Search results for "Retina"
showing 10 items of 864 documents
Automatic detection and classification of retinal vascular landmarks
2014
The main contribution of this paper is introducing a method to distinguish between different landmarks of the retina: bifurcations and crossings. The methodology may help in differentiating between arteries and veins and is useful in identifying diseases and other special pathologies, too. The method does not need any special skills, thus it can be assimilated to an automatic way for pinpointing landmarks; moreover it gives good responses for very small vessels. A skeletonized representation, taken out from the segmented binary image (obtained through a preprocessing step), is used to identify pixels with three or more neighbors. Then, the junction points are classified into bifurcations or…
Retinoblastoma epidemiology: Does the evidence matter?
2007
It has been proposed that retinoblastoma is 'caused' by two sequential mutations affecting the RB1 gene, but this is a rather outdated view of cancer aetiology that does not take into account a large amount of new acquisitions such as chromosomal and epigenetic alterations. Retinoblastoma remains probably the only cancer in which the rather simplistic 'two hit' mutational model is still considered of value, although cancer is known to be associated with genomic and microsatellite instability, defects of the DNA mismatch repair system, alterations of DNA methylation and hystone acethylation/deacethylation, and aneuploidy. Moreover, as it is shown herein, the predictions made by the 'two hit'…
Effects of Early Postfiltration Ocular Hypotony on Visual Acuity, Long-term Intraocular Pressure Control, and Posterior Segment Morphology
2001
Purpose To determine whether hypotony after filtration surgery has any influence on visual acuity and intraocular pressure (IOP) lowering. Patients and methods We prospectively investigated 43 eyes of 43 patients undergoing trabeculectomy without the use of antimetabolites for 12 months. Results The lowest postoperative IOP valued 4.9 +/- 3.6 mm Hg (range, 0-14 mm Hg). It correlated statistically significant with the IOP 6 weeks (P = 0.016), 6 months (P = 0.009), and 1 year after surgery (P = 0.027). Eyes with a deterioration of visual acuity 6 weeks after surgery had undergone a stronger postoperative hypotony (correlation with lowest postoperative IOP, P = 0.035). The mean period with an …
A Highly Decreased Binding of Cyclic Adenosine Monophosphate to Protein Kinase A in Erythrocyte Membranes is Specific for Active Psoriasis
2002
A cyclic adenosine monophosphate binding abnormality in psoriatic erythrocytes that could be corrected by retinoid treatment has been reported. It was tested whether this binding abnormality is specific for psoriasis and the effects of treatment were compared with etretinate, cyclosporine A, or anthralin on 2-(3)H-8-N(3)-cyclic adenosine monophosphate binding to the regulatory subunit of protein kinase A in erythrocyte membranes. One hundred and fifteen individuals were evaluated, including: (i) 34 healthy persons; (ii) 15 patients with nonatopic inflammatory skin diseases (eczema, erythroderma, tinea, Grover's disease, erysipelas, urticaria); (iii) eight with other dermatoses mediated by i…
Retinal vessel analysis and heart rate variability
2014
Heart rate variability (HRV) is used to index the vegetative nervous system and is linked with cardiovascular and nervous diseases [1]. Funduscopic assessment of the retinal vasculature can be utilized to evaluate the health status of microcirculation and to assess the predisposition of major vascular diseases [2]. The purpose of this study was, for the first time, to examine the influence of HRV on microcirculation as an early marker of cardiovascular alteration. The study population was comprised of apparently healthy employees of a high-tech company in Germany. The participants spanned the entire age of the work force (18–65 years) and all levels of socioeconomic status. A total of 292 s…
Two Novel Deletions (Array CGH Findings) in Pigment Dispersion Syndrome
2007
Purpose: We report the first male with pigment dispersion syndrome and a balanced translocation t(10;15)(p11.1;q11.1). Methods: Cytogenetic analyses using Giemsa banding and FISH methods, and array CGH were performed. Results: Array CGH analyses did not show altered DNA sequences in the breakpoints of the translocation, but revealed two novel deletions in 2q22.1 and 18q22.1. Conclusion: We suppose that the coexistence of t(10;15) and pigment dispersion syndrome in our patient is a coincidence. The deletion in 2q22.1, where the gene LRP1B has been located, may play a major role in the dysembryogenesis of the eye and cause the disorder.
CORRELATION OF OPTICAL COHERENCE TOMOGRAPHY PATTERN AND VISUAL RECOVERY AFTER VITRECTOMY WITH SILICONE OIL FOR RETINAL DETACHMENT
2006
PURPOSE: To assess prospectively the features of the macular surface in silicone oil-filled eyes after surgery by analyzing whether silicone oil affects optical coherence tomography (OCT) measurements and their reproducibility and whether a statistical correlation exists between postoperative best-corrected visual acuity (BCVA) and foveal thickness measured by OCT. METHODS: Twenty eyes of 20 patients underwent vitrectomy with silicone oil tamponade for retinal detachment. After vitrectomy, complete ophthalmic examination including determination of BCVA and OCT was performed to quantify the visual recovery and the foveal thickness. RESULTS: Ophthalmoscopy revealed that the retina appeared to…
Association of Birth Weight With Foveolar Thickness in Adulthood: Results From a Population-Based Study
2021
Purpose Low birth weight (BW) is associated with alterations of foveal shape development in childhood—leading to an increased retinal thickness of the fovea. The aim of the present study was to assess whether BW has a long-term effect on foveal retinal thickness (RT) and is still present in adulthood. Methods In the German population-based Gutenberg Health Study (GHS), participants were examined with spectral-domain optical coherence tomography. The association between self-reported BW and RT in the foveolar and perifoveal locations was assessed. Multivariable linear regression analyses with adjustment for potential confounders and grading of foveal hypoplasia were performed. Results Overal…
Analysis of Autoantibodies Against Human Retinal Antigens in Sera of Patients with Glaucoma and Ocular Hypertension
2008
The aim of this study was to show that complex antibody patterns against retinal antigens in sera of patients with glaucoma, found in previous studies, are autoantibodies against human antigens.Sera of 179 patients were collected at the Department of Ophthalmology (University of Mainz, Germany): non-glaucomatous control patients (n=45), primary open-angle glaucoma (n=45), ocular hypertension (n=44), and normal tension glaucoma patients (n=45). The sera were tested against Western blots of human retinal antigens. IgG antibody patterns were analyzed by multivariate statistical techniques, and some significant antigens were identified by mass spectrometry.All subjects, even healthy ones, showe…
PREVALENCE AND ASSOCIATIONS OF MYELINATED RETINAL NERVE FIBERS
2016
PURPOSE To determine the prevalence, ocular, and systemic associations of myelinated retinal nerve fibers (MRNF) in a Caucasian cohort. METHODS The Gutenberg Health Study (GHS) is a population-based, prospective cohort study encompassing 15,010 subjects in Germany. Gutenberg Health Study participants, aged 35 to 74 years, stratified for gender, decades of age, and residence were examined for ophthalmologic and systemic conditions. Optic disc centered and macular photographs were reviewed for the presence of MRNF. RESULTS In 25,728 eyes of 12,906 participants (86.0% of the cohort), the prevalence of MRNF was 0.4%. In a binary logistic regression analysis, MRNF was positively associated with …