Search results for " topography"

Multifokale Intraokularlinsen

2001

Modern cataract surgery has developed tremendously during the past 10-15 years. Improved surgical techniques, as well as improved implant materials and designs, have enlarged patient profiles and indications for cataract surgery. This also created much higher expectations from the patients' site. The loss of accommodation is loss of quality of life for presbyopic and especially young pseudophakic patients. Therefore cataract surgery with multifocal IOL implantation is not only of academic interest, but reflects demands and expectations of our patients. Multifocal IOLs have been implanted since 1986, starting with 2-3 zone refractive and diffractive designs. Due to surgical techniques of tha…

Geophysical investigations in the Flumendosa River Delta, Sardinia (Italy) — Seismic reflection imaging

2006

A geophysical investigation that included seismic-reflection surveying and time-domain electromagnetics (EM) was carried out in the Flumendosa River Delta plain in southeastern Sardinia, Italy. The objective was to improve knowledge of geologic and hydrogeologic controls on a highly productive aquifer hosted in thick Quaternary deposits and known to be affected by an extensive saltwater intrusion. The seismic reflection survey, whose results are reported here, aimed to image the Paleozoic bedrock topography and to obtain detailed structural and stratigraphic information on the sequence of largely fluvial sediments extending from the surface down to bedrock. The survey consisted of two inli…

Flow-bed interactions analysis and application of automatic close range digital photogrammetric survey in a laboratory flume

2014

This paper reports on a laboratory study in which the automatic digital photogrammetric survey was applied to derive the high-resolution Digital Surface Model (DSM) of the bed topography, used for the flow-bed interactions analysis, in a large amplitude meandering laboratory flume. The analysis has been conducted with the aid of detailed data of three-dimensional flow field previously collected using the acoustic Doppler velocity profiler DOP2000. The applied surveying procedure has allowed the evaluation of the DSM with a resolution of ±0.5 mm. The detailed DSM has been compared with peculiar maps describing the flow velocity pattern (downstream and the crossstream flows) and the shear vel…

Implantation of a custom intraocular lens with a 30-diopter torus for the correction of high astigmatism after penetrating keratoplasty.

2003

Abstract We present a 62-year-old woman who had implantation of an intraocular lens (IOL) with a torus of 30.0 diopters (D) in an eye after penetrating keratoplasty. The patient presented with cataract and a best corrected visual acuity of 20/400. Penetrating keratoplasty was performed in 1975 because of decompensated keratoconus. With a clear but inferiorly decentered corneal graft, visual acuity was limited because of keratoplasty-related high corneal astigmatism of 22.5@156 that could not be successfully treated with spectacles or contact lenses. A custom toric IOL with –30.0 D of cylindrical power was implanted in the capsular bag via a sclerocorneal tunnel incision. Additionally, a sph…

Reduced corneal thickness values in postmenopausal women with dry eye.

2004

To study and compare the corneal thickness values of postmenopausal women with dry eye and postmenopausal women without dry eye.The corneal thickness value of 30 postmenopausal women with dry eye (dry eye group; aged 52 to 55 years) and 32 postmenopausal women without dry eye (normal group; aged 51 to 55 years) was analyzed with the Orbscan Topography System II. Each woman underwent a tear breakup test, the Schirmer test, fluorescein staining of the cornea, and an analysis of the meibomian gland by slit lamp before corneal thickness measurement. The statistical analysis was performed by means of the unpaired Student t test.The mean corneal thickness value was significantly decreased in post…

Biometric characterization of the anterior segment in a Sahrawi pediatric population

2013

Purpose: To examine the biometric characteristics of the anterior segment in a group of Sahrawi children. Methods: A total of 66 children (33 male and 33 female, aged between 8 and 13 years) participated in this prospective, observational study. The non-invasive Pentacam Scheimpflug imaging device was used to measure corneal thickness (CT) (at the thinnest corneal point), mean anterior (Km Ant) and posterior (Km Post) corneal radii, corneal volume (CVol), anterior chamber depth (ACD) and anterior chamber volume (ACVol). The contribution of age and gender to the various parameters was investigated. Results: CT values of the present group of Sahrawi children were 521.70 ± 3.92 m. Boys had thi…

Role of the tear film in the optical quality of the human eye.

2007

This paper reviews recent studies of the role of the tear film in the optical quality of the eye. Recent investigations focus on the dynamics of the tear film after a blink and its important role in the optical quality of the eye. The results in this review were used in an attempt to understand the optical and visual impact of tear-film breakup in normal eyes and dry eyes. It was noted that patients with dry-eye syndrome have large optical aberrations compared with those in normal eyes, which may be the cause of blurry vision associated with the syndrome. In addition, instillation of artificial tears reduces optical aberrations and thus improves the optical quality of vision in these patien…

Monastères et espace urbain au haut Moyen Âge

2012

In both episcopal cities studied here, Auxerre and Autun, in Burgundy, the sites chosen for the establishment of monasteries can be partly determined by their functions, more or less restrictive. The most frequent in the cities are communities of monks settled in the seventh-eighth centuries to serve a funerary basilica or a tomb. This function involves an extra muros situation whatever the age of the foundation of the basilica. Inside the cities, truly monasteries, that is to say, communities of ascetics, are few; these are located outside the walls, but, although isolated from the city by the rampart, these remain in contact with it by symbolic functions. Unlike that is attested in Autun …

Experimental study in a meandering channel: 1. Analysis of bed topography

1999

Sabratha. La catacomba e le aree funerarie cristiane

2016

This paper starts from the processing of the data, both edited and acquired in 2010 by a series of dedicated surveys in Sabratha made by researchers at the University of Palermo, in collaboration whit the cnr itabc for the prin 2008 Project, carried out under the responsibility of Prof. Rosa Maria Carra Bonacasa. The researchers have made a preliminary study for an archaeological gis of Sabratha to gather informations on the monuments already studied, or under study, and to promote analysis regarding the riuse of space in the Regiones iii-v of Sabratha, after the destruction attribuited to the earthquake on 21th July 365. We present the results of the study on the Early Christian funerary a…