Search results for "Retina"
showing 10 items of 864 documents
TRANSCONJUNCTIVAL NONVITRECTOMIZING VITREOUS SURGERY VERSUS 25-GAUGE VITRECTOMY IN PATIENTS WITH EPIRETINAL MEMBRANE
2015
Purpose: To compare the clinical outcomes and the rate of complications of 27-gauge transconjunctival nonvitrectomizing vitreous surgery (NVS) and of 25-gauge transconjunctival sutureless vitrectomy surgery for idiopathic epiretinal membrane removal. Methods: In this prospective randomized study, 83 phakic eyes of 83 consecutive patients with an idiopathic epiretinal membrane were randomized to receive 27-gauge NVS (NVS-group) or 25-gauge vitrectomy (Standard-group). Main outcome measures were best-corrected visual acuity, central retinal thickness, nuclear density units' changes, and rate of complications. Results: Thirty-nine eyes of the Standard-group and 40 of the NVS-group were conside…
Microvascular effects of the inhibition of dipeptidylpeptidase IV by linagliptin in nondiabetic hypertensive patients
2015
Recent studies suggest vascular benefits of dipeptidylpeptidase IV (DPP-IV) inhibition in patients with diabetes mellitus. Only little is known about potential vascular effects of DPP-IV inhibitors in nondiabetic individuals. The aim of this study was to investigate the effect of DPP-IV inhibition in a nondiabetic hypertensive population.This was a double-blinded, randomized, placebo-controlled, mechanistic study, comparing microvascular effects of the DPP-IV inhibitor linagliptin with placebo in nondiabetic individuals with a history of arterial hypertension. Twenty-one patients received 5 mg linagliptin (5 women; age 67.6 ± 6.0 years; mean ± SD), whereas 22 patients were randomized to pla…
Melatonin signaling modulates clock genes expression in the mouse retina.
2014
Previous studies have shown that retinal melatonin plays an important role in the regulation of retinal daily and circadian rhythms. Melatonin exerts its influence by binding to G-protein coupled receptors named melatonin receptor type 1 and type 2 and both receptors are present in the mouse retina. Earlier studies have shown that clock genes are rhythmically expressed in the mouse retina and melatonin signaling may be implicated in the modulation of clock gene expression in this tissue. In this study we determined the daily and circadian expression patterns of Per1, Per2, Bmal1, Dbp, Nampt and c-fos in the retina and in the photoreceptor layer (using laser capture microdissection) in C3H-f…
Retinal nerve fibre layer and brain grey substance as early prognostic factors for disability in multiple sclerosis.
2012
We read with interest the article by Bock et al ,1 in which the association between retinal nerve fibre layer (RNFL) and total macular volume (TMV) was analysed by optical coherence tomography (OCT) and contrast sensitivity was measured by functional acuity contrast testing in relapsing-remitting multiple sclerosis (MS) patients. The authors found that the functional contrast vision in MS is influenced by morphological changes in the anterior visual pathway. This work emphasised that contrast sensitivity is reduced in MS, and that RNFL and TMV, as morphological measures of retinal axon loss, are predictors of contrast sensitivity. Ophthalmological examinations were the basis of the Bock et …
Enhanced depth imaging optical coherence tomography of the choroid in idiopathic macular hole: A cross-sectional prospective study.
2010
Purpose To determine the choroidal thickness in the macular area in patients with idiopathic macular hole in one eye and an unaffected fellow eye and in healthy controls. Design Cross-sectional, prospective study. Methods Twenty-two patients with a full-thickness unilateral idiopathic macular hole and 22 age- and sex-matched controls were recruited. Enhanced depth imaging optical coherence tomography images were obtained by using spectral-domain optical coherence tomography. The choroidal thickness was measured in the subfoveal area and 1000 μm and 2000 μm away from the fovea in the nasal and temporal regions. The diameter of the macular hole and the axial length were determined. Results Ch…
Color Doppler Imaging of the Ocular Ischemic Syndrome
1992
Purpose: This study describes hemodynamic characteristics of the ophthalmic, central retinal, and posterior ciliary arteries in 16 eyes of 11 patients with the ocular ischemic syndrome. Understanding the hemodynamic characteristics of the retrobulbar circulation may elucidate the natural history and pathophysiology of the ocular ischemic syndrome and perhaps form the basis for rational treatment of this condition. Methods: Color Doppler imaging, a procedure that permits rapid noninvasive imaging of the ophthalmic, central retinal, and posterior ciliary arteries, was used to quantitate peak systolic blood flow velocities and vascular resistance (pulsatility index) within these vessels in stu…
Betulinic Acid Protects from Ischemia-Reperfusion Injury in the Mouse Retina
2021
Ischemia/reperfusion (I/R) events are involved in the pathophysiology of numerous ocular diseases. The purpose of this study was to test the hypothesis that betulinic acid protects from I/R injury in the mouse retina. Ocular ischemia was induced in mice by increasing intraocular pressure (IOP) to 110 mm Hg for 45 min, while the fellow eye served as a control. One group of mice received betulinic acid (50 mg/kg/day p.o. once daily) and the other group received the vehicle solution only. Eight days after the I/R event, the animals were killed and the retinal wholemounts and optic nerve cross-sections were prepared and stained with cresyl blue or toluidine blue, respectively, to count cells in…
Involvement of plasmalogens in post-natal retinal vascular development
2014
Objective: Proper development of retinal blood vessels is essential to ensure sufficient oxygen and nutrient supplies to the retina. It was shown that polyunsaturated fatty acids (PUFAs) could modulate factors involved in tissue vascularization. A congenital deficiency in ether-phospholipids, also termed "plasmalogens'', was shown to lead to abnormal ocular vascularization. Because plasmalogens are considered to be reservoirs of PUFAs, we wished to improve our understanding of the mechanisms by which plasmalogens regulate retinal vascular development and whether the release of PUFAs by calcium-independent phospholipase A2 (iPLA2) could be involved. [br/] Methods and Results: By characterizi…
Chromatic-achromatic perimetry in four clinic cases: Glaucoma and diabetes
2015
Color perimetry has interesting clinical application for the diagnosis and detection of certain eye conditions, due to the variations that certain diseases can cause in chromatic thresholds, both in the red-green (RG) and the blue-yellow (BY) pathways.[1,2,3,4] The separate study of the visual function of both the chromatic and achromatic mechanisms could be more efficient in detecting sensitivity variations, and such variations would not be obscured by the intrusion of other mechanisms. Currently, the supply of conventional perimeters that are capable of performing a chromatic perimetry test is very limited and with reduced options regarding the possibility of choosing the physical charact…
Effect of sport-tinted contact lenses for contrast enhancement on retinal straylight measurements
2008
PURPOSE: To investigate the effect of two tinted contact lenses (CL) designed for outdoor sports activity on the psychometric determination of retinal straylight using the compensation comparison method. METHODS: Thirteen emmetropic subjects were randomly fitted with two different tinted Nike Maxsight (Bausch & Lomb, Rochester, NY, USA) CL in one eye, while the contralateral eye was fitted with a clear lens made of the same material (Optima 38, Bausch & Lomb). Three valid straylight measurements were taken on each eye before and a few minutes after lens insertion, when lens stabilization had occurred. RESULTS: The subjects' mean straylight values were 0.90 +/- 0.09 at baseline and 0.95 +/- …