Search results for "Cornea"

Monoclonal gammopathy of ocular significance (MGOS) – a short survey of corneal manifestations and treatment outcomes

2021

Monoclonal gammopathy of ocular significance (MGOS) is a rare subset of monoclonal gammopathy of clinical significance occurring secondary to plasma cell disorders and causing ocular manifestations. We identified 23 patients with paraproteinemic keratopathy (PPK) in the setting of monoclonal gammopathy of unknown significance (MGUS, 10), smoldering multiple myeloma (SMM, 3) or multiple myeloma (MM, 10). Many of these patients with PPK (11/23) presented decreased vision. All patients with MM and 40% of those with other diagnoses such as SMM and MGUS received systemic therapy with or without autologous stem cell transplantation. Four eyes of four patients were treated by penetrating keratopla…

Spectral Transmission of the Human Corneal Layers

2021

Este artículo se encuentra disponible en la siguiente URL: https://www.mdpi.com/2077-0383/10/19/4490 Este artículo de investigación pertenece a la sección "Ophthalmology". We have assessed the spectral transmittance of the different layers of the human cornea in the ultraviolet (UV), visible, and near-infrared (IR) spectral ranges. Seventy-four corneal sample donors were included in the study. Firstly, the corneal transmittance was measured using a spectrophotometer. Then, all samples were fixed for histopathological analysis, which allowed us to measure the thickness of each corneal layer. Finally, the absorption coefficients of the corneal layers were computed by a linear model reproducin…

Testing abnormality in the spatial arrangement of cells in the corneal endothelium using spatial point processes

2001

The study of central corneal endothelium morphology is important in Ophthalmology. Some of the pathologies that could compromise endothelial cell morphology are trauma, cataract, surgery, use of contact lenses, corneal dystrophies or degenerations. The quantitative analysis of cell shape and cellular pattern is more sensitive in detecting subtle changes in endothelial morphology than cell density measurement or cell area analysis. In this paper, the morphology of the central cornea, the most important area from the point of view of vision, is studied through an associated bivariate spatial point pattern: the centroids of the cells and the triple points, that is, the points where three diffe…

Refractive analysis of the human cornea through propagated fields

2001

A new technique for analysing the optical quality of the human cornea is presented. Corneal maps are obtained through keratographies and then converted into phase maps. The propagated fields generated from this surface are plotted and studied. It is shown that any irregularity in the cornea affects the propagated field and the energy distribution at the focal plane. Simple applications are also indicated.

Improvement of dry eye symptoms with polyunsaturated fatty acids

2006

International audience; Purpose: Polyunsaturated fatty acids (PUFA) are involved in inflammatory pathways via prostaglandins. Conjunctival inflammation is a hallmark of all dry eye syndromes. We investigated the role of dietary n–6 and n–3 fatty acids in patients suffering from ocular dryness with peculiar attention to inflammatory markers. Methods: 70 patients presenting with mild to moderate dry eye syndromes were randomly assigned to Nutrilarm® or placebo pills, thrice a day for 6 months. Schirmer test, BUT, fluorescein and lissamin green stainings were performed at inclusion and after 1, 3 and 6 months. Impression cytology to evaluate MHCII antigens was harvested at D0, Month 3 and 6. T…

Tono oculare espessore oculare

2004

Estudio comparativo de la morfología de la superficie anterior de la córnea en dos grupos poblacionales ecuatorianos: indígenas y afroecuatorianos en…

2019

Introducción: El principal motivo de este estudio es determinar las características morfológicas de la superficie corneal anterior de dos grupos poblacionales en la provincia de Imbabura- Ecuador, obtenidos por medio de un topógrafo corneal de reflexión Tomey TMS– 4N. Metodología: Se incluyeron dos grupos poblacionales dentro de esta investigación. Se analizaron 100 ojos de 100 sujetos (mujeres 66, hombres 34) y como segundo grupo, a la población afroecuatoriana ubicada en la misma provincia, donde se estudiaron 95 ojos de 95 sujetos (mujeres 46, hombres 49). Rango de edad comprendido entre los 20 y 45 años. En todos los pacientes se realizó un examen de topografía corneal anterior mediante…

Anillos intracorneales de 5mm versus 6mm en el tratamiento de la ectasia corneal: estudio comparativo

2014

El queratocono (QTC) es la patología ectásica corneal por excelencia. Es una enfermedad corneal progresiva, donde la córnea adopta forma cónica, por adelgazamiento del estroma, con el consiguiente astigmatismo irregular y miopía, que conducen a un compromiso visual. Aparece en la pubertad y progresa hasta la tercera o cuarta década de la vida cuando se paraliza, por ello se considera única entre las enfermedades oculares. La aparición de una técnica aditiva de materiales sintéticos intraestromales llena un espacio en el tratamiento de la ectasia, retrasando el trasplante. Entre ellos están los anillos de sección triangular Keraring ® , que son los que ocupan este estudio. La redistribución …

Presbyopia and the aging eye: Existing refractive approaches and their potential impact on dry eye signs and symptoms.

2020

Every part of the human body is subject to aging, including the eye. Increased prevalence of dry eye disease with age is widely acknowledged: aging threatens ocular surface homeostasis, altering the normal functioning of the lacrimal functional unit and potentially leading to signs and symptoms of dry eye. Parallelly, two additional degenerative processes take place within the crystalline lens, leading to presbyopia and cataractogenesis. With continuously increasing life expectancies both conditions are expected to impact society further. Correction strategies for presbyopia and cataracts either directly or indirectly challenge ocular surface additionally. On one hand, contact lens presbyop…

Microphthalmia, persistent hyperplastic hyaloid vasculature and lens anomalies following overexpression of VEGF-A188 from the αA-crystallin promoter

2007

Purpose During growth of the embryonic eye, dose- and site-specific expression of heparin-binding growth factors is critical for the formation of an appropriate vascular supply. Overexpression of vascular endothelial growth factor-A188 (VEGF-A188), a strongly heparin-binding, endothelial-specific mitogen, leads to severe disturbance of vascular and overall ocular morphology. This study aimed to evaluate the effects of VEGF-A188 overexpression on growth of ocular tissue components. Methods Stereological and immunohistochemical methods were employed to identify the vascular profiles, ocular tissue proportions, and cell types in VEGF-A188 transgenic mice and compare them with wild-type mice. R…