Search results for "Eye"

Gaze cueing in naturalistic scenes under top-down modulation – Effects on gaze behaviour and memory performance

2022

Humans as social beings rely on information provided by conspecifics. One important signal in social communication is eye gaze. The current study (n = 93) sought to replicate and extend previous findings of attentional guidance by eye gaze in complex everyday scenes. In line with previous studies, longer, more and earlier fixations for objects cued by gaze compared to objects that were not cued were observed in free viewing conditions. To investigate how robust this prioritization is against top-down modulation, half of the participants received a memory task that required scanning the whole scene instead of exclusively focusing on cued objects. Interestingly, similar gaze cueing effects oc…

The use of in vivo confocal microscopy in fungal keratitis – Progress and challenges

2022

Fungal keratitis (FK) is a serious and sight-threatening corneal infection with global reach. The need for prompt diagnosis is paramount, as a delay in initiation of treatment could lead to irreversible vision loss. Current “gold standard” diagnostic methods, namely corneal smear and culture, have limitations due to diagnostic insensitivity and their time-consuming nature. PCR is a newer, complementary method used in the diagnosis of fungal keratitis, whose results are also sample-dependent. In vivo confocal microscopy (IVCM) is a promising complementary diagnostic method of increasing importance as it allows non-invasive real-time direct visualization of potential fungal pathogens and mani…

Entwicklung der Hornhautdicke während der UV-Vernetzungstherapie unter Anwendung verschiedener Kompositionen von Riboflavin-Augentropfen

2011

Background During the UVA-cross-linking treatment in keratoconus patients, the UVA rays are partially absorbed in the stroma of the riboflavin-loaded cornea. This effect protects the corneal endothelium from UVA irradiation damage. The intensity of UVA light reaching the endothelium is inversely correlated with corneal thickness. The common composition of riboflavin eye drops may lead to a marked reduction in corneal thickness increasing the risk of endothelial damage. Patients and methods In a retrospective analysis of 23 UVA-cross-linking procedures on 23 patients we collected data about the pre-, intra- and postoperative corneal thickness (measured with ultrasound). Among these patients …

Collagenolytic proteinases in keratoconus.

2006

To study the proteolytic phenomena contributing to the pathogenesis of keratoconus, corneal enzymes with potential to cleave fibrillar collagen were studied.Immunohistochemical labeling was undertaken of conventional and novel mammalian collagenases (MMP-1, -2, -8, -13, and -14) of the matrix metalloproteinase (MMP) family and other collagenolytic proteinases of the serine (human trypsin-2) and cysteine (cathepsin K) endoproteinase families. The results were analyzed using a semiquantitative scoring system.Labeling of MMP-8 was moderate in healthy controls, but weak in keratoconus. Moderate MMP-2 and weak MMP-14 expressions were similar in controls and keratoconus. MMP-1 was slightly overex…

Nonsurgical Procedures for Keratoconus Management

2017

Objectives. To describe the past 20 years’ correction modalities for keratoconus and their visual outcomes and possible complications.Methods. A review of the published literature related to the visual outcomes and possible complications in the context of keratoconus management using nonsurgical procedures for the last 20 years (glasses and contact lenses) was performed. Original articles that reported the outcome of any correction modalities of keratoconus management were reviewed.Results. The most nonsurgical procedure used on keratoconus management is the contact lens fitting. Soft contact lenses and soft toric contact lenses, rigid gas-permeable contact lenses, piggyback contact lens sy…

2019

Aims To report corneal topometric and aberrometric values in mucopolysaccharidosis (MPS) and to investigate their correlation with biomechanical corneal parameters. Methods One randomly chosen eye of 20 MPS patients with no to moderate corneal clouding and one eye of 23 healthy controls with comparable age were prospectively included into this study. Corneal surface regularity was assessed by index of surface variance (ISV), -vertical asymmetry (IVA), -height asymmetry (IHA), -height decentration (IHD); keratoconus index (KI), central keratoconus index (CKI) and Zernike indices of anterior and posterior corneal surface using Scheimpflug imaging (Pentacam). Corneal resistance factor (CRF) an…

Visual quality with corneo-scleral contact lenses for keratoconus management

2018

Purpose: To assess the visual quality achieved by fitting corneo-scleral contact lenses (CScL) for keratoconus management. Methods: Thirty patients with keratoconus presented to have CScL fitted because of the unsatisfactory visual quality they experienced with their contact lenses or spectacles. The eye examination included visual acuity assessment, anterior eye biomicroscopy, ocular fundus examination, corneal topographic analysis, endothelialcell count, contrast sensitivity and aberrometry. The fitting process was performed using a diagnostic trial set. Subjective visual quality and comfort, and contact lens wear time were also reported. Patients were monitored for one year. Results: Thr…

Are Ocular Response Analyzer useful to measure corneal hysteresis in patients with intracorneal rings?

2008

Purpose Corneal hysteresis is a viscoelastic property characterized by the difference in behavior under loading and unloading. The aim of the study was to determine corneal hysteresis in different eyes: healthy eyes, keratoconic eyes and keratoconic eyes after intracorneal ring implants. Methods This study comprised 95 eyes of 59 patients. The study population was divided into 3 groups. We analyze 30 healthy human eyes, 35 keratoconic eyes (Amsler grade II-III) and 30 keratoconic eyes after intracorneal rings implantation. Corneal biomechanical properties of these eyes were measured with the Ocular Response Analyser (ORA-Reichert) according to two parameters: corneal hysteresis (CH) and cor…

Integrated Optical Technique for Detection of Electro-Optical Non-Linearities in Thin Films

1976

A simple method for detection of electro-optical non-linearities in thin films is presented. The method involves an easily fabricated structure and a little practice in integrated optical techniques. It is also possible to detect small induced variations of refractive index, using lower voltage with respect to those applied in a conventional Kerr cell. We have sucessfully tested our method using two different polymer materials as thin films. In both of these we have observed an induced ?n ? 3 10?5 with an electric field of 60 V/?, with a response time round about 300 nsec. The experimental values of induced ?n versus electric field fit very well a parabola, proving the quadratic behavior of…

Some thoughts about the conceptual / procedural distinction in translation: a key-logging and eye-tracking study of processing effort

2014

This article builds on the conceptual / procedural distinction postulated by Relevance Theory to investigate processing effort in translation task execution. Drawing on relevance-theoretic assumptions, it assumes that instances related to procedural encodings will require more effortful processing not only in relation to the time spent on the task but also in terms of product indicators such as seconds per word and number of micro translation units per word. Drawing on key-logging and eye-tracking data, the article shows that there are statistically significant differences when conceptual and procedural encodings are analysed in selected areas of interest, with instances related to procedur…