Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Eye Contact Lens ; 48(9): 391-395, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36002944

RESUMO

OBJECTIVES: To compare ocular biometric parameters between Hispanic and non-Hispanic White adult patients undergoing cataract surgery. METHODS: We included 433 adult patients undergoing surgery for senile cataract. Only patients with race and ethnicities of Hispanic and non-Hispanic White were included. The following parameters measured by the IOLMaster 700 were compared between Hispanic and non-Hispanic patients: mean keratometry, corneal astigmatism, anterior chamber depth (ACD), lens thickness, vitreous length, axial length, white-to-white diameter, and emmetropic intraocular lens power. RESULTS: There were 219 Hispanic patients and 214 non-Hispanic patients with a mean age of 70.1±7.7 years (range, 50-88 years), and 66.7% were women. Although sex distribution was similar between the two groups, Hispanic patients had a lower age compared with non-Hispanic patients (69.3±8.3 vs. 70.9±6.9 years, P=0.02). In biometric values, ACD was significantly lower in Hispanic patients (3.07±0.40 mm) than in non-Hispanic patients (3.16±0.37 mm, P=0.01). Such statistically significant difference persisted after adjustment for age and sex (P=0.01). No other significant differences were found in other ocular parameters measured. CONCLUSIONS: Anterior chamber depth is significantly shorter in Hispanic patients compared with non-Hispanic patients. Such ethnic difference should be considered when performing cataract and corneal surgeries because this ethnic difference may be associated with a higher risk of corneal endothelial injury.


Assuntos
Astigmatismo , Extração de Catarata , Catarata , Adulto , Idoso , Câmara Anterior/anatomia & histologia , Astigmatismo/etiologia , Comprimento Axial do Olho , Biometria , Extração de Catarata/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
2.
Eye Contact Lens ; 47(12): 674-676, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34520409

RESUMO

OBJECTIVE: To report the ocular and systemic risk factors, clinical manifestations, and management outcomes of Moraxella keratitis. METHODS: This retrospective study included patients with culture-proven Moraxella keratitis in South Texas between 2012 and 2018. Clinical data including demographics, ocular and systemic risk factors, clinical presentation, speciation, and treatment course were collected. RESULTS: Fourteen eyes of 14 patients had culture-proven Moraxella keratitis which made up 8.1% of cases of culture-proven bacterial keratitis in the period studied. These included 10 men and 4 women with a mean age of 52.7±11.3 years. Ten patients (71.4%) had different ocular risk factors such as ocular trauma, corneal foreign body, contact lens use, preceding viral keratitis, neurotrophic cornea, and recent corneal transplant on topical steroids. Systemic risk factors included diabetes mellitus, systemic immunosuppressive therapy, cancer chemotherapy, and AIDS. There was no specific clinical manifestation. The size of stromal infiltration on initial presentation varied among the cases, with 71.4% stromal infiltrations of 4 mm or less. The patients were managed with fortified tobramycin, fortified vancomycin, and moxifloxacin eye drops. No eyes required surgical intervention during treatment for the active infection, except for one eye with pre-existing no light perception that was enucleated because of chronic pain. CONCLUSIONS: Moraxella keratitis is a less frequent form of bacterial keratitis that appears more prevalent in patients with previous ocular conditions. Early diagnosis of this infection and medical treatment with a conventional corneal ulcer regimen can result in good clinical outcomes without the need for a surgical intervention.


Assuntos
Úlcera da Córnea , Infecções Oculares Bacterianas , Ceratite , Adulto , Antibacterianos/uso terapêutico , Córnea , Úlcera da Córnea/diagnóstico , Úlcera da Córnea/tratamento farmacológico , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Bacterianas/tratamento farmacológico , Infecções Oculares Bacterianas/epidemiologia , Feminino , Humanos , Ceratite/diagnóstico , Ceratite/tratamento farmacológico , Ceratite/epidemiologia , Masculino , Pessoa de Meia-Idade , Moraxella , Estudos Retrospectivos , Fatores de Risco
3.
Nature ; 473(7346): 203-7, 2011 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-21562560

RESUMO

Diatoms dominate the biomass of phytoplankton in nutrient-rich conditions and form the basis of some of the world's most productive marine food webs. The diatom nuclear genome contains genes with bacterial and plastid origins as well as genes of the secondary endosymbiotic host (the exosymbiont), yet little is known about the relative contribution of each gene group to diatom metabolism. Here we show that the exosymbiont-derived ornithine-urea cycle, which is similar to that of metazoans but is absent in green algae and plants, facilitates rapid recovery from prolonged nitrogen limitation. RNA-interference-mediated knockdown of a mitochondrial carbamoyl phosphate synthase impairs the response of nitrogen-limited diatoms to nitrogen addition. Metabolomic analyses indicate that intermediates in the ornithine-urea cycle are particularly depleted and that both the tricarboxylic acid cycle and the glutamine synthetase/glutamate synthase cycles are linked directly with the ornithine-urea cycle. Several other depleted metabolites are generated from ornithine-urea cycle intermediates by the products of genes laterally acquired from bacteria. This metabolic coupling of bacterial- and exosymbiont-derived proteins seems to be fundamental to diatom physiology because the compounds affected include the major diatom osmolyte proline and the precursors for long-chain polyamines required for silica precipitation during cell wall formation. So far, the ornithine-urea cycle is only known for its essential role in the removal of fixed nitrogen in metazoans. In diatoms, this cycle serves as a distribution and repackaging hub for inorganic carbon and nitrogen and contributes significantly to the metabolic response of diatoms to episodic nitrogen availability. The diatom ornithine-urea cycle therefore represents a key pathway for anaplerotic carbon fixation into nitrogenous compounds that are essential for diatom growth and for the contribution of diatoms to marine productivity.


Assuntos
Diatomáceas/classificação , Diatomáceas/metabolismo , Fotossíntese , Filogenia , Ureia/metabolismo , Carbamoil-Fosfato Sintase (Amônia)/metabolismo , Diatomáceas/enzimologia , Diatomáceas/genética , Diatomáceas/crescimento & desenvolvimento , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Nitratos/metabolismo , Interferência de RNA
4.
J Appl Clin Med Phys ; 15(3): 4638, 2014 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-24892335

RESUMO

The purpose of this study is to investigate an effect of angular dependence and calibration field size of MapCHECK 2 on RapidArc QA for 6, 8, 10, and 15 MV. The angular dependence was investigated by comparing MapCHECK 2 measurements in MapPHAN-MC2 to the corresponding Eclipse calculations every 10° using 10× 10 cm2 and 3 × 3 cm2 fields. Fourteen patients were selected to make RapidArc plans using the four energies, and verification plans were delivered to two phantom setups: MapCHECK 2/MapPHAN phantom (MapPHAN QA) and MapCHECK 2 on an isocentric mounting fixture (IMF QA). Migration of MapCHECK 2 on IMF was simulated by splitting arcs every 10° and displacing an isocenter of each partial arc in the Eclipse system (IMFACTUAL QA). To investigate the effect of calibration field size, MapCHECK 2 was calibrated by two field sizes (10 × 10 cm2 and 3 × 3 cm2) and applied to all QA measurements. The γ test was implemented using criteria of 1%/1 mm, 2%/2 mm, and 3%/3 mm. A mean dose of all compared points for each plan was compared with respect to a mean effective field size of the RapidArc plan. The angular dependence was considerably high at gantry angles of 90° ± 10° and 270° ± 10° (for 10 × 10/3 × 3 cm2 at 90°, 30.6% ± 6.6%/33.4%± 5.8% (6 MV), 17.3% ± 5.3%/15.0% ± 6.8% (8 MV), 8.9%± 2.9%/7.8% ± 3.2% (10 MV), and 2.2% ± 2.3%/-1.3% ± 2.6% (15 MV)). For 6 MV, the angular dependence significantly deteriorated the γ passing rate for plans of large field size in MapPHAN QA (< 90% using 3%/3 mm); however, these plans passed the γ test in IMFACTUAL QA (> 95%). The different calibration field sizes did not make any significant dose difference for both MapPHAN QA and IMFACTUAL QA. For 8, 10, and 15 MV, the angular dependence does not make any clinically meaningful impact on MapPHAN QA. Both MapPHAN QA and IMFACTUAL QA presented clinically acceptable γ passing rates using 3%/3 mm. MapPHAN QA showed better passing rates than IMFACTUAL QA for the tighter criteria. The 10 × 10 cm2 calibration showed better agreement for plans of small effective field size (< 5 × 5 cm2) in MapPHAN QA. There was no statistical difference between IMF QA and IMFACTUAL QA. In conclusion, MapPHAN QA is not recommended for plans of large field size, especially for 6 MV, and MapCHECK2 should be calibrated using a field size similar to a mean effective field size of a RapidArc plan for better agreement for IMF QA.


Assuntos
Garantia da Qualidade dos Cuidados de Saúde/normas , Radiometria/instrumentação , Radiometria/normas , Radioterapia de Intensidade Modulada/instrumentação , Radioterapia de Intensidade Modulada/normas , Calibragem , Desenho de Equipamento , Análise de Falha de Equipamento , Dosagem Radioterapêutica , Reprodutibilidade dos Testes , Espalhamento de Radiação , Semicondutores , Sensibilidade e Especificidade , Estados Unidos
5.
Surv Ophthalmol ; 67(2): 331-341, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34077767

RESUMO

Superior limbic keratoconjunctivitis (SLK) is characterized by chronic inflammation of the superior limbus and superior bulbar and tarsal conjunctivae. Patients also often have fine punctate staining of the limbus and adjacent area, superior limbic proliferation seen as thickening of the limbal epithelium and surrounding conjunctiva, and occasionally filaments at the superior limbus and upper cornea. SLK frequently presents with ocular irritation, foreign body sensation, and photophobia. SLK can be associated with other ocular and non-ocular conditions, such as thyroid disease. Although the pathogenesis of SLK is still unknown, it is thought to be related to mechanical injury, tear film instability, or an autoimmune/inflammatory etiology. Many patients with SLK can be asymptomatic or have symptoms that resolve or remit spontaneously. For symptomatic SLK, patients are managed medically with treatments such as lubricants, topical anti-inflammatory or immunomodulatory medications, punctal occlusion, and bandage contact lenses. Patients with symptoms refractory to medical management may need surgical interventions. We detail the current literature on the epidemiology, clinical manifestations, associated conditions, histopathology, pathogenesis, and treatment of SLK.


Assuntos
Ceratoconjuntivite , Limbo da Córnea , Túnica Conjuntiva/patologia , Humanos , Inflamação/patologia , Ceratoconjuntivite/diagnóstico , Ceratoconjuntivite/epidemiologia , Ceratoconjuntivite/etiologia , Limbo da Córnea/patologia , Lágrimas
6.
Surv Ophthalmol ; 67(1): 52-59, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33862042

RESUMO

Filamentary keratitis (FK) is characterized by the presence of filaments on the corneal surface that are often associated with symptoms of foreign body sensation, irritation, and eye pain. FK is associated with a variety of ocular and systemic conditions, most notably dry eye disease. These filaments are composed primarily of epithelium, mucus, and cellular debris; however, their pathogenesis remains an area of debate. Aggravating factors for FK include desiccation, inflammatory mediators, as well as eyelid mechanical forces. Management consists of addressing associated conditions, especially dry eye disease, and providing medical and procedural treatments to alleviate symptoms and restore the ocular surface. Mainstay treatments include filament removal, increased lubrication with artificial tears and punctal occlusion, hypertonic saline, antiinflammatory and mucolytic medications, and autologous serum eye drops, as well as bandage contact lenses. A stepwise approach is required to manage patients with acute or chronic FK. Prolonged therapy is often necessary to prevent recurrence of this bothersome condition.


Assuntos
Síndromes do Olho Seco , Ceratite , Córnea/patologia , Síndromes do Olho Seco/complicações , Síndromes do Olho Seco/terapia , Humanos , Ceratite/diagnóstico , Ceratite/etiologia , Ceratite/terapia , Lubrificantes Oftálmicos/uso terapêutico , Lágrimas
7.
Korean J Ophthalmol ; 36(2): 108-113, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34743490

RESUMO

PURPOSE: Central retinal artery occlusion (CRAO) is a vision-threatening condition with a potentially poor visual prognosis. Many different treatment modalities are suggested but controversy remains regarding effectiveness of these treatments. The purpose of this study is to perform a systematic review and meta-analysis in addition to analyzing retrospective data at our own tertiary care center regarding effectiveness of hyperbaric oxygen therapy (HBOT) in treatment of CRAO. METHODS: The PubMed, Scopus, and the Cochrane Library are searched from the date of database inception to September 2021 to conduct a review based on the PRISMA (preferred reporting items for systematic review and meta-analysis), evaluating the role of HBOT in visual recovery of CRAO patients. In addition, a retrospective chart review of patients clinically diagnosed with CRAO at our university-based hospital (University of Texas Health, San Antonio, TX, USA) from year 2011 to 2021 was conducted. RESULTS: After a review of 376 articles, three articles met the inclusion criteria for meta-analysis, where a total of 207 patients received HBOT versus 89 patients that did not receive any form of oxygen therapy. Analysis of these results demonstrate that HBOT in CRAO patients does not enhance the final visual outcome (p = 0.83). Similar conclusion was also drawn from retrospective analysis of 48 patients (15 HBOT versus 33 controls) at our tertiary care center, where no visual benefit was observed in the HBOT group. CONCLUSIONS: HBOT does not appear to improve final visual outcome and concerns remain regarding adverse reactions such as barotrauma and generalized seizures. Large, randomized studies are required for further understanding of the role of HBOT in treatment of CRAO.


Assuntos
Oxigenoterapia Hiperbárica , Oclusão da Artéria Retiniana , Humanos , Oxigenoterapia Hiperbárica/efeitos adversos , Oxigenoterapia Hiperbárica/métodos , Oclusão da Artéria Retiniana/diagnóstico , Oclusão da Artéria Retiniana/etiologia , Oclusão da Artéria Retiniana/terapia , Estudos Retrospectivos , Transtornos da Visão/etiologia
8.
Indian J Ophthalmol ; 70(8): 2835-2841, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35918923

RESUMO

Adjunctive treatment of bacterial endophthalmitis with intravitreal steroids is a topic of controversy among many ophthalmologists. The objective of this study is to evaluate the effects of intravitreal dexamethasone on the visual outcomes of patients with acute bacterial endophthalmitis through a systematic review and meta-analysis. A literature search of PubMed, Scopus, and Cochrane Library databases was performed to include studies on the visual outcomes of adjuvant intravitreal dexamethasone in patients with acute bacterial endophthalmitis. The review is based on the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) protocol. A total of 1545 articles met our search criteria and after further review, two randomized controlled trials and three retrospective case series were included in the final analysis. A total of 126 eyes were treated with intravitreal dexamethasone combined with antibiotics, and another 139 eyes were treated with antibiotics alone. All cases of endophthalmitis were post-operative or post-intravitreal injection, with pooled results demonstrating no visual benefit with supplementation of intravitreal dexamethasone. Our meta-analysis does not show any visual benefit from steroid supplementation and yet, considering a relatively small number of patients included in each study, larger randomized controlled trials are required to further clarify the role of steroids in the treatment of acute bacterial endophthalmitis.


Assuntos
Endoftalmite , Infecções Oculares Bacterianas , Antibacterianos/uso terapêutico , Bactérias , Dexametasona , Endoftalmite/diagnóstico , Endoftalmite/tratamento farmacológico , Endoftalmite/microbiologia , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Bacterianas/tratamento farmacológico , Infecções Oculares Bacterianas/microbiologia , Glucocorticoides , Humanos , Injeções Intravítreas , Estudos Retrospectivos
9.
Curr Eye Res ; 47(7): 978-981, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35180019

RESUMO

PURPOSE: To determine the role of race and ethnicity in the prevalence of occult ocular surface squamous neoplasia in pterygium specimens. METHODS: This retrospective study reviewed pathology reports and medical records of 504 patients who underwent pterygium surgery in South Texas. Those with clinical signs of ocular surface squamous neoplasia were excluded. Clinical data including age, sex, and self-reported race and ethnicity were analyzed to determine risk factors for presence of occult ocular surface squamous neoplasia in pterygium specimens. RESULTS: There were 504 specimens; 95.8% were from patients identified as White, 1.8% from African Americans, and 2.4% from Asians. Ethnicity included Hispanic in 70.8% and non-Hispanic in 29.2%. Among all specimens, 18 (3.6%) were positive for occult ocular surface squamous neoplasia. The prevalence of occult ocular surface squamous neoplasia in pterygium specimens was higher in Hispanics compared to non-Hispanics (4.8% vs. 0.7%, respectively, p = .025). The prevalence of occult ocular surface squamous neoplasia in different races included 8.3% for Asians, 3.5% for Whites, and 0% for African Americans. However, the racial difference did not reach statistical significance (p = .57). There were also no statistically significant differences between those with or without occult ocular surface squamous neoplasia regarding age or sex. CONCLUSIONS: A significant but low rate of occult ocular surface squamous neoplasia was found in pterygium specimens. The percentage of those with ocular surface squamous neoplasia in pterygium specimens was significantly greater in Hispanics compared to non-Hispanics. As treatment and prognosis of pterygium and ocular surface squamous neoplasia differ, histopathologic evaluation of all pterygium specimens is warranted.


Assuntos
Carcinoma de Células Escamosas , Neoplasias da Túnica Conjuntiva , Pterígio , Carcinoma de Células Escamosas/epidemiologia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Túnica Conjuntiva/anormalidades , Neoplasias da Túnica Conjuntiva/patologia , Humanos , Pterígio/epidemiologia , Pterígio/cirurgia , Estudos Retrospectivos
10.
Am J Physiol Heart Circ Physiol ; 300(3): H736-44, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21186274

RESUMO

Whole brain radiation therapy (WBRT) leads to cognitive impairment in 40-50% of brain tumor survivors following treatment. Although the etiology of cognitive deficits post-WBRT remains unclear, vascular rarefaction appears to be an important component of these impairments. In this study, we assessed the effects of WBRT on the cerebrovasculature and the effects of systemic hypoxia as a potential mechanism to reverse the microvascular rarefaction. Transgenic mice expressing green fluorescent protein driven by the Acta2 (smooth muscle actin) promoter for blood vessel visualization were randomly assigned to control or radiated groups. Animals received a clinical series of 4.5 Gy WBRT two times weekly for 4 wk followed by 1 mo of recovery. Subsequently, mice were subjected to 11% (hypoxia) or 21% (normoxia) oxygen for 1 mo. Capillary density in subregions of the hippocampus revealed profound vascular rarefaction that persisted despite local tissue hypoxia. Nevertheless, systemic hypoxia was capable of completely restoring cerebrovascular density. Thus hippocampal microvascular rarefaction post-WBRT is not capable of stimulating angiogenesis and can be reversed by chronic systemic hypoxia. Our results indicate a potential shift in sensitivity to angiogenic stimuli and/or the existence of an independent pathway of regulating cerebral microvasculature.


Assuntos
Transtornos Cognitivos/fisiopatologia , Transtornos Cognitivos/terapia , Cognição/efeitos da radiação , Hipocampo/irrigação sanguínea , Hipocampo/efeitos da radiação , Oxigênio/fisiologia , Actinas/genética , Actinas/metabolismo , Anaerobiose , Animais , Cognição/fisiologia , Masculino , Camundongos , Camundongos Transgênicos , Microvasos/fisiopatologia , Microvasos/efeitos da radiação , Regiões Promotoras Genéticas
11.
PLoS Genet ; 4(10): e1000211, 2008 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-18833300

RESUMO

The deluge of data generated by genome sequencing has led to an increasing reliance on bioinformatic predictions, since the traditional experimental approach of characterizing gene function one at a time cannot possibly keep pace with the sequence-based discovery of novel genes. We have utilized Biolog phenotype MicroArrays to identify phenotypes of gene knockout mutants in the opportunistic pathogen and versatile soil bacterium Pseudomonas aeruginosa in a relatively high-throughput fashion. Seventy-eight P. aeruginosa mutants defective in predicted sugar and amino acid membrane transporter genes were screened and clear phenotypes were identified for 27 of these. In all cases, these phenotypes were confirmed by independent growth assays on minimal media. Using qRT-PCR, we demonstrate that the expression levels of 11 of these transporter genes were induced from 4- to 90-fold by their substrates identified via phenotype analysis. Overall, the experimental data showed the bioinformatic predictions to be largely correct in 22 out of 27 cases, and led to the identification of novel transporter genes and a potentially new histamine catabolic pathway. Thus, rapid phenotype identification assays are an invaluable tool for confirming and extending bioinformatic predictions.


Assuntos
Proteínas de Bactérias/metabolismo , Biologia Computacional/métodos , Proteínas de Membrana Transportadoras/metabolismo , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Proteínas de Bactérias/genética , Proteínas de Membrana Transportadoras/genética , Mutagênese Insercional , Fenótipo , Análise Serial de Proteínas , Pseudomonas aeruginosa/crescimento & desenvolvimento
12.
Korean J Ophthalmol ; 35(3): 215-222, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34120420

RESUMO

PURPOSE: Visual impairment from retinal re-detachment could be debilitating. The aim of this review is to evaluate the role of 360° laser retinopexy on success rate of rhegmatogenous retinal detachment (RRD) repair by a meta-analysis study. METHODS: The PubMed, Scopus, and the Cochrane Library databases were searched comprehensively from the date of database inception to January 2021, evaluating the role of 360° laser retinopexy in visual and anatomical success rate of RRD repair. This review was conducted based on the preferred reporting items for systematic review and meta-analysis (PRISMA) protocols. RESULTS: Among 202 articles screened for eligibility, six studies were found to be eligible for inclusion in our final analysis. Our meta-analysis demonstrates that prophylactic treatment with circumferential laser photocoagulation has no significant effect on the initial rate of retinal re-detachment or final best-corrected visual acuity following pars plana vitrectomy repair of RRD. Subgroup analysis of studies (n = 3) with 23-gauge pars plana vitrectomy, however, favors attachment rate in patients undergoing 360° prophylactic laser treatment. CONCLUSIONS: Three hundred and sixty degree laser retinopexy appears to have favorable outcomes in patients undergoing 23-gauge retinal detachment repair. This protective effect, however, is not apparent with inclusion of 20-gauge vitrectomy studies.


Assuntos
Descolamento Retiniano , Humanos , Lasers , Retina/diagnóstico por imagem , Retina/cirurgia , Descolamento Retiniano/cirurgia , Acuidade Visual , Vitrectomia
13.
J Xray Sci Technol ; 18(3): 309-18, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20714088

RESUMO

The objective of this work has been to develop and implement an empirical calculation method for the determination of clinical electron output factors. Electron beams with various energies, field sizes, and source to surface distances using cutouts of varying radii were used to measure dose output at the depth of maximum dose in water. A 30 cm x 30 cm x 17.8 cm water equivalent phantom with a 0.125 cc cylindrical ion-chamber (PTW Model 31010) was used. The calculation model predicted the output factor as a product of the cone factor, radius dependent cutout factor, the effective source to surface distance factor and the area dependent aspect ratio factor. A comparative analysis of clinical cutout output factors, determined through both empirical calculation and direct measurement was performed to evaluate the clinical viability of the calculation method before its implementation in our clinic. A total of 643 output factors for 294 different cutout shapes were determined through both traditional measurement and predictive calculation. Predictive calculation differed from definitive measurement by at most 3.5% for all cases, a majority of cases falling within 1%. The method developed successfully predicts electron output factors on the basis of cutout geometry with accuracy better than 96% for all cases and better then 98% for most cases. This ability holds true for all practical SSD, electron energy, cone, and irregular shape combinations. The method has been clinically implemented and in use at our center since 2007.


Assuntos
Dosagem Radioterapêutica , Radioterapia/métodos , Algoritmos , Elétrons , Humanos , Neoplasias/radioterapia , Imagens de Fantasmas
14.
Ocul Surf ; 18(1): 31-39, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31593763

RESUMO

Floppy eyelid syndrome (FES) is defined as eyelid hyperlaxity with reactive palpebral conjunctivitis. It is a common condition that can be associated with significant ocular irritation. FES presents with easily everted eyelids and chronic papillary conjunctivitis in the upper eyelids. It is frequently associated with ocular and systemic diseases, notably keratoconus and obstructive sleep apnea, respectively. This comprehensive review describes the epidemiology, pathological changes, proposed pathogenesis, clinical manifestations, and a variety of treatment options for this condition. Conservative treatment of FES includes aggressive lubrication, nighttime eye shield, and avoiding sleeping on the affected eye. Patients with FES and obstructive sleep apnea may have an improvement in their ocular signs and symptoms after long-term therapy with continuous positive airway pressure. In refractory cases, a corrective surgery that addresses the eyelid laxity can result in significant improvement. All patients with ocular irritation should be evaluated for the presence of FES.


Assuntos
Doenças Palpebrais , Conjuntivite , Doenças Palpebrais/diagnóstico , Doenças Palpebrais/epidemiologia , Doenças Palpebrais/terapia , Pálpebras , Humanos , Apneia Obstrutiva do Sono
15.
Ocul Surf ; 18(3): 396-402, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32339665

RESUMO

Giant papillary conjunctivitis (GPC), which is characterized by the development of "giant" papillae on the superior tarsal conjunctiva, is a common complication in contact lens wearers. This condition can be associated with excessive mucus production, itching, blurry vision, and diminished contact lens tolerance. Risk factors for GPC include non-disposable lenses, infrequent lens replacement, long wearing time, inadequate lens hygiene, and atopy. Although the exact pathophysiology of GPC remains incompletely understood, it likely develops from the combination of mechanical trauma to the superior tarsal conjunctiva and an immunologic response by the conjunctiva to deposits on the anterior surface of the contact lens. With proper management, GPC has an excellent prognosis. In mild cases, prompt contact lens cessation is sufficient for the resolution of signs and symptoms. For more severe cases, the use of topical anti-histaminic agents is indicated. Uncommonly, topical steroids, non-steroidal anti-inflammatory agents, immunomodulatory medications, or very rarely surgery may be needed. In this review article, we provide a comprehensive review of the available literature on GPC, with an emphasis on recent findings and treatment advances for this common condition.


Assuntos
Conjuntivite Alérgica , Túnica Conjuntiva , Conjuntivite Alérgica/diagnóstico , Conjuntivite Alérgica/etiologia , Conjuntivite Alérgica/terapia , Lentes de Contato , Humanos , Fatores de Risco
16.
J Ophthalmic Vis Res ; 15(2): 128-137, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32308946

RESUMO

PURPOSE: To determine the causative organisms and associated risk factors for infectious keratitis in South Texas. METHODS: This retrospective study was performed at a tertiary teaching hospital system in South Texas. Medical records of all patients who presented with infectious keratitis from 2012 to 2018 were reviewed. Only patients with culture-proven bacterial, fungal, and Acanthamoeba keratitis were included. RESULTS: In total, 182 eyes of 181 patients had culture-proven bacterial, fungal, or Acanthamoeba keratitis. The age of patients ranged from 3 to 93 years, with a mean of 48.3 ± 20.8 years. The most common etiologic agent was bacteria, with 173 bacterial cultures (95.1%) recovered, followed by 13 fungal cultures (7.1%), and 3 Acanthamoeba cultures (1.6%). Of the 218 bacterial isolates, coagulase-negative Staphylococcus was the most common (25.7%), followed by Pseudomonas aeruginosa (23.4%), Staphylococcus aureus (11.0%), and Moraxella (7.8%). Fusarium was the most common fungal isolate (46.2%). The most common risk factors for infectious keratitis included contact lens wear (32.4%), underlying corneal disease (17.6%), trauma (14.3%), and ocular surface disease (13.7%). CONCLUSIONS: Bacteria are the most common cause of infectious keratitis in this patient population, with coagulase-negative Staphylococcus and Pseudomonas as the most common isolates. The prevalence of culture-positive fungal keratitis is significantly lower than that of bacterial keratitis. Contact lens wear is the most common risk factor associated with infectious keratitis in South Texas.

17.
J Pediatr Ophthalmol Strabismus ; 56: e65-e67, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31821509

RESUMO

This report discusses the potential ocular injuries associated with an air-powered salt gun, a new product that may appeal to children. The authors hope to inform both providers and patients of the potential risks and treatment considerations if an injury of this type is sustained. [J Pediatr Ophthalmol Strabismus. 2019;56:e65-e67.].


Assuntos
Córnea/patologia , Traumatismos Oculares/diagnóstico , Cloreto de Sódio , Ferimentos por Arma de Fogo/diagnóstico , Cadáver , Feminino , Humanos , Pessoa de Meia-Idade , Índices de Gravidade do Trauma
18.
Biol Psychiatry ; 62(11): 1228-35, 2007 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-17651703

RESUMO

BACKGROUND: Selective serotonin reuptake inhibitor (SSRI) antidepressant drugs have a delayed onset and commonly produce an incomplete therapeutic response. The therapeutic actions of SSRIs are thought to depend on increased forebrain extracellular serotonin (5-HT), after desensitization of somatodendritic 5-HT(1A) autoreceptors. Here we determined whether concurrent glucocorticoid receptor (GR) blockade enhances these neurochemical responses to the SSRI fluoxetine. METHODS: Male rats were treated (3, 7, or 14 days) with either fluoxetine (10 mg/kg IP) or vehicle once daily, in combination with either a GR antagonist (Org 34850 15 mg/kg SC or Org 34517 25 mg/kg SC) or vehicle twice daily. After treatment, 5-HT in the medial prefrontal cortex was measured by microdialysis. RESULTS: Chronic fluoxetine treatment (14 days) raised basal 5-HT and also attenuated the fall in 5-HT after acute systemic administration of fluoxetine (10 mg/kg IP), indicating desensitization of 5-HT(1A) autoreceptors. Concurrent chronic administration (14 days) of Org 34850 or Org 34517 enhanced the fluoxetine-induced increase in basal 5-HT. Org 34850 also hastened the 5-HT(1A) autoreceptor desensitization induced by chronic fluoxetine treatment. Org 34850 alone (14 days) failed to alter basal 5-HT or 5-HT(1A) autoreceptor desensitization. CONCLUSIONS: Antidepressant response is proposed to depend on 5-HT(1A) autoreceptor desensitization and elevation of forebrain 5-HT. These data suggest adjunctive GR antagonists might both hasten and enhance antidepressant responses to SSRIs.


Assuntos
Benzodioxóis/uso terapêutico , Química Encefálica/efeitos dos fármacos , Fluoxetina/uso terapêutico , Receptores de Glucocorticoides/antagonistas & inibidores , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Serotonina/metabolismo , Esteroides/uso terapêutico , Sulfonas/uso terapêutico , Animais , Sinergismo Farmacológico , Masculino , Microdiálise , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Ratos , Receptor 5-HT1A de Serotonina/efeitos dos fármacos
20.
Am J Ophthalmol ; 141(1): 198-200, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16387002

RESUMO

PURPOSE: To report cases of ocular argyrosis that developed after long-term self-application of commercially available eyelash tint. DESIGN: Observational case series. METHODS: Case review, clinicopathologic analysis, and literature review. RESULTS: Three patients developed ocular argyrosis after the long-term self-application of Revlon Professional Roux Lash and Brow Tint (Colomer USA Corp, New York, New York, USA). Clinical evaluation revealed various degrees of silver deposition on the upper eyelid, lid margin, caruncle and conjunctiva, and diffuse Descemet's membrane deposits. In one case, histologic examination demonstrated silver deposition in the basement membrane and superficial substantia propria of the conjunctiva. CONCLUSIONS: Argyrosis can occur after long-term application of readily available eyelash tints, and the deposition of silver may be permanent. In certain circumstances, conjunctival argyrosis may simulate benign and malignant lesions, including conjunctival melanoma. These products should only be applied by trained cosmetologists.


Assuntos
Argiria/etiologia , Doenças da Túnica Conjuntiva/etiologia , Doenças da Córnea/etiologia , Pestanas , Doenças Palpebrais/etiologia , Tinturas para Cabelo/efeitos adversos , Idoso , Argiria/patologia , Doenças da Túnica Conjuntiva/patologia , Doenças da Córnea/patologia , Lâmina Limitante Posterior/efeitos dos fármacos , Doenças Palpebrais/patologia , Feminino , Humanos , Autoadministração
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa