Search results for "ocular"

Central corneal thickness in mucopolysaccharidosis II and VI.

2010

Objective To describe the ultrasonographically detected central corneal thickness (CCT) in patients with Type II and VI mucopolysaccharidosis (MPS) and its impact on applanation tonometry and glaucoma detection. Methods Twenty-eight patients with MPS (19 MPS II, nine MPS VI) underwent pachymetric investigation of CCT. Additionally, ultrasound measurements of axial length of the globe, slit-lamp evaluation with semiquantitative grading of corneal clouding, applanation tonometry, and assessment of refractive error were performed. Results Median average corneal thickness was 534.5 microm (range, 491.5-579.0 microm) in the MPS II and 547.0 microm (range, 492.5-693.05 microm) in the MPS VI group…

A comparison of the Canon TX-20P™ non-contact tonometer and pachymeter in healthy eyes

2012

Background: The aim of this study was to compare the intraocular pressure (IOP) and the central corneal thickness (CCT) measurements obtained with the Canon TX-20P™ with IOP measured with Goldmann applanation tonometer (GAT) and the CCT measured with ultrasound (US) pachymetry in healthy eyes. Methods: Thirty one healthy voluntary subjects participated in the study, age ranging from 16 to 81 years (mean age 50.9 years). In total 58 eyes were selected for analysis. All measurements were performed by the same examiner. The measurements were taken in the same order in all subjects: Canon IOP and CCT, Goldmann IOP and US CCT. Results: A strong correlation was found between IOP for both CCT comp…

Computer-aided-diagnosis for ocular abnormalities from a single color fundus photography with deep learning

2023

Any damage to the retina can lead to severe consequences like blindness. This visual impairment is preventable by early detection of ocular abnormalities. Computer-aided diagnosis (CAD) for ocular abnormalities is built by analyzing retinal imaging modalities, for instance, Color Fundus Photography (CFP). The main objectives of this thesis are to build two CAD models, one to detect the microaneurysms (MAs), the first visible symptom of diabetic retinopathy, and the other for multi-label detection of 28 ocular abnormalities consisting of frequent and rare abnormalities from a single CFP by using deep learning-based approaches. Two methods were proposed for MAs detection: ensemble-based and c…

Image quality with multifocal intraocular lenses and the effect of pupil size

2007

Purpose To analyze the image quality with a refractive and 2 hybrid refractive–diffractive multifocal intraocular lenses (IOLs) in vitro to determine the IOL modulation transfer function (MTF) following the EN-ISO international standard for distance and near vision and to study the IOLs' behavior with different pupil sizes. Setting Fundacion Oftalmologica del Mediterraneo, Valencia, Spain. Methods This study evaluated 4 IOLs: the hybrid refractive–diffractive AcrySof ReSTOR SN60D3 (Alcon) and Tecnis ZM900 (AMO), the refractive ReZoom NXG (AMO), and the monofocal AcrySof SN60WF (Alcon). The MTF was calculated from the cross-line spread function recorded with the OPAL Vector System (Image Sci…

Imaging Quality of Bifocal Piggyback Intraocular Lens versus ReSTOR and TECNIS Multifocal Lenses

2009

Purpose The imaging quality provided by a piggyback integrated by a monofocal intraocular lens (IOL) + a bifocal IOL of zero power and +3.75 diopters of addition is compared with the optics quality of a simple multifocal IOL of the same power and addition. Methods The imaging quality was evaluated by determining the modulation transfer function (MTF), using an artificial eye simulating in vivo conditions of the anterior chamber, including an artificial cornea and a wet cell containing physiologic solution where the IOL was positioned. The MTFs of the bifocal piggyback for near and distance vision were measured, with pupil diameters of 3 and 5 mm, and compared with the MTFs of an equivalent …

Insight into the noble crayfish morphological diversity: a geometric morphometric approach.

2022

The noble crayfish (Astacus astacus), a keystone species of high ecological, economic, and cultural importance in Europe, is threatened due to a long-term population decline caused by anthropogenic pressure on its habitats, the presence of non-indigenous invasive crayfish species and climate change. Since the effective protection of the remaining populations requires conservation measures based on the comprehensive knowledge of the species, including good understanding of its genetic and morphological variability, our aim was to study morphological features of the noble crayfish in Croatia using geometric morphometrics for the first time. We applied two-dimensional geometric morphometrics t…

Semiautomatic growth analysis of multicellular tumor spheroids.

2011

Multicellular tumor spheroids (MCTS) are routinely employed as three-dimensional in vitro models to study tumor biology. Cultivation of MCTS in spinner flasks provides better growing conditions, especially with regard to the availability of nutrients and oxygen, when compared with microtiter plates. The main endpoint of drug response experiments is spheroid size. It is common practice to analyze spheroid size manually with a microscope and an ocular micrometer. This requires removal of some spheroids from the flask, which entails major limitations such as loss of MCTS and the risk of contamination. With this new approach, the authors present an efficient and highly reproducible method to an…

The marbled crayfish as a paradigm for saltational speciation by autopolyploidy and parthenogenesis in animals

2015

ABSTRACT The parthenogenetic all-female marbled crayfish is a novel research model and potent invader of freshwater ecosystems. It is a triploid descendant of the sexually reproducing slough crayfish, Procambarus fallax, but its taxonomic status has remained unsettled. By cross-breeding experiments and parentage analysis we show here that marbled crayfish and P. fallax are reproductively separated. Both crayfish copulate readily, suggesting that the reproductive barrier is set at the cytogenetic rather than the behavioural level. Analysis of complete mitochondrial genomes of marbled crayfish from laboratory lineages and wild populations demonstrates genetic identity and indicates a single o…

The potential of elastic bands to optimize ocular and cardiovascular responses, subjective effort, and performance in squats

2022

Introducción La práctica de ejercicio físico y actividades deportivas es cada vez más habitual en la población general. El ejercicio físico y, de manera más específica el entrenamiento de la fuerza, presenta numerosos beneficios para la salud y el rendimiento de las personas. En pro de maximizar estos beneficios, se hace necesario evaluar las diferentes adaptaciones fisiológicas y de rendimiento que se pueden dar en base a las características metodológicas de la actividad o ejercicio realizados. Tal como se muestra en el Capítulo 1, existen diferentes variables de programación del entrenamiento (por ejemplo, selección de ejercicio, intensidad, volumen, carácter del esfuerzo y material emple…

2014

The face inversion effect is regarded as a hallmark of face-specific processing, and can be observed in a large variety of visual tasks. Face inversion effects are also reported in binocular rivalry. However, it is unclear whether these effects are face-specific, and distinct from the general tendency of visual awareness to privilege upright objects. We studied continuous rivalry across more than six hundred dominance epochs for each observer, having faces and houses rival against their inverted counterparts, and letting faces rival against houses in both upright and inverted orientation. We found strong inversion effects for faces and houses in both the frequency of dominance epochs and th…