Search results for "Retina"
showing 10 items of 864 documents
Central retinal artery occlusion-A new, provisional treatment approach.
2019
The retinal ganglion cells infarcted in central retinal artery occlusion (CRAO) are the somata of the optic nerve axons, part of the central nervous system. Consequently, CRAO with inner retinal infarction is a small vessel stroke, usually with the devastating consequence of severe visual loss in the affected eye. At present, there is no generally accepted, evidence-based therapy of nonarteritic CRAO in contrast to ischemic cerebral stroke that has well-accepted treatment protocols. Widely divergent and controversial therapeutic options for CRAO reflect the desperation of treating physicians and disparate conflicting studies. We examine reasons why treatment of nonarteritic CRAO remains pro…
Measuring the refractive state of an eye based on the intensity of the retinal reflex
2017
AbstractWhen examining the fundus of the eye with an ophthalmoscope, the intensity of the retinal reflex depends on the refractive state of the eye. In this study, application of this phenomenon for measuring the refractive state of the eye is demonstrated. First, a calibration curve relating the intensity of the retinal reflex and the refractive state was obtained using a model eye. Next, the intensity of the retinal reflex was measured while subjects were viewing a checker-board pattern, the distance of which was varied within the range from 0.17 to 1 m. Further, the relation between the refractive state and the optical power of the stimulus could be determined based on the measured light…
Retinal nerve fibre layer thickness measurements in myopia by optical coherence tomography
2014
Aim: Our study aimed to evaluate through OCT, in a homogeneous group of subjects with various degrees of myopia, the macular thickness and that of the RNFL with the purpose of highlighting the possible presence of a correlation between their impairment and the degree of myopia. Material and Methods : 83 students of the Faculty of Medicine were considered, distinguished into 4 groups, 3 of them according to the degree of myopia and the last group (control group) was made of emmetropic subjects. Each subject was submitted to a determination of visual acuity and refractive defect and evaluation of the thickness of the macular fibres and of the retinal nerve fibre layer (RNFL) through OCT (Stra…
Characterization of a new murine retinal cell line (MU-PH1) with glial, progenitor and photoreceptor characteristics
2013
Unlike fish and amphibians, mammals do not regenerate retinal neurons throughout life. However, neurogenic potential may be conserved in adult mammal retina and it is necessary to identify the factors that regulate retinal progenitor cells (RPC) proliferative capacity to scope their therapeutic potential. Müller cells can be progenitors for retinal neuronal cells and can play an essential role in the restoration of visual function after retinal injury. Some members of the Toll-like receptor (TLR) family, TLR2, TLR3 and TLR4, are related to progenitor cells proliferation. Müller cells are important in retinal regeneration and stable cell lines are useful for the study of retinal stem cell bi…
Chronoendokinologia — Quo vadis?
2002
The present review deals with important new chronobiological results especially in the field of chronoendocrinology, shedding new light on the circadian organisation of mammals including man. In vitro studies have shown that the concept of the existence of a single circadian oscillator located in the suprachiasmatic nucleus has to be extended. Circadian oscillators have also been found to exist in the retina, islets of Langerhans, liver, lung, and fibroblasts. Another major result is the detection of a new photopigment, melanopsin, present in a subpopulation of retinal ganglion cells which are lightsensitive and project to the suprachiasmatic nucleus, acting as zeitgeber for the photic entr…
Daily Profile in Melanopsin Transcripts Depends on Seasonal Lighting Conditions in the Rat Retina
2007
The retinal photopigment melanopsin (Opn4) mediates photoentrainment of the circadian system. In the present study, seasonal regulation of the melanopsin gene was investigated in comparison with the arylalkylamine N-acetyltransferase (AA-NAT) gene as an indicator of retinal pacemaker output. For this purpose, the daily profiles in the amount of melanopsin mRNA and AA-NAT mRNA were monitored under 8 : 16 h light/dark, 12 : 12 h light/dark and 16 : 8 h light/dark photoperiods using real-time polymerase chain reaction analysis. We found that, under all of the lighting regimes, melanopsin and AA-NAT expression oscillated with a peak around dark onset and the middle of the dark phase, respective…
Microaneurysms detection with the radon cliff operator in retinal fundus images
2010
ABSTRACT Diabetic Retinopathy (DR) is one of the leading causes of blindness in the industrialized world. Early detection is thekey in providing effective treatment. However, the current number of trained eye care specialists is inadequate to screenthe increasing number of diabetic patients. In recent years, automated and semi-automated systems to detect DR withcolor fundus images have been developedwith encouraging,but not fully satisfactory results. In this study we present theinitial results of a new techniquefor the detection and localization of microaneurysms,an early sign of DR. The algorithmis based on three steps: candidates selection, the actual microaneurysms detection and a Þnal …
Dectin-1 mediatesin vitrophagocytosis ofCandida albicansyeast cells by retinal microglia: Figure 1
2011
We have investigated the expression of TLR2 and Dectin-1 in retinal microglia and their involvement in Candida albicans phagocytosis using a cytometric approach. The expression of both receptors has been demonstrated in CD11b+ retinal cells. Phagocytosis of pHrodo-labelled C. albicans yeasts by microglial CD11b+ cells of C57BL/6 mice was inhibited both by the Dectin-1 antagonist laminarin and anti-Dectin-1 antibodies, whereas phagocytosis of yeasts by retinal microglia of TLR2 KO mice was unaffected. These data indicate that phagocytosis of C. albicans yeasts by retinal microglia is mediated by Dectin-1, whereas TLR2 does not play a significant role in this process.
Long-term intake of Lacticaseibacillus helveticus enhances bioavailability of omega-3 fatty acids in the mouse retina
2023
Omega-3 (n-3) polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA), are required for the structure and function of the retina. They could also help to prevent or delay the development of retinopathies. Given the accumulating evidence showing the role of gut microbiota in regulating retinal physiology and host lipid metabolism, we evaluated the potential of long-term dietary supplementation with the Gram-positive bacterium Lacticaseibacillus helveticus strain VEL12193 to modulate the retinal n-3 PUFA content. A set of complementary approaches was used to study the impact of such a supplementation on the gut microbiota and host lipid/fatty acid (FA) metabolism. L. helv…
Total retinal detachment caused by a KIF11 mutation.
2017
Purpose This is a case report of bilateral retinal detachment associated with KIF11 mutation. Methods In our university hospital, an 8-week-old patient presented with a potential bilateral congenital cataract, iris atrophy, and iridocorneal contact in the left eye. An examination revealed microcephaly and edema of the dorsa of the feet. The eye examination showed a clear lens in both eyes with a dislodged anterior chamber in the left eye with vessels drawn from the iris to the lens. A retrolental white bilateral mass with vessels was also observed. The MRI and the ultrasound revealed a potential peritoneal hyperplastic glass body. Bilateral retinal detachment was diagnosed during surgery. R…