Search results for "Eye"
showing 10 items of 2511 documents
Quantitative corneal anatomy: evaluation of the effect of diabetes duration on the endothelial cell density and corneal thickness.
2014
Purpose To evaluate the differences in endothelial cell density (ECD) and central corneal thickness (CCT) between type II diabetic patients and age-matched healthy controls, and determine the impact of time from diagnosis. Methods This is a comparative study of 77 eyes of type II diabetic patients (33 males, 44 females) and 80 eyes of healthy subjects (42 males, and 38 females) whose ages ranged from 38 to 56 years. CCT, ECD, HbA1c levels, and Goldmann tonometry were measured. Results The CCT was significantly higher and the ECD significantly lower in long-term diabetic patients (10 years + since diagnosis) when compared with short-term diabetic patients (<1 year since diagnosis) and contro…
Axial Length and Anterior Segment Alterations in Former Preterm Infants and Full-Term Neonates Analyzed With Scheimpflug Imaging.
2017
Purpose To compare the axial length and anterior segment alterations in preterm infants with and without retinopathy of prematurity with those of full-term infants. Methods The Wiesbaden Prematurity Study investigated 503 participants of former gestational age ≤32 weeks and gestational age ≥37 weeks now being aged 4 to 10 years. This study included 485 participants in the prospective controlled cross-sectional, hospital-based study with successful Pentacam Scheimpflug imaging. Anterior segment parameters, axial length measurements, and associated factors were analyzed. Results Corneal thickness did not differ between former preterm and full-term infants. Significant differences were found b…
Agreement among 3 optical imaging methods for the assessment of optic disc topography.
2005
Purpose To assess the agreement of disc topography measurements between the Heidelberg Retina Tomograph (HRT II), Retinal Thickness Analyzer (RTA), and Optical Coherence Tomograph (StratusOCT). Design Observational cross-sectional study. Participants Forty-two randomly chosen eyes of 42 subjects. Methods Each subject underwent HRT II, RTA, and StratusOCT examination. Two experienced examiners drew the contour lines for the HRT II and RTA. Bland and Altman plots were used to evaluate agreement for each topographic parameter among the instruments. The Spearman coefficient of rank correlation was evaluated for each topographic parameter. Main Outcome Measures Agreement in the measurement of op…
Fractal-structured multifocal intraocular lens
2017
[EN] In this work, we present a new concept of IOL design inspired by the demonstrated properties of reduced chromatic aberration and extended depth of focus of Fractal zone plates. A detailed description of a proof of concept IOL is provided. The result was numerically characterized, and fabricated by lathe turning. The prototype was tested in vitro using dedicated optical system and software. The theoretical Point Spread Function along the optical axis, computed for several wavelengths, showed that for each wavelength, the IOL produces two main foci surrounded by numerous secondary foci that partially overlap each other for different wavelengths. The result is that both, the near focus an…
Experimental observation of temporal dispersion gratings in fiber optics
2017
We experimentally demonstrate a temporal analog to the diffraction optical grating in the Fraunhofer formalism. Using amplitude and phase temporal periodic modulations, we show that the accumulation of dispersion in fiber optics induces the development of temporally well-separated sidebands similar to the spatial orders of diffraction that are commonly observed in an optical grating operating in the far field.
Accommodation in human eye models: a comparison between the optical designs of Navarro, Arizona and Liou-Brennan.
2017
Aim To simulate and compare accommodation in accommodative and non-accommodative human eye models. Methods Ray tracing and optical design program was used. Three eye models were designed and studied: the Navarro, the Arizona and the Liou-Brennan. In order to make the Navarro and Liou-Brennan models to accommodate, specific geometric parameters of the models were altered with values that were chosen from the literature. For the Arizona model, its' mathematical functions for accommodation were used for the same accommodative demands. The simulation included four distances of accommodation for each model: at infinity, 3, 1 and 0.5 m.The results were diffraction images of a "letter F" for graph…
Bibliotecas abiertas. El programa de visitas de la Biblioteca Valenciana Nicolau Primitiu. Información bibliográfica y difusión bibliotecaria. Biblio…
2022
En un contexto de reducción de la financiación pública y de cambio de paradigma en el acceso a la información, la supervivencia de las bibliotecas está ligada a un mayor y mejor conocimiento de la ciudadanía de sus colecciones, productos y servicios. En este estudio se analiza el programa de visitas de la Biblioteca Valenciana Nicolau Primitiu, sus características, destinatarios y tipologías, así como los resultados alcanzados hasta ahora. In a context of reduced public funding and a paradigm shift in access to information, the survival of libraries is linked to greater and better knowledge by citizens of their collections, products, and services. This study analyzes the visits program of t…
Teprotumumab Efficacy, Safety, and Durability in Longer-Duration Thyroid Eye Disease and Re-treatment
2022
PURPOSE To evaluate teprotumumab safety/efficacy in patients with thyroid eye disease (TED) who were nonresponsive or who experienced a disease flare. DESIGN The Treatment of Graves' Orbitopathy to Reduce Proptosis with Teprotumumab Infusions in an Open-Label Clinical Extension Study (OPTIC-X) is a teprotumumab treatment and re-treatment trial following the placebo-controlled teprotumumab Phase 3 Treatment of Graves' Orbitopathy (Thyroid Eye Disease) to Reduce Proptosis with Teprotumumab Infusions in a Randomized, Placebo-Controlled, Clinical Study (OPTIC) trial. PARTICIPANTS Patients who previously received placebo (n = 37) or teprotumumab (n = 14) in OPTIC. METHODS OPTIC nonresponders or …
Juvenile nasopharyngeal angiofibroma with orbital extension
2015
Abstract Clinical case The case of a 21-year-old male with a history of left proptosis and diplopia of two weeks of onset is presented. The MRI showed an ethmoid-orbital vascular lesion with anterior skull base invasion and orbital extension. Biopsy of the ethmoid confirmed fibrovascular tissue, which supported the diagnosis of angiofibroma. Discussion It is a benign neoplasm with local characteristics of malignancy due to its ability to invade adjacent areas. In this case, the debut presented with manifestations of orbital extension. A broad and multidisciplinary approach is needed in order to improve prognosis.
Síndrome de Horner como manifestación de disección carotídea
2011
Caso Clínico: Un varón de 42 años se presenta con ptosis y miosis izquierda después de una historia de cefalea homolateral de 20 días de evolución, que empeora progresivamente durante los últimos días. Una angioresonancia revela disección de la arteria carótida interna. Discusión: El «síndrome de Horner doloroso» destaca como una urgencia médica por posible manifestación de una disección carotídea. Consideramos que el perfecto conocimiento de las urgencias neurooftalmológicas es de gran necesidad para el médico oftalmólogo y que estas requieren una atención multidisciplinaria para asegurar un seguimiento y tratamiento adecuado. Clinical Case: A 42-year-old man presented with ptosis and mios…