1
|
Yano-Ozawa Y, Lobsiger N, Muto Y, Mori T, Yoshimura K, Yano Y, Stark WJ, Maeda M, Asahi T, Ogawa A, Zako T. Molecular detection using aptamer-modified gold nanoparticles with an immobilized DNA brush for the prevention of non-specific aggregation. RSC Adv 2021; 11:11984-11991. [PMID: 35423740 PMCID: PMC8696536 DOI: 10.1039/d0ra05149g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 03/15/2021] [Indexed: 12/12/2022] Open
Abstract
Gold nanoparticles (AuNPs) are often used for biosensing. In particular, aptamer-modified AuNPs are often used for colorimetric molecular detection, where target molecule-induced AuNP aggregates can be recognized by a color change from red to blue. However, non-specific aggregation could be induced by various compounds, leading to false-positive results. In this work we employed high-density ssDNA modification on the AuNP surface to prevent non-specific aggregation. The covalently immobilized DNA brush was used as an anchor for an aptamer specific for the target molecule. Herein, as a proof-of-concept study, we demonstrated detection of estradiol (E2), one of the endocrine-disrupting estrogen molecules as a model target, in the presence of antibiotic kanamycin (KN) as a model of co-contaminating compounds that induce non-specific aggregation of AuNPs. We also developed a smartphone dark field microscope (DFM) to visualize AuNP aggregation. Our previous study demonstrated that the observation of light scattering by AuNP aggregates with DFM can be applied for versatile molecular detection. In this work, we could successfully detect E2 with the smartphone DFM, and the results were verified by the results from a conventional benchtop DFM. This study would contribute to the future field applicability of AuNP-based sensors. We demonstrated molecular detection using aptamer-modified gold nanoparticles with DNA-brush for the prevention of non-specific aggregation and smartphone darkfield microscopy.![]()
Collapse
Affiliation(s)
- Yuki Yano-Ozawa
- Department of Chemistry and Biology, Graduate School of Science and Engineering, Ehime University 2-5 Bunkyo Matsuyama Ehime 790-8577 Japan
| | - Nadine Lobsiger
- Department of Chemistry and Biology, Graduate School of Science and Engineering, Ehime University 2-5 Bunkyo Matsuyama Ehime 790-8577 Japan .,Institute for Chemical and Bioengineering, ETH Zürich Wolfgang-Pauli-Strasse 10 CH-8093 Zürich Switzerland
| | - Yu Muto
- Department of Chemistry and Biology, Graduate School of Science and Engineering, Ehime University 2-5 Bunkyo Matsuyama Ehime 790-8577 Japan .,Tokyo Research Center, TOSOH Corporation 2743-1 Hayakawa Ayase Kanagawa 252-1123 Japan
| | - Takahiro Mori
- Department of Chemistry and Biology, Graduate School of Science and Engineering, Ehime University 2-5 Bunkyo Matsuyama Ehime 790-8577 Japan
| | - Ken Yoshimura
- Department of Chemistry and Biology, Graduate School of Science and Engineering, Ehime University 2-5 Bunkyo Matsuyama Ehime 790-8577 Japan
| | - Yuki Yano
- Department of Chemistry and Biology, Graduate School of Science and Engineering, Ehime University 2-5 Bunkyo Matsuyama Ehime 790-8577 Japan
| | - Wendelin Jan Stark
- Institute for Chemical and Bioengineering, ETH Zürich Wolfgang-Pauli-Strasse 10 CH-8093 Zürich Switzerland
| | - Mizuo Maeda
- Bioengineering Laboratory, RIKEN Cluster for Pioneering Research 2-1 Hirosawa Wako Saitama 351-0198 Japan
| | - Tsuyoshi Asahi
- Department of Chemistry and Biology, Graduate School of Science and Engineering, Ehime University 2-5 Bunkyo Matsuyama Ehime 790-8577 Japan
| | - Atsushi Ogawa
- Proteo-Science Center, Ehime University 3 Bunkyo Matsuyama Ehime 790-8577 Japan
| | - Tamotsu Zako
- Department of Chemistry and Biology, Graduate School of Science and Engineering, Ehime University 2-5 Bunkyo Matsuyama Ehime 790-8577 Japan
| |
Collapse
|
2
|
Doswald S, Stark WJ. Low molecular weight glycerol derived coatings on magnetic nanoparticles: role of initiator, temperature, rate of monomer addition, enhanced biocompatibility and stability. RSC Adv 2021; 11:40140-40147. [PMID: 35494117 PMCID: PMC9044556 DOI: 10.1039/d1ra03475h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 11/27/2021] [Indexed: 11/21/2022] Open
Abstract
Biocompatible polymer coatings for magnetic nanoparticles have shown to drastically increase their usability towards biomedical applications. The coatings imprint characteristics such as stability, resistance to non-specific adsorption and tolerance in complex media for biomedicine. Herein, a thorough investigation towards the anionic ring-opening polymerization of glycidol on the surface of carbon-coated cobalt nanoparticle was performed. Reaction parameters that influence polymer growth have been investigated. Thereafter, a maximal achievable hyperbranched polyglycidol Mw of up to 1148 g mol−1 under optimal reaction conditions was obtained. With this coating, the dispersion stability of the particles could be substantially increased, the non-specific adsorption of proteins could be decreased to 10% while retaining an efficient magnetic separation. A highly efficient coating process of magnetic nanoparticles with hyperbranched polyglycidol was investigated and the resulting particles were tested towards their biocompatible capabilities.![]()
Collapse
Affiliation(s)
- Simon Doswald
- Departement of Chemistry and Applied Science, Institute of Chemical Engineering and Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland
| | - Wendelin Jan Stark
- Departement of Chemistry and Applied Science, Institute of Chemical Engineering and Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, 8093 Zurich, Switzerland
| |
Collapse
|
3
|
Doswald S, Stark WJ, Beck-Schimmer B. Biochemical functionality of magnetic particles as nanosensors: how far away are we to implement them into clinical practice? J Nanobiotechnology 2019; 17:73. [PMID: 31151445 PMCID: PMC6544934 DOI: 10.1186/s12951-019-0506-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 05/27/2019] [Indexed: 01/09/2023] Open
Abstract
Magnetic nanosensors have become attractive instruments for the diagnosis and treatment of different diseases. They represent an efficient carrier system in drug delivery or in transporting contrast agents. For such purposes, magnetic nanosensors are used in vivo (intracorporeal application). To remove specific compounds from blood, magnetic nanosensors act as elimination system, which represents an extracorporeal approach. This review discusses principles, advantages and risks on recent advances in the field of magnetic nanosensors. First, synthesis methods for magnetic nanosensors and possibilities for enhancement of biocompatibility with different coating materials are addressed. Then, attention is devoted to clinical applications, in which nanosensors are or may be used as carrier- and elimination systems in the near future. Finally, risk considerations and possible effects of nanomaterials are discussed when working towards clinical applications with magnetic nanosensors.
Collapse
Affiliation(s)
- Simon Doswald
- Institute for Chemical and Bioengineering, ETH Zurich, Zurich, Switzerland
| | - Wendelin Jan Stark
- Institute for Chemical and Bioengineering, ETH Zurich, Zurich, Switzerland
| | - Beatrice Beck-Schimmer
- Institute of Anesthesiology, University of Zurich and University Hospital Zurich, Raemistrasse 100, 8091, Zurich, Switzerland.
| |
Collapse
|
4
|
Dual SA, Zimmermann JM, Neuenschwander J, Cohrs NH, Solowjowa N, Stark WJ, Meboldt M, Schmid Daners M. Ultrasonic sensor concept to fit a ventricular assist device cannula evaluated using geometrically accurate heart phantoms. Artif Organs 2018; 43:467-477. [PMID: 30357874 DOI: 10.1111/aor.13379] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/05/2018] [Accepted: 10/18/2018] [Indexed: 12/12/2022]
Abstract
Future left ventricular assist devices (LVADs) are expected to respond to the physiologic need of patients; however, they still lack reliable pressure or volume sensors for feedback control. In the clinic, echocardiography systems are routinely used to measure left ventricular (LV) volume. Until now, echocardiography in this form was never integrated in LVADs due to its computational complexity. The aim of this study was to demonstrate the applicability of a simplified ultrasonic sensor to fit an LVAD cannula and to show the achievable accuracy in vitro. Our approach requires only two ultrasonic transducers because we estimated the LV volume with the LV end-diastolic diameter commonly used in clinical assessments. In order to optimize the accuracy, we assessed the optimal design parameters considering over 50 orientations of the two ultrasonic transducers. A test bench was equipped with five talcum-infused silicone heart phantoms, in which the intra-ventricular surface replicated papillary muscles and trabeculae carnae. The end-diastolic LV filling volumes of the five heart phantoms ranged from 180 to 480 mL. This reference volume was altered by ±40 mL with a syringe pump. Based on the calibrated measurements acquired by the two ultrasonic transducers, the LV volume was estimated well. However, the accuracies obtained are strongly dependent on the choice of the design parameters. Orientations toward the septum perform better, as they interfere less with the papillary muscles. The optimized design is valid for all hearts. Considering this, the Bland-Altman analysis reports the LV volume accuracy as a bias of ±10% and limits of agreement of 0%-40% in all but the smallest heart. The simplicity of traditional echocardiography systems was reduced by two orders of magnitude in technical complexity, while achieving a comparable accuracy to 2D echocardiography requiring a calibration of absolute volume only. Hence, our approach exploits the established benefits of echocardiography and makes them applicable as an LV volume sensor for LVADs.
Collapse
Affiliation(s)
- Seraina Anne Dual
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Jan Michael Zimmermann
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Jürg Neuenschwander
- Swiss Federal Laboratories for Materials Science and Technology, Empa, Dübendorf, Switzerland
| | - Nicholas Heinrich Cohrs
- Functional Materials Laboratory, Institute for Chemical and Bioengineering, ETH Zurich, Zurich, Switzerland
| | - Natalia Solowjowa
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Wendelin Jan Stark
- Functional Materials Laboratory, Institute for Chemical and Bioengineering, ETH Zurich, Zurich, Switzerland
| | - Mirko Meboldt
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| | - Marianne Schmid Daners
- Product Development Group Zurich, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland
| |
Collapse
|
5
|
Hess SC, Stark WJ, Mohn D, Cohrs N, Märsmann S, Calcagni M, Cinelli P, Buschmann J. Gene expression in human adipose-derived stem cells: comparison of 2D films, 3D electrospun meshes or co-cultured scaffolds with two-way paracrine effects. Eur Cell Mater 2017; 34:232-248. [PMID: 29028070 DOI: 10.22203/ecm.v034a15] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Finding the appropriate cues to trigger the desired differentiation is a challenge in tissue engineering when stem cells are involved. In this regard, three-dimensional environments are often compared to cells' two-dimensional culture behaviour (plastic culture dish). Here, we compared the gene expression pattern of human adipose-derived stem cells (ASC) seeded in a three-dimensional (3D) electrospun mesh and on a two-dimensional (2D) film - both of exactly the same material. Additionally, we conducted experiments with a scaffold floating above a film to investigate two-way paracrine effects (co-system). Electrospun meshes (3D scaffolds) and films (2D), consisting either of pristine poly-lactic-co-glycolic acid (PLGA) or of PLGA-containing dispersed amorphous calcium phosphate nanoparticles (PLGA/aCaP), were seeded with ASCs and cultured either in Dulbecco Minimum Essential Medium (DMEM) or in osteogenic medium. After two weeks, minimum stem cell criteria markers as well as typical markers for osteogenesis, endothelial cell differentiation, adipogenesis and chondrogenesis were analysed by quantitative real-time PCR. Interestingly, mostly osteogenic genes of cells seeded on 3D meshes were upregulated compared to those on 2D films, while stem cell markers seemed to be only slightly affected. Runx2 and osteocalcin showed an especially strong upregulation under all conditions, while most other factors analysed for 2D/3D changes were highly dependent on the material composition, the culture medium and on paracrine signalling effects. The beneficial 3D environment for stem cells found in many studies has therefore not to be attributed to the third dimension alone and should carefully be compared to 2D films fabricated of the same material. Furthermore, paracrine interactions triggering differentiation are not negligible.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - J Buschmann
- University Hospital Zurich, Plastic Surgery and Hand Surgery, E LAB 27, Sternwartstrasse 14, CH-8091 Zürich,
| |
Collapse
|
6
|
Pan Q, Jampel HD, Ramulu P, Schwartz GF, Cotter F, Cute D, Daoud YJ, Murakami P, Stark WJ. Clinical outcomes of gamma-irradiated sterile cornea in aqueous drainage device surgery: a multicenter retrospective study. Eye (Lond) 2017; 31:430-436. [PMID: 27834965 PMCID: PMC5350361 DOI: 10.1038/eye.2016.230] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 09/22/2016] [Indexed: 11/08/2022] Open
Abstract
PurposeThe purpose of the study was to evaluate the safety and efficacy of gamma-irradiated sterile cornea (GISC) for covering the tube in aqueous drainage device (ADD) surgery in a retrospective, multicenter case series.Patients and methodsParticipants included 297 patients (321 procedures) who had undergone ADD surgery for the first time using GISC patch at three clinic centers in the United States between April 2009 and July 2012. The medical records of those consecutive patients were reviewed. Preoperative, intraoperative, and postoperative parameters about GISC were collected and analyzed. The main outcome measures were patch graft failure (PGF) and postoperative complications related to GISC.ResultsThree hundred and nineteen eyes in 295 patients were included in the current analysis. Ten out of the 319 eyes experienced PGF with a mean follow-up of 15.4±9.8 (SD) months. The overall cumulative PGF proportion from Kaplan-Meier analysis was 2.6% (95% CI: 0.6-4.7%) at 18 months. We detected two cases of presumed endophthalmitis related to PGF.ConclusionsGISC appears to have a reasonable success rate for preventing tube exposure related to PGF over an 18-month period. This success rate, in combination with other features of GISC (transparency and storage at room temperature), makes it a viable choice for patch graft material during ADD.
Collapse
Affiliation(s)
- Q Pan
- Eye Center, Zhejiang Provincial People's Hospital, Hangzhou, China
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD, USA
| | - H D Jampel
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD, USA
| | - P Ramulu
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD, USA
| | | | - F Cotter
- Vistar Eye Center, Roanoke, VA, USA
| | - D Cute
- Walter Reed National Military Medical Center, Bethesda, MD, USA
| | - Y J Daoud
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD, USA
| | - P Murakami
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - W J Stark
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD, USA
| |
Collapse
|
7
|
Herrmann IK, Schlegel AA, Graf R, Stark WJ, Beck-Schimmer B. Magnetic separation-based blood purification: a promising new approach for the removal of disease-causing compounds? J Nanobiotechnology 2015; 13:49. [PMID: 26253109 PMCID: PMC4528690 DOI: 10.1186/s12951-015-0110-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 07/29/2015] [Indexed: 01/02/2023] Open
Abstract
Recent studies report promising results regarding extracorporeal magnetic separation-based blood purification for the rapid and selective removal of disease-causing compounds from whole blood. High molecular weight compounds, bacteria and cells can be eliminated from blood within minutes, hence offering novel treatment strategies for the management of intoxications and blood stream infections. However, risks associated with incomplete particle separation and the biological consequences of particles entering circulation remain largely unclear. This article discusses the promising future of magnetic separation-based purification while keeping important safety considerations in mind.
Collapse
Affiliation(s)
- I K Herrmann
- Institute of Anesthesiology, University Hospital Zurich, Rämistrasse 100, 8091, Zurich, Switzerland.
- Institute of Physiology and Zurich Center for Integrative Human Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
| | - A A Schlegel
- Department of Surgery, Swiss HPB and Transplant Center, University Hospital Zurich, Rämistrasse 100, 8091, Zurich, Switzerland.
| | - R Graf
- Department of Surgery, Swiss HPB and Transplant Center, University Hospital Zurich, Rämistrasse 100, 8091, Zurich, Switzerland.
| | - W J Stark
- Institute for Chemical and Bioengineering, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland.
| | - Beatrice Beck-Schimmer
- Institute of Anesthesiology, University Hospital Zurich, Rämistrasse 100, 8091, Zurich, Switzerland.
- Institute of Physiology and Zurich Center for Integrative Human Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
| |
Collapse
|
8
|
Urner M, Schläpfer M, Herrmann IK, Hasler M, Schimmer RR, Booy C, Roth Z'graggen B, Rehrauer H, Aigner F, Minshall RD, Stark WJ, Beck-Schimmer B. Insight into the beneficial immunomodulatory mechanism of the sevoflurane metabolite hexafluoro-2-propanol in a rat model of endotoxaemia. Clin Exp Immunol 2015; 181:468-79. [PMID: 25925908 DOI: 10.1111/cei.12648] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/19/2015] [Indexed: 12/13/2022] Open
Abstract
Volatile anaesthetics such as sevoflurane attenuate inflammatory processes, thereby impacting patient outcome significantly. Their inhalative administration is, however, strictly limited to controlled environments such as operating theatres, and thus an intravenously injectable immunomodulatory drug would offer distinct advantages. As protective effects of volatile anaesthetics have been associated with the presence of trifluorinated carbon groups in their basic structure, in this study we investigated the water-soluble sevoflurane metabolite hexafluoro-2-propanol (HFIP) as a potential immunomodulatory drug in a rat model of endotoxic shock. Male Wistar rats were subjected to intravenous lipopolysaccharide (LPS) and thereafter were treated with HFIP. Plasma and tissue inflammatory mediators, neutrophil invasion, tissue damage and haemodynamic stability were the dedicated end-points. In an endotoxin-induced endothelial cell injury model, underlying mechanisms were elucidated using gene expression and gene reporter analyses. HFIP reduced the systemic inflammatory response significantly and decreased endotoxin-induced tissue damage. Additionally, the LPS-provoked drop in blood pressure of animals was resolved by HFIP treatment. Pathway analysis revealed that the observed attenuation of the inflammatory process was associated with reduced nuclear factor kappa B (NF-κΒ) activation and suppression of its dependent transcripts. Taken together, intravenous administration of HFIP exerts promising immunomodulatory effects in endotoxaemic rats. The possibility of intravenous administration would overcome limitations of volatile anaesthetics, and thus HFIP might therefore represent an interesting future drug candidate for states of severe inflammation.
Collapse
Affiliation(s)
- M Urner
- Institute of Anesthesiology, University Hospital Zurich, Zurich, Switzerland.,Institute of Physiology, Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - M Schläpfer
- Institute of Anesthesiology, University Hospital Zurich, Zurich, Switzerland.,Institute of Physiology, Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - I K Herrmann
- Institute of Anesthesiology, University Hospital Zurich, Zurich, Switzerland
| | - M Hasler
- Institute of Anesthesiology, University Hospital Zurich, Zurich, Switzerland
| | - R R Schimmer
- Institute of Physiology, Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - C Booy
- Institute of Anesthesiology, University Hospital Zurich, Zurich, Switzerland.,Institute of Physiology, Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - B Roth Z'graggen
- Institute of Physiology, Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,Functional Genomics Center Zurich, University of Zurich, Zurich, Switzerland
| | - H Rehrauer
- Functional Genomics Center Zurich, University of Zurich, Zurich, Switzerland
| | - F Aigner
- Institute of Physiology, Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - R D Minshall
- Department of Anesthesiology, University of Illinois Chicago, Chicago, IL, USA
| | - W J Stark
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, Zurich, Switzerland
| | - B Beck-Schimmer
- Institute of Anesthesiology, University Hospital Zurich, Zurich, Switzerland.,Institute of Physiology, Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,Department of Anesthesiology, University of Illinois Chicago, Chicago, IL, USA
| |
Collapse
|
9
|
Abstract
In 12 consecutive cases of epithelial ingrowth operated on during the past 50 months, therapy included photocoagulation on the iris followed by excision of involved iris tissue and vitreous gel by means of instruments designed for vitreous surgery. Epithelium remaining on the posterior surface of the cornea, the ciliary body, and in the anterior chamber was destroyed by controlled transcorneal and transscleral cryotherapy. An intraocular air bubble was used to provide an insulating effect and a more effective, controllable freeze. All patients except two had improved vision postoperatively, and 3 of the 12 patients has postoperative visual acuity of 6/12 (20/40) or better. Similar closed-eye cryodestructive techniques have been used for treatment of enlarging epithelial cysts.
Collapse
|
10
|
Abstract
Instruments designed for pars plana vitrectomy can be used to manage complicated congenital cataracts such as those with persistent hyperplastic primary vitreous (PHPV). We have applied closed-eye vitrectomy techniques through a limbal approach in seven eyes with PHPV. A clear pupillary space was achieved in all cases. The management of children with complicated congenital cataracts such as PHPV is discussed.
Collapse
|
11
|
Bernitsky DA, Stark WJ, McCartney DL, Wong SK, Maumenee AE. Current concepts in intraocular lens implantation. Dev Ophthalmol 2015; 14:146-51. [PMID: 3498656 DOI: 10.1159/000414382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
PC IOLs appear to be safe and effective and there are few contraindications. Based on the available data we feel confident about implanting PC IOLs in healthy eyes of patients aged 40 or older. For younger patients, we do not recommended an IOL unless glasses or contact lens use is not feasible. Caution is urged however in the use of semiflexible, closed-loop AC IOLs as well as 'soft' PC IOLs. Other questions regarding material of choice, bag versus sulcus fixation, and UV absorbers remain controversial.
Collapse
Affiliation(s)
- D A Bernitsky
- Wilmer Ophthalmological Institute, Johns Hopkins Hospital, Baltimore, Md
| | | | | | | | | |
Collapse
|
12
|
|
13
|
Koehler FM, Raso RA, Grass RN, Stark WJ. β-D-glucosidase assisted gold dissolution as non-optical and quantifiable detection technique for immunoassays. Small 2013; 9:4000-4005. [PMID: 23670861 DOI: 10.1002/smll.201300925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Indexed: 06/02/2023]
Abstract
Immunoassays are used for detecting protein targets for various applications. Here, a modification of immunoassays to allow a purely electrical detection of the target protein concentration is shown. The modification comprises a β-D-glucosidase as reporter enzyme and a cyanogenic glycoside as substrate. The enzymatic reaction produces cyanide in small quantities. For electrical detection of the cyanide, a novel sensor is developed, based on a gold micro wire. The cyanide dissolves the gold wire and changes the electrical resistance of the wire. Monitoring the resistance change allows a quantitative measurement of the target human C-reactive protein (an inflammatory marker) in blood plasma in the physiological relevant concentration range.
Collapse
Affiliation(s)
- F M Koehler
- Institute of Chemical- and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland, Fax: (+) 41 44 633 15 71
| | | | | | | |
Collapse
|
14
|
Rotzetter ACC, Kellenberger CR, Schumacher CM, Mora C, Grass RN, Loepfe M, Luechinger NA, Stark WJ. Combining phosphate and bacteria removal on chemically active filter membranes allows prolonged storage of drinking water. Adv Mater 2013; 25:6057-6063. [PMID: 23913409 DOI: 10.1002/adma.201303119] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Indexed: 06/02/2023]
Abstract
A chemically active filtration membrane with incorporated lanthanum oxide nanoparticles enables the removal of bacteria and phosphate at the same time and thus provides a simple device for preparation of drinking water and subsequent safe storage without using any kind of disinfectants.
Collapse
Affiliation(s)
- A C C Rotzetter
- Institute for Chemical and Bioengineering, ETH Zurich, 8093, Zurich, Switzerland
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Rotzetter ACC, Schumacher CM, Bubenhofer SB, Grass RN, Gerber LC, Zeltner M, Stark WJ. Thermoresponsive polymer induced sweating surfaces as an efficient way to passively cool buildings. Adv Mater 2012; 24:5352-5356. [PMID: 22933383 DOI: 10.1002/adma.201202574] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Indexed: 06/01/2023]
Abstract
Buildings can be effectively cooled by a bioinspired sweating-like action based on thermoresponsive hydrogels (PNIPAM), which press out their stored water when exceeding the lower critical solution temperature. The surface temperature is reduced by 15 °C compared to that of a conventional hydrogel (pHEMA) and by 25 °C compared to the bare ground.
Collapse
Affiliation(s)
- A C C Rotzetter
- Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich, Switzerland
| | | | | | | | | | | | | |
Collapse
|
16
|
Athanassiou EK, Grass RN, Stark WJ. One-step large scale gas phase synthesis of Mn(2 + ) doped ZnS nanoparticles in reducing flames. Nanotechnology 2010; 21:215603. [PMID: 20431199 DOI: 10.1088/0957-4484/21/21/215603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Metal sulfide nanoparticles have attracted considerable interest because of their unique semiconducting and electronic properties. In order to prepare these fascinating materials at an industrial scale, however, solvent-free, dry processes would be most advantageous. In the present work, we demonstrate how traditional oxide nanoparticle synthesis in flames can be extended to sulfides if we apply a careful control on flame gas composition and sulfur content. The ultra-fast (<1 ms) gas phase kinetics at elevated temperatures allow direct sulfidization of metals in flames ([Formula: see text]). As a representative example, we prepared air-stable Mn(2 + ) doped zinc sulfide nanoparticles. Post-sintering of the initially polycrystalline nanopowder resulted in a material of high crystallinity and improved photoluminescence. An analysis of the thermodynamics, gas composition, and kinetics in these reducing flames indicates that the here-presented extension of flame synthesis provides access to a broad range of metal sulfide nanoparticles and offers an alternative to non-oxide phosphor preparation.
Collapse
Affiliation(s)
- E K Athanassiou
- Institute for Chemical and Bioengineering, ETH Zurich, Zurich, CH-8093, Switzerland
| | | | | |
Collapse
|
17
|
Herrmann IK, Urner M, Koehler FM, Schimmer BB, Stark WJ. Therapeutic blood purification using functionalized core/shell nanomagnets. Crit Care 2010. [PMCID: PMC2934481 DOI: 10.1186/cc8643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
| | - M Urner
- University Hospital Zurich, Switzerland
| | | | | | | |
Collapse
|
18
|
Bubenhofer SB, Athanassiou EK, Grass RN, Koehler FM, Rossier M, Stark WJ. Magnetic switching of optical reflectivity in nanomagnet/micromirror suspensions: colloid displays as a potential alternative to liquid crystal displays. Nanotechnology 2009; 20:485302. [PMID: 19880975 DOI: 10.1088/0957-4484/20/48/485302] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Two-particle colloids containing nanomagnets and microscale mirrors can be prepared from iron oxide nanoparticles, microscale metal flakes and high-density liquids stabilizing the mirror suspension against sedimentation by matching the constituent's density. The free Brownian rotation of the micromirrors can be magnetically controlled through an anisotropic change in impulse transport arising from impacts of the magnetic nanoparticles onto the anisotropic flakes. The resulting rapid mirror orientation allows large changes in light transmission and switchable optical reflectivity. The preparation of a passive display was conceptually demonstrated through colloid confinement in a planar cavity over an array of individually addressable solenoids and resulted in 4 x 4 digit displays with a reaction time of less than 100 ms.
Collapse
Affiliation(s)
- S B Bubenhofer
- Institute for Chemical and Bioengineering, ETH Zurich, Zurich CH-8093, Switzerland
| | | | | | | | | | | |
Collapse
|
19
|
Waltimo T, Mohn D, Paqué F, Brunner TJ, Stark WJ, Imfeld T, Schätzle M, Zehnder M. Fine-tuning of bioactive glass for root canal disinfection. J Dent Res 2009; 88:235-8. [PMID: 19329456 DOI: 10.1177/0022034508330315] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
An ideal preparation of 45S5 bioactive glass suspensions/slurries for root canal disinfection should combine high pH induction with capacity for continuing release of alkaline species. The hypothesis of this study was that more material per volume of bioactive glass slurry is obtained with a micrometric material (< 5 microm particle size) or a micrometric/ nanometric hybrid, rather than a solely nanometric counterpart. This should correlate with alkaline capacity and antimicrobial effectiveness. Slurries at the plastic limit were prepared with test and reference materials in physiological saline. Total mass and specific surface area of glass material per volume were determined. Continuous titration with hydrochloric acid was performed, and antimicrobial effectiveness was tested in extracted human premolars mono-infected with E. faecalis ATTC 29212 (N = 12 per material). While the nanometric slurry had a 12-fold higher specific surface area than the micrometric counterpart, the latter had a considerably higher alkaline capacity and disinfected significantly better (Fisher's exact test, P < 0.05). The hybrid slurry behaved similarly to the micrometric preparation.
Collapse
Affiliation(s)
- T Waltimo
- Institute of Oral Microbiology and Preventive Dentistry, University of Basel Center of Dental Medicine
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Fuhrer R, Athanassiou EK, Luechinger NA, Stark WJ. Crosslinking metal nanoparticles into the polymer backbone of hydrogels enables preparation of soft, magnetic field-driven actuators with muscle-like flexibility. Small 2009; 5:383-8. [PMID: 19180549 DOI: 10.1002/smll.200801091] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The combination of force and flexibility is at the core of biomechanics and enables virtually all body movements in living organisms. In sharp contrast, presently used machines are based on rigid, linear (cylinders) or circular (rotator in an electrical engine) geometries. As a potential bioinspired alternative, magnetic elastomers can be realized through dispersion of micro- or nanoparticles in polymer matrices and have attracted significant interest as soft actuators in artificial organs, implants, and devices for controlled drug delivery. At present, magnetic particle loss and limited actuator strength have restricted the use of such materials to niche applications. We describe the direct incorporation of metal nanoparticles into the backbone of a hydrogel and application as an ultra-flexible, yet strong magnetic actuator. Covalent bonding of the particles prevents metal loss or leaching. Since metals have a far higher saturation magnetization and higher density than oxides, the resulting increased force/volume ratio afforded significantly stronger magnetic actuators with high mechanical stability, elasticity, and shape memory effect.
Collapse
Affiliation(s)
- Roland Fuhrer
- ETH Zurich, Institute for Chemical and Bioengineering, HCI E107, Zurich, Switzerland
| | | | | | | |
Collapse
|
21
|
Athanassiou EK, Krumeich F, Grass RN, Stark WJ. Advanced piezoresistance of extended metal-insulator core-shell nanoparticle assemblies. Phys Rev Lett 2008; 101:166804. [PMID: 18999701 DOI: 10.1103/physrevlett.101.166804] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Indexed: 05/27/2023]
Abstract
Assembled metal-insulator nanoparticles with a core-shell geometry provide access to materials containing a large number (>10(6)) of tunneling barriers. We demonstrate the production of ceramic coated metal nanoparticles exhibiting an exceptional pressure-sensitive conductivity. We further show that graphene bi- and trilayers on 20 nm copper nanoparticles are insulating in such a core-shell geometry and show a similar pressure-dependent conductivity. This demonstrates that core-shell metal-insulator assemblies offer a route to alternative sensing materials.
Collapse
Affiliation(s)
- E K Athanassiou
- Institute for Chemical and Bioengineering, ETH Zürich, Zurich, Switzerland
| | | | | | | |
Collapse
|
22
|
Abstract
AIM To test whether bioactive glasses kill microbiota via mineralization or the release of ions other than sodium. METHODOLOGY Flame-spray synthesis was applied to produce nanometric glasses of different sodium content and constant Ca/P ratio: 28S5, 45S5 and 77S. Calcium hydroxide and nanometric tricalcium phosphate (TCP) were used as controls. Apatite induction was monitored by Raman spectroscopy. Bovine dentine disks with adherent Enterococcus faecalis cells were exposed to test and control suspensions or buffered solutions for 1 h, 1 day and 1 week. Colony-forming units were counted and disks were inspected using scanning electron microscopy. Suspension supernatants and solutions were analysed for their pH, osmolarity, calcium and silicon content. RESULTS Sodium containing glasses induced pH levels above 12, compared with less than pH 9 with sodium-free 77S. Calcium hydroxide, 45S5 and 28S5 killed all bacteria after 1 day and lysed them after 1 week. TCP caused the highest apatite induction and substantial calcification on bacteria adhering to dentine, but did not reduce viable counts. 77S achieved disinfection after 1 week without visible apatite formation, whilst the buffer solution at pH 9 caused only minimal reduction in counts. CONCLUSION Bioactive glasses have a directly and an indirectly pH-related antibacterial effect. The effect not directly linked to pH is because of ion release rather than mineralization.
Collapse
Affiliation(s)
- M Gubler
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | | | | | | | | | | |
Collapse
|
23
|
Halim SC, Brunner TJ, Grass RN, Bohner M, Stark WJ. Preparation of an ultra fast binding cement from calcium silicate-based mixed oxide nanoparticles. Nanotechnology 2007; 18:395701. [PMID: 21730426 DOI: 10.1088/0957-4484/18/39/395701] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Building construction takes time, in part because the binding process of cement is based on the slow re-crystallization and precipitation of calcium silicate species. Since the material's reactivity is surface area limited, a reduction in particle size of Portland cements has been used to prepare faster binding formulations. The present work investigates a new and direct, one-step preparation of calcium silicate-based nanoparticles of a typical Portland cement composition by flame spray synthesis. Isothermal calorimetry revealed that the hardening of this new nano-cement corroborated a more than tenfold increase of initial reactivity with different reaction kinetics if compared to conventionally prepared cements. At present, the unfavourably high porosity of nano-cements, however, underlines the need for additional improvements of chemical composition and formulation to make these highly reactive materials applicable to modern construction work, where load-bearing strength is of importance.
Collapse
Affiliation(s)
- S C Halim
- Institute for Chemical and Bioengineering ETH Zurich, 8093 Zurich, Switzerland
| | | | | | | | | |
Collapse
|
24
|
Marending M, Luder HU, Brunner TJ, Knecht S, Stark WJ, Zehnder M. Effect of sodium hypochlorite on human root dentine – mechanical, chemical and structural evaluation. Int Endod J 2007; 40:786-93. [PMID: 17697105 DOI: 10.1111/j.1365-2591.2007.01287.x] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To investigate the mechanical, chemical and structural alterations of human root dentine following exposure to ascending sodium hypochlorite concentrations. METHODOLOGY Three-point bending tests were carried out on standardized root dentine bars (n = 8 per group, sectioned from sound extracted human third molar teeth) to evaluate their flexural strength and modulus of elasticity after immersion in 5 mL of water (control), 1% NaOCl, 5% NaOCl or 9% NaOCl at 37 degrees C for 1 h. Additional dentine specimens were studied using microelemental analysis, light microscopy following bulk staining with basic fuchsin, and scanning electron microscopy (SEM). Numerical data were compared using one-way ANOVA. Bonferroni's correction was applied for multiple testing. RESULTS Immersion in 1% NaOCl did not cause a significant drop in elastic modulus or flexural strength values in comparison to water, whilst immersion in 5% and 9% hypochlorite reduced these values by half (P < 0.05). Both, carbon and nitrogen contents of the specimens were significantly (P < 0.05) reduced by 5% and 9% NaOCl, whilst 1% NaOCl had no such effect. Exposure to 5% NaOCl rendered the superficial 80-100 mum of the intertubular dentine permeable to basic fuchsin. Three-dimensional SEM reconstructions of partly demineralized specimens showed NaOCl concentration-dependent matrix deterioration. Backscattered electron micrographs revealed that hypochlorite at any of the tested concentrations left the inorganic dentine components intact. CONCLUSIONS The current data link the concentration-dependent hypochlorite effect on the mechanical dentine properties with the dissolution of organic dentine components.
Collapse
Affiliation(s)
- M Marending
- Division of Endodontology, Department of Preventive Dentistry, Periodontology, and Cariology, University of Zürich Center of Dental Medicine, Zürich, Switzerland
| | | | | | | | | | | |
Collapse
|
25
|
Abstract
Most recent advances in nanomaterials fabrication have given access to complex materials such as SiO(2)-Na(2)O-CaO-P(2)O(5) bioactive glasses in the form of amorphous nanoparticles of 20- to 60-nm size. The clinically interesting antimicrobial properties of commercially available, micron-sized bioactive glass 45S5 have been attributed to the continuous liberation of alkaline species during application. Here, we tested the hypothesis that, based on its more than ten-fold higher specific surface area, nanometric bioactive glass releases more alkaline species, and consequently displays a stronger antimicrobial effect, than the currently applied micron-sized material. Ionic dissolution profiles were monitored in simulated body fluid. Antimicrobial efficacy was assessed against clinical isolates of enterococci from persisting root canal infections. The shift from micron- to nano-sized treatment materials afforded a ten-fold increase in silica release and solution pH elevation by more than three units. Furthermore, the killing efficacy was substantially higher with the new material against all tested strains.
Collapse
Affiliation(s)
- T Waltimo
- Institute of Oral Microbiology and Preventive Dentistry, University of Basel Center of Dental Medicine, Switzerland
| | | | | | | | | |
Collapse
|
26
|
Grass RN, Dietiker M, Solenthaler C, Spolenak R, Stark WJ. Grain growth resistance and increased hardness of bulk nanocrystalline fcc cobalt prepared by a bottom-up approach. Nanotechnology 2007; 18:035703. [PMID: 19636134 DOI: 10.1088/0957-4484/18/3/035703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Bulk nanocrystalline cobalt was prepared from reducing flame-spray-derived cobalt nanopowders exclusively in the face-centred cubic (fcc) modification. Compacts of approximately 60% density were obtained from uniaxial compression at room temperature and showed a strong resistance towards grain growth upon subsequent sintering to 90% relative density. The nanocrystalline structure remained stable well above 1000 degrees C and resulted in a pore-rich metal with about 10(15) nanovoids cm(-3). These sintered compacts displayed an up to three times higher bulk hardness if compared to conventional cobalt and local ductility as evidenced from scanning electron microscopy and nanoindentation. The strong grain-growth resistance and consequent increase in material hardness are discussed in respect of the presence of nanovoids, twin boundaries and material contamination.
Collapse
Affiliation(s)
- R N Grass
- Institute for Chemical and Bioengineering, ETH Zurich, CH-8093 Zurich, Switzerland. Materials Research Center, ETH Zurich, CH-8093 Zurich, Switzerland
| | | | | | | | | |
Collapse
|
27
|
Abstract
Copper nanoparticles with a mean carbon coating of about 1 nm were continuously produced at up to 10 g h(-1) using a modified flame spray synthesis unit under highly reducing conditions. Raman spectroscopy and solid state (13)C magic angle spinning nuclear magnetic resonance spectroscopy revealed that the thin carbon layer consisted of a sp(2)-hybridized carbon modification in the form of graphene stacks. The carbon layer protected the copper nanoparticles from oxidation in air. Bulk pills of pressed carbon/copper nanoparticles displayed a highly pressure- and temperature-dependent electrical conductivity with sensitivity at least comparable to commercial materials. These properties suggest the use of thin carbon/copper nanocomposites as novel, low-cost sensor materials and offer a metal-based alternative to the currently used brittle oxidic spinels or perovskites.
Collapse
Affiliation(s)
- E K Athanassiou
- Institute for Chemical and Bioengineering, ETH Zurich, 8093 Zurich, Switzerland
| | | | | |
Collapse
|
28
|
Stark WJ, Goyal RK, Awad O, Vito E, Kouzis AC. The safety and efficacy of combined phacoemulsification and trabeculectomy with releasable sutures. Br J Ophthalmol 2006; 90:146-9. [PMID: 16424522 PMCID: PMC1860160 DOI: 10.1136/bjo.2005.078212] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
AIM To evaluate the combined phacoemulsification with acrylic intraocular lens implantation and trabeculectomy with releasable sutures, without the use of antimetabolites, performed by one surgeon. METHODS A retrospective analysis was performed on 251 eyes of 198 patients after a combined phaco/trabeculectomy procedure, followed up for an average of 16 months for vision, intraocular pressure (IOP), and number of glaucoma medications. Cox proportional hazard regression analysis provided measures of relative risk (RR) or hazards ratios and 95% confidence intervals (CIs) associated with the occurrence of several conditions or complications of surgery. RESULTS Mean preoperative variables were best corrected vision, 0.6 (SD 0.4) logMAR (20/80 Snellen); IOP, 18.7 (4.9) mm Hg; and number of glaucoma medications, 1.7 (0.8). Mean postoperative results were best corrected vision, 0.2 (0.4) logMAR (20/32 Snellen); IOP, 15.1 (3.2) mm Hg; and number of glaucoma medications, 0.3 (0.6). Postoperatively, the mean decreases from baseline were 19.2% for IOP and 84.1% for number of glaucoma medications; 85% of eyes required fewer glaucoma medications and 78% of eyes were medication free, with IOP control. There were no significant operative or postoperative complications. CONCLUSION Combined phacoemulsification and trabeculectomy with releasable sutures, in the absence of antimetabolites, is a safe, effective, and stable alternative for patients with cataracts and glaucoma.
Collapse
Affiliation(s)
- W J Stark
- 600 N Wolfe Street, Maumenee 327, Baltimore, MD 21287, USA.
| | | | | | | | | |
Collapse
|
29
|
Suwan-apichon O, Rizen M, Reyes JMG, Herretes S, Behrens A, Stark WJ, Chuck RS. A new donor cornea harvesting technique for posterior lamellar keratoplasty. Br J Ophthalmol 2005; 89:1100-1. [PMID: 16113357 PMCID: PMC1772800 DOI: 10.1136/bjo.2004.064337] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To describe a technique for posterior lamellar keratoplasty donor preparation. METHODS In an experimental study eight human donor research corneas were mounted onto an artificial anterior chamber and deep stromal pockets dissected. Four corneas were mounted in the standard endothelial side down orientation and dissected using standard instruments (group 1). Another four corneas were mounted endothelial side up and dissected using a flat spatula (group 2). Trephined lamellar graft thickness was assessed by ultrasound pachymetry. The grafts were also analysed using vital staining of the endothelium and standard histological preparation. RESULTS Achieved posterior graft thickness was 118 (SD 32) microm (group 1) and 92 (23) microm (group 2) (p=0.324). Percentage of devitalised endothelial cells was 0.86% (1.48%) (group 1) and 3.9% (2.9%) (group 2) (p=0.185). The dissections using both harvesting techniques remained in plane and were smooth. CONCLUSIONS A blunt spatula and endothelium side up orientation on an artificial anterior chamber can be used to create posterior lamellar dissections without compromising endothelial cell number or planarity when compared to standard endothelium side down harvest.
Collapse
Affiliation(s)
- O Suwan-apichon
- Wilmer Ophthalmological Institute, Johns Hopkins University, 3-127 Jefferson Building, 600 North Wolfe Street, Baltimore, MD 21287-9278, USA
| | | | | | | | | | | | | |
Collapse
|
30
|
|
31
|
Affiliation(s)
- N S Jabbur
- The Wilmer Eye Institute at Greenspring Station, 10755 Falls Rd, Suite 110, Baltimore, MD 21093, USA
| | | | | |
Collapse
|
32
|
Abstract
OBJECTIVES To use microarray analysis to identify genes expressed in human donor corneas and to create a preliminary, comprehensive database of human corneal gene expression. METHODS A complementary DNA (cDNA) library was constructed from transplant-quality, human donor corneas. Biotin-labeled RNA was transcribed from the cDNA library and hybridized in duplicate to microarrays containing approximately 5600 human genes. Results were analyzed using a gene database of the National Institutes of Health, Bethesda, Md. Reverse transcriptase polymerase chain reaction analysis was performed to confirm corneal expression of genes identified by microarray analysis. RESULTS Duplicate microarrays identified the expression of 1200 genes in human donor corneas. Chromosomal loci had been assigned to 1025 (85%) of these genes. A preliminary database of human corneal gene expression was compiled. A Web site containing these genes was created. Six collagen genes were identified that had not previously been localized within the cornea. Five apoptosis-related genes were identified, 4 of which had not previously been localized within the cornea. Three genes previously shown to cause corneal diseases were identified. Reverse transcriptase polymerase chain reaction analysis of genes identified by microarray analysis confirmed the corneal expression of 2 apoptosis-related genes and 1 collagen gene. CONCLUSIONS Microarray analysis of healthy human donor corneas has produced a preliminary, comprehensive database of corneal gene expression. Large-scale analysis of gene expression has the potential to generate large amounts of data, which should be made readily accessible to the scientific community. The Internet offers many potential advantages as a medium for the maintenance of these large data sets. CLINICAL RELEVANCE Identification of structural, apoptosis-related, and disease-causing genes within the cornea by microarrays may increase the understanding of normal and abnormal corneal function with likely relevance to corneal diseases and transplants.
Collapse
Affiliation(s)
- A S Jun
- Cornea and External Disease Division, Wilmer Ophthalmological Institute, The Johns Hopkins Medical Institutions, Maumenee 317, 600 N Wolfe St, Baltimore, MD 21287, USA
| | | | | | | | | | | |
Collapse
|
33
|
Li QJ, Ashraf MF, Shen DF, Green WR, Stark WJ, Chan CC, O'Brien TP. The role of apoptosis in the pathogenesis of Fuchs endothelial dystrophy of the cornea. Arch Ophthalmol 2001; 119:1597-604. [PMID: 11709009 DOI: 10.1001/archopht.119.11.1597] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To investigate the potential role of apoptosis in the pathogenesis of Fuchs endothelial dystrophy of the cornea. METHODS Twenty-one corneal buttons from patients with Fuchs dystrophy and 15 control corneas were studied. Apoptosis was assessed by the in situ end-labeling of double-stranded DNA breaks, and by immunohistochemical characterization of cellular markers associated with apoptosis (Fas, FasL, Bcl-2, and Bax). Expression of Bcl-2 and Bax mRNA in the corneal stroma and endothelium was separately analyzed by a semiquantitative reverse transcriptase polymerase chain reaction. Furthermore, cultivated keratocytes generated from diseased corneal buttons and donor rims were exposed to camptothecin, an apoptotic inducer, for 6 and 24 hours. They were then examined for protein and messenger RNA (mRNA) expression of apoptotic regulatory molecules. RESULTS DNA fragmentation was seen in the epithelium, stroma, and endothelium in 6 of 7 corneas with Fuchs dystrophy. A statistically significant difference was identified in the expression of Bax and its mRNA in the stroma, but not in the endothelium of Fuchs dystrophy corneas. Following exposure to camptothecin, keratocytes from patients with Fuchs dystrophy responded with an increased level of Bax and a low level of Bcl-2. This trend was distinctively different from the response of normal keratocytes. CONCLUSIONS The evidence in this study points to a disease-related disturbance in the regulation of apoptosis in Fuchs dystrophy. Our findings suggest that excessive apoptosis may be an important mechanism in the pathogenesis of Fuchs dystrophy.
Collapse
Affiliation(s)
- Q J Li
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, 600 N Wolfe St, Woods Bldg, Room 255, Baltimore, MD, USA
| | | | | | | | | | | | | |
Collapse
|
34
|
Akpek EK, Altan-Yaycioglu R, Gottsch JD, Stark WJ. Spontaneous corneal perforation in a patient with unusual unilateral pellucid marginal degeneration. J Cataract Refract Surg 2001; 27:1698-700. [PMID: 11687374 DOI: 10.1016/s0886-3350(01)00792-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A 56-year-old man presented with acute loss of vision and tearing in his left eye. Slitlamp examination demonstrated peripheral corneal edema extending between the 2 and 6 o'clock positions as well as a perforation located inferiorly. The right eye was unremarkable. An emergent crescentic lamellar keratoplasty was performed. The patch graft remained clear during the 30-month follow-up, and visual acuity improved significantly. No changes occurred in the right eye. This case represents an unusual, unilateral corneal ectatic disorder, most likely pellucid marginal degeneration.
Collapse
Affiliation(s)
- E K Akpek
- Cornea and External Disease Service, Wilmer Eye Institute, Johns Hopkins Medical School, Baltimore, Maryland21287-9238, USA.
| | | | | | | |
Collapse
|
35
|
Abstract
PURPOSE To report the preoperative, operative, and postoperative factors associated with phacoemulsification cataract surgery in adults with retinopathy of prematurity. METHODS Records of patients with retinopathy of prematurity who underwent phacoemulsification at The Wilmer Institute between January 1990 and January 2000 were retrospectively searched. Seventeen adults (9 women, 8 men) with retinopathy of prematurity were identified who had undergone phacoemulsification for visually significant cataract or phacomorphic glaucoma and who had at least 6 months of postoperative follow-up. RESULTS Cataract extraction by phacoemulsification was performed on 20 eyes. Follow-up ranged from 6 to 103 months (mean, 32 months). A posterior chamber intraocular lens was placed in 18 eyes; two eyes were left aphakic for refractive reasons. Zonular weakness was noted in two eyes in which the intraocular lens was suture fixated to the sclera. Concomitant trabeculectomy was performed in one eye. Visual acuity improved in 18 of 20 eyes and remained unchanged in two eyes. Postoperatively, visual acuity was worse than 5/200 in two eyes, 5/200 to worse than 20/100 in five eyes, 20/100 to 20/50 in five eyes, and 20/40 or better in eight eyes. One eye developed a rhegmatogenous retinal detachment 1 month after cataract surgery; the retina was successfully reattached. CONCLUSIONS Although cataract extraction in eyes with regressed retinopathy of prematurity may present challenges, such as high myopia, monocularity, glaucoma, and previous ocular surgery, phacoemulsification in this series proved to be relatively safe as well as visually rehabilitating. The surgeon should be aware of the special considerations in this population, alert to potential zonular weakness intraoperatively, and careful of increased postoperative risks, including retinal detachment.
Collapse
Affiliation(s)
- A K Farr
- The Wilmer Ophthalmological Institute, The Johns Hopkins Hospitals, Baltimore, MD 21287-9028, USA.
| | | | | |
Collapse
|
36
|
Abstract
There have been no comprehensive investigations of striae after LASIK. The ophthalmic literature has few reports, and no one consistent therapy has been recommended. Striae are relatively uncommon; nevertheless, refractive surgeons need a systematic approach in prevention and therapy for striae. Careful flap handling and positioning can prevent many striae. Early recognition is very important and makes treatment significantly more likely to eliminate or reduce the striae. If the striae are identified within 24 hours, lifting and refloating will likely result in resolution of the striae. If the striae are more imbedded and have been present longer, additional techniques, such as those discussed, are helpful. New techniques will likely be developed because of an increase in lamellar procedures and an increase in the occurrence of striae.
Collapse
Affiliation(s)
- P von Kulajta
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD 21287, USA
| | | | | |
Collapse
|
37
|
Li Q, Ashraf MF, Bekoe NA, Stark WJ, Chan CC, O'Brien TP. The role of apoptosis in the early corneal wound healing after excimer laser keratectomy in the rat. Graefes Arch Clin Exp Ophthalmol 2000; 238:853-60. [PMID: 11127573 DOI: 10.1007/s004170000182] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND The potential role of apoptosis in corneal wound healing after excimer laser keratectomy was investigated in a rat model. METHODS Lewis rats underwent laser keratectomy using a 193-nm excimer laser. The central corneas were ablated in three depths: group A, epithelium; group B, superficial stroma; group C, deep stroma. Eyes were collected at 1, 12, 24, and 36 h and 1 week. Cellular markers associated with apoptosis--Fas, Fas ligand (FasL), Bcl-2, and Bax were examined by immunohistochemistry. Keratocyte depletion and endothelial changes were evaluated histologically. In situ end labeling of double-stranded DNA breaks was used to demonstrate apoptosis in corneal sections. RESULTS Keratocyte depletion was observed in 6 (50%) of 12 rats (total from groups A, B, and C) at 12 h, 11 (73%) of 15 at 24 h, 3 (20%) of 15 at 36 h, and 2 (15%) of 13 at 1 week after laser surgery. Corneal endothelial edema was observed in the ablation zone. Expression of Fas, FasL, Bcl-2, and Bax in corneal cells showed dynamics similar to that of keratocyte depletion and endothelial changes. There was less expression of apoptotic molecules in newly generated epithelial cells and more in endothelial cells of the stromal ablation groups. CONCLUSIONS Excimer laser keratectomy triggered apoptosis of corneal keratocytes and endothelial cells. More endothelial edema was observed in the stromal ablation than in the epithelial ablation group. The expression of apoptotic molecules coincided with the period of keratocyte depletion and regeneration and of endothelial recovery, suggesting that apoptosis is a dynamic part of corneal wound healing and remodeling after excimer laser keratectomy.
Collapse
Affiliation(s)
- Q Li
- Refractive Surgery Research, The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287-9121, USA
| | | | | | | | | | | |
Collapse
|
38
|
Abstract
PURPOSE To report the clinical history and surgical management of recurrent congenital iris stromal cyst. METHOD Case report. Argon laser endophotocoagulation and cryotherapy were used to treat a recurrent iris stromal cyst in an 18-month-old boy. RESULTS At 43 months of follow-up, there was no recurrence or evidence of epithelial ingrowth. CONCLUSION Treatment with argon laser endophotocoagulation and cryotherapy resulted in complete resolution of a recurrent congenital iris cyst.
Collapse
Affiliation(s)
- S Y Shin
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | | | | |
Collapse
|
39
|
|
40
|
Barequet IS, Li Q, Wang Y, O'Brien TP, Hooks JJ, Stark WJ. Herpes simplex virus DNA identification from aqueous fluid in Fuchs heterochromic iridocyclitis. Am J Ophthalmol 2000; 129:672-3. [PMID: 10844066 DOI: 10.1016/s0002-9394(00)00409-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To report the presence of herpes simplex virus DNA in the aqueous humor of an eye with Fuchs heterochromic iridocyclitis. METHODS In an eye with a clinical diagnosis of Fuchs heterochromic iridocyclitis, samples of aqueous humor and anterior capsule of the lens were obtained during cataract surgery. Polymerase chain reaction was performed on the samples to detect the presence of viral DNA including herpes simplex virus, varicella-zoster virus, and cytomegalovirus. Serologic analysis was also performed for antiviral immunoglobulins. RESULTS Herpes simplex virus DNA was identified in the aqueous humor but not in the anterior capsule. Serum immunoglobulin G was positive for herpes simplex virus, varicella-zoster virus, and cytomegalovirus. CONCLUSIONS The presence of herpes simplex virus DNA in the aqueous humor of an eye with Fuchs heterochromic iridocyclitis suggests that herpes simplex virus infection may play a role in the pathogenesis of Fuchs heterochromic iridocyclitis.
Collapse
Affiliation(s)
- I S Barequet
- The Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | | | | | | | | | | |
Collapse
|
41
|
Abstract
We report on 4 patients who developed superficial corneal fibrosis after radial keratotomy. All 4 were treated successfully with manual debridement of the epithelium and manual excision of the fibrous scar, followed by phototherapeutic keratectomy.
Collapse
Affiliation(s)
- Y C Fong
- Doheny Eye Institute, University of Southern California, Los Angeles, CA, USA
| | | | | | | |
Collapse
|
42
|
Davis EA, Stark WJ. The triple procedure--is it the best approach for the patient? The triple procedure may be superior to sequential surgery. Arch Ophthalmol 2000; 118:414-5. [PMID: 10721968 DOI: 10.1001/archopht.118.3.414] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- E A Davis
- Cornea and External Disease Service, The Wilmer Eye Institute at Johns Hopkins, Baltimore, MD 21287, USA
| | | |
Collapse
|
43
|
Beck RW, Gal RL, Mannis MJ, Holland EJ, Cavanagh HD, Foulks GN, Heck EL, Lindquist T, Macsai MS, Smith RE, Stark WJ, Stulting RD, Sugar J. Is donor age an important determinant of graft survival? Cornea 1999; 18:503-10. [PMID: 10487423 DOI: 10.1097/00003226-199909000-00001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- R W Beck
- Jaeb Center for Health Research, Tampa, Florida 33613, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Abstract
The authors have identified a corneal stromal protein (CO-Ag) that may be involved in the pathogenesis of Mooren's ulcer. The CO-Ag cDNA sequence is identical to that of human neutrophil calgranulin C (CaGC). This study sought to demonstrate expression of the CaGC gene in the human cornea and in corneal keratocytes after cytokine stimulation. In situ hybridization and immunohistochemistry were used to localize CaGC mRNA and protein in normal and diseased human corneas, including a specimen with Mooren's ulcer. Cultured bovine keratocytes were stimulated with IL-1 alpha or TNF-alpha, and reverse transcription polymerase chain reaction (RT-PCR) was performed to amplify CaGC cDNA from cytokine-stimulated keratocytes and unstimulated controls. Southern blotting verified the specificity of the RT-PCR amplification products. In situ hybridization detected human CaGC mRNA in the stroma of corneas with Fuchs' dystrophy, postinfection corneas, and a cornea with Mooren's ulcer. In cultured bovine keratocytes, peak levels of CaGC mRNA were reached 6 h after cytokine stimulation. Southern blots with an oligonucleotide probe specific for CaGC detected the RT-PCR products of expected sizes (273 bp) and confirmed that the amplified CO-Ag sequence was identical to that of CaGC. These studies are the first to demonstrate the presence of CaGC in the human cornea and the ability of stromal keratocytes to produce CaGC (CO-Ag). The up-regulation of CaGC gene expression by corneal keratocytes due to proinflammatory cytokines from trauma or inflammation may induce autoimmunity that ultimately results in Mooren's ulceration.
Collapse
Affiliation(s)
- J D Gottsch
- Wilmer Ophthalmological Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | | | | | | | | | | |
Collapse
|
45
|
Del Toro MF, Stark WJ, Bell WR. Aspirin intake and bleeding during cataract surgery. J Cataract Refract Surg 1999; 25:301-2. [PMID: 10079426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
|
46
|
O'Brien TP, Li Q, Ashraf MF, Matteson DM, Stark WJ, Chan CC. Inflammatory response in the early stages of wound healing after excimer laser keratectomy. Arch Ophthalmol 1998; 116:1470-4. [PMID: 9823348 DOI: 10.1001/archopht.116.11.1470] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To evaluate the inflammatory response and its potential role in the early stages of corneal wound healing after excimer laser keratectomy. MATERIALS AND METHODS Lewis rats underwent excimer keratectomy using a 193-nm excimer laser. The central corneas were ablated in 3 depths: group A, epithelium; group B, superficial stroma; or group C, deep stroma. Eyes were harvested 1, 12, 24, and 36 hours, and 1 week after the rats were killed. Immunohistochemistry was used to test frozen sections with monoclonal antibodies of various inflammatory cellular markers. RESULTS Reepithelialization was observed at 12 hours in group A, and at 24 hours in groups B and C. Regenerated epithelium covered the denuded corneal surface in groups B and C after 1 week. The expression of major histocompatibility complex II antigen was detected in infiltrating cells, corneal epithelial cells, and endothelial cells 1 hour after surgery. Only a few macrophages and Langerhans cells were in the limbus at baseline. Macrophages migrated from the limbus to the corneal ablation zone and increased 2-fold after 36 hours in all 3 groups compared with baseline. Occasional lymphocytic infiltration was identified after 25 to 36 hours. CONCLUSION Macrophages play an active role in the wound healing after laser keratectomy and may contribute to transient corneal haze.
Collapse
Affiliation(s)
- T P O'Brien
- Cornea Service, Wilmer Eye Institute, Johns Hopkins University, Baltimore, Md., USA
| | | | | | | | | | | |
Collapse
|
47
|
Abstract
PURPOSE To determine whether defensin genes are expressed in human corneas and bovine corneal keratocytes. METHODS In situ hybridization and immunohistochemistry were used to localize defensin mRNA and protein in normal and diseased human corneas. Cultured bovine keratocytes were stimulated with IL-1alpha or TNFalpha to determine whether defensin mRNA production occurred. Reverse transcription polymerase chain reaction (RT-PCR) was performed to amplify defensin cDNA from cytokine-induced keratocytes, and Southern blots were used to verify the specificity of RT-PCR amplification products. RESULTS Defensin mRNA and protein were not detected in normal human corneal stroma, but were readily detectable in the corneal stroma in cases of rejected transplants and postinfectious keratitis. IL-1alpha was a potent inducer of defensin gene expression in keratocytes, which began 12 h after challenge and peaked at 18 to 24 h. TNFalpha weakly induced defensin mRNA in keratocytes at about 18 h. Southern blots of the RT-PCR products probed with an oligonucleotide complementary to internal sequences of defensin demonstrated the appropriately sized products (198 bp) specific for defensin. CONCLUSIONS This report demonstrates the presence of defensin in the human cornea and the capacity of corneal keratocytes to produce defensin mRNA in response to IL-1alpha and TNFalpha. Release of defensins by keratocytes in response to cytokines elaborated in corneal inflammation may contribute to the host defense response in microbial keratitis.
Collapse
Affiliation(s)
- J D Gottsch
- Wilmer Ophthalmological Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | | | | | | | | |
Collapse
|
48
|
Abstract
Cataracts are the most common treatable form of reduced vision in older adults. Although the incidence of cataracts is high after age 65, careful history taking and clinical examination are essential to establish the diagnosis. Cataract surgery is medically indicated when the view to the retina is obscured or lens-induced disorders place the eye at risk for further damage. However, even when patients have no specific associated medical problem, other than decreased visual acuity, cataract extraction offers an important means for maintaining independence and improving quality of life.
Collapse
Affiliation(s)
- E W Trudo
- Ophthalmology Service, Walter Reed Army Medical Center, Washington, DC 20307-5001, USA
| | | |
Collapse
|
49
|
Davis EA, Azar DT, Jakobs FM, Stark WJ. Refractive and keratometric results after the triple procedure: experience with early and late suture removal. Ophthalmology 1998; 105:624-30. [PMID: 9544635 DOI: 10.1016/s0161-6420(98)94015-5] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE The objective of this study was to determine the outcome of early and late suture removal after the triple procedure (i.e., penetrating keratoplasty, cataract extraction, lens implant). DESIGN AND PARTICIPANTS The refractive and keratometric results of 106 eyes undergoing the triple procedure were reviewed. The target postoperative refractive error was -1 diopter (D). RESULTS Average length of follow-up was 40.3 months. Twenty eyes had sutures removed early (<18 months after surgery), 39 had sutures removed late (> or = 18 months after surgery), and 47 had sutures still intact at last follow-up. A best spectacle-corrected visual acuity of 20/40 or better was achieved in 90% of eyes with sutures removed early, 82.1% with sutures removed late, and 70.2% with sutures in place. For all eyes, the mean spherical equivalent at last follow-up was -2.50 D, with 75% of eyes falling between -4 and +2 D. The mean final refractive error was -3.40 +/- 3.53 D for eyes with sutures removed early and -1.79 +/- 3.99 D for eyes with sutures removed late. Eyes with sutures remaining had a mean final refractive error of -0.33 +/- 2.25 D. There was an overall decrease in refractive and keratometric astigmatism after both early and late suture removal with no significant difference between groups. However, there was a wide range of change with some eyes experiencing a decrease and others an increase in astigmatism. Mean postoperative K readings increased significantly for both groups after suture removal (final mean K, 47.00 D) but remained stable for eyes with sutures in. CONCLUSION The authors data suggest that the final refractive error and net change in refractive and keratometric astigmatism after the triple procedure are not dependent on the timing of suture removal.
Collapse
Affiliation(s)
- E A Davis
- Corneal and Refractive Surgery Service, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston 02114, USA
| | | | | | | |
Collapse
|
50
|
Azar DT, Stark WJ, Dodick J, Khoury JM, Vitale S, Enger C, Reed C. Prospective, randomized vector analysis of astigmatism after three-, one-, and no-suture phacoemulsification. J Cataract Refract Surg 1997; 23:1164-73. [PMID: 9368159 DOI: 10.1016/s0886-3350(97)80310-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE To compare surgically induced astigmatism and visual outcomes after three-, one-, and no-suture phacoemulsification. SETTING Johns Hopkins Hospital, Baltimore, Maryland and Manhattan Eye, Ear, and Throat Hospital, New York, New York, USA. METHODS This prospective, randomized study followed 131 patients treated with phacoemulsification with a 5.5 mm self-sealing scleral tunnel and implantation of a 5.5 mm poly(methyl methacrylate) posterior chamber lens. Radial 10-0 nylon sutures were used in the three- and one-suture groups. RESULTS Mean astigmatism was greatest in the first postoperative week in all groups and stabilized after 8 weeks. The percentage of patients with with-the-rule (WTR) astigmatism increased from baseline in the one- and three-suture groups and decreased in the sutureless group. Mean uncorrected Snellen acuity was significantly better in the no- and one-suture groups than in the three-suture group at 1 week. There were no significant differences in uncorrected acuity at other times. No statistically significant differences in the surgically induced spherical equivalent were noted among the three groups during the 1 year follow-up. There was significantly less surgically induced keratometric astigmatism in the one-suture group at 4 (P = .03) and 8 (P = .007) weeks postoperatively. At all follow-ups, the sutureless group had the greatest proportion of patients, with significant ATR astigmatic shift (1 week, 17%; 4 weeks, 32%); and the lowest proportion of patients with significant WTR astigmatic shift (10% after 1 week). At 4 weeks, the percentage of patients with significant WTR shift in the one-suture group dropped to that in the sutureless group (10%); however, those in the one-suture group had less ATR astigmatic shift (16%). CONCLUSION Sutureless and one-suture surgery resulted in a low percentage of WTR induced astigmatism 4 weeks postoperatively. Compared with sutureless surgery, the one-suture surgery resulted in less ATR shift.
Collapse
Affiliation(s)
- D T Azar
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, USA
| | | | | | | | | | | | | |
Collapse
|