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A detailed knowledge of the decay properties of the so called Hoyle state in the 12 C nucleus ( E x = 7.654 MeV, 0 + ) is required to calculate the rate at which carbon is forged in typical red-giant stars. This paper reports on a new almost background-free measurement of the radiative decay branching ratio of the Hoyle state using advanced charged particle coincidence techniques. The exploitation, for the first time in a similar experiment, of a bidimensional map of the coincidence efficiency allows to reach an unitary value and, consequently, to strongly reduce sources of systematic uncertainties. The present results suggest a value of the radiative branching ratio of Γ rad / Γ tot = 4.4 ( 6 ) · 10 - 4 . This finding helps to resolve the tension between recent data published in the literature.
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To analyze the performance of ultra-wide-field (UWF) fundus photography compared with ophthalmoscopy in identifying and classifying retinal diseases. Patients examined for presumed major retinal disorders were consecutively enrolled. Each patient underwent indirect ophthalmoscopic evaluation, with scleral depression and/or fundus biomicroscopy, when clinically indicated, and mydriatic UWF fundus imaging by means of CLARUS 500™ fundus camera. Each eye was classified by a clinical grader and two image graders in the following groups: normal retina, diabetic retinopathy, vascular abnormalities, macular degenerations and dystrophies, retinal and choroidal tumors, peripheral degenerative lesions and retinal detachment and myopic alterations. 7024 eyes of new patients were included. The inter-grader agreement for images classification was perfect (kappa = 0.998, 95% Confidence Interval (95%CI) = 0.997-0.999), as the two methods concordance for retinal diseases diagnosis (kappa = 0.997, 95%CI = 0.996-0.999) without statistically significant difference. UWF fundus imaging might be an alternative to ophthalmoscopy, since it allows to accurately classify major retinal diseases, widening the range of disorders possibly diagnosed with teleophthalmology. Although the clinician should be aware of the possibility that a minority of the most peripheral lesions may be not entirely visualized, it might be considered a first line diagnostic modality, in the context of a full ophthalmological examination.
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Retinopatía Diabética , Oftalmología , Enfermedades de la Retina , Telemedicina , Humanos , Oftalmoscopía/métodos , Fotograbar/métodos , Fondo de Ojo , Enfermedades de la Retina/diagnóstico por imagen , Retinopatía Diabética/diagnósticoRESUMEN
Age-related macular degeneration (AMD) is one of the major causes of visual loss and legal blindness in people over 55. Visual function tests are the cornerstone of visual function investigation and any therapeutic approach to AMD implies, as primary endpoint, the maintenance or improvement of visual function. The progression of visual impairment and the quantification of final residual visual function are currently determined by means of visual acuity quantification. The quantification of high-contrast visual acuity though has many drawbacks and cannot be considered a complete functional examination. Microperimetry is a non-invasive method used to analyse fixation and central visual field defects in a topographic related manner. The introduction of mesopic and more recently scotopic microperimetry, in research and clinical practice of macular disorders, now allows us to better investigate macular function as it strictly relates to macular morphology. We therefore can monitor the functional natural history and quantify the beneficial or detrimental effects of different therapies. The application of microperimetry in clinical studies has provided interesting diagnostic and prognostic information on functional macular changes in AMD patients. The present review brings new updates on the correlation between macular changes, mainly described with optical coherence tomography, and microperimetry changes in patients with AMD.
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Pruebas del Campo Visual/métodos , Campos Visuales/fisiología , Degeneración Macular Húmeda/diagnóstico , Humanos , Agudeza Visual , Degeneración Macular Húmeda/fisiopatologíaRESUMEN
PURPOSE: Photodynamic therapy (PDT) is the treatment of choice for subfoveal choroidal neovascularization (CNV) in age-related macular degeneration (ARMD). Interpretation of PDT mechanism of action is not yet fully understood and causes of CNV recurrences are unclear. The authors have conducted a retrospective analysis of fluorescein and indocyanine green angiographies in patients treated with multiple PDT in order to identify risk factors for recurrence. METHODS: A total of 342 eyes of 342 patients (207 women and 135 men) with ARMD and subfoveal CNV were treated with at least two PDT. Angiographic (fluorescein and indocyanine green) features of recurrences were confronted to pretreatment examinations in all patients. RESULTS: Post-PDT angiographies showed in all eyes a dark circle corresponding to the laser spot even 1 year after treatment. Persistence or progressive regrowth of CNV developed in an area adjacent or corresponding to the original lesion, without any specific relationship with the location of fluorescein and indocyanine green late leakage or with presence of abnormal fluorescence due to pigment abnormalities. At the 3-month angiographic follow-up, 23 patients (6.7%) showed a recurrent CNV resembling shape and dimension of the laser spot used for the PDT treatment. CONCLUSIONS: The authors failed to identify angiographic signs helpful to predict the risk of CNV persistence or recurrence. PDT leaves minor but persistent changes in the choroidal vasculature within the treatment area. In some cases, the recurrent CNV seems to be related to the laser spot of the PDT.
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Neovascularización Coroidal/tratamiento farmacológico , Degeneración Macular/tratamiento farmacológico , Fotoquimioterapia/métodos , Anciano , Neovascularización Coroidal/etiología , Neovascularización Coroidal/patología , Exudados y Transudados , Femenino , Angiografía con Fluoresceína , Estudios de Seguimiento , Fondo de Ojo , Humanos , Degeneración Macular/complicaciones , Degeneración Macular/patología , Masculino , Estudios Retrospectivos , Prevención Secundaria , Resultado del TratamientoRESUMEN
PURPOSE: To determine systemic factors associated with central serous chorioretinopathy. METHODS: In a retrospective study, 230 consecutive patients with central serous chorioretinopathy examined in a referral setting were compared with a historical gender-matched and age-matched control group of 230 patients with ocular findings who were examined in the same referral setting. RESULTS: The median age of the patients was 49.8 years, and of the control subjects, 50.0 years. The male-female ratio for both groups was 2.7:1. Patients with central serous chorioretinopathy were more likely to use psychopharmacologic medications (odds ratio = 2.6; 95% confidence interval = 1.30 to 5.19; P = .0049) and corticosteroids (odds ratio = 3.17; 95% confidence interval = 1.30 to 7.70; P = .0067) and were more likely to have hypertension (odds ratio = 2.25; 95% confidence interval = 1.39 to 3.63; P = .0008) than were the control subjects. CONCLUSIONS: This study identified psychopharmacologic medication use, corticosteroid use, and hypertension as factors associated with central serous chorioretinopathy. These findings reinforce the concept that stress and adaptations to stress play a role in this disorder. The findings of possible associations between central serous chorioretinopathy and both hypertension and corticosteroid usage suggest that these modifiable factors may influence morbidity of central serous chorioretinopathy.
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Enfermedades de la Coroides/etiología , Enfermedades de la Retina/etiología , Adulto , Anciano , Anciano de 80 o más Años , Exudados y Transudados , Femenino , Glucocorticoides/efectos adversos , Humanos , Hipertensión/complicaciones , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Psicofarmacología , Psicotrópicos/efectos adversos , Estudios Retrospectivos , Factores de RiesgoRESUMEN
Uveitis is often a manifestation of sarcoidosis. Less well-recognized, however, is the development of uveitis several years before the diagnosis of systemic sarcoidosis. The possibility that presentation of uveitis is a marker for the chronicity of sarcoidosis has never been investigated. The aim of this work was to evaluate, in a Caucasian population, the epidemiology of uveitis as the primary manifestation of sarcoidosis with long-term follow-up, and the relationship of uveitis to the chronicity of sarcoidosis. The records of 1,156 Caucasian patients with histologically proven sarcoidosis, first seen in the period 1976-1992, were reviewed. In patients in whom uveitis was the primary feature of sarcoidosis, the following parameters were identified: systemic manifestations; time interval between the diagnosis of uveitis and sarcoidosis; therapy; the evolution of chest radiographic image over time; chronicity; the relationship between sarcoidosis and uveitis; and, finally, status in October 1994. In nine patients, uveitis was the reason for seeking medical treatment, resulting in the discovery of systemic sarcoidosis, which was then found to be chronic in 7 out of 9 cases. In an additional eight patients, uveitis preceded the diagnosis of systemic sarcoidosis by 1-11 yrs, and yet most subjects had systemic manifestations that went unrecognized during this time period, with chest radiograph at the time of diagnosis suggesting a long-standing chronic disease. Thus, uveitis appeared to be the primary manifestation of sarcoidosis in 17 of the 1,156 patients studied (1.5%). In conclusion, any uveitis of unknown origin may be due to sarcoidosis, although its systemic manifestations may not occur for up to 11 yrs. Uveitis patients need a very long-term follow-up, including periodic diagnostic tests for systemic sarcoidosis. Furthermore, when uveitis precedes the systemic symptoms and diagnosis of sarcoidosis by more than one year, it may be regarded as a marker of the chronicity of sarcoidosis.
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Sarcoidosis/diagnóstico , Uveítis/diagnóstico , Adulto , Anciano , Enfermedad Crónica , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Sarcoidosis/fisiopatología , Sarcoidosis/terapia , Uveítis/fisiopatología , Uveítis/terapiaRESUMEN
The effects of auditory biofeedback training on myopia, visual acuity (VA), and psychological distress were evaluated in a controlled prospective study involving 55 mildly myopic (< or = -3.5 D) high school students. These myopes were divided into 2 groups, matched for age and dioptric defect: 33 were treated with visual training and 22 were not; 27 emmetropic subjects formed a further control group. Subjects were evaluated at the baseline (T0), at 10 weeks after the end of the treatment (T1), and after an interval of 12 months (T2) from the baseline for: (1) manifest and cycloplegic refraction, and the difference between them (cycloplegic tonus); (2) VA measured with a conventional optotype in all subjects, and also with a computer-generated optotype in the treated group; and (3) psychometric values and personality profile. At T2, myopia had significantly worsened both in the treated and in the control myopes; VA in the treated myopes appeared significantly improved when measured by the conventional optotype, but unchanged when measured by computer. Psychometric scores improved significantly in the treated myopes and in the emmetropic controls. Objectively the autorefractometer showed that 38% of the myopes had voluntary control of positive accommodation, i.e., the ability to increase spherical defect; no voluntary control of negative accommodation was observed. An increase in VA was associated with a significant increase in the foveation time (i.e., the period of time when the target is imaged on the fovea and the eye is motionless), and was partly attributable to a learning effect. In conclusion, biofeedback visual training had a positive effect on psychological distress and subjective VA improvement, but failed to reduce the existing myopia or delay its evolution.
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Biorretroalimentación Psicológica , Miopía/fisiopatología , Miopía/terapia , Estrés Psicológico/psicología , Visión Ocular , Agudeza Visual , Adolescente , Adulto , Femenino , Humanos , Psicometría , SensaciónRESUMEN
OBJECTIVE: The effects of a visual training technique on changes in myopia, visual acuity, and psychological distress were studied in a controlled prospective study. METHOD: A group of 33 female students with myopia < or = 3.50 diopters (D) underwent visual training using an acoustic biofeedback technique. A group of 22 female students with myopia and a group of 27 students with emmetropia formed the two control groups, matched for school, age, sex, and refractive error. Manifest and cycloplegic refraction, visual acuity, personality profile (CPI), and psychological distress (SCL-90) were measured at the baseline (T0), at 10 weeks (T1), and after 12 months (T2). RESULTS: At T2, myopia significantly progressed both in the treated and in the untreated students with myopia. Visual acuity improved only in the treated myopia group (despite refraction objectively being worse). No differences were found among the personality profiles in the three groups. All items indicative of psychological suffering improved in the group treated for myopia whose visual acuity was ameliorated. CONCLUSIONS: The visual training technique led to no improvement in objective measures of visual acuity, but did lead to an improvement in one relatively subjective measure of visual acuity and a parallel improvement in psychological conditions. The students with myopia who were treated consequently had a greater sense of general well-being.
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Nivel de Alerta , Biorretroalimentación Psicológica , Miopía/terapia , Agudeza Visual , Acomodación Ocular , Estimulación Acústica , Adaptación Psicológica , Adolescente , Adulto , Femenino , Humanos , Miopía/psicología , Inventario de Personalidad , Estudios Prospectivos , Refracción Ocular , Resultado del Tratamiento , Selección VisualRESUMEN
BACKGROUND: von Hippel-Lindau disease (VHL) is a hereditary cancer syndrome in which affected individuals are at risk of developing tumors in multiple organs, including eyes, cerebellum, spinal cord, kidneys, inner ear, adrenal glands and pancreas. METHODS: We performed a fundus examination and fluorescein and indocyanine green (ICG) angiography in both eyes of a young woman affected by VHL with bilateral pheochromocytoma, retinal angioma, retinal microaneurysms and unusual alterations of the deep retinal layers. A molecular analysis of the VHL gene was carried out. RESULTS: Ophthalmoscopy disclosed in her right eye a small retinal hemangioma, some microaneurysms in both eyes at the posterior pole and multiple, small, whitish, dome-shaped lesions scattered in the retinal pigment epithelium (RPE) of the posterior retina. Fluorescein angiograms revealed in the early phase multiple hyperfluorescent spots that showed progressive discoloration in the late phase of angiography. Some of these spots were ophthalmoscopically undetectable. The late phase of ICG angiography showed some small hyperfluorescent points located at the level of the RPE, and some of them corresponded to the hyperfluorescent spots seen on fluorescein angiography. The molecular analysis revealed the presence of a "missense" mutation of the VHL gene at nucleotide 683. CONCLUSIONS: Alterations in the RPE have never been observed in the VHL syndrome. We describe an unusual case of VHL with a capillary hemangioma associated to diffuse alterations with the RPE of the posterior retina. The possibility exists that these lesions form part of the eye modifications in VHL.