Search results for "RETINA"

Mutations in ARL2BP, Encoding ADP-Ribosylation-Factor-Like 2 Binding Protein, Cause Autosomal-Recessive Retinitis Pigmentosa

2013

Retinitis pigmentosa (RP) is a genetically heterogeneous retinal degeneration characterized by photoreceptor death, which results in visual failure. Here, we used a combination of homozygosity mapping and exome sequencing to identify mutations in ARL2BP, which encodes an effector protein of the small GTPases ARL2 and ARL3, as causative for autosomal-recessive RP (RP66). In a family affected by RP and situs inversus, a homozygous, splice-acceptor mutation, c.101−1G>C, which alters pre-mRNA splicing of ARLBP2 in blood RNA, was identified. In another family, a homozygous c.134T>G (p.Met45Arg) mutation was identified. In the mouse retina, ARL2BP localized to the basal body and cilium-associated…

Computer assisted evaluation of retinal vessels tortuosity in Fabry disease.

2012

. Purpose:  Fabry Disease (FD) is a rare X-linked metabolic disorder characterized by diffuse deposition of sphingolipids in many tissues. Retinal vessel tortuosity is a common ocular manifestation in FD and may represent a useful marker for the disease. Unfortunately its clinical evaluation is poorly reproducibile and alternative means of evaluation may be of interest. We tested a new semi-automatic software measuring retinal vessel tortuosity from eye fundus digital images in a group of FD patients. Methods:  Observational case-control study evaluating four mathematical parameters describing tortuosity (relative length, sum of angle metric [SOAM], product of angle distance [PAD], triangul…

A novel constitutional mutation affecting splicing of retinoblastoma tumor suppressor gene intron 23 causes partial loss of pRB activity.

2005

Hereditary predisposition to retinoblastoma is caused by germ line mutations in the RB1 gene. Genetic counseling of affected individuals and accurate risk prediction for their families requires identification of the disease causing mutation. Furthermore, the nature of a mutation can determine genetic penetrance, disease presentation and prognosis. We describe, and functionally characterize here, a novel mutant allele of RB1 present in the germ line of a patient with sporadic bilateral retinoblastoma. The mutation generates an operational splice acceptor site resulting in a predicted protein product with loss of 81 amino acids from its carboxy terminus. We demonstrate that the aberrantly spl…

Immunohistochemical analysis of cellular adhesion molecules (ICAM-1, VCAM-1) and VEGF in fibrovascular membranes of patients with proliferative diabe…

2009

Abstract Purpose Diabetic fibrovascular membranes are the main pathological changes of proliferative diabetic retinopathy that can cause serious complications leading to blindness. Since the mechanism of fibrovascular membrane development is still unknown, the aim of our study was to identify potential biomarkers for this pathology. To this end, we analyzed the simultaneous expression of ICAM-1, VCAM-1 and VEGF within tissues of diabetic fibrovascular membranes. Patients and methods Fibrovascular membranes were taken from nine diabetic patients with proliferative diabetic retinopathy. The fibrovascular membrane specimens were analyzed by immunohistochemistry to determine ICAM-1, VCAM-1 and …

Ranibizumab for Branch Retinal Vein Occlusion Associated Macular Edema Study (RABAMES): six-month results of a prospective randomized clinical trial

2014

Purpose To compare standard-of-care grid laser photocoagulation versus intravitreal ranibizumab (IVR) versus a combination of both in the treatment of chronic (>3 months) macular oedema secondary to branch retinal vein occlusion. Methods Prospective, randomized, multicentre clinical trial. Thirty patients with a best-corrected visual acuity (BCVA) between 20/320 and 20/40 were randomized 1:1:1 to receive grid laser or three monthly injections of 0.5 mg IVR or both followed by 3 months of observation. Results Mean change from baseline BCVA at month 6 was +2 letters [laser; 0.04 logMAR, 95% confidence interval (−0.17; 0.25)], +17 letters [IVR; 0.34 (0.19; 0.5)] and +6 letters [combination; 0.…

Elevated protein carbonyl and HIF-1α levels in eyes with proliferative diabetic retinopathy.

2013

Purpose: To evaluate the role of protein carbonyls and hypoxia inducible factor-1a (HIF-1a) in diabetic eyes with proliferative diabetic retinopathy (PDR). Methods: Prospective consecutive controlled observational study was performed. Vitreous samples were collected at the start of the 3-ppp vitrectomy. Protein carbonylation analysis was performed by Western blotting with antibody against 2,4-Dinitrophenol (anti-DNP), following derivatization of protein carbonyls with 2,4 Dinitrophenylhydrazine (DNHP). Protein carbonylation was quantified by scanning densitometry analysis and relativized to the total amount of protein into the ponceau staining of membranes. Vitreous HIF-1 a was determined w…

Monocular Versus Binocular Calibrations in Evaluating Fixation Disparity With a Video-Based Eye-Tracker

2015

When measuring fixation disparity (an oculomotor vergence error), the question arises as to whether a monocular or binocular calibration is more precise and physiologically more appropriate. In monocular calibrations, a single eye fixates on a calibration target that is taken as having been projected onto the center of the fovea; the corresponding vergence state represents the heterophoria (the resting vergence position), which has no effect on the calibration procedure. In binocular calibrations, a vergence error may be present and may affect the subsequent measurement of the fixation disparity during binocular recordings. This study includes a test of the precision of both monocular and …

Methodological Aspects of the Application of the Naka-Rushton Equation to Clinical Electroretinogram

1993

The nonlinear relation between stimulus intensity and response amplitude of the electroretinogram (ERG) scotopic b wave can be described by a curve based on the Naka-Rushton (NR) equation. Up to now, the NR equation has been used to assess the features of the normal and pathological ERG, but the best approach for a correct evaluation of the parameters is still debatable. The parameters are thought to be related to the different conditions of retinal activities. The method is well known in experimental laboratories but is quite unusual at the clinical level. In the present paper the derivative analysis of the NR function is proposed as an easier approach to understand the variations of the N…

Birthweight and its association with retinal vessel equivalents – Results from the population‐based German Gutenberg Health Study

2020

Associations of cardiovascular risk factors and retinal vessel dimensions at present and their evolution over time in a healthy working population.

2019

Purpose The aim of this study was to investigate whether an association between retinal vessel diameters with blood pressure and other risk factors exists in a healthy working population and whether current risk factors can be used as predictors for retinal vessel changes over time. Methods Retinal photographs and medical data were obtained during a voluntary work health check in 2010 and 2013. The central retinal arterial equivalent (CRAE) and central retinal venular equivalent (CRVE) were assessed using a semi-automated software. Linear regression analysis was carried out to determine associations with systemic parameters and cardiovascular risk factors. Results A total of 1685 participan…