A simple method for panretinal imaging with the slit lamp.

PubMed

Gellrich, Marcus-Matthias

2016-12-01

Slit lamp biomicroscopy of the retina with a convex lens is a key procedure in clinical practice. The methods presented enable ophthalmologists to adequately image large and peripheral parts of the fundus using a video-slit lamp and freely available stitching software. A routine examination of the fundus with a slit lamp and a +90 D lens is recorded on a video film. Later, sufficiently sharp still images are identified on the video sequence. These still images are imported into a freely available image-processing program (Hugin, for stitching mosaics together digitally) and corresponding points are marked on adjacent still images with some overlap. Using the digital stitching program Hugin panoramic overviews of the retina can be built which can extend to the equator. This allows to image diseases involving the whole retina or its periphery by performing a structured fundus examination with a video-slit lamp. Similar images with a video-slit lamp based on a fundus examination through a hand-held non-contact lens have not been demonstrated before. The methods presented enable those ophthalmologists without high-end imaging equipment to monitor pathological fundus findings. The suggested procedure might even be interesting for retinological departments if peripheral findings are to be documented which might be difficult with fundus cameras.

Evaluation of white-to-white distance and anterior chamber depth measurements using the IOL Master, slit-lamp adapted optical coherence tomography and digital photographs in phakic eyes.

PubMed

Wilczyński, Michał; Pośpiech-Zabierek, Aleksandra

2015-01-01

The accurate measurement of the anterior chamber internal diameter and depth is important in ophthalmic diagnosis and before some eye surgery procedures. The purpose of the study was to compare the white-to-white distance measurements performed using the IOL-Master and photography with internal anterior chamber diameter determined using slit lamp adapted optical coherence tomography in healthy eyes, and to compare anterior chamber depth measurements by IOL-Master and slit lamp adapted optical coherence tomography. The data were gathered prospectively from a non-randomized consecutive series of patients. The examined group consisted of 46 eyes of 39 patients. White-to-white was measured using IOL-Master and photographs of the eye were taken with a digital camera. Internal anterior chamber diameter was measured with slit-lamp adapted optical coherence tomography. Anterior chamber depth was measured using the IOL Master and slit-lamp adapted optical coherence tomography. Statistical analysis was performed using parametric tests. A Bland-Altman plot was drawn. White-to-white distance by the IOL Master was 11.8 +/- 0.40 mm, on photographs it was 11.29 +/- 0.58 mm and internal anterior chamber diameter by slit-lamp adapted optical coherence tomography was 11.34?0.54 mm. A significant difference was found between IOL-Master and slit-lamp adapted optical coherence tomography (p<0.01), as well as between IOL Master and digital photographs (p<0.01). There was no difference between SL-OCT and digital photographs (p>0.05). All measurements were correlated (Spearman p<0.001). Mean anterior chamber depth determined using the IOL-Master was 2.99 +/- 0.50 mm and by slit-lamp adapted optical coherence tomography was 2.56 +/- 0.46 mm. The difference was statistically significant (p<0.001). The correlation between the values was also statistically significant (Spearman, p<0.001). Automated measurements using IOL-Master yield constantly higher values than measurements based on direct eye visualization slit-lamp adapted optical coherence tomography and digital photographs. In order to obtain accurate measurements of the internal anterior chamber diameter and anterior chamber depth, a method involving direct visualization of intraocular structures should be used.

Slit lamps and lenses: a potential source of nosocomial infections?

PubMed

Sobolewska, Bianka; Buhl, Michael; Liese, Jan; Ziemssen, Focke

2018-01-30

The aim of the study was to evaluate the bacterial contamination level of contact surfaces on slit lamps and the grip areas of lenses. Within unannounced audits, two regions of the slit lamps (headrest and joystick), indirect ophthalmoscopy devices, and ultrasound probes were obtained with rayon-tipped swab. Non-contact lenses used for indirect fundoscopy were pressed on RODAC (Replicate Organism Detection and Counting) plates. One hundred and eighty-one surfaces were sampled. The total number of colony-forming units was assessed and bacterial species were identified. Spa-typing and antimicrobial susceptibility testing were performed from Staphylococcus aureus isolates. Among the total bacterial isolates from ophthalmological equipment (lenses: 51 of 78, slit lamps: 43 of 88, ophthalmoscopy helmets: 3 of 8, ultrasound probes: 2 of 7), coagulase-negative staphylococci (CNS) was most frequently found, followed by Micrococcus spp. (lenses vs. slit lamps: P < 0.001 and P = 0.01, respectively). The bacterial contamination of lenses (76%) was significantly higher than that of slit lamps (54%) (P < 0.003). A significantly higher contamination with CNS was observed on lenses from residents vs. from consultants (78% vs. 35%, P = 0.01). A total of seven different spa-types of S. aureus were isolated. No correlation was found between S. aureus contamination of different ophthalmological equipments (Spearman's rank correlation coefficient, ρ = 0.04, P = 0.75). Methicillin-resistant S. aureus was not detected. Bacterial species of the normal skin flora were isolated from the ophthalmological equipment. The bacterial contamination of the portable devices was significantly higher than that of slit lamps. Therefore, proper hygiene of the mobile instruments should be monitored in order to prevent transmission of bacteria in residents and consultants.

Commercial Slit-Lamp Anterior Segment Photography versus Digital Compact Camera Mounted on a Standard Slit-Lamp with an Adapter.

PubMed

Oliphant, Huw; Kennedy, Alasdair; Comyn, Oliver; Spalton, David J; Nanavaty, Mayank A

2018-06-16

To compare slit lamp mounted cameras (SLC) versus digital compact camera (DCC) with slit-lamp adaptor when used by an inexperienced technician. In this cross sectional study, where posterior capsule opacification (PCO) was used as a comparator, patients were consented for one photograph with SLC and two with DCC (DCC1 and DCC2), with a slit-lamp adaptor. An inexperienced clinic technician, who took all the photographs and masked the images, recruited one eye of each patient. Images were graded for PCO using ECPO2000 software by two independent masked graders. Repeatability between DCC1 & DCC2 and limits-of-agreement between SLC and DCC1 mounted on slit-lamp with an adaptor were assessed. Coefficient-of-repeatability and Bland-Altmann plots were analyzed. Seventy-two patients (eyes) were recruited in the study. First 9 patients (eyes) were excluded due to unsatisfactory image quality from both the systems. Mean EPCO score for SLC was 2.28 (95% CI: 2.09 -2.45), for DCC1 was 2.28 (95% CI: 2.11-2.45), and for the DCC2 was 2.11 (95% CI: 2.11-2.45). There was no significant difference in EPCO scores between SLC Vs. DCC1 (p = 0.98) and between DCC1 and DCC 2 (p = 0.97). Coefficient of repeatability between DCC images was 0.42, and the coefficient of repeatability between DCC and SLC was 0.58. DCC on slit-lamp with an adaptor is comparable to a SLC. There is an initial learning curve, which is similar for both for an inexperienced person. This opens up the possibility for low cost anterior segment imaging in the clinical, research and teaching settings.

In vivo laser confocal microscopy findings of a cornea with osteogenesis imperfecta.

PubMed

Kobayashi, Akira; Higashide, Tomomi; Yokogawa, Hideaki; Yamazaki, Natsuko; Masaki, Toshinori; Sugiyama, Kazuhisa

2014-01-01

To report the in vivo laser confocal microscopy findings of a cornea with osteogenesis imperfecta (OI) with special attention to the abnormality of Bowman's layer and sub-Bowman's fibrous structures (K-structures). Two patients (67-year-old male and his 26-year-old son) with OI type I were included in this study. Slit lamp biomicroscopic and in vivo laser confocal microscopic examinations were performed for both patients. Central corneal thickness and central endothelial cell density were also measured. Although the corneas looked clear with normal endothelial density for both eyes in both patients, they were quite thin (386 μm oculus dexter (OD) (the right eye) and 384 μm oculus sinister (OS) (the left eye) in the father and 430 μm OD and 425 μm OS in the son). In both patients, slit lamp biomicroscopic and in vivo laser confocal microscopic examination showed similar results. Anterior corneal mosaics produced by rubbing the eyelid under fluorescein were completely absent in both eyes. In vivo laser confocal microscopy revealed an absent or atrophic Bowman's layer; a trace of a presumed Bowman's layer and/or basement membrane was barely visible with high intensity. Additionally, K-structures were completely absent in both eyes. The absence of K-structures and fluorescein anterior corneal mosaics strongly suggested an abnormality of Bowman's layer in these OI patients.

Monitoring and Morphologic Classification of Pediatric Cataract Using Slit-Lamp-Adapted Photography.

PubMed

Long, Erping; Lin, Zhuoling; Chen, Jingjing; Liu, Zhenzhen; Cao, Qianzhong; Lin, Haotian; Chen, Weirong; Liu, Yizhi

2017-11-01

To investigate the feasibility of pediatric cataract monitoring and morphologic classification using slit lamp-adapted anterior segmental photography in a large cohort that included uncooperative children. Patients registered in the Childhood Cataract Program of the Chinese Ministry of Health were prospectively selected. Eligible patients underwent slit-lamp adapted anterior segmental photography to record and monitor the morphology of their cataractous lenses. A set of assistance techniques for slit lamp-adapted photography was developed to instruct the parents of uncooperative children how to help maintain the child's head position and keep the eyes open after sleep aid administration. Briefly, slit lamp-adapted photography was completed for all 438 children, including 260 (59.4%) uncooperative children with our assistance techniques. All 746 images of 438 patients successfully confirmed the diagnoses and classifications. Considering the lesion location, pediatric cataract morphologies could be objectively classified into the seven following types: total; nuclear; polar, including two subtypes (anterior and posterior); lamellar; nuclear combined with cortical, including three subtypes (coral-like, dust-like, and blue-dot); cortical; and Y suture. The top three types of unilateral cataracts were polar (55, 42.3%), total (42, 32.3%), and nuclear (23, 17.7%); and the top three types of bilateral cataracts were nuclear (110, 35.8%), total (102, 33.2%), and lamellar (34, 11.1%). Slit lamp-adapted anterior segmental photography is applicable for monitoring and classifying the morphologies of pediatric cataracts and is even safe and feasible for uncooperative children with assistance techniques and sleep aid administration. This study proposes a novel strategy for the preoperative evaluation and evidence-based management of pediatric ophthalmology (Clinical Trials.gov, NCT02748031).

New gonioscopy system using only infrared light.

PubMed

Sugimoto, Kota; Ito, Kunio; Matsunaga, Koichi; Miura, Katsuya; Esaki, Koji; Uji, Yukitaka

2005-08-01

To describe an infrared gonioscopy system designed to observe the anterior chamber angle under natural mydriasis in a completely darkened room. An infrared light filter was used to modify the light source of the slit-lamp microscope. A television monitor connected to a CCD monochrome camera was used to indirectly observe the angle. Use of the infrared system enabled observation of the angle under natural mydriasis in a completely darkened room. Infrared gonioscopy is a useful procedure for the observation of the angle under natural mydriasis.

In vivo laser confocal microscopy findings of a cornea with osteogenesis imperfecta

PubMed Central

Kobayashi, Akira; Higashide, Tomomi; Yokogawa, Hideaki; Yamazaki, Natsuko; Masaki, Toshinori; Sugiyama, Kazuhisa

2014-01-01

Objective To report the in vivo laser confocal microscopy findings of a cornea with osteogenesis imperfecta (OI) with special attention to the abnormality of Bowman’s layer and sub-Bowman’s fibrous structures (K-structures). Patients and methods Two patients (67-year-old male and his 26-year-old son) with OI type I were included in this study. Slit lamp biomicroscopic and in vivo laser confocal microscopic examinations were performed for both patients. Central corneal thickness and central endothelial cell density were also measured. Results Although the corneas looked clear with normal endothelial density for both eyes in both patients, they were quite thin (386 μm oculus dexter (OD) (the right eye) and 384 μm oculus sinister (OS) (the left eye) in the father and 430 μm OD and 425 μm OS in the son). In both patients, slit lamp biomicroscopic and in vivo laser confocal microscopic examination showed similar results. Anterior corneal mosaics produced by rubbing the eyelid under fluorescein were completely absent in both eyes. In vivo laser confocal microscopy revealed an absent or atrophic Bowman’s layer; a trace of a presumed Bowman’s layer and/or basement membrane was barely visible with high intensity. Additionally, K-structures were completely absent in both eyes. Conclusion The absence of K-structures and fluorescein anterior corneal mosaics strongly suggested an abnormality of Bowman’s layer in these OI patients. PMID:24591812

Ultra-wide field imaging system and traditional retinal examinations for screening fundus changes after cataract surgery.

PubMed

Peng, Jie; Zhang, Qi; Jin, Hai-Ying; Lu, Wu-Yi; Zhao, Pei-Quan

2016-01-01

To compare the results of non-mydriatic ultra-wide field imaging system, mydriatic slit-lamp lens (Volk +90 D) and mydriatic Goldmann three-mirror contact lens examinations in screening fundus lesions among patients after cataract surgery. Non-mydriatic images were obtained with an Optomap panoramic 200Tx (Optomap 200Tx) 3d after surgery and graded by a blinded ophthalmologist. A mydriatic slit-lamp lens examination was performed by another blinded retinal specialist on the same day. A third blinded retinal specialist examined patients two weeks after surgery using a Goldmann three-mirror contact lens. In total, 160 patients (184 eyes) were examined, and 66, 69, and 75 cases of retinal lesion(s) were identified using the Optomap 200Tx, slit-lamp lens, and Goldmann three-mirror contact lens, respectively. In 13 cases, fundus changes were sight-threatening. The results obtained by Optomap 200Tx examination and by mydriatic slit-lamp lens examination have good consistency (P=0.375, Kappa=0.942). The mydriatic Goldmann three-mirror lens examination revealed more fundus lesions but are consistent with Optomap 200Tx (P=0.004, Kappa=0.897) and mydriatic slit-lamp lens examination (P=0.031, Kappa=0.932). Early post-operative fundus screening in cataract patients is extremely important and necessary to prevent further vision loss. Wide-field imaging is a feasible and convenient tool for fundus examination that can be used as a primary screening method among patients after cataract surgery.

Retinal slit lamp video mosaicking.

PubMed

De Zanet, Sandro; Rudolph, Tobias; Richa, Rogerio; Tappeiner, Christoph; Sznitman, Raphael

2016-06-01

To this day, the slit lamp remains the first tool used by an ophthalmologist to examine patient eyes. Imaging of the retina poses, however, a variety of problems, namely a shallow depth of focus, reflections from the optical system, a small field of view and non-uniform illumination. For ophthalmologists, the use of slit lamp images for documentation and analysis purposes, however, remains extremely challenging due to large image artifacts. For this reason, we propose an automatic retinal slit lamp video mosaicking, which enlarges the field of view and reduces amount of noise and reflections, thus enhancing image quality. Our method is composed of three parts: (i) viable content segmentation, (ii) global registration and (iii) image blending. Frame content is segmented using gradient boosting with custom pixel-wise features. Speeded-up robust features are used for finding pair-wise translations between frames with robust random sample consensus estimation and graph-based simultaneous localization and mapping for global bundle adjustment. Foreground-aware blending based on feathering merges video frames into comprehensive mosaics. Foreground is segmented successfully with an area under the curve of the receiver operating characteristic curve of 0.9557. Mosaicking results and state-of-the-art methods were compared and rated by ophthalmologists showing a strong preference for a large field of view provided by our method. The proposed method for global registration of retinal slit lamp images of the retina into comprehensive mosaics improves over state-of-the-art methods and is preferred qualitatively.

Intraocular light scatter, reflections, fluorescence and absorption: what we see in the slit lamp.

PubMed

van den Berg, Thomas J T P

2018-01-01

Much knowledge has been collected over the past 20 years about light scattering in the eye- in particular in the eye lens- and its visual effect, called straylight. It is the purpose of this review to discuss how these insights can be applied to understanding the slit lamp image. The slit lamp image mainly results from back scattering, whereas the effects on vision result mainly from forward scatter. Forward scatter originates from particles of about wavelength size distributed throughout the lens. Most of the slit lamp image originates from small particle scatter (Rayleigh scatter). For a population of middle aged lenses it will be shown that both these scatter components remove around 10% of the light from the direct beam. For slit lamp observation close to the reflection angles, zones of discontinuity (Wasserspalten) at anterior and posterior parts of the lens show up as rough surface reflections. All these light scatter effects increase with age, but the correlations with age, and also between the different components, are weak. For retro-illumination imaging it will be argued that the density or opacity seen in areas of cortical or posterior subcapsular cataract show up because of light scattering, not because of light loss. NOTES: (1) Light scatter must not be confused with aberrations. Light penetrating the eye is divided into two parts: a relatively small part is scattered, and removed from the direct beam. Most of the light is not scattered, but continues as the direct beam. This non-scattered part is the basis for functional imaging, but its quality is under the control of aberrations. Aberrations deflect light mainly over small angles (<1°), whereas light scatter is important because of the straylight effects over large angles (>1°), causing problems like glare and hazy vision. (2) The slit lamp image in older lenses and nuclear cataract is strongly influenced by absorption. However, this effect is greatly exaggerated by the light path lengths concerned. This obviates proper judgement of the functional importance of absorption, and hinders the appreciation of the Rayleigh nature of what is seen in the slit lamp image. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

Software-based evaluation of toric IOL orientation in a multicenter clinical study.

PubMed

Kasthurirangan, Sanjeev; Feuchter, Lucas; Smith, Pamela; Nixon, Donald

2014-12-01

To evaluate the rotational stability of a new one-piece hydrophobic acrylic toric intraocular lens (IOL) using a custom-developed software for analysis of slit-lamp photographs. In a prospective, multicenter study, 174 eyes were implanted with the TECNIS Toric IOL (Abbott Medical Optics, Inc., Santa Ana, CA). A custom-developed software was used to analyze high-resolution slit-lamp photographs of 156 eyes taken at day 1 (baseline) and 1, 3, and 6 months postoperatively. The software uses iris and sclera landmarks to align the baseline image and later images for comparison. Validation of software was performed through repeated analyses of protractor images rotated from 0.1° to 10.0° and randomly selected photographs of 20 eyes. Software validation showed precision (repeatability plus reproducibility variation) of 0.02° using protractor images and 2.22° using slit-lamp photographs. Good quality slit-lamp images and clear landmarks were necessary for precise measurements. At 6 months, 94.2% of eyes had 5° or less change in IOL orientation versus baseline; only 2 eyes (1.4%) had axis shift greater than 30°. Most eyes were within 5° or less of rotation between 1 and 3 months (92.9%) and 3 and 6 months (94.1%). Mean absolute axis change (± standard deviation) from 1 day to 6 months was 2.70° ± 5.51°. The new custom software was precise and quick in analyzing slit-lamp photographs to determine postoperative toric IOL rotation. Copyright 2014, SLACK Incorporated.

Corneal crystalline deposits associated with topically applied gatifloxacin.

PubMed

Elia, Maxwell; Khodadadeh, Sarah; Chow, Jessica

2014-06-01

To report a case of corneal crystalline deposits from the use of gatifloxacin 0.5% topical antibiotic after combined cataract extraction and trabeculotomy ab interno surgery. A 59-year-old woman presented after combined cataract extraction and trabeculotomy ab interno with crystalline deposits in the anterior corneal stroma. Clinical examination and slit-lamp photography were performed. The slit-lamp examination showed inferior white crystal deposition in the anterior stroma with overlying punctate epithelial erosions 4 weeks postoperatively. The eye was asymptomatic, but the deposition was cosmetically noticeable to the patient. Serial slit-lamp photography demonstrated resolution of the crystalline deposits 30 days after the discontinuation of eye drops. The authors present a rare case of stromal crystallization from topical gatifloxacin treatment. Complete resolution of corneal deposits was seen 30 days after the discontinuation of the drops without sequelae.

Appraisal of Bleb Using Trio of Intraocular Pressure, Morphology on Slit Lamp, and Gonioscopy.

PubMed

Thatte, Shreya; Rana, Rimpi; Gaur, Neeraj

2016-01-01

The aim of this study was to assess bleb function using Wuerzburg bleb classification score (WBCS) for bleb morphology on slit lamp, intraocular pressure (IOP), and gonioscopy. A total of randomly selected 30 eyes posttrabeculectomy were assessed for bleb function with the trio of bleb morphology, IOP, and gonioscopy. Bleb was assessed using the WBCS of 0-12 on slit lamp, IOP was assessed using applanation tonometry, and visualization of inner ostium and iridectomy were assessed using gonioscopy. Postoperative patients of less than six weeks were excluded from the study. The correlation between WBCS and the duration of trabeculectomy was found to be highly significant ( P value = 0.029). The correlation of IOP with WBCS was also found to be strongly positive ( P = 0.000). IOP was found to be highly associated with peripheral iridectomy ( P = 0.000), internal window ( P = 0.001), and bleb characteristics.

Slit Lamp-Based Ocular Scoring Systems in Toxicology and Drug Development: A Literature Survey.

PubMed

Eaton, Joshua Seth; Miller, Paul E; Bentley, Ellison; Thomasy, Sara M; Murphy, Christopher J

2017-12-01

To present a survey of the features of published slit lamp-based scoring systems and their applicability in the context of modern ocular toxicology and drug development. References describing original or modified slit lamp-based scoring systems for human or veterinary clinical patients or in investigative or toxicologic research were collected following a comprehensive literature review using textbooks and online publication searches. Each system's indications and features were compiled to facilitate comparison. Literature review identified 138 original or modified scoring systems. Most (48%) were published for evaluation of the ocular surface, 34% for the general anterior segment, and 18% for the lens. Most systems were described for assessment of human patients (50%) and small albino laboratory species such as rabbits (19%), rats (12%), and mice (8%). Systems described for pigmented laboratory species and for larger species such as dogs, cats, pigs, and nonhuman primates (NHPs) were comparatively underrepresented. No systems described a lens scoring scheme specific to the dog, cat, pig, or NHP. Scoring schemes for aqueous and vitreous cells were infrequently described for laboratory species. Many slit lamp-based scoring systems have been published, but the features of each differ and complicate translation of findings between different species. Use and interpretation of any scoring system in toxicology and drug development must be done with awareness of the limitations of the system being used.

The SL SCAN-1: Fourier Domain Optical Coherence Tomography Integrated into a Slit Lamp

NASA Astrophysics Data System (ADS)

Verbraak, F. D.; Stehouwer, M.

The detailed cross-sectional images of OCT can be used for diagnosis and follow-up, assessing therapeutic success or failure. Recently, the OCT technology has been implemented in a small unit compatible with existing slit lamps. This increases the efficiency of the routine clinical examination of a patient, will increase the comfort of the patient, and saves time. Additionally, the posterior segment can be scanned through a handheld lens and even through a three-mirror lens.

Punctiform and Polychromatophilic Dominant Pre-Descemet Corneal Dystrophy.

PubMed

Lagrou, Lisa; Midgley, Julian; Romanchuk, Kenneth Gerald

2016-04-01

To describe the slit-lamp appearance and corneal confocal microscopy of autosomal dominant punctiform and polychromatophilic pre-Descemet corneal dystrophy in 3 members of the same family. Slit-lamp examination of a 9-year-old boy showed bilateral polychromatophilic corneal opacities in a pre-Descemet membrane location evenly deposited limbus to limbus, both horizontally and vertically, with an intervening clear cornea. The corneal endothelium was normal on corneal confocal microscopy, with hyperreflective opacities of various sizes located pre-Descemet membrane. Slit-lamp examination of the patient's father and brother revealed identical crystalline deposition in the pre-Descemet corneal stroma. The remainders of the eye examinations were otherwise normal in all 3 individuals, and all were asymptomatic. The general physical examination and laboratory investigations of the patient were all normal, as were the laboratory investigations of the other 2 family members. There was no progression in the corneal findings over 6 months of follow-up. These patients likely illustrate a rare autosomal dominant pre-Descemet crystalline keratopathy that has been reported only once previously.

Localization and diagnosis framework for pediatric cataracts based on slit-lamp images using deep features of a convolutional neural network

PubMed Central

Zhang, Kai; Long, Erping; Cui, Jiangtao; Zhu, Mingmin; An, Yingying; Zhang, Jia; Liu, Zhenzhen; Lin, Zhuoling; Li, Xiaoyan; Chen, Jingjing; Cao, Qianzhong; Li, Jing; Wu, Xiaohang; Wang, Dongni

2017-01-01

Slit-lamp images play an essential role for diagnosis of pediatric cataracts. We present a computer vision-based framework for the automatic localization and diagnosis of slit-lamp images by identifying the lens region of interest (ROI) and employing a deep learning convolutional neural network (CNN). First, three grading degrees for slit-lamp images are proposed in conjunction with three leading ophthalmologists. The lens ROI is located in an automated manner in the original image using two successive applications of Candy detection and the Hough transform, which are cropped, resized to a fixed size and used to form pediatric cataract datasets. These datasets are fed into the CNN to extract high-level features and implement automatic classification and grading. To demonstrate the performance and effectiveness of the deep features extracted in the CNN, we investigate the features combined with support vector machine (SVM) and softmax classifier and compare these with the traditional representative methods. The qualitative and quantitative experimental results demonstrate that our proposed method offers exceptional mean accuracy, sensitivity and specificity: classification (97.07%, 97.28%, and 96.83%) and a three-degree grading area (89.02%, 86.63%, and 90.75%), density (92.68%, 91.05%, and 93.94%) and location (89.28%, 82.70%, and 93.08%). Finally, we developed and deployed a potential automatic diagnostic software for ophthalmologists and patients in clinical applications to implement the validated model. PMID:28306716

Slit-lamp management in contact lenses laboratory classes: learning upgrade with monitor visualization of webcam video recordings

NASA Astrophysics Data System (ADS)

Arines, Justo; Gargallo, Ana

2014-07-01

The training in the use of the slit lamp has always been difficult for students of the degree in Optics and Optometry. Instruments with associated cameras helps a lot in this task, they allow teachers to observe and control if the students evaluate the eye health appropriately, correct use errors and show them how to do it with a visual demonstration. However, these devices are more expensive than those that do not have an integrated camera connected to a display unit. With the aim to improve students' skills in the management of slit lamp, we have adapted USB HD webcams (Microsoft Lifecam HD-5000) to the objectives of the slit lamps available in our contact lenses laboratory room. The webcams are connected to a PC running Linux Ubuntu 11.0; therefore that is a low-cost device. Our experience shows that single method has several advantages. It allows us to take pictures with a good quality of different conditions of the eye health; we can record videos of eye evaluation and make demonstrations of the instrument. Besides it increases the interactions between students because they could see what their colleagues are doing and take conscious of the mistakes, helping and correcting each others. It is a useful tool in the practical exam too. We think that the method supports the training in optometry practice and increase the students' confidence without a huge outlay.

[Development of non-invasive clinical examination methods for the anterior segment of the eye and their clinical significance].

PubMed

Sawa, Mitsuru

2011-03-01

1. Slit-lamp microscopy is a principal ophthalmic clinical method, because it provides microscopic findings of the anterior segment of the eye noninvasively. Its findings, however, are qualitative and there are large inter-observer variations in their evaluation. Furthermore, slit-lamp microscopy provides morphological findings, but a functional evaluation is difficult. We developed two novel methods that establish a qualitative methodology of the slit-lamp microscope and the pathophysiology of the anterior segment of the eye. One is the flare-cell photometer to evaluate flare and cells in the aqueous humor of the eye and the other is an immunohistochemical examination method using tear fluid to evaluate ocular surface disorders. The comprehensive evaluation of these studies is herein overviewed. 2. INNOVATION OF THE FLARE-CELL PHOTOMETER AND ITS CLINICAL SIGNIFICANCE: The breakdown of the blood-aqueous barrier (BAB) causes an increase in protein (flare) and leakage of blood cells (cell) into the aqueous humor of the eye and the severity of BAB breakdown has a positive correlation with the intensity of flare and cells. The flare and cells in the aqueous can be observed qualitatively by slit-lamp microscopy. These findings are primarily distinguished in optics by light scattering. Therefore, detection of the intensity of light scattering due to flare and cells can evaluate the BAB function. The flare-cell photometer comprises 3 novel components: a laser beam system as an incident light, a photomultiplier to detect scattered light intensity and a computer-assisted system to operate the whole system and analyze detected scattered light signals due to flare and cells. The instrument enables us to quantitatively analyze the flare and cells non-invasively and accurately with a wide dynamic measurement range, resulting in a repeated examination of each individual case. It also enables the evaluation of inflammation in the aqueous not only postoperatively but also in endogenous uveitis, evaluation of the effects of anti-inflammatory drugs on BAB and evaluation of aqueous humor dynamics. Furthermore, repeating the examination can minimize inter-individual variations and reduce the number of animals in animal experiments. 3. Sampling of tears can be performed noninvasively, but the obtainable volume is limited. Therefore, a determination of targeting biomarkers and a development of their micro-volume analysis methods play a crucial role in pathophysiological studies of the ocular surface. Targeting biomarkers should be determined according to the various specified bioactive substances such as eosinophil cationic protein (ECP), cytokines and others. A number of microvolume analysis methods, such as chemiluminescent enzyme immunoassay, immunochromatography, micro-array system and polymerase chain reaction method are used. Objective disorders in the studies include allergic conjunctivitis and infectious diseases such as herpetic keratitis. Quantitative evaluation methods for ECP concentration, antigen-specific secretory IgA in allergic diseases and herpetic keratitis, herpes simplex virus-DNA and cytokine and chemokine profile in tear fluid sampled by filter paper method were investigated. We developed a clinically applicable quantitative immunochemical method for ECP concentration in tear fluid. The results revealed that tear fluid analysis using the above mentioned methods is a clinically useful to investigate the pathophysiology of the ocular surface. 4. Laser flare-cell photometer and tear fluid analysis are potent clinical quantitative methods to investigate the pathophysiology of the anterior segment of the eye.

Functional slit lamp biomicroscopy for imaging bulbar conjunctival microvasculature in contact lens wearers

PubMed Central

Jiang, Hong; Zhong, Jianguang; DeBuc, Delia Cabrera; Tao, Aizhu; Xu, Zhe; Lam, Byron L.; Liu, Che; Wang, Jianhua

2014-01-01

Purpose To develop, test and validate functional slit lamp biomicroscopy (FSLB) for generating non-invasive bulbar conjunctival microvascular perfusion maps (nMPMs) and assessing morphometry and hemodyanmics. Methods FSLB was adapted from a traditional slit-lamp microscope by attaching a digital camera to image the bulbar conjunctiva to create nMPMs and measure venular blood flow hemodyanmics. High definition images with a large field of view were obtained on the temporal bulbar conjunctiva for creating nMPMs. A high imaging rate of 60 frame per second and a ~210× high magnification were achieved using the camera inherited high speed setting and movie crop function, for imaging hemodyanmics. Custom software was developed to segment bulbar conjunctival nMPMs for further fractal analysis and quantitatively measure blood vessel diameter, blood flow velocity and flow rate. Six human subjects were imaged before and after 6 hours of wearing contact lenses. Monofractal and multifractal analyses were performed to quantify fractality of the nMPMs. Results The mean bulbar conjunctival vessel diameter was 18.8 ± 2.7 μm at baseline and increased to 19.6 ± 2.4 μm after 6 hours of lens wear (P = 0.020). The blood flow velocity was increased from 0.60 ± 0.12 mm/s to 0.88 ± 0.21 mm/s (P = 0.001). The blood flow rate was also increased from 129.8 ± 59.9 pl/s to 207.2 ± 81.3 pl/s (P = 0.001). Bulbar conjunctival nMPMs showed the intricate details of the bulbar conjunctival microvascular network. At baseline, fractal dimension was 1.63 ± 0.05 and 1.71 ± 0.03 analyzed by monofractal and multifractal analysis, respectively. Significant increases in fractal dimensions were found after 6 hours of lens wear (P < 0.05). Conclusions Microvascular network’s fractality, morphometry and hemodyanmics of the human bulbar conjunctiva can be measured easily and reliably using FSLB. The alternations of the fractal dimensions, morphometry and hemodyanmics during contact lens wear may indicate ocular microvascular responses to contact lens wear. PMID:24444784

Scleral Buckling under a Slit-lamp Illumination System with a Contact Wide-angle Viewing Lens Compared with an Indirect Ophthalmoscope.

PubMed

Choi, Seung Yong; Lee, Youlim; Kim, Mirinae; Park, Young Hoon

2018-04-01

To investigate the outcomes of scleral buckling surgery performed under a slit-lamp illumination system (Visulux) with a contact wide-angle viewing lens (Mini Quad) in patients with rhegmatogenous retinal detachment (RRD) and to compare these outcomes with those of surgery performed under an indirect ophthalmoscope. By retrospective review of electronic medical records, patients with RRD who had undergone scleral buckling surgery were identified. Scleral buckling surgeries were performed with two illumination instruments, a slit-lamp (SL group) and an indirect ophthalmoscope (IO group). Subretinal fluid drainage, cryopexy, and intravitreal gas injection were performed optionally. At 6 months after surgery, anatomical and functional outcomes were evaluated and compared between the two groups. Operation time was also compared between the two groups. Of the 45 total patients (45 eyes), 28 were included in the SL group, and 17 were included in the IO group. In the SL and IO groups, the primary anatomical success rate was 89.3% and 88.2%, respectively (p = 0.92). The logarithm of the minimal angle of resolution change, which reflects improvement in best-corrected visual acuity after surgery, was -0.19 ± 0.38 in the SL group and -0.21 ± 0.63 in the IO group; this difference was not statistically significant (p = 0.91). The mean operation time was significantly shorter in the SL group (78.9 ± 11.8 minutes) than in the IO group (100.0 ± 13.9 minutes, p < 0.001), especially for patients who underwent additional procedures such as subretinal fluid drainage and cryopexy (81.4 ± 12.9 and 103.5 ± 12.3 minutes, respectively, p < 0.001). Scleral buckling surgery performed under a slit-lamp illumination system yielded a similar anatomical success rate and similar functional improvement in RRD compared with surgery performed under an indirect ophthalmoscope. The slit-lamp system could save time, especially in bullous RRD, which requires additional subretinal fluid drainage. © 2018 The Korean Ophthalmological Society.

Rabbit intraocular reactivity to endotoxin measured by slit-lamp biomicroscopy and laser flare photometry.

PubMed

Nussenblatt, Robert B; Calogero, Don; Buchen, Shelley Y; Leder, Henry A; Goodkin, Margot; Eydelman, Malvina B

2012-07-01

To evaluate the ocular reactivity of the rabbit to an intracameral injection of a dispersive ophthalmic viscosurgical device (OVD) containing various levels of bacterial endotoxin using slit-lamp biomicroscopy and laser flare photometry. Experimental, randomized, masked animal study. Thirty Dutch-Belted rabbits. The rabbits were randomized into 6 groups to receive 0.05 ml of a hydroxypropyl methylcellulose-based dispersive OVD to which had been added one of 5 different doses of bacterial endotoxin ranging from 0.02 to 1.4 endotoxin units (EUs) or a vehicle control to both eyes. The eyes were evaluated for anterior segment inflammation at baseline and 3, 6, 9, 24, 48, and 72 hours after injection using slit-lamp biomicroscopy and laser flare photometry. Corneal clarity and anterior chamber (AC) inflammation. All the corneas remained clear throughout the study. Anterior chamber cells were seen at 6, 9, and 24 hours in 60% to 100% of the eyes intracamerally injected with endotoxin-containing OVD, and the response declined rapidly after 24 hours. A dose-response effect was seen between the concentration of endotoxin and the AC cell response. The aqueous flare response in eyes injected with the 2 highest doses of endotoxin was significantly greater (P<0.05) than that of controls. The amounts of fibrin observed in the AC were random, with no apparent dose-response effect seen. The flare values as obtained by laser flare photometry were consistent with the slit-lamp biomicroscopy flare findings up to grade 3+. However, the increase in laser flare value seemed to level off in eyes with more than 3+ flare. Neither measure of flare correlated with endotoxin level. Among the parameters evaluated in this study, the AC cell response, evaluated by slit-lamp biomicroscopy and graded using a standard grading system, was found to be the most reliable indicator of the amount of endotoxin in the dispersive OVD. The use of laser flare photometry alone does not seem to be useful in detecting an ocular response to endotoxin contamination in OVDs. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Is screening with digital imaging using one retinal view adequate?

PubMed

Herbert, H M; Jordan, K; Flanagan, D W

2003-05-01

To compare the detection of diabetic retinopathy from digital images with slit-lamp biomicroscopy, and to determine whether British Diabetic Association (BDA) screening criteria are attained (>80% sensitivity, >95% specificity, &<5% technical failure). Diabetics referred for screening were studied in a prospective fashion. A single 45 degrees fundus image was obtained using the nonmydriatic digital camera. Each patient subsequently underwent slit-lamp biomicroscopy and diabetic retinopathy grading by a consultant ophthalmologist. Diabetic retinopathy and maculopathy was graded according to the Early Treatment of Diabetic Retinopathy Study. A total of 145 patients (288 eyes) were identified for screening. Of these, 26% of eyes had diabetic retinopathy, and eight eyes (3%) had sight-threatening diabetic retinopathy requiring treatment. The sensitivity for detection of any diabetic retinopathy was 38% and the specificity 95%. There was a 4% technical failure rate. There were 42/288 false negatives and 10/288 false positives. Of the 42 false negatives, 18 represented diabetic maculopathy, 20 represented peripheral diabetic retinopathy and four eyes had both macular and peripheral changes. Three eyes in the false-negative group (1% of total eyes) had sight-threatening retinopathy. There was good concordance between the two consultants (79% agreement on slit-lamp biomicroscopy and 84% on digital image interpretation). The specificity value and technical failure rate compare favourably with BDA guidelines. The low sensitivity for detection of any retinopathy reflects failure to detect minimal maculopathy and retinopathy outside the 45 degrees image. This could be improved by an additional nasal image and careful evaluation of macular images with a low threshold for slit-lamp biomicroscopy if image quality is poor.

Argon endolaser suture lysis

NASA Astrophysics Data System (ADS)

Cameron, Bruce D.; Joos, Karen M.; Shen, Jin-Hui

1996-05-01

Purpose: To develop a simple suture lysis technique for post-trabeculectomy examinations under anesthesia since slit lamp laser suture lysis in the clinic cannot be performed on infants and young children. Methods: An argon endolaser probe lysed 10-0 nylon suture through conjunctiva harvested from human cadaver eyes. Since suture lysis failed with the thick Hoskins lens, clear plastic from the suture package compressed the conjunctiva. The conjunctiva was examined histologically. Results: Argon laser suture lysis (250 mW, 0.1 sec, 488 - 514 nm) was achieved without conjunctival damage. Conclusion: The argon endolaser probe is effective for suture lysis when the slit lamp cannot be used.

A gas discharge lamp for the extreme ultraviolet.

PubMed

Nicholson, A J

1970-05-01

A gas discharge lamp is described suitable for producing the many-lined spectrum of hydrogen (85-160 nm) and the Hopfield continuum in helium (60-100 nm). It was designed for use with a window-less monochromator to study photoionization and operates at pressures below 50 Torr. The hydrogen lamp has a mode of operation which concentrates the discharge into the monochromator entrance slit.

Measuring the differences in work ratios between pediatric and adult ophthalmologic examinations.

PubMed

Hyun, Joo; Chang, Jee Ho; Kim, Seung Hoon; Park, Song Hee; Kim, Sunghoon

2017-06-01

To assess the differences in work needed for pediatric and adult ophthalmologic examinations. Seven ophthalmology residents conducted slit-lamp and refraction examinations on children 3-7 years of age and adults 20-69 years of age. The examiners reported the magnitude estimate (ME) of their work in relation to two references (cross-reference ME): average adult examination and average pediatric examination. The examination time was also measured. For the slit-lamp examination, 50 children and 58 adults were recruited. The ME was 1.45 (95% CI, 1.30-1.62) times higher for the pediatric examinations than for the adult examinations when the reference was an average adult case. With respect to time, the pediatric examinations took 1.22 (95% CI, 1.06-1.41) times longer than the adult examinations. For the refraction examinations, 58 children and 96 adults were recruited. The ME was 1.35 (95% CI, 1.21-1.52) times higher for the pediatric examinations. The pediatric examination took 1.32 (95% CI, 1.16-1.50) times longer than the adult examination. The cross-reference ME ratios measuring the pediatric over adult examinations against both the pediatric and adult reference cases were equivalent in both the slit-lamp and the refraction examinations; however, the ME and time ratios of the pediatric over the adult examinations were not equivalent for the slit-lamp or for the refraction examinations. The cross-reference ME showed that pediatric ophthalmologic examinations require more work than the adult examination with validity and reliability. The time estimate was insufficient as a single indicator for work estimation. Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Advantages of using newly developed quartz contact lens with slit illumination from operating microscope.

PubMed

Kiyokawa, Masatoshi; Sakuma, Toshiro; Hatano, Noriko; Mizota, Atsushi; Tanaka, Minoru

2009-06-01

The purpose of this article is to report the characteristics and advantages of using a newly designed quartz contact lens with slit illumination from an operating microscope for intraocular surgery. The new contact lens is made of quartz. The lens is convex-concave and is used in combination with slit illumination from an operating microscope. The optical properties of quartz make this lens less reflective with greater transmittance. The combination of a quartz contact lens with slit illumination provided a brighter and wider field of view than conventional lenses. This system enabled us to perform bimanual vitrectomy and scleral buckling surgery without indirect ophthalmoscope. Small intraocular structures in the posterior pole or in the periphery were detected more easily. In conclusion, the newly designed quartz lens with slit beam illumination from an operating microscope provided a bright, clear and wide surgical field, and allowed intraocular surgery to be performed more easily.

[Gonioscopy - How, Why, What for?

PubMed

Unterlauft, J D

2017-08-01

Aim Gonioscopy is used to exam the anterior chamber angle and the neighbouring structures. Gonioscopy can be performed using a contact lens, with the patient sitting at the slit lamp or in a supine position. Due to the total inner reflection of the cornea, the anterior chamber angle would otherwise be invisible in a healthy eye. During normal daily clinical routine, gonioscopy is often omitted, due to lack of time, although additional information could be gained. Materials and Methods The aim is to give a summary of the diagnostic possibilities using gonioscopy and to emphasise the importance of this relatively easy clinical method. Results The development of gonioscopy, the appropriate tools, proper procedure at the slit lamp and the most popular grading systems are described. In addition, an overview of detectable pathological changes in the anterior chamber angle is given and future prospects about developments in gonioscopy. Conclusion Gonioscopy can provide additional information otherwise missed by slit lamp examination or ophthalmoscopy alone. Up to now, no (semi-)automatic devices have been developed which could completely replace gonioscopy. Therefore gonioscopy remains an important part of a complete ophthalmological examination and should be learned, mastered and performed regularly by every ophthalmologist. Georg Thieme Verlag KG Stuttgart · New York.

Endophthalmitis after descemet stripping endothelial keratoplasty with concave-oriented dislocation on slit-lamp optical coherence topography.

PubMed

Kaiura, Terry L; Ritterband, David C; Koplin, Richard S; Shih, Carolyn; Palmierto, Pat M; Seedor, John A

2010-02-01

To present the first reported case of Descemet membrane stripping endothelial keratoplasty (DSEK)-associated endophthalmitis with concave dislocation on slit-lamp optical coherence topography (SL-OCT). An 86-year-old man underwent DSEK for corneal decompensation secondary to prior surgery. On all postoperative visits, a slit-lamp examination and SL-OCT were performed. On the first postoperative day, the lenticle was dislocated in a concave configuration as imaged with the SL-OCT. On the second postoperative day, the patient had eye pain, nausea, and increased intraocular pressure. On SL-OCT imaging, the concave configuration and fibrin stranding were imaged. With intraocular pressure lowering, the patient's pain subsided, and he was scheduled for a lenticle refloat the following day. The next day, endophthalmitis was diagnosed secondary to exuberant purulent inflammation. At surgery, the lenticle was removed, cultures were obtained, and pars plana vitrectomy and intravitreal injections were administered. Intraoperative cultures were positive for heavy growth of Streptococcus pneumoniae. Endophthalmitis is a potential complication for any intraocular procedure including DSEK. SL-OCT imaging postoperatively may reveal concave lenticle configuration and subtle anterior chamber fibrin stranding may be early sign of endophthalmitis.

An evaluation of 1-day disposable contact lens wear in a population of allergy sufferers.

PubMed

Hayes, Valérie Y; Schnider, Cristina M; Veys, Jane

2003-06-01

This was a multi-site, 128-subject, bilateral crossover study to evaluate subjective comfort and slit-lamp findings with 1-day disposable contact lenses in a population of allergy sufferers during periods when allergen levels were elevated. The study involved 1-month of single-use daily wear with a 1-day disposable test lens (1. DAY ACUVUE Brand Contact Lenses, Johnson & Johnson Vision Care) and 1-month of daily wear with subjects' habitual lenses replaced to their usual replacement schedule. Pollen and mould counts were obtained for each site 1 week prior to the study and twice weekly throughout the study period. Subjective comfort and slit-lamp findings were recorded at baseline and after 1-month's wear of each modality. Sixty-seven percent of subjects agreed that the 1-day disposable lenses provided improved comfort when compared to the lenses they wore prior to the study, compared with 18% agreeing that the new pair of habitual lenses provided improved comfort. The 1-day disposable lenses showed greater improvement in slit-lamp findings from baseline than new habitual lenses. The use of 1-day disposable lenses is an effective strategy for managing allergy-suffering contact lens wearers.

Interference experiment with asymmetric double slit by using 1.2-MV field emission transmission electron microscope.

PubMed

Harada, Ken; Akashi, Tetsuya; Niitsu, Kodai; Shimada, Keiko; Ono, Yoshimasa A; Shindo, Daisuke; Shinada, Hiroyuki; Mori, Shigeo

2018-01-17

Advanced electron microscopy technologies have made it possible to perform precise double-slit interference experiments. We used a 1.2-MV field emission electron microscope providing coherent electron waves and a direct detection camera system enabling single-electron detections at a sub-second exposure time. We developed a method to perform the interference experiment by using an asymmetric double-slit fabricated by a focused ion beam instrument and by operating the microscope under a "pre-Fraunhofer" condition, different from the Fraunhofer condition of conventional double-slit experiments. Here, pre-Fraunhofer condition means that each single-slit observation was performed under the Fraunhofer condition, while the double-slit observations were performed under the Fresnel condition. The interference experiments with each single slit and with the asymmetric double slit were carried out under two different electron dose conditions: high-dose for calculation of electron probability distribution and low-dose for each single electron distribution. Finally, we exemplified the distribution of single electrons by color-coding according to the above three types of experiments as a composite image.

Delayed progression of diabetic cataractogenesis and retinopathy by Litchi chinensis in STZ-induced diabetic rats.

PubMed

Kilari, Eswar Kumar; Putta, Swathi

2017-03-01

The study was carried out to evaluate the effect of the aqueous fruit pericarp extract of Litchi chinensis (APLC) on parameters which leads to diabetic cataractogenesis and retinopathy in the streptozotocin-induced diabetic rats. The objective of the study is to evaluate the APLC for in vivo antioxidant activity and its role in inhibiting the polyol pathway and formation of advanced glycation end products (AGEs). The diabetic animals were treated with L. chinensis for a period of 12 weeks. At the end of 12 weeks, the animals were killed and the biochemical pathways involved in the pathogenesis of cataract such as oxidative stress by protein content, superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and polyolpathway by aldose reductase (AR) in lens homogenates, alterations in protein carbonyl content (PCO) and AGEs in both serum and lens the APLC-treated diabetic rats were compared against diabetic control rats. Cataract progression due to hyperglycemia was monitored by slit lamp bio microscope and classified into four stages. Fundoscope test and retinal histopathology were done for assessing retinopathy. Statistically significant reduction in glucose, and elevation of protein content, SOD, CAT, and GSH levels and decreased levels of AR and PCO in lens homogenate and significant reduction in AGEs serum and lens homogenate were observed. Slit lamp examination, fundoscope, and histopathology showed improvement in retinal changes in APLC-treated rats compared to diabetic control animals. The treatment with APLC found to delay the progression of diabetic cataractogenesis and retinopathy, which might be due to its antioxidant activity, because of the presence of active phytochemicals in APLC.

iPhone 4s and iPhone 5s Imaging of the Eye.

PubMed

Jalil, Maaz; Ferenczy, Sandor R; Shields, Carol L

2017-01-01

To evaluate the technical feasibility of a consumer-grade cellular iPhone camera as an ocular imaging device compared to existing ophthalmic imaging equipment for documentation purposes. A comparison of iPhone 4s and 5s images was made with external facial images (macrophotography) using Nikon cameras, slit-lamp images (microphotography) using Zeiss photo slit-lamp camera, and fundus images (fundus photography) using RetCam II. In an analysis of six consecutive patients with ophthalmic conditions, both iPhones achieved documentation of external findings (macrophotography) using standard camera modality, tap to focus, and built-in flash. Both iPhones achieved documentation of anterior segment findings (microphotography) during slit-lamp examination through oculars. Both iPhones achieved fundus imaging using standard video modality with continuous iPhone illumination through an ophthalmic lens. Comparison to standard ophthalmic cameras, macrophotography and microphotography were excellent. In comparison to RetCam fundus photography, iPhone fundus photography revealed smaller field and was technically more difficult to obtain, but the quality was nearly similar to RetCam. iPhone versions 4s and 5s can provide excellent ophthalmic macrophotography and microphotography and adequate fundus photography. We believe that iPhone imaging could be most useful in settings where expensive, complicated, and cumbersome imaging equipment is unavailable.

The Muranga Teleophthalmology Study: Comparison of Virtual (Teleglaucoma) with in-Person Clinical Assessment to Diagnose Glaucoma.

PubMed

Kiage, Dan; Kherani, Irfan N; Gichuhi, Stephen; Damji, Karim F; Nyenze, Muindi

2013-01-01

While the effectiveness of teleophthalmology is generally accepted, its ability to diagnose glaucomatous eye disease remains relatively unknown. This study aimed to compare a web-based teleophthalmology assessment with clinical slit lamp examination to screen for glaucoma among diabetics in a rural African district. Three hundred and nine diabetic patients underwent both the clinical slit lamp examination by a comprehensive ophthalmologist and teleglaucoma (TG) assessment by a glaucoma subspecialist. Both assessments were compared for any focal glaucoma damage; for TG, the quality of photographs was assessed, and vertical cup-to-disk ratio (VCDR) was calculated in a semi-automated manner. In patients with VCDR > 0.7, the diagnostic precision of the Frequency Doubling Technology (FDT) C-20 screening program was assessed. Of 309 TG assessment photos, 74 (24%) were deemed unreadable due to media opacities, patient cooperation, and unsatisfactory photographic technique. While the identification of individual optic nerve factors showed either fair or moderate agreement, the ability to diagnose glaucoma based on the overall assessment showed moderate agreement (Kappa [κ] statistic 0.55% and 95% confidence interval [CI]: 0.48-0.62). The use of FDT to detect glaucoma in the presence of disc damage (VCDR > 0.7) showed substantial agreement (κ statistic of 0.84 and 95% CI 0.79-0.90). A positive TG diagnosis of glaucoma carried a 77.5% positive predictive value, and a negative TG diagnosis carried an 82.2% negative predicative value relative to the clinical slit lamp examination. There was moderate agreement between the ability to diagnose glaucoma using TG relative to clinical slit lamp examination. Poor quality photographs can severely limit the ability of TG assessment to diagnose optic nerve damage and glaucoma. Although further work and validation is needed, the TG approach provides a novel, and promising method to diagnose glaucoma, a major cause of ocular morbidity throughout the world.

The Muranga Teleophthalmology Study: Comparison of Virtual (Teleglaucoma) with in-Person Clinical Assessment to Diagnose Glaucoma

PubMed Central

Kiage, Dan; Kherani, Irfan N.; Gichuhi, Stephen; Damji, Karim F.; Nyenze, Muindi

2013-01-01

Purpose: While the effectiveness of teleophthalmology is generally accepted, its ability to diagnose glaucomatous eye disease remains relatively unknown. This study aimed to compare a web-based teleophthalmology assessment with clinical slit lamp examination to screen for glaucoma among diabetics in a rural African district. Materials and Methods: Three hundred and nine diabetic patients underwent both the clinical slit lamp examination by a comprehensive ophthalmologist and teleglaucoma (TG) assessment by a glaucoma subspecialist. Both assessments were compared for any focal glaucoma damage; for TG, the quality of photographs was assessed, and vertical cup-to-disk ratio (VCDR) was calculated in a semi-automated manner. In patients with VCDR > 0.7, the diagnostic precision of the Frequency Doubling Technology (FDT) C-20 screening program was assessed. Results: Of 309 TG assessment photos, 74 (24%) were deemed unreadable due to media opacities, patient cooperation, and unsatisfactory photographic technique. While the identification of individual optic nerve factors showed either fair or moderate agreement, the ability to diagnose glaucoma based on the overall assessment showed moderate agreement (Kappa [κ] statistic 0.55% and 95% confidence interval [CI]: 0.48-0.62). The use of FDT to detect glaucoma in the presence of disc damage (VCDR > 0.7) showed substantial agreement (κ statistic of 0.84 and 95% CI 0.79-0.90). A positive TG diagnosis of glaucoma carried a 77.5% positive predictive value, and a negative TG diagnosis carried an 82.2% negative predicative value relative to the clinical slit lamp examination. Conclusion: There was moderate agreement between the ability to diagnose glaucoma using TG relative to clinical slit lamp examination. Poor quality photographs can severely limit the ability of TG assessment to diagnose optic nerve damage and glaucoma. Although further work and validation is needed, the TG approach provides a novel, and promising method to diagnose glaucoma, a major cause of ocular morbidity throughout the world. PMID:23741134

Eyelid drooping

MedlinePlus

... around or behind the eye Diabetes Horner syndrome Myasthenia gravis Stroke Swelling in the eyelid, such as with ... performed include: Slit-lamp examination Tension test for myasthenia gravis Visual field testing

In vivo laser confocal microscopy findings of Thygeson superficial punctate keratitis.

PubMed

Kobayashi, Akira; Yokogawa, Hideaki; Sugiyama, Kazuhisa

2011-06-01

We looked for microstructural corneal characteristics of Thygeson superficial punctate keratitis (TSPK) in an in vivo investigation using laser scanning confocal microscopy. Five patients (3 men and 2 women; mean age, 51.8 years) with clinically diagnosed TSPK were enrolled in this study. All patients were examined by slit-lamp biomicroscopy and in vivo laser confocal microscopy. Deposits in selected confocal images of all corneal layers were evaluated qualitatively for shape and degree of light reflection. The most characteristic finding was aggregates of highly reflective deposits with a starburst-like appearance that corresponded with epithelial punctate lesions identified by slit-lamp biomicroscopy; the aggregates were sporadically observed in all cases at the superficial and basal epithelial cell layers. Subepithelial haze was observed in all cases. Langerhans cells were also sporadically observed in all cases at the basal epithelial layer. Bowman layer abnormalities were observed in 3 of 5 cases; all these patients had a long history of TSPK (eg, more than 1 year). In addition, the 3 patients had highly reflective, tiny, needle-shaped materials in the corneal stroma. In vivo laser confocal microscopy is capable of identifying characteristic corneal microstructural changes related to TSPK with a higher resolution than is available with slit-lamp biomicroscopy. It may also be a valuable tool for further research to elucidate both pathogenesis and the natural course of TSPK.

iPhone 4s and iPhone 5s Imaging of the Eye

PubMed Central

Jalil, Maaz; Ferenczy, Sandor R.; Shields, Carol L.

2017-01-01

Background/Aims To evaluate the technical feasibility of a consumer-grade cellular iPhone camera as an ocular imaging device compared to existing ophthalmic imaging equipment for documentation purposes. Methods A comparison of iPhone 4s and 5s images was made with external facial images (macrophotography) using Nikon cameras, slit-lamp images (microphotography) using Zeiss photo slit-lamp camera, and fundus images (fundus photography) using RetCam II. Results In an analysis of six consecutive patients with ophthalmic conditions, both iPhones achieved documentation of external findings (macrophotography) using standard camera modality, tap to focus, and built-in flash. Both iPhones achieved documentation of anterior segment findings (microphotography) during slit-lamp examination through oculars. Both iPhones achieved fundus imaging using standard video modality with continuous iPhone illumination through an ophthalmic lens. Comparison to standard ophthalmic cameras, macrophotography and microphotography were excellent. In comparison to RetCam fundus photography, iPhone fundus photography revealed smaller field and was technically more difficult to obtain, but the quality was nearly similar to RetCam. Conclusions iPhone versions 4s and 5s can provide excellent ophthalmic macrophotography and microphotography and adequate fundus photography. We believe that iPhone imaging could be most useful in settings where expensive, complicated, and cumbersome imaging equipment is unavailable. PMID:28275604

Vision problems

MedlinePlus

... shade or curtain hanging across part of your visual field. Optic neuritis : inflammation of the optic nerve ... to ask your doctor Images Crossed eyes Eye Visual acuity test Slit-lamp exam Visual field test ...

Anterior capsule phimosis and capsular block syndrome in a patient with Steinert myotonic dystrophy: a case report

PubMed Central

2009-01-01

A 55-year-old man with myotonic dystrophy underwent phacoemulsification with IOL implantation in the right eye. 3 months after surgery, the patient showed a decreased visual acuity and an intraocular pressure (IOP) of 30 mmHg. Slit lamp examination showed a dense fibrosis of the anterior capsule with capsulorexis' shrinkage. Gonioscopy showed a closed angle. After a YAG laser iridotomy no decrease in the IOP was detected; following surgical peeling of the anterior capsule, the slit lamp showed a distended capsular bag. A YAG laser posterior capsulotomy was performed, without decrease in the IOP. Myotonic patients need to be closely followed up after cataract surgery, because in case of CBS development a prompt posterior capsulotomy could avoid more severe complications. PMID:20062622

Anterior chamber configuration in patients with glaucoma: MR gonioscopy evaluation with half-Fourier single-shot RARE sequence and microscopy coil.

PubMed

Tanitame, Keizo; Sasaki, Ko; Sone, Takashi; Uyama, Shinji; Sumida, Masumi; Ichiki, Toshio; Ito, Katsuhide

2008-10-01

The purpose of the study was to determine the accuracy of half-Fourier single-shot rapid acquisition with relaxation enhancement high-spatial-resolution magnetic resonance (MR) imaging performed with a microscopy coil in the diagnosis of narrow anterior chamber angle in patients with glaucoma. Slit-lamp biomicroscopy served as the reference standard. The institutional review board approved this study, and written informed consent was obtained from the 20 recruited patients. There was excellent agreement between MR gonioscopy and slit-lamp biomicroscopy in the classification of anterior chamber angles as narrow or open (kappa = 0.89 [95% confidence interval: 0.69, 1.10]). MR gonioscopy has substantial potential as a technique used to evaluate glaucoma. (c) RSNA, 2008.

Comparison of Fucithalmic viscous eye drops and Chloramphenicol eye ointment as a single treatment in corneal abrasion.

PubMed

Boberg-Ans, G; Nissen, K R

1998-02-01

To compare the healing of the cornea and the incidence of infection after traumatic corneal epithelial defect after single treatment with double bandage combined with either Fucithalmic single unit dose eye drops or chloramphenicol eye ointment. This is a single-centre, randomised, single-blind, parallel-group study of 144 patients with accidental corneal abrasion or corpus alieni cornea who were referred to the Eye Department at Gentofte Hospital. The injured eye was examined with a photo slit-lamp before and 24 hours after treatment. The size of the abrasion was recorded and calculated on a PCX computerized video system and by slit-lamp photography. The Fucithalmic and chloramphenicol ointment treated groups showed no significant difference in corneal healing, local side effects, or signs of local infection.

Slit-lamp exam

MedlinePlus

... eyes, especially the eyelids, cornea, conjunctiva, sclera, and iris. Often a yellow dye (fluorescein) is used to ... lens on the front of the eye) Eyelids Iris (colored part of the eye between the cornea ...

Identification of the source of permanent glare from a three-piece IOL.

PubMed

Wolffe, M; Landry, R J; Alpar, J J

2007-08-01

To identify the source of unwanted glare images from a three-piece intraocular lens (IOL) implant following cataract surgery. The IOL and posterior capsule were examined under mydriatic and nonmydriatic conditions using direct focal illumination from a slit lamp biomicroscope. Direct focal illumination was undertaken with both a narrow beam (0.1 mm in width) and small spot (0.1 mm in diameter) to identify the points at which the glare images were stimulated. While observing the location of the beam with the slit lamp biomicroscope, the patient indicated when the glare images were stimulated. The nasal haptic insertion into the optic was identified as the source of temporal line images arising from lights such as headlamps from oncoming cars and street lamps. The adjacent edge of the IOL was also identified as the likely source of additional cob web-like light rays. The haptic insertions in three-piece IOLs may, under certain conditions, interfere with light entering the pupil and produce extraneous images. Large mesopic pupils and decentred IOLs are conditions that increase the likelihood of unwanted glare images.

Corneal ulcers and infections

MedlinePlus

... eye Scratches (abrasions) on the eye surface Severely dry eyes Severe allergic eye disease Various inflammatory disorders Wearing ... response Refraction test Slit-lamp examination Tests for dry eye Visual acuity Blood tests to check for inflammatory ...

Managing corneal foreign bodies in office-based general practice.

PubMed

Fraenkel, Alison; Lee, Lawrence R; Lee, Graham A

2017-03-01

Patients with a corneal foreign body may first present to their general practitioner (GP). Safe and efficacious management of these presentations avoids sight-threatening and eye-threatening complications. Removal of a simple, superficial foreign body without a slit lamp is within The Royal Australian College of General Practitioners' (RACGP's) curriculum and scope of practice. Knowing the rele-vant procedural skills and indications for referral is equally important. The objective of this article is to provide an evidence-based and expert-based guide to the management of corneal foreign bodies in the GP's office. History is key to identifying patient characteristics and mechanisms of ocular injury that are red flags for referral. Examination tech-niques and methods of superficial foreign body removal without a slit lamp are outlined, as well as the procedural threshold for referral to an ophthalmologist.

Rapid corneal thinning and perforated ulcerative keratitis in a patient with relapsing polychondritis.

PubMed

Lai, Tracy Hiu Ting; Far, Nikki; Young, Alvin Lerrmann; Jhanji, Vishal

2017-01-01

To report rapid corneal thinning and perforation in a case with relapsing polychondritis. A 43 year-old male diagnosed with relapsing polychondritis suffered from bilateral scleritis, bilateral swelling of pinna, saddle nose and tracheal stenosis. The patient presented with right eye pain and redness for one month. Slit lamp examination of the right eye showed 80% peripheral corneal thinning between 3 and 7 o'clock. The best-corrected visual acuity (BCVA) was 1.0 bilaterally. The degree of corneal thinning worsened to 90% after one week of oral corticosteroid use. Subsequently, topical cyclosporine 2% eye drops four times a day, oral doxycycline 100 mg twice a day and oral vitamin C 2 g daily were added. The corneal thinning gradually improved to about 60%. However, the patient rapidly tapered oral prednisolone against medical advice and returned with an acute drop in vision in his right eye. Slit lamp examination of the right eye showed peripheral corneal perforation with iris prolapse. An emergency repair with cyanoacrylate glue was performed. Intravenous methylprednisolone 1 mg/kg body weight was administered for three days and 1 g/day intravenous immunoglobulin was administered every four weeks. At 3 months postoperatively, BCVA in the right eye was 0.6. Slit lamp examination showed a well-formed anterior chamber with glue in situ. Relapsing polychondritis may be associated with rapid corneal thinning. The clinicians should be aware of the possibility of corneal perforation in these cases. Cyanoacrylate glue is a viable temporary management option in such scenarios.

Multimodal Assessment of Corneal Thinning Using Optical Coherence Tomography, Scheimpflug Imaging, Pachymetry, and Slit-Lamp Examination.

PubMed

Oatts, Julius T; Keenan, Jeremy D; Mannis, Tova; Lietman, Tom M; Rose-Nussbaumer, Jennifer

2017-04-01

To assess the relationship between corneal thinning measured by clinician-graded slit-lamp examination compared with ultrasound pachymetry (USP), anterior segment optical coherence tomography (AS-OCT), and the Pentacam. Patients with corneal thinning underwent USP, AS-OCT, Pentacam measurements and standardized clinical grading by 2 cornea specialists estimating thinning on slit-lamp examination. Reproducibility of each testing modality was assessed using the intraclass correlation coefficient. Bland-Altman plots were used to determine precision and limits of agreement (LOA) between imaging modalities and clinical grading. We included 22 patients with corneal thinning secondary to infectious or inflammatory keratitis. Mean percent stromal thinning estimated by grader 1 was 51% (SD 31) and grader 2 was 49% (SD 33). The intraclass correlation coefficient between the masked examiners was 0.95 (95% confidence interval, 0.88-0.98). Graders were more similar to each other than to any other modality with 2% difference and 4.6% of measurements outside the LOA. When measuring the area of maximum thinning, AS-OCT measured approximately 10% thicker than human graders while the Pentacam measured approximately 10% thinner than human graders with 16.7% outside the LOA. USP measured approximately 20% thinner than human graders with 5.6% outside the LOA. Trained corneal specialists have a high degree of agreement in location and degree of corneal thinning when measured in a standardized fashion on the same day. Other testing modalities had acceptable reproducibility and agreement with clinical examination and each other, although Scheimpflug imaging fared worse for corneal thinning, particularly in the periphery, than the other modalities.

Spectral domain optical coherence tomography imaging of spectacular ecdysis in the royal python (Python regius).

PubMed

Tusler, Charlotte A; Maggs, David J; Kass, Philip H; Paul-Murphy, Joanne R; Schwab, Ivan R; Murphy, Christopher J

2015-01-01

To describe using spectral domain optical coherence tomography (SD-OCT), digital slit-lamp biomicroscopy, and external photography, changes in the ophidian cuticle, spectacle, and cornea during ecdysis. Four normal royal pythons (Python regius). Snakes were assessed once daily throughout a complete shed cycle using nasal, axial, and temporal SD-OCT images, digital slit-lamp biomicroscopy, and external photography. Spectral domain optical coherence tomography (SD-OCT) images reliably showed the spectacular cuticle and stroma, subcuticular space (SCS), cornea, anterior chamber, iris, and Schlemm's canal. When visible, the subspectacular space (SSS) was more distended peripherally than axially. Ocular surface changes throughout ecdysis were relatively conserved among snakes at all three regions imaged. From baseline (7 days following completion of a full cycle), the spectacle gradually thickened before separating into superficial cuticular and deep, hyper-reflective stromal components, thereby creating the SCS. During spectacular separation, the stroma regained original reflectivity, and multiple hyper-reflective foci (likely fragments from the cuticular-stromal interface) were noted within the SCS. The cornea was relatively unchanged in character or thickness throughout all stages of ecdysis. Slit-lamp images did not permit observation of these changes. Spectral domain optical coherence tomography (SD-OCT) provided excellent high-resolution images of the snake anterior segment, and especially the cuticle, spectacle, and cornea of manually restrained normal snakes at all stages of ecdysis and warrants investigation in snakes with anterior segment disease. The peripheral spectacle may be the preferred entry point for diagnostic or therapeutic injections into the SSS and for initiating spectacular surgery. © 2014 American College of Veterinary Ophthalmologists.

Anterior Segment Optical Coherence Tomography for Tear Meniscus Evaluation and its Correlation with other Tear Variables in Healthy Individuals

PubMed Central

Dhasmana, Renu; Nagpal, Ramesh Chander

2016-01-01

Introduction Dry eye is one of the most common ocular diseases in this cyber era. Despite availability of multiple tests, no single test is accurate for the diagnosis of dry eye. Anterior segment optical coherence tomography is the recent tool which can be added in the armentarium of dry eye tests. Aim To evaluate tear meniscus with anterior segment optical coherence tomography and its correlation with other tear variables in normal healthy individuals. Materials and Methods In this prospective cross-sectional observational study, right eye of 203 consecutive patients were studied. All the patients were divided into three groups Group 1, 2 and 3 according to their age ≤20 years, 21-40 years and >40 years respectively. All patients underwent routine ophthalmologic examinations along with slit-lamp bio-microscopy for tear meniscus height measurement, tear film break up time, Schirmer’s I test (with anaesthesia) and optical coherence tomography imaging of inferior tear meniscus height. After focusing of the instrument with a Cross Line (CL) centered on lower tear meniscus at 6’0 clock of cornea, a 6 mm long scan was obtained. The tear meniscus height (μm) and tear meniscus area (mm2) were measured manually with help of callipers by joining upper corneo-meniscus junction to the lower lid-meniscus junction and tear meniscus height and area within the plotted line respectively and calculated by using the integrated analysis available in the custom software. Results There was significant decrease in the all tear variables with the increase in the age. According to age groups in group 1, the mean Schirmer’s (24.0±4.9)mm, tear film break up time (11.1±1.9) sec, tear meniscus height on slit lamp (600.2±167.3)mm were higher but decreased in group 2 (21.5±5.4,10.8±1.4, 597.5±186.3) and group 3 (19.8 ± 5.1, 10.2 ± 1.6, 485.6 ± 157.7) respectively. Schirmer’s test values and tear film break up time were similar in both sexes (p=0.1 and p= 0.9). Tear meniscus height on slit lamp and Optical coherence based tear meniscus area were similar in both sexes (p=0.5 and p=0.1). However, tear meniscus height on optical coherence tomography was significantly higher in females (p=0.04). Value of Schirmer’s and tear film break up time (r =0.2; p= 0.001) and Schirmer’s and tear meniscus height on slit lamp (r=0.6; p<0.001) had positive correlation. Tear meniscus height and tear meniscus area on optical coherence tomography had positive correlation (r =.9; p<0.001). Conclusion On optical coherence tomography tear meniscus height and area significantly correlated. Despite higher values of Schirmer’s, tear film break up time, Slit lamp based tear meniscus height in younger age group the tear meniscus height and tear meniscus area with optical coherence tomography were lower. PMID:27437253

Meta-analysis of the ocular biocompatibility of a new multipurpose lens care system.

PubMed

Reindel, William; Merchea, Mohinder M; Rah, Marjorie J; Zhang, Lening

2013-01-01

The purpose of this paper is to evaluate the biocompatibility of a novel multipurpose solution (MPS) with a dual disinfectant system containing polyaminopropyl biguanide and polyquaternium-1 (Biotrue®) by analysis of biomicroscopy signs and adverse events in six large clinical trials. Data from six consecutive, prospective clinical trials conducted from February 2008 to March 2010 were combined for meta-analysis. Subjects used the new MPS daily for periods of 2 weeks to 6 months. Slit-lamp signs were graded at each follow-up visit using an ordinal scale (0, one; 1, trace; 2, mild; 3, moderate; 4, severe). Analysis for biocompatibility included tracking of greater than grade 2 slit-lamp findings and number of adverse events. A total of 1,567 subjects (3,134 eyes) and 81 clinical investigators participated in the six studies, with 1,499 subjects completing the studies. Based on subject days in the studies, there were 72,904 exposures to the MPS and 7,212 biomicroscopy examinations. The completion rate for the studies was 96.3%. Per observation incidence of any finding greater than grade 2 at the follow-up visits were: corneal staining 0.08%, limbal injection 0.04%, bulbar injection 0.04%, tarsal conjunctiva abnormality 0.09%, and neovascularization 0.01%. There were no other slit-lamp signs greater than grade 2 and no statistically significant difference between hydrogels and silicone hydrogels for any finding. There were no reports of adverse events during the trials. Analysis of over 72,000 daily exposures and 7,212 eye examinations showed that the novel MPS exhibited excellent biocompatibility in subjects using daily wear hydrogel or silicone hydrogel lenses.

Slit-lamp Needling of the Anterior Capsule for Aqueous Misdirection After Hyaloido-zonulectomy and Iridectomy.

PubMed

Mardelli, Pierre G; Mardelli, Marc E

2018-04-01

We present a case of persistent aqueous misdirection, after Ahmed glaucoma valve surgery, despite undergoing an anterior vitrectomy with hyaloido-zonulectomy and iridectomy. A 73-year-old female patient, 4 months after phacotrabeculectomy, was referred with persistent high intraocular pressure (IOP). Postoperatively, she developed aqueous misdirection with a flat anterior chamber (AC) but with an IOP of 15 mm Hg. On presentation, her AC was shallow with peripheral iris-cornea touch, and her IOP was 39 mm Hg. Posterior Nd:Yag capsulotomy with disruption of anterior hyaloid face partially deepened the AC. With failure of the trabeculectomy and high IOP, an Ahmed valve was placed. On the first operative day the AC was deep with an IOP of 10 mm Hg. On day 6 the patient presented with pain, flat AC, and an IOP of 10 mm Hg. Fundus examination revealed no choroidal effusion. Despite repeated reformation with viscoelastic, the AC failed to deepen. An anterior vitrectomy with hyaloido-zonulectomy was performed. Initially, the AC was deep, but, a few days later, it was flat. Multiple reformations and vitreous tap failed to keep the AC deep. A 30-G needle was passed at the slit lamp across the temporal cornea, iris, and anterior capsule into the anterior vitreous cavity. The needle was then partially withdrawn and used to create a space between the intraocular lens and anterior capsule. This immediately deepened the AC and remained so for the duration of follow-up (4 mo). Slit-lamp needling of the anterior lens capsule can be successfully performed to help resolve a persistent case of aqueous misdirection after anterior vitrectomy.

Corneal Densitometry as a Tool to Measure Epithelial Ingrowth After Laser In Situ Keratomileusis.

PubMed

Adran, Daniel; Vaillancourt, Louis; Harissi-Dagher, Mona; Kruh, Jonathan N; Syed, Zeba A; Robinson, Steven; Melki, Samir

2017-04-01

This study evaluates the correlation between corneal densitometry and epithelial ingrowth (EI) after laser in situ keratomileusis (LASIK). Corneal densitometry of 3 patients who developed EI after LASIK was measured with the Oculus Pentacam. Corneal densitometry readings of each patient were obtained preoperatively and postoperatively after ingrowth was discovered. Densitometry was recorded at the central nest of opacity and at the leading edges of EI. For all patients, the most severe stages of EI observed on slit-lamp photographs correlated with the highest densitometry readings, with peak densitometry ranging from 73.3 to 95.1. These values were much higher than preoperative densitometry readings, which ranged from 21.8 to 27.2. In 2 cases, the Pentacam densitometry map revealed progression of EI toward the visual axis that was only faintly detectable or not detectable at all on the corresponding slit-lamp photographs. Corneal densitometry seems to be an objective measure of the severity and progression of EI after LASIK.

A computer-aided diagnosis system of nuclear cataract.

PubMed

Li, Huiqi; Lim, Joo Hwee; Liu, Jiang; Mitchell, Paul; Tan, Ava Grace; Wang, Jie Jin; Wong, Tien Yin

2010-07-01

Cataracts are the leading cause of blindness worldwide, and nuclear cataract is the most common form of cataract. An algorithm for automatic diagnosis of nuclear cataract is investigated in this paper. Nuclear cataract is graded according to the severity of opacity using slit lamp lens images. Anatomical structure in the lens image is detected using a modified active shape model. On the basis of the anatomical landmark, local features are extracted according to clinical grading protocol. Support vector machine regression is employed for grade prediction. This is the first time that the nucleus region can be detected automatically in slit lamp images. The system is validated using clinical images and clinical ground truth on >5000 images. The success rate of structure detection is 95% and the average grading difference is 0.36 on a 5.0 scale. The automatic diagnosis system can improve the grading objectivity and potentially be used in clinics and population studies to save the workload of ophthalmologists.

Corneal reshaping using a pulsed UV solid-state laser

NASA Astrophysics Data System (ADS)

Ren, Qiushi; Simon, Gabriel; Parel, Jean-Marie A.; Shen, Jin-Hui; Takesue, Yoshiko

1993-06-01

Replacing the gas ArF (193 nm) excimer laser with a solid state laser source in the far-UV spectrum region would eliminate the hazards of a gas laser and would reduce its size which is desirable for photo-refractive keratectomy (PRK). In this study, we investigated corneal reshaping using a frequency-quintupled (213 nm) pulsed (10 ns) Nd:YAG laser coupled to a computer-controlled optical scanning delivery system. Corneal topographic measurements showed myopic corrections ranging from 2.3 to 6.1 diopters. Post-operative examination with the slit-lamp and operating microscope demonstrated a smoothly ablated surface without corneal haze. Histological results showed a smoothly sloping surface without recognizable steps. The surface quality and cellular effects were similar to that of previously described excimer PRK. Our study demonstrated that a UV solid state laser coupled to an optical scanning delivery system is capable of reshaping the corneal surface with the advantage of producing customized, aspheric corrections without corneal haze which may improve the quality of vision following PRK.

A hyperspectral imaging system for the evaluation of the human iris spectral reflectance

NASA Astrophysics Data System (ADS)

Di Cecilia, Luca; Marazzi, Francesco; Rovati, Luigi

2017-02-01

According to previous studies, the measurement of the human iris pigmentation can be exploited to detect certain eye pathological conditions in their early stage. In this paper, we propose an instrument and a method to perform hyperspectral quantitative measurements of the iris spectral reflectance. The system is based on a simple imaging setup, which includes a monochrome camera mounted on a standard ophthalmic microscope movement controller, a monochromator, and a flashing LED-based slit lamp. To assure quantitative measurements, the system is properly calibrated against a NIST reflectance standard. Iris reflectance images can be obtained in the spectral range 495-795 nm with a resolution of 25 nm. Each image consists of 1280 x 1024 pixels having a spatial resolution of 18 μm. Reflectance spectra can be calculated both from discrete areas of the iris and as the average of the whole iris surface. Preliminary results suggest that hyperspectral imaging of the iris can provide much more morphological and spectral information with respect to conventional qualitative colorimetric methods.

Improved Scanners for Microscopic Hyperspectral Imaging

NASA Technical Reports Server (NTRS)

Mao, Chengye

2009-01-01

Improved scanners to be incorporated into hyperspectral microscope-based imaging systems have been invented. Heretofore, in microscopic imaging, including spectral imaging, it has been customary to either move the specimen relative to the optical assembly that includes the microscope or else move the entire assembly relative to the specimen. It becomes extremely difficult to control such scanning when submicron translation increments are required, because the high magnification of the microscope enlarges all movements in the specimen image on the focal plane. To overcome this difficulty, in a system based on this invention, no attempt would be made to move either the specimen or the optical assembly. Instead, an objective lens would be moved within the assembly so as to cause translation of the image at the focal plane: the effect would be equivalent to scanning in the focal plane. The upper part of the figure depicts a generic proposed microscope-based hyperspectral imaging system incorporating the invention. The optical assembly of this system would include an objective lens (normally, a microscope objective lens) and a charge-coupled-device (CCD) camera. The objective lens would be mounted on a servomotor-driven translation stage, which would be capable of moving the lens in precisely controlled increments, relative to the camera, parallel to the focal-plane scan axis. The output of the CCD camera would be digitized and fed to a frame grabber in a computer. The computer would store the frame-grabber output for subsequent viewing and/or processing of images. The computer would contain a position-control interface board, through which it would control the servomotor. There are several versions of the invention. An essential feature common to all versions is that the stationary optical subassembly containing the camera would also contain a spatial window, at the focal plane of the objective lens, that would pass only a selected portion of the image. In one version, the window would be a slit, the CCD would contain a one-dimensional array of pixels, and the objective lens would be moved along an axis perpendicular to the slit to spatially scan the image of the specimen in pushbroom fashion. The image built up by scanning in this case would be an ordinary (non-spectral) image. In another version, the optics of which are depicted in the lower part of the figure, the spatial window would be a slit, the CCD would contain a two-dimensional array of pixels, the slit image would be refocused onto the CCD by a relay-lens pair consisting of a collimating and a focusing lens, and a prism-gratingprism optical spectrometer would be placed between the collimating and focusing lenses. Consequently, the image on the CCD would be spatially resolved along the slit axis and spectrally resolved along the axis perpendicular to the slit. As in the first-mentioned version, the objective lens would be moved along an axis perpendicular to the slit to spatially scan the image of the specimen in pushbroom fashion.

Imaging slit-coupled surface plasmon polaritons using conventional optical microscopy.

PubMed

Mehfuz, R; Chowdhury, F A; Chau, K J

2012-05-07

We develop a technique that now enables surface plasmon polaritons (SPPs) coupled by nano-patterned slits in a metal film to be detected using conventional optical microscopy with standard objective lenses. The crux of this method is an ultra-thin polymer layer on the metal surface, whose thickness can be varied over a nanoscale range to enable controllable tuning of the SPP momentum. At an optimal layer thickness for which the SPP momentum matches the momentum of light emerging from the slit, the SPP coupling efficiency is enhanced about six times relative to that without the layer. The enhanced efficiency results in distinctive and bright plasmonic signatures near the slit visible by naked eye under an optical microscope. We demonstrate how this capability can be used for parallel measurement through a simple experiment in which the SPP propagation distance is extracted from a single microscope image of an illuminated array of nano-patterned slits on a metal surface. We also use optical microscopy to image the focal region of a plasmonic lens and obtain results consistent with a previously-reported results using near-field optical microscopy. Measurement of SPPs near a nano-slit using conventional and widely-available optical microscopy is an important step towards making nano-plasmonic device technology highly accessible and easy-to-use.

Demonstrating Fermat's Principle in Optics

ERIC Educational Resources Information Center

Paleiov, Orr; Pupko, Ofir; Lipson, S. G.

2011-01-01

We demonstrate Fermat's principle in optics by a simple experiment using reflection from an arbitrarily shaped one-dimensional reflector. We investigated a range of possible light paths from a lamp to a fixed slit by reflection in a curved reflector and showed by direct measurement that the paths along which light is concentrated have either…

16 CFR 1500.42 - Test for eye irritants.

Code of Federal Regulations, 2011 CFR

2011-01-01

... noted below. (2) The eyes are examined and the grade of ocular reaction is recorded at 24, 48, and 72 hours. Reading of reactions is facilitated by use of a binocular loupe, hand slit-lamp, or other expert... positive reaction if the test substance produces at any of the readings ulceration of the cornea (other...

Cornea and anterior eye assessment with slit lamp biomicroscopy, specular microscopy, confocal microscopy, and ultrasound biomicroscopy

PubMed Central

Martin, Raul

2018-01-01

Current corneal assessment technologies make the process of corneal evaluation extremely fast and simple, and several devices and technologies show signs that help in identification of different diseases thereby, helping in diagnosis, management, and follow-up of patients. The purpose of this review is to present and update readers on the evaluation of cornea and ocular surface. This first part reviews a description of slit lamp biomicroscopy (SLB), endothelial specular microscopy, confocal microscopy, and ultrasound biomicroscopy examination techniques and the second part describes the corneal topography and tomography, providing up-to-date information on the clinical recommendations of these techniques in eye care practice. Although the SLB is a traditional technique, it is of paramount importance in clinical diagnosis and compulsory when an eye test is conducted in primary or specialist eye care practice. Different techniques allow the early diagnosis of many diseases, especially when clinical signs have not yet become apparent and visible with SLB. These techniques also allow for patient follow-up in several clinical conditions or diseases, facilitating clinical decisions and improving knowledge regarding the corneal anatomy. PMID:29380757

CW laser use in biomedical research and practice

NASA Astrophysics Data System (ADS)

Matthopoulos, D. P.

2003-04-01

The communication of humans with their surrouding is achieved through their senses and the related organs. Visual communication using the eyes is made possible because the various sources of light, natural i.e. the sun or the lightning, or artificial such as Lasers, emit electromagnetic radiation which is either reflected or scattered by surfaces. This radiation received by eyes is processed in the brain where the images of the environment are developed. The luminous processing can be either macro- or microscopic. The macroscopic processing is the result of light coming from the sun or from wide range lamps, while the microscopic results from light coming from wide range lamps, mercury lamps, lasers or electron beam. The microscopic processing is the subject we are dealing with in this presentation.

A prospective observational study of techniques to remove corneal foreign body in the emergency department.

PubMed

Quirke, Michael; Mullarkey, Caitriona; Askoorum, Shakti; Coffey, Norma; Binchy, James

2014-06-01

Patients  with corneal foreign bodies (CFBs) often present to the emergency department (ED). However, removal techniques vary among emergency physicians (EPs). A prospective, single-blinded, observational study was performed to compare slit-lamp-aided (SLA) versus non-slit-lamp-aided (NSLA) CFB removal by EPs. Five EPs enrolled consecutive patients with a CFB over 3 months. One blinded EP reviewed patients after 3 days. The study end points were: change in visual acuity; visual analogue pain scale (VAS) score at 12 and 24 h; satisfaction rating; symptoms at follow-up; and rate of complications. 54 patients were enrolled: 28 had SLA removal and 26 NSLA removal; 52 were male; 22 had undergone previous CFB removal; six were wearing eye protection at the time of injury. Forty-three patients were reviewed: 26 by attendance and 18 by telephone. There was no difference in any end points at review. However, patients in the SLA group had median VAS scores that were 1.5 cm lower after 24 h than patients in the NSLA group (p=0.43, 95% CI -2.0 to 1.0). One patient in the SLA group developed keratitis. We show that patient satisfaction ratings, complications and visual acuity were similar for the two methods. There was a trend for increased pain in the NSLA group at 12 and 24 h. Slit-lamp biomicroscopy and the use of magnification to remove CFBs remains the gold standard of care, and more intensive training should be given to EPs at the departmental level, particularly in EDs that receive patients with eye injuries. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Efficacy and Safety Comparison Between Suberoylanilide Hydroxamic Acid and Mitomycin C in Reducing the Risk of Corneal Haze After PRK Treatment In Vivo.

PubMed

Anumanthan, Govindaraj; Sharma, Ajay; Waggoner, Michael; Hamm, Chuck W; Gupta, Suneel; Hesemann, Nathan P; Mohan, Rajiv R

2017-12-01

This study compared the efficacy and safety of suberoylanilide hydroxamic acid (SAHA) and mitomycin C (MMC) up to 4 months in the prevention of corneal haze induced by photorefractive keratectomy (PRK) in rabbits in vivo. Corneal haze in rabbits was produced with -9.00 diopter PRK. A single application of SAHA (25 μM) or MMC (0.02%) was applied topically immediately after PRK. Effects of the two drugs were analyzed by slit-lamp microscope, specular microscope, TUNEL assay, and immunofluorescence. Single topical adjunct use of SAHA (25 μM) or MMC (0.02%) after PRK attenuated more than 95% corneal haze and myofibroblast formation (P < .001). SAHA did not reduce keratocyte density, cause keratocyte apoptosis, or increase immune cell infiltration compared to MMC (P < .01 or .001). Furthermore, SAHA dosing did not compromise corneal endothelial phenotype, density, or function in rabbit eyes, whereas MMC application did (P < .01 or .001). SAHA and MMC significantly decreased corneal haze after PRK in rabbits in vivo. SAHA exhibited significantly reduced short- and long-term damage to the corneal endothelium compared to MMC in rabbits. SAHA is an effective and potentially safer alternative to MMC for the prevention of corneal haze after PRK. Clinical trials are warranted. [J Refract Surg. 2017;33(12):834-839.]. Copyright 2017, SLACK Incorporated.

Cytomegalovirus retinitis in HIV/AIDS patients.

PubMed

Chiotan, C; Radu, L; Serban, R; Cornăcel, C; Cioboata, M; Anghel, A

2014-06-15

Human immunodeficiency virus (HIV) has the ability to affect any organ in the body. In 70% of HIV-infected patients ocular manifestations were observed, which in the vast majority reflect the systemic disease and may be the first sign of a disseminated infection. The purpose of this paper is to determine the prevalence and the clinical aspects of cytomegalovirus retinitis in HIV/AIDS (Acquired Immunodeficiency Syndrome) patients. The study is retrospective, conducted in the Ophthalmology Office of "Matei Bals" Infectious Diseases Hospital in Bucharest during the period August 1, 2007 - August 1, 2013. Each patient was examined thoroughly at the slit lamp biomicroscope by using a lens of 90D and a 20D lens using the indirect microscope after administration of topical mydriatics. 131 patients were followed for HIV / AIDS with posterior segment ocular involvement. 36.64% of the 131 patients having affected the posterior segment have been diagnosed with CMV retinitis. Doctors should be aware of the existence of ocular damage in HIV/AIDS and to emphasize the importance of regular ophthalmologic examination of patients with HIV/AIDS.

Pilot study about dose-effect relationship of ocular injury in argon laser photocoagulation

NASA Astrophysics Data System (ADS)

Chen, P.; Zhang, C. P.; Fu, X. B.; Zhang, T. M.; Wang, C. Z.; Qian, H. W.; San, Q.

2011-03-01

The aim of this article was to study the injury effect of either convergent or parallel argon laser beam on rabbit retina, get the dose-effect relationship for the two types of laser beams, and calculate the damage threshold of argon laser for human retinas. An argon laser therapeutic instrument for ophthalmology was used in this study. A total of 80 rabbit eyes were irradiated for 600 lesions, half of which were treated by convergent laser and the other half were done with parallel laser beam. After irradiation, slit lamp microscope and fundus photography were used to observe the lesions, change and the incidence of injury was processed statistically to get the damage threshold of rabbit retina. Based on results from the experiments on animals and the data from clinical cases of laser treatment, the photocoagulation damage thresholds of human retinas for convergent and parallel argon laser were calculated to be 0.464 and 0.285 mJ respectively. These data provided biological reference for safely operation when employing laser photocoagulation in clinical practice and other fields.

In vivo confocal microscopy, an inner vision of the cornea - a major review.

PubMed

Guthoff, Rudolf F; Zhivov, Andrey; Stachs, Oliver

2009-01-01

The demands of modern ophthalmology have evolved from descriptive findings from the slit lamp to in vivo assessment of cellular level changes. Nowadays, the latter can be provided by in vivo confocal microscopy. This article gives an overview of confocal principles using tandem scanning, scanning slit and laser scanning techniques used in ophthalmology. The main part of the paper describes the clinical applications emphasizing the anatomy of the normal and pathological cornea, and illustrates side-effects of topical medication, contact lens wear, cross-linking and refractive surgery. Finally, a summary about experimental applications, including animal studies, surface characterization and volume rendering as well as future developments, is given.

Riot Control Agents

DTIC Science & Technology

2009-01-01

However, a local anesthetic applied to the eye will help with eye pain and allow for further evaluation of the eye by slit lamp. Contact lenses...RCAs. Eye findings from RCA toxicity can range in severity from conjunctival erythema to ocular necrosis . Lacrimation, conjunctival erythema/edema...and ocular necrosis (Grant, 1986). Figure 12.12 illustrates and summarizes the common toxic ophthalmological signs and symptoms associated with

Asymptomatic snowflake degeneration in a polymethyl methacrylate (PMMA) intraocular lens implant.

PubMed

Tan, Lee T; Shuttleworth, Garry N

2008-01-01

Snowflake degeneration is a late complication of polymethyl methacrylate (PMMA) intraocular lens implants. We report a case of asymptomatic advanced snowflake opacification presenting 13 years after implantation who maintained a visual acuity of 6/6. This report serves to illustrate the variability of the clinical effects of snowflake degeneration, which do not necessarily correlate with slit-lamp appearances.

Altered bulbar conjunctival microcirculation in response to contact lens wear

PubMed Central

Chen, Wan; Xu, Zhe; Jiang, Hong; Zhou, Jin; Wang, Liang; Wang, Jianhua

2015-01-01

Purpose This study was conducted to determine blood flow velocities and corresponding vessel diameters to characterize the response of the bulbar conjunctival microvasculature to contact lens wear. Methods A Functional Slit-lamp Biomicroscope (FSLB), an adapted traditional slit-lamp, was used to image the temporal bulbar conjunctiva of 22 healthy subjects before and after 6 hours of contact lens wear. All of the measurable venules on the conjunctiva were processed to yield vessel diameters and blood flow velocities. Results The averaged blood flow velocity increased from 0.51 ± 0.20 mm/s to 0.65 ± 0.22 mm/s (P < 0.001) after 6 hours of lens wear. The blood flow velocity distribution showed a velocity increase that correlated with the vessel diameter increase from the baseline (r = 0.826, P < 0.05). This pattern maintained a similar trend after 6 hours of lens wear (r = 0.925, P < 0.05), and increased velocities were found across all of the vessel diameter ranges (P < 0.001). Conclusions Blood flow velocity increases across all of the vessel diameter ranges in response to contact lens wear. FSLB is capable of characterizing the bulbar microvascular response to contact lens wear. PMID:27078615

In vivo study of the biocompatibility of a novel compressed collagen hydrogel scaffold for artificial corneas.

PubMed

Xiao, Xianghua; Pan, Shiyin; Liu, Xianning; Zhu, Xiuping; Connon, Che John; Wu, Jie; Mi, Shengli

2014-06-01

The experiments were designed to evaluate the biocompatibility of a plastically compressed collagen scaffold (PCCS). The ultrastructure of the PCCS was observed via scanning electron microscopy. Twenty New Zealand white rabbits were randomly divided into experimental and control groups that received corneal pocket transplantation with PCCS and an amniotic membrane, respectively. And the contralateral eye of the implanted rabbit served as the normal group. On the 1st, 7th, 14th, 21st, 30th, 60th, 90th, and 120th postoperative day, the eyes were observed via a slit lamp. On the 120th postoperative day, the rabbit eyes were enucleated to examine the tissue compatibility of the implanted stroma. The PCCS was white and translucent. The scanning electron microscopy results showed that fibers within the PCCS were densely packed and evenly arranged. No edema, inflammation, or neovascularization was observed on ocular surface under a slit lamp and few lymphocytes were observed in the stroma of rabbit cornea after histological study. In conclusion, the PCCS has extremely high biocompatibility and is a promising corneal scaffold for an artificial cornea. Copyright © 2013 Society of Plastics Engineers.

Evaluation of prior photorefractive keratectomy in donor tissue.

PubMed

Terry, M A; Ousley, P J; Rich, L F; Wilson, D J

1999-05-01

To describe a case in which an eye donor had prior bilateral photorefractive keratectomies and to elucidate possible methods of evaluation and screening of donor tissue. Case report. A 62-year-old eye donor was reported to have received radial keratotomy before his death. Further investigation by the eye bank showed a history of photorefractive keratectomy (PRK), not radial keratotomy. The corneas were therefore not used for transplantation, and the eyes were evaluated by slit-lamp examination, photography, corneal topography, and histology. Slit-lamp and photographic examination did not indicate the presence of PRK ablations. Corneal topography mapping with the TMS-1 was relatively ambiguous for identifying PRK flattening, while multiple data formatting of the cornea with the Orbscan resulted in the strongest suggestion of prior PRK. Histologic analysis showed central corneal thinning and loss of Bowman's membrane consistent with PRK. In the absence of a positive donor history for PRK, current methods of screening donor tissue for prior PRK often are insufficient to exclude these corneas from use in transplantation. More refined placido imagery corneal topography or newer technologies such as the Orbscan may allow more sensitive and specific methods of donor tissue screening.

The extent of slits at the interfaces between luting cements and enamel, dentin and alloy.

PubMed

Oilo, G

1978-01-01

Four different cements were used to assess the presence of slits at the cement/tooth or the cement/alloy interfaces using a tooth-crown model. The model consisted of ground sections of teeth and plane plates of silver/palladium alloy. The plates were fixed with bolts between two brass plates and with three different dimensions of the cement film between tooth and alloy, i.e. 50 micrometer, 100 micrometer and 200 micrometer. The tooth-alloy specimens were sectioned and the adaption of cements was studied with an indirect technique (replica) in a scanning electron microscope. The extent of slits was expressed as the length of all slits relative to the total length of the interface in each specimen. The results showed that the zinc phosphate cement and polycarboxylate cement exhibited a slight to moderate tendency to formation of slits at the interfaces. The EBA cement had a small extent of slits adjacent to thin cement films, but more slits were observed with increasing film thickness. The composite resin cement had a marked tendency to slit formation independent of the cement film thickness.

Multimodal ophthalmic imaging using spectrally encoded scanning laser ophthalmoscopy and optical coherence tomography

NASA Astrophysics Data System (ADS)

El-Haddad, Mohamed T.; Malone, Joseph D.; Li, Jianwei D.; Bozic, Ivan; Arquitola, Amber M.; Joos, Karen M.; Patel, Shriji N.; Tao, Yuankai K.

2017-08-01

Ophthalmic surgery involves manipulation of delicate, layered tissue structures on milli- to micrometer scales. Traditional surgical microscopes provide an inherently two-dimensional view of the surgical field with limited depth perception which precludes accurate depth-resolved visualization of these tissue layers, and limits the development of novel surgical techniques. We demonstrate multimodal swept-source spectrally encoded scanning laser ophthalmoscopy and optical coherence tomography (SS-SESLO-OCT) to address current limitations of image-guided ophthalmic microsurgery. SS-SESLO-OCT provides inherently co-registered en face and cross-sectional field-of-views (FOVs) at a line rate of 400 kHz and >2 GPix/s throughput. We show in vivo imaging of the anterior segment and retinal fundus of a healthy volunteer, and preliminary results of multi-volumetric mosaicking for ultrawide-field retinal imaging with 90° FOV. Additionally, a scan-head was rapid-prototyped with a modular architecture which enabled integration of SS-SESLO-OCT with traditional surgical microscope and slit-lamp imaging optics. Ex vivo surgical maneuvers were simulated in cadaveric porcine eyes. The system throughput enabled volumetric acquisition at 10 volumes-per-second (vps) and allowed visualization of surgical dynamics in corneal sweeps, compressions, and dissections, and retinal sweeps, compressions, and elevations. SESLO en face images enabled simple real-time co-registration with the surgical microscope FOV, and OCT cross-sections provided depth-resolved visualization of instrument-tissue interactions. Finally, we demonstrate novel augmented-reality integration with the surgical view using segmentation overlays to aid surgical guidance. SS-SESLO-OCT may benefit clinical diagnostics by enabling aiming, registration, and mosaicking; and intraoperative imaging by allowing for real-time surgical feedback, instrument tracking, and overlays of computationally extracted biomarkers of disease.

Experimental realization of the Ehrenberg-Siday thought experiment

NASA Astrophysics Data System (ADS)

Pozzi, Giulio; Boothroyd, Chris B.; Tavabi, Amir H.; Yücelen, Emrah; Dunin-Borkowski, Rafal E.; Frabboni, Stefano; Gazzadi, Gian Carlo

2016-02-01

In 1949, at the end of a paper dedicated to the concept of the refractive index in electron optics, Ehrenberg and Siday noted that wave-optical effects will arise from an isolated magnetic field even when the rays themselves travel in magnetic-field-free space. They proposed a two-slit experiment, in which a magnetic flux is enclosed between interfering electron beams. Now, through access to modern nanotechnology tools, we used a focused ion beam to open two nanosized slits in a gold-coated silicon nitride membrane and focused electron beam induced deposition to fabricate a thin magnetic bar between the two slits. We then performed Fraunhofer experiments in a transmission electron microscope equipped with a field emission gun and a Lorentz lens. By tilting the specimen in the objective lens field of the electron microscope, the magnetization of the bar could be reversed and the corresponding change in the phase of the electron wave observed directly in the form of a shift in the interference fringe pattern.

Diode-pumped solid state green laser for ophthalmologic application

NASA Astrophysics Data System (ADS)

Eno, Taizo; Goto, Yoshiaki; Momiuchi, Masayuki

2002-10-01

We have developed diode pumped solid state green laser suitable for ophthalmologic applications. Beam parameters were designed by considering the coagulation system. We have lowered the beam quality to multi transverse and longitudinal mode on purpose to improve the speckle noise of the slit lamp output beam. The beam profile shows homogeneous intensity and it is very useful for ophthalmologic application. End pumping and short cavity configuration made it possible.

High-Speed Laser Imaging, Emission and Temperature Measurements of Explosions

DTIC Science & Technology

2006-09-01

of these optical fibers illuminated the entrance slit of a dedicated Ocean Optics model HR-2000 spectrograph. The seven spectrographs were modified...Hewlett-Packard). The spectral response of the system was calibrated using an ARC Model XS432 Xenon lamp. Time resolution is approximately 12...F FOROHAR 101 STRAUSS AVE INDIAN HEAD MD 20640-5035 1 NAVAL SURFACE WARFARE CTR CODE 920J R GUIRGUIS 101 STRAUSS AVE INDIAN

Intrafamilial variability of the ocular phenotype in a Polish family with a missense mutation (A63D) in the Norrie disease gene.

PubMed

Zaremba, J; Feil, S; Juszko, J; Myga, W; van Duijnhoven, G; Berger, W

1998-09-01

To describe the phenotypic variability in a Polish Norrie disease (ND) family associated with the missense mutation A63D. A patient with spared vision from a Polish ND family underwent detailed ophthalmological examinations including slit-lamp biomicroscopy, ultrasound (USG), angiography, Goldmann kinetic visual field, and electroretinography (ERG). Mutation screening was carried out using the single-strand conformation polymorphism (SSCP) technique and subsequent DNA sequencing of the coding part of the ND gene. A mutation was detected (exon 3, A63D) in a large Polish family with 12 affected males, all but one presenting with classical ND symptoms. In one male, partially preserved vision was observed up to 40 years of age (distance acuity of the right eye 1/50 and left eye 2/50). Slit-lamp examination revealed remnants of a persistent primary vitreous and hyaloid artery. Upon angiography, the retina was vascularized within the posterior pole but not in the periphery. The ERG revealed pathological changes characteristic for chorioretinal degenerations. Within one family, individuals with identical sequence alterations in the ND gene can show remarkable phenotypic variability of the ocular symptoms. These findings indicate the involvement of additional factors (epigenetic or genetic) in ocular pathogenesis of ND.

In vivo imaging of coin-shaped lesions in cytomegalovirus corneal endotheliitis by anterior segment optical coherence tomography.

PubMed

Yokogawa, Hideaki; Kobayashi, Akira; Yamazaki, Natsuko; Sugiyama, Kazuhisa

2014-12-01

The aim of this study was to investigate in vivo corneal changes of coin-shaped lesions in cytomegalovirus corneal endotheliitis using anterior segment optical coherence tomography (AS-OCT). Two eyes of 2 patients (69- and 71-year-old men), with polymerase chain reaction-proven CMV corneal endotheliitis presenting coin-shaped lesions, were included in this study. AS-OCT examination was performed on the initial visit and at follow-up visits by paying special attention to the coin-shaped lesions. Selected AS-OCT images of the cornea were evaluated qualitatively for changes in the shape and degree of light reflection. In both cases, coin-shaped lesions were observed at the corneal endothelial surface as clusters of fine precipitates using slit-lamp biomicroscopy. Using AS-OCT, high-resolution images of the putative coin-shaped lesions were successfully obtained in both patients as an irregularly thickened highly reflective endothelial cell layer. After anti-CMV treatment, the coin-shaped lesions were resolved as assessed by slit-lamp biomicroscopy and AS-OCT in both patients. High-resolution AS-OCT provides novel and detailed visual information of coin-shaped lesions in patients with CMV corneal endotheliitis. Visualization of coin-shaped lesions by AS-OCT may be a useful adjunct to the diagnosis and follow-up of CMV corneal endotheliitis.

Near-infrared transillumination photography of intraocular tumours.

PubMed

Krohn, Jørgen; Ulltang, Erlend; Kjersem, Bård

2013-10-01

To present a technique for near-infrared transillumination imaging of intraocular tumours based on the modifications of a conventional digital slit lamp camera system. The Haag-Streit Photo-Slit Lamp BX 900 (Haag-Streit AG) was used for transillumination photography by gently pressing the tip of the background illumination cable against the surface of the patient's eye. Thus the light from the flash unit was transmitted into the eye, leading to improved illumination and image resolution. The modification for near-infrared photography was done by replacing the original camera with a Canon EOS 30D (Canon Inc) converted by Advanced Camera Services Ltd. In this camera, the infrared blocking filter was exchanged for a 720 nm long-pass filter, so that the near-infrared part of the spectrum was recorded by the sensor. The technique was applied in eight patients: three with anterior choroidal melanoma, three with ciliary body melanoma and two with ocular pigment alterations. The good diagnostic quality of the photographs made it possible to evaluate the exact location and extent of the lesions in relation to pigmented intraocular landmarks such as the ora serrata and ciliary body. The photographic procedure did not lead to any complications. We recommend near-infrared transillumination photography as a supplementary diagnostic tool for the evaluation and documentation of anteriorly located intraocular tumours.

Panoramic view of human corneal endothelial cell layer observed by a prototype slit-scanning wide-field contact specular microscope.

PubMed

Tanaka, Hiroshi; Okumura, Naoki; Koizumi, Noriko; Sotozono, Chie; Sumii, Yasuhiro; Kinoshita, Shigeru

2017-05-01

To observe the most peripheral region of the corneal endothelial cell (CEC) layer as long as optically recordable by use of a prototype slit-scanning wide-field contact specular microscope and produce a panoramic image to evaluate the variation of CEC density with ageing. Observational case series study. This study involved 15 eyes of 15 normal healthy subjects divided into three groups according to age: A (20-40 years), B (41-60 years) and C (>60 years). The corneal endothelial layer of each eye was recorded in a horizontal direction, from nasal to temporal, with a slit-scanning wide-field contact specular microscope (Konan) and endothelial cell density (ECD) in three specific regions (central, mid-peripheral, and peripheral) was automatically calculated via built-in analysis software. Corneal endothelial images from near the surgical limbus to limbus in all eyes were clearly recorded and panoramic images were made by combining still images. ECD in groups A, B and C were 2809±186, 2717±91 and 2580±129 cells/mm 2 at the centre, 2902±242, 2772±97 and 2604±187 cells/mm 2 at the mid-periphery and 2893±308, 2691±99 and 2533±112 cells/mm 2 at the periphery. Significance differences in ECD was found between groups A and C in all regions and groups between B and C at mid-peripheral region. A prototype slit-scanning wide-field contact specular microscope enabled us to record the endothelial layer from the surgical limbus to limbus of the cornea and compare specific areas among subjects, and showed that ECD in each region of the cornea decreases with ageing. UMIN000021264, Results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Production of anterior segment ischemia.

PubMed Central

Hiatt, R L

1977-01-01

Anterior segment ischemic changes can occur without detachment of any muscles. The most common cause of such ischemic changes of the anterior segment is the removal of too many rectus muscles in one operation. Twenty dog eyes and eight monkey eyes were subjected to the disinsertion and detachment of various combinations of extraocular muscles. The dogs were sacrificed at intervals from 30 to 90 days. During the observation period, they were observed for gross and slit-lamp changes. The enucleated eyes were studied microscopically for signs of ischemic and necrotic changes. Two patients who were studied, observed, and treated for anterior segment ischemia following muscle surgery are described. The changes which occur after extraocular muscle surgery are extensive and include corneal edema, cataract, chemosis, corneal changes, decreases in intraocular pressure, decreases in outflow or glaucoma, and frank necrosis. The variables which lead to this reaction are described in detail. Also, some unanswered queries, such as the duration of the reaction and the time interval of the reaction after multiple muscle operations are discussed. Images FIGURE 1 A FIGURE 1 B FIGURE 1 C FIGURE 2 A FIGURE 2 B FIGURE 2 C FIGURE 2 D FIGURE 3 FIGURE 4 PMID:418549

Tick Infestation of the Eyelid and Removal With Forceps and Punch Biopsy.

PubMed

Park, Jongyeop; Suh, Eoksoo

2016-11-01

Ocular tick infestation can occur in any age group or sex with exposure in an endemic setting. All parts of the ocular tissue have been reported to be susceptible to tick infestation. The authors present a rare patient with tick infestation of eyelid.An 88-year-old woman was referred for a yellowish lesion of the right upper eyelid. She had a history of sting 2 days before presentation, and developed eyelid swelling with mucopurulent discharge the next day. Slit lamp examination showed blepharitis and revealed that the lesion was the body of a hard tick, firmly attached to eyelid. First, blunt forceps were used for removal of the tick under a surgical microscope. However, attempted removal resulted in the disembodiement of the parasite and retention of the mouthparts in the skin. The retained tick parts were excised en bloc by skin punch biopsy. The tick was identified as Ixodes nipponensis. Subsequent treatment was given for blepharitis and skin lesion.This case introduces a rare patient with tick infestation of eyelid, and the proper management. Less than 20 documented patients with tick infestation of eyelid have been reported worldwide, and this is the first patient from South Korea in ophthalmological society.

Neurotrophic factors and corneal nerve regeneration

PubMed Central

Sacchetti, Marta; Lambiase, Alessandro

2017-01-01

The cornea has unique features that make it a useful model for regenerative medicine studies. It is an avascular, transparent, densely innervated tissue and any pathological changes can be easily detected by slit lamp examination. Corneal sensitivity is provided by the ophthalmic branch of the trigeminal nerve that elicits protective reflexes such as blinking and tearing and exerts trophic support by releasing neuromediators and growth factors. Corneal nerves are easily evaluated for both function and morphology using standard instruments such as corneal esthesiometer and in vivo confocal microscope. All local and systemic conditions that are associated with damage of the trigeminal nerve cause the development of neurotrophic keratitis, a rare degenerative disease. Neurotrophic keratitis is characterized by impairment of corneal sensitivity associated with development of persistent epithelial defects that may progress to corneal ulcer, melting and perforation. Current neurotrophic keratitis treatments aim at supporting corneal healing and preventing progression of corneal damage. Novel compounds able to stimulate corneal nerve recovery are in advanced development stage. Among them, nerve growth factor eye drops showed to be safe and effective in stimulating corneal healing and improving corneal sensitivity in patients with neurotrophic keratitis. Neurotrophic keratitis represents an useful model to evaluate in clinical practice novel neuro-regenerative drugs. PMID:28966630

Elastic and inelastic electrons in the double-slit experiment: A variant of Feynman's which-way set-up.

PubMed

Frabboni, Stefano; Gazzadi, Gian Carlo; Grillo, Vincenzo; Pozzi, Giulio

2015-07-01

Modern nanotechnology tools allowed us to prepare slits of 90 nm width and 450 nm spacing in a screen almost completely opaque to 200 keV electrons. Then by covering both slits with a layer of amorphous material and carrying out the experiment in a conventional transmission electron microscope equipped with an energy filter we can demonstrate that the diffraction pattern, taken by selecting the elastically scattered electrons, shows the presence of interference fringes, but with a bimodal envelope which can be accounted for by taking into account the non-constant thickness of the deposited layer. However, the intensity of the inelastically scattered electrons in the diffraction plane is very broad and at the limit of detectability. Therefore the experiment was repeated using an aluminum film and a microscope also equipped with a Schottky field emission gun. It was thus possible to observe also the image due to the inelastically scattered electron, which does not show interference phenomena both in the Fraunhofer or Fresnel regimes. If we assume that inelastic scattering through the thin layer covering the slits provides the dissipative process of interaction responsible for the localization mechanism, then these experiments can be considered a variant of the Feynman which-way thought experiment. Copyright © 2015 Elsevier B.V. All rights reserved.

A System Approach to Navy Medical Education and Training. Appendix 32- Competency Curricula for Ophthalmic Clinic Assistant and Ophthalmic Technician

DTIC Science & Technology

1974-08-31

chamber fluid, and gonioscopy exam (Conditions) With direct supervision (Criteria) In accordance with physician’s instructions (Consequence) Completion of...posterior chambers Gonioscopy techniques Slit-lamp biomicroscopy techniques Smear and culture techniques Accuracy in recording ard charting Manual...CILIARY BODY/ANGLE STRUCTURE TESTS I TASXS a. Assist with gonioscopy PERFO-RANCE OBJECTIVE (Stimulus) Upon physician’s orders (Behavior) The OPHTA

VizieR Online Data Catalog: Orphan stream high-resolution spectroscopic study (Casey+, 2014)

NASA Astrophysics Data System (ADS)

Casey, A. R.; Keller, S. C.; da Costa, G.; Frebel, A.; Maunder, E.

2017-06-01

High-resolution spectra for five Orphan stream candidates and seven well-studied standard stars have been obtained with the Magellan Inamori Kyocera Echelle spectrograph (Bernstein et al. 2003SPIE.4841.1694B) on the Magellan Clay telescope. These objects were observed in 2011 March using a 1" wide slit in mean seeing of 0.9". This slit configuration provides continuous spectral coverage from 333 nm to 915 nm, with a spectral resolution of R=25000 in the blue arm and R=28000 in the red arm. A minimum of 10 exposures of each calibration type (biases, flat fields, and diffuse flats) were observed in the afternoon of each day, with additional flat-field and Th-Ar arc lamp exposures performed throughout the night to ensure an accurate wavelength calibration. (3 data files).

Precision Pulse Capsulotomy: Preclinical Safety and Performance of a New Capsulotomy Technology.

PubMed

Chang, David F; Mamalis, Nick; Werner, Liliana

2016-02-01

To assess the preclinical safety and performance of a new precision pulse capsulotomy (PPC) method. Human cadaver eye studies and surgical, slit-lamp, and histopathologic evaluation in a consecutive series of 20 live rabbits. Human cadaver eyes and New Zealand white rabbits. Precision pulse capsulotomy uses a highly focused, fast, multipulse, low-energy discharge to produce a perfectly round anterior capsulotomy instantaneously and simultaneously along all 360°. Capsulotomies are performed using a disposable handpiece with a soft collapsible tip and circular nitinol cutting element. Miyake-Apple imaging and scanning electron microscopy (SEM) of PPC were conducted in human cadaver eyes. Surgical, postoperative slit-lamp, and histopathologic assessments of PPC were performed in 20 live rabbits and were compared with manual continuous curvilinear capsulorrhexis (CCC) in the fellow eye. Anterior chamber (AC) thermocouple temperature measurements were evaluated in a subset of rabbit eyes. Capsulotomy edge circularity, SEM morphologic features and zonular movement with PPC in human cadaver eyes. Anterior chamber temperature during PPC and grading of ocular inflammation, corneal endothelial damage, anterior capsular opacification (ACO), and posterior capsular opacification (PCO). Miyake-Apple imaging showed minimal zonular stress, and thermocouple measurements demonstrated negligible AC temperature changes during PPC. Precision pulse capsulotomy produced round, complete capsulotomies in all 20 rabbit eyes, leading to successful in-the-bag intraocular lens (IOL) implantation. Slit-lamp examinations at 3 days and 1, 2, and 4 weeks after surgery showed no significant differences between PPC and CCC in corneal edema, AC inflammatory reaction, capsular fibrosis, ACO, and PCO. Postmortem studies showed no difference in the corneal endothelium between PPC and CCC eyes. All IOLs were well centered in PPC eyes, and histopathologic analysis showed no greater inflammatory infiltrates. Precision pulse capsulotomy is a new method to automate consistent creation of a perfectly circular anterior capsulotomy with a disposable handheld instrument that can be used in the normal phacoemulsification surgical sequence. Compared with CCC in fellow rabbit eyes, PPC was equally safe and showed no greater zonular stress compared with CCC in human cadaver eyes. Human cadaver eye SEM showed a much smoother capsulotomy edge compared to those produced by femtosecond laser. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Development of the micro-scanning optical system of yellow laser applied to the ophthalmologic area

NASA Astrophysics Data System (ADS)

Ortega, Tiago A.; Mota, Alessandro D.; Costal, Glauco Z.; Fontes, Yuri C.; Rossi, Giuliano; Yasuoka, Fatima M. M.; Stefani, Mario A.; de Castro N., Jarbas C.

2012-10-01

In this work, the development of a laser scanning system for ophthalmology with micrometric positioning precision is presented. It is a semi-automatic scanning system for retina photocoagulation and laser trabeculoplasty. The equipment is a solid state laser fully integrated to the slit lamp. An optical system is responsible for producing different laser spot sizes on the image plane and a pair of galvanometer mirrors generates the scanning patterns.

[New international classification of corneal dystrophies and clinical landmarks].

PubMed

Lisch, W; Seitz, B

2008-07-01

The International Committee on Classification of Corneal Dystrophies, briefly IC (3)D, was founded with the sponsorship of the American Cornea Society and the American Academy of Ophthalmology in July 2005. This committee consists of 17 corneal experts (1) from USA, Asia and Europe. The goal of this group was to develop a new, internationally accepted classification of corneal dystrophies (CD) based on modern clinical, histological and genetical knowledge. The aim of the new classification should be to avoid wrong interpretations and misnomers of the different forms of CD. The IC (3)D extensive manuscript is in press as Supplement publication in the journal "Cornea". The 25 different CD are divided in four categories by clinical and genetical knowledge. Additionally, templates for each type of CD are included. Finally, many typical color slit-lamp photos are presented in the publication together with essential references and current genetical results in tabular form. As members of IC (3)D the authors present a clinical landmark survey of the different corneal dystrophies. The ophthalmologist is the first to examine and to diagnose a new patient with a probable CD at the slit-lamp. Our elaborated table of landmarks is supposed to be a "bridge" for the ophthalmologist to precisely define the corneal opacities of a presumed CD. This "bridge" makes it easier for them to study the IC (3)D Supplement publication and to get more information including adequate differential diagnosis.

Rapid diagnosis of acanthamoeba keratitis using non-nutrient agar with a lawn of E. coli.

PubMed

Borin, Samuel; Feldman, Ilan; Ken-Dror, Shifra; Briscoe, Daniel

2013-02-27

A patient presented with a corneal foreign body in his only eye. He was treated with prophylactic antibiotics and sent home, but deteriorated. He returned to the hospital 5 days later, and on slit-lamp examination, there was ciliary injection, corneal oedema and a 1 mm × 1 mm corneal abscess with mild anterior uveitis. Corneal scrapings were taken for culture on a non-nutrient agar with a lawn of Escherichia coli, on chocolate agar and on blood agar. He was treated with fortified gentamicin and cefazolin drops. He improved and was discharged 4 days after admission. On day 5, the culture results showed acanthamoeba. He was brought back to the hospital and treated with hourly chlorhexidine drops, ofloxacin six times daily and neomycin/dexamethasone drops once daily. On day 7, he was discharged to continue treatment at home, at which time his visual acuity in that eye was 6/9, and slit-lamp examination showed punctate keratitis and a stromal opacity with mild peripheral infiltration. Culture on non-nutrient agar with a lawn of E. coli is a rapid, reliable and less invasive alternative to corneal biopsy for the diagnosis of acanthamoeba infection. We suggest using this method where acanthamoeba is suspected. Owing to the risk of corneal abscess, orthokeratology should be avoided in an amblyopic patient or an only eye. Acanthamoeba infection may be masked by other eye diseases.

Navigated Pattern Laser System versus Single-Spot Laser System for Postoperative 360-Degree Laser Retinopexy.

PubMed

Kulikov, Alexei N; Maltsev, Dmitrii S; Boiko, Ernest V

2016-01-01

Purpose . To compare three 360°-laser retinopexy (LRP) approaches (using navigated pattern laser system, single-spot slit-lamp (SL) laser delivery, and single-spot indirect ophthalmoscope (IO) laser delivery) in regard to procedure duration, procedural pain score, technical difficulties, and the ability to achieve surgical goals. Material and Methods . Eighty-six rhegmatogenous retinal detachment patients (86 eyes) were included in this prospective randomized study. The mean procedural time, procedural pain score (using 4-point Verbal Rating Scale), number of laser burns, and achievement of the surgical goals were compared between three groups (pattern LRP (Navilas® laser system), 36 patients; SL-LRP, 28 patients; and IO-LRP, 22 patients). Results . In the pattern LRP group, the amount of time needed for LRP and pain level were statistically significantly lower, whereas the number of applied laser burns was higher compared to those in the SL-LRP group and in the IO-LRP group. In the pattern LRP, SL-LRP, and IO-LRP groups, surgical goals were fully achieved in 28 (77.8%), 17 (60.7%), and 13 patients (59.1%), respectively ( p > 0.05). Conclusion . The navigated pattern approach allows improving the treatment time and pain in postoperative 360° LRP. Moreover, 360° pattern LRP is at least as effective in achieving the surgical goal as the conventional (slit-lamp or indirect ophthalmoscope) approaches with a single-spot laser.

[Slit lamp optical coherence tomography study of anterior segment changes after phacoemulsification and foldable intraocular lens implantation].

PubMed

Yan, Pi-song; Zhang, Zhen-ping; Lin, Hao-tian; Wu, Wen-jie; Bai, Ling

2009-09-01

To investigate quantitative changes of the anterior segment configuration after clear corneal incision phacoemulsification and foldable intraocular lens (IOL) implantation with slit-lamp-adapted optical coherence tomography (SL-OCT). In prospective consecutive case series, clear corneal incision phacoemulsification and foldable intraocular lens implantation were performed in 44 eyes of 40 patients. The changes of the anterior segment configuration were performed by SL-OCT before and 1 day, 1 week, 2 weeks and 1 month after surgery. SPSS 16.0 software was used to analyze statistical difference. For all patients, the central corneal thickness (CCT) and the incisional corneal thickness (ICT) increased significantly 1 day after surgery (CCT increased 99.59 microm, ICT increased 234.57 microm; P = 0.490). At 1 month, the CCT almost had returned to baseline, but the ICT had been thicker about 19.25 microm than baseline(P = 0.001). The measurements of ACD, AOD500, AOD750, TISA500, TISA750 also increased significantly 1 day after surgery. Although the ACD had no changes within 2 weeks (all P < 0.05), it had been not stable. The changes of the width of the anterior chamber had been stable in the early period after surgery (all P > 0.05). The SL-OCT could impersonality and quantificationally evaluate the anterior segment changes induced by cataract surgery.

Local Resistance Profiling of Ultra Shallow Junction Annealed with Combination of Spike Lamp and Laser Annealing Processes using Scanning Spreading Resistance Microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abo, Satoshi; Nishikawa, Kazuhisa; Ushigome, Naoya

2011-01-07

Local resistance profiles of ultra shallow boron and arsenic implanted into silicon with energies of 2.0 and 4.0 keV and doses of 2.0x10{sup 15} and 1.0x10{sup 15} ions/cm{sup 2} activated by a combination of conventional spike lamp and laser annealing processes were measured by scanning spreading resistance microscope (SSRM) with a depth resolution of less than 10 nm. The lowest local resistance at the low resistance region in 2.0 keV boron implanted silicon with 1050 deg. C spike lamp annealing followed by 0.35 kW/mm{sup 2} laser annealing was half of that without laser annealing. The lowest local resistance at themore » low resistance region in the arsenic implanted silicon activated by 1050 deg. C spike lamp annealing followed by 0.39 kW/mm{sup 2} laser annealing was 74% lower than that followed by 0.36 kW/mm{sup 2} laser annealing. The lowest local resistances at the low resistance regions in the arsenic implanted silicon with 0.36 and 0.39 kW/mm{sup 2} laser annealing followed by 1050 deg. C spike lamp annealing were 41 and 33% lower than those with spike lamp annealing followed by laser annealing. Laser annealing followed by spike lamp annealing could suppress the diffusion of the impurities and was suitable for making the ultra shallow and low resistance regions.« less

Proceedings of the Symposium of Medical (Ophthalmic) Surveillance of Personnel Potentially Exposed to Laser Radiation Held on 8-9 September 1982.

DTIC Science & Technology

1982-01-01

Hardy, Rand, and Rittler (HRR) pseudoisochromatic plates and the Farnsworth D15 color panel; these tests were normal. However, in an anomaloscopic...measures (e.g., slit-lamp and ophthalmoscopic examinations ) rather than quantitative visual function tests (e.g., Snellen acuity, contrast transfer, color...arose from eye examination programs ii ..’ 1C- following field tests at Fort Hunter Liggett, California and at Yuma Proving Ground, Arizona. Most, if

VizieR Online Data Catalog: WINERED CN-red band emission in comet C/2013 R1 (Shinnaka+, 2017)

NASA Astrophysics Data System (ADS)

Shinnaka, Y.; Kawakita, H.; Kondo, S.; Ikeda, Y.; Kobayashi, N.; Hamano, S.; Sameshima, H.; Fukue, K.; Matsunaga, N.; Yasui, C.; Izumi, N.; Mizumoto, M.; Otsubo, S.; Takenaka, K.; Watase, A.; Kawanishi, T.; Nakanishi, K.; Nakaoka, T.

2018-05-01

High-resolution spectroscopic observations of comet C/2013 R1 (Lovejoy; hereafter, comet Lovejoy) in the near-infrared wavelength region were performed using the WINERED spectrograph (Ikeda et al. 2016SPIE.9908E..5ZI) mounted on the Nasmyth focus of the 1.3 m Araki telescope (F/10) at Koyama Astronomical Observatory, Japan (Yoshikawa et al. 2012SPIE.8444E..6GY). We used a slit of length 47" and width 1.5". This slit width corresponds to a spectral resolving power of R=28000 (two pixels). The observations of comet Lovejoy were performed on 2013 November 30, from 19:08 UT to 21:04 UT; the total integration time was 6000 s on source. The heliocentric and geocentric distances were 0.91 au and 0.49 au, respectively, and the relative velocities of the comet to the Sun and observer were -14.5 km/s and 25.8 km/s, respectively, at the observations. We put the comet at the center of the slit during the exposures. Other calibration data (darks, flats, and comparison-lamp frames) were also acquired. (1 data file).

Does corneal hysteresis correlate with endothelial cell density?

PubMed

Akova-Budak, Berna; Kıvanç, Sertaç Argun

2015-05-21

Our aim was to determine if there is a correlation between corneal biomechanical properties, endothelial cell count, and corneal pachymetry in healthy corneas. Ninety-two eyes of all subjects underwent complete ocular examination, including intraocular pressure measurement by Goldmann applanation tonometer, objective refraction, and slit-lamp biomicroscopy. Topographic measurements and corneal pachymetry were performed using a Scheimpflug-based (Pentacam, Oculus, Germany) corneal topographer. Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured with an Ocular Response Analyzer (ORA, Reichert Ophthalmic Instruments, Buffalo, NY). Endothelial cell count measurement was done using a specular microscope (CellChek, Konan, USA). Right eye values of the subjects were taken for the study. The mean CH was 11.5±1.7 mmHg and the mean CRF was 11.2±1.4 mmHg. Mean intraocular pressure was 15.3±2.3 mmHg. The mean endothelial cell count was 2754±205 cells/mm2. No correlation was found between biomechanical properties of cornea and endothelial cell count. There was a significant positive correlation between CH, CRF, and corneal thickness (p<0.001; r=0.79). The corneal biomechanical properties significantly correlated with corneal thickness. We found no correlation between CH and CRF with the endothelial cell density in normal subjects.

External ophthalmomyiasis presenting to an emergency department: corneal findings as a sign of Oestrus ovis.

PubMed

Gholamhossein, Yaghoubi; Behrouz, Heydari

2013-10-01

This study aims to determine the frequency of opthalmyomyiasis externa and the ocular findings of disease in Southern Khorasan. All patients referred to the emergency department of Valiaser hospital during the year 2011 with external ophthalmomyiasis were enrolled in this study. The diagnosis of external ophthalmomyiasis was made according to clinical findings and the presence of Oestrus ovis larvae. There were 18 cases of external ophthalmomyiasis in the emergency department of Valiaser hospital in 2011. Most cases had the common signs and symptoms of allergic conjunctivitis, except for three males who were referred with respective complaints of red eye, foreign body sensation, and swelling around the eyelids after contact injury the previous day; corneal infiltration was present in three cases. The visual acuity among the three cases that had peripheral corneal involvement was 20 / 30 in both eyes. The bulbar conjunctiva showed chemosis in all cases and a ropy pattern discharge that was clinically compatible with external ophthalmomyiasis. However, in one case, microscopic slit lamp examination did not show Oestrus ovis larvae. The frequency of external ophthalmomyiasis was high in this region. Although external ophthalmomyiasis usually manifests as allergic conjunctivitis, coronary-like corneal infiltration may be considered in the differential diagnosis of external ophthalmomyiasis or toxic insult.

Corneal endothelial cell density and morphology in Phramongkutklao Hospital

PubMed Central

Sopapornamorn, Narumon; Lekskul, Manapon; Panichkul, Suthee

2008-01-01

Objective To describe the corneal endothelial density and morphology in patients of Phramongkutklao Hospital and the relationship between endothelial cell parameters and other factors. Methods Four hundred and four eyes of 202 volunteers were included. Noncontact specular microscopy was performed after taking a history and testing the visual acuity, intraocular pressure measurement, Schirmer’s test and routine eye examination by slit lamp microscope. The studied parameters included mean endothelial cell density (MCD), coefficient of variation (CV), and percentage of hexagonality. Results The mean age of volunteers was 45.73 years; the range being 20 to 80 years old. Their MCD (SD), mean percentage of CV (SD) and mean (SD) percentage of hexagonality were 2623.49(325) cell/mm2, 39.43(8.23)% and 51.50(10.99)%, respectively. Statistically, MCD decreased significantly with age (p < 0.01). There was a significant difference in the percentage of CV between genders. There was no statistical significance between parameters and other factors. Conclusion The normative data of the corneal endothelium of Thai eyes indicated that, statistically, MCD decreased significantly with age. Previous studies have reported no difference in MCD, percentage of CV, and percentage of hexagonality between gender. Nevertheless, significantly different percentages of CV between genders were presented in this study. PMID:19668398

External Ophthalmomyiasis Presenting to an Emergency Department: Corneal Findings as a Sign of Oestrus ovis

PubMed Central

Behrouz, Heydari

2013-01-01

Purpose This study aims to determine the frequency of opthalmyomyiasis externa and the ocular findings of disease in Southern Khorasan. Methods All patients referred to the emergency department of Valiaser hospital during the year 2011 with external ophthalmomyiasis were enrolled in this study. The diagnosis of external ophthalmomyiasis was made according to clinical findings and the presence of Oestrus ovis larvae. Results There were 18 cases of external ophthalmomyiasis in the emergency department of Valiaser hospital in 2011. Most cases had the common signs and symptoms of allergic conjunctivitis, except for three males who were referred with respective complaints of red eye, foreign body sensation, and swelling around the eyelids after contact injury the previous day; corneal infiltration was present in three cases. The visual acuity among the three cases that had peripheral corneal involvement was 20 / 30 in both eyes. The bulbar conjunctiva showed chemosis in all cases and a ropy pattern discharge that was clinically compatible with external ophthalmomyiasis. However, in one case, microscopic slit lamp examination did not show Oestrus ovis larvae. Conclusions The frequency of external ophthalmomyiasis was high in this region. Although external ophthalmomyiasis usually manifests as allergic conjunctivitis, coronary-like corneal infiltration may be considered in the differential diagnosis of external ophthalmomyiasis or toxic insult. PMID:24082771

Size of the Lesions of Superficial Punctate Keratitis in Dry Eye Syndrome Observed With a Slit Lamp.

PubMed

Courrier, Emilie; Lépine, Thierry; Hor, Guillaume; Fournier, Corinne; He, Zhiguo; Chikh, Mehdi; Urrea, Caroline; Al Anazi, Fahran-Falgi; Thuret, Gilles; Gain, Philippe

2016-07-01

To evaluate the size distribution of epithelial lesions of superficial punctate keratitis (SPK) in dry eye after staining of the ocular surface by sodium fluorescein. Fluorescein was instilled in 10 patients with dry eye graded using the Oxford Scheme. Pictures were taken using a standard Topcon slit lamp with cobalt blue light, without barrier filter. Two magnifications (×10 and ×16) were used and calibrated using a certified standard reference grating, allowing the diameter of the observed objects to be determined with ImageJ software. The most visible and isolated SPK lesions (green dots) were selected. The size of 254 SPK lesions was measured by tracing the irradiance profile and manually measuring the full width at half maximum. For all patients, with the 2 magnifications combined, the median diameter was 20.9 μm (15.2-26.6 μm, 10-90 percentile). There was a significant difference between the size of SPK lesions measured with ×10 and ×16 magnifications, respectively, 24.3 μm (18.2-29.8) versus 19.0 μm (15.2-26.6) (P < 0.001). Lesions seem to be smaller than normal superficial epithelial cells (which are approximately 25 × 50 μm) and might correspond to the staining of dying shrunken cells, according to recent investigations. These new quantitative data will help in developing automated recognition algorithms to obtain reliable objective classification of corneal staining.

Aesthetic Total Reconstruction of Lower Eyelid Using Scapha Cartilage Graft on a Vascularized Propeller Flap.

PubMed

Uemura, Tetsuji; Watanabe, Hidekata; Masumoto, Kazuyuki; Kikuchi, Mamoru; Satake, Yoshiyasu; Yanai, Tetsu; Harada, Yoshimi; Ishihara, Yasuhiro; Yasuta, Masato

2016-04-01

The aim of this study was to review the results of a cohort of patients based on our experience with a new technique for total lower eyelid reconstruction after a large defect caused by malignant tumor and trauma. A scapha cartilage graft with small skin on a vascularized propeller flap was used for 16 cases requiring lower eyelid reconstruction. Patients were identified from a database, and a retrospective case note review was conducted. The scapha cartilage graft was sutured to the margin of the defect of the palpebral conjunctiva and tarsus. The propeller flap, rotated by a perforator-based lateral orbital flap or a subcutaneous-based nasolabial flap, was vascularized on the scapha cartilage graft as anterior lining of the lower eyelid. The follow-up, including results of slit-lamp examination, lasted for varying periods, but often it was for 12 months. The scapha cartilage graft with small skin on a vascularized propeller flap was viable in all cases. Slit-lamp examination detected no irritation or injury of the conjunctiva and cornea, and visual acuity was maintained in all cases. A deformity in the donor helix by this technique was also improved by getting a smaller skin harvested from the scapha. Use of the scapha cartilage graft with small skin on a vascularized propeller flap allows for a good fit to the orbit, short operative time under local anesthesia, good graft viability, and a good esthetic result with minimal donor site morbidity.

Retroillumination Photography Analysis Enhances Clinical Definition of Severe Fuchs Corneal Dystrophy.

PubMed

Eghrari, Allen O; Garrett, Brian S; Mumtaz, Aisha A; Edalati, Armand E; Meadows, Danielle N; McGlumphy, Elyse J; Iliff, Benjamin W; Gottsch, John D

2015-12-01

Retroillumination photography analysis (RPA) provides an objective assessment of the number and distribution of guttae in Fuchs corneal dystrophy. Here, we assess its correlation with clinical grading using slit-lamp biomicroscopy across varying levels of severity. Retroillumination photographs were conducted for 95 affected corneas with slit-lamp flash photography after pupillary dilation. Individual guttae were counted manually and the position of individual points recorded. Clinical grading using the Krachmer scale was documented for each eye during examination, and regression analyses were performed to identify the strength of association with number of guttae. We assessed range at each stage of clinical grading and used the Mann-Whitney U test to assess whether clinical grading levels demonstrated successively higher numbers of guttae. Krachmer score ranged from 1 to 5, with mean of 2.6. Mean numbers of guttae at each level of severity were 289 (1+), 999 (2+), 2669 (3+), 5474 (4+), and 7133 (5+). Each stage demonstrated significantly higher numbers of guttae than its preceding level except from 4+ to 5+ (P = 0.30), consistent with the definition of 4+ as the highest level defined by the presence of guttae. Higher levels of clinical grading were associated with larger ranges of guttae (P < 0.01). A linear regression model resulted in a strong fit between RPA and Krachmer score (r = 0.81). In this largest study of RPA data and comparison with subjective clinical grading of Fuchs dystrophy severity, RPA correlates strongly and demonstrates enhanced definition of severity at advanced stages of disease.

The Progression of Haze Formation in Rabbit Corneas Following Phototherapeutic Keratectomy

PubMed Central

Gibson, Daniel J.; Tuli, Sonal S.; Schultz, Gregory S.

2013-01-01

Purpose. To determine the topographical location and time course of development of corneal haze in a phototherapeutic keratectomy model using slit lamp examination, macrophotography, quantitative image analysis, and immunofluorescence staining of corneal sections. Methods. Rabbit corneas were ablated with an excimer laser and were observed and graded for haze via slit lamp, imaged, and graded by macrophotography. Corneal sections were stained for α-smooth muscle actin (α-SMA) and tenascin-C (TNC). The distribution of haze imaged in the macrophotographs and density of α-SMA and TNC staining were compared. A daily image time course of haze formation was generated using macrophotography. Results. The first signs of corneal haze were apparent shortly after reepithelialization. The haze was distributed as a ring at the wound margin in all cases, while nearly all corneas also had some central islands of haze initiation. With time, the haze spread within the ablated zone and intensified. The pattern of immunofluorescent staining for α-SMA and TNC at the wound margin mirrored the haze distribution, spread, and intensification with time. Conclusions. The initiation and spread of subepithelial haze begins shortly after reepithelialization. The haze then spreads from the loci of initiation and becomes more dense with time, maturing as early as 14 days after wounding. The improved temporal and spatial resolution provided by these data improve the current model of light-scattering haze formation in wounded corneas, which will improve the design of studies aimed at maintaining corneal clarity following acute injury or surgery. PMID:23800768

[Evaluation of corneal tissue by slit lamp and specular microscopy during the preservation period].

PubMed

Farias, Roberta Jansen de Mello; Kubokawa, Karen Miyuki; Schirmer, Maurício; Sousa, Luciene Barbosa de

2007-01-01

To analyze changes evaluation of corneal grafts by slit lamp and electron microscopy examination in order to ensure a donor cornea of good quality level for the patient. 203 corneas donated to the Sorocaba Eye Bank between September 2002 and February 2003 were prospectively evaluated. The evaluation was graded from 0 to 3 according to the following factors: exposure and epithelial damage, stromal opacity, Descemet folds, pleomorphism, polymegatism and guttata, endothelial snail track, edema, reflectivity. The data were correlated with time between death and preservation, endothelial cell count and donor's age. 203 corneas were evaluated. The mean age of donors was 55 years (dp= 14.8 years). The mean time between death and preservation was 9.1 h (minimum of 2 h and maximum of 25 h). Eighty-six corneas suffered worsening of evaluation, whereby 66.3% had less than 2,500 endothelial cell count and 59.3% presented time between death and preservation over 6 hours. The mean day of the grading change was the 5th. Corneal grafts from younger donors had significantly better evaluation than those of older donors. The mean time of the evaluation change was on the 5th day in 50% of the corneas, however, an expressive number of corneas suffered changes on the 6th, 7th and 8th day. Corneal graft preserved after 6 hours of death had a greater tendency to lower cell count and to decrease in evaluation grades.

Theoretical Odds and Practical Ends

ERIC Educational Resources Information Center

Siddons, J. C.

1974-01-01

Describes a variety of experiments and activities such as refractive index by an interference method, Young's third slit, a microscope problem, uses of a hand stroboscope, an acceleration game, an aluminum thermometer, why milk boils over, and others. (BR)

Surface-plasmon-polariton hybridized cavity modes in submicrometer slits in a thin Au film

NASA Astrophysics Data System (ADS)

Walther, R.; Fritz, S.; Müller, E.; Schneider, R.; Maniv, T.; Cohen, H.; Matyssek, C.; Busch, K.; Gerthsen, D.

2016-06-01

The excitation of cavity standing waves in double-slit structures in thin gold films, with slit lengths between 400 and 2560 nm, was probed with a strongly focused electron beam in a transmission electron microscope. The energies and wavelengths of cavity modes up to the 11 th mode order were measured with electron energy loss spectroscopy to derive the corresponding dispersion relation. For all orders, a significant redshift of mode energies accompanied by a wavelength elongation relative to the expected resonator energies and wavelengths is observed. The resultant dispersion relation is found to closely follow the well-known dispersion law of surface-plasmon polaritons (SPPs) propagating on a gold/air interface, thus providing direct evidence for the hybridized nature of the detected cavity modes with SPPs.

A fiber optic sensor for ophthalmic refractive diagnostics

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Dhadwal, Harbans S.; Campbell, Melanie C. W.; Dellavecchia, Michael A.

1992-01-01

This paper demonstrates the application of a lensless fiber optic spectrometer (sensor) to study the onset of cataracts. This new miniaturized and rugged fiber optic probe is based upon dynamic light scattering (DLS) principles. It has no moving parts, no apertures, and requires no optical alignment. It is flexible and easy to use. Results are presented for cold-induced cataract in excised bovine eye lenses, and aging effects in excised human eye lenses. The device can be easily incorporated into a slit-lamp apparatus (ophthalmoscope) for complete eye diagnostics.

Design and Adaptation of an Optical System for Slit Lamp Delivery of a CO2 Laser Beam.

DTIC Science & Technology

1981-12-01

laser’s efficacy to serve as a photocoagulator. A non-linear barium sodium niobate crystal converted the near infrared radiation (1.064 pm) to green...recommendations. 10 II. Theoretical Development and Predictions Corneal tissue is an excellent absorber of infrared radiation. Therefore, when high power CO2...in general, that the waist will be formed slightly to one Lde of the focal plane, as shown in Eq (4) (Ref 18:31). f2 (zl-f) 2. = + wW2 (4) (zl-f) 2

Evaluation of a glaucoma patient

PubMed Central

Thomas, Ravi; Loibl, Klaus; Parikh, Rajul

2011-01-01

The diagnosis of glaucoma is usually made clinically and requires a comprehensive eye examination, including slit lamp, applanation tonometry, gonioscopy and dilated stereoscopic evaluation of the optic disc and retina. Automated perimetry is obtained if glaucoma is suspected. This establishes the presence of functional damage and provides a baseline for follow-up. Imaging techniques are not essential for the diagnosis but may have a role to play in the follow-up. We recommend a comprehensive eye examination for every clinic patient with the objective of detecting all potentially sight-threatening diseases, including glaucoma. PMID:21150033

MTF Determination of SENTINEL-4 Detector Arrays

NASA Astrophysics Data System (ADS)

Reulke, R.; Sebastian, I.; Williges, C.; Hohn, R.

2017-05-01

The Institute for Optical Sensor Systems was involved in many international space projects in recent years. These include, for example, the fokal plane array (FPA) of the hyperspectral sensors ENMAP or Sentinel-4, but also the FPA for the high resolution FPA for Kompsat-3. An important requirement of the customer is the measurement of the detector MTF for different wavelengths. A measuring station under clean room conditions and evaluation algorithms was developed for these measurements. The measurement setup consist of a collimator with slit target in focus for illumination at infinity, a gimbal mounted detector facing an auxiliary lens in front, a halogen lamp with monochromator or filter, as well as optical and electrical ground support equipment. Different targets and therefore also different measurement and data evaluation opportunities are possible with this setup. Examples are slit, edge, pin hole but also a Siemens star. The article describes the measurement setup, the different measuring and evaluation procedures and exemplary results for Sentinel-4 detector.

Smartphone confocal microscopy for imaging cellular structures in human skin in vivo.

PubMed

Freeman, Esther E; Semeere, Aggrey; Osman, Hany; Peterson, Gary; Rajadhyaksha, Milind; González, Salvador; Martin, Jeffery N; Anderson, R Rox; Tearney, Guillermo J; Kang, Dongkyun

2018-04-01

We report development of a low-cost smartphone confocal microscope and its first demonstration of in vivo human skin imaging. The smartphone confocal microscope uses a slit aperture and diffraction grating to conduct two-dimensional confocal imaging without using any beam scanning devices. Lateral and axial resolutions of the smartphone confocal microscope were measured as 2 and 5 µm, respectively. In vivo confocal images of human skin revealed characteristic cellular structures, including spinous and basal keratinocytes and papillary dermis. Results suggest that the smartphone confocal microscope has a potential to examine cellular details in vivo and may help disease diagnosis in resource-poor settings, where conducting standard histopathologic analysis is challenging.

Smartphone confocal microscopy for imaging cellular structures in human skin in vivo

PubMed Central

Freeman, Esther E.; Semeere, Aggrey; Osman, Hany; Peterson, Gary; Rajadhyaksha, Milind; González, Salvador; Martin, Jeffery N.; Anderson, R. Rox; Tearney, Guillermo J.; Kang, Dongkyun

2018-01-01

We report development of a low-cost smartphone confocal microscope and its first demonstration of in vivo human skin imaging. The smartphone confocal microscope uses a slit aperture and diffraction grating to conduct two-dimensional confocal imaging without using any beam scanning devices. Lateral and axial resolutions of the smartphone confocal microscope were measured as 2 and 5 µm, respectively. In vivo confocal images of human skin revealed characteristic cellular structures, including spinous and basal keratinocytes and papillary dermis. Results suggest that the smartphone confocal microscope has a potential to examine cellular details in vivo and may help disease diagnosis in resource-poor settings, where conducting standard histopathologic analysis is challenging. PMID:29675328

Prevention of bacterial colonization of contact lenses with covalently attached selenium and effects on the rabbit cornea.

PubMed

Mathews, Steven M; Spallholz, Julian E; Grimson, Mark J; Dubielzig, Richard R; Gray, Tracy; Reid, Ted W

2006-08-01

Although silicone hydrogel materials have produced many corneal health benefits to patients wearing contact lenses, bacteria that cause acute red eye or corneal ulcers are still a concern. A coating that inhibits bacterial colonization while not adversely affecting the cornea should improve the safety of contact lens wear. A covalent selenium (Se) coating on contact lenses was evaluated for safety using rabbits and prevention of bacterial colonization of the contact lenses in vitro. Contact lenses coated with Se were worn on an extended-wear schedule for up to 2 months by 10 New Zealand White rabbits. Corneal health was evaluated with slit-lamp biomicroscopy, pachymetry, electron microscopy, and histology. Lenses worn by the rabbits were analyzed for protein and lipid deposits. In addition, the ability of Se to block bacterial colonization was tested in vitro by incubating lenses in a Pseudomonas aeruginosa broth followed by scanning electron microscopy of the contact lens surface. The covalent Se coating decreased bacterial colonization in vitro while not adversely affecting the corneal health of rabbits in vivo. The Se coating produced no noticeable negative effects as observed with slit-lamp biomicroscopy, pachymetry, electron microscopy, and histology. The Se coating did not affect protein or lipid deposition on the contact lenses. The data from this pilot study suggest that a Se coating on contact lenses might reduce acute red eye and bacterial ulceration because of an inhibition of bacterial colonization. In addition, our safety tests suggest that this positive effect can be produced without an adverse effect on corneal health.

Retroillumination photography analysis enhances clinical definition of severe Fuchs Corneal Dystrophy

PubMed Central

Eghrari, Allen O.; Garrett, Brian S.; Mumtaz, Aisha A.; Edalati, Armand E.; Meadows, Danielle N.; McGlumphy, Elyse J.; Iliff, Benjamin W.; Gottsch, John D.

2015-01-01

Purpose Retroillumination photography analysis (RPA) provides objective assessment of the number and distribution of guttae in Fuchs Corneal Dystrophy. Here, we assess its correlation with clinical grading using slit-lamp biomicroscopy across varying levels of severity. Methods Retroillumination photographs were conducted of 95 affected corneas with slit-lamp flash photography after pupillary dilation. Individual guttae were counted manually and the position of individual points recorded. Clinical grading using the Krachmer scale was documented for each eye during examination, and regression analyses were performed to identify the strength of association with number of guttae. We assessed range at each stage of clinical grading, and utilized the Mann-Whitney U test to assess whether clinical grading levels demonstrated successively higher numbers of guttae. Results Krachmer score ranged from 1 to 5, with mean of 2.6. Mean numbers of guttae at each level of severity were 289 (1+), 999 (2+), 2669 (3+), 5474 (4+), and 7133 (5+). Each stage demonstrated significantly higher numbers of guttae than its preceding level except from 4+ to 5+ (p=0.30), consistent with the definition of 4+ as the highest level defined by presence of guttae. Higher levels of clinical grading were associated with larger ranges of guttae (p<0.01). A linear regression model resulted in a strong fit between RPA and Krachmer score (r=0.81). Conclusion In this largest study of RPA data and comparison with subjective clinical grading of FCD severity, RPA correlates strongly and demonstrates enhanced definition of severity at advanced stages of disease. PMID:26488628

Management of moderate and severe corneal astigmatism with AcrySof® toric intraocular lens implantation - Our experience.

PubMed

Farooqui, Javed Hussain; Koul, Archana; Dutta, Ranjan; Shroff, Noshir Minoo

2015-01-01

Visual performance following toric intraocular lens implantation for cataract with moderate and severe astigmatism. Cataract services, Shroff Eye Centre, New Delhi, India. Case series. This prospective study included 64 eyes of 40 patients with more than 1.50 dioptre (D) of pre-existing corneal astigmatism undergoing phacoemulsification with implantation of the AcrySof® toric IntraOcular Lens (IOL). The unaided visual acuity (UCVA), best corrected visual acuity (BCVA), residual refractive sphere and refractive cylinders were evaluated. Toric IOL axis and alignment error was measured by slit lamp method and Adobe Photoshop (version 7) method. Patient satisfaction was evaluated using a satisfaction questionnaire at 3 months. The mean residual refractive astigmatism was 0.57 D at the final follow-up of 3 months. Mean alignment error was 3.44 degrees (SD = 2.60) by slit lamp method and 3.88 degrees (SD = 2.86) by Photoshop method. Forty-six (71.9%) eyes showed misalignment of 5 degrees or less, and 60 (93.8%) eyes showed misalignment of 10 degrees or less. The mean log MAR UCVA at 1st post-op day was 0.172 (SD = 0.02), on 7th post-op day was 0.138 (SD = 0.11), and on 30th post-op day was 0.081 (SD = 0.11). The mean log MAR BCVA at three months was -0.04 (SD = 0.76). We believe that implantation of AcrySof® toric IOL is an effective, safe and predictable method to correct high amounts of corneal astigmatism during cataract surgery.

The SPOTS System: An Ocular Scoring System Optimized for Use in Modern Preclinical Drug Development and Toxicology.

PubMed

Eaton, Joshua Seth; Miller, Paul E; Bentley, Ellison; Thomasy, Sara M; Murphy, Christopher J

2017-12-01

To present a semiquantitative ocular scoring system comprising elements and criteria that address many of the limitations associated with systems commonly used in preclinical studies, providing enhanced cross-species applicability and predictive value in modern ocular drug and device development. Revisions to the ocular scoring systems of McDonald-Shadduck and Hackett-McDonald were conducted by board-certified veterinary ophthalmologists at Ocular Services On Demand (OSOD) over the execution of hundreds of in vivo preclinical ocular drug and device development studies and general toxicological investigations. This semiquantitative preclinical ocular toxicology scoring (SPOTS) system was driven by limitations of previously published systems identified by our group's recent review of slit lamp-based scoring systems in clinical ophthalmology, toxicology, and vision science. The SPOTS system provides scoring criteria for the anterior segment, posterior segment, and characterization of intravitreal test articles. Key elements include: standardized slit lamp settings; expansion of criteria to enhance applicability to nonrabbit species; refinement and disambiguation of scoring criteria for corneal opacity, fluorescein staining severity, and aqueous flare; introduction of novel criteria for scoring of aqueous and anterior vitreous cell; and introduction of criteria for findings observed with drugs/devices targeting the posterior segment. A modified Standardization of Uveitis Nomenclature (SUN) system is also introduced to facilitate accurate use of SUN's criteria in laboratory species. The SPOTS systems provide criteria that stand to enhance the applicability of semiquantitative scoring criteria to the full range of laboratory species, in the context of modern approaches to ocular therapeutics and drug delivery and drug and device development.

Is Pseudoexfoliation Syndrome a Risk Factor for Cerebro Vascular Disease?

PubMed

Kan, Emrah; Yılmaz, Ahmet; Demirağ, Mehmet Derya; Çalık, Murat

2017-01-01

To determine the relationship between cerebro vascular disease and pseudoexfoliation syndrome. This cross-sectional case control study consisted of 50 patients with ischemic-type cerebro vascular disease and 50 control subjects. All subjects were investigated for diabetes mellitus and hypertension status and underwent a detailed ophthalmic examination. A diagnosis of pseudoexfoliation syndrome was made if characteristic greyish particulate matter was found on the anterior lens capsule after pupillary dilatation by slit-lamp examination. All subjects were compared in terms of pseudoexfoliation syndrome, diabetes mellitus, and hypertension. Pearson Chi Square and Student's t test were used for statistical analysis. Logistic regression analyses of the risk factors between groups were also made. The presence of pseudoexfoliation syndrome was significantly higher in patients with cerebro vascular disease when compared to the control subjects (p = 0.02). The frequency of diabetes mellitus was similar between the two groups. Arterial hypertension was significantly more frequent in the patient group when compared to the control subjects (p < 0.01). The logistic regression analysis showed that both pseudoexfoliation syndrome and hypertension were significantly associated with cerebro vascular disease. In the present study, we found that pseudoexfoliation syndrome frequency was found to be higher in patients with cerebro vascular disease than in control subjects. A slit-lamp examination of the eye could be an important marker that indicates the risk of cerebro vascular disease. We recommend an evaluation of all subjects with pseudoexfoliation syndrome for the presence of cerebro vascular disease. Longitudinal studies with larger populations are needed to confirm this relationship.

Meibomian Gland Dysfunction Model in Hairless Mice Fed a Special Diet With Limited Lipid Content.

PubMed

Miyake, Hideki; Oda, Tomoko; Katsuta, Osamu; Seno, Masaharu; Nakamura, Masatsugu

2016-06-01

A novel meibomian gland dysfunction (MGD) model was developed to facilitate understanding of the pathophysiology of MGD and to evaluate treatment with azithromycin ophthalmic solution (azithromycin). MGD was induced in HR-1 hairless mice by feeding them a special diet with limited lipid content (HR-AD). Male HR-1 hairless mice were fed an HR-AD diet for 16 weeks. Development of MGD was assessed by histopathology at 4-week intervals. The lid margin was observed by slit-lamp examination. After cessation of the HR-AD diet, the mice were fed a normal diet to restore normal eye conditions. Expression of cytokeratin 6 was determined by immunostaining. We evaluated the effects of topically applied azithromycin on the plugged orifice in this model. After mice were fed the HR-AD diet, histopathology analysis showed hyperkeratinization of the ductal epithelium in the meibomian gland. Ductal hyperkeratinization resulted in the loss of acini, followed by atrophy of the gland. Slit-lamp examination revealed a markedly plugged orifice, telangiectasia, and a toothpaste-like meibum compared with that of a normal eyelid. Cessation of feeding with HR-AD ameliorated both the MGD signs and the expression of cytokeratin 6, restoring the tissue to a histologically normal state. Azithromycin treatment significantly decreased the number of plugged orifices and ameliorated atrophy, as revealed by histopathologic analysis. We developed a novel model that mimics human MGD signs in HR-1 hairless mice fed an HR-AD diet. Azithromycin treatment led to therapeutic improvement in this model. This MGD model could be useful for the evaluation of drug candidates for MGD.

Effect of topical administration of tramadol on corneal wound healing in rats.

PubMed

Cuvas Apan, Ozgun; Ozer, Murat Atabey; Takir, Selcuk; Apan, Alparslan; Sengul, Demet

2016-10-01

In this study, we aimed to investigate the effects of topical tramadol administration on corneal wound healing, and examine ophthalmic structures and intraocular pressure 7 days after tramadol administration. The experiments were conducted on eight male Wistar rats (250-300 g). After ophthalmic examination, epithelial cell layers in the central cornea were wounded. Rats received 30 μL of tramadol hydrochloride in one eye (Group Tramadol) and the same volume of vehicle in the other (Group Control) every 12 h for 7 days. Both eyes were stained with fluorescein dye, photographed, and wound area was calculated every 8 h until complete healing was observed. Eye blink frequency and corneal reflex tests were measured before and after drug administrations. After 7 days, slit lamp biomicroscopy, fundoscopy, Goldmann applanation tonometry, and histological evaluation were performed. There was no difference in the corneal wound healing rates between the tramadol and control groups. Reduction in wound area over time was also similar; group-time interaction was insignificant (F = 738.911; p = 0.225). Tramadol application resulted in blinking and blepharospasm for 30 s, but vehicle did not. Corneal reflex was intact and eye blink frequency test results were similar in all measurement times in both groups. Slit lamp biomicroscopy, fundoscopy, and intraocular pressures were within normal range. Corneal cells appeared unaffected by the repeated doses of tramadol for 7 days. Topical tramadol application on the cornea did not cause any side effect, except for initial temporary blinking and blepharospasm. Corneal wound healing was not affected, either.

Anterior stromal puncture with staining: A modified technique for preoperative reference corneal marking for toric lenses and its retrospective analyses.

PubMed

Bhandari, Sahil; Nath, Manas

2016-08-01

Toric intraocular lenses (IOLs) are an effective way of compensating preexisting corneal astigmatism during cataract surgery. To achieve success, it is imperative to align the toric IOLs in desired position and preoperative reference marking is one among the three important steps for accurate alignment. To make the marking procedure simpler and effective, we have modified the conventional three-step slit lamp-based technique. Patient is seated in front of the slit lamp and asked to keep the chin over chin rest. A 26-gauge bent needle with tip stained by sterile blue ink marker is used to make anterior stromal puncture (ASP) at the edges of horizontal 180° axis near the limbus. A total of 58 eyes were retrospectively evaluated. Mean (+/-SD) IOL deviation on day 1 and day 30 was 5.7 ± 6.5° and 4.7 ± 5.6°, respectively. Median IOL misalignment on day 1 and day 30 was 3°. Redialing of IOL was required in 2 (3.4%) eyes only, all of which were performed within 1 week of surgery. In total, 2 (3.7%) eyes had a residual astigmatism of - 0.5 Dcyl and - 1.0 Dcyl, respectively. ASP is an effective technique for reference marking, technically simpler and can be practiced by most of the surgeons. It avoids the necessity of high-end sophisticated machinery and gives a better platform for the reference corneal marking along with the benefit of reproducibility and simplicity.

Effects of Repeated Intravitreal Aflibercept Injection on the Corneal Endothelium in Patients With Age-Related Macular Degeneration: Outcomes From the RE-VIEW Study.

PubMed

Lass, Jonathan H; Benetz, Beth Ann; Menegay, Harry J; Tsipis, Constantinos P; Cook, Jane Caty; Boyer, David S; Singer, Michael; Erickson, Kristine; Saroj, Namrata; Vitti, Robert; Chu, Karen W; Moini, Hadi; Soo, Yuhwen; Cheng, Yenchieh

2018-05-01

The effects of repeated intravitreal aflibercept injection (IAI) on the corneal endothelium were studied in patients with unilateral neovascular age-related macular degeneration. RE-VIEW was a phase 4, open-label, single-arm, multicenter study. Patients received IAI every 8 weeks after 3 monthly doses. Slit-lamp biomicroscopy was performed at all study visits. The central corneal endothelial health was evaluated by specular microscopy in the treated versus untreated fellow eyes at baseline and weeks 24 and 52. No slit-lamp abnormalities were noted in 154 enrolled patients (eyes). Baseline versus 52-week mean (±SD) endothelial morphometric values (n = 118) for the treated versus untreated fellow eyes were respectively as follows: endothelial cell density was 2410 ± 364 versus 2388 ± 384 cells/mm at baseline and remained unchanged at 2401 ± 353 versus 2376 ± 364 cells/mm at 52 weeks (P = 0.87); the coefficient of variation was 33.5 ± 4.4% versus 34.0 ± 5.0% at baseline and remained unchanged at 34.2 ± 4.7% versus 34.1 ± 4.9% at 52 weeks (P = 0.18); the percentage of hexagonal cells was 59.5 ± 5.8% versus 59.6 ± 6.4% at baseline and remained unchanged at 59.5 ± 6.0% versus 59.5 ± 5.8% at 52 weeks (P = 0.96). Repeated IAI for 52 weeks had no apparent corneal endothelial toxicity noted on specular microscopy in patients treated for neovascular age-related macular degeneration.

Long-term ocular consequences of sulfur mustard in seriously eye-injured war veterans.

PubMed

Ghasemi, Hassan; Ghazanfari, Tooba; Ghassemi-Broumand, Mohammad; Javadi, Mohammad Ali; Babaei, Mahmoud; Soroush, Mohammad Reza; Yaraee, Roya; Faghihzadeh, Soghrat; Poorfarzam, Shahriar; Owlia, Parviz; Naghizadeh, Mohammad Mehdi; Etezad-Razavi, Mohammad; Jadidi, Khosro; Naderi, Mostafa; Hassan, Zuhair Mohammad

2009-01-01

Sulfur mustard (SM) has been used as a dangerous chemical warfare agent since the early 20th century. Although many descriptive studies about SM-induced ocular injuries are present in the medical literature, few of them have been conducted over a large group with serious ocular involvement. This descriptive study was conducted on 149 severe SM-intoxicated war veterans. Ocular history, anterior and posterior segment findings using a slit lamp, and direct and indirect ophthalmoscopic findings were recorded. Severity of the disease was also recorded based on a chart of the Foundation of Martyrs and Veterans Affairs. Ocular complains included photophobia (73.2%), sense of decreased vision (72.5%), dry eye sensation (66.4%), foreign body sensation (61.1%), tearing (46.3%), and pain (43.0%). Slit lamp findings were meibomian gland dysfunction (MGD; 96%), blepharitis, punctal closure, trichiasis, tear break-up time, and tear meniscus layer abnormality (80% to 90%). Conjunctival disturbances included vascular abnormality, ischemia, hyperemia, subconjunctival fibrosis, and pterygium. Limbal changes were abnormal vessels, limbal tissue loss and pigment loss, and pannus formation. Corneal problems included epithelial and stromal disturbances, calcium deposition, and melting. The most frequent previous surgeries were punctal closure, lamellar keratoplasty (LK), and stem cell allograft. Severity of intoxication included mild (17%), moderate (25%), and severe (57%). Chronic blepharitis and decreased tear secretion are the 2 most important and influencing factors in progression of ocular problems in SM injuries. The more severe the initial exposure, percentage of disability, and duration of ocular involvement, the higher the likelihood of mustard gas keratopathy.

A novel diagnostic method for malaria using loop-mediated isothermal amplification (LAMP) and MinION™ nanopore sequencer.

PubMed

Imai, Kazuo; Tarumoto, Norihito; Misawa, Kazuhisa; Runtuwene, Lucky Ronald; Sakai, Jun; Hayashida, Kyoko; Eshita, Yuki; Maeda, Ryuichiro; Tuda, Josef; Murakami, Takashi; Maesaki, Shigefumi; Suzuki, Yutaka; Yamagishi, Junya; Maeda, Takuya

2017-09-13

A simple and accurate molecular diagnostic method for malaria is urgently needed due to the limitations of conventional microscopic examination. In this study, we demonstrate a new diagnostic procedure for human malaria using loop mediated isothermal amplification (LAMP) and the MinION™ nanopore sequencer. We generated specific LAMP primers targeting the 18S-rRNA gene of all five human Plasmodium species including two P. ovale subspecies (P. falciparum, P. vivax, P. ovale wallikeri, P. ovale curtisi, P. knowlesi and P. malariae) and examined human blood samples collected from 63 malaria patients in Indonesia. Additionally, we performed amplicon sequencing of our LAMP products using MinION™ nanopore sequencer to identify each Plasmodium species. Our LAMP method allowed amplification of all targeted 18S-rRNA genes of the reference plasmids with detection limits of 10-100 copies per reaction. Among the 63 clinical samples, 54 and 55 samples were positive by nested PCR and our LAMP method, respectively. Identification of the Plasmodium species by LAMP amplicon sequencing analysis using the MinION™ was consistent with the reference plasmid sequences and the results of nested PCR. Our diagnostic method combined with LAMP and MinION™ could become a simple and accurate tool for the identification of human Plasmodium species, even in resource-limited situations.

Effects of hydrogen-rich saline on endotoxin-induced uveitis.

PubMed

Yan, Wei-Ming; Zhang, Lei; Chen, Tao; Zhao, Guan-Hua; Long, Pan; An, Jing; Zhang, Zuo-Ming

2017-01-01

The therapeutic effects of hydrogen-rich saline (HRS) have been reported for a wide range of diseases mainly via selectively reducing the amount of reactive oxygen species. Oxidative stress plays an important role in the pathogenesis of uveitis and endotoxin-induced uveitis (EIU). In this study, we investigated whether HRS can mitigate EIU in rats. Sprague-Dawley rats were randomly divided into Norm group, Model group, HRS group, dexamethasone (DEX) group, and rats in the latter three groups were injected with equal amount of lipopolysaccharide (LPS) to induce EIU of different severities (by 1 mg/kg of LPS, or 1/8 mg/kg of LPS). Rats in HRS group were injected with HRS intraperitoneally at three different modes to purse an ameliorating effect of EIU (10 mL/kg of HRS immediately after injection of 1 mg/kg of LPS, 20 mL/kg of HRS once a day for 1 week before injection of 1 mg/kg of LPS and at 0, 0.5, 1, 2, 6, 8, 12 hours after LPS administration, or 20 mL/kg of HRS once a day for 1 week before injection of 1/8 mg/kg of LPS, and at 0, 0.5, 1, 2, 6, 8, 12, 24 hours and once a day for 3 weeks after LPS administration). Rats of DEX group were injected with 1 mL/kg of DEX solution intraperitoneally immediately after LPS administration. Rats in Norm and Model groups did not receive any treatment. All rats were examined under slit lamp microscope and graded according to the clinical signs of uveitis. Electroretinogram, quantitative analysis of protein in aqueous humor (AqH) and histological examination of iris and ciliary body were also carried out. Our results showed that HRS did not obviously ameliorate the signs of uveitis under slit lamp examination and the inflammatory cells infiltration around iris and cilliary body of EIU induced by 1 mg/kg or 1/8 mg/kg of LPS ( P > 0.05), while DEX significantly reduced the inflammation reflected by the above two indicators ( P < 0.05). The impaired retinal function of mild EIU induced by 1/8 mg/kg of LPS, showed by delay of peak time of b-wave of Dark adapted 3.0 electroretinogram, was not significantly restored by HRS ( P > 0.05), while DEX had an obvious therapeutic effect ( P < 0.05). However, HRS exerted an inhibition trend on elevation of protein in AqH of EIU induced by 1 mg/kg of LPS, and significantly reduced the increasing amount of protein in AqH of mild EIU induced by 1/8 mg/kg of LPS ( P < 0.05). In conclusion, HRS could not obviously mitigate EIU in rats, while it could inhibit the elevation of AqH protein.

Four Cases of Pediatric Photokeratitis Present to the Emergency Department After Watching the Same Theater Show.

PubMed

Mangan, Mehmet Serhat; Arıcı, Ceyhun; Atalay, Eray; Tanyıldız, Burak; Oruçoğlu, Faik

2015-10-01

We report four consecutive cases of photokeratitis that presented to the emergency department, interestingly after having watched the same theatre performance in the same school. The patients' ages (3 male, 1 female) ranged from 9 to 13 years. All patients presented with similar complaints consisting of pain, tearing, foreign body sensation, photophobia and blurred vision in both eyes. Patients reported watching a theatre performance in the same school approximately 4 hours before symptom onset. On slit-lamp examination, conjunctival injection and corneal punctate epithelial erosions were observed in the interpalpebral zone in both eyes. On fundus examination, no pathology was observed in the vitreous, posterior pole or peripheral retina. All cases were treated with topical antibiotics and lubricant eye drops. Corneas were clear two days later in the control visit. In this case report, exposure to ultraviolet light from high-power lamps used in the theatre was proposed as a possible cause of corneal epithelial cell damage and subsequent photokeratitis.

Brown-McLean Syndrome in a Pediatric Patient

PubMed Central

Tourkmani, Abdo Karim; Martinez, Jaime D.; Berrones, David; Juárez-Domínguez, Brenda Y.; Beltrán, Francisco; Galor, Anat

2015-01-01

The purpose of this manuscript is to report the case of a 12-year-old patient who presented for routine ophthalmic examination after congenital cataract surgery performed at 2 months of age. The patient was diagnosed with bilateral Brown-McLean syndrome by slit lamp examination. No treatment was required because the patient was asymptomatic and had a clear central cornea. This is the first described case of Brown-McLean syndrome in a pediatric patient, representing the importance of clinical examination in the pediatric age group after cataract surgery because of the risk for patients of developing peripheral edema. PMID:26034485

Procedure for rapid determination of nickel, cobalt, and chromium in airborne particulate samples

NASA Technical Reports Server (NTRS)

Davis, W. F.; Graab, J. W.

1972-01-01

A rapid, selective procedure for the determination of 1 to 20 micrograms of nickel, chromium, and cobalt in airborne particulates is described. The method utilizes the combined techniques of low temperature ashing and atomic absorption spectroscopy. The airborne particulates are collected on analytical filter paper. The filter papers are ashed, and the residues are dissolved in hydrochloric acid. Nickel, chromium, and cobalt are determined directly with good precision and accuracy by means of atomic absorption. The effects of flame type, burner height, slit width, and lamp current on the atomic absorption measurements are reported.

A laser-spectroscopy complex for fluorescent diagnostics and photodynamic therapy of age-related macula degeneration

NASA Astrophysics Data System (ADS)

Shevchik, S. A.; Meerovich, Gennadii A.; Budzinskaya, M. V.; Ermakova, N. A.; Kharnas, Sergey S.; Loschenov, Victor B.

2004-06-01

A laser-spectroscopy complex was developed for fluorescent diagnostics and photodynamic therapy of age related macula degeneration using the Russian photosensitizer Photosense. The complex is based on slit lamp which was additionally equipped with an optical adapter, and the video adapter allows to combine the procedure of photodynamic therapy and the control of its carrying in the frame work of one procedure. The sensitivity and spatial resolution of the complex were investigated using a special test object. The availability of the developed complex and Photosense itself was examined on experimental animals.

Ocular Onchocerciasis in the Yanomami Communities from Brazilian Amazon: Effects on Intraocular Pressure

PubMed Central

Herzog-Neto, Guilherme; Jaegger, Karen; do Nascimento, Erika S.; Marchon-Silva, Verônica; Banic, Dalma M.; Maia-Herzog, Marilza

2014-01-01

To determine the influence of onchocercal eye disease on the intraocular pressure of the Yanomami Tribe Aratha-ú of Roraima State, Brazil, considered endemic for onchocerciasis, a total of 86 patients were submitted to an ophthalmologic exam that included external examination, slit lamp examination, intraocular pressure measurement, and a fundus ophthalmoscope examination. A high prevalence of onchocerciasis-related eye lesions was encountered in 68.6% of the patients. Punctate keratitis and microfilariae in the anterior chamber were found in ∼28%. The mean of intraocular eye pressure found was 10.47 mm of Hg. PMID:24297812

Ocular onchocerciasis in the Yanomami communities from Brazilian Amazon: effects on intraocular pressure.

PubMed

Herzog-Neto, Guilherme; Jaegger, Karen; Nascimento, Erika S do; Marchon-Silva, Verônica; Banic, Dalma M; Maia-Herzog, Marilza

2014-01-01

To determine the influence of onchocercal eye disease on the intraocular pressure of the Yanomami Tribe Aratha-ú of Roraima State, Brazil, considered endemic for onchocerciasis, a total of 86 patients were submitted to an ophthalmologic exam that included external examination, slit lamp examination, intraocular pressure measurement, and a fundus ophthalmoscope examination. A high prevalence of onchocerciasis-related eye lesions was encountered in 68.6% of the patients. Punctate keratitis and microfilariae in the anterior chamber were found in ∼28%. The mean of intraocular eye pressure found was 10.47 mm of Hg.

Brown-McLean Syndrome in a Pediatric Patient.

PubMed

Tourkmani, Abdo Karim; Martinez, Jaime D; Berrones, David; Juárez-Domínguez, Brenda Y; Beltrán, Francisco; Galor, Anat

2015-01-01

The purpose of this manuscript is to report the case of a 12-year-old patient who presented for routine ophthalmic examination after congenital cataract surgery performed at 2 months of age. The patient was diagnosed with bilateral Brown-McLean syndrome by slit lamp examination. No treatment was required because the patient was asymptomatic and had a clear central cornea. This is the first described case of Brown-McLean syndrome in a pediatric patient, representing the importance of clinical examination in the pediatric age group after cataract surgery because of the risk for patients of developing peripheral edema.

Bilateral acute angle closure glaucoma after hyperopic LASIK correction

PubMed Central

Osman, Essam A.; Alsaleh, Ahmed A.; Al Turki, Turki; AL Obeidan, Saleh A.

2009-01-01

Acute angle closure glaucoma is unexpected complication following laser in situ keratomileusis (LASIK). We are reporting a 49-years-old lady that was presented to the emergency department with acute glaucoma in both eyes soon after LASIK correction. Diagnosis was made on detailed clinical history and examination, slit lamp examination, intraocular pressure measurement and gonioscopy. Laser iridotomy in both eyes succeeded in controlling the attack and normalizing the intraocular pressure (IOP) more than 6 months of follow-up. Prophylactic laser iridotomy is essential for narrow angle patients before LASIK surgery if refractive laser surgery is indicated. PMID:23960863

Sensitivity improvement of one-shot Fourier spectroscopic imager for realization of noninvasive blood glucose sensors in smartphones

NASA Astrophysics Data System (ADS)

Kawashima, Natsumi; Nogo, Kosuke; Hosono, Satsuki; Nishiyama, Akira; Wada, Kenji; Ishimaru, Ichiro

2016-11-01

The use of the wide-field-stop and beam-expansion method for sensitivity enhancement of one-shot Fourier spectroscopy is proposed to realize health care sensors installed in smartphones for daily monitoring. When measuring the spectral components of human bodies noninvasively, diffuse reflected light from biological membranes is too weak for detection using conventional hyperspectral cameras. One-shot Fourier spectroscopy is a spatial phase-shift-type interferometer that can determine the one-dimensional spectral characteristics from a single frame. However, this method has low sensitivity, so that only the spectral characteristics of light sources with direct illumination can be obtained, because a single slit is used as a field stop. The sensitivity of the proposed spectroscopic method is improved by using the wide-field-stop and beam-expansion method. The use of a wider field stop slit width increases the detected light intensity; however, this simultaneously narrows the diffraction angle. The narrower collimated objective beam diameter degrades the visibility of interferograms. Therefore, a plane-concave cylindrical lens between the objective plane and the single slit is introduced to expand the beam diameter. The resulting sensitivity improvement achieved when using the wide-field-stop and beam-expansion method allows the spectral characteristics of hemoglobin to be obtained noninvasively from a human palm using a midget lamp.

VizieR Online Data Catalog: Spectra of 7 Hα emission line stars in MBM 18 (Brand+ 2012)

NASA Astrophysics Data System (ADS)

Brand, J.; Wouterloot, J. G. A.; Magnani, L.

2012-10-01

Data in tabular form (wavelength and flux) are presented of the spectra of seven candidate Hα emission line stars in the direction of translucent cloud MBM 18. The data were obtained on 5 different nights in 2009 and 2010 with the 3.58-m Telescopio Nazionale Galileo (TNG; La Palma, Canary Islands, Spain). The spectra are shown in the appendix of the paper, only visible in the on line version. The spectra were taken with the low-resolution spectrograph DOLORES on the TNG, using long-slit spectroscopy. We used grism VHR-R, which covers a wavelength range of 6240-7720 Angstrom with a dispersion of 0.80Å/pix. The scale of the CCD detector is 0.252 arcsec/pixel. The observations were carried out with a slit width of 1 or 1.5 arcsec, depending on the seeing, resulting in a spectral resolution of 3.2Å and 4.8Å, respectively. To avoid problems with cosmic rays, 2 to 4 separate spectra per star were obtained. Two of the stars (Ha4 and Ha6) were observed simultaneously with another target (Ha1 and Ha5, respectively) by positioning the slit at an appropriate angle. The integration time was based on the brighter star in the slit, thus the signal-to-noise ratio for the other target is smaller than for the primary one. To allow absolute flux calibration the standard star Feige24 or Feige34 (for Ha5-Ha6) was observed immediately before or after the target observations, using the same instrumental setup as for the target observations. Flat-fielding was performed using 10 (5 for Ha5-Ha6) frames, which were uniformly illuminated by a halogen lamp. Wavelength calibration was performed using an arc-spectrum of an Ar, Ne+Hg, and Kr lamp, or a Ne+Hg (for Ha7) comparison lamp. A bias frame, to be subtracted from the other frames before analysis, was constructed from ten individual bias frames. Flat-, arc-, and bias-frames were obtained on the same day as the science observations and with the same instrumental setup. Data were reduced with the IRAF package. From all science frames a bias was subtracted, after which they were divided by the normalised flat field. From each of the science frames the trace(s) of the star(s) were extracted and these were wavelength-calibrated using one of the frames with the arc-spectrum. Each target was wavelength-calibrated with the arc-spectrum extracted at the same location on the detector, to compensate for small deviations that might occur in the alignment of the reference emission lines across the detector. The spectra were then corrected for extinction, and flux-calibrated using the standard star observations. The individual one-dimensional wavelength- and flux-calibrated spectra of each target were then averaged into a final spectrum. To further correct the wavelength calibration, we used the sky lines that were subtracted from the stellar spectra. For each spectrum, Gaussian fits were made to tens of sky lines, and their wavelengths were compared to those listed in Osterbrock et al. (1996PASP..108..277O, Cat. III/211. Three stars were found to need a small correction: Ha2 (-1.5Å) and Ha5 and 6 (both -2.2Å); these corrections have been applied in the tables. For the other four stars the difference was negligible, although for the sky lines in Ha1 and Ha4 (which were observed in the same slit) the deviation between measured and literature wavelengths varied slightly, but systematically, with wavelengths between 6250Å and 7600Å, while at longer wavelengths the deviations became rapidly larger (up to several Angstroms). (8 data files).

Development and Evaluation of a Loop-Mediated Isothermal Amplification (Lamp) Assay for the Detection of Haemonchus contortus in Goat Fecal Samples.

PubMed

Yang, X; Qi, M W; Zhang, Z Z; Gao, C; Wang, C Q; Lei, W Q; Tan, L; Zhao, J L; Fang, R; Hu, M

2017-04-01

Haemonchus contortus is one of the most significant strongylid nematodes infecting small ruminants, and it causes great economic losses to the livestock industry worldwide. Accurate diagnosis of H. contortus is crucial to control strategies. Traditional microscopic examinations are the most common methods for the diagnosis of H. contortus , but they are time-consuming and inaccurate. Molecular methods based on PCR are more accurate, but need expensive machines usually only used in the laboratory. Loop-mediated isothermal amplification (LAMP) is a rapid, simple, specific, and sensitive method that has been widely used to detect viruses, bacteria, and parasites. In the present study, a LAMP method targeting ribosomal ITS-2 gene for detection of the H. contortus in goat fecal samples has been established. The established LAMP method was H. contortus specific, and the sensitivity of LAMP was the same as that of the H. contortus species-specific PCR, with the lowest DNA level detected as being 1 pg. Examination of the clinical samples indicated that the positive rate of LAMP was higher than that of PCR, but no statistical difference was observed between LAMP and PCR (χ 2 = 17.991, P = 0.053). In conclusion, a LAMP assay with a high specificity and a good sensitivity has been developed to detect H. contortus infection in goats. The established LAMP assay is useful for clinical diagnosis of H. contortus .

Light and portable novel device for diabetic retinopathy screening.

PubMed

Ting, Daniel S W; Tay-Kearney, Mei Ling; Kanagasingam, Yogesan

2012-01-01

To validate the use of an economical portable multipurpose ophthalmic imaging device, EyeScan (Ophthalmic Imaging System, Sacramento, CA, USA), for diabetic retinopathy screening. Evaluation of a diagnostic device. One hundred thirty-six (272 eyes) were recruited from diabetic retinopathy screening clinic of Royal Perth Hospital, Western Australia, Australia. All patients underwent three-field (optic disc, macular and temporal view) mydriatic retinal digital still photography captured by EyeScan and FF450 plus (Carl Zeiss Meditec, North America) and were subsequently examined by a senior consultant ophthalmologist using the slit-lamp biomicroscopy (reference standard). All retinal images were interpreted by a consultant ophthalmologist and a medical officer. The sensitivity, specificity and kappa statistics of EyeScan and FF450 plus with reference to the slit-lamp examination findings by a senior consultant ophthalmologist. For detection of any grade of diabetic retinopathy, EyeScan had a sensitivity and specificity of 93 and 98%, respectively (ophthalmologist), and 92 and 95%, respectively (medical officer). In contrast, FF450 plus images had a sensitivity and specificity of 95 and 99%, respectively (ophthalmologist), and 92 and 96%, respectively (medical officer). The overall kappa statistics for diabetic retinopathy grading for EyeScan and FF450 plus were 0.93 and 0.95 for ophthalmologist and 0.88 and 0.90 for medical officer, respectively. Given that the EyeScan requires minimal training to use and has excellent diagnostic accuracy in screening for diabetic retinopathy, it could be potentially utilized by the primary eye care providers to widely screen for diabetic retinopathy in the community. © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.

Management of moderate and severe corneal astigmatism with AcrySof® toric intraocular lens implantation – Our experience

PubMed Central

Farooqui, Javed Hussain; Koul, Archana; Dutta, Ranjan; Shroff, Noshir Minoo

2015-01-01

Purpose Visual performance following toric intraocular lens implantation for cataract with moderate and severe astigmatism. Setting Cataract services, Shroff Eye Centre, New Delhi, India. Design Case series. Method This prospective study included 64 eyes of 40 patients with more than 1.50 dioptre (D) of pre-existing corneal astigmatism undergoing phacoemulsification with implantation of the AcrySof® toric IntraOcular Lens (IOL). The unaided visual acuity (UCVA), best corrected visual acuity (BCVA), residual refractive sphere and refractive cylinders were evaluated. Toric IOL axis and alignment error was measured by slit lamp method and Adobe Photoshop (version 7) method. Patient satisfaction was evaluated using a satisfaction questionnaire at 3 months. Results The mean residual refractive astigmatism was 0.57 D at the final follow-up of 3 months. Mean alignment error was 3.44 degrees (SD = 2.60) by slit lamp method and 3.88 degrees (SD = 2.86) by Photoshop method. Forty-six (71.9%) eyes showed misalignment of 5 degrees or less, and 60 (93.8%) eyes showed misalignment of 10 degrees or less. The mean log MAR UCVA at 1st post-op day was 0.172 (SD = 0.02), on 7th post-op day was 0.138 (SD = 0.11), and on 30th post-op day was 0.081 (SD = 0.11). The mean log MAR BCVA at three months was −0.04 (SD = 0.76). Conclusion We believe that implantation of AcrySof® toric IOL is an effective, safe and predictable method to correct high amounts of corneal astigmatism during cataract surgery. PMID:26586976

Survey of ophthalmic anterior segment findings and intraocular pressure in 95 North American box turtles (Terrapene spp.).

PubMed

Espinheira Gomes, Filipe; Brandão, João; Sumner, Julia; Kearney, Michael; Freitas, Inês; Johnson, James; Cutler, Daniel; Nevarez, Javier

2016-03-01

To describe the ophthalmic biomicroscopy findings and intraocular pressures (IOP) in a captive population of box turtles and to determine whether a relationship exists between body morphometrics or health status and IOP. Hundred and three box turtles (69 Gulf coast, 24 three-toed, one ornate, one eastern, and eight unidentified) were triaged into three different color-coded groups: green (healthy), yellow (abnormal physical examination with no need for immediate care), and red (immediate care required). Both eyes were evaluated by rebound tonometry and slit-lamp biomicroscopy. Body weight and morphometric data were recorded. Intraocular pressures measurements were available for 190 eyes, slit-lamp biomicroscopy was available for 170 eyes, and morphometric data were available for 81 turtles. IOP in Gulf coast turtles (138 eyes) was 6.7 ± 1.4 mmHg OU. IOP in three-toed turtles (48 eyes) was 8.3 ± 1.5 mmHg OU, which was significantly higher than in Gulf coast turtles (P < 0.0001). No significant IOP differences were noted between genders in both subspecies (P = 0.768). There was a correlation between IOP and health status in three-toed turtles only. There was a mild negative correlation between morphometrics and IOP in Gulf coast and three-toed turtles. Fifteen of 87 turtles had unilateral corneal or lenticular opacities; 3/87 had bilateral corneal or lenticular disease; and 3/87 had adnexal abnormalities. Different subspecies of box turtles have different normal intraocular pressures as measured by rebound tonometry, which was influenced by the animals' health status in one subspecies. Some morphometric parameters were found to be associated with IOP. Box turtles are often affected with ophthalmic abnormalities of unknown clinical significance. © 2015 American College of Veterinary Ophthalmologists.

Cataract prevalence varies substantially with assessment systems: comparison of clinical and photographic grading in a population-based study.

PubMed

Tan, Anna C S; Wang, Jie Jin; Lamoureux, Ecosse L; Wong, Wanling; Mitchell, Paul; Li, Jialiang; Tan, Ava Grace; Wong, Tien Y

2011-08-01

Cataract is the major cause of blindness worldwide yet there is no consensus on its assessment and definition. This study compares age-related cataract prevalence derived from two commonly used methods: clinical assessment using the Lens Opacity Classification System (LOCS III) and photographic grading using the Wisconsin Cataract Grading System (Wisconsin System). The Singapore Malay Eye Study is a population-based study of 3,280 Singapore Malays aged 40-80 years. Presence of nuclear, cortical and posterior sub-capsular cataract was assessed clinically during slit-lamp examination using LOCS III, and via slit-lamp and retro-illumination photographic grading using the Wisconsin System. Analyses were conducted to determine agreement in cataract prevalence estimates between the two grading Systems and approaches. Poor agreement was found between severity levels of the two grading scales for all three cataract types. Using currently accepted cut-offs to define nuclear (≥ 4 on both LOCS III and Wisconsin System), cortical (≥ 2 in LOCS III, ≥ 25% in Wisconsin) and PSC (≥ 2 in LOCS III, ≥ 5 % in Wisconsin) cataract, the LOCS III overestimated the prevalence of significant cataract as compared to the Wisconsin System, with nuclear cataract prevalence, 27.5% (LOCS III) versus 17.0% (Wisconsin System), cortical cataract prevalence, 27.9% versus 7.0% and posterior sub-capsular cataract prevalence, 7.8% versus 5.1%. The prevalence of cataract in a population varies substantially by measurement methods, with systematically different estimates found using the two most frequent cataract grading systems. This study re-emphasizes the need for global standards to assess and define cataract for epidemiologic and clinical studies.

Clinical significance of owl eye morphologic features by in vivo laser confocal microscopy in patients with cytomegalovirus corneal endotheliitis.

PubMed

Kobayashi, Akira; Yokogawa, Hideaki; Higashide, Tomomi; Nitta, Koji; Sugiyama, Kazuhisa

2012-03-01

To demonstrate the clinical significance of owl eye morphologic features observed by in vivo laser confocal microscopy in patients with cytomegalovirus (CMV) corneal endotheliitis. Observational case series. participants: Six eyes of 6 patients (6 men; mean age, 73.3 years) with cytomegalovirus corneal endotheliitis diagnosed by clinical manifestations together with polymerase chain reaction from aqueous humor samples. intervention: All patients were examined by slit-lamp biomicroscopy and in vivo laser confocal microscopy. main outcome measures: Clinical manifestations were summarized by reviewing medical records. Selected confocal images of corneal layers were evaluated qualitatively for shape and degree of light reflection of abnormal cells and deposits. All patients had long histories of anterior uveitis with intraocular pressure elevation, corneal edema with keratic precipitates, and decrease of endothelial cell densities. Coin-shaped lesions were observed by slit lamp only in 1 patient at the first visit and in 2 additional patients at subsequent follow-up. In all patients, confocal microscopy demonstrated reduced subepithelial nerves, subepithelial opacity, increased reflectivity of keratocytes, highly reflective dots, and needle-shaped bodies. Owl eye morphologic features were observed consistently in all patients at the initial visit, and highly reflective round bodies were detected in 5 patients; most notably, these confocal features were reversible after resolution of endotheliitis. Owl eye morphologic features and highly reflective round bodies observed by confocal microscopy may be useful as an adjunct for the noninvasive diagnosis of cytomegalovirus corneal endotheliitis. Reversibility of these features after resolution of endotheliitis may be useful for monitoring the therapeutic effects without multiple anterior chamber tap. Copyright © 2012 Elsevier Inc. All rights reserved.

Relationship between iris surface features and angle width in Asian eyes.

PubMed

Sidhartha, Elizabeth; Nongpiur, Monisha Esther; Cheung, Carol Y; He, Mingguang; Wong, Tien Yin; Aung, Tin; Cheng, Ching-Yu

2014-10-23

To examine the associations between iris surface features with anterior chamber angle width in Asian eyes. In this prospective cross-sectional study, we recruited 600 subjects from a large population-based study, the Singapore Epidemiology of Eye Diseases (SEED) study. We obtained standardized digital slit-lamp iris photographs and graded the iris crypts (by number and size), furrows (by number and circumferential extent), and color (higher grade denoting darker iris). Vertical and horizontal cross-sections of anterior chamber were imaged using anterior segment optical coherence tomography. Angle opening distance (AOD), angle recess area (ARA), and trabecular-iris space area (TISA) were measured using customized software. Associations of the angle width with the iris surface features in the subject's right eyes were assessed using linear regression analysis. A total of 464 eyes of the 464 subjects (mean age: 57.5 ± 8.6 years) had complete and gradable data for crypts and color, and 423 eyes had gradable data for furrows. After adjustment for age, sex, ethnicity, pupil size, and corneal arcus, higher crypt grade was independently associated with wider AOD750 (β [change in angle width per grade higher] = 0.018, P = 0.023), ARA750 (β = 0.022, P = 0.049), and TISA750 (β = 0.011, P = 0.019), and darker iris was associated narrower ARA750 (β = -0.025, P = 0.044) and TISA750 (β = -0.013, P = 0.011). Iris surface features, assessed and measured from slit-lamp photographs, correlated well with anterior chamber angle width; irises with more crypts and lighter color were associated with wider angle. These findings may provide another imaging modality to assess angle closure risk based on iris surface features. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

[Summary of the practice guideline 'The red eye' (first revision) of the Dutch College of General Practitioners (NHG)].

PubMed

van der Weele, G M; Rietveld, R P; Wiersma, Tj; Goudswaard, A N

2007-06-02

The revised NHG-guideline 'The red eye' provides recommendations for the diagnosis and therapy in patients with a red eye. In the presence of pain, decreased visual acuity and photophobia (alarm symptoms) should be considered as sight threatening conditions. In most instances a red eye results from conjunctivitis. The complaint of (an) early morning glued eye(s) makes a bacterial origin of acute infectious conjunctivitis more likely. Itching and a history of infectious conjunctivitis make the probability of bacterial involvement less likely. The type of discharge does not help to adequately distinguish bacterial from viral conjunctivitis. Since an infectious conjunctivitis is a self-limiting condition, no treatment is necessary as a rule. Antibiotic treatment is only rational if conjunctivitis is (most probably) caused by bacteria. It has to be considered only if a patient suffers from much discomfort, if complaints do not begin to decline after 3 days and in patients with preexisting corneal defects. Because of widespread resistance to fusidic acid this should in principle not be prescribed for treatment of conjunctivitis; chloramphenicol is still the drug of choice. During revision of the guideline discussions concentrated on 2 aspects: the position of slit lamp biomicroscopy in general practice and giving a patient with keratoconjunctivitis photoelectrica the remainder of a 'minim' with anaesthetic eye drops. Regarding both topics it was decided not to change the recommendations of the former version of the guideline: the use of slit lamp biomicroscopy remains optional for general practitioners and it remains permitted to give the remainder of a 'minim' with anaesthetic eye drops to a patient with keratoconjunctivitis photoelectrica.

An advanced uracil DNA glycosylase-supplemented loop-mediated isothermal amplification (UDG-LAMP) technique used in the sensitive and specific detection of Cryptosporidium parvum, Cryptosporidium hominis, and Cryptosporidium meleagridis in AIDS patients.

PubMed

Fallahi, Shirzad; Moosavi, Seyedeh Fatemeh; Karimi, Azadeh; Chegeni, Ali Sharafi; Saki, Mohammad; Namdari, Parsa; Rashno, Mohammad Menati; Varzi, Ali Mohamad; Tarrahi, Mohammad Javad; Almasian, Mohammad

2018-05-01

The rapid and accurate detection of Cryptosporidium spp. is critically important for the prevention and timely treatment of cryptosporidiosis in AIDS patients (APs). This study was conducted to examine a UDG-LAMP technique for the first time to diagnose cryptosporidiosis in APs. After collecting demographic and clinical data, three stool samples were collected from the participants (120 volunteering APs). The microscopic examination of stained smears using the acid-fast method and the UDG-LAMP assay were performed for each sample. 10% of APs were infected with Cryptosporidium spp. The number of detected cryptosporidiosis cases using the acid-fast staining and UDG-LAMP methods were significantly different (P < 0.001). Diarrhea and weight loss were found to be significantly associated with cryptosporidiosis in patients (P < 0.05). The pretreatment of LAMP reagents with UDG successfully eliminated the likelihood of product re-amplification remaining from previous reactions. The UDG-LAMP technique could detect cryptosporidiosis in APs with high sensitivity and rapidity without carryover contamination. Copyright © 2017 Elsevier Inc. All rights reserved.

VizieR Online Data Catalog: 1H 0323+342 rest frame optical spectrum with GHAO (Leon+, 2014)

NASA Astrophysics Data System (ADS)

Leon Tavares, J.; Kotilainen, J.; Chavushyan, V.; Anorve, C.; Puerari, I.; Cruz-Gonzalez, I.; Patino-Alvarez, V.; Anton, S.; Carraminana, A.; Carrasco, L.; Guichard, J.; Karhunen, K.; Olguin-Iglesias, A.; Sanghvi, J.; Valdes, J.

2017-05-01

Within the framework of a spectrophotometric monitoring program of bright γ-ray sources (Patino-Alvarez et al. 2013, Proc. Fermi Symposium, arXiv:1303.1893), we undertook spectroscopic observations of 1H 0323+342 using the Boller & Chivens long-slit spectrograph on the 2.1 m Guillermo Haro Astrophysical Observatory (GHAO) in Sonora, Mexico. The spectra were obtained under photometric weather conditions (2012 September 17, 2013 January 9, 2013 February 7 and 11) using a slit width of 2.5 arcsec. The spectral resolution was R=15 Å and R=7 Å (FWHM) for the low-resolution and intermediate-resolution spectra, respectively. The wavelength range for the three low-resolution spectra is 3800-7100 Å, and for one intermediate-resolution spectrum the wavelength range is 4300-5900 Å. The signal-to-noise ratio (S/N) was >40 in the continuum near H{Beta}. To enable a wavelength calibration, HeAr lamp spectra were taken after each object exposure. Spectrophotometric standard stars were observed every night (at least two per night) to enable flux calibration. (1 data file).

Control and near-field detection of surface plasmon interference patterns.

PubMed

Dvořák, Petr; Neuman, Tomáš; Břínek, Lukáš; Šamořil, Tomáš; Kalousek, Radek; Dub, Petr; Varga, Peter; Šikola, Tomáš

2013-06-12

The tailoring of electromagnetic near-field properties is the central task in the field of nanophotonics. In addition to 2D optics for optical nanocircuits, confined and enhanced electric fields are utilized in detection and sensing, photovoltaics, spatially localized spectroscopy (nanoimaging), as well as in nanolithography and nanomanipulation. For practical purposes, it is necessary to develop easy-to-use methods for controlling the electromagnetic near-field distribution. By imaging optical near-fields using a scanning near-field optical microscope, we demonstrate that surface plasmon polaritons propagating from slits along the metal-dielectric interface form tunable interference patterns. We present a simple way how to control the resulting interference patterns both by variation of the angle between two slits and, for a fixed slit geometry, by a proper combination of laser beam polarization and inhomogeneous far-field illumination of the structure. Thus the modulation period of interference patterns has become adjustable and new variable patterns consisting of stripelike and dotlike motifs have been achieved, respectively.

Multi-wavelength lenses for terahertz surface wave.

PubMed

Wei, Minggui; Yang, Quanlong; Xu, Quan; Zhang, Xueqian; Li, Yanfeng; Gu, Jianqiang; Han, Jiaguang; Zhang, Weili

2017-10-16

Metasurface-based surface wave (SW) devices working at multi-wavelength has been continuously arousing enormous curiosity recently, especially in the terahertz community. In this work, we propose a multi-layer metasurface structure composed of metallic slit pairs to build terahertz SW devices. The slit pair has a narrow bandwidth and its response frequency can be altered by its geometric parameter, thereby suppressing the frequency crosstalk and reducing the difficulty of design. By elaborately tailoring the distribution of the slit pairs, a series of achromatic SW lenses (SWLs) working at 0.6, 0.75 and 1 THz are experimentally demonstrated by the near field scanning terahertz microscope (NSTM) system. In addition, a wavelength-division-multiplexer (WDM) is further designed and implemented, which is promising in building multiplexed devices for plasmonic circuits. The structure proposed here cannot only couple the terahertz wave from free space to SWs, but also control its propagation. Moreover, our findings demonstrate the great potential to design multi-wavelength plasmonic metasurface devices, which can be extended to microwave and visible frequencies as well.

Contact lenses fitting teaching: learning improvement with monitor visualization of webcam video recordings

NASA Astrophysics Data System (ADS)

Gargallo, Ana; Arines, Justo

2014-08-01

We have adapted low cost webcams to the slit lamps objectives with the aim of improving contact lens fitting practice. With this solution we obtain good quality pictures and videos, we also recorded videos of eye examination, evaluation routines of contact lens fitting, and the final practice exam of our students. In addition, the video system increases the interactions between students because they could see what their colleagues are doing and take conscious of their mistakes, helping and correcting each others. We think that the proposed system is a low cost solution for supporting the training in contact lens fitting practice.

First report of ophthalmomyaisis externa in Pakistan.

PubMed

Ali, Azam; Feroze, Agha Hassan; Ferrar, Paul; Abbas, Asad; Beg, Mohammad Asim

2006-02-01

Two individuals presented to the Aga Khan University Opthalmology service with foreign-body sensation, pain and redness in one of their eyes. Slit-lamp biomicroscopy revealed tiny larvae crawling around the conjunctival sac. They were mechanically removed under topical anaesthesia and preserved for light microscopy and photography. Comprehensive liaison was established with the Australian Centre for International Agriculture Research for identification of these larvae. Their morphology characterized them as members of fruit-fly, Oestridae family. At least one of them was positively identified as first instar larva of Oestrus ovis. This report describes the first instance of such infections in Southern Pakistan, as concluded after a Medline search.

A unique case of isolated sebaceous adenoma of the bulbar conjunctiva.

PubMed

Ilhan, Hatice Deniz; Turkoglu, Elif Betul; Bilgin, Ahmet Burak; Bassorgun, Ibrahim; Dogan, M Erkan; Unal, Mustafa

2016-01-01

Our patient was a 34 year-old male who presented with a painless conjunctival mass that had developed 3 months before his first visit. On performing slit-lamp biomicroscopy, a lobulated pink-yellowish solid mobile mass was observed on the nasal bulbar conjunctival surface of his left eye. The tumor was excised, and histopathologic examination of the tumor revealed a sebaceous adenoma. Systemic examination was normal. No recurrence was observed during the 24-month follow-up period. Sebaceous adenoma of the bulbar conjunctiva is an extremely rare benign tumor, which may be observed to be isolated in the absence of malignancy.

A case of unilateral phthiriasis palpebrarum infestation involving the left eye.

PubMed

Ashraf, Mohammad; Waris, Abdul; Kumar, Ashwini; Akhtar, Nahid

2014-06-06

Phthiriasis palpebrarum is a rare cause of eyelid infestation. We report a case of unilateral phthiriasis palpebrarum. A 28-year-old man presented with moderate itching associated with lacrimation and irritation in the left eye. The initial evaluation of the patient revealed multiple white dots on the left upper eyelashes. Slit-lamp examination revealed multiple nits attached to the base and shaft of the cilia. There was no hyperaemia or discharge present in the conjunctiva and the cornea was clear and shiny. The right eye was perfectly normal. The patient was treated with moxifloxacin eye ointment and was completely cured in 1 week. 2014 BMJ Publishing Group Ltd.

Presumed minor salivary gland secretion in a patient with a history of oral mucous membrane graft.

PubMed

Kitagawa, Kiyotaka; Hayasaka, Seiji; Matsunou, Hisao; Nagaki, Yasunori

2003-08-01

To describe presumed minor salivary gland secretion in a patient with a history of oral mucous membrane graft in conjunctival plastic surgery. Interventional case report. A 74-year-old woman who had had an oral mucous membrane graft in the left eye complained of mucous discharge. Slit-lamp examination revealed a yellowish-red mass lesion in the superior bulbar conjunctiva. The lesion was excised. Histopathologic examination of the excised tissue revealed lobules and a duct of minor salivary glands. After removal of the mass, mucous discharge decreased. Minor salivary glands within a mucous membrane graft may cause mucous discharge in the eye.

New solutions to realize complex optical systems by a combination of diffractive and refractive optical components

NASA Astrophysics Data System (ADS)

Brunner, Robert; Steiner, Reinhard; Dobschal, Hans-Juergen; Martin, Dietrich; Burkhardt, Matthias; Helgert, Michael

2003-11-01

Diffractive optical elements (DOEs) have a great potential in the complete or partial substitution of refractive or reflective optical elements in imaging systems. The greater design flexibility compared to an all-refractive/reflective solution allows a more convenient realization of the optical systems and additionally opens up new possibilities for optimizing the performance or compactness. To demonstrate the opportunities of the hybrid optical concept we discuss different imaging systems for various applications. We present the lens design of a hybrid microscope objective which is especially applicable for wafer inspection technologies. Meeting the requirements for such a system used in the deep-UV regime (248 nm) is very challenging. The short wavelength limits the material selection and demands cement free optical groups. The additional requirement of an autofocus system, working at a wavelength in the near infrared region, is fulfilled by the special combination of two selected and adjusted DOEs. Furthermore, we discuss the opportunities of the hybrid concept c of a slit lamp used for ophthalmologic examinations. The DOEs are the basic elements of this hybrid concept. We demonstrate that holographic lithography is an appropriate technology to realize a wide variety of elements with different profile geometries. We address in particular the additional possibilities of an UV-laser system as an exposure tool. Additionally to the high spatial frequencies, the 266 nm exposure wavelength allows the use of novel photo resists with advantageous development behavior.

Toxic keratopathy associated with abuse of low-dose anesthetic: a case report.

PubMed

Chen, Hsiao-Ting; Chen, Ko-Hua; Hsu, Wen-Ming

2004-07-01

To describe the clinical course and treatment of toxic keratopathy associated with abuse of topical anesthetic at a very low concentration, 0.05%. Case report. A 47-year-old female systemic lupus erythematosus (SLE) patient with blurred vision and irritated right eye was referred to the ophthalmology department of our hospital. Under slit-lamp microscope, a 5.5 x 4.5 mm central corneal epithelial defect with underlying infiltrative and opaque stroma was noted in her right eye. Two weeks before, a corneal ulcer was diagnosed, and oxybuprocaine 0.05% (Lacrimin, Santen, Osaka, Japan) eye drops were prescribed 4 times daily but used every 5 to 10 minutes because the right eye was severely irritated. She was admitted immediately under the impression of toxic corneal ulcer. Preservative-free lubricants and prophylactic topical antibiotics 4 times daily were applied. Therapeutic soft contact lens was started after no infective agents were detected. Two weeks later, the stromal infiltration subsided, and the corneal epithelium was slowly healing, but superficial punctate epithelial defects at the lesion site persisted for another 6 months. The vision of her right eye improved from finger-counting at a 30-cm distance to 20/1200 with correction. Toxic keratopathy may result from abuse of topically administered anesthetics even at a very low concentration, 0.05%. Because this SLE patient has tear problems, we suggest that topical anesthetics must be used very cautiously and never prescribed to patients with dry eyes where the integrity of ocular surface is altered.

Prevalence of dry eye syndrome after a three-year exposure to a clean room.

PubMed

Cho, Hyun A; Cheon, Jae Jung; Lee, Jong Seok; Kim, Soo Young; Chang, Seong Sil

2014-01-01

To measure the prevalence of dry eye syndrome (DES) among clean room (relative humidity ≤1%) workers from 2011 to 2013. Three annual DES examinations were performed completely in 352 clean room workers aged 20-40 years who were working at a secondary battery factory. Each examination comprised the tear-film break-up test (TFBUT), Schirmer's test I, slit-lamp microscopic examination, and McMonnies questionnaire. DES grades were measured using the Delphi approach. The annual examination results were analyzed using a general linear model and post-hoc analysis with repeated-ANOVA (Tukey). Multiple logistic regression was performed using the examination results from 2013 (dependent variable) to analyze the effect of years spent working in the clean room (independent variable). The prevalence of DES among these workers was 14.8% in 2011, 27.1% in 2012, and 32.8% in 2013. The TFBUT and McMonnies questionnaire showed that DES grades worsened over time. Multiple logistic regression analysis indicated that the odds ratio for having dry eyes was 1.130 (95% CI 1.012-1.262) according to the findings of the McMonnies questionnaire. This 3-year trend suggests that the increased prevalence of DES was associated with longer working hours. To decrease the prevalence of DES, employees should be assigned reasonable working hours with shift assignments that include appropriate break times. Workers should also wear protective eyewear, subdivide their working process to minimize exposure, and utilize preservative-free eye drops.

P.S.

ERIC Educational Resources Information Center

South Australian Science Teachers Journal, 1973

1973-01-01

Presents ideas from readers on techniques and equipment that might be useful in teaching secondary school science. Suggests how to construct cheap wall charts, modify a vacuum cleaner into a blower, construct a stereo microscope lamp holder, and outlines simple physics laboratory experiments. (JR)

Construction and characterization of the fringe field monochromator for a field emission gun

PubMed

Mook; Kruit

2000-04-01

Although some microscopes have shown stabilities sufficient to attain below 0.1 eV spectral resolution in high-resolution electron energy loss spectroscopy, the intrinsic energy width of the high brightness source (0.3-0.6 eV) has been limiting the resolution. To lower the energy width of the source to 50 meV without unnecessary loss of brightness, a monochromator has been designed consisting of a short (4 mm) fringe field Wien filter and a 150 nm energy selection slit (nanoslit) both to be incorporated in the gun area of the microscope. A prototype has been built and tested in an ultra-high-vacuum setup (10(-9) mbar). The monochromator, operating on a Schottky field emission gun, showed stable and reproducible operation. The nanoslits did not contaminate and the structure remained stable. By measuring the current through the slit structure a direct image of the beam in the monochromator could be attained and the monochromator could be aligned without the use of a microscope. Good dispersed imaging conditions were found indicating an ultimate resolution of 55 meV. A Mark II fringe field monochromator (FFM) was designed and constructed compatible with the cold tungsten field emitter of the VG scanning transmission microscope. The monochromator was incorporated in the gun area of the microscope at IBM T.J. Watson research center, New York. The monochromator was aligned on 100 kV and the energy distribution measured using the monochromator displayed a below 50 meV filtering capability. The retarding Wien filter spectrometer was used to show a 61 meV EELS system resolution. The FFM is shown to be a monochromator which can be aligned without the use of the electron microscope. This makes it directly applicable for scanning transmission microscopy and low-voltage scanning electron microscopy, where it can lower the resolution loss which is caused by chromatic blur of the spot.

Improvement of malaria diagnostic system based on acridine orange staining.

PubMed

Kimura, Masatsugu; Teramoto, Isao; Chan, Chim W; Idris, Zulkarnain Md; Kongere, James; Kagaya, Wataru; Kawamoto, Fumihiko; Asada, Ryoko; Isozumi, Rie; Kaneko, Akira

2018-02-07

Rapid diagnosis of malaria using acridine orange (AO) staining and a light microscope with a halogen lamp and interference filter was deployed in some malaria-endemic countries. However, it has not been widely adopted because: (1) the lamp was weak as an excitation light and the set-up did not work well under unstable power supply; and, (2) the staining of samples was frequently inconsistent. The halogen lamp was replaced by a low-cost, blue light-emitting diode (LED) lamp. Using a reformulated AO solution, the staining protocol was revised to make use of a concentration gradient instead of uniform staining. To evaluate this new AO diagnostic system, a pilot field study was conducted in the Lake Victoria basin in Kenya. Without staining failure, malaria infection status of about 100 samples was determined on-site per one microscopist per day, using the improved AO diagnostic system. The improved AO diagnosis had both higher overall sensitivity (46.1 vs 38.9%: p = 0.08) and specificity (99.0 vs 96.3%) than the Giemsa method (N = 1018), using PCR diagnosis as the standard. Consistent AO staining of thin blood films and rapid evaluation of malaria parasitaemia with the revised protocol produced superior results relative to the Giemsa method. This AO diagnostic system can be set up easily at low cost using an ordinary light microscope. It may supplement rapid diagnostic tests currently used in clinical settings in malaria-endemic countries, and may be considered as an inexpensive tool for case surveillance in malaria-eliminating countries.

Application of line-scanning microscopy using a linear sensor in semiconductor industry: shape and thickness measurements

NASA Astrophysics Data System (ADS)

Macedo, Milton P.; Correia, C. M. B. A.

2013-04-01

This work aims at showing the applicability of a scanning-stage bench-microscope in bright-field reflection mode for wirebonding inspection of integrated circuits (IC) as well as quality assurance of tracks in printed circuit boards (PCB). The main issues of our laboratorial prototype arise from the use of a linear image sensor taking advantage of its geometry to achieve lower acquisition time in comparison to traditional (pinhole) confocal approach. The use of a slit-detector is normally related to resolution degradation for details parallel to sensor. But an improvement will surely arise using light distribution along line pixels of the sensor which establishes a great advantage in comparison to (pure) slit detectors. The versatility of this bench-microscope affords excellent means to develop and test algorithms. Those to improve lateral resolution isotropy as well as image visualization and 3D mesh reconstruction under different setups namely illumination modes. Based on the results of these tests tests both wide-field illumination and parallel slit illumination and detection configurations were used in these two applications. Results from IC wire-bonding show the ability of the system to extract 3D information. A comparison of auto-focus images and 3D profiles obtained using different 3D reconstruction algorithms as well as a method for the determination of the diameter of the bond wire are presented. Measurements of PCB track width and thickness were performed and the comparison of these results from both longitudinal and transverse tracks stress the limitations of a lower spatial sampling rate induced by the resolution of object stage positioners.

Development and clinical performance of high throughput loop-mediated isothermal amplification for detection of malaria

PubMed Central

Perera, Rushini S.; Ding, Xavier C.; Tully, Frank; Oliver, James; Bright, Nigel; Bell, David; Chiodini, Peter L.; Gonzalez, Iveth J.; Polley, Spencer D.

2017-01-01

Background Accurate and efficient detection of sub-microscopic malaria infections is crucial for enabling rapid treatment and interruption of transmission. Commercially available malaria LAMP kits have excellent diagnostic performance, though throughput is limited by the need to prepare samples individually. Here, we evaluate the clinical performance of a newly developed high throughput (HTP) sample processing system for use in conjunction with the Eiken malaria LAMP kit. Methods The HTP system utilised dried blood spots (DBS) and liquid whole blood (WB), with parallel sample processing of 94 samples per run. The system was evaluated using 699 samples of known infection status pre-determined by gold standard nested PCR. Results The sensitivity and specificity of WB-HTP-LAMP was 98.6% (95% CI, 95.7–100), and 99.7% (95% CI, 99.2–100); sensitivity of DBS-HTP-LAMP was 97.1% (95% CI, 93.1–100), and specificity 100% against PCR. At parasite densities greater or equal to 2 parasites/μL, WB and DBS HTP-LAMP showed 100% sensitivity and specificity against PCR. At densities less than 2 p/μL, WB-HTP-LAMP sensitivity was 88.9% (95% CI, 77.1–100) and specificity was 99.7% (95% CI, 99.2–100); sensitivity and specificity of DBS-HTP-LAMP was 77.8% (95% CI, 54.3–99.5) and 100% respectively. Conclusions The HTP-LAMP system is a highly sensitive diagnostic test, with the potential to allow large scale population screening in malaria elimination campaigns. PMID:28166235

Modern retinal laser therapy

PubMed Central

Kozak, Igor; Luttrull, Jeffrey K.

2014-01-01

Medicinal lasers are a standard source of light to produce retinal tissue photocoagulation to treat retinovascular disease. The Diabetic Retinopathy Study and the Early Treatment Diabetic Retinopathy Study were large randomized clinical trials that have shown beneficial effect of retinal laser photocoagulation in diabetic retinopathy and have dictated the standard of care for decades. However, current treatment protocols undergo modifications. Types of lasers used in treatment of retinal diseases include argon, diode, dye and multicolor lasers, micropulse lasers and lasers for photodynamic therapy. Delivery systems include contact lens slit-lamp laser delivery, indirect ophthalmocope based laser photocoagulation and camera based navigated retinal photocoagulation with retinal eye-tracking. Selective targeted photocoagulation could be a future alternative to panretinal photocoagulation. PMID:25892934

Keratolimbal autograft transplantation as a possible new treatment of Lisch epithelial corneal dystrophy.

PubMed

Celis Sánchez, J; Mesa Varona, D V; Avendaño Cantos, E; López-Romero Moraleda, S; Cebrian Rosado, E; González Del Valle, F

2016-07-01

The case concerns 64-year-old woman with visual acuity of 20/40 in the right eye. Slit-lamp examination revealed a grey, feathery corneal opacification with intraepithelial microcysts compatible with Lisch epithelial corneal dystrophy (LECD). It was treated with epithelial debridements, contact lenses and mitomycin C, but the opacification recurred within months. The removal of limbus sector and autologous limbal transplantation (KLAT) were used successfully without recurrence. After removal of damaged limbus, KLAT should be considered as a treatment option for asymmetric LECD when other treatments have failed. Copyright © 2016 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

Demodex folliculitis presenting as periocular vesiculopustular rash.

PubMed

Yun, Samuel H; Levin, Flora; Servat, Javier

2013-12-01

To report an unusual case of Demodex folliculitis presenting as periocular vesiculopustular rash. Case report. A 68 year-old woman presented with a unilateral periocular rash that was initially treated by her primary ophthalmologist with topical steroids and antivirals. Slit-lamp examination revealed severe bilateral blepharitis, right greater than left, with waxy sleeves around the eyelashes. The diagnosis of Demodex infestation was considered. Treatment with daily lid scrub with polyhexamethylene biguanide (PHMB), 1,2-hexanediol and 1,2-octanediol (OCuSOFT PLUS) and erythromycin ointment twice a day resulted in complete resolution of the symptoms after 4 weeks. Ophthalmologists should be aware of Demodex and consider it in the differential diagnosis of periocular skin lesions.

Use of iris recognition camera technology for the quantification of corneal opacification in mucopolysaccharidoses.

PubMed

Aslam, Tariq Mehmood; Shakir, Savana; Wong, James; Au, Leon; Ashworth, Jane

2012-12-01

Mucopolysaccharidoses (MPS) can cause corneal opacification that is currently difficult to objectively quantify. With newer treatments for MPS comes an increased need for a more objective, valid and reliable index of disease severity for clinical and research use. Clinical evaluation by slit lamp is very subjective and techniques based on colour photography are difficult to standardise. In this article the authors present evidence for the utility of dedicated image analysis algorithms applied to images obtained by a highly sophisticated iris recognition camera that is small, manoeuvrable and adapted to achieve rapid, reliable and standardised objective imaging in a wide variety of patients while minimising artefactual interference in image quality.

Bilateral anterior segment dysgenesis with the presumed Peters' anomaly in a cat.

PubMed

Park, Sangwan; Kim, Kiwoong; Kim, Youngbeum; Seo, Kangmoon

2018-02-20

A seven-month-old female domestic shorthaired cat was presented for buphthalmos in the right eye and corneal cloudiness in the left eye. Full ophthalmic examinations were performed for both eyes and enucleation was done for the right nonvisual eye. Congenital glaucoma caused by anterior segment dysgenesis was confirmed for the right eye. In the left eye, slit-lamp examination revealed focal corneal edema with several iris strands from iris collarette to the affected posterior corneal surfaces. Circular posterior corneal defect was suggested to be the cause of edema. Goniodysgenesis, additionally, was identified. Taken together, the diagnosis of Peters' anomaly which is a subtype of anterior segment dysgenesis was suggested in the left eye.

From double-slit interference to structural information in simple hydrocarbons

PubMed Central

Kushawaha, Rajesh Kumar; Patanen, Minna; Guillemin, Renaud; Journel, Loic; Miron, Catalin; Simon, Marc; Piancastelli, Maria Novella; Skates, C.; Decleva, Piero

2013-01-01

Interferences in coherent emission of photoelectrons from two equivalent atomic centers in a molecule are the microscopic analogies of the celebrated Young’s double-slit experiment. By considering inner-valence shell ionization in the series of simple hydrocarbons C2H2, C2H4, and C2H6, we show that double-slit interference is widespread and has built-in quantitative information on geometry, orbital composition, and many-body effects. A theoretical and experimental study is presented over the photon energy range of 70–700 eV. A strong dependence of the oscillation period on the C–C distance is observed, which can be used to determine bond lengths between selected pairs of equivalent atoms with an accuracy of at least 0.01 Å. Furthermore, we show that the observed oscillations are directly informative of the nature and atomic composition of the inner-valence molecular orbitals and that observed ratios are quantitative measures of elusive many-body effects. The technique and analysis can be immediately extended to a large class of compounds. PMID:24003155

Effectiveness of interactive tutorials in promoting "which-path" information reasoning in advanced quantum mechanics

NASA Astrophysics Data System (ADS)

Maries, Alexandru; Sayer, Ryan; Singh, Chandralekha

2017-12-01

Research suggests that introductory physics students often have difficulty using a concept in contexts different from the ones in which they learned it without explicit guidance to help them make the connection between the different contexts. We have been investigating advanced students' learning of quantum mechanics concepts and have developed interactive tutorials which strive to help students learn these concepts. Two such tutorials, focused on the Mach-Zehnder interferometer (MZI) and the double-slit experiment (DSE), help students learn how to use the concept of "which-path" information to reason about the presence or absence of interference in these two experiments in different situations. After working on a pretest that asked students to predict interference in the MZI with single photons and polarizers of various orientations placed in one or both paths of the MZI, students worked on the MZI tutorial which, among other things, guided them to reason in terms of which-path information in order to predict interference in similar situations. We investigated the extent to which students were able to use reasoning related to which-path information learned in the MZI tutorial to answer analogous questions on the DSE (before working on the DSE tutorial). After students worked on the DSE pretest they worked on a DSE tutorial in which they learned to use the concept of which-path information to answer questions about interference in the DSE with single particles with mass sent through the two slits and a monochromatic lamp placed between the slits and the screen. We investigated if this additional exposure to the concept of which-path information promoted improved learning and performance on the DSE questions with single photons and polarizers placed after one or both slits. We find evidence that both tutorials promoted which-path information reasoning and helped students use this reasoning appropriately in contexts different from the ones in which they had learned it.

Evaluation of the Loop Mediated Isothermal DNA Amplification (LAMP) Kit for Malaria Diagnosis in P. vivax Endemic Settings of Colombia

PubMed Central

Vallejo, Andrés F.; Martínez, Nora L.; González, Iveth J.; Arévalo-Herrera, Myriam; Herrera, Sócrates

2015-01-01

Background Most commonly used malaria diagnostic tests, including microscopy and antigen-detecting rapid tests, cannot reliably detect low-density infections which are frequent in low transmission settings. Molecular methods such as polymerase chain reaction (PCR) are highly sensitive but remain too laborious for field deployment. In this study, the applicability of a malaria diagnosis kit based on loop-mediated isothermal amplification (mLAMP) was assessed in malaria endemic areas of Colombia with Plasmodium vivax predominance. Methodology/Principal Findings First, a passive case detection (PCD) study on 278 febrile patients recruited in Tierralta (department of Cordoba) was conducted to assess the diagnostic performance of the mLAMP method. Second, an active case detection (ACD) study on 980 volunteers was conducted in 10 sentinel sites with different epidemiological profiles. Whole blood samples were processed for microscopic and mLAMP diagnosis. Additionally RT-PCR and nested RT-PCR were used as reference tests. In the PCD study, P. falciparum accounted for 23.9% and P. vivax for 76.1% of the infections and no cases of mixed-infections were identified. Microscopy sensitivity for P. falciparum and P. vivax were 100% and 86.1%, respectively. mLAMP sensitivity for P. falciparum and P. vivax was 100% and 91.4%, respectively. In the ACD study, mLAMP detected 65 times more cases than microscopy. A high proportion (98.0%) of the infections detected by mLAMP was from volunteers without symptoms. Conclusions/Significance mLAMP sensitivity and specificity were comparable to RT-PCR. LAMP was significantly superior to microscopy and in P. vivax low-endemicity settings and under minimum infrastructure conditions, it displayed sensitivity and specificity similar to that of single-well RT-PCR for detection of both P. falciparum and P. vivax infections. Here, the dramatically increased detection of asymptomatic malaria infections by mLAMP demonstrates the usefulness of this new tool for diagnosis, surveillance, and screening in elimination strategies. PMID:25569550

A comparison of undergraduate clinical ophthalmology learning methods: smart phone television display versus slit-lamp teaching telescope.

PubMed

Wenting, Sandy Zhou; Samin, Margaret Million; Sanjay, Srinivasan; Neelam, Kumari; Shibli, Khalil; Chang, Su; Cheng, Jason

2017-08-01

To compare medical students' preference of smart phone television display (SPTD) to a slit-lamp teaching telescope (SLTT) in undergraduate clinical ophthalmology education. This is a randomized, crossover, comparative study. Pairs of medical students were randomly assigned to 2 teaching sessions using either SPTD first followed by SLTT or in reverse order. Students were asked to give feedback on the 2 teaching devices by answering 6 questions using a numeric rating score from 1 to 10. All participating students were sent the results of the study 1 month after the completion of the study and were asked to reflect upon the outcome. Thirty-eight students were recruited. The overall satisfaction scores were significantly higher for SPTD than SLTT (8.6 ± 1.4 vs 7.5 ± 1.0, p < 0.01). The students preferred SPTD compared with SLTT in terms of "visualization" (8.5 ± 1.4 vs 7.0 ± 1.3, p < 0.01), "ocular sign description" (8.4 ± 1.3 vs 7.2 ± 1.2, p < 0.01), "ocular anatomy understanding" (8.3 ± 1.2 vs 7.6 ± 1.2, p < 0.01), and "confidence in identifying clinical signs" (8.4 ± 1.2 vs 7.5 ± 1.2, p < 0.01). A larger proportion of the students gave higher scores to SPTD compared with SLTT in all questions. All students who responded to the follow-up questionnaire (n = 14) agreed with our interpretation of the data and would support the use of SPTD in undergraduate clinical ophthalmology teaching. Our study has demonstrated that the utility of SPTD as a teaching aid can significantly increase the satisfaction of undergraduate medical students during their ophthalmology attachment. It offers specific practical advantages in teaching medical students over the traditional SLTT. Copyright © 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

A pilot study on slit lamp-adapted optical coherence tomography imaging of trabeculectomy filtering blebs.

PubMed

Theelen, Thomas; Wesseling, Pieter; Keunen, Jan E E; Klevering, B Jeroen

2007-06-01

Our study aims to identify anatomical characteristics of glaucoma filtering blebs by means of slit lamp-adapted optical coherence tomography (SL-OCT) and to identify new parameters for the functional prognosis of the filter in the early post-operative period. Patients with primary open-angle glaucoma, aged 18 years and older, scheduled for primary trabeculectomy at the Department of Ophthalmology, Radboud University Nijmegen Medical Centre, were considered for our study. All patients underwent standardized trabeculectomy with intra-operative application of mitomycin C. The filtering blebs were evaluated clinically and with SL-OCT on day 1 and 1, 2, 4 and 12 weeks following surgery. The resulting data were analysed and weighed against surgical success. To better understand the SL-OCT data a small comparative histologic study was performed. The study included 20 eyes of 20 patients. After completion of our study, 15 eyes of 15 patients (mean age+/-SD 67 +/- 16 years) were eligible for data analysis and 5 eyes missed at least one follow-up visit. Filtering surgery was considered successful (intraocular pressure < or = 21 mmHg without antiglaucomatous medication) in 11 of 15 eyes. SL-OCT frequently demonstrated multiple hypo-reflective layers within Tenon's capsule ("striping" phenomenon) in the first post-operative week. Presumably, these layers corresponded with drainage channels in the histological specimen. These channels were present in functional filters but not in the failures. In addition, the visualisation of the sclera below the filtering zone was better defined in failures compared with successful filtering blebs ("shading" phenomenon). We observed no differences in the volume and clinical aspect of the blebs in the successful group compared with the unsuccessful group. Successful filtering blebs show characteristic optical properties on SL-OCT. These phenomena suggest a diffusely enhanced fluid content and the presence of intra-bleb drainage channels in functional filtering blebs.

Eye Disorders in Old People

PubMed Central

M., Khalaj; A., Barikani; H., Ghasemi

2013-01-01

Background: Visual impairment is one of a major public health problem among elderly people. Object: Aim of this study was determining the prevalence of visual impairment in median and old peoples in Qazvin (Iran). Method: In this cross sectional study, with a simple random sampling, 446 patients older than 5o years who were referred to outpatient ophthalmology clinics at Avecina hospital of Qazvin (a province of Iran) in 2010 were enrolled. Participants first complete a questionnaire with 25 questions toward demographic and past medical history and then were examined by ophthalmologist. These examinations includes direct and indirect ophthalmoscopy, slit lamp examination, measurement of uncorrected visual acuity and visual acuity with current glasses, lensometery of the previous glasses, refraction with and without the use of cycloplegic and determining the best corrected visual acuity. All slit lamp examinations were performed by the same ophthalmologist. Data were analyzed with SPSS16 with use of Chi – Square test with Pvalue <0.05. Results: In this study 446 patients were examined that 54.7% were male. Mean age of study population was 62+-9.3 years old. 96.4% of participants had refractory disorder. Prevalence of myopia, hyperopia and astigmatism were 33.6%, 45.9% and 16.8% respectively. Of patients 17.4% had diabetes. Of participants 28.9% had temporal headache, 37% red eye, 41.2% flashing, 27.3% and 28% had dryness and discharge of eye respectively. 31.1% of participants had eyelide problem, 4.7% Color Vision Deficiency (CVD) and 3.8% had family history of CVD. Of total 4.5% had glaucoma, 3.3% macular degeneration and 21.7% had hypertension. 0.6% of population had macular degeneration, 0.4% of population had glaucoma Of 892 eyes (446 individuals), 36.2% had visual acuity less than 7/10, 1.7% light perception (LP) and 0.22% no light perception (NLP) and 2.7% finger count. Conclusion: Refractory errors, cataract and amblyopia were most important eye disorders in older people in Qazvin. PMID:23283039

Scleral Lens Clearance Assessment with Biomicroscopy and Anterior Segment Optical Coherence Tomography.

PubMed

Yeung, Debby; Sorbara, Luigina

2018-01-01

It is important to be able to accurately estimate the central corneal clearance when fitting scleral contact lenses. Tools available have intrinsic biases due to the angle of viewing, and therefore an idea of the amount of error in estimation will benefit the fitter. To compare the accuracy of observers' ability to estimate scleral contact lens central corneal clearance (CCC) with biomicroscopy to measurements using slit-lamp imaging and anterior segment optical coherence tomography (AS-OCT). In a Web-based survey with images of four scleral lens fits obtained with a slit-lamp video imaging system, participants were asked to estimate the CCC. Responses were compared with known values of CCC of these images determined with an image-processing program (digital CCC) and using the AS-OCT (AS-OCT CCC). Bland-Altman plots and concordance correlation coefficients were used to assess the agreement of CCC measured by the various methods. Sixty-six participants were categorized for analysis based on the amount of experience with scleral lens fitting into novice, intermediate, or advanced fitters. Comparing the estimated CCC to the digital CCC, all three groups overestimated by an average of +27.3 ± 67.3 μm. The estimated CCC was highly correlated to the digital CCC (0.79, 0.92, and 0.94 for each group, respectively). Compared with the CCC measurements using AS-OCT, the three groups of participants overestimated by +103.3 μm and had high correlations (0.79, 0.93, and 0.94 for each group). Results from this study validate the ability of contact lens practitioners to observe and estimate the CCC in scleral lens fittings through the use of biomicroscopic viewing. Increasing experience with scleral lens fitting does not improve the correlation with measured CCC from digital or the AS-OCT. However, the intermediate and advanced groups display significantly less inter-observer variability compared with the novice group.

Clinical and histologic description of ocular anatomy in captive black-tailed prairie dogs (Cynomys ludovicianus).

PubMed

Meekins, Jessica M; Eshar, David; Rankin, Amy J; Henningson, Jamie N

2016-03-01

To describe the clinical and histologic ocular anatomy of the black-tailed prairie dog (PD). Seventeen captive black-tailed PDs (11 males and six females), ranging in age from approximately 4 months to 4.5 years. Complete ocular examinations, including slit-lamp biomicroscopy, direct and indirect ophthalmoscopy, were performed under isoflurane anesthesia. The globes (n = 2) of one black-tailed PD were harvested immediately after euthanasia and processed after formalin fixation. Staining with hematoxylin-eosin, cytokeratin AE1/AE3, glial fibrillary acidic protein, chromogranin A, claudin-5, smooth muscle actin, and vimentin was performed for light microscopic evaluation. A thick mucinous precorneal tear film was present on the ocular surface. A vestigial nictitating membrane was identified in the medial canthus area. The limbus was heavily pigmented, the iris was a dark homogenous brown, and the pupil was round. Funduscopically, there was no tapetum lucidum, the retinal vascular pattern was holangiotic, and a horizontally elongated optic disk was visualized. The most common ocular abnormalities were acquired eyelid margin defects, present in seven eyes of six black-tailed PDs (35.3%). On histologic examination, the retina was asymmetric, thicker below the optic disk and thinner above it. The black-tailed PD fundus is atapetal with a holangiotic retinal vessel pattern and a horizontally elongated optic disk. Acquired lesions of the peri-ocular and eyelid region were the most common documented abnormality. Unique anatomic features of the globe and adnexa were confirmed with histologic and immunohistochemical analysis. © 2015 American College of Veterinary Ophthalmologists.

Investigative modalities in infectious keratitis.

PubMed

Gupta, Noopur; Tandon, Radhika

2008-01-01

Standard recommended guidelines for diagnosis of infectious keratitis do exist. Based on an extensive Medline literature search, the various investigative modalities available for aiding the diagnosis of microbial keratitis have been reviewed and described briefly. Preferred practice patterns have been outlined and the importance of routine pre-treatment cultures in the primary management of infectious keratitis has been highlighted. Corneal scraping, tear samples and corneal biopsy are few of the specimens needed to carry out the investigative procedures for diagnosis and for initiating therapy in cases of microbial keratitis. In bacterial, fungal and amoebic keratitis, microscopic examination of smears is essential for rapid diagnosis. Potassium hydroxide (KOH) wet mount, Gram's stain and Giemsa stain are widely used and are important for clinicians to start empirical therapy before microbial culture results are available. The usefulness of performing corneal cultures in all cases of suspected infectious keratitis has been well established. In cases of suspected viral keratitis, therapy can be initiated on clinical judgment alone. If a viral culture is needed, scrapings should directly be inoculated into the viral transport media. In vivo confocal microscopy is a useful adjunct to slit lamp bio-microscopy for supplementing diagnosis in most cases and establishing early diagnosis in many cases of non-responding fungal and amoebic keratitis. This is a non-invasive, high resolution technique which allows rapid detection of Acanthamoeba cysts and trophozoites and fungal hyphae in the cornea long before laboratory cultures give conclusive results. Other new modalities for detection of microbial keratitis include molecular diagnostic techniques like polymerase chain reaction, and genetic finger printing by pulsed field gel electrophoresis.

Corona sign: manifestation of peripheral corneal epithelial edema as a possible marker of the progression of corneal endothelial dysfunction.

PubMed

Inoue, Tomoyuki; Hara, Yuko; Kobayashi, Takeshi; Zheng, Xiaodong; Suzuki, Takashi; Shiraishi, Atsushi; Ohashi, Yuichi

2016-09-01

To describe a characteristic form of the corona sign and its clinical relevance to the degree of corneal endothelial decompensation and investigate the underlying mechanism using a rabbit model. These observational cases include 31 patients undergoing penetrating keratoplasty (PKP) and 15 patients undergoing Descemet stripping automated endothelial keratoplasty (DSAEK) with special attention to the circumferentially developed corneal epithelial edema. We also conducted a laboratory observation of horizontal water flow in the rabbit cornea. We consistently observed the corona sign at the superior periphery during the initial stage of corneal endothelial decompensation after PKP. With progressive corneal endothelial cellular loss, the epithelial edema gradually expanded circumferentially in the periphery. The endothelial cellular density associated with the corona sign significantly (P < 0.01) decreased compared with that without the sign. The endothelial cellular density decreased significantly (P < 0.05) in cases with a circumferential corona sign compared with a superior corona sign. After DSAEK, however, the corneal epithelial edema subsided from the center but persisted peripherally as a corona sign in all cases. By 3 months postoperatively, the epithelial edema was confined to the superior periphery along with uneventful corneal endothelial healing. Rabbit experiments showed that total corneal endothelial decompensation decreased the horizontal intracorneal water migration (Inoue-Ohashi phenomenon) in the corneal periphery and induced peripheral corneal edema. The slit-lamp microscopic findings of the corona-like epithelial edema in the peripheral cornea are associated with the stage of corneal endothelial function. To support this, the developmental mechanism of the corona sign was demonstrated experimentally.

Pirfenidone Nanoparticles Improve Corneal Wound Healing and Prevent Scarring Following Alkali Burn

PubMed Central

Chowdhury, Sushovan; Guha, Rajdeep; Trivedi, Ruchit; Kompella, Uday B.; Konar, Aditya; Hazra, Sarbani

2013-01-01

Purpose To evaluate the effects of pirfenidone nanoparticles on corneal re-epithelialization and scarring, major clinical challenges after alkali burn. Methods Effect of pirfenidone on collagen I and α-smooth muscle actin (α-SMA) synthesis by TGFβ induced primary corneal fibroblast cells was evaluated by immunoblotting and immunocytochemistry. Pirfenidone loaded poly (lactide-co-glycolide) (PLGA) nanoparticles were prepared, characterized and their cellular entry was examined in primary corneal fibroblast cells by fluorescence microscopy. Alkali burn was induced in one eye of Sprague Dawley rats followed by daily topical treatment with free pirfenidone, pirfenidone nanoparticles or vehicle. Corneal re-epithelialization was assessed daily by flourescein dye test; absence of stained area indicated complete re-epithelialization and the time for complete re-epithelialization was determined. Corneal haze was assessed daily for 7 days under slit lamp microscope and graded using a standard method. After 7 days, collagen I deposition in the superficial layer of cornea was examined by immunohistochemistry. Results Pirfenidone prevented (P<0.05) increase in TGF β induced collagen I and α-SMA synthesis by corneal fibroblasts in a dose dependent manner. Pirfenidone could be loaded successfully within PLGA nanoparticles, which entered the corneal fibroblasts within 5 minutes. Pirfenidone nanoparticles but not free pirfenidone significantly (P<0.05) reduced collagen I level, corneal haze and the time for corneal re-epithelialization following alkali burn. Conclusion Pirfenidone decreases collagen synthesis and prevents myofibroblast formation. Pirfenidone nanoparticles improve corneal wound healing and prevent fibrosis. Pirfenidone nanoparticles are of potential value in treating corneal chemical burns and other corneal fibrotic diseases. PMID:23940587

Biocompatibility of Genipin and Glutaraldehyde Cross-Linked Chitosan Materials in the Anterior Chamber of the Eye

PubMed Central

Lai, Jui-Yang

2012-01-01

Chitosan is a naturally occurring cationic polysaccharide and has attracted much attention in the past decade as an important ophthalmic biomaterial. We recently demonstrated that the genipin (GP) cross-linked chitosan is compatible with human retinal pigment epithelial cells. The present work aims to further investigate the in vivo biocompatibility of GP-treated chitosan (GP-chi group) by adopting the anterior chamber of a rabbit eye model. The glutaraldehyde (GTA) cross-linked samples (GTA-chi group) were used for comparison. The 7-mm-diameter membrane implants made from either non-cross-linked chitosan or chemically modified materials with a cross-linking degree of around 80% were inserted in the ocular anterior chamber for 24 weeks and characterized by slit-lamp and specular microscopic examinations, intraocular pressure measurements, and corneal thickness measurements. The interleukin-6 expressions at mRNA level were also detected by quantitative real-time reverse transcription polymerase chain reaction. Results of clinical observations showed that the overall ocular scores in the GTA-chi groups were relatively high. In contrast, the rabbits bearing GP-chi implants in the anterior chamber of the eye exhibited no signs of ocular inflammation. As compared to the non-cross-linked counterparts, the GP-chi samples improved the preservation of corneal endothelial cell density and possessed better anti-inflammatory activities, indicating the benefit action of the GP cross-linker. In summary, the intracameral tissue response to the chemically modified chitosan materials strongly depends on the selection of cross-linking agents. PMID:23109832

Contact Lens Induced Corneal Ulcer Management in a Tertiary Eye Unit in Oman - A descriptive study

PubMed Central

Shah, Rikin; Shah, Manali; Khandekar, Rajiv; Al-Raisi, Abdulatif

2008-01-01

Objectives: The corneal disease is a priority problem in Oman. We present patients with contact lens (CL) induced severe keratitis, admitted in the corneal unit of Al Nahdha Hospital in Oman. Methods: The study was conducted in 2005–2006. Ophthalmologists examined the eyes using slit lamp bio-microscope. Visual acuity was noted using Snellen’s distance vision chart. Specimens of corneal scraping and CLs were sent for culture and sensitivity tests. Patients with severe keratitis were admitted and treated with medicines. Corneal and visual statuses were noted at the time of discharge from hospital and after six weeks. Numbers, percentages and their 95% confidence intervals were calculated. Pre- and post-treatment vision were compared using a scattergram. Results: The 52 eyes of 15 males and 37 female patients with corneal ulcers were examined. Thirty-two patients were between 20 to 30 years of age. Only 13 (25%) patients had visited an ophthalmologist within 24 hours of developing severe keratitis. Seventeen (33%) had central ulcers and six (11.5%) had ulcer ≥5 mm in size. Pseudomonas was found in 29 (55.8%) of CL and corneal material scraped from the eyes of 15 (28.8%) patients. Vision was <6/60 (legally blind) in 12 (23.1%) eyes before and in five (9.6%) eyes after treatment. Twenty-six (50%) patients were lost to follow up. Conclusion: CL related severe keratitis causes visual disabilities. Prevention and proper records are essential. Treatment improves vision and hence facilities for management should be strengthened. PMID:21748073

Retinal injury thresholds for 532, 578, and 630 nm lasers in connection to photodynamic therapy for choroidal neovascularization.

PubMed

Chen, Hongxia; Yang, Zaifu; Zou, Xianbiao; Wang, Jiarui; Zhu, Jianguo; Gu, Ying

2014-01-01

The purpose of this study was to explore the retinal injury thresholds in rabbits and evaluate the influence of retinal pigmentation on threshold irradiance at laser wavelengths of 532, 578, and 630 nm which might be involved in hypocrellin B (HB) and hematoporphyrin monomethyl ether (HMME) photodynamic therapy (PDT) for choroidal neovascularization (CNV). The eyes of pigmented and non-pigmented rabbits were exposed to 532, 578, and 630 nm lasers coupled to a slit lamp biological microscope. The exposure duration was 100 seconds and the retinal spot size was 2 mm throughout the experiment. The minimum visible lesions were detected by funduscopy at 1 and 24 hours post exposure. Bliss probit analysis was performed to determine the ED50 thresholds, fiducial limits and probit slope. In pigmented rabbits, the 24-hour retinal threshold irradiances at 532, 578, and 630 nm were 1,003, 1,475, and 1,720 mW/cm(2) , respectively. In non-pigmented rabbits, the 24-hour threshold irradiances were 1,657, 1,865, and 15,360 mW/cm(2) , respectively. The ED50 for 24-hour observation differed very little from the ED50 for 1-hour observation. The non-pigmented rabbits required a ninefold increase in threshold irradiance at 630 nm comparing to the pigmented rabbits. This study will contribute to the knowledge base for the limits of laser irradiance in application of HB or HMME PDT for CNV. © 2013 Wiley Periodicals, Inc.

Prevalence of Dry Eye Syndrome after a Three-Year Exposure to a Clean Room

PubMed Central

2014-01-01

Objective To measure the prevalence of dry eye syndrome (DES) among clean room (relative humidity ≤1%) workers from 2011 to 2013. Methods Three annual DES examinations were performed completely in 352 clean room workers aged 20–40 years who were working at a secondary battery factory. Each examination comprised the tear-film break-up test (TFBUT), Schirmer’s test I, slit-lamp microscopic examination, and McMonnies questionnaire. DES grades were measured using the Delphi approach. The annual examination results were analyzed using a general linear model and post-hoc analysis with repeated-ANOVA (Tukey). Multiple logistic regression was performed using the examination results from 2013 (dependent variable) to analyze the effect of years spent working in the clean room (independent variable). Results The prevalence of DES among these workers was 14.8% in 2011, 27.1% in 2012, and 32.8% in 2013. The TFBUT and McMonnies questionnaire showed that DES grades worsened over time. Multiple logistic regression analysis indicated that the odds ratio for having dry eyes was 1.130 (95% CI 1.012–1.262) according to the findings of the McMonnies questionnaire. Conclusions This 3-year trend suggests that the increased prevalence of DES was associated with longer working hours. To decrease the prevalence of DES, employees should be assigned reasonable working hours with shift assignments that include appropriate break times. Workers should also wear protective eyewear, subdivide their working process to minimize exposure, and utilize preservative-free eye drops. PMID:25339991

Loop-mediated isothermal amplification with the Procedure for Ultra Rapid Extraction kit for the diagnosis of pneumocystis pneumonia.

PubMed

Kawano, Shuichi; Maeda, Takuya; Suzuki, Takefumi; Abe, Tatsuhiro; Mikita, Kei; Hamakawa, Yusuke; Ono, Takeshi; Sonehara, Wataru; Miyahira, Yasushi; Kawana, Akihiko

2015-03-01

Loop-mediated isothermal amplification (LAMP) is an innovative molecular technique requiring only a heating device and isothermal conditions to amplify a specific target gene. The results of current microscopic diagnostic tools for pneumocystis pneumonia are not sufficiently consistent for detecting infection with a low-density of Pneumocystis jirovecii. Although polymerase chain reaction (PCR) is highly sensitive, it is not suitable for resource-limited facilities. LAMP is a potential diagnostic replacement for PCR in such settings but a critical disadvantage of DNA extraction was still remained. Therefore, we employed the Procedure for Ultra Rapid Extraction (PURE) kit, which uses a porous material, to isolate the DNA from clinical samples in a simple way in combination with previously reported LAMP procedure for diagnosing PCP. The detection limit of the PURE-LAMP method applied to artificial bronchoalveolar lavage fluid samples was 100 copies/tube, even with the use of massive blood-contaminated solutions. In addition, we concluded the diagnostic procedure within 1 h without the need for additional equipment. PURE-LAMP coupled with suitable primers for specific pathogens has good potential for diagnosing various infectious diseases. Copyright © 2014 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Realism in the Realized Popper's Experiment

NASA Astrophysics Data System (ADS)

Hunter, Geoffrey

2002-12-01

The realization of Karl Popper's EPR-like experiment by Shih and Kim (published 1999) produced the result that Popper hoped for: no ``action at a distance'' on one photon of an entangled pair when a measurement is made on the other photon. This experimental result is interpretable in local realistic terms: each photon has a definite position and transverse momentum most of the time; the position measurement on one photon (localization within a slit) disturbs the transverse momentum of that photon in a non-predictable way in accordance with the uncertainty principle; however, there is no effect on the other photon (the photon that is not in a slit) no action at a distance. The position measurement (localization within a slit) of the one photon destroys the coherence (entanglement) between the photons; i.e. decoherence occurs. This realistic (albeit retrodictive) interpretation of the Shih-Kim realization of what Popper called his ``crucial experiment'' is in accord with Bohr's original concept of the nature of the uncertainty principle, as being an inevitable effect of the disturbance of the measured system by the measuring apparatus. In this experiment the impact parameter of an incident photon with the centerline of the slit is an uncontrollable parameter of each individual photon scattering event; this impact parameter is variable for every incident photon, the variations being a statistical aspect of the beam of photons produced by the experimental arrangement. These experimental results are also in accord with the proposition of Einstein, Podolski and Rosen's 1935 paper: that quantum mechanics provides only a statistical, physically incomplete, theory of microscopic physical processes, for the quantum mechanical description of the experiment does not describe or explain the individual photon scattering events that are actually observed; the angle by which an individual photon is scattered is not predictable, because the photon's impact parameter with the centerline of the slit is not observable, and because the electromagnetic interaction between the photon and the matter forming the walls of the slit is not calculable.

Detection of Plasmodium knowlesi, Plasmodium falciparum and Plasmodium vivax using loop-mediated isothermal amplification (LAMP) in a co-endemic area in Malaysia.

PubMed

Piera, Kim A; Aziz, Ammar; William, Timothy; Bell, David; González, Iveth J; Barber, Bridget E; Anstey, Nicholas M; Grigg, Matthew J

2017-01-13

Plasmodium knowlesi is the most common cause of malaria in Malaysia. However, microscopic diagnosis is inaccurate and rapid diagnostic tests (RDTs) are insufficiently sensitive. PCR is sensitive and specific but not feasible at a district level. Loop-mediated isothermal amplification (LAMP) shows potential with only basic requirements. A commercially available LAMP assay, the Eiken Loopamp™ MALARIA Pan Detection kit, is sensitive for Plasmodium falciparum and Plasmodium vivax, but has not previously been evaluated for P. knowlesi. This study aims to determine the sensitivity of this LAMP assay for detecting P. knowlesi infection. Study participants included 73 uncomplicated malaria patients with PCR species confirmation: 50 P. knowlesi, 20 P. falciparum and 3 P. vivax. Nineteen malaria-negative, non-endemic area controls were also included. The sensitivity of the Eiken Loopamp™ MALARIA Pan Detection kit (Pan LAMP) for detecting each Plasmodium species was evaluated. Sensitivity and specificity of the Eiken Loopamp™ MALARIA Pf Detection kit (Pf LAMP) for P. falciparum were also determined. The limit of detection for each LAMP assay was evaluated, with results compared to PCR. All P. knowlesi patients were also tested by CareStart™ (Pf/VOM) and OptiMAL-IT™ (Pan/Pf) RDTs. The sensitivity of the Pan LAMP assay was 100% for P. knowlesi (95% CI 92.9-100), P. falciparum (95% CI 83.2-100), and P. vivax (95% CI 29.2-100). The Pf LAMP was 100% sensitive and specific for P. falciparum detection, with all P. knowlesi samples having a negative reaction. LAMP sensitivity was superior to both RDTs, with only 10 and 28% of P. knowlesi samples testing positive to CareStart™ and OptiMAL-IT™, respectively. Limit of detection using the Pan LAMP for both P. knowlesi and P. vivax was 2 parasites/μL, comparable to PCR. For P. falciparum both the Pan LAMP and Pf LAMP demonstrated a limit of detection of 20 parasites/μL. The Eiken Loopamp™ MALARIA Pan Detection kit is sensitive for detection of P. knowlesi in low parasitaemia clinical infections, as well as P. falciparum and P. vivax. However, a P. knowlesi-specific field assay in a simpler format would assist correct species identification and initiation of optimal treatment for all malaria patients.

Retinitis due to opportunistic infections in Iranian HIV infected patients.

PubMed

Abdollahi, Ali; Mohraz, Minoo; Rasoulinejad, Mehrnaz; Shariati, Mona; Kheirandish, Parastou; Abdollahi, Maryam; Soori, Tahereh

2013-01-01

We tried to evaluate prevalence and characteristics of Iranian HIV infected patients with retinitis due to opportunistic infections. In this cross sectional study, we evaluated 106 HIV infected patients via indirect ophthalmoscopy and slit lamp examination by 90 lens to find retinitis cases. General information and results of ophthalmologic examination were analyzed. Prevalence of retinitis due to opportunistic infections was 6.6%: cytomegalovirus (CMV) retinitis 1.88%, toxoplasmosis retinochoroiditis 1.88% and tuberculosis chorioretinitis 2.83%. CD4 count was higher than 50 cell/µlit in both cases with CMV retinitis. Along with increasing survival in the HIV infected patients, the prevalence of complications such as ocular manifestation due to opportunistic infections are increasing and must be more considered.

Treatment of Phthiriasis Palpebrarum and Crab Louse: Petrolatum Jelly and 1% Permethrin Shampoo.

PubMed

Karabela, Yunus; Yardimci, Gurkan; Yildirim, Isik; Atalay, Eray; Karabela, Semsi Nur

2015-01-01

Phthiriasis palpebrarum is an uncommon cause of blepharoconjunctivitis in which Pthirus pubis infest the eyelashes. We report a case of unilateral phthiriasis palpebrarum with crab louse. A 45-year-old man presented with conjunctival hyperaemia and moderate itching associated with irritation, and crusty excretions of the eyelashes in the left eye. Careful slit-lamp examination revealed many lice and nits in left eye and mild conjunctival hyperaemia. No abnormality was found in the right eye. On dermatologic examination, only one louse was found at the pubic area. The patient was treated effectively with petrolatum jelly (Vaseline) and 1% permethrin shampoo (Kwellada 1% shampoo). At the end of the first week no louse or nit was present on eyelashes and pubic area.

VizieR Online Data Catalog: Stellar kinematics for NGC 2859 and NGC 4371 (Erwin+, 2015)

NASA Astrophysics Data System (ADS)

Erwin, P.; Saglia, R. P.; Fabricius, M.; Thomas, J.; Nowak, N.; Rusli, S.; Bender, R.; Vega Beltran, J. C.; Beckman, J. E.

2017-11-01

We obtained long-slit spectroscopy of NGC 2959 with the ISIS spectrograph of the WHT on 2000 December 13, using the blue arm with the R600B grating. NGC 4371 was observed with an almost identical instrumental setup as part of ING service-time observations on 2001 June 4. Following standard MIDAS reduction of the ISIS observations, including bias subtraction, flat-fielding and wavelength calibration using CuAr and CuNe+CuAr lamp exposures, the extracted galaxy spectra were analysed using the Fourier Correlation Quotient method (Bender 1990A&A...229..441B; Bender, Saglia & Gerhard 1994MNRAS.269..785B) in order to determine the stellar kinematics. (2 data files).

Fast Confocal Raman Imaging Using a 2-D Multifocal Array for Parallel Hyperspectral Detection.

PubMed

Kong, Lingbo; Navas-Moreno, Maria; Chan, James W

2016-01-19

We present the development of a novel confocal hyperspectral Raman microscope capable of imaging at speeds up to 100 times faster than conventional point-scan Raman microscopy under high noise conditions. The microscope utilizes scanning galvomirrors to generate a two-dimensional (2-D) multifocal array at the sample plane, generating Raman signals simultaneously at each focus of the array pattern. The signals are combined into a single beam and delivered through a confocal pinhole before being focused through the slit of a spectrometer. To separate the signals from each row of the array, a synchronized scan mirror placed in front of the spectrometer slit positions the Raman signals onto different pixel rows of the detector. We devised an approach to deconvolve the superimposed signals and retrieve the individual spectra at each focal position within a given row. The galvomirrors were programmed to scan different focal arrays following Hadamard encoding patterns. A key feature of the Hadamard detection is the reconstruction of individual spectra with improved signal-to-noise ratio. Using polystyrene beads as test samples, we demonstrated not only that our system images faster than a conventional point-scan method but that it is especially advantageous under noisy conditions, such as when the CCD detector operates at fast read-out rates and high temperatures. This is the first demonstration of multifocal confocal Raman imaging in which parallel spectral detection is implemented along both axes of the CCD detector chip. We envision this novel 2-D multifocal spectral detection technique can be used to develop faster imaging spontaneous Raman microscopes with lower cost detectors.

There are no particles, there are only fields

NASA Astrophysics Data System (ADS)

Hobson, Art

2013-03-01

Quantum foundations are still unsettled, with mixed effects on science and society. By now it should be possible to obtain consensus on at least one issue: Are the fundamental constituents fields or particles? As this paper shows, experiment and theory imply that unbounded fields, not bounded particles, are fundamental. This is especially clear for relativistic systems, implying that it's also true of nonrelativistic systems. Particles are epiphenomena arising from fields. Thus, the Schrödinger field is a space-filling physical field whose value at any spatial point is the probability amplitude for an interaction to occur at that point. The field for an electron is the electron; each electron extends over both slits in the two-slit experiment and spreads over the entire pattern; and quantum physics is about interactions of microscopic systems with the macroscopic world rather than just about measurements. It's important to clarify this issue because textbooks still teach a particles- and measurement-oriented interpretation that contributes to bewilderment among students and pseudoscience among the public. This article reviews classical and quantum fields, the two-slit experiment, rigorous theorems showing particles are inconsistent with relativistic quantum theory, and several phenomena showing particles are incompatible with quantum field theories.

Evaluation of Kayser-Fleischer ring in Wilson disease by anterior segment optical coherence tomography.

PubMed

Sridhar, Mittanamalli S; Rangaraju, Advithi; Anbarasu, Kavitha; Reddy, Sharat Putta; Daga, Sachin; Jayalakshmi, Sita; Shaik, Bajibhi

2017-05-01

The purpose of the study is to present anterior segment optical coherence tomography (AS-OCT) as an alternative method of evaluating Kayser-Fleischer (KF) ring in Wilson disease (WD) not only by ophthalmologists but also by other clinicians dealing with WD. This was a retrospective case series of six WD patients with KF ring. Evaluation of KF ring was done by naked eye examination using torch light, slit lamp biomicroscopy (SL), and AS-OCT. SL examination was done using a narrow slit of the superior cornea. AS-OCT was done using the Optovue RTvue PremierTM device (Fremont, CA, USA). AS-OCT revealed KF ring as an intense hyperreflective band at the level of Descemet membrane (DM). Color scale of AS-OCT showed KF ring as greenish/greenish yellow/orange yellow/yellowish/red band. Validation of AS-OCT findings was done by second ophthalmologist, medical gastroenterologist, surgical gastroenterologist, and neurophysician. After seeing the first observation, they could identify the AS-OCT features in all pictures with ease. This is the first observation of KF ring in WD on AS-OCT. On AS-OCT, KF ring is visualized as intense hyperreflectivity at the level of DM in the peripheral cornea. Further, studies are needed to evaluate the usefulness of AS-OCT in WD management.

Flash lamp-excited time-resolved fluorescence microscope suppresses autofluorescence in water concentrates to deliver an 11-fold increase in signal-to-noise ratio.

PubMed

Connally, Russell; Veal, Duncan; Piper, James

2004-01-01

The ubiquity of naturally fluorescing components (autofluorophores) encountered in most biological samples hinders the detection and identification of labeled targets through fluorescence-based techniques. Time-resolved fluorescence (TRF) is a technique by which the effects of autofluorescence are reduced by using specific fluorescent labels with long fluorescence lifetimes (compared with autofluorophores) in conjunction with time-gated detection. A time-resolved fluorescence microscope (TRFM) is described that is based on a standard epifluorescence microscope modified by the addition of a pulsed excitation source and an image-intensified time-gateable CCD camera. The choice of pulsed excitation source for TRFM has a large impact on the price and performance of the instrument. A flash lamp with rapid discharge characteristics was selected for our instrument because of the high spectral energy in the UV region and short pulse length. However, the flash output decayed with an approximate lifetime of 18 micros and the TRFM required a long-lived lanthanide chelate label to ensure that probe fluorescence was visible after decay of the flash plasma. We synthesized a recently reported fluorescent chelate (BHHCT) and conjugated it to a monoclonal antibody directed against the waterborne parasite Giardia lamblia. For a 600-nm bandpass filter set and a gate delay of 60 micros, the TRFM provided an 11.3-fold improvement in the signal-to-noise ratio (S/N) of labeled Giardia over background. A smaller gain in an SNR of 9.69-fold was achieved with a 420-nm longpass filter set; however, the final contrast ratio between labeled cyst and background was higher (11.3 versus 8.5). Despite the decay characteristics of the light pulse, flash lamps have many practical advantages compared with optical chopper wheels and modulated lasers for applications in TRFM.

Sensitive and inexpensive molecular test for falciparum malaria: detecting Plasmodium falciparum DNA directly from heat-treated blood by loop-mediated isothermal amplification.

PubMed

Poon, Leo L M; Wong, Bonnie W Y; Ma, Edmund H T; Chan, Kwok H; Chow, Larry M C; Abeyewickreme, Wimal; Tangpukdee, Noppadon; Yuen, Kwok Y; Guan, Yi; Looareesuwan, Sornchai; Peiris, J S Malik

2006-02-01

Malaria is one of the most important parasitic infections in humans. A sensitive diagnostic test for malaria that could be applied at the community level could be useful in programs to control the disease. The aim of the present work was to develop a simple, inexpensive molecular test for Plasmodium falciparum. Blood was collected from controls (n = 100) and from patients diagnosed with falciparum malaria infection (n = 102), who were recruited to the study. Heat-treated blood samples were tested by a loop-mediated isothermal amplification (LAMP) assay for P. falciparum. Results were interpreted by a turbidity meter in real time or visually at the end of the assay. To evaluate the assay, DNA from these samples was purified and tested by PCR. Results from the LAMP and PCR assays were compared. The LAMP assay detected P. falciparum directly from heat-treated blood. The quantitative data from the assay correlated to the parasite counts obtained by blood-film microscopic analyses. When we used the PCR assay as the comparison method, the sensitivity and specificity of the LAMP assay were 95% and 99%, respectively. Unlike PCR, the LAMP assay does not require purified DNA for efficient DNA amplification, thereby reducing the cost and turnaround time for P. falciparum diagnosis. The assay requires only basic instruments, and assay positivity can be verified by visual inspection.

Nonthermal effects in photostimulated solid state reaction of Mn doped SrTiO3

NASA Astrophysics Data System (ADS)

Daraselia, D.; Japaridze, D.; Jibuti, Z.; Shengelaya, A.; Müller, K. A.

2017-04-01

The effect of a photostimulated solid state reaction was investigated in Mn doped SrTiO3 samples. Light irradiation was performed by either halogen or UV lamps in order to study the effect of the spectral composition, and the results were compared with samples prepared at the same temperatures in a conventional furnace. The obtained samples were studied by X-ray diffraction for structural characterization and by Electron Paramagnetic Resonance, which provides microscopic information about the local environment as well as the valence state of Mn ions. It was found that light irradiation significantly enhances the solid state reaction rate compared to synthesis in the conventional furnace. Moreover, it was observed that UV lamp irradiation is much more effective compared to halogen lamps. This indicates that the absorption of light with energy larger than the materials band gap plays an important role and points towards the nonthermal mechanism of the photostimulated solid state reaction.

Millikan's Oil-Drop Experiment: A Centennial Setup Revisited in Virtual World

ERIC Educational Resources Information Center

Gagnon, Michel

2012-01-01

Early in the last century, Robert Millikan developed a precise method of determining the electric charge carried by oil droplets. Using a microscope and a small incandescent lamp, he observed the fall of charged droplets under the influence of an electric field inside a small observation chamber. In so doing, Millikan demonstrated the existence of…

Simple alignment procedure for a VNIR imaging spectrometer with a Shack-Hartmann wavefront sensor and a field identifier

NASA Astrophysics Data System (ADS)

Lee, Jun Ho; Hwang, Sunglyoung; Jeong, Dohwan; Hong, Jinsuk; Kim, Youngsoo; Kim, Yeonsoo; Kim, Hyunsook

2017-09-01

We report an innovative simple alignment method for a VNIR spectrometer in the wavelength region of 400-900 nm; this device is later combined with fore-optics (a telescope) to form a f/2.5 hyperspectral imaging spectrometer with a field of view of +/-7.68°. The detector at the final image plane is a 640×480 charge-coupled device with a 24 μm pixel size. We first assembled the fore-optics and the spectrometer separately and then combined them via a slit co-located on the image plane of the fore-optics and the object plane of the spectrometer. The spectrometer was assembled in three steps. In the initial step, the optics was simply assembled with an optical axis guiding He-Ne laser. In the second step, we located a pin-hole on the slit plane and a Shack-Hartmann sensor on the detector plane. The wavefront errors over the full field were scanned simply by moving the point source along the slit direction while the Shack-Hartmann sensor was constantly conjugated to the pin-hole position by a motorized stage. Optimal alignment was then performed based on the reverse sensitivity method. In the final stage, the pin-hole and the Shack-Hartmann sensor were exchanged with an equispaced 10 pin-hole slit called a field identifier and a detector. The light source was also changed from the laser (single wavelength source) to a krypton lamp (discrete multi-wavelength source). We were then easily able to calculate the distortion and keystone on the detector plane without any scanning or moving optical components; rather, we merely calculated the spectral centroids of the 10 pin-holes on the detector. We then tuned the clocking angles of the convex grating and the detector to minimize the distortion and keystone. The final assembly was tested and found to have an RMS WFE < 90 nm over the entire field of view, a keystone of 0.08 pixels, a smile of 1.13 pixels and a spectral resolution of 4.32 nm.

Corneal haze following PRK with mitomycin C as a retreatment versus prophylactic use in the contralateral eye.

PubMed

Netto, Marcelo V; Chalita, Maria Regina; Krueger, Ronald R

2007-01-01

To report photorefractive keratectomy (PRK) treated with mitomycin C (MMC) for previous corneal haze in one eye and PRK with MMC to prevent corneal haze formation in the fellow eye. A 40-year-old woman underwent PRK with MMC to treat previous corneal haze (secondary to previous PRK without MMC) for residual refractive error of +0.50 +0.25 x 165 in the left eye and PRK with MMC to prevent corneal haze in the right eye. Postoperative slit-lamp examination revealed no haze in the right eye, but continued mild haze in the left eye. Treatment with PRK and MMC for previous corneal haze is not as effective as primary PRK with MMC in preventing postoperative corneal haze formation.

[SOPHOCLE (Ophthalmologic Simulator of Laser PHOtocoagulation): contribution to virtual reality].

PubMed

Rouland, J F; Dubois, P; Chaillou, C; Meseuree, P; Karpf, S; Godin, S; Duquenoy, F

1995-01-01

This study was undertaken to teach laser retinal photocoagulation in different disorders using a "virtual eye". Most ophthalmologists routinely use laser photocoagulator. Both indications and laser effects are well-known. However, in various diseases (diabetic retinopathy, age-related-macular degeneration, myopia...) complications rate increase or at least does not decrease. The main reasons are: - ignorance of risk factors, - misuse of the instrument. We developed a new automated device stimulating a real laser photocoagulator. Only slit-lamp exists. The three-mirror lens, the fundus and the retinal photocoagulation impacts are "virtual". The aim of the simulator is to help practitioners to recognize various pathologies almost as in real conditions and to be familiar with different technics of photocoagulation. By using computer assisted learning, a constant evaluation determines the level and the progress of practitioners.

Treatment of Phthiriasis Palpebrarum and Crab Louse: Petrolatum Jelly and 1% Permethrin Shampoo

PubMed Central

Karabela, Yunus; Yardimci, Gurkan; Yildirim, Isik; Karabela, Semsi Nur

2015-01-01

Phthiriasis palpebrarum is an uncommon cause of blepharoconjunctivitis in which Pthirus pubis infest the eyelashes. We report a case of unilateral phthiriasis palpebrarum with crab louse. A 45-year-old man presented with conjunctival hyperaemia and moderate itching associated with irritation, and crusty excretions of the eyelashes in the left eye. Careful slit-lamp examination revealed many lice and nits in left eye and mild conjunctival hyperaemia. No abnormality was found in the right eye. On dermatologic examination, only one louse was found at the pubic area. The patient was treated effectively with petrolatum jelly (Vaseline) and 1% permethrin shampoo (Kwellada 1% shampoo). At the end of the first week no louse or nit was present on eyelashes and pubic area. PMID:26451147

Experimental uveitis can be maintained in rabbits for a period of six weeks after a safe sensitization method.

PubMed

Eperon, S; Balaskas, K; Vaudaux, J; Guex-Crosier, Y

2013-03-01

New treatments against long-lasting uveitis need to be tested. Our aim was to develop a six-week model of uveitis in rabbits. Rabbits were presensitized with an s.c. injection of Mycobacterium tuberculosis H37RA emulsified with TiterMax Gold adjuvant. Uveitis was induced at day 28 and 50, by intravitreal challenges of antigen suspension. Ocular inflammation was assessed till euthanasia at day 71 after s.c. injection of M. tuberculosis H37RA by: (a) the number of inflammatory cells in aqueous humor (AH); (b) the protein concentration in AH; (c) the clinical score (mean of conjunctival hyperaemia, conjunctival chemosis, oedema and secretion); (d) the microscopical score (mean presence of fibrin and synechiae, aqueous cell density and aqueous flare grade, as scored by slit lamp). At the sites of presensitization injection, rabbits presented flat nodules which progressively vanished. The first challenge induced a significant increase in the four parameters (p < 0.05 the Wilcoxon/Kruskal-Wallis test). The AH contained 764 ± 82 cells/µl and 32 ± 0.77 mg protein/ml. During the following days, inflammatory parameters decreased slightly. The second intravitreal challenge increased inflammation (3564 ± 228 cells/µl AH and 31 ± 1 mg protein/ml), which remained at a high level for a longer period of time. We developed a model of long-term uveitis, which could be maintained in rabbits for at least six weeks. Such a model could be used to test the efficacy of either new drugs or various drug delivery systems intended to deliver active agents during a few months.

Early Corneal Innervation and Trigeminal Alterations in Parkinson Disease: A Pilot Study.

PubMed

Arrigo, Alessandro; Rania, Laura; Calamuneri, Alessandro; Postorino, Elisa Imelde; Mormina, Enricomaria; Gaeta, Michele; Marino, Silvia; Di Lorenzo, Giuseppe; Quartarone, Angelo; Anastasi, Giuseppe; Puzzolo, Domenico; Aragona, Pasquale

2018-04-01

To describe corneal innervation and trigeminal alterations in drug-naive patients with Parkinson disease (PD). A case series study was conducted by recruiting 3 early drug-naive patients with PD, 2 men and 1 woman (age: 72, 68, and 66, respectively). Ophthalmologic assessment included Ocular Surface Disease Index questionnaire, visual acuity by the logarithm of the minimum angle of resolution score, pupillary light reflexes, extrinsic ocular movements, corneal sensitivity, and slit-lamp examination. Corneal innervation parameter changes were evaluated in vivo using the Confoscan 4 confocal microscope, and they were compared with a control data set. The Heidelberg Retina Tomograph 3 (HRT3) has been used to assess retinal alterations in our patients, if compared with normal range values provided by the HRT3. Moreover, 3T magnetic resonance imaging (MRI) analysis of water diffusion property changes of trigeminal nerves was performed. All data were analyzed and compared with 2 control data sets made by 14 age-matched controls. Patients with PD showed profound alterations of corneal innervation and of trigeminal diffusion MRI parameters, compared with controls. Strong differences (PD vs. controls) were found for deep nerve tortuosity (Kallinikos mean 19.94 vs. 2.13) and the number of beadings (mean 34.2 vs. 15.5). HRT3 retinal evaluation revealed less structural changes compared with the normal range. Diffusion MRI showed profound changes of white matter diffusion properties (PD vs. controls), with fractional anisotropy decrement (mean 0.3029 vs. 0.3329) and mean diffusivity increment (mean 0.00127 vs. 0.00106). Corneal innervation changes might occur earlier in patients with PD than in retinal ones. Confocal corneal innervation analysis might provide possible early biomarkers for a better PD evaluation and for its earlier diagnosis.

Mincle in the innate immune response of mice fungal keratitis.

PubMed

Yu, Guo-Rong; Lin, Jing; Zhang, Jie; Che, Cheng-Ye; Peng, Xu-Dong; Li, Cui; Hu, Li-Ting; Zhu, Guo-Qiang; He, Kun; Zhao, Gui-Qiu

2018-01-01

To investigate how macrophage inducible C-type lectin (Mincle) influences inflammation in mice fungal keratitis induced by Aspergillus fumigatus ( A. fumigatus ). C57BL/6 mice were infected with A. fumigatus after pretreated with Mincle agonist TDB or Mincle neutralizing antibody (MincleAb), taking DMSO or IgG as control group respectively. The cornea lesions were monitored with slit-lamp microscope and evaluated by clinical score. Mincle expression was assessed using reverse transcription-ploymerase chain reaction (RT-PCR) and immunostaining. The expression of cytokines (IL-1β, TNF-α and IL-6) chemokines (CXCL-1 and MIP-2) was determined by RT-PCR and ELISA. Neutrophil infiltration was observed by immunostaining. The levels of nitric oxide (NO) generated by corneas were tested by Griess reaction. Mincle mRNA and protein levels were higher in infected corneas than normal corneas of C57BL/6 mice, saving clinical scores revealed differences. When pretreated with Mincle agonist TDB, the mRNA and protein levels of IL-1β, TNF-α and IL-6 in infected corneas were significantly increased compared with the control group ( P <0.01). Results of the counterpart in corneas pretreated with Mincle neutralizing antibody was decreased consistently ( P <0.01). Expression of CXCL1 and MIP-2 mRNA levels were up-regulated in TDB group and down-regulated in MincleAb group ( P <0.01), coincide with neutrophil aggregation degree in corneas showed by immunostaining. As for the concentration of NO, it was promoted in TDB group compared with DMSO control group, and decreased in MincleAb group compared with IgG control group. Mincle plays a dual role in mice fungal keratitis. It participates in the innate immune system by enhancing inflammation. What's more, Mincle can mediate cytotoxic effects by regulating the formation of NO.

[The blood coagulation system and microcirculatory disorders in ixodid tick-borne borreliosis caused by Borrelia miyamotoi].

PubMed

Platonov, A E; Sarksyan, D S; Karan, L S; Shipulin, G A; Gordygina, E V; Malinin, O V; Maleev, V V

2015-01-01

To study blood coagulation and microcirculatory disorders as a possible cause of transient dysfunctions of organs (the kidney, liver, heart, lung, etc.) in patients with ixodid tick-borne borreliosis caused by Borrelia miyamotoi (Bmt). SUBJECTS AND METHODS; Twenty-four patients with Lyme disease (LD) and 28 Bmt patients treated at Izhevsk City Hospital (Udmurtia) were examined in the study. Platelet counts and the presence of D-dimers were determined; activated partial thromboplastin time, prothrombin time, thrombin time, fibrinogen and antithrombin III levels, and Factor XIIa-dependent fibrin clot lysis time were measured. Slit lamp microscopy of the conjunctiva was. also carried out. Results. Platelet counts'were less than 150,000 per pL of blood in 43% of the Bmt patients. All the Bmt patients had at least one abnormal coagulation parameter of the eight ones that were tested; 64% of them had marked coagulation disorders with three or more abnormal laboratory findings. In contrast, all the eight parameters were normal in 71% of the LD patients. The other seven LD patients had only one or two abnormal coagulation parameters (p < 0.001 in comparison with Bmt patients). Microscopic examination of eye capillary blood flow revealed pathological findings that included aggregates of erythrocytes and obstructed and/or sinuous capillaries in 22 (79%) of the Bmt patients, but none of the LD patients. A total of 14 Bmt patients had both coagulation and microcirculatory abnormalities. Eleven of them also had transient signs of organ dysfunction. As far as Borrelia secrete no known toxins, we hypothesized that uncovered disorders of blood coagulation and microcirculation in Bmt patients may contribute to organ dysfunction.

Decreased visual acuity resulting from glistening and sub-surface nano-glistening formation in intraocular lenses: A retrospective analysis of 5 cases

PubMed Central

Matsushima, Hiroyuki; Nagata, Mayumi; Katsuki, Yoko; Ota, Ichiro; Miyake, Kensaku; Beiko, George H.H.; Grzybowski, Andrzej

2015-01-01

Background To report on five patients with decreased visual acuity due to glistening and severe sub-surface nano-glistening (SSNG) formation within their intraocular lenses (IOLs). Design Case reports and analysis of extracted IOLs. Participants and samples We report improved visual acuity when IOLs with severe glistening and SSNG were exchanged for clear IOLs in five patients. Methods Case reports. Main outcome measures The main outcome measure was visual acuity. The secondary outcome measure was light transmission. Explanted IOLs were subjected to investigation. Pre- and postoperative slit lamp images of the anterior eye and microscopic images of the extracted IOLs were taken and compared. Light transmission of the IOL was measured using a double beam type spectrophotometer. An integrated value of the percentage light transmittance in the visible light spectrum was calculated. Results We report on five patients whose visual acuity improved when IOLs were exchanged because of severe glistening and SSNG. All of the affected IOLs were MA60BM (Alcon, Forth Wroth Texas, USA) and the original implantation had occurred over a range of 6–15 years prior to the IOL exchange. Light transmission was decreased in all affected lenses compared to a similar control IOL. Conclusions Although only a few reports of cases in which glistening and SSNG have progressed to the level of decreased visual function have been published, the likelihood is that this phenomena will increase as the severity and incidence of these inclusions have been shown to increase with time. Appropriate evaluations of visual function in such patients are needed and consideration should be given to IOL exchange in symptomatic patients. PMID:26586975

Prevalence and determinants of age-related macular degeneration in the 50 years and older population: A hospital based study in Maharashtra, India

PubMed Central

Kulkarni, Sucheta R; Aghashe, Supriya R; Khandekar, Rajiv B; Deshpande, Madan D

2013-01-01

Background: We present the magnitude and determinants of age-related macular degeneration (ARMD) among the 50 year and older population that visited our hospital. Materials and Methods: This was a cohort of eye patients with ARMD, seen from 2006 to 2009. Optometrist noted the best-corrected vision. Ophthalmologists examined eyes using a slit-lamp bio-microscope. The ARMD was confirmed by fluoresceine angiography and optical coherent tomography. The age, sex, history of smoking, sun exposure, family history of ARMD, diet, body mass index (BMI), hypertension, and diabetes were associated with ARMD. Result: Of the 19,140 persons of ≥ 50 years of age-attending eye clinic in our hospital, 302 persons had ARMD in at least one eye. The proportion of overall ARMD was 1.38% (95% CI 1.21--1.55). The proportion of age-related maculopathy (ARM) and late ARMD was 1.14% (95% CI 0.99--1.29) and 0.24% (95% CI 0.21–0.24) respectively. ARM was unilateral and bilateral in 64 (29.2%) and 155 (70.8%) persons respectively. Dry ARMD was found in 47.8%. On regression analysis, old age (OR = 1.05), male (OR = 0.54), and history of smoking (OR = 2.32) were significant risk factors of ARMD. A total of 4.2% of persons with ARMD were blind (vision <3/60). Only 43% of persons with ARMD had J6 grade of the best-corrected near vision. Conclusion: ARMD does not seem to be of public health magnitude in the study area. Early stages of ARMD were common among patients. ge, being male, and history of smoking were significant risk factors for ARMD. PMID:23571245

Photodermatitis and photokeratoconjunctivitis in a ball python (Python regius) and a blue-tongue skink (Tiliqua spp.).

PubMed

Gardiner, David W; Baines, Frances M; Pandher, Karamjeet

2009-12-01

A male ball python (Python regius) and a female blue tongue skink (Tiliqua spp.) of unknown age were evaluated for anorexia, lethargy, excessive shedding, corneal opacity (python), and weight loss (skink) of approximately three weeks' duration. These animals represented the worst affected animals from a private herpetarium where many animals exhibited similar signs. At necropsy, the python had bilateral corneal opacity and scattered moderate dysecdysis. The skink had mild dysecdysis, poor body condition, moderate intestinal nematodiasis, and mild liver atrophy. Microscopic evaluation revealed epidermal erosion and ulceration, with severe epidermal basal cell degeneration and necrosis, and superficial dermatitis (python and skink). Severe bilateral ulcerative keratoconjunctivitis with bacterial colonization was noted in the ball python. Microscopic findings within the skin and eyes were suggestive of ultraviolet (UV) radiation damage or of photodermatitis and photokeratoconjunctivitis. Removal of the recently installed new lamps from the terrariums of the surviving reptiles resulted in resolution of clinical signs. Evaluation of a sample lamp of the type associated with these cases revealed an extremely high UV output, including very-short-wavelength UVB, neither found in natural sunlight nor emitted by several other UVB lamps unassociated with photokeratoconjunctivitis. Exposure to high-intensity and/or inappropriate wavelengths of UV radiation may be associated with significant morbidity, and even mortality, in reptiles. Veterinarians who are presented with reptiles with ocular and/or cutaneous disease of unapparent cause should fully evaluate the specifics of the vivarium light sources. Further research is needed to determine the characteristics of appropriate and of toxic UV light for reptiles kept in captivity.

Compact whole-body fluorescent imaging of nude mice bearing EGFP expressing tumor

NASA Astrophysics Data System (ADS)

Chen, Yanping; Xiong, Tao; Chu, Jun; Yu, Li; Zeng, Shaoqun; Luo, Qingming

2005-01-01

Issue of tumor has been a hotspot of current medicine. It is important for tumor research to detect tumors bearing in animal models easily, fast, repetitively and noninvasivly. Many researchers have paid their increasing interests on the detecting. Some contrast agents, such as green fluorescent protein (GFP) and Discosoma red fluorescent protein (Dsred) were applied to enhance image quality. Three main kinds of imaging scheme were adopted to visualize fluorescent protein expressing tumors in vivo. These schemes based on fluorescence stereo microscope, cooled charge-coupled-device (CCD) or camera as imaging set, and laser or mercury lamp as excitation light source. Fluorescence stereo microscope, laser and cooled CCD are expensive to many institutes. The authors set up an inexpensive compact whole-body fluorescent imaging tool, which consisted of a Kodak digital camera (model DC290), fluorescence filters(B and G2;HB Optical, Shenyang, Liaoning, P.R. China) and a mercury 50-W lamp power supply (U-LH50HG;Olympus Optical, Japan) as excitation light source. The EGFP was excited directly by mercury lamp with D455/70 nm band-pass filter and fluorescence was recorded by digital camera with 520nm long-pass filter. By this easy operation tool, the authors imaged, in real time, fluorescent tumors growing in live mice. The imaging system is external and noninvasive. For half a year our experiments suggested the imaging scheme was feasible. Whole-body fluorescence optical imaging for fluorescent expressing tumors in nude mouse is an ideal tool for antitumor, antimetastatic, and antiangiogenesis drug screening.

Three-dimensional microscopic tomographic imagings of the cataract in a human lens in vivo

NASA Astrophysics Data System (ADS)

Masters, Barry R.

1998-10-01

The problem of three-dimensional visualization of a human lens in vivo has been solved by a technique of volume rendering a transformed series of 60 rotated Scheimpflug (a dual slit reflected light microscope) digital images. The data set was obtained by rotating the Scheimpflug camera about the optic axis of the lens in 3 degree increments. The transformed set of optical sections were first aligned to correct for small eye movements, and then rendered into a volume reconstruction with volume rendering computer graphics techniques. To help visualize the distribution of lens opacities (cataracts) in the living, human lens the intensity of light scattering was pseudocolor coded and the cataract opacities were displayed as a movie.

3D structured illumination microscopy using an incoherent illumination system based on a Fresnel biprism

NASA Astrophysics Data System (ADS)

Shabani, H.; Doblas, A.; Saavedra, G.; Preza, C.

2018-02-01

Three-dimensional (3D) structured illumination (SI) patterns that include lateral and axial variations have attracted more attention recently as their use in fluorescence microscope enhances the 3D resolution of the native imaging system. 3D SI patterns have already been created by interfering three mutually-coherent waves using a diffraction grating or some electro-optical devices such as spatial light modulators. Here, an interesting approach to generate a 3D SI pattern of tunable modulation frequency is shown. Our proposed illumination system is based on the incoherent illumination of a Fresnel biprism using several equidistant linear sources (i.e., slits). Previously, we investigated and compared numerically this tunable SI microscopy (SIM) system with the one achieved with three-wave interference. In this contribution, we implement our proposed incoherent 3D SIM system of tunable-frequency in an open-setup. We evaluate the axial confinement of the illumination pattern obtained with this system by recording the SI pattern using a mirror sample and different number of slits and compare these data with simulation results. Moreover, we verify that with a higher number of slits used, the axial confinement of the pattern increases, and consequently, the system's optical sectioning capability improves.

Optical coherence tomography of the eye

NASA Astrophysics Data System (ADS)

Hee, Michael Richard

1997-10-01

Optical Coherence Tomography (OCT) is a new technique for high-resolution, cross-sectional imaging of tissue in which the time-of-flight delay of light reflected from internal tissue structures is resolved with high precision using interferometry. Tomographic images are obtained which are analogous to those provided by ultrasound except that image contrast relies on differences in optical rather than acoustic properties of tissue. The use of light rather than sound enables higher resolution (10 μm) and non-contact imaging. A clinically viable high-sensitivity, fiber-optic based OCT instrument has been constructed based on engineering principles derived from optical communication theory. Computer algorithms have also been developed for quantitative image analysis and restoration. OCT has been used to image patients with a variety of ocular diseases. In patients with macular pathology, OCT images have been correlated with conventional clinical examination and fluorescein angiography. Optical coherence tomograms are effective in staging macular holes, evaluating the vitreoretinal interface in eyes at risk for a macular hole, and providing a structural assessment of macular hole surgery. In eyes with central serous chorioretinopathy, OCT can evaluate sensory retinal separations undetected at the slit-lamp. Serial OCT images of macular edema are able to track both the progression of macular thickening and the resolution of macular edema following laser photocoagulation. In patients with diabetic retinopathy, measurements of macular thickness correlate with visual acuity and OCT is more sensitive to small changes in retinal thickness than slit-lamp biomicroscopy. OCT may provide a novel method of defining occult choroidal neovascular membranes in patients with age-related macular degeneration. OCT can also profile the thickness of the retinal nerve fiber layer with high resolution which is potentially important for the objective assessment of early glaucoma progression. OCT images have been correlated with visual field performance and optic nerve appearance in a cross- section of patients with various stages of glaucoma. These studies suggest that OCT has the potential to become an important diagnostic tool for the practicing ophthalmologist. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

Efficacy and tolerability of brinzolamide/brimonidine suspension and prostaglandin analogs in patients previously treated with dorzolamide/timolol solution and prostaglandin analogs.

PubMed

Lo, Jonathan S; Pang, Pierre M; Lo, Samuel C

2016-01-01

Fixed combination glaucoma medication is increasingly used in glaucoma treatment. There is a lack of comparative study in the literature of non-beta blocker combination agents used adjunctively with a glaucoma agent in a different class. The objective of this study is to evaluate the effect of intraocular pressure (IOP) control and tolerability of non-beta blocker combination suspension with prostaglandin analogs (PGA) in patients with open angle glaucoma who were previously treated with beta blocker combination solution with PGA. Open-label retrospective review of patient records. This study looked at patients with open angle glaucoma taking dorzolamide/timolol solution with PGA that were switched to brinzolamide/brimonidine combination suspension with PGA. This study reviewed the charts of all patients who were at least 21 years old with a clinical diagnosis of open-angle glaucoma or ocular hypertension in at least one eye. Patients needed to have been treated with concomitant use of PGA and dorzolamide/timolol solution for at least one month. Patients using dorzolamide/timolol solution plus PGA with medication related ocular irritation were switched to brinzolamide/brimonidine suspension with the same PGA. Best-corrected visual acuity, ocular hyperemia grading, slit lamp biomicroscopy and Goldmann applanation tonometry measurements, and patient medication preferences were assessed at baseline, 1 month and 3 months. Forty eyes with open angle glaucoma. The mean age of the patients was 68 and 60% were females. The IOP before the switch was 17.2 and 16.5 (P=0.70) following the switch at 3 months. We found a decreasing trend of ocular hyperemia (P=0.064) and strong preference (P=0.011) for non-beta blocker combination suspension but no difference of visual acuity and slit lamp findings. Brinzolamide/brimonidine combination suspension when used adjunctively with PGA is equally effective. Patients in this study reported greatly reduced ocular redness and shorter duration of stinging with non-beta blocker combination suspension. Their preference of it over dorzolamide/timolol combination solution makes it a viable treatment option, particularly for the aging glaucoma patient with comorbidities that restrict the beta blocker use.

Preference for a fixed combination of brinzolamide/timolol versus dorzolamide/timolol among patients with open-angle glaucoma or ocular hypertension.

PubMed

Sanseau, Ana; Sampaolesi, Juan; Suzuki, Emilio Rintaro; Lopes, Joao Franca; Borel, Hector

2013-01-01

To assess ocular discomfort upon instillation and patient preference for brinzolamide/timolol relative to dorzolamide/timolol, in patients with open-angle glaucoma or ocular hypertension. This was a multicenter, prospective, patient-masked, randomized, crossover study. On day 0, patients received one drop of brinzolamide/timolol in one eye and one drop of dorzolamide/timolol in the contralateral eye. On day 1, patients were randomly assigned to receive one drop of either brinzolamide/timolol or dorzolamide/timolol in both eyes; on day 2, patients received one drop of the alternate treatment in both eyes. Measures included a patient preference question on day 2 (primary) and mean ocular discomfort scale scores on days 1 and 2 (secondary). Safety assessments included adverse events, visual acuity, and slit-lamp examinations. Of 120 patients who enrolled, 115 completed the study. Of these, 112 patients instilled both medications and expressed a study medication preference on day 2. A significantly greater percentage preferred brinzolamide/timolol to dorzolamide/timolol (67.0% versus 30.4%; P < 0.001). The ocular discomfort (expressed as mean [standard deviation]) with brinzolamide/timolol was significantly lower than with dorzolamide/timolol (day 2:1.9 [2.3] versus 3.7 [2.8], respectively [P = 0.0003]; both days combined: 2.1 [2.5] versus 3.5 [2.9], respectively [P = 0.00014]). On day 1, five patients receiving brinzolamide/timolol reported five nonserious adverse events (AEs): flu (n = 1), bitter taste (n = 2), and headache (n = 2). Four events, bitter taste (two events) and headache (two events), were considered related to brinzolamide/timolol. Events were mild in intensity, except bitter taste of moderate intensity reported by one patient. No AEs were reported at day 2. All AEs resolved without additional treatment. No clinically relevant changes from baseline were observed in best-corrected visual acuity or slit-lamp examinations of ocular signs. Patients had less discomfort with brinzolamide/timolol than with dorzolamide/timolol, and more expressed a preference for brinzolamide/timolol. Both treatments were generally safe and well tolerated.

The use of postoperative slit-lamp optical coherence tomography to predict primary failure in descemet stripping automated endothelial keratoplasty.

PubMed

Shih, Carolyn Y; Ritterband, David C; Palmiero, Pat-Michael; Seedor, John A; Papachristou, George; Harizman, Noga; Liebmann, Jeffrey M; Ritch, Robert

2009-05-01

To determine if central donor lenticle thickness as measured by slit-lamp optical coherence tomography (SL OCT; Heidelberg Engineering, Heidelberg, Germany) is predictive of primary donor failure in patients undergoing Descemet stripping automated endothelial keratoplasty (DSAEK). Retrospective cross-sectional study. Eighty-four patients who underwent DSAEK surgery by 2 surgeons (D.C.R. and J.A.S.) were enrolled. At each postoperative visit (postoperative day 1, week 1, month 1, and month 2), an SL OCT scan was obtained. Statistical differences in SL OCT measurements of successful and failed DSAEK procedures were measured using the Student t test. A successful DSAEK surgery was defined as having an anatomically attached, clear recipient corneal stroma and donor lenticle compatible with good vision 2 months after surgery. A failed DSAEK surgery was defined as an attached donor lenticle with SL evidence of corneal edema and thickening visible at 2 months or more. Ninety-three eyes of 84 consecutive patients who underwent DSAEK surgery also underwent postoperative SL OCT. After 2 months of follow-up, 82 (88%) procedures were successful and 11 (12%) procedures were failures. The average donor lenticle thickness in successful DSAEK eyes was 314 +/- 128 microm on postoperative day 1 as compared with failed DSAEK eyes, which averaged 532 +/- 259 microm (P = .0013). This was independent regardless of whether the lenticle was attached on the first postoperative visit. Seventy-nine (98%) successful DSAEK eyes had a lenticle thickness of < or = 350 microm at the 1-week visit. All of the failed DSAEK eyes (11 eyes) had a lenticle thickness > or = 350 microm at the 1-week postoperative visit. Statistically significant differences in SL OCT thickness measurements were seen between successful and failed DSAEK cases at all examinations after postoperative week 1. Corneal thickness measurements made with SL OCT are an important predictor of DSAEK failure in both attached and detached lenticles within the first week of surgery. DSAEK lenticle thickness of 350 microm or less at 1 week had a predictability of success of more than 98%.

The development of loop-mediated isothermal amplification targeting alpha-tubulin DNA for the rapid detection of Plasmodium vivax.

PubMed

Dinzouna-Boutamba, Sylvatrie-Danne; Yang, Hye-Won; Joo, So-Young; Jeong, Sookwan; Na, Byoung-Kuk; Inoue, Noboru; Lee, Won-Ki; Kong, Hyun-Hee; Chung, Dong-Il; Goo, Youn-Kyoung; Hong, Yeonchul

2014-06-30

Malaria that is caused by Plasmodium vivax is the most widely distributed human malaria. Its recent resurgence in many parts of the world, including the Republic of Korea (ROK), emphasizes the importance of improved access to the early and accurate detection of P. vivax to reduce disease burden. In this study, a rapid and efficient loop-mediated isothermal amplification (LAMP)-based method was developed and validated using blood samples from malaria-suspected patients. A LAMP assay targeting the α-tubulin gene for the detection of P. vivax was developed with six primers that recognize different regions of the target gene. The diagnostic performance of the α-tubulin LAMP assay was compared to three other tests: microscopic examinations, rapid diagnostic tests (RDTs), and nested polymerase chain reactions (PCRs) using 177 whole blood specimens obtained from ROK military personnel from May to December 2011. The α-tubulin LAMP assay was highly sensitive with a detection limit of 100 copies of P. vivax α-tubulin gene per reaction within 50 min. It specifically amplified the target gene only from P. vivax. Validation of the α-tubulin LAMP assay showed that the assay had the highest sensitivity (P < 0.001 versus microscopy; P = 0.0023 versus RDT) when nested PCR was used as the gold standard and better agreement (concordance: 94.9%, kappa value: 0.865) with nested PCR than RDT and microscopy. A Receiver Operation Characteristics analysis showed that the diagnostic accuracy of the α-tubulin LAMP assay for vivax malaria was higher (Area Under Curve = 0.908) than RDT and microscopy. This study showed that the P. vivax α-tubulin LAMP assay, which can be used to diagnose early infections of vivax malaria, is an alternative molecular diagnostic tool and a point-of-care test that may help to prevent transmission in endemic areas.

Development of a highly sensitive loop-mediated isothermal amplification (LAMP) method for the detection of Loa loa.

PubMed

Fernández-Soto, Pedro; Mvoulouga, Prosper Obolo; Akue, Jean Paul; Abán, Julio López; Santiago, Belén Vicente; Sánchez, Miguel Cordero; Muro, Antonio

2014-01-01

The filarial parasite Loa loa, the causative agent of loiasis, is endemic in Central and Western Africa infecting 3-13 million people. L. loa has been associated with fatal encephalopathic reactions in high Loa-infected individuals receiving ivermectin during mass drug administration programs for the control of onchocerciasis and lymphatic filariasis. In endemic areas, the only diagnostic method routinely used is the microscopic examination of mid-day blood samples by thick blood film. Improved methods for detection of L. loa are needed in endemic regions with limited resources, where delayed diagnosis results in high mortality. We have investigated the use of a loop-mediated isothermal amplification (LAMP) assay to facilitate rapid, inexpensive, molecular diagnosis of loiasis. Primers for LAMP were designed from a species-specific repetitive DNA sequence from L. loa retrieved from GenBank. Genomic DNA of a L. loa adult worm was used to optimize the LAMP conditions using a thermocycler or a conventional heating block. Amplification of DNA in the LAMP mixture was visually inspected for turbidity as well as addition of fluorescent dye. LAMP specificity was evaluated using DNA from other parasites; sensitivity was evaluated using DNA from L. loa 10-fold serially diluted. Simulated human blood samples spiked with DNA from L. loa were also tested for sensitivity. Upon addition of fluorescent dye, all positive reactions turned green while the negative controls remained orange under ambient light. After electrophoresis on agarose gels, a ladder of multiple bands of different sizes could be observed in positive samples. The detection limit of the assay was found to be as little as 0.5 ag of L. loa genomic DNA when using a heating block. We have designed, for the first time, a highly sensitive LAMP assay for the detection of L. loa which is potentially adaptable for field diagnosis and disease surveillance in loiasis-endemic areas.

Development of a Highly Sensitive Loop-Mediated Isothermal Amplification (LAMP) Method for the Detection of Loa loa

PubMed Central

Fernández-Soto, Pedro; Mvoulouga, Prosper Obolo; Akue, Jean Paul; Abán, Julio López; Santiago, Belén Vicente; Sánchez, Miguel Cordero; Muro, Antonio

2014-01-01

The filarial parasite Loa loa, the causative agent of loiasis, is endemic in Central and Western Africa infecting 3–13 million people. L. loa has been associated with fatal encephalopathic reactions in high Loa-infected individuals receiving ivermectin during mass drug administration programs for the control of onchocerciasis and lymphatic filariasis. In endemic areas, the only diagnostic method routinely used is the microscopic examination of mid-day blood samples by thick blood film. Improved methods for detection of L. loa are needed in endemic regions with limited resources, where delayed diagnosis results in high mortality. We have investigated the use of a loop-mediated isothermal amplification (LAMP) assay to facilitate rapid, inexpensive, molecular diagnosis of loiasis. Primers for LAMP were designed from a species-specific repetitive DNA sequence from L. loa retrieved from GenBank. Genomic DNA of a L. loa adult worm was used to optimize the LAMP conditions using a thermocycler or a conventional heating block. Amplification of DNA in the LAMP mixture was visually inspected for turbidity as well as addition of fluorescent dye. LAMP specificity was evaluated using DNA from other parasites; sensitivity was evaluated using DNA from L. loa 10-fold serially diluted. Simulated human blood samples spiked with DNA from L. loa were also tested for sensitivity. Upon addition of fluorescent dye, all positive reactions turned green while the negative controls remained orange under ambient light. After electrophoresis on agarose gels, a ladder of multiple bands of different sizes could be observed in positive samples. The detection limit of the assay was found to be as little as 0.5 ag of L. loa genomic DNA when using a heating block. We have designed, for the first time, a highly sensitive LAMP assay for the detection of L. loa which is potentially adaptable for field diagnosis and disease surveillance in loiasis-endemic areas. PMID:24722638

The Rapid-Heat LAMPellet Method: A Potential Diagnostic Method for Human Urogenital Schistosomiasis

PubMed Central

Carranza-Rodríguez, Cristina; Pérez-Arellano, José Luis; Vicente, Belén; López-Abán, Julio; Muro, Antonio

2015-01-01

Background Urogenital schistosomiasis due to Schistosoma haematobium is a serious underestimated public health problem affecting 112 million people - particularly in sub-Saharan Africa. Microscopic examination of urine samples to detect parasite eggs still remains as definitive diagnosis. This work was focussed on developing a novel loop-mediated isothermal amplification (LAMP) assay for detection of S. haematobium DNA in human urine samples as a high-throughput, simple, accurate and affordable diagnostic tool to use in diagnosis of urogenital schistosomiasis. Methodology/Principal Findings A LAMP assay targeting a species specific sequence of S. haematobium ribosomal intergenic spacer was designed. The effectiveness of our LAMP was assessed in a number of patients´ urine samples with microscopy confirmed S. haematobium infection. For potentially large-scale application in field conditions, different DNA extraction methods, including a commercial kit, a modified NaOH extraction method and a rapid heating method were tested using small volumes of urine fractions (whole urine, supernatants and pellets). The heating of pellets from clinical samples was the most efficient method to obtain good-quality DNA detectable by LAMP. The detection limit of our LAMP was 1 fg/µL of S. haematobium DNA in urine samples. When testing all patients´ urine samples included in our study, diagnostic parameters for sensitivity and specificity were calculated for LAMP assay, 100% sensitivity (95% CI: 81.32%-100%) and 86.67% specificity (95% CI: 75.40%-94.05%), and also for microscopy detection of eggs in urine samples, 69.23% sensitivity (95% CI: 48.21% -85.63%) and 100% specificity (95% CI: 93.08%-100%). Conclusions/Significance We have developed and evaluated, for the first time, a LAMP assay for detection of S. haematobium DNA in heated pellets from patients´ urine samples using no complicated requirement procedure for DNA extraction. The procedure has been named the Rapid-Heat LAMPellet method and has the potential to be developed further as a field diagnostic tool for use in urogenital schistosomiasis-endemic areas. PMID:26230990

Comparison of two techniques of marking the horizontal axis during excimer laser keratorefractive surgery for myopic astigmatism.

PubMed

Burka, Jenna M; Bower, Kraig S; Cute, David L; Stutzman, Richard D; Subramanian, Prem S; Rabin, Jeff C

2005-04-01

To compare two methods of limbal marking used during laser refractive surgery for myopic astigmatism. Retrospective chart review. Forty-two eyes of 42 patients who underwent photorefractive keratectomy (PRK) or laser-assisted in-situ keratomileusis (LASIK) for myopic astigmatism were marked preoperatively to identify the horizontal axis. In 18 eyes, marks were placed at the slit lamp (SL) with the slit beam set at 180 degrees as a reference. In 24 eyes, marks were placed in the laser room (LR) immediately before reclining under the laser. All treatments were performed with the Alcon LADARVision excimer laser system. Vector analysis of postoperative cylinder and reduction in cylinder and uncorrected and best-corrected visual acuity were evaluated for both groups. The mean postoperative magnitude of error was -0.19 +/- 0.44 diopters for the LR group and -0.09 +/- 0.42 diopters for the SL group (P = .439, NS). Both groups had a mean angle of error indicating an overall counterclockwise rotation of axis with an angle of error of 6.3 +/- 8.7 degrees for the LR group and 8.0 +/- 10.2 degrees for the SL group (P = .562, NS). We found no significant difference in outcomes with an overall trend toward undercorrection of cylinder in both groups, leaving room for improvement after refractive surgery for myopic astigmatism.

In-situ cyclic pulse annealing of InN on AlN/Si during IR-lamp-heated MBE growth

NASA Astrophysics Data System (ADS)

Suzuki, Akira; Bungi, Yu; Araki, Tsutomu; Nanishi, Yasushi; Mori, Yasuaki; Yamamoto, Hiroaki; Harima, Hiroshi

2009-05-01

To improve crystal quality of InN, an in-situ cyclic rapid pulse annealing during growth was carried out using infrared-lamp-heated molecular beam epitaxy. A cycle of 4 min growth of InN at 400 °C and 3 s pulse annealing at a higher temperature was repeated 15 times on AlN on Si substrate. Annealing temperatures were 550, 590, 620, and 660 °C. The back of Si was directly heated by lamp irradiation through a quartz rod. A total InN film thickness was about 200 nm. With increasing annealing temperature up to 620 °C, crystal grain size by scanning electron microscope showed a tendency to increase, while widths of X-ray diffraction rocking curve of (0 0 0 2) reflection and E 2 (high) mode peak of Raman scattering spectra decreased. A peak of In (1 0 1) appeared in X-ray diffraction by annealing higher than 590 °C, and In droplets were found on the surface by annealing at 660 °C.

Age-related retention of fiber cell nuclei and nuclear fragments in the lens cortices of multiple species

PubMed Central

Pendergrass, William; Zitnik, Galynn; Urfer, Silvan R.

2011-01-01

Purpose To determine the differences between species in the retention of lens fiber cell nuclei and nuclear fragments in the aging lens cortex and the relationship of nuclear retention to lens opacity. For this purpose old human, monkey, dog, and rat lenses were compared to those of three strains of mouse. We also investigated possible mechanisms leading to nuclear retention. Methods Fixed specimens of the species referred to above were obtained from immediate on site sacrifice of mice and rats, or from recently fixed lenses of other species, dogs, monkeys, and humans, obtained from collaborators. The retention of undegraded nuclei and nuclear fragments was graded 1–4 from histologic observation. All species lenses were examined microscopically in fixed sections stained with hematoxylin and eosin (H&E) or 4',6-diamidino-2-phenylindole (DAPI). Slit lamp observations were made only on the mice and rats before sacrifice and lens fixation. Values of 0 to 4 (clear lens to cataract) were given to degree of opacity. MRNA content in young versus old C57BL/6 mouse lenses was determined by quantitative PCR (qPCR) for DNase II-like acid DNase (DLAD) and other proteins. DLAD protein was determined by immunofluorescence of fixed eye sections. Results In old C57BL/6 and DBA mice and, to a lesser degree, in old CBA mice and old Brown Norway (BN) rats lenses were seen to contain a greatly expanded pool of unresolved whole nuclei or fragments of nuclei in differentiating lens fiber cells. This generally correlated with increased slit lamp opacities in these mice. Most old dog lenses also had an increase in retained cortical nuclei, as did a few old humans. However, a second rat strain, BNF1, in which opacity was quite high had no increase in retained nuclei with age nor did any of the old monkeys, indicating that retained nuclei could not be a cause of opacity in these animals. The nuclei and nuclear fragments were located at all levels in the outer cortex extending inward from the lens equator and were observable by the DAPI. These nuclei and nuclear fragments were seen from 12 months onward in all C57BL/6 and DBA/2 mice and to a lesser degree in the CBA, increasing in number and in space occupancy with increasing age. Preliminary results suggest that retention of nuclei in the C57BL/6 mouse is correlated with an age-related loss of DLAD from old lenses. Conclusions A very marked apparently light refractive condition caused by retained cortical nuclei and nuclear fragments is present in the lens cortices, increasing with age in the three strains of mice examined and in one of two strains of rats (BN). This condition was also seen in some old dogs and a few old humans. It may be caused by an age-related loss of DLAD, which is essential for nuclear DNA degradation in the lens. However, this condition does not develop in old BNF1 rats, or old monkeys and is only seen sporadically in humans. Thus, it can not be a universal cause for age related lens opacity or cataract presence, although it develops concurrently with opacity in mice. This phenomenon should be considered when using the old mouse as a model for human age-related cataract. PMID:22065920

Development of two-channel prototype ITER vacuum ultraviolet spectrometer with back-illuminated charge-coupled device and microchannel plate detectors.

PubMed

Seon, C R; Choi, S H; Cheon, M S; Pak, S; Lee, H G; Biel, W; Barnsley, R

2010-10-01

A vacuum ultraviolet (VUV) spectrometer of a five-channel spectral system is designed for ITER main plasma impurity measurement. To develop and verify the system design, a two-channel prototype system is fabricated with No. 3 (14.4-31.8 nm) and No. 4 (29.0-60.0 nm) among the five channels. The optical system consists of a collimating mirror to collect the light from source to slit, two holographic diffraction gratings with toroidal geometry, and two different electronic detectors. For the test of the prototype system, a hollow cathode lamp is used as a light source. To find the appropriate detector for ITER VUV system, two kinds of detectors of the back-illuminated charge-coupled device and the microchannel plate electron multiplier are tested, and their performance has been investigated.

Toric multifocal intraocular lens implantation in a case of bilateral anterior and posterior lenticonus in Alport syndrome

PubMed Central

Ladi, Jeevan S; Shah, Nitant A

2016-01-01

We report the first case of toric multifocal intraocular lens (IOL) implantation in both the eyes of a young patient of Alport syndrome with anterior and posterior lenticonus with a successful outcome. An 18-year-old female patient presented with progressively blurred vision in both eyes since 4–5 years not improving with glasses. Refraction showed high myopia with astigmatism; however, the vision did not improve beyond 6/60 with glasses correction. Clinical examination on slit lamp showed anterior and posterior lenticonus bilaterally with a classical oil droplet appearance. We performed clear lens extraction by phacoemulsification with toric multifocal IOL implantation in both eyes. Postoperatively, the patient achieved an excellent refractive outcome with the unaided vision of 6/9, N6 in both eyes. PMID:27958211

Smartphone-based Video of Demodex folliculorum In Biopsied Human Eyelash Follicles.

PubMed

Vahedi, Mithaq; Davis, Gavin; Coleman, Michael James; Garrett, Brian Steven; Eghrari, Allen Omid

2015-01-01

The ability of smartphone technology to document static microscopy images has been well documented and is gaining widespread use in ophthalmology, where slit-lamp biomicroscopy is frequently utilized. However, little has been described regarding the use of smartphone technology to relay video of tissue microscopy results to patients, particularly when a tissue sample integrates motility of organisms as a characteristic feature of the disease. Here, we describe the method to use smartphone video to document motility of Demodex folliculorum in human eyelashes, individual results of which can be shown to patients for education and counseling purposes. The use of smartphone video in documenting the motility of organisms may prove to be beneficial in a variety of medical fields; producers of electronic medical records, therefore, may find it helpful to integrate video drop box tools.

[Application of BaSO4 diffuser plate in 250-400 nm spectral radiance calibration].

PubMed

Jia, Hui; Li, Fu-tian

2004-01-01

Sprayed BaSO4 diffuser plate is the most Lambertian surface actually used in spectral radiance calibration known by now. Its hemispheric reflectance and Bi-directional Reflectance Distribution Functions (BRDF) were measured in the experiment. Its diffuse characteristics were compared with Lambertian surface. In order to calibrate spectral radiance more accurately, the small variation of diffuser's BRDF with scattered angles and the nonuniformity of spectral irradiance on diffuser surface illuminated by the standard lamp should be considered. By integrating the radiation flux reflected by the element area and that entering the entrance slit within the viewing area of spectrometer, the measured spectral radiance can be calculated. Furthermore, the spectral radiance of Lambertian surface whose BRDF was derived from hemispheric reflectance was compared with that from the average of the measured BRDF.

A Penning discharge source for extreme ultraviolet calibration

NASA Technical Reports Server (NTRS)

Finley, David S.; Jelinsky, Patrick; Bowyer, Stuart; Malina, Roger F.

1986-01-01

A Penning discharge lamp for use in the calibration of instruments and components for the extreme ultraviolet has been developed. This source is sufficiently light and compact to make it suitable for mounting on the movable slit assembly of a grazing incidence Rowland circle monochromator. Because this is a continuous discharge source, it is suitable for use with photon counting detectors. Line radiation is provided both by the gas and by atoms sputtered off the interchangeable metal cathodes. Usable lines are produced by species as highly ionized as Ne IV and Al V. The wavelength coverage provided is such that a good density of emission lines is available down to wavelengths as short as 100A. This source fills the gap between 100 and 300A, which is inadequately covered by the other available compact continuous radiation sources.

Development and evaluation of a Loop Mediated Isothermal Amplification (LAMP) technique for the detection of hookworm (Necator americanus) infection in fecal samples.

PubMed

Mugambi, Robert Muriuki; Agola, Eric L; Mwangi, Ibrahim N; Kinyua, Johnson; Shiraho, Esther Andia; Mkoji, Gerald M

2015-11-06

Hookworm infection is a major concern in sub-Saharan Africa, particularly in children and pregnant women. Necator americanus and Ancylostoma duodenale are responsible for this condition. Hookworm disease is one of the Neglected tropical diseases (NTDs) that are targeted for elimination through global mass chemotherapy. To support this there is a need for reliable diagnostic tools. The conventional diagnostic test, Kato-Katz that is based on microscopic detection of parasite ova in faecal samples, is not effective due to its low sensitivity that is brought about mainly by non-random distribution of eggs in stool and day to day variation in egg output. It is tedious, cumbersome to perform and requires experience for correct diagnosis. LAMP-based tests are simple, relatively cheap, offer greater sensitivity, specificity than existing tests, have high throughput capability, and are ideal for use at the point of care. We have developed a LAMP diagnostic test for detection of hookworm infection in faecal samples. LAMP relies on auto cycling strand displacement DNA synthesis performed at isothermal temperature by Bst polymerase and a set of 4 specific primers. The primers used in the LAMP assay were based on the second Internal Transcribed Spacer (ITS-2) region and designed using Primer Explorer version 4 Software. The ITS-2 region of the ribosomal gene (rDNA) was identified as a suitable target due to its low mutation rates and substantial differences between species. DNA was extracted directly from human faecal samples, followed by LAMP amplification at isothermal temperature of 63 °C for 1 h. Amplicons were visualized using gel electrophoresis and SYBR green dye. Both specificity and sensitivity of the assay were determined. The LAMP based technique developed was able to detect N. americanus DNA in faecal samples. The assay showed 100 % specificity and no cross-reaction was observed with other helminth parasites (S. mansoni, A. lumbricoides or T. trichiura). The developed LAMP assay was 97 % sensitive and DNA at concentrations as low as 0.4 fg were amplified. The LAMP assay developed is an appropriate diagnostic method for the detection of N. americanus DNA in human stool samples because of its simplicity, low cost, sensitivity, and specificity. It holds great promise as a useful diagnostic tool for use in disease control where infection intensities have been significantly reduced.

Toward single mode, atomic size electron vortex beams.

PubMed

Krivanek, Ondrej L; Rusz, Jan; Idrobo, Juan-Carlos; Lovejoy, Tracy J; Dellby, Niklas

2014-06-01

We propose a practical method of producing a single mode electron vortex beam suitable for use in a scanning transmission electron microscope (STEM). The method involves using a holographic "fork" aperture to produce a row of beams of different orbital angular momenta, as is now well established, magnifying the row so that neighboring beams are separated by about 1 µm, selecting the desired beam with a narrow slit, and demagnifying the selected beam down to 1-2 Å in size. We show that the method can be implemented by adding two condenser lenses plus a selection slit to a straight-column cold-field emission STEM. It can also be carried out in an existing instrument, the monochromated Nion high-energy-resolution monochromated electron energy-loss spectroscopy-STEM, by using its monochromator in a novel way. We estimate that atom-sized vortex beams with ≥ 20 pA of current should be attainable at 100-200 keV in either instrument.

Morphologies of femtosecond laser ablation of ITO thin films using gaussian or quasi-flat top beams for OLED repair

NASA Astrophysics Data System (ADS)

Kim, Hoon-Young; Choi, Won-Suk; Ji, Suk-Young; Shin, Young-Gwan; Jeon, Jin-Woo; Ahn, Sanghoon; Cho, Sung-Hak

2018-02-01

This study compares the ablation morphologies obtained with a femtosecond laser of both Gaussian and quasi-flat top beam profiles when applied to indium tin oxide (ITO) thin films for the purpose of OLED repair. A femtosecond laser system with a wavelength of 1030 nm and pulse duration of 190 fs is used to pattern an ITO thin film. The laser fluence is optimized for patterning at 1.38 J/cm2. The patterned ITO thin film is then evaluated through both optical microscope and atomic force microscope. Ablations with a square quasi-flat top beam are demonstrated using slits with varying x- y axes. With the Gaussian beam, the pattern width of the ablated area is shown to range from 9.17 to 9.99 μm when the number of irradiation pulse increases from one to six. In contrast, when slit control is used to obtain a quasi-flat top beam, the ablated pattern width remains constant at 10 μm, despite the increase in the number of pulse. The improved surface roughness is correlated with the quasi-flat top beam through measured Ra values. Furthermore, when using the Gaussian beam, the minimum resolution of the controllable ablation depth on the ITO thin film is found to be 60 nm. In contrast, when the quasi-flat top beam is used, the minimum ablation depth decreases to 40 nm.

In vivo volumetric depth-resolved vasculature imaging of human limbus and sclera with 1 μm swept source phase-variance optical coherence angiography

NASA Astrophysics Data System (ADS)

Poddar, Raju; Zawadzki, Robert J.; Cortés, Dennis E.; Mannis, Mark J.; Werner, John S.

2015-06-01

We present in vivo volumetric depth-resolved vasculature images of the anterior segment of the human eye acquired with phase-variance based motion contrast using a high-speed (100 kHz, 105 A-scans/s) swept source optical coherence tomography system (SSOCT). High phase stability SSOCT imaging was achieved by using a computationally efficient phase stabilization approach. The human corneo-scleral junction and sclera were imaged with swept source phase-variance optical coherence angiography and compared with slit lamp images from the same eyes of normal subjects. Different features of the rich vascular system in the conjunctiva and episclera were visualized and described. This system can be used as a potential tool for ophthalmological research to determine changes in the outflow system, which may be helpful for identification of abnormalities that lead to glaucoma.

Methotrimeprazine-induced Corneal Deposits and Cataract Revealed by Urine Drug Profiling Test

PubMed Central

Kim, Seong Taeck; Kim, Joon Mo; Kim, Won Young; Choi, Gwang Ju

2010-01-01

Two schizophrenic patients who had been taking medication for a long period presented with visual disturbance of 6-month duration. Slit-lamp examination revealed fine, discrete, and brownish deposits on the posterior cornea. In addition, bilateral star-shaped anterior subcapsular lens opacities, which were dense, dust-like granular deposits, were noted. Although we strongly suspected that the patient might have taken one of the drugs of the phenothiazine family, we were unable to obtain a history of medications other than haloperidol and risperidone, which were taken for 3 yr. We performed a drug profiling test using urine samples and detected methotrimeprazine. The patient underwent surgery for anterior subcapsular lens opacities. Visual acuity improved in both eyes, but the corneal deposits remained. We report an unusual case of methotrimeprazine-induced corneal deposits and cataract in a patient with psychosis, identified by using the urine drug profiling test. PMID:21060765

Acute corneal hydrops mimicking full thickness perforation.

PubMed

Ch'ng, S W; Pillai, M B; Aazeem, S; Tu, K L

2012-05-11

A 26-year-old Caucasian female with keratoconus presented with an acutely painful and red left eye. Visual acuity on presentation was 3/60. Slit lamp examination revealed localised Descemet's membrane break with iris partially plugging it. There was a bulging stromal cyst which would intermittently flatten and reform. The appearance when the cyst was flattened mimicked a full thickness corneal perforation. However, no obvious overlying epithelial defect was detected and an intermittent leakage through micro-perforations in the corneal epithelium was the probable cause of the variable appearance. The anterior chamber reformed and iris plug freed following an insertion of a bandage contact lens and taped eyelid. On follow-up, the Descement's membrane had healed with visual acuity improving to 6/18. Our case illustrates the importance of identifying corneal hydrops mimicking a full thickness perforation as conservative management has a greater chance of recovery.

Transient anterior subcapsular vacuolar change of the crystalline lens in patients after posterior chamber phakic intraocular lens implantation.

PubMed

Chung, Jin Kwon; Shin, Jin Hee; Lee, Sung Jin

2013-10-25

We present two cases of transient vacuolar changes in the anterior subcapsular space of the crystalline lens in patients after posterior chamber phakic intraocular lens implantation. Implantable collamer lenses (ICL) were implanted in healthy myopic patients. Vacuolar changes developed just after the irrigating procedure through the narrow space between the ICL and the crystalline lens. Slit-lamp examinations and spectral domain optical coherence tomography showed bleb-like lesions in the anterior subcapsular space of one eye in each case, though the lesions gradually improved without visual deterioration. Consequently, the lesions turned into a few anterior subcapsular small faint opacities. Direct irrigation of the narrow space confined by the ICL and the crystalline lens is at risk for the development of vacuolar changes in the crystalline lens. The observed spontaneous reversal indicates that surgeons should not rush to surgical intervention but rather opt for close follow over several weeks.

Sequels, complications and management of a chemical burn associated with cement splash.

PubMed

Lim, Gerald C S; Yeh, Lung-Kun; Lin, Hsin-Chiung; Hwang, Chao-Ming

2006-01-01

We present a case of successful superficial keratectomy and amniotic membrane grafting to re-establish ocular surface from denuded stroma and significant limbal ischemia caused by a cement splash. We fully documented a case report about the sequels, complications and management strategies of a chemical burn to the eyes associated with a cement splash. Slit lamp examination, visual acuity test as well as all common cultures and stains were performed to measure the outcome. Visual acuity significantly improved from 0.2 to best-corrected visual acuity 0.7 at the 5-month postoperative visit. The cornea regained its clarity. Total re-epithelialization of the injured area was observed. It is of primary importance to remove all the debris from a cement splash at the first available opportunity. Superficial keratectomy and amniotic membrane grafting may be the best methods for the re-epithelialization and reconstruction of the ocular surface.

Biometry and clinical characteristics of congenital cataracts and microphthalmia in the Miniature Schnauzer.

PubMed

Gelatt, K N; Samuelson, D A; Barrie, K P; Das, N D; Wolf, E D; Bauer, J E; Andresen, T L

1983-07-01

Forty-two Miniature Schnauzer pups and adults with congenital cataracts and microphthalmia were evaluated by serial ophthalmic examinations, slit lamp biomicroscopic photography, and A-scan ultrasonography. The cataracts were evident when the eyelids opened at 2 weeks, affecting predominantly the lens nucleus and posterior cortex. Lenticonus was evident in 19% of the cataractous lenses. Progression of the cataracts was variable and related to involvement of the equatorial and posterior cortices. Lens-induced uveitis developed in some adult dogs with advanced hypermature cataracts. The globe and lens were smaller than normal in the cataractous eyes, as ascertained by A-scan ultrasonography. Age-matched comparisons of clear lens carrier Miniature Schnauzers and normal Beagles with the cataractous Miniature Schnauzers indicated affected globes and cataractous lenses were reduced 10% to 20% in their anteroposterior lengths. The microphthalmia appeared related to the congenital microphakic cataract.

[Comparison of anterior chamber angle examination by UBM, SL-OCT and gonioscopy].

PubMed

Liu, Rui-jue; Wang, Men; Xia, Wen-tao; Yu, Xiao-ying; Chen, Jie-min; Zhou, Shu; Peng, Shu-ya; Liu, Dong-mei

2014-08-01

To compare the agreement of anterior chamber angle examination by ultrasound biomicroscope (UBM), slit lamp optical coherence tomography (SL-OCT), and gonioscopy in angle recession and angle closure. The anterior chamber angle was measured with UBM, SL-OCT and gonioscopy in turns for temporal, nasal, superior and inferior quadrant in the same dark room. The results were compared with the agreement of the three methods in angle recession and angle closure by χ2 test and Kappa test. There were no statistically significant differences of the three methods in testing angle closure and angle recession (P>0.05). The consistency of UBM and gonioscopy was better (Kappa value of 0.882) than that of SL-OCT and gonioscopy (Kappa value of 0.624). When testing angle recession, UBM is better than SL-OCT with gonioscopy as the standard. When testing angle closure, UBM, SL-OCT and gonioscopy have good agreement.

Early Clinical Features of Pseudoexfoliation Syndrome in Anterior Segment and Gonioscopy Examination.

PubMed

Gür Güngör, Sirel; Bayer, Atilla; Akman, Ahmet; Asena, Leyla

2017-01-01

To determine the early signs of pseudoexfoliation (PEX) in fellow eyes of cases with unilateral PEX. Fellow eyes of 34 cases with unilateral PEX were evaluated by slit-lamp and gonioscopy. Findings associated with PEX were recorded. Mean age was 67.8±8.1 years (range 55-86 years). Twenty-five patients (73.5%) had pigmentation in the inferior angle and 23 patients (67.6%) had Sampaolesi's line located on the inferior angle in fellow eyes. The other most common findings were loss of peripupillary ruff in 10 patients (29.4%) and pigment dispersion following pupil dilation in 14 patients (41.1%). Pigmentation in the inferior angle and Sampaolesi's line on the inferior angle seem to be the most common early findings associated with PEX. Special attention should be paid to these findings in cases with ocular hypertension for proper management.

Bilateral rhegmatogenous retinal detachment due to unusual retinal degeneration in Down syndrome: A case report.

PubMed

Yonemoto, Yumiko; Morishita, Seita; Fukumoto, Masanori; Mimura, Masashi; Sato, Takaki; Kida, Teruyo; Kojima, Shota; Oku, Hidehiro; Sugasawa, Jun; Ikeda, Tsunehiko

2018-06-01

The aim of this study was to report a case of Down syndrome (DS) complicated with bilateral retinal detachment (RD) due to unusual retinal degeneration. A 9-year-old girl complained of bilateral visual disturbance during a follow-up examination for myopia and strabismus. Slit-lamp examination revealed moderate posterior subcapsular cataract in both eyes. B-mode echography showed bilateral bullous RD; however, it was difficult to detect the causal retinal breaks due to poor mydriasis. For treatment, the patient underwent bilateral lensectomy, vitrectomy, and silicone oil tamponade. Intraoperative findings revealed symmetrical retinal breaks and unusual caterpillar-like retinal degeneration on the upper temporal side of both eyes. Three months later, the patient underwent bilateral silicone oil removal and intraocular lens implantation. In this case, the retinal degeneration was morphologically different from retinal lattice degeneration, thus suggesting that it might be involved in the onset of DS-related bilateral RD.

Herpetic keratouveitis mixed with bilateral Pseudomonas corneal ulcers in vitamin A deficiency.

PubMed

Hsu, Hung-Yuan; Tsai, I-Lun; Kuo, Li-Lin; Tsai, Ching-Yao; Liou, Shiow-Wen; Woung, Lin-Chung

2015-02-01

A 56-year-old woman complained of blurred vision and pain in her right eye for several days. Slit lamp examination revealed a large epithelial defect and disciform stromal edema with ring infiltration in her right cornea. Unfortunately, hypopyon and purulent discharge subsequently developed in both eyes. Herpetic keratouveitis and a superimposed pseudomonas infection were diagnosed. A systemic review on the patient showed malnutrition due to her dietary preference and vegetarianism. After the infection was controlled, bilateral epithelial defects persisted for a long time. We performed amniotic membrane transplantation on both eyes and the clinical status improved with administration of vitamin and protein supplements. Although rare in Taiwan, vitamin A deficiency should be kept in mind when conjunctival and corneal xerosis occurred. Vitamin A supplements are suggested because of the increased susceptibility to infection in patients with this clinical status. Copyright © 2012. Published by Elsevier B.V.

A 1.5 cm-long unknown subconjunctival grass inflorescence misdiagnosed as relapsing conjunctivitis for one year.

PubMed

Sen, Emine; Elgin, Ufuk; Koç, Fatih; Oztürk, Faruk

2011-01-01

Foreign bodies are usually detected at the first visit. However, they may be overlooked sometimes, especially in children, and may cause some clinical conditions including unilateral relapsing conjunctivitis. A five-year-old girl was presented to the emergency clinic of our hospital with epiphora, purulent discharge, eyelid swelling, and a foreign body feeling in her right eye. The symptoms had been present for one year, and the patient was treated for relapsing conjunctivitis. In slit lamp examination performed with difficulty because of the patient's lack of cooperation, a localized edema and erythema were observed under the right eyelid. An exploration under general anesthesia was planned, and a 1.5 cm-long subconjunctival grass inflorescence was removed. An unknown subconjunctival foreign body should be considered in each patient with relapsing conjunctivitis, especially in children, even in the absence of ocular trauma.

Origins of the elastic behavior of nanoparticle chain aggregates: Measurements using nanostructure manipulation device

NASA Astrophysics Data System (ADS)

Suh, Yong J.; Friedlander, Sheldon K.

2003-03-01

Nanoscale studies were conducted on the dynamic behavior of individual nanoparticle chain aggregates (NCAs) and their networks. For this purpose, device was fabricated to apply tension to NCA under controlled conditions. The device is composed of a specimen support and a cartridge. The specimen support is a deformable alloy disk with a narrow slit across which the NCAs are deposited; the cartridge is used to connect the specimen support to a specimen elongation support holder. The aggregates were stretched using the specimen holder to widen or narrow the slit gap at speeds from 0.5 to 300 nm/s and the motion was observed with a transmission electron microscope. Most of the studies were made with carbon NCA (primary particle size between 11 and 16 nm) generated by laser ablation of a graphite target. The aggregates were deposited on the specimen support (disk) to form bridges across the slit. When tension was applied, the NCA chains remained attached at the slit edges; the chains stretched as kinks on the scale of a few particle diameters were straightened by rotation and/or grain boundary sliding at particle-particle interfaces. After the chain became taut, increasing tension produced little additional extension. Eventually, the chain broke, the tension relaxed, and the elastically strained portions along the NCA recovered. This led to fast contraction of the two broken ends. In one of the cases studied in detail, a small primary particle in the chain doubled in length before the chain broke at this site. This probably occurred because of the high tensile stress in the small particle. In separate experiments, a network of carbon NCA was produced by increased deposition around the slit of a specimen support. Chains in the network broke successively as the network stretched. Some of the chains broke midway and not at the junctures with each other. They contracted fast showing behavior similar to that of the individual aggregates. Possible applications to the behavior of nanocomposite materials composed of blends of NCAs and molecular polymers (e.g., rubber) are described.

VizieR Online Data Catalog: Spectroscopy of EG And over roughly 14 years (Kenyon+, 2016)

NASA Astrophysics Data System (ADS)

Kenyon, S. J.; Garcia, M. R.

2016-08-01

From 1994 September to 2016 January, P. Berlind, M. Calkins, and other observers acquired 480 low-resolution optical spectra of EG And with FAST, a high throughput, slit spectrograph mounted at the Fred L. Whipple Observatory 1.5m telescope on Mount Hopkins, Arizona They used a 300g/mm grating blazed at 4750Å, a 3'' slit, and a thinned 512*2688 CCD. These spectra cover 3800-7500Å at a resolution of 6Å. The full wavelength solution is derived from calibration lamps acquired immediately after each exposure. The wavelength solution for each frame has a probable error of <~+/-0.5Å. Most of the resulting spectra have moderate signal-to-noise ratio, S/N >~15-30 per pixel. Prior to the start of the FAST observations, we obtained occasional optical spectrophotometric observations of EG And throughout 1982-1989 with the cooled dual-beam intensified Reticon scanner (IRS) mounted on the white spectrograph at the KPNO No. 1 and No. 2 90cm telescopes. Various remote observers acquired high-resolution spectroscopic observations of EG And with the echelle spectrographs and Reticon detectors on the 1.5m telescopes of the Fred L. Whipple Observatory on Mount Hopkins, Arizona and the Oak Ridge Observatory in Harvard, Massachusetts. These spectra cover a 44Å bandpass centered near 5190Å or 5200Å and have a resolution of roughly 12km/s. (1 data file).

Electronic health record systems in ophthalmology: impact on clinical documentation.

PubMed

Sanders, David S; Lattin, Daniel J; Read-Brown, Sarah; Tu, Daniel C; Wilson, David J; Hwang, Thomas S; Morrison, John C; Yackel, Thomas R; Chiang, Michael F

2013-09-01

To evaluate quantitative and qualitative differences in documentation of the ophthalmic examination between paper and electronic health record (EHR) systems. Comparative case series. One hundred fifty consecutive pairs of matched paper and EHR notes, documented by 3 attending ophthalmologist providers. An academic ophthalmology department implemented an EHR system in 2006. Database queries were performed to identify cases in which the same problems were documented by the same provider on different dates, using paper versus EHR methods. This was done for 50 consecutive pairs of examinations in 3 different diseases: age-related macular degeneration (AMD), glaucoma, and pigmented choroidal lesions (PCLs). Quantitative measures were used to compare completeness of documenting the complete ophthalmologic examination, as well as disease-specific critical findings using paper versus an EHR system. Qualitative differences in paper versus EHR documentation were illustrated by selecting representative paired examples. (1) Documentation score, defined as the number of examination elements recorded for the slit-lamp examination, fundus examination, and complete ophthalmologic examination and for critical clinical findings for each disease. (2) Paired comparison of qualitative differences in paper versus EHR documentation. For all 3 diseases (AMD, glaucoma, PCL), the number of complete examination findings recorded was significantly lower with paper than the EHR system (P ≤ 0.004). Among the 3 individual examination sections (general, slit lamp, fundus) for the 3 diseases, 5 of the 9 possible combinations had significantly lower mean documentation scores with paper than EHR notes. For 2 of the 3 diseases, the number of critical clinical findings recorded was significantly lower using paper versus EHR notes (P ≤ 0.022). All (150/150) paper notes relied on graphical representations using annotated hand-drawn sketches, whereas no (0/150) EHR notes contained drawings. Instead, the EHR systems documented clinical findings using textual descriptions and interpretations. There were quantitative and qualitative differences in the nature of paper versus EHR documentation of ophthalmic findings in this study. The EHR notes included more complete documentation of examination elements using structured textual descriptions and interpretations, whereas paper notes used graphical representations of findings. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Edge contact angle and modified Kelvin equation for condensation in open pores.

PubMed

Malijevský, Alexandr; Parry, Andrew O; Pospíšil, Martin

2017-08-01

We consider capillary condensation transitions occurring in open slits of width L and finite height H immersed in a reservoir of vapor. In this case the pressure at which condensation occurs is closer to saturation compared to that occurring in an infinite slit (H=∞) due to the presence of two menisci that are pinned near the open ends. Using macroscopic arguments, we derive a modified Kelvin equation for the pressure p_{cc}(L;H) at which condensation occurs and show that the two menisci are characterized by an edge contact angle θ_{e} that is always larger than the equilibrium contact angle θ, only equal to it in the limit of macroscopic H. For walls that are completely wet (θ=0) the edge contact angle depends only on the aspect ratio of the capillary and is well described by θ_{e}≈sqrt[πL/2H] for large H. Similar results apply for condensation in cylindrical pores of finite length. We test these predictions against numerical results obtained using a microscopic density-functional model where the presence of an edge contact angle characterizing the shape of the menisci is clearly visible from the density profiles. Below the wetting temperature T_{w} we find very good agreement for slit pores of widths of just a few tens of molecular diameters, while above T_{w} the modified Kelvin equation only becomes accurate for much larger systems.

Early Development of Cloned Bovine Embryos Produced from Oocytes Enucleated by Fluorescence Metaphase II Imaging Using a Conventional Halogen-Lamp Microscope

PubMed Central

Iwamoto, Daisaku; Yamagata, Kazuo; Kishi, Masao; Hayashi-Takanaka, Yoko; Kimura, Hiroshi; Wakayama, Teruhiko

2015-01-01

Abstract Enucleation of a recipient oocyte is one of the key processes in the procedure of somatic cell nuclear transfer (SCNT). However, especially in bovine species, lipid droplets spreading in the ooplasm hamper identification and enucleation of metaphase II (MII) chromosomes, and thereby the success rate of the cloning remains low. In this study we used a new experimental system that enables fluorescent observation of chromosomes in living oocytes without any damage. We succeeded in visualizing and removing the MII chromosome in matured bovine oocytes. This experimental system consists of injecting fluorescence-labeled antibody conjugates that bind to chromosomes and fluorescent observation using a conventional halogen-lamp microscope. The cleavage rates and blastocyst rates of bovine embryos following in vitro fertilization (IVF) decreased as the concentration of the antibody increased (p<0.05). The enucleation rate of the conventional method (blind enucleation) was 86%, whereas all oocytes injected with the antibody conjugates were enucleated successfully. Fusion rates and developmental rates of SCNT embryos produced with the enucleated oocytes were the same as those of the blind enucleation group (p>0.05). For the production of SCNT embryos, the new system can be used as a reliable predictor of the location of metaphase plates in opaque oocytes, such as those in ruminant animals. PMID:25826723

Epi-Fluorescence Microscopy

PubMed Central

Webb, Donna J.; Brown, Claire M.

2012-01-01

Epi-fluorescence microscopy is available in most life sciences research laboratories, and when optimized can be a central laboratory tool. In this chapter, the epi-fluorescence light path is introduced and the various components are discussed in detail. Recommendations are made for incident lamp light sources, excitation and emission filters, dichroic mirrors, objective lenses, and charge-coupled device (CCD) cameras in order to obtain the most sensitive epi-fluorescence microscope. The even illumination of metal-halide lamps combined with new “hard” coated filters and mirrors, a high resolution monochrome CCD camera, and a high NA objective lens are all recommended for high resolution and high sensitivity fluorescence imaging. Recommendations are also made for multicolor imaging with the use of monochrome cameras, motorized filter turrets, individual filter cubes, and corresponding dyes that are the best choice for sensitive, high resolution multicolor imaging. Images should be collected using Nyquist sampling and should be corrected for background intensity contributions and nonuniform illumination across the field of view. Photostable fluorescent probes and proteins that absorb a lot of light (i.e., high extinction co-efficients) and generate a lot of fluorescence signal (i.e., high quantum yields) are optimal. A neuronal immune-fluorescence labeling protocol is also presented. Finally, in order to maximize the utility of sensitive wide-field microscopes and generate the highest resolution images with high signal-to-noise, advice for combining wide-field epi-fluorescence imaging with restorative image deconvolution is presented. PMID:23026996

Current Calibration Efforts and Performance of the HST Space Telescope Imaging Spectrograph: Echelle Flux Calibration, the BAR5 Occulter, and Lamp Lifetimes

NASA Astrophysics Data System (ADS)

Monroe, TalaWanda R.; Aloisi, Alessandra; Debes, John H.; Jedrzejewski, Robert I.; Lockwood, Sean A.; Peeples, Molly S.; Proffitt, Charles R.; Riley, Allyssa; Walborn, Nolan R.

2016-06-01

The variety of operating modes of the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST) continues to allow STIS users to obtain unique, high quality observations and cutting-edge results 19 years after its installation on HST. STIS is currently the only instrument available to the astronomy community that allows high spectral and spatial resolution spectroscopy in the FUV and NUV, including echelle modes. STIS also supports solar-blind imaging in the FUV. In the optical, STIS provides long-slit, first-order spectra that take advantage of HST's superb spatial resolution, as well as several unique unfiltered coronagraphic modes, which continue to benefit the exoplanet and debris-disk communities. The STIS instrument team monitors the instrument’s health and performance over time to characterize the effects of radiation damage and continued use of the detectors and optical elements. Additionally, the STIS team continues to improve the quality of data products for the user community. We present updates on efforts to improve the echelle flux calibration of overlapping spectral orders due to changes in the grating blaze function since HST Servicing Mission 4, and efforts to push the contrast limit and smallest inner working angle attainable with the coronagraphic BAR5 occulter. We also provide updates on the performance of the STIS calibration lamps, including work to maintain the accuracy of the wavelength calibration for all modes.

Topical administration of Esculetin as a potential therapy for experimental dry eye syndrome.

PubMed

Jiang, D; Liu, X; Hu, J

2017-12-01

PurposeIn this study, we investigated the therapeutic effects of topical Esculetin for dry eye rabbits through the ocular tests, inflammatory factor levels and specific phosphorylated protein expressions of ERK1/2 singnal pathway.Patients and methodsThirty-two healthy adult male New Zealand white rabbits were chosen for the study. DES models were established after removing of the main lacrimal gland, Harderian gland and nictitating membrane in the left eyes and randomly divided into group DES control, group CsA, group Esculetin and group Esculetin combined with CsA (C&E), meanwhile the right eyes served as group Normal control. Schirmer's I tests, fluorescein scores, goblet cell densities, inflammatory cytokines IL-1α,IL-1β,TNF-αlevels were observed by slit-lamp microscope, conjunctival impression cytology and ELISA essay at week 0, 1, 2, 4, 8. Phosphorylated-ERK1/2 expressions were detected in Western blot analysis at week 8.ResultsAfter induction of DES, aqueous tear production and goblet cell density were decreased, FL score was much higher in group DES control throughout the study (P<0.05). Both topical Esculetin and Esculetin combing CsA increased the SIT values (10±1 mm, 14±3 mm, P<0.05) and goblet cell densities (77±12/HP, 92±12/HP, P<0.05), decreased FL scores (7.48±0.33, 5.09±0.24, P<0.05) at week 8. Alternations of IL-1α,IL-1β,TNF-αlevels had similar trend. In Western blot analysis, downregulations of p-ERK1/2 were observed in therapy groups when compared with group DES control and the most decreasing was found in group C&E (P<0.05).ConclusionTopical Esculetin improved DES symptoms, downregulated the inflammatory cytokine expressions, suppressed the ERK1/2 pathway and enhanced the therapeutic effect of CsA.

Effects of calcium dobesilate on Nrf2, Keap1 and HO-1 in the lenses of D-galactose-induced cataracts in rats

PubMed Central

Sun, Jinfeng; Wang, Bin; Hao, Youjuan; Yang, Xueli

2018-01-01

This study investigated the effects of calcium dobesilate on Nrf2, Keap1 and HO-1 in the lenses of D-galactose-induced cataracts in rats. Thirty Sprague-Dawley rats were randomly divided into three groups: a blank control group, a model control group and a model administration group. A normal diet was given to the rats in the blank control group and the rats with D-galactose-induced cataracts of the model control group. Calcium dobesilate was also given to the rats with D-galactose-induced cataracts of the model administration group. A slit lamp microscope was used to check the degree of lens opacity. RT-PCR and western blot analysis were used to detect the mRNA and protein expression of Nrf2, Keap1 and HO-1 in the lenses of the three groups. There was a significant difference in the degree of lens opacity among the three groups (P<0.05). The model control group was the most turbid of the three groups, followed by the model administration group. Moreover, the mRNA and protein expression of Nrf2, Keap1 and HO-1 in the lenses of the three groups were also significantly different (P<0.05). The mRNA levels of Nrf2 and HO-1 were the highest in the model control group, followed by the model administration group, and were the lowest in the blank control group. However, the mRNA expression level of Keap1 among the three groups had an opposite trend. In conclusion, calcium dobesilate can effectively increase the levels of Nrf2 and HO-1 in the lenses of diabetic cataract rats and inhibit the level of Keap1. Therefore, the therapeutic effect of calcium dobesilate against cataracts is related to the improvement of the Nrf2-Keap1 signaling pathway. PMID:29399076

Effect of H-7 on secondary cataract after phacoemulsification in the live rabbit eye.

PubMed

Tian, Baohe; Heatley, Gregg A; Filla, Mark S; Kaufman, Paul L

2010-12-01

This study is aimed to determine if the serine-threonine kinase inhibitor H-7 inhibits secondary cataract after phacoemulsification in the live rabbit eye. Eighteen rabbits underwent extracapsular lens extraction by phacoemulsification in 1 eye. The eye was treated with intravitreal H-7 (300 or 1,200 μM; n = 6 or 5) or balanced salt solution (BSS) (n = 7) immediately after the surgery and twice weekly for 10 weeks. Each eye received slit lamp biomicroscopy once a week, during which posterior capsule opacification (PCO) was evaluated. The eye was then enucleated and the lens capsule was prepared, fixed, and imaged. PCO was evaluated again on the isolated lens capsule under a phase microscope. Soemmering's ring area (SRA) and the entire lens capsule area were measured from capsule images on a computer and the percentage of SRA (PSRA) in the entire capsule area was calculated. Wet weight of the capsule (WW) was determined on a balance. No significant difference in PCO was observed in any comparison. No significant differences in SRA, PSRA, and WW were observed between the 300 μM H-7-treated eye and the BSS-treated eye. However, SRA, PSRA, and WW in the 1,200 μM H-7-treated eye were significantly smaller than those in the BSS-treated eye [28.3 ± 16.2 vs. 61.4 ± 8.86 mm(2) (P = 0.001), 33% ± 20% vs. 65% ± 15% (P = 0.01), and 65.6 ± 27.9 vs. 127.0 ±37.3 mg (P = 0.01)]. Intravitreal H-7 (1,200 μM) significantly inhibits Soemmering's ring formation in the live rabbit eye, suggesting that agents that inhibit the actomyosin system in cells may prevent secondary cataract after phacoemulsification.

Larval anatomy of the pterobranch Cephalodiscus gracilis supports secondarily derived sessility concordant with molecular phylogenies

NASA Astrophysics Data System (ADS)

Stach, Thomas

2013-12-01

Pterobranchs have been interpreted as "missing links" combining primitive invertebrate features with advanced vertebrate-like characteristics. The first detailed morphological description of an ontogenetic stage of a pterobranch, based on digital 3D-reconstruction at electron microscopic resolution, reveals a triploblastic animal with monociliated epithelia, an extensive coelomic cavity, a through gut with an asymmetrically developed gill slit but no signs of planktonic specializations, such as ciliated bands. Therefore, this crawling larva supports the hypothesis proposed in previous molecular phylogenetic studies that pterobranchs could be derived within enteropneusts rather than being "missing links".

Finite element modeling of arachnid slit sensilla-I. The mechanical significance of different slit arrays.

PubMed

Hössl, Bernhard; Böhm, Helmut J; Rammerstorfer, Franz G; Barth, Friedrich G

2007-04-01

Arachnid strain sensitive slit sensilla are elongated openings in the cuticle with aspect ratios (slit length l/slit width b) of up to 100. Planar Finite Element (FE) models are used to calculate the relative slit face displacements, Dc, at the centers of single slits and of arrangements of mechanically interacting slits under uni-axial compressive far-field loads. Our main objective is to quantitatively study the role of the following geometrical parameters in stimulus transformation: aspect ratio, slit shape, geometry of the slits' centerlines, load direction, lateral distance S, longitudinal shift lambda, and difference in slit length Deltal between neighboring slits. Slit face displacements are primarily sensitive to slit length and load direction but little affected by aspect ratios between 20 and 100. In stacks of five parallel slits at lateral distances typical of lyriform organs (S=0.03 l) the longitudinal shift lambda substantially influences slit compression. A change of lambda from 0 to 0.85 l causes changes of up to 420% in Dc. Even minor morphological variations in the arrangements can substantially influence the stimulus transformation. The site of transduction in real slit sensilla does not always coincide with the position of maximum slit compression predicted by simplified models.

Performance results from in-flight commissioning of the Juno Ultraviolet Spectrograph (Juno-UVS)

NASA Astrophysics Data System (ADS)

Greathouse, T. K.; Gladstone, G. R.; Davis, M. W.; Slater, D. C.; Versteeg, M. H.; Persson, K. B.; Walther, B. C.; Winters, G. S.; Persyn, S. C.; Eterno, J. S.

2013-09-01

We present a description of the Juno ultraviolet spectrograph (Juno-UVS) and results from its in-flight commissioning performed between December 5th and 13th 2011 and its first periodic maintenance between October 10th and 12th 2012. Juno-UVS is a modest power (9.0 W) ultraviolet spectrograph based on the Alice instruments now in flight aboard the European Space Agency's Rosetta spacecraft, NASA's New Horizons spacecraft, and the LAMP instrument aboard NASA's Lunar Reconnaissance Orbiter. However, unlike the other Alice spectrographs, Juno-UVS sits aboard a spin stabilized spacecraft. The Juno-UVS scan mirror allows for pointing of the slit approximately +/-30° from the spacecraft spin plane. This ability gives Juno-UVS access to half the sky at any given spacecraft orientation. The planned 2 rpm spin rate for the primary mission results in integration times per 0.2° spatial resolution element per spin of only ~17 ms. Thus, for calibration purposes, data were retrieved from many spins and then remapped and co-added to build up exposure times on bright stars to measure the effective area, spatial resolution, scan mirror pointing positions, etc. The primary job of Juno-UVS will be to characterize Jupiter's UV auroral emissions and relate them to in-situ particle measurements. The ability to point the slit will make operations more flexible, allowing Juno-UVS to observe the atmospheric footprints of magnetic field lines through which Juno flies, giving a direct connection between energetic particle measurements on the spacecraft and the far-ultraviolet emissions produced by Jupiter's atmosphere in response to those particles.

Permeation of macromolecules into the renal glomerular basement membrane and capture by the tubules

PubMed Central

Lawrence, Marlon G.; Altenburg, Michael K.; Sanford, Ryan; Willett, Julian D.; Bleasdale, Benjamin; Ballou, Byron; Wilder, Jennifer; Li, Feng; Miner, Jeffrey H.; Berg, Ulla B.; Smithies, Oliver

2017-01-01

How the kidney prevents urinary excretion of plasma proteins continues to be debated. Here, using unfixed whole-mount mouse kidneys, we show that fluorescent-tagged proteins and neutral dextrans permeate into the glomerular basement membrane (GBM), in general agreement with Ogston's 1958 equation describing how permeation into gels is related to molecular size. Electron-microscopic analyses of kidneys fixed seconds to hours after injecting gold-tagged albumin, negatively charged gold nanoparticles, and stable oligoclusters of gold nanoparticles show that permeation into the lamina densa of the GBM is size-sensitive. Nanoparticles comparable in size with IgG dimers do not permeate into it. IgG monomer-sized particles permeate to some extent. Albumin-sized particles permeate extensively into the lamina densa. Particles traversing the lamina densa tend to accumulate upstream of the podocyte glycocalyx that spans the slit, but none are observed upstream of the slit diaphragm. At low concentrations, ovalbumin-sized nanoparticles reach the primary filtrate, are captured by proximal tubule cells, and are endocytosed. At higher concentrations, tubular capture is saturated, and they reach the urine. In mouse models of Pierson’s or Alport’s proteinuric syndromes resulting from defects in GBM structural proteins (laminin β2 or collagen α3 IV), the GBM is irregularly swollen, the lamina densa is absent, and permeation is increased. Our observations indicate that size-dependent permeation into the lamina densa of the GBM and the podocyte glycocalyx, together with saturable tubular capture, determines which macromolecules reach the urine without the need to invoke direct size selection by the slit diaphragm. PMID:28246329

Molecular dynamics investigations of liquid-vapor interaction and adsorption of formaldehyde, oxocarbons, and water in graphitic slit pores.

PubMed

Huang, Pei-Hsing; Hung, Shang-Chao; Huang, Ming-Yueh

2014-08-07

Formaldehyde exposure has been associated with several human cancers, including leukemia and nasopharyngeal carcinoma, motivating the present investigation on the microscopic adsorption behaviors of formaldehyde in multi-component-mixture-filled micropores. Molecular dynamics (MD) simulation was used to investigate the liquid-vapor interaction and adsorption of formaldehyde, oxocarbons, and water in graphitic slit pores. The effects of the slit width, system temperature, concentration, and the constituent ratio of the mixture on the diffusion and adsorption properties are studied. As a result of interactions between the components, the z-directional self-diffusivity (D(z)) in the mixture substantially decreased by about one order of magnitude as compared with that of pure (single-constituent) adsorbates. When the concentration exceeds a certain threshold, the D(z) values dramatically decrease due to over-saturation inducing barriers to diffusion. The binding energy between the adsorbate and graphite at the first adsorption monolayer is calculated to be 3.99, 2.01, 3.49, and 2.67 kcal mol(-1) for CO2, CO, CH2O, and H2O, respectively. These values agree well with those calculated using the density functional theory coupled cluster method and experimental results. A low solubility of CO2 in water and water preferring to react with CH2O, forming hydrated methanediol clusters, are observed. Because the cohesion in a hydrated methanediol cluster is much higher than the adhesion between clusters and the graphitic surface, the hydrated methanediol clusters were hydrophobic, exhibiting a large contact angle on graphite.

Multipurpose Hyperspectral Imaging System

NASA Technical Reports Server (NTRS)

Mao, Chengye; Smith, David; Lanoue, Mark A.; Poole, Gavin H.; Heitschmidt, Jerry; Martinez, Luis; Windham, William A.; Lawrence, Kurt C.; Park, Bosoon

2005-01-01

A hyperspectral imaging system of high spectral and spatial resolution that incorporates several innovative features has been developed to incorporate a focal plane scanner (U.S. Patent 6,166,373). This feature enables the system to be used for both airborne/spaceborne and laboratory hyperspectral imaging with or without relative movement of the imaging system, and it can be used to scan a target of any size as long as the target can be imaged at the focal plane; for example, automated inspection of food items and identification of single-celled organisms. The spectral resolution of this system is greater than that of prior terrestrial multispectral imaging systems. Moreover, unlike prior high-spectral resolution airborne and spaceborne hyperspectral imaging systems, this system does not rely on relative movement of the target and the imaging system to sweep an imaging line across a scene. This compact system (see figure) consists of a front objective mounted at a translation stage with a motorized actuator, and a line-slit imaging spectrograph mounted within a rotary assembly with a rear adaptor to a charged-coupled-device (CCD) camera. Push-broom scanning is carried out by the motorized actuator which can be controlled either manually by an operator or automatically by a computer to drive the line-slit across an image at a focal plane of the front objective. To reduce the cost, the system has been designed to integrate as many as possible off-the-shelf components including the CCD camera and spectrograph. The system has achieved high spectral and spatial resolutions by using a high-quality CCD camera, spectrograph, and front objective lens. Fixtures for attachment of the system to a microscope (U.S. Patent 6,495,818 B1) make it possible to acquire multispectral images of single cells and other microscopic objects.

Volumetric bioimaging based on light field microscopy with temporal focusing illumination

NASA Astrophysics Data System (ADS)

Hsu, Feng-Chun; Sie, Yong Da; Lai, Feng-Jie; Chen, Shean-Jen

2018-02-01

Light field technique at a single shot can get the whole volume image of observed sample. Therefore, the original frame rate of the optical system can be taken as the volumetric image rate. For dynamically imaging whole micron-scale biosample, a light field microscope with temporal focusing illumination has been developed. In the light field microscope, the f-number of the microlens array (MLA) is adopted to match that of the objective; hence, the subimages via adjacent lenslets do not overlay each other. A three-dimensional (3D) deconvolution algorithm is utilized to deblur the out-of-focusing part. Conventional light field microscopy (LFM) illuminates whole volume sample even noninteresting parts; nevertheless, whole volume excitation causes even more damage on bio-sample and also increase the background noise from the out of range. Therefore, temporal focusing is integrated into the light field microscope for selecting the illumination volume. Herein, a slit on the back focal plane of the objective is utilized to control the axial excitation confinement for selecting the illumination volume. As a result, the developed light field microscope with the temporal focusing multiphoton illumination (TFMPI) can reconstruct 3D images within the selected volume, and the lateral resolution approaches to the theoretical value. Furthermore, the 3D Brownian motion of two-micron fluorescent beads is observed as the criterion of dynamic sample. With superior signal-to-noise ratio and less damage to tissue, the microscope is potential to provide volumetric imaging for vivo sample.

A high-resolution, confocal laser-scanning microscope and flash photolysis system for physiological studies.

PubMed

Parker, I; Callamaras, N; Wier, W G

1997-06-01

We describe the construction of a high-resolution confocal laser-scanning microscope, and illustrate its use for studying elementary Ca2+ signalling events in cells. An avalanche photodiode module and simple optical path provide a high efficiency system for detection of fluorescence signals, allowing use of a small confocal aperture giving near diffraction-limited spatial resolution (< 300 nm lateral and < 400 nm axial). When operated in line-scan mode, the maximum temporal resolution is 1 ms, and the associated computer software allows complete flexibility to record line-scans continuously for long (minutes) periods or to obtain any desired pixel resolution in x-y scans. An independent UV irradiation system permits simultaneous photolysis of caged compounds over either a uniform, wide field (arc lamp source) or at a tightly focussed spot (frequency-tripled Nd:YAG laser). The microscope thus provides a versatile tool for optical studies of dynamic cellular processes, as well as excellent resolution for morphological studies. The confocal scanner can be added to virtually any inverted microscope for a component cost that is only a small fraction of that of comparable commercial instruments, yet offers better performance and greater versatility.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosch, R.; Boutin, J. Y.; Le Breton, J. P.

This article describes x-ray imaging with grazing-incidence microscopes, developed for the experimental program carried out on the Ligne d'Integration Laser (LIL) facility [J. P. Le Breton et al., Inertial Fusion Sciences and Applications 2001 (Elsevier, Paris, 2002), pp. 856-862] (24 kJ, UV--0.35 nm). The design includes a large target-to-microscope (400-700 mm) distance required by the x-ray ablation issues anticipated on the Laser MegaJoule facility [P. A. Holstein et al., Laser Part. Beams 17, 403 (1999)] (1.8 MJ) which is under construction. Two eight-image Kirkpatrick-Baez microscopes [P. Kirkpatrick and A. V. Baez J. Opt. Soc. Am. 38, 766 (1948)] with differentmore » spectral wavelength ranges and with a 400 mm source-to-mirror distance image the target on a custom-built framing camera (time resolution of {approx}80 ps). The soft x-ray version microscope is sensitive below 1 keV and its spatial resolution is better than 30 {mu}m over a 2-mm-diam region. The hard x-ray version microscope has a 10 {mu}m resolution over an 800-{mu}m-diam region and is sensitive in the 1-5 keV energy range. Two other x-ray microscopes based on an association of toroidal/spherical surfaces (T/S microscopes) produce an image on a streak camera with a spatial resolution better than 30 {mu}m over a 3 mm field of view in the direction of the camera slit. Both microscopes have been designed to have, respectively, a maximum sensitivity in the 0.1-1 and 1-5 keV energy range. We present the original design of these four microscopes and their test on a dc x-ray tube in the laboratory. The diagnostics were successfully used on LIL first experiments early in 2005. Results of soft x-ray imaging of a radiative jet during conical shaped laser interaction are shown.« less

Retinal complications of gout: a case report and review of the literature.

PubMed

Jiang, Ying; Brenner, Jason E; Foster, William J

2018-01-19

There have been few reported findings of posterior segment complications of gout. While exudative lesions, an increased risk of macular degeneration, and vascular occlusions have been previously reported, to our knowledge, refractile macular lesions have not been reported in a patient with chronic uncontrolled gout. Highly refractile, crystal-like lesions were found in the macula of a 62 year old male patient with chronically uncontrolled gout. The lesions appeared at the termination of retinal arterioles and were located at the level of the retinal pigment epithelium. The lesions did not stain with fluorescein and were associated with larger areas geographic atrophy. Review of the patient's blood tests revealed well-controlled vasculopathic risk factors. Fundus appearance and best-corrected visual acuity remained stable over 12 months of follow-up during which the uric acid levels were well controlled. Retinopathy may be associated with chronically uncontrolled gout and patients with visual complaints should undergo a dilated examination in addition to the typical anterior segment slit-lamp exam.

Genetic heterogeneity in familial exudative vitreoretinopathy; exclusion of the EVR1 locus on chromosome 11q in a large autosomal dominant pedigree.

PubMed

Bamashmus, M A; Downey, L M; Inglehearn, C F; Gupta, S R; Mansfield, D C

2000-04-01

Familial exudative vitreoretinopathy (FEVR) is associated with mutations in the Norrie disease gene in X linked pedigrees and with linkage to the EVR1 locus at 11q13 in autosomal dominant cases. A large autosomal dominant FEVR family was studied, both clinically and by linkage analysis, to determine whether it differed from the known forms of FEVR. Affected members and obligate gene carriers from this family were examined by slit lamp biomicroscopy, indirect ophthalmoscopy, and in some cases fluorescein angiography. Patient DNAs were genotyped for markers at the EVR1 locus on chromosome 11q13. The clinical evaluation in this family is consistent with previous descriptions of FEVR pedigrees, but linkage analysis proves that it has a form of FEVR genetically distinct from the EVR1 locus on 11q. This proves that there are at least three different loci associated with comparable FEVR phenotypes, a situation similar to that existing for many forms of retinal degeneration.

In vivo confocal microscopy of human cornea covered with human amniotic membrane.

PubMed

Mimura, Tatsuya; Yamagami, Satoru; Usui, Tomohiko; Honda, Norihiko; Araki, Fumiyuki; Amano, Shiro

2008-01-01

Amniotic membrane transplantation has been widely performed to reconstruct the surface of the eye and treat chemical burns or epithelial defects. However, we have difficulty observing the cornea through the opaque transplanted amniotic membrane by slit-lamp biomicroscopy. We investigated the use of confocal microscopy for observation of human corneas covered with amniotic membrane. Human amniotic membrane was placed onto the normal corneas of five volunteers aged 22-24 years. Then, all layers of the covered corneas were observed by in vivo confocal microscopy. Confocal microscopy displayed the epithelium, basement membrane, and stroma of the amniotic membrane. It also displayed the corneal epithelium. Furthermore, corneal stromal keratocytes and the corneal endothelium were clearly observed through the amniotic membrane by confocal microscopy. We demonstrated that in vivo confocal microscopy enabled us to observe all layers of corneas covered with amniotic membrane in normal human eyes. Our findings suggest that confocal microscopy may have advantages for clinical examination of the ocular surface, including all layers of the cornea.

The mouse cornea micropocket angiogenesis assay.

PubMed

Rogers, Michael S; Birsner, Amy E; D'Amato, Robert J

2007-01-01

The mouse corneal micropocket angiogenesis assay uses the avascular cornea as a canvas to study angiogenesis in vivo. Through the use of standardized slow-release pellets, a predictable angiogenic response is generated over the course of 5 d and then quantified. Uniform slow-release pellets are prepared by mixing purified angiogenic growth factors such as basic fibroblast growth factor or vascular endothelial growth factor with sucralfate (a stabilizer) and Hydron (poly-HEMA (poly(2-hydroxyethyl methacrylate)) to allow slow release). This mixture is applied to a mesh that controls unit size and then allowed to harden. A micropocket is surgically created in the mouse cornea and a pellet implanted. Five days later, the area of the cornea overgrown by the angiogenic response is measured using a slit lamp. A skilled investigator can implant and grade 40 eyes in about 2.5 h. The results of the assay are used to assess the ability of potential therapeutic molecules or genetic differences to modulate angiogenesis in vivo.

Clinical characteristics and current treatment of glaucoma.

PubMed

Cohen, Laura P; Pasquale, Louis R

2014-06-02

Glaucoma is a neurodegenerative disorder in which degenerating retinal ganglion cells (RGC) produce significant visual disability. Clinically, glaucoma refers to an array of conditions associated with variably elevated intraocular pressure (IOP) that contributes to RGC loss via mechanical stress, vascular abnormalities, and other mechanisms, such as immune phenomena. The clinical diagnosis of glaucoma requires assessment of the ocular anterior segment with slit lamp biomicroscopy, which allows the clinician to recognize signs of conditions that can produce elevated IOP. After measurement of IOP, a specialized prismatic lens called a gonioscope is used to determine whether the angle is physically open or closed. The structural manifestation of RGC loss is optic nerve head atrophy and excavation of the neuroretinal rim tissue. Treatment is guided by addressing secondary causes for elevated IOP (such as inflammation, infection, and ischemia) whenever possible. Subsequently, a variety of medical, laser, and surgical options are used to achieve a target IOP. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

Role of the vitreous in age-related macular degeneration.

PubMed

Ondeş, F; Yilmaz, G; Acar, M A; Unlü, N; Kocaoğlan, H; Arsan, A K

2000-01-01

To investigate the relationship between posterior vitreous detachment (PVD) and age-related macular degeneration (AMD). The condition of the vitreous was examined by slit-lamp funduscopy and ultrasonography in 93 eyes of 50 patients with AMD (exudative or dry) and 100 eyes of 50 controls. There was complete PVD in 31 of the 93 eyes (33.3%) of 50 patients with AMD and the posterior vitreous was attached in 62 of these eyes (66.6%). In the control group, in 50 eyes (50%) of 50 subjects there was posterior vitreous detachment. The prevalence of PVD in eyes with macular degeneration was significantly lower (P < .05). There was no statistically significant difference between the exudative and the nonexudative groups in respect to PVD. PVD may have a protective role against the development of AMD. Chronic vitreomacular traction and/or continuous exposure to free radicals and cytokines may possibly be one of the causes of AMD in eyes with attached vitreous.

[Transplantation of autologous labial salivary glands for severe dry eye].

PubMed

Luo, Shun-rong; Zou, Liu-he; Yan, Chao; Pan, Zhi-qiang; Liu, Jing-ming; Chen, Zhi-yuan; Yin, Wei-hong

2013-01-01

Autologous labial salivary gland transplantation has been a promising alternative for the treatment of severe dry eye. In this article, we describe the results of the ocular surface changes after labial salivary gland transplantation and investigate the feasibility of this treatment. The results of this technique in 8 patients (eyes) who suffered from severe dry eye were prospectively analyzed after surgery (follow-up of 6 months). The best-corrected visual acuity, Schirmer I test, degree of discomfort, usage of pharmaceutical tear substitutes, tear interferometry and slit lamp examination were investigated at different time before and after surgery. All grafts remained viable and the survival rate is 100%. All patients showed significant increase in the Schirmer's test and they expressed great improvement in their ocular discomfort. The use of artificial tear substitutes was reduced because of the increased ocular surface lubrication. Although the authors' long-term experience still is limited, we believe that the procedure is a promising alternative approach for severe dry eye.

Use of Scheimpflug imaging in the management of intra-lenticular foreign body.

PubMed

Singh, R; Ram, J; Gupta, R

2015-01-01

Asymptomatic traumatic intra-lenticular foreign body is very uncommon and few case reports have been published. To report a case of post-traumatic intra-lenticular foreign body and use of Scheimpflug imaging in its management. A 41-year-old male with history of injury to right eye during hammering a chisel 1 year back presented with decreased vision since 6 months. An intra-lenticular foreign body was found on slit lamp bio-microscopy and was confrmed by Scheimpflug imaging. Posterior capsule was intact on Scheimpflug imaging. Thus, Scheimpflug imaging helps in exact localization of the foreign body in the intralenticular space or behind the iris. We ruled out other foreign bodies by x-ray and ultrasonography of the orbit. The foreign body with post-traumatic cataract was removed using phacoemulsification and three piece foldable intraocular lens was implanted in the bag. An intra- lenticular foreign body may remain asymptomatic for months. Scheimpflug imaging can be useful in its localization. It can be removed during phacoemulsification. © NEPjOPH.

A Fiber Optic Probe for the Detection of Cataracts

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Dhadwal, Harbans S.

1993-01-01

A compact fiber optic probe developed for on-orbit science experiments was used to detect the onset of cataracts, a capability that could eliminate physicians' guesswork and result in new drugs to 'dissolve' or slow down the cataract formation before surgery is necessary. The probe is based upon dynamic light scattering (DLS) principles. It has no moving parts, no apertures, and requires no optical alignment. It is flexible and easy to use. Results are presented for excised but intact human eye lenses. In a clinical setting, the device can be easily incorporated into a slit-lamp apparatus (ophthalmoscope) for complete eye diagnostics. In this set-up, the integrated fiber optic probe, the size of a pencil, delivers a low power cone of laser light into the eye of a patient and guides the light which is backscattered by the protein molecules of the lens through a receiving optical fiber to a photo detector. The non-invasive DLS measurements provide rapid determination of protein crystalline size and its size distribution in the eye lens.

A histopathological study of bulbar conjunctival flaps occurring in 2 contact lens wearers.

PubMed

Markoulli, Maria; Francis, Ian C; Yong, Jim; Jalbert, Isabelle; Carnt, Nicole; Cole, Nerida; Papas, Eric

2011-09-01

To study the histopathology of paralimbal bulbar conjunctival flaps occurring secondary to soft contact lens wear. Slit-lamp biomicroscopy using sodium fluorescein, cobalt blue light, and a Wratten filter was used to observe the presence, location, and dimensions of bulbar conjunctival flaps presenting in a cohort of contact lens wearers. Two subjects who exhibited such flaps agreed to undergo conjunctival biopsy. Tissue samples, obtained from the region of the flap, and an adjacent unaffected area were processed by standard histopathological methods. In the first subject, analysis of the flap tissue showed even collagen distribution and overall normal histology. The flap of the second subject displayed a mild focal increase in collagen and mild degeneration of collagen, but no increase in elastic tissue. Conjunctival epithelium was normal in both cases. In these 2 subjects, conjunctival flap tissue either was normal or showed only minimal abnormality. There is insufficient evidence for significant pathological change on the time scale of this study.

Corneal Neovascularization with Associated Lipid Keratopathy in a Patient with Obstructive Sleep Apnea-Hypopnea Syndrome Using a Continuous Positive Airway Pressure Machine.

PubMed

Oikonomakis, Konstantinos; Petrelli, Myrsini; Andreanos, Konstantinos; Mouchtouris, Andreas; Petrou, Petros; Georgalas, Ilias; Papaconstantinou, Dimitrios; Kymionis, George

2017-01-01

To report a case of corneal neovascularization with secondary lipid keratopathy in a patient treated with continuous positive airway pressure (CPAP) for obstructive sleep apnea-hypopnea syndrome (OSAHS). A 49-year-old male had been diagnosed with obstructive sleep apnea syndrome 10 years ago and has been treated with the application of a CPAP machine during night sleep ever since. For the past year, the patient had been complaining for ocular irritation and excessive tearing of the left eye on awakening. Slit-lamp biomicroscopy revealed the presence of neovascularization and lipid exudation in the inferior third of the cornea of the left eye. Ocular patching during night sleep resulted in recession of the reported symptoms and shrinkage of the neovascularization, while the area of lipid exudation ceased to enlarge. To the best of our knowledge, this is the first report of corneal neovascularization in a patient using a CPAP machine for OSAHS.

Novel human CRYGD rare variant in a Brazilian family with congenital cataract

PubMed Central

Giordano, Gabriel Gorgone; Tavares, Anderson; da Silva, Márcio José; de Vasconcellos, José Paulo Cabral; Arieta, Carlos Eduardo Leite; de Melo, Mônica Barbosa

2011-01-01

Purpose To describe a novel polymorphism in the γD-crystallin (CRYGD) gene in a Brazilian family with congenital cataract. Methods A Brazilian four-generation family was analyzed. The proband had bilateral lamellar cataract and the phenotypes were classified by slit lamp examination. Genomic DNA was extracted from peripheral blood and coding regions and intron/exon boundaries of the αA-crystallin (CRYAA), γC-crystallin (CRYGC), and CRYGD genes were amplified by polymerase chain reaction and directly sequenced. Results Sequencing of the coding regions of CRYGD showed the presence of a heterozygous A→G transversion at c.401 position, which results in the substitution of a tyrosine to a cysteine (Y134C). The polymorphism was identified in three individuals, two affected and one unaffected. Conclusions A novel rare variant in CRYGD (Y134C) was detected in a Brazilian family with congenital cataract. Because there is no segregation between the substitution and the phenotypes in this family, other genetic alterations are likely to be present. PMID:21866214

Correcting STIS CCD Point-Source Spectra for CTE Loss

NASA Technical Reports Server (NTRS)

Goudfrooij, Paul; Bohlin, Ralph C.; Maiz-Apellaniz, Jesus

2006-01-01

We review the on-orbit spectroscopic observations that are being used to characterize the Charge Transfer Efficiency (CTE) of the STIS CCD in spectroscopic mode. We parameterize the CTE-related loss for spectrophotometry of point sources in terms of dependencies on the brightness of the source, the background level, the signal in the PSF outside the standard extraction box, and the time of observation. Primary constraints on our correction algorithm are provided by measurements of the CTE loss rates for simulated spectra (images of a tungsten lamp taken through slits oriented along the dispersion axis) combined with estimates of CTE losses for actual spectra of spectrophotometric standard stars in the first order CCD modes. For point-source spectra at the standard reference position at the CCD center, CTE losses as large as 30% are corrected to within approx.1% RMS after application of the algorithm presented here, rendering the Poisson noise associated with the source detection itself to be the dominant contributor to the total flux calibration uncertainty.

Staphylococcus aureus causes acute inflammatory episodes in the cornea during contact lens wear.

PubMed

Wu, P Z; Thakur, A; Stapleton, F; Willcox, M D

2000-06-01

The aim of this investigation was to determine the ability of Staphylococcus aureus to cause keratitis during contact lens wear in the rabbit. Rabbits were fitted with hydrogel lenses and wore them on an extended wear schedule for 7 weeks. At the end of each week of wear, one drop of S. aureus was added to the eyes, and the eyes were monitored using slit lamp bio-microscopy, with subsequent microbial and histological studies of the cornea. In the presence of S. aureus, keratitis occurred after 3 weeks of lens wear, a condition that was characterized by diffuse infiltration of the peripheral cornea and limbal redness. In the absence of bacteria, there was no infiltration until week 6. Contact lens wear also prolonged the retention of bacteria in the eye. Extended contact lens wear and S. aureus caused non-ulcerative keratitis in a rabbit model, and disturbances in the ability of the eye to remove bacteria.

Diagnosis of dry eye disease and emerging technologies

PubMed Central

Zeev, Maya Salomon-Ben; Miller, Darby Douglas; Latkany, Robert

2014-01-01

Dry eye is one of the most commonly encountered problems in ophthalmology. Signs can include punctate epithelial erosions, hyperemia, low tear lakes, rapid tear break-up time, and meibomian gland disease. Current methods of diagnosis include a slit-lamp examination with and without different stains, including fluorescein, rose bengal, and lissamine green. Other methods are the Schirmer test, tear function index, tear break-up time, and functional visual acuity. Emerging technologies include meniscometry, optical coherence tomography, tear film stability analysis, interferometry, tear osmolarity, the tear film normalization test, ocular surface thermography, and tear biomarkers. Patient-specific considerations involve relevant history of autoimmune disease, refractive surgery or use of oral medications, and allergies or rosacea. Other patient considerations include clinical examination for lid margin disease and presence of lagophthalmos or blink abnormalities. Given a complex presentation and a variety of signs and symptoms, it would be beneficial if there was an inexpensive, readily available, and reproducible diagnostic test for dry eye. PMID:24672224

[Ocular graft-versus-host disease: An often misdiagnosed etiology of dry eye syndrome].

PubMed

Moyal, L; Adam, R; Akesbi, J; Rodallec, F T; Nordmann, J-P

2017-02-01

To report a case of severe ocular graft-versus-host disease (GVHD) after cataract surgery. Observational case report. We describe the case of a 59-year-old man with postoperative corneal ulcer on his only functional eye. His past history reported allogenic bone marrow transplant. His visual acuity (VA) was limited to hand motions. Slit lamp examination revealed diffuse conjunctival hyperemia, severe blepharitis, Meibomian dysfunction, total corneal opacification with epithelial and stromal keratitis and neovascular invasion. Because of the severe dry eye symptoms and history of allogenic hematological stem cell transplantation, ocular GVHD was diagnosed. Functional and anatomical improvement occurred rapidly with topical cyclosporine 2%, with improved VA after treatment. With any severe dry eye syndrome in the context of allogenic bone marrow transplant, ocular GVHD must be considered. For planned ocular surgery, we recommend adding cyclosporine 0.1% treatment before and after surgery to prevent severe ocular GVHD. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Posterior Segment Toxicity Following Gemcitabine and Docetaxel Chemotherapy

PubMed Central

Valeshabad, Ali Kord; Mieler, William F.; Setlur, Vikram; Thomas, Merina; Shahidi, Mahnaz

2015-01-01

Purpose To report outer retinal disruption and uveal effusion following gemcitabine and docetaxel combination therapy. Case Report A 78-year-old woman presented with blurry vision following two cycles of gemcitabine and docetaxel combination chemotherapy for stage IV sarcoma. At presentation, visual acuity (VA) was finger counting and 20/25 in the right and left eyes, respectively. Slit lamp examination and B scan ultrasonography revealed severe uveal effusion in the right eye and choroidal folds in the left eye. Spectral domain optical coherence tomography showed disruption of photoreceptor inner segment ellipsoid band in the right eye. The patient was monitored weekly with ophthalmic examination and B scan ultrasonography, while continuing with gemcitabine monotherapy. At 8 weeks follow up, uveal effusion improved considerably and VA was 20/40 and 20/20 in the right and left eyes, respectively. Conclusions Uveal effusion and outer retinal disruption were reported following gemcitabine and docetaxel chemotherapy. Early detection and close ophthalmic monitoring may allow concurrent cancer treatment and prevention of possible chemotherapy-induced ocular side effects. PMID:25822016

[Case report of melanoma-associated retinopathy associated with positive auto-antibodies against retinal bipolar cells].

PubMed

Hanaya, Junko; Nakamura, Yasuko; Nejima, Ryouhei; Miyata, Kazunori; Mera, Kentarou; Ohguro, Hiroshi; Yamamoto, Shuichi

2011-06-01

We report a case of melanoma-associated retinopathy (MAR) associated with positive auto-antibodies against retinal bipolar cells, which has been rarely reported in Japan. A 33 year-old woman noticed shimmering vision, photopsias, blurred vision, and night blindness OS in April 2009, and visited Kagoshima Miyata Eye Clinic in May 2009. She had been continuously treated for malignant melanoma on her left finger since 2007. At her initial visit, the corrected visual acuity was 1.5 OD and 1.2 OS, and slit-lamp examination revealed clear ocular media OU. Funduscopic examination showed normal appearance of the retina OU, except for a mild narrowing of the retinal arteries OS. Humphrey field analyzer revealed a reduction of retinal sensitivity within the central 30 degrees OS. The maximum left eye response of electroretinogram (ERG) showed a negative waveform. The immuno-cytochemical test revealed antibodies against retinal bipolar cells, which confirmed the diagnosis of MAR. Characteristic subjective symptoms, Humphrey field analyzer and ERG are useful for the diagnosis of MAR.

A Severe Case of Pigmentary Glaucoma in a Child With a Family History of Pigment Dispersion Syndrome.

PubMed

Aragno, Vittoria; Zeboulon, Pierre; Baudouin, Christophe; Labbé, Antoine

2016-08-01

To report a case of severe pigmentary glaucoma (PG) in a 13-year-old boy of a family affected by pigment dispersion syndrome (PDS). A 13-year-old child was referred to our hospital for severe bilateral glaucoma. A complete ophthalmologic evaluation including refraction, intraocular pressure, central corneal thickness, slit-lamp biomicroscopy, gonioscopy, fundus examination, and ultrasound biomicroscopy was performed. Family members were also examined and a family pedigree was obtained. Ophthalmologic examination revealed a severe bilateral PG with Krukenberg spindle and a widely open heavily pigmented iridocorneal angle. Ultrasound biomicroscopy showed a deep anterior chamber with pronounced iris concavity in both eyes. Within his family, his 15-year-old sister and 7-year-old brother were both affected by PDS diagnosed on gonioscopy findings. We report for the first time a severe case of pediatric PG with a family history of PDS. This case demonstrates that accurate screening is necessary in cases of familial PDS and PG, even in the pediatric population.

Acute vision loss: a fuzzy presentation of sarcoidosis.

PubMed

Austin, Andrea L; Day, Luke T; Bishop, Frank M

2013-04-01

Acute vision loss is a devastating problem for patients and a challenging diagnostic dilemma for Emergency Physicians. This chief complaint is one in which we must be adept at quickly evaluating and initiating either care or referral. This case reviews the approach to acute vision loss and shows the importance of expanding the differential in atypical and complex presentations. A 31-year-old, previously healthy, white woman presented to the Emergency Department (ED) with 1 day of painless right eye vision loss. Ocular ultrasound and slit-lamp examination were unremarkable. Fundoscopic examination revealed retinal hemorrhages and papillitis. Her chest X-ray study was significant for bilateral hilar adenopathy, and subsequent lymph node biopsy confirmed the diagnosis of sarcoidosis. Although sarcoidosis is more common in African Americans, it must be considered in all patients in the appropriate clinical context. Sarcoidosis is an important diagnosis to include on the differential of many chief complaints that present to the ED, including acute vision loss and dyspnea. Published by Elsevier Inc.

Microsporidial Stromal Keratitis: Successful Treatment with Topical Voriconazole and Oral Itraconazole

PubMed Central

Kim, James; Shenoy, Sudhir; Chévez-Barrios, Patricia; Kapur, Manuj

2016-01-01

We report a case of microsporidial stromal keratitis successfully treated with topical voriconazole and oral itraconazole. A 30-year-old Hispanic male construction worker who wears contacts lenses presented with left eye erythematous, epiphora, and mild pain increasing over few days after failing previous antibiotics treatment. His best corrected visual acuity in the left eye was count fingers at three feet, and the slit lamp examination showed 3+ conjunctival injection, a circular central corneal ulcer 3.2 mm in diameter, stromal thinning, and an anterior chamber with white cells, flair, and 0.1 mm hypopyon. A cornea punch biopsy identified microsporidial organisms with some features suggestive of Vittaforma corneae. After treatment with topical voriconazole and oral itraconazole for eight weeks, the patient had complete resolution with no recurrence for over 12 months of follow-up. To our knowledge, this is the first reported case of successful treatment of microsporidial stromal keratitis with antifungals. PMID:28123915

Spontaneous Corneal Hydrops in a Patient with a Corneal Ulcer

PubMed Central

Batawi, Hatim; Kothari, Nikisha; Camp, Andrew; Bernhard, Luis; Karp, Carol L.; Galor, Anat

2016-01-01

Purpose We report the case of a 77-year-old man with no history of keratoconus or other ectatic disorders who presented with corneal hydrops in the setting of a corneal ulcer. The risk factors, pathogenesis and treatment options of corneal hydrops are discussed. Method This is an observational case report study. Results A 77-year-old man presented with a 1-day history of severe pain, redness, mucous discharge and photophobia in the right eye. A slit-lamp examination of the right eye showed an area of focal corneal edema and protrusion. Within the area of edema and protrusion, there was an infiltrate with an overlying epithelial defect consistent with an infectious corneal ulcer. The Seidel test showed no leakage, so a clinical diagnosis of corneal hydrops associated with nonperforated corneal ulcer was made. With appropriate antibiotic treatment, the corneal ulcer and hydrops both resolved over a 1-month period. Conclusion Corneal hydrops can occur in the setting of corneal infections. PMID:26889160

Apparent Corneal Ectasia After Bilateral Intrastromal Femtosecond Laser Treatment for Presbyopia.

PubMed

Dukic, Adrijana; Bohac, Maja; Pasalic, Adi; Koncarevic, Mateja; Anticic, Marija; Patel, Sudi

2016-11-01

To report a case of apparent corneal ectasia after intrastromal femtosecond laser treatment for presbyopia (INTRACOR). A healthy 56-year-old male with low hyperopia underwent an unremarkable bilateral INTRACOR procedure in March/April 2011. The patient was discharged after follow-up and returned 5 years later. Before discharge, the monocular logarithm of the minimal angle of resolution uncorrected distance visual acuity (UDVA) values were R, 0.0 and L, 0.10. In both eyes near (UNVA) visual acuities were 0.0. There were signs of slight posterior central corneal steepening without loss of corneal stability. Five years postop, monocular UDVA and UNVA values were 0.4 and 0.0, respectively. Ectasia was observed in both eyes, and the centrally placed 5 concentric rings after the INTRACOR procedure were visible under slit-lamp biomicroscopy. There is no clear reason to explain why the patient developed bilateral corneal steepening. It could be that the patient's corneal stromal fibers gradually weakened over this 5-year period.

Spontaneous Corneal Hydrops in a Patient with a Corneal Ulcer.

PubMed

Batawi, Hatim; Kothari, Nikisha; Camp, Andrew; Bernhard, Luis; Karp, Carol L; Galor, Anat

2016-01-01

We report the case of a 77-year-old man with no history of keratoconus or other ectatic disorders who presented with corneal hydrops in the setting of a corneal ulcer. The risk factors, pathogenesis and treatment options of corneal hydrops are discussed. This is an observational case report study. A 77-year-old man presented with a 1-day history of severe pain, redness, mucous discharge and photophobia in the right eye. A slit-lamp examination of the right eye showed an area of focal corneal edema and protrusion. Within the area of edema and protrusion, there was an infiltrate with an overlying epithelial defect consistent with an infectious corneal ulcer. The Seidel test showed no leakage, so a clinical diagnosis of corneal hydrops associated with nonperforated corneal ulcer was made. With appropriate antibiotic treatment, the corneal ulcer and hydrops both resolved over a 1-month period. Corneal hydrops can occur in the setting of corneal infections.

Fungal corneal ulcer and bacterial orbital cellulitis occur as complications of bacterial endophthalmitis after cataract surgery in an immunocompetent patient.

PubMed

Kim, Eun Chul; Kim, Man Soo; Kang, Nam Yeo

2013-03-01

To report a case of fungal corneal ulcer and bacterial orbital cellulitis as complications of bacterial endophthalmitis following cataract surgery. A 51-year-old man underwent anterior chamber irrigation and aspiration in the left eye one day after cataract surgery because of bacterial endophthalmitis. Marked lid swelling with purulent discharge was developed after 5 days. Slit lamp examination showed generalized corneal ulcer and pus in the total anterior chamber. A computerized tomography scan showed left retrobulbar fat stranding with thickened optic disc. Streptococcus pneumonia was cultured from corneal scraping, vireous, and subconjunctival pus. The patient improved gradually with antibiotics treatments, but the corneal ulcer did not fully recover 2 months after cataract surgery. Candida albicans was detected in repetitive corneal culture. After antifungal and antibacterial therapy, the corneal epithelium had healed, but phthisis bulbi had developed. Fungal corneal ulcer and bacterial orbital cellulitis can occur as complications of endophthalmitis in an immunocompetent patient.

[Fabry's disease and hypoparathyroidism].

PubMed

Misery, Laurent; Gregoire, Madeleine; Prieur, Fabienne; Froissart, Régis; Guffon, Nathalie; Maitre, Séverine; Fond, Laurent; Denis, Laurence; Perrot, Jean-Luc; Cambazard, Frédéric

2002-06-01

Fabry's disease is due to alpha-galactosidase deficiency. This rare lysosomal storage disease is transmitted by recessive X-linked heredity. Sphingolipids (galactosyl-glucosyl-ceramide) accumulate in many organs. A 19-year-old man with known hypoparathyroidism presented with telangiectasia and angiokeratomas on the buttocks, the hips, the hands and around the navel. For many years, he suffered from paroxysmal pain in the hands and feet. From childhood, he had complained of diffuse abdominal pain, associated with diarrhea. Ophthalmological slit lamp fundus examination showed corneal telangiectasia and cornea verticella. There was no kidney or heart involvement. The diagnosis of Fabry's disease was confirmed by very low levels of alpha-galactosidase. We did not find any other association of hypoparathyroidism and Fabry's disease in the literature. Hypoparathyroidism is not a manifestation of Fabry's disease. Idiopathic hypoparathyroidism is very rare and a genetic origin is known. This disease can be recessive X-linked. A co-transmission of idiopathic hypoparathyroidism and Fabry's disease is probable in our patient.

Bilateral ocular abnormalities in a wild stranded harp seal (Phoca groenlandica) suggestive of anterior segment dysgenesis and persistent hyperplastic primary vitreous.

PubMed

Erlacher-Reid, Claire; Colitz, Carmen M H; Abrams, Ken; Smith, Ainsley; Tuttle, Allison D

2011-06-01

A male yearling harp seal (Phoca groenlandica) stranded and was brought to Mystic Aquarium & Institute for Exploration's Seal Rescue and Rehabilitation Center. The seal presented with a bilateral pendular vertical nystagmus, negative menace response, and a positive palpebral response. Ophthalmological examination by slit lamp biomicroscopy revealed perilimbal corneal edema, excessive iridal surface structures, pupils that appeared to be shaped improperly (dyscoria), and suspected cataracts. Attempts to dilate the pupils with both dark-lighted conditions and repeated dosages of 10% phenylephrine and 1% atropine ophthalmic solution in each eye (OU) were unsuccessful. Ocular ultrasonography findings suggested bilateral cataracts with flattened anterior-posterior (A-P) diameter and possible persistent hyperplastic primary vitreous. It is possible that these structural congenital abnormalities could produce further ocular complications for this seal including uveitis, secondary glaucoma, retinal detachment, and/or vitreal hemorrhage in the future. This case demonstrates the importance of a thorough ophthalmological examination in stranded wild animals, especially if their symptoms appear neurological.

The application of imaging technologies in the detection of trace evidence in forensic medical investigation.

PubMed

Cocks, Jeannie; du Toit-Prinsloo, Lorraine; Steffens, Francois; Saayman, Gert

2015-04-01

In a country notorious for violent crime, it seems that South African medico-legal laboratories make minimal application of technology in the death investigation process and little attention is given to trace evidence. Non-destructive, non-invasive, portable and cost-effective tools are required. This study was conducted at the Pretoria Medico-Legal Laboratory. The surface area of the bodies and clothing of victims of fatal interpersonal violence were examined using a torch, magnifying lamp, portable digital microscope and alternate light source to gauge their potential for trace evidence detection. Most studies apply these and similar tools to inert surfaces, with few focusing on their application to human skin. There was a statistically significant difference in the detection of many of the evidence types between the naked-eye observation of the pathologists and the technologies. The different imaging technologies were compared as to their cost, evidence detection ability and ease of use. The most common evidence types discovered on the bodies and clothing of victims of fatal interpersonal violence, as well as the propensity of each tool to detect these, was evaluated in order to devise the best option for incorporation into the Pretoria Medico-Legal Laboratory routine. The digital microscope performed best overall followed by the magnifying lamp, torch and the Polilight(®). This study aimed to justify the investment of more time, effort and funding into trace evidence recovery in the South African mortuary environment. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Three-dimensional characterization of extreme ultraviolet mask blank defects by interference contrast photoemission electron microscopy.

PubMed

Lin, Jingquan; Weber, Nils; Escher, Matthias; Maul, Jochen; Han, Hak-Seung; Merkel, Michael; Wurm, Stefan; Schönhense, Gerd; Kleineberg, Ulf

2008-09-29

A photoemission electron microscope based on a new contrast mechanism "interference contrast" is applied to characterize extreme ultraviolet lithography mask blank defects. Inspection results show that positioning of interference destructive condition (node of standing wave field) on surface of multilayer in the local region of a phase defect is necessary to obtain best visibility of the defect on mask blank. A comparative experiment reveals superiority of the interference contrast photoemission electron microscope (Extreme UV illumination) over a topographic contrast one (UV illumination with Hg discharge lamp) in detecting extreme ultraviolet mask blank phase defects. A depth-resolved detection of a mask blank defect, either by measuring anti-node peak shift in the EUV-PEEM image under varying inspection wavelength condition or by counting interference fringes with a fixed illumination wavelength, is discussed.

Boundary-Layer Effects on Acoustic Transmission Through Narrow Slit Cavities.

PubMed

Ward, G P; Lovelock, R K; Murray, A R J; Hibbins, A P; Sambles, J R; Smith, J D

2015-07-24

We explore the slit-width dependence of the resonant transmission of sound in air through both a slit array formed of aluminum slats and a single open-ended slit cavity in an aluminum plate. Our experimental results accord well with Lord Rayleigh's theory concerning how thin viscous and thermal boundary layers at a slit's walls affect the acoustic wave across the whole slit cavity. By measuring accurately the frequencies of the Fabry-Perot-like cavity resonances, we find a significant 5% reduction in the effective speed of sound through the slits when an individual viscous boundary layer occupies only 5% of the total slit width. Importantly, this effect is true for any airborne slit cavity, with the reduction being achieved despite the slit width being on a far larger scale than an individual boundary layer's thickness. This work demonstrates that the recent prevalent loss-free treatment of narrow slit cavities within acoustic metamaterials is unrealistic.

In vivo laser scanning confocal microscopy of the cornea in patients with silicone oil tamponade after vitreoretinal surgery.

PubMed

Le, Qihua; Wang, Xin; Lv, Jiahua; Sun, Xinghuai; Xu, Jianjiang

2012-08-01

To evaluate the morphological changes in the cornea by in vivo laser scanning confocal microscopy (LSCM) in a large case series with silicone oil endotamponade after vitreoretinal surgery and to explore the value of LSCM in the early detection of silicone keratopathy (SK). Ninety-nine patients (99 eyes) with silicone oil endotamponade after vitreoretinal surgery were included in the current study. Slit-lamp examination and measurement of intraocular pressure (IOP) were performed first. Then the central corneas of the subjects' eyes were examined by in vivo LSCM. The analysis of images of each corneal layer was performed and the endothelial cellular density (ECD), endothelial cellular area (ECA), coefficient of variation of cell size (CoV), and percentage of hexagonal cells (PHC) were measured. Moreover, the total size of stromal deposits was measured, and the correlation between the size of deposits and the parameters of endothelial cells was analyzed. Clinically recognizable abnormalities involving the cornea were identified in only 12 eyes (12.1%) under slit-lamp biomicroscopy, whereas in vivo LSCM revealed morphological abnormalities in 40 eyes (40.4%). The manifestations of endothelial lesions varied from decreased cellular density, increased polymegathism and pleomorphism to hyperreflective silicone oil membrane or droplets adhering to the endothelium. Moreover, hyperreflective deposits with various shapes could be identified in both posterior and anterior stroma, along with the infiltration of Langerhans cells beneath the epithelium. The average ECD and PHC of eyes with corneal abnormalities were significantly lower than those of normal corneas, whereas the average ECA and CoV were significantly larger (all Ps < 0.001). The patients with corneal abnormalities were significantly older than those others (P = 0.003). The rate of pseudophakic and aphakic eyes having corneal abnormalities was significantly higher than that of phakic eyes (P = 0.045). Interestingly, the total size of stromal deposits had a significant negative correlation with ECD and PHC but a significant positive correlation with ECA and CoV (all Ps < 0.001). Further correlation analysis performed in groups divided according to the lens status showed similar results and even stronger correlations in aphakic and pseudophakic eyes, whereas no statistically significant correlations were found in phakic eyes. In vivo LSCM was a useful tool in the early detection of corneal abnormalities caused by silicone oil injection, including varying corneal endothelium lesions and stromal abnormalities. Pseudophakic or aphakic eyes, as well as those of older patients, should receive more attention because they are more inclined to develop silicone keratopathy.

Effect of eye rubbing on signs and symptoms of allergic conjunctivitis in cat-sensitive individuals.

PubMed

Raizman, M B; Rothman, J S; Maroun, F; Rand, W M

2000-12-01

To evaluate the effect of eye rubbing on signs and symptoms of allergic conjunctivitis in cat-sensitive individuals. Two prospective, nonrandomized comparative studies. Thirteen patients in the first study and 20 patients in the second study with a documented history of acute allergic conjunctivitis induced by exposure to cats were enrolled. In the first trial, all patients had one eye rubbed 15 times by the investigator without exposure to airborne allergens. Both eyes were evaluated after 5, 15, 30, and 60 minutes using subject questionnaires and slit-lamp examination. At least 1 week later, each patient was exposed to cat dander for 75 minutes; 15 minutes after entering the cat room, each patient had one eye rubbed 15 times by the examiner. Subjects' eyes were then evaluated using questionnaires and slit-lamp examination. In the second trial, the visits were identical to the first trial, except that the rubbed eye in each visit was rubbed 20 times and with more force, and that patients wore masks during exposure to cat dander. In both studies, the difference between patients' rubbed and nonrubbed eyes with respect to ocular itching, chemosis, and hyperemia was noted 5, 15, 30, and 60 minutes after controlled eye rubbing. Without exposure to the cat room, rubbed eyes exhibited increased itching at 5 minutes in both studies and at 15 minutes in the second study (P < 0.05), increased chemosis at 5 and 15 minutes in the second study (P < 0.05), and increased hyperemia at 5 minutes in the second study (P < 0.05) compared with nonrubbed eyes. During exposure to cat dander, rubbed eyes consistently exhibited increased itching at 5, 15, and 30 minutes in the first and second study as well as at 60 minutes in the second study compared with nonrubbed eyes. Furthermore, during exposure to cat dander, rubbed eyes consistently exhibited increased chemosis at 5 and 15 minutes (P < 0.05) and increased hyperemia at 5, 15, and 30 minutes (P < 0.05) in the second study compared with nonrubbed eyes. Firm eye rubbing causes a mild and transient increase in ocular itching, chemosis, and hyperemia. However, after exposure to cat allergens in cat-sensitive individuals, the effects of eye rubbing are longer and more dramatic. Eye rubbing may play a role in ocular signs and symptoms of allergic conjunctivitis in cat-sensitive individuals, especially after exposure to cat dander.

Use of fluorescence and scanning electron microscopy as tools in teaching biology

NASA Astrophysics Data System (ADS)

Ghosh, Nabarun; Silva, Jessica; Vazquez, Aracely; Das, A. B.; Smith, Don W.

2011-06-01

Recent nationwide surveys reveal significant decline in students' interest in Math and Sciences. The objective of this project was to inspire young minds in using various techniques involved in Sciences including Scanning Electron Microscopy. We used Scanning Electron Microscope in demonstrating various types of Biological samples. An SEM Tabletop model in the past decade has revolutionized the use of Scanning Electron Microscopes. Using SEM Tabletop model TM 1000 we studied biological specimens of fungal spores, pollen grains, diatoms, plant fibers, dust mites, insect parts and leaf surfaces. We also used fluorescence microscopy to view, to record and analyze various specimens with an Olympus BX40 microscope equipped with FITC and TRITC fluorescent filters, a mercury lamp source, DP-70 digital camera with Image Pro 6.0 software. Micrographs were captured using bright field microscopy, the fluoresceinisothiocyanate (FITC) filter, and the tetramethylrhodamine (TRITC) filter settings at 40X. A high pressure mercury lamp or UV source was used to excite the storage molecules or proteins which exhibited autofluorescence. We used fluorescent microscopy to confirm the localization of sugar beet viruses in plant organs by viewing the vascular bundles in the thin sections of the leaves and other tissues. We worked with the REU summer students on sample preparation and observation on various samples utilizing the SEM. Critical Point Drying (CPD) and metal coating with the sputter coater was followed before observing some cultured specimen and the samples that were soft in textures with high water content. SEM Top allowed investigating the detailed morphological features that can be used for classroom teaching. Undergraduate and graduate researchers studied biological samples of Arthropods, pollen grains and teeth collected from four species of snakes using SEM. This project inspired the research students to pursue their career in higher studies in science and 45% of the undergraduates participated in this project entered Graduate school.

Alkali metal vapors - Laser spectroscopy and applications

NASA Technical Reports Server (NTRS)

Stwalley, W. C.; Koch, M. E.

1980-01-01

The paper examines the rapidly expanding use of lasers for spectroscopic studies of alkali metal vapors. Since the alkali metals (lithium, sodium, potassium, rubidium and cesium) are theoretically simple ('visible hydrogen'), readily ionized, and strongly interacting with laser light, they represent ideal systems for quantitative understanding of microscopic interconversion mechanisms between photon (e.g., solar or laser), chemical, electrical and thermal energy. The possible implications of such understanding for a wide variety of practical applications (sodium lamps, thermionic converters, magnetohydrodynamic devices, new lasers, 'lithium waterfall' inertial confinement fusion reactors, etc.) are also discussed.

Slits are chemorepellents endogenous to hypothalamus and steer thalamocortical axons into ventral telencephalon.

PubMed

Braisted, Janet E; Ringstedt, Thomas; O'Leary, Dennis D M

2009-07-01

Thalamocortical axons (TCAs) originate in dorsal thalamus, extend ventrally along the lateral thalamic surface, and as they approach hypothalamus make a lateral turn into ventral telencephalon. In vitro studies show that hypothalamus releases a chemorepellent for TCAs, and analyses of knockout mice indicate that Slit chemorepellents and their receptor Robo2 influence TCA pathfinding. We show that Slit chemorepellents are the hypothalamic chemorepellent and act through Robos to steer TCAs into ventral telencephalon. During TCA pathfinding, Slit1 and Slit2 are expressed in hypothalamus and ventral thalamus and Robo1 and Robo2 are expressed in dorsal thalamus. In collagen gel cocultures of dorsal thalamus and Slit2-expressing cells, axon number and length are decreased on the explant side facing Slit2-expressing cells, overall axon outgrowth is diminished, and axons turn away from the Slit2-expressing cells. Thus, Slit2 is an inhibitor and chemorepellent for dorsal thalamic axons. Collagen gel cocultures of dorsal thalamus with sections of live diencephalon, with and without the hypothalamus portion overlaid with Robo2-fc-expressing cells to block Slit function, identify Slits as the hypothalamic chemorepellent. Thus, Slits are chemorepellents for TCAs endogenous to hypothalamus and steer TCAs from diencephalon into ventral telencephalon, a critical pathfinding event defective in Slit and Robo2 mutant mice.

In situ high temperature microwave microscope for nondestructive detection of surface and sub-surface defects.

PubMed

Wang, Peiyu; Li, Zhencheng; Pei, Yongmao

2018-04-16

An in situ high temperature microwave microscope was built for detecting surface and sub-subsurface structures and defects. This system was heated with a self-designed quartz lamp radiation module, which is capable of heating to 800°C. A line scanning of a metal grating showed a super resolution of 0.5 mm (λ/600) at 1 GHz. In situ scanning detections of surface hole defects on an aluminium plate and a glass fiber reinforced plastic (GFRP) plate were conducted at different high temperatures. A post processing algorithm was proposed to remove the background noises induced by high temperatures and the 3.0 mm-spaced hole defects were clearly resolved. Besides, hexagonal honeycomb lattices were in situ detected and clearly resolved under a 1.0 mm-thick face panel at 20°C and 50°C, respectively. The core wall positions and bonding width were accurately detected and evaluated. In summary, this in situ microwave microscope is feasible and effective in sub-surface detection and super resolution imaging at different high temperatures.

Calibrating excitation light fluxes for quantitative light microscopy in cell biology

PubMed Central

Grünwald, David; Shenoy, Shailesh M; Burke, Sean; Singer, Robert H

2011-01-01

Power output of light bulbs changes over time and the total energy delivered will depend on the optical beam path of the microscope, filter sets and objectives used, thus making comparison between experiments performed on different microscopes complicated. Using a thermocoupled power meter, it is possible to measure the exact amount of light applied to a specimen in fluorescence microscopy, regardless of the light source, as the light power measured can be translated into a power density at the sample. This widely used and simple tool forms the basis of a new degree of calibration precision and comparability of results among experiments and setups. Here we describe an easy-to-follow protocol that allows researchers to precisely estimate excitation intensities in the object plane, using commercially available opto-mechanical components. The total duration of this protocol for one objective and six filter cubes is 75 min including start-up time for the lamp. PMID:18974739

Color-tunable properties of Eu3+- and Dy3+-codoped Y2O3 phosphor particles

PubMed Central

2012-01-01

Rare-earth phosphors are commonly used in display panels, security printing, and fluorescent lamps, and have potential applications in lasers and bioimaging. In the present study, Eu3+- and Dy3+-codoped uniform-shaped Y2O3 submicron particles were prepared using the urea homogeneous precipitation method. The structure and morphology of the resulting particles were characterized by X-ray diffraction, field emission scanning electron microscope, and field emission transmission electron microscope, whereas their optical properties were monitored by photoluminescence spectroscopy. The room-temperature luminescence color emission of the synthesized particles can be tuned from red to yellow by switching the excitation wavelength from 254 to 350 nm. The luminescence intensities of red and yellow emissions could be altered by varying the dopant concentration. Strong quenching was observed at high Eu3+ and Dy3+ concentrations in the Y2O3 host lattice. PMID:23043645

Determination Of Slitting Criterion Parameter During The Multi Slit Rolling Process

NASA Astrophysics Data System (ADS)

Stefanik, Andrzej; Mróz, Sebastian; Szota, Piotr; Dyja, Henryk

2007-05-01

The rolling of rods with slitting of the strip calls for the use of special mathematical models that would allow for the separating of metal. A theoretical analysis of the effect of the gap of slitting rollers on the process of band slitting during the rolling of 20 mm and 16 mm-diameter ribbed rods rolled according to the two-strand technology was carried out within this study. For the numerical modeling of strip slitting the Forge3® computer program was applied. The strip slitting in the simulation is implemented by the algorithm of removing elements in which the critical value of the normalized Cockroft - Latham criterion has been exceeded. To determine the value of the criterion the inverse method was applied. Distance between a point, where crack begins, and point of contact metal with the slitting rollers was the parameter for analysis. Power and rolling torque during slit rolling were presented. Distribution and change of the stress in strand while slitting were presented.

Fabrication of magnetic Fe@ZnO0.6S0.4 nanocomposite for visible-light-driven photocatalytic inactivation of Escherichia coli

NASA Astrophysics Data System (ADS)

Peng, Ziling; Wu, Dan; Wang, Wei; Tan, Fatang; Ng, Tsz Wai; Chen, Jianguo; Qiao, Xueliang; Wong, Po Keung

2017-02-01

Bacterial inactivation by magnetic photocatalysts has now received growing interests due to the easy separation for recycle and reuse of photocatalysts. In this study, magnetic Fe@ZnO0.6S0.4 photocatalyst was prepared by a facile two-step precipitation method. Multiple techniques such as X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffused reflectance spectra (UV-vis DRS) and vibrating sample magnetometer (VSM) were employed to characterize the structure, morphology and physicochemical properties of the photocatalyst. The as-obtained Fe@ZnO0.6S0.4 possessing magnetic property was easily collected from the reaction system by a magnet. Under white light-emitting-diode (LED) lamp irradiation, Fe@ZnO0.6S0.4 nanocomposite could completely inactivate 7-log of Escherichia coli K-12 within 5 h. More importantly, almost no decrease of photocatalytic efficiency in bacterial inactivation was observed even after five consecutive cycles, demonstrating Fe@ZnO0.6S0.4 exhibited good stability for reuse. The low released rate of Fe2+/Fe3+ and Zn2+ from Fe@ZnO0.6S0.4 composite further indicated the photocatalyst showed low cytotoxicity to bacterium and high stability under LED lamp irradiation. Facile preparation, high photocatalytic efficiency, good stability and reusability, and magnetic recovery property endow Fe@ZnO0.6S0.4 nanocomposite to be a promising photocatalytic material for bacterial inactivation.

Characterization of aeroallergen of Texas panhandle using scanning and fluorescence microscopy

NASA Astrophysics Data System (ADS)

Ghosh, Nabarun; Whiteside, Mandy; Ridner, Chris; Celik, Yasemin; Saadeh, C.; Bennert, Jeff

2010-06-01

Aeroallergens cause serious allergic and asthmatic reactions. Characterizing the aeroallergen provides information regarding the onset, duration, and severity of the pollen season that clinicians use to guide allergen selection for skin testing and treatment. Fluorescence Microscopy has useful approaches to understand the structure and function of the microscopic objects. Prepared slides from the pollen were observed under an Olympus BX40 microscope equipped with FITC and TRITC fluorescent filters, a mercury lamp source, an Olympus DP-70 digital camera connected to the computer with Image Pro 6.0 software. Aeroallergens were viewed, recorded and analyzed with DP Manager using the Image Pro 6.0 software. Photographs were taken at bright field, the fluorescein-isothiocyanate (FITC) filter, and the tetramethylrhodamine (TRITC) filter settings at 40X. A high pressure mercury lamp or UV source was used to excite the storage molecules or proteins which exhibited autofluorescence. The FITC filter reveals the green fluorescent proteins (GFP and EGFP), and the TRITC filter for red fluorescent proteins (DsRed). SEM proved to be useful for observing ultra-structural details like pores, colpi, sulci and ornamentations on the pollen surface. Samples were examined with an SEM (TM-1000) after gold coating and Critical Point Drying. Pollen grains were measured using the TM-1000 imaging software that revealed the specific information on the size of colpi or sulci and the distance between the micro-structures. This information can be used for classification and circumscription in Angiosperm taxonomy. Data were correlated clinical studies established at Allergy A.R.T.S. Clinical Research Laboratory.

Micromechanical slit positioning system as a transmissive spatial light modulator

NASA Astrophysics Data System (ADS)

Riesenberg, Rainer

2001-11-01

Micro-slits have been prepared with a slit-width and a slit- length of 2 ... 1000 micrometers . Linear and two-dimensional arrays up to 10 x 110 slits have been developed and completed with a piezo-actuator for shifting. This system is a so-called mechanical slit positioning system. The light is switched by simple one- or two-dimensional displacement of coded slit masks in a one- or two-layer architecture. The slit positioning system belongs to the transmissive class of MEMS-based spatial light modulators (SLM). It has fundamental advantages for optical contrast and also can be used in the full spectral region. Therefore transmissive versions of SLM should be a future solution. Instrument architectures based on the slit positioning system can increase the resolution by subpixel generation, the throughput by HADAMARD transform mode, or select objects for multi-object-spectroscopy. The linear slit positioning system was space qualified within an advanced micro- spectrometer. A NIR multi-object-spectrometer for the Next Generation Space Telescope (NGST) is based on a field selector for selecting objects. The field selector is a SLM, which could be implemented by a slit positioning system.

Passive control of base pressure on an axisymmetric blunt body using a perimetric slit

NASA Astrophysics Data System (ADS)

García de la Cruz, Juan Marcos; Oxlade, Anthony R.; Morrison, Jonathan F.

2017-04-01

The effect on the base pressure of a thin slit located at the base edge of a blunt axisymmetric body, communicating an internal cavity with the external flow, is investigated. A parametric study is performed of the effect on base pressure of changes in slit size and cavity depth. The base pressure increases initially with increasing cavity depth, but saturates at a depth which depends on the slit size. The base pressure increases monotonically up to 5 % with increasing slit size for the geometries tested. An upper limit of base pressure recovery of 20 % is extrapolated from the data. It is observed that the main effect of the slit is to reduce the instantaneous pressure asymmetry, which is linked to the total base pressure in a similar fashion for all the slit sizes. As a second-order effect, for highly asymmetric pressure distributions, the slit produces a base pressure increase not associated with the base pressure asymmetry. The results suggest a global effect of the slit on the wake due to a diametrical flow within the cavity driven by the pressure differences across the slit and regulated by the largest of the pressure drops between the slit and cavity. The slit also reduces the periodic base pressure fluctuations, corresponding mainly to the vortex shedding, and increases the rotational speed of the wake.

Slit2 signaling through Robo1 and Robo2 is required for retinal neovascularization

PubMed Central

Rama, Nicolas; Dubrac, Alexandre; Mathivet, Thomas; Chárthaigh, Róisín-Ana Ní; Genet, Gael; Cristofaro, Brunella; Pibouin-Fragner, Laurence; Ma, Le; Eichmann, Anne; Chédotal, Alain

2016-01-01

Ocular neovascular diseases are a leading cause of blindness. Vascular endothelial growth factor (VEGF) blockade improves vision, but not all individuals respond to anti-VEGF treatment, making additional means to prevent neovascularization necessary. Slit-family proteins (Slits) are ligands of Roundabout (Robo) receptors that repel developing axons in the nervous system. Robo1 expression is altered in ocular neovascular diseases, and previous in vitro studies have reported both pro- and anti-angiogenic effects of Slits. However, genetic evidence supporting a role for Slits in ocular neovascularization is lacking. Here we generated conditional knockout mice deficient in various Slit and Robo proteins and found that Slit2 potently and selectively promoted angiogenesis via Robo1 and Robo2 in mouse postnatal retina and in a model of ocular neovascular disease. Mechanistically, Slit2 acting through Robo1 and Robo2 promoted the migration of endothelial cells. These receptors are required for both Slit2- and VEGF-induced Rac1 activation and lamellipodia formation. Thus, Slit2 blockade could potentially be used therapeutically to inhibit angiogenesis in individuals with ocular neovascular disease. PMID:25894826

Geometrical optics modeling of the grating-slit test.

PubMed

Liang, Chao-Wen; Sasian, Jose

2007-02-19

A novel optical testing method termed the grating-slit test is discussed. This test uses a grating and a slit, as in the Ronchi test, but the grating-slit test is different in that the grating is used as the incoherent illuminating object instead of the spatial filter. The slit is located at the plane of the image of a sinusoidal intensity grating. An insightful geometrical-optics model for the grating-slit test is presented and the fringe contrast ratio with respect to the slit width and object-grating period is obtained. The concept of spatial bucket integration is used to obtain the fringe contrast ratio.

The expression of the Slit-Robo signal in the retina of diabetic rats and the vitreous or fibrovascular retinal membranes of patients with proliferative diabetic retinopathy.

PubMed

Zhou, Weiyan; Wang, Hongya; Yu, Wenzhen; Xie, Wankun; Zhao, Min; Huang, Lvzhen; Li, Xiaoxin

2017-01-01

The Slit-Robo signal has an important role in vasculogenesis and angiogenesis. Our study examined the expression of Slit2 and its receptor, Robo1, in a rat model of streptozotocin-induced diabetes and in patients with proliferative diabetic retinopathy. Diabetes was induced in male Sprague-Dawley rats via a single, intraperitoneal injection of streptozotocin. The rats were sacrificed 1, 3 or 6 months after the injection. The expression of Slit2 and Robo1 in retinal tissue was measured by real-time reverse transcription polymerase chain reaction (RT-PCR), and protein levels were measured by western blotting and immunohistochemistry. Recombinant N-Slit2 protein was used to study the effects of Slit2 on the expression of VEGF in vivo. The concentration of Slit2 protein in human eyes was measured by enzyme-linked immunosorbent assay in 27 eyes with proliferative diabetic retinopathy and 28 eyes in control group. The expression of Slit2, Robo1 and VEGF in the excised human fibrovascular membranes was examined by fluorescence immunostaining and semi-quantitative RT-PCR. The expression of Slit2 and Robo1 in the retina was altered after STZ injection. Recombinant N-Slit2 protein did not increase the retinal VEGF expression. Vitreous concentrations of Slit2 were significantly higher in the study group than in the control group. In the human fibrovascular membranes of the study group, the co-localization of VEGF with the markers for Slit2 and Robo1was observed. The expression of Slit2 mRNA, Robo1 mRNA, and VEGF mRNA was significantly higher in human fibrovascular proliferative diabetic retinopathy membranes than in the control membranes. The alteration of Slit2 and Robo1 expression in the retinas of diabetic rats and patients with proliferative diabetic retinopathy suggests a role for the Slit-Robo signal in the various stages diabetic retinopathy. Further studies should address the possible involvement of the Slit-Robo signal in the pathophysiological progress of diabetic retinopathy.

Potential Role of Axonal Chemorepellent Slit2 in Modulating Adventitial Inflammation in a Rat Carotid Artery Balloon Injury Model

PubMed Central

Liu, Dong; Xiao, Yan; Subramanian, Romesh R.; Okamoto, Ei-ichi; Wilcox, Josiah N.; Anderson, Leonard; De Leon, Hector

2016-01-01

Leukocyte infiltration of adventitial and perivascular tissues is an early event in the development of vascular remodeling after injury. We investigated whether Slit/Robo—an axonal chemorepellent system in vertebrate and invertebrate development—is activated during the inflammatory phase that follows endothelial denudation. Using the rat carotid artery model of angioplasty, we conducted a time course analysis of mRNAs encoding Slit ligands (Slit2 and Slit3) and Robo receptors (Robo1, Robo2 and Robo4), as well as proinflammatory cell adhesion molecule (CAM) genes. Adventitial inflammatory cells were counted in immunostained arterial sections. E-selectin, vascular CAM-1 (VCAM-1), and intercellular CAM-1 (ICAM-1) were upregulated 2–3 hr after injury, followed by infiltration of neutrophils and monocytes as evidenced by real-time PCR, in situ hybridization, and immunohistochemistry. Slit2, Slit3, and Robo genes exhibited no expression changes at 3 hr; however, they were markedly upregulated 1 day after angioplasty. ICAM-1 expression was reduced by 50%, and the number of adventitial neutrophils decreased by >75% one day after angioplasty. Slit2 has been shown to be a potent chemorepelent of leukocytes, endothelial cells and smooth muscle cells. Thus, we decided to further investigate the localization of Slit2 in injured vessels. Immunohistochemical stainings revealed the presence of Slit2 within the vessel wall and in the perivascular vasa vasorum of naive and injured arteries. Double immunohistochemical analyses showed that infiltrating monocytes expressed Slit2 in the perivascular and adventitial tissues of injured arteries 1 and 3 days postangioplasty. In addition, recombinant full-length Slit2 and Slit2-N/1118, an N-terminal fragment of Slit2, inhibited stromal cell-derived factor 1 (SDF-1)-mediated migration of circulating rat peripheral blood mononuclear cells. In summary, adventitial activation of CAM genes and neutrophil infiltration preceded upregulation of Slit/Robo genes. Sli2 expression colocalized with infiltrating inflammatory cells in the adventitial layer. This temporospatial association suggests that leukocyte chemorepellent Slit2 may be involved in halting the adventitial accumulation of inflammatory cells in injured vessels. PMID:26841069

Epinephrine Use in Clinical Trials of Sublingual Immunotherapy Tablets.

PubMed

Nolte, Hendrik; Casale, Thomas B; Lockey, Richard F; Fogh, Bodil Svanholm; Kaur, Amarjot; Lu, Susan; Nelson, Harold S

Allergy immunotherapy can result in systemic allergic reactions and even life-threatening anaphylaxis requiring epinephrine administration. The objective of this study was to describe epinephrine use in the clinical trial development programs of 3 rapidly dissolving sublingual immunotherapy tablets (SLIT-tablets; Merck & Co., Inc., Kenilworth, NJ/ALK, Hørsholm, Denmark/Torii Pharmaceutical Co., Ltd., Tokyo, Japan). Data on epinephrine use were collected from 13 timothy grass SLIT-tablet trials (MK-7243; ≤2800 bioequivalent allergen units/75,000 SQ-T dose, n = 2497; placebo, n = 2139), 5 short ragweed SLIT-tablet trials (MK-3641; ≤12 Amb a 1-U, n = 1725; placebo, n = 770), and 11 house dust mite (HDM) SLIT-tablet trials (MK-8237; ≤12 SQ-HDM; n = 3930; placebo, n = 2246). In grass SLIT-tablet trials, epinephrine was used 13 times (grass SLIT-tablet, n = 10; placebo, n = 3). Eight administrations were for grass SLIT-tablet-related adverse events (AEs): 4 for systemic allergic reactions and 4 for local mouth and/or throat swelling. In ragweed SLIT-tablet trials, epinephrine was used 9 times in 8 subjects (ragweed SLIT-tablet, n = 7; placebo, n = 1 [2 administrations for protracted anaphylaxis]). Four administrations were for ragweed SLIT-tablet-related AEs: 1 for systemic allergic reaction and 3 for local mouth and/or pharynx/throat swelling. In HDM SLIT-tablet trials, epinephrine was administered 13 times (HDM SLIT-tablet, n = 8; placebo, n = 5). Four administrations were for HDM SLIT-tablet-related AEs: 1 for systemic allergic reaction and 3 for local events. Of the 16 epinephrine administrations for events related to SLIT-tablet treatment, 11 occurred within the first week of treatment (7 administrations on day 1) and 5 were subject self-administered. Epinephrine administrations in response to SLIT-tablet-related reactions in clinical trials are uncommon, typically occur within the first week of treatment, and are rarely self-administered. All SLIT-tablet-related events treated with epinephrine were nonserious. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Three Dimensional Forming Simulation of the Shielded Slot Plate for the MCFC Using a Ductile Fracture Criterion

NASA Astrophysics Data System (ADS)

Lee, C. H.; Yang, D. Y.; Lee, S. R.; Chang, I. G.; Lee, T. W.

2011-08-01

The shielded slot plate, which has a sheared corrugated trapezoidal pattern, is a component of the metallic bipolar plate for the molten carbonate fuel cell (MCFC). In order to increase the efficiency of the fuel cell, the unit cell of the shielded slot plate should have a relatively large upper area. Additionally, defects from the forming process should be minimized. In order to simulate the slitting process, whereby sheared corrugated patterns are formed, ductile fracture criteria based on the histories of stress and strain are employed. The user material subroutine VUMAT is employed for implementation of the material and ductile fracture criteria in the commercial FEM software ABAQUS. The variables of the ductile fracture criteria were determined by comparing the simulation results and the experimental results of the tension test and the shearing test. Parametric studies were conducted to determine the critical value of the ductile fracture criterion. Employing these ductile fracture criteria, the three dimensional forming process of the shielded slot plate was numerically simulated. The effects of the slitting process in the forming process of the shielded slot plate were analyzed through a FEM simulation and experimental studies. Finally, experiments involving microscopic and macroscopic observations were conducted to verify the numerical simulations of the 3-step forming process.

Gross anatomy and histology of the olfactory rosette of the shark Heptranchias perlo.

PubMed

Ferrando, Sara; Gallus, Lorenzo; Amaroli, Andrea; Gambardella, Chiara; Waryani, Baradi; Di Blasi, Davide; Vacchi, Marino

2017-06-01

Sharks belonging to the family Hexanchidae have six or seven gill slits, unlike all other elasmobranchs, which have five gill slits. Their olfactory organs have a round shape, which is common for holocephalans, but not for elasmobranchs. Thus, the shape of the olfactory organ represents a further, less striking, peculiarity of this family among elasmobranchs. Despite that, the microscopic anatomy and histology of the olfactory organ have not yet been studied in any species of this family. Here, an anatomical and histological description of the olfactory organ of the sharpnose sevengill shark Heptranchias perlo is given. The organ is a rosette, with a central raphe and 31-34 primary lamellae, which bear secondary lamellae with a more or less branched shape. The elastic connective capsule which envelops the olfactory rosette possibly changes its shape along with water influx. In the olfactory epithelium, the supporting cells also have a secretory function, while no specialized mucous cells are visible; regarding this feature the olfactory epithelium of H. perlo differs from that of other chondrichthyan species. The immunohistochemical investigation of the sensory epithelium shows the absence of immunoreactivity for Gαolf in receptor neurons, which confirms previous observations in Chondrichthyes. Copyright © 2017 Elsevier GmbH. All rights reserved.

Plasmonic interferometers: From physics to biosensing applications

NASA Astrophysics Data System (ADS)

Zeng, Xie

Optical interferometry has a long history and wide range of applications. In recent years, plasmonic interferometer arouses great interest due to its compact size and enhanced light-matter interaction. They have demonstrated attractive applications in biomolecule sensing, optical modulation/switching, and material characterization, etc. In this work, we first propose a practical far-field method to extract the intrinsic phase dispersion, revealing important phase information during interactions among free-space light, nanostructure, and SPs. The proposed approach is confirmed by both simulation and experiment. Then we design novel plasmonic interferometer structure for sensitive optical sensing applications. To overcome two major limitations suffered by previously reported double-slit plasmonic Mach-Zehnder interferometer (PMZI), two new schemes are proposed and investigated. (1) A PMZI based on end-fire coupling improves the SP coupling efficiency and enhance the interference contrast more than 50 times. (2) In another design, a multi-layered metal-insulator-metal PMZI releases the requirement for single-slit illumination, which enables sensitive, high-throughput sensing applications based on intensity modulation. We develop a sensitive, low-cost and high-throughput biosensing platform based on intensity modulation using ring-hole plasmonic interferometers. This biosensor is then integrated with cell-phone-based microscope, which is promising to develop a portable sensor for point-of-care diagnostics, epidemic disease control and food safety monitoring.

Tip-Enhanced Raman Nanographs: Mapping Topography and Local Electric Fields

DOE PAGES

El-Khoury, Patrick Z.; Gong, Yu; Abellan, Patricia; ...

2015-03-05

We report tip-enhanced Raman scattering experiments in which topographic and local electric field images are recorded simultaneously. We employ a Raman-active 4,4’-dimercaptostilbene (DMS)-coated gold tip of an atomic force microscope to map the topography and image electric fields localized at nanometric (20 and 5 nm-wide) slits lithographically etched in silver. Bi-modal imaging is feasible by virtue of the recorded scanning probe position-dependent frequency-resolved optical response, which can be sub-divided into two components. The first is a 500-2250 cm-1 Raman-shifted signal, characteristic of DMS. The molecular response reports on topography through intensity contrast in the absence/presence of a plasmonic junction formedmore » between the scanning probe and patterned silver surface. Here, we demonstrate that sub-15 nm spatial resolution is attainable using a 30 nm DMS-coated gold tip. The second response consists of two correlated sub-500 cm-1 signals arising from mirror-like reflections of (i) the incident laser, and (ii) the Raman scattered response of an underlying glass support (at 100-500 cm-1) off the gold tip. We show that both the low-wavenumber signals trace the local electric fields in the vicinity of the nanometric slits.« less

Light Spectral Quality Effects on the Growth of Potato (Solanum Tuberosum L.) Nodal Cuttings in Vitro

NASA Technical Reports Server (NTRS)

Wilson, Deborah A.; Weigel, Russell C.; Wheeler, Raymond M.; Sager, John C.

1993-01-01

The effects of light spectral quality on the growth of in vitro nodal cuttings of potato (Solanum tuberosum L.) cultivars Norland, Superior, Kennebec, and Denali were examined. The different light spectra were provided by Vita-Lite fluorescent (VF) (a white light control), blue fluorescent (BF), red fluorescent (RF), low-pressure sodium (LPS), and a combination of low-pressure sodium plus cool-white fluorescent lamps (LPS/CWF). For cultivars, stem lengths after 4 wks were longest under LPS, follow by RF, LPS/CWF, VF, and BF (in descending order). Microscopic studies revealed that cells were shortest when cultured in BF or VF environments, and were longest in RF or LPS lamp environments. The highest number axillary branches occurred on plantlets grown with LPS or LPS/CWF, whereas the lowest number occurred with BF. No leaf or stem edema (callus or gall-like growths) occurred iwth LPS or LPS/cwf lighting, and no edema occurred on cv. Norland plantlets, regardless of lighting. Results suggest that shoot morphologic development of in vitro grown potato plants can be controlled by controlling irradiant spectral quality.

Intraoperative Fluorescence Cerebral Angiography by Laser Surgical Microscopy: Comparison With Xenon Microscopy and Simultaneous Observation of Cerebral Blood Flow and Surrounding Structures.

PubMed

Ito, Yuhei; Suzuki, Kyouichi; Ichikawa, Tsuyoshi; Watanabe, Yoichi; Sato, Taku; Sakuma, Jun; Saito, Kiyoshi

2018-06-12

Laser surgical microscopes should enable uniform illumination of the operative field, and require less luminous energy compared with existing xenon surgical microscopes. To examine the utility of laser illumination in fluorescence cerebral angiography. Fluorescein sodium (fluorescein) was used as a fluorescent dye. We first compared the clarity of cerebral blood flow images collected by fluorescence angiography between the laser illumination and xenon illumination methods. We then assessed use of the laser illuminator for simultaneous observation of blood flow and surrounding structures during fluorescence angiography. Furthermore, the study was designed to evaluate usefulness of the thus determined excitation light in clinical cases. Fluorescence angiography using blue light laser for excitation provided higher clarity and contrast blood flow images compared with using blue light generated from a xenon lamp. Further, illumination with excitation light consisting of a combination of 3 types of laser (higher level of blue light, no green light, and lower level of red light) enabled both blood flow and surrounding structures to be observed through the microscope directly by the surgeon. Laser-illuminated fluorescence angiography provides high clarity and contrast images of cerebral blood flow. Further, a laser providing strong blue light and weak red light for excitation light enables simultaneous visual observation of fluorescent blood flow and surrounding structures by the surgeon using a surgical microscope. Overall, these data suggest that laser surgical microscopes are useful for both ordinary operative manipulations and fluorescence angiography.

The effect of Slit homolog 2 (SLIT2) on populations of preantral follicles in cultured cortical tissue from pig ovaries

USDA-ARS?s Scientific Manuscript database

SLIT guidance ligands are secreted glycoproteins involved in organogenesis. SLIT proteins and their receptor have been linked to ovarian development in fetal sheep and luteal function in adult humans. In pigs, SLIT proteins have been associated with age at puberty (GWAS) and as a major node in genom...

Relation between one- and two-dimensional noise power spectra of magnetic resonance images.

PubMed

Ichinoseki, Yuki; Machida, Yoshio

2017-06-01

Our purpose in this study was to elucidate the relation between the one-dimensional (1D) and two-dimensional (2D) noise power spectra (NPSs) in magnetic resonance imaging (MRI). We measured the 1D NPSs using the slit method and the radial frequency method. In the slit method, numerical slits 1 pixel wide and L pixels long were placed on a noise image (128 × 128 pixels) and scanned in the MR image domain. We obtained the 1D NPS using the slit method (1D NPS_Slit) and the 2D NPS of the noise region scanned by the slit (2D NPS_Slit). We also obtained 1D NPS using the radial frequency method (1D NPS_Radial) by averaging the NPS values on the circumference of a circle centered at the origin of the original 2D NPS. The properties of the 1D NPS_Slits varied with L and the scanning direction in PROPELLER MRI. The 2D NPS_Slit shapes matched that of the original 2D NPS, but were compressed by L/128. The central line profiles of the 2D NPS_Slits and the 1D NPS_Slits matched exactly. Therefore, the 1D NPS_Slits reflected not only the NPS values on the central axis of the original 2D NPS, but also the NPS values around the central axis. Moreover, the measurement precisions of the 1D NPS_Slits were lower than those of the 1D NPS_Radial. Consequently, it is necessary to select the approach applied for 1D NPS measurements according to the data acquisition method and the purpose of the noise evaluation.

Near-field thermal radiation of deep- subwavelength slits in the near infrared range.

PubMed

Guo, Yan; Li, Kuanbiao; Xu, Ying; Wei, Kaihua

2017-09-18

We numerically investigate the thermal radiation of one-dimensional deep subwavelength slits in the near infrared range. Using numerical calculations of single-slit and multi-slit structures, we find that high-level radiation efficiency can be achieved for a wide spectrum when ultra-thin intermediate layers are used, and it is less affected by structure parameters. The underlying mechanisms involve Surface Plasmon Polaritons resonance and Fabry-Perot interference at each slit and the interaction between adjacent slits. This structure helps understand and improve the design of thermal radiation control devices.

Successful single treatment with ziv-aflibercept for existing corneal neovascularization following ocular chemical insult in the rabbit model.

PubMed

Gore, Ariel; Horwitz, Vered; Cohen, Maayan; Gutman, Hila; Cohen, Liat; Gez, Rellie; Kadar, Tamar; Dachir, Shlomit

2018-06-01

To evaluate the efficacy of ziv-aflibercept as a treatment for established corneal neovascularization (NV) and to compare its efficacy to that of bevacizumab following ocular chemical insult of sulfur mustard (SM) in the rabbit model. Chemical SM burn was induced in the right eye of NZW rabbits by vapor exposure. Ziv-aflibercept (2 mg) was applied once to neovascularized eyes by subconjunctival injection while subconjunctival bevacizumab (5 mg) was administered twice a week, for 3 weeks. Non-treated exposed eyes served as a control. A clinical follow-up employed by slit-lamp microscope, was performed up to 12 weeks following exposure and digital photographs of the cornea were taken for measurement of blood vessels length using the image analysis software. Eyes were taken for histological evaluation 2, 4 and 8 weeks following treatment for general morphology and for visualization of NV, using H&E and Masson Trichrome stainings, while conjunctival goblet cell density was determined by PAS staining. Corneal NV developed, starting as early as two weeks after exposure. A single subconjunctival treatment of ziv-aflibercept at 4 weeks post exposure, significantly reduced the extent of existing NV already one week following injection, an effect which lasted for at least 8 weeks following treatment, while NV in the non-treated exposed eyes continued to advance. The extensive reduction in corneal NV in the ziv-aflibercept treated group was confirmed by histological evaluation. Bevacizumab multiple treatment showed a benefit in NV reduction, but to a lesser extent compared to the ziv-aflibercept treatment. Finally, ziv-aflibercept increased the density of conjunctival goblet cells as compared to the exposed non-treated group. Subconjunctival ziv-aflibercept single treatment presented a highly efficient long-term therapeutic benefit in reducing existing corneal NV, following ocular sulfur mustard exposure. These findings show the robust anti-angiogenic efficacy of ziv-aflibercept and demonstrate the advantage of this treatment over the other anti-angiogenic therapies in ameliorating corneal NV and protecting the ocular surface. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparison of corneal endothelial image analysis by Konan SP8000 noncontact and Bio-Optics Bambi systems.

PubMed

Benetz, B A; Diaconu, E; Bowlin, S J; Oak, S S; Laing, R A; Lass, J H

1999-01-01

Compare corneal endothelial image analysis by Konan SP8000 and Bio-Optics Bambi image-analysis systems. Corneal endothelial images from 98 individuals (191 eyes), ranging in age from 4 to 87 years, with a normal slit-lamp examination and no history of ocular trauma, intraocular surgery, or intraocular inflammation were obtained by the Konan SP8000 noncontact specular microscope. One observer analyzed these images by using the Konan system and a second observer by using the Bio-Optics Bambi system. Three methods of analyses were used: a fixed-frame method to obtain cell density (for both Konan and Bio-Optics Bambi) and a "dot" (Konan) or "corners" (Bio-Optics Bambi) method to determine morphometric parameters. The cell density determined by the Konan fixed-frame method was significantly higher (157 cells/mm2) than the Bio-Optics Bambi fixed-frame method determination (p<0.0001). However, the difference in cell density, although still statistically significant, was smaller and reversed comparing the Konan fixed-frame method with both Konan dot and Bio-Optics Bambi comers method (-74 cells/mm2, p<0.0001; -55 cells/mm2, p<0.0001, respectively). Small but statistically significant morphometric analyses differences between Konan and Bio-Optics Bambi were seen: cell density, +19 cells/mm2 (p = 0.03); cell area, -3.0 microm2 (p = 0.008); and coefficient of variation, +1.0 (p = 0.003). There was no statistically significant difference between these two methods in the percentage of six-sided cells detected (p = 0.55). Cell densities measured by the Konan fixed-frame method were comparable with Konan and Bio-Optics Bambi's morphometric analysis, but not with the Bio-Optics Bambi fixed-frame method. The two morphometric analyses were comparable with minimal or no differences for the parameters that were studied. The Konan SP8000 endothelial image-analysis system may be useful for large-scale clinical trials determining cell loss; its noncontact system has many clinical benefits (including patient comfort, safety, ease of use, and short procedure time) and provides reliable cell-density calculations.

[The study of new soft one-piece PHEMA keratoprosthesis implanted into alkali burned rabbits cornea].

PubMed

Bai, Hua; Huang, Yi-fei; Wang, Li-qiang

2013-10-01

This study was to evaluate clinical results of two types soft one-piece keratoprosthesis (KPros) made of PHEMA implanted to alkali burned rabbit corneas. Experimental study. Twelve pieces KPros were implanted alkali burned rabbit corneas(type I and II, 6 pieces respectively). The examinations including slit-lamp, fundus photography,B-ultrasound and ultrasound biomicroscopy (UBM) were carried out. All Kpros were stable and no complications happened including conjunctiva flap dehiscence, aqueous leak and infection. IOP were normal by finger touch. B-ultrasound show no retina detachment and UBM show synechia in most animals (10 case). Retroprosthetic membrane happened in type I (3 case) . Visible conjunctiva hyperplasia covering the optical region happened in all KPros. (1) The same material, integrated design, maybe eliminating the material interface problem. (2)Simple surgical skills. (3)IOP measurement is possible because of soft material. (4)KPro I do not need removal of the lens and vitrectomy. The projecting portion of KPro II may reduce the incidence of proliferative membrane. Long term effects need more cases and further observation.

Use of non-subjective analysis of lens transparency in experimental radiation cataract research

NASA Technical Reports Server (NTRS)

Worgul, B. V.; Medvedovsky, C.; Wu, B.

1995-01-01

Historically the major impediment to radiation cataract follow-up has been the necessarily subjective nature of assessing the degree of lens transparency. This has spurred the development of instruments which produce video images amenable to digital analysis. One such system, the Zeiss Scheimpflug slit lamp measuring system (SLC), was incorporated into our ongoing studies of radiation cataractogenesis. It was found that the Zeiss SLC measuring system has high resolution and permits the acquisition of reproducible images of the anterior segment of the eye. Our results, based on about 650 images of lenses followed over a period of 91 weeks of radiation cataract development, showed that the changes in the light scatter of the lens correlated well with conventional assessment of radiation cataracts with the added advantages of objectivity, permanent and transportable records and linearity as cataracts become more severe. This continuous data acquisition, commencing with cataract onset, can proceed through more advanced stages. The SLC exhibits much greater sensitivity reflected in a continuously progressive severity thereby avoiding the artifactual plateaus in staging which occur using conventional scoring methods.

Ocular Effects of Exposure to 40, 75, and 95 GHz Millimeter Waves

NASA Astrophysics Data System (ADS)

Kojima, Masami; Suzuki, Yukihisa; Sasaki, Kensuke; Taki, Masao; Wake, Kanako; Watanabe, Soichi; Mizuno, Maya; Tasaki, Takafumi; Sasaki, Hiroshi

2018-05-01

The objective of this study was to develop a model of ocular damage induced by 40, 75, and 95 GHz continuous millimeter waves (MMW), thereby allowing assessment of the clinical course of ocular damage resulting from exposure to thermal damage-inducing MMW. This study also examined the dependence of ocular damage on incident power density. Pigmented rabbit eyes were exposed to 40, 75, and 95 GHz MMW from a spot-focus-type lens antenna. Slight ocular damage was observed 10 min after MMW exposure, including reduced cornea thickness and reduced transparency. Diffuse fluorescein staining around the pupillary area indicated corneal epithelial injury. Slit-lamp examination 1 day after MMW exposure revealed a round area of opacity, accompanied by fluorescence staining, in the central pupillary zone. Corneal edema, indicative of corneal stromal damage, peaked 1 day after MMW exposure, with thickness gradually subsiding to normal. Three days after exposure, ocular conditions had almost normalized, though corneal thickness was slightly greater than that before exposure. The 50% probability of ocular damage (DD50) was in the order 40 > 95 ≈ 75 GHz at the same incident power densities.

Does Posterior Capsule Opacification Affect the Results of Diagnostic Technologies to Evaluate the Retina and the Optic Disc?

PubMed Central

Garcia-Medina, Jose Javier; del Rio-Vellosillo, Monica; Santos-Bueso, Enrique

2015-01-01

The visual outcome obtained after cataract removal may progressively decline because of posterior capsular opacification (PCO). This condition can be treated by creating an opening in the posterior lens capsule by Nd:YAG laser capsulotomy. PCO optical imperfections cause several light reflection, refraction, and diffraction phenomena, which may interfere with the functional and structural tests performed in different ocular locations for the diagnosis and follow-up of ocular disease, like macular and optic nerve diseases. Some parameters measured by visual field examinations, scanning laser polarimetry, and optical coherence tomography (OCT) have changed after PCO removal. Imaging quality also changes following capsulotomy. Consequently, the results of ancillary tests in pseudophakic eyes for studying ocular diseases like glaucoma or maculopathies should be correlated with other clinical examinations, for example, slit-lamp biomicroscopy or funduscopy. If PCO is clinically significant, a new baseline should be set for future comparisons following capsulotomy when using automated perimetry and scanning laser polarimetry. To perform OCT in the presence of PCO, reliable examinations (considering signal strength) apparently guarantee that measurements are not influenced by PCO. PMID:26167499

Phenotypic variability in monozygotic twins with neurofibromatosis 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baser, M.E.; Ragge, N.K.; Riccardi, V.M.

Mutations in the neurofibromatosis 2 (NF2) tumor suppressor gene on chromosome 22q12 cause a clinically variable autosomal dominant syndrome characterized by bilateral vestibular schwannomas (VSs), other nervous system tumors, and early onset lenticular cataracts. We studied three pairs of monozygotic (MZ) twins with NF2, all with bilateral VSs, to separate genetic from nongenetic causes of clinical variability. The evaluation included gadolinium-enhanced high-resolution magnetic resonance imaging of the head and spine, neuro-ophthalmic examination with slit lamp, physical examination, and zygosity testing with microsatellite markers. Each MZ pair was concordant for general phenotypic subtype (mild or severe) and often for the affectedmore » organ systems. However, the MZ pairs were discordant for some features of disease presentation or progression. For example, all three pairs were discordant for presence or type of associated cranial tumors. We hypothesize that phenotypic differences between NF2 MZ twins are at least partly due to stochastic processes, such as the loss of the second NF2 allele or alleles of other genes. 42 refs., 1 tab.« less

A patient with cystinosis presenting like bartter syndrome and review of literature.

PubMed

Ertan, Pelin; Evrengul, Havva; Ozen, Serkan; Emre, Sinan

2012-12-01

Nephropathic cystinosis is an autosomal recessively inherited metabolic disorder presenting with metabolic acidosis, Fanconi syndrome and renal failure. We present a 6-year-old girl with severe growth failure, hyponatremia and hypokalemia. Her parents were 4(th) degree relatives. Two relatives were diagnosed as end stage renal failure. She also had persistant hypokalemic hypochloremic metabolic alkalosis. Her renal function was normal at presentation. She was thought to have Bartter syndrome with supporting findings of elevated levels of renin and aldosterone with normal blood pressure, and hyperplasia of juxtaglomerular apparatus. Her metabolic alkalosis did not resolve despite supportive treatment. At 6(th) month of follow-up proteinuria, glucosuria and deterioration of renal function developed. Diagnosis of cystinosis was made with slit lamp examination and leukocyte cystine levels. At 12(th) month of follow-up her metabolic alkalosis has converted to metabolic acidosis. In children presenting with persistant metabolic alkalosis, with family history of renal failure, and parental consanguinity, cystinosis should always be kept in mind as this disease is an important cause of end stage renal failure which may have features mimmicking Bartter syndrome.

Objective categorization of interferential tear film lipid layer pattern: validation of the technique

NASA Astrophysics Data System (ADS)

García-Resúa, C.; Giráldez, M. J.; Barreira, N.; Penedo, M. G.; Yebra-Pimentel, E.

2011-05-01

Purpose: The lipid layer of the tear film limits evaporation during the inter-blink interval and also affects tear stability. This study was designed to validate a new software application designed to characterize the tear film lipid layer through texture and colour pattern recognition. Methods: Using the Tearscope-plus (slit lamp magnification 200X), the lipid layer was examined in 105 healthy young adults and interference photographs acquired with a Topcon DV-3 digital camera. The photographs were classified by the new software and by 2 further observers (observer 1 and observer 2) with experience in examining the eye surface. Results: Strong correlation was detected between the categories determined by the new application, observer 1 and observer 2 (Cramer's V, from 0.81 to 0.87, p<0.001). Best agreement (96.2%) was noted between the new method and observers 1 and 2 for recognizing meshwork patterns, whereas observers 1 and 2 showed greatest correspondence when classifying colour fringe patterns. Conclusions: The new application can objectively categorize LLPs using the Tearscope-plus.

Radiation-induced eye lens changes and risk for cataract in interventional cardiology.

PubMed

Ciraj-Bjelac, O; Rehani, M; Minamoto, A; Sim, K H; Liew, H B; Vano, E

2012-01-01

Recent studies have reported a significant increase in eye lens opacities among staff in the cardiac catheterization laboratory but indicated further studies are needed to confirm the findings. To evaluate the prevalence of opacities in eyes of cardiologists, radiographers and nurses working in interventional cardiology. The eyes of 52 staff in interventional cardiology facilities and 34 age- and sex-matched unexposed controls were screened in a cardiology conference held in Kuala Lumpur by dilated slit-lamp examination, and posterior lens changes were graded. Individual cumulative lens X-ray exposures were calculated from responses to a questionnaire in terms of workload and working practice. The prevalence of posterior lens opacities among interventional cardiologists was 53%, while in nurses and radiographers it was 45%. Corresponding relative risks were 2.6 (95% CI: 1.2-5.4) and 2.2 (95% CI: 0.98-4.9), for interventional cardiologists and support staff, respectively. This study confirms a statistically significant increase in radiation-associated posterior lens changes in the eyes of interventional cardiology staff. Copyright © 2012 S. Karger AG, Basel.

Red-free light for measurement of intraocular pressure using Goldmann applanation tonometer without fluorescein.

PubMed

Ghoneim, Ehab M

2014-01-01

To evaluate the use of red-free light for the measurement of intraocular pressure (IOP) using a Goldmann applanation tonometer without fluorescein. This cross-sectional study was carried out on 500 eyes in 250 patients attending the Ophthalmology Outpatient Clinic at Suez Canal University Hospital. The IOP was measured using a Goldmann applanation tonometer mounted on a Haag-Streit slit-lamp. The measurements were performed first using red-free light without fluorescein. Then the measurements were repeated with cobalt blue light and topical fluorescein on the same eyes. The mean IOP was 15.23 ± 3.3 (SD) mm Hg using the red-free light without fluorescein, whereas it was 15.78 ± 3.7 (SD) mm Hg when measured using cobalt blue light after the application of fluorescein to the conjunctival sac. This difference was not statistically significant. Measurement of IOP with a Goldmann applanationtonometer with red-free light and without the use of fluorescein is simple, saves time, and gives an accurate IOP measurement relative to the traditional measurement technique with cobalt blue light and topical fluorescein.

Severe keratomalacia after 12 months of continuous hydrogel contact lens wear in a psychiatric patient.

PubMed

Rico-Sergado, Laura; Pérez-Canales, Jose L; Pérez-Santonja, Juan J; Cigüenza-Sancho, Sonia

2015-04-01

A 53-year-old cachectic patient diagnosed with major depressive disorder was referred to our department for evaluation of a visible deformation of the right eye. She had been wearing hydrogel contact lenses on a continuous basis without removal for the last 12 months, influenced by low self-esteem and social isolation. Slit-lamp examination of the right eye showed a conical cornea, extensive neovascularization, severe stromal melting with descemetocele formation and forward bulging of the iris. Examination of the left eye revealed multiple corneal opacities, deep stromal neovascularization and anterior chamber inflammation. No sign of infection was present. Vitamin A deficiency was suspected and later confirmed. The patient required evisceration of the right eye and psychiatric treatment. Inflammatory signs of the left eye resolved within 1 week of initiating treatment. This case illustrates the synergistic effect of soft contact lens abuse and vitamin A deficiency in a psychiatric patient, and emphasizes the importance of instructing vulnerable patients on appropriate lens use and care. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Enterococcus faecalis Endogenous Endophthalmitis from Valvular Endocarditis

PubMed Central

Barge, Sidnei; Rothwell, Renata; Varandas, Rosário; Agrelos, Luís

2013-01-01

We report a case of a 74-year-old female, with a mitral heart valve, who presented with pain and blurred vision in the right eye for 2 days. Her visual acuity was light perception (LP) in the right eye and 20/40 in the left eye. Slit lamp examination showed corneal edema and hypopyon, and a view of the right fundus was impossible. Echography showed vitreous condensation. One day after presentation, the patient developed acute lung edema requiring hospitalization, so she was not submitted to vitreous tap and intravitreal treatment. The cardiac and systemic evaluations revealed a mitral endocarditis secondary to Enterococcus faecalis. The patient improved systemically with treatment with gentamicin, vancomycin, and linezolid. Her visual acuity remained as no LP, and her intraocular pressure (IOP) has been controlled with brimonidine bid despite developing a total cataract with 360° posterior synechia. A cardiac source for endogenous endophthalmitis should be considered in the presence of a prosthetic cardiac valve. The treatment and followup must be made in cooperation with a cardiologist specialist, but the ophthalmologist can play a key role in the diagnosis. PMID:23936701

Clinical correlations of dry eye syndrome and allergic conjunctivitis in Korean children.

PubMed

Kim, Tae Hyung; Moon, Nam Ju

2013-01-01

Clinical patterns in pediatric patients with dry eye syndrome and allergic conjunctivitis were investigated. Children aged 6 to 15 years with dry eye symptoms were included. Slit-lamp examinations including tear film break-up time, Schirmer's test, and fluorescent staining were performed, and subjective symptoms were investigated. Patients with allergic conjunctivitis were subjected to skin prick tests. Tear film break-up time was shorter and the number of symptoms related to dry eyes was higher in pediatric patients with allergic conjunctivitis than in those without allergic conjunctivitis. Patients with allergic conjunctivitis who had higher numbers of positive allergens on the skin prick test also had shorter tear film break-up time. Because pediatric patients with dry eye syndrome tend to complain less about their symptoms than adult patients, dry eye syndrome is commonly overlooked. This study showed that dry eyes tended to be more severe with the presence of allergic conjunctivitis; the more allergens present, the more severe the dry eyes. More attention should be paid to the treatment of pediatric patients with dry eyes accompanied by allergies. Copyright 2013, SLACK Incorporated.

Chemical Burn-Induced Stromal Demarcation Line.

PubMed

Brosh, Koby; Rozenman, Yaacov

2016-02-01

A stromal demarcation line is a well-known sign after collagen cross-linking. It has been proposed that this line is the transition zone between cellular and acellular stroma, and thus it might reveal the depth of photochemical changes in the corneal stroma. We report 2 cases of a similar demarcation line after chemical alkali burns. To the best of our knowledge, this is the first report of a stromal demarcation line after a chemical burn. Two patients presented to the emergency department after an ocular alkali burn. At presentation, both had total corneal erosion, corneal edema, and limbal ischemia. After 12 to 15 days, a stromal line was apparent by both slit-lamp examination and anterior segment optical coherence tomography. The stromal demarcation lines disappeared approximately 3 months after the injury. A stromal demarcation line may appear not only after collagen cross-linking but also after a chemical burn. The line depth may be associated with the severity of the injury, and therefore, may have prognostic significance. Patients with chemical burns should be examined for evidence of a stromal line in the cornea.

Optical coherence tomography in anterior segment imaging

PubMed Central

Kalev-Landoy, Maya; Day, Alexander C.; Cordeiro, M. Francesca; Migdal, Clive

2008-01-01

Purpose To evaluate the ability of optical coherence tomography (OCT), designed primarily to image the posterior segment, to visualize the anterior chamber angle (ACA) in patients with different angle configurations. Methods In a prospective observational study, the anterior segments of 26 eyes of 26 patients were imaged using the Zeiss Stratus OCT, model 3000. Imaging of the anterior segment was achieved by adjusting the focusing control on the Stratus OCT. A total of 16 patients had abnormal angle configurations including narrow or closed angles and plateau irides, and 10 had normal angle configurations as determined by prior full ophthalmic examination, including slit-lamp biomicroscopy and gonioscopy. Results In all cases, OCT provided high-resolution information regarding iris configuration. The ACA itself was clearly visualized in patients with narrow or closed angles, but not in patients with open angles. Conclusions Stratus OCT offers a non-contact, convenient and rapid method of assessing the configuration of the anterior chamber. Despite its limitations, it may be of help during the routine clinical assessment and treatment of patients with glaucoma, particularly when gonioscopy is not possible or difficult to interpret. PMID:17355288

A novel IMPDH1 mutation (Arg231Pro) in a family with a severe form of autosomal dominant retinitis pigmentosa.

PubMed

Grover, Sandeep; Fishman, Gerald A; Stone, Edwin M

2004-10-01

To define ophthalmic findings in a family with autosomal dominant retinitis pigmentosa and a novel IMPDH1 gene mutation. Genetic and observational family study. Sixteen affected members of a family with autosomal dominant retinitis pigmentosa. Ophthalmic examination, including best-corrected visual acuity (VA), slit-lamp biomicroscopy, direct and indirect ophthalmoscopy, Goldmann kinetic perimetry, and electroretinography were performed. Deoxyribonucleic acid single-strand conformation polymorphism (SSCP) analysis was done. Abnormal polymerase chain reaction products identified by SSCP analysis were sequenced bidirectionally. All affected patients had the onset of night blindness within the first decade of life. Ocular findings were characterized by diffuse retinal pigmentary degenerative changes, marked restriction of peripheral visual fields, severe loss of VA, nondetectable electroretinography amplitudes, and a high frequency of posterior subcapsular lens opacities. Affected members were observed to harbor a novel IMPDH1 gene mutation. A novel IMPDH1 gene mutation (Arg231Pro) was associated with a severe form of autosomal dominant retinitis pigmentosa. Families affected with a severe form of this genetic subtype should be investigated for a mutation in the IMPDH1 gene.

Laser flare photometry: a noninvasive, objective, and quantitative method to measure intraocular inflammation.

PubMed

Tugal-Tutkun, Ilknur; Herbort, Carl P

2010-10-01

Aqueous flare and cells are the two inflammatory parameters of anterior chamber inflammation resulting from disruption of the blood-ocular barriers. When examined with the slit lamp, measurement of intraocular inflammation remains subjective with considerable intra- and interobserver variations. Laser flare cell photometry is an objective quantitative method that enables accurate measurement of these parameters with very high reproducibility. Laser flare photometry allows detection of subclinical alterations in the blood-ocular barriers, identifying subtle pathological changes that could not have been recorded otherwise. With the use of this method, it has been possible to compare the effect of different surgical techniques, surgical adjuncts, and anti-inflammatory medications on intraocular inflammation. Clinical studies of uveitis patients have shown that flare measurements by laser flare photometry allowed precise monitoring of well-defined uveitic entities and prediction of disease relapse. Relationships of laser flare photometry values with complications of uveitis and visual loss further indicate that flare measurement by laser flare photometry should be included in the routine follow-up of patients with uveitis.

Smartphone-based imaging of the corneal endothelium at sub-cellular resolution

NASA Astrophysics Data System (ADS)

Toslak, Devrim; Thapa, Damber; Erol, Muhammet Kazim; Chen, Yanjun; Yao, Xincheng

2017-07-01

This aim of this study was to test the feasibility of smartphone-based specular microscopy of the corneal endothelium at a sub-cellular resolution. Quantitative examination of endothelial cells is essential for evaluating corneal disease such as determining a diagnosis, monitoring progression and assessing treatment. Smartphone-based technology promises a new opportunity to develop affordable devices to foster quantitative examination of endothelial cells in rural and underserved areas. In our study, we incorporated an iPhone 6 and a slit lamp to demonstrate the feasibility of smartphone-based microscopy of the corneal endothelium at a sub-cellular resolution. The sub-cellular resolution images allowed quantitative calculation of the endothelial cell density. Comparative measurements revealed a normal endothelial cell density of 2978 cells/mm2 in the healthy cornea, and a significantly reduced cell density of 1466 cells/mm2 in the diseased cornea with Fuchs' dystrophy. Our ultimate goal is to develop a smartphone-based telemedicine device for low-cost examination of the corneal endothelium, which can benefit patients in rural areas and underdeveloped countries to reduce health care disparities.

A new solid-state, frequency-doubled neodymium-YAG photocoagulation system.

PubMed

Jalkh, A E; Pflibsen, K; Pomerantzeff, O; Trempe, C L; Schepens, C L

1988-06-01

We have developed a solid-state laser system that produces a continuous green monochromatic laser beam of 532 nm by doubling the frequency of a neodymium-YAG laser wavelength of 1064 nm with a potassium-titamyl-phosphate crystal. Photocoagulation burns of equal size and intensity were placed in two rabbit eyes with the solid-state laser system and the regular green argon laser system, respectively, using the same slit-lamp mode of delivery. Histologic findings of lesion sections revealed no important differences between the two systems. In theory, the longer wavelength of the solid-state laser offers the advantages of less scattering in ocular media, higher absorption by oxyhemoglobin, and less absorption by macular xanthophyll than the 514-nm wavelength of the regular green argon laser. The solid-state laser has impressive technical advantages: it contains no argon-ion gas tube that wears out and is expensive to replace; it is much more power efficient, and thus considerably smaller and compact; it is sturdier and easily movable; it does not require external cooling; it uses a 220-V monophasic alternating current; and it requires little maintenance.

Effect of combined topical heparin and steroid on corneal neovascularization in children.

PubMed

Michels, Rike; Michels, Stephan; Kaminski, Stephan

2012-01-01

To demonstrate the effect of topical heparin combined with topical steroid on corneal neovascularization (CN) in children. Four children (5 eyes) with new-onset progressive CN in at least one eye received topical rimexolone or dexamethasone in combination with heparin until complete regression of CN was obtained. The regression of CN was documented by slit-lamp or anterior segment photography. All 5 eyes showed complete regression of CN within 5 months. An anti-angiogenic effect was found as early as 1 week after starting topical combination treatment. No ocular and systemic side effects were detected and treatment was well tolerated by all children. In the 3 eyes with involvement of the optical axis, symmetrical visual acuity was obtained by amblyopia treatment. Recurrence of the CN was detectable in 2 eyes at 1 and 6 months, respectively, after ending combination therapy. Both eyes responded favorably to re-treatment. Combination of topical heparin and steroid leads to rapid regression and complete inactivity of CN. This therapeutic approach is promising, especially in children with limited therapeutic alternatives and a high risk for amblyopia. Copyright 2012, SLACK Incorporated.

Infectious crystalline keratopathy associated with Klebsiella oxytoca.

PubMed

Chou, Timothy Y; Adyanthaya, Rohit

2012-12-01

The purpose of this study is to report a novel case of a Klebsiella oxytoca-associated infectious crystalline keratopathy This is a case report study. An 80-year-old woman presented with complaint of noticing a white spot in the left eye for 2 to 3 days, as well as mild soreness and discharge. Past ocular history was notable for a failed left corneal transplant for which she was taking prednisolone acetate 1 % twice per day. On slit-lamp examination, there was an extensive stromal ulcer and infiltrate in the inferior half of the transplant. Extending superiorly in the graft were branching, needle-like deep stromal opacities, characteristic of infectious crystalline keratopathy. Diagnostic scrapings revealed Gram-negative bacilli, subsequently identified on culture as K. oxytoca. There was also light growth of Staphylococcus species. The patient was placed on double topical antibiotic therapy with moxifloxacin and fortified tobramycin. After 2 months of treatment there was gradual resolution of the infection. K. oxytoca is a microorganism which can be associated with clinical infectious crystalline keratopathy, presenting as a mixed infection along with Staphylococcus species.

Bilateral fungal keratitis with ring infiltrates: a rare scenario.

PubMed

Chaniyara, Manthan Hasmukhbhai; Pujari, Amar; Urkude, Jayanand; Sharma, Namrata

2017-10-09

A 12-year-old boy presented to the emergency department with chief complaints of pain, redness, discharge and diminution of vision in both eyes over the previous 20 days. There was no history of preceding trauma, contact lens use, any eye drop usage or ocular surgery. Systemic history was not significant. Presenting uncorrected visual acuity in his right eye was counting fingers at 1 m and 20/200 in the left eye, with accurate projection of rays in both eyes. Slit lamp biomicroscopy showed the presence of bilateral diffuse conjunctival congestion, corneal ring infiltrates and epithelial defect with corneal oedema. Potassium hydroxide wet mount showed the presence of septate fungal hyphae. The patient was treated with topical 5% natamycin and 1% voriconazole over a period of 6 weeks. Best-corrected visual acuity was 20/600 in the right eye and 20/20 in the left eye at 6-month follow-up. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Endogenous Serratia marcescens endophthalmitis.

PubMed

Shah, Sonya B; Bansal, Alok S; Rabinowitz, Michael P; Park, Carl; Bedrossian, Edward H; Eagle, Ralph C

2014-01-01

The purpose of this study was to describe a rare case of endogenous endophthalmitis associated with dental disease secondary to Serratia marcescens in an HIV-negative individual. Retrospective case report. A 50-year-old white man with a history of intravenous drug use presented with pain and decreased vision in his right eye. Slit-lamp examination showed a hazy cornea, hypopyon with fibrin in the anterior chamber, and elevated intraocular pressure. B-scan ultrasound showed vitritis and choroidal thickening. Computed tomography showed gingival inflammation and lucencies of several teeth. Blood and urine cultures were negative, and HIV testing was negative. Echocardiography was negative for vegetations. Intravitreal culture revealed S. marcescens. Despite intravitreal and systemic antibiotics, the patient's clinical situation rapidly deteriorated, and the eye was eviscerated. The patient underwent dental extraction and was subsequently discharged in stable condition. The first case of endogenous endophthalmitis secondary to S. marcescens in an otherwise healthy, HIV-negative, intravenous drug user in association with severe dental disease is reported. Serratia may be found in oral biofilm, and this mechanism should be considered in cases where other etiologies have been ruled out.

Near-Field Scanning Optical Microscopy and Raman Microscopy.

NASA Astrophysics Data System (ADS)

Harootunian, Alec Tate

1987-09-01

Both a one dimensional near-field scanning optical microscope and Raman microprobe were constructed. In near -field scanning optical microscopy (NSOM) a subwavelength aperture is scanned in the near-field of the object. Radiation transmitted through the aperture is collected to form an image as the aperture scans over the object. The resolution of an NSOM system is essentially wavelength independent and is limited by the diameter of the aperture used to scan the object. NSOM was developed in an effort to provide a nondestructive in situ high spatial resolution probe while still utilizing photons at optical wavelengths. The Raman microprobe constructed provided vibrational Raman information with spatial resolution equivalent that of a conventional diffraction limited microscope. Both transmission studies and near-field diffration studies of subwavelength apertures were performed. Diffraction theories for a small aperture in an infinitely thin conducting screen, a slit in a thick conducting screen, and an aperture in a black screen were examined. All three theories indicate collimation of radiation to the size to the size of the subwavelength aperture or slit in the near-field. Theoretical calculations and experimental results indicate that light transmitted through subwavelength apertures is readily detectable. Light of wavelength 4579 (ANGSTROM) was transmitted through apertures with diameters as small as 300 (ANGSTROM). These studies indicate the feasibility of constructing an NSOM system. One dimensional transmission and fluorescence NSOM systems were constructed. Apertures in the tips of metallized glass pipettes width inner diameters of less than 1000 (ANGSTROM) were used as a light source in the NSOM system. A tunneling current was used to maintain the aperture position in the near-field. Fluorescence NSOM was demonstrated for the first time. Microspectroscopic and Raman microscopic studies of turtle cone oil droplets were performed. Both the Raman vibrational frequencies and the Raman excitation data indicate that the carotenoids are unaggregated. The carotenoid astaxanthin was identified in the orange and red droplets by Raman microscopy. Future applications for both Raman microscopy and near-field microscopy were proposed. Four methods of near-field distance regulation were also examined. Finally, theoretical exposure curves for near-field lithography were calculated. Both the near-field lithographic results and the near field diffraction studies indicate essentially wavelength independent resolution. (Abstract shortened with permission of author.).

Slit2 promotes tumor growth and invasion in chemically induced skin carcinogenesis.

PubMed

Qi, Cuiling; Lan, Haimei; Ye, Jie; Li, Weidong; Wei, Ping; Yang, Yang; Guo, Simei; Lan, Tian; Li, Jiangchao; Zhang, Qianqian; He, Xiaodong; Wang, Lijing

2014-07-01

Slit, a neuronal guidance cue, binds to Roundabout (Robo) receptors to modulate neuronal, leukocytic, and endothelial migration. Slit has been reported to have an important effect on tumor growth and metastasis. In the current study, we evaluated the role of Slit2 in skin tumor growth and invasion in mice using a two-step chemical carcinogenesis protocol. We found that Slit2 expression correlated with the loss of basement membrane in the samples of human skin squamous cell carcinoma at different stages of disease progression. Slit2-Tg mice developed significantly more skin tumors than wild-type mice. Furthermore, the skin tumors that occurred in Slit2-Tg mice were significantly larger than those in the wild-type mice 10 weeks after 7,12-dimethylbenz[a]anthracene initiation until the end of the experiment. We also found that pathological development of the wild-type mice was delayed compared with that of Slit2-Tg mice. To further investigate the mechanism of increasing tumors in Slit2-Tg mice, we analyzed the expression of 5-bromo-2'-deoxyuridine (BrdU) in mouse skin lesions and found that the number of BrdU-positive cells and microvessel density in skin lesions were significantly higher in Slit2-Tg mice than in wild-type mice. Histological staining of PAS and type IV collagen and the colocalization of Slit2 and type IV collagen demonstrated varying degrees of loss of the basement membrane in the skin lesions from Slit2-Tg mice that were at the stage of carcinoma in situ. However, the basement membrane was well defined in the wild-type mice. In addition, MMP2, but not MMP9, was upregulated in the skin tissue of Slit2-Tg mice. Interruption of Slit2-Robo1 signaling by the antibody R5 significantly repressed the invasive capability of the squamous cell carcinoma cell line A431. Taken together, our findings reveal that Slit2 promotes DMBA/TPA-induced skin tumorigenesis by increasing cell proliferation, microvessel density, and invasive behavior of cutaneous squamous cell carcinoma, along with loss of basement membrane, by upregulation of MMP2 expression.

A measurement of electron-wall interactions using transmission diffraction from nanofabricated gratings

NASA Astrophysics Data System (ADS)

Barwick, Brett; Gronniger, Glen; Yuan, Lu; Liou, Sy-Hwang; Batelaan, Herman

2006-10-01

Electron diffraction from metal coated freestanding nanofabricated gratings is presented, with a quantitative path integral analysis of the electron-grating interactions. Electron diffraction out to the 20th order was observed indicating the high quality of our nanofabricated gratings. The electron beam is collimated to its diffraction limit with ion-milled material slits. Our path integral analysis is first tested against single slit electron diffraction, and then further expanded with the same theoretical approach to describe grating diffraction. Rotation of the grating with respect to the incident electron beam varies the effective distance between the electron and grating bars. This allows the measurement of the image charge potential between the electron and the grating bars. Image charge potentials that were about 15% of the value for that of a pure electron-metal wall interaction were found. We varied the electron energy from 50to900eV. The interaction time is of the order of typical metal image charge response times and in principle allows the investigation of image charge formation. In addition to the image charge interaction there is a dephasing process reducing the transverse coherence length of the electron wave. The dephasing process causes broadening of the diffraction peaks and is consistent with a model that ascribes the dephasing process to microscopic contact potentials. Surface structures with length scales of about 200nm observed with a scanning tunneling microscope, and dephasing interaction strength typical of contact potentials of 0.35eV support this claim. Such a dephasing model motivated the investigation of different metallic coatings, in particular Ni, Ti, Al, and different thickness Au-Pd coatings. Improved quality of diffraction patterns was found for Ni. This coating made electron diffraction possible at energies as low as 50eV. This energy was limited by our electron gun design. These results are particularly relevant for the use of these gratings as coherent beam splitters in low energy electron interferometry.

Slit Function Measurement of An Imaging Spectrograph Using Fourier Transform Techniques

NASA Technical Reports Server (NTRS)

Park, Hongwoo; Swimyard, Bruce; Jakobsen, Peter; Moseley, Harvey; Greenhouse, Matthew

2004-01-01

Knowledge of a spectrograph slit function is necessary to interpret the unresolved lines in an observed spectrum. A theoretical slit function can be calculated from the sizes of the entrance slit, the detector aperture when it functions as an exit slit, the dispersion characteristic of the disperser, and the point spread function of the spectrograph. A measured slit function is preferred to the theoretical one for the correct interpretation of the spectral data. In a scanning spectrometer with a single exit slit, the slit function is easily measured. In a fixed grating/or disperser spectrograph, illuminating the entrance slit with a near monochromatic light from a pre-monochrmator or a tunable laser and varying the wavelength of the incident light can measure the slit function. Even though the latter technique had been used successfully for the slit function measurements, it had been very laborious and it would be prohibitive to an imaging spectrograph or a multi-object spectrograph that has a large field of view. We explore an alternative technique that is manageable for the measurements. In the proposed technique, the imaging spectrograph is used as a detector of a Fourier transform spectrometer. This method can be applied not only to an IR spectrograph but also has a potential to a visible/UV spectrograph including a wedge filter spectrograph. This technique will require a blackbody source of known temperature and a bolometer to characterize the interferometer part of the Fourier Transform spectrometer. This pa?er will describe the alternative slit function measurement technique using a Fourier transform spectrometer.

Color calibration of an RGB camera mounted in front of a microscope with strong color distortion.

PubMed

Charrière, Renée; Hébert, Mathieu; Trémeau, Alain; Destouches, Nathalie

2013-07-20

This paper aims at showing that performing color calibration of an RGB camera can be achieved even in the case where the optical system before the camera introduces strong color distortion. In the present case, the optical system is a microscope containing a halogen lamp, with a nonuniform irradiance on the viewed surface. The calibration method proposed in this work is based on an existing method, but it is preceded by a three-step preprocessing of the RGB images aiming at extracting relevant color information from the strongly distorted images, taking especially into account the nonuniform irradiance map and the perturbing texture due to the surface topology of the standard color calibration charts when observed at micrometric scale. The proposed color calibration process consists first in computing the average color of the color-chart patches viewed under the microscope; then computing white balance, gamma correction, and saturation enhancement; and finally applying a third-order polynomial regression color calibration transform. Despite the nonusual conditions for color calibration, fairly good performance is achieved from a 48 patch Lambertian color chart, since an average CIE-94 color difference on the color-chart colors lower than 2.5 units is obtained.

Quasi-cylindrical wave contribution in experiments on extraordinary optical transmission.

PubMed

van Beijnum, Frerik; Rétif, Chris; Smiet, Chris B; Liu, Haitao; Lalanne, Philippe; van Exter, Martin P

2012-12-20

A metal film perforated by a regular array of subwavelength holes shows unexpectedly large transmission at particular wavelengths, a phenomenon known as the extraordinary optical transmission (EOT) of metal hole arrays. EOT was first attributed to surface plasmon polaritons, stimulating a renewed interest in plasmonics and metallic surfaces with subwavelength features. Experiments soon revealed that the field diffracted at a hole or slit is not a surface plasmon polariton mode alone. Further theoretical analysis predicted that the extra contribution, from quasi-cylindrical waves, also affects EOT. Here we report the experimental demonstration of the relative importance of surface plasmon polaritons and quasi-cylindrical waves in EOT by considering hole arrays of different hole densities. From the measured transmission spectra, we determine microscopic scattering parameters which allow us to show that quasi-cylindrical waves affect EOT only for high densities, when the hole spacing is roughly one wavelength. Apart from providing a deeper understanding of EOT, the determination of microscopic scattering parameters from the measurement of macroscopic optical properties paves the way to novel design strategies.

Emittance formula for slits and pepper-pot measurement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, M.

1996-10-01

In this note, a rigid formula for slits and pepper-pot emittance measurement is derived. The derivation is based on the one- dimensional slit measurement setup. A mathematical generalization of the slit emittance formula to the pepper-pot measurement is discussed.

Finite element modeling of arachnid slit sensilla: II. Actual lyriform organs and the face deformations of the individual slits.

PubMed

Hössl, Bernhard; Böhm, Helmut J; Schaber, Clemens F; Rammerstorfer, Franz G; Barth, Friedrich G

2009-09-01

Arachnid slit sensilla respond to minute strains in the exoskeleton. After having applied finite element (FE) analysis to simplified arrays of five straight slits (Hössl et al. J Comp Physiol A 193:445-459, 2007) we now present a computational study of the effects of more subtle natural variations in geometry, number and arrangement of slits on the slit face deformations. Our simulations show that even minor variations in these parameters can substantially influence a slit's directional response. Using white-light interferometric measurements of the surface deformations of a lyriform organ, it is shown that planar FE models are capable of predicting the principal characteristics of the mechanical responses. The magnitudes of the measured and calculated slit face deformations are in good agreement. At threshold, they measure between 1.7 and 43 nm. In a lyriform organ and a closely positioned loose group of slits, the detectable range of loads increases to approximately 3.5 times the range of the lyriform organ alone. Stress concentration factors (up to ca. 29) found in the vicinity of the slits were evaluated from the models. They are mitigated due to local thickening of the exocuticle and the arrangement of the chitinous microfibers that prevents the formation of cracks under physiological loading conditions.

White Beam Slits and Pink Beam Slits for the Hard X-ray Nanoprobe Beamline at the Advanced Photon Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benson, C.; Jaski, Y.; Powers, T.

2007-01-19

A new type of slit has been designed for use in the hard x-ray nanoprobe beamline at the Advanced Photon Source (APS). The design incorporates monolithic GlidCop slit bodies mounted to commercially available x-y drive systems. Long, tapered apertures with adjacent water-cooling channels intercept the x-ray beam, removing the high heat load produced by two collinear APS undulators. The apertures are L-shaped and provide both horizontal and vertical slits. The beam-defining edges, positioned at the end of the tapered surfaces, consist of two sets of tungsten blades. These blades produce an exit beam with sharp corners and assure a cleanmore » cut-off for the white beam edges. The slit assembly is designed to allow overlap of the slit edges to stop the beam.The white beam slit design accommodates 3100 W of total power with a peak power density of 763 W/mm2. The pink beam slit design accommodates 400 W of total power with a peak power density of 180 W/mm2. Detailed thermal analyses were performed to verify the slits' accuracy under full beam loading. The new concept allows beamline operations to 180 mA with a simplified design approach.« less

White beam slits and pink beam slits for the hard x-ray nanoprobe beamline at the Advanced Photon Source.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benson, C.; Jaski, Y.; Maser, J.

2007-01-01

A new type of slit has been designed for use in the hard x-ray nanoprobe beamline at the Advanced Photon Source (APS). The design incorporates monolithic GlidCop slit bodies mounted to commercially available x-y drive systems. Long, tapered apertures with adjacent water-cooling channels intercept the x-ray beam, removing the high heat load produced by two collinear APS undulators. The apertures are L-shaped and provide both horizontal and vertical slits. The beam-defining edges, positioned at the end of the tapered surfaces, consist of two sets of tungsten blades. These blades produce an exit beam with sharp corners and assure a cleanmore » cut-off for the white beam edges. The slit assembly is designed to allow overlap of the slit edges to stop the beam. The white beam slit design accommodates 3100 W of total power with a peak power density of 763 W/mm2. The pink beam slit design accommodates 400 W of total power with a peak power density of 180 W/mm2. Detailed thermal analyses were performed to verify the slits accuracy under full beam loading. The new concept allows beamline operations to 180 mA with a simplified design approach.« less

On the mechanical interaction between a fluid-filled fracture and the earth's surface

USGS Publications Warehouse

Pollard, D.D.; Holzhausen, G.

1979-01-01

The mechanical interaction between a fluid-filled fracture (e.g., hydraulic fracture joint, or igneous dike) and the earth's surface is analyzed using a two-dimensional elastic solution for a slit of arbitrary inclination buried beneath a horizontal free surface and subjected to an arbitrary pressure distribution. The solution is obtained by iteratively superimposing two fundamental sets of analytical solutions. For uniform internal pressure the slit behaves essentially as if it were in an infinite region if the depth-to-center is three times greater than the half-length. For shallower slits interaction with the free surface is pronounced: stresses and displacements near the slit differ by more than 10% from values for the deeply buried slit. The following changes are noted as the depth-to-center decreases: 1. (1) the mode I stress intensity factor increases for both ends of the slit, but more rapidly at the upper end; 2. (2) the mode II stress-intensity factor is significantly different from zero (except for vertical slits) suggesting propagation out of the original plane of the slit; 3. (3) displacements of the slit wall are asymmetric such that the slit gaps open more widely near the upper end. Similar changes are noted if fluid density creates a linear pressure gradient that is smaller than the lithostatic gradient. Under such conditions natural fractures should propagate preferentially upward toward the earth's surface requiring less pressure as they grow in length. If deformation near the surface is of interest, the model should account explicitly for the free surface. Stresses and displacements at the free surface are not approximated very well by values calculated along a line in an infinite region, even when the slit is far from the line. As depth-to-center of a shallow pressurized slit decreases, the following changes are noted: 1. (1) displacements of the free surface increase to the same order of magnitude as the displacements of the slit walls, 2. (2) tensile stresses of magnitude greater than the pressure in the slit are concentrated along the free surface. The relative surface displacements over a shallow vertical slit are downward over the slit and upward to both sides of this area. The tensile stress acting parallel to the free surface over a shallow vertical slit is concentrated in two maxima adjacent to a point of very low stress immediately over the slit. The solution is used to estimate the length-to-depth ratio at which igneous sills have gained sufficient leverage on overlying strata to bend these strata upward and form a laccolith. The pronounced mode II stress intensity associated with shallow horizontal slits explains the tendency for some sills to climb to higher stratigraphie horizons as they grow in length. The bimodal tensile stress concentration over shallow vertical slits correlates qualitatively with the distribution of cracks and normal faults which flank fissure eruptions on volcanoes. The solution may be used to analyze surface displacements and tilts over massive hydraulic fractures in oil fields and to understand the behavior of hydraulic fractures in granite quarries. ?? 1979.

Star scanner. [with a reticle with a pair of slits having differing separation

NASA Technical Reports Server (NTRS)

Gutshall, R. L.; Mcconaughey, R. T.; Volpe, F. A. (Inventor)

1974-01-01

A star scanner on a spin stabilized spacecraft is described which includes a reticle with a pair of slits having different separations as a function of the spacecraft vertical plane, to form a V slit. The time between a star image crossing one of the slits relative to a reference telemetry time provides an indication of azimuth angle. The time between the image crossing the two slits provides an indication of elevation angle of the star. If a star cluster is detected such that two stars pass the slits in less time than normally required for a single star to cross the two slits, an indication of the cluster occurrence is derived. Means are provided to prevent effective detection of large celestial bodies, such as the sun or moon.

Stromal haze, myofibroblasts, and surface irregularity after PRK.

PubMed

Netto, Marcelo V; Mohan, Rajiv R; Sinha, Sunilima; Sharma, Ajay; Dupps, William; Wilson, Steven E

2006-05-01

The aim of this study was to investigate the relationship between the level of stromal surface irregularity after photorefractive keratectomy (PRK) and myofibroblast generation along with the development of corneal haze. Variable levels of stromal surface irregularity were generated in rabbit corneas by positioning a fine mesh screen in the path of excimer laser during ablation for a variable percentage of the terminal pulses of the treatment for myopia that does not otherwise generate significant opacity. Ninety-six rabbits were divided into eight groups: [see table in text]. Slit lamp analysis and haze grading were performed in all groups. Rabbits were sacrificed at 4 hr or 4 weeks after surgery and histochemical analysis was performed on corneas for apoptosis (TUNEL assay), myofibroblast marker alpha-smooth muscle actin (SMA), and integrin alpha4 to delineate the epithelial basement membrane. Slit-lamp grading revealed severe haze formation in corneas in groups IV and VI, with significantly less haze in groups II, III, and VII and insignificant haze compared with the unwounded control in groups I and V. Analysis of SMA staining at 4 weeks after surgery, the approximate peak of haze formation in rabbits, revealed low myofibroblast formation in group I (1.2+/-0.2 cells/400x field) and group V (1.8+/-0.4), with significantly more in groups II (3.5+/-1.8), III (6.8+/-1.6), VII (7.9+/-3.8), IV (12.4+/-4.2) and VI (14.6+/-5.1). The screened groups were significantly different from each other (p < 0.05), with myofibroblast generation increasing with higher surface irregularity in the -4.5 diopter PRK groups. The -9.0 diopter PRK group VI had significantly more myofibroblast generation than the -9.0 diopter PRK with PTK-smoothing group VII (p < 0.01). Areas of basement membrane disruption were demonstrated by staining corneas for integrin alpha4 and were prominent in corneas with grade I or higher haze. SMA-positive myofibroblasts tended to be present sub-adjacent to basement membrane defects. Late apoptosis was detected at 1 month after surgery within clusters of myofibroblasts in the sub-epithelial stroma. In conclusion, these results demonstrated a relationship between the level of corneal haze formation after PRK and the level of stromal surface irregularity. PTK-smoothing with methylcellulose was an effective method to reduce stromal surface irregularity and decreased both haze and associated myofibroblast density. We hypothesize that stromal surface irregularity after PRK for high myopia results in defective basement membrane regeneration and increased epithelium-derived TGFbeta signalling to the stroma that increases myofibroblast generation. Late apoptosis appears to have a role in the disappearance of myofibroblasts and haze over time.

A New Low Cost Wide-Field Illumination Method for Photooxidation of Intracellular Fluorescent Markers

PubMed Central

da Silva Filho, Manoel; Santos, Daniel Valle Vasconcelos; Costa, Kauê Machado

2013-01-01

Analyzing cell morphology is crucial in the fields of cell biology and neuroscience. One of the main methods for evaluating cell morphology is by using intracellular fluorescent markers, including various commercially available dyes and genetically encoded fluorescent proteins. These markers can be used as free radical sources in photooxidation reactions, which in the presence of diaminobenzidine (DAB) forms an opaque and electron-dense precipitate that remains localized within the cellular and organelle membranes. This method confers many methodological advantages for the investigator, including absence of photo-bleaching, high visual contrast and the possibility of correlating optical imaging with electron microscopy. However, current photooxidation techniques require the continuous use of fluorescent or confocal microscopes, which wastes valuable mercury lamp lifetime and limits the conversion process to a few cells at a time. We developed a low cost optical apparatus for performing photooxidation reactions and propose a new procedure that solves these methodological restrictions. Our “photooxidizer” consists of a high power light emitting diode (LED) associated with a custom aluminum and acrylic case and a microchip-controlled current source. We demonstrate the efficacy of our method by converting intracellular DiI in samples of developing rat neocortex and post-mortem human retina. DiI crystals were inserted in the tissue and allowed to diffuse for 20 days. The samples were then processed with the new photooxidation technique and analyzed under optical microscopy. The results show that our protocols can unveil the fine morphology of neurons in detail. Cellular structures such as axons, dendrites and spine-like appendages were well defined. In addition to its low cost, simplicity and reliability, our method precludes the use of microscope lamps for photooxidation and allows the processing of many labeled cells simultaneously in relatively large tissue samples with high efficacy. PMID:23441199

Transmission characteristics of a subwavelength metallic slit with perpendicular groove

NASA Astrophysics Data System (ADS)

Jin, Li; Zhou, Jun; Zou, Weibo; Zhang, Haopeng; Zhang, Lingfen

2011-12-01

The transmission property of a subwavelength metallic slit with perpendicular groove is investigated by using finite element method. The lengths for the slits at both sides of the groove are set as the length of a metallic slit without groove at the surface plasmon fundamental mode resonance. In the grooved subwavelength metallic slit, enhanced transmission is found to be attributed to two kinds of resonance including surface plasmon waveguide resonance along the propagating direction and the transversely constructive interferential resonance. For the former resonance, integer antinodes of surface plasmon are formed in the groove. For the later resonance, there is a tradeoff between the maximum amplitude and the full width at half maximum of the transmitted peaks with the change of the groove width. And, the transmission enhancement of the grooved subwavelength metallic slit is related to the number of groove and the incident wavelength. Furthermore, the above resonances also exist in the structure whose lengths of metallic slits are set as the length of a slit without groove at the surface plasmon high-order mode resonance. By optimizing the geometric parameters, the transmission enhancement of the grooved subwavelength metallic slit as high as about 15367% is achieved.

Extraordinary optical transmission through wedge-shape metallic slits array embedded with rectangular cavities

NASA Astrophysics Data System (ADS)

Qi, Yunping; Zhang, Xuewei; Hu, Yue; Nan, Xianghong; Wang, Xiangxian

2017-10-01

The non-resonantly enhanced optical transmission phenomenon of sub-wavelength metallic slits on a thin film is significant for broadband light integrated devices. In order to improve the EOT characteristics of sub-wavelength metallic slits further more, in this paper, wedge-shape metallic slits array embedded with rectangular cavities structure is proposed and its transmission properties are investigated using the finite element method. The results show that wedgeshape metallic slits array can achieve higher transmission compared with straight slits array embedded with rectangular cavities and the light is strongly localized and enhanced at the slit exits. We describe the phenomenon with a transmission line model. The width of entrance of the slit influences the transmission property: the transmittance can be 94%, after optimizing the structure parameters, with the widths 150nm and 30nm at the entrance and exit of the slit, respectively. The thickness of metal film influences the transmission peak position and transmission rate: when the increase of the thickness of the metal film, the transmittance increases and the transmission peak is red-shift, however, the law of long wavelength range is opposite. In addition, the effects of structural period of wedge-shaped slits embedded with rectangular cavities structure on the transmission property are also studied. These results would be helpful for optical signal transmission and the design of near field optical conductor devices with higher transmission capability.

Slit2/Robo1 signaling is involved in angiogenesis of glomerular endothelial cells exposed to a diabetic-like environment.

PubMed

Liu, Junhui; Hou, Weiping; Guan, Tao; Tang, Luyao; Zhu, Xufei; Li, Yi; Hou, Shihui; Zhang, Jun; Chen, Hua; Huang, Yunjian

2018-05-01

Abnormal angiogenesis plays a pathological role in diabetic nephropathy (DN), contributing to glomerular hypertrophy and microalbuminuria. Slit2/Robo1 signaling participates in angiogenesis in some pathological contexts, but whether it is involved in glomerular abnormal angiogenesis of early DN is unclear. The present study evaluated the effects of Slit2/Robo1 signaling pathway on angiogenesis of human renal glomerular endothelial cells (HRGECs) exposed to a diabetic-like environment or recombinant Slit2-N. To remove the effect of Slit2 derived from mesangial cells, human renal mesangial cells (HRMCs) grown in high glucose (HG) medium (33 mM) were transfected with Slit2 siRNA and then the HG-HRMCs-CM with Slit2 depletion was collected after 48 h. HRGECs were cultured in the HG-HRMCs-CM or recombinant Slit2-N for 0, 6, 12, 24, or 48 h. The mRNA and protein expressions of Slit2/Robo1, PI3K/Akt and HIF-1α/VEGF signaling pathways were detected by quantitative real-time PCR, western blotting, and ELISA, respectively. The CCK-8 cell proliferation assay, flow cytometry and the scratch wound-healing assay were used to assess cell proliferation, cycles, and migration, respectively. Matrigel was used to perform a tubule formation assay. Our results showed that the HG-HRMCs-CM with Slit2 depletion enhanced the activation of Slit2/Robo1, PI3K/Akt, and HIF-1α/VEGF signaling in HRGECs in time-dependent manner (0-24 h post-treatment). In addition, the HG-HRMCs-CM with Slit2 depletion significantly promoted HRGECs proliferation, migration, and tube formation. Pretreatment of HRGECs with Robo1 siRNA suppressed the activation of PI3K/Akt and HIF-1α/VEGF signaling and inhibited angiogenesis, whereas PI3K inhibitor suppressed HIF-1α/VEGF signaling, without influencing Robo1 expression. In the HRGECs treated with Slit2-N, Slit2-N time-dependently enhanced the activation of Robo1/PI3K/Akt/VEGF pathway but not HIF-1α activity, and promoted HRGECs proliferation, migration, and tube formation. The effects induced by Slit2 were also abolished by Robo1 siRNA and PI3K inhibitor. Taken together, our findings indicate that in a diabetic-like environment, in addition to mesangial cells, autocrine activation of Slit2/Robo1 signaling of HRGECs may contribute to angiogenesis of HRGECs through PI3K/Akt/VEGF pathway; therefore, Slit2/Robo1 signaling may be a potent therapeutic target for the treatment of abnormal angiogenesis in early DN and may have broad implications for the treatment of other diseases dependent on pathologic angiogenesis.

Diffraction limited focusing and routing of gap plasmons by a metal-dielectric-metal lens

DOE PAGES

Dennis, Brian S.; Czaplewski, David A.; Haftel, Michael I.; ...

2015-08-12

Passive optical elements can play key roles in photonic applications such as plasmonic integrated circuits. Here we experimentally demonstrate passive gap-plasmon focusing and routing in two-dimensions. This is accomplished using a high numerical-aperture metal-dielectric-metal lens incorporated into a planar-waveguide device. Fabrication via metal sputtering, oxide deposition, electron- and focused-ion- beam lithography, and argon ion-milling is reported on in detail. Diffraction-limited focusing is optically characterized by sampling out-coupled light with a microscope. The measured focal distance and full-width-half-maximum spot size agree well with the calculated lens performance. The surface plasmon polariton propagation length is measured by sampling light from multiple out-couplermore » slits.« less

A study of damage zones or characteristic lengths as related to the fracture behavior of graphite/epoxy laminates

NASA Technical Reports Server (NTRS)

Yeow, Y. T.; Brinson, H. F.

1977-01-01

Uniaxial tensile tests conducted on a variety of graphite/epoxy laminates, containing narrow rectangular slits, square or circular holes with various aspect ratios are discussed. The techniques used to study stable crack or damage zone growth--namely, birefringence coatings, COD gages, and microscopic observations are discussed. Initial and final fracture modes are discussed as well as the effect of notch size and shape, and laminate type on the fracture process. Characteristic lengths are calculated and compared to each other using the point, average and inherent flaw theories. Fracture toughnesses are calculated by the same theories and compared to a boundary integral equation technique. Finite width K-calibration factors are also discussed.

Radiographic screen-film noise power spectrum: variation with microdensitometer slit length.

PubMed

Sandrik, J M; Wagner, R F

1981-08-15

When the noise power spectrum (NPS) of a radiographic screen-film system is measured by microdensito-metrically scanning the film with a long narrow slit, sufficient slit length allows estimation of a section of the 2-D NPS from the 1-D film scans; insufficient length causes underestimation of the NPS, particularly at low frequencies ( greater, similar1 cycle/mm). Spectra of Hi-Plus, Par Speed, and Detail screens used with XRP films measured as a function of microdensitometer slit length tended to plateau at long slit lengths. The slit length was considered sufficient when NPS components at 0.4 cycle/mm were within 5% of the plateau. This occurred for slit lengths of at least 4.2, 2.6, and 2.5 mm for Hi-Plus, Par Speed, and Detail systems, respectively.

Slit Effect of Common Ground Patterns in Affecting Cross-Talk Noise between Two Parallel Signal Traces on Printed Circuit Boards

NASA Astrophysics Data System (ADS)

Maeno, Tsuyoshi; Sakurai, Yukihiko; Unou, Takanori; Ichikawa, Kouji; Fujiwara, Osamu

It is well-known that electromagnetic (EM) disturbances in vehicle-mounted radios are mainly caused by conducted noise currents flowing through wiring-harnesses from vehicle-mounted printed circuit boards (PCBs) with common ground patterns with slits. To evaluate the noise current outflows from the PCBs of this kind, we previously measured noise current outflows from four types of simple three-layer PCBs having two perpendicular signal traces and different ground patterns with/without slits, and showed that slits on a ground pattern allow conducted noise currents to flow out from PCBs, while the levels for the symmetric slits ground type are smaller compared to the case for two asymmetric slits ground types. In the present study, to further investigate the above finding, we fabricated six types of simple two-layer PCBs having two parallel signal traces and different ground patterns with/without slits, and measured the cross-talk noise between the traces. As a result, we found that the ground patterns with the slits perpendicular to the traces increase the cross-talk noise levels, which are larger by 19-42 dB than those for the ground pattern with no slits, while the ground patterns with the slits in parallel with the traces can suppress the noise levels, which are slightly smaller by 2.5-4.5 dB compared to the case for the no-slit ground pattern. These results were confirmed by the FDTD simulation, and were also qualitatively explained from an equivalent bridge circuit model we previously proposed.

Reconstruction of spherically symmetric objects from slit-imaged emission: limitations due to finite slit width

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mueller, M.M.

1979-11-01

A simple method for reconstructing spherically symmetric objects from slit-imaged emission was recently described by Vest and Steel. Although this method is valid for infinitesimal slit widths and practically noise-free irradiance data, it is shown here that its validity does not extend to slits of practical width in the laser-fusion program. However, a method is given for reducing the Vest--Steel plots with practical apertures to obtain information on core diameter, shell diameter, and shell thickness.

OPTiM: Optical projection tomography integrated microscope using open-source hardware and software

PubMed Central

Andrews, Natalie; Davis, Samuel; Bugeon, Laurence; Dallman, Margaret D.; McGinty, James

2017-01-01

We describe the implementation of an OPT plate to perform optical projection tomography (OPT) on a commercial wide-field inverted microscope, using our open-source hardware and software. The OPT plate includes a tilt adjustment for alignment and a stepper motor for sample rotation as required by standard projection tomography. Depending on magnification requirements, three methods of performing OPT are detailed using this adaptor plate: a conventional direct OPT method requiring only the addition of a limiting aperture behind the objective lens; an external optical-relay method allowing conventional OPT to be performed at magnifications >4x; a remote focal scanning and region-of-interest method for improved spatial resolution OPT (up to ~1.6 μm). All three methods use the microscope’s existing incoherent light source (i.e. arc-lamp) and all of its inherent functionality is maintained for day-to-day use. OPT acquisitions are performed on in vivo zebrafish embryos to demonstrate the implementations’ viability. PMID:28700724

Precision optical slit for high heat load or ultra high vacuum

DOEpatents

Andresen, N.C.; DiGennaro, R.S.; Swain, T.L.

1995-01-24

This invention relates generally to slits used in optics that must be precisely aligned and adjusted. The optical slits of the present invention are useful in x-ray optics, x-ray beam lines, optical systems in which the entrance slit is critical for high wavelength resolution. The invention is particularly useful in ultra high vacuum systems where lubricants are difficult to use and designs which avoid the movement of metal parts against one another are important, such as monochromators for high wavelength resolution with ultra high vacuum systems. The invention further relates to optical systems in which temperature characteristics of the slit materials is important. The present invention yet additionally relates to precision slits wherein the opposing edges of the slit must be precisely moved relative to a center line between the edges with each edge retaining its parallel orientation with respect to the other edge and/or the center line. 21 figures.

Precision optical slit for high heat load or ultra high vacuum

DOEpatents

Andresen, Nord C.; DiGennaro, Richard S.; Swain, Thomas L.

1995-01-01

This invention relates generally to slits used in optics that must be precisely aligned and adjusted. The optical slits of the present invention are useful in x-ray optics, x-ray beam lines, optical systems in which the entrance slit is critical for high wavelength resolution. The invention is particularly useful in ultra high vacuum systems where lubricants are difficult to use and designs which avoid the movement of metal parts against one another are important, such as monochrometers for high wavelength resolution with ultra high vacuum systems. The invention further relates to optical systems in which temperature characteristics of the slit materials is important. The present invention yet additionally relates to precision slits wherein the opposing edges of the slit must be precisely moved relative to a center line between the edges with each edge retaining its parallel orientation with respect to the other edge and/or the center line.

Measuring Slit Width and Separation in a Diffraction Experiment

ERIC Educational Resources Information Center

Gan, K. K.; Law, A. T.

2009-01-01

We present a procedure for measuring slit width and separation in single- and double-slit diffraction experiments. Intensity spectra of diffracted laser light are measured with an optical sensor (PIN diode). Slit widths and separations are extracted by fitting to the measured spectra. We present a simple fitting procedure to account for the…

Time-resolved double-slit interference pattern measurement with entangled photons

PubMed Central

Kolenderski, Piotr; Scarcella, Carmelo; Johnsen, Kelsey D.; Hamel, Deny R.; Holloway, Catherine; Shalm, Lynden K.; Tisa, Simone; Tosi, Alberto; Resch, Kevin J.; Jennewein, Thomas

2014-01-01

The double-slit experiment strikingly demonstrates the wave-particle duality of quantum objects. In this famous experiment, particles pass one-by-one through a pair of slits and are detected on a distant screen. A distinct wave-like pattern emerges after many discrete particle impacts as if each particle is passing through both slits and interfering with itself. Here we present a temporally- and spatially-resolved measurement of the double-slit interference pattern using single photons. We send single photons through a birefringent double-slit apparatus and use a linear array of single-photon detectors to observe the developing interference pattern. The analysis of the buildup allows us to compare quantum mechanics and the corpuscular model, which aims to explain the mystery of single-particle interference. Finally, we send one photon from an entangled pair through our double-slit setup and show the dependence of the resulting interference pattern on the twin photon's measured state. Our results provide new insight into the dynamics of the buildup process in the double-slit experiment, and can be used as a valuable resource in quantum information applications. PMID:24770360

Progesterone down-regulates SLIT/ROBO expression in mouse corpus luteum.

PubMed

Zhang, Xuejing; Mi, Meiyan; Hao, Weili; Fan, Qiongying; Gao, Bulang

2017-09-01

Progesterone produced by the corpus luteum (CL) is essential for preparation, implantation and maintenance of gestation. Furthermore, progesterone plays a protective role against luteolysis in rodents. It has been reported that Slit/Robo family members expressed in the CL and involved in prostaglandin F 2α (PGF 2α ) induced luteolysis. However, the interactions between progesterone and Slits/Robos in CL are not clear. This study was designed to examine whether or not luteolysis is regulated by the interaction of progesterone and Slits/Robos in mouse CL. In the current study, we used Real-time PCR to identify the effect of progesterone on Slit2/Robo1 expression in cultured luteal cells in vitro, and the exogenous progesterone injection on mouse luteolysis and Slit/Robo expression in vivo was studied via Real-time PCR and Western bolt. Our in vitro experiment revealed that 1μM progesterone significantly decreased Slit2/Robo1 mRNA levels at 6h, 12h and 24h. Our in vivo experiment showed that the mRNA and protein levels of Slit2 and Robo1 decreased significantly 7days after progesterone supplement. These findings indicate that progesterone maintains CL function and resists luteolysis possibly through down-regulating Slit/Robo signaling pathway in the CL. Copyright © 2017 Elsevier GmbH. All rights reserved.

The SLIT/ROBO pathway: a regulator of cell function with implications for the reproductive system

PubMed Central

Dickinson, Rachel E; Duncan, W Colin

2010-01-01

The secreted SLIT glycoproteins and their Roundabout (ROBO) receptors were originally identified as important axon guidance molecules. They function as a repulsive cue with an evolutionarily conserved role in preventing axons from migrating to inappropriate locations during the assembly of the nervous system. In addition the SLIT-ROBO interaction is involved in the regulation of cell migration, cell death and angiogenesis and, as such, has a pivotal role during the development of other tissues such as the lung, kidney, liver and breast. The cellular functions that the SLIT/ROBO pathway controls during tissue morphogenesis are processes that are dysregulated during cancer development. Therefore inactivation of certain SLITs and ROBOs is associated with advanced tumour formation and progression in disparate tissues. Recent research has indicated that the SLIT/ROBO pathway could also have important functions in the reproductive system. The fetal ovary expresses most members of the SLIT and ROBO families. The SLITs and ROBOs also appear to be regulated by steroid hormones and regulate physiological cell functions in adult reproductive tissues such as the ovary and endometrium. Furthermore several SLITs and ROBOs are aberrantly expressed during the development of ovarian, endometrial, cervical and prostate cancer. This review will examine the roles this pathway could have in the development, physiology and pathology of the reproductive system and highlight areas for future research that could further dissect the influence of the SLIT/ROBO pathway in reproduction. PMID:20100881

The SLIT-ROBO pathway: a regulator of cell function with implications for the reproductive system.

PubMed

Dickinson, Rachel E; Duncan, W Colin

2010-04-01

The secreted SLIT glycoproteins and their Roundabout (ROBO) receptors were originally identified as important axon guidance molecules. They function as a repulsive cue with an evolutionarily conserved role in preventing axons from migrating to inappropriate locations during the assembly of the nervous system. In addition the SLIT-ROBO interaction is involved in the regulation of cell migration, cell death and angiogenesis and, as such, has a pivotal role during the development of other tissues such as the lung, kidney, liver and breast. The cellular functions that the SLIT/ROBO pathway controls during tissue morphogenesis are processes that are dysregulated during cancer development. Therefore inactivation of certain SLITs and ROBOs is associated with advanced tumour formation and progression in disparate tissues. Recent research has indicated that the SLIT/ROBO pathway could also have important functions in the reproductive system. The fetal ovary expresses most members of the SLIT and ROBO families. The SLITs and ROBOs also appear to be regulated by steroid hormones and regulate physiological cell functions in adult reproductive tissues such as the ovary and endometrium. Furthermore several SLITs and ROBOs are aberrantly expressed during the development of ovarian, endometrial, cervical and prostate cancer. This review will examine the roles this pathway could have in the development, physiology and pathology of the reproductive system and highlight areas for future research that could further dissect the influence of the SLIT/ROBO pathway in reproduction.

Electron beam diagnostic for profiling high power beams

DOEpatents

Elmer, John W [Danville, CA; Palmer, Todd A [Livermore, CA; Teruya, Alan T [Livermore, CA

2008-03-25

A system for characterizing high power electron beams at power levels of 10 kW and above is described. This system is comprised of a slit disk assembly having a multitude of radial slits, a conducting disk with the same number of radial slits located below the slit disk assembly, a Faraday cup assembly located below the conducting disk, and a start-stop target located proximate the slit disk assembly. In order to keep the system from over-heating during use, a heat sink is placed in close proximity to the components discussed above, and an active cooling system, using water, for example, can be integrated into the heat sink. During use, the high power beam is initially directed onto a start-stop target and after reaching its full power is translated around the slit disk assembly, wherein the beam enters the radial slits and the conducting disk radial slits and is detected at the Faraday cup assembly. A trigger probe assembly can also be integrated into the system in order to aid in the determination of the proper orientation of the beam during reconstruction. After passing over each of the slits, the beam is then rapidly translated back to the start-stop target to minimize the amount of time that the high power beam comes in contact with the slit disk assembly. The data obtained by the system is then transferred into a computer system, where a computer tomography algorithm is used to reconstruct the power density distribution of the beam.

Ultra-sensing with slit-enhanced infrared spectroscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Mayerhöfer, Thomas G.; Knipper, Richard; Hübner, Uwe; Cialla-May, Dana; Weber, Karina; Popp, Jürgen

2017-02-01

Infrared spectroscopy enables the label-free detection of structure specific fingerprints of analytes. The sensitivity of corresponding methods can strongly be enhanced by attaching analytes on plasmonic active surfaces. We introduce a slit array metamaterial perfect absorber (SAMPA) [1] consisting of a dielectric layer sandwiched between two Au layers of which the upper layer is perforated with a periodic array of slits. This structure combines the principle of Extraordinary Optical Transmission (more light is transmitted through a hole than is incident on its surface) with that of Perfect Absorption (reflectance and transmittance are virtually zero). Accordingly, within the slights the electric fields are strongly enhanced and light-matter interaction is correspondingly greatly amplified. Thus, already small concentrations of analytes down to a monolayer can be detected and identified by their spectral fingerprints with a standard mid-infrared spectrometer. Closely related to the SAMPAs are plasmonic slit absorbers, which simply consist of slit arrays in thin gold layers deposited on a layer of Si3N4.[2] These slit arrays operate like unstructured gold layers if the incident light is polarized parallel to the long slit axes. In contrast, for light polarized perpendicular to the long slit axis, the plasmon is excited. By the introduction of a second slit, which is rotated relative to the first slit, both principal polarization states excite plasmon resonances which can be made to differ in wavelength. As a consequence, the operating wavelength range of this slit array can be tuned by adjusting the polarization state of the incoming light. [1] Mayerhöfer, T.G., et al.. ACS Photonics, 2015. 2(11): p. 1567-1575. [2] Knipper, R., et. al., in preparation.

Diagnostic testing for Giardia infections.

PubMed

Heyworth, Martin F

2014-03-01

The traditional method for diagnosing Giardia infections involves microscopic examination of faecal specimens for Giardia cysts. This method is subjective and relies on observer experience. From the 1980s onwards, objective techniques have been developed for diagnosing Giardia infections, and are superseding diagnostic techniques reliant on microscopy. Detection of Giardia antigen(s) by immunoassay is the basis of commercially available diagnostic kits. Various nucleic acid amplification techniques (NAATs) can demonstrate DNA of Giardia intestinalis, and have the potential to become standard approaches for diagnosing Giardia infections. Of such techniques, methods involving either fluorescent microspheres (Luminex) or isothermal amplification of DNA (loop-mediated isothermal amplification; LAMP) are especially promising.

VizieR Online Data Catalog: Radial velocities of 35 cataclysmic variables (Thorstensen+, 2016)

NASA Astrophysics Data System (ADS)

Thorstensen, J. R.; Alper, E. H.; Weil, K. E.

2017-02-01

We present spectroscopic follow-up observations of 35 newly discovered cataclysmic variables (CVs), 32 of which were found by the Catalina Real Time Transient Surveys (CRTS; Drake et al. 2009, Cat. J/ApJ/696/870; Drake et al. 2014, Cat. J/MNRAS/441/1186; Breedt et al. 2014, Cat. J/MNRAS/443/3174), ASAS-SN (Shappee et al. 2014ApJ...788...48S), and/or MASTER (Lipunov et al. 2010AdAst2010E..30L). All our observations are from Michigan-Dartmouth-MIT (MDM) Observatory on Kitt Peak, Arizona. For nearly all the spectra, we used the "modspec" spectrograph (a description of the modspec can be found at http://mdm.kpno.noao.edu/Manuals/ModSpec/modspec_man.html) with a 600line/mm grating. We mostly used a SITe 20482 CCD detector, which yielded 2Å/pixel from 4210 to 7500Å, with declining throughput toward the ends of the spectral range. When this detector was unavailable, we used a very similar 10242 SITe detector ("Templeton"), which covered 4660 to 6730Å. The modspec was mounted mostly on the 2.4m Hiltner telescope, but for some of the brighter objects, we used the 1.3m McGraw-Hill telescope. For a few of the 1.3m spectra, we used the Mark III grism spectrograph, which covered 4580 to 6850Å at 2.3Å/pixel. On both telescopes and with both spectrographs, we used an Andor Ikon camera to view the reflective slit jaws through a microscope and guided the telescope with a separate off-axis guider. With this arrangement we could place any object that was bright enough for a usable spectrum in the slit and track it accurately even if the portion of the light spilling onto the slit jaws was invisible. Our emission-line radial velocities are almost entirely of Hα, since it almost always gives the best signal-to-noise ratio with our instrument. (3 data files).

Concentrated aqueous sodium chloride solution in clays at thermodynamic conditions of hydraulic fracturing: Insight from molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Svoboda, Martin; Lísal, Martin

2018-06-01

To address a high salinity of flow-back water during hydraulic fracturing, we use molecular dynamics (MD) simulations and study the thermodynamics, structure, and diffusion of concentrated aqueous salt solution in clay nanopores. The concentrated solution results from the dissolution of a cubic NaCl nanocrystal, immersed in an aqueous NaCl solution of varying salt concentration and confined in clay pores of a width comparable to the crystal size. The size of the nanocrystal equals to about 18 Å which is above a critical nucleus size. We consider a typical shale gas reservoir condition of 365 K and 275 bar, and we represent the clay pores as pyrophyllite and Na-montmorillonite (Na-MMT) slits. We employ the Extended Simple Point Charge (SPC/E) model for water, Joung-Cheatham model for ions, and CLAYFF for the slit walls. We impose the pressure in the normal direction and the resulting slit width varies from about 20 to 25 Å when the salt concentration in the surrounding solution increased from zero to an oversaturated value. By varying the salt concentration, we observe two scenarios. First, the crystal dissolves and its dissolution time increases with increasing salt concentration. We describe the dissolution process in terms of the number of ions in the crystal, and the crystal size and shape. Second, when the salt concentration reaches a system solubility limit, the crystal grows and attains a new equilibrium size; the crystal comes into equilibrium with the surrounding saturated solution. After crystal dissolution, we carry out canonical MD simulations for the concentrated solution. We evaluate the hydration energy, density profiles, orientation distributions, hydrogen-bond network, radial distribution functions, and in-plane diffusion of water and ions to provide insight into the microscopic behaviour of the concentrated aqueous sodium chloride solution in interlayer galleries of the slightly hydrophobic pyrophyllite and hydrophilic Na-MMT pores.

Concentrated aqueous sodium chloride solution in clays at thermodynamic conditions of hydraulic fracturing: Insight from molecular dynamics simulations.

PubMed

Svoboda, Martin; Lísal, Martin

2018-06-14

To address a high salinity of flow-back water during hydraulic fracturing, we use molecular dynamics (MD) simulations and study the thermodynamics, structure, and diffusion of concentrated aqueous salt solution in clay nanopores. The concentrated solution results from the dissolution of a cubic NaCl nanocrystal, immersed in an aqueous NaCl solution of varying salt concentration and confined in clay pores of a width comparable to the crystal size. The size of the nanocrystal equals to about 18 Å which is above a critical nucleus size. We consider a typical shale gas reservoir condition of 365 K and 275 bar, and we represent the clay pores as pyrophyllite and Na-montmorillonite (Na-MMT) slits. We employ the Extended Simple Point Charge (SPC/E) model for water, Joung-Cheatham model for ions, and CLAYFF for the slit walls. We impose the pressure in the normal direction and the resulting slit width varies from about 20 to 25 Å when the salt concentration in the surrounding solution increased from zero to an oversaturated value. By varying the salt concentration, we observe two scenarios. First, the crystal dissolves and its dissolution time increases with increasing salt concentration. We describe the dissolution process in terms of the number of ions in the crystal, and the crystal size and shape. Second, when the salt concentration reaches a system solubility limit, the crystal grows and attains a new equilibrium size; the crystal comes into equilibrium with the surrounding saturated solution. After crystal dissolution, we carry out canonical MD simulations for the concentrated solution. We evaluate the hydration energy, density profiles, orientation distributions, hydrogen-bond network, radial distribution functions, and in-plane diffusion of water and ions to provide insight into the microscopic behaviour of the concentrated aqueous sodium chloride solution in interlayer galleries of the slightly hydrophobic pyrophyllite and hydrophilic Na-MMT pores.

Transmission properties of a single metallic slit: from the subwavelength regime to the geometrical-optics limit.

PubMed

Bravo-Abad, J; Martín-Moreno, L; García-Vidal, F J

2004-02-01

In this work we explore the transmission properties of a single slit in a metallic screen. We analyze the dependence of these properties on both slit width and angle of incident radiation. We study in detail the crossover between the subwavelength regime and the geometrical-optics limit. In the subwavelength regime, resonant transmission linked to the excitation of waveguide resonances is analyzed. Linewidth of these resonances and their associated electric-field intensities are controlled by just the width of the slit. More complex transmission spectra appear when the wavelength of light is comparable to the slit width. Rapid oscillations associated with the emergence of different propagating modes inside the slit are the main features appearing in this regime.

Lysosome-associated membrane proteins-1 and -2 (LAMP-1 and LAMP-2) assemble via distinct modes.

PubMed

Terasawa, Kazue; Tomabechi, Yuri; Ikeda, Mariko; Ehara, Haruhiko; Kukimoto-Niino, Mutsuko; Wakiyama, Motoaki; Podyma-Inoue, Katarzyna A; Rajapakshe, Anupama R; Watabe, Tetsuro; Shirouzu, Mikako; Hara-Yokoyama, Miki

2016-10-21

Lysosome-associated membrane proteins 1 and 2 (LAMP-1 and LAMP-2) have a large, heavily glycosylated luminal domain composed of two subdomains, and are the most abundant protein components in lysosome membranes. LAMP-1 and LAMP-2 have distinct functions, and the presence of both proteins together is required for the essential regulation of autophagy to avoid embryonic lethality. However, the structural aspects of LAMP-1 and LAMP-2 have not been elucidated. In the present study, we demonstrated that the subdomains of LAMP-1 and LAMP-2 adopt the unique β-prism fold, similar to the domain structure of the dendritic cell-specific-LAMP (DC-LAMP, LAMP-3), confirming the conserved aspect of this family of lysosome-associated membrane proteins. Furthermore, we evaluated the effects of the N-domain truncation of LAMP-1 or LAMP-2 on the assembly of LAMPs, based on immunoprecipitation experiments. We found that the N-domain of LAMP-1 is necessary, whereas that of LAMP-2 is repressive, for the organization of a multimeric assembly of LAMPs. Accordingly, the present study suggests for the first time that the assembly modes of LAMP-1 and LAMP-2 are different, which may underlie their distinct functions. Copyright © 2016 Elsevier Inc. All rights reserved.

Ultrathin multi-slit metamaterial as excellent sound absorber: Influence of micro-structure

NASA Astrophysics Data System (ADS)

Ren, S. W.; Meng, H.; Xin, F. X.; Lu, T. J.

2016-01-01

An ultrathin (subwavelength) hierarchy multi-slit metamaterial with simultaneous negative effective density and negative compressibility is proposed to absorb sound over a wide frequency range. Different from conventional acoustic metamaterials having only negative real parts of acoustic parameters, the imaginary parts of effective density and compressibility are both negative for the proposed metamaterial, which result in superior viscous and thermal dissipation of sound energy. By combining the slit theory of sound absorption with the double porosity theory for porous media, a theoretical model is developed to investigate the sound absorption performance of the metamaterial. To verify the model, a finite element model is established to calculate the effective density, compressibility, and sound absorption of the metamaterial. It is theoretically and numerically confirmed that, upon introducing micro-slits into the meso-slits matrix, the multi-slit metamaterial possesses indeed negative imaginary parts of effective density and compressibility. The influence of micro-slits on the acoustical performance of the metamaterial is analyzed in the context of its specific surface area and static flow resistivity. This work shows great potential of multi-slit metamaterials in noise control applications that require both small volume and small weight of sound-absorbing materials.

Shape distortions and Gestalt grouping in anorthoscopic perception

PubMed Central

Aydın, Murat; Herzog, Michael H.; Öğmen, Haluk

2011-01-01

When a figure moves behind a stationary narrow slit, observers often report seeing the figure as a whole, a phenomenon called slit viewing or anorthoscopic perception. Interestingly, in slit viewing, the figure is perceived compressed along the axis of motion. As with other perceptual distortions, it is unclear whether the perceptual space in the vicinity of the slit or the representation of the figure itself undergoes compression. In a psychophysical experiment, we tested these two hypotheses. We found that the percept of a stationary bar, presented within the slit, was not distorted even when at the same time a circle underwent compression by moving through the slit. This result suggests that the compression of form results from figural rather than from space compression. In support of this hypothesis, we found that when the bar was perceptually grouped with the circle, the bar appeared compressed. Our results show that, in slit viewing, the distortion occurs at a non-retinotopic level where grouped objects are jointly represented. PMID:19757947

TE-polarized design for metallic slit lenses: a way to deep-subwavelength focusing over a broad wavelength range.

PubMed

Zhu, Yechuan; Yuan, Weizheng; Li, Wenli; Sun, Hao; Qi, Kunlun; Yu, Yiting

2018-01-15

Slit arrays based on noble metals have been widely proposed as planar transverse-magnetic (TM)-lenses, illuminated by a linearly polarized light with the polarization perpendicular to slits and implementing the focusing capability beyond the diffraction limit. However, due to intrinsic plasmonic losses, these TM-lenses cannot work efficiently in the ultraviolet wavelengths. In this Letter, taking advantage of the unique transmission through metallic slits not involving plasmonic losses, a metallic slit array with transverse-electric (TE)-polarized design is proposed, showing for the first time, to the best of our knowledge, the realization of sub-diffraction-limit focusing for ultraviolet light. Additionally, in contrast to the situations of TM-lenses, a wider slit leads to a greater phase delay and much larger slits can be arranged to construct the TE-lenses, which is quite beneficial for practical fabrication. Furthermore, deep-subwavelength focusing can be achieved by utilizing the immersing technology.

Performance Results from In-Flight Commissioning of the Juno Ultraviolet Spectrograph (Juno-UVS)

NASA Astrophysics Data System (ADS)

Greathouse, Thomas K.; Gladstone, G. R.; Davis, M. W.; Slater, D. C.; Versteeg, M. H.; Persson, K. B.; Winters, G. S.; Persyn, S. C.; Eterno, J. S.

2012-10-01

We present a description of the Juno ultraviolet spectrograph (Juno-UVS), results from the successful in-flight commissioning performed between December 5th and 13th 2011, and some predictions of future Jupiter observations. Juno-UVS is a modest power (9.0 W) ultraviolet spectrograph based on the Alice instruments now in flight aboard the European Space Agency’s Rosetta spacecraft, NASA’s New Horizons spacecraft, and the LAMP instrument aboard NASA’s Lunar Reconnaissance Orbiter. However, unlike the other Alice spectrographs, Juno-UVS sits aboard a rotationally stabilized spacecraft. The planned 2 rpm rotation rate for the primary mission results in integration times per spatial resolution element per spin of only 17 ms. Thus, data was retrieved from many spins and then remapped and co-added to build up integration times on bright stars to measure the effective area, spatial resolution, map out scan mirror pointing positions, etc. The Juno-UVS scan mirror allows for pointing of the slit approximately ±30° from the spacecraft spin plane. This ability gives Juno-UVS access to half the sky at any given spacecraft orientation. We will describe our process for solving for the pointing of the scan mirror relative to the Juno spacecraft and present our initial half sky survey of UV bright stars complete with constellation overlays. The primary job of Juno-UVS will be to characterize Jupiter’s UV auroral emissions and relate them to in situ particle measurements. The ability to point the slit will facilitate these measurements, allowing Juno-UVS to observe the surface positions of magnetic field lines Juno is flying through giving a direct connection between the particle measurements on the spacecraft to the observed reaction of Jupiter’s atmosphere to those particles. Finally, we will describe planned observations to be made during Earth flyby in October 2013 that will complete the in-flight characterization.

Vitritis in Pediatric Genetic Retinal Disorders

PubMed Central

Stunkel, Maria; Bhattarai, Sajag; Kemerley, Andrew; Stone, Edwin M.; Wang, Kai; Mullins, Robert F.; Drack, Arlene V.

2014-01-01

Structured Abstract Purpose To determine which types of pediatric retinal degeneration are associated with inflammatory cells in the anterior vitreous (AV). Design Retrospective, observational study in humans. Methods Retrospective chart review was performed for pediatric patients with suspected retinal degeneration presenting to a single examiner from 2008–2013. Age, visual acuity (VA), slit lamp examination of AV (SLAV), clinical and molecular genetic diagnoses were documented. Anterior vitreous cells were graded clinically with SLAV from rare cells (1–4) to 1+ (5–9), 2+ (10–30), or 3+ (more than 30). Cells were also counted in magnified slit beam photographs masked to molecular diagnosis when obtainable. Main outcome measures Cell counts in SLAV, best corrected VA, molecular and clinical diagnoses. Results One hundred and five charts were evaluated, 68 of which (64.8%) included SLAV data. Numerous (1+ or greater) cells were present in 22/68 (32.4%) patients, whereas 4/68 (5.9%) had rare cells and 42/68 (61.8%) had no cells. The average age between patients with cells, no-cells, and rare cells did not differ significantly (p=0.25). VA averaged 20/124 in patients with cells, 20/143 in patients with no-cells, and 20/68 in patients with rare cells (p= 0.70). The most frequent diagnoses with cells included Bardet Biedl syndrome, Leber congenital amaurosis (LCA), and retinitis pigmentosa. The most frequent diagnoses without cells included congenital stationary night blindness, LCA, Stargardt disease, and blue cone monochromacy. Discussion A non-random subset of pediatric retinal degenerations exhibit vitritis. Cells were present in 5/5 BBS patients (a progressive degeneration) whereas cells were not detected in any of the 12 patients with CSNB (a stable dysfunction). Conclusion Studying vitritis in pediatric retinal degenerations may reveal whether inflammation accompanies progressive vision loss in certain sub-types. Potentially, inflammation could be treated. SLAV may also aid in clinical diagnosis. PMID:25217415

Vitritis in pediatric genetic retinal disorders.

PubMed

Stunkel, Maria; Bhattarai, Sajag; Kemerley, Andrew; Stone, Edwin M; Wang, Kai; Mullins, Robert F; Drack, Arlene V

2015-01-01

To determine which types of pediatric retinal degeneration are associated with inflammatory cells in the anterior vitreous. Retrospective, observational study in humans. Retrospective chart review was performed for pediatric patients with suspected retinal degeneration presenting to a single examiner from 2008 to 2013. Age, visual acuity (VA), slit-lamp examination of anterior vitreous (SLAV), and clinical and molecular genetic diagnoses were documented. Anterior vitreous cells were graded clinically with SLAV from rare cells (1-4) to 1+ (5-9), 2+ (10-30), or 3+ (>30). Cells were also counted in magnified slit beam photographs masked to molecular diagnosis when obtainable. Cell counts in SLAV, best-corrected VA, and molecular and clinical diagnoses. We evaluated 105 charts, 68 of which (64.8%) included SLAV data. Numerous (1+ or greater) cells were present in 22 of 68 patients (32.4%), whereas 4 of 68 (5.9%) had rare cells and 42 of 68 (61.8%) had no cells. The average age between patients with cells, no cells, and rare cells did not differ significantly (P = 0.25). The VA averaged 20/124 in patients with cells, 20/143 in patients with no cells, and 20/68 in patients with rare cells (P = 0.70). The most frequent diagnoses with cells included Bardet Biedl syndrome (BBS), Leber congenital amaurosis (LCA), and retinitis pigmentosa. The most frequent diagnoses without cells included congenital stationary night blindness (CSNB), LCA, Stargardt disease, and blue cone monochromacy. A nonrandom subset of pediatric retinal degenerations exhibit vitritis. Cells were present in 5 of 5 BBS patients (a progressive degeneration), whereas cells were not detected in any of the 12 patients with CSNB (a stable dysfunction). Studying vitritis in pediatric retinal degenerations may reveal whether inflammation accompanies progressive vision loss in certain subtypes. Potentially, inflammation could be treated. In addition, SLAV may aid in clinical diagnosis. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Comparative analysis of endothelial cell loss following phacoemulsification in pupils of different sizes.

PubMed

Maggon, Rakesh; Bhattacharjee, Raghudev; Shankar, Sandeep; Kar, Rajesh Chandra; Sharma, Vivek; Roy, Shyamal

2017-12-01

To compare Endothelial cell(EC) loss following Phacoemulsification (PKE) in pupils of different sizes. A prospective double masked observational study in which a total of 150 eyes of 150 patients between 50 & 70 years of age with senile cataract of nuclear sclerosis grade II were enrolled. Patients were allocated into three groups of 50 eyes each in Group A (pupil size <5 mm), Group B (pupil size 5-7 mm) and Group C (pupil size >7 mm). Pupillary size was measured by determining the height of slit on slit-lamp biomicroscope examination. PKE was done by the same expert surgeon using vertical chop technique and a foldable intraocular lens was implanted in the capsular bag. Corneal EC count and pachymetry were performed twice and average of 2 readings was taken for the purpose of this study. Measurements were taken preoperatively and postoperatively on day 1, day 7 and day 30. The mean EC count loss on postoperative day 1 in Group A was 19.45%, Group B 14.89%, Group C 10.19% with statistical significant difference between Group A and Group B, as also Group A and Group C. The difference was not significant between Group B and Group C, though there was a fall in EC count in Group C as well. Increase in corneal thickness on postoperative day 1 in group A was 5.43%, Group B 3.55%, Group C 2.14% with statistical significant difference between Group A and Group B, as also Group A and Group C with no difference in Group B and Group C. PKE done in eyes with maximal pupillary dilatation of <5 mm causes a greater EC loss and results in thicker corneas postoperatively as compared to eyes with pupillary dilatation of >5 mm at the end of one month.

Characteristics and performance of a two-lens slit spatial filter for high power lasers

NASA Astrophysics Data System (ADS)

Xiong, Han; Gao, Fan; Zhang, Xiang; Zhuang, Zhenwu; Zhao, Jianjun; Yuan, Xiao

2017-05-01

The characteristics of a two-lens slit spatial filtering system on image relay and spatial filtering are discussed with detailed theoretical calculation and numerical simulation. The slit spatial filter can be used as the cavity spatial filter in large laser systems, such as National Ignition Facility, which can significantly decrease the focal intensity in cavity spatial filter and suppress or even avoid the pinhole (slit) closure while keeping the output power and beam quality. Additionally, the overall length of the cavity spatial filter can be greatly reduced with the use of the two-lens slit spatial filter.

Slit/Robo1 signaling regulates neural tube development by balancing neuroepithelial cell proliferation and differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Guang; Li, Yan; Wang, Xiao-yu

2013-05-01

Formation of the neural tube is the morphological hallmark for development of the embryonic central nervous system (CNS). Therefore, neural tube development is a crucial step in the neurulation process. Slit/Robo signaling was initially identified as a chemo-repellent that regulated axon growth cone elongation, but its role in controlling neural tube development is currently unknown. To address this issue, we investigated Slit/Robo1 signaling in the development of chick neCollege of Life Sciences Biocentre, University of Dundee, Dundee DD1 5EH, UKural tube and transgenic mice over-expressing Slit2. We disrupted Slit/Robo1 signaling by injecting R5 monoclonal antibodies into HH10 neural tubes tomore » block the Robo1 receptor. This inhibited the normal development of the ventral body curvature and caused the spinal cord to curl up into a S-shape. Next, Slit/Robo1 signaling on one half-side of the chick embryo neural tube was disturbed by electroporation in ovo. We found that the morphology of the neural tube was dramatically abnormal after we interfered with Slit/Robo1 signaling. Furthermore, we established that silencing Robo1 inhibited cell proliferation while over-expressing Robo1 enhanced cell proliferation. We also investigated the effects of altering Slit/Robo1 expression on Sonic Hedgehog (Shh) and Pax7 expression in the developing neural tube. We demonstrated that over-expressing Robo1 down-regulated Shh expression in the ventral neural tube and resulted in the production of fewer HNK-1{sup +} migrating neural crest cells (NCCs). In addition, Robo1 over-expression enhanced Pax7 expression in the dorsal neural tube and increased the number of Slug{sup +} pre-migratory NCCs. Conversely, silencing Robo1 expression resulted in an enhanced Shh expression and more HNK-1{sup +} migrating NCCs but reduced Pax7 expression and fewer Slug{sup +} pre-migratory NCCs were observed. In conclusion, we propose that Slit/Robo1 signaling is involved in regulating neural tube development by tightly coordinating cell proliferation and differentiation during neurulation. - Highlights: ► The role of Slit/Robo1 signaling was investigated with chick and mouse models. ► Disturbance of Slit/Robo1 signaling resulted in neural tube defects. ► Slit/Robo1 signaling regulated the proliferation of neural tube cells. ► Slit/Robo1 signaling modulated the differentiation of neural tube cells. ► Slit/Robo1 signaling balanced the proliferation and differentiation of neural tube.« less

Maintenance dosing for sublingual immunotherapy by prominent European allergen manufacturers expressed in bioequivalent allergy units.

PubMed

Larenas-Linnemann, Désirée; Esch, Robert; Plunkett, Greg; Brown, Shannon; Maddox, Daniel; Barnes, Charles; Constable, Derek

2011-11-01

Sublingual immunotherapy (SLIT) has become established in Europe, and its efficacy is being evaluated in the United States. The doses used for SLIT in Europe today are difficult to evaluate, because each manufacturer expresses the potency of its extracts differently. To compare in vitro European SLIT maintenance solutions against US licensed standardized allergenic extract concentrates and to determine the monthly SLIT doses delivered expressed in bioequivalent allergy units ([B]AU). We studied Dermatophagoides pteronyssinus, timothy grass pollen, cat (hair) and short ragweed pollen allergen extracts. The SLIT maintenance solutions of 4 leading European manufacturers and standardized concentrate extracts of 3 US manufacturers were analyzed with the following assays: protein content, relative potency (immunoglobulin E [IgE]-binding enzyme-linked immunosorbent assay [ELISA] inhibition) and major allergen content. The relative monthly allergen dose in (B)AU was calculated for each recommended SLIT schedule. Relative potency was approximately 10 times higher for US concentrate standardized extracts-which are meant to be diluted-than for European SLIT maintenance solutions of D pteronyssinus and timothy grass pollen. For cat (hair) and short ragweed pollen, the difference was less. Measurements of relative potency and major allergen content correlated well. In our assays, European mite extracts contain a very low quantity of Der p 2 compared with US mites. Recommended SLIT doses in Europe vary widely among the manufacturers, but are consistently lower (Eur1) or higher (Eur4) over all four allergens tested. SLIT efficacy probably depends on additional factors apart from the exact dose. SLIT dose finding studies should be done for each product. Copyright © 2011 American College of Allergy. Published by Elsevier Inc. All rights reserved.

Ultra short pre-seasonal subcutaneous immunotherapy and pre-coseasonal sublingual immunotherapy for pollen allergy: an evaluation of patient's preference in real life.

PubMed

Manzotti, G; Pappacoda, A; Dimatteo, M; Scolari, C; Riario-Sforza, G G; Incorvaia, C

2013-08-01

Specific immunotherapy (SIT) efficacy and safety by subcutaneous (SCIT) and sublingual (SLIT) route is supported by literature data. Pre-coseasonal treatment is currently the more accepted option for pollen immunotherapy in terms of costs and patient's compliance. This retrospective study evaluated the patient's preference concerning subcutaneous or sublingual route in pre-coseasonal treatment. We evaluated 145 patients (79 males, 66 females, age ranging from 14 to 69 years), suffering from moderate-severe rhino-conjunctivitis or mild bronchial asthma and with homogeneous characteristic according to allergic disease severity. We proposed either SLIT, with extracts by different producers, or SCIT with Pollinex 4 (Allergy Therapeutics, Worthing, UK), a product designed for ultra-short administration in 4 injections, highlighting for each kind of SIT the major practical advantages or burdens. Of 145 patients, 72 chose Pollinex 4 SCIT and 73 chose SLIT. SCIT-treated patients received a total of 90 vaccines (18 patients had double course of SCIT). SLIT-treated patients received a total of 87 vaccines (14 patients had double course of SLIT). In the SCIT group, there were 49 males and 23 females; in the SLIT group, there were 30 males and 43 females. Mean age was 36.5 years in SCIT group and 28.5 years in SLIT group. Males preferred SCIT (49 of 72 patients) and females preferred SLIT (43 of 73 patients). No severe reaction was observed either in SCIT or SLIT group. Patients are active subjects in decisional process. Trying to apply in real life the indications coming from guidelines about patient's preference is an important matter. In our patients SCIT with ultra short schedule and SLIT are similarly preferred.

Diffraction limited focusing and routing of gap plasmons by a metal-dielectric-metal lens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dennis, Brian S.; Czaplewski, David A.; Haftel, Michael I.

2015-01-01

Passive optical elements can play key roles in photonic applications such as plasmonic integrated circuits. Here we experimentally demonstrate passive gap-plasmon focusing and routing in two-dimensions. This is accomplished using a high numerical-aperture metal-dielectric-metal lens incorporated into a planar-waveguide device. Fabrication via metal sputtering, oxide deposition, electron-and focused-ion-beam lithography, and argon ion-milling is reported on in detail. Diffraction-limited focusing is optically characterized by sampling out-coupled light with a microscope. The measured focal distance and full-width-half-maximum spot size agree well with the calculated lens performance. The surface plasmon polariton propagation length is measured by sampling light from multiple out-coupler slits. (C)more » 2015 Optical Society of America« less

The double slit experiment and the time reversed fire alarm

NASA Astrophysics Data System (ADS)

Halabi, Tarek

2011-03-01

When both slits of the double slit experiment are open, closing one paradoxically increases the detection rate at some points on the detection screen. Feynman famously warned that temptation to "understand" such a puzzling feature only draws us into blind alleys. Nevertheless, we gain insight into this feature by drawing an analogy between the double slit experiment and a time reversed fire alarm. Much as closing the slit increases probability of a future detection, ruling out fire drill scenarios, having heard the fire alarm, increases probability of a past fire (using Bayesian inference). Classically, Bayesian inference is associated with computing probabilities of past events. We therefore identify this feature of the double slit experiment with a time reversed thermodynamic arrow. We believe that much of the enigma of quantum mechanics is simply due to some variation of time's arrow.

[A micro-silicon multi-slit spectrophotometer based on MEMS technology].

PubMed

Hao, Peng; Wu, Yi-Hui; Zhang, Ping; Liu, Yong-Shun; Zhang, Ke; Li, Hai-Wen

2009-06-01

A new mini-spectrophotometer was developed by adopting micro-silicon slit and pixel segmentation technology, and this spectrophotometer used photoelectron diode array as the detector by the back-dividing-light way. At first, the effect of the spectral bandwidth on the tested absorbance linear correlation was analyzed. A theory for the design of spectrophotometer's slit was brought forward after discussing the relationships between spectrophotometer spectrum band width and pre-and post-slits width. Then, the integrative micro-silicon-slit, which features small volume, high precision, and thin thickness, was manufactured based on the MEMS technology. Finally, a test was carried on linear absorbance solution by this spectrophotometer. The final result showed that the correlation coefficients were larger than 0.999, which means that the new mini-spectrophotometer with micro-silicon slit pixel segmentation has an obvious linear correlation.

Force transformation in spider strain sensors: white light interferometry

PubMed Central

Schaber, Clemens F.; Gorb, Stanislav N.; Barth, Friedrich G.

2012-01-01

Scanning white light interferometry and micro-force measurements were applied to analyse stimulus transformation in strain sensors in the spider exoskeleton. Two compound or ‘lyriform’ organs consisting of arrays of closely neighbouring, roughly parallel sensory slits of different lengths were examined. Forces applied to the exoskeleton entail strains in the cuticle, which compress and thereby stimulate the individual slits of the lyriform organs. (i) For the proprioreceptive lyriform organ HS-8 close to the distal joint of the tibia, the compression of the slits at the sensory threshold was as small as 1.4 nm and hardly more than 30 nm, depending on the slit in the array. The corresponding stimulus forces were as small as 0.01 mN. The linearity of the loading curve seems reasonable considering the sensor's relatively narrow biological intensity range of operation. The slits' mechanical sensitivity (slit compression/force) ranged from 106 down to 13 nm mN−1, and gradually decreased with decreasing slit length. (ii) Remarkably, in the vibration-sensitive lyriform organ HS-10 on the metatarsus, the loading curve was exponential. The organ is thus adapted to the detection of a wide range of vibration amplitudes, as they are found under natural conditions. The mechanical sensitivities of the two slits examined in this organ in detail differed roughly threefold (522 and 195 nm mN−1) in the biologically most relevant range, again reflecting stimulus range fractionation among the slits composing the array. PMID:22031733

SLIT: indications, follow-up, and management.

PubMed

Dávila, I; Navarro, A; Domínguez-Ortega, J; Alonso, A; Antolín-Amérigo, D; Diéguez, M C; González-Mancebo, E; Martíns, C; Martínez, C; Núñez, B; Prior, N; Rechel, M; Rosado, A; Ruiz-Hornillos, J; Sansosti, A; Torrecillas, M; Jerez, M J

2014-01-01

Specific sublingual immunotherapy (SLIT) has been proved to be a safe and effective approach in respiratory allergy. However, further research is required on aspects such as patient selection, use of optimal dosing, effects on asthma, long-term effects, and management of adverse reactions. In addition, the widely heterogeneous nature of studies on SLIT performed to date and the application of the criteria for subcutaneous immunotherapy make it difficult for the prescribing clinician to draw accurate and useful conclusions. Therefore, the QUASAR Group (QUality in the Administration of SLIT in Allergic Rhinitis), which comprises allergologists with broad clinical experience in SLIT, investigated the latest research findings and available data on this approach. Working parties were formed in 3 different categories: selection of candidates for SLIT, treatment efficacy, and adverse reactions. We performed a PubMed search for articles that were representative of each category and found 850. From these, we finally selected 266 articles, which were reviewed to retrieve data on SLIT. Evidence for each clinical question was graded according to the Oxford classification. The resulting text was evaluated on 3 occasions by all the members of the group until the final version was agreed upon. In this version, we review available evidence on SLIT, particularly with pollens, which is the subject of most articles. In areas where evidence is insufficient, an alternative agreed upon by the members of the QUASAR group is presented. Finally, we propose algorithms for selecting candidates for SLIT and for management of adverse events.

Direct nanopatterning of polymer/silver nanoblocks under low energy electron beam irradiation.

PubMed

El Mel, Abdel-Aziz; Stephant, Nicolas; Gautier, Romain

2016-10-06

In this communication, we report on the growth, direct writing and nanopatterning of polymer/silver nanoblocks under low energy electron beam irradiation using a scanning electron microscope. The nanoblocks are produced by placing a droplet of an ethylene glycol solution containing silver nitrate and polyvinylpyrrolidone diluted in ethanol directly on a hot substrate heated up to 150 °C. Upon complete evaporation of the droplet, nanospheres, nano- and micro-triangles and nanoblocks made of silver-containing polymers, form over the substrate surface. Considering the nanoblocks as a model system, we demonstrate that such nanostructures are extremely sensitive to the e-beam extracted from the source of a scanning electron microscope operating at low acceleration voltages (between 5 and 7 kV). This sensitivity allows us to efficiently create various nanopatterns (e.g. arrays of holes, oblique slits and nanotrenches) in the material under e-beam irradiation. In addition to the possibility of writing, the nanoblocks revealed a self-healing ability allowing them to recover a relatively smooth surface after etching. Thanks to these properties, such nanomaterials can be used as a support for data writing and erasing on the nanoscale under low energy electron beam irradiation.

Detection-gap-independent optical sensor design using divergence-beam-controlled slit lasers for wearable devices

NASA Astrophysics Data System (ADS)

Yoon, Young Zoon; Kim, Hyochul; Park, Yeonsang; Kim, Jineun; Lee, Min Kyung; Kim, Un Jeong; Roh, Young-Geun; Hwang, Sung Woo

2016-09-01

Wearable devices often employ optical sensors, such as photoplethysmography sensors, for detecting heart rates or other biochemical factors. Pulse waveforms, rather than simply detecting heartbeats, can clarify arterial conditions. However, most optical sensor designs require close skin contact to reduce power consumption while obtaining good quality signals without distortion. We have designed a detection-gap-independent optical sensor array using divergence-beam-controlled slit lasers and distributed photodiodes in a pulse-detection device wearable over the wrist's radial artery. It achieves high biosignal quality and low power consumption. The top surface of a vertical-cavity surface-emitting laser of 850 nm wavelength was covered by Au film with an open slit of width between 500 nm and 1500 nm, which generated laser emissions across a large divergence angle along an axis orthogonal to the slit direction. The sensing coverage of the slit laser diode (LD) marks a 50% improvement over nonslit LD sensor coverage. The slit LD sensor consumes 100% more input power than the nonslit LD sensor to obtain similar optical output power. The slit laser sensor showed intermediate performance between LD and light-emitting diode sensors. Thus, designing sensors with multiple-slit LD arrays can provide useful and convenient ways for incorporating optical sensors in wrist-wearable devices.

Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

DOE PAGES

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit; ...

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials and in situ and operando diffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, overmore » a continuous range of diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. In addition, the design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less

A microbeam slit system for high beam currents

NASA Astrophysics Data System (ADS)

Vallentin, T.; Moser, M.; Eschbaumer, S.; Greubel, C.; Haase, T.; Reichart, P.; Rösch, T.; Dollinger, G.

2015-04-01

A new microbeam slit system for high beam currents of 10 μA was built up to improve the brightness transport of a proton beam with a kinetic energy of up to 25 MeV into the microprobe SNAKE. The new slit system features a position accuracy of less than 1 μm under normal operating conditions and less than 2 μm if the beam is switched on and off. The thermal management with a powerful watercooling and potential-free thermocouple feedback controlled heating cables is optimized for constant slit aperture at thermal power input of up to 250 W. The transparent zone is optimized to 0.7 μm due to the use of tungsten formed to a cylindrical surface with a radius r = 100 mm and mechanically lapped surface to minimize small angle scattering effects and to minimize the number of ions passing the slits with low energy loss. Electrical isolation of the slit tip enables slit current monitoring, e.g. for tandem accelerator feedback control. With the ability to transport up to 10 μA of protons with the new microslit system, the brightness Bexp transported into the microprobe was increased by a factor of 2 compared to low current injection using the old slit system.

Fabrication and testing of a newly designed slit system for depth-resolved X-ray diffraction measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinsheimer, John; Bouet, Nathalie; Ghose, Sanjit

2016-10-06

A new system of slits called `spiderweb slits' have been developed for depth-resolved powder or polycrystalline X-ray diffraction measurements. The slits act on diffracted X-rays to select a particular gauge volume of sample, while absorbing diffracted X-rays from outside of this volume. Although the slit geometry is to some extent similar to that of previously developed conical slits or spiral slits, this new design has advantages over the previous ones in use for complex heterogeneous materials andin situandoperandodiffraction measurements. For example, the slits can measure a majority of any diffraction cone for any polycrystalline material, over a continuous range ofmore » diffraction angles, and work for X-ray energies of tens to hundreds of kiloelectronvolts. The design is generated and optimized using ray-tracing simulations, and fabricated through laser micromachining. The first prototype was successfully tested at the X17A beamline at the National Synchrotron Light Source, and shows similar performance to simulations, demonstrating gauge volume selection for standard powders, for all diffraction peaks over angles of 2–10°. A similar, but improved, design will be implemented at the X-ray Powder Diffraction beamline at the National Synchrotron Light Source II.« less

Diagnostic system for profiling micro-beams

DOEpatents

Elmer, John W.; Palmer, Todd A.; Teruya, Alan T.; Walton, Chris C.

2007-10-30

An apparatus for characterization of a micro beam comprising a micro modified Faraday cup assembly including a first layer of material, a second layer of material operatively connected to the first layer of material, a third layer of material operatively connected to the second layer of material, and a fourth layer of material operatively connected to the third layer of material. The first layer of material comprises an electrical conducting material and has at least one first layer radial slit extending through the first layer. An electrical ground is connected to the first layer. The second layer of material comprises an insulating material and has at least one second layer radial slit corresponding to the first layer radial slit in the first layer of material. The second layer radial slit extends through the second layer. The third layer of material comprises a conducting material and has at least one third layer radial slit corresponding to the second layer radial slit in the second layer of material. The third layer radial slit extends through the third layer. The fourth layer of material comprises an electrical conducting material but does not have slits. An electrical measuring device is connected to the fourth layer. The micro modified Faraday cup assembly is positioned to be swept by the micro beam.

Spectral optical coherence tomography: a novel technique for cornea imaging.

PubMed

Kaluzny, Bartłomiej J; Kaluzy, Bartłomiej J; Kałuzny, Jakub J; Szkulmowska, Anna; Gorczyńska, Iwona; Szkulmowski, Maciej; Bajraszewski, Tomasz; Wojtkowski, Maciej; Targowski, Piotr

2006-09-01

Spectral optical coherence tomography (SOCT) is a new, noninvasive, noncontact, high-resolution technique that provides cross-sectional images of the objects that weakly absorb and scatter light. SOCT, because of very short acquisition time and high sensitivity, is capable of providing tomograms of substantially better quality than the conventional OCT. The aim of this paper is to show the application of the SOCT to cross-sectional imaging of the cornea and its pathologies. Eleven eyes with different corneal pathologies were examined with a slit lamp and the use of a prototype SOCT instrument constructed in the Institute of Physics, Nicolaus Copernicus University, Toruń, Poland. Our SOCT system provides high-resolution (4 microm axial, 10 microm transversal) tomograms composed of 3000-5000 A-scans with an acquisition time of 120-200 ms. The quality of the images is adequate for detailed cross-sectional evaluation of various corneal pathologies. Objective assessment of the localization, size, shape, and light-scattering properties of the changed tissue is possible. Corneal and epithelial thickness and the depth and width of lesions can be estimated. SOCT technique allows acquiring clinically valuable cross-sectional optical biopsy of the cornea and its pathologies.

Comet P/Halley 1910, 1986: An objective-prism study

NASA Technical Reports Server (NTRS)

Carsenty, U.; Bus, E. S.; Wyckoff, S.; Lutz, B.

1986-01-01

V. M. Slipher of the Lowell Obs. collected a large amount of spectroscopic data during the 1910 apparition of Halley's comet. Three of his post perihelion objective-prism plates were selected, digitized, and subjected to modern digital data reduction procedures. Some of the important steps in the analysis where: (1) Density to intensity conversion for which was used 1910 slit spectra of Fe-arc lamp on similar plates (Sigma) and derived an average characteristic curve; (2) Flux calibration using the fact that during the period June 2 to 7 1910 P/Halley was very close (angular distance) to the bright star Alpha Sex (A0III, V-4.49), and the spectra of both star and comet were recorded on the same plates. The flux distribution of Alpha Sex was assumed to be similar to that of the standard star 58 Aql and derived a sensitivity curve for the system; (3) Atmospheric extinction using the standard curve for the Lowell Obs.; (4) Solar continuum subtraction using the standard solar spectrum binned to the spectral resolution. An example of a flux-calibrated spectrum of the coma (integrated over 87,000km) before the subtraction of solar continuum is presented.

Cystinosis Presenting with Findings of Bartter Syndrome

PubMed Central

Özkan, Behzat; Çayır, Atilla; Koşan, Celalettin; Alp, Handan

2011-01-01

A five-year-old boy was referred to our pediatric clinic for evaluation of failure to thrive, headache, intermittent high fever, restlessness, polyuria, and polydipsia. His weight and height measurements were under the 3rd percentile. Clinical findings consisted of frontal bossing, carious teeth, O-bain deformity of the lower extremities, and moderate dehydration. The presence of metabolic alkalosis, hypokalemia, hypochloremia, and high renin and aldosterone levels were suggestive of Bartter syndrome and a treatment regimen for Bartter syndrome was started. At follow-up, the polyuria and hyponatremia were found to persist. A reassessment of the patient revealed findings consistent with proximal renal tubular acidosis such as metabolic acidosis with a high urinary pH, proteinuria, aminoaciduria with phosphaturia and hypercalciuria. Based on the presence of parental consanguinity as well as polyuria, proteinuria, low tubular reabsorption of phosphorus, generalized aminoaciduria, light yellow skin and hair color, the probable diagnosis of cystinosis was established and was confirmed by slit-lamp examination of the cornea showing cystine crystal deposition. Our case is a good example demonstrating that development of metabolic alkalosis does not exclude cystinosis and that all findings of the patient should be thoroughly evaluated. Conflict of interest:None declared. PMID:21750641

Cystinosis presenting with findings of Bartter syndrome.

PubMed

Özkan, Behzat; Çayır, Atilla; Koşan, Celalettin; Alp, Handan

2011-01-01

A five-year-old boy was referred to our pediatric clinic for evaluation of failure to thrive, headache, intermittent high fever, restlessness, polyuria, and polydipsia. His weight and height measurements were under the 3rd percentile. Clinical findings consisted of frontal bossing, carious teeth, O-bain deformity of the lower extremities, and moderate dehydration. The presence of metabolic alkalosis, hypokalemia, hypochloremia, and high renin and aldosterone levels were suggestive of Bartter syndrome and a treatment regimen for Bartter syndrome was started. At follow-up, the polyuria and hyponatremia were found to persist. A reassessment of the patient revealed findings consistent with proximal renal tubular acidosis such as metabolic acidosis with a high urinary pH, proteinuria, aminoaciduria with phosphaturia and hypercalciuria. Based on the presence of parental consanguinity as well as polyuria, proteinuria, low tubular reabsorption of phosphorus, generalized aminoaciduria, light yellow skin and hair color, the probable diagnosis of cystinosis was established and was confirmed by slit-lamp examination of the cornea showing cystine crystal deposition. Our case is a good example demonstrating that development of metabolic alkalosis does not exclude cystinosis and that all findings of the patient should be thoroughly evaluated. ©Journal of Clinical Research in Pediatric Endocrinology, Published by Galenos Publishing.

A Patient with Cystinosis Presenting Like Bartter Syndrome and Review of Literature

PubMed Central

Ertan, Pelin; Evrengul, Havva; Ozen, Serkan; Emre, Sinan

2012-01-01

Background Nephropathic cystinosis is an autosomal recessively inherited metabolic disorder presenting with metabolic acidosis, Fanconi syndrome and renal failure. Case Presentation We present a 6-year-old girl with severe growth failure, hyponatremia and hypokalemia. Her parents were 4th degree relatives. Two relatives were diagnosed as end stage renal failure. She also had persistant hypokalemic hypochloremic metabolic alkalosis. Her renal function was normal at presentation. She was thought to have Bartter syndrome with supporting findings of elevated levels of renin and aldosterone with normal blood pressure, and hyperplasia of juxtaglomerular apparatus. Her metabolic alkalosis did not resolve despite supportive treatment. At 6th month of follow-up proteinuria, glucosuria and deterioration of renal function developed. Diagnosis of cystinosis was made with slit lamp examination and leukocyte cystine levels. At 12th month of follow-up her metabolic alkalosis has converted to metabolic acidosis. Conclusion In children presenting with persistant metabolic alkalosis, with family history of renal failure, and parental consanguinity, cystinosis should always be kept in mind as this disease is an important cause of end stage renal failure which may have features mimmicking Bartter syndrome. PMID:23431081

Comparative analysis of image classification methods for automatic diagnosis of ophthalmic images

NASA Astrophysics Data System (ADS)

Wang, Liming; Zhang, Kai; Liu, Xiyang; Long, Erping; Jiang, Jiewei; An, Yingying; Zhang, Jia; Liu, Zhenzhen; Lin, Zhuoling; Li, Xiaoyan; Chen, Jingjing; Cao, Qianzhong; Li, Jing; Wu, Xiaohang; Wang, Dongni; Li, Wangting; Lin, Haotian

2017-01-01

There are many image classification methods, but it remains unclear which methods are most helpful for analyzing and intelligently identifying ophthalmic images. We select representative slit-lamp images which show the complexity of ocular images as research material to compare image classification algorithms for diagnosing ophthalmic diseases. To facilitate this study, some feature extraction algorithms and classifiers are combined to automatic diagnose pediatric cataract with same dataset and then their performance are compared using multiple criteria. This comparative study reveals the general characteristics of the existing methods for automatic identification of ophthalmic images and provides new insights into the strengths and shortcomings of these methods. The relevant methods (local binary pattern +SVMs, wavelet transformation +SVMs) which achieve an average accuracy of 87% and can be adopted in specific situations to aid doctors in preliminarily disease screening. Furthermore, some methods requiring fewer computational resources and less time could be applied in remote places or mobile devices to assist individuals in understanding the condition of their body. In addition, it would be helpful to accelerate the development of innovative approaches and to apply these methods to assist doctors in diagnosing ophthalmic disease.

Millimeter wave absorption in the nonhuman primate eye at 35 GHz and 94 GHz.

PubMed

Chalfin, Steven; D'Andrea, John A; Comeau, Paul D; Belt, Michael E; Hatcher, Donald J

2002-07-01

The purpose of this study was to evaluate anterior segment bioeffects of pulsed 35 GHz and 94 GHz microwave exposure in the nonhuman primate eye. Five juvenile rhesus monkeys (Macaca mulatta) underwent baseline anterior segment ocular assessment consisting of slit lamp examination, corneal topography, specular microscopy, and pachymetry. These studies were repeated after exposure of one eye to pulsed 35 GHz or 94 GHz microwaves at varied fluences, with the other eye serving as a control. The mean fluence required to produce a threshold corneal lesion (faint epithelial edema and fluorescein staining) was 7.5 J cm(-2) at 35 GHz and 5 J cm(-2) at 94 GHz. Transient changes in corneal topography and pachymetry were noted at these fluences. Endothelial cell counts remained unchanged. Threshold corneal injury from 35 GHz and 94 GHz microwave exposure is produced at fluences below those previously reported for CO2 laser radiation. These data may help elucidate the mechanism of thermal injury to the cornea, and resolve discrepancies between IEEE C95.1 (1999), NCRP (1986), and ICNIRP (1998) safety standards for exposure to non-ionizing radiation at millimeter wavelengths.

[Cytomegalovirus retinitis in immunocompetent patients].

PubMed

Yoshinaga, Wakako; Mizushima, Yuka; Abematsu, Noriko; Nakao, Kumiko; Sakamoto, Taiji

2008-08-01

Cytomegalovirus (CMV) retinitis usually affects severely immunosuppressed individuals. We report two immunocompetent patients who developed CMV retinitis. Case 1 was a 65-year-old man who was referred to us with blurred vision and floaters of 2 weeks duration in his left eye. Slit-lamp biomicroscopy showed keratic precipitates, aqueous cells, and vitreous opacity in his left eye. Funduscopic examination revealed yellow-white retinal lesions with arterial sheathing in the superotemporal midperiphery. Case 2 was a 63-year-old man who presented with a 2-week history of blurred vision in his left eye. Ophthalmologic examination of the left eye showed keratic precipitates, aqueous cells, vitreous opacity, and yellow-white lesions in the superotemporal peripheral retina. In both cases, CMV DNA was detected in the aqueous humor and therefore the diagnosis was CMV retinitis. CMV retinitis in both cases was indolent and was resolved in one month without treatment with antiviral drugs. Although both patients had diabetes mellitus, the results of their laboratory examinations were unremarkable and they were immunocompetent. Unlike CMV retinitis in immunocompromised patients, CMV retinitis in immunocompetent patients had significant anterior and vitreous inflammation but did not require antiviral treatment. A possible association between CMV retinitis and diabetes mellitus was suggested.

Retinal diseases in a reference center from a Western Amazon capital city.

PubMed

Malerbi, Fernando Korn; Matsudo, Nilson Hideo; Carneiro, Adriano Biondi Monteiro; Lottenberg, Claudio Luiz

2015-01-01

To describe retinal diseases found in patients who were waiting for treatment at a tertiary care hospital in Rio Branco, Acre, Brazil. Patients underwent slit lamp biomicroscopy, dilated fundus exam and ocular ultrasound. Patients were classified according to phakic status and retinal disease of the most severely affected eye. A total of 138 patients were examined. The mean age was 51.3 years. Diabetes was present in 35.3% and hypertension in 45.4% of these patients. Cataract was found in 23.2% of patients, in at least one eye. Retinal examination was possible in 129 patients. The main retinal diseases identified were rhegmatogenous retinal detachment (n=23; 17.8%) and diabetic retinopathy (n=32; 24.8%). Out of 40 patients evaluated due to diabetes, 13 (32.5%) had absent or mild forms of diabetic retinopathy and did not need further treatment, only observation. Diabetic retinopathy was the main retinal disease in this population. It is an avoidable cause of blindness and can be remotely evaluated, in its initial stages, by telemedicine strategies. In remote Brazilian areas, telemedicine may be an important tool for retinal diseases diagnosis and follow-up.

Prevalence and causes of corneal blindness.

PubMed

Wang, Haijing; Zhang, Yaoguang; Li, Zhijian; Wang, Tiebin; Liu, Ping

2014-04-01

The study aimed to assess the prevalence and causes of corneal blindness in a rural northern Chinese population. Cross-sectional study. The cluster random sampling method was used to select the sample. This population-based study included 11 787 participants of all ages in rural Heilongjiang Province, China. These participants underwent a detailed interview and eye examination that included the measurement of visual acuity, slit-lamp biomicroscopy and direct ophthalmoscopy. An eye was considered to have corneal blindness if the visual acuity was <9/18 because of corneal diseases. The main outcome measure was prevalence rates of corneal blindness and low vision. Among the 10 384 people enrolled in the study, the prevalence of corneal blindness is 0.3% (95% confidence interval 0.2-0.4%). The leading cause was keratitis in childhood (40.0%), followed by ocular trauma (33.3%) and keratitis in adulthood (20.0%). Age and illiteracy were found to be associated with an increased prevalence of corneal blindness. Blindness because of corneal diseases in rural areas of Northern China is a significant public health problem that needs to be given more attention. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

Evaluation of Dry Eye and Meibomian Gland Dysfunction in Teenagers with Myopia through Noninvasive Keratograph

PubMed Central

Wang, Xiu; Lu, Xiaoxiao; Yang, Jun; Wei, Ruihua; Yang, Liyuan; Zhao, Shaozhen; Wang, Xilian

2016-01-01

Purpose. This study aims to evaluate dry eye and ocular surface conditions of myopic teenagers by using questionnaire and clinical examinations. Methods. A total of 496 eyes from 248 myopic teenagers (7–18 years old) were studied. We administered Ocular Surface Disease Index (OSDI) questionnaire, slit-lamp examination, and Keratograph 5M. The patients were divided into 2 groups based on OSDI dry eye standard, and their ocular surfaces and meibomian gland conditions were evaluated. Results. The tear meniscus heights of the dry eye and normal groups were in normal range. Corneal fluorescein scores were significantly higher whereas noninvasive break-up time was dramatically shorter in the dry eye group than in the normal group. All three meibomian gland dysfunction parameters (i.e., meibomian gland orifice scores, meibomian gland secretion scores, and meibomian gland dropout scores) of the dry eye group were significantly higher than those of the normal group (P < 0.0001). Conclusions. The prevalence of dry eye in myopic teenagers is 18.95%. Meibomian gland dysfunction plays an important role in dry eye in myopic teenagers. The Keratograph 5M appears to provide an effective noninvasive method for assessing ocular surface situation of myopic teenagers. PMID:26881059

Safety study of intravitreal and suprachoroidal Laponite clay in rabbit eyes.

PubMed

Prieto, Esther; Vispe, Eugenio; De Martino, Alba; Idoipe, Miriam; Rodrigo, María J; Garcia-Martin, Elena; Fraile, José M; Polo-Llorens, Vicente; Mayoral, José A

2018-03-01

To study the safety and biocompatibility of Laponite clay (LAP) within an intravitreal and suprachoroidal administration in rabbit eyes. Thirty-two New Zealand albino rabbits were divided into two experimental groups to test intravitreal (IVT group) and suprachoroidal (SCS group) administration of a 100-μl and 50-μl Laponite suspension respectively. Following injection, the eyes were monitored by ocular tonometry, slit-lamp eye examination and indirect ophthalmoscopy, at 24 h, 1, 4, 12, and 14 weeks post administration. Histological examination was also performed to determine whether any ocular pathological change had occurred. Throughout the study, LAP presence in vitreous was estimated by complexometric titration with ethylenediaminetetraacetic acid (EDTA), taking advantage of the Laponite high content of magnesium ions. Neither significant differences in the intraocular pressure, nor relevant ocular complications were found in the two experimental groups after LAP administration. The histology of the retina remained unchanged. LAP presence in vitreous could be indirectly confirmed by complexometric titration until 14 weeks post administration in eyes of IVT group. Laponite could be considered as a vehicle for potential clinical use in ocular drug administration, due to its proven ocular biocompatibility and its transparency in gel state.

Fusarium dimerum Species Complex (Fusarium penzigii) Keratitis After Corneal Trauma.

PubMed

do Carmo, Anália; Costa, Esmeralda; Marques, Marco; Quadrado, Maria João; Tomé, Rui

2016-12-01

We report a case of a keratitis associated with a Fusarium penzigii-a Fusarium dimerum species complex (FDSC)-in a 81-year-old woman after a corneal trauma with a tree branch. At patient admittance, slit lamp biomicroscopy revealed an exuberant chemosis, an inferior corneal ulcer with an associated inflammatory infiltrate, a central corneal abscess, bullous keratopathy and posterior synechiae. Corneal scrapes were obtained for identification of bacteria and fungi, and the patient started antibiotic treatment on empirical basis. Few days later, the situation worsened with the development of hypopyon. By that time, Fusarium was identified in cultures obtained from corneal scrapes and the patient started topical amphotericin B 0.15 %. Upon the morphological identification of the Fusarium as a FDSC, and since there was no clinical improvement, the treatment with amphotericin B was suspended and the patient started voriconazole 10 mg/ml, eye drops, hourly and voriconazole 200 mg iv, every 12 h for 1 month. The hypopyon resolved and the inflammatory infiltrate improved, but the abscess persisted at the last follow-up visit. The molecular identification revealed that the FDSC was a F. penzigii.

Incidence and evolution of subretinal precipitates in optic disc pit maculopathy.

PubMed

Chatziralli, Irini; Theodossiadis, George; Brouzas, Dimitrios; Theodossiadis, Panagiotis

2017-06-26

To study the evolution of subretinal precipitates coexistent with optic disc pit (ODP) maculopathy from their appearance at baseline examination until their absorption after successful treatment. Participants in this retrospective, multicenter study were 42 patients with ODP maculopathy, in whom complete ocular examination was performed, including visual acuity (VA) measurement, slit-lamp examination, color or red-free fundus photography, and optical coherence tomography at baseline after surgical treatment. Out of 42 cases, 17 (40.5%) cases of ODP maculopathy, which were examined between 2002 and 2015, were found to have subretinal precipitates associated with multilayer fluid accumulation at baseline. Precipitates were located at the outer part of the photoreceptor layer and remained for 3-6 months after successful treatment and absorption of subretinal fluid. The mean VA was 0.99 ± 0.21 logMAR at baseline and improved to 0.54 ± 0.25 logMAR at the final examination. Macular precipitates in association with signs of disease chronicity, such as multilayer fluid accumulation, became evident at baseline examination. Precipitates' disappearance in 15 out of 17 cases coincided with the absorption of subretinal fluid. The relative low VA at baseline probably could be attributed to the chronicity of the disease.

Study on Fins' Effect of Boiling Flow in Millimeter Channel Heat Exchanger

NASA Astrophysics Data System (ADS)

Watanabe, Satoshi

2005-11-01

Recently, a lot of researches about compact heat exchangers with mini-channels have been carried out with the hope of obtaining a high-efficiency heat transfer, due to the higher ratio of surface area than existing heat exchangers. However, there are many uncertain phenomena in fields such as boiling flow in mini-channels. Thus, in order to understand the boiling flow in mini-channels to design high-efficiency heat exchangers, this work focused on the visualization measurement of boiling flow in a millimeter channel. A transparent acrylic channel (heat exchanger form), high-speed camera (2000 fps at 1024 x 1024 pixels), and halogen lamp (backup light) were used as the visualization system. The channel's depth is 2 mm, width is 30 mm, and length is 400 mm. In preparation for commercial use, two types of channels were experimented on: a fins type and a normal slit type (without fins). The fins are circular cylindrical obstacles (diameter is 5 mm) to promote heat transfer, set in a triangular array (distance between each center point is 10 mm). Especially in this work, boiling flow and heat transfer promotion in the millimeter channel heat exchanger with fins was evaluated using a high-speed camera.

Refractive Errors in Patients with Migraine Headache.

PubMed

Gunes, Alime; Demirci, Seden; Tok, Levent; Tok, Ozlem; Koyuncuoglu, Hasan; Yurekli, Vedat Ali

2016-01-01

To evaluate refractive errors in patients with migraine headache and to compare with healthy subjects. This prospective case-control study includes patients with migraine and age- and sex-matched healthy subjects. Clinical and demographic characteristics of the patients were noted. Detailed ophthalmological examinations were performed containing spherical refractive error, astigmatic refractive error, spherical equivalent (SE), anisometropia, best-corrected visual acuity, intraocular pressure, slit lamp biomicroscopy, fundus examination, axial length, anterior chamber depth, and central corneal thickness. Spectacle use in migraine and control groups was compared. Also, the relationship between refractive components and migraine headache variables was investigated. Seventy-seven migraine patients with mean age of 33.27 ± 8.84 years and 71 healthy subjects with mean age of 31.15 ± 10.45 years were enrolled (p = 0.18). The migraine patients had higher degrees of astigmatic refractive error, SE, and anisometropia when compared with the control subjects (p = 0.01, p = 0.03, p = 0.02, respectively). Migraine patients may have higher degrees of astigmatism, SE, and anisometropia. Therefore, they should have ophthalmological examinations regularly to ensure that their refractive errors are appropriately corrected.

The influence of dose, dose-rate and particle fragmentation on cataract induction by energetic iron ions

NASA Technical Reports Server (NTRS)

Medvedovsky, C.; Worgul, B. V.; Huang, Y.; Brenner, D. J.; Tao, F.; Miller, J.; Zeitlin, C.; Ainsworth, E. J.

1994-01-01

Because activities in space necessarily involve chronic exposure to a heterogeneous charged particle radiation field it is important to assess the influence of dose-rate and the possible modulating role of heavy particle fragmentation on biological systems. Using the well-studied cataract model, mice were exposed to plateau 600 MeV/amu Fe-56 ions either as acute or fractionated exposures at total doses of 5-504 cGy. Additional groups of mice received 20, 360 and 504 cGy behind 50 mm of polyethylene, which simulates body shielding. The reference radiation consisted of Co-60 gamma radiation. The animals were examined by slit lamp biomicroscopy over their three year life spans. In accordance with our previous observations with heavy particles, the cataractogenic potential of the 600 MeV/amu Fe-56 ions was greater than for low-Linear Energy Transfer (LET) radiation and increased with decreasing dose relative to gamma rays. Fractionation of a given dose of Fe-56 ions did not reduce the cataractogenicity of the radiation compared to the acute regimen. Fragmentation of the beam in the polyethylene did not alter the cataractotoxicity of the ions, either when administered singly or in fractions.

Intraocular pressure control of a novel glaucoma drainage device - in vitro and in vivo studies

PubMed Central

Cui, Li-Jun; Li, Di-Chen; Liu, Jian; Zhang, Lei; Xing, Yao

2017-01-01

AIM To evaluate the intraocular pressure (IOP) control of an artificial trabeculum drainage system (ATDS), a newly designed glaucoma drainage device, and postoperative complications in normal rabbit eyes. METHODS Pressure drops in air and fluid of 30 ATDS were measured after being connected to a closed manometric system. Twenty of them were then chosen and implanted randomly into the eyes of 20 rabbits. Postoperative slit-lamp, gonioscopic examination and IOP measurements were recorded periodically. Ultrasound biomicroscopy and B-scan ultrasonography were also used to observe the complications. Eyes were enucleated on day 60. RESULTS Pressure drops of 4.6-9.4 mm Hg were obtained at physiological aqueous flow rates in the tests in vitro. The average postoperative IOP of the experimental eyes (11.6-12.8 mm Hg) was lower than the controls significantly (P<0.05) at each time point. Complications of hemorrhage (n=1), cellulosic exudation (two cases) and local iris congestion (two cases) were observed. The lumina of the devices were devoid of obstructions in all specimens examined and a thin fibrous capsule was found around the endplate. CONCLUSION ATDS reduce IOP effectively. However, further studies on the structure are needed to reduce complications. PMID:28944192

The influence of dose, dose-rate and particle fragmentation on cataract induction by energetic iron ions

NASA Astrophysics Data System (ADS)

Medvedovsky, C.; Worgul, B. V.; Huang, Y.; Brenner, D. J.; Tao, F.; Miller, J.; Zeitlin, C.; Ainsworth, E. J.

1994-10-01

Because activities in space necessarily involve chronic exposure to a heterogeneous charged particle radiation field it is important to assess the influence of dose-rate and the possible modulating role of heavy particle fragmentation on biological systems. Using the well-studied cataract model, mice were exposed to plateau 600 MeV/amu 56Fe ions either as acute or fractionated exposures at total doses of 5 - 504 cGy. Additional groups of mice received 20, 360 and 504 cGy behind 50 mm of polyethylene, which simulates body shielding. The reference radiation consisted of 60Co γ radiation. The animals were examined by slit lamp biomicroscopy over their three year life spans. In accordance with our previous observations with heavy particles, the cataractogenic potential of the 600 MeV/amu 56Fe ions was greater than for low-LET radiation and increased with decreasing dose relative to γ-rays. Fractionation of a given dose of 56Fe ions did not reduce the cataractogenicity of the radiation compared to the acute regimen. Fragmentation of the beam in the polyethylene did not alter the cataractotoxicity of the ions, either when administered singly or in fractions.

Vitiligo iridis and glaucoma: a rare sequelae of small pox.

PubMed

Kavitha, S; Patel, S R; Mohini, P; Venkatesh, R; Sengupta, S

2015-10-01

Vitiligo iridis refers to focal areas of iris atrophy as sequelae of small pox infection. We report a series of patients with unilateral vitiligo iridis, some of whom presented with secondary open-angle glaucoma. Three patients with vitiligo iridis underwent a comprehensive ophthalmic examination including intraocular pressure (IOP) measurement, slit lamp biomicroscopy, gonioscopy, and fundus evaluation. Patients' facial features were also documented and photographed. All patients were in their sixth decade. Two out the three had elevated IOP (52 mm Hg and 36 mm Hg) in the same eye as vitiligo iridis, at initial presentation. Gonioscopy showed patchy iris hyperpigmentation and fundus evaluation showed glaucomatous optic disc changes in the involved eye. One patient responded favourably to topical antiglaucoma medications, whereas the other was taken up for combined phacoemulsification-trabeculectomy with good results. The third patient had normal IOP in the involved eye. All three patients gave a history of small pox in childhood and had pitted facial scars typical of previous small pox infection. Vitiligo iridis may be associated with the secondary glaucoma as a long-term sequelae of small pox. It may be prudent to periodically follow-up such patients for development of raised IOP in the future.

Emergency eye care in rural Australia: role of internet.

PubMed

Kumar, S; Yogesan, K; Hudson, B; Tay-Kearney, M-L; Constable, I J

2006-12-01

Significant differences exist in the utilization of emergency eye care services in rural and urban Australia. Meanwhile, influence of internet-based technology in emergency eye care service utilization has not been established. This study aims to demonstrate, from a health provider perspective, an internet-based service's impact on emergency eye care in rural Australia. The teleophthalmology service was initiated in the Carnarvon Regional Hospital (CRH) of the Gascoyne region in Western Australia. A digital, slit lamp and fundus camera were used for the service. Economic data was gathered from the Department of Health of Western Australia (DOHWA), the CRH and the Lions Eye Institute. During the study period (January-December, 2003) 118 persons took part in teleophthalmology consultations. Emergency cases constituted 3% of these consultations. Previous year, there were seven eye-related emergency evacuations (inter-hospital air transfers) from the Gascoyne region to City of Perth. Analysis demonstrates implementation of internet-based health services has a marked impact on rural emergency eye care delivery. Internet is well suited to ophthalmology for the diagnosis and management of acute conditions in remote areas. Integration of such services to mainstream health care is recommended.

Chromatic and achromatic visual fields in relation to choroidal thickness in patients with high myopia: A pilot study.

PubMed

García-Domene, M C; Luque, M J; Díez-Ajenjo, M A; Desco-Esteban, M C; Artigas, J M

2018-02-01

To analyse the relationship between the choroidal thickness and the visual perception of patients with high myopia but without retinal damage. All patients underwent ophthalmic evaluation including a slit lamp examination and dilated ophthalmoscopy, subjective refraction, best corrected visual acuity, axial length, optical coherence tomography, contrast sensitivity function and sensitivity of the visual pathways. We included eleven eyes of subjects with high myopia. There are statistical correlations between choroidal thickness and almost all the contrast sensitivity values. The sensitivity of magnocellular and koniocellular pathways is the most affected, and the homogeneity of the sensibility of the magnocellular pathway depends on the choroidal thickness; when the thickness decreases, the sensitivity impairment extends from the center to the periphery of the visual field. Patients with high myopia without any fundus changes have visual impairments. We have found that choroidal thickness correlates with perceptual parameters such as contrast sensitivity or mean defect and pattern standard deviation of the visual fields of some visual pathways. Our study shows that the magnocellular and koniocellular pathways are the most affected, so that these patients have impairment in motion perception and blue-yellow contrast perception. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Ophthalmic parameters in adult lowland paca (Cuniculus paca) raised in captivity.

PubMed

Balthazar da Silveira, Camila P; Lima, Tiago B; Crivelaro, Roberta M; de Lacerda, Luciana C C; Pádua, Ivan R M; Renzo, Roberta; de Barros Sobrinho, Alexandre A F; Oliveira, Fabrício S; Aldrovani, Marcela; Laus, José L

2018-01-01

To investigate the ophthalmic parameters of lowland pacas, including the anatomic features, tear production, intraocular pressure, central corneal thickness, and morphology of the corneal endothelium. Thirteen adult, anesthetized Cuniculus paca. Eyes were evaluated using slit-lamp biomicroscopy, the Schirmer tear test I, digital applanation tonometry, binocular indirect ophthalmoscopy, and noncontact specular microscopy. The biomicroscopy findings showed blue/brown pigmented bulbar conjunctivae, well-developed cilia (only in the upper eyelid margin), superior and inferior lacrimal puncta, brown irides, round pupils, and vestiges of the nictitating membrane. The results of the Schirmer tear test I revealed (mean ± SD) a lacrimation rate of 4.10 ± 0.44 mm/min. The intraocular pressure was 6.34 ± 0.43 mmHg. Central corneal thickness measured by specular microscopy was 0.35 ± 0.01 mm. The mean values of density, hexagonality, and the area of the endothelial cells were 2083.15 ± 42.47 cells/mm 2 , 67.07 ± 3.30%, and 486.30 ± 9.56 μm 2 , respectively. The ocular parameters defined in this study may be used for reference in future studies and might also contribute to therapeutic approaches appropriate to this species. © 2017 American College of Veterinary Ophthalmologists.

Identification of cytomegalovirus and human herpesvirus-6 DNA in a patient with corneal endotheliitis.

PubMed

Yokogawa, Hideaki; Kobayashi, Akira; Yamazaki, Natsuko; Sugiyama, Kazuhisa

2013-03-01

To report the case of a patient with unilateral corneal endotheliitis in which both cytomegalovirus (CMV) and human herpesvirus-6 (HHV6) DNA was identified in the aqueous humor. A 67-year-old man with corneal endotheliitis OD was referred to us for decreased visual acuity. Local corneal stromal edema, pigmented keratic precipitates, a coin-shaped lesion and minimal anterior chamber reaction were observed by slit-lamp biomicroscopy. Cells with owl's eye appearance in the endothelial cell layer were observed by in vivo laser confocal microscopy. The patient had rheumatoid arthritis, which was treated by oral prednisolone and intravenous abatacept. Polymerase chain reaction analysis of aqueous humor samples detected both CMV and HHV6 DNA, but not other HHVs. Treatment with topical ganciclovir and systemic valganciclovir resulted in a clear cornea. A patient with corneal endotheliitis had both CMV and HHV6 DNA identified in the aqueous humor. Although both viruses were identified in this case, clinical manifestations resembled CMV corneal endotheliitis, and it was unclear whether HHV6 could affect the clinical course. Systemic abatacept and corticosteroid therapy might play a positive role in cases with both CMV and HHV6 DNA in this corneal endotheliitis.

Case of adult-onset neuronal intranuclear hyaline inclusion disease with negative electroretinogram.

PubMed

Yamada, Wataru; Takekoshi, Akira; Ishida, Kyoko; Mochizuki, Kiyofumi; Sone, Jun; Sobue, Gen; Hayashi, Yuichi; Inuzuka, Takashi; Miyake, Yozo

2017-06-01

To report the findings in a 72-year-old man with neuronal intranuclear hyaline inclusion disease (NIHID) with the negative-type electroretinogram (ERG) and without night blindness. Standard ophthalmological examinations including the medical history, measurements of the best-corrected visual acuity and intraocular pressures, slit-lamp biomicroscopy, ophthalmoscopy, spectral-domain optical coherence tomography, fundus autofluorescence, and perimetry were performed. In addition, neurological and electrophysiological examinations were performed. NIHID was confirmed by skin biopsy. The ophthalmologic examinations revealed sluggish pupillary reflexes without visual disturbances and retinal abnormalities. The amplitudes of the dark-adapted 0.01 ERG was absent, and light-adapted 3 ERG and light-adapted 30 Hz flicker ERG were reduced in amplitude and delayed in implicit time. The rod system was more severely affected than the cone system, indicating that NIHID is classified as one of rod-cone dysfunction syndrome. The dark-adapted 3 ERG consisted of a markedly reduced b-wave with larger a-wave (negative ERG), but the amplitude of a-wave was smaller than normal. Since the ophthalmoscopical findings and the subjective visual functions may be essentially normal, the characteristic ERG abnormalities can be an important findings in adult-onset NIHID without night blindness.

Ophthalmological abnormalities in wild European hedgehogs (Erinaceus europaeus): a survey of 300 animals

PubMed Central

Williams, David; Adeyeye, Nina; Visser, Erni

2017-01-01

In this study we aimed to examine wild European hedgehogs (Erinaceus europaeus) in rescue centres and to determine ocular abnormalities in this animal population. Three hundred animals varying in age from 2 months to 5 years were examined, 147 being male and 153 female. All animals were evaluated with direct and indirect ophthalmoscopy and slit lamp biomicroscopy in animals where lesions were detected. Tonometry using the Tonovet rebound tonometer was undertaken in selected animals as was assessment of tear production using the Schirmer I tear test. Four animals were affected by orbital infection, 3 were anophthalmic, 2 unilaterally and one bilaterally, 3 by conjunctivitis, 3 by non-ulcerative keratitis and 4 by uveitis with corneal oedema. Fifty seven animals were affected by cataract, 54 with bilateral nuclear lens opacities. Twenty six of these animals were young animals considered too small to hibernate. This report documents the first prospective study of ocular disease in the European hedgehog. The predominant finding was bilateral nuclear cataract seen particularly in young poorly growing animals. Investigation into the potential causation of cataracts by poor nutrition or poor feeding ability by lens opacification requires further study. PMID:29038778

Simultaneous refraction measurement and OCT axial biometry of the eye during accommodation (Conference Presentation)

NASA Astrophysics Data System (ADS)

De Freitas, Carolina; Hernandez, Victor M.; Ruggeri, Marco; Durkee, Heather A.; Williams, Siobhan; Gregori, Giovanni; Ho, Arthur; Manns, Fabrice; Parel, Jean-Marie

2016-03-01

The purpose of this project is to design and evaluate a system that will enable objective assessment of the optical accommodative response in real-time while acquiring axial biometric information. The system combines three sub-systems which were integrated and mounted on a joystick x-y-z adjustable modified slit-lamp base to facilitate alignment and data acquisition: (1) a Shack-Hartmann wavefront sensor for dynamic refraction measurement, provided software calculates sphere, cylinder and axis values, (2) an extended-depth Optical Coherence Tomography (OCT) system using an optical switch records high-resolution cross-sectional images across the length of the eye, from which, dynamic axial biometry (corneal thickness, anterior chamber depth, crystalline lens thickness and vitreous depth) can be extracted, and (3) a modified dual-channel accommodation stimulus unit based on the Badal optometer for providing a step change in accommodative stimulus. The prototypal system is capable of taking simultaneous measurements of both the optical and the mechanical response of lens accommodation. These measurements can provide insight into correlating changes in lens shape with changes in lens power and ocular refraction and ultimately provide a more comprehensive understanding of accommodation, presbyopia and an objective assessment of presbyopia correction techniques.

Unilateral phthiriasis palpebrarum infestation in a child during occlusion therapy for amblyopia: Case report.

PubMed

Biler, Elif Demirkilinc; Selver, Ozlem Barut; Palamar, Melis; Uner, Ahmet; Uretmen, Onder

2016-01-01

An 8-year-old mentally retarded boy is brought to the hospital because of itching and burning at his right eye for 10 days. He was on full time right eye occlusion therapy for left amblyopia. Slit lamp examination revealed nits and adult lice anchored to the eyelashes in his occluded eye. Eyelashes and all detected lice and nits were mechanically trimmed, and sent for parasitological examination, which confirmed the diagnosis. Upon familial evaluation for additional infestation, the father was also found to have genital phthiriasis pubis and received appropriate treatment. While phthiriasis palpebrarum in children may signify sexual abuse, a detailed investigation by a child psychiatrist was performed and revealed no sign of abuse. Since the infestation was at only on occluded eye, the most possible explanation for the transmission was evaluated as the misusage of the adhesive patch in our case. In conclusion, sexual abuse should be excluded in children with phthiriasis palpebrarum and parents of amblyopic children on occlusion therapy should be warned about the importance of the hygiene of the patching in order to avoid any kind of infection and infestation.

Cylindrocarpon lichenicola keratomycosis in Nigeria: the challenge of limited access to effective antimicrobials.

PubMed

Irek, Emmanuel O; Obadare, Temitope O; Udonwa, Patrick A; Laoye, Olajumoke; Abiri, Oyekola V; Adeoye, Adenike O; Aboderin, Aaron O

2017-01-01

We report a rare cause of keratitis, due to Cylindrocarpon lichenicola , in a farmer with keratomycosis. Despite the acknowledged virulence of this fungus, a suitable antifungal for its management was not accessible. A 67-year-old farmer presented with a two-week history of pain, mucopurulent discharge, redness and a corneal ulcer with a visual acuity of hand movement in the right eye. With a working diagnosis of infective keratitis, corneal scrapings were taken under a slit lamp biomicroscope for microbiological testing. Direct lactophenol cotton blue mounts revealed septate fungal hyphae, while fungal culture on Sabouraud dextrose agar at room temperature grew woolly mould phenotypically consistent with C. lichenicola . The patient was started on hourly topical natamycin (5%), ciprofloxacin (0.3%), two-hourly instillation of tobramycin (0.3%) and atropine (1%) twice daily for three months following the isolation of the fungus. The eye healed with a corneal scar and no improvements in visual acuity. This infection was difficult to manage due to the inaccessibility of a suitable antifungal, namely, voriconazole in our setting. Hence, there is a need for prompt identification and early institution of suitable antifungals in any patient with suspected keratomycosis.

Inexpensive Masks for Film Deposition

NASA Technical Reports Server (NTRS)

Conley, W. R.

1986-01-01

Sputtered sprayed lines less than 2 millimeters wide made by superimposing masks with partially overlapping openings. Slits first cut in masks by stamping or other economical process. Masks superimposed so slits define new openings narrower than original slits.

Improvement of unbalanced illumination induced telecentricity within the exposure slit

NASA Astrophysics Data System (ADS)

Jang, Jonghoon; Lee, ByeongSoo; Kang, Young Seog; Chang, Chansam; Kong, Jeong-Heung; Kim, Young Ha; Bouman, Wim; de Graaf, Roelof; Weichselbaum, Stefan; Droste, Richard; de Boeij, Wim P.; van Bussel, Bart; Neefs, Patrick; Rijke, Arij

2016-03-01

Adjustment and control of the illumination pupil asymmetry is relevant for wafer alignment and overlay of lithography tools. Pupil asymmetries can cause a tilt in aerial image (Aerial Image Tilt, or AIT). This AIT, combined with a focus offset, leads to a horizontal image shift. Pupil asymmetries can be related to a shift of the entire illumination pupil (geometrical telecentricity) caused by illuminator misalign. Another type of pupil asymmetry is energetic imbalance (quantified by pupil Center of Gravity, COG). The scanner can show pupil variation across the exposure slit. In general the COG at the edge of the slit is often worse than in the center part of the slit. Recently, ASML has released the NXT:1980Di that is equipped with an enhanced illuminator to improve pupil COG variation across the slit. In this paper we explore the performance of this scanner system and show that the AIT variation across the slit is also reduced significantly.

Generalization of the Schwarz–Christoffel mapping to multiply connected polygonal domains

PubMed Central

Vasconcelos, Giovani L.

2014-01-01

A generalization of the Schwarz–Christoffel mapping to multiply connected polygonal domains is obtained by making a combined use of two preimage domains, namely, a rectilinear slit domain and a bounded circular domain. The conformal mapping from the circular domain to the polygonal region is written as an indefinite integral whose integrand consists of a product of powers of the Schottky-Klein prime functions, which is the same irrespective of the preimage slit domain, and a prefactor function that depends on the choice of the rectilinear slit domain. A detailed derivation of the mapping formula is given for the case where the preimage slit domain is the upper half-plane with radial slits. Representation formulae for other canonical slit domains are also obtained but they are more cumbersome in that the prefactor function contains arbitrary parameters in the interior of the circular domain. PMID:24910523

Generalization of the Schwarz-Christoffel mapping to multiply connected polygonal domains.

PubMed

Vasconcelos, Giovani L

2014-06-08

A generalization of the Schwarz-Christoffel mapping to multiply connected polygonal domains is obtained by making a combined use of two preimage domains, namely, a rectilinear slit domain and a bounded circular domain. The conformal mapping from the circular domain to the polygonal region is written as an indefinite integral whose integrand consists of a product of powers of the Schottky-Klein prime functions, which is the same irrespective of the preimage slit domain, and a prefactor function that depends on the choice of the rectilinear slit domain. A detailed derivation of the mapping formula is given for the case where the preimage slit domain is the upper half-plane with radial slits. Representation formulae for other canonical slit domains are also obtained but they are more cumbersome in that the prefactor function contains arbitrary parameters in the interior of the circular domain.

HIGH RESOLUTION EMITTANCE MEASUREMENTS AT SNS FRONT END

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aleksandrov, Alexander V; Zhukov, Alexander P

2013-01-01

The Spallation Neutron Source (SNS) linac accelerates an H- beam from 2.5MeV up to 1GeV. Recently the emittance scanner in the MEBT (2.5 MeV) was upgraded. In addition to the slit - harp measurement, we now can use a slit installed on the same actuator as the harp. In combination with a faraday cup located downstream in DTL part of the linac, it represents a classical slit-slit emittance measurement device. While a slit slit scan takes much longer, it is immune to harp related problems such as wire cross talk, and thus looks promising for accurate halo measurements. Time resolutionmore » of the new device seems to be sufficient to estimate the amount of beam in the chopper gap (the scanner is downstream of the chopper), and probably to measure its emittance. This paper describes the initial measurements with the new device and some model validation data.« less

FDTD Calculation of FM-Band Crosstalks between Perpendicular Traces on Printed Circuit Board with Ground-Pattern Slits

NASA Astrophysics Data System (ADS)

Ueyama, Hiroya; Maeno, Tsuyoshi; Hirata, Akimasa; Wang, Jianqing; Fujiwara, Osamu

Electromagnetic disturbances for vehicle-mounted radios are well known to be caused mainly by conduction noise currents flowing out wire harnesses from printed circuit boards (PCBs) having a common ground layer with slits. In this study, in order to investigate how ground-layer slits affect the above conduction noise currents, we paid FM band induced voltages or crosstalks on the trace connected to the wire harnesss, and simulated with the FDTD method the crosstalk levels between two traces perpendicularly fabricated on three kinds of simple PCBs with different ground-layer slits, which were compared with measurement in the frequency range from 10 MHz to 1 GHz. As a result, we could confirm that the FDTD calculation approximately agrees with the measured results, and also that the crosstalk levels do not always increase with the slit number, which can be reduced by the slit layout.

49 CFR 393.24 - Requirements for head lamps, auxiliary driving lamps and front fog lamps.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 5 2012-10-01 2012-10-01 false Requirements for head lamps, auxiliary driving lamps and front fog lamps. 393.24 Section 393.24 Transportation Other Regulations Relating to... MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Lamps, Reflective...

49 CFR 393.24 - Requirements for head lamps, auxiliary driving lamps and front fog lamps.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 5 2014-10-01 2014-10-01 false Requirements for head lamps, auxiliary driving lamps and front fog lamps. 393.24 Section 393.24 Transportation Other Regulations Relating to... MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Lamps, Reflective...

49 CFR 393.24 - Requirements for head lamps, auxiliary driving lamps and front fog lamps.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 5 2013-10-01 2013-10-01 false Requirements for head lamps, auxiliary driving lamps and front fog lamps. 393.24 Section 393.24 Transportation Other Regulations Relating to... MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Lamps, Reflective...

Enhanced Output Power of Near-Ultraviolet Light-Emitting Diodes by p-GaN Micro-Rods

NASA Astrophysics Data System (ADS)

Wang, Dong-Sheng; Zhang, Ke-Xiong; Liang, Hong-Wei; Song, Shi-Wei; Yang, De-Chao; Shen, Ren-Sheng; Liu, Yang; Xia, Xiao-Chuan; Luo, Ying-Min; Du, Guo-Tong

2014-02-01

Near-ultraviolet (UV) InGaN/AlGaN light-emitting diodes (LEDs) are grown by low-pressure metal-organic chemical vapor deposition. The scanning electronic microscope image shows that the p-GaN micro-rods are formed above the interface of p-AlGaN/p-GaN due to the rapid growth rate of p-GaN in the vertical direction. The p-GaN micro-rods greatly increase the escape probability of photons inside the LED structure. Electroluminescence intensities of the 372 nm UV LED lamps with p-GaN micro rods are 88% higher than those of the flat surface LED samples.

Structural phase study in un-patterned and patterned PVDF semi-crystalline films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pramod, K., E-mail: rameshg.phy@pondiuni.edu.in; Gangineni, Ramesh Babu, E-mail: rameshg.phy@pondiuni.edu.in

2014-04-24

This work explores the structural phase studies of organic polymer- polyvinylidene fluoride (PVDF) thin films in semi-crystallized phase and nano-patterned PVDF thin films. The nanopatterns are transferred with the CD layer as a master using soft lithography technique. The semi-crystalline PVDF films were prepared by a still and hot (SH) method, using a homemade spin coater that has the proficiency of substrate heating by a halogen lamp. Using this set up, smooth PVDF thin films in semi-crystalline α-phase were prepared using 2-Butanone as solvent. XRD, AFM and confocal Raman microscope have been utilized to study the structural phase, crystallinity andmore » quality of the films.« less

Single-Slit Diffraction and the Uncertainty Principle

ERIC Educational Resources Information Center

Rioux, Frank

2005-01-01

A theoretical analysis of single-slit diffraction based on the Fourier transform between coordinate and momentum space is presented. The transform between position and momentum is used to illuminate the intimate relationship between single-slit diffraction and uncertainty principle.

Optical Alignment and Diffraction Analysis for AIRES: An Airborne Infrared Echelle Spectrometer

NASA Technical Reports Server (NTRS)

Haas, Michael R.; Fonda, Mark (Technical Monitor)

2002-01-01

The optical design is presented for a long-slit grating spectrometer known as AIRES (Airborne InfraRed Echelle Spectrometer). The instrument employs two gratings in series: a small order sorter and a large steeply blazed echelle. The optical path includes four pupil and four field stops, including two narrow slits. A detailed diffraction analysis is performed using GLAD by Applied Optics Research to evaluate critical trade-offs between optical throughput, spectral resolution, and system weight and volume. The effects of slit width, slit length, oversizing the second slit relative to the first, on- vs off-axis throughput, and clipping at the pupil stops and other optical elements are discussed.

Screen for Slit/Robo signaling in trunk neural cells reveals new players.

PubMed

Martinez, Darwin; Zuhdi, Nora; Reyes, Michelle; Ortega, Blanca; Giovannone, Dion; Lee, Vivian M; de Bellard, Maria Elena

2018-06-01

Slits ligands and their Robo receptors are involved in quite disparate cell signaling pathways that include axon guidance, cell proliferation, cell motility and angiogenesis. Neural crest cells emerge by delamination from neural cells in the dorsal neural tube, and give rise to various components of the peripheral nervous system in vertebrates. It is well established that these cells change from a non-migratory to a highly migratory state allowing them to reach distant regions before they differentiate. However, but the mechanism controlling this delamination and subsequent migration are still not fully understood. The repulsive Slit ligand family members, have been classified also as true tumor suppressor molecules. The present study explored in further detail what possible Slit/Robo signals are at play in the trunk neural cells and neural crest cells by carrying out a microarray after Slit2 gain of function in trunk neural tubes. We found that in addition to molecules known to be downstream of Slit/Robo signaling, there were a large set of molecules known to be important in maintaining cells in non-motile, epithelia phenotype. Furthermore, we found new molecules previously not associated with Slit/Robo signaling: cell proliferation markers, Ankyrins and RAB intracellular transporters. Our findings suggest that neural crest cells use and array of different Slit/Robo pathways during their transformation from non-motile to highly motile cells. Copyright © 2018. Published by Elsevier B.V.

Enhanced modified faraday cup for determination of power density distribution of electron beams

DOEpatents

Elmer, John W.; Teruya, Alan T.

2001-01-01

An improved tomographic technique for determining the power distribution of an electron or ion beam using electron beam profile data acquired by an enhanced modified Faraday cup to create an image of the current density in high and low power ion or electron beams. A refractory metal disk with a number of radially extending slits, one slit being about twice the width of the other slits, is placed above a Faraday cup. The electron or ion beam is swept in a circular pattern so that its path crosses each slit in a perpendicular manner, thus acquiring all the data needed for a reconstruction in one circular sweep. The enlarged slit enables orientation of the beam profile with respect to the coordinates of the welding chamber. A second disk having slits therein is positioned below the first slit disk and inside of the Faraday cup and provides a shield to eliminate the majority of secondary electrons and ions from leaving the Faraday cup. Also, a ring is located below the second slit disk to help minimize the amount of secondary electrons and ions from being produced. In addition, a beam trap is located in the Faraday cup to provide even more containment of the electron or ion beam when full beam current is being examined through the center hole of the modified Faraday cup.

10 CFR 429.27 - General service fluorescent lamps, general service incandescent lamps, and incandescent reflector...

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false General service fluorescent lamps, general service incandescent lamps, and incandescent reflector lamps. 429.27 Section 429.27 Energy DEPARTMENT OF ENERGY ENERGY... EQUIPMENT Certification § 429.27 General service fluorescent lamps, general service incandescent lamps, and...

10 CFR 429.27 - General service fluorescent lamps, general service incandescent lamps, and incandescent reflector...

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false General service fluorescent lamps, general service incandescent lamps, and incandescent reflector lamps. 429.27 Section 429.27 Energy DEPARTMENT OF ENERGY ENERGY... EQUIPMENT Certification § 429.27 General service fluorescent lamps, general service incandescent lamps, and...

10 CFR 429.27 - General service fluorescent lamps, general service incandescent lamps, and incandescent reflector...

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false General service fluorescent lamps, general service incandescent lamps, and incandescent reflector lamps. 429.27 Section 429.27 Energy DEPARTMENT OF ENERGY ENERGY... EQUIPMENT Certification § 429.27 General service fluorescent lamps, general service incandescent lamps, and...

Treatment effect of sublingual immunotherapy tablets and pharmacotherapies for seasonal and perennial allergic rhinitis: Pooled analyses.

PubMed

Durham, Stephen R; Creticos, Peter S; Nelson, Harold S; Li, Ziliang; Kaur, Amarjot; Meltzer, Eli O; Nolte, Hendrik

2016-10-01

Data comparing the treatment effect of allergy immunotherapy and pharmacotherapy are lacking. We sought to indirectly compare the treatment effect of sublingual immunotherapy (SLIT)-tablets with pharmacotherapy for seasonal allergic rhinitis (SAR) and perennial allergic rhinitis (PAR). Pooled data from randomized, double-blind, placebo-controlled trials for the clinical development programs of selected allergic rhinitis treatments were evaluated. Total nasal symptom scores (TNSSs) relative to placebo were compared. Subjects scored symptoms daily during entire pollen seasons in 6 timothy grass SLIT-tablet trials (n = 3094) and 2 ragweed SLIT-tablet trials (n = 658) and during the last 8 weeks of treatment in 2 house dust mite (HDM) SLIT-tablet trials (n = 1768). Subjects scored symptoms daily in 7 montelukast (10 mg, n = 6799), 9 desloratadine (5 mg, n = 4455), and 8 mometasone furoate nasal spray (MFNS; 200 μg daily, n = 2140) SAR or PAR trials. SLIT-tablet trials allowed rescue medication use, whereas most pharmacotherapy trials did not. A fixed-effect meta-analysis method estimated differences in on-treatment average TNSSs. In grass and ragweed SLIT-tablet trials, overall improvement in TNSSs relative to placebo was 16.3% and 17.1%, respectively. In HDM SLIT-tablet trials, TNSS overall improvement relative to placebo was 16.1%. In the montelukast, desloratadine, and MFNS trials, TNSS overall improvement relative to placebo was 5.4%, 8.5%, and 22.2%, respectively, for SAR trials, and 3.7%, 4.8%, and 11.2%, respectively, for PAR trials. Although comparisons were limited by study design heterogeneity and use of rescue medications in SLIT-tablet trials, effects on nasal symptoms with timothy grass and ragweed SLIT-tablets were nearly as great as with MFNS and numerically greater than with montelukast and desloratadine for SAR. HDM SLIT-tablet effects were numerically greater than all pharmacotherapies for PAR. SLIT-tablets offer the additional benefit of long-term efficacy. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Contralateral migration of oculomotor neurons is regulated by Slit/Robo signaling.

PubMed

Bjorke, Brielle; Shoja-Taheri, Farnaz; Kim, Minkyung; Robinson, G Eric; Fontelonga, Tatiana; Kim, Kyung-Tai; Song, Mi-Ryoung; Mastick, Grant S

2016-10-22

Oculomotor neurons develop initially like typical motor neurons, projecting axons out of the ventral midbrain to their ipsilateral targets, the extraocular muscles. However, in all vertebrates, after the oculomotor nerve (nIII) has reached the extraocular muscle primordia, the cell bodies that innervate the superior rectus migrate to join the contralateral nucleus. This motor neuron migration represents a unique strategy to form a contralateral motor projection. Whether migration is guided by diffusible cues remains unknown. We examined the role of Slit chemorepellent signals in contralateral oculomotor migration by analyzing mutant mouse embryos. We found that the ventral midbrain expresses high levels of both Slit1 and 2, and that oculomotor neurons express the repellent Slit receptors Robo1 and Robo2. Therefore, Slit signals are in a position to influence the migration of oculomotor neurons. In Slit 1/2 or Robo1/2 double mutant embryos, motor neuron cell bodies migrated into the ventral midbrain on E10.5, three days prior to normal migration. These early migrating neurons had leading projections into and across the floor plate. In contrast to the double mutants, embryos which were mutant for single Slit or Robo genes did not have premature migration or outgrowth on E10.5, demonstrating a cooperative requirement of Slit1 and 2, as well as Robo1 and 2. To test how Slit/Robo midline repulsion is modulated, we found that the normal migration did not require the receptors Robo3 and CXCR4, or the chemoattractant, Netrin 1. The signal to initiate contralateral migration is likely autonomous to the midbrain because oculomotor neurons migrate in embryos that lack either nerve outgrowth or extraocular muscles, or in cultured midbrains that lacked peripheral tissue. Overall, our results demonstrate that a migratory subset of motor neurons respond to floor plate-derived Slit repulsion to properly control the timing of contralateral migration.

Evaluation of the RT-LAMP and LAMP methods for detection of Mycobacterium tuberculosis.

PubMed

Wu, Dandan; Kang, Jiwen; Li, Baosheng; Sun, Dianxing

2018-05-01

The current methods for detecting Mycobacterium tuberculosis (Mtb) are not clinically optimal. Standard culture methods (SCMs) are slow, costly, or unreliable, and loop-mediated isothermal amplification (LAMP) cannot differentiate live Mtb. This study compared reverse transcription (RT)-LAMP, LAMP, and an SCM for detecting Mtb. A first experiment tested the sensitivity and specificity of primers for 9 species of Mycobacterium (H37Rv, M. intracellulare, M. marinum, M. kansasii, M. avium, M. flavescens, M. smegmatis, M. fortuitum, and M. chelonae); and 3 non-Mycobacterium species (Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae). A second experiment tested sputum specimens for the presence of Mtb, from 100 patients with tuberculosis (clinical) and 22 from patients without tuberculosis (control), using Roche solid culture (SCM), LAMP, and RT-LAMP. In the clinical samples. The rates of positivity for Mtb of the SCM, LAMP, and RT-LAMP methods were 88%, 92%, and 100%, respectively. The difference in detection rate was significant between RT-LAMP and SCM, but RT-LAMP and LAMP were comparable. In the control group, the detection rates were nil for all three methods. The specificities of the methods were similar. The sensitivity of RT-LAMP was ~10-fold higher than that of LAMP for detecting Mtb. Unlike LAMP, RT-LAMP could identify viable bacteria, and was able to detect a single copy of Mtb. Among SCM, LAMP, and RT-LAMP, the latter is the most suitable for wide use in the lower-level hospitals and clinics of China for detecting Mtb in sputum samples. © 2017 Wiley Periodicals, Inc.

Are snakes particles or waves? Scattering of a limbless locomotor through a single slit

NASA Astrophysics Data System (ADS)

Qian, Feifei; Dai, Jin; Gong, Chaohui; Choset, Howie; Goldman, Daniel

Droplets on vertically vibrated fluid surfaces can walk and diffract through a single slit by a pilot wave hydrodynamic interaction [Couder, 2006; Bush, 2015]. Inspired by the correspondence between emergent macroscale dynamics and phenomena in quantum systems, we tested if robotic snakes, which resemble wave packets, behave emergently like particles or waves when interacting with an obstacle. In lab experiments and numerical simulations we measured how a multi-module snake-like robot swam through a single slit. We controlled the snake undulation gait as a fixed serpenoid traveling wave pattern with varying amplitude and initial phase, and we examined the snake trajectory as it swam through a slit with width d. Robot trajectories were straight before interaction with the slit, then exited at different scattering angle θ after the interaction due to a complex interaction of the body wave with the slit. For fixed amplitude and large d, the snake passed through the slit with minimal interaction and theta was ~ 0 . For sufficiently small d, θ was finite and bimodally distributed, depending on the initial phase. For intermediate d, θ was sensitive to initial phase, and the width of the distribution of θ increased with decreasing d.

Practical implementation, characterization and applications of a multi-colour time-gated luminescence microscope.

PubMed

Zhang, Lixin; Zheng, Xianlin; Deng, Wei; Lu, Yiqing; Lechevallier, Severine; Ye, Zhiqiang; Goldys, Ewa M; Dawes, Judith M; Piper, James A; Yuan, Jingli; Verelst, Marc; Jin, Dayong

2014-10-13

Time-gated luminescence microscopy using long-lifetime molecular probes can effectively eliminate autofluorescence to enable high contrast imaging. Here we investigate a new strategy of time-gated imaging for simultaneous visualisation of multiple species of microorganisms stained with long-lived complexes under low-background conditions. This is realized by imaging two pathogenic organisms (Giardia lamblia stained with a red europium probe and Cryptosporidium parvum with a green terbium probe) at UV wavelengths (320-400 nm) through synchronization of a flash lamp with high repetition rate (1 kHz) to a robust time-gating detection unit. This approach provides four times enhancement in signal-to-background ratio over non-time-gated imaging, while the average signal intensity also increases six-fold compared with that under UV LED excitation. The high sensitivity is further confirmed by imaging the single europium-doped Y₂O₂S nanocrystals (150 nm). We report technical details regarding the time-gating detection unit and demonstrate its compatibility with commercial epi-fluorescence microscopes, providing a valuable and convenient addition to standard laboratory equipment.

Practical Implementation, Characterization and Applications of a Multi-Colour Time-Gated Luminescence Microscope

NASA Astrophysics Data System (ADS)

Zhang, Lixin; Zheng, Xianlin; Deng, Wei; Lu, Yiqing; Lechevallier, Severine; Ye, Zhiqiang; Goldys, Ewa M.; Dawes, Judith M.; Piper, James A.; Yuan, Jingli; Verelst, Marc; Jin, Dayong

2014-10-01

Time-gated luminescence microscopy using long-lifetime molecular probes can effectively eliminate autofluorescence to enable high contrast imaging. Here we investigate a new strategy of time-gated imaging for simultaneous visualisation of multiple species of microorganisms stained with long-lived complexes under low-background conditions. This is realized by imaging two pathogenic organisms (Giardia lamblia stained with a red europium probe and Cryptosporidium parvum with a green terbium probe) at UV wavelengths (320-400 nm) through synchronization of a flash lamp with high repetition rate (1 kHz) to a robust time-gating detection unit. This approach provides four times enhancement in signal-to-background ratio over non-time-gated imaging, while the average signal intensity also increases six-fold compared with that under UV LED excitation. The high sensitivity is further confirmed by imaging the single europium-doped Y2O2S nanocrystals (150 nm). We report technical details regarding the time-gating detection unit and demonstrate its compatibility with commercial epi-fluorescence microscopes, providing a valuable and convenient addition to standard laboratory equipment.

Two rare species of tylenchids, Discotylenchus biannulatus n. sp. and Labrys chinensis Qing Bert, 2018 (Nematoda: Tylenchidae) from western Iran.

PubMed

Konani, Ehsan; Panahandeh, Yousef; Pourjam, Ebrahim; Álvarez-Ortega, Sergio; Pedram, Majid

2018-04-23

Two rare species of the family Tylenchidae are described and illustrated based on morphological and morphometric characters. Scanning electron microscope (SEM) studies provided details of anterior end structures, helpful in generic identification of the studied populations. Discotylenchus biannulatus n. sp. is characterized by its dorso-ventrally flattened smooth cephalic region having two proximal annuli and a rectangular perioral disc, short longitudinal amphidial slits, lateral field with four incisures, stylet 9-10 μm long, with the conus shorter than half the total stylet length and with posteriorly directed knobs, well-developed median bulb, mono-prodelphic reproductive system with rounded empty spermatheca and short postvulval uterine sac (PUS), and filiform tail with pointed end. It is compared with other species of Discotylenchus having four lines in the lateral field. The Iranian population of Labrys chinensis is characterized by its long and slender (a = 45.2-57.2) body, smooth rounded cephalic region and an offset disc-like apical labial plate, short longitudinal lateral amphidial slits, lateral field with two incisures, moderately developed stylet with the conus less than half the total length and posteriorly directed knobs, median bulb fusiform with distinct but weak valve, gradually joining the isthmus, vulva at 57.2-59.1% with small flaps, elongate conoid tail, uniformly and slightly narrowing toward end with broadly rounded terminus and rare males. The minor morphological differences of the recovered population with the type population are discussed.

Comparison of direct and alternating current vacuum ultraviolet lamps in atmospheric pressure photoionization.

PubMed

Vaikkinen, Anu; Haapala, Markus; Kersten, Hendrik; Benter, Thorsten; Kostiainen, Risto; Kauppila, Tiina J

2012-02-07

A direct current induced vacuum ultraviolet (dc-VUV) krypton discharge lamp and an alternating current, radio frequency (rf) induced VUV lamp that are essentially similar to lamps in commercial atmospheric pressure photoionization (APPI) ion sources were compared. The emission distributions along the diameter of the lamp exit window were measured, and they showed that the beam of the rf lamp is much wider than that of the dc lamp. Thus, the rf lamp has larger efficient ionization area, and it also emits more photons than the dc lamp. The ionization efficiencies of the lamps were compared using identical spray geometries with both lamps in microchip APPI mass spectrometry (μAPPI-MS) and desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS). A comprehensive view on the ionization was gained by studying six different μAPPI solvent compositions, five DAPPI spray solvents, and completely solvent-free DAPPI. The observed reactant ions for each solvent composition were very similar with both lamps except for toluene, which showed a higher amount of solvent originating oxidation products with the rf lamp than with the dc lamp in μAPPI. Moreover, the same analyte ions were detected with both lamps, and thus, the ionization mechanisms with both lamps are similar. The rf lamp showed a higher ionization efficiency than the dc lamp in all experiments. The difference between the lamp ionization efficiencies was greatest when high ionization energy (IE) solvent compositions (IEs above 10 eV), i.e., hexane, methanol, and methanol/water, (1:1 v:v) were used. The higher ionization efficiency of the rf lamp is likely due to the larger area of high intensity light emission, and the resulting larger efficient ionization area and higher amount of photons emitted. These result in higher solvent reactant ion production, which in turn enables more efficient analyte ion production. © 2012 American Chemical Society

Development of loop-mediated isothermal amplification methods for detecting Taylorella equigenitalis and Taylorella asinigenitalis

PubMed Central

KINOSHITA, Yuta; NIWA, Hidekazu; KATAYAMA, Yoshinari; HARIU, Kazuhisa

2015-01-01

ABSTRACT Taylorella equigenitalis is a causative bacterium of contagious equine metritis (CEM), and Taylorella asinigenitalis is species belonging to genus Taylorella. The authors developed two loop-mediated isothermal amplification (LAMP) methods, Te-LAMP and Ta-LAMP, for detecting T. equigenitalis and T. asinigenitalis, respectively. Using experimentally spiked samples, Te-LAMP was as sensitive as a published semi-nested PCR method, and Ta-LAMP was more sensitive than conventional PCR. Multiplex LAMP worked well without nonspecific reactions, and the analytical sensitivities of multiplex LAMP in the spiked samples were almost equivalent to those of Te-LAMP and Ta-LAMP. Therefore, the LAMP methods are considered useful tools to detect T. equigenitalis and/or T. asinigenitalis, and preventive measures will be rapidly implemented if the occurrence of CEM is confirmed by the LAMP methods. PMID:25829868

Transition from a spectrum filter to a polarizer in a metallic nano-slit array

PubMed Central

Zhou, Jing; Guo, L. Jay

2014-01-01

The transition from a spectrum filter (resonant transmission) to a polarizer (broadband transmission) for TM polarized light is observed in a metallic nano-slit array as period is decreased. A theoretical model is developed and shows that the spectrum filter behavior is caused by the coupled slit/grating resonance. With decreasing period, the slit resonance is decoupled from the grating resonance, which then dominates the transmission spectrum and broadens the transmission peak. With further reducing period, the slit resonance diminishes and the peak spectrum transforms to a broadband transmission. This effect is the basis for the operation of wire grid polarizers. The transition is explained by the change of the impedance to the incoming wave. PMID:24402443

Transition from a spectrum filter to a polarizer in a metallic nano-slit array.

PubMed

Zhou, Jing; Guo, L Jay

2014-01-09

The transition from a spectrum filter (resonant transmission) to a polarizer (broadband transmission) for TM polarized light is observed in a metallic nano-slit array as period is decreased. A theoretical model is developed and shows that the spectrum filter behavior is caused by the coupled slit/grating resonance. With decreasing period, the slit resonance is decoupled from the grating resonance, which then dominates the transmission spectrum and broadens the transmission peak. With further reducing period, the slit resonance diminishes and the peak spectrum transforms to a broadband transmission. This effect is the basis for the operation of wire grid polarizers. The transition is explained by the change of the impedance to the incoming wave.

Transition from a spectrum filter to a polarizer in a metallic nano-slit array

NASA Astrophysics Data System (ADS)

Zhou, Jing; Guo, L. Jay

2014-01-01

The transition from a spectrum filter (resonant transmission) to a polarizer (broadband transmission) for TM polarized light is observed in a metallic nano-slit array as period is decreased. A theoretical model is developed and shows that the spectrum filter behavior is caused by the coupled slit/grating resonance. With decreasing period, the slit resonance is decoupled from the grating resonance, which then dominates the transmission spectrum and broadens the transmission peak. With further reducing period, the slit resonance diminishes and the peak spectrum transforms to a broadband transmission. This effect is the basis for the operation of wire grid polarizers. The transition is explained by the change of the impedance to the incoming wave.

Regeneration and maintenance of the planarian midline is regulated by a slit orthologue.

PubMed

Cebrià, Francesc; Guo, Tingxia; Jopek, Jessica; Newmark, Phillip A

2007-07-15

Several families of evolutionarily conserved axon guidance cues orchestrate the precise wiring of the nervous system during embryonic development. The remarkable plasticity of freshwater planarians provides the opportunity to study these molecules in the context of neural regeneration and maintenance. Here we characterize a homologue of the Slit family of guidance cues from the planarian Schmidtea mediterranea. Smed-slit is expressed along the planarian midline, in both dorsal and ventral domains. RNA interference (RNAi) targeting Smed-slit results in the collapse of many newly regenerated tissues at the midline; these include the cephalic ganglia, ventral nerve cords, photoreceptors, and the posterior digestive system. Surprisingly, Smed-slit RNAi knockdown animals also develop morphologically distinguishable, ectopic neural structures near the midline in uninjured regions of intact and regenerating planarians. These results suggest that Smed-slit acts not only as a repulsive cue required for proper midline formation during regeneration but that it may also act to regulate the behavior of neural precursors at the midline in intact planarians.

Lysosome associated membrane proteins maintain pancreatic acinar cell homeostasis: LAMP-2 deficient mice develop pancreatitis.

PubMed

Mareninova, Olga A; Sendler, Matthias; Malla, Sudarshan Ravi; Yakubov, Iskandar; French, Samuel W; Tokhtaeva, Elmira; Vagin, Olga; Oorschot, Viola; Lüllmann-Rauch, Renate; Blanz, Judith; Dawson, David; Klumperman, Judith; Lerch, Markus M; Mayerle, Julia; Gukovsky, Ilya; Gukovskaya, Anna S

2015-11-01

The pathogenic mechanism of pancreatitis is poorly understood. Recent evidence implicates defective autophagy in pancreatitis responses; however, the pathways mediating impaired autophagy in pancreas remain largely unknown. Here, we investigate the role of lysosome associated membrane proteins (LAMPs) in pancreatitis. We analyzed changes in LAMPs in experimental models and human pancreatitis, and the underlying mechanisms: LAMP de-glycosylation and degradation. LAMP cleavage by cathepsin B (CatB) was analyzed by mass spectrometry. We used mice deficient in LAMP-2 to assess its role in pancreatitis. Pancreatic levels of LAMP-1 and LAMP-2 greatly decrease across various pancreatitis models and in human disease. Pancreatitis does not trigger LAMPs' bulk de-glycosylation, but induces their degradation via CatB-mediated cleavage of LAMP molecule close to the boundary between luminal and transmembrane domains. LAMP-2 null mice spontaneously develop pancreatitis that begins with acinar cell vacuolization due to impaired autophagic flux, and progresses to severe pancreas damage characterized by trypsinogen activation, macrophage-driven inflammation, and acinar cell death. LAMP-2 deficiency causes a decrease in pancreatic digestive enzymes content, stimulates the basal and inhibits CCK-induced amylase secretion by acinar cells. The effects of LAMP-2 knockout and acute cerulein pancreatitis overlap, which corroborates the pathogenic role of LAMP decrease in experimental pancreatitis models. The results indicate a critical role for LAMPs, particularly LAMP-2, in maintaining pancreatic acinar cell homeostasis, and provide evidence that defective lysosomal function, resulting in impaired autophagy, leads to pancreatitis. Mice with LAMP-2 deficiency present a novel genetic model of human pancreatitis caused by lysosomal/autophagic dysfunction.

Spectrally resolved laser interference microscopy

NASA Astrophysics Data System (ADS)

Butola, Ankit; Ahmad, Azeem; Dubey, Vishesh; Senthilkumaran, P.; Singh Mehta, Dalip

2018-07-01

We developed a new quantitative phase microscopy technique, namely, spectrally resolved laser interference microscopy (SR-LIM), with which it is possible to quantify multi-spectral phase information related to biological specimens without color crosstalk using a color CCD camera. It is a single shot technique where sequential switched on/off of red, green, and blue (RGB) wavelength light sources are not required. The method is implemented using a three-wavelength interference microscope and a customized compact grating based imaging spectrometer fitted at the output port. The results of the USAF resolution chart while employing three different light sources, namely, a halogen lamp, light emitting diodes, and lasers, are discussed and compared. The broadband light sources like the halogen lamp and light emitting diodes lead to stretching in the spectrally decomposed images, whereas it is not observed in the case of narrow-band light sources, i.e. lasers. The proposed technique is further successfully employed for single-shot quantitative phase imaging of human red blood cells at three wavelengths simultaneously without color crosstalk. Using the present technique, one can also use a monochrome camera, even though the experiments are performed using multi-color light sources. Finally, SR-LIM is not only limited to RGB wavelengths, it can be further extended to red, near infra-red, and infra-red wavelengths, which are suitable for various biological applications.

Efficacy of photodynamic therapy against larvae of Aedes aegypti: confocal microscopy and fluorescence-lifetime imaging

NASA Astrophysics Data System (ADS)

de Souza, L. M.; Pratavieira, S.; Inada, N. M.; Kurachi, C.; Corbi, J.; Guimarães, F. E. G.; Bagnato, V. S.

2014-03-01

Recently a few demonstration on the use of Photodynamic Reaction as possibility to eliminate larvae that transmit diseases for men has been successfully demonstrated. This promising tool cannot be vastly used due to many problems, including the lake of investigation concerning the mechanisms of larvae killing as well as security concerning the use of photosensitizers in open environment. In this study, we investigate some of the mechanisms in which porphyrin (Photogem) is incorporated on the Aedes aegypti larvae previously to illumination and killing. Larvae at second instar were exposed to the photosensitizer and after 30 minutes imaged by a confocal fluorescence microscope. It was observed the presence of photosensitizer in the gut and at the digestive tract of the larva. Fluorescence-Lifetime Imaging showed greater photosensitizer concentration in the intestinal wall of the samples, which produces a strong decrease of the Photogem fluorescence lifetime. For Photodynamic Therapy exposition to different light doses and concentrations of porphyrin were employed. Three different light sources (LED, Fluorescent lamp, Sun light) also were tested. Sun light and fluorescent lamp shows close to 100% of mortality after 24 hrs. of illumination. These results indicate the potential use of photodynamic effect against the LARVAE of Aedes aegypti.

Increasing lanthanide luminescence by use of the RETEL effect.

PubMed

Leif, Robert C; Vallarino, Lidia M; Becker, Margie C; Yang, Sean

2006-08-01

Luminescent lanthanide complexes produce emissions with the narrowest-known width at half maximum; however, their significant use in cytometry required an increase in luminescence intensity. The companion review, Leif et al., Cytometry 2006;69A:767-778, described a new technique for the enhancement of lanthanide luminescence, the Resonance Energy Transfer Enhanced Luminescence (RETEL) effect, which increases luminescence and is compatible with standard slide microscopy. The luminescence of the europium ion macrocyclic complex, EuMac, was increased by employing the RETEL effect. After adding the nonluminescent gadolinium ion complex of the thenoyltrifluoroacetonate (TTFA) ligand or the sodium salt of TTFA in ethanol solution, the EuMac-labeled sample was allowed to dry. Both a conventional arc lamp and a time-gated UV LED served as light sources for microscopic imaging. The emission intensity was measured with a CCD camera. Multiple time-gated images were summed with special software to permit analysis and effective presentation of the final image. With the RETEL effect, the luminescence of the EuMac-streptavidin conjugate increased at least six-fold upon drying. Nuclei of apoptotic cells were stained with DAPI and tailed with 5BrdUrd to which a EuMac-anti-5BrdU conjugate was subsequently attached. Time-gated images showed the long-lived EuMac luminescence but did not show the short-lived DAPI fluorescence. Imaging of DNA-synthesizing cells with an arc lamp showed that both S phase and apoptotic cells were labeled, and that their labeling patterns were different. The images of the luminescent EuMac and fluorescent DAPI were combined to produce a color image on a white background. This combination of simple chemistry, instrumentation, and presentation should make possible the inexpensive use of the lanthanide macrocycles, Quantum Dyes, as molecular diagnostics for cytological and histopathological microscopic imaging. (c) 2006 International Society for Analytical Cytology.

Influence of Corticosteroids and Vitamin E Deficiency on Onset and Cytopathology of Radiation-Induced Cataract

NASA Astrophysics Data System (ADS)

Junk, A. K.; Worgul, B. V.

Cataracts characteristic of those arising from radiation exposure have been reported among the astronaut and cosmonaut corps. This being the case it is critical to appreciate how radiogenic cataracts relate to those arising from other exogenous causes such as therapeutics, which may, one day, have to be administered on an extended mission. Because they produce precisely the same clinical picture, corticosteroids are examples of a class of drugs that potentially can exacerbate damage to the lens from radiation. On the other hand, Vitamin E, a free radical scavenger, has been shown to ameliorate oxidative damage as caused by ionizing radiation and evidence is accumulating that it may constitute protection from radiogenic damage. An experimental study was conducted to understand if corticosteroids with and in the absence of Vitamin E deficiency modulate the onset of cataract induced by ionizing radiation. The right eyes of 72 28-day-old Brown-Norway rats were irradiated with 6 Gy of 240 kV X-rays, the shielded left eyes served as controls. Half of the animals were maintained on a Vitamin E free diet after irradiation, the others were kept on regular chow. In each nutritional group 18 rats additionally received dexamethasone. The initial daily dose of 10 mg/kg body weight injected subcutaneously was reduced to 0.5 mg/kg over the course of 6 months. Cataract onset and development were followed by weekly slit-lamp exam. After 6 month the lenses were harvested for microscopic analyses. Irradiated eyes in all treatment subgroups showed early cataract onset [5 wks versus 11 wks in controls (p<0.0001)]. Corticosteroids accounted for accelerated cataract development in both irradiated (p<0.0005) and non-irradiated eyes (p<0.0001) relative to respective control eyes. Vitamin E deficiency did not affect cataract incidence in combination with radiation or steroids alone. Unexpectedly, when compared to irradiated controls, cataract development was inhibited in the group that received radiation, dexamethasone and the Vitamin E free diet (p<0.0005). Radiation, at the applied dose, was the predominant risk factor for early cataract onset. However, corticosteroids accelerate cataract formation. The surprising protective influence of Vitamin E deficiency may be the result of a stathmokinetic effect on mitosis - a possibility that is supported by lens epithelial histopathology in the regions of cell mitosis and differentiation.

Influence of corticosteroids and vitamin E deficiency on onset of radiation-induced cataract

NASA Astrophysics Data System (ADS)

Junk, A. K.; Worgul, B. W.

Cataracts characteristic of those arising from radiation exposure have been reported among the astronaut and cosmonaut corps. This being the case it is critical to appreciate how radiogenic cataracts relate to those arising from other exogenous causes such as therapeutics, which may, one day, have to be administered on an extended mission. Because they produce precisely the same clinical picture, corticosteroids are examples of a class of drugs that potentially can exacerbate damage to the lens from radiation. On the other hand, Vitamin E, a free radical scavenger, has been shown to ameliorate oxidative damage as caused by ionizing radiation and evidence is accumulating that it may constitute protection from radiogenic damage. An experimental study was conducted to understand if corticosteroids with, and in the absence of Vitamin E deficiency modulate the onset of cataract induced by ionizing radiation. The right eyes of seventy-two 28-day-old Brown-Norway rats were irradiated with 6 Gy of 240 kV X-rays, the shielded left eyes served as controls. Half of the animals were maintained on a Vitamin E free diet after irradiation, the others were kept on standard chow. Fifty per cent of the animals in each nutritional group received dexamethasone. The initial daily dose of 10 mg/kg body weight injected subcutaneously was reduced to 0.5 mg/kg over the course of six months. Cataract onset and development were followed by weekly slit-lamp exam. After six month the lenses were harvested for microscopic analyses. Irradiated eyes in all treatment subgroups showed early cataract onset [5 wks vs. 11 wks in controls ( p < 0.0001)]. Corticosteroids accounted for accelerated cataract development in both irradiated ( p < 0.0005) and non-irradiated eyes ( p < 0.0001) relative to respective control eyes. Vitamin E deficiency did not affect cataract incidence in combination with radiation or steroids alone. Unexpectedly, when compared to irradiated controls, cataract development was inhibited in the group that received radiation, dexamethasone and the Vitamin E free diet ( p < 0.0005). Radiation, at the applied dose, was the predominant risk factor for early cataract onset. However, corticosteroids accelerate cataract formation. The surprising protective influence of Vitamin E deficiency may be the result of a stathmokinetic effect on mitosis - a possibility that is supported by lens epithelial histopathology in the regions of cell mitosis and differentiation.

Association of fluorescein anterior corneal mosaic and corneal K-structures by in vivo laser confocal microscopy in patients with keratoconus.

PubMed

Kobayashi, Akira; Yokogawa, Hideaki; Mori, Natsuko; Masaki, Toshinori; Sugiyama, Kazuhisa

2017-01-01

To report the in vivo laser confocal microscopy findings of corneas with keratoconus, with special attention to abnormality of Bowman's layer and sub-Bowman's fibrous structures (Kobayashi-structures [K-structures]). Sixteen keratoconic eyes in 8 consecutive patients with keratoconus (4 males, 4 females, mean age, 41.1 years) were included in this study. Slit-lamp biomicroscopic photos were taken with or without fluorescein staining. The existence of anterior corneal mosaic (ACM) after eyelid rubbing under fluorescein staining was documented. In vivo laser confocal microscopic examinations were performed for all patients in both the central cone and the peripheral cornea to examine the existence of K-structures. According to the Amsler-Krumeich scale, the eyes were graded as follows: stage 1 (n=3), stage 2 (n=1), stage 3 (n=1), and stage 4 (n=11). ACM was observed in 7 eyes (61.1%) in the cone area and 16 eyes (100%) in the peripheral cornea among all keratoconic eyes enrolled in this study. In addition, K-structures were observed in the 7 eyes (61.1%) and 16 eyes (100%) in the peripheral cornea among all keratoconic eyes. The presence of the K-structures was completely matched (100%) with the presence of ACM in both the central cone and the peripheral cornea. In 11 eyes with stage 4 keratoconus, ACM and K-structure was absent in 9 eyes (81.8%) in the cone area. On the contrary, in 5 eyes with mild-to-moderate keratoconus (grade 1 to 3), ACM and K-structure was present in all eyes (100%) in the cone area. The absent ratio of ACM and K-structures in the cone area was significantly higher in stage 4 severe keratoconus compared to mild-to-moderate keratoconus (grade 1 to 3) (Fisher, P =0.005). The existence of ACM and K-structures in both the central cone and the peripheral cornea showed perfect accord in patients with keratoconus, indicating a strong association of ACM and K-structures in patients with keratoconus. With the progress of the keratoconus, it seemed that ACM and K-structure progressively disappeared, suggesting Bowman's layer abnormalities due to keratoconus. Further study in larger groups of patients with keratoconus is required to fully understand the significance of ACM/K-structures in keratoconic eyes and their association with Bowman's layer.

Application of image recognition-based automatic hyphae detection in fungal keratitis.

PubMed

Wu, Xuelian; Tao, Yuan; Qiu, Qingchen; Wu, Xinyi

2018-03-01

The purpose of this study is to evaluate the accuracy of two methods in diagnosis of fungal keratitis, whereby one method is automatic hyphae detection based on images recognition and the other method is corneal smear. We evaluate the sensitivity and specificity of the method in diagnosis of fungal keratitis, which is automatic hyphae detection based on image recognition. We analyze the consistency of clinical symptoms and the density of hyphae, and perform quantification using the method of automatic hyphae detection based on image recognition. In our study, 56 cases with fungal keratitis (just single eye) and 23 cases with bacterial keratitis were included. All cases underwent the routine inspection of slit lamp biomicroscopy, corneal smear examination, microorganism culture and the assessment of in vivo confocal microscopy images before starting medical treatment. Then, we recognize the hyphae images of in vivo confocal microscopy by using automatic hyphae detection based on image recognition to evaluate its sensitivity and specificity and compare with the method of corneal smear. The next step is to use the index of density to assess the severity of infection, and then find the correlation with the patients' clinical symptoms and evaluate consistency between them. The accuracy of this technology was superior to corneal smear examination (p < 0.05). The sensitivity of the technology of automatic hyphae detection of image recognition was 89.29%, and the specificity was 95.65%. The area under the ROC curve was 0.946. The correlation coefficient between the grading of the severity in the fungal keratitis by the automatic hyphae detection based on image recognition and the clinical grading is 0.87. The technology of automatic hyphae detection based on image recognition was with high sensitivity and specificity, able to identify fungal keratitis, which is better than the method of corneal smear examination. This technology has the advantages when compared with the conventional artificial identification of confocal microscope corneal images, of being accurate, stable and does not rely on human expertise. It was the most useful to the medical experts who are not familiar with fungal keratitis. The technology of automatic hyphae detection based on image recognition can quantify the hyphae density and grade this property. Being noninvasive, it can provide an evaluation criterion to fungal keratitis in a timely, accurate, objective and quantitative manner.

Dispenser printed electroluminescent lamps on textiles for smart fabric applications

NASA Astrophysics Data System (ADS)

de Vos, Marc; Torah, Russel; Tudor, John

2016-04-01

Flexible electroluminescent (EL) lamps are fabricated onto woven textiles using a novel dispenser printing process. Dispenser printing utilizes pressurized air to deposit ink onto a substrate through a syringe and nozzle. This work demonstrates the first use of this technology to fabricate EL lamps. The luminance of the dispenser printed EL lamps is compared to screen-printed EL lamps, both printed on textile, and also commercial EL lamps on polyurethane film. The dispenser printed lamps are shown to have a 1.5 times higher luminance than the best performing commercially available lamp, and have a comparable performance to the screen-printed lamps.

49 CFR 393.24 - Requirements for head lamps, auxiliary driving lamps and front fog lamps.

Code of Federal Regulations, 2010 CFR

2010-10-01

... this paragraph. (b) Auxiliary driving lamps and front fog lamps. Commercial motor vehicles may be... Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Lamps, Reflective...

10 CFR 431.282 - Test Procedures [Reserved

Code of Federal Regulations, 2013 CFR

2013-01-01

... EQUIPMENT Mercury Vapor Lamp Ballasts § 431.282 Definitions concerning mercury vapor lamp ballasts. Ballast...) The arc tube wall loading is in excess of 3 Watts/cm2, including such lamps that are mercury vapor, metal halide, and high-pressure sodium lamps. Mercury vapor lamp means a high intensity discharge lamp...

10 CFR 431.282 - Test Procedures [Reserved

Code of Federal Regulations, 2011 CFR

2011-01-01

... EQUIPMENT Mercury Vapor Lamp Ballasts § 431.282 Definitions concerning mercury vapor lamp ballasts. Ballast...) The arc tube wall loading is in excess of 3 Watts/cm2, including such lamps that are mercury vapor, metal halide, and high-pressure sodium lamps. Mercury vapor lamp means a high intensity discharge lamp...

10 CFR 431.282 - Test Procedures [Reserved

Code of Federal Regulations, 2014 CFR

2014-01-01

... EQUIPMENT Mercury Vapor Lamp Ballasts § 431.282 Definitions concerning mercury vapor lamp ballasts. Ballast...) The arc tube wall loading is in excess of 3 Watts/cm2, including such lamps that are mercury vapor, metal halide, and high-pressure sodium lamps. Mercury vapor lamp means a high intensity discharge lamp...

10 CFR 431.282 - Test Procedures [Reserved

Code of Federal Regulations, 2012 CFR

2012-01-01

... EQUIPMENT Mercury Vapor Lamp Ballasts § 431.282 Definitions concerning mercury vapor lamp ballasts. Ballast...) The arc tube wall loading is in excess of 3 Watts/cm2, including such lamps that are mercury vapor, metal halide, and high-pressure sodium lamps. Mercury vapor lamp means a high intensity discharge lamp...

49 CFR 393.11 - Lamps and reflective devices.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 5 2012-10-01 2012-10-01 false Lamps and reflective devices. 393.11 Section 393... ACCESSORIES NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.11 Lamps and reflective devices. (a)(1) Lamps and reflex reflectors. Table 1 specifies the requirements for lamps...

10 CFR 429.40 - Candelabra base incandescent lamps and intermediate base incandescent lamps.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Candelabra base incandescent lamps and intermediate base incandescent lamps. 429.40 Section 429.40 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION CERTIFICATION....40 Candelabra base incandescent lamps and intermediate base incandescent lamps. (a) Sampling plan for...

49 CFR 393.11 - Lamps and reflective devices.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 5 2014-10-01 2014-10-01 false Lamps and reflective devices. 393.11 Section 393... ACCESSORIES NECESSARY FOR SAFE OPERATION Lamps, Reflective Devices, and Electrical Wiring § 393.11 Lamps and reflective devices. (a)(1) Lamps and reflex reflectors. Table 1 specifies the requirements for lamps...

LAMP-3 (Lysosome-Associated Membrane Protein 3) Promotes the Intracellular Proliferation of Salmonella typhimurium.

PubMed

Lee, Eun-Ju; Park, Kwan-Sik; Jeon, In-Sook; Choi, Jae-Woon; Lee, Sang-Jeon; Choy, Hyun E; Song, Ki-Duk; Lee, Hak-Kyo; Choi, Joong-Kook

2016-07-01

Lysosomes are cellular organelles containing diverse classes of catabolic enzymes that are implicated in diverse cellular processes including phagocytosis, autophagy, lipid transport, and aging. Lysosome-associated membrane proteins (LAMP-1 and LAMP-2) are major glycoproteins important for maintaining lysosomal integrity, pH, and catabolism. LAMP-1 and LAMP-2 are constitutively expressed in Salmonella-infected cells and are recruited to Salmonella-containing vacuoles (SCVs) as well as Salmonella-induced filaments (Sifs) that promote the survival and proliferation of the Salmonella. LAMP-3, also known as DC-LAMP/CD208, is a member of the LAMP family of proteins, but its role during Salmonella infection remains unclear. DNA microarray analysis identified LAMP-3 as one of the genes responding to LPS stimulation in THP-1 macrophage cells. Subsequent analyses reveal that LPS and Salmonella induced the expression of LAMP-3 at both the transcriptional and translational levels. Confocal Super resolution N-SIM imaging revealed that LAMP-3, like LAMP-2, shifts its localization from the cell surface to alongside Salmonella. Knockdown of LAMP-3 by specific siRNAs decreased the number of Salmonella recovered from the infected cells. Therefore, we conclude that LAMP-3 is induced by Salmonella infection and recruited to the Salmonella pathogen for intracellular proliferation.

LAMP-3 (Lysosome-Associated Membrane Protein 3) Promotes the Intracellular Proliferation of Salmonella typhimurium

PubMed Central

Lee, Eun-Ju; Park, Kwan-Sik; Jeon, In-Sook; Choi, Jae-Woon; Lee, Sang-Jeon; Choy, Hyun E.; Song, Ki-Duk; Lee, Hak-Kyo; Choi, Joong-Kook

2016-01-01

Lysosomes are cellular organelles containing diverse classes of catabolic enzymes that are implicated in diverse cellular processes including phagocytosis, autophagy, lipid transport, and aging. Lysosome-associated membrane proteins (LAMP-1 and LAMP-2) are major glycoproteins important for maintaining lysosomal integrity, pH, and catabolism. LAMP-1 and LAMP-2 are constitutively expressed in Salmonella-infected cells and are recruited to Salmonella-containing vacuoles (SCVs) as well as Salmonella-induced filaments (Sifs) that promote the survival and proliferation of the Salmonella. LAMP-3, also known as DC-LAMP/CD208, is a member of the LAMP family of proteins, but its role during Salmonella infection remains unclear. DNA microarray analysis identified LAMP-3 as one of the genes responding to LPS stimulation in THP-1 macrophage cells. Subsequent analyses reveal that LPS and Salmonella induced the expression of LAMP-3 at both the transcriptional and translational levels. Confocal Super resolution N-SIM imaging revealed that LAMP-3, like LAMP-2, shifts its localization from the cell surface to alongside Salmonella. Knockdown of LAMP-3 by specific siRNAs decreased the number of Salmonella recovered from the infected cells. Therefore, we conclude that LAMP-3 is induced by Salmonella infection and recruited to the Salmonella pathogen for intracellular proliferation. PMID:27329040

LAMP-2C Inhibits MHC Class II Presentation of Cytoplasmic Antigens by Disrupting Chaperone-Mediated Autophagy.

PubMed

Pérez, Liliana; McLetchie, Shawna; Gardiner, Gail J; Deffit, Sarah N; Zhou, Delu; Blum, Janice S

2016-03-15

Cells use multiple autophagy pathways to sequester macromolecules, senescent organelles, and pathogens. Several conserved isoforms of the lysosome-associated membrane protein-2 (LAMP-2) regulate these pathways influencing immune recognition and responses. LAMP-2A is required for chaperone-mediated autophagy (CMA), which promotes Ag capture and MHC class II (MHCII) presentation in B cells and signaling in T cells. LAMP-2B regulates lysosome maturation to impact macroautophagy and phagocytosis. Yet, far less is known about LAMP-2C function. Whereas LAMP2A and LAMP2B mRNA were broadly detected in human tissues, LAMP2C expression was more limited. Transcripts for the three LAMP2 isoforms increased with B cell activation, although specific gene induction varied depending on TLR versus BCR engagement. To examine LAMP-2C function in human B cells and specifically its role in Ag presentation, we used ectopic gene expression. Increased LAMP-2C expression in B cells did not alter MHCII expression or invariant chain processing, but did perturb cytoplasmic Ag presentation via CMA. MHCII presentation of epitopes from exogenous and membrane Ags was not affected by LAMP-2C expression in B cells. Similarly, changes in B cell LAMP-2C expression did not impact macroautophagy. The gene expression of other LAMP2 isoforms and proteasome and lysosomal proteases activities were unperturbed by LAMP-2C ectopic expression. LAMP-2C levels modulated the steady-state expression of several cytoplasmic proteins that are targeted for degradation by CMA and diminished peptide translocation via this pathway. Thus, LAMP-2C serves as a natural inhibitor of CMA that can selectively skew MHCII presentation of cytoplasmic Ags. Copyright © 2016 by The American Association of Immunologists, Inc.

LAMP-2C inhibits MHC class II presentation of cytoplasmic antigens by disrupting chaperone-mediated autophagy

PubMed Central

Pérez, Liliana; McLetchie, Shawna; Gardiner, Gail J.; Deffit, Sarah N.; Zhou, Delu; Blum, Janice S.

2016-01-01

Cells utilize multiple autophagy pathways to sequester macromolecules, senescent organelles, and pathogens. Several conserved isoforms of the lysosome-associated membrane protein (LAMP)-2 regulate these pathways influencing immune recognition and responses. LAMP-2A is required for chaperone-mediated autophagy (CMA) which promotes Ag capture and MHC class II (MHCII) presentation in B cells and signaling in T cells. LAMP-2B regulates lysosome maturation to impact macroautophagy (MA) and phagocytosis. Yet, far less is known about LAMP-2C function. While LAMP2A and LAMP2B mRNA were broadly detected in human tissues, LAMP2C expression was more limited. Transcripts for the three LAMP2 isoforms increased with B cell activation, although specific gene induction varied depending on TLR versus BCR engagement. To examine LAMP-2C function in human B cells and specifically its role in Ag presentation, ectopic gene expression was used. Increased LAMP-2C expression in B cells did not alter MHCII expression or invariant chain processing, but did perturb cytoplasmic Ag presentation via CMA. MHCII presentation of epitopes from exogenous and membrane Ags was not affected by LAMP-2C expression in B cells. Similarly, changes in B cell LAMP-2C expression did not impact MA. The gene expression of other LAMP2 isoforms as well as the proteasome and lysosomal proteases activities were unperturbed by LAMP-2C ectopic expression. LAMP-2C levels modulated the steady-state expression of several cytoplasmic proteins which are targeted for degradation by CMA and diminished peptide translocation via this pathway. Thus, LAMP-2C serves as a natural inhibitor of CMA which can selectively skew MHCII presentation of cytoplasmic Ags. PMID:26856698

The safety and efficacy of sublingual and oral immunotherapy for milk allergy.

PubMed

Keet, Corinne A; Frischmeyer-Guerrerio, Pamela A; Thyagarajan, Ananth; Schroeder, John T; Hamilton, Robert G; Boden, Stephen; Steele, Pamela; Driggers, Sarah; Burks, A Wesley; Wood, Robert A

2012-02-01

Oral immunotherapy (OIT) and sublingual immunotherapy (SLIT) are potential therapies for food allergy, but the optimal method of administration, mechanism of action, and duration of response remain unknown. We sought to explore the safety and efficacy of OIT and SLIT for the treatment of cow's milk (CM) allergy. We randomized children with CM allergy to SLIT alone or SLIT followed by OIT. After screening double-blind, placebo-controlled food challenges and initial SLIT escalation, subjects either continued SLIT escalation to 7 mg daily or began OIT to either 1000 mg (the OITB group) or 2000 mg (the OITA group) of milk protein. They were challenged with 8 g of milk protein after 12 and 60 weeks of maintenance. If they passed the 60-week challenge, therapy was withdrawn, with challenges repeated 1 and 6 weeks later. Mechanistic correlates included end point titration skin prick testing and measurement of CM-specific IgE and IgG(4) levels, basophil histamine release, constitutive CD63 expression, CD203c expression, and intracellular spleen tyrosine kinase levels. Thirty subjects with CM allergy aged 6 to 17 years were enrolled. After therapy, 1 of 10 subjects in the SLIT group, 6 of 10 subjects in the SLIT/OITB group, and 8 of 10 subjects in the OITA group passed the 8-g challenge (P = .002, SLIT vs OIT). After avoidance, 6 of 15 subjects (3 of 6 subjects in the OITB group and 3 of 8 subjects in the OITA group) regained reactivity, 2 after only 1 week. Although the overall reaction rate was similar, systemic reactions were more common during OIT than during SLIT. By the end of therapy, titrated CM skin prick test results and CD63 and CD203c expression decreased and CM-specific IgG(4) levels increased in all groups, whereas CM-specific IgE and spontaneous histamine release values decreased in only the OIT group. OIT was more efficacious for desensitization to CM than SLIT alone but was accompanied by more systemic side effects. Clinical desensitization was lost in some cases within 1 week off therapy. Copyright © 2011 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.