Search results for "Detachment"
showing 10 items of 106 documents
Middle Miocene graben development in Crete and its possible relation to large-scale detachment faults in the southern Aegean
2001
The linkage between the development of south-facing Cretan graben and large-scale detachment faulting in the southern Aegean is unknown. Widespread Serravallian deposits in the Ierapetra graben of Crete supply constraints to Middle Miocene graben development in the southern Aegean. The Ierapetra graben, and by inference the Cretan graben in general, were hitherto believed to have formed as a result of sinistral transpression during N–S shortening. We argue that the formation of the Cretan graben is due to N–S extension. The south-dipping, N–S-extending Kritsa normal fault served as the master fault controlling graben development in the Ierapetra graben. The Kritsa normal fault is either an …
Concise review of interrill erosion studies in SE Spain (Alicante and Murcia): erosion rates and progress of knowledge from the 1980s
2005
From the 1980s onward studies on interrill soil erosion were intensified in SE Spain. The main achievements of the research carried out in the field areas of Alicante and Murcia concern: first, (1) the estimation of erosion rates directly in the field under a wide range of methodologies, different scales and different environmental conditions; (2) estimations based on existing models, such as the USLE, carried out for different subcatchments of the Segura and Júcar catchments; and (3) other parametric and physical event-based models have also been calibrated and validated. Second, the progress of the knowledge in understanding erosion mechanisms. New and reviewed concepts regarding mainly h…
Frictionless contact-detachment analysis: iterative linear complementarity and quadratic programming approaches.
2012
The object of the paper concerns a consistent formulation of the classical Signorini’s theory regarding the frictionless contact problem between two elastic bodies in the hypothesis of small displacements and strains. The employment of the symmetric Galerkin boundary element method, based on boundary discrete quantities, makes it possible to distinguish two different boundary types, one in contact as the zone of potential detachment, called the real boundary, the other detached as the zone of potential contact, called the virtual boundary. The contact-detachment problem is decomposed into two sub-problems: one is purely elastic, the other regards the contact condition. Following this method…
Pars Plana Vitrectomy for Visually Disturbing Vitreous Floaters in Pseudophacic Eyes
2011
Background The aim of this study was to evaluate the role of vitrectomy in patients with visually disturbing vitreous opacities. Patients and methods A retrospective analysis of the patient characteristics and the outcome of all pseudophacic eyes, which consecutively received in the decade 1996 to 2005 20 G pars plana vitrectomy for visually disturbing floaters, was carried out at the Mainz University Eye Clinic. Results Forty-one eyes of 32 patients (63 % university graduates, median age: 64 years) were included in the study. The mean axial length of the globe was 25.3 mm (range: 22.8 to 28.9 mm). Additional pathologies having influence on the vitreous condition were history of laser or cr…
Characteristics and pathologies of the vitreo‐macular interface—results from the Gutenberg Health Study
2019
Purpose We aimed to determine the prevalence of characteristics and pathologies of the vitreo-macular interface within the general population. Methods The Gutenberg Health Study is a population-based study in Germany, including an ophthalmological examination with refraction, biometry and optical coherence tomography (OCT) imaging. Characteristics of the vitreo-macular interface were graded on volume scans including visibility of an epiretinal membrane, full-thickness macular hole, lamellar hole and pseudohole. Overall and age-specific prevalences including 95% confidence intervals [95%-CI] were calculated. Association analyses were conducted to determine systemic and ocular factors that ar…
Optical coherence tomography angiography evaluation of peripapillary microvascular changes after rhegmatogenous retinal detachment repair
2021
PURPOSE To evaluate the radial peripapillary capillary plexus (RPCP) vessel density (VD) and the retinal nerve fiber layer (RNFL) thickness in eyes successfully treated with pars plana vitrectomy for primary rhegmatogenous retinal detachment. METHODS In this cross-sectional multicenter clinical study, eyes with a minimum 12-month follow-up were reexamined. The RPCP VD and RNFL thickness in the rhegmatogenous retinal detachment subfields of the affected eye (study group) were compared with the corresponding areas of the healthy fellow eyes (control group). RESULTS Fifty-three eyes were included in the study. A significantly lower RPCP VD and RNFL thickness were observed in those subfields af…
Heavy versus standard silicone oil in the management of retinal detachment with macular hole in myopic eyes
2011
PURPOSE: The purpose of this study was to compare pars plana vitrectomy (PPV) with 1000 cSt silicone oil endotamponade and PPV with densiron endotamponade for retinal detachment with macular hole and posterior staphyloma in highly myopic eyes. PATIENTS AND METHODS: In a prospective study, 30 eyes of 30 patients were randomly assigned to PPV and densiron (n = 15) or PPV with silicone oil (n = 15). All eyes had laser photocoagulation of the macular hole rim after PPV. Silicone oil or densiron was removed 12 weeks after surgery. Patients were followed-up for 6 months after oil removal. RESULTS: In the densiron group, the retinal reattachment rate was 100% with densiron in situ and 87% after it…
Bilateral implantation of the Acri.LISA bifocal intraocular lens in myopic eyes.
2009
Purpose To asses visual quality after bilateral implantation of the Acri.LISA 366D intraocular lens (IOL) (Carl Zeiss Meditec) in patients with high and low–moderate myopia. Methods A total of 304 eyes of 152 patients had bilateral implantation of the Acri.LISA 366D IOL. The patients were divided into 2 groups: low–moderate myopia (IOL power from 15 to 20.5 D) and high myopia (IOL power from 0 to 14.5 D). Monocular and binocular best-corrected distance visual acuity (BCVA) and best distance-corrected near visual acuity (BCNVA), binocular best distance-corrected intermediate visual acuity (BCIVA), and distance contrast sensitivity (OS) under photopic (85 cd/m2) and mesopic (5 cd/m2) conditio…
PHOTODYNAMIC THERAPY WITH VERTEPORFIN FOR CHOROIDAL NEOVASCULARIZATION ASSOCIATED WITH RETINAL PIGMENT EPITHELIAL DETACHMENT IN AGE-RELATED MACULAR D…
2007
Abstract PURPOSE: To assess the effectiveness of photodynamic therapy (PDT) with verteporfin for choroidal neovascularization (CNV) associated with retinal pigment epithelium detachment (PED) in age-related macular degeneration. METHODS: Thirty eyes of 26 patients with CNV and PED were treated with PDT. The eyes were divided in two groups based on CNV location in relation to PED; group 1 included 13 eyes with CNV within PED, and group 2 included 17 eyes with CNV at the edge of PED. The median follow-up was 16 months. RESULTS: Patients received a mean +/- SD of 2.83 +/- 1.26 treatments (range, 1-6 treatments). In the whole cohort, the mean preoperative visual acuity changed from 20/144 (0.86…
Effect of head position on refraction in aphakic and phakic silicone-filled eyes.
1997
BACKGROUND The refraction of the eye is altered significantly after the instillation of silicone oil into the vitreous cavity because of the silicone oil's high refractive index. The degree of the refractive change shows diurnal variation and depends on the patient's head position. PATIENTS AND METHODS To analyze the degree and time course of refractive changes with respect to head position, the authors performed objective refraction in five aphakic and five phakic silicone oil-instilled eyes with attached maculae using an automatic hand-held refractometer. In each patient, 25 measurements were taken at short intervals using a hand-held autorefractometer with the patient in different positi…