C7).Observed lateral cervical spine,cervical hyperextension flexion X-rays and cervical MR, before and after surg ery and follow-up phase,so as to learn spinal cord compression,cervical stability and postoperative cervical height,curvature,titanium cage plate screw position and cervical fusion. Compared preoperative to postoperative and follow-up,pain visual analog scale (VAS) and the Japan Orthopaedics Association (JOA) pain score.Results Operative time (120±30) min,blood loss (150±50)ml.The surgery does not appear related complications.The followed up time are 2~24 months (mean 12.5 months). Nerve function significantly improved.JOA score increased from preoperative 6.2±1.1 to the last follow-up 14.3±1.5,with an average improvement rate was (82.3±11.4)%.VAS average score is 2.1 points.The follow-up period is not found that the titanium cage shift,loose screws and lesion spinal cord compression phenomenon.Conclusion Anterior corpectomy cut with titanium cage and locking plate screw fixation for the treatment of two adjacent segments of cervical spondylotic myelopathy,effectively relieve nerve compression of the spinal cord,quickly restored cervical curvature and height,reconstruction of spinal stability,shorter operative time,less bleeding, and less damage.It has created favorable conditions for the rehabilitation of neurological function in patients,which is an

  13. 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.

  14. Intradural anterior transpetrosal approach.

    Science.gov (United States)

    Ichimura, Shinya; Hori, Satoshi; Hecht, Nils; Czabanka, Marcus; Vajkoczy, Peter

    2016-10-01

    The standard anterior transpetrosal approach (ATPA) for petroclival lesions is fundamentally an epidural approach and has been practiced for many decades quite successfully. However, this approach has some disadvantages, such as epidural venous bleeding around foramen ovale. We describe here our experience with a modified technique for anterior petrosectomy via an intradural approach that overcomes these disadvantages. Five patients with petroclival lesions underwent surgery via the intradural ATPA. The intraoperative hallmarks are detailed, and surgical results are reported. Total removal of the lesions was achieved in two patients with petroclival meningioma and two patients with pontine cavernoma, whereas subtotal removal was achieved in one patient with petroclival meningioma without significant morbidity. No patient experienced cerebrospinal fluid leakage. The intradural approach is allowed to tailor the extent of anterior petrosectomy to the individually required exposure, and the surgical procedure appeared to be more straightforward than via the epidural route. Caveats encountered with the approach were the temporal basal veins that could be spared as well as identification of the petrous apex due to the lack of familial epidural landmarks. The risk of injury to the temporal bridging veins is higher in this approach than in the epidural approach. Intradural approach is recommended in patients with a large epidural venous route, such as sphenobasal and sphenopetrosal vein. Navigation via bone-window computed tomography is useful to identify the petrous apex.

  15. Metrology of IXO Mirror Segments

    Science.gov (United States)

    Chan, Kai-Wing

    2011-01-01

    For future x-ray astrophysics mission that demands optics with large throughput and excellent angular resolution, many telescope concepts build around assembling thin mirror segments in a Wolter I geometry, such as that originally proposed for the International X-ray Observatory. The arc-second resolution requirement posts unique challenges not just for fabrication, mounting but also for metrology of these mirror segments. In this paper, we shall discuss the metrology of these segments using normal incidence metrological method with interferometers and null lenses. We present results of the calibration of the metrology systems we are currently using, discuss their accuracy and address the precision in measuring near-cylindrical mirror segments and the stability of the measurements.

  16. Scleral spur visibility of anterior chamber angle measured by Fourier optic coherence tomography%傅立叶光学相干断层扫描检测眼房角巩膜突可见性分析

    Institute of Scientific and Technical Information of China (English)

    张海涛; 徐英英; 王保君; 朱红军

    2011-01-01

    Objective To assess visibility of scleral spur in images of anterior chamber angle measured by the CAM model of Fourier optic coherence tomography (OCT). Methods Subjects aged 40 years or older were selected from outpatients in our opthalmologic clinic. All participants underwent standard ocular examinations, and anterior chamber angle was measured by CAM-L model of RTVue-OCT (Optovue Inc,USA) and gonioscopy. Visibility of scleral spur in OCT images and its related factor were analyzed. Results 98 subjects (98 eyes) aged (63.3±10.5)y included 62 females (63.3%) were selected in this study. There were 286 in 392 quadrants (73.0%) with visualized scleral spur, which had significant difference among local bulbar conjunctiva thickened or not (P<0.01). Logistic multiple regression showed that the visibility of scleral spur was not associated with gender, age, gonioscope grades (P>0.05), but significant associated with local bulbar conjunctiva thickened (OR=0.113, P<0.01) and quadrants (OR of superior/temporal=0.210, OR of inferior/temporal=0.340, P<0.01), of which there were different scleral spur visibility in superior and inferior quadrants compared with temporal(OR=0.210, 0.340, P<0.01). Angle status was still identified in 80.2% quadrants on condition that scleral spur was not visualized. Conclusions Fourier optic coherence tomography has good feasibility to detect anterior chamber angle as an alternative method, and may supply helpful information to estimate the pathogenesis of angle closure glaucoma.%目的 探讨傅立叶光学相干断层扫描仪CAM模块房角测量图像中巩膜突可见性及其影响因素.方法 连续选择本院眼科门诊40岁及以上患者,所有受试者均接受眼科常规项目检查,房角均分别接受Rtvue OCT(Optovue Inc,USA)CAM模块和房角镜检查.分析OCT图像中巩膜突的可见性及其影响因素.结果 受试者共98例(98眼),年龄(63.3±10.5)岁,其中女性62例(63.3%).在392

  17. 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.

  18. Optic disc boundary segmentation from diffeomorphic demons registration of monocular fundus image sequences versus 3D visualization of stereo fundus image pairs for automated early stage glaucoma assessment

    Science.gov (United States)

    Gatti, Vijay; Hill, Jason; Mitra, Sunanda; Nutter, Brian

    2014-03-01

    Despite the current availability in resource-rich regions of advanced technologies in scanning and 3-D imaging in current ophthalmology practice, world-wide screening tests for early detection and progression of glaucoma still consist of a variety of simple tools, including fundus image-based parameters such as CDR (cup to disc diameter ratio) and CAR (cup to disc area ratio), especially in resource -poor regions. Reliable automated computation of the relevant parameters from fundus image sequences requires robust non-rigid registration and segmentation techniques. Recent research work demonstrated that proper non-rigid registration of multi-view monocular fundus image sequences could result in acceptable segmentation of cup boundaries for automated computation of CAR and CDR. This research work introduces a composite diffeomorphic demons registration algorithm for segmentation of cup boundaries from a sequence of monocular images and compares the resulting CAR and CDR values with those computed manually by experts and from 3-D visualization of stereo pairs. Our preliminary results show that the automated computation of CDR and CAR from composite diffeomorphic segmentation of monocular image sequences yield values comparable with those from the other two techniques and thus may provide global healthcare with a cost-effective yet accurate tool for management of glaucoma in its early stage.

  19. 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

  20. Storing tooth segments for optimal esthetics

    NARCIS (Netherlands)

    Tuzuner, T.; Turgut, S.; Özen, B.; Kılınç, H.; Bagis, B.

    2016-01-01

    Objective: A fractured whole crown segment can be reattached to its remnant; crowns from extracted teeth may be used as pontics in splinting techniques. We aimed to evaluate the effect of different storage solutions on tooth segment optical properties after different durations. Study design: Sixty c

  1. 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.

  2. 新型三维眼前节分析仪Sirius和Pentacam测量准分子激光角膜原位磨镶术后眼前节参数的对比研究%Comparison of anterior segment measuring parameters in myopia after laser in situ keratomileusis between Sirius and Pentacam

    Institute of Scientific and Technical Information of China (English)

    徐真; 黄锦海; 成拾明; 冯一帆; 王勤美

    2013-01-01

    者的结果一致性欠佳,95%CI为-27.70~6.20 mm3. 结论 Sirius和Pentacam测量LASIK术后眼前房参数结果的重复性和稳定性好,此外两种方法测量的角膜曲率、角膜厚度和ACD具有很好的一致性,两种测量结果的差异在临床上可以接受,二者可以互相替代使用,但在测量角膜最薄点位置及ACV时两种方法的测量结果差异较大,临床上相互替代使用时需谨慎.%Background Sirius system,a new Scheimpflug camera combined with Placido topography,improved the capability of imaging the anterior eye segment significantly.However,the study of assessing the repeatability and agreement between Sirius and Pentacam is still lack up to now.Objective This study was to evaluate the repeatability and agreement of the anterior ocular segment measuring parameters by Sirius and Pentacam in myopia received laser in situ keratomileusis (LASIK).Methods Thirty-five myopic eyes of 35 patients received LASIK were included in School of Optometry and Ophthalmology Eye Hospital from 2010 May through 2010 July.Corneal power flat keratometry (Kf),step keratometry (Ks),mean keratometry (Km),thinnest corneal thickness(TCT),the location of TCT,anterior chamber depth (ACD) and anterior chamber volume (ACV) were measured by Sirius and Pentacam in all the eyes,respectively.The repeatability of the measuring results were evaluated using intraclass correlation coefficients (ICC) and Cronbach's coefficient alpha (CoA),and the agreement of measuring parameters between Sirius and Pentacam was analyzed using Bland-Altman plot.Results Both Sirius and Pentacam demonstrated high intraobserver repeatability,with all ICC and CoA more than 0.90.No significant differences were found in Kf values and Ks values between the two methods (t =-1.533,-1.750,P>0.05).Km value was (39.14 ± 1.95) D by Sirius measurement,which was sígnificantly higher than (39.05 ± 1.91) D by Pentacam measurement (t =3.572,P =0.001).The TCT was (457.6 ± 40.9) μm by Sirius method,showing a

  3. Expression of engrailed-family genes in the jumping bristletail and discussion on the primitive pattern of insect segmentation.

    Science.gov (United States)

    Nakagaki, Yasutaka; Sakuma, Masashi; Machida, Ryuichiro

    2015-09-01

    It has been shown that segmentation in the short-germ insects proceeds by a two-step mechanism. The anterior region is simultaneously segmented in a manner similar to that in Drosophila, which is apparently unique to insects, and the rest of the posterior region is segmented sequentially by a mechanism involving a segmentation clock, which is derived from the common ancestor of arthropods. In order to propose the evolutionary scenario of insect segmentation, we examined segmentation in the jumping bristletail, the basalmost extant insect. Using probes for engrailed-family genes for in situ hybridization, we found no sign of simultaneous segmentation in the anterior region of the jumping bristletail embryos. All segments except the anteriormost segment are formed sequentially. This condition shown in the jumping bristletail embryos may represent the primitive pattern of insect segmentation. The intercalating formation of the intercalary segment is assumed to be a synapomorphic trait shared among all insects after the branching of the jumping bristletail.

  4. 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

    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...

  5. Anterior knee pain

    Energy Technology Data Exchange (ETDEWEB)

    LLopis, Eva [Hospital de la Ribera, Alzira, Valencia (Spain) and Carretera de Corbera km 1, 46600 Alzira Valencia (Spain)]. E-mail: ellopis@hospital-ribera.com; Padron, Mario [Clinica Cemtro, Ventisquero de la Condesa no. 42, 28035 Madrid (Spain)]. E-mail: mario.padron@clinicacemtro.com

    2007-04-15

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries.

  6. 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.

  7. 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

  8. 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

  9. Multidisciplinary management of anterior diastemata

    DEFF Research Database (Denmark)

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

    2007-01-01

    Anterior diastemata may compromise the harmony of a patient's smile. Consideration of etiologic factors, previous gingival conditioning, and individual treatment planning are essential in the proper management of anterior diastemata. An integrated orthodontic-restorative approach may enhance...... 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...

  10. Triple procedure in posterior segment intraocular foreign body

    Directory of Open Access Journals (Sweden)

    Azad Rajvardhan

    1998-01-01

    Full Text Available Three patients with intraocular foreign bodies and traumatic cataracts underwent single stage pars plana lensectomy with anterior capsule preservation, vitrectomy, removal of the foreign body, and intraocular lens implantation. The preserved anterior capsule permitted support for the placement of an intraocular lens in the posterior chamber in the ciliary sulcus. The procedure enabled early visual rehabilitation. This procedure seems useful in the management of posterior segment intraocular foreign body associated with cataract.

  11. 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

  12. 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.

  13. Wavefront Compensation Segmented Mirror Sensing and Control

    Science.gov (United States)

    Redding, David C.; Lou, John Z.; Kissil, Andrew; Bradford, Charles M.; Woody, David; Padin, Stephen

    2012-01-01

    The primary mirror of very large submillimeter-wave telescopes will necessarily be segmented into many separate mirror panels. These panels must be continuously co-phased to keep the telescope wavefront error less than a small fraction of a wavelength, to ten microns RMS (root mean square) or less. This performance must be maintained continuously across the full aperture of the telescope, in all pointing conditions, and in a variable thermal environment. A wavefront compensation segmented mirror sensing and control system, consisting of optical edge sensors, Wavefront Compensation Estimator/Controller Soft ware, and segment position actuators is proposed. Optical edge sensors are placed two per each segment-to-segment edge to continuously measure changes in segment state. Segment position actuators (three per segment) are used to move the panels. A computer control system uses the edge sensor measurements to estimate the state of all of the segments and to predict the wavefront error; segment actuator commands are computed that minimize the wavefront error. Translational or rotational motions of one segment relative to the other cause lateral displacement of the light beam, which is measured by the imaging sensor. For high accuracy, the collimator uses a shaped mask, such as one or more slits, so that the light beam forms a pattern on the sensor that permits sensing accuracy of better than 0.1 micron in two axes: in the z or local surface normal direction, and in the y direction parallel to the mirror surface and perpendicular to the beam direction. Using a co-aligned pair of sensors, with the location of the detector and collimated light source interchanged, four degrees of freedom can be sensed: transverse x and y displacements, as well as two bending angles (pitch and yaw). In this approach, each optical edge sensor head has a collimator and an imager, placing one sensor head on each side of a segment gap, with two parallel light beams crossing the gap. Two sets

  14. 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.

  15. [Anterior cervical hypertrichosis: case report].

    Science.gov (United States)

    Orozco-Gutiérrez, Mario H; Sánchez-Corona, José; García-Ortiz, José E; Castañeda-Cisneros, Gema; Dávalos-Rodríguez, Nory O; Corona-Rivera, Jorge R; García-Cruz, Diana

    2016-10-01

    The non-syndromic anterior cervical hypertrichosis (OMIM N° 600457) is a genetic disorder characterized by a patch of hair at the level of the laryngeal prominence. We present a 12-year-old boy with anterior cervical hypertrichosis and mild generalized hypertrichosis. He has no neurological, ophthalmological or skeletal anomalies. The clinical follow up is 10 years.

  16. 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...... at 6-month follow-up in comparison with angiographic guidance alone. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02272283....

  17. 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.

  18. 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.

  19. Inestabilidad Anterior de Hombro

    Directory of Open Access Journals (Sweden)

    Pablo David Flint Kuran

    2013-11-01

    Full Text Available In­tro­duc­ción La luxación recidivante de hombro es una patología frecuente en pacientes jóvenes, laboralmente activos. Existen numerosas técnicas quirúrgicas para la inestabilidad glenohumeral. La técnica de Bristow, discutida por no ser anatómica y por sus complicaciones, continúa vigente debido al bajo índice de reluxaciones. Los objetivos fueron determinar el índice de recidiva, alteraciones funcionales e índice de consolidación del injerto. Materiales­ y­ Métodos Se evaluaron 24 pacientes del sexo masculino, de entre 19 y 40 años, operados por luxación anterior recidivante de hombro según la técnica de Bristow, entre enero de 2003 y agosto de 2011. Se evaluó la tasa de reluxación, la función articular según el puntaje de Constant y el posicionamiento del injerto con respecto a la superficie articular con tomografía y radiografías para evaluar la consolidación del injerto. Se registraron las complicaciones quirúrgicas. Resultados ­Todos los pacientes eran hombres, con rango de edad de 19 a 40 años. La causa fue traumática en 24 pacientes. Dieciséis pacientes presentaron más de 3 episodios de luxación prequirúrgicos. Según la escala de Constant, 21 obtuvieron entre 96 y 100 puntos, y los restantes, entre 90 y 95 puntos. No hubo nuevos episodios de luxaciones. La tomografía mostró la consolidación en todos los casos. Un paciente tuvo una imagen osteolítica alrededor del tornillo, sin compromiso funcional del hombro. Conclusión La técnica de Bristow para tratar la luxación anterior recidivante de hombro provocó un bajo índice de complicaciones, con resultados funcionales entre excelentes y buenos. No hubo episodios de reluxación y se logró la consolidación del injerto óseo en todos los casos.

  20. Indications of Optical Coherence Tomography in Keratoplasties: Literature Review

    Directory of Open Access Journals (Sweden)

    Thiago Trindade Nesi

    2012-01-01

    Full Text Available Optical coherence tomography (OCT of the anterior segment, in particular corneal OCT, has become a reliable tool for the cornea specialist, as it provides the acquisition of digital images at high resolution with a noncontact technology. In penetrating or lamellar keratoplasties, OCT can be used to assess central corneal thickness and pachymetry maps, as well as precise measurements of deep stromal opacities, thereby guiding the surgeon to choose the best treatment option. OCT has also been used to evaluate the keratoplasty postoperative period, for early identification of possible complications, such as secondary glaucoma or donor disc detachments in endothelial keratoplasties. Intraoperatively, OCT can be used to assess stromal bed regularity and transparency in anterior lamellar surgeries, especially for those techniques in which a bare Descemet’s membrane is the goal. The purpose of this paper is to review and discuss the role of OCT as a diagnostic tool in various types of keratoplasties.

  1. 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

  2. 微螺钉结合片段弓技术内收上前牙的临床研究%Micro-screw with Segmental Arch Technique for En-masse Retraction of Maxillary Anterior Teeth:A Clinical Cephalometric Study

    Institute of Scientific and Technical Information of China (English)

    张燕琴; 林新平

    2013-01-01

    目的:评估微螺钉结合片段弓技术内收上前牙对上切牙垂直向和转矩控制的效果.方法:选取16例上颌前突患者分为实验组(微螺钉结合片段弓技术)和对照组(微螺钉全牙弓).测量治疗前后的X线头颅定位侧位片相关指标,使用SPSS17.0软件分析.结果:实验组上切牙切缘至RL(通过翼上颌裂点作腭平面的垂线)距离U1E-RL减小7.26 mm,阻抗中心至RL距离U1CR-RL减小3.72 mm,根尖至RL距离U1AP-RL减小1.23 mm,切缘至腭平面的距离U1E-PP增加0.49 mm,阻抗中心至腭平面的距离U1CR-PP减小0.19 mm,根尖至腭平面的距离U1AP-PP减小0.25 mm,上切牙长轴与腭平面交角U1-PP减小11.65°;对照组U1E-RL减小6.18mm,U1CR-RL减小2.94 mm,减小U1AP-RL 0.47 mm,U1E-PP增加0.53 mm,U1CR-PP增加0.27 mm,U1 AP-PP增加0.28 mm,U1-PP减小16.31°.结论:微螺钉结合片段弓技术内收上前牙对上切牙的转矩和垂直向控制较好.%Objective:To evaluate the efficiency of micro-screw with segmental arch technique for en-masse retraction of maxillary anterior teeth.Methods:Sixteen subjects with upper dental alveolar bone protrusion were selected for this study.They were divided into two groups:experimental group (micros-crew with sectional arch technique) and control group (micro-screw with the whole arch).Torque and vertical of the central incisor were evaluated cephalometrically before and after orthodontic retraction.All data were analyzed by SPSS17.0 software.Results:Experimental group:U1E-RL was decreased by 7.26mm,U1CR-RL was decreased by 3.72mm,U1AP -RL was decreased by 1.23mm,U1E-PP was increased by 0.49mm,U1CR-PP was decreased by 0.19mm,U1AP-PP was decreased by 0.25mm,U1-PP was decreased by 11.65°; control group:U1E-RL was decreased by 6.18mm,U1CR-RL was decreased by 2.94mm,U1AP-RL was decreased by 0.47mm,U1E-PP was increased by 0.53mm,U1CR-PP was increased by 0.27mm,U1AP-PP was increased by 0.28mm,U1-PP was decreased by 16.31

  3. Bilateral optic neuropathy in acute cryptococcal meningitis

    Institute of Scientific and Technical Information of China (English)

    Qi Zhe Ngoo; Li Min Evelyn Tai; Wan Hazabbah Wan Hitam; John Tharakan

    2016-01-01

    We reported a case of cryptococcal meningitis presenting with bilateral optic neuropathy in an immunocompetent patient. A 64-year-old Malay gentleman with no medical comorbidities presented with acute bilateral blurring of vision for a week, which was associated with generalised throbbing headache and low grade fever. He also had som-nolence and altered consciousness. Visual acuity in both eyes was no perception of light with poor pupillary reflexes. Extraocular muscle movements were normal. Anterior segments were unremarkable bilaterally. Fundoscopy revealed bilateral optic disc swelling. CT scan of the brain showed multifocal infarct, but no meningeal enhancement or mass. Cerebrospinal fluid opening pressure was normal, while its culture grew Cryptococcus neoformans. A diagnosis of cryptococcal meningitis with bilateral optic neuropathy was made. Patient was treated with a six-week course of intravenous flu-conazole and started concomitantly on a fortnight's course of intravenous amphotericin B. After that, his general condition improved, but there was still no improvement in his visual acuity. On reviewing at two months post-initiation of treatment, fundi showed bilateral optic atrophy. Bilateral optic neuropathy secondary to cryptococcal meningitis was rare. The prognosis was guarded due to the sequelae of optic atrophy. Anti-fungal medication alone may not be sufficient to manage this condition. However, evidence for other treatment modalities is still lacking and further clinical studies are required.

  4. Segmentation Similarity and Agreement

    CERN Document Server

    Fournier, Chris

    2012-01-01

    We propose a new segmentation evaluation metric, called segmentation similarity (S), that quantifies the similarity between two segmentations as the proportion of boundaries that are not transformed when comparing them using edit distance, essentially using edit distance as a penalty function and scaling penalties by segmentation size. We propose several adapted inter-annotator agreement coefficients which use S that are suitable for segmentation. We show that S is configurable enough to suit a wide variety of segmentation evaluations, and is an improvement upon the state of the art. We also propose using inter-annotator agreement coefficients to evaluate automatic segmenters in terms of human performance.

  5. 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.

  6. 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.

  7. STUDY ON VARIATIONS OF INFERIOR SEGMENTAL BRANCH OF RENAL ARTERY

    Directory of Open Access Journals (Sweden)

    Chandragirish S

    2014-11-01

    Full Text Available Background: The segmental arteries of the kidney supply the organ in such a way that, each renal pole receives its own artery while, the anterior portion between the poles is supplied by an upper and lower segmental vessel. These two arteries also include in their territory the lateral edge of the kidney and adjacent to the strip of parenchyma on the dorsal or posterior aspect of the organ. The knowledge of inferior segmental branch of renal artery is very important for surgeries in its distribution area in kidney. Materials and Methods: 100 kidneys (Fifty pairs intact with abdominal aorta were collected from department of Forensic medicine, JSS Medical College and Mysore Medical College. For study of segmental variation Corrosion cast technique method was used. The variations of inferior segmental branch of renal artery were observed and recorded. Results: In present study type I inferior segmental branch of renal artery were found in - 59% cases, type II in - 6% cases, type III in - 28% cases, type IV in - 2% cases. Conclusion: The inferior segmental artery from the anterior division of the renal artery is the commonest event –arising in 59%. This is Type I, the normal type. It arises from the renal artery (28% or from the posterior division (6% or from the aorta (2%. The knowledge of inferior segmental branch of renal artery helpful in kidney transplantation and renal surgery because these type of surgeries success mainly depends on arterial ligations.

  8. 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.

  9. 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.

  10. 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.)

  11. 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...

  12. 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