Search results for "Cornea"
showing 10 items of 404 documents
Blink reflex R2 changes and localisation of lesions in the lower brainstem (Wallenberg's syndrome): an electrophysiological and MRI study
1999
OBJECTIVES—Pathways of late blink reflexes are detected by high resolution MRI. Electronically matched stroke lesions superimposed to an anatomical atlas show the suspected course. METHODS—Fifteen patients with infarction of the lower brainstem, MRI lesions and electrically elicited blink reflexes were examined. The involved structures in patients with R2 and R2c blink reflex changes were identified by biplane high resolution MRI with individual slices matched to an anatomical atlas at 10 different levels using digital postprocessing methods. RESULTS—The blink reflexes were normal in five of 15 patients (33%) and showed loss or delay of R2 and R2c to stimulation ipsilaterally to lesion (R2-…
Ocular Phenotype of Relaxin Gene Knockout (Rln-/-) Mice
2020
Purpose: To test if relaxin deficiency affects ocular structure and function we investigated expression of relaxin (Rln) and RXFP receptors (Rxfp1, Rxfp2), and compared ocular phenotypes in relaxin gene knockout (Rln-/- ) and wild type (Rln+/+ ) mice. Materials and Methods: Rln, Rxfp1 and Rxfp2 mRNA expression was detected in ocular tissues of Rln+/+ mice using RT-PCR. The eyes of 11 Rln-/- and 5 Rln+/+ male mice were investigated. Corneal and retinal thickness was assessed using optical coherence tomography. Intraocular pressure was measured using a rebound tonometer. Retinal, choroidal and sclera morphology and thickness were evaluated histologically. Eyes were collected and fixed for imm…
Amyloidosis and Ocular Involvement: an Overview.
2019
Purpose: To describe the ophthalmic manifestations of amyloidosis and the corresponding therapeutic measures.Methods: The 178 patients included in the study had different types of amyloidosis, diagnosed at a single internal medicine institution (Bari, Italy). To provide a comprehensive review of the types of amyloidosis that can be associated with ocular involvement, the images and clinical descriptions of patients with amyloidosis structurally related to gelsolin, keratoepithelin and lactoferrin were obtained in collaborations with the ophthalmology departments of hospitals in Mainz (Germany) and Helsinki (Finland).Results: Overall, ocular morbidity was detected in 41 of the 178 patients w…
Recurrent Granular Dystrophy of the Cornea
2006
Purpose: To describe a case of severe corneal granular dystrophy with clinicopathologic and molecular genetic findings. Methods: The DNAs of a 53-year-old male patient suffering from corneal granular dystrophy and nonaffected family members was analyzed by molecular genetic methods. Clinical features, and histopathologic and immunohistochemical findings from the penetrating keratoplasty specimen, are described. Results: Histopathologic and molecular genetic findings confirmed the diagnosis. A new genetic polymorphism is described. Histopathologic evidence supports the assumption of the epithelial origin of the described dystrophy. Conclusions: A severe course of corneal granular dystrophy c…
Polyhydroxyethylaspartamide-based micelles for ocular drug delivery
2009
In this paper three copolymers of polyhydroxyethylaspartamide (PHEA), bearing in the side chains polyethylene glycol (PEG) and/or hexadecylamine (C(16)) (PHEA-PEG, PHEA-PEG-C(16) and PHEA-C(16) respectively) have been studied as potential colloidal drug carriers for ocular drug delivery. The physical characterization of all three PHEA derivatives, using the Langmuir trough (LT) and micellar affinity capillary electrophoresis (MACE) techniques allowed to assume that whereas alone PHEA backbone is an inert polymer with respect to the interactions with lipid membranes and drug complexation, when PHEA chains are grafted with long alkyl chains like C(16) or in combination C(16) chains and hydrop…
Genome-wide association study for refractive astigmatism reveals genetic co-determination with spherical equivalent refractive error: the CREAM conso…
2015
To identify genetic variants associated with refractive astigmatism in the general population, meta-analyses of genome-wide association studies were performed for: White Europeans aged at least 25 years (20 cohorts, N = 31,968); Asian subjects aged at least 25 years (7 cohorts, N = 9,295); White Europeans aged <25 years (4 cohorts, N = 5,640); and all independent individuals from the above three samples combined with a sample of Chinese subjects aged <25 years (N = 45,931). Participants were classified as cases with refractive astigmatism if the average cylinder power in their two eyes was at least 1.00 diopter and as controls otherwise. Genome-wide association analysis was carried out for …
No evidence for an association of plasma homocysteine levels and refractive error – Results from the population-based Gutenberg Health Study (GHS)
2020
Purpose There is a strong association between severe hyperhomocysteinemia and myopia. Thus we studied the hypothesis that even moderately increased levels of homocysteine (Hcy) might be a potentially treatable risk factor for myopia. Methods The Gutenberg Health Study (GHS) is a population-based, prospective, observational cohort study in Germany, including 15,010 participants aged between 35 and 74 at recruitment. The baseline examination was conducted from 2007–2012. Refraction was measured using autorefraction (HARK 599, Carl Zeiss AG, Jena, Germany). Hcy was measured by an immunoassay. We included only phakic participants without a history of corneal surgery or corneal laser treatment. …
Genetic variants associated with human eye size are distinct from those conferring susceptibility to myopia
2021
Purpose: Emmetropization requires coordinated scaling of the major ocular components, corneal curvature and axial length. This coordination is achieved in part through a shared set of genetic variants that regulate eye size. Poorly coordinated scaling of corneal curvature and axial length results in refractive error. We tested the hypothesis that genetic variants regulating eye size in emmetropic eyes are distinct from those conferring susceptibility to refractive error.Methods: A genome-wide association study (GWAS) for corneal curvature in 22,180 adult emmetropic individuals was performed as a proxy for a GWAS for eye size. A polygenic score created using lead GWAS variants was tested for…
Relative Peripheral Myopia Induced by Fractal Contact Lenses
2018
[EN] Purpose: To assess the peripheral refraction induced by Fractal Contact Lenses (FCLs) in myopic eyes by means of a two-dimensional Relative Peripheral Refractive Error (RPRE) map. Materials and Methods: This study involved 26 myopic subjects ranging from -0.50 D to -7.00 D. FCLs prototypes were custom-manufactured and characterized. Corneal topographies were taken in order to assess correlations between corneal asphericity and lens decentration. Two-dimensional RPREs were measured with an open-field autorefractor at 67 points, covering the central 60 x 30 degrees of the visual field. The bidimensional RPRE vector components: M, J(0) and J(45) of the difference between the values obtain…
XEN-augmented Baerveldt Implantation for Refractory Childhood Glaucoma: A Retrospective Case Series
2019
Background Tube implants can lead to long-term decompensation of the cornea after decades, in particular in complicated childhood glaucoma, because of a variety of causes including contact between the tube tip and the corneal endothelium. The augmentation of a XEN implant with a Baerveldt (250) tube implant, introduced 2016 by Mermoud et al for refractory glaucoma in adult patients, may reduce this risk in children. In our retrospective study, we report on the XEN-augmented Baerveldt (250) tube implant in children. Patients and methods Ten consecutive patients with refractory childhood glaucoma who underwent XEN-augmented Baerveldt implantation by a single surgeon (F.G.) between January 201…