WorldWideScience
1

Thyroid abnormality secondary to tortuous carotid artery  

International Nuclear Information System (INIS)

A 59-year-old man was referred to the nuclear medicine service for a thyroid scan, as his neck was thick and the thyroid was not palpable. In the past the patient had undergone head and neck irradiation for acne. A 123I-thyroid scan was interpreted as a ''cold'' nodule in the lower pole of the right lobe, but thyroid ultrasound showed no thyroid abnormality. Repeat ultrasound examination eventually showed a tortuous carotid artery behind the lower pole of the right lobe of the thyroid that corresponded to the ''cold'' defect. (orig.)

2

New techniques for intracranial stent navigation in patients with tortuous arteries  

International Nuclear Information System (INIS)

We wanted to describe several new techniques of intracranial stenting that are helpful for navigating the stent delivery system in the tortuous carotid or vertebral arteries. Between May 1998 and June 2004, 65 patients with 73 symptomatic, stenotic intracranial arteries (more than 50%) were successfully treated with stent-assisted angioplasty. In eleven of the total cases, the standard technique failed to navigate the stent delivery system into the objective lesion because of the tortuous path of the carotid or vertebral arteries. In these cases, several new techniques were used to overcome the vessels' tortuous path. The several new techniques were 1) the waiting method (20-30 minutes) after advancement of microwire across the lesion; 2) the double wires technique using an additional microwire; and 3) the coaxial double guiding catheters technique using an additional smaller guiding catheter. Five lesions were located in the middle cerebral arteries, four were in the supraclinoid internal carotid arteries, and two were in the distal vertebral arteries. In all difficult cases, intracranial artery stenting was performed successfully by using the several new techniques. The waiting method made smooth stent navigation possible in 5 cases, the double wire technique was successful in 4 cases and the coaxial double guiding catheter technique was successful in 2 case. There was no complication related to the new techniques. In difficult cases where the standard technique faiult cases where the standard technique failed to navigate the stent delivery system into the objective lesion because of the vessels' tortuous path, these new techniques for intracranial stent navigation were usefully implemented

3

Iliac artery occlusion with "oxbow lake" formation following stent deployment in a tortuous external iliac artery during EVAR: a case report.  

Science.gov (United States)

In this case report, we describe a complication that we term the "oxbow lake" deformity. This phenomenon occurs when a tortuous elongated external iliac artery segment is artificially straightened by an iliac stent resulting in kinking and compression of a redundant loop with lumen compromise. We describe the anatomy, corrective treatment, and outcome. This occurrence is potentially foreseeable with tortuous vascular anatomy and recognition can allow appropriate management planning avoiding complications for the patient. PMID:21788283

Culverwell, Adam D; Kent, Patrick; Puppala, Sapna

2011-10-01

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Computation of hemodynamics in tortuous left coronary artery: a morphological parametric study.  

Science.gov (United States)

Coronary tortuosity (CT) would alter the local wall shear stress (WSS) and may become a risk factor for atherosclerosis. Here we performed a systematic computational study to relate CT morphological parameters to abnormal WSS, which is a predisposing factor to the formation of atherosclerotic lesions. Several idealized left coronary artery (LCA) models were created to conduct a series of morphological parametric studies, in which we concentrate on three specific morphological parameters, the center line radius (CLR), the bend angle (BA), and the length between two adjust bends (LBB). The time averaged WSS (TAWSS), the oscillatory shear index (OSI), and the time averaged WSS gradient (WSSGnd) were explored by using the computational fluid dynamics (CFD) method, in order to determine susceptible sites for the onset of early atherosclerosis. In addition, two realistic LCA models were reconstructed to further validate the finding's credibility. The CLR and LBB had great impact on the distributions of WSS-derived parameters, while the BA had minor impact on the hemodynamic of the tortuous arteries. Abnormal regions with low TAWSS (TAWSS??0.1) and high WSSGnd (WSSGnd?>?8) were observed at the inner wall of bend sections in the models with small CLR or small LBB. These findings were also confirmed in the realistic models. Severe CT with small CLR or LBB would lead to the formation of abnormal WSS regions at the bend sections and providing these regions with favorable conditions for the onset and/or progression of atherosclerosis. PMID:25048524

Xie, Xinzhou; Wang, Yuanyuan; Zhu, Hongmin; Zhou, Jingmin

2014-10-01

5

Idiopathic pediatric retinal artery occlusion  

OpenAIRE

We report a case of branch retinal artery occlusion (BRAO) in a healthy young girl. An eight-year-old girl presented with sudden loss of vision in her left eye. She had a pale retina with macular edema consistent with extensive BRAO. A thorough workup was performed to determine any etiologic factor. All test results were within normal limits. Her visual acuity improved from finger counting to 20/40 over two weeks, on immediate treatment with intravenous steroids (methyl prednisolone). This ca...

Manayath George; Shah Parag; Narendran V; Morris Rodney

2010-01-01

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Idiopathic pediatric retinal artery occlusion  

Directory of Open Access Journals (Sweden)

Full Text Available We report a case of branch retinal artery occlusion (BRAO in a healthy young girl. An eight-year-old girl presented with sudden loss of vision in her left eye. She had a pale retina with macular edema consistent with extensive BRAO. A thorough workup was performed to determine any etiologic factor. All test results were within normal limits. Her visual acuity improved from finger counting to 20/40 over two weeks, on immediate treatment with intravenous steroids (methyl prednisolone. This case suggests that BRAO can occur in healthy children without any detectable systemic or ocular disorders and a dramatic improvement may be achieved with prompt treatment with intravenous steroids.

Manayath George

2010-01-01

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Bail-out coronary stenting in an extremely tortuous right coronary artery with the Palmaz-Schatz stent and Teleguide sheath.  

Science.gov (United States)

Significant vessel tortuosity is a relative contraindication to the use of the Palmaz-Schatz coronary stent for fear of stent displacement during delivery. We describe a patient with unstable angina in whom conventional coronary angioplasty in an extremely tortuous right coronary artery resulted in an occlusive dissection. Emergency bypass surgery was avoided by the successful placement of a protected Palmaz-Schatz stent using a 5F Teleguide sheath. PMID:8402861

Foran, J P; Nordrehaug, J E; Xynopoulos, G; Wainwright, R J

1993-09-01

8

Retinal arterial plaques in acquired immunodeficiency syndrome  

OpenAIRE

The authors report the unusual observation discrete plaque like excrescencies along the retinal arterial wall in a young patient with acquired immunodeficiency syndrome. Though bilateral, in the right eye there was severe arteriolar narrowing and so these plaques were less identifiable. Fluorescein angiography did not reveal any arteriolar occlusion or areas of capillary occlusion in both eyes. There were no other signs of HIV associated microangiopathy and the patient did not have any concur...

Satpal Garg; Harish Pathak; Pradeep Venkatesh

2012-01-01

9

Central retinal artery occlusion following cosmetic blepharoplasty.  

OpenAIRE

A case is presented of a 70-year-old white male who underwent a bilateral cosmetic lower lid blepharoplasty with fat removal. He subsequently developed a right orbital haemorrhage which resulted in the occlusion of the central retinal artery. The patient had no light perception with his right eye for approximately 1 hour, but vision was eventually restored to 20/20 after emergency therapeutic measures. There are many possible causes of visual loss following blepharoplasty, with orbital haemor...

Kelly, P. W.; May, D. R.

1980-01-01

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Treatment Options for Central Retinal Artery Occlusion  

OpenAIRE

Central retinal artery occlusion (CRAO) is an ocular emergency and is the ocular analogue of cerebral stroke. It results in profound, usually monocular vision loss, and is associated with significant functional morbidity. The risk factors for CRAO are the same atherosclerotic risk factors as for stroke and heart disease. As such, individuals with CRAO may be at risk of ischemic end organ damage such as a cerebral stroke. Therefore, the management of CRAO is not only to restore vision, but at ...

Cugati, Sudha; Varma, Daniel D.; Chen, Celia S.; Lee, Andrew W.

2012-01-01

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PHACE association with intracranial, oropharyngeal hemangiomas, and an atypical patent ductus arteriosus arising from the tortuous left subclavian artery in a premature infant  

Directory of Open Access Journals (Sweden)

Full Text Available PHACE association is a rare neurocutaneous condition in which facial hemangiomas associate with a spectrum of posterior fossa malformations, arterial cerebrovascular anomalies, cardiovascular anomalies, and eye anomalies. We reported a case of PHACE association in a premature infant showing facial, intracranial, and oropharyngeal hemangiomas with evidence of the Dandy-Walker variant and complicated cardiovascular anomalies, including a right-sided aortic arch and an atypical patent ductus arteriosus arising from a tortuous left subclavian artery. To our knowledge, intracranial hemangiomas are rare in PHACE association, and a concomitant oropharyngeal hemangioma has not been previously reported in the PHACE association literature. In infants presenting with large, plaque-like facial hemangiomas, it is important to conduct active cardiovascular and neurological evaluations. Special attention should be given to the laryngoscopic examination to search for additional hemangiomas in the airway.

Do-Hyun Kim

2012-01-01

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Orbital mucormycosis with retinal and ciliary artery occlusions.  

Science.gov (United States)

A 61-year-old man presented with acute, painful loss of vision in the left eye due to a central retinal artery occlusion. Fluorescein angiography confirmed the central retinal artery occlusion and also identified a nasal posterior ciliary artery occlusion. CT scanning revealed a left medial orbital mass with adjacent ethmoid sinusitis. Transnasal ethmoid biopsy disclosed mucormycosis. A left external ethmoidectomy, maxillectomy, and orbital exploration were performed, after which the patient was treated with daily intravenous amphotericin B for six weeks. Coexistence of retinal and nasal posterior ciliary artery occlusion due to mucormycosis may relate to their common origin from the ophthalmic artery. Treatment without exenteration was successful. PMID:2765451

Luo, Q L; Orcutt, J C; Seifter, L S

1989-08-01

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Retinal arterial plaques in acquired immunodeficiency syndrome  

Directory of Open Access Journals (Sweden)

Full Text Available The authors report the unusual observation discrete plaque like excrescencies along the retinal arterial wall in a young patient with acquired immunodeficiency syndrome. Though bilateral, in the right eye there was severe arteriolar narrowing and so these plaques were less identifiable. Fluorescein angiography did not reveal any arteriolar occlusion or areas of capillary occlusion in both eyes. There were no other signs of HIV associated microangiopathy and the patient did not have any concurrent cardiovascular or hematological abnormality. The cause of these plaques remains unexplained and we conjecture that they could represent macro immunecomplex deposition along the arteriolar walls.

Satpal Garg

2012-03-01

14

Retinal arterial plaques in acquired immunodeficiency syndrome  

Directory of Open Access Journals (Sweden)

Full Text Available The authors report the unusual observation discrete plaque like excrescencies along the retinal arterial wall in a young patient with acquired immunodeficiency syndrome. Though bilateral, in the right eye there was severe arteriolar narrowing and so these plaques were less identifiable. Fluorescein angiography did not reveal any arteriolar occlusion or areas of capillary occlusion in both eyes. There were no other signs of HIV associated microangiopathy and the patient did not have any concurrent cardiovascular or hematological abnormality. The cause of these plaques remains unexplained and we conjecture that they could represent macro immunecomplex deposition along the arteriolar walls.

Satpal Garg

2012-01-01

15

Orbital mucormycosis with retinal and ciliary artery occlusions.  

OpenAIRE

A 61-year-old man presented with acute, painful loss of vision in the left eye due to a central retinal artery occlusion. Fluorescein angiography confirmed the central retinal artery occlusion and also identified a nasal posterior ciliary artery occlusion. CT scanning revealed a left medial orbital mass with adjacent ethmoid sinusitis. Transnasal ethmoid biopsy disclosed mucormycosis. A left external ethmoidectomy, maxillectomy, and orbital exploration were performed, after which the patient ...

Luo, Q. L.; Orcutt, J. C.; Seifter, L. S.

1989-01-01

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Presumed toxoplasmic central retinal artery occlusion and multifocal retinitis with perivascular sheathing  

Directory of Open Access Journals (Sweden)

Full Text Available Haruka Arai,1 Tsutomu Sakai,1 Kiichiro Okano,1 Ranko Aoyagi,1 Ayano Imai,2 Hiroshi Takase,2 Manabu Mochizuki,2 Hiroshi Tsuneoka11Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan; 2Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University, Tokyo, JapanAbstract: Central retinal artery occlusion (CRAO and multifocal retinitis with perivascular sheathing are rare in ocular toxoplasmosis. We report a case of toxoplasmic CRAO and multifocal retinitis with perivascular sheathing. A healthy 83-year-old male developed left panuveitis. Funduscopic examination of the left eye showed a swollen optic disc and sheathing of the retinal artery with a dense vitreous haze and a white retinal lesion. Serum anti-toxoplasma antibodies were positive in a latex agglutination assay. Vitrectomy was performed to improve visualization of the retinal lesions and for examination of causative microorganisms. A postoperative fundus examination revealed CRAO with optic disc involvement and multifocal retinitis with perivascular sheathing. Qualitative multiplex polymerase chain reaction detected the Toxoplasma gondii B1 gene in ocular fluid from both the aqueous and vitreous humor. The presumed diagnosis of ocular toxoplasmosis was made and treatment was started with prednisone and acetylspiramycin with subsequent improvement. Two months later, the patient developed active retinochoroiditis in the left eye. After 6 weeks of anti-toxoplasma therapy, the disease involuted. Retinal vascular occlusions and multifocal retinitis with perivascular sheathing are rare in toxoplasmosis. This is the first case report of toxoplasmic CRAO and multifocal retinitis with perivascular sheathing. The diagnosis of ocular toxoplasmosis should be considered in patients with retinal artery occlusions and multifocal retinitis with perivascular sheathing associated with inflammation.Keywords: ocular toxoplasmosis, toxoplasma retinochoroiditis, retinal vascular occlusion, polymerase chain reaction, vitrectomy

Arai H

2014-04-01

17

Tortuous path chemical preconcentrator  

Science.gov (United States)

A non-planar, tortuous path chemical preconcentrator has a high internal surface area having a heatable sorptive coating that can be used to selectively collect and concentrate one or more chemical species of interest from a fluid stream that can be rapidly released as a concentrated plug into an analytical or microanalytical chain for separation and detection. The non-planar chemical preconcentrator comprises a sorptive support structure having a tortuous flow path. The tortuosity provides repeated twists, turns, and bends to the flow, thereby increasing the interfacial contact between sample fluid stream and the sorptive material. The tortuous path also provides more opportunities for desorption and readsorption of volatile species. Further, the thermal efficiency of the tortuous path chemical preconcentrator is comparable or superior to the prior non-planar chemical preconcentrator. Finally, the tortuosity can be varied in different directions to optimize flow rates during the adsorption and desorption phases of operation of the preconcentrator.

Manginell, Ronald P. (Albuquerque, NM); Lewis, Patrick R. (Albuquerque, NM); Adkins, Douglas R. (Albuquerque, NM); Wheeler, David R. (Albuquerque, NM); Simonson, Robert J. (Cedar Crest, NM)

2010-09-21

18

Retinal arterial occlusion in Takayasu?s arteritis  

Directory of Open Access Journals (Sweden)

Full Text Available Takayasu?s arteritis is an auto-immune disorder of the large and medium-sized arteries, commonly involving the heart and its main vessels. It is now recognised that the inflammatory process of the large arteries affects regions of the walls supplied by the vasa vasorum, suggesting that primary small vessel involvement may contribute to the development of the clinico-pathological features of Takayasu aorto-arteritis. Classical ophthalmic features of the disease result from reduced ocular perfusion, which manifests as hypoxic retinal changes such as microaneurysms, arterio-venous anastomosis and non-perfused areas. Branch retinal artery occlusion has not been previously described in this condition. This case illustrates retinal arterial occlusion as the presenting feature of Takayasu?s arteritis.

Kaushik Sushmita

2005-01-01

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Superselective transcatheter thrombolysis for treatment of central retinal artery occlusion  

International Nuclear Information System (INIS)

Objective: Intra-arterial administration of urokinase to the territory of the ophthalmic artery was performed in 12 patients with occlusion of the central retinal artery. Methods: The thrombolysis was carried out with a microcatheter placed in the proximal part of the ophthalmic artery, for thrombolysis of the central ophthalmice arterial thrombosis covering impediment of visibility. Results: All patients achieved improvement of visual acuity, continually with one month follow up. Conclusions: Early diagnosis and early superselective trans-microcatheter thrombolytic infusion would be more effective than traditional treatment. (author)

20

Central retinal artery occlusion: an unusual complication of snakebite  

Directory of Open Access Journals (Sweden)

Full Text Available Snakebites are endemic in some parts of India, being associated with a number of complications. Ocular disturbances are rare, except for injury to the cornea or conjunctiva when the eye is directly exposed to the venom. In this work, we present a case of central retinal artery occlusion caused by snakebite.

A. Bhalla

2004-01-01

21

Central retinal artery occlusion resembling Purtscher-like retinopathy  

OpenAIRE

Takuji Kurimoto1, Norio Okamoto2, Hidehiro Oku1, Yuko Kanbara1, Tomohiko Etomi1, Masahiro Tonari1, Tsunehiko Ikeda11Department of Ophthalmology, Osaka Medical College, Takatsuki, Japan; 2Okamoto Eye Clinic, Suita, Osaka, JapanAbstract: This paper reports three cases of central retinal artery occlusion (CRAO) with Purtscher-like retinopathy and good recovery of visual function. The three cases of CRAO had similar fundus changes, ie, cotton wool patches surrounding the optic disc and whitening ...

Etomi T; Kanbara Y; Oku H; Okamoto N; Kurimoto T; Tonari M; Ikeda T

2011-01-01

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Unilateral electronegative ERG in a presumed central retinal artery occlusion  

Directory of Open Access Journals (Sweden)

Full Text Available Luiz H Lima1, Wener Cella2,4, Claudia Brue5, Stephen H Tsang2.31Federal University of Sao Paulo (UNIFESP, Sao Paulo, Brazil; 2Department of Ophthalmology, 3Bernard and Shirlee Brown Glaucoma Laboratory, Edward S Harkness Eye Institute and Departments of Opthamology, Pathology and Cell Biology, Columbia University, New York, NY, USA; 4Department of Ophthalmology, University of Brasilia, Brasilia, Brazil; 5Department of Opthamology, University Politecnica delle Marche, Ancona, ItalyAbstract: A unilateral electronegative electroretinogram (ERG was seen in a 94-year-old man with presumed central retinal artery occlusion. Goldmann perimetry revealed central scotoma in the right eye and no abnormalities in the left eye. Full-field ERG in the right eye described a reduction of the b-wave with a relative preservation of the a-wave which is characteristic of electronegative ERG. Hence, our case illustrates that ERG testing is essential for the work-up of individuals with suspected retinal vascular disorders.Keywords: central retinal artery occlusion, electronegative ERG, inner retina, spectral domain optical coherence tomography

Luiz H Lima

2010-11-01

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Acute central retinal artery occlusion associated with livedoid vasculopathy: a variant of Sneddon's syndrome.  

Science.gov (United States)

Livedoid vasculopathy (LV) is characterized by a long history of ulceration of the feet and legs and histopathology indicating a thrombotic process. We report a case of acute central retinal artery occlusion in a 32-year-old woman who had LV. She showed no discernible laboratory abnormalities such as antiphospholipid antibodies and no history of cerebrovascular accidents. Attempted intra-arterial thrombolysis showed no effect in restoring retinal arterial perfusion or vision. The central retinal artery occlusion accompanied by LV in this case could be regarded as a variant form of Sneddon's syndrome, which is characterized by livedo reticularis and cerebrovascular accidents. PMID:24082777

Song, Hyun Beom; Woo, Se Joon; Jung, Cheol Kyu; Lee, Yun Jong; Ahn, Jeeyun; Park, Kyu Hyung; Kwon, O-Ki

2013-10-01

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Acute Central Retinal Artery Occlusion Associated with Livedoid Vasculopathy: A Variant of Sneddon's Syndrome  

OpenAIRE

Livedoid vasculopathy (LV) is characterized by a long history of ulceration of the feet and legs and histopathology indicating a thrombotic process. We report a case of acute central retinal artery occlusion in a 32-year-old woman who had LV. She showed no discernible laboratory abnormalities such as antiphospholipid antibodies and no history of cerebrovascular accidents. Attempted intra-arterial thrombolysis showed no effect in restoring retinal arterial perfusion or vision. The central reti...

Song, Hyun Beom; Woo, Se Joon; Jung, Cheol Kyu; Lee, Yun Jong; Ahn, Jeeyun; Park, Kyu Hyung; Kwon, O-ki

2013-01-01

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Oclusão de ramo arterial retiniano bilateral / Bilateral branch retinal artery occlusion  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Languages: English, Portuguese Abstract in portuguese Os autores relatam o caso de uma paciente que apresentou quadro bilateral de oclusão de ramos arteriais da retina sem causas sistêmicas identificáveis para o aparecimento da doença. [...] Abstract in english The authors report a case of a patient who presented bilateral branch retinal artery occlusion without any meaningful systemic underlying conditions. [...

Luiz Guilherme Azevedo de, Freitas; David Leonardo Cruvinel, Isaac; Luiz Alexandre Rassi, Gabriel; Lívia Carla de Souza Nassar, Bianchi; Marcos Pereira de, Ávila.

2013-08-01

26

Severity of middle cerebral artery occlusion determines retinal deficits in rats.  

Science.gov (United States)

Middle cerebral artery occlusion (MCAO) using the intraluminal suture technique is a common model used to study cerebral ischemia in rodents. Due to the proximity of the ophthalmic artery to the middle cerebral artery, MCAO blocks both arteries, causing both cerebral ischemia and retinal ischemia. While previous studies have shown retinal dysfunction at 48h post-MCAO, we investigated whether these retinal function deficits persist until 9days and whether they correlate with central neurological deficits. Rats received 90min of transient MCAO followed by electroretinography at 2 and 9days to assess retinal function. Retinal damage was assessed with cresyl violet staining, immunohistochemistry for glial fibrillary acidic protein (GFAP) and glutamine synthetase, and TUNEL staining. Rats showed behavioral deficits as assessed with neuroscore that correlated with cerebral infarct size and retinal function at 2days. Two days after surgery, rats with moderate MCAO (neuroscore <5) exhibited delays in electroretinogram implicit time, while rats with severe MCAO (neuroscore ?5) exhibited reductions in amplitude. Glutamine synthetase was upregulated in Müller cells 3days after MCAO in both severe and moderate animals; however, retinal ganglion cell death was only observed in MCAO retinas from severe animals. By 9days after MCAO, both glutamine synthetase labeling and electroretinograms had returned to normal levels in moderate animals. Early retinal function deficits correlated with behavioral deficits. However, retinal function decreases were transient, and selective retinal cell loss was observed only with severe ischemia, suggesting that the retina is less susceptible to MCAO than the brain. Temporary retinal deficits caused by MCAO are likely due to ischemia-induced increases in extracellular glutamate that impair signal conduction, but resolve by 9days after MCAO. PMID:24518488

Allen, Rachael S; Sayeed, Iqbal; Cale, Heather A; Morrison, Katherine C; Boatright, Jeffrey H; Pardue, Machelle T; Stein, Donald G

2014-04-01

27

The tortuous behavior of lightning  

OpenAIRE

The complex branched structure of lightning induce scientists to think that dielectric breakdown is a very complicated phenomena, we will show that this is not true and that simulating the structure of lightning is an easy task, but depends strongly on boundary conditions. In this work we will introduce a new way of understanding the origin of this tortuous path that relies on minimizing the total energy stored in the system.

Vera, Francisco

2002-01-01

28

Protein kinase C in porcine retinal arteries and neuroretina following retinal ischemia-reperfusion  

DEFF Research Database (Denmark)

Identification of the intracellular signal-transduction pathways activated in retinal ischemia may be important in revealing novel pharmacological targets. To date, most studies have focused on identifying neuroprotective agents. The retinal blood vessels are key organs in circulatory failure, and this study was therefore designed to examine the retinal vasculature separately from the neuroretina.

Gesslein, Bodil; Gustafsson, Lotta

2009-01-01

29

Transluminal Nd:YAG laser embolysis: A reasonable method to reperfuse occluded branch retinal arteries  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction. Central retinal artery occlusion (CRAO and branch retinal artery occlusion (BRAO result in partial or complete retinal ischemia and sudden loss of vision; at this moment, there is no effective therapy for CRAO and BRAO. Transluminal Nd:YAG laser embolysis (TYE represents a therapeutic approach used for retinal vascular occlusive diseases. The main indication is branch retinal artery occlusion with visible embolus; for central retinal artery occlusion this tehnique is hardly applicable. The principle of this method consists of intravascular embolus breakage using the 1064 nm Nd:YAG laser, focused on the embolus surface. Case report. We presented 5 cases with BRAO, 3 with infero-temporal and 2 with supero-temporal BRAO, all of them treated with TYE, with variable results. All the patients had a visible embolus within the BRA, the laser applications being delivered directly to the embolus. Conclusion. Despite our short-term experience regarding this therapeutical approach, we can resume that the moment of emboli distruction, as close as possible to the onset of the occlusion, is decisive for regaining vision and that applying the procedure correctly is superior to observation in most cases. Worldwide experience with TYE is still limited, but the technique seems feasible also when treating CRAO caused by visible emboli on the optic disc surface. This most certainly calls for random trials for identifying precisely the role of TYE in treatment of retinal occlusion pathology, though the relatively small number of properly diagnosed cases affects this objective. In all cases, the risks of TYE must be weighed against the possibility of severe and permanent loss of vision secondary to retinal artery occlusions.

Stanca Horia T.

2014-01-01

30

Branch retinal artery occlusion in Susac's syndrome / Oclusão de ramo arterial da retina na Síndrome de Susac  

Scientific Electronic Library Online (English)

Full Text Available Síndrome de Susac é uma microangiopatia rara que afeta as arteríolas da cóclea, retina e encéfalo. Encefalopatia, perda auditiva e baixa da acuidade visual formam a tríade clássica da doença. A baixa de acuidade visual ocorre devido a múltiplas e recorrentes oclusões de ramo arterial da retina. Rela [...] tamos o caso de uma paciente de 20 anos com síndrome de Susac apresentando síndrome vestibular periférica, perda auditiva, vertigem, ataxia e baixa da acuidade visual por oclusão de ramo arterial de retina. Abstract in english Susac's syndrome is a rare disease attribuited to a microangiopathy involving the arterioles of the cochlea, retina and brain. Encefalopathy, hearing loss, and visual deficits are the hallmarks of the disease. Visual loss is due to multiple, recurrent branch arterial retinal occlusions. We report a [...] case of a 20-year-old women with Susac syndrome presented with peripheral vestibular syndrome, hearing loss, ataxia, vertigo, and vision loss due occlusion of the retinal branch artery.

Ricardo Evangelista Marrocos de, Aragão; Lorena Maria Araújo, Gomes; Ieda Maria Alexandre, Barreira; Francisco Holanda, Oliveira Neto; Ariane Sá Vieira, Bastos.

2015-02-01

31

Usefulness of retinal microvascular endothelial dysfunction as a predictor of coronary artery disease.  

Science.gov (United States)

Endothelial dysfunction is a key feature of atherosclerosis. Retinal microvascular endothelial function can be assessed using noninvasive dynamic vessel imaging techniques. Whether it is impaired in subjects with coronary artery disease (CAD) is unknown. The aim of this study was to examine the relation of retinal microvascular endothelial function with CAD. Vascular studies were performed in 197 prospectively recruited subjects divided into 2 groups: those without CAD but ?2 cardiovascular risk factors (non-CAD controls; n = 119) and those with stable CAD (n = 78). Retinal microvascular endothelial dysfunction was assessed by measuring retinal arteriolar and venular dilatation to flicker light, a nitric oxide-dependent phenomenon, expressed as percentage increase over baseline diameter. Fingertip pulse-volume amplitude was measured to calculate reactive hyperaemia index and brachial artery flow-mediated dilatation assessed as measures of peripheral microvascular and conduit vessel endothelial function, respectively. Mean retinal arteriolar dilatation was attenuated in patients with CAD compared with non-CAD controls (1.51 ± 1.51% vs 2.37 ± 1.95%, p = 0.001). Retinal arteriolar dilatation was independently associated with CAD after adjustment for age, gender, cardiovascular risk factors, and medication use (odds ratio 1.60, 95% confidence interval 1.14 to 2.25, p = 0.007). Reactive hyperaemia index and flow-mediated dilatation were not different. In conclusion, the capacity of retinal arterioles to dilate in response to flicker light is an independent predictor of the presence of CAD and suggests that retinal microvascular endothelial dysfunction is a marker for underlying CAD. PMID:25591896

Al-Fiadh, Ali H; Wong, Tien Y; Kawasaki, Ryo; Clark, David J; Patel, Sheila K; Freeman, Melanie; Wilson, Andrew; Burrell, Louise M; Farouque, Omar

2015-03-01

32

Automated artery-venous classification of retinal blood vessels based on structural mapping method  

Science.gov (United States)

Retinal blood vessels show morphologic modifications in response to various retinopathies. However, the specific responses exhibited by arteries and veins may provide a precise diagnostic information, i.e., a diabetic retinopathy may be detected more accurately with the venous dilatation instead of average vessel dilatation. In order to analyze the vessel type specific morphologic modifications, the classification of a vessel network into arteries and veins is required. We previously described a method for identification and separation of retinal vessel trees; i.e. structural mapping. Therefore, we propose the artery-venous classification based on structural mapping and identification of color properties prominent to the vessel types. The mean and standard deviation of each of green channel intensity and hue channel intensity are analyzed in a region of interest around each centerline pixel of a vessel. Using the vector of color properties extracted from each centerline pixel, it is classified into one of the two clusters (artery and vein), obtained by the fuzzy-C-means clustering. According to the proportion of clustered centerline pixels in a particular vessel, and utilizing the artery-venous crossing property of retinal vessels, each vessel is assigned a label of an artery or a vein. The classification results are compared with the manually annotated ground truth (gold standard). We applied the proposed method to a dataset of 15 retinal color fundus images resulting in an accuracy of 88.28% correctly classified vessel pixels. The automated classification results match well with the gold standard suggesting its potential in artery-venous classification and the respective morphology analysis.

Joshi, Vinayak S.; Garvin, Mona K.; Reinhardt, Joseph M.; Abramoff, Michael D.

2012-03-01

33

Intravitreal Bevacizumab for the Treatment of Neovascular Glaucoma Associated With Central Retinal Artery Occlusion  

OpenAIRE

We report three cases of neovascular glaucoma secondary to central retinal artery occlusion (CRAO) which were effectively managed with intravitreal bevacizumab (IVB) followed by panretinal photocoagulation (PRP). Neovascular glaucoma without peripheral anterior synechiae developed between one and five weeks following CRAO onset. All patients received 0.75 mg (0.03 ml) IVB. In all patients, complete regression of the iris and anterior chamber angle neovascularization was confirmed within one w...

Sagong, Min; Kim, Jinseon; Chang, Woohyok

2009-01-01

34

High correlation of scotopic and photopic electroretinogram components with severity of central retinal artery occlusion  

OpenAIRE

Celso S Matsumoto1,2, Kei Shinoda1, Kazuo Nakatsuka21Department of Ophthalmology, Teikyo University School of Medicine, Tokyo, Japan; 2Department of Ophthalmology, Faculty of Medicine, Oita University, Oita, JapanPurpose: The aim of this study was to determine whether a significant correlation exists between the scotopic and photopic components of electroretinograms (ERGs) and the degree of circulation disturbances caused by a central retinal artery occlusion (CRAO).Design: Observational clin...

Matsumoto, Celso S.; Kei Shinoda; Kazuo Nakatsuka

2011-01-01

35

Retina derived relaxation is mediated by Kir channels and the inhibition of Ca(2+) sensitization in isolated bovine retinal arteries.  

Science.gov (United States)

Retinal relaxing factor (RRF) has recently been identified as a novel paracrine regulator of retinal circulation acting differently from well known mediators of the endothelium and the retina. Herein, we aimed to characterize the relaxing mechanism of the retina, i.e. RRF, by evaluating the role of Ca(+2)-dependent and -independent signaling mechanisms as well as inward rectifier K(+) (Kir) channels. Retinal relaxation was determined by placing a piece of retinal tissue just on top of the precontracted bovine retinal arteries mounted in a wire myograph. The retina produced a complete relaxation response, which display a biphasic character, in depolarized arteries contracted by L-type Ca(2+) channel agonist, Bay k 8644. Blockade of L-type Ca(2+) channel by nifedipine, inhibition of sarcoplasmic reticulum Ca(2+)-ATPase by cyclopiazonic acid or removal of extracellular Ca(2+) did not influence the prominent relaxation to the retina. Originally, retinal relaxation was found to be unaffected from the inhibition of myosin light chain kinase by ML7, whereas, completely abolished in the presence of myosin light chain phosphatase (MLCP) inhibitor, Calyculin A. Moreover, the inhibition of Rho kinase by its putative inhibitor, Y-27632 displayed comparable relaxant effects to RRF in retinal arteries precontracted either by prostaglandin F2? or K(+), and augmented the moderate response to the retina in K(+) precontracted arteries. In addition, retinal relaxation was significantly inhibited and lost its biphasic character in the presence of Kir channel blocker, Ba(2+). Our results suggested that inhibition of Ca(2+) sensitization through the activation of MLCP, possibly via interfering with Rho kinase, and the opening of Kir channels are likely to be involved in the inhibitory influence of RRF on the retinal arteries. PMID:25662314

Tak?r, Selçuk; Uyde?-Do?an, B Sönmez; Özdemir, Osman

2015-03-01

36

Central Retinal and Posterior Ciliary Artery Occlusion After Intralesional Injection of Sclerosant to Glabellar Subcutaneous Hemangioma  

International Nuclear Information System (INIS)

The aim of this study is to describe vision loss caused by central retinal artery and posterior ciliary artery occlusion as a consequence of sclerotherapy with a polidocanol injection to a glabellar hemangioma. An 18-year-old man underwent direct injection with a 23-gauge needle of 1 mL of a polidocanol-carbon dioxide emulsion into the glabellar subcutaneous hemangioma under ultrasound visualization of the needle tip by radiologists. He developed lid swelling the next day, and 3 days later at referral, the visual acuity in the left eye was no light perception. Funduscopy revealed central retinal artery occlusion and fluorescein angiography disclosed no perfusion at all in the left fundus, indicating concurrent posterior ciliary artery occlusion. The patient also showed mydriasis, blepharoptosis, and total external ophthalmoplegia on the left side. Magnetic resonance imaging demonstrated the swollen medial rectus muscle. In a month, blepharoptosis and ophthalmoplegia resolved but the visual acuity remained no light perception. Sclerosing therapy for facial hemangioma may develop a severe complication such as permanent visual loss.

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A case of central retinal artery occlusion after chiropractic manipulation of the neck.  

Science.gov (United States)

Here we report a case of central retinal artery occlusion after chiropractic manipulation on the neck. A 49-year old man presented at the hospital because of sudden visual loss in his right eye after chiropractic neck manipulation. He had received chiropractic manipulation of the neck by a chiropractor eight days prior. When he first visited us, his best corrected visual acuity in his right eye was hand motion. A full ophthalmic examination was performed. There was cherry-red spot in the macula in his right eye. We performed a fluorescein angiogram and cervical color Doppler. The arterio-venous transit time in the fluorescein angiogram was delayed, and we detected stenosis of the right internal carotid artery with diffuse atherosclerotic plaques in the right common carotid artery. We prescribed ginko biloba extract (Tanamin). Three years after his first visit, the best corrected visual acuity of his right eye was 20 / 200. PMID:22511840

Jang, Young-Jun; Chun, Jun-Woo; Lee, Seung-Woo; Kim, Ho-Chang

2012-04-01

38

Cerebro-retinal ischemia after bilateral occlusion of internal carotid artery  

Energy Technology Data Exchange (ETDEWEB)

Six patients with occlusion of internal carotid arteries (ICAs) were prospectively followed during a mean period of 14 months. Prior to demonstration of occlusions, four patients suffered a mild stroke, and three isolated transient ischemic attacks (TIAs) or amaurosis fugax. All patients remained alive and with an unchanged functional ability. During follow-up, one patient suffered amaurosis fugax and TIAs followed by a mild stroke, three suffered isolated TIAs or amaurosis fugax, two suffered reversible cerebro-retinal ischemia of more than 24 hours, and one remained symptomfree. In three cases, delayed cerebro-retinal ischemia distal to one of the occluded ICAs was systematically triggered by orthostatic, cardiogenic or iatrogenic hypotension, and resolved after adequate medical treatment or restoration of a functional collateral circulation by endarterectomy of a tightly stenosed ipsilateral external carotid artery (ECA), suggesting hemodynamic phenomena. In three cases, micro-emboli originating from a stump or an ulcerated ipsilateral common carotid artery and migrating through well-developed ECA collateral channels explained delayed episodes of ipsilateral TIAs or amaurosis fugax, which disappeared in two cases after adequate anticoagulant therepy was introduced. Bilateral occlusion of ICA may be a relatively benign condition, if the patients are carefully controlled and treated.

Bogousslavsky, J.; Regli, F.

1985-05-01

39

Cerebro-retinal ischemia after bilateral occlusion of internal carotid artery  

International Nuclear Information System (INIS)

Six patients with occlusion of internal carotid arteries (ICAs) were prospectively followed during a mean period of 14 months. Prior to demonstration of occlusions, four patients suffered a mild stroke, and three isolated transient ischemic attacks (TIAs) or amaurosis fugax. All patients remained alive and with an unchanged functional ability. During follow-up, one patient suffered amaurosis fugax and TIAs followed by a mild stroke, three suffered isolated TIAs or amaurosis fugax, two suffered reversible cerebro-retinal ischemia of more than 24 hours, and one remained symptomfree. In three cases, delayed cerebro-retinal ischemia distal to one of the occluded ICAs was systematically triggered by orthostatic, cardiogenic or iatrogenic hypotension, and resolved after adequate medical treatment or restoration of a functional collateral circulation by endarterectomy of a tightly stenosed ipsilateral external carotid artery (ECA), suggesting hemodynamic phenomena. In three cases, micro-emboli originating from a stump or an ulcerated ipsilateral common carotid artery and migrating through well-developed ECA collateral channels explained delayed episodes of ipsilateral TIAs or amaurosis fugax, which disappeared in two cases after adequate anticoagulant therepy was introduced. Bilateral occlusion of ICA may be a relatively benign condition, if the patients are carefully controlled and treated. (orig.)

40

A Case of Central Retinal Artery Occlusion after Chiropractic Manipulation of the Neck  

OpenAIRE

Here we report a case of central retinal artery occlusion after chiropractic manipulation on the neck. A 49-year old man presented at the hospital because of sudden visual loss in his right eye after chiropractic neck manipulation. He had received chiropractic manipulation of the neck by a chiropractor eight days prior. When he first visited us, his best corrected visual acuity in his right eye was hand motion. A full ophthalmic examination was performed. There was cherry-red spot in the macu...

Jang, Young-jun; Chun, Jun-woo; Lee, Seung-woo; Kim, Ho-chang

2012-01-01

41

NaHS induces relaxation response in prostaglandin F2? precontracted bovine retinal arteries partially via Kv and Kir channels.  

Science.gov (United States)

Hydrogen sulphide (H2S) is known to be produced endogenously in ocular tissues with the highest levels in the retina and cornea. However, it is yet unclear whether it can modulate retinal arterial tone. Herein, we aimed to investigate the effectiveness and the mechanism of the action of H2S in the isolated bovine retinal arteries. For this purpose, the probable vasorelaxant and inhibitory effects of H2S on vascular reactivity were tested comparatively in the retinal arteries by using the donor, sodium hydrosulphide (NaHS). Thereafter, in relation to the mechanism of action of H2S, the role of nitric oxide (NO) and endothelial vasodilators of cyclooxygenase pathway as well as ATP-sensitive potassium channel (KATP), voltage-dependent potassium channel (Kv), calcium-activated potassium channel (KCa(++)), inwardly rectifying potassium channel (Kir), L-type voltage-dependent calcium channel and adenylate cyclase pathway were evaluated. NaHS (1?M-3mM) displayed prominent relaxations over the concentrations of 300 ?M in both PGF2? and K(+) precontracted retinal arteries. Comparatively, in the presence of NaHS (3 mM) pretreatment, the maximum contractile responses and pEC50 values to PGF2? and K(+) were significantly reduced as well. Neither the presence of the known inhibitors of NO synthase, guanylate cyclase, cyclooxygenase, adenylate cyclase, KATP and KCa(++) type K(+) channels, and L-type voltage-dependent calcium channels nor the removal of endothelium, modified the relaxation response to NaHS in retinal arteries. However, a remarkable decrease was observed in the presence of the inhibitors of Kv or Kir type K(+) channels. In addition, administration of l-cysteine (1?M-3mM), the precursor of H2S, induced a modest relaxation response in PGF2? precontracted retinal arteries, which was significantly decreased in the presence of cystathionine-?-synthase (CBS) inhibitor, aminooxyacetic acid, but was unmodified in the presence of the cystathionine-?-lyase (CSE) inhibitor, dl-propargylglycine or the deendothelization of retinal arteries. Our findings suggested that H2S might play a substantial role in the regulation of retinal arterial tone possibly by acting on Kv and Kir channels. PMID:25662313

Tak?r, S; Ortaköylü, G Z; Toprak, A; Uyde?-Do?an, B S

2015-03-01

42

Classification of Arteries and Veins in Retinal Images using Vessel Profile Features  

Science.gov (United States)

In this work an automated method is introduced to distinguish arteries from veins in eye fundus images. The main challenges of this task are the similarity of the two vessel types and the vast variability in different images. We assume that the vasculature is already extracted and represented by vessel segments. Based on local image features, vessel profile characteristics are extracted and used for clustering the major vessels near the optic disc. The presented method is tested on the MARS database including 448 retinal images with ground truth (artery and vein labels). The achieved results are promising: for 80% of the images the classification error is less than 30%. These results can be further improved by structural analysis of the vasculature.

Rothaus, Kai; Jiang, Xiaoyi

2011-06-01

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Multi-layered haemorrhage secondary to retinal arterial macroaneurysm: A case report and review.  

Science.gov (United States)

Retinal macroaneurysms are an acquired vascular anomaly primarily associated with advancing age and hypertension. Although a rare pathology, it is not uncommon for a patient with a macroaneurysm to present to the primary care optometrist. Macroaneurysms have various presentations and they constitute one of the few clinical entities that can produce preretinal, intraretinal, subretinal or vitreal haemorrhage or any combination thereof. A review of the pathophysiology, differential diagnosis and newest treatments will be provided. A 68-year-old Caucasian male patient with a history of a previously treated retinal macroaneurysm presented to the eye clinic with acute-onset visual loss in the same eye. The patient had a known diagnosis of hypertension and had been untreated by his primary care physician for one year. Dilated fundus examination revealed extensive multi-layered haemorrhaging along with significant macular oedema. A choroidal neovascular membrane was ruled out with fluorescein angiography. The patient was treated with monthly bevacizumab injections over a period of three months. At six months optical coherence tomography confirmed the resolution of macular oedema and the patient achieved a marked improvement in his visual acuity. Retinal arterial macroaneurysm is one of the few clinical entities with the potential to produce any combination of preretinal, intraretinal, subretinal and/or vitreal haemorrhage. When the macula is threatened, treatment must be pursued. Although laser treatment has traditionally been used, anti-vascular endothelial growth factor therapy has been used with promising visual outcomes. PMID:25349052

Aumiller, Mira Silbert; Rinehart, Jason

2015-03-01

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Efficacy of hyperbaric oxygen therapy in a young woman with idiopathic branch retinal artery occlusion.  

Science.gov (United States)

We present a case of branch retinal artery occlusion (BRAO) in a healthy 20-year-old woman with no history of ocular or systemic diseases or drug use. She presented with a sudden decrease in visual acuity associated with a visual field defect of the right eye, which she had first noticed 4 hours earlier. Examination showed a BRAO with oedema at the upper part of the macula and surrounding area, and confirmed on fluorescein angiography. The left eye was normal. She was sent immediately for hyperbaric oxygen therapy (HBOT) and received 10 sessions (over 20 days) of 2 hours each at a pressure of 253 kPa. Follow up at four months showed a normal fundus, and visual acuity of 20/25. Visual field and fundoscopy were normal. Investigations for a cause of the BRAO proved negative. Retinal artery occlusion is rare in young people, and early application of HBOT in patients with RAO appears to improve outcome. PMID:24122193

Demir, Mehmet; Kara, Orhan; Y?ld?z, Atakhan; Guven, Dilek

2013-09-01

45

Retinal protective effects of topically administered agmatine on ischemic ocular injury caused by transient occlusion of the ophthalmic artery  

Directory of Open Access Journals (Sweden)

Full Text Available Agmatine, an endogenous polyamine and putative neuromodulator, is known to have neuroprotective effects on various neurons in the central nervous system. We determined whether or not topically administered agmatine could reduce ischemic retinal injury. Transient ocular ischemia was achieved by intraluminal occlusion of the middle cerebral artery of ddY mice (30-35 g for 2 h, which is known to also induce occlusion of the ophthalmic artery. In the agmatine group (N = 6, a 1.0 mM agmatine-containing ophthalmic solution was administered four times daily for 2 weeks before occlusion. In the control group (N = 6, a 0.1% hyaluronic acid ophthalmic solution was instilled at the same times. At 22 h after reperfusion, the eyeballs were enucleated and the retinal sections were stained by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL. Transient ocular ischemia induced apoptosis of retinal cells in the entire retinal layer, and topically administered agmatine can significantly reduce this ischemic retinal injury. The proportion of apoptotic cells was definitely decreased (P < 0.001; Kruskal-Wallis test. Overall, we determined that topical agmatine application effectively decreases retinal damage in an in vivo ocular ischemic injury model. This implies that agmatine is a good candidate as a direct neuroprotective agent for eyes with ocular ischemic diseases.

S. Hong

2012-03-01

46

Retinal protective effects of topically administered agmatine on ischemic ocular injury caused by transient occlusion of the ophthalmic artery  

Scientific Electronic Library Online (English)

Full Text Available Agmatine, an endogenous polyamine and putative neuromodulator, is known to have neuroprotective effects on various neurons in the central nervous system. We determined whether or not topically administered agmatine could reduce ischemic retinal injury. Transient ocular ischemia was achieved by intra [...] luminal occlusion of the middle cerebral artery of ddY mice (30-35 g) for 2 h, which is known to also induce occlusion of the ophthalmic artery. In the agmatine group (N = 6), a 1.0 mM agmatine-containing ophthalmic solution was administered four times daily for 2 weeks before occlusion. In the control group (N = 6), a 0.1% hyaluronic acid ophthalmic solution was instilled at the same times. At 22 h after reperfusion, the eyeballs were enucleated and the retinal sections were stained by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Transient ocular ischemia induced apoptosis of retinal cells in the entire retinal layer, and topically administered agmatine can significantly reduce this ischemic retinal injury. The proportion of apoptotic cells was definitely decreased (P

S., Hong; H., Hara; M., Shimazawa; K., Hyakkoku; C.Y., Kim; G.J., Seong.

2012-03-01

47

Relationship between Retinal Vascular Caliber and Coronary Artery Disease in Patients with Non-Alcoholic Fatty Liver Disease (NAFLD  

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Full Text Available Objective: To evaluate the relationship between retinal vascular caliber and cardiovascular disease in non-alcoholic fatty liver disease (NAFLD patients without diabetes and hypertension. Methods: Intention to treat study of individuals who underwent cardiac computed tomography (CT during a two year period. Coronary artery disease (CAD was defined as stenosis of >50% in at least one major coronary artery. Liver and spleen density were measured by abdominal (CT; intima-media thickness (IMT by Doppler ultrasound; retinal artery and vein diameter by colored-retinal angiography; and metabolic syndrome by ATP III guidelines. Serum biomarkers of insulin resistance, inflammation, and oxidant-antioxidant status were assessed. Results: Compared with 22 gender and age matched controls, the 29 NAFLD patients showed higher prevalence of coronary plaques (70% vs. 30%, p < 0.001, higher prevalence of coronary stenosis (30% vs. 15%, p < 0.001, lower retinal arteriole-to-venule ratio (AVR (0.66 ± 0.06 vs. 0.71 ± 0.02, p < 0.01, higher IMT (0.98 ± 0.3 vs. 0.83 ± 0.1, p < 0.04, higher carotid plaques (60% vs. 40%, p < 0.001, higher homeostasis model assessment of insulin resistance (HOMA (4.0 ± 3.4 vs. 2.0 ± 1.0, p < 0.005, and higher triglyceride levels (200 ± 80 vs. 150 ± 60, p < 0.005 than controls. Multivariate analysis showed fatty liver (OR 2.5; p < 0.01, IMT (OR 2.3 p < 0.001, and retinal AVR ratio (OR 1.5, p < 0.01 to be strongly associated with CAD independent of metabolic syndrome (OR 1.2, p < 0.05. Conclusions: Patients with smaller retinal AVR (<0.7 are likely to be at increased risk for CAD and carotid atherosclerosis in patients with NAFLD even without hypertension or diabetes.

Marmor Alon

2013-08-01

48

High correlation of scotopic and photopic electroretinogram components with severity of central retinal artery occlusion  

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Full Text Available Celso S Matsumoto1,2, Kei Shinoda1, Kazuo Nakatsuka21Department of Ophthalmology, Teikyo University School of Medicine, Tokyo, Japan; 2Department of Ophthalmology, Faculty of Medicine, Oita University, Oita, JapanPurpose: The aim of this study was to determine whether a significant correlation exists between the scotopic and photopic components of electroretinograms (ERGs and the degree of circulation disturbances caused by a central retinal artery occlusion (CRAO.Design: Observational clinical study.Participants: Sixteen patients with a CRAO (16 eyes.Methods: The circulatory disturbance in eyes with CRAO was graded as mild (group 1 when the arm-to-retina transmission time was <30 sec and severe (group 2 when the arm-to-retina transmission time was ?30 sec. Scotopic and photopic ERG components in eyes with CRAO were compared with those in healthy fellow eyes with respect to the degree of circulation disturbance.Results: The scotopic and photopic b-waves were significantly reduced only in group 2, whereas the amplitudes of the photopic negative response (PhNR of the photopic cone ERGs were significantly reduced in both groups. The amplitudes of each ERG component, except for the a-wave of the mixed rod-cone ERG, were significantly smaller in group 2 than in group 1.Conclusions: The PhNR was reduced even in group 1 with minimal circulatory disturbance and thus may be a good functional indicator.Keywords: scotopic electroretinogram, photopic electroretinogram, photopic negative response, central retinal artery occlusion, fluorescein angiography

Celso S Matsumoto

2011-01-01

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Egfl7 is differentially expressed in arteries and veins during retinal vascular development.  

Science.gov (United States)

The vasculature of the central nervous system (CNS) is composed of vascular endothelial and mural cells which interact closely with glial cells and neurons. The development of the CNS vascularisation is a unique process which requires the contribution of specific regulators in addition to the classical angiogenic factors. The egfl7 gene is mainly detected in endothelial cells during physiological and pathological angiogenesis. Egfl7 codes for a secreted protein which predominantly accumulates into the extracellular space where it controls vascular elastin deposition or the Notch pathway. Egfl7 is the host gene of the microRNA miR126 which is also expressed in endothelial cells and which plays major functions during blood vessel development. While the expression of egfl7 and that of miR126 were well described in endothelial cells during development, their pattern of expression during the establishment of the CNS vasculature is still unknown. By analysing the expression of egfl7 and miR126 during mouse retina vascularisation, we observed that while expression of miR126 is detected in all endothelia, egfl7 is initially expressed in all endothelial cells and then is progressively restricted to veins and to their neighbouring capillaries. The recruitment of mural cells around retina arteries coincides with the down-regulation of egfl7 in the arterial endothelial cells, suggesting that this recruitment could be involved in the loss of egfl7 expression in arteries. However, the expression pattern of egfl7 is similar when mural cell recruitment is prevented by the injection of a PDGFR? blocking antibody, suggesting that vessel maturation is not responsible for egfl7 down-regulation in retinal arteries. PMID:24595089

Poissonnier, Loïc; Villain, Gaëlle; Soncin, Fabrice; Mattot, Virginie

2014-01-01

50

Obstrucción de rama macular de arteria central de la retina Occlusion of the macular branch of the central retinal artery  

Directory of Open Access Journals (Sweden)

Full Text Available We report a 54 years old female on oral anticoagulant treatment with a mitral valve disease, with a history of two transient ischemic attacks and a decreased visual acuity. She was assessed by an ophthalmologist and signs of retinal vascular disease were found. During follow up, the patient experienced an acute unilateral loss of vision in the left eye. Fundoscopy revealed an obstruction of a macular branch of central retinal artery. Aspirin was added to oral anticoagulants and one month later, the patient experienced an upper gastrointestinal bleeding. After four months of follow up, there is no recovery of left eye vision (Rev Méd Chile 2002; 130: 86-89

Jorge Orellana R

2002-01-01

51

Decreased peripheral arterial volume distensibility in patients with branch retinal vein occlusion in comparison with normal subjects.  

Science.gov (United States)

This study aimed to quantify arterial volume distensibility in patients with branch retinal vein occlusion (BRVO) in comparison with normal subjects and to investigate factors associated with their differences. 40 normal subjects and 30 BRVO patients were studied. Brachial-ankle pulse wave velocity (baPWV) was measured to determine arterial volume distensibility. In comparison with the normal subjects, after adjusting for pulse pressure, baPWV in the BRVO patients was significantly higher by 2.3?m/s (P blood pressures (SBP and DBP) and ageing for both groups (all P blood pressures and ageing had more prominent effect on arterial volume distensibility. Peripheral arterial distensibility has been shown to be significantly lower in BRVO patients in comparison with normal subjects. The more prominent effect of SBP, DBP and ageing on arterial distensibility indicates the potential underlying mechanisms of the interaction between higher blood pressures, ageing and BRVO disease. PMID:25328000

Chen, Zhiqing; Mao, Lingna; Liu, Chengyu; Blake, James R; Zheng, Dingchang

2014-01-01

52

Mitogen-activated protein kinases in the porcine retinal arteries and neuroretina following retinal ischemia-reperfusion  

DEFF Research Database (Denmark)

The aim of the present study was to examine changes in the expression of intracellular signal-transduction pathways, specifically mitogen-activated protein kinases, following retinal ischemia-reperfusion.

Gesslein, Bodil; Håkansson, Gisela

2010-01-01

53

Central Retinal Artery Occlusion- A rare complication of oral contraceptive pills  

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Full Text Available Aim: To propose a hypothesis of causal association between central retinal artery occlusion (CRAO and oral contraceptive pills (OCPCase Summary:A case report-A 22 yr old, female presented with sudden painless loss of vision in OS [Right Eye] for 1 day. VA [Visual Activity] in OS was PL PR [Perception of Light and Projection of Rays] Faulty with RAPD [Relative Afferent Papillary Defect] with normal for fifteen minutes, given five hundred mg of acetazolamide orally stat, 0.4 ml of anterior chamber paracentesis done, 5400 IU LMW [Low Molecular Weight] heparin given SC[Subcutaneous] with carbogen inhalation. Retrospectively she was on oral contraceptives(Mala D for 1 month. She was not hypertensive or diabetic with normal blood, coagulation profile & carotid Doppler. She was evaluated by an intern to find the cause of coagulation disorder and was found to be normal. On first day FFA [Fundus Florescien Angiography] showed no blockage with normal cilioretinal artery perfusion established. Visual fields after one week showed central tubular vision and OCT [Ocular Coherent Tomography] showed normal fovea. After 2 weeks vision was 20/80 with persistent RAPD papilla macular bundle being perfused.

Nidhi Pancholi

2013-07-01

54

The arterially perfused eyecup of the tree squirrel, Sciurus carolinensis: a preparation for intracellular recording from mammalian retinal neurons.  

Science.gov (United States)

The arterially perfused eyecup of the Eastern gray squirrel, Sciurus carolinensis, has been developed for the study of mammalian retinal neurons by the technique of intracellular recording. Particular emphasis is placed in this report on the development of a convenient perfusion chamber. The choice of this animal and the reason for choosing the arterially perfused open eyecup are also discussed. Intracellular recordings were made from all major types of neurons in the squirrel retina. Data are presented here from ganglion cells and bipolar cells. PMID:3999804

Charlton, J S; Leeper, H F

1985-04-01

55

Retinal protective effects of topically administered agmatine on ischemic ocular injury caused by transient occlusion of the ophthalmic artery  

OpenAIRE

Agmatine, an endogenous polyamine and putative neuromodulator, is known to have neuroprotective effects on various neurons in the central nervous system. We determined whether or not topically administered agmatine could reduce ischemic retinal injury. Transient ocular ischemia was achieved by intraluminal occlusion of the middle cerebral artery of ddY mice (30-35 g) for 2 h, which is known to also induce occlusion of the ophthalmic artery. In the agmatine group (N = 6), a 1.0 mM agmatine-con...

Hong, S.; Hara, H.; Shimazawa, M.; Hyakkoku, K.; Kim, C. Y.; Seong, G. J.

2012-01-01

56

Changes in central retinal artery blood flow after ocular warming and cooling in healthy subjects  

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Full Text Available Context: Retinal perfusion variability impacts ocular disease and physiology. Aim: To evaluate the response of central retinal artery (CRA blood flow to temperature alterations in 20 healthy volunteers. Setting and Design: Non-interventional experimental human study. Materials and Methods: Baseline data recorded: Ocular surface temperature (OST in °C (thermo-anemometer, CRA peak systolic velocity (PSV and end diastolic velocity (EDV in cm/s using Color Doppler. Ocular laterality and temperature alteration (warming by electric lamp/cooling by ice-gel pack were randomly assigned. Primary outcomes recorded were: OST and intraocular pressure (IOP immediately after warming or cooling and ten minutes later; CRA-PSV and EDV at three, six and nine minutes warming or cooling. Statistical Analysis: Repeated measures ANOVA. Results: (n = 20; ?±SD: Pre-warming values were; OST: 34.5±1.02°C, CRA-PSV: 9.3±2.33cm/s, CRA-EDV: 4.6±1.27cm/s. OST significantly increased by 1.96°C (95% CI: 1.54 to 2.37 after warming, but returned to baseline ten minutes later. Only at three minutes, the PSV significantly rose by 1.21cm/s (95% CI: 0.51to1.91. Pre-cooling values were: OST: 34.5±0.96°C, CRA-PSV: 9.7±2.45 cm/s, CRA-EDV: 4.7±1.12cm/s. OST significantly decreased by 2.81°C (95% CI: -2.30 to -3.37 after cooling, and returned to baseline at ten minutes. There was a significant drop in CRA-PSV by 1.10cm/s (95% CI: -2.05 to -0.15 and CRA-EDV by 0.81 (95% CI: -1.47 to -0.14 at three minutes. At six minutes both PSV (95% CI: -1.38 to -0.03 and EDV (95% CI: -1.26 to -0.02 were significantly lower. All values at ten minutes were comparable to baseline. The IOP showed insignificant alteration on warming (95% CI of difference: -0.17 to 1.57mmHg, but was significantly lower after cooling (95% CI: -2.95 to -4.30mmHg. After ten minutes, IOP had returned to baseline. Conclusion : This study confirms that CRA flow significantly increases on warming and decreases on cooling, the latter despite a significant lowering of IOP.

Shamshad M

2010-01-01

57

Obstrucción de rama macular de arteria central de la retina / Occlusion of the macular branch of the central retinal artery  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish [...] Abstract in english We report a 54 years old female on oral anticoagulant treatment with a mitral valve disease, with a history of two transient ischemic attacks and a decreased visual acuity. She was assessed by an ophthalmologist and signs of retinal vascular disease were found. During follow up, the patient experien [...] ced an acute unilateral loss of vision in the left eye. Fundoscopy revealed an obstruction of a macular branch of central retinal artery. Aspirin was added to oral anticoagulants and one month later, the patient experienced an upper gastrointestinal bleeding. After four months of follow up, there is no recovery of left eye vision (Rev Méd Chile 2002; 130: 86-89)

Jorge, Orellana R; Ricardo, Garibaldi D; Fernando, Leiva P; Gustavo, Núñez C; César, Vicencio T; Ana L, Quiñones T.

2002-01-01

58

HIGH DIVISION ABDOMINAL AORTA WITH TORTUOUS ILIAC ARTERIES  

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Full Text Available Abdominal Aorta is considered as principle arteryof the abdominal cavity through which thevarious branches will be arises to supply differentparts of the gut according to their developmentalrelationship.As per the standard Anatomical text bookdescription, abdominal aorta begins at themedian, aortic hiatus of the diaphragm, anteriorto the inferior border of the 12th thoracicvertebra and the thoracolumbar intervertebraldisc. It descends anterior to the lumbarvertebrae to end at the lower border of thefourth lumbar vertebra, a little to the left of themidline, by dividing into two common iliacarteries.

Pradeep Kumar H Murudkar

2013-05-01

59

Optical coherence tomography findings in acute phase of branch retinal artery occlusion: case report Achados da tomografia de coerência óptica na fase aguda da oclusão de ramo da artéria central da retina: relato de caso  

OpenAIRE

PURPOSE: to report a case of branch retinal artery occlusion in the acute phase, using optical coherence tomography to evaluate the morphologic changes. A 27 year-old man had a sudden superior scotoma in the right eye, with fundus examination compatible with inferior temporal branch retinal artery obstruction. The optical coherence tomography revealed increase in thickness and hyper-reflectivity of the inner retinal layers in affected area, with decreased reflectivity of photoreceptor and ret...

Cíntia Maria Felix Medrado Parcero; Bruno de Paula Freitas; Eduardo Ferrari Marback; Otacílio Oliveira Maia Júnior; Roberto Lorens Marback

2010-01-01

60

Hyperbaric oxygen therapy in branch retinal artery occlusion in a 15-year-old boy with methylenetetrahydrofolate reductase mutation.  

Science.gov (United States)

Purpose. To report the efficacy of hyperbaric oxygen (HBO) therapy in a case of branch retinal artery occlusion (BRAO) in a 15-year-old boy. Methods. We report a 15-year-old boy with sudden loss of vision due to BRAO. Examination included laboratory evaluation for systemic risk factors. Follow-up exams included visual acuity, fundus examination, fundus fluorescein angiography, and visual field testing. HBO therapy was employed for treatment. Results. Medical history was positive for isolated glucocorticoid deficiency. Laboratory evaluation disclosed hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR) mutation. The visual acuity 0.05 at presentation improved to 0.8 after 20 days of HBO therapy. There was no change on visual fields. Conclusion. In this pediatric case, HBO therapy was useful in the treatment of BRAO. PMID:25722905

Celebi, Ali Riza Cenk; Kadayifcilar, Sibel; Eldem, Bora

2015-01-01

61

Tomografía óptica de coherencia en oclusión de arteria central de la retina Optical coherence tomography in central retinal artery occlusion  

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Full Text Available Casos clínicos: Presentamos tres ojos afectados de obstrucción de arteria central de la retina (OACR. En todos ellos realizamos exploración con tomografía óptica de coherencia (OCT. Dependiendo del tiempo de evolución del cuadro clínico, los signos oftalmoscópicos de OACR eran más o menos evidentes. Sin embargo, la presencia de una banda hiporreflectante en las imágenes de OCT pudo objetivarse en todos los casos. Discusión: La presencia en las imágenes de OCT de una banda hiporreflectante por debajo de la retina neurosensorial en los casos de OACR, que persiste incluso meses después del inicio del cuadro clínico, resulta útil en el diagnóstico de esta patología retiniana.Clinical cases: Three eyes with central retinal artery occlusion (CRAO have been studied. Optical coherence tomography (OCT was performed in each of them. Ophthalmoscopic signs of CRAO were equivocal in the three eyes. However, the presence of a hyporeflective signal in the OCT scan could be seen clearly in each of them. Discussion: The presence of a hyporeflective band between the neurosensory retina and the retinal pigment epithelium in OCT images, that persist for several months after a CRAO episode, is useful in establishing the diagnosis in these patients.

A. Salinas-Alamán

2006-09-01

62

Tomografía óptica de coherencia en oclusión de arteria central de la retina / Optical coherence tomography in central retinal artery occlusion  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Casos clínicos: Presentamos tres ojos afectados de obstrucción de arteria central de la retina (OACR). En todos ellos realizamos exploración con tomografía óptica de coherencia (OCT). Dependiendo del tiempo de evolución del cuadro clínico, los signos oftalmoscópicos de OACR eran más o menos evidente [...] s. Sin embargo, la presencia de una banda hiporreflectante en las imágenes de OCT pudo objetivarse en todos los casos. Discusión: La presencia en las imágenes de OCT de una banda hiporreflectante por debajo de la retina neurosensorial en los casos de OACR, que persiste incluso meses después del inicio del cuadro clínico, resulta útil en el diagnóstico de esta patología retiniana. Abstract in english Clinical cases: Three eyes with central retinal artery occlusion (CRAO) have been studied. Optical coherence tomography (OCT) was performed in each of them. Ophthalmoscopic signs of CRAO were equivocal in the three eyes. However, the presence of a hyporeflective signal in the OCT scan could be seen [...] clearly in each of them. Discussion: The presence of a hyporeflective band between the neurosensory retina and the retinal pigment epithelium in OCT images, that persist for several months after a CRAO episode, is useful in establishing the diagnosis in these patients.

A., Salinas-Alamán; A., García-Layana; H., Heras-Mulero; P.J., García-Gómez.

2006-09-01

63

Efeito da tibolona sobre parâmetros doplervelocimétricos das artérias oftálmica e retiniana Tibolone's effect on retinal and ophthalmic arteries flowmetry  

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Full Text Available OBJETIVO: avaliar o efeito do uso da tibolona sobre os parâmetros doplervelocimétricos das artérias oftálmica e retiniana. MÉTODOS: realizou-se ensaio clínico, prospectivo, longitudinal, aleatorizado, controlado com placebo, duplo-cego, no qual dentre 100 mulheres na menopausa, 50 usaram o princípio ativo tibolona 2,5 mg (Grupo Tib e 50, o placebo para formar o grupo controle (Grupo Plac. No Grupo Tib, das 50 mulheres que iniciaram o estudo, 44 retornaram após 84 dias para a finalização dos exames. No Grupo Plac retornaram 47 delas. As artérias oftálmica e retiniana foram estudadas, determinando-se o índice de resistência (IR, índice de pulsatilidade (IP e relação sístole/diástole (S/D. As aferições foram feitas antes e 84 dias após a medicação. Utilizou-se o teste t de Student para amostras independentes na comparação das medianas entre os grupos e para amostras dependentes na comparação entre as medianas dentro do mesmo grupo. RESULTADOS: as características das mulheres nos dois grupos foram semelhantes em relação à idade, ao tempo de menopausa, ao índice de massa corporal, à pressão arterial, à paridade e à freqüência cardíaca. O Grupo Tib apresentou as seguintes medianas: IR(pré=0,71±0,05, IR(pós=0,72±0,08 (p=0,43; IP(pré=1,29±0,22, IP(pós=1,30±0,25 (p=0,4 e SD(pré=3,49±0,77, SD(pós=3,65±0,94 (p=0,32. Na artéria retiniana foram obtidas as seguintes medianas na artéria oftálmica: IR(pré=0,67±0,09, IR(pós=0,69±0,10 (p=0,7; IP(pré=1,20±0,29, IP(pós=1,22±0,3 (p=0,2 e SD(pré=3,29±0,95, SD(pós=3,30±1,07 (p=0,3. Os grupos tibolona e controle não apresentaram diferenças significantes nos índices quando avaliados ao final do estudo. CONCLUSÕES: a tibolona, na dose de 2,5 mg, não apresenta efeitos sobre os índices doppler das artérias oftálmica e retiniana.PURPOSE: to evaluate the effect of tibolone use on dopplervelocimetric parameters of ophthalmic and retinal arteries. METHODS: clinical, prospective, longitudinal, randomized, placebo-controlled, triple-blind study, in which among 100 menopausal women, 50 have used 2.5 mg of the active principle tibolone (Tib Group and 50, placebo as a means to form the control-group (Plac Group. In the Tib Group, 44 of the 50 women returned after 84 days to finish the exams, and in the Plac Group, 47. The ophthalmic and retinal arteries were studied to determine the resistance index (RI, the pulsatility index (PI and the systole/diastole ratio (S/D. Assessments have been done before and 84 days after medication. The t-Student test has been used for the comparison of means between the groups in independent samples, as well as for within-group comparisons in dependent samples. RESULTS: in both groups, the women's characteristics were similar in age, menopause duration, body mass index, arterial blood pressure, deliveries and cardiac rate. The Tib Group presented the following values in the ophthalmic artery: RI(pre=0.71±0.05, RI(post0.72±0.08 (p=0.43; PI(pre=1.29±0.22, PI(post=1.30±0.25 (p=0.4 and S/D(pre=3.49±0.77, SD(post=3.65±0.94 (p=0.32. In the retinal artery, the following values have been found: RI(pre=0.67±0.09, RI(post=0.69±0.10 (p=0.7; PI(pre=1.20±0.29, PI(post=1.22±0.3 (p=0.2 and SD(pre=3.29±0.95, SD(post=3.30±1.07 (p=0.3. Also, the tibolone and control groups did not show any significant difference in regard to the above indexes in the end of the study. CONCLUSIONS: the 2.5 mg dose of tibolone had no effect on the Doppler velocimetry indexes of the ophthalmic and retinal arteries.

Marco Aurélio Martins de Souza

2008-11-01

64

Efeito da tibolona sobre parâmetros doplervelocimétricos das artérias oftálmica e retiniana / Tibolone's effect on retinal and ophthalmic arteries flowmetry  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: avaliar o efeito do uso da tibolona sobre os parâmetros doplervelocimétricos das artérias oftálmica e retiniana. MÉTODOS: realizou-se ensaio clínico, prospectivo, longitudinal, aleatorizado, controlado com placebo, duplo-cego, no qual dentre 100 mulheres na menopausa, 50 usaram o princípio [...] ativo tibolona 2,5 mg (Grupo Tib) e 50, o placebo para formar o grupo controle (Grupo Plac). No Grupo Tib, das 50 mulheres que iniciaram o estudo, 44 retornaram após 84 dias para a finalização dos exames. No Grupo Plac retornaram 47 delas. As artérias oftálmica e retiniana foram estudadas, determinando-se o índice de resistência (IR), índice de pulsatilidade (IP) e relação sístole/diástole (S/D). As aferições foram feitas antes e 84 dias após a medicação. Utilizou-se o teste t de Student para amostras independentes na comparação das medianas entre os grupos e para amostras dependentes na comparação entre as medianas dentro do mesmo grupo. RESULTADOS: as características das mulheres nos dois grupos foram semelhantes em relação à idade, ao tempo de menopausa, ao índice de massa corporal, à pressão arterial, à paridade e à freqüência cardíaca. O Grupo Tib apresentou as seguintes medianas: IR(pré)=0,71±0,05, IR(pós)=0,72±0,08 (p=0,43); IP(pré)=1,29±0,22, IP(pós)=1,30±0,25 (p=0,4) e SD(pré)=3,49±0,77, SD(pós)=3,65±0,94 (p=0,32). Na artéria retiniana foram obtidas as seguintes medianas na artéria oftálmica: IR(pré)=0,67±0,09, IR(pós)=0,69±0,10 (p=0,7); IP(pré)=1,20±0,29, IP(pós)=1,22±0,3 (p=0,2) e SD(pré)=3,29±0,95, SD(pós)=3,30±1,07 (p=0,3). Os grupos tibolona e controle não apresentaram diferenças significantes nos índices quando avaliados ao final do estudo. CONCLUSÕES: a tibolona, na dose de 2,5 mg, não apresenta efeitos sobre os índices doppler das artérias oftálmica e retiniana. Abstract in english PURPOSE: to evaluate the effect of tibolone use on dopplervelocimetric parameters of ophthalmic and retinal arteries. METHODS: clinical, prospective, longitudinal, randomized, placebo-controlled, triple-blind study, in which among 100 menopausal women, 50 have used 2.5 mg of the active principle tib [...] olone (Tib Group) and 50, placebo as a means to form the control-group (Plac Group). In the Tib Group, 44 of the 50 women returned after 84 days to finish the exams, and in the Plac Group, 47. The ophthalmic and retinal arteries were studied to determine the resistance index (RI), the pulsatility index (PI) and the systole/diastole ratio (S/D). Assessments have been done before and 84 days after medication. The t-Student test has been used for the comparison of means between the groups in independent samples, as well as for within-group comparisons in dependent samples. RESULTS: in both groups, the women's characteristics were similar in age, menopause duration, body mass index, arterial blood pressure, deliveries and cardiac rate. The Tib Group presented the following values in the ophthalmic artery: RI(pre)=0.71±0.05, RI(post)0.72±0.08 (p=0.43); PI(pre)=1.29±0.22, PI(post)=1.30±0.25 (p=0.4) and S/D(pre)=3.49±0.77, SD(post)=3.65±0.94 (p=0.32). In the retinal artery, the following values have been found: RI(pre)=0.67±0.09, RI(post)=0.69±0.10 (p=0.7); PI(pre)=1.20±0.29, PI(post)=1.22±0.3 (p=0.2) and SD(pre)=3.29±0.95, SD(post)=3.30±1.07 (p=0.3). Also, the tibolone and control groups did not show any significant difference in regard to the above indexes in the end of the study. CONCLUSIONS: the 2.5 mg dose of tibolone had no effect on the Doppler velocimetry indexes of the ophthalmic and retinal arteries.

Marco Aurélio Martins de, Souza; Selmo, Geber.

2008-11-01

65

Clinical significance of retinal emboli during diagnostic and therapeutic cardiac catheterization in patients with coronary artery disease  

OpenAIRE

Abstract Background Cardiac catheterization may cause retinal embolization, a risk factor for cerebrovascular emboli and stroke. We describe the incidence of clinically silent and apparent retinal emboli following diagnostic and interventional coronary catheterization and associated risk factors. Methods Three hundred selected patients attending a tertiary referral center for diagnostic and therapeutic cardiac catheterization were studied. Retinal examination and examination of the visual fie...

Rostami Hamed; Mehdizadeh Morteza; Kojuri Javad; Shahidian Danial

2011-01-01

66

Apelin and APLN single nucleotide polymorphisms and combined hypertension and central retinal artery stenosis in a Chinese population.  

Science.gov (United States)

Abstract Apelin activity plays a role in regulating blood pressure. This study explored the relationship between single nucleotide polymorphisms (SNPs) in the Apelin gene (APLN) with hypertension and hypertension with central retinal artery equivalent (CRAE) stenosis in a coastal Chinese population. All subjects answered an epidemiological survey for demographic and disease characteristics. Apelin levels were determined and three APLN SNPs, rs56204867, rs3115757, and rs3761581, were evaluated. CRAE was measured using fundus photography. Apelin levels were significantly lower in subjects with hypertension and hypertension with CRAE stenosis (0.23?±?0.10?ng/ml and 0.21?±?0.08?ng/ml, respectively) compared with control subjects (0.25?±?0.11?ng/ml; p?Apelin levels. Genetic analysis indicated that in both males and females SNP rs3761581 was associated with hypertension and that more males carrying rs56204867 and rs3761581?T-A haplotype had hypertension (61.88%) and hypertension with CRAE stenosis (56.82%) than control males (39.33%). In this Chinese population, Apelin and APLN SNP rs3761581 was associated with combined hypertension with CRAE, indicating that the expression of APLN gene products may be involved in vascular injury. PMID:25272042

Zhu, Pengli; Lin, Fan; Huang, Feng; Huang, Qiuxia; Li, Qiaowei; Gao, Zhonghai; Chen, Falin

2014-10-01

67

Optical coherence tomography findings in acute phase of branch retinal artery occlusion: case report / Achados da tomografia de coerência óptica na fase aguda da oclusão de ramo da artéria central da retina: relato de caso  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O objetivo é demonstrar alterações morfológicas retinianas por meio da tomografia de coerência óptica na oclusão de ramo de artéria central da retina na fase aguda. Homem de 27 anos apresentando escotoma súbito no campo superior de olho direito, com exame fundoscópico compatível com oclusão de ramo [...] ínfero-temporal da artéria central da retina. A tomografia de coerência óptica revelou aumento da espessura e hiperrefletividade das camadas internas da retina, com redução da refletividade das camadas de fotorreceptores e epitélio pigmentar da retina. Os achados na tomografia de coerência óptica são compatíveis com edema intracelular, e não com fluido extracelular secundário a extravasamento vascular, reforçando teorias histopatológicas da isquemia e necrose retiniana, que ocorrem após oclusão arterial retiniana. Abstract in english PURPOSE: to report a case of branch retinal artery occlusion in the acute phase, using optical coherence tomography to evaluate the morphologic changes. A 27 year-old man had a sudden superior scotoma in the right eye, with fundus examination compatible with inferior temporal branch retinal artery o [...] bstruction. The optical coherence tomography revealed increase in thickness and hyper-reflectivity of the inner retinal layers in affected area, with decreased reflectivity of photoreceptor and retinal pigment epithelial layers. The optical coherence tomography findings are consistent with intracellular edema, and not with secondary vascular leakage of extracellular fluid, according to histopathological theories of retinal ischemia and necrosis that occurs after retinal artery occlusion.

Cíntia Maria Felix Medrado, Parcero; Bruno de Paula, Freitas; Eduardo Ferrari, Marback; Otacílio de Oliveira, Maia Júnior; Roberto Lorens, Marback.

2010-04-01

68

Optical coherence tomography findings in acute phase of branch retinal artery occlusion: case report Achados da tomografia de coerência óptica na fase aguda da oclusão de ramo da artéria central da retina: relato de caso  

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Full Text Available PURPOSE: to report a case of branch retinal artery occlusion in the acute phase, using optical coherence tomography to evaluate the morphologic changes. A 27 year-old man had a sudden superior scotoma in the right eye, with fundus examination compatible with inferior temporal branch retinal artery obstruction. The optical coherence tomography revealed increase in thickness and hyper-reflectivity of the inner retinal layers in affected area, with decreased reflectivity of photoreceptor and retinal pigment epithelial layers. The optical coherence tomography findings are consistent with intracellular edema, and not with secondary vascular leakage of extracellular fluid, according to histopathological theories of retinal ischemia and necrosis that occurs after retinal artery occlusion.O objetivo é demonstrar alterações morfológicas retinianas por meio da tomografia de coerência óptica na oclusão de ramo de artéria central da retina na fase aguda. Homem de 27 anos apresentando escotoma súbito no campo superior de olho direito, com exame fundoscópico compatível com oclusão de ramo ínfero-temporal da artéria central da retina. A tomografia de coerência óptica revelou aumento da espessura e hiperrefletividade das camadas internas da retina, com redução da refletividade das camadas de fotorreceptores e epitélio pigmentar da retina. Os achados na tomografia de coerência óptica são compatíveis com edema intracelular, e não com fluido extracelular secundário a extravasamento vascular, reforçando teorias histopatológicas da isquemia e necrose retiniana, que ocorrem após oclusão arterial retiniana.

Cíntia Maria Felix Medrado Parcero

2010-04-01

69

A case report and brief review of the literature on bilateral retinal infarction following cardiopulmonary bypass for coronary artery bypass grafting  

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Full Text Available Abstract Postoperative visual loss is a devastating perioperative complication. The commonest aetiologies are anterior ischaemic optic neuropathy (AION, posterior ischaemic optic neuropathy (PION, and central retinal artery occlusion (CRAO. These appear to be related to certain types of operation, most commonly spinal and cardiac bypass procedures; with the rest divided between: major trauma causing excessive blood loss; head/neck and nasal or sinus surgery; major vascular procedures (aortic aneurysm repair, aorto-bifemoral bypass; general surgery; urology; gynaecology; liposuction; liver transplantation and duration of surgery. The non-surgical risk factors are multifactorial: advanced age, prolonged postoperative anaemia, positioning (supine v prone, alteration of venous drainage of the retina, hypertension, smoking, atherosclerosis, hyperlipidaemia, diabetes, hypercoagulability, hypotension, blood loss and large volume resuscitation. Other important cardiac causes are septic emboli from bacterial endocarditis and emboli caused by atrial myxomata. The majority of AION cases occur during CPB followed by head/neck surgery and prone spine surgery. CPB is used to allow coronary artery bypass grafting on a motionless heart. It has many side-effects and complications associated with its use and we report here a case of bilateral retinal infarction during routine coronary artery bypass grafting in a young male patient with multiple risk factors for developing this complication despite steps to minimise its occurrence.

Trethowan Brian A

2011-11-01

70

Doplervelocimetria das artérias oftálmica e central da retina em gestantes normais Dopplervelocimetry of ophthalmic and central retinal arteries in normal pregnancies  

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Full Text Available OBJETIVOS: avaliar os padrões dos índices doplervelocimétricos das artérias oftálmica e central da retina durante o segundo e terceiro trimestres da gestação normal e comparar os valores obtidos do olho direito e esquerdo das gestantes. MÉTODOS: estudo transversal no qual se avaliaram seis índices doplervelocimétricos das artérias central da retina e oftálmica em 51 gestantes normais, com idades gestacionais entre a 20ª e a 38ª semana. As variáveis analisadas foram os índices de resistência e pulsatilidade (IR, IP, os picos de velocidade sistólica e diastólica (PVS, PVD e a razão entre picos de velocidade (RPV. A análise dos índices doplervelocimétricos dos olhos direito e esquerdo foi realizada utilizando-se a mediana dos valores. Para a comparação dos valores dos índices entre os dois olhos das gestantes, utilizou-se o teste t de Student para dados pareados. A associação entre a idade gestacional e os índices foi testada empregando-se o coeficiente de correlação linear de Pearson. Adotou-se o nível de significância de 5% para os testes estatísticos. RESULTADOS: a mediana dos índices doplervelocimétricos das artérias oftálmica e central da retina foram, respectivamente: IP=1,83; IR=0,78; PVS=34,20; PVD=6,80; RPV=0,48 e IP=1,34; IR=0,70; PVS=7,40; PVD=2,10. Não houve diferenças na análise comparativa dos índices doplervelocimétricos entre os olhos direito e esquerdo das gestantes normais. O coeficiente de correlação linear entre a idade gestacional e os índices de ambas as artérias não mostrou diferença significante durante a gestação normal. CONCLUSÃO: é factível a análise unilateral dos índices doplervelocimétricos das artérias oftálmica e central da retina no estudo de doenças maternas sistêmicas. Não há mudança significativa dos índices doplervelocimétricos das artérias oftálmica e central da retina ao longo da gestação normal entre a 20ª e a 38ª semana.PURPOSE: to evaluate ophthalmic and retinal central artery Doppler indices during the second and third trimesters of normal pregnancy and to compare the right with left eye Doppler indices of normotensive women. METHODS: a cross-sectional study which evaluated central retinal and ophthalmic artery Doppler velocimetry values of 51 normal pregnant women, in the 20th to 38th week of gestation. The following values were analyzed: pulsatility and resistance indexes (PI, RI, peak systolic and end-diastolic flow velocity (PSV, EDFV and peak velocity ratio (PVR. The Doppler indices in the right and left eyes were studied by the median. The paired Student's t test was used to confront the right and left eye values and the Pearson linear correlation analysis was performed to study the value changes throughout the gestation, with the level of significance set at 5%. RESULTS: Doppler velocimetry indices of ophthalmic and central retinal arteries (median values were, respectively: PI=1.83; RI=0.78; PSV=34.20; EDFV=6.80; PVR=0.48 and PI=1.34; RI=0.70; PSV=7.40; EDFV=2.10. There was no significant difference between the right and left side Doppler values. Linear correlation analysis showed no association between the arterial values and pregnancy age. CONCLUSION: the unilateral analysis of ophthalmic and central retinal artery Doppler velocimetry values can be used in systemic maternal disease. There is no significant change in ophthalmic and central retinal artery Doppler velocimetry values throughout normal pregnancy.

Angélica Lemos Debs Diniz

2005-04-01

71

A tortuous proximal urethra in urorectal septum malformation sequence?  

Science.gov (United States)

We observed a newborn boy with urorectal septum malformation sequence. Anomalies of the genitalia and rectum were present. He expired on the first day of life, due to severe lung hypoplasia. Autopsy showed a colon that ended in a blind sac, an enlarged bladder with no grossly visible urethra, and dysplastic kidneys. A cone-shaped tissue at the usual site of the bladder outlet contained tortuous and slit-like lumina, suggesting an undeveloped proximal urethra. The urethral structure was lined by transitional epithelium with squamous metaplasia. Many small buds-lined with columnar epithelium-branched from the urethral structure. These ductal buds lined with columnar epithelium stained for prostatic acid phosphatase. Basal cells surrounding the ductal buds stained for p63 and high molecular weight cytokeratin-supporting an interpretation that the buds were early prostatic ducts with normal histology. To our knowledge, these are the first histological images of an undeveloped, obstructed urethra associated with the urorectal septum malformation sequence. PMID:24665006

Lin, Henry J; Lugo, Hector; Tran, Thu; Tovar, Jason P; Corral, Julia; Zork, Noelia M; Smith, Lynne M; French, Samuel W; Barajas, Luciano

2014-05-01

72

Letter to the editor: partial central retinal artery occlusion offers a unique insight into the ischemic penumbra  

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Full Text Available David McLeodUniversity of Manchester and Manchester Royal Eye Hospital, UKKurimoto and colleagues recently reported three cases of unilateral visual loss associated with striking ischemic changes in the posterior retina and impressive visual recovery following treatment.1 The presenting signs included an indistinct foveal cherry-red spot and a circle of cotton-wool spots (CWSs surrounding the optic disc. Fundus fluorescein angiography (FFA revealed a marked delay in the arm-retina circulation time, together with "areas of occlusion of the retinal arterioles" that corresponded to the location of the CWSs.

McLeod D

2011-12-01

73

Retinal detachment  

OpenAIRE

Rhegmatogenous retinal detachment (RRD) is the most common form of retinal detachment, where a retinal "break" allows the ingress of fluid from the vitreous cavity to the subretinal space, resulting in retinal separation. It occurs in about 1 in 10,000 people a year. This review considers only acute progressive RRD.

Fraser, Scott; Steel, David

2010-01-01

74

Retinal detachment  

OpenAIRE

Rhegmatogenous retinal detachment (RRD) is the most common form of retinal detachment, where a retinal "break" allows the ingress of fluid from the vitreous cavity to the subretinal space, resulting in retinal separation. It occurs in about 1 in 10,000 people a year. This review considers only acute progressive RRD.

Fraser, Scott; Steel, David

2009-01-01

75

Variação do fluxo sanguíneo da artéria central da retina durante as diferentes fases do ciclo menstrual ovulatório Central retinal artery blood flow variation during menstrual cycle  

Directory of Open Access Journals (Sweden)

Full Text Available OBJETIVO: avaliar a resistência vascular da artéria central da retina, por meio do fluxo Doppler, nas diferentes fases do ciclo menstrual ovulatório. MÉTODOS: estudo observacional, longitudinal e prospectivo com avaliação de 34 mulheres saudáveis, submetidas a estudo dopplerfluxométrico do fundo do olho para avaliação da resistência vascular da artéria central da retina nas posições sentada e deitada, durante quatro fases do ciclo menstrual: fase folicular inicial, fase folicular média, fase periovulatória e fase lútea média. A confirmação da ovulação no ciclo de estudo foi feita pela dosagem de progesterona sérica na fase lútea média. Foram avaliados os índices de pulsatilidade (IP e de resistência, e as velocidades máxima, mínima e média. RESULTADOS: a idade média foi de 29,7 anos. Não foram observadas diferenças entre os índices obtidos para ambos os olhos; assim, utilizamos as médias dos índices para realizar o cálculo estatístico. Quando comparadas às posições de realização do exame, detectou-se um IP maior na posição sentada; assim, as análises foram avaliadas em separado, respeitando-se a posição da paciente. O IP da artéria central da retina, avaliado com a paciente deitada, variou durante o ciclo menstrual, apresentando-se significativamente mais baixo nas fases folicular média (1,5±0,3 e periovulatória (1,5±0,3 quando comparadas às fases folicular precoce (1,7±0,4 e lútea média (1,7±0,4. Quando a avaliação foi feita com a paciente sentada não foram observadas diferenças para as diferentes fases do ciclo. CONCLUSÕES: num ciclo menstrual ovulatório ocorre diminuição da resistência vascular na artéria central da retina e posterior reversão do efeito, como demonstrado pelas variações do IP.PURPOSE: to evaluate the vascular blood flow of the central retinal arteries using dopplervelocimetry in the different phases of the ovulatory menstrual cycle. METHODS: we performed an observational, longitudinal and prospective study evaluating 34 healthy and ovulatory women. All women were submitted to Doppler scan of the eye to evaluate the vascular resistance of the central retinal arteries, either lying down or on a seated position, during four phases of the menstrual cycle. Confirmation of ovulation was performed by measuring serum progesterone during the luteal phase. We analyzed the pulsatility and resistance index and the maximum, minimum and mean velocity. RESULTS: mean age was 29.7 years. No differences were observed between the indexes obtained in both eyes, therefore a mean index was used for comparisons. As the comparison between the positions used for the exams showed a higher PI for the seated position, the analyses were performed separately. The pulsatility index in the lying position was different among the different phases of the menstrual cycle. The arterial resistance was significantly lower during the intermediate follicular and the periovulatory phases, as compared to the early follicular and luteal phases. When the comparison was performed with the patient in the seated position, no differences were observed. CONCLUSIONS: Our results demonstrate a reduction in the vascular resistance of the cerebral microcirculation and a posterior reversal, as shown by changes in the PI.

Luiz Carlos Viana

2007-03-01

76

Variação do fluxo sanguíneo da artéria central da retina durante as diferentes fases do ciclo menstrual ovulatório / Central retinal artery blood flow variation during menstrual cycle  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: avaliar a resistência vascular da artéria central da retina, por meio do fluxo Doppler, nas diferentes fases do ciclo menstrual ovulatório. MÉTODOS: estudo observacional, longitudinal e prospectivo com avaliação de 34 mulheres saudáveis, submetidas a estudo dopplerfluxométrico do fundo do [...] olho para avaliação da resistência vascular da artéria central da retina nas posições sentada e deitada, durante quatro fases do ciclo menstrual: fase folicular inicial, fase folicular média, fase periovulatória e fase lútea média. A confirmação da ovulação no ciclo de estudo foi feita pela dosagem de progesterona sérica na fase lútea média. Foram avaliados os índices de pulsatilidade (IP) e de resistência, e as velocidades máxima, mínima e média. RESULTADOS: a idade média foi de 29,7 anos. Não foram observadas diferenças entre os índices obtidos para ambos os olhos; assim, utilizamos as médias dos índices para realizar o cálculo estatístico. Quando comparadas às posições de realização do exame, detectou-se um IP maior na posição sentada; assim, as análises foram avaliadas em separado, respeitando-se a posição da paciente. O IP da artéria central da retina, avaliado com a paciente deitada, variou durante o ciclo menstrual, apresentando-se significativamente mais baixo nas fases folicular média (1,5±0,3) e periovulatória (1,5±0,3) quando comparadas às fases folicular precoce (1,7±0,4) e lútea média (1,7±0,4). Quando a avaliação foi feita com a paciente sentada não foram observadas diferenças para as diferentes fases do ciclo. CONCLUSÕES: num ciclo menstrual ovulatório ocorre diminuição da resistência vascular na artéria central da retina e posterior reversão do efeito, como demonstrado pelas variações do IP. Abstract in english PURPOSE: to evaluate the vascular blood flow of the central retinal arteries using dopplervelocimetry in the different phases of the ovulatory menstrual cycle. METHODS: we performed an observational, longitudinal and prospective study evaluating 34 healthy and ovulatory women. All women were submitt [...] ed to Doppler scan of the eye to evaluate the vascular resistance of the central retinal arteries, either lying down or on a seated position, during four phases of the menstrual cycle. Confirmation of ovulation was performed by measuring serum progesterone during the luteal phase. We analyzed the pulsatility and resistance index and the maximum, minimum and mean velocity. RESULTS: mean age was 29.7 years. No differences were observed between the indexes obtained in both eyes, therefore a mean index was used for comparisons. As the comparison between the positions used for the exams showed a higher PI for the seated position, the analyses were performed separately. The pulsatility index in the lying position was different among the different phases of the menstrual cycle. The arterial resistance was significantly lower during the intermediate follicular and the periovulatory phases, as compared to the early follicular and luteal phases. When the comparison was performed with the patient in the seated position, no differences were observed. CONCLUSIONS: Our results demonstrate a reduction in the vascular resistance of the cerebral microcirculation and a posterior reversal, as shown by changes in the PI.

Luiz Carlos, Viana; Michelle Amorim Costa, Burmann; Marcos, Sampaio; Selmo, Geber.

2007-03-01

77

Resolution of vitreomacular traction following intravitreal triamcinolone acetonide injection in an eye with branch retinal vein occlusion  

OpenAIRE

Göktu? Seymeno?lu,1 Özcan Kayikçio?lu,1 Bilge Öztürk ?ahin21Department of Ophthalmology, Faculty of Medicine, Celal Bayar University, Manisa, Turkey; 2Department of Ophthalmology, Akhisar State Hospital, Akhisar, Manisa, TurkeyAbstract: A 60-year-old woman with a past medical history of branch retinal vein occlusion presented with decreased vision and metamorphopsia in her left eye. A fundus examination revealed a tortuous retinal vein with a...

Seymeno?lu G; Kayikçio?lu O; Bo, S?ahin

2012-01-01

78

Retinitis Pigmentosa.  

Science.gov (United States)

The author describes the etiology of retinitis pigmentosa, a visual dysfunction which results from progressive loss of the retinal photoreceptors. Sections address signs and symptoms, ancillary findings, heredity, clinical diagnosis, therapy, and research. (SBH)

Carr, Ronald E.

1979-01-01

79

Spectrophotometric retinal oximetry in pigs  

DEFF Research Database (Denmark)

PURPOSE: To assess the validity of spectrophotometric retinal oximetry, by comparison to blood gas analysis and intra-vitreal measurements of partial pressure of oxygen (pO2). METHODS: Female domestic pigs were used for all experiments (n=8). Oxygen fraction in inspired air was changed using a mixture of room air, pure oxygen and pure nitrogen, ranging from 5% to 100% oxygen. Femoral arterial blood gas analysis and retinal oximetry was performed at each level of inspiratory oxygen fraction. Retinal oximetry was performed using a commercial instrument, the Oxymap Retinal Oximeter T1 (Oxymap ehf, Reykjavik, Iceland). The device simultaneously acquires images at two wavelengths (570 nm and 600 nm) and specialized software automatically detects retinal blood vessels. In three pigs, invasive pO2-measurements were performed after the initial non-invasive measurements. RESULTS: Comparison of femoral arterial oxygen saturation and the optical density ratio over retinal arteries revealed an approximately linear relationship (R(2) = 0.74, p = 3.4 x 10(-9)). In order to test the validity of applying the arterial calibration to veins, we compared non-invasive oximetry measurements to invasive pO2-measurements in three pigs. This relationship was approximately linear (R(2) = 0.45, p = 0.04). CONCLUSIONS: Non-invasive spectrophotometric oximetry is sensitive to changes in oxygen saturation in pigs and correlated with intravitreal pO2-measurements and with femoral artery pO2. Pigs present a higher intra-individual variability in retinal oxygen saturation and a lower overall saturation than humans. The difference between porcine and human eyes makes direct comparisons of measurements difficult.

Traustason, Sindri; Kiilgaard, Jens Folke

2013-01-01

80

Imaging of a Cilioretinal Artery Embolisation  

OpenAIRE

Retinal artery occlusion can be the first indicator of a significant cardiovascular disorder and the need for treatment. We present the case of a 69-year-old man with a cilioretinal artery occlusion and retinal ischemia. Retinal imaging, in particular fundus autofluorescence, highlighted an intraluminal hyperautofluorescent lesion which led to the diagnosis of retinal emboli. Subsequently a severe, previously undiagnosed carotid occlusive disease was discovered. The patient underwent prompt...

Munk, Marion R.; Mirza, Rukhsana G.; Jampol, Lee M.

2014-01-01

81

Constitutive Modeling of Anisotropic Finite-Deformation Hyperelastic Behaviors of Soft Materials Reinforced by Tortuous Fibers  

OpenAIRE

Many biological materials are composites composed of a soft matrix reinforced with stiffer fibers. These stiffer fibers may have a tortuous shape and wind through the soft matrix. At small material deformation, these fibers deform in a bending mode and contribute little to the material stiffness; at large material deformation, these fibers deform in a stretching mode and induce a stiffening effect in the material behavior. The transition from bending mode deformation to stretching mode deform...

Kao, Philip H.; Lammers, Steven R.; Hunter, Kendall; Stenmark, Kurt R.; Shandas, Robin; Qi, H. Jerry

2010-01-01

82

Learning about Retinitis Pigmentosa  

Science.gov (United States)

... genetic terms used on this page Learning About Retinitis Pigmentosa What is retinitis pigmentosa? What are the symptoms ... Pigmentosa Additional Resources for Retinitis Pigmentosa What is retinitis pigmentosa? Retinitis pigmentosa (RP) is the name given to ...

83

Artery buckling stimulates cell proliferation and NF-?B signaling.  

Science.gov (United States)

Tortuous carotid arteries are often seen in aged populations and are associated with atherosclerosis, but the underlying mechanisms to explain this preference are unclear. Artery buckling has been suggested as one potential mechanism for the development of tortuous arteries. The objective of this study, accordingly, was to determine the effect of buckling on cell proliferation and associated NF-?B activation in arteries. We developed a technique to generate buckling in porcine carotid arteries using long artery segments in organ culture without changing the pressure, flow rate, and axial stretch ratio. Using this technique, we examined the effect of buckling on arterial wall remodeling in 4-day organ culture under normal and hypertensive pressures. Cell proliferation, NF-?B p65, I?B-?, ERK1/2, and caspase-3 were detected using immunohistochemistry staining and immunoblot analysis. Our results showed that cell proliferation was elevated 5.8-fold in the buckling group under hypertensive pressure (n = 7, P fluid-structure interaction model showed reduced wall stress on the inner side of buckled arteries and elevated wall stress on the outer side. We conclude that arterial buckling promotes site-specific wall remodeling with increased cell proliferation and NF-?B activation. These findings shed light on the biomechanical and molecular mechanisms of the pathogenesis of atherosclerosis in tortuous arteries. PMID:24929858

Xiao, Yangming; Hayman, Danika; Khalafvand, Seyed Saeid; Lindsey, Merry L; Han, Hai-Chao

2014-08-15

84

Retinitis pigmentosa  

OpenAIRE

Abstract Retinitis pigmentosa (RP) is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination. Prevalence of non syndromic RP is approximately 1/4,000. The most common form of RP is a rod-cone dystrophy, in which the first symptom is night blindness, followed by the progressive loss in the peripheral visual field in daylight, and eventually leading to blindness after several decades. Some extreme cases may...

Hamel Christian

2006-01-01

85

Localised retinal vasculitis in cat scratch disease  

OpenAIRE

We report an atypical presentation of ocular cat scratch disease (CSD) in an 8-year-old Caucasian male who presented with localised retinal arterial vasculitis and associated retinal oedema. His history of headaches, frequent contact with a kitten and a high Bartonella henslelae titre confirmed the diagnosis of CSD. Over an 18-month follow-up period, his best corrected visual acuity in the affected eye improved from 20/30?2 to 20/25+3 without treatment; however, the affected retinal artery ...

Jacobs, David Jonathan; Scott, Michele L.; Slusher, M. Madison

2009-01-01

86

Localised retinal vasculitis in cat scratch disease.  

Science.gov (United States)

We report an atypical presentation of ocular cat scratch disease (CSD) in an 8-year-old Caucasian male who presented with localised retinal arterial vasculitis and associated retinal oedema. His history of headaches, frequent contact with a kitten and a high Bartonella henslelae titre confirmed the diagnosis of CSD. Over an 18-month follow-up period, his best corrected visual acuity in the affected eye improved from 20/30-2 to 20/25+3 without treatment; however, the affected retinal artery remained sheathed. PMID:21686569

Jacobs, David Jonathan; Scott, Michele L; Slusher, M Madison

2009-01-01

87

Constitutive Modeling of Anisotropic Finite-Deformation Hyperelastic Behaviors of Soft Materials Reinforced by Tortuous Fibers.  

Science.gov (United States)

Many biological materials are composites composed of a soft matrix reinforced with stiffer fibers. These stiffer fibers may have a tortuous shape and wind through the soft matrix. At small material deformation, these fibers deform in a bending mode and contribute little to the material stiffness; at large material deformation, these fibers deform in a stretching mode and induce a stiffening effect in the material behavior. The transition from bending mode deformation to stretching mode deformation yields a characteristic J-shape stress-strain curve. In addition, the spatial distribution of these fibers may render the composite an anisotropic behavior. In this paper, we present an anisotropic finite-deformation hyperelastic constitutive model for such materials. Here, the matrix is modeled as an isotropic neo-Hookean material. "The behaviors of single tortuous fiber are represented by a crimped fiber model". The anisotropic behavior is introduced by a structure tensor representing the effective orientation distribution of crimped fibers. Parametric studies show the effect of fiber tortuosity and fiber orientation distribution on the overall stress-strain behaviors of the materials. PMID:21822502

Kao, Philip H; Lammers, Steven R; Hunter, Kendall; Stenmark, Kurt R; Shandas, Robin; Qi, H Jerry

2010-04-01

88

Retinal prosthesis.  

Science.gov (United States)

Retinal prosthesis has been translated from the laboratory to the clinic over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitis pigmentosa. These devices provide partial sight restoration and patients use this improved vision in their everyday lives. Improved mobility and object detection are some of the more notable findings from the clinical trials. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. This paper reviews the recent clinical trials and highlights technology breakthroughs that will contribute to next generation of retinal prostheses. PMID:24710817

Weiland, James D; Humayun, Mark S

2014-05-01

89

Anatomic and functional outcome of eyes with massive submacular hemorrhage secondary to retinal macroaneurysm submitted to vitrectomy / Resultados anatômicos e funcionais em pacientes com hemorragia submacular maciça secundária à macroaneurisma arterial de retina submetidos à vitrectomia posterior  

Scientific Electronic Library Online (English)

Full Text Available Objetivo: Relatar os resultados anatômicos e funcionais em uma série de pacientes com perda visual grave por hemorragia submacular maciça aguda secundária a macroaneurisma arterial de retina (MAR) e descrever a técnica cirúrgica utilizada. Métodos: Este é um estudo retrospectivo, observacional, sér [...] ie de casos, incluindo 4 olhos de 4 pacientes que foram submetidos à cirurgia de vitrectomia posterior (VP), associada a peeling da membrane limitante interna (MLI) e injeção sub-retiniana de ativador do plasminogênio tecidual recombinante (rtPA-12,5 mg/0.1 ml) por hemorragia submacular maciça recente (?7 dias) secundária MAR. Em todos os casos, o exame de tomografia de coerência óptica (OCT) foi obtido na consulta inicial e nas subsequentes para avaliação das alterações estruturais da retina. Resultados: A idade dos pacientes variou entre 63 a 78 anos e todos apresentavam hipertensão arterial sistêmica. A acuidade visual inicial nos olhos afetados variou de movimento de mãos a conta dedos a 50 cm. Todos os olhos apresentaram hemorragia retiniana extensa ocupando mais do que dois terços da região macular. O tempo decorrido entre a perda visual e a cirurgia variou entre 3 a 7 dias. Após um seguimento médio de 15.5 ± 5.19 meses (variando entre 10 a 22 meses), a acuidade visual pós-operatória variou entre 20/30 e 20/80. Todos os olhos apresentaram um deslocamento completo da hemorragia subretiniana da região macular central no pós operatório. As imagens seccionais da retina obtidas pela OCT revelaram um afilamento da retina neurossensorial e interrupções na linha refletiva que representa a junção entre os segmentos internos e externos dos fotorreceptores na região macular, além de falhas na membrane limitante externa em todos os casos. Conclusão: De acordo com os resultados do presente estudo, a VP associada à injeção sub-retiniana de rtPA parece ser uma técnica segura e eficaz em promover melhora visual em pacientes com hemorragia submacular maciça secundária a MAR. Os achados do OCT revelaram que, apesar da grande melhora visual apresentada, a presença de hemorragia submacular pode promover danos estruturais permanentes da retina neurossensorial, em especial ao segmento externo dos fotorreceptores. Abstract in english Purpose: To report the anatomic and functional outcome in patients with severe visual loss after acute massive submacular hemorrhage secondary to retinal arterial macroaneurysm submitted to vitrectomy and subretinal recombinant tissue plasminogen activator injection. Methods: Retrospective, observa [...] tional, case-series of 4 eyes of 4 patients submitted to pars plana posterior vitrectomy (ppV) combined with internal limiting membrane (ILM) removal and subretinal recombinant tissue plasminogen activator (rtPA-12.5 mg/0.1 ml) injection with dilute (20%) sulfur hexafluoride (SF6) gas in the vitreous cavity of eyes with recent onset (?7 days) massive macular hemorrhage due to retinal arterial macroaneurysm (RAMA). Optical coherence tomography (OCT) was obtained both at presentation and during follow up. Results: Patients ranged in age from 63 to 78 years and all had systemic arterial hypertension. Visual acuity at presentation ranged from hand motions to count fingers at 50 cm. All eyes showed extensive retinal hemorrhage involving more than two-thirds of macular area. The time between the onset of symptoms and the surgery ranged from 3 to 7 days. After a mean postoperative follow-up of 15.5 ± 5.19 months (range, 10-22 months), all eyes showed visual acuity improvement and final visual acuity ranged from 20/30 to 20/80. All had complete displacement of the subretinal hemorrhage from the fovea after the surgery. OCT images showed neurosensory retina thinning and disruption of the reflective line that represents the junction between inner and outer photoreceptors segments (IS/OS line) beneath the macular area and absence of the external limiting membrane (ELM). Conclusions: ppV associated with subretinal rtPA injection with intravitreal g

Leonardo Provetti, Cunha; Luciana Virgínia Ferreira Costa, Cunha; Carolina Ferreira, Costa; Hugo Henrique, Moreira; Mário Luiz Ribeiro, Monteiro.

2015-02-01

90

Coronary artery anatomy and variants  

Energy Technology Data Exchange (ETDEWEB)

Variants and congenital anomalies of the coronary arteries are usually asymptomatic, but may present with severe chest pain or cardiac arrest. The introduction of multidetector CT coronary angiography (MDCT-CA) allows the detection of significant coronary artery stenosis. Improved performance with isotropic spatial resolution and higher temporal resolution provides a valid alternative to conventional coronary angiography (CCA) in many patients. MDCT-CA is now considered the ideal tool for three-dimensional visualization of the complex and tortuous anatomy of the coronary arteries. With multiplanar and volume-rendered reconstructions, MDCT-CA may even outperform CCA in determining the relative position of vessels, thus providing a better view of the coronary vascular anatomy. The purpose of this review is to describe the normal anatomy of the coronary arteries and their main variants based on MDCT-CA with appropriate reconstructions. (orig.)

Malago, Roberto; Pezzato, Andrea; Barbiani, Camilla; Alfonsi, Ugolino; Nicoli, Lisa; Caliari, Giuliana; Pozzi Mucelli, Roberto [Policlinico G.B. Rossi, University of Verona, Department of Radiology, Verona (Italy)

2011-12-15

91

Coronary artery anatomy and variants  

International Nuclear Information System (INIS)

Variants and congenital anomalies of the coronary arteries are usually asymptomatic, but may present with severe chest pain or cardiac arrest. The introduction of multidetector CT coronary angiography (MDCT-CA) allows the detection of significant coronary artery stenosis. Improved performance with isotropic spatial resolution and higher temporal resolution provides a valid alternative to conventional coronary angiography (CCA) in many patients. MDCT-CA is now considered the ideal tool for three-dimensional visualization of the complex and tortuous anatomy of the coronary arteries. With multiplanar and volume-rendered reconstructions, MDCT-CA may even outperform CCA in determining the relative position of vessels, thus providing a better view of the coronary vascular anatomy. The purpose of this review is to describe the normal anatomy of the coronary arteries and their main variants based on MDCT-CA with appropriate reconstructions. (orig.)

92

Hypoxia-ischemia and retinal ganglion cell damage  

OpenAIRE

Charanjit Kaur1, Wallace S Foulds2, Eng-Ang Ling11Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 2Singapore Eye Research Institute, SingaporeAbstract: Retinal hypoxia is the potentially blinding mechanism underlying a number of sight-threatening disorders including central retinal artery occlusion, ischemic central retinal vein thrombosis, complications of diabetic eye disease and some types of glaucoma. Hypoxia is implicated in loss of re...

Charanjit Kaur; Foulds, Wallace S.; Eng-Ang Ling

2008-01-01

93

Treatment of splenic artery aneurysm with double overlapping bare stents: case report  

Energy Technology Data Exchange (ETDEWEB)

The traditional treatment of splenic artery aneurysm (SAA) is generally surgery and/or transcatheter arterial embolization, but recently, the treatment of SAA using a stent graft has been reported. However, the acute angle of the celiac axis, as well as the tortuous path of the splenic artery makes the use of stent graft difficult for treatment of aneurysma. We report here a case of SAA treated with the technique of double overlapping metallic stents.

Kwak, Hyo Sung; Han, Young Min; Jin, Gong Yong [School of Medicine, Chonbuk National Univ., Chonju (Korea, Republic of)

2004-09-01

94

The Norrin/Frizzled4 signaling pathway in retinal vascular development and disease  

OpenAIRE

Disorders of retinal vascular growth and function are responsible for vision loss in a variety of diseases, including diabetic retinopathy, age-related macular degeneration, retinopathy of prematurity, and retinal artery or vein occlusion. Over the past decade, a new signaling pathway that controls retinal vascular development has emerged from the study of inherited disorders - in both humans and mice - that are characterized by retinal hypovascularization. This pathway utilizes a glial-deriv...

Ye, Xin; Wang, Yanshu; Nathans, Jeremy

2010-01-01

95

Retinitis pigmentosa  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Retinitis pigmentosa (RP is an inherited retinal dystrophy caused by the loss of photoreceptors and characterized by retinal pigment deposits visible on fundus examination. Prevalence of non syndromic RP is approximately 1/4,000. The most common form of RP is a rod-cone dystrophy, in which the first symptom is night blindness, followed by the progressive loss in the peripheral visual field in daylight, and eventually leading to blindness after several decades. Some extreme cases may have a rapid evolution over two decades or a slow progression that never leads to blindness. In some cases, the clinical presentation is a cone-rod dystrophy, in which the decrease in visual acuity predominates over the visual field loss. RP is usually non syndromic but there are also many syndromic forms, the most frequent being Usher syndrome. To date, 45 causative genes/loci have been identified in non syndromic RP (for the autosomal dominant, autosomal recessive, X-linked, and digenic forms. Clinical diagnosis is based on the presence of night blindness and peripheral visual field defects, lesions in the fundus, hypovolted electroretinogram traces, and progressive worsening of these signs. Molecular diagnosis can be made for some genes, but is not usually performed due to the tremendous genetic heterogeneity of the disease. Genetic counseling is always advised. Currently, there is no therapy that stops the evolution of the disease or restores the vision, so the visual prognosis is poor. The therapeutic approach is restricted to slowing down the degenerative process by sunlight protection and vitaminotherapy, treating the complications (cataract and macular edema, and helping patients to cope with the social and psychological impact of blindness. However, new therapeutic strategies are emerging from intensive research (gene therapy, neuroprotection, retinal prosthesis.

Hamel Christian

2006-10-01

96

Prevalent misconceptions about acute retinal vascular occlusive disorders.  

Science.gov (United States)

Acute retinal vascular occlusive disorders collectively constitute one of the major causes of blindness or seriously impaired vision, and yet there is marked controversy on their pathogeneses, clinical features and particularly their management. This is because the subject is plagued by multiple misconceptions. These include that: (i) various acute retinal vascular occlusions represent a single disease; (ii) estimation of visual acuity alone provides all the information necessary to evaluate visual function; (iii) retinal venous occlusions are a single clinical entity; (iv) retinal vein occlusion is essentially a disease of the elderly and is not seen in the young; (v) central retinal vein occlusion (CRVO) is one disease; (vi) fluorescein fundus angiography is the best test to differentiate ischemic from nonischemic CRVO; (vii) the site of occlusion in CRVO is invariably at the lamina cribrosa; (viii) clinical picture of CRVO is often due to compression or strangulation of the central retinal vein (CRV) in the lamina cribrosa and not its occlusion; (ix) an eye can develop both CRVO and central retinal artery occlusion (CRAO) simultaneously; (x) every eye with CRVO is at risk of developing neovascular glaucoma; (xi) lowering intraocular pressure (IOP) helps to improve retinal circulation in an eye with CRVO; (xii) every patient with retinal vein occlusion should have complete hematologic and coagulation evaluation; (xiii) the natural history of CRVO does not usually involve spontaneous visual improvement; (xiv) management of CRVO is similar to that of venous thrombosis anywhere else in the body, i.e. with aspirin and/or anti-coagulants; (xv) fibrinolytic agents can dissolve an organized thrombus in the CRV; (xvi) it is beneficial to lower blood pressure in patients with CRVO; (xvii) panretinal photocoagulation used in ischemic retinal venous occlusive disorders has no deleterious side-effects; (xviii) glaucoma or ocular hypertension can cause branch retinal vein occlusion; (xix) branch retinal vein occlusion can cause neovascular glaucoma; (xx) in eyes with CRAO, the artery is usually not completely occluded; (xxi) CRAO is always either embolic or thrombotic in origin; (xxii) amaurosis fugax is always due to retinal ischemia secondary to transient retinal arterial embolism; (xxiii) asymptomatic plaque(s) in retinal arteries do not require a detailed evaluation; (xxiv) retinal function can improve even when acute retinal ischemia due to CRAO has lasted for 20h or more; (xxv) CRAO, like ischemic CRVO, can result in development of ocular neovascularization; (xxvi) panretinal photocoagulation is needed for "disc neovascularization" in CRAO; (xxvii) fibrinolytic agents are the treatment of choice in CRAO; (xxviii) there is no chance of an eye with retinal arterial occlusion having spontaneous visual improvement; (xxix) absence of any abnormality on Doppler evaluation of the carotid artery or echography of the heart always rules out those sites as the source of embolism; and (xxx) absence of an embolus in the retinal artery means the occlusion was not caused by an embolus. The major cause of all these misconceptions is the lack of a proper understanding of basic scientific facts related to the various diseases. The objective of this paper is to discuss these misconceptions, based on these scientific facts, to clarify the understanding of these blinding disorders, and to place their management on a rational, scientific basis. PMID:15845346

Hayreh, Sohan Singh

2005-07-01

97

Anomalous origin of the left coronary artery from the pulmonary artery detected by echocardiography in an asymptomatic adult.  

Science.gov (United States)

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital malformation. It is unusual for an ALCAPA patient to survive to adulthood. We present a case of an asymptomatic 54-year-old woman with this syndrome in which visualization of a markedly enlarged and tortuous right coronary artery and intercoronary collaterals by echocardiography raises suspicion for this disease and subsequently guides a step-by-step diagnosis. The patient lives well without surgery 3 years after diagnosis. PMID:23318854

Tian, Zhuang; Fang, Li-Gang; Liu, Yong-Tai; Zhang, Shu-Yang

2013-01-01

98

Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery: Diagnosis with CT Angiography.  

Science.gov (United States)

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly. It is associated with early infant mortality and sudden death in adults. Traditionally, ALCAPA has been diagnosed by angiography or autopsy; however, the development of cardiac computed tomography (CT) and magnetic resonance imaging (MRI) has allowed noninvasive evaluation of the coronary anatomy by direct visualization of the origin of the left coronary artery (LCA) from the pulmonary artery. We report a case of 10-year-old girl who has been on follow up for dilated cardiomyopathy for 4 years. The definitive diagnosis of ALCAPA is reached by multislice computed tomography (MSCT). The MSCT scan showed an anomalous origin of LCA from the pulmonary trunk, with a tortuous and dilated right coronary artery and right-to-left collateralization. Consequently, the patient was successfully treated with surgery. PMID:23607073

Oncel, Guray; Oncel, Dilek

2013-01-01

99

Unusual retinal manifestations of cat scratch disease.  

Science.gov (United States)

We report on 2 patients with unusual retinal manifestations of cat scratch disease (CSD), caused by Bartonella henselae. Case 1. A 42-year-old farmer presented with a 5-day history of blurred vision in his right eye. Right visual acuity was 20/25. Fundus examination of the right eye revealed mild vitreous hemorrhage and diffuse retinal hemorrhages in the mid-peripheral retina. Fluorescein angiography showed multiple vasculitic occlusions in the same area. A blood sample taken on the day of examination revealed the presence of immunoglobulin (Ig)M and IgG to B. henselae. Oral azithromycin was given for 8 days. One month later, right visual acuity was 20/20, the vitreous and retinal hemorrhages resolved, and arteriolar attenuation and sclerosis was observed in the peripheral temporal retina. Case 2. A 66-year-old craftsman with systemic hypertension and hypercholesterolemia complained of sudden visual loss (light perception) in his left eye. Fundus evaluation and fluorescein angiography revealed central retinal artery occlusion (CRAO) in the affected eye. About 2 weeks earlier, he had been bitten and scratched on his right hand by a stray cat. Serologic testing detected the presence of IgM to B. henselae. Oral azithromycin was given for 6 days. One month later, left visual acuity was hand motion. Ophthalmologists should be aware that unusual ocular complications associated with CSD include vitreous hemorrhage with retinal vasculitis and isolated CRAO. Vitreous hemorrhage and retinal vasculitis may be the only clinical manifestation of CSD. PMID:21267628

Pinna, Antonio; Puglia, Ester; Dore, Stefano

2011-04-01

100

Retinal detachment repair  

Science.gov (United States)

... around it. This article describes the repair of rhegmatogenous retinal detachments. These occur due to a hole ... Connolly BP, Regillo CD. Rhegmatogenous retinal detachment. In: ... ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2013:vol 3, ...

101

Ocular manifestations of internal carotid artery insufficiency  

Directory of Open Access Journals (Sweden)

Full Text Available 8 cases of internal carotid artery insufficiency were studied to find out the various ophthalmic manifestations in such cases. 50% cases had ophthalmic signs and symptoms. These manifestations were amaurosis fugax, central retinal artery block, field defects, pupillary abnormalities and disc oedema. Ammaurosis fugax is a sign of impending carotid insufficiency and these cases must be investigated thoroughly.

Nath Rajiv

1987-01-01

102

Ophthalmodynamometric determination of the central retinal vessel collapse pressure correlated with systemic blood pressure  

OpenAIRE

Aims: To evaluate whether determination of the central retinal artery and vein collapse pressure correlate with systemic blood pressure measurements, using a new Goldmann contact lens associated ophthalmodynamometric device

Jonas, J. B.

2004-01-01

103

[A case of vasoocclusive retinal damage in moya-moya disease].  

Science.gov (United States)

Retinal vessel occlusion and eye haemodynamics damage is described in moya-moya disease, a rare occlusive cerebrovascular condition characterized by progressing stenosis and occlusion of cerebral arteries with collateral development in basal vascular system. Data concerning neuroophthalmological features, diagnostic and treatment methods are presented. Necessity of MR-tomography and MR-angiography in ischemic retinal damage is emphasized. PMID:21721280

Kiseleva, T N; Vlasov, S K; Shchegolova, I V; Liutkevich, E V

2011-01-01

104

Retinal atheromatous plaques: their recognition by elevating the intraocular pressure.  

Science.gov (United States)

Recognition and further study of existing retinal atheromatous plaques in the central retinal artery may be enhanced by pressure on the globe. This simple maneuver should be used when patients with transient ischemic attacks (cerebral or ocular) are examined with or without atheromatous disease of the carotid artery. Previously unseen or suspected plaques may be brought into view. Plaques already visible may appear larger or vary greatly in both color and texture giving indication of their composition. The recognition of these atheromatous plaques is important in the diagnosis of atheromatous disease. PMID:867624

Hedges, T R

1976-01-01

105

Anomalous origin of the left coronary artery from the pulmonary artery initially visualized by echocardiography and multidetector computed tomography coronary angiography.  

Science.gov (United States)

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly associated with very high mortality during infancy. We report a 35-year-old female patient with ALCAPA initially visualized by echocardiography. She visited outpatient department presenting with intermittent chest discomfort for 3 weeks. Transthoracic echocardiography showed left coronary artery arising from main pulmonary artery and abundant septal color flow Doppler signals. Transesophageal echocardiography clearly revealed markedly dilated and tortuous right coronary artery showing windsock appearance. Multidetector computed tomography and coronary angiography enabled visualization of anomalous left coronary artery originating from left side of main pulmonary trunk. After treadmill exercise test which showed ST-segment depression presenting inducible myocardial ischemia, patient underwent direct re-implantation of the anomalous coronary artery into the aorta without any complication. PMID:23346290

Kim, Byung-Ho; Park, Yon Woong; Hong, Seung-Pyo; Son, Ja-Yung; Lee, Young-Soo; Lee, Jin-Bae; Ryu, Jae-Kean; Choi, Ji-Yong; Kim, Kee-Sik; Chang, Sung-Guk

2012-12-01

106

Regulation of retinal oxygen metabolism in humans during graded hypoxia.  

Science.gov (United States)

Animal experiments indicate that the inner retina keeps its oxygen extraction constant despite systemic hypoxia. For the human retina no such data exist. In the present study we hypothesized that systemic hypoxia does not alter inner retinal oxygen extraction. To test this hypothesis we included 30 healthy male and female subjects aged between 18 and 35 years. All subjects were studied at baseline and during breathing 12% O? in 88% N? as well as breathing 15% O? in 85% N?. Oxygen saturation in a retinal artery (SO?art) and an adjacent retinal vein (SO?vein) were measured using spectroscopic fundus reflectometry. Measurements of retinal venous blood velocity using bidirectional laser Doppler velocimetry and retinal venous diameters using a Retinal Vessel Analyzer (RVA) were combined to calculate retinal blood flow. Oxygen and carbon dioxide partial pressure were measured from earlobe arterialized capillary blood. Retinal blood flow was increased by 43.0 ± 23.2% (P < 0.001) and 30.0 ± 20.9% (P < 0.001) during 12% and 15% O? breathing, respectively. SO?art as well as SO?vein decreased during both 12% O? breathing (SO?art: -11.2 ± 4.3%, P < 0.001; SO?vein: -3.9 ± 8.5%, P = 0.012) and 15% O? breathing (SO?art: -7.9 ± 3.6%, P < 0.001; SO?vein: -4.0 ± 7.0%, P = 0.010). The arteriovenous oxygen difference decreased during both breathing periods (12% O2: -28.9 ± 18.7%; 15% O?: -19.1 ± 16.7%, P < 0.001 each). Calculated oxygen extraction did, however, not change during our experiments (12% O?: -2.8 ± 18.9%, P = 0.65; 15% O?: 2.4 ± 15.8%, P = 0.26). Our results indicate that in healthy humans, oxygen extraction of the inner retina remains constant during systemic hypoxia. PMID:25217648

Palkovits, Stefan; Told, Reinhard; Schmidl, Doreen; Boltz, Agnes; Napora, Katarzyna J; Lasta, Michael; Kaya, Semira; Werkmeister, René M; Popa-Cherecheanu, Alina; Garhöfer, Gerhard; Schmetterer, Leopold

2014-11-15

107

Cytomegalovirus retinitis in AIDS.  

OpenAIRE

Cytomegalovirus retinitis is common in adults with AIDS but has been reported infrequently in children with perinatally acquired HIV infection. The cases are presented of two infants with vertically acquired HIV infection who developed disseminated cytomegalovirus infection and retinitis, and who posed difficult management issues.

Peters, M. J.; Moeller, H. U.; Russell-eggitt, I.; Novelli, V.

1995-01-01

108

Transient tractional retinal detachment in an eye with retinitis pigmentosa  

Directory of Open Access Journals (Sweden)

Full Text Available Shuichiro Hirahara, Yoshio Hirano, Tsutomu Yasukawa, Yuichiro OguraDepartment of Ophthalmology and Visual Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, JapanAbstract: We present a case of retinitis pigmentosa with vitreoretinal traction-associated retinal detachment. The retinal detachment was detected in the nasal periphery. No retinal breaks and no active vascular leakage were observed by fundus scopy and fluorescein angiography, respectively. However, 8 months later, the tractional retinal detachment was spontaneously resolved with posterior vitreous detachment.Keywords: retinitis pigmentosa, vitreoretinal traction, retinal detachment

Shuichiro Hirahara

2010-09-01

109

Retinal thickness vs. retinal sensitivity at the central human macula  

OpenAIRE

Purpose To assess the detailed correlation between retinal thickness and retinal visual function in the central 300 µm human macular area. Methods Twenty-four eyes with clinically significant macular edema (CSME) (12 eyes with and 12 eyes without central foveal involvement) underwent retinal thickness measurement (RT) and retinal sensitivity, performed by Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA, USA) and MP1 (Microperimetry, Nidek, Japan) systems, respectively. The average retinal thic...

Bernardes, R.; Cunha-vaz, J.

2008-01-01

110

Renal Stenting from the Radial Artery: A Novel Approach  

International Nuclear Information System (INIS)

Purpose: To describe the technique and feasibility of renal artery angioplasty and stenting from the radial artery. Methods: A series of 19 patients were evaluated for transradial renal artery intervention. Procedures were performed using carbon dioxide gas (CO2) as the preferred angiographic contrast agent. Intervention was performed through a 5 Fr radial artery sheath using low-profile balloons and balloon-expandable stents. Results: Nineteen patients with 26 stenosed renal arteries were considered for treatment via the radial route. A negative Allen's test precluded radial puncture in two (11%). In one patient the descending aorta could not be catheterized. Stenting from the radial route was successful in 22 renal arteries in 16 patients. On an intention-to-treat basis 16 of the 19 (84%) were treatable from the radial route. In the 17 patients with radial access technical success was 94% (16 of 17) patients and 91% (21 of 23) of renal arteries. One patient experienced a cerebrovascular event during intervention. Conclusion: Transradial renal artery intervention is technically feasible using low-profile angioplasty balloons and stents.This route offers advantages in renal arteries with a caudal angulation and in patients with diseases or tortuous iliac arteries

111

Resolution of vitreomacular traction following intravitreal triamcinolone acetonide injection in an eye with branch retinal vein occlusion  

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Full Text Available Göktu? Seymeno?lu,1 Özcan Kayikçio?lu,1 Bilge Öztürk ?ahin21Department of Ophthalmology, Faculty of Medicine, Celal Bayar University, Manisa, Turkey; 2Department of Ophthalmology, Akhisar State Hospital, Akhisar, Manisa, TurkeyAbstract: A 60-year-old woman with a past medical history of branch retinal vein occlusion presented with decreased vision and metamorphopsia in her left eye. A fundus examination revealed a tortuous retinal vein with a few retinal hemorrhages in the inferotemporal quadrant. Optical coherence tomography revealed a partially separated posterior vitreous membrane pulling up the fovea. The patient refused surgical treatment so intravitreal triamcinolone acetonide (4 mg/0.1 mL was administered. The patient reported resolution of symptoms in her left eye following this treatment, but her visual acuity did not show any improvement. Optical coherence tomography scanning revealed a complete detachment of the posterior hyaloid with release of the vitreomacular traction. In patients with vitreomacular traction and branch retinal vein occlusion, the combination of the possible vitreous liquefaction and mechanical increase of vitreous volume caused by an intravitreal injection with a degree of reduction in retinal thickness may play a role in the resolution of vitreomacular traction.Keywords: macular edema, vitreomacular traction syndrome, intravitreal injection, posterior vitreous detachment

Seymeno?lu G

2012-08-01

112

Thrombophilia and retinal vascular occlusion  

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Full Text Available Charles J Glueck,1 Robert K Hutchins,2,3 Joel Jurantee,1 Zia Khan,1 Ping Wang11Cholesterol Center, Jewish Hospital of Cincinnati, Cincinnati, OH, USA; 2Department of Ophthalmology, University of Cincinnati College of Medicine, Cincinnati, OH, USA; 3Cincinnati Eye Institute, Cincinnati, OH, USAPurpose: The purpose of this research was to assess associations of thrombophilia with central retinal vein occlusion (CRVO, central retinal artery occlusion (CRAO, and amaurosis fugax (AF; to evaluate outcomes of normalizing high homocysteine; and to study CRVO, CRAO, and AF developing in estrogens/estrogen agonists in women subsequently shown to have thrombophilia.Methods: Measures of thrombophilia–hypofibrinolysis were obtained in 132 CRVO cases, 15 CRAO cases, and 17 AF cases. Cases were compared to 105 healthy control subjects who did not differ by race or sex and were free of any ophthalmologic disorders. All cardiovascular disease (CVD risk factors were compared to healthy general populations.Main outcome measures: The main outcome measure of this study was thrombophilia.Results: CRVO cases were more likely than controls to have high homocysteine (odds ratio [OR] 8.64, 95% confidence intervals [CI]: 1.96–38, high anticardiolipin immunoglobulin M (IgM; OR 6.26, 95% CI: 1.4–28.2, and high Factor VIII (OR 2.47, 95% CI: 1.31–7.9. CRAO-AF cases were more likely than controls to have high homocysteine (OR 14, 95% CI: 2.7–71.6 or the lupus anticoagulant (OR 4.1, 95% CI: 1.3–13.2. In four of 77 women with CRVO (two found to have high homocysteine, two with inherited high Factor XI, CRVO occurred after starting estrogen–progestins, estrogen–testosterone, or estrogen agonists. In one of eight women with CRAO found to have high anticardiolipin antibody IgG, CRAO occurred after starting conjugated estrogens, and AF occurred after starting conjugated estrogens in one of eleven women with AF (inherited protein S deficiency. Therapy for medians of 21 months (CRVO and 6 months (CRAO-AF was 5 mg folic acid, 100 mg B6, and 2000 mcg/day B12 normalized homocysteine in 13 of 16 (81% CRVO cases and all five CRAO-AF cases with pretreatment hyperhomocysteinemia. The CRVO cases had an excess of hypertension; CRAO-AF cases had an excess of type 2 diabetes and hypertension.Conclusion: Treatable thrombophilia, hyperhomocysteinemia in particular, is more common in RVO cases than in normal controls. RVO occurs after estrogens or estrogen agonists were administered in women subsequently shown to have thrombophilia.Keywords: central retinal vein occlusion, central retinal artery occlusion, amaurosis fugax, retinal vascular occlusion, thrombophilia, estrogen, estrogen agonist

Glueck CJ

2012-08-01

113

Recognition of carotid stenosis with bilateral simultaneous retinal fluorescein angiography.  

Science.gov (United States)

In order to study the arm to retina circulation time (ARCT), we simultaneously photographed both fundi in patients with suspected or known carotid artery occlusive disease. Noninvasive carotid artery tests, selective carotid arteriography, or both, were performed on all of the patients. In the 11 patients with arteriographically proven significant carotid stenosis, or with noninvasive carotid tests demonstrating carotid occlusive disease, a triad of fluoroangiographic features (delayed ARCT, disparity of ARCT between eyes, and delayed ciliary circulation at the optic disc) was found. We believe that bilateral simultaneous retinal fluorescein angiography is a sensitive and accurate method for the recognition of patients with carotid artery occlusive disease. PMID:7155525

Choromokos, E A; Raymond, L A; Sacks, J G

1982-10-01

114

Kyrieleis´ vasculitis in acute retinal necrosis  

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Full Text Available Ester Francés-Muñoz1, Roberto Gallego-Pinazo1, Ruth López-Lizcano1, Salvador García-Delpech1, J Luis Mullor3, Manuel Díaz-Llopis1,21Department of Ophthalmology, Hospital La Fe, Valencia, Spain; 2University of Valencia, Valencia, Spain; 3Unit of Experimental Ophthalmology. Fundación para la Investigación del Hospital Universitario La Fe. Valencia, Valencia, SpainAbstract: We report the first case in the literature of Kyrieleis´ vasculitis related to acute retinal necrosis by Varicella zoster virus in a 76-year-old woman with bilateral involvement. In our patient the arterial lesions appeared 15 days after the initial presentation.Keywords: Kyrieleis´ vasculitis, retinal necrosis, herpes virus

Ester Francés-Muñoz

2010-07-01

115

Unsupervised recognition of retinal vascular junction points.  

Science.gov (United States)

Landmark points in retinal images can be used to create a graph representation to understand and to diagnose not only different pathologies of the eye, but also a variety of more general diseases. Aim of this paper is the description of a non-supervised methodology to distinguish between bifurcations and crossings of the retinal vessels, which can be used in differentiating between arteries and veins. A thinned representation of the binarized image, is used to identify pixels with three or more neighbors. Junction points are classified into bifurcations or crossovers according to their geometrical and topological properties. The proposed approach is successfully compared with the state-of-the-art methods with the benchmarks DRIVE and STARE. The recall, precision and F-score average detection values are 91.5%, 88.8% and 89.8% respectively. PMID:25569919

Di Rosa, Luigi; Hamad, Hadi; Tegolo, Domenico; Valenti, Cesare

2014-01-01

116

Differential diagnosis of retinal vasculitis  

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Full Text Available Retinal vaculitis is a sight-threatening inflammatory eye condition that involves the retinal vessels. Detection of retinal vasculitis is made clinically, and confirmed with the help of fundus fluorescein angiography. Active vascular disease is characterized by exudates around retinal vessels resulting in white sheathing or cuffing of the affected vessels. In this review, a practical approach to the diagnosis of retinal vasculitis is discussed based on ophthalmoscopic and fundus fluorescein angiographic findings.

Abu El-Asrar Ahmed

2009-01-01

117

Management of massive hemoptysis in pulmonary tuberculosis and bronchiectasis by bronchial arterial embolization  

International Nuclear Information System (INIS)

Objective: To probe into the angiographic signs and the variations of bronchial arteries for pulmonary tuberculosis or bronchiectasis with massive hemoptysis. Methods: 25 patients with pulmonary tuberculosis and 15 patients suffered from bronchiectasis accompanied by massive hemoptysis were undertaken bronchial arterial embolization (BAE). All patients were embolized with gelfoam including 32 with spring coils in addition. Results: 63 arteries demonstrated angiographic signs of hemoptysis in 40 patients. The immediate stanching rate was 92.5%(37/40). The bronchopulmonary shunt formation sign shown by angiograph was the major feature of tuberculosis (P=0.0528) and the enlarged tortuous arteries in bronchiectasis were more to be demonstrated than in tuberculosis (P<0.05). Conclusions: The BAE for patients with tuberculosis ought to be performed in the smaller arteries. BAE for patients with bronchiectasis should to be taken in the trunk of arteries. (authors)

118

Retinal and choroidal intravascular spectral-domain optical coherence tomography  

DEFF Research Database (Denmark)

Purpose:? To examine retinal and choroidal blood vessels using spectral-domain optical coherence tomography (SD-OCT). Methods:? Retrospective case series. Results:? Scans through retinal blood vessels in healthy subjects demonstrated vessel wall reflexes and a tri-layer profile of the blood column on longitudinal scans and a figure-of-eight configuration on cross-sectional scans. Intravascular reflectivity decreased with increasingly oblique angles of observation and was absent when blood flow was parallel to the line of sight. The high blood flow in the choroidal vessels in healthy subjects and the low flow in the retinal vessels in patients with ocular ischaemic syndrome and central retinal artery occlusion were both associated with lower reflectivity of the blood and an unstructured intravascular SD-OCT profile. Discussion:? This qualitative in vivo study found a characteristically structured SD-OCT profile of the blood column in retinal vessels with normal blood flow. Both structure and total reflectivityfaded when blood flow was lower or higher than normal or at oblique angles to the line of sight. In conclusion, SD-OCT scans of the vessels in the posterior pole of the eye may assist the clinical assessment of gross abnormalities of ocular blood flow, e.g. in carotid artery stenosis.

Willerslev, Anne; Li, Xiao Q

2013-01-01

119

Empirical description of bronchial and nonbronchial arteries with MDCT  

Energy Technology Data Exchange (ETDEWEB)

Purpose: We aimed to retrospectively evaluate bronchial and nonbronchial systemic arteries using multi-detector row helical computed tomographic (MDCT) angiography in patients with pulmonary disorders. Materials and Methods: Thirty-nine patients (24 men, 15 women; mean age, 63.4 years; range, 20-82 years) with congenital and acquired pulmonary disorders of the bronchial and nonbronchial systemic arteries underwent multi-detector row helical computed tomographic angiography of the thorax using a 16-detector row scanner. Each of these patients had experienced an episode of hemoptysis. Computed tomographic angiogram data, which included maximum intensity projections, multiplanar reconstruction, and three-dimensional volume-rendered images, were used to retrospectively analyse the characteristics of the bronchial and nonbronchial systemic arteries. Results: We identified a total of 128 bronchial arteries (76 on the right side and 52 on the left) in 39 patients. We detected 42 nonbronchial systemic artery branches, including 19 internal mammary artery branches, 8 subclavian artery branches, 8 inferior phrenic artery branches, 5 intercostal artery branches, 1 thyrocervical trunk branch, and 1 celiac trunk branch. Thirty-five dilated and tortuous nonbronchial systemic arteries entered into the lung parenchyma and extended down to the lesions. Every case, except the one case of sequestration, was associated with pleural thickening where the vascular structures passed through the extrapleural fat. Conclusions: The variations in both the bronchial artery anatomy and the location and type of the nonbronchial arteries were great. Nonbronchial arteries may be a significant source of hemoptysis. MDCT angiography can be used to detect detailed anatomical information about the origins and courses of bronchial and nonbronchial systemic arteries and their pathophysiologic features.

Yu Hong, E-mail: yuhong.2002@hotmail.co [Department of Imageology, Changzheng hospital, Second Military Medical University, Shanghai 200003 (China); Liu Shiyuan, E-mail: cjr.liushiyuan@vip.163.co [Department of Imageology, Changzheng hospital, Second Military Medical University, Shanghai 200003 (China); Li Huimin, E-mail: yuhongphd@163.co [Department of Imageology, Changzheng hospital, Second Military Medical University, Shanghai 200003 (China); Xiao Xiangsheng, E-mail: cjr.xxsh@vip.163.co [Department of Imageology, Changzheng hospital, Second Military Medical University, Shanghai 200003 (China); Dong Weihua, E-mail: dongweihua2000@163.co [Department of Imageology, Changzheng hospital, Second Military Medical University, Shanghai 200003 (China)

2010-08-15

120

The postprocessing techniques in renal artery reconstructions and clinical application with multidetector spiral CT angiography  

International Nuclear Information System (INIS)

Objective: To investigate the value and predominance for imaging postprocessing techniques of renal artery variation and lesions by multidetector spiral CT angiography. Methods: 51 patients with renal artery disease including 12 artery variation, 27 artery stenosis, 3 renal anenrysm, 3 thrombosis of renal artery and 3 dissecting aneurysm of renal artery by SSD, MIP and CPR were enrolled. The effectiveness of these imaging postprocessing methods was compared, 29 of them were confirmed by DSA and 3 by operation, others were checked by MRA and follow up. Results: All abnormalities and diseases were cleariy displayed. The specificity and sensitivity were 100% respectively. In the all imaging postprocessing techniques, MPR can clearly display the calcification of the arteries, stenosis, embolism, aneurysm but do not display the anatomy satisfactorily. MIP can not only clearly display the anatomy but display the different configurations. VR can display the artery figures but can not display the information of lumen of blood vessels. SSD can display the complex vessel anatomy but it was influenced by its threshold selection. CPR can spread and display directly the tortuous renal artery and measure the section area of stenosis. Conclusions: MSCTA is helpful to accurately display the renal artery variation and lesions. Both MIP and VR are the best choice to illustrate the renal artery abnormalities. And MPR and SSD are assistant in the diagnosis of' renal artery lesions. (auth diagnosis of' renal artery lesions. (authors)

121

Hypoxia-ischemia and retinal ganglion cell damage  

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Full Text Available Charanjit Kaur1, Wallace S Foulds2, Eng-Ang Ling11Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 2Singapore Eye Research Institute, SingaporeAbstract: Retinal hypoxia is the potentially blinding mechanism underlying a number of sight-threatening disorders including central retinal artery occlusion, ischemic central retinal vein thrombosis, complications of diabetic eye disease and some types of glaucoma. Hypoxia is implicated in loss of retinal ganglion cells (RGCs occurring in such conditions. RGC death occurs by apoptosis or necrosis. Hypoxia-ischemia induces the expression of hypoxia inducible factor-1? and its target genes such as vascular endothelial growth factor (VEGF and nitric oxide synthase (NOS. Increased production of VEGF results in disruption of the blood retinal barrier leading to retinal edema. Enhanced expression of NOS results in increased production of nitric oxide which may be toxic to the cells resulting in their death. Excess glutamate release in hypoxic-ischemic conditions causes excitotoxic damage to the RGCs through activation of ionotropic and metabotropic glutamate receptors. Activation of glutamate receptors is thought to initiate damage in the retina by a cascade of biochemical effects such as neuronal NOS activation and increase in intracellular Ca2+ which has been described as a major contributing factor to RGC loss. Excess production of proinflammatory cytokines also mediates cell damage. Besides the above, free-radicals generated in hypoxic-ischemic conditions result in RGC loss because of an imbalance between antioxidant- and oxidant-generating systems. Although many advances have been made in understanding the mediators and mechanisms of injury, strategies to improve the damage are lacking. Measures to prevent neuronal injury have to be developed.Keywords: retinal hypoxia, retinal ganglion cells, glutamate receptors, neuronal injury, retina

Charanjit Kaur

2008-08-01

122

Transient tractional retinal detachment in an eye with retinitis pigmentosa  

OpenAIRE

Shuichiro Hirahara, Yoshio Hirano, Tsutomu Yasukawa, Yuichiro OguraDepartment of Ophthalmology and Visual Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, JapanAbstract: We present a case of retinitis pigmentosa with vitreoretinal traction-associated retinal detachment. The retinal detachment was detected in the nasal periphery. No retinal breaks and no active vascular leakage were observed by fundus scopy and fluorescein angiography, respectively. However, 8 month...

Shuichiro Hirahara; Yoshio Hirano; Tsutomu Yasukawa; et al.

2010-01-01

123

If I Had - Retinitis Pigmentosa  

Medline Plus

Full Text Available ... Ph.D., whose research focuses on the cause, prevention, treatment, and cure of retinal disease, discuss retinitis ... Medicine. Dr. Charder’s research focuses on the cause, prevention, and treatment, as well as the cure of ...

124

If I Had - Retinitis Pigmentosa  

Medline Plus

Full Text Available ... that are known to ultimately result in one form or another of retinitis pigmentosa. What is noticed ... is very good. I know adults with various forms of retinitis pigmentosa who have what is called ...

125

If I Had - Retinitis Pigmentosa  

Science.gov (United States)

... as Alternative MS Treatment VIDEO: If I Had - Retinitis Pigmentosa - Dr. Gerry Chader, MD, PhD, University of Southern ... Back to Home Page VIDEO: If I Had - Retinitis Pigmentosa - Dr. Gerry Chader, MD, PhD, University of Southern ...

126

Increased ER stress as a mechanism of retinal neurovasculopathy in mice with severe hyperhomocysteinemia  

OpenAIRE

Hyperhomocysteinemia is implicated in retinal neurovascular diseases including arterial occlusive disease, venous occlusive disease and pseudoexfoliation glaucoma. The mechanism for these diseases is not known. Here we used hyperhomocysteinemic mice lacking the gene encoding cystathionine-beta-synthase (cbs ?/?) to examine whether ER stress could be a mechanism for the retinal neurovasculopathy reported in these mice. Retinas of cbs+/+ and cbs ?/? mice (age: 3–5 wks) were used...

Tawfik, Amany; Smith, Sylvia B.

2014-01-01

127

Retinal hemodynamic influence of compound xueshuantong capsule on nonproliferative diabetic retinopathy after laser photocoagulation  

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Full Text Available AIM: To observe retinal hemodynamic influence of compound xueshuantong capsule on nonproliferative diabetic retinopathy(NPDRafter laser photocoagulation. METHODS: A total of 41 patients(72 eyeswith NPDR after laser photocoagulation were enrolled in this study. They were all given compound xueshuantong capsule, and used color Doppler flow imaging for detection of retinal hemodynamics. RESULTS: After treatment, patients with retinal blood perfusion significantly improved; central retinal arterial peak systolic velocity(PSV, end-diastolic velocity(EDVand medial velocity(Vmwere increased, while the resistance index(RIdecreased. The difference have statistical significance(PCONCLUSION: Compound xueshuantong capsule can improve retinal blood perfusion for nonproliferative diabetic retinopathy after laser photocoagulation, which is related to improvement of visual prognosis.

Yu-Yan Wang

2014-07-01

128

A linking framework for pixel classification based retinal vessel segmentation  

Science.gov (United States)

Retinal vessel segmentation is a prerequisite for the analysis of vessel parameters such as tortuosity, variation of the vessel width along the vessel and the ratio between the venous and arterial vessel width. This analysis can provide indicators for the presence of a wide range of diseases. Different types of approaches have been proposed to segment the retinal vasculature and two important groups are vessel tracking and pixel processing based methods. An advantage of tracking based methods is the guaranteed connectedness of vessel segments, in pixel processing based methods connectedness is not guaranteed. In this work an automated vessel linking framework is presented. The framework links together separate pieces of the retinal vasculature into a connected vascular tree. To determine which vessel sections should be linked together the use of a supervised cost function is proposed. Evaluation is performed on the vessel centerlines. The results show that the vessel linking framework outperforms other automated vessel linking methods especially for the narrowest vessels.

Niemeijer, Meindert; van Ginneken, Bram; Abràmoff, Michael D.

2009-02-01

129

Finding the retinal break in rhegmatogenous retinal detachment  

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Full Text Available The development of subretinal fluid is governed by a limited number of anatomical factors and gravity. As a result, rhegmatogenous retinal detachments form in a predictable manner around the retinal break of their origin. The shape of the detachments points to the position of the break. The purpose of this review is to describe the characterstic contours of subretinal fluid in rhegmatogenous retinal detachments, and to highlight some rules and methodology which can help in the detection of the retinal break in phakic, psuedophakic and recurrent retinal detachments.

Saxena Sandeep

2001-01-01

130

Automated measurement of retinal blood vessel tortuosity  

Science.gov (United States)

Abnormalities in the vascular pattern of the retina are associated with retinal diseases and are also risk factors for systemic diseases, especially cardiovascular diseases. The three-dimensional retinal vascular pattern is mostly formed congenitally, but is then modified over life, in response to aging, vessel wall dystrophies and long term changes in blood flow and pressure. A characteristic of the vascular pattern that is appreciated by clinicians is vascular tortuosity, i.e. how curved or kinked a blood vessel, either vein or artery, appears along its course. We developed a new quantitative metric for vascular tortuosity, based on the vessel's angle of curvature, length of the curved vessel over its chord length (arc to chord ratio), number of curvature sign changes, and combined these into a unidimensional metric, Tortuosity Index (TI). In comparison to other published methods this method can estimate appropriate TI for vessels with constant curvature sign and vessels with equal arc to chord ratios, as well. We applied this method to a dataset of 15 digital fundus images of 8 patients with Facioscapulohumeral muscular dystrophy (FSHD), and to the other publically available dataset of 60 fundus images of normal cases and patients with hypertensive retinopathy, of which the arterial and venous tortuosities have also been graded by masked experts (ophthalmologists). The method produced exactly the same rank-ordered list of vessel tortuosity (TI) values as obtained by averaging the tortuosity grading given by 3 ophthalmologists for FSHD dataset and a list of TI values with high ranking correlation with the ophthalmologist's grading for the other dataset. Our results show that TI has potential to detect and evaluate abnormal retinal vascular structure in early diagnosis and prognosis of retinopathies.

Joshi, Vinayak; Reinhardt, Joseph M.; Abramoff, Michael D.

2010-03-01

131

Clinical and immunological features of retinal vasculitis in systemic diseases  

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Full Text Available Background/Aim. Vasculitis is a clinical, pathologic process characterized by inflammation and necrosis of blood vessel occurring anywhere in the body. The aim of the study was to present some clinical and immunologic features of retinal vasculitis in systemic diseases: systemic lupus erythematosus, multiple sclerosis, sarcoidosis, Behcet's diseases, and others. Methods. A total of 1 254 patients with uveitis were included in the study. The immunochemical diagnostic methods were used to determine the pathogenesis of ocular manifestations. Ocular manifestations were examined using biomicroscope, direct or indirect ophtalmoscopy. Results. Primary retinal vasculitis was diagnosed in 85/1254 (6.8% of total uveitis. In more than half of the cases of vasculitis (58.8%, both arteries and veins were involved in inflammatory process. Periphlebitis was diagnosed far more commonly (36.5% than periarteritis (4.7%. Retinal vasculitis associated with systemic lupus erythematosus was characterized by microinfarctions and the consequent foci of inflammatory cells or diseases of large arteries manifesting in vasospasm and occlusions. Cotton wool spots occurred in 38.3% and retinal hemorrhages in 34% of the cases. In this study periphlebitis of the retina was one of the less frequent ocular manifestations of multiple sclerosis. Comparing with the other changes of the retinal blood vessels, venous sheating occurred in 25.1% and occlusion and vein trombosis in 43.75% of the cases. Retinal vasculitis associated with chronic sarcoidosis occured in 37.5% of patients with sarcoidosis. The most frequent manifestation of ocular sarcoidosis was intermediary uveitis (43.75%. Anterior granulomatous uveitis occured in 37.5% of patients with sarcoidoses. Immune complexes occurred in 13/20 (65% of the patients. Antiretinal anti-S antibody in the serum occurred in 73% of the patients with retinal detachment as a complication of primary disease and in 25% those with vasculitis. Conclusion. Systemic diseases such as Behcet's syndrome, collagen vascular diseases, systemic granulomatous diseases (sarcoidosis and tuberculosis were the main causes of retinal vasculitis. Knowledge of the symptomatology and pathogenesis of retinal vasculitis is of the major significance for the diagnosis and therapy of the disease.

Paovi? Jelena

2009-01-01

132

Retinal Detachment in Preeclampsia  

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Full Text Available Preeclampsia is an obstetric disease of unknown cause that affects approximately 5% of pregnant women. The visual system may be affected with variable intensity, being the retinal detachment a rare complication. The retinal detachment in preeclampsia is usually bilateral and serous, and its pathogenesis is related to the choroidal ischemia secondary to an intense arteriolar vasospasm. The majority of patients have complete recovery of vision with clinical management, and surgery is unnecessary. This is a case report of a 27 year old patient who developed the severe form of preeclampsia on her first pregnancy. She had progressive blurred vision, until she could see only shadows. Ophthalmic examination diagnosed spread and bilateral retinal detachment. With blood pressure control at postpartum, the patient had her retina reattached, and recovery of vision.

Renata Silva do Prado

2002-08-01

133

Reflectance pulse oximetry measurements from the retinal fundus.  

OpenAIRE

Conventional transmission pulse oximetry is a noninvasive technique for the continuous monitoring of arterial oxygen saturation (SaO2) from peripheral vascular beds such as the finger tip or earlobe. In this paper we propose to exploit the unique transparency of the ocular media to make reflectance pulse oximetry measurements on the retinal fundus. This technique potentially offers significant advantages over conventional pulse oximetry, primarily the ability to monitor cerebral, as opposed t...

Kock, Jp; Tarassenko, L.; Glynn, Cj; Hill, Ar

1993-01-01

134

Isolated retinal cotton wool spot after coronary angiography  

OpenAIRE

Visual symptoms after coronary angiography are rarely encountered and mostly related to contrast induced transient cortical blindness or retinal artery occlusions. We report an intriguing case of a 50-year-old woman, who presented with vision deterioration in her right eye 12 h after coronary angiography for cardiac palpitation. Fundoscopy and optical coherence tomography scan revealed an isolated parafoveal cotton wool spot in her right eye that has totally resolved 6 weeks after initial pre...

Kopsachilis, Nikolaos; Brar, Manpreet; Marinescu, Anca I. C.; Sivaprasad, Sobha

2013-01-01

135

Ovarian Artery: Angiographic Appearance, Embolization and Relevance to Uterine Fibroid Embolization  

International Nuclear Information System (INIS)

Purpose: To describe the angiographic appearance of the ovarian artery and its main variations that may be relevant to uterine fibroid embolization. Methods: The flush aortograms of 294 women who had been treated by uterine artery embolization for fibroids were reviewed. Significant arterial supply to the fibroid, and the origin and diameter of identified ovarian arteries were recorded. In patients with additional embolization of the ovarian artery, the follow-up evaluation also included hormonal levels and Doppler imaging of the ovaries. Results: A total of 75 ovarian arteries were identified in 59 women (bilaterally in 16 women and unilaterally in 43 women). All ovarian arteries originated from the aorta below the level of the renal arteries with a characteristic tortuous course. Fifteen women had at least one enlarged ovarian artery supplying the fibroids. Fourteen women (14/15, 93%) presented at least one of the following factors: prior pelvic surgery, tubo-ovarian pathology or large fundal fibroids. Conclusion: We advocate the use of flush aortography in women with prior tubo-ovarian pathology or surgery or in cases of large fundal fibroids. In the case of an ovarian artery supply to the fibroids, superselective catheterization and embolization of the ovarian artery should be considered

136

Influence of cataract surgery and blood pressure changes caused by sodium restriction on retinal vascular diameter  

Directory of Open Access Journals (Sweden)

Full Text Available Takatoshi Tano1, Yoshimune Hiratsuka2, Koichi Ono1, Akira Murakami11Department of Ophthalmology, Juntendo University School of Medicine, Tokyo; 2National Institute of Public Health, Tokyo, JapanPurpose: To investigate the impact of cataract surgery and blood pressure changes induced by one week of sodium restriction on retinal vascular diameter.Methods: Fundus photographs of 200 patients were obtained before and one week after cataract surgery. For one week after admission, 100 patients received sodium restriction and 100 patients (ie, the control group did not receive sodium restriction. The diameter of the retinal vessels and blood pressure were compared between the sodium restriction group and the control group. The vascular diameter was measured using an objective computer-based method.Results: Neither group had a significant change in the diameter of the retinal vessels after cataract surgery. Although there was no significant change in retinal arterial and venular diameter in the sodium restriction group, one-week sodium restriction significantly reduced mean blood pressure. However, multiple linear regression analyses indicated that an increase in retinal arteriolar diameter was significantly associated with diabetes, hyperlipidemia, and alcohol intake.Conclusion: Cataract surgery and blood pressure reduction induced by one week of sodium restriction resulted in no significant change in retinal arteriolar diameter.Keywords: cataract surgery, hypertension, retinal blood vessel diameter, retinal fundus camera, sodium restriction.

Takatoshi Tano

2010-11-01

137

Retinal tolerance to dyes  

OpenAIRE

Background: Dye solutions for intraoperative staining of epiretinal membranes and the internal limiting membrane improve the visualisation of these thin structures and facilitate their removal. In the present study the authors investigated the effects of indocyanine green 0.05%, trypan blue 0.15%, and patent blue 0.48% on bovine retinal function.

Lu?ke, C.; Lu?ke, M.; Dietlein, T. S.; Hueber, A.; Jordan, J.; Sickel, W.; Kirchhof, B.

2005-01-01

138

Ischemic Retinal Vasculitis and Its Management  

OpenAIRE

Ischemic retinal vasculitis is an inflammation of retinal blood vessels associated with vascular occlusion and subsequent retinal hypoperfusion. It can cause visual loss secondary to macular ischemia, macular edema, and neovascularization leading to vitreous hemorrhage, fibrovascular proliferation, and tractional retinal detachment. Ischemic retinal vasculitis can be idiopathic or secondary to systemic disease such as in Behçet's disease, sarcoidosis, tuberculosis, multiple sclerosis, and sy...

Lazha Talat; Sue Lightman; Oren Tomkins-Netzer

2014-01-01

139

Automated method for the identification and analysis of vascular tree structures in retinal vessel network  

Science.gov (United States)

Structural analysis of retinal vessel network has so far served in the diagnosis of retinopathies and systemic diseases. The retinopathies are known to affect the morphologic properties of retinal vessels such as course, shape, caliber, and tortuosity. Whether the arteries and the veins respond to these changes together or in tandem has always been a topic of discussion. However the diseases such as diabetic retinopathy and retinopathy of prematurity have been diagnosed with the morphologic changes specific either to arteries or to veins. Thus a method describing the separation of retinal vessel trees imaged in a two dimensional color fundus image may assist in artery-vein classification and quantitative assessment of morphologic changes particular to arteries or veins. We propose a method based on mathematical morphology and graph search to identify and label the retinal vessel trees, which provides a structural mapping of vessel network in terms of each individual primary vessel, its branches and spatial positions of branching and cross-over points. The method was evaluated on a dataset of 15 fundus images resulting into an accuracy of 92.87 % correctly assigned vessel pixels when compared with the manual labeling of separated vessel trees. Accordingly, the structural mapping method performs well and we are currently investigating its potential in evaluating the characteristic properties specific to arteries or veins.

Joshi, Vinayak S.; Garvin, Mona K.; Reinhardt, Joseph M.; Abramoff, Michael D.

2011-03-01

140

Laparoscopic management of uterine arteriovenous malformation via occlusion of internal iliac arteries.  

Science.gov (United States)

Uterine arteriovenous malformation (AVM) can be congenital or acquired. When acquired (e.g., fistula), it results from abnormal arteriovenous communication between one or more uterine arteries and a myometrial and/or endometrial venous plexus, without the interposition of a vascular nidus. Arteriovenous malformation is composed of a tortuous net of fragile low-resistant arteriovenous shunts. Other arteries can be involved in fistulas, including ovarian arteries or those from the round ligaments of the uterus, in particular in congenital AVMs, which develop from failure in embryologic differentiation that leads to multiple abnormal vascular connections. In these cases, extension to pelvic vessels other than uterine arteries is frequent. Acquired AVMs often result in trauma to the uterus such as dilation and curettage in 85% of cases, gestational trophoblastic disease, or endometrial carcinoma. PMID:23084688

Levy-Zaubermann, Y; Capmas, Perrine; Legendre, G; Fernandez, H

2012-01-01

141

Finding the retinal break in rhegmatogenous retinal detachment  

OpenAIRE

The development of subretinal fluid is governed by a limited number of anatomical factors and gravity. As a result, rhegmatogenous retinal detachments form in a predictable manner around the retinal break of their origin. The shape of the detachments points to the position of the break. The purpose of this review is to describe the characterstic contours of subretinal fluid in rhegmatogenous retinal detachments, and to highlight some rules and methodology which can help in the detection of th...

Saxena Sandeep; Lincoff Harvey

2001-01-01

142

Contrast sensitivity in retinitis pigmentosa.  

OpenAIRE

Arden gratings were used to measure contrast sensitivity in 40 patients with retinitis pigmentosa whose Snellen visual acuity was 6/12 or better. When compared with a group of 30 normal subjects the patients with retinitis pigmentosa had substantially decreased contrast sensitivity, especially at high frequencies. The Arden grating test appeared to be a sensitive test of abnormal central visual function in patients with retinitis pigmentosa.

Lindberg, C. R.; Fishman, G. A.; Anderson, R. J.; Vasquez, V.

1981-01-01

143

Elastic fibres in retinal detachment  

Directory of Open Access Journals (Sweden)

Full Text Available Generalised abnormalities have been described previously in familial and bilateral retinal detachment 1.2.3. Some studies have shown the presence of specific histological skin changes in cases of retinal detachment per se as well as in other syndromes having associated retinal detachment, hence pointing towards a generalised abnormality of constitution3.9.12. Drawing an analogy from these observations, the aim of our study was to study the histological changes in the skin of patients with rhegmatogenous retinal detachment and to relate its a etiopathogenesis to a generalized abnormality.

Azad Rajvardhan

1990-01-01

144

Trombocitemia esencial y trombosis venosa retiniana / Essential thrombocythemia and retinal vein thrombosis  

Scientific Electronic Library Online (English)

Full Text Available Casos Clínicos: La trombocitosis esencial es una enfermedad de las células madres hematopoyéticas que se caracteriza por un exceso de plaquetas. Se presentan dos casos, una mujer de 72 años con retina isquémica, venas tortuosas y convertidas en cordones blanquecinos en la retina superior y hemorragi [...] as difusas en la retina inferior con hemorragias puntiformes en la región ecuatorial en el ojo izquierdo y un varón de 62 años con oclusión de la vena central de la retina en el ojo izquierdo, como manifestaciones de trombocitemia esencial. Discusión: Estos casos clínicos son ejemplos de las posibles complicaciones de la trombocitosis esencial. Estos pacientes deberían ser controlados ante posibles complicaciones oclusivas retinianas, especialmente al reducir el recuento plaquetario por debajo de 10(6)/mm³. Abstract in english Case Report: Essential thrombocytosis is a disorder of the hematopoietic stem cell that causes proliferation of platelets. We report two cases: a 72-year-old woman with ischemic retina and tortuous and white veins in the superior retina and diffuse hemorrhages in the inferior retina with blot hemorr [...] hages scattered throughout the equatorial region in the left eye; and a 62-year-old man with a central retinal vein occlusion in the left eye as signs of essential thrombocythemia. Discusion: These cases are examples of potential complications of essential thrombocytosis. Vulnerable patients should be monitored for retinal vascular occlusions, especially when platelet counts do not exceed 106/mm³.

VM, Asensio Sánchez; G, Manteca Jiménez; E, Cano Navarro.

2004-12-01

145

Trombocitemia esencial y trombosis venosa retiniana Essential thrombocythemia and retinal vein thrombosis  

Directory of Open Access Journals (Sweden)

Full Text Available Casos Clínicos: La trombocitosis esencial es una enfermedad de las células madres hematopoyéticas que se caracteriza por un exceso de plaquetas. Se presentan dos casos, una mujer de 72 años con retina isquémica, venas tortuosas y convertidas en cordones blanquecinos en la retina superior y hemorragias difusas en la retina inferior con hemorragias puntiformes en la región ecuatorial en el ojo izquierdo y un varón de 62 años con oclusión de la vena central de la retina en el ojo izquierdo, como manifestaciones de trombocitemia esencial. Discusión: Estos casos clínicos son ejemplos de las posibles complicaciones de la trombocitosis esencial. Estos pacientes deberían ser controlados ante posibles complicaciones oclusivas retinianas, especialmente al reducir el recuento plaquetario por debajo de 10(6/mm³.Case Report: Essential thrombocytosis is a disorder of the hematopoietic stem cell that causes proliferation of platelets. We report two cases: a 72-year-old woman with ischemic retina and tortuous and white veins in the superior retina and diffuse hemorrhages in the inferior retina with blot hemorrhages scattered throughout the equatorial region in the left eye; and a 62-year-old man with a central retinal vein occlusion in the left eye as signs of essential thrombocythemia. Discusion: These cases are examples of potential complications of essential thrombocytosis. Vulnerable patients should be monitored for retinal vascular occlusions, especially when platelet counts do not exceed 106/mm³.

VM Asensio Sánchez

2004-12-01

146

Oxygen saturation imaging of human retinal vessels and measurement in eye disease patient for clinical application  

Science.gov (United States)

We have proposed a new automatic visualization procedure based the ratio of optical densities (ODs) obtained at two different wavelength for the oxygen saturation imaging in human retinal vessels. This method utilized the morphological processing and the line convergence index filter to estimate the reflection image of outside vessels and extract the vessel structure from retinal image, respectively. In the experimental measurement, clear difference between retinal arteries and veins has been observed. In this study, the data processing technique of the line convergence index filter was applied to a color fundus image to investigate the ability of vessel extraction. In addition, four-wavelength imaging was proposed to evaluate oxygen saturation of the retinal capillary vessels and to decrease the influence of the melanin pigmentation.

Nakamura, D.; Matsuoka, N.; Tatsuguchi, K.; Ogata, M.; Yoshinaga, Y.; Enaida, H.; Okada, T.; Ishibashi, T.

2010-02-01

147

Acute hyperinsulinemia increases the contraction of retinal arterioles induced by elevated blood pressure  

DEFF Research Database (Denmark)

Diabetic retinopathy is accompanied by disturbances in retinal blood flow, which is assumed to be related to the diabetic metabolic dysregulation. It has previously been shown that normoinsulinemic hyperglycemia has no effect on the diameter of retinal arterioles at rest and during an increase in the arterial blood pressure induced by isometric exercise. However, the influence of hyperinsulinemia on this response has not been studied in detail. In seven normal persons, the diameter response of retinal arterioles to an increased blood pressure induced by isometric exercise, to stimulation with flickering light, and to the combination of these stimuli was studied during euglycemic normoinsulinemia (protocol N) on one examination day, and euglycemic hyperinsulinemia (protocol H) on another examination day. Isometric exercise induced significant contraction of retinal arterioles at all examinations, but during a repeated examination the diameter response was significantly reduced in the test persons following theN protocol and increased in the persons following the H protocol. Flicker stimulation induced a significant dilatation of retinal arterioles at all examinations, and the response was significantly higher during a repeated examination, irrespective of the insulin level. Repeated exposure to isometric exercise reduces contraction, whereas repeated exposure to flickering light increases dilatation of retinal arterioles in vivo. Hyperinsulinemia increases contraction of retinal arterioles induced by isometric exercise.

Jeppesen, Peter; Knudsen, SØren Tang

2013-01-01

148

Automatic arteriovenous crossing phenomenon detection on retinal fundus images  

Science.gov (United States)

Arteriolosclerosis is one cause of acquired blindness. Retinal fundus image examination is useful for early detection of arteriolosclerosis. In order to diagnose the presence of arteriolosclerosis, the physicians find the silver-wire arteries, the copper-wire arteries and arteriovenous crossing phenomenon on retinal fundus images. The focus of this study was to develop the automated detection method of the arteriovenous crossing phenomenon on the retinal images. The blood vessel regions were detected by using a double ring filter, and the crossing sections of artery and vein were detected by using a ring filter. The center of that ring was an interest point, and that point was determined as a crossing section when there were over four blood vessel segments on that ring. And two blood vessels gone through on the ring were classified into artery and vein by using the pixel values on red and blue component image. Finally, V2-to-V1 ratio was measured for recognition of abnormalities. V1 was the venous diameter far from the blood vessel crossing section, and V2 was the venous diameter near from the blood vessel crossing section. The crossing section with V2-to-V1 ratio over 0.8 was experimentally determined as abnormality. Twenty four images, including 27 abnormalities and 54 normal crossing sections, were used for preliminary evaluation of the proposed method. The proposed method was detected 73% of crossing sections when the 2.8 sections per image were mis-detected. And, 59% of abnormalities were detected by measurement of V1-to-V2 ratio when the 1.7 sections per image were mis-detected.

Hatanaka, Yuji; Muramatsu, Chisako; Hara, Takeshi; Fujita, Hiroshi

2011-03-01

149

Retinal detachment surgery without cryotherapy.  

OpenAIRE

A series of cases of retinal detachment treated without the application of cryotherapy at the time of surgery has been studied. The omission of cryotherapy while not interfering with retinal reattachment, carries the risk of redetachment at a later date. Macular pucker may still occur in spite of the absence of cryotherapy.

Chignell, A. H.; Markham, R. H.

1981-01-01

150

Retinal microvasculature in Alzheimer's disease.  

Science.gov (United States)

Although cerebral small vessel disease has been implicated in the development of Alzheimer's disease (AD), the cerebral microcirculation is difficult to visualize directly in vivo. As the retina and the brain share similar embryological origin, anatomical features and physiological properties with the cerebral small vessels, the retinal vessels thus offer a unique and easily accessible "window" to study the correlates and consequences of cerebral small vessel diseases in vivo. Retinal microvasculature can now be visualized, quantified and monitored non-invasively using state-of-the-art retinal imaging technology. Recent clinic- and population-based studies have demonstrated a link between retinal vascular changes and dementia, in particular AD, and cerebral small vessel disease. In this review, we summarize the current findings on retinal vascular changes such as retinopathy signs and changes in novel retinal vascular network parameters and retinal vascular caliber with dementia, cognitive dysfunction and cerebral small vessel disease, and discuss possible future research to further evaluate whether retinal vascular imaging might help to elucidate vascular mechanisms contributing to the development of AD and provide additional value in predicting who may be at risk of developing AD. PMID:25351108

Cheung, Carol Yim-Lui; Ong, Yi-Ting; Ikram, M Kamran; Chen, Christopher; Wong, Tien Yin

2014-01-01

151

If I Had - Retinitis Pigmentosa  

Medline Plus

Full Text Available ... as Alternative MS Treatment VIDEO: If I Had - Retinitis Pigmentosa - Dr. Gerry Chader, MD, PhD, University of Southern ... Back to Home Page VIDEO: If I Had - Retinitis Pigmentosa - Dr. Gerry Chader, MD, PhD, University of Southern ...

152

Diagnosis of arterial sequestration using multidetector CT angiography  

Energy Technology Data Exchange (ETDEWEB)

Background: Arterial sequestration is a rare congenital disorder. The diagnostic evaluation of this condition using multidetector computerized tomography (MDCT) has not been described previously. The purpose of this study was to describe the characteristic features of this disorder and to assess the use of MDCT in visualizing the characteristic anatomic features. Methods: We retrospectively reviewed the records of seven patients with anomalous systemic blood supply to left lower lobe of the lung. All the patients had undergone MDCT angiography. To evaluate the lung parenchyma, bronchial branching pattern, and vascular anatomy, four series of images were systematically reconstructed as follows: contiguous transverse CT scans viewed at mediastinal and pulmonary window settings, oblique coronal and sagittal maximum intensity projections (MIP), multiplanar reconstruction (MPR), and three-dimensional volume-rendered images (VR) of airway and thoracic vascular structures. Results: All 7 cases had isolated and tortuous arterial anatomy from the descending thoracic aorta to the basal segment of the left lower lobe; however, variable distribution of branches was observed. Characteristic findings of anomalous systemic arterial (ASA) supply were distinct from those seen in other pulmonary sequestration syndromes and were well visualized by the use of noninvasive MDCT. Conclusion: Complex CT findings allow clear imaging of arterial sequestration and the ASA blood supply; MDCT angiography has demonstrated its value and accuracy in diagnosing this condition, obviating the use of digital subtraction angiography and magnetic resonance angiography for the diagnosis of arterial sequestration.

Yu Hong, E-mail: yuhong.2002@hotmail.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, Shanghai, 200003 (China); Li Huimin, E-mail: lihuiminphd@163.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, Shanghai, 200003 (China); Liu Shiyuan, E-mail: cjr.liushiyuan@vip.163.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, Shanghai, 200003 (China); Xiao Xiangsheng, E-mail: cjr.xxsh@vip.163.com [Department of Radiology, Changzheng Hospital, Second Military Medical University, Shanghai, 200003 (China)

2010-11-15

153

The ovarian and uterine arteries in the chinchilla (Chinchilla lanigera)  

Scientific Electronic Library Online (English)

Full Text Available SciELO South Africa | Language: English Abstract in english The purpose of this study was to describe arteries supplying the ovaries and uterus in the chinchilla. Five healthy adult female chinchillas were used. In order to reveal the arterial network by dissecting under a stereoscopic microscope, latex coloured with red ink was injected through the common c [...] arotid artery. The ovaries of the chinchilla are supplied by the arteriae ovaricae which formed end-to-end anastomoses with the cranial termination of the arteria uterina. Soon after leaving the aorta abdominalis, the arteriae ovaricae extended 2-3 mm caudolaterally, then released 1 branch and extended caudally and bifurcated into 2 further branches. One of these supplied branches to fat tissue. The other branch coursed caudally and anastomosed with the arteria circumflexa ilium profunda and dispersed into fat tissue. The arteria ovarica further subdivided into 2 rami ovaricae. The origins of the uterine arteries were exclusively from the left arteria iliaca externa. The arteria uterina gave a branch to the arteria umbilicalis and consecutive branches which supplied to the ureter, urinary bladder and cranial aspects of the vagina. It also gave rise to 2-3 branches to the cervix and further supplied 10-12 meandering branches to the uterine horns. The arteria uterina gave rise to many tortuous arteries to the uterus and provided 2 further branches to the ovary.

A, Çevik-Demirkan; V, Özdemir; I, Demirkan.

154

The ovarian and uterine arteries in the chinchilla (Chinchilla lanigera  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this study was to describe arteries supplying the ovaries and uterus in the chinchilla. Five healthy adult female chinchillas were used. In order to reveal the arterial network by dissecting under a stereoscopic microscope, latex coloured with red ink was injected through the common carotid artery. The ovaries of the chinchilla are supplied by the arteriae ovaricae which formed end-to-end anastomoses with the cranial termination of the arteria uterina. Soon after leaving the aorta abdominalis, the arteriae ovaricae extended 2-3mm caudolaterally, then released 1 branch and extended caudally and bifurcated into 2 further branches. One of these supplied branches to fat tissue. The other branch coursed caudally and anastomosed with the arteria circumflexa ilium profunda and dispersed into fat tissue. The arteria ovarica further subdivided into 2 rami ovaricae. The origins of the uterine arteries were exclusively from the left arteria iliaca externa. The arteria uterina gave a branch to the arteria umbilicalis and consecutive branches which supplied to the ureter, urinary bladder and cranial aspects of the vagina. It also gave rise to 2-3 branches to the cervix and further supplied 10-12 meandering branches to the uterine horns. The arteria uterina gave rise to many tortuous arteries to the uterus and provided 2 further branches to the ovary.

I. Demirkan

2012-05-01

155

Delayed appearance of high altitude retinal hemorrhages  

OpenAIRE

When closely examined, a very large amount of climbers exhibit retinal hemorrhages during exposure to high altitudes. The incidence of retinal hemorrhages may be greater than previously appreciated as a definite time lag was observed between highest altitude reached and development of retinal bleeding. Retinal hemorrhages should not be considered warning signs of impending severe altitude illness due to their delayed appearance.

Barthelmes, D.; Bosch, M. M.; Merz, T. M.; Petrig, B. L.; Truffer, F.; Bloch, K. E.; Holmes, T. A.; Cattin, P.; Hefti, U.; Sellner, M.; Sutter, F. K. P.; Maggiorini, M.; Landau, K.

2011-01-01

156

Occlusive Peripheral Arterial Disease  

Science.gov (United States)

... Disease Peripheral Arterial Disease Aneurysms and Aortic Dissection Venous Disorders Lymphatic Disorders Topics in Peripheral Arterial Disease Overview of Peripheral Arterial Disease Occlusive Peripheral Arterial ...

157

Seasonal variability in spontaneous cervical artery dissection  

OpenAIRE

We examined the seasonal variability of spontaneous cervical artery dissection (sCAD) by analysing prospectively collected data from 352 patients with 380 sCAD (361 symptomatic sCAD; 305 carotid and 75 vertebral artery dissections) admitted to two university hospitals with a catchment area of 2?200?000 inhabitants between 1985 and 2004. Presenting symptoms and signs of the 380 sCAD were ischaemic stroke in 241 (63%), transient ischaemic attack in 40 (11%), retinal ischemia in seven (2%), ...

Paciaroni, M.; Georgiadis, D.; Arnold, M.; Gandjour, J.; Keseru, B.; Fahrni, G.; Caso, V.; Baumgartner, R. W.

2006-01-01

158

Transcranial direct middle meningeal artery puncture for the onyx embolization of dural arteriovenous fistula involving the superior sagittal sinus.  

Science.gov (United States)

A 66-year-old woman presented with intermittent paraparesis and generalized tonic-clonic seizure. Cerebral angiography demonstrated dural arteriovenous fistula (AVF) involving superior sagittal sinus (SSS), which was associated with SSS occlusion on the posterior one third. The dural AVF was fed by bilateral middle meningeal arteries (MMAs), superficial temporal arteries (STAs) and occipital arteries with marked retrograde cortical venous reflux. Transfemoral arterial Onyx embolization was performed through right MMA and STA, but it was not successful, which resulted in partial obliteration of dural AVF because of tortuous MMA preventing the microcatheter from reaching the fistula closely enough. Second procedure was performed through left MMA accessed by direct MMA puncture following small decortications of cranium overlying the MMA using diamond drill one week later. Microcatheter could be located far distally to the fistula through 5 F sheath placed into the MMA and complete obliteration of dural AVF was achieved using 3.9 cc of Onyx. PMID:25674345

Oh, Jae-Sang; Yoon, Seok-Mann; Shim, Jai-Joon; Bae, Hack-Gun

2015-01-01

159

Transcranial Direct Middle Meningeal Artery Puncture for the Onyx Embolization of Dural Arteriovenous Fistula Involving the Superior Sagittal Sinus  

Science.gov (United States)

A 66-year-old woman presented with intermittent paraparesis and generalized tonic-clonic seizure. Cerebral angiography demonstrated dural arteriovenous fistula (AVF) involving superior sagittal sinus (SSS), which was associated with SSS occlusion on the posterior one third. The dural AVF was fed by bilateral middle meningeal arteries (MMAs), superficial temporal arteries (STAs) and occipital arteries with marked retrograde cortical venous reflux. Transfemoral arterial Onyx embolization was performed through right MMA and STA, but it was not successful, which resulted in partial obliteration of dural AVF because of tortuous MMA preventing the microcatheter from reaching the fistula closely enough. Second procedure was performed through left MMA accessed by direct MMA puncture following small decortications of cranium overlying the MMA using diamond drill one week later. Microcatheter could be located far distally to the fistula through 5 F sheath placed into the MMA and complete obliteration of dural AVF was achieved using 3.9 cc of Onyx. PMID:25674345

Oh, Jae-Sang; Shim, Jai-Joon; Bae, Hack-Gun

2015-01-01

160

Retinal Arteriolar Dilation Predicts Retinopathy in Adolescents With Type 1 Diabetes  

Science.gov (United States)

OBJECTIVE—Alterations in retinal vascular caliber may reflect early subclinical microvascular dysfunction. In this study, we examined the association of retinal vascular caliber to incident retinopathy in young patients with type 1 diabetes. RESEARCH DESIGN AND METHODS—This was a prospective cohort study of 645 initially retinopathy-free type 1 diabetic patients, aged 12–20 years. Participants had seven-field stereoscopic retinal photographs taken of both eyes at baseline and follow-up. Retinal vascular caliber was measured from baseline photographs using a computer-based program following a standardized protocol. Incident retinopathy was graded according to the modified Airlie House classification from follow-up photographs. RESULTS—Over a median follow-up of 2.5 years, 274 participants developed retinopathy (14.8 per 100 person-years). After adjustments for age, sex, diabetes duration, glycemia, mean arterial blood pressure, BMI, and cholesterol levels, larger retinal arteriolar caliber (fourth versus first quartile) was associated with a more than threefold higher risk of retinopathy (hazard rate ratio 3.44 [95% CI 2.08–5.66]). Each SD increase in retinal arteriolar caliber was associated with a 46% increase in retinopathy risk (1.46 [1.22–1.74]). This association was stronger in female than in male participants. After similar adjustments, retinal venular caliber was not consistently associated with incident retinopathy. CONCLUSIONS—Retinal arteriolar dilatation predicts retinopathy development in young patients with type 1 diabetes. Our data suggest that arteriolar dysfunction may play a critical role in the pathogenesis of early diabetic retinopathy and that computer-based retinal vascular caliber measurements may provide additional prognostic information regarding risk of diabetes microvascular complications. PMID:18523143

Cheung, Ning; Rogers, Sophie L.; Donaghue, Kim C.; Jenkins, Alicia J.; Tikellis, Gabriella; Wong, Tien Yin

2008-01-01

161

Sector retinitis pigmentosa in juvenile nephronophthisis.  

OpenAIRE

In a patient with juvenile nephronophthisis, sector retinitis pigmentosa was found as an extrarenal manifestation, establishing a hitherto undescribed variety of retinal degeneration occurring in this disorder. The retinal function in this case was identical with that in the classic type of sector retinitis pigmentosa, namely, subnormal ERG amplitudes but normal cone and rod implicit times. The range of the retinal findings and their autosomal recessive transmission are discussed. Paucity of ...

Godel, V.; Iaina, A.; Nemet, P.; Lazar, M.

1980-01-01

162

Automated retinal vessel type classification in color fundus images  

Science.gov (United States)

Automated retinal vessel type classification is an essential first step toward machine-based quantitative measurement of various vessel topological parameters and identifying vessel abnormalities and alternations in cardiovascular disease risk analysis. This paper presents a new and accurate automatic artery and vein classification method developed for arteriolar-to-venular width ratio (AVR) and artery and vein tortuosity measurements in regions of interest (ROI) of 1.5 and 2.5 optic disc diameters from the disc center, respectively. This method includes illumination normalization, automatic optic disc detection and retinal vessel segmentation, feature extraction, and a partial least squares (PLS) classification. Normalized multi-color information, color variation, and multi-scale morphological features are extracted on each vessel segment. We trained the algorithm on a set of 51 color fundus images using manually marked arteries and veins. We tested the proposed method in a previously unseen test data set consisting of 42 images. We obtained an area under the ROC curve (AUC) of 93.7% in the ROI of AVR measurement and 91.5% of AUC in the ROI of tortuosity measurement. The proposed AV classification method has the potential to assist automatic cardiovascular disease early detection and risk analysis.

Yu, H.; Barriga, S.; Agurto, C.; Nemeth, S.; Bauman, W.; Soliz, P.

2013-02-01

163

Retinal pseudoangiitis after intravitreal triamcinolone.  

Science.gov (United States)

We present a case of a 40-year-old woman with a fundus image similar to frosted retinal angiitis after undergoing pars plana vitrectomy and intravitreal triamcinolone injection. The patient with diabetic retinopathy was referred to our hospital with vision loss in her right eye secondary to vitreous haemorrhage. After pars plana vitrectomy and injection of triamcinolone acetonide a funduscopy examination revealed deposits of triamcinolone along the retinal vessels simulating a frosted retinal angiitis. Triamcinolone deposits along blood vessels could be the result of the reabsorption process of these crystals by the perivascular macrophages. Further studies are needed. PMID:25678611

García-Campos, Jose Manuel; García-Basterra, Ignacio; Kamal-Salah, Radua; Baquero-Aranda, Isabel

2015-01-01

164

Bilateral carotid and vertebral rete mirabile presenting with subarachnoid hemorrhage caused by the rupture of spinal artery aneurysm.  

Science.gov (United States)

Rete mirabile (or carotid rete) is a normal structure that plays physiological roles in the lower mammals. However, the rete does not exist in the normal carotid circulation of humans. Carotid rete mirabile (CRM) is a rare condition compensating for congenital dysplastic internal carotid artery. Arterial plexus at the cavernous region, which supplies intradural internal carotid artery instead of the aplastic cavernous portion of internal carotid artery, looks like the "rete mirabile" seen in the lower mammals, and is a characteristic angiographical finding of CRM. In addition to the CRM, existence of segmental occlusion and tortuous collaterals of vertebral artery, so-called carotid and vertebral rete mirabile (CVRM), is a very rare condition. We report a 70-year-old female patient with bilateral CVRM presenting with subarachnoid hemorrhage (SAH) caused by the rupture of a cervical spinal artery aneurysm. Our patient is the oldest, compared with the previously reported four patients with CVRM. Moreover, this is the first report of ruptured spinal artery aneurysm as a cause of SAH associated with CRM/CVRM. To avoid rebleeding in the patient, we successfully treated the patients by performing coil embolization of the remaining spinal aneurysms. In patients with CVRM, aneurysm formation of the cervical spinal artery may be a reasonable consequence because of the hemodynamic stress on the spinal artery as a collateral pathway. Detailed evaluation of the cervical spinal arteries should be performed to detect or to rule out ruptured aneurysm in patients with SAH associated with CVRM. PMID:23903351

Nagahata, Morio; Kondo, Rei; Mouri, Wataru; Sato, Atsushi; Ito, Miiko; Sato, Shinji; Itagaki, Hiroshi; Yamaki, Tetsu; Nagahata, Satoko; Saito, Shinjiro; Kayama, Takamasa

2013-01-01

165

Anatomy-based image processing analysis of the running pattern of the perioral artery for minimally invasive surgery.  

Science.gov (United States)

We aimed to elucidate the tortuous course of the perioral artery with the aid of image processing, and to suggest accurate reference points for minimally invasive surgery. We used 59 hemifaces from 19 Korean and 20 Thai cadavers. A perioral line was defined to connect the point at which the facial artery emerged on the mandibular margin, and the ramification point of the lateral nasal artery and the inferior alar branch. The course of the perioral artery was reproduced as a graph based on the perioral line and analysed by adding the image of the artery using MATLAB. The course of the artery could be classified into 2 according to the course of the alar branch - oblique and vertical. Two distinct inflection points appeared in the course of the artery along the perioral line at the ramification points of the alar branch and the inferior labial artery, respectively, and the course of the artery across the face can be predicted based on the following references: the perioral line, the ramification point of the alar branch (5?10 mm medial to the perioral line at the level of the lower third of the upper lip) and the inferior labial artery (5?10 mm medial to the perioral line at the level of the middle of the lower lip). PMID:25081954

Lee, Sang-Hee; Lee, Minho; Kim, Hee-Jin

2014-10-01

166

Ray tracing model for the estimation of power spectral properties in laser Doppler velocimetry of retinal vessels and its potential application to retinal vessel oximetry  

Science.gov (United States)

A new model based on ray tracing was developed to estimate power spectral properties in laser Doppler velocimetry of retinal vessels and to predict the effects of laser beam size and eccentricity as well as absorption of laser light by oxygenated and reduced hemoglobin. We describe the model and show that it correctly converges to the traditional rectangular shape of the Doppler shift power spectrum, given the same assumptions, and that reduced beam size and eccentric alignment cause marked alterations in this shape. The changes in the detected total power of the Doppler-shifted light due to light scattering and absorption by blood can also be quantified with this model and may be used to determine the oxygen saturation in retinal arteries and veins. The potential of this approach is that it uses direct measurements of Doppler signals originating from moving red blood cells. This may open new avenues for retinal vessel oximetry.

Petrig, Benno L.; Follonier, Lysianne

2005-12-01

167

If I Had - Retinitis Pigmentosa  

Medline Plus

Full Text Available ... discuss retinitis pigmentosa. Dr. Chader is a Chief Scientist at the Doheny Retina Institute at University of ... with Dr. Gerry Chader, who is the chief scientist at the Doheny Retina Institute at the University ...

168

If I Had - Retinitis Pigmentosa  

Medline Plus

Full Text Available ... Autologous Stem Cell Transplantation Shows Potential as Alternative MS Treatment VIDEO: If I Had - Retinitis Pigmentosa - Dr. ... coming. OUR TEAM Sanjay Sharma BSc, MD, FRCS, MS (Epid), MBA Susan M. Sharma BSc, MD, CCFP ...

169

Genetics Home Reference: Retinitis pigmentosa  

Science.gov (United States)

... most common cause of autosomal dominant retinitis pigmentosa, accounting for 20 to 30 percent of all cases. ... management of genetic conditions is available in the Handbook. Read more about genetic testing , particularly the difference ...

170

If I Had - Retinitis Pigmentosa  

Medline Plus

Full Text Available ... Insidermedicine In 60 In Depth In the Spotlight If I Had... Universities and Hospitals By Disease or ... Transplantation Shows Potential as Alternative MS Treatment VIDEO: If I Had - Retinitis Pigmentosa - Dr. Gerry Chader, MD, ...

171

Retinal detachment repair - series (image)  

Science.gov (United States)

... floaters", or loss of part of the visual field. Emergency retinal detachment surgery is necessary to prevent ... buckle is applied. This consists of a silicone patch wrapped around the eye, compressing the globe and ...

172

If I Had - Retinitis Pigmentosa  

Medline Plus

Full Text Available ... In 60 In Depth In the Spotlight If I Had... Universities and Hospitals By Disease or Symptom ... Shows Potential as Alternative MS Treatment VIDEO: If I Had - Retinitis Pigmentosa - Dr. Gerry Chader, MD, PhD, ...

173

Retinal Oximetry with 510-600 nm Light Based on Partial Least-Squares Regression Technique  

Science.gov (United States)

The oxygen saturation distribution in the retinal blood stream is estimated by measuring spectral images and adopting the partial-least squares regression. The wavelengths range used for the calculation is from 510 to 600 nm. The regression model for estimating the retinal oxygen saturation is built on the basis of the arterial and venous blood spectra. The experiment is performed using an originally designed spectral ophthalmoscope. The obtained two-dimensional (2D) oxygen saturation indicates the reasonable oxygen level across the retina. The measurement quality is compared with those obtained using other wavelengths sets and data processing methods.

Arimoto, Hidenobu; Furukawa, Hiromitsu

2010-11-01

174

Flexible retinal electrode array  

Energy Technology Data Exchange (ETDEWEB)

An electrode array which has applications for neural stimulation and sensing. The electrode array can include a large number of electrodes each of which is flexibly attached to a common substrate using a plurality of springs to allow the electrodes to move independently. The electrode array can be formed from a combination of bulk and surface micromachining, with electrode tips that can include an electroplated metal (e.g. platinum, iridium, gold or titanium) or a metal oxide (e.g. iridium oxide) for biocompatibility. The electrode array can be used to form a part of a neural prosthesis, and is particularly well adapted for use in an implantable retinal prosthesis where the electrodes can be tailored to provide a uniform gentle contact pressure with optional sensing of this contact pressure at one or more of the electrodes.

Okandan, Murat (Albuquerque, NM); Wessendorf, Kurt O. (Albuquerque, NM); Christenson, Todd R. (Albuquerque, NM)

2006-10-24

175

Microsystems Technology for Retinal Implants  

Science.gov (United States)

The retinal prosthesis is targeted to treat age-related macular degeneration, retinitis pigmentosa, and other outer retinal degenerations. Simulations of artificial vision have predicted that 600-1000 individual pixels will be needed if a retinal prosthesis is to restore function such as reading large print and face recognition. An implantable device with this many electrode contacts will require microsystems technology as part of its design. An implantable retinal prosthesis will consist of several subsystems including an electrode array and hermetic packaging. Microsystems and microtechnology approaches are being investigated as possible solutions for these design problems. Flexible polydimethylsiloxane (PDMS) substrate electrode arrays and silicon micromachined electrode arrays are under development. Inactive PDMS electrodes have been implanted in 3 dogs to assess mechanical biocompatibility. 3 dogs were followed for 6 months. The implanted was securely fastened to the retina with a single retinal tack. No post-operative complications were evident. The array remained within 100 microns of the retinal surface. Histological evaluation showed a well preserved retina underneath the electrode array. A silicon device with electrodes suspended on micromachined springs has been implanted in 4 dogs (2 acute implants, 2 chronic implants). The device, though large, could be inserted into the eye and positioned on the retina. Histological analysis of the retina from the spring electrode implants showed that spring mounted posts penetrated the retina, thus the device will be redesigned to reduce the strength of the springs. These initial implants will provide information for the designers to make the next generation silicon device. We conclude that microsystems technology has the potential to make possible a retinal prosthesis with 1000 individual contacts in close proximity to the retina.

Weiland, James

2005-03-01

176

Cytomegalovirus retinitis mimicking intraocular lymphoma  

Directory of Open Access Journals (Sweden)

Full Text Available Patrick Gooi1, James Farmer2, Bernard Hurley3, Elliott Brodbaker41Department of Ophthalmology, University of Calgary, Calgary, Alberta, Canada; 2Department of Pathology and Lab Medicine University of Ottawa and The Ottawa Hospital, Ottawa, Ontario, Canada; 3Department of Ophthalmology, University of Ottawa Eye Institute and The Ottawa Hospital, Ottawa, Ontario, Canada; 4Faculty of Medicine, University of Ottawa, Ottawa, Ontario, CanadaAbstract: We present a case of an unusual retinal infiltrate requiring retinal biopsy for definitive diagnosis. A 62-year-old man with treated lymphoma presented with decreased vision in the right eye associated with a white retinal lesion, which extended inferonasally from an edematous disc. Intraocular lymphoma was considered as a diagnosis; thus, the patient was managed with vitrectomy and retinal biopsy. Cytological analysis of the vitreous aspirate could not rule out a lymphoproliferative disorder. The microbial analysis was negative. Histology of the lesion showed extensive necrosis and large cells with prominent nucleoli. To rule out lymphoma, a battery of immunostains was performed and all were negative. However the limited amount of tissue was exhausted in the process. Subsequently, a hematoxylin and eosin (H/E slide was destained, on which a CMV immunostain was performed. This revealed positivity in the nuclei and intranuclear inclusions within the large atypical cells. A diagnosis of CMV retinitis was made. Retinal biopsy may provide a definitive diagnosis and direct patient care toward intravenous gancyclovir in the case of CMV or toward radiation and chemotherapy for intraocular lymphoma. When faced with a limited amount of tissue, destaining regular H/E slides is a possible avenue to performing additional immunohistochemical studies.Keywords: CMV retinitis, retinal biopsy, immunohistochemistry, destaining

Patrick Gooi

2008-12-01

177

Uterine artery embolization: an effective treatment for intractable obstetric haemorrhage  

Energy Technology Data Exchange (ETDEWEB)

AIM: To present the findings of uterine artery embolization (UAE) in the management of obstetric haemorrhage. MATERIALS AND METHODS: From October 1999 to February 2003, 10 women with postpartum haemorrhage (n=7) and post-abortion haemorrhage with placenta accreta (n=3), were referred to our department for pelvic angiography and possible arterial embolization. RESULTS: Angiography revealed engorged and tortuous uterine arteries in all patients; and contrast medium extravasation in three patients. Eight patients (three with and five without detectable active bleeding) then underwent bilateral UAE. Medium-sized (250-355 {mu}m) polyvinyl alcohol particles were injected via a coaxial catheter into the uterine arteries, followed by gelatin sponge pieces via a 4 F Cobra catheter. Microcoil devascularization was also performed in the two patients with visible, active bleeding. The vaginal bleeding resolved in all patients, without any ischaemic complications. At follow-up, all patients who underwent UAE had normal menstruation; three of them subsequently gave birth to full-term healthy babies. CONCLUSION: Selective UAE by the coaxial method is safe and effective to control obstetric haemorrhage, with the potential to preserve fertility.

Hong, T.-M.; Tseng, H.-S. E-mail: hstseng@vghtpe.gov.tw; Lee, R.-C.; Wang, J.-H.; Chang, C.-Y

2004-01-01

178

Uterine artery embolization: an effective treatment for intractable obstetric haemorrhage  

International Nuclear Information System (INIS)

AIM: To present the findings of uterine artery embolization (UAE) in the management of obstetric haemorrhage. MATERIALS AND METHODS: From October 1999 to February 2003, 10 women with postpartum haemorrhage (n=7) and post-abortion haemorrhage with placenta accreta (n=3), were referred to our department for pelvic angiography and possible arterial embolization. RESULTS: Angiography revealed engorged and tortuous uterine arteries in all patients; and contrast medium extravasation in three patients. Eight patients (three with and five without detectable active bleeding) then underwent bilateral UAE. Medium-sized (250-355 ?m) polyvinyl alcohol particles were injected via a coaxial catheter into the uterine arteries, followed by gelatin sponge pieces via a 4 F Cobra catheter. Microcoil devascularization was also performed in the two patients with visible, active bleeding. The vaginal bleeding resolved in all patients, without any ischaemic complications. At follow-up, all patients who underwent UAE had normal menstruation; three of them subsequently gave birth to full-term healthy babies. CONCLUSION: Selective UAE by the coaxial method is safe and effective to control obstetric haemorrhage, with the potential to preserve fertility

179

Vision loss after maxillary artery embolization secondary to compressive optic neuropathy.  

Science.gov (United States)

The authors report a case of no light perception (NLP) vision in a patient with sinonasal melanoma after maxillary artery embolization secondary to presumptive compressive optic neuropathy. Two reports of NLP vision occurring after maxillary artery embolization are reported in the literature,, both occurring secondary to collateral blood flow to the ophthalmic artery resulting in central retinal artery occlusion. In the current case report, the presumed mechanism of vision loss is secondary to compressive optic neuropathy from local edema occurring after maxillary artery embolization. PMID:23503054

Finnerty, Katie N; Mancini, Ronald

2013-01-01

180

The mechanics of retinal detachment  

Science.gov (United States)

We present a model of the mechanical and fluid forces associated with exudative retinal detachments where the retinal photoreceptor cells separate typically from the underlying retinal pigment epithelium (RPE). By computing the total fluid volume flow arising from transretinal, vascular, and retinal pigment epithelium (RPE) pump currents, we determine the conditions under which the subretinal fluid pressure exceeds the maximum yield stress holding the retina and RPE together, giving rise to an irreversible, extended retinal delamination. We also investigate localized, blister-like retinal detachments by balancing mechanical tension in the retina with both the retina-RPE adhesion energy and the hydraulic pressure jump across the retina. For detachments induced by traction forces, we find a critical radius beyond which the blister is unstable to growth. Growth of a detached blister can also be driven by inflamed tissue within which e.g., the hydraulic conductivities of the retina or choroid increase, the RPE pumps fail, or the adhesion properties change. We determine the parameter regimes in which the blister either becomes unstable to growth, remains stable and finite-sized, or shrinks, allowing possible healing.

Chou, Tom; Siegel, Michael

2013-03-01

181

Advances in Retinal Stem Cell Biology  

Science.gov (United States)

Tremendous progress has been made in recent years to generate retinal cells from pluripotent cell sources. These advances provide hope for those suffering from blindness due to lost retinal cells. Understanding the intrinsic genetic network in model organisms, like fly and frog, has led to a better understanding of the extrinsic signaling pathways necessary for retinal progenitor cell formation in mouse and human cell cultures. This review focuses on the culture methods used by different groups, which has culminated in the generation of laminated retinal tissue from both embryonic and induced pluripotent cells. The review also briefly describes advances made in transplantation studies using donor retinal progenitor and cultured retinal cells. PMID:23943690

Viczian, Andrea S.

2013-01-01

182

Embolization of a Bleeding Maxillary Arteriovenous Malformation via the Superficial Temporal Artery after External Carotid Artery Ligation  

International Nuclear Information System (INIS)

An arteriovenous malformation (AVM) of the jaw is an uncommon lesion found mainly in children. It can present with massive oral bleeding, resulting in death. The external carotid artery (ECA) is often the feeding artery and can be ligated to control the hemorrhage. As a result, transarterial embolization is difficult or even impossible to perform when re-bleeding occurs. We report a new approach of a successful embolization of a bleeding maxillary AVM via the superficial temporal artery (STA) after a previous ECA ligation. This technique has not yet been reported for endovascular management of a bleeding maxillary AVM. This approach of embolization of a maxillary AVM via the STA is minimally invasive, repeatable and has little effect on the physical appearance of the patient. It may be performed on patients with hyper vascular craniofacial lesions whose feeding arteries have been ligated or are too tortuous to navigate a catheter. It can also be performed urgently during active bleeding, pre-operatively and before trans-venous embolization

183

Tortuosity and calcification of the splenic artery. More than an additional finding  

International Nuclear Information System (INIS)

Tortuosity of the splenic artery and calcification of the vessel wall are typical additional findings on plain abdominal x-ray. The combination of both anomalies is common in elderly persons presenting without symptoms of splenic ischemia. Its pathogenesis is thought to be multifactorial. In infancy and childhood, the splenic artery is stretched in its entire course. A growing difference between the length of the vessel and the distance between its origin and the splenic hilum gives rise to tortuosity. The artery's proximal segment is involved more frequently and more severely than the distal one. The tortuous route of the vessel is accentuated by the direction of its major branches, which is roughly perpendicular to the main trajectory. Neither tortuosity nor calcification should be taken to be risk factors for the comparatively common splenic artery aneurysm. Calcific deposits are not confined to the media but are also detected in the intima of the vascular wall. Critical narrowings of the lumen arising on the calcium deposits are not observed. Calcifying atherosclerosis of the splenic artery is comparable to medial sclerosis of the peripheral arteries frequently noticed in diabetics and dialysis patients. Only the less important calcification of the intima may be attributed to mechanisms of the hydrohemodynamic theory of atherosclerosis. The spleen's blood storage capacity may contribute to the characteristic age-dependent alterations of the shape and course of thealterations of the shape and course of the splenic artery. (orig.)

184

Wavelength dependence of the apparent diameter of retinal blood vessels  

Science.gov (United States)

Imaging of retinal blood vessels may assist in the diagnosis and monitoring of diseases such as glaucoma, diabetic retinopathy, and hypertension. However, close examination reveals that the contrast and apparent diameter of vessels are dependent on the wavelength of the illuminating light. In this study multispectral images of large arteries and veins within enucleated swine eyes are obtained with a modified fundus camera by use of intravitreal illumination. The diameters of selected vessels are measured as a function of wavelength by cross-sectional analysis. A fixed scale with spectrally independent dimension is placed above the retina to isolate the chromatic effects of the imaging system and eye. Significant apparent differences between arterial and venous diameters are found, with larger diameters observed at shorter wavelengths. These differences are due primarily to spectral absorption in the cylindrical blood column.

Park, Robert; Twietmeyer, Karen; Chipman, Russell; Beaudry, Neil; Salyer, David

2005-04-01

185

Cirsoid Aneurysm of Coronary Arteries Associated with Arterioventricular Fistula Evaluated by 64-Multidetector CT Coronary Angiography: Depiction of a Case  

International Nuclear Information System (INIS)

A female patient with severe pulmonary hypertension was admitted for lung transplant evaluation. As an incidental finding, the chest CT showed diffuse and dilated coronaries, not detected at previous echocardiography. A coronary CT angiography was then performed using a 64-multidetector computed tomography (MDCT) scanner to better evaluate the coronary tree. The images obtained after postprocessing demonstrated tremendously aneurysmatic and tortuous coronary arteries and the presence of a septal branch deepening into the myocardium and penetrating the right ventricle cavity, forming an abnormal arterioventricular fistula. A causal relation between the aneurysms and the fistula is suspected.

186

Retinal detachment in paediatric patients  

International Nuclear Information System (INIS)

Objective: To assess the causes of retinal detachment in children and the various operative procedures requiring vitreoretinal surgical intervention for the same. Study Design: Case series. Place and Duration of Study: Department of Ophthalmology, Al-Shifa Trust Eye Hospital, Rawalpindi, from January 2006 to May 2009. Methodology: A total of 281 eyes of 258 patients, (aged 0 - 18 years) who underwent vitreo-retinal surgical intervention for retinal detachment were included. Surgical log was searched for the type of retinal detachment and its causes. Frequencies of various interventions done in these patients viz. vitrectomy, scleral buckle, use of tamponading agents, laser photocoagulation and cryotherapy were noted. Results were described as descriptive statistics. Results: Myopia was the cause in 62 (22.1%) and trauma in 51 (18.1%) of the eyes. Total retinal detachment (RD) was treated in 94 (33.5%) eyes, sub total RD in 36 (12.8%), recurrent RD in 32 (11.4%), giant retinal tear in 28 (10%), tractional RD in 15 (5.3%) and exudative RD in 2 (0.7%). Prophylactic laser or cryotherapy was applied in 74 (26.3%) of the eyes. Pars plana vitrectomy (PPV) was carried out in 159 (56.6%) eyes while scleral buckle procedure was done in 129 (45.9%) eyes. Silicon oil was used in 149 (53%), perfluorocarbon liquid in 32 (11.4%) and gas tamponade in 20 (7.1%) eyes. Conclusion: The most common cause of retinal detachment in paediatric patients was myopia, followed by trauma. Total RD was more common as compared to the other types. The most common procedure adopted was pars plana vitrectomy followed by scleral buckle procedure. (author)

187

Arterial embolism  

Science.gov (United States)

... or leg (pallor) Weakness of an arm or leg Later symptoms: Blisters of the skin fed by the affected artery Shedding (sloughing) of skin Skin erosion ( ulcer ) Tissue death (necrosis; skin is dark and damaged) ...

188

Arterial stick  

Science.gov (United States)

... injected or applied before the needle is inserted. Blood flows into a special collecting syringe. The needle is ... to breathing problems or problems with the body's metabolism. Sometimes arterial sticks are done to get blood culture or blood chemistry samples.

189

Reading visual Braille with a retinal prosthesis  

OpenAIRE

Retinal prostheses, which restore partial vision to patients blinded by outer retinal degeneration, are currently in clinical trial. The Argus II retinal prosthesis system was recently awarded CE approval for commercial use in Europe. While retinal prosthesis users have achieved remarkable visual improvement to the point of reading letters and short sentences, the reading process is still fairly cumbersome. This study investigates the possibility of using an epiretinal prosthesis to stimulate...

ThomasZaccarinLauritzen; JordanHarris; JoseSahel

2012-01-01

190

Shifting subretinal fluid in rhegmatogenous retinal detachment.  

OpenAIRE

In a consecutive series of 470 cases of rhegmatogenous retinal detachment 25 (5%) were found to have shifting subretinal fluid (SRF) at the preoperative examination. The study showed that the association between SRF and rhegmatogenous retinal detachment is unusual but not rare. Shifting SRF was most often associated with aphakic and longstanding retinal detachment, and found in cases in which the retinal holes were small.

Kirkby, G. R.; Chignell, A. H.

1985-01-01

191

Retinal imaging using adaptive optics technology?  

OpenAIRE

Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effect of wave front distortions. Retinal imaging using AO aims to compensate for higher order aberrations originating from the cornea and the lens by using deformable mirror. The main application of AO retinal imaging has been to assess photoreceptor cell density, spacing, and mosaic regularity in normal and diseased eyes. Apart from photoreceptors, the retinal pigment epithelium, retinal ...

Kozak, Igor

2014-01-01

192

Photon Echoes from Retinal Proteins  

Science.gov (United States)

This thesis focuses on the ultrafast isomerization reaction of retinal in both rhodopsin and bacteriorhodopsin, examples of sensory and energy transduction proteins that exploit the same photoactive chromophore for two very different functions. In bacteriorhodopsin, retinal isomerizes from an all-trans to 13-cis conformation as the primary event in light- driven proton pumping. In the visual pigment rhodopsin, the retinal chromophore isomerizes from an 11-cis to all-trans geometry as the primary step leading to our sense of vision. This diversity of function for nominally identical systems raises the question as to just how optimized are these proteins to arrive at such drastically different functions? Previous work has employed transient absorption spectroscopy to probe retinal protein photochemistry, but many of the relevant electronic and nuclear dynamics of isomerization are masked by inhomogeneous broadening effects and strong spectral overlap between reactant and photoproduct states. This work exploits the unique properties of two-dimensional photon echo spectroscopy to deconvolve inhomogeneous broadening and spectral overlap effects and fully reveal the dynamics that direct retinal isomerization in proteins. In bacteriorhodopsin, vibrational coupling to the reaction coordinate results in a surface crossing event prior to the conventional conical intersection associated with isomerization to the J intermediate. In rhodopsin, however, a similarly early vibrationally-mediated barrier crossing event is observed, resulting in spectral signals consistent with the known photoproduct state appearing an order of magnitude faster than determined from conventional transient absorption measurements. The competing overlapping spectral signals that obscured the initial dynamics when probed with transient absorption spectroscopy are now clearly resolved with two-dimensional photon echo spectroscopy. These experiments illustrate the critical role of the protein in directing the outcome of retinal photochemistry. The protein controls the reaction pathway through steric interactions between the binding pocket and the retinal chromophore, the result of which directly sets the isomerization coordinate and indirectly controls the vibrational coupling to the reaction coordinate based on the local retinal structure. The new insight from this work is the extraordinary degree of selective vibrational coupling involved in directing the isomerization reaction in retinal proteins.

Johnson, Philip James Maddigan

193

Retinal Neovascularization and An Angioma-like Lesion after Demarcation Photocoagulation for Rhegmatogenous Retinal Detachment  

OpenAIRE

Laser photocoagulation might aggravate the ischemia of an area of retinal detachmentand predispose the retina to formation of neovascularization and an angioma-like lesion. Wepresent a case of retinal neovascularization (RNV) and an angioma-like lesion occurringafter demarcation photocoagulation for rhegmatogenous retinal detachment (RRD). A 20-year-old woman suffered from a retinal atrophic hole with localized shallow retinal detachmentin the right eye. Laser photocoagulation was performed t...

San-Ni Chen; Yi-Cheng Chen; Chia-Yun Li

2006-01-01

194

Clinical application of uterine arterial embolization for treatment of placenta praevia with hemorrhage in advanced stage of pregnancy  

International Nuclear Information System (INIS)

Objective: To investigate the value of the uterine arterial embolization for the placenta praevia and hemorrhage in late stage of pregnancy. Methods: 16 patients of placenta praevia with hemorrhage in late stage of pregnancy were treated with uterine arterial embolization (UAE)and simultaneously with Lee Rivanol intra-amniotic membrane injection for artificial laboring. Results: During late stage of pregnancy, uterine arteries appeared to be elongated and enlarged with numerous dilated tortuous branches with positive proportion to gestalional age, and rich in blood supply of the placenta. 15 cases passed successfully through the induced abortion. The procedure completed with an average of 4.5 h afterwards, without postpartum hemorrhage. The other ease failed due to complicated reasons and cured by caesarean section. Conclusion: UAE is a safe and effective method for late stage placenta praevia with hemaorrhage and also provides the reservation of fertility and together with promotion of induced abortion. (authors)

195

Retinal Migraine: A Case Report  

Directory of Open Access Journals (Sweden)

Full Text Available Retinal migraine is a subgroup of migraine. Retinal migraines are transient monocular visual disturbances that can occur simultaneously with migraine headaches or in a patient with a prior history of migraines. Retinal migraines occur because of hypoperfusion of either the eye or the optic nerve. A 28-year woman was admitted to the emergency department with decreased vision in the right eye and headache. Neurologic and other systemic examinations were normal. Ophthalmologist consultation was performed. Her best corrected visual acuity was 20/20 and the intraocular pressures in both eyes were within normal limits. Color vision testing, fundus examination, and extra ocular muscle function were normal bilaterally. Visual field to confrontation suggested a left temporal hemianopia. Left temporal hemianopia was confirmed by the automatic perimetry test. The diagnosis was retinal migraine in the light of the anamnesis and physical exam findings. Headache and visual complaints had resolved during the follow up in the emergency department. The patient was discharged on the 2nd day of admission with full recovery. As a result, for patients presenting with complaints of headache and visual disturbances, emergency physicians should be alert in terms of retinal migraine, and patients should be considered comprehensively for this reason.

Ayhan Sar?ta?

2013-03-01

196

Challenges in retinal circuit regeneration.  

Science.gov (United States)

Tremendous progress has been made in retinal regeneration, as exemplified by successful transplantation of retinal pigment epithelia and photoreceptor cells in the adult retina, as well as by generation of retinal tissue from embryonic stem cells and induced pluripotent cells. However, it remains unknown how new photoreceptors integrate within retinal circuits and contribute to vision restoration. There is a large gap in our understanding, at both the cellular and behavioral levels, of the functional roles of new neurons in the adult retina. This gap largely arises from the lack of appropriate methods for analyzing the organization and function of new neurons at the circuit level. To bridge this gap and understand the functional roles of new neurons in living animals, it will be necessary to identify newly formed connections, correlate them with function, manipulate their activity, and assess the behavioral outcome of these manipulations. Recombinant viral vectors are powerful tools not only for controlling gene expression and reprogramming cells, but also for tracing cell fates and neuronal connectivity, monitoring biological functions, and manipulating the physiological state of a specific cell population. These virus-based approaches, combined with electrophysiology and optical imaging, will provide circuit-level insight into neural regeneration and facilitate new strategies for achieving vision restoration in the adult retina. Herein, we discuss challenges and future directions in retinal regeneration research. PMID:25757915

Osakada, Fumitaka; Takahashi, Masayo

2015-03-01

197

Prostatic Artery Embolization for Enlarged Prostates Due to Benign Prostatic Hyperplasia. How I Do It  

International Nuclear Information System (INIS)

Prostatic artery embolization (PAE) has emerged as an alternative to surgical treatments for benign prostatic hyperplasia (BPH). Patient selection and refined technique are essential for good results. Urodynamic evaluation and magnetic resonance imaging are very important and technical limitations are related to elderly patients with tortuous and atherosclerotic vessels, anatomical variations, difficulty visualizing and catheterizing small diameter arteries feeding the prostate, and the potential risk of bladder and rectum ischemia. The use of small-diameter hydrophilic microcatheters is mandatory. Patients can be treated safely by PAE with low rates of side effects, reducing prostate volume with clinical symptoms and quality of life improvement without urinary incontinence, ejaculatory disorders, or erectile dysfunction. A multidisciplinary approach with urologists and interventional radiologists is essential to achieve better results

198

Multimodality imaging and transcatheter coil embolization of an iatrogenic subclavian artery-internal jugular vein fistula.  

Science.gov (United States)

A 69-year-old man was found to have a loud continuous bruit in the neck. Duplex carotid ultrasound showed high-velocity turbulent flow in the dilated and pulsatile right internal jugular vein. Computed tomography angiogram demonstrated markedly enlarged right internal jugular vein with a posteriorly located arteriovenous communication. Invasive angiography revealed an arteriovenous fistula originating from the right subclavian artery draining into the dilated and tortuous right internal jugular vein. An endovascular coil was successfully deployed in the fistula tract. Subclavian artery-internal jugular vein fistula is rare. Our case is most likely iatrogenic towing to previous central venous cannulation during coronary bypass grafting. The anatomic challenge of this fistula, being located in the thoracic outlet, makes endovascular repair particularly favourable. PMID:25286164

Cai, Qiangjun; Sickler, Cory; Christenson, Stuart; Dotani, Imran

2015-01-01

199

Human retinal circuitry and physiology  

Scientific Electronic Library Online (English)

Full Text Available Every second, in an average daytime light environment, hundreds of millions of photons enter the human eye and arrive at the photoreceptor layer of the retina. All our information about the visible world is contained in this rain of photons. The retina is a complex tissue, literally an extension of [...] the brain, which transforms the rain of photons into bioelectric signals containing all the information available to the brain to interpret and respond to the external visual world. A considerable amount of processing takes place within the retinal tissue itself. Understanding what kind of processing takes place at each retinal stage is crucial for understanding normal vision, vision in the presence of diseases affecting the retina, and, ultimately, for the development of therapies to treat such diseases. This manuscript reviews the relation between structure and function of the different retinal pathways and addresses their possible roles for visual perception.

Christina, Joselevitch.

2008-12-01

200

Retinal vessel diameters in relation to hematocrit variation during acclimatization of highlanders to sea level altitude  

DEFF Research Database (Denmark)

PURPOSE: To examine variations in retinal vessel diameters during acclimatization of native highlanders to normobaric normoxia at sea level. METHODS: Fifteen healthy residents of the greater La Paz region in Bolivia (3600 m above sea level) were examined thrice over a 72-day period, after having traveled by airplane to Copenhagen, Denmark, near sea level. RESULTS: In the study subjects, hematocrit decreased from 49.6% (day 2) to 45.9% (P = 0.0066, day 23) and 41.7% (P <0.0001, day 72); from days 2 to 23, retinal vein diameter increased by 2.68% (P = 0.0079); whereas retinal artery and vein diameters were indistinguishable from baseline after 72 days. No funduscopic signs of retinopathy were observed. Arterial blood pressure remained stable throughout the study. CONCLUSIONS: Although a 16% reduction in hematocrit occurred between days 2 and 72 after arrival at sea level, the only significant excursion observed was that the diameter of the veins was larger at day 23 than at days 2 and 72. Retinal vessel diameters demonstrated a wide homeostatic range during acclimatization-driven hematocrit variation.

Kofoed, Peter Kristian; Sander, Birgit

2009-01-01

201

Stem Cells Therapy for Retinal Degeneration  

Directory of Open Access Journals (Sweden)

Full Text Available Stem cell therapy is widely considered as a therapeutic approach for retinal degeneration. Retinal injury results in permanent visual disturbance or blindness. Repair of such damage by stem cells is one of the most feasible types of central nervous system repair. In this review, we consider how stem cells might be optimized for use as donor cells. We discuss the benefits of stem cells for transplantation in retinal degenerative disease. A wide range of stem cells from different sources is being investigated for the treatment of retinal degeneration. This study reviews the recent and old achievements about stem cells for retinal repair.

M. Safari

2010-01-01

202

Severe combined hyperlipidaemia and retinal lipid infiltration in a patient with Type 2 diabetes mellitus  

OpenAIRE

Abstract Severe combined hyperlipidaemia has occasionally been associated with infiltration of tissues in addition to arteries and the skin. We report a woman with Type 2 diabetes mellitus (DM) and severe combined hyperlipidaemia who developed retinal lipid infiltration, resulting in blindness. A 61-year-old woman with a 15-year history of Type 2 DM was admitted following a two-week history of progressive visual loss. Examination identified lipid infiltration into the retina. Phenotypically s...

Rae Derek; O'Neal David N; Favaloro Jenny M; Tebbutt Niall C; Davey Rachel A; Zajac Jeffrey D; Best James D

2006-01-01

203

Erythropoietin administration protects retinal neurons from acute ischemia-reperfusion injury  

OpenAIRE

Erythropoietin (EPO) plays an important role in the brain's response to neuronal injury. Systemic administration of recombinant human EPO (rhEPO) protects neurons from injury after middle cerebral artery occlusion, traumatic brain injury, neuroinflammation, and excitotoxicity. Protection is in part mediated by antiapoptotic mechanisms. We conducted parallel studies of rhEPO in a model of transient global retinal ischemia induced by raising intraocular pressure, which is a clinically relevant ...

Junk, Anna K.; Mammis, Antonios; Savitz, Sean I.; Singh, Manjeet; Roth, Steven; Malhotra, Samit; Rosenbaum, Pearl S.; Cerami, Anthony; Brines, Michael; Rosenbaum, Daniel M.

2002-01-01

204

Dorzolamide increases retinal oxygen tension after branch retinal vein occlusion  

DEFF Research Database (Denmark)

PURPOSE: To study the effect of dorzolamide on the preretinal oxygen tension (RPO(2)) in retinal areas affected by experimental branch retinal vein occlusion (BRVO) in pigs. METHODS: Experimental BRVO was induced by diathermy close to the optic disc. RPO(2) was measured with an oxygen-sensitive electrode 0.5 mm above the BRVO-affected area, which was compared to the retinal areas not affected by BRVO. In one group of five pigs, RPO(2) was measured at baseline, 1 and 3 hours after BRVO, and after intravenous injection of 500 mg dorzolamide. In a second group of five pigs, RPO(2) was measured 1 week after the BRVO, both before and after intravenous injection of 500 mg dorzolamide. RESULTS: The average baseline RPO(2) was 2.64 +/- 0.09 kPa (mean +/- SD). In the BRVO-affected areas, RPO(2) decreased significantly (by 0.67 +/- 0.29 and 0.94 +/- 0.13 kPa) at 1 hour and 3 hours after BRVO induction. In the non-BRVO areas RPO(2) increased significantly (by 0.51 +/- 0.14 kPa) 1 hour after BRVO induction, but subsequently decreased and reached baseline 3 hours after BRVO induction. One week after BRVO induction, RPO(2) was 0.67 +/- 0.29 kPa lower in affected areas when compared with the non-BRVO areas. In the BRVO-affected areas, dorzolamide increased RPO(2) significantly (by 0.36 +/- 0.21 kPa at 3 to 4 hours and by 0.67 +/- 0.40 kPa) 1 week after BRVO induction. CONCLUSIONS: Retinal hypoxia induced by experimental BRVO remained significant 1 week after BRVO. Dorzolamide increased retinal oxygen tension in the BRVO-affected areas both at 4 hours and 1 week after experimental BRVO in pigs Udgivelsesdato: 2008/3

Noergaard, Michael Hove; Bach-Holm, Daniella

2008-01-01

205

[Surgical Managment of Retinal Detachment.  

Science.gov (United States)

The detachment of the neurosensory retina from the underlying retinal pigment epithelium can be related to breaks of the retina allowing vitreous fluid to gain access to the subretinal space, to exudative changes of the choroid such as tumours or inflammatory diseases or to excessive tractional forces exerted by interactions of the collagenous vitreous and the retina. Tractional retinal detachment is usually treated by vitrectomy and exudative detachment can be addressed by treatment of the underlying condition in many cases. In rhegmatogenous retinal detachment two different surgical procedures, vitrectomy and scleral buckling, can be applied for functional and anatomic rehabilitation of our patients. The choice of the surgical procedure is not really standardised and often depends on the experience of the surgeon and other more ocular factors including lens status, the number of retinal breaks, the extent of the detachment and the amount of preexisting PVR. Using both techniques, anatomic success rates of over 90?% can be achieved. Especially in young phakic patients scleral buckling offers the true advantage to prevent the progression of cataract formation requiring cataract extraction and intraocular lens implantation. Therefore, scleral buckling should be considered in selected cases as an alternative surgical option in spite of the very important technical refinements in modern vitrectomy techniques. PMID:25393439

Haritoglou, C; Wolf, A

2014-11-13

206

Retinal projections in gymnotid fishes  

International Nuclear Information System (INIS)

Retinal projections were studied in four species of gymnotid fishes, Gymnotus carapo, Hypopomus artedi, Eigenmannia virescens and Sternopygus sp. with the aid of cobalt or horseradish peroxidase labelling and autoradiographic techniques. The optic tract gives off a small branch, the axial optic tract and then, after crossing in the midline, splits into a dorsomedial, dorsal and ventral fascicle. E. virescens and Sternopygys sp. display in addition an accessory optic tract. In all four species retinal projections are bilateral; ipsilateral projections, however, are extremely sparse. In all four species, the retinal fibres terminate bilaterally in the suprachiasmatic nucleus, dorsolateral optic nucleus of the thalamus and the optic nucleus of the posterior commissure; a bilateral retinotectal projection was only found in E. virescens and G. carapo. Retinal projections are only contralateral to the ventromedical nucleus of the thalamus, the central pretectal nucleus and the accessory optic nucleus. The contralateral retinotectal fibres terminate in the stratum fibrosum and griseum superficiale, and in the stratum album centrale and stratum periventriculare. A small accessory optic tract and nucleus were detected in E. virescens and Sternopygys sp. but not in G. carapo and H. artedi. The results indicate that the visual system of gymnotid fish is as simple as that of mormyrids. The poor visibility in the environment where these animals live and the additional sensory systimals live and the additional sensory system which these animals possess may explain the poor development of the visual system. (author)

207

Retinitis Pigmentosa and Education Issues  

Science.gov (United States)

Retinitis Pigmentosa includes a number of inherited diseases which usually result in blindness. The disease is progressive in nature and begins with the deterioration of cells in the eye responsible for peripheral vision. As the condition worsens there is a gradual loss of peripheral vision and night blindness. Proper educational planning requires…

Brown, Thomas J.

2005-01-01

208

Automatic temperature controlled retinal photocoagulation  

Science.gov (United States)

Laser coagulation is a treatment method for many retinal diseases. Due to variations in fundus pigmentation and light scattering inside the eye globe, different lesion strengths are often achieved. The aim of this work is to realize an automatic feedback algorithm to generate desired lesion strengths by controlling the retinal temperature increase with the irradiation time. Optoacoustics afford non-invasive retinal temperature monitoring during laser treatment. A 75 ns/523 nm Q-switched Nd:YLF laser was used to excite the temperature-dependent pressure amplitudes, which were detected at the cornea by an ultrasonic transducer embedded in a contact lens. A 532 nm continuous wave Nd:YAG laser served for photocoagulation. The ED50 temperatures, for which the probability of ophthalmoscopically visible lesions after one hour in vivo in rabbits was 50%, varied from 63°C for 20 ms to 49°C for 400 ms. Arrhenius parameters were extracted as ?E=273 J mol-1 and A=3.1044 s-1. Control algorithms for mild and strong lesions were developed, which led to average lesion diameters of 162+/-34 ?m and 189+/-34 ?m, respectively. It could be demonstrated that the sizes of the automatically controlled lesions were widely independent of the treatment laser power and the retinal pigmentation.

Schlott, Kerstin; Koinzer, Stefan; Ptaszynski, Lars; Bever, Marco; Baade, Alex; Roider, Johann; Birngruber, Reginald; Brinkmann, Ralf

2012-06-01

209

Failed retinal surgery caused by intraocular gas injection.  

OpenAIRE

Four patients developed inferior retinal redetachment following initially successful surgery which included intraocular injection of air and sulphahexafluoride (SF6) mixture. In each case the intravitreal gas bubble produced vitreoretinal traction which opened inferior retinal breaks and led to retinal separation. Cautious use of intraocular gas is advised when bullous upper rhegmatogenous retinal detachments are accompanied by inferior retinal breaks.

Johnston, P. B.; Maguire, C. J.; Logan, W. C.

1988-01-01

210

Arterial Catheterization  

Science.gov (United States)

... to better monitor blood pressure and/or blood gases. ? Blood clots— If blood clots form on the tips of arterial catheters, the clots can block blood flow. If another blood vessel does not carry blood to the area beyond the clot, this can cause the loss ...

211

Impaired retinal vasodilator response to acetylcholine in a rat model of NMDA-induced retinal degeneration.  

Science.gov (United States)

Previous studies have shown that degeneration of retinal capillaries occurs following N-methyl-d-aspartate (NMDA)-induced retinal neurotoxicity, but it is unclear whether vasodilatory mechanisms are altered in retinal blood vessels. The purpose of the present study was to determine whether retinal vasodilator responses are affected in a rat model of NMDA-induced retinal damage. At 14 days after a single intravitreal injection of NMDA (200 nmol), retinal vasodilator responses were assessed by measuring the diameter of retinal arterioles in fundus images. Acetylcholine-induced vasodilation of retinal arterioles was significantly reduced in NMDA-treated retinas, whereas retinal vasodilatory effects of the nitric oxide (NO) donor NOR3, the ?2-adrenoceptor agonist salbutamol, and the ?3-adrenoceptor agonist CL316243 were unaltered. The vasodilator response to acetylcholine observed under the combined blockade of NO synthase and cyclooxygenase with N(G)-nitro-l-arginine methyl ester (30 mg/kg, i.v.) plus indomethacin (5 mg/kg, i.v.), possibly an endothelium-derived hyperpolarizing factor-mediated response, was also reduced. These results suggest that endothelium-dependent vasodilatory mechanisms in retinal blood vessels are impaired in the rat model of NMDA-induced retinal degeneration. Glutamate-induced neurotoxicity is implicated in several retinal diseases; therefore, abnormal retinal circulation would contribute to the progression of the diseases. PMID:25727959

Mori, Asami; Hanada, Masayuki; Sakamoto, Kenji; Nakahara, Tsutomu; Ishii, Kunio

2015-02-01

212

Radiological review of intercostal artery: anatomical considerations when performing procedures via intercostal space  

International Nuclear Information System (INIS)

The aim of this study was to closely examine the course of the intercostal arteries within the intercostal spaces particularly with regard to where the arteries were located in relation to their adjacent ribs. The degree of tortuosity of the arteries was also examined, along with anatomical differences in different age groups. A total of 81 patients between the age of 30 and 90 years who had underwent a CT examination of the chest for any indication were included in the study. All studies were performed on a dual source 64 slice CT (Siemens Definition Erlangen Germany). Analysis of the intercostal arteries was performed on a CT workstation using volume rendered 3D reconstructions F, or each patient the 10'n intercostals pacesb ilaterally were examined for the course and tortuosity of the intercostal arteries. The ICA is located relatively inferiorly in the intercostal space at costovertebral junction and it gradually becomes more superiorly positioned within the intercostal space it as courses laterally. This finding was consistent in all age groups. In addition, analysis of the data demonstrated increasing intercostal artery tortuosity with advancing age. In this study we have examined the course of the posterior intercostal arteries using MDCT. This study confirms the classical description of the course of ICA. We have shown that in the medial chest, posteriorly, the artery is located in the inferior half of the intercostal space. As it moves away from the costovertebral junction it travels closer to the inferior border of the rib above and reaches the intercostal groove. We have also shown that the artery tends to be more tortuous in elderly patients, decreasing the area of 'safe' space for interventions. Both of these findings are relevant to radiologists and non-radiologists performing interventional procedures via the intercostal space.

213

The porcine retinal vasculature accessed using an endovascular approach : a new experimental model for retinal ischemia  

DEFF Research Database (Denmark)

The aim of this study was to examine whether the retinal circulation in the pig can be accessed using interventional neuroradiology and to explore the possibility of creating occlusions that result in experimental retinal ischemia.

Morén, Håkan; Undrén, Per

2009-01-01

214

Endovascular Therapy of Bronchial Artery Aneurysm: Five Cases With Six Aneurysms  

International Nuclear Information System (INIS)

The objective of this study was to investigate the effect of transcatheter arterial embolization (TAE) with N-butyl-2-cyanoacrylate (NBCA)–Lipiodol mixture in patients with bronchial artery aneurysm (BAA). From January 2005 to January 2010, five patients presenting hemoptysis with six BAAs were treated with NBCA–Lipiodol mixture, including intra-aneurysm embolization (IAE) in one patient. Adjuvant embolization with spherical polyvinyl alcohol (PVA) embolic microparticles or NBCA was first performed to embolize the distal engorged bronchiectatic arteries. Bronchial arterial angiography showed six BAAs (four in the right lobe and two in the left lobe) and some engorged, tortuous bronchial arteries. TAE through microcatheter was successful in all cases. Postembolization angiogram demonstrated the NBCA cast and total occlusion of BAAs and bronchiectatic engorged vessels. After these procedures, hemoptysis completely disappeared in all patients. Follow-up computed tomography (CT) scan was performed at an average of 3 months (range 2 to 6), which showed no enhancement of BAAs and accumulation of NBCA. TAE is a minimally invasive, effective, and reliable approach for treatment for patients with BAA. NBCA–Lipiodol mixture provides a good choice for treatment of BAA, especially when catheterization of the efferent branches is impossible.

215

Accordion effect during carotid artery stenting. Report of two cases and review of the literature  

Energy Technology Data Exchange (ETDEWEB)

The term ''accordion effect'' is used to describe a mechanical distortion of tortuous arteries mimicking spasm or dissection. This phenomenon has been reported in patients undergoing percutaneous coronary intervention. To our knowledge, this is the first documentation of the accordion effect during carotid artery intervention. Two patients who developed the accordion effect during carotid artery stenting (CAS) are described. Angiograms obtained just after CAS showed a stenosing lesion with wall irregularity at the distal part of the stent. This lesion disappeared and tortuosity of the internal carotid artery developed after withdrawing the guidewire until its floppy segment rested equally on the lesion. In another patient, the lesion did not disappear completely until the guiding catheter had been withdrawn to the proximal portion of the common carotid artery. We conclude that these stenosing lesions reflected the accordion effect. It is essential to differentiate the accordion effect from dissection, spasm, and thrombosis because the management is importantly different. We report our findings and present a review of the literature. (orig.)

Tsutsumi, Masanori; Kazekawa, Kiyoshi; Onizuka, Masanari; Aikawa, Hiroshi; Iko, Minoru; Kodama, Tomonobu; Nii, Kouhei; Matsubara, Shuko; Etou, Housei; Tanaka, Akira [Fukuoka University Chikushi Hospital, Department of Neurosurgery, Fukuoka (Japan)

2007-07-15

216

Accordion effect during carotid artery stenting. Report of two cases and review of the literature  

International Nuclear Information System (INIS)

The term ''accordion effect'' is used to describe a mechanical distortion of tortuous arteries mimicking spasm or dissection. This phenomenon has been reported in patients undergoing percutaneous coronary intervention. To our knowledge, this is the first documentation of the accordion effect during carotid artery intervention. Two patients who developed the accordion effect during carotid artery stenting (CAS) are described. Angiograms obtained just after CAS showed a stenosing lesion with wall irregularity at the distal part of the stent. This lesion disappeared and tortuosity of the internal carotid artery developed after withdrawing the guidewire until its floppy segment rested equally on the lesion. In another patient, the lesion did not disappear completely until the guiding catheter had been withdrawn to the proximal portion of the common carotid artery. We conclude that these stenosing lesions reflected the accordion effect. It is essential to differentiate the accordion effect from dissection, spasm, and thrombosis because the management is importantly different. We report our findings and present a review of the literature. (orig.)

217

Retinal Ganglion Cells are Resistant to Photoreceptor Loss in Retinal Degeneration  

OpenAIRE

The rapid and massive degeneration of photoreceptors in retinal degeneration might have a dramatic negative effect on retinal circuits downstream of photoreceptors. However, the impact of photoreceptor loss on the morphology and function of retinal ganglion cells (RGCs) is not fully understood, precluding the rational design of therapeutic interventions that can reverse the progressive loss of retinal function. The present study investigated the morphological changes in several identified RGC...

Lin, Bin; Peng, Edward Bo

2013-01-01

218

Current perspectives of herpesviral retinitis and choroiditis.  

Science.gov (United States)

Vision-threatening viral retinitis are primarily caused by members of the herpesvirus family. The biology and molecular characterization of herpesviruses, clinical presentations of retinopathies, pathology and pathogenesis including the host responses, epidemiology and the laboratory methods of aetiological diagnosis of these diseases are described. Clinical syndromes are acute retinal necrosis (ARN), progressive outer retinal necrosis (PORN), cytomegalovirus (CMV) retinitis, multifocal choroiditis and serpiginous choroiditis besides other viral retinopathies. Herpes simplex virus (HSV) retinitis is more common in immunocompetent persons while varicella zoster virus (VZV) affects both immunocompetent and immunosuppressed patients equally. CMV retinitis is most common among patients with AIDS. The currently employed laboratory methods of antigen detection, virus isolation and antibody detection by enzyme linked immuno-sorbent assay (ELISA) have low sensitivity. Polymerase chain reaction (PCR) has increased the value of diagnosis due to its high clinical sensitivity and absolute specificity in detection of herpesviruses in intraocular specimens. PMID:16295367

Madhavan, H N; Priya, K; Biswas, J

2004-10-01

219

Advances in Retinal Stem Cell Biology  

OpenAIRE

Tremendous progress has been made in recent years to generate retinal cells from pluripotent cell sources. These advances provide hope for those suffering from blindness due to lost retinal cells. Understanding the intrinsic genetic network in model organisms, like fly and frog, has led to a better understanding of the extrinsic signaling pathways necessary for retinal progenitor cell formation in mouse and human cell cultures. This review focuses on the culture methods used by different grou...

Viczian, Andrea S.

2013-01-01

220

Retinal microangiopathy in pigmented paravenous chorioretinal atrophy.  

OpenAIRE

This report describes an atypical case of pigmented paravenous chorioretinal atrophy, associated with focal progressive peripheral retinal microangiopathy, in a 51-year-old black female. The eyes were asymmetrically involved. Although several cases have been reported with typical features of this uncommon entity, none of them have been known to be associated with retinal microangiopathy. The occurrence of such microangiopathy supports the hypothesis that damage to the retinal photoreceptors m...

Limaye, S. R.; Mahmood, M. A.

1987-01-01

221

Operational challenges of retinal prostheses.  

Science.gov (United States)

Two computational models for research on retinal implants are presented. In the first model, the electric field produced by a multi-electrode array in a uniform retina is calculated. It is shown how cross talk of activated electrodes and the resulting bunching of field lines in monopole and dipole activation prevent high resolution imaging with retinal implants. Furthermore, it is demonstrated how sequential stimulation and multipolar stimulation may overcome this limitation. In the second model a target volume, i.e., a probe cylinder approximating a bipolar cell, in the retina is chosen, and the passive Heaviside cable equation is solved inside this target volume to calculate the depolarization of the cell membrane. The depolarization as a function of time indicates that shorter signals stimulate better as long as the current does not change sign during stimulation of the retina, i.e., mono-phasic stimulation. Both computational models are equally applicable to epiretinal, subretinal, and suprachoroidal vision implants. PMID:25443535

Schmid, Erich W; Fink, Wolfgang; Wilke, Robert

2014-12-01

222

Prothrombin time in retinitis pigmentosa  

Directory of Open Access Journals (Sweden)

Full Text Available The prothrombin time was recorded for 87 primary retinitis pigmentosa (RP patients belonging to three different clinical categories. All categories showed prothrombin time higher than normal. There was no correlation between the age of onset and the prothrombin time, nor between duration of disease and the prothrombin time. The high prothrombin time in patients with RP suggests that further study of prothrombin time and related factors may help in better understanding of the pathogenesis of RP.

Vinchurkar Manisha

1998-01-01

223

A Novel Retinal Identification System  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a novel biometric identification system with high performance based on the features obtained from human retinal images. This system is composed of three principal modules including blood vessel segmentation, feature generation, and feature matching. Blood vessel segmentation module has the role of extracting blood vessels pattern from retinal images. Feature generation module includes the following stages. First, the optical disk is found and a circular region of interest (ROI around it is selected in the segmented image. Then, using a polar transformation, a rotation invariant template is created from each ROI. In the next stage, these templates are analyzed in three different scales using wavelet transform to separate vessels according to their diameter sizes. In the last stage, vessels position and orientation in each scale are used to define a feature vector for each subject in the database. For feature matching, we introduce a modified correlation measure to obtain a similarity index for each scale of the feature vector. Then, we compute the total value of the similarity index by summing scale-weighted similarity indices. Experimental results on a database, including 300 retinal images obtained from 60 subjects, demonstrated an average equal error rate equal to 1 percent for our identification system.

Mohammad-Shahram Moin

2008-05-01

224

Retinal arterioles have impaired reactivity to hyperoxia in type 1 diabetes  

DEFF Research Database (Denmark)

PURPOSE: Diabetes has adverse effects on the retinal microvasculature. The purpose of this study was to compare the effects of inhalation of hypoxic, hyperoxic and normoxic-hypercapnic gas mixtures on retinal vessel diameter in people with and without diabetes. METHODS: Sixty-one participants (aged 24-50 years) 29 with (male : female ratio 2.6 : 1) and 32 without (male : female ratio 0.7 : 1) diabetes, inhaled hypoxic, hyperoxic and normoxic-hypercapnic gas mixtures for 3-5 mins. The diameters of arterioles and venules were measured using digital retinal images taken before and after gas inhalation. RESULTS: There was no significant difference in the diameters of arterioles and venules prior to gas inhalation in people with and without diabetes. Inhalation of the hyperoxic gas mixture caused a statistically significant decrease in arteriolar and venular diameters without altering mean arterial pressure significantly. Arteriolar vasoconstriction in response to the hyperoxic gas mixture was significantly reduced in people with diabetes (3.95% versus 7.75%; p = 0.04), but venular vasoconstriction did not differ significantly. A hypoxic gas mixture caused increased arteriolar and venular diameter and a normoxic-hypercapnic gas mixture had no significant effect on vessel diameter. Responses to hypoxic and normoxic-hypercapnic gas did not differ significantly between diabetes and non-diabetes subjects. CONCLUSIONS: Type 1 diabetes impairs retinal arteriolar responses to hyperoxia. Abnormalities in retinal arteriolar reactivity in response to oxygen may play a role in the development of diabetic retinopathy and this technique may represent a simple means of identifying early abnormalities in the reactivity of retinal arterioles in diabetes.

Justesen, Birgitte L; Mistry, Paresh

2010-01-01

225

A Pilot Study of Uterine Artery Embolization with Tris-Acryl Gelatin Microspheres in Guinea Pigs  

International Nuclear Information System (INIS)

Objective: This study was designed to establish guinea pigs as an animal model for uterine artery embolization (UAE) with tris-acryl gelatin microspheres (TAGM). Methods: Twenty-five female adult guinea pigs were randomly divided into two groups, including a uterine artery casting mould group (n = 10) and a UAE group (n = 15). Pelvic angiography and vascular casting mould were performed in the first group. The anatomical characters of the pelvic cavity in guinea pigs were described. In the second group, the technical feasibility of performing UAE with TAGM in guinea pigs was investigated. The histopathological slides of the uterus of guinea pigs after UAE were examined to inspect the outcomes of UAE. Results: The uterine artery springs from the internal iliac artery, ascends tortuously along the cervix, and gives off vertically 8–10 branches to the cervix uteri and uterine horns. The diameters of the trunk of the uterine artery and its first branch were 0.32 ± 0.027 mm and 0.14 ± 0.01 mm, respectively. For UAE animals, the dosages of 40–120 and 100–300 ?m TAGM were 0.033 ± 0.003 ml and 0.015 ± 0.002 ml, respectively. On histopathological slides, embosphere particles were found in the first branches of the uterine artery, the subserous arteries, and the intramural arteries. Inflammatory reactions in the uterus were common in guinea pigs after UAE. Local or dispersed areas of necrosis in uterus also were observed in a few guinea pigs. Conclusions: Guinea pigs pigs. Conclusions: Guinea pigs are an appropriate and feasible model for UAE with TAGM.

226

Superselective intra-arterial chemotherapy for advanced retinoblastoma complicated by metastatic disease.  

Science.gov (United States)

We present a case of a child with unilateral group E retinoblastoma (according to the International Classification of Retinoblastoma) who received superselective intra-arterial chemotherapy as primary therapy. Although the tumor showed signs of regression, the patient developed orbital metastases requiring surgical excision and chemotherapy. Eventually the affected eye progressed to total retinal detachment and required enucleation. PMID:25727592

Mathew, Anu A; Sachdev, Nisha; Staffieri, Sandra E; McKenzie, John D; Elder, James E

2015-02-01

227

Stability of carotid artery under steady-state and pulsatile blood flow: a fluid-structure interaction study.  

Science.gov (United States)

It has been shown that arteries may buckle into tortuous shapes under lumen pressure, which in turn could alter blood flow. However, the mechanisms of artery instability under pulsatile flow have not been fully understood. The objective of this study was to simulate the buckling and post-buckling behaviors of the carotid artery under pulsatile flow using a fully coupled fluid-structure interaction (FSI) method. The artery wall was modeled as a nonlinear material with a two-fiber strain-energy function. FSI simulations were performed under steady-state flow and pulsatile flow conditions with a prescribed flow velocity profile at the inlet and different pressures at the outlet to determine the critical buckling pressure. Simulations were performed for normal (160 ml/min) and high (350 ml/min) flow rates and normal (1.5) and reduced (1.3) axial stretch ratios to determine the effects of flow rate and axial tension on stability. The results showed that an artery buckled when the lumen pressure exceeded a critical value. The critical mean buckling pressure at pulsatile flow was 17-23% smaller than at steady-state flow. For both steady-state and pulsatile flow, the high flow rate had very little effect (stresses were drastically altered at the location with maximum deflection. The maximum lumen shear stress occurred at the inner side of the bend and maximum tensile wall stresses occurred at the outer side. These findings improve our understanding of artery instability in vivo. PMID:25761257

Saeid Khalafvand, Seyed; Han, Hai-Chao

2015-06-01

228

Acute retinal periphlebitis mimicking frosted branch angiitis associated with exudative retinal detachment after blunt eye trauma.  

Science.gov (United States)

We report a case of a 14-year-old otherwise healthy patient who developed acute retinal periphlebitis mimicking frosted branch angiitis inferotemporally and associated exudative retinal detachment in the left eye following blunt trauma. Fluorescein angiography revealed delayed filling of inferotemporal branch retinal vein and late leakage of sheathed retinal venules, and late pooling in the area of exudative retinal detachment. Indocyanine green angiography showed a crescent-shaped hypofluorescent streak concentric to the optic disk inferiorly highly suggestive of choroidal rupture. The patient was treated with oral prednisone, with gradual tapering over a period of 15 days. One month after presentation, retinal vein sheathing and exudative retinal detachment had resolved, with the development of peripapillary subretinal fibrosis, macular atrophy, pseudomacular hole, and epiretinal membrane. The acute perivenular sheathing in our patient might be related to autoimmune-mediated reaction induced by retinal vascular damage caused by severe ocular trauma. Fluorescein angiography and indocyanine green angiography findings might suggest that the retinal detachment could be caused by leakage from choroid through Bruch's membrane and retinal pigment epithelium rupture or by transient dysfunction of the outer or inner blood-retinal barrier. PMID:24912935

Kahloun, Rim; Abroug, Nesrine; Ammari, Wafa; Mahmoud, Anis; Jelliti, Bechir; Ben Yahia, Salim; Khairallah, Moncef

2014-10-01

229

Coronary artery disease (image)  

Science.gov (United States)

... through these arteries is critical for the heart. Coronary artery disease usually results from the build-up of fatty material and plaque, a condition called atherosclerosis. As the coronary arteries narrow, the flow of blood to the ...

230

Hardening of the arteries  

Science.gov (United States)

Hardening of the arteries, also called atherosclerosis, occurs when fat, cholesterol, and other substances build up in ... the arteries and cause problems throughout the body. Hardening of the arteries is a common disorder.

231

Retinal vessel diameters decrease with macular ganglion cell layer thickness in autosomal dominant optic atrophy and in healthy subjects  

DEFF Research Database (Denmark)

PURPOSE: To investigate retinal trunk vessel diameters in subjects with autosomal dominant optic atrophy (ADOA) and mutation-free healthy relatives. METHODS: This cross-sectional study included 52 ADOA patients with the optic atrophy 1 (OPA1) exon 28 (c.2826_2836delinsGGATGCTCCA) mutation (age 8.6-83.5 years) (best-corrected visual acuity (BCVA) 8-94 Early Treatment Diabetic Retinopathy Study (ETDRS) letters) and 55 mutation-free first-degree healthy relatives (age 8.9-68.7 years, BCVA 80-99). Analysis of fundus photographs provided integrated magnification-corrected measures of retinal vessel diameters (central retinal artery equivalent, CRAE, and central retinal vein equivalent, CRVE). Statistical analysis was corrected for age, gender, spherical equivalent refraction, axial length and mean arterial blood pressure (MABP) in a mixed model analysis. RESULTS: Retinal arteries and veins were thinner in ADOA than in healthy controls (CRAE (mean ± 2 standard deviations (SD)) 153.9 ± 41.0 ?m and CRVE 236.1 ± 42.0 ?m in ADOA, CRAE 172.5 ± 25.0 ?m (p = 0.0004) and CRVE 254.2 ± 37.6 ?m (p = 0.0019) in healthy controls). MABP was comparable in the two groups (p = 0.18), and in both groups, CRAE decreased with increasing MABP (p = 0.01 and p < 0.0001, respectively). In ADOA, CRAE and CRVE decreased with age (p = 0.011 and p = 0.020, respectively) and CRAE decreased with decreasing BCVA (p = 0.011). In patients with ADOA and in healthy controls, CRAE decreased with decreasing average macular ganglion cell-inner plexiform layer (GC-IPL) thickness (p = 0.0017 and p = 0.0057, respectively). CONCLUSION: Narrow retinal arteries and veins were associated not only with the severity of ADOA but with ganglion cell volume in patients with ADOA and in healthy subjects. This suggests that narrow vessels are a consequence rather than the cause of inner retinal hypoplasia or atrophy, although longitudinal studies are needed to confirm this hypothesis.

Rönnbäck, Cecilia; GrØnskov, Karen

2014-01-01

232

Preconditioning with volatile anaesthetic sevoflurane in ischemic retinal lesion in rats.  

Science.gov (United States)

Volatile anaesthetic agents have been recognized for their neuroprotective properties since the 1960s. However, little is known regarding the potential retinoprotective effects of preconditioning by anaesthetic drugs. Retinal ischemia can be modeled by permanent bilateral common carotid artery occlusion (BCCAO). Here we studied the degree of ischemic injury with preconditioning by sevoflurane in the rat retina. During the BCCAO operation and preconditioning Wistar rats were anaesthetized with 1 MAC of sevoflurane. The oxygen, carbon dioxide, and anaesthetic vapor concentration in the anaesthetizing box was monitored with a gas analyzer. We examined 4 groups: non- and preconditioning groups in control and BCCAO animals. The duration of preconditioning period was 1 h and it was performed 1 day before BCCAO. The retinas were processed for histological evaluation after 2 weeks survival to determine the cell number in the ganglion cell layer and the thickness of the whole retina and that of all retinal layers. BCCAO-induced retinal ischemic injury was ameliorated by sevoflurane preconditioning. Retinal thickness and the cell number in the ganglion cell layer were more retained in preconditioned animals after BCCAO compared to non-preconditioned group. These results suggest that preconditioning using sevoflurane could provide a new perspective in retinoprotective strategies. PMID:22684245

Szabadfi, Krisztina; Danyadi, Bese; Kiss, Peter; Manavalan, Sridharan; Gabriel, Robert; Reglodi, Dora; Tamas, Andrea; Trasy, Domonkos; Batai, Istvan

2012-10-01

233

Effect of PACAP on MAP kinases, Akt and cytokine expressions in rat retinal hypoperfusion.  

Science.gov (United States)

Pituitary adenylate cyclase activating polypeptide (PACAP) is known for its potent neuroprotective effects, including the retinoprotective actions in several types of retinal injuries. We have shown earlier that PACAP treatment causes activation of protective pathways and inhibition of pro-apoptotic signaling in excitotoxic retinal lesions. The aim of the present study was to gain insight into the in vivo protective mechanism of PACAP in retinal hypoperfusion injury induced by bilateral common carotid artery occlusion (BCCAO). Rats underwent BCCAO and received intravitreal PACAP (PACAP38) treatment. We investigated the activation level of the protective Akt pathway as well as the different mitogen activated protein kinases (MAPKs) by Western blot analysis and the expression of cytokines using a cytokine array kit. We found that PACAP treatment alone did not influence the phosphorylation of Akt or the MAPKs, but decreased the hypoperfusion-induced activation of both p38MAPK and JNK and increased the activation of the protective Akt and ERK1/2 in hypoperfused retinas. The cytokine profile was dramatically changed after BCCAO, with most cytokines and chemokines showing an increase, which was attenuated by PACAP (such as CINC, CNTF, fractalkine, sICAM, IL-1, LIX, Selectin, MIP-1, RANTES and TIMP-1). In addition, PACAP increased the expression of VEGF and thymus chemokine. The present results provide further insight into the neuroprotective mechanism induced by PACAP in ischemic retinal injuries, showing that PACAP ameliorates hypoperfusion injury involving Akt, MAPK pathways and anti-inflammatory actions. PMID:22750211

Szabo, Aliz; Danyadi, Bese; Bognar, Eszter; Szabadfi, Krisztina; Fabian, Eszter; Kiss, Peter; Mester, Laszlo; Manavalan, Sridharan; Atlasz, Tamas; Gabriel, Robert; Toth, Gabor; Tamas, Andrea; Reglodi, Dora; Kovacs, Krisztina

2012-08-15

234

Nampt/PBEF/visfatin serum levels: a new biomarker for retinal blood vessel occlusions  

Science.gov (United States)

The main objective of the study was to quantify serum levels of nicotinamide phosphoribosyltransferase (Nampt/pre-B-Cell colony-enhancing factor 1/visfatin) in subjects with a history of retinal vascular occlusions (RVOs), disease conditions characterized by pronounced ischemia, and metabolic energy deficits. A case–control study of 18 subjects with a history of RVO as well as six healthy volunteers is presented. Serum Nampt levels were quantified using a commercially available enzyme-linked immunosorbent assay kit. Serum Nampt levels were 79% lower in patients with a history of RVO compared with that in healthy volunteers (P<0.05). There was no statistically significant difference among the types of RVOs, specifically branch retinal vein occlusions (n=7), central retinal vein occlusions (n=5), hemiretinal vein occlusions (n=3), and central retinal artery occlusions (n=3; P=0.69). Further studies are needed to establish the temporal kinetics of Nampt expression and to determine whether Nampt may represent a novel biomarker to identify at-risk populations, or whether it is a druggable target with the potential to ameliorate the long-term complications associated with the condition, ie, macular edema, macular ischemia, neovascularization, and permanent loss of vision.

Kaja, Simon; Shah, Anna A; Haji, Shamim A; Patel, Krishna B; Naumchuk, Yuliya; Zabaneh, Alexander; Gerdes, Bryan C; Kunjukunju, Nancy; Sabates, Nelson R; Cassell, Michael A; Lord, Ron K; Pikey, Kevin P; Poulose, Abraham; Koulen, Peter

2015-01-01

235

[Arterial stenosis after radiotherapy].  

Science.gov (United States)

Published reports of arterial stenosis following radiotherapy are reviewed. In oncological practice, this complication is rare but experimental studies have demonstrated the role of irradiation in producing arterial lesions. The histological specificity and the mechanisms of radiation and related arterial lesions are discussed. Atherosclerosis risk factors and chemotherapy could have a synergic role on artery stenosis. Cases reported of arterial stenosis after radiotherapy include subclavicular artery after breast cancer, carotid artery after head and neck cancer, coronary artery and abdominal aorta or its trunks after pelvic and abdominal irradiation. The radiotherapy parameters described are not unusual. Therapeutical modalities and their indications are presented. PMID:8703540

Piedbois, P; Becquemin, J P; Pierquin, B; Blanc, I; Mazeron, J J; Pavlovitch, J M; Otmezguine, Y; Calitchi, E; Brun, B; Feuilhade, F

1990-01-01

236

Arterial stenosis following radiotherapy  

International Nuclear Information System (INIS)

Published reports of arterial stenosis following radiotherapy are reviewed. In oncological practice, this complication is rare but experimental studies have demonstrated the role of irradiation in producing arterial lesions. The histological specificity and the mechanisms of radiation and related arterial lesions are discussed. Atherosclerosis risk factors and chemotherapy could have a synergic role on artery stenosis. Cases reported of arterial stenosis after radiotherapy include subclavicular artery after breast cancer, carotid artery after head and neck cancer, coronary artery and abdominal aorta or its trunks after pelvic and abdominal irradiation. The radiotherapy parameters described are not unusual. Therapeutical modalities and their indications are presented

237

Uterine artery embolization with Pingyangmycin lipiodol emulsion for treatment of symptomatic uterine fibroids  

International Nuclear Information System (INIS)

Objective: To evaluate the effectiveness and side effects of uterine arterial embolization with Pingyangmycin(a homogenous bleomycin) lipiodol emulsion(PLE) for symptomatic uterine fibroids. Methods: Uterine arterial embolization with PLE was performed in 25 patients. The improvement of symptoms and uterine size changes were followed up in 3-18 months(mean 6 months) after the procedure. Results: All but 2 cases were successfully treated bilaterally. Super-selective angiography showed enlargement of uterine artery, accompanied by tortuous branches. The uterine size was increased. The uterus itself was significantly stained and emptied slowly. Coagulation necrosis was found in resected fibroids after embolization in 3 patients. One month after the procedure, a mean 40% reduction of uterine volume was obtained in 18 followed-up cases. The clinical symptoms were relieved significantly. The main side effects were hypogastric pain(13/25),which was intense in 6 cases. Conclusion: Uterine arterial embolization with PLE is a good non-surgical therapy in symptomatic uterine fibroids with mild side effects

238

Homocysteine, MTHFR C677T gene polymorphism, folic acid and vitamin B 12 in patients with retinal vein occlusion  

OpenAIRE

Abstract Background Many available data have suggested that hyperhomocysteinaemia, an established independent risk factor for thrombosis (arterial and venous), may be associated with an increased risk of retinal vein occlusion (RVO). Aim of the study To evaluate homocysteine metabolism in consecutive caucasian patients affected by RVO from Northern Italy. Patients and Methods 69 consecutive patients from Northern Italy (mean age 64.1 ± 14.6 yy) with recent RVO, were tested for plasma levels ...

Gaspari Giorgio; Bellatorre Alessandro; Rossi Lisa; Quaglia Ilaria; Di Micco Pierpaolo; Ferrazzi Paola; Rota Lidia; Lodigiani Corrado

2005-01-01

239

Massive hemoptysis due to pulmonary tuberculosis: management with bronchial artery embolization  

International Nuclear Information System (INIS)

Objective: To evaluate the clinical effects of interventional bronchial artery embolization in the management of massive hemoptysis as a complication of pulmonary tuberculosis. Methods: Interventional bronchial arterial embolization was performed in 26 cases with secondary pulmonary tuberculosis and massive hemoptysis. Tuberculosis was found in bilateral lung in 20 cases out of 26. Unilateral lung was evolved in the rest 6. The dose of hemoptysis was 200 ml/d-1200 ml/d. Bronchial arteriography was undertaken and the target blood vessel was confirmed in all patients. Then PVA grain or silk segment (1-2 mm) were injected into bronchial artery until blood flow was blocked. The procedures were guided under the fluoroscopy. Gelfoam particles were used in 2 cases when tortuous feeding arteries were revealed in angiogram. Results: Bleeding was demonstrated in 58 branches of bronchial artery in all cases. 19 cases were bilateral and 7 unilateral. After the primary intervention, hemoptysis was controlled completely in 23 patients, slight hemoptysis was noted in 2 patients, and no improvement was obtained in one patient. The short term efficiency was 96.1%. No serious complication occurred. In a post-interventional follow up of 6 months to 6 years, 3 patients had relapse after 6 months and reembolization with silk segments was done. The other 23 patients were in stable condition. Long-term efficiency was 88.4%. Conclusion: Embolization of bronchial artery with PVA grain or withof bronchial artery with PVA grain or with silk segments is an effective and safe method in the management of hemoptysis as a complication of pulmonary tuberculosis, especially in patients with severe hemoptysis. The anti-tuberculosis chemotherapy is helpful in preventing the relapse. (authors)

240

[Percutaneous occlusion of arterial vessels using permanent embolization for the treatment of an air sac hemorrhage in horses. A case report].  

Science.gov (United States)

This article reports a case of guttural pouch bleeding which was managed successfully by using intravascular embolisation systems to occlude the damaged vessels. Percutaneous catheterisation of the common carotid artery allowed angiographic visualisation of the main head arteries: A. carotis externa, A. carotis interna and A. occipitalis, which showed no abnormalities angiographically. Originating from the A. occipitalis, one artery sent smaller, extensively branching and tortuous vessels to the guttural pouch area. This branching was interpreted as a sign of inflammatory hypervascularization. The artery was occluded by positioning of a detachable balloon distally of the origin of the two small vessels. Insertion of two coils in the A. occipitalis proximally of the origin of this artery completed the embolisation. Occlusion of the distal part was necessary to avoid blood supply to the lesion from the contralateral arterial system via the circle of Willis. The technique used allowed occlusion of a selected head artery without direct surgical intervention in this area. There is no need to remove the implants. After catheterisation, no more episodes of epistaxis occurred. The causing diphtheroid inflammation in the guttural pouch was treated by local infusions of iodine-solutions and resolved completely within 24 days. PMID:9710924

Schneider, M; Fey, K; Tellhelm, B; Litzke, L F; Sasse, H H

1998-07-01

241

Arterial pulse modulates steady-state ocular accommodation.  

Science.gov (United States)

Rapid and continuous fluctuations in ocular focus are known to occur when the eye views a stationary target. The advent of high-speed infra-red optometers has established that these microfluctuations of ocular accommodation have two dominant components: low frequency of less than 0.6 Hz and high frequency between 1.0-2.3Hz. Although the retinal image blur associated with microfluctuations has the potential to guide and maintain optimum accommodation levels, there is no consensus with regard to the respective contribution of each of the dominant frequency components. Using a newly-designed measurement and recording system we show that, when viewing a stationary target located at 25cm, individuals exhibit little variation in the frequency of low frequency components but significant variation in high frequency components. Simultaneous measurements of ocular accommodation and systemic arterial pulse demonstrate that the variation in high frequency component is significantly correlated with arterial pulse frequency. Since control experiments indicate that the microfluctuations are derived from activity of the crystalline lens our observations could provide the basis for a non-invasive method of assessing the effects of arterial pulse on ciliary body/choroidal vasculature, the vitreous/lens interface and intraocular pressure. Further, it is feasible that under certain conditions an abnormal increase in the magnitude of arterial pulse may affect the aggregate nature of accommodative microfluctuations to an extent that disrupts the normal control processes maintaining optimum retinal contrast during sustained near vision. PMID:2276274

Winn, B; Pugh, J R; Gilmartin, B; Owens, H

1990-10-01

242

Review: Retinal degeneration: Focus on the unfolded protein response  

OpenAIRE

Recently published literature has provided evidence that the unfolded protein response (UPR) is involved in the development of retinal degeneration. The scope of these studies encompassed diabetic retinopathy, retinopathy of prematurity, glaucoma, retinal detachment, light-induced retinal degeneration, age-related macular degeneration, and inherited retinal degeneration. Subsequent studies investigating the role of individual UPR markers in retinal pathogenesis and examining the therapeutic p...

Gorbatyuk, Marina; Gorbatyuk, Oleg

2013-01-01

243

A mechanical model of retinal detachment.  

Science.gov (United States)

We present a model of the mechanical and fluid forces associated with exudative retinal detachments where the retinal photoreceptor cells separate, typically from the underlying retinal pigment epithelium (RPE). By computing the total fluid volume flow arising from transretinal, vascular and RPE pump currents, we determine the conditions under which the subretinal fluid pressure exceeds the maximum yield stress holding the retina and RPE together, giving rise to an irreversible, extended retinal delamination. We also investigate localized, blister-like retinal detachments by balancing mechanical tension in the retina with both the retina-RPE adhesion energy and the hydraulic pressure jump across the retina. For detachments induced by traction forces, we find a critical radius beyond which the blister is unstable to growth. Growth of a detached blister can also be driven by inflamed lesions in which the tissue has a higher choroidal hydraulic conductivity, has insufficient RPE pump activity, or has defective adhesion bonds. We determine the parameter regimes in which the blister either becomes unstable to growth, remains stable and finite-sized, or shrinks, allowing possible healing. The corresponding stable blister radius and shape are calculated. Our analysis provides a quantitative description of the physical mechanisms involved in exudative retinal detachments and can help guide the development of retinal reattachment protocols or preventative procedures. PMID:22733081

Chou, Tom; Siegel, Michael

2012-08-01

244

Genomic Analysis of Mouse Retinal Development  

Directory of Open Access Journals (Sweden)

Full Text Available The vertebrate retina is comprised of seven major cell types that are generated in overlapping but well-defined intervals. To identify genes that might regulate retinal development, gene expression in the developing retina was profiled at multiple time points using serial analysis of gene expression (SAGE. The expression patterns of 1,051 genes that showed developmentally dynamic expression by SAGE were investigated using in situ hybridization. A molecular atlas of gene expression in the developing and mature retina was thereby constructed, along with a taxonomic classification of developmental gene expression patterns. Genes were identified that label both temporal and spatial subsets of mitotic progenitor cells. For each developing and mature major retinal cell type, genes selectively expressed in that cell type were identified. The gene expression profiles of retinal Müller glia and mitotic progenitor cells were found to be highly similar, suggesting that Müller glia might serve to produce multiple retinal cell types under the right conditions. In addition, multiple transcripts that were evolutionarily conserved that did not appear to encode open reading frames of more than 100 amino acids in length ("noncoding RNAs" were found to be dynamically and specifically expressed in developing and mature retinal cell types. Finally, many photoreceptor-enriched genes that mapped to chromosomal intervals containing retinal disease genes were identified. These data serve as a starting point for functional investigations of the roles of these genes in retinal development and physiology.

Blackshaw Seth

2004-01-01

245

Retinitis pigmentosa, pigmentary retinopathies, and neurologic diseases.  

Science.gov (United States)

Retinitis pigmentosa (RP) refers to a group of inherited retinal diseases with phenotypic and genetic heterogeneity. The pathophysiologic basis of the progressive visual loss in patients with RP is not completely understood but is felt to be due to a primary retinal photoreceptor cell degenerative process mainly affecting the rods of the peripheral retina. In most cases RP is seen in isolation (nonsyndromic), but in some other cases it may be a part of a genetic, metabolic, or neurologic syndrome or disorder. Nyctalopia, or night blindness, is the most common symptom of RP. The classic fundus appearance of RP includes retinal pigment epithelial cell changes resulting in retinal hypo- or hyperpigmentation ("salt-and-pepper"), retinal granularity, and bone spicule formation. The retinal vessels are often narrowed or attenuated and there is a waxy pallor appearance of the optic nerve head. Electroretinography will demonstrate rod and cone photoreceptor cell dysfunction and is a helpful test in the diagnosis and monitoring of patients with RP. A detailed history with pedigree analysis, a complete ocular examination, and the appropriate paraclinical testing should be performed in patients complaining of visual difficulties at night or in dim light. This review discusses the clinical manifestations of RP as well as describing the various systemic diseases, with a special emphasis on neurologic diseases, associated with a pigmentary retinopathy. PMID:16928351

Bhatti, M Tariq

2006-09-01

246

Digital tracking and control of retinal images  

Science.gov (United States)

Laser induced retinal lesions are used to treat a variety of eye diseases such as diabetic retinopathy and retinal detachment. An instrumentation system has been developed to track a specific lesion coordinate on the retinal surface and provide corrective signals to maintain laser position on the coordinate. High resolution retinal images are acquired via a CCD camera coupled to a fundus camera and video frame grabber. Optical filtering and histogram modification are used to enhance the retinal vessel network against the lighter retinal background. Six distinct retinal landmarks are tracked on the high contrast image obtained from the frame grabber using two-dimensional blood vessel templates. The frame grabber is hosted on a 486 PC. The PC performs correction signal calculations using an exhaustive search on selected image portions. An X and Y laser correction signal is derived from the landmark tracking information and provided to a pair of galvanometer steered mirrors via a data acquisition and control subsystem. This subsystem also responds to patient inputs and the system monitoring lesion growth. This paper begins with an overview of the robotic laser system design followed by implementation and testing of a development system for proof of concept. The paper concludes with specifications for a real time system.

Barrett, Steven F.; Jerath, Maya R.; Rylander, Henry G., III; Welch, Ashley J.

1993-06-01

247

Bilateral acute retinal necrosis after herpetic meningitis  

Directory of Open Access Journals (Sweden)

Full Text Available Keisho Hirota1,2, Masayuki Akimoto1,3, Toshiaki Katsura21Department of Ophthalmology, Kyoto Medical Center, National Hospital Organization, 2Internal Medicine, Kyoto Medical Center, 3Clinical Research Center, Kyoto Medical Center, Kyoto, JapanPurpose: The report of a case of bilateral acute retinal necrosis after herpetic meningitis.Case report: A 47-year-old man was admitted with the chief complaint of persistent high fever and transient loss of consciousness. Although his general condition improved after intravenous acyclovir administration, the patient presented with visual loss in both eyes 4 days after admission. Visual acuity in his right eye was 20/200 and his left eye had light perception alone. Both eyes showed panretinal arteritis diagnosed as acute retinal necrosis. Panretinal photocoagulation was performed for both eyes. Progression of retinal detachment was prevented in both eyes; however, visual acuity of the left eye was totally lost because of neovascular glaucoma. Visual acuity of the right eye recovered to 20/20.Conclusion: Although cases of bilateral acute retinal necrosis have been reported after herpetic encephalitis, this condition is rare after herpetic meningitis. Prophylactic acyclovir therapy and early panretinal photocoagulation may prevent retinal detachment and improve the prognosis. Neurologists and ophthalmologists should be aware that not only herpetic encephalitis but also herpetic meningitis can lead to acute retinal necrosis within a very short interval.Keywords: acute retinal necrosis, herpetic meningitis, herpes simplex, varicella zoster virus

Katsura T

2012-04-01

248

A mechanical model of retinal detachment  

Science.gov (United States)

We present a model of the mechanical and fluid forces associated with exudative retinal detachments where the retinal photoreceptor cells separate, typically from the underlying retinal pigment epithelium (RPE). By computing the total fluid volume flow arising from transretinal, vascular and RPE pump currents, we determine the conditions under which the subretinal fluid pressure exceeds the maximum yield stress holding the retina and RPE together, giving rise to an irreversible, extended retinal delamination. We also investigate localized, blister-like retinal detachments by balancing mechanical tension in the retina with both the retina-RPE adhesion energy and the hydraulic pressure jump across the retina. For detachments induced by traction forces, we find a critical radius beyond which the blister is unstable to growth. Growth of a detached blister can also be driven by inflamed lesions in which the tissue has a higher choroidal hydraulic conductivity, has insufficient RPE pump activity, or has defective adhesion bonds. We determine the parameter regimes in which the blister either becomes unstable to growth, remains stable and finite-sized, or shrinks, allowing possible healing. The corresponding stable blister radius and shape are calculated. Our analysis provides a quantitative description of the physical mechanisms involved in exudative retinal detachments and can help guide the development of retinal reattachment protocols or preventative procedures.

Chou, Tom; Siegel, Michael

2012-08-01

249

Retinal vein occlusion: genetic predisposition and systemic risk factors.  

Science.gov (United States)

The role of systemic risk factors (age, smoking, diabetes, arterial hypertension) in the development of retinal vein occlusion (RVO) is well established. However, the association of RVO with genetic predisposition to thrombosis remains poorly understood. The aim of the study was to assess any possible additional effect of genetic predisposition to the already well known 'classical' risk factors of RVO in a cohort of elderly Greek patients. Fifty-one elderly patients with RVO and 51 healthy individuals matched for age and sex were evaluated for systemic risk factors (smoking, diabetes, dyslipidemia, arterial hypertension) and coagulation defects (lupus anticoagulant, natural inhibitors of coagulation). Additionally, genotyping was performed for mutations/polymorphisms involved in haemostasis such as: FV G1691A, FV G4070A, FIIG 20210A, MTHFR C677T and A1298C, PAI-1-675 4G/5G, F XIII exon 2G/T, EPCR A4600G and G4678C. We identified systemic risk factors in the majority of the patients Hypertension (P=0.001), dyslipidemia (P=0.029) and diabetes (P=0.01) are associated with RVO in the majority of the patients. The prevalence of prothrombotic risk factors was not significantly different in the patients with RVO compared to controls. Apart from systemic risk factors, genetic predisposition to thrombosis does not seem to have an important association with RVO in this group of elderly patients. PMID:23337712

Giannaki, Kassiani; Politou, Marianna; Rouvas, Alexandros; Merkouri, Efrossyni; Travlou, Anthi; Theodosiadis, Panayiotis; Gialeraki, Argyri

2013-04-01

250

Retinal Remodeling in the Tg P347L Rabbit, a Large-Eye Model of Retinal Degeneration  

OpenAIRE

Retinitis pigmentosa (RP) is an inherited blinding disease characterized by progressive loss of retinal photo-receptors. There are numerous rodent models of retinal degeneration, but most are poor platforms for interventions that will translate into clinical practice. The rabbit possesses a number of desirable qualities for a model of retinal disease including a large eye and an existing and substantial knowledge base in retinal circuitry, anatomy, and ophthalmology. We have analyzed degenera...

Jones, Bryan William; Kondo, Mineo; Terasaki, Hiroko; Watt, Carl Brock; Rapp, Kevin; Anderson, James; Lin, Yanhua; Shaw, Marguerite Victoria; Yang, Jia-hui; Marc, Robert Edward

2011-01-01

251

Computational molecular phenotyping of retinal sheet transplants to rats with retinal degeneration  

OpenAIRE

Retinal progenitor sheet transplants have been shown to extend neuronal processes into a degenerating host retina and to restore visual responses in the brain. The aim of this study was the first attempt to identify cells involved in transplant signals to retinal degenerate hosts using computational molecular phenotyping (CMP). - S334ter line 3 rats received fetal retinal sheet transplants at the age of 24-40d. Donor tissues were incubated with slow-releasing microspheres containing BDNF or G...

Seiler, M. J.; Jones, B. W.; Aramant, R. B.; Yang, P. B.; Keirstead, H. S.; Marc, R. E.

2012-01-01

252

Missense Mutations in a Retinal Pigment Epithelium Protein, Bestrophin-1, Cause Retinitis Pigmentosa  

OpenAIRE

Bestrophin-1 is preferentially expressed at the basolateral membrane of the retinal pigmented epithelium (RPE) of the retina. Mutations in the BEST1 gene cause the retinal dystrophies vitelliform macular dystrophy, autosomal-dominant vitreochoroidopathy, and autosomal-recessive bestrophinopathy. Here, we describe four missense mutations in bestrophin-1, three that we believe are previously unreported, in patients diagnosed with autosomal-dominant and -recessive forms of retinitis pigmentosa (...

Davidson, Ae; Millar, Id; Urquhart, Je; Burgess-mullan, R.; Shweikh, Y.; Parry, N.; O Sullivan, J.; Maher, Gj; Mckibbin, M.; Downes, Sm; Lotery, Aj; Jacobson, Sg; Brown, Pd; Black, Gc; Manson, Fd

2009-01-01

253

Management of inferior retinal breaks during pars plana vitrectomy for retinal detachment  

OpenAIRE

AIMS—To determine whether it is necessary to support inferior retinal breaks with a scleral explant during pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RD).?METHODS—A prospective study was carried out on nine eyes of nine consecutive patients undergoing PPV for primary RD with associated inferior retinal breaks and no significant proliferative vitreoretinopathy.?RESULTS—Eight eyes were successfully reattached with a single operation. No cases presented with red...

Tanner, V.; Minihan, M.; Williamson, T.

2001-01-01

254

Photostress Testing Device for Diagnosing Retinal Disease  

Directory of Open Access Journals (Sweden)

Full Text Available Retinal diseases such as Age-Related Macular Degeneration (ARMD affect nearly one in three elderly patients. ARMD damages the central vision photoreceptors in the fovea. The Photostress Test is a simple technique for testing for the early effects of ARMD. Here, the illumination sources in a novel self-administered Photostress Testing device were modeled for safety and distribution in illumination software. After satisfying the design constraints in the model, a prototype of the illumination system was fabricated and tested to confirm the modeling results. The resultant prototype can be used to aid in the diagnosis of retinal disease and is well within retinal safety levels.

Elizabeth Swan

2014-08-01

255

[New drug therapy for retinal degeneration].  

Science.gov (United States)

Retinitis pigmentosa (RP) is an inherited retinal degeneration characterized by nyctalopia, ring scotoma, and bone-spicule pigmentation of the retina. So far, no effective therapy has been found for RP. As a possible molecular etiology of RP, retina-specific gene deficits are most likely involved, but little has been identified in terms of intracellular mechanisms leading to retinal photoreceptor cell death at post-translational levels. In order to find an effective therapy for RP, we must look for underlying common mechanisms that are responsible for the development of RP, instead of designing a specific therapy for each of the RP types with different causes. Therefore, in the present study, several animal models with different causes of RP were studied, including (1)Royal College of Surgeons (RCS) rats with a deficit of retinal pigment epithelium (RPE) function caused by rhodopsin mutation; (2) P23H rats, (3) S334ter rats, (4) photo stress rats, (5) retinal degeneration (rd) mice with a deficit of phosphodiesterase(PDE) function; and (6) cancer-associated retinopathy (CAR) model rats with a deficit of recoverin-dependent photoreceptor adaptation function. In each of these models, the following assessments were made in order to elucidate common pathological mechanisms among the models: (1) retinal function assessed by electroretinogram (ERG), (2) retinal morphology, (3) retinoid analysis, (4) rhodopsin regeneration, (5) rhodopsin phosphorylation and dephosphorylation, and (6) cytosolic cGMP levels. We found that unregulated photoreceptor adaptation processes caused by an imbalance of rhodopsin phosphorylation and dephosphorylation caused retinal dysfunction leading to photoreceptor cell death. As possible candidate drugs for normalizing these retinal dysfunctions and stopping further retinal degeneration, nilvadipine, a Ca channel blocker, retinoid derivatives, and anthocyanine were chosen and tested to determine their effect on the above animal models with retinal degeneration. Nilvadipine showed beneficial effects against retinal degeneration in all models tested, but retinoid derivatives and anthocyanine showed these beneficial effects in only some models. Thus our present data allowed us to test the effectiveness of nilvadipine in the treatment of human RP patients. PMID:18240599

Ohguro, Hiroshi

2008-01-01

256

Chickenpox-associated acute retinal necrosis syndrome.  

Science.gov (United States)

Acute retinal necrosis (ARN) syndrome usually occurs as the result of secondary reactivation of latent, previously acquired, varicella-zoster or herpes simplex virus. The authors report four patients who developed a mild form of ARN within 1 month (5 to 28 days) after the onset of chickenpox. In contrast to typical cases of ARN, these cases were less severe, with retinitis limited to two quadrants or less (three patients), no retinal detachment (four patients), minimal vitreitis (four patients), and no loss of visual acuity (four patients). Thus, ARN may occur during the course of primary varicella-zoster infection. PMID:1666176

Culbertson, W W; Brod, R D; Flynn, H W; Taylor, B C; Brod, B A; Lightman, D A; Gordon, G

1991-11-01

257

Bilateral pericallosal arterial ectasia  

Energy Technology Data Exchange (ETDEWEB)

We report a rare case of ectasia of both pericallosal arteries in a non-hypertensive 37-year-old female, whose internal carotid arteries and vertebrobasilar arteries were normal. The computed tomography (CT) showed irregular calcifications in the midline in the frontal region extending to the corpus callosum, which became partially enhanced along the course of the pericallosal artery following intravenous contrast administration. The diagnosis of arterial ectasia was established by angiography.

Tsukamoto, Y.; Nakata, H.; Soejima, T.; Yamamoto, H.; Araki, R.

1985-05-01

258

Basilar artery dissection.  

OpenAIRE

Dissection of the basilar artery caused sudden coma and death in a 40-year-old man. Atypical clinical features were explained at necropsy. A ventral dissection of the artery within its outer layers resulted in destruction of the pontine tegmentum with sparing of the basis pontis. An unsuspected defect in the internal elastic lamina in the left internal carotid artery was also found suggesting a more generalised disorder of arterial walls. Basilar artery dissection should be considered in the ...

Berkovic, S. F.; Spokes, R. L.; Anderson, R. M.; Bladin, P. F.

1983-01-01

259

Automatic diagnosis of retinal diseases from color retinal images  

CERN Document Server

Teleophthalmology holds a great potential to improve the quality, access, and affordability in health care. For patients, it can reduce the need for travel and provide the access to a superspecialist. Ophthalmology lends itself easily to telemedicine as it is a largely image based diagnosis. The main goal of the proposed system is to diagnose the type of disease in the retina and to automatically detect and segment retinal diseases without human supervision or interaction. The proposed system will diagnose the disease present in the retina using a neural network based classifier.The extent of the disease spread in the retina can be identified by extracting the textural features of the retina. This system will diagnose the following type of diseases: Diabetic Retinopathy and Drusen.

Jayanthi, D; SwarnaParvathi, S

2010-01-01

260

Coronary artery to pulmonary artery fistula  

Science.gov (United States)

Patient: Male, 69 Final Diagnosis: Coronary artery to pulmonary artery fistula Symptoms: Chest pain Medication: — Clinical Procedure: Echocardiography • angiography • surgical intervention Specialty: Cardiology • Cardiac Surgery Objective: Rare disease Background: A coronary artery fistula is an abnormal communication between a coronary artery and one of the cardiac chambers or a great vessel, so bypassing the myocardial capillary network. They are usually discovered incidentally upon coronary angiography. Clinical manifestations are variable depending on the type of fistula, the severity of shunt, site of shunt, and presence of other cardiac condition. Case Report: We report a 69-year-old man without any previous medical history, who was admitted to our hospital with chest pain. The electrocardiogram (ECG) showed a sinus rhythm with ST depression in V2 to V6 precordial leads. Coronary angiography revealed a coronary artery fistula from left anterior descending coronary artery (LAD) to the main pulmonary artery, right coronary artery blockage and significant stenoses on the LAD and left circumflex artery (LCX). Conclusions: Surgical treatment was chosen because of the total occlusion of the right coronary artery and to relieve of pain to improve quality of life. PMID:24298301

Dadkhah-Tirani, Heidar; Salari, Arsalan; Shafighnia, Shora; Hosseini, Seyed Fazel; Naghdipoor, Misa

2013-01-01

261

Changes in the retrobulbar arterial circulation after decrease of the elevated intraocular pressure in men and women with primary open angle glaucoma  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction. An altered perfusion of the optic nerve head has been proposed as a pathogenic factor of glaucoma. Objective. The aim of this study was to evaluate the changes of the hemodynamic parameters in the retrobulbar arterial circulation after decrease of the elevated intraocular pressure (IOP in women and men with primary open angle glaucoma. Methods. The study included 60 patients (33 males and 27 females older than 50 years, with diagnosed and treated primary open angle glaucoma (77 eyes of 39 patients had increased IOP, >25 mm Hg. They were examined at the Clinic of Eye Diseases (complete ophthalmologic exam and Clinic of Neurology, Clinical Center of Serbia, Belgrade, from December 2009 to December 2010. Imaging of hemodynamic parameters of three retrobulbar arterial vessels: ophthalmic, central retinal and posterior ciliary arteries with color Doppler was performed. Results. Among women, hemodynamic arterial parameter of the peak-systolic velocity was increased in the central retinal artery and decreased in the ophthalmic artery and posterior ciliary arteries; end- diastolic velocity was increased in all three retrobulbar vascular levels; Pourcelot resistivity index was increased, but pulsatility index was decreased in all three vessels. Among men, peak-systolic velocity, end-diastolic velocity and pulsatility index were decreased in all three vessels; resistivity index was increased in the ophthalmic artery, but decreased in the central retinal artery and posterior ciliary arteries. There was a significant change of the ophthalmic artery pulsatility index in women, and the end-diastolic velocity of the ophthalmic artery in men. Conclusion. There was a difference of the retrobulbar arterial circulation between women and men with primary open angle glaucoma after decrease of the elevated intraocular pressure. The role of vascular factors in the supply of the optic disc neuroretinal rim is important.

Marjanovi? Ivan

2013-01-01

262

New Device Offers Hope to People Blinded Due to Incurable Eye Disorders (Retinitis Pigmentosa)  

Science.gov (United States)

... first FDA-approved retinal implant for adults with retinitis pigmentosa. Retinitis pigmentosa is a group of genetic disorders that affect ... Up to one-quarter of all patients with retinitis pigmentosa will become legally blind in both eyes. [ii] ...

263

Retinal degeneration and local oxygen metabolism.  

Science.gov (United States)

Vision loss due to various forms of outer retinal degeneration remains a major problem in clinical ophthalmology. Most retinal degenerations are precipitated by genetic mutations affecting the retinal pigment epithelium and sensory retina, but it is becoming increasingly evident that resultant metabolic changes within the retina may also contribute to the further progression of photoreceptor cell loss. In particular, a role for the local oxygen environment within the retina has been proposed. The correct balance between retinal oxygen supply and oxygen consumption in the retina is essential for retinal homeostasis, and disruption of this balance is a factor in many retinal diseases. In animal models of photoreceptor degeneration, manipulation of environmental oxygen levels has been reported to be able to modulate the rate of photoreceptor degeneration. Clinically, hyperbaric oxygen therapy has already been used in retinitis pigmentosa patients and other types of oxygen therapy have been proposed. It therefore seems appropriate to review our current understanding of the oxygen environment in the normal and degenerating retina, and to build a clearer picture of how the retinal oxygen environment can be modulated. We focus on techniques that have been, or may be, applied clinically, such as modulation of systemic oxygen levels and modulation of retinal oxygen metabolism by light deprivation. Data from direct measurements of intraretinal oxygen distribution in rat models at different stages of photoreceptor degeneration will be reviewed. These models include the Royal College of Surgeons (RCS) rat, and the P23H rat model of outer retinal degeneration. Microelectrode based techniques have allowed the intraretinal oxygen distribution to be measured as a function of retinal depth under well-controlled systemic conditions at different stages of the degeneration process. Both models showed changes in the intraretinal oxygen distribution during the degenerative period, with the changes reflecting the gradual loss of oxygen metabolism of the degenerating photoreceptors. This results in higher than normal oxygen levels in the remaining outer retina and a significant alteration in the oxygen flux from the choroid to the inner retina. The maintenance of normal oxygen levels in the inner retina implies that inner retinal oxygen uptake is well preserved, and that there is also reduced oxygen input from the deeper capillary layer of the retinal circulation. Choroidal oxygen tension and the oxygen tension in the pre-retinal vitreous were unaffected at any of the time periods studied prior to, and during, the degeneration process. It is well known that both hypoxia and hyperoxia can cause neural cell stress and damage. Logically, any therapeutic intervention based on oxygen therapy should attempt to restore the oxygen environment of the remaining retinal cells to within the physiological range. Before any oxygen based therapies for the treatment of retinal degeneration should be seriously considered, the oxygen environment in the degenerating retina should be determined, along with clinically usable methods to restore the oxygen environment to the critical cell layers. PMID:15939030

Yu, Dao-Yi; Cringle, Stephen J

2005-06-01

264

Retinal breaks due to intravitreal ocriplasmin  

Directory of Open Access Journals (Sweden)

Full Text Available Ruwan A Silva, Darius M Moshfeghi, Theodore Leng Byers Eye Institute at Stanford, Stanford University School of Medicine, Palo Alto, CA, USA Abstract: Ocriplasmin represents a new treatment option for numerous vitreoretinopathies involving an abnormal vitreomacular interface. While the drug may circumvent the traditional risks of surgical treatment, pharmacologic vitreolysis is not devoid of risk itself. This report presents two cases, one of vitreomacular traction syndrome and the other of a full-thickness macular hole, both of which were treated with an intravitreal injection of ocriplasmin. Notably, in both cases, vitreomacular traction of the macula appears to have been alleviated; however, failure to completely relieve vitreoretinal traction from the peripheral retina generated retinal breaks with one patient eventually developing a macula-involving retinal detachment. Thus, even in instances of ‘successful’ pharmacologic treatment of vitreomacular traction, continued follow-up evaluation is essential. Keywords: posterior vitreous detachment, retinal detachment, vitreomacular traction, ocriplasmin, retinal break, macular hole, laser retinopexy

Silva RA

2014-08-01

265

[Retinal detachment. The vitrectomy technique].  

Science.gov (United States)

One hundred and ten eyes from 110 patients who in 1992 had undergone vitrectomy for regmatogenous retinal detachment were included in a retrospective study. Two year follow-up was obtained for 97 eyes. At the end of follow-up 45% of the eyes had complete anatomical success. Fifty-five percent had attachment of the macula. Anatomical success after a single operation was obtained in 33%. A visual acuity of more than 0.05 was obtained for 35% of the eyes at the end of follow-up. Eighty patients had a follow-up interview; of these 56% stated that the advantages of the operation outweighed the disadvantages. PMID:9446262

de la Cour, M D; Nielsen, N V; Scherfig, E

1997-12-29

266

Multimodal Imaging in Hereditary Retinal Diseases  

OpenAIRE

Introduction. In this retrospective study we evaluated the multimodal visualization of retinal genetic diseases to better understand their natural course. Material and Methods. We reviewed the charts of 70 consecutive patients with different genetic retinal pathologies who had previously undergone multimodal imaging analyses. Genomic DNA was extracted from peripheral blood and genotyped at the known locus for the different diseases. Results. The medical records of 3 families of a 4-generation...

Francesco Pichi; Mariachiara Morara; Chiara Veronese; Paolo Nucci; Ciardella, Antonio P.

2013-01-01

267

Retinal iron homeostasis in health and disease  

OpenAIRE

Iron is essential for life, but excess iron can be toxic. As a potent free radical creator, iron generates hydroxyl radicals leading to significant oxidative stress. Since iron is not excreted from the body, it accumulates with age in tissues, including the retina, predisposing to age-related oxidative insult. Both hereditary and acquired retinal diseases are associated with increased iron levels. For example, retinal degenerations have been found in hereditary iron overload disorders, like a...

DeluSong; JoshuaL.Dunaief

2013-01-01

268

Exudate Segmentation on Retinal Atlas Space  

OpenAIRE

Diabetic macular edema is characterized by hard exudates. Presence of such exudates cause vision loss in the affected areas. We present a novel approach of segmenting exudates for screening and follow-ups by building an ethnicity based statistical atlas. The chromatic distribution in such an atlas gives a good measure of probability of the pixels belonging to the healthy retinal pigments or to the abnormalities (like lesions, imaging artifacts etc.) in the retinal fundus image. Post-processin...

Ali, Sharib; Adal, Kedir; Sidibe?, De?sire?; Karnowski, T. P.; Edward Chaum, M. D.; Meriaudeau, Fabrice

2013-01-01

269

Retinitis pigmentosa and ocular blood flow  

OpenAIRE

Abstract Is the concept of integrative, preventive and personalised medicine applicable to the relationship between retinitis pigmentosa (RP) and ocular blood flow (OBF)? RP encompasses a group of hereditary diseases of the posterior segment of the eye characterised by degeneration, atrophy and finally loss of photoreceptors and retinal pigment epithelium, leading to progressive visual loss. Many different mutations affecting different genes can lead to the clinical picture of RP. Even though...

Konieczka Katarzyna; Flammer Andreas, J.; Todorova Margarita; Meyer Peter; Flammer Josef

2012-01-01

270

Alpha-interferon administration in cytomegalovirus retinitis.  

OpenAIRE

Four patients, including three with the acquired immunodeficiency syndrome (AIDS), were treated with high-dose, buffy coat-derived alpha-interferon for progressive cytomegalovirus retinitis. Two of these patients had decreased viruria during therapy and the other two had increased viruria. There was evidence of progression of disease despite therapy in all patients, although the retinitis eventually became quiescent in the patient without AIDS. The severe immunosuppression encountered in AIDS...

Chou, S. W.; Dylewski, J. S.; Gaynon, M. W.; Egbert, P. R.; Merigan, T. C.

1984-01-01

271

Dynamic eye phantom for retinal oximetry measurements  

OpenAIRE

Measurements of oxygen saturation and flow in the retina can yield information about eye health and the onset of eye pathologies such as diabetic retinopathy. Recently, we developed a multiaperture camera that uses the division of the retinal image into several wavelength-sensitive subimages to compute retinal oxygen saturation. The calibration of such instruments is particularly difficult due to the layered structure of the eye and the lack of alternative measurement techniques. For this pur...

Lemaillet, Paul; Ramella-roman, Jessica C.

2009-01-01

272

The course of the V1 segment of the vertebral artery  

Directory of Open Access Journals (Sweden)

Full Text Available Background: It has become important to know the exact origin and course of the vertebral artery as well as the percentage of the abnormalities of these variations from the point of view of surgery, angiography and in all non-invasive procedures. In decompressive procedures and for subsequent stabilization procedures of the cervical spine, thorough knowledge of the anatomy of the vertebral artery is mandatory to avoid a potentially catastrophic injury to the vertebral artery. Aims of the Study: The present study was aimed at investigating the frequency of occurrence of the variations of the pre-transverse segment of the vertebral artery especially concerning the level of its entry into the foramen transversarium, tortuosity and size in formalin fixed adult cadavers and fetuses with the view of keeping the surgeons alert regarding the frequency of occurrence of these variations in the local subjects. Materials and Methods: The pre-transverse segment of the vertebral artery (V1 segment was studied in 19 formalin fixed cadavers (6 females and 13 males and ten formalin fixed newborn fetuses. The total length and the diameter of the V1 segment of the vertebral artery were measured in adult cadavers to the nearest millimeter using a sliding caliper. Variations in the level of entry of the vertebral artery in to the foramen transversarium and also tortuosity of the artery were noted down. Results: The vertebral artery measured a mean length of 4.9 ± 1.24 cms and a mean diameter of 3.58 ±1.59 mms. In over 71% of the cases the vertebral artery entered the foramen transversarium at the level of C6. The next highest frequency was C7 (18.42% and in small percentage of the cases at C5 (5.3%, C4 (2.6% and C3 (2.6%. The vertebral artery was found to be tortuous in nine cases (23.7%. Conclusions: Data derived from gross anatomical studies serve as an indicator of prevalence of variations within a population group. But it would be safest for the surgeon to investigate each case by a computed tomographic scan before the cervical surgery.

Ranganatha Sastry V

2006-01-01

273

Cone dysfunctions in retinitis pigmentosa with retinal nerve fiber layer thickening  

OpenAIRE

Güngör Sobaci, Gökhan Özge, Fatih Ç Gündo?anDepartment of Ophthalmology, Gülhane Military Medical Academy and Medical School, Etlik, Ankara, TurkeyPurpose: To investigate whether or not thicker retinal nerve fiber layer (RNFL) in retinitis pigmentosa (RP) patients relates to functional abnormalities of the photoreceptors.Methods: Optical coherence tomography-based RNFL thickness was measured by Stratus-3™ (Zeiss, Base...

Sobaci G; Özge G; Amp Ccedil, G. Amp Uuml Ndog?an F.

2012-01-01

274

Dual stent migration to the heart and pulmonary artery.  

Science.gov (United States)

The practice of intravascular stenting largely grew out of the concept of stenting the coronaries in acute myocardial infarction. According to the recent United States Renal Data System data registry, there has been a significant increase in endovascular intervention (1.8-fold increase-from 52,380 to 98,148) with a 2.2-fold increase in stent deployment in hemodialysis access (3792-8514). With the increasing use of endovascular stents in the management of dialysis access stenosis, the incidence of stent-related complications has increased significantly. Stent-related complications include stent restenosis, thrombosis (narrowing of the vessel lumen and being a nidus for thombus formation), stent shortening, stent fracture, stent infection, and stent migration. Physiologic variation in the diameter of veins due to respiration, which along with the geometry of the stent, can lead to a shortening lengthening of the stent-resulting in poor wall contact or high-speed impact of shock; in the case of trauma, mechanical bucking can result in tortuous blood vessels thereby resulting in stent migration (however proving this association was not the aim of this article). We report a case of a 44-year-old female with end-stage renal disease on hemodialysis, with stent placement to treat a compromised arteriovenous graft. There have been many cases of stent migration in the past; however, this is the first case of dual stent migration to the heart and pulmonary artery from an unusual (lower extremity) arteriovenous graft location. PMID:23567791

Balasubramaniyam, Nivas; Garg, Jalaj; Rawat, Naveen; Chugh, Savneek; Mittal, Varun; Baby, Banessaa; Aronow, Wilbert S; Lehrman, Stuart G

2014-01-01

275

Internal carotid artery dissection in a patient with recent respiratory infection: case report of a possible link Dissecção da artéria carótida interna em um paciente com infecção respiratória recente: relato de caso de uma possível associação  

OpenAIRE

The pathogenesis of spontaneous cervical artery dissection remains unknown. Infection-mediated damage of the arterial wall may be an important triggering mechanism. We describe a 21 year-old man with respiratory infection (bronchial pneumonia) which was diagnosed and treated with antibiotic few days prior to the right internal carotid artery dissection. The patient presented ischemic retinal and cerebral strokes. Based on literature review, we discuss the possibility of a causal link between ...

Cynthia Resende Campos; Thiago Gasperini Bassi; Fabiano Pinto; Abraha?o, Deme?trius Kasak P.

2005-01-01

276

Retinal Neovascularization and An Angioma-like Lesion after Demarcation Photocoagulation for Rhegmatogenous Retinal Detachment  

Directory of Open Access Journals (Sweden)

Full Text Available Laser photocoagulation might aggravate the ischemia of an area of retinal detachmentand predispose the retina to formation of neovascularization and an angioma-like lesion. Wepresent a case of retinal neovascularization (RNV and an angioma-like lesion occurringafter demarcation photocoagulation for rhegmatogenous retinal detachment (RRD. A 20-year-old woman suffered from a retinal atrophic hole with localized shallow retinal detachmentin the right eye. Laser photocoagulation was performed to wall off the area of detachment.Fifteen months later, RNV and an angioma-like lesion had developed in the previouslydetached retina. Treatment with demarcation photocoagulation for RRD may run a risk offormation of RNV and angioma-like lesion if the retina is not reattached.

San-Ni Chen

2006-04-01

277

An image-based software tool for screening retinal fundus images using vascular morphology and network transport analysis  

Science.gov (United States)

As the number of digital retinal fundus images taken each year grows at an increasing rate, there exists a similarly increasing need for automatic eye disease detection through image-based analysis. A new method has been developed for classifying standard color fundus photographs into both healthy and diseased categories. This classification was based on the calculated network fluid conductance, a function of the geometry and connectivity of the vascular segments. To evaluate the network resistance, the retinal vasculature was first manually separated from the background to ensure an accurate representation of the geometry and connectivity. The arterial and venous networks were then semi-automatically separated into two separate binary images. The connectivity of the arterial network was then determined through a series of morphological image operations. The network comprised of segments of vasculature and points of bifurcation, with each segment having a characteristic geometric and fluid properties. Based on the connectivity and fluid resistance of each vascular segment, an arterial network flow conductance was calculated, which described the ease with which blood can pass through a vascular system. In this work, 27 eyes (13 healthy and 14 diabetic) from patients roughly 65 years in age were evaluated using this methodology. Healthy arterial networks exhibited an average fluid conductance of 419 ± 89 ?m3/mPa-s while the average network fluid conductance of the diabetic set was 165 ± 87 ?m3/mPa-s (p diseased eyes from color fundus imagery.

Clark, Richard D.; Dickrell, Daniel J.; Meadows, David L.

2014-03-01

278

Regulation of Taurine transporter activity in cultured rat retinal ganglion cells and rat retinal Muller Cells  

International Nuclear Information System (INIS)

Diabetic retinopathy is one of the most common complications of diabetes. The amino acid taurine is believed to play an antioxidant protective role in diabetic retinopathy through the scavenging of the reactive species. It is not well established whether taurine uptake is altered in retina cells during diabetic conditions. Thus, the present study was designed to investigate the changes in taurine transport in cultures of rat retinal Muller cells and rat retinal ganglion cells under conditions associated with diabetes. Taurine was abundantly taken up by retinal Muller cells and rat retinal ganglion cells under normal glycemic condition. Taurine was actively transported to rat Muller cells and rat retinal ganglion cells in a Na and Cl dependant manner. Taurine uptake further significantly elevated in both type of cells after the incubation with high glucose concentration. This effect could be attributed to the increase in osmolarity. Because Nitric Oxide (NO) is a molecule implicated in the pathogenesis of diabetes, we also determined the activity of taurine transporter in cultured rat retinal Muller cells and rat retinal ganglion cells in the presence of the NO donors, SIN-1 and SNAP. Taurine uptake was elevated above control value after 24-h incubation with low concentration of NO donors. We finally investigated the ability of neurotoxic glutamate to change taurine transporter activity in both types of cells. Uptake of taurine was significantly increased in rat retina was significantly increased in rat retinal ganglion cells when only incubated with high concentration of glutamate. Our data provide evidence that taurine transporter is present in cultured rat retinal ganglion and Muller cells and is regulated by hyperosmolarity. The data are relevant to disease such as diabetes and neuronal degeneration where retinal cell volume may dramatically change. (author)

279

Coronary Artery Bypass Grafting  

Science.gov (United States)

... Coronary Artery Bypass Grafting? Coronary artery bypass grafting (CABG) is a type of surgery that improves blood flow to the heart. Surgeons use CABG to treat people who have severe coronary heart ...

280

Prenylation defects in inherited retinal diseases.  

Science.gov (United States)

Many proteins depend on post-translational prenylation for a correct subcellular localisation and membrane anchoring. This involves the covalent attachment of farnesyl or geranylgeranyl residues to cysteines residing in consensus motifs at the C-terminal parts of proteins. Retinal photoreceptor cells are highly compartmentalised and membranous structures, and therefore it can be expected that the proper function of many retinal proteins depends on prenylation, which has been proven for several proteins that are absent or defective in different inherited retinal diseases (IRDs). These include proteins involved in the phototransduction cascade, such as GRK1, the phosphodiesterase 6 subunits and the transducin ? subunit, or proteins involved in transport processes, such as RAB28 and retinitis pigmentosa GTPase regulator (RPGR). In addition, there is another class of general prenylation defects due to mutations in proteins such as AIPL1, PDE6D and rab escort protein-1 (REP-1), which can act as chaperones for subsets of prenylated retinal proteins that are associated with IRDs. REP-1 also is a key accessory protein of geranylgeranyltransferase II, an enzyme involved in the geranylgeranylation of almost all members of a large family of Rab GTPases. Finally, mutations in the mevalonate kinase (MVK) gene, which were known to be principally associated with mevalonic aciduria, were recently associated with non-syndromic retinitis pigmentosa. We hypothesise that MVK deficiency results in a depletion of prenyl moieties that affects the prenylation of many proteins synthesised specifically in the retina, including Rabs. In this review, we discuss the entire spectrum of prenylation defects underlying progressive degeneration of photoreceptors, the retinal pigment epithelium and the choroid. PMID:24401286

Roosing, Susanne; Collin, Rob W J; den Hollander, Anneke I; Cremers, Frans P M; Siemiatkowska, Anna M

2014-03-01

281

Toward high-resolution optoelectronic retinal prosthesis  

Science.gov (United States)

It has been already demonstrated that electrical stimulation of retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. Current retinal implants provide very low resolution (just a few electrodes), while several thousand pixels are required for functional restoration of sight. We present a design of the optoelectronic retinal prosthetic system that can activate a retinal stimulating array with pixel density up to 2,500 pix/mm2 (geometrically corresponding to a visual acuity of 20/80), and allows for natural eye scanning rather than scanning with a head-mounted camera. The system operates similarly to "virtual reality" imaging devices used in military and medical applications. An image from a video camera is projected by a goggle-mounted infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. Such a system provides a broad field of vision by allowing for natural eye scanning. The goggles are transparent to visible light, thus allowing for simultaneous utilization of remaining natural vision along with prosthetic stimulation. Optical control of the implant allows for simple adjustment of image processing algorithms and for learning. A major prerequisite for high resolution stimulation is the proximity of neural cells to the stimulation sites. This can be achieved with sub-retinal implants constructed in a manner that directs migration of retinal cells to target areas. Two basic implant geometries are described: perforated membranes and protruding electrode arrays. Possibility of the tactile neural stimulation is also examined.

Palanker, Daniel; Huie, Philip; Vankov, Alexander; Asher, Alon; Baccus, Steven

2005-04-01

282

Expression of peptide NAP in rat retinal Müller cells prevents hypoxia-induced retinal injuries and promotes retinal neurons growth.  

Science.gov (United States)

NAP (NAPVSIPQ) is a short peptide derived from activity-dependent neuroprotective protein (ADNP) sequence, whose potent and direct neuroprotective capabilities have been widely accepted. However, due to the high risk and inconvenience of intraocular injections, NAP is difficult to be clinically administered as therapeutic agent in treating retinal diseases. Currently, stable transfection of this octapeptide into cells has not been reported, partly because of its small size and lacking of 5' signal sequence. Here, we have developed a novel NT4-NAP fusion gene by attaching the 5' nonfunctional preproregion of neurotrophin 4 (NT4) to NAP cDNA. Recombinant adeno-associated virus was established to introduce NT4-NAP construct into cultured rat retinal Müller cells (RMC), resulting in sustained high level NAP production from stable transfection. Functional analyses of RMC cells transfected with NAP revealed the remarkably reduced cytotoxicity and apoptosis of the cells under hypoxia. Furthermore, coculturing of transfected RMC-NAP cells with primary rat retinal neural cells offer marked protection to the latter against hypoxia induced cellular damages. Together our data indicate that stable transfection of NAP into retinal Müller cells with constant NAP production is possible. NAP produced from cellular transfection maintained its biological neuroprotective activities. This targeted gene expression may provide an effective treatment for retinal diseases in the near future. PMID:20359852

Zheng, Yuping; Zeng, Hao; She, Huaning; Liu, Hui; Sun, Naixue

2010-07-01

283

Gastroepiploic artery aneurysm  

International Nuclear Information System (INIS)

Full text: 61-year-old man was referred to our radiology department for abdominal Multi detector computed tomography (MDCT) evaluation because of undefined abdominal discomfort. MIP and curved MPR scans revealed that, the mass is a true sacculary aneurysm at the midportion of the right gastroepiploic artery. Gastroduodenal artery aneurysms are the least common of all the splanchnic artery aneurysms. We appreciated the case as a right gastroepiploic artery aneurysm. We couldn't find any similar case in the literature

284

Spectral imaging technique for retinal perfusion detection using confocal scanning laser ophthalmoscopy  

Science.gov (United States)

To evaluate retinal perfusion in the human eye, a dual-wavelength confocal scanning laser ophthalmoscope (cSLO) was developed that provides spectral imaging of the fundus using a combination of red (670 nm) and near-infrared (810 nm) wavelengths. The image of the ocular fundus was analyzed to find out if quantitative measurements of the reflectivity of tissue permit assessment of the oxygen perfusion of tissue. We explored problems that affect the reproducibility of patient measurements such as non-uniformity errors on the image. For the first time, an image processing technique was designed and used to minimize the errors of oxygen saturation measurements by illumination correction in retina wide field by increasing SNR. Retinal images were taken from healthy and diabetic retinopathy eyes using the cSLO with a confocal aperture of 100 ?m. The ratio image (RI) of red/IR, as oxygen saturation (SO2) index, was calculated for normal eyes. The image correction technique improved the reproducibility of the measurements. Average RI intensity variation of healthy retina tissue was determined within a range of about 5.5%. The capability of the new technique to discriminate oxygenation levels of retinal artery and vein was successfully demonstrated and showed good promise in the diagnosis of the perfused retina.

Rasta, Seyed Hossein; Manivannan, Ayyakkannu; Sharp, Peter F.

2012-11-01

285

Retinal imaging with virtual reality stimulus for studying Salticidae retinas  

Science.gov (United States)

We present a 3-path optical system for studying the retinal movement of jumping spiders: a visible OLED virtual reality system presents stimulus, while NIR illumination and imaging systems observe retinal movement.

Schiesser, Eric; Canavesi, Cristina; Long, Skye; Jakob, Elizabeth; Rolland, Jannick P.

2014-12-01

286

Genetics Home Reference: Neuropathy, ataxia, and retinitis pigmentosa  

Science.gov (United States)

... OMIM Genetic disorder catalog Conditions > Neuropathy, ataxia, and retinitis pigmentosa (often shortened to NARP ) On this page: Description ... November 2006 What is NARP? Neuropathy, ataxia, and retinitis pigmentosa (NARP) is a condition that causes a variety ...

287

Promises of stem cell therapy for retinal degenerative diseases  

OpenAIRE

With the development of stem cell technology, stem cell-based therapy for retinal degeneration has been proposed to restore the visual function. Many animal studies and some clinical trials have shown encouraging results of stem cell-based therapy in retinal degenerative diseases. While stem cell-based therapy is a promising strategy to replace damaged retinal cells and ultimately cure retinal degeneration, there are several important challenges which need to be overcome before stem cell tech...

Wong, Ian Yat-hin; Poon, Ming-wai; Pang, Rosita Tsz-wai; Lian, Qizhou; Wong, David

2011-01-01

288

Detection of Retinitis Pigmentosa by Differential Interference Contrast Microscopy  

OpenAIRE

Differential interference contrast microscopy is designed to image unstained and transparent specimens by enhancing the contrast resulting from the Nomarski prism-effected optical path difference. Retinitis pigmentosa, one of the most common inherited retinal diseases, is characterized by progressive loss of photoreceptors. In this study, Differential interference contrast microscopy was evaluated as a new and simple application for observation of the retinal photoreceptor layer and retinitis...

Oh, Juyeong; Kim, Seok Hwan; Kim, Yu Jeong; Lee, Hyunho; Cho, Joon Hyong; Cho, Young Ho; Kim, Chul-ki; Lee, Taik Jin; Lee, Seok; Park, Ki Ho; Yu, Hyeong Gon; Lee, Hyuk-jae; Jun, Seong Chan; Kim, Jae Hun

2014-01-01

289

A Developmental Mechanism of Spontaneous Reattachment in Rhegmatogenous Retinal Detachment  

OpenAIRE

This retrospective observational case series on eyes from three patients was done to elucidate the developmental mechanism of spontaneous reattachment of rhegmatogenous retinal detachment (SRRRD). The study eyes of each patients showed evidence of retinal break and diffuse retinal pigmentary change. Ultrasound biomicroscopic examination revealed vitreous fibers attached to the area around the retinal break. Posterior vitreous attachment was confirmed in each eye. A thin fibrovascular membrane...

Chung, Song Ee; Kang, Se Woong; Yi, Chan-hui

2012-01-01

290

Evaluation and management of pediatric rhegmatogenous retinal detachment  

OpenAIRE

Pediatric rhegmatogenous retinal detachments are rare, accounting for less than ten percent of all rhegmatogenous retinal detachments. While most retinal detachments in the adult population are related to posterior vitreous detachment, pediatric retinal detachment are often related to trauma or an underlying congenital abnormalities or genetic syndrome. The anatomy of pediatric eyes, the often late presentation of the disease, and the high incidence of bilateral pathology in children all pose...

Wenick, Adam S.; Baran?ano, David E.

2012-01-01

291

Application of Morphological Bit Planes in Retinal Blood Vessel Extraction  

OpenAIRE

The appearance of the retinal blood vessels is an important diagnostic indicator of various clinical disorders of the eye and the body. Retinal blood vessels have been shown to provide evidence in terms of change in diameter, branching angles, or tortuosity, as a result of ophthalmic disease. This paper reports the development for an automated method for segmentation of blood vessels in retinal images. A unique combination of methods for retinal blood vessel skeleton detection and multidirect...

Fraz, M. M.; Basit, A.; Barman, S. A.

2012-01-01

292

Optimal management of cytomegalovirus retinitis in patients with AIDS  

OpenAIRE

Michael W StewartDepartment of Ophthalmology, Mayo School of Medicine, Jacksonville, FL, USAAbstract: Cytomegalovirus (CMV) retinitis is the most common cause of vision loss in patients with acquired immunodeficiency syndrome (AIDS). CMV retinitis afflicted 25% to 42% of AIDS patients in the pre-highly active antiretroviral therapy (HAART) era, with most vision loss due to macula-involving retinitis or retinal detachment. The introduction of HAART significantly decreased the incidence and sev...

Stewart, Michael W.

2010-01-01

293

Protocadherin-17 Function in Zebrafish Retinal Development  

Science.gov (United States)

Cadherin cell adhesion molecules play crucial roles in vertebrate development including the development of the retina. Most studies have focused on examining functions of classic cadherins (e.g. N-cadherin) in retinal development. There is little information on the function of protocadherins in the development of the vertebrate visual system. We previously showed that protocadherin-17 mRNA was expressed in developing zebrafish retina during critical stages of the retinal development. To gain insight into protocadherin-17 function in the formation of the retina, we analyzed eye development and differentiation of retinal cells in zebrafish embryos injected with protocadherin-17 specific antisense morpholino oligonucleotides (MOs). Protocadherin-17 knockdown embryos (pcdh17 morphants) had significantly reduced eyes due mainly to decreased cell proliferation. Differentiation of several retinal cell types (e.g. retinal ganglion cells) was also disrupted in the pcdh17 morphants. Phenotypic rescue was achieved by injection of protocadherin-17 mRNA. Injection of a vivo-protocadherin-17 MO into one eye of embryonic zebrafish resulted in similar eye defects. Our results suggest that protocadherin-17 plays an important role in the normal formation of the zebrafish retina. PMID:22927092

Chen, Yun; Londraville, Richard; Brickner, Sarah; El-Shaar, Lana; Fankhauser, Kelsee; Dearth, Cassandra; Fulton, Leah; Sochacka, Alicja; Bhattarai, Sunil; Marrs, James A.; Liu, Qin

2012-01-01

294

Bilateral intraocular calcification in necrotizing cytomegalovirus retinitis.  

Science.gov (United States)

We report a unique case of bilateral intraocular calcification due to necrotizing cytomegalovirus (CMV) retinitis associated with congenital CMV infection. A 7-month-old boy with a history of congenital CMV infection showed bilateral intraocular calcific plaques on computed tomography (CT) and ultrasonography. We reviewed the patient's medical files for the purpose of this report. The patient had a prior medical history of hospitalization for fever and swelling in the neck at 3 months of age. Systemic findings (anemia, neutropenia, hepatosplenomegaly, and reactive lymphadenomegaly) in association with a low CD4 count, high blood CMV viral load, and positivity for urine CMV DNA by polymerase chain reaction led to the diagnosis of bone marrow suppression and congenital CMV infection. At 7 months, he developed horizontal nystagmus and bilateral leukocoria over 20 days. Cranial CT and ultrasonography revealed bilateral intraocular calcific plaques and the patient was referred to rule out retinoblastoma. Fundoscopy was consistent with bilateral hemorrhagic, necrotizing CMV retinitis. Significant resolution of the retinal infiltrations occurred 2 weeks after initiation of systemic treatment with ganciclovir. Intraocular calcification may be a sign of active CMV retinitis. To our knowledge this is the first report of bilateral intraocular calcification serving as the presenting clinical manifestation of necrotizing CMV retinitis. PMID:24550055

Tuncer, Samuray; Oray, Merih; Yildirim, Yeliz; Camcioglu, Yildiz; Tugal-Tutkun, Ilknur

2014-10-01

295

Low Vision Rehabilitation of Retinitis Pigmentosa. Practice Report  

Science.gov (United States)

Retinitis pigmentosa is a rod-cone dystrophy, commonly genetic in nature. Approximately 60-80% of those with retinitis pigmentosa inherit it by an autosomal recessive transmission (Brilliant, 1999). There have been some reported cases with no known family history. The symptoms of retinitis pigmentosa are decreased acuity, photophobia, night…

Rundquist, John

2004-01-01

296

Popliteal artery entrapment syndrome  

International Nuclear Information System (INIS)

Popliteal artery entrapment syndrome is an uncommon cause of intermittent claudication in young athletic persons. A 32 years old soldier presented with 14 months history of intermittent claudication. On the basis of history, physical examination and angiographic findings a diagnosis of popliteal artery entrapment was made. Exploration revealed a fibrous band tightly compressing popliteal artery and irreversibly damaged popliteal artery. Short saphenous vein graft was used to bypass the occluded segment of popliteal artery. This led to complete resolution of symptoms and continuation of active service. (author)

297

Jet pump assisted artery  

Science.gov (United States)

A procedure for priming an arterial heat pump is reported; the procedure also has a means for maintaining the pump in a primed state. This concept utilizes a capillary driven jet pump to create the necessary suction to fill the artery. Basically, the jet pump consists of a venturi or nozzle-diffuser type constriction in the vapor passage. The throat of this venturi is connected to the artery. Thus vapor, gas, liquid, or a combination of the above is pumped continuously out of the artery. As a result, the artery is always filled with liquid and an adequate supply of working fluid is provided to the evaporator of the heat pipe.

1975-01-01

298

Enhanced generation of retinal progenitor cells from human retinal pigment epithelial cells induced by amniotic fluid  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Retinal progenitor cells are a convenient source of cell replacement therapy in retinal degenerative disorders. The purpose of this study was to evaluate the expression patterns of the homeobox genes PAX6 and CHX10 (retinal progenitor markers during treatment of human retinal pigment epithelium (RPE cells with amniotic fluid (AF, RPE cells harvested from neonatal cadaver globes were cultured in a mixture of DMEM and Ham's F12 supplemented with 10% FBS. At different passages, cells were trypsinized and co-cultured with 30% AF obtained from normal fetuses of 1416 weeks gestational age. Results Compared to FBS-treated controls, AF-treated cultures exhibited special morphological changes in culture, including appearance of spheroid colonies, improved initial cell adhesion and ordered cell alignment. Cell proliferation assays indicated a remarkable increase in the proliferation rate of RPE cells cultivated in 30% AF-supplemented medium, compared with those grown in the absence of AF. Immunocytochemical analyses exhibited nuclear localization of retinal progenitor markers at a ratio of 33% and 27% for CHX10 and PAX6, respectively. This indicated a 3-fold increase in retinal progenitor markers in AF-treated cultures compared to FBS-treated controls. Real-time PCR data of retinal progenitor genes (PAX6, CHX10 and VSX-1 confirmed these results and demonstrated AF's capacity for promoting retinal progenitor cell generation. Conclusion Taken together, the results suggest that AF significantly promotes the rate of retinal progenitor cell generation, indicating that AF can be used as an enriched supplement for serum-free media used for the in vitro propagation of human progenitor cells.

Sanie-Jahromi Fatemeh

2012-04-01

299

Transplantation of Embryonic and Induced Pluripotent Stem Cell-Derived 3D Retinal Sheets into Retinal Degenerative Mice  

OpenAIRE

In this article, we show that mouse embryonic stem cell- or induced pluripotent stem cell-derived 3D retinal tissue developed a structured outer nuclear layer (ONL) with complete inner and outer segments even in an advanced retinal degeneration model (rd1) that lacked ONL. We also observed host-graft synaptic connections by immunohistochemistry. This study provides a “proof of concept” for retinal sheet transplantation therapy for advanced retinal degenerative diseases.

Assawachananont, Juthaporn; Mandai, Michiko; Okamoto, Satoshi; Yamada, Chikako; Eiraku, Mototsugu; Yonemura, Shigenobu; Sasai, Yoshiki; Takahashi, Masayo

2014-01-01

300

Retinal vascular signs in diabetes and hypertension - review / Sinais vasculares retinianos no diabetes e hipertensão  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A vasculatura retiniana apresenta uma oportunidade única de observação não-invasiva da microcirculação e de suas estruturas in vivo. Recentemente, uma série de estudos populacionais desenvolveu métodos quantitativos de observação destes sinais retinianos e suas relações com distúrbios metabólicos, t [...] ais como diabetes, obesidade, hipertensão arterial e síndrome metabólica. Esses estudos demonstraram associações das lesões retinianas, entre elas estreitamento arteriolar e dilatação venular, com essas alterações metabólicas, sugerindo um componente microvascular na patogênese ou na manifestação destes distúrbios. Ainda, vários destes sinais foram associados com risco de doença cardiovascular, tais como doença arterial coronariana e acidente vascular cerebral independente dos fatores de risco clássicos. Esta revisão discute em detalhes as evidências entre os sinais retinianos e os distúrbios metabólicos e suas possíveis implicações na pesquisa e na prática clínica. Abstract in english The retinal vasculature is a unique site where the microcirculation can be noninvasively imaged in vivo. This presents an opportunity to study otherwise inaccessible structural features of the microcirculation. Recently, a number of population-based studies have developed quantitative methods of mea [...] suring these retinal signs, and investigated how these signs relate to metabolic disorders such as diabetes, hypertension, obesity, and metabolic syndrome. These studies have reported fairly consistent associations of retinopathy lesions, arteriolar narrowing and venular dilation with these metabolic disorders, suggesting a microvascular component in either the pathogenesis or manifestation of these disorders. Further, several of these signs have been associated with future risk of cardiovascular outcomes, such as coronary heart disease and stroke, independently of traditional risk factors. This review will examine in detail the evidence linking retinal vascular signs with metabolic disorders and discuss their implications for research and clinical practice.

Gerald, Liew; Jie Jin, Wang.

2007-03-01

301

An automated retinal image quality grading algorithm.  

Science.gov (United States)

This paper introduces an algorithm for the automated assessment of retinal fundus image quality grade. Retinal image quality grading assesses whether the quality of the image is sufficient to allow diagnostic procedures to be applied. Automated quality analysis is an important preprocessing step in algorithmic diagnosis, as it is necessary to ensure that images are sufficiently clear to allow pathologies to be visible. The algorithm is based on standard recommendations for quality analysis by human screeners, examining the clarity of retinal vessels within the macula region. An evaluation against a reference standard data-set is given; it is shown that the algorithm's performance correlates closely with that of clinicians manually grading image quality. PMID:22255696

Hunter, Andrew; Lowell, James A; Habib, Maged; Ryder, Bob; Basu, Ansu; Steel, David

2011-01-01

302

Identification system by eye retinal pattern  

International Nuclear Information System (INIS)

Identification system by eye retinal pattern is introduced from the view-point of history of R and D, measurement, apparatus, evaluation tests, safety and application. According to our evaluation tests, enrolling time is approximately less than 1 min, verification time is a few seconds and false accept rate is 0 %. Evaluation tests at Sandia National Laboratories in USA show the comparison data of false accept rates such as 0 % for eye retinal pattern, 10.5 % for finger-print, 5.8 % for signature dynamics and 17.7 % for speaker voice. The identification system by eye retinal pattern has only three applications in Japan, but there has been a number of experience in USA. This fact suggests that the system will become an important means for physical protections not only in nuclear field but also in other industrial fields in Japan. (author)

303

Retinal Fiber Tracing by In Ovo Electroporation  

Science.gov (United States)

Axonal tracing techniques are the fundamentals for the investigation of neural circuit formation. In ovo electroporation system allows us to transfect a gene of interest to the desired place in chick embryos (Odani et al., 2008). Recently, Tol2 transposase element, which was originally found in medaka fish (Koga et al., 1996), has been adapted to an in ovo electroporation system (Niwa et al., 1991; Kawakami et al., 1998, 2000, 2004a, 2004b; Kawakami & Noda, 2004; Kawakami, 2005, 2007; Sato et al., 2007). This system assures the integration of the transgene into the genome by electroporation (Niwa et al., 1991; Sato et al., 2007). We applied this system for tracing retinal fibers (Harada et al., 2008). In this chapter, we demonstrate the method of tracing retinal fibers from both small and large groups of the retinal ganglion cell (RGC) with transposon-mediated gene transfer by in ovo electroporation to chick embryos.

Harada, Hidekiyo; Nakamura, Harukazu

304

Enhancing retinal images by nonlinear registration  

CERN Document Server

Being able to image the human retina in high resolution opens a new era in many important fields, such as pharmacological research for retinal diseases, researches in human cognition, nervous system, metabolism and blood stream, to name a few. In this paper, we propose to share the knowledge acquired in the fields of optics and imaging in solar astrophysics in order to improve the retinal imaging at very high spatial resolution in the perspective to perform a medical diagnosis. The main purpose would be to assist health care practitioners by enhancing retinal images and detect abnormal features. We apply a nonlinear registration method using local correlation tracking to increase the field of view and follow structure evolutions using correlation techniques borrowed from solar astronomy technique expertise. Another purpose is to define the tracer of movements after analyzing local correlations to follow the proper motions of an image from one moment to another, such as changes in optical flows that would be o...

Molodij, Guillaume; Glanc, Marie; Chenegros, Guillaume

2014-01-01

305

Shedding New Light on Retinal Protein Photochemistry  

Science.gov (United States)

The ultrafast spectroscopic investigation of novel retinal proteins challenges existing notions concerning the course of primary events in these natural photoreceptors. We review two illustrations here. The first demonstrates that changes in the initial retinal configuration can alter the duration of photochemistry by nearly an order of magnitude in Anabaena sensory rhodopsin, making it as rapid as the ballistic photoisomerization in visual pigments. This prompted a reinvestigation of the much studied bacteriorhodopsin, leading to a similar trend as well, contrary to earlier reports. The second involves the study of xanthorhodopsin, an archaeal proton pump that includes an attached light-harvesting carotenoid. Pump-probe experiments demonstrate the efficient transfer of energy from carotenoid to retinal, providing a first glimpse at a cooperative multichromophore function, which is probably characteristic of many other proteins as well. Finally, we discuss measures required to advance our knowledge from kinetics to mode-specific dynamics concerning this expanding family of biological photoreceptors.

Wand, Amir; Gdor, Itay; Zhu, Jingyi; Sheves, Mordechai; Ruhman, Sanford

2013-04-01

306

Preservation of retinotopic map in retinal degeneration.  

Science.gov (United States)

Retinal degenerations trigger the loss of photoreceptors and cause the remaining de-afferented neural retina to undergo remodeling. Concerns over this potential retinal synaptic reorganization following visual loss have raised questions regarding the usefulness of visual restoration via retinal electrical stimulation. We have used quantitative positron emission tomography (PET) and 2-deoxy-2-[18F]fluoro-d-glucose (FDG) to objectively evaluate the connection between the retina and the primary visual cortex under both light and transcorneal electrical stimulation (TcES) in five subjects with retinal degeneration (RD) who have had more than ten years of light-perception-only best visual acuity and five age-matched normal-sighted controls. All subjects underwent quantitative PET with FDG as the metabolic tracer during stimulation of the right eye under both light stimulation condition and transcorneal electrical stimulation (TcES) using ERG-Jet contact lens electrode. Cortical activation maps from each stimulation condition were obtained using statistical parametric mapping. TcES phosphene threshold current and qualitative visual cortex activation from both stimulation conditions were compared between the two subject groups. Average phosphene threshold current was 0.72 ± 0.18 mA for the five normal-sighted controls and 3.08 ± 2.01 mA for the retinal degenerative subjects. Phosphene threshold current was significantly higher in retinal degenerative subjects compared to normal-sighted controls (p < 0.05). We found both light stimulation and TcES resulted in retinotopically mapped primary visual cortex activation in both groups. In addition, the patterns of early visual area activation between the two subject groups are more similar during TcES than light stimulation. Our findings suggest primary visual cortex continues to maintain its retinotopy in RD subjects despite prolonged visual loss. PMID:22685713

Xie, John; Wang, Gene-Jack; Yow, Lindy; Humayun, Mark S; Weiland, James D; Cela, Carlos J; Jadvar, Hossein; Lazzi, Gianluca; Dhrami-Gavazi, Elona; Tsang, Stephen H

2012-05-01

307

Retinal image analysis: preprocessing and feature extraction  

International Nuclear Information System (INIS)

Image processing, analysis and computer vision techniques are found today in all fields of medical science. These techniques are especially relevant to modern ophthalmology, a field heavily dependent on visual data. Retinal images are widely used for diagnostic purposes by ophthalmologists. However, these images often need visual enhancement prior to apply a digital analysis for pathological risk or damage detection. In this work we propose the use of an image enhancement technique for the compensation of non-uniform contrast and luminosity distribution in retinal images. We also explore optic nerve head segmentation by means of color mathematical morphology and the use of active contours.

308

Retinal image analysis: preprocessing and feature extraction  

Energy Technology Data Exchange (ETDEWEB)

Image processing, analysis and computer vision techniques are found today in all fields of medical science. These techniques are especially relevant to modern ophthalmology, a field heavily dependent on visual data. Retinal images are widely used for diagnostic purposes by ophthalmologists. However, these images often need visual enhancement prior to apply a digital analysis for pathological risk or damage detection. In this work we propose the use of an image enhancement technique for the compensation of non-uniform contrast and luminosity distribution in retinal images. We also explore optic nerve head segmentation by means of color mathematical morphology and the use of active contours.

Marrugo, Andres G; Millan, Maria S, E-mail: andres.marrugo@upc.edu [Grup d' Optica Aplicada i Processament d' Imatge, Departament d' Optica i Optometria Univesitat Politecnica de Catalunya (Spain)

2011-01-01

309

Polylaminin recognition by retinal cells.  

Science.gov (United States)

Polylaminin (polyLM) is a flat biomimetic polymer of laminin capable of promoting axonal growth both in vitro and in vivo. It is assembled in a cell-free system when laminin 111 is incubated in acidic pH, whereas incubation in neutral buffer leads to the formation of bulky and irregular polymers (LM). In the present work, we compared the behaviors of cells isolated from the P1 rat retina on polyLM and LM. PolyLM induced cellular spreading and the outgrowth of neurites in contact with the substrate, whereas LM led to the formation of large clusters of cells, with neurites growing only inward. After 24 hr in culture, the number of cells on polyLM increased threefold, and this increase was inhibited by 60% in the presence of the PKA inhibitor H89 and by 41% in the presence of the PKC inhibitor chelerythrine chloride, whereas both inhibitors abolished neuritogenesis. Neither the cell number nor the outgrowth of neurites was affected by the ERK1/2 inhibitor PD98059 on polyLM. On the other hand, PD98059 was able to reduce the cell number on LM, whereas the other inhibitors were not. Immunostaining of P1 retina with an antilaminin antibody revealed that the protein was expressed not only at its inner surface but also within the neuroblast layer in close contact with individual cells. Our results indicate that, when provided in its active polymerized form, laminin can influence both neuritogenesis and proliferation of retinal cells. PMID:24265135

Hochman-Mendez, Camila; Lacerda de Menezes, João Ricardo; Sholl-Franco, Alfred; Coelho-Sampaio, Tatiana

2014-01-01

310

Retinitis pigmentosa and congenital toxoplasmosis: A rare coexistence  

Directory of Open Access Journals (Sweden)

Full Text Available We describe a previously unreported co-existence of retinitis pigmentosa and congenital toxoplasmosis. An eight year old male presented to our center with complaints of decreased night vision. Fundus evaluations in both the eyes demonstrated features typical of retinitis pigmentosa. There were well-defined punched out healed chorio-retinal scars suggestive of congenital toxoplasmosis. On the basis of history, clinical findings and reduction of a and b wave amplitudes on scotopic and photopic electroretinograph, a diagnosis of retinitis pigmentosa with congenital toxoplasmosis was made. Retinitis pigmentosa may co-exist with congenital toxoplasmosis that may affect the patient?s overall ocular morbidity and visual acuity.

Chhabra Manpreet

2007-01-01

311

Bilateral retinal detachment in a case of preeclampsia  

Science.gov (United States)

Serous retinal detachment is an unusual cause of visual loss in preeclampsia. We report the case of 24-years-old primipara with severe preeclampsia who developed bilateral serous retinal detachment a few hours after delivery. A few weeks after delivery there was spontaneous resorption of the subretinal fluid and complete resolution bilateral serous retinal detachment, with residual pigmentary changes of the retinal pigment epithelium. Visual acuity was normal in each eye. The management of retinal detachment as a complication in preeclampsia is conservative and the prognosis is usually good. PMID:21619562

Sre?kovi?, Sun?ica B.; Jani?ijevi?-Petrovi?, Mirjana A.; Stefanovi?, Ivan B.; Petrovi?, Nenad T.; Šarenac, Tatjana S.; Paunovi?, Svetlana S.

2011-01-01

312

Probing how initial retinal configuration controls photochemical dynamics in retinal proteins  

Science.gov (United States)

The effects of the initial retinal configuration and the active isomerization coordinate on the photochemistry of retinal proteins (RPs) are assessed by comparing photochemical dynamics of two stable retinal ground state configurations (all-trans,15-anti vs. 13-cis,15-syn), within two RPs: Bacteriorhodopsin (BR) and Anabaena Sensory Rhodopsin (ASR). Hyperspectral pump-probe spectroscopy shows that photochemistry starting from 13-cis retinal in both proteins is 3-10 times faster than when started in the all-trans state, suggesting that the hastening is ubiquitous to microbial RPs, regardless of their different biological functions and origin. This may also relate to the known disparity of photochemical rates between microbial RPs and visual pigments. Importance and possible underlying mechanisms are discussed as well.

Wand, A.; Rozin, R.; Eliash, T.; Friedman, N.; Jung, K. H.; Sheves, M.; Ruhman, S.

2013-03-01

313

Cytomegalovirus retinitis after central retinal vein occlusion in a patient on systemic immunosuppression: does venooclusive disease predispose to cytomegalovirus retinitis in patients already at risk?  

Directory of Open Access Journals (Sweden)

Full Text Available John D Welling, Ahmad B Tarabishy, John ChristoforidisDepartment of Ophthalmology, Havener Eye Institute, Ohio State University, Columbus, OH, USAAbstract: Cytomegalovirus (CMV retinitis remains the most common opportunistic ocular infection in immunocompromised patients. Patients with immunocompromising diseases, such as acquired immunodeficiency syndrome, inherited immunodeficiency states, malignancies, and those on systemic immunosuppressive therapy, are known to be at risk. Recently, it has been suggested that patients undergoing intravitreal injection of immunosuppressive agents may also be predisposed. One previous case report speculated that there may be an additional risk for CMV retinitis in acquired immunodeficiency syndrome patients with venoocclusive disease. This case study presents a case of CMV retinitis following central retinal vein occlusion in a patient on systemic immunosuppressants.Keywords: cytomegalovirus retinitis, central retinal vein occlusion, immunosuppression, solid organ transplant, venous stasis, risk factor

Welling JD

2012-04-01

314

Comparison of non-mydriatic retinal photography with ophthalmoscopy in 2159 patients: mobile retinal camera study.  

OpenAIRE

OBJECTIVE--To determine whether non-mydriatic Polaroid retinal photography was comparable to ophthalmoscopy with mydriasis in routine clinic screening for early, treatable diabetic retinopathy. DESIGN--Prospective study of ophthalmoscopic findings according to retinal camera screening and ophthalmoscopy and outcome of referral to ophthalmologist. SETTING--Outpatient diabetic clinics of three teaching hospitals and three district general hospitals. PATIENTS--2159 Adults selected randomly from ...

Taylor, R.; Lovelock, L.; Tunbridge, W. M.; Alberti, K. G.; Brackenridge, R. G.; Stephenson, P.; Young, E.

1990-01-01

315

Vitreous inflammatory factors and serous retinal detachment in central retinal vein occlusion: a case control series  

OpenAIRE

Abstract Background This study investigated whether the vitreous fluid levels of soluble vascular endothelial growth factor receptor-2 (sVEGFR-2), pigment epithelium-derived factor (PEDF), and soluble intercellular adhesion molecule 1 (sICAM-1) were associated with the occurrence of serous retinal detachment (SRD) in patients with central retinal vein occlusion (CRVO). Methods We recruited 33 patients with CRVO and macular edema, as well as 18 controls with nonischemic ocular diseases. Eighte...

Noma Hidetaka; Funatsu Hideharu; Mimura Tatsuya; Eguchi Shuichiro

2011-01-01

316

Retinal-protein interactions in halorhodopsin from Natronomonas pharaonis: binding and retinal thermal isomerization catalysis.  

Science.gov (United States)

Halorhodopsin from Natronomonas pharaonis (NpHR) is a member of the retinal protein group and serves as a light-driven chloride pump in which chloride ions are transported through the membrane following light absorption by the retinal chromophore. In this study, we examined two main issues: (1) factors controlling the binding of the retinal chromophore to the NpHR opsin and (2) the ability of the NpHR opsin to catalyze the thermal isomerization of retinal isomers. We have revealed that the reconstitution process of pharaonis HR (NpHR) pigment from its apoprotein and all-trans retinal depends on the pH, and the process has a pK(a) of 5.8+/-0.1. It was proposed that this pK(a) is associated with the pK(a) of the lysine residue that binds the retinal chromophore (Lys256). The pigment formation is regulated by the concentration of sodium chloride, and the maximum yield was observed at 3.7 M NaCl. The low yield of pigment in a lower concentration of NaCl (sodium chloride concentration. However, in the absence of sodium chloride, the apoprotein adopts such a conformation, which does not prevent the isomerization of retinal, but it prevents a covalent bond formation with the lysine residue. The rate and the thermodynamic parameter analysis of the retinal isomerization by NpHR apoprotein led to the conclusion that the apomembrane catalyzes the isomerization via a triplet mechanism. PMID:19766652

Maiti, Tushar Kanti; Engelhard, Martin; Sheves, Mordechai

2009-12-01

317

Automated segmentation of outer retinal layers in macular OCT images of patients with retinitis pigmentosa  

OpenAIRE

To provide a tool for quantifying the effects of retinitis pigmentosa (RP) seen on spectral domain optical coherence tomography images, an automated layer segmentation algorithm was developed. This algorithm, based on dual-gradient information and a shortest path search strategy, delineates the inner limiting membrane and three outer retinal boundaries in optical coherence tomography images from RP patients. In addition, an automated inner segment (IS)/outer segment (OS) contour detection met...

Yang, Qi; Reisman, Charles A.; Chan, Kinpui; Ramachandran, Rithambara; Raza, Ali; Hood, Donald C.

2011-01-01

318

Environmental Enrichment Effects on Development of Retinal Ganglion Cell Dendritic Stratification Require Retinal BDNF  

OpenAIRE

A well-known developmental event of retinal maturation is the progressive segregation of retinal ganglion cell (RGC) dendrites into a and b sublaminae of the inner plexiform layer (IPL), a morphological rearrangement crucial for the emergence of the ON and OFF pathways. The factors regulating this process are not known, although electrical activity has been demonstrated to play a role. Here we report that Environmental Enrichment (EE) accelerates the developmental segregation of RGC dendrites...

Landi, Silvia; Cenni, Maria Cristina; Maffei, Lamberto; Berardi, Nicoletta

2007-01-01

319

Modifications of retinal neurons in a mouse model of retinitis pigmentosa  

OpenAIRE

Animal models of retinitis pigmentosa include the rd mouse, in which a mutation of a rod-specific phosphodiesterase leads to the rapid loss of photoreceptors during the early postnatal life. Very little is known about changes occurring in inner retinal neurons after photoreceptor loss. These changes are important in view of the possibility of restoring vision in retinas with photoreceptor degeneration by means of cell transplantation or direct stimulation of inner ...

Strettoi, Enrica; Pignatelli, Vincenzo

2000-01-01

320

Altered retinal microRNA expression profile in a mouse model of retinitis pigmentosa.  

OpenAIRE

Background The role played by microRNAs (miRs) as common regulators in physiologic processes such as development and various disease states was recently highlighted. Retinitis pigmentosa (RP) linked to RHO (which encodes rhodopsin) is the most frequent form of inherited retinal degeneration that leads to blindness, for which there are no current therapies. Little is known about the cellular mechanisms that connect mutations within RHO to eventual photoreceptor cell death by apoptosis. ...

Farrar, Jane; Humphries, Peter

2007-01-01

321

Unilateral Double Axillary and Double Brachial Arteries: Embryological Basis and Clinical Implications / Arterias Axilar y Braquial Dobles Unilaterales: Bases Embriológicas e Implicaciones Clínicas  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish Este reporte describe la presencia de las arterias axilar y braquial duplicadas en el lado derecho de un cadáver adulto de sexo masculino. La arteria axilar derecha se bifurcó en arterias axilares I y II, localizadas posteriormente al músculo pectoral menor. Ambas arterias, con sus respectivas ramas [...] atravesaron bajo el músculo redondo mayor y continuaron como arterias braquiales I y II, respectivamente. La arteria axilar I, que se continuó como arteria braquial I, tuvo un trayecto superficial y tortuoso, mientras que la arteria axilar II fue de poco calibre y de localización profunda. Las arterias toracoacromial, torácica lateral y subescapular se originaron de la arteria axilar I. La arteria torácica superior se originó de la arteria toracoacromial. Las arterias circunflejas humerales anterior y posterior se originaron desde la arteria axilar II. La arteria braquial profundase originó de la arteria braquial II, mientras que a nivel de la línea intercondílea, la arteria ulnar se originó de la arteria braquial I. En la fosa cubital, la arteria braquial I se dividió en arterias radial e interósea común, mientras que la arteria braquial II terminó anastomosándose con la arteria braquial I. Las arterias ulnar, radial e interóseas común continuaron como arterias independientes y tuvieron un trayecto y distribución normales en el antebrazo. La persistencia de arterias axilar y braquial dobles tiene una base embriológica, pudiendo ser de interés para la embriología experimental. El conocimiento de estas variaciones arteriales múltiples, como el presente caso, es de importancia fundamental durante la medición de flujo en los vasos sanguíneos a través de Doppler, para el diagnóstico clínico y manejo quirúrgico de enfermedades que afectan al miembro superior Abstract in english This report presents double axillary and double brachial arteries on the right side of an adult male cadaver. In this case, the right axillary artery bifurcated into axillary artery I and axillary artery II posterior to the pectoralis minor muscle. Both the axillary arteries with their branches trav [...] ersed upto lower border of teres major muscle and continued further as seperate entities into the cubital fossa as brachial artery I and brachial artery II respectively. The axillary artery I which continued as brachial artery I was superficial and tortuous in its course, while the axillary artery II was slender and deeply situated. The thoraco-acromial, lateral thoracic and subscapular arteries took origin from axillary artery I. The superior thoracic artery was seen arising from the thoraco-acromial artery. The anterior and posterior circumflex humeral arteries arose from axillary artery II.The profunda brachii artery was given off by the brachial artery II, while at the level of intercondylar line, the ulnar artery was given off by brachial artery I. In the cubital fossa, the brachial artery divided into radial and common interosseous artery, while the brachial artery II ended by anastomosis with brachial artery I. The ulnar, radial and common interosseous arteries continued as separate entities and exhibited a normal course and distribution in the forearm.The hypothesis for the embryological basis of persistence of double axillary and double brachical arteries may be useful for experimental embryology. The knowledge of such multiple arterial variations as in the present case is of immense significance during Doppler scanning of blood vessels for clinical diagnosis and surgical management of diseases of superior extremity

S, Jayakumari; Gayatri, Rath; Jyoti, Arora.

2006-09-01

322

Optimal management of cytomegalovirus retinitis in patients with AIDS  

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Full Text Available Michael W StewartDepartment of Ophthalmology, Mayo School of Medicine, Jacksonville, FL, USAAbstract: Cytomegalovirus (CMV retinitis is the most common cause of vision loss in patients with acquired immunodeficiency syndrome (AIDS. CMV retinitis afflicted 25% to 42% of AIDS patients in the pre-highly active antiretroviral therapy (HAART era, with most vision loss due to macula-involving retinitis or retinal detachment. The introduction of HAART significantly decreased the incidence and severity of CMV retinitis. Optimal treatment of CMV retinitis requires a thorough evaluation of the patient’s immune status and an accurate classification of the retinal lesions. When retinitis is diagnosed, HAART therapy should be started or improved, and anti-CMV therapy with oral valganciclovir, intravenous ganciclovir, foscarnet, or cidofovir should be administered. Selected patients, especially those with zone 1 retinitis, may receive intravitreal drug injections or surgical implantation of a sustained-release ganciclovir reservoir. Effective anti-CMV therapy coupled with HAART significantly decreases the incidence of vision loss and improves patient survival. Immune recovery uveitis and retinal detachments are important causes of moderate to severe loss of vision. Compared with the early years of the AIDS epidemic, the treatment emphasis in the post-HAART era has changed from short-term control of retinitis to long-term preservation of vision. Developing countries face shortages of health care professionals and inadequate supplies of anti-CMV and anti-HIV medications. Intravitreal ganciclovir injections may be the most cost effective strategy to treat CMV retinitis in these areas.Keywords: cytomegalovirus, AIDS, retinitis, immune recovery uveitis, retinal detachment, treatment

Michael W Stewart

2010-04-01

323

Adeno-associated viral vectors for retinal gene transfer and treatment of retinal diseases.  

Science.gov (United States)

Retinal gene transfer holds big promises for the treatment of inherited and non-inherited blinding diseases, such as retinitis pigmentosa or age-related macular degeneration. Key to the development of successful gene-based therapies for the eye are efficient tools for retinal gene transfer. Vectors based on adeno-associated viruses (AAV) are able to transduce robustly and persistently different retinal cell types of animal models after a single intraocular administration. Recombinant AAV (rAAV) vectors are versatile gene transfer tools in that capsid proteins from dozens of AAV serotypes can be easily interchanged, resulting in the creation of recombinant vectors with unique transduction properties. This has allowed successful proof-of-principle studies using rAAV-mediated gene transfer to restore retinal morphology and function in small and large animal models of retinal diseases. In addition, gene delivery using rAAV vectors in the eye seems to have appropriate biosafety characteristics to rapidly move it from bench to bedside. All the above aspects will be reviewed and discussed in detail below. PMID:15975011

Auricchio, Alberto; Rolling, Fabienne

2005-06-01

324

A Novel In Vitro Sensing Configuration for Retinal Physiology Analysis of a Sub-Retinal Prosthesis  

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Full Text Available This paper presents a novel sensing configuration for retinal physiology analysis, using two microelectrode arrays (MEAs. In order to investigate an optimized stimulation protocol for a sub-retinal prosthesis, retinal photoreceptor cells are stimulated, and the response of retinal ganglion cells is recorded in an in vitro environment. For photoreceptor cell stimulation, a polyimide-substrate MEA is developed, using the microelectromechanical systems (MEMS technology. For ganglion cell response recording, a conventional glass-substrate MEA is utilized. This new sensing configuration is used to record the response of retinal ganglion cells with respect to three different stimulation methods (monopolar, bipolar, and dual-monopolar stimulation methods. Results show that the geometrical relation between the stimulation microelectrode locations and the response locations seems very low. The threshold charges of the bipolar stimulation and the monopolar stimulation are in the range of 10~20 nC. The threshold charge of the dual-monopolar stimulation is not obvious. These results provide useful guidelines for developing a sub-retinal prosthesis.

Kyung Hwan Kim

2012-03-01

325

Laser-induced retinal damage thresholds for annular retinal beam profiles  

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The dependence of retinal damage thresholds on laser spot size, for annular retinal beam profiles, was measured in vivo for 3 ?s, 590 nm pulses from a flashlamp-pumped dye laser. Minimum Visible Lesion (MVL)ED50 thresholds in rhesus were measured for annular retinal beam profiles covering 5, 10, and 20 mrad of visual field; which correspond to outer beam diameters of roughly 70, 160, and 300 ?m, respectively, on the primate retina. Annular beam profiles at the retinal plane were achieved using a telescopic imaging system, with the focal properties of the eye represented as an equivalent thin lens, and all annular beam profiles had a 37% central obscuration. As a check on experimental data, theoretical MVL-ED50 thresholds for annular beam exposures were calculated using the Thompson-Gerstman granular model of laser-induced thermal damage to the retina. Threshold calculations were performed for the three experimental beam diameters and for an intermediate case with an outer beam diameter of 230 ?m. Results indicate that the threshold vs. spot size trends, for annular beams, are similar to the trends for top hat beams determined in a previous study; i.e., the threshold dose varies with the retinal image area for larger image sizes. The model correctly predicts the threshold vs. spot size trends seen in the biological data, for both annular and top hat retinal beam profiles.

Kennedy, Paul K.; Zuclich, Joseph A.; Lund, David J.; Edsall, Peter R.; Till, Stephen; Stuck, Bruce E.; Hollins, Richard C.

2004-07-01

326

Investigation of Retinal Morphology Alterations Using Spectral Domain Optical Coherence Tomography in a Mouse Model of Retinal Branch and Central Retinal Vein Occlusion  

Science.gov (United States)

Retinal vein occlusion is a leading cause of visual impairment. Experimental models of this condition based on laser photocoagulation of retinal veins have been described and extensively exploited in mammals and larger rodents such as the rat. However, few reports exist on the use of this paradigm in the mouse. The objective of this study was to investigate a model of branch and central retinal vein occlusion in the mouse and characterize in vivo longitudinal retinal morphology alterations using spectral domain optical coherence tomography. Retinal veins were experimentally occluded using laser photocoagulation after intravenous application of Rose Bengal, a photo-activator dye enhancing thrombus formation. Depending on the number of veins occluded, variable amounts of capillary dropout were seen on fluorescein angiography. Vascular endothelial growth factor levels were markedly elevated early and peaked at day one. Retinal thickness measurements with spectral domain optical coherence tomography showed significant swelling (poptical coherence tomography imaging. The inner layers were predominantly affected by degeneration with the outer nuclear layer and the photoreceptor outer segments largely preserved. The application of this retinal vein occlusion model in the mouse carries several advantages over its use in other larger species, such as access to a vast range of genetically modified animals. Retinal changes after experimental retinal vein occlusion in this mouse model can be non-invasively quantified by spectral domain optical coherence tomography, and may be used to monitor effects of potential therapeutic interventions. PMID:25775456

Ebneter, Andreas; Agca, Cavit; Dysli, Chantal; Zinkernagel, Martin S.

2015-01-01

327

Fundus autofluorescence changes in cytomegalovirus retinitis  

OpenAIRE

A retrospective case series was undertaken to evaluate nine eyes of six patients with active CMV retinitis. Patients were evaluated with a comprehensive ophthalmic examination, fundus autofluorescence imaging, and fundus photography. Oral valganciclovir, intravitreal ganciclovir, intravitreal foscarnet, or a ganciclovir implant was administered as clinically indicated.

Yeh, Steven; Forooghian, Farzin; Faia, Lisa J.; Weichel, Eric D.; Wong, Wai T.; Sen, H. Nida; Chan-kai, Brian; Witherspoon, S. Robert; Lauer, Andreas K.; Chew, Emily Y.; Nussenblatt, Robert B.

2010-01-01

328

Stem cell therapy for retinal diseases.  

Science.gov (United States)

In this review, we discuss about current knowledge about stem cell (SC) therapy in the treatment of retinal degeneration. Both human embryonic stem cell and induced pluripotent stem cell has been growth in culture for a long time, and started to be explored in the treatment of blinding conditions. The Food and Drug Administration, recently, has granted clinical trials using SC retinal therapy to treat complex disorders, as Stargardt's dystrophy, and patients with geographic atrophy, providing good outcomes. This study's intent is to overview the critical regeneration of the subretinal anatomy through retinal pigment epithelium transplantation, with the goal of reestablish important pathways from the retina to the occipital cortex of the brain, as well as the differentiation from pluripotent quiescent SC to adult retina, and its relationship with a primary retinal injury, different techniques of transplantation, management of immune rejection and tumorigenicity, its potential application in improving patients' vision, and, finally, approaching future directions and challenges for the treatment of several conditions. PMID:25621115

Garcia, José Mauricio; Mendonça, Luisa; Brant, Rodrigo; Abud, Murilo; Regatieri, Caio; Diniz, Bruno

2015-01-26

329

Idiopathic Juxtafoveolar Retinal Telangiectasis: A Current Review  

OpenAIRE

Idiopathic juxtafoveolar retinal telangiectasis (IJFT), also known as parafoveal telangiectasis or idiopathic macular telangiectasia, refers to a heterogeneous group of well-recognized clinical entities characterized by telangiectatic alterations of the juxtafoveolar capillary network of one or both eyes, but which differ in appearance, presumed pathogenesis, and management strategies. Classically, three groups of IJFT are identified. Group I is unilateral easily visible telangiectasis occurr...

Nowilaty Sawsan; Al-Shamsi Hanan; Al-Khars Wajeeha

2010-01-01

330

a Review of Retinal Prosthesis Approaches  

Science.gov (United States)

Age-related macular degeneration and retinitis pigmentosa are two of the most common diseases that cause degeneration in the outer retina, which can lead to several visual impairments up to blindness. Vision restoration is an important goal for which several different research approaches are currently being pursued. We are concerned with restoration via retinal prosthetic devices. Prostheses can be implemented intraocularly and extraocularly, which leads to different categories of devices. Cortical Prostheses and Optic Nerve Prostheses are examples of extraocular solutions while Epiretinal Prostheses and Subretinal Prostheses are examples of intraocular solutions. Some of the prostheses that are successfully implanted and tested in animals as well as humans can restore basic visual functions but still have limitations. This paper will give an overview of the current state of art of Retinal Prostheses and compare the advantages and limitations of each type. The purpose of this review is thus to summarize the current technologies and approaches used in developing Retinal Prostheses and therefore to lay a foundation for future designs and research directions.

Kien, Tran Trung; Maul, Tomas; Bargiela, Andrzej

331

A Psychophysical Test for Retinitis Pigmentosa.  

Science.gov (United States)

A new test designed to detect an hereditary eye disease called retinitis pigmentosa (RP) is described. This condition is revealed by pigmentation in the retina, but early diagnosis is difficult because the symptoms are subtle, and since it is genetically recessive it frequently occurs in families with no history of early blindness. In many cases…

Corwin, Thomas R; Mancini, Michael

332

The Retinitis Pigmentosa Student: Selected Aspects.  

Science.gov (United States)

The characteristic features of RP (retinitis pigmentosa-an untreatable conditions usually resulting in night blindness) are discussed and functioning considerations in the classroom (including the use of protective devices and mobility aids) are noted. Classroom modifications such as darklined paper and black pens are suggested. (CL)

Sullivan, Franklin N.

1984-01-01

333

Photovoltaic retinal prosthesis with high pixel density  

Science.gov (United States)

Retinal degenerative diseases lead to blindness due to loss of the `image capturing' photoreceptors, while neurons in the `image-processing' inner retinal layers are relatively well preserved. Electronic retinal prostheses seek to restore sight by electrically stimulating the surviving neurons. Most implants are powered through inductive coils, requiring complex surgical methods to implant the coil-decoder-cable-array systems that deliver energy to stimulating electrodes via intraocular cables. We present a photovoltaic subretinal prosthesis, in which silicon photodiodes in each pixel receive power and data directly through pulsed near-infrared illumination and electrically stimulate neurons. Stimulation is produced in normal and degenerate rat retinas, with pulse durations of 0.5-4 ms, and threshold peak irradiances of 0.2-10 mW mm-2, two orders of magnitude below the ocular safety limit. Neural responses were elicited by illuminating a single 70 µm bipolar pixel, demonstrating the possibility of a fully integrated photovoltaic retinal prosthesis with high pixel density.

Mathieson, Keith; Loudin, James; Goetz, Georges; Huie, Philip; Wang, Lele; Kamins, Theodore I.; Galambos, Ludwig; Smith, Richard; Harris, James S.; Sher, Alexander; Palanker, Daniel

2012-06-01

334

Dynamic eye phantom for retinal oximetry measurements  

Science.gov (United States)

Measurements of oxygen saturation and flow in the retina can yield information about eye health and the onset of eye pathologies such as diabetic retinopathy. Recently, we developed a multiaperture camera that uses the division of the retinal image into several wavelength-sensitive subimages to compute retinal oxygen saturation. The calibration of such instruments is particularly difficult due to the layered structure of the eye and the lack of alternative measurement techniques. For this purpose, we realize an in vitro model of the human eye composed of a lens, the retina vessel, and three layers: the choroid, the retinal pigmented epithelium, and the sclera. The retinal vessel is modeled with a microtube connected to a micropump and a hemoglobin reservoir in a closed circulatory system. Hemoglobin oxygenation in the vessel could be altered using a reversible fuel cell. The sclera is represented by a Spectralon slab. The optical properties of the other layers are mimicked using titanium dioxide as a scatterer, ink as an absorber, and epoxy as a supporting structure. The optical thickness of each layer of the eye phantom is matched to each respective eye layer.

Lemaillet, Paul; Ramella-Roman, Jessica C.

2009-11-01

335

Stem cell therapy for retinal diseases  

Science.gov (United States)

In this review, we discuss about current knowledge about stem cell (SC) therapy in the treatment of retinal degeneration. Both human embryonic stem cell and induced pluripotent stem cell has been growth in culture for a long time, and started to be explored in the treatment of blinding conditions. The Food and Drug Administration, recently, has granted clinical trials using SC retinal therapy to treat complex disorders, as Stargardt’s dystrophy, and patients with geographic atrophy, providing good outcomes. This study’s intent is to overview the critical regeneration of the subretinal anatomy through retinal pigment epithelium transplantation, with the goal of reestablish important pathways from the retina to the occipital cortex of the brain, as well as the differentiation from pluripotent quiescent SC to adult retina, and its relationship with a primary retinal injury, different techniques of transplantation, management of immune rejection and tumorigenicity, its potential application in improving patients’ vision, and, finally, approaching future directions and challenges for the treatment of several conditions. PMID:25621115

Garcia, José Mauricio; Mendonça, Luisa; Brant, Rodrigo; Abud, Murilo; Regatieri, Caio; Diniz, Bruno

2015-01-01

336

A continuum model of retinal electrical stimulation  

Science.gov (United States)

A continuum mathematical model of retinal electrical stimulation is described. The model is represented by a passive vitreous domain, a thin layer of active retinal ganglion cell (RGC) tissue adjacent to deeper passive neural layers of the retina, the retinal pigmented epithelium (RPE) and choroid thus ending at the sclera. To validate the model, in vitro epiretinal responses to stimuli from 50 µm disk electrodes, arranged in a hexagonal mosaic, were recorded from rabbit retinas. 100 µs/phase anodic-first biphasic current pulses were delivered to the retinal surface in both the mathematical model and experiments. RGC responses were simulated and recorded using extracellular microelectrodes. The model's epiretinal thresholds compared favorably with the in vitro data. In addition, simulations showed that single-return bipolar electrodes recruited a larger area of the retina than twin-return or six-return electrodes arranged in a hexagonal layout in which a central stimulating electrode is surrounded by six, eqi-spaced returns. Simulations were also undertaken to investigate the patterns of RGC activation in an anatomically-accurate model of the retina, as well as RGC activation patterns for subretinal and suprachoroidal bipolar stimulation. This paper was originally submitted for the special issue containing contributions from the Sixth Biennial Research Congress of The Eye and the Chip.

Joarder, Saiful A.; Abramian, Miganoosh; Suaning, Gregg J.; Lovell, Nigel H.; Dokos, Socrates

2011-10-01

337

Study of the variations of superior cerebellar artery in human cadavers  

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Methods: 150 SCAs were studied by gross dissection of 75 formalin embalmed brains obtained from the department of anatomy Mysore medical college and MVJ medical college over a period of 5 years. Results: Variations like duplication in the origin was seen in 23.3%, triplication in 2% of SCAs, and abnormal origin from Posterior Cerebellar Artery (PCA in 25.3% were noted. Other variations like tortuous course and fenestration of SCA were found. The distance from the origin of SCA to PCA ranged between 0.7-4.5 mm. The length from SCA origin to its bifurcation ranged from 6-23 mm. Outer diameter of SCA trunk at its origin varied from 1.2-2.8 mm. The outer diameter of the Basilar Artery (BA at the basilar apex ranged between 3.2-6 mm. Conclusion: The presence of variations can alter the plan of surgical and radiological procedures. The knowledge of such variations and anomalies along with potential clinical manifestations is of paramount importance primarily for neurosurgeons and neuroradiologists. [Int J Res Med Sci 2014; 2(2.000: 699-703

Padmavathi G

2014-04-01

338

Anomalous left coronary artery from the pulmonary artery  

Science.gov (United States)

... left coronary artery arising from the pulmonary artery; ALCAPA; ALCAPA syndrome; Bland-White-Garland syndrome ... the rest of the body. In children with ALCAPA, the left coronary artery starts at the pulmonary ...

339

Iron homeostasis and toxicity in retinal degeneration  

Science.gov (United States)

Iron is essential for many metabolic processes but can also cause damage. As a potent generator of hydroxyl radical, the most reactive of the free radicals, iron can cause considerable oxidative stress. Since iron is absorbed through diet but not excreted except through menstruation, total body iron levels build up with age. Macular iron levels increase with age, in both men and women. This iron has the potential to contribute to retinal degeneration. Here we present an overview of the evidence suggesting that iron may contribute to retinal degenerations. Intraocular iron foreign bodies cause retinal degeneration. Retinal iron buildup resulting from hereditary iron homeostasis disorders aceruloplasminemia, Friedreich’s Ataxia, and panthothenate kinase associated neurodegeneration cause retinal degeneration. Mice with targeted mutation of the iron exporter ceruloplasmin have age-dependent retinal iron overload and a resulting retinal degeneration with features of age-related macular degeneration (AMD). Post mortem retinas from patients with AMD have more iron and the iron carrier transferrin than age- matched controls. Over the past ten years much has been learned about the intricate network of proteins involved in iron handling. Many of these, including transferrin, transferrin receptor, divalent metal transporter 1, ferritin, ferroportin, ceruloplasmin, hephaestin, iron regulatory protein, and histocompatibility leukocyte antigen class I-like protein involved in iron homeostasis (HFE) have been found in the retina. Some of these proteins have been found in the cornea and lens as well. Levels of the iron carrier transferrin are high in the aqueous and vitreous humors. The functions of these proteins in other tissues, combined with studies on cultured ocular tissues, genetically engineered mice, and eye exams on patients with hereditary iron diseases provide clues regarding their ocular functions. Iron may play a role in a broad range of ocular diseases, including glaucoma, cataract, AMD, and conditions causing intraocular hemorrhage. While iron deficiency must be prevented, the therapeutic potential of limiting iron induced ocular oxidative damage is high. Systemic, local, or topical iron chelation with an expanding repertoire of drugs has clinical potential. PMID:17921041

He, Xining; Hahn, Paul; Iacovelli, Jared; Wong, Robert; King, Chih; Bhisitkul, Robert; Massaro-Giordano, Mina; Dunaief, Joshua L.

2007-01-01

340

Arterial waveform analysis.  

Science.gov (United States)

The bedside measurement of continuous arterial pressure values from waveform analysis has been routinely available via indwelling arterial catheterization for >50 years. Invasive blood pressure monitoring has been utilized in critically ill patients, in both the operating room and critical care units, to facilitate rapid diagnoses of cardiovascular insufficiency and monitor response to treatments aimed at correcting abnormalities before the consequences of either hypo- or hypertension are seen. Minimally invasive techniques to estimate cardiac output (CO) have gained increased appeal. This has led to the increased interest in arterial waveform analysis to provide this important information, as it is measured continuously in many operating rooms and intensive care units. Arterial waveform analysis also allows for the calculation of many so-called derived parameters intrinsically created by this pulse pressure profile. These include estimates of left ventricular stroke volume (SV), CO, vascular resistance, and during positive-pressure breathing, SV variation, and pulse pressure variation. This article focuses on the principles of arterial waveform analysis and their determinants, components of the arterial system, and arterial pulse contour. It will also address the advantage of measuring real-time CO by the arterial waveform and the benefits to measuring SV variation. Arterial waveform analysis has gained a large interest in the overall assessment and management of the critically ill and those at a risk of hemodynamic deterioration. PMID:25480767

Esper, Stephen A; Pinsky, Michael R

2014-12-01

341

Photovoltaic retinal prosthesis: implant fabrication and performance.  

Science.gov (United States)

The objective of this work is to develop and test a photovoltaic retinal prosthesis for restoring sight to patients blinded by degenerative retinal diseases. A silicon photodiode array for subretinal stimulation has been fabricated by a silicon-integrated-circuit/MEMS process. Each pixel in the two-dimensional array contains three series-connected photodiodes, which photovoltaically convert pulsed near-infrared light into bi-phasic current to stimulate nearby retinal neurons without wired power connections. The device thickness is chosen to be 30 µm to absorb a significant portion of light while still being thin enough for subretinal implantation. Active and return electrodes confine current near each pixel and are sputter coated with iridium oxide to enhance charge injection levels and provide a stable neural interface. Pixels are separated by 5 µm wide trenches to electrically isolate them and to allow nutrient diffusion through the device. Three sizes of pixels (280, 140 and 70 µm) with active electrodes of 80, 40 and 20 µm diameter were fabricated. The turn-on voltages of the one-diode, two-series-connected diode and three-series-connected diode structures are approximately 0.6, 1.2 and 1.8 V, respectively. The measured photo-responsivity per diode at 880 nm wavelength is ?0.36 A W(-1), at zero voltage bias and scales with the exposed silicon area. For all three pixel sizes, the reverse-bias dark current is sufficiently low (<100 pA) for our application. Pixels of all three sizes reliably elicit retinal responses at safe near-infrared light irradiances, with good acceptance of the photodiode array in the subretinal space. The fabricated device delivers efficient retinal stimulation at safe near-infrared light irradiances without any wired power connections, which greatly simplifies the implantation procedure. Presence of the return electrodes in each pixel helps to localize the current, and thereby improves resolution. PMID:22791690

Wang, Lele; Mathieson, K; Kamins, T I; Loudin, J D; Galambos, L; Goetz, G; Sher, A; Mandel, Y; Huie, P; Lavinsky, D; Harris, J S; Palanker, D V

2012-08-01

342

Direct access to the middle meningeal artery for embolization of complex dural arteriovenous fistula: a hybrid treatment approach.  

Science.gov (United States)

Endovascular embolization has become increasingly favored over microsurgical resection for treatment of complex dural arteriovenous fistulas (DAVFs). However, endovascular treatment can be restricted by tortuous transarterial access and a transvenous approach is not always feasible. We present a Borden III DAVF treated by direct access to the middle meningeal artery (MMA) and Onyx embolization performed in a hybrid operating room-angiography suite. A middle-aged patient with pulsatile headaches was found to have left transverse sinus occlusion and DAVF with retrograde cortical venous drainage fed by multiple external carotid artery (ECA) feeders. Endovascular attempts via conventional transvenous and transarterial routes were unsuccessful, and the major MMA feeder was accessed directly after temporal craniotomy was performed under neuronavigation. Onyx embolization was performed; complete occlusion of the fistula was achieved. Three-month follow-up angiography showed no residual filling; the patient remains complication-free. A combined surgical-endovascular technique in a hybrid operating room-angiography suite can be an effective treatment for DAVFs complicated by inaccessible arterial and transvenous approaches. PMID:24916414

Lin, Ning; Brouillard, Adam M; Mokin, Maxim; Natarajan, Sabareesh K; Snyder, Kenneth V; Levy, Elad I; Siddiqui, Adnan H

2014-06-10

343

Regional morphology and pathophysiology of retinal vascular disease  

DEFF Research Database (Denmark)

Disturbances in the retinal vascular supply are involved in the pathophysiology of the most frequent diseases causing visual impairment and blindness in the Western World. These diseases are diagnosed by noting how morphological lesions in the retina vary in shape, size, location and dynamics, and subsequently concluding the presence of a specific disease entity. This diagnostic approach can be used to identify the site of a retinal vascular occlusion, to assess whether retinal diseases are primarily due to changes in the larger retinal vessels or the microcirculation, and to differentiate the relative involvement of the choroidal and the retinal vascular systems. However, a number of morphological manifestations of retinal vascular disease cannot presently be related to the underlying pathophysiology. The review concludes that there is a need for developing new methods for assessing vascular structure and function in the ciliary vascular system supplying the choroid and the optic nerve head. Presently, the study of these structures relies on imaging techniques with limited penetration and resolution into the tissue. Secondly, there is a need for studying oscillations in retinal vascular function occurring within days to weeks, and for studying regional manifestations of retinal vascular disease. This may constitute the basis for future research in retinal vascular pathophysiology and for the development of new treatment modalities to reduce blindness secondary to retinal vascular disease.

Bek, Toke

2013-01-01

344

Prophylactic treatment of retinal breaks - a systematic review  

DEFF Research Database (Denmark)

Prophylactic treatment of retinal breaks has been examined in several studies and reviews, but so far, no studies have successfully applied a systematic approach. In the present systematic review, we examined the need of follow-up after posterior vitreous detachment (PVD) - diagnosed by slit-lamp biomicroscopy or Goldmann 3-mirror examination - with regard to retinal breaks as well as the indication of prophylactic treatment in asymptomatic and symptomatic breaks. A total of 2941 publications were identified with PubMed and Medline searches. Two manual search strategies were used for papers in English published before 2012. Four levels of screening identified 13 studies suitable for inclusion in this systematic review. No meta-analysis was conducted as no data suitable for statistical analysis were identified. In total, the initial examination after symptomatic PVD identified 85-95% of subsequent retinal breaks. Additional retinal breaks were only revealed at follow-up in patients where a full retinal examination was compromised at presentation by, for example, vitreous haemorrhage. Asymptomatic and symptomatic retinal breaks progressed to rhegmatogenous retinal detachment (RRD) in 0-13.8% and 35-47% of cases, respectively. The cumulated incidence of RRD despite prophylactic treatment was 2.1-8.8%. The findings in this review suggest that follow-up after symptomatic PVD is only necessary in cases of incomplete retinal examination at presentation. Prophylactic treatment of symptomatic retinal breaks must be considered, whereas no unequivocal conclusion could be reached with regard to prophylactic treatment of asymptomatic retinal breaks.

Blindbaek, SØren; Grauslund, Jakob

2015-01-01

345

Avulsed retinal vessels with and without retinal breaks--treatment and extended follow-up.  

Science.gov (United States)

Between 1975 and 1984 65 cases of avulsed retinal vessels were studied. Of these 57 had avulsed vessels with retinal tear and 8 without. Of the affected eyes: 55.38 per cent were emmetropic, while myopia was present only in 29.23 per cent. Degenerative alterations (lattice-like lesions) were found in 4.61 per cent of cases. Argon laser treatment was applied in 30 cases (Group A), episcleral sponge implant with cryopexy and, in some instances, subsequent laser treatment in 34 cases (Group B). In one case vitrectomy with endodiathermy was performed. With the silastic sponge implants (Group B) we tried to obtain a high buckle in order to achieve immobilisation of the avulsed vessel through contact with the implant. The implants were applied in cases of avulsed vessels located posterior to the equator. Group B (sponge implant) showed fewer haemorrhagic recurrences after treatment than did Group A (laser application), the difference however was not statistically significant. It is also worth mentioning that in Group B the avulsed vessels which were occluded or empty of blood were to a statistically significant extent more numerous than in the laser-treated Group A. Retinal breaks with one or more avulsed retinal vessels constitute a distinct but uncommon clinical entity, which was first noted by Clark in 1962. Retinal vessels can also be avulsed by vitreous traction without a concurrent retinal tear, but can also be avulsed by vitreous traction without a concurrent retinal tear, but this condition is found much more rarely.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3868882

Theodossiadis, G P; Koutsandrea, C N

1985-01-01

346

23-Gauge Sutureless Vitreo-Retinal Surgery for Superior Rhegmatogenous Retinal Detachment  

International Nuclear Information System (INIS)

Objective: To determine the results of 23-gauge sutureless vitreo-retinal surgery for superior/supero-temporal rhegmatogenous retinal detachment (RRD). Study Design: Quasi experimental study. Place and Duration of Study: LRBT, Free Base Eye Hospital, Karachi, from January 2010 to December 2011. Methodology: Adult patients who underwent 23-gauge sutureless vitreo-retinal surgery along with use of Perfluoropropane (C3F8) gas as internal tamponading agent for fresh (upto 3 weeks) superior/supero-temporal RRD was reviewed. Major outcome measures were anatomical success, best corrected visual acuity (BCVA) with Log Mar and complications during and after surgery. Postoperative follow-up was done on 1st day and at 1st, 4th, 8th and finally at 12th week. Results: Sixty eyes of 60 patients, age between 30 - 60 years including 37 (61.67%) males and 23 (38.33%) females having superior or superatemporal RRD underwent 23-guage sutureless vitreo-retinal surgery with the use of perfluoropropane (C3 F8) gas as internal temponade at the end of procedure. Anatomical success rate was 81.66% (49 out of 60 eyes) with first surgery and raised to 90% (54 cases) with second surgery. Log Mar BCVA significantly improved from mean baseline 0.93 to 0.49 with mean difference of 0.43 (p < 0.001), 95% confidence interval. Postoperative complications were sub-conjunctival haemorrhage in 11 eyes (18.33%), wound leak in 7 eyes (11.66%), anterior chamber became shallow in 6 eyes (10%), cataract developed in 5 eyes (8.33%), re-retinal detachment in 4 eyes (6.66%), ocular hypotony and sterile inflammatory reaction in 3 eyes (5%) each, while iatrogenic breaks developed in 2 eyes (3.33%). Conclusion: The 23-gauge sutureless vitreo-retinal surgery for superior rhegmatogenous retinal detachment achieved high anatomical success and significant visual improvement. Sub-conjunctival haemorrhage was the most frequent procedural complication. (author)

347

Melanopsin-expressing intrinsically photosensitive retinal ganglion cells in retinal disease.  

Science.gov (United States)

Melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs) are a class of photoreceptors with established roles in non-image-forming processes. Their contributions to image-forming vision may include the estimation of brightness. Animal models have been central for understanding the physiological mechanisms of ipRGC function and there is evidence of conservation of function across species. Intrinsically photosensitive retinal ganglion cells can be divided into five ganglion cell subtypes that show morphological and functional diversity. Research in humans has established that ipRGCs signal environmental irradiance to entrain the central body clock to the solar day for regulating circadian processes and sleep. In addition, ipRGCs mediate the pupil light reflex (PLR), making the PLR a readily accessible behavioral marker of ipRGC activity. Less is known about ipRGC function in retinal and optic nerve disease, with emerging research providing insight into their function in diabetes, retinitis pigmentosa, glaucoma, and hereditary optic neuropathy. We briefly review the anatomical distributions, projections, and basic physiological mechanisms of ipRGCs and their proposed and known functions in animals and humans with and without eye disease. We introduce a paradigm for differentiating inner and outer retinal inputs to the pupillary control pathway in retinal disease and apply this paradigm to patients with age-related macular degeneration (AMD). In these cases of patients with AMD, we provide the initial evidence that ipRGC function is altered and that the dysfunction is more pronounced in advanced disease. Our perspective is that with refined pupillometry paradigms, the PLR can be extended to AMD assessment as a tool for the measurement of inner and outer retinal dysfunction. PMID:24879087

Feigl, Beatrix; Zele, Andrew J

2014-08-01

348

Organoprotective effects of benasepril in patients with arterial hypertension  

Directory of Open Access Journals (Sweden)

Full Text Available Aim. To evaluate antihypertensive efficiency of benasepril therapy (Lotensin, Novartis and its effects on microcirculation, endothelium function, system of cytoprotection, ophthalmoscopic and functional characteristics of eye retina in patients with arterial hypertension (AH.Material and methods. 40 patients with AH of 1-3 degree (AH1, AH2, and AH3 were studied. After wash-out period all patients were prescribed benasepril 5-10 mg daily. If necessary, hydrochlorothiazide 12,5 mg daily was added. Treatment lasted during 6 months. Patients were examined at the beginning and at the end of the study. Ambulatory blood pressure (BP monitoring was carried out. Microcirculation was assessed by method of laser Doppler flowmetry. Stable plasma metabolites of nitric oxide (NO were determined by spectral photometry. Cytoprotection was assessed by content of heat shock proteins (HSP70 in leucocytes of peripheral blood. Ophthalmoscopy, color and contrast static campimetry with evaluation of sensory-motor reaction (SMR time in different fields of vision were carried out.Results. Therapy with benasepril allowed to improve daily profile of BP and to reach its target level in all AH patients. Number of patients with spastic type of microcirculation decreased. Functional condition of endothelium improved which revealed in normalization of endothelial production of NO. Therapy with benasepril resulted in intracellular HSP70 level decrease which testified restriction of cellular destruction. The cytoprotective effect of benasepril was stronger in patient with severe AH. Therapy with benasepril resulted in SMR time decrease which signifies its positive influence on retinal blood flow. Evaluation of contrast and color sensitiveness of retina allowed to reveal and quantitatively assess earlier dysfunctions of retinal tissue perfusion, compared to ophthalmoscopy.Conclusion. Benasepril is an efficient antihypertensive drug which improves microcirculation, endothelium function and retinal perfusion, has cytoprotective effect. Color and contrast static campimetry is an adequate method for quantitative assessment of retinal perfusion and allows objectively to evaluate damage of eye as target organ of AH.

V.S. Zadionchenko

2006-01-01

349

Variable involvement of the perivascular retinal tissue in carbonic anhydrase inhibitor induced relaxation of porcine retinal arterioles in vitro.  

DEFF Research Database (Denmark)

PURPOSE: Inhibition of carbonic anhydrase in the eye is an important treatment modality for reducing the intraocular pressure in glaucoma. However, evidence suggests that carbonic anhydrase inhibition also exerts a relaxing effect on the vessels in the optic nerve, and it has been suggested that this vasorelaxing effect is a result of an interplay between the perivascular tissue and constituents in the retinal vascular wall. However, the exact nature of this interplay is unknown. METHODS: Isolated porcine retinal arterioles and arterioles with preserved perivascular retinal tissue were mounted in a myograph. After precontraction with the prostaglandin analogue U46619, the vasorelaxing effect of the carbonic anhydrase inhibitors methyl bromopyruvate, ethyl bromopyruvate, acetazolamide, and dorzolamide were studied. RESULTS: All the examined carbonic anhydrase inhibitors induced a significant relaxation of retinal arterioles. There was no significant difference between the effect of the different carbonic anhydrase inhibitors in the presence of perivascular retinal tissue. However, in the isolated retinal arterioles the vasodilating effect of dorzolamide was significantly lower, and the vasodilating effect of acetazolamide almost disappeared. CONCLUSIONS: A further elucidation of the mechanisms of action of carbonic anhydrase-induced dilation of retinal arterioles may contribute to a better understanding of the regulation of retinal blood flow. The perivascular retinal tissue may play a significant role in diameter control of retinal arterioles. Udgivelsesdato: 2007-Oct

Kehler, Anne Katrine; Holmgaard, Kim

2007-01-01

350

Splanchnic artery aneurysms  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction. Splanchnic artery aneurysms are uncommon but important vascular entity because nearly 25% of all cases present as surgical emergency. Objective. The purpose of our study was to present nine patients operated on at the Institute of cardiovascular diseases, as well as literature review of clinical presentation of the disease. Method. There were three splenic artery aneurysms, two celiac trunk aneurysms, and one aneurysm of the hepatic, superior mesenteric, inferior mesenteric and gastroduodenal artery. All patients were males, mean aged 67.5 years (60-73. In four patients, splanchnic artery aneurysm was discovered accidentally during routine ultrasonographic and angiographic examinations of the abdominal aorta. At that time, arteriovenous fistula was diagnosed in a patient No 1; it was formed after rupture of the splenic artery aneurysm into the splenic vein. Three aneurysms were manifested by abdominal pain and palpable pulsating abdominal mass. Two patients were admitted as urgent cases in the state of hemorrhagic shock and signs of intraabdominal bleeding due to rupture of the splenic and hepatic arteries. In 7 cases, diagnosis was made preoperatively by means of ultrasonography and angiography; in two patients, accurate diagnosis was confirmed during surgery. Results. Proximal and distal ligation of the artery was performed in a patient with rupture of the splenic aneurysm into the splenic vein that caused arteriovenous fistula. Gastroduodenal artery aneurysm was treated by trans-aneurysmatic ligation of its "entering" and "exiting" branches. Aneurysms of distal part of the superior mesenteric and splenic artery were resected without further reconstruction. Partial resection of the aneurysm and endoaneurysmorrhaphy was carried out in one case of celiac trunk aneurysm, and in another, after aneurysm resection, the restoration of blood flow through the hepatic and lienal artery was achieved by Dacron grafts. In a patient with the inferior mesenteric artery aneurysm, the resection of aneurysm was followed by reimplantation of medial part of the artery into bifurcated Dacron graft which replaced abdominal aorta. In 5 patients, some of additional surgical procedures were performed. There were 4 reconstructive procedures of abdominal aorta and one splenectomy. The patient with ruptured hepatic artery aneurysm died during surgery due to uncontrolled hemorrhage. In other patients, there was neither morbidity nor mortality in the early postoperative period (first 30 days after surgery. Mean follow up was 1 to 5 years (mean 3.4 years. One patient died after 5 years due to myocardial infarction. CONCLUSION Although the introduction of precise diagnostic procedures (computerized tomography, magnetic resonance imaging, spiral scan make diagnosis easier, the splanchnic artery aneurysms are still difficult to detect due to their uncommon clinical presentations.

Davidovi? Lazar B.

2006-01-01

351

Retinal angiographic blood flowmetry is reduced in the ocular ischaemic syndrome  

DEFF Research Database (Denmark)

INTRODUCTION: The aim of this study was to examine the use of quantitative fluorescein angiographic analysis as a means of estimating rates of perfusion of the retina in eyes with a circulatory deficit secondary to carotid artery stenosis. MATERIAL AND METHODS: The study included 21 eyes with ocular ischaemic syndrome (OIS) and 20 control eyes from subjects with carotid artery stenosis but without signs of ocular ischaemia. Analyses of video fluorescein angiograms extracting time intervals for the time delay between specific phases of the angiogram were performed. Time delay was compared between groups and in relation to degree of carotid artery stenosis and ocular systolic blood pressure. RESULTS: Among the three flow indices of retinal perfusion (arteriovenous passage time 1 (AVP1), arteriovenous passage time 2 (AVP2) and venous filling time (VP)), those including the venous filling phase were significantly prolonged in the OIS group. Furthermore, AVP2 was delayed by 3 sec. in OIS eyes (16.6 sec. versus 13.6 sec. in controls). VP was 2.4 sec. longer in OIS eyes (11.5 sec. versus 9.1 sec.). We found a significant correlation between AVP2 and ocular perfusion pressure, but no correlation between the degree of carotid artery stenosis and any of the flow indices. CONCLUSION: In a patient population spanning a wide ocular systolic blood pressure range, angiography-based quantitative flowmetry demonstrated a difference between carotid artery stenosis patients with and without OIS and a correlation between flow and ocular perfusion pressure. While angiographic flowmetry proved effective in discriminating between groups of individuals, it can only be used to support the diagnosis of the ocular ischaemic syndrome in patients with extreme flow reduction.

Hansen, Grith Lssrkholm; Kofoed, Peter Kristian

2013-01-01

352

Inflammation in arterial diseases.  

Science.gov (United States)

The pathophysiology of some inflammatory arterial diseases (such as vasculitis, atherogenesis and aneurysms) has been widely investigated in the last decades. Among different soluble molecules, proinflammatory cytokines (such as TNF-?, IL-1 and IL-6) were shown to trigger critical pathways regulating these arterial diseases. Together with these cytokines, chemokines were also associated with endothelial dysfunction and intima injury in arterial diseases. Recently, autoantibodies have been also described to pathophysiologically influence not only autoimmune vasculitis but also atherogenesis and more in general vascular inflammation. These soluble mediators actively trigger inflammatory functions of leukocytes and vascular cells. For instance, B and T lymphocytes, macrophages and neutrophils were shown to actively participate in inflammatory processes within the arterial wall in vasculitis, atherogenesis and aneurysms. The aim of this narrative review is to provide an overview of pathophysiology and treatments targeting arterial inflammation in these diseases. © 2015 IUBMB Life, 67(1):18-28, 2015. PMID:25631520

Carbone, Federico; Montecucco, Fabrizio

2015-01-01

353

Adaptive Optics Technology for High-Resolution Retinal Imaging  

Directory of Open Access Journals (Sweden)

Full Text Available Adaptive optics (AO is a technology used to improve the performance of optical systems by reducing the effects of optical aberrations. The direct visualization of the photoreceptor cells, capillaries and nerve fiber bundles represents the major benefit of adding AO to retinal imaging. Adaptive optics is opening a new frontier for clinical research in ophthalmology, providing new information on the early pathological changes of the retinal microstructures in various retinal diseases. We have reviewed AO technology for retinal imaging, providing information on the core components of an AO retinal camera. The most commonly used wavefront sensing and correcting elements are discussed. Furthermore, we discuss current applications of AO imaging to a population of healthy adults and to the most frequent causes of blindness, including diabetic retinopathy, age-related macular degeneration and glaucoma. We conclude our work with a discussion on future clinical prospects for AO retinal imaging.

Giuseppe Lombardo

2012-12-01

354

Adaptive optics technology for high-resolution retinal imaging.  

Science.gov (United States)

Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of optical aberrations. The direct visualization of the photoreceptor cells, capillaries and nerve fiber bundles represents the major benefit of adding AO to retinal imaging. Adaptive optics is opening a new frontier for clinical research in ophthalmology, providing new information on the early pathological changes of the retinal microstructures in various retinal diseases. We have reviewed AO technology for retinal imaging, providing information on the core components of an AO retinal camera. The most commonly used wavefront sensing and correcting elements are discussed. Furthermore, we discuss current applications of AO imaging to a population of healthy adults and to the most frequent causes of blindness, including diabetic retinopathy, age-related macular degeneration and glaucoma. We conclude our work with a discussion on future clinical prospects for AO retinal imaging. PMID:23271600

Lombardo, Marco; Serrao, Sebastiano; Devaney, Nicholas; Parravano, Mariacristina; Lombardo, Giuseppe

2013-01-01

355

Effects of pyruvate on retinal oxidative damage and retinal ultrastructure in diabetic rats  

Directory of Open Access Journals (Sweden)

Full Text Available AIM:To investigate the changes of retinal histology and oxidative stress in diabetic retinopathy and its reversal by pyruvate in diabetic rats. METHODS:Eighty Wistar rats were divided into 3 groups: control group(20 rats, model group(30 ratsand treatment group(30 rats. After streptozotocin(STZinduced diabetes mellitus in the model group and the treatment group, the treatment group received 2% pyruvate in diet and drinking. The changes of body weight and blood glucose were observed and the changes of glutathione peroxidase(GSH-PX, malonie dialdehyde(MDA, and Na+-K+-ATPase levels of retinal tissue and retinal ultrastructure were investigated in three groups at 12wk after occurrence of diabetes. RESULTS:Compared with control group, the body weight of the model group were significantly decreased, the activities of GSH-PX and ATP in the retina of diabetic rats were significantly lower, the MDA was signigicantly higher and significant changes occurred in retinal ultrastructure. Compared with model group, the blood glucose of the treatment group had no significant changes. However, the activities of GSH and ATP in the retina of diabetic rats were higher, the MDA was lower and the retinal ultrastructure was comparatively mild. CONCLUSION:Pyruvate can alleviate oxidatie stress reaction, improve the energy metabolism of retina, and delay the development of retinopathy.

Yan-Xiu Qi

2014-12-01

356

Variation of laser-induced retinal damage threshold with retinal image size (Abstract Only)  

Science.gov (United States)

The dependence of retinal damage threshold on laser spot size was examined for two pulsewidth regimes; nanosecond- duration Q-switched pluses from a doubled Nd:YAG laser and microsecond-duration pulses from a flashlamp-pumped dye laser. Threshold determination were conducted for nominal retinal image sizes ranging form 1.5 mrad to 100 mrad of visual field, corresponding to image diameters of approximately 22 micrometers to 1.4 mm on the primate retina. Together, this set of retinal damage threshold reveals the functional dependence of threshold on spot size. The threshold dose was found to vary with the area of the image for larger image sizes. The experimental results were compared to the predictions of the Thompson-Gerstman granular model of laser-induced retinal damage. The experimental and theoretical trends of threshold variation with retinal spot size were essentially the same, with both data sets showing threshold dose proportional to image area for spot sizes >= 150 micrometers . The absolute values predicted by the model, however, were significantly higher than experimental values, possibly because of uncertainty in various biological input parameters, such as the melanosome absorption coefficient and the number of melanosomes per RPE cell.

Zuclich, Joseph A.; Lund, David J.; Edsall, Peter R.; Hollins, Richard C.; Smith, Peter A.; Stuck, Bruce E.; McLin, Leon N.; Kennedy, Paul K.; Till, Stephen

2000-03-01

357

Role of Transthoracic Echocardiography in the Evaluation of Patients with Retinal Vein Occlusion  

OpenAIRE

Introduction: Retinal vein occlusion  is a common vascular disorder disrupting vision. Two basic types of RVO are branch retinal vein occlusion and central retinal vein occlusion (CRVO).  Retinal vein occlusion is a multifactor process including systemic illness and local retinal factors.RVO may be associated with atherosclerotic risk factors. We analyzed the role of 2 dimensional transthoracic echocardiography (TTE) for detecting the cardiac disease in patients with retinal veins occlusion...

Afsoon Fazlinezhad; Toka Banaee; Ali Azari; Leila Bigdelu; Mojde Amini

2014-01-01

358

Interventions for prevention of giant retinal tear in the fellow eye  

OpenAIRE

BACKGROUND: A giant retinal tear is a full-thickness retinal break that extends circumferentially around the retina for 90 degrees or more in the presence of a posteriorly detached vitreous. It causes significant visual morbidity from retinal detachment and proliferative vitreoretinopathy. The fellow eye of patients who have had a spontaneous giant retinal tear has an increased risk of developing a giant retinal tear, a retinal detachment or both. Interventions such as 360-degree encircling s...

Ang, Gs; Townend, J.; Lois, N.

2009-01-01

359

Retinal Dehydrogenase 12 (RDH12) Mutations in Leber Congenital Amaurosis  

OpenAIRE

Leber congenital amaurosis (LCA), the most early-onset and severe form of all inherited retinal dystrophies, is responsible for congenital blindness. Ten LCA genes have been mapped, and seven of these have been identified. Because some of these genes are involved in the visual cycle, we regarded the retinal pigment epithelium and photoreceptor-specific retinal dehydrogenase (RDH) genes as candidate genes in LCA. Studying a series of 110 unrelated patients with LCA, we found mutations in the p...

Perrault, Isabelle; Hanein, Sylvain; Gerber, Sylvie; Barbet, Fabienne; Ducroq, Dominique; Dollfus, Helene; Hamel, Christian; Dufier, Jean-louis; Munnich, Arnold; Kaplan, Josseline; Rozet, Jean-michel

2004-01-01

360

Treatment of macular edema due to retinal vein occlusions  

OpenAIRE

Roomasa Channa, Michael Smith, Peter A CampochiaroDepartments of Ophthalmology and Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD, USA Abstract: Retinal vein occlusion (RVO) is a prevalent retinal vascular disease, second only to diabetic retinopathy. Previously there was no treatment for central retinal vein occlusion (CRVO) and patients were simply observed for the development of severe complications, generally resulting in poor visual outcomes. The only treatm...

Channa R; Smith M; Campochiaro P

2011-01-01

361

Retinal oximeter for the blue-green oximetry technique  

OpenAIRE

Retinal oximetry offers potential for noninvasive assessment of central venous oxyhemoglobin saturation (SO2) via the retinal vessels but requires a calibrated accuracy of ±3% saturation in order to be clinically useful. Prior oximeter designs have been hampered by poor saturation calibration accuracy. We demonstrate that the blue-green oximetry (BGO) technique can provide accuracy within ±3% in swine when multiply scattered light from blood within a retinal vessel is isolated. A noninvasiv...

Denninghoff, Kurt R.; Sieluzycka, Katarzyna B.; Hendryx, Jennifer K.; Ririe, Tyson J.; Deluca, Lawrence; Chipman, Russell A.

2011-01-01

362

Electroretinographic assessment of retinal function at high altitude.  

OpenAIRE

Although hypoxia plays a key role in the pathophysiology of many common and well studied retinal diseases, little is known about the effects of high-altitude hypoxia on retinal function. The aim of the present study was to assess retinal function during exposure to high-altitude hypoxia using electroretinography (ERG). This work is related to the Tübingen High Altitude Ophthalmology (THAO) study. Electroretinography was performed in 14 subjects in Tübingen, Germany (341 m) and at high altit...

Schatz, A.; Willmann, G.; Fischer, Md; Schommer, K.; Messias, A.; Zrenner, E.; Bartz-schmidt, Ku; Gekeler, F.

2013-01-01

363

Adaptive Optics Technology for High-Resolution Retinal Imaging  

OpenAIRE

Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of optical aberrations. The direct visualization of the photoreceptor cells, capillaries and nerve fiber bundles represents the major benefit of adding AO to retinal imaging. Adaptive optics is opening a new frontier for clinical research in ophthalmology, providing new information on the early pathological changes of the retinal microstructures in various retinal diseases. We have ...

Giuseppe Lombardo; Mariacristina Parravano; Nicholas Devaney; Marco Lombardo; Sebastiano Serrao

2012-01-01

364

Management of retinal vascular diseases: a patient-centric approach  

OpenAIRE

Retinal vascular diseases are a leading cause of blindness in the Western world. Advancement in the clinical management of these diseases has been fast-paced, with new treatments becoming available as well as license extensions of existing treatments. Vascular endothelial growth factor (VEGF) has been implicated in certain retinal vascular diseases, including wet age-related macular degeneration (AMD), diabetic macular oedema (DMO), and retinal vein occlusion (RVO). Treatment of wet AMD and v...

Brand, C. S.

2012-01-01

365

Intrinsic Light Response of Retinal Horizontal Cells of Teleosts  

OpenAIRE

The discovery of intrinsically photosensitive retinal ganglion cells (ipRGCs) has overthrown the long-held belief that rods and cones are the exclusive retinal photoreceptors1, 2. IpRGCs use melanopsin3 as the photopigment, and mediate non-image-forming visual functions such as circadian photoentrainment. In fish, melanopsin has been suggested by in situ hybridization studies to be in retinal horizontal cells (HCs)4-6– lateral association neurons critical for creating the center-surround re...

Cheng, Ning; Tsunenari, Takashi; Yau, King-wai

2009-01-01

366

A Mosaic of Synaptic Contacts among Three Retinal Neurons  

OpenAIRE

Retinal bipolar, amacrine and ganglion cells contact each other within precisely defined synaptic laminae, but the spatial distribution of contacts between the cells is generally treated as random. Here, we show that not to be the case. Excitatory inputs to inner retinal neurons were visualized by introduction of a plasmid coding for the postsynaptic protein PSD95-GFP. Our initial finding was that synapses upon the dendrites of retinal ganglion cells are regularly spaced, at 2–3 µm interva...

Koizumi, Amane; Jakobs, Tatjana C.; Masland, Richard H.

2011-01-01

367

Chick Retinal Pigment Epithelium Transdifferentiation Assay for Proneural Activities  

OpenAIRE

We describe a cell culture system for assaying proneural activities of genes hypothesized to play instrumental roles in neuronal fate specification during vertebrate retinal development. The retinal pigment epithelium (RPE) is collected from embryonic day 6 (E6) chick to establish a primary RPE cell culture. The culture is then infected with a replication competent retrovirus RCAS expressing the gene of interest. The presence of retinal neurons in the otherwise nonneural, RPE cell culture is ...

Wang, Shu-zhen; Yan, Run-tao

2012-01-01

368

Management of varicella zoster virus retinitis in AIDS  

OpenAIRE

AIMS/BACKGROUND—Varicella zoster virus retinitis (VZVR) in patients with AIDS, also called progressive outer retinal necrosis (PORN), is a necrotising viral retinitis which has resulted in blindness in most patients. The purposes of this study were to investigate the clinical course and visual outcome, and to determine if the choice of a systemic antiviral therapy affected the final visual outcome in patients with VZVR and AIDS.?METHODS—A review of the clinical records of 20 patients w...

Moorthy, R.; Weinberg, D.; Teich, S.; Berger, B.; Minturn, J.; Kumar, S.; Rao, N.; Fowell, S.; Loose, I.; Jampol, L.

1997-01-01

369

Scleral buckling for retinal detachment in patients with retinoblastoma  

Energy Technology Data Exchange (ETDEWEB)

Three children (two girls and one boy) with bilateral retinoblastoma each developed a presumed rhegmatogenous retinal detachment in one eye. All three eyes had previously received radiation and cryotherapy. In each case the retinal detachment responded promptly to conventional surgical methods via scleral buckling in the area of treated retinoblastoma and presumed retinal break. All three eyes have retained useful vision for follow-up periods of 3.5 to 12 years.

Buzney, S.M.; Pruett, R.C.; Regan, C.D.; Walton, D.S.; Smith, T.R.

1984-10-15

370

Guidelines for the management of rhegmatogenous retinal detachment  

OpenAIRE

Current techniques of rhegmatogenous retinal detachment repair allow most detachments to be repaired successfully. The success of repair depends on a careful pre-operative examination and choice of an appropriate procedure. The surgery is usually tailored to individual needs. Improvements in surgical techniques coupled with a better understanding of the pathophysiology of rhegmatogenous retinal detachment continue to improve the anatomic and functional success of retinal detachment repair.

Das Taraprasad

1993-01-01

371

Scleral buckling for retinal detachment in patients with retinoblastoma  

International Nuclear Information System (INIS)

Three children (two girls and one boy) with bilateral retinoblastoma each developed a presumed rhegmatogenous retinal detachment in one eye. All three eyes had previously received radiation and cryotherapy. In each case the retinal detachment responded promptly to conventional surgical methods via scleral buckling in the area of treated retinoblastoma and presumed retinal break. All three eyes have retained useful vision for follow-up periods of 3.5 to 12 years

372

Guidelines for the management of rhegmatogenous retinal detachment  

Directory of Open Access Journals (Sweden)

Full Text Available Current techniques of rhegmatogenous retinal detachment repair allow most detachments to be repaired successfully. The success of repair depends on a careful pre-operative examination and choice of an appropriate procedure. The surgery is usually tailored to individual needs. Improvements in surgical techniques coupled with a better understanding of the pathophysiology of rhegmatogenous retinal detachment continue to improve the anatomic and functional success of retinal detachment repair.

Das Taraprasad

1993-01-01

373

Retinal Proliferation Response in the Buphthalmic Zebrafish, bugeye  

OpenAIRE

The zebrafish retina regenerates in response to acute retinal lesions, replacing damaged neurons with new neurons. In this study we test the hypothesis that chronic stress to inner retinal neurons also triggers a retinal regeneration response in the bugeye zebrafish. Mutations in the lrp2 gene in zebrafish are associated with a progressive eye phenotype (bugeye) that models several risk factors for human glaucoma including buphthalmos (enlarged eyes), elevated intraocular pressure (IOP), and ...

Sherpa, Tshering; Hunter, Samuel S.; Frey, Ruth A.; Robison, Barrie D.; Stenkamp, Deborah L.

2011-01-01

374

Structural Changes in Individual Retinal Layers in Diabetic Macular Edema  

OpenAIRE

Optical coherence tomography (OCT) has enabled objective measurement of the total retinal thickness in diabetic macular edema (DME). The central retinal thickness is correlated modestly with visual impairment and changes paradoxically after treatments compared to the visual acuity. This suggests the clinical relevance of the central retinal thickness in DME and the presence of other factors that affect visual disturbance. Recent advances in spectral-domain (SD) OCT have provided better deline...

Tomoaki Murakami; Nagahisa Yoshimura

2013-01-01

375

Retinitis pigmentosa and congenital toxoplasmosis: A rare coexistence  

OpenAIRE

We describe a previously unreported co-existence of retinitis pigmentosa and congenital toxoplasmosis. An eight year old male presented to our center with complaints of decreased night vision. Fundus evaluations in both the eyes demonstrated features typical of retinitis pigmentosa. There were well-defined punched out healed chorio-retinal scars suggestive of congenital toxoplasmosis. On the basis of history, clinical findings and reduction of a and b wave amplitudes on scotopic and photopic ...

Chhabra Manpreet; Prakash Gunjan; Vashisht Nagender; Garg S

2007-01-01

376

Pre-mRNA splicing and retinitis pigmentosa  

OpenAIRE

Retinitis pigmentosa (RP) is a group of genetically and clinically heterogeneous retinal diseases and a common cause of blindness. Among the 12 autosomal dominant RP (adRP) genes identified, four encode ubiquitously expressed proteins involved in pre-mRNA splicing, demonstrating the important role that pre-mRNA splicing plays in the pathogenesis of retinal degeneration. This review focuses on recent progress in identifying adRP mutations in genes encoding pre-mRNA splicing factors and the pot...

Mordes, Daniel; Luo, Xiaoyan; Kar, Amar; Kuo, David; Xu, Lili; Fushimi, Kazuo; Yu, Guowu; Sternberg, Paul; Wu, Jane Y.

2006-01-01

377

Taurine Provides Neuroprotection against Retinal Ganglion Cell Degeneration  

OpenAIRE

Retinal ganglion cell (RGC) degeneration occurs in numerous retinal diseases leading to blindness, either as a primary process like in glaucoma, or secondary to photoreceptor loss. However, no commercial drug is yet directly targeting RGCs for their neuroprotection. In the 70s, taurine, a small sulfonic acid provided by nutrition, was found to be essential for the survival of photoreceptors, but this dependence was not related to any retinal disease. More recently, taurine deprivation was inc...

Froger, Nicolas; Cadetti, Lucia; Lorach, Henri; Martins, Joao; Bemelmans, Alexis-pierre; Dubus, Elisabeth; Degardin, Julie; Pain, Dorothe?e; Forster, Vale?rie; Chicaud, Laurent; Ivkovic, Ivana; Simonutti, Manuel; Fouquet, Ste?phane; Jammoul, Firas; Le?veillard, Thierry

2012-01-01

378

Dissecting aneurysm of the cervical internal carotid artery  

International Nuclear Information System (INIS)

On lifting a heavy case, a 51-year-old male experienced a sudden onset of headache with giddiness and clouded vision. A week later, vertigo and right hand numbness were added to his symptoms. The next day anisocoria (right > left) and dilation of the left retinal veins were noted. Cranial computed tomography (CT) scan appeared normal and there were no other remarkable neurological findings. The patient was treated conservatively for cerebral infarction, however, the headache worsened and diplopia occurred. Neurological examination on admission revealed nothing unusual except for left Horner's syndrome. Physical examination showed a palpable sausage-like painless tumor on the left side of the neck. Angiography showed a narrowing of the internal carotid artery in the cervical region with a small dissecting aneurysm at the C3 level. Cervical CT scan at the upper C3 level showed a low density lunar defect in the high density section of the enlarged left internal carotid artery. The patient was operated on by superficial temporal artery-middle cerebral artery anastomosis to increase the intracranial blood flow. Postoperatively the symptoms were quickly relieved. Angiography 1 month later showed less narrowing of the carotid artery, though the dissecting aneurysm still remained. Postoperative cervical CT scan showed the left internal carotid artery to be of normal size. The patient returned to his work in normal condition 2 months later. It is emphasized that cervical CT scater. It is emphasized that cervical CT scan may be useful in the diagnosis of this unusual type of cervical dissecting aneurysm. (author)

379

Retinal imaging after corneal inlay implantation.  

Science.gov (United States)

We report 2 cases of implantation with the Kamra corneal inlay to describe central and peripheral retinal visibility and the quality of optical coherence tomography (OCT) scans. Under pharmacological mydriasis, the central and peripheral retina was explored without disturbance by an experienced retinal ophthalmologist. Central color imaging was done without difficulty, and peripheral imaging was accurate despite a small bright shadow in every image. The quality of the OCT scans of the macular line, macular 3-dimensional cube, and macular radial protocols were 156.51, 77.49, and 84.35, respectively, in patient 1 and 106.66, 63.03, and 64.69, respectively, in patient 2 without artifact scanning. The inlay allowed normal visualization of the central and peripheral fundus, as well as good-quality central and peripheral imaging and OCT scans. PMID:21855770

Casas-Llera, Pilar; Ruiz-Moreno, José M; Alió, Jorge L

2011-09-01

380

Practical management of retinal vein occlusions.  

Science.gov (United States)

Retinal vein occlusion (RVO) is the second most common cause of visual impairment due to retinal disease after diabetic retinopathy. Nowadays, the introduction of new, powerful diagnostic tools, such as spectral domain optical coherence tomography, and the widespread diffusion of intravitreal drugs, such as vascular endothelial grow factor inhibitors or implantable steroids, have dramatically changed the management and prognosis of RVO. The authors aim to summarize and review the main clinical, diagnostic, and therapeutic aspects of this condition. The authors conducted a review of the most relevant clinical trials and observational studies published within the last 30 years using a keyword search of MEDLINE, EMBASE, Current Contents, and Cochrane Library. Furthermore, for all treatments discussed, the level of evidence supporting its use, as per the US Preventive Task Force Ranking System, is provided. PMID:25135583

La Spina, Carlo; De Benedetto, Umberto; Parodi, Maurizio Battaglia; Coscas, Gabriel; Bandello, Francesco

2012-12-01

381

Retinal injury from a welding arc  

International Nuclear Information System (INIS)

An 18-year-old man stared at a welding arc for approximately ten minutes, sustaining moderate facial erythema, keratoconjunctivitis, marked visual loss, a pupillary abnormality, and a retinal injury accompanied by a dense central scotoma and peripheral field constriction. A residual, partially pigmented foveal lesion remained after 16 months, with normal visual acuity. Since the degree of keratoconjunctivitis and facial erythema was known, we substantiated the duration of exposure to the arc by weighting the known action spectrum of moderate ultraviolet erythema with the ultraviolet spectral irradiance measurements of the arc. From the radiometric measurements of the visible brightness and visible and near infrared spectrum of the arc and from knowledge of pupil size, we calculated the retinal exposure dose rate, which was less than normally considered necessary to produce a chorioretinal burn. This case may provide a clinical example of photic maculopathy recently reported in experimental investigations

382

Retinal stem/progenitor cells in the ciliary marginal zone complete retinal regeneration: a study of retinal regeneration in a novel animal model.  

Science.gov (United States)

Our research group has extensively studied retinal regeneration in adult Xenopus laevis. However, X. laevis does not represent a suitable model for multigenerational genetics and genomic approaches. Instead, Xenopus tropicalis is considered as the ideal model for these studies, although little is known about retinal regeneration in X. tropicalis. In the present study, we showed that a complete retina regenerates at approximately 30 days after whole retinal removal. The regenerating retina was derived from the stem/progenitor cells in the ciliary marginal zone (CMZ), indicating a novel mode of vertebrate retinal regeneration, which has not been previously reported. In a previous study, we showed that in X. laevis, retinal regeneration occurs primarily through the transdifferentiation of retinal pigmented epithelial (RPE) cells. RPE cells migrate to the retinal vascular membrane and reform a new epithelium, which then differentiates into the retina. In X. tropicalis, RPE cells also migrated to the vascular membrane, but transdifferentiation was not evident. Using two tissue culture models of RPE tissues, it was shown that in X. laevis RPE culture neuronal differentiation and reconstruction of the retinal three-dimensional (3-D) structure were clearly observed, while in X. tropicalis RPE culture neither ßIII tubulin-positive cells nor 3-D retinal structure were seen. These results indicate that the two Xenopus species are excellent models to clarify the cellular and molecular mechanisms of retinal regeneration, as these animals have contrasting modes of regeneration; one mode primarily involves RPE cells and the other mode involves stem/progenitor cells in the CMZ. PMID:24488715

Miyake, Ayumi; Araki, Masasuke

2014-07-01

383

Genetic determinants of hyaloid and retinal vasculature in zebrafish  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The retinal vasculature is a capillary network of blood vessels that nourishes the inner retina of most mammals. Developmental abnormalities or microvascular complications in the retinal vasculature result in severe human eye diseases that lead to blindness. To exploit the advantages of zebrafish for genetic, developmental and pharmacological studies of retinal vasculature, we characterised the intraocular vasculature in zebrafish. Results We show a detailed morphological and developmental analysis of the retinal blood supply in zebrafish. Similar to the transient hyaloid vasculature in mammalian embryos, vessels are first found attached to the zebrafish lens at 2.5 days post fertilisation. These vessels progressively lose contact with the lens and by 30 days post fertilisation adhere to the inner limiting membrane of the juvenile retina. Ultrastructure analysis shows these vessels to exhibit distinctive hallmarks of mammalian retinal vasculature. For example, smooth muscle actin-expressing pericytes are ensheathed by the basal lamina of the blood vessel, and vesicle vacuolar organelles (VVO, subcellular mediators of vessel-retinal nourishment, are present. Finally, we identify 9 genes with cell membrane, extracellular matrix and unknown identity that are necessary for zebrafish hyaloid and retinal vasculature development. Conclusion Zebrafish have a retinal blood supply with a characteristic developmental and adult morphology. Abnormalities of these intraocular vessels are easily observed, enabling application of genetic and chemical approaches in zebrafish to identify molecular regulators of hyaloid and retinal vasculature in development and disease.

Hyde David R

2007-10-01

384

Retinal detachment secondary to ocular perforation during retrobulbar Anaesthesia  

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Full Text Available The clinical characteristics and the retinal breaks associated with rhegmatogenous retinal detachments secondary to accidental globe perforation during local infiltration anaesthesia in five highly myopic eyes are presented. Retinal detachment was total with variable proliferative vitreoretinopathy. The pattern of retinal breaks was rather typical and predictable. Management involved vitreous surgery with internal tamponade by silicone oil in four eyes and perfluoropropane gas in one eye. At the last follow-up, all eyes had attached retina. One eye did not recover useful vision due to possible concurrent optic nerve damage.

Gopal Lingam

1995-01-01

385

Internal retinal biopsy: surgical technique and results.  

Science.gov (United States)

I have performed an internal retinal biopsy on fourteen patients. The technique involves the use of vitrectomy instrumentation endodiathermy, endolaser and vitreous scissors to remove a 1-2 mm2 area of the diseased retina. Endolaser photocoagulation and air-fluid exchange with and without the use of silicone oil conclude the surgery. No significant postoperative complication has been noted in patients undergoing this procedure. PMID:2338383

Peyman, G A

1990-03-01

386

Operational Design Considerations for Retinal Prostheses  

OpenAIRE

Three critical improvements for present day and future retinal vision implants are proposed and discussed: (1) A time profile for the stimulation current that leads predominantly to transverse stimulation of nerve cells; (2) auxiliary electric currents for electric field shaping with a time profile chosen such that these currents have small probability to cause stimulation; and (3) a local area scanning procedure that results in high pixel density for image/percept formation...

Schmid, Erich W.; Fink, Wolfgang

2012-01-01

387

Iron homeostasis and toxicity in retinal degeneration  

OpenAIRE

Iron is essential for many metabolic processes but can also cause damage. As a potent generator of hydroxyl radical, the most reactive of the free radicals, iron can cause considerable oxidative stress. Since iron is absorbed through diet but not excreted except through menstruation, total body iron levels build up with age. Macular iron levels increase with age, in both men and women. This iron has the potential to contribute to retinal degeneration.

He, Xining; Hahn, Paul; Iacovelli, Jared; Wong, Robert; King, Chih; Bhisitkul, Robert; Massaro-giordano, Mina; Dunaief, Joshua L.

2007-01-01

388

Retinal Encoding of Ultrabrief Shape Recognition Cues  

OpenAIRE

Shape encoding mechanisms can be probed by the sequential brief display of dots that mark the boundary of the shape, and delays of less that a millisecond between successive dots can impair recognition. It is not entirely clear whether this is accomplished by preserving stimulus timing in the signal being sent to the brain, or calls for a retinal binding mechanism. Two experiments manipulated the degree of simultaneity among and within dot pairs, requiring also that the pair members be in the...

Greene, Ernest

2007-01-01

389

Retinal representation of the elementary visual signal  

OpenAIRE

The propagation of visual signals from individual cone photoreceptors through parallel neural circuits was examined in the primate retina. Targeted stimulation of individual cones was combined with simultaneous recording from multiple retinal ganglion cells of identified types. The visual signal initiated by an individual cone produced strong responses with different kinetics in three of the four numerically dominant ganglion cell types. The magnitude and kinetics of light responses in each g...

Li, Peter H.; Field, Greg D.; Greschner, Martin; Ahn, Daniel; Gunning, Deborah E.; Mathieson, Keith; Sher, Alexander; Litke, Alan M.; Chichilnisky, E. J.

2014-01-01

390

VEGF Modulation of Retinal Pigment Epithelium Resistance  

OpenAIRE

Fluid accumulation into the subretinal space and the development of macular edema is a common condition in age-related macular degeneration, diabetic retinopathy, and following ocular surgery, or injury. Vascular endothelial growth factor (VEGF) and other cytokines have been implicated in the disruption of retinal pigment epithelium (RPE) barrier function and a reduction in the regulated removal of subretinal fluid; however, the cellular and molecular events linking these agents to the disrup...

Ablonczy, Zsolt; Crosson, Craig E.

2007-01-01

391

Interconnection Between Brain and Retinal Neurodegenerations.  

Science.gov (United States)

The eye is a special sensory organ, which is basically an extension of the brain. Both are derived from neural tube and consist of neurons. Therefore, diseases of both the brain and eye should have some similarity. Neurodegenerative disorders like Alzheimer's disease (AD) is the major cause of dementia in the world. Amyloid deposition in the cerebral cortex and hippocampal region is the basic pathology in AD. But along with it, there are various changes that take place in the eye, i.e., abnormal pupillary reaction, decreased vision, decreased contrast sensitivity, visual field changes, loss of retinal ganglionic cells and retinal fiber layer, peripapillary atrophy, increased cup-disk ratio, retinal thinning, tortuosity of blood vessels, and deposition of A?-like substance in the retina. And these changes are present in the early part of the disease when only mild cognitive impairment is there. As the brain is covered by a hard bony skull which makes it difficult to directly visualize the changes occurring in the brain at molecular levels, finer details of disease progression are not available with us. But the eye is the window of the brain; with advanced modern techniques, we can directly visualize the changes in the retina at a very fine level. Therefore, by depicting neurodegenerative changes in the eye, we can diagnose and manage AD at very early stages. Along with it, retinal neurodegenerations like glaucoma and age-related macular degeneration (ARMD) are the major cause of loss of vision, and still, there are no effective treatment modalities for these blinding conditions. So if we can understand its pathogenesis and progression by correlating with brain neurodegenerations, we can come up with a better therapy for glaucoma and ARMD. PMID:24826919

Jindal, Vishal

2014-05-15

392

Retinal prosthetics, optogenetics, and chemical photoswitches.  

Science.gov (United States)

Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral delivery of type 1 opsin genes from prokaryotes or eukaryote algae to restore light responses in survivor neurons. Targeting and expression remain major problems, but are potentially soluble. Importantly, optogenetics could provide the ultimate in high-resolution vision due to the long persistence of gene expression achieved in animal models. Nevertheless, optogenetics remains challenging to implement in human eyes with large volumes, complex disease progression, and physical barriers to viral penetration. Now, a new generation of photochromic ligands or chemical photoswitches (azobenzene-quaternary ammonium derivatives) can be injected into a degenerated mouse eye and, in minutes to hours, activate light responses in neurons. These photoswitches offer the potential for rapidly and reversibly screening the vision restoration expected in an individual patient. Chemical photoswitch variants that persist in the cell membrane could make them a simple therapy of choice, with resolution and sensitivity equivalent to optogenetics approaches. A major complexity in treating retinal degenerations is retinal remodeling: pathologic network rewiring, molecular reprogramming, and cell death that compromise signaling in the surviving retina. Remodeling forces a choice between upstream and downstream targeting, each engaging different benefits and defects. Prosthetics and optogenetics can be implemented in either mode, but the use of chemical photoswitches is currently limited to downstream implementations. Even so, given the high density of human foveal ganglion cells, the ultimate chemical photoswitch treatment could deliver cost-effective, high-resolution vision for the blind. PMID:25089879

Marc, Robert; Pfeiffer, Rebecca; Jones, Bryan

2014-10-15

393

Urinary neopterin in idiopathic retinal vasculitis  

OpenAIRE

AIMS—To determine whether urinary neopterin:creatinine (UNC) ratios relate to disease activity in idiopathic retinal vasculitis (RV).?METHODS—18 patients with RV were prospectively recruited into a year long longitudinal study. Patients collected first morning urine samples on a weekly basis and on the same day completed a diary which documented their subjective view of RV activity and any concurrent infection. They were examined in clinic on a 6-8 weekly basis and an objective assessme...

Palmer, H.; Giovannoni, G.; Stanford, M.; Wallace, G.; Graham, E.

2001-01-01

394

Retinitis Pigmentosa in Childhood: A Case Report  

Directory of Open Access Journals (Sweden)

Full Text Available Retinitis pigmentosa (RP is characterized by progressive loss of vision and accompanied by many syndromes. Therefore, early diagnosis is very important in RP. Now, definitive treatment of RP is not available. Diagnosis is performed with good medical history and ophthalmolojical examination. We present a patient with RP and describe diagnosis, treatment and approach to this disease. (Journal of Current Pediatrics 2008; 6: 43-6

Erdal Eren

2008-06-01

395

[Scleral buckling for Rhegmatogenous retinal detachment].  

Science.gov (United States)

Rhegmatogenous retinal detachment (RRD) is the separation of the sensory retina from the pigment epithelium (RPE). RRD is caused by a retinal tear in the periphery and the vitreoretinal (VR) traction, which allows access of the vitreous fluid to the subretinal space. Treatment of symptomatic retinal detachment is currently surgical only. Surgical options are intraocular and extraocular. This is the retrospective evaluation of the group of 17 eyes of 17 patients with RRD, which were operated by scleral buckling. Patients were 9 men and 8 women, age range 19-61 (median 46) years. The observation period is 1-13 months (median 7). The possible types of external interventions procedure were used only two: the radial plombage (in one case double) and cerclage. 15 patients (88 %) were phakic, and 2 were pseudophakic. In 12 eyes (71 %) were the quadrant RRDs, 2 eyes had dialysis in periphery of the retina, 1x it was the top half and 1x bottom half, and 1 patient had a subtotal RRD. In 9 (53 %) cases were used type of operation cryocoagulation with radial buckle and in 8 cases cryocoagulation with the cerclage. In four cases, was injected the gas tamponade into the vitreous at the end of the surgery. Primary attaching the retina occurred in 16 cases (94 %) and the retina remained flat in 14 eyes (82.4% ), in 2 cases occurred re-detachment (11.7 %). Preoperative best corrected visual acuity (BCVA) ranged from hand movement to 20/20 (average Snellen equivalent 20/63) and postoperative BCVA was 1/50 - 20/20 (average 20/50). Improving BCVA was statistically significant (Wilcoxon p=0.01). We consider the cryosurgical procedure for phakic eyes as the gold standard of the surgical treatment of uncomplicated rhegmatogenous retinal detachment. The main reason for the eventual failure of this technique is persistent vitreous traction and proliferative vitreoretinopathy (PVR). PMID:25032797

Hejsek, L; Dusová, J; Stepanov, A; Rozsíval, P

2014-06-01

396

Laser-induced retinal damage threshold as a function of retinal image size  

Science.gov (United States)

The dependence of retinal damage threshold on laser spot size was examined for two pulsewidth regimes; nanosecond- duration Q-switched pulses from a doubled Nd:YAG laser and microsecond-duration pulses from a flashlamp-pumped dye laser. Threshold determinations were conducted for nominal retinal image sizes ranging from 1.5 mrad to 100 mrad of visual field, corresponding to image diameters of approximately 22 ?m to 1.4 mm on the primate retina. In addition, baseline collimated-beam damage thresholds were determined for comparison to the extended source data. Together, this set of retinal damage thresholds reveals the functional dependence of threshold on spot size. The threshold dose was found to vary with the area of the image for larger image sizes. The results are compared to previously published extended source damage thresholds and to the ANSI Z136.1 laser safety standard maximum permissible exposure levels for diffuse reflections.

Zuclich, Joseph A.; Lund, David J.; Edsall, Peter R.; Hollins, Richard C.; Smith, Peter A.; Stuck, Bruce E.; McLin, Leon N.

1999-06-01

397

Idiopathic juxtafoveolar retinal telangiectasis: A current review  

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Full Text Available Idiopathic juxtafoveolar retinal telangiectasis (IJFT, also known as parafoveal telangiectasis or idiopathic macular telangiectasia, refers to a heterogeneous group of well-recognized clinical entities characterized by telangiectatic alterations of the juxtafoveolar capillary network of one or both eyes, but which differ in appearance, presumed pathogenesis, and management strategies. Classically, three groups of IJFT are identified. Group I is unilateral easily visible telangiectasis occurring predominantly in males, and causing visual loss as a result of macular edema. Group II, the most common, is bilateral occurring in both middle-aged men and women, and presenting with telangiectasis that is more difficult to detect on biomicroscopy, but with characteristic and diagnostic angiographic and optical coherence tomography features. Vision loss is due to retinal atrophy, not exudation, and subretinal neovascularization is common. Group III is very rare characterized predominantly by progressive obliteration of the perifoveal capillary network, occurring usually in association with a medical or neurologic disease. This paper presents a current review of juxtafoveolar retinal telangiectasis, reviewing the classification of these entities and focusing primarily on the two most common types encountered in clinical practice, i.e., groups I and II, describing their clinical features, histopathology, natural history, complications, latest results from imaging modalities and functional studies, differential diagnosis, and treatment modalities.

Nowilaty Sawsan

2010-01-01

398

Finite element modeling of retinal prosthesis mechanics  

Science.gov (United States)

Epiretinal prostheses used to treat degenerative retina diseases apply stimulus via an electrode array fixed to the ganglion cell side of the retina. Mechanical pressure applied by these arrays to the retina, both during initial insertion and throughout chronic use, could cause sufficient retinal damage to reduce the device's effectiveness. In order to understand and minimize potential mechanical damage, we have used finite element analysis to model mechanical interactions between an electrode array and the retina in both acute and chronic loading configurations. Modeling indicates that an acute tacking force distributes stress primarily underneath the tack site and heel edge of the array, while more moderate chronic stresses are distributed more evenly underneath the array. Retinal damage in a canine model chronically implanted with a similar array occurred in correlating locations, and model predictions correlate well with benchtop eyewall compression tests. This model provides retinal prosthesis researchers with a tool to optimize the mechanical electrode array design, but the techniques used here represent a unique effort to combine a modifiable device and soft biological tissues in the same model and those techniques could be extended to other devices that come into mechanical contact with soft neural tissues.

Basinger, B. C.; Rowley, A. P.; Chen, K.; Humayun, M. S.; Weiland, J. D.

2009-10-01

399

Automatic retinal interest evaluation system (ARIES).  

Science.gov (United States)

In recent years, there has been increasing interest in the use of automatic computer-based systems for the detection of eye diseases such as glaucoma, age-related macular degeneration and diabetic retinopathy. However, in practice, retinal image quality is a big concern as automatic systems without consideration of degraded image quality will likely generate unreliable results. In this paper, an automatic retinal image quality assessment system (ARIES) is introduced to assess both image quality of the whole image and focal regions of interest. ARIES achieves 99.54% accuracy in distinguishing fundus images from other types of images through a retinal image identification step in a dataset of 35342 images. The system employs high level image quality measures (HIQM) to perform image quality assessment, and achieves areas under curve (AUCs) of 0.958 and 0.987 for whole image and optic disk region respectively in a testing dataset of 370 images. ARIES acts as a form of automatic quality control which ensures good quality images are used for processing, and can also be used to alert operators of poor quality images at the time of acquisition. PMID:25569922

Yin, Fengshou; Wong, Damon Wing Kee; Yow, Ai Ping; Lee, Beng Hai; Quan, Ying; Zhang, Zhuo; Gopalakrishnan, Kavitha; Li, Ruoying; Liu, Jiang

2014-01-01

400

Retinal image quality assessment using generic features  

Science.gov (United States)

Retinal image quality assessment is an important step in automated eye disease diagnosis. Diagnosis accuracy is highly dependent on the quality of retinal images, because poor image quality might prevent the observation of significant eye features and disease manifestations. A robust algorithm is therefore required in order to evaluate the quality of images in a large database. We developed an algorithm for retinal image quality assessment based on generic features that is independent from segmentation methods. It exploits the local sharpness and texture features by applying the cumulative probability of blur detection metric and run-length encoding algorithm, respectively. The quality features are combined to evaluate the image's suitability for diagnosis purposes. Based on the recommendations of medical experts and our experience, we compared a global and a local approach. A support vector machine with radial basis functions was used as a nonlinear classifier in order to classify images to gradable and ungradable groups. We applied our methodology to 65 images of size 2592×1944 pixels that had been graded by a medical expert. The expert evaluated 38 images as gradable and 27 as ungradable. The results indicate very good agreement between the proposed algorithm's predictions and the medical expert's judgment: the sensitivity and specificity for the local approach are respectively 92% and 94%. The algorithm demonstrates sufficient robustness to identify relevant images for automated diagnosis.

Fasih, Mahnaz; Langlois, J. M. Pierre; Ben Tahar, Houssem; Cheriet, Farida

2014-03-01

401

Corneal topographic changes following retinal surgery  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background To study the effect of retinal/ vitreoretinal surgeries on corneal elevations. Methods Patients who underwent retinal/ vitreoretinal surgeries were divided into 3 groups. Scleral buckling was performed in 11 eyes (Group 1. In 8 (25% eyes, vitreoretinal surgery was performed along with scleral buckling (Group 2. In 12 eyes, pars plana vitrectomy was performed for vitreous hemorrhage (Group 3. An encircling element was used in all the eyes. The parameters evaluated were best-corrected visual acuity (BCVA, change in axial length, and corneal topographic changes on Orbscan topography system II, preoperative and at 12 weeks following surgery. Results There was a statistically significant increase in anterior corneal elevation in all the three groups after surgery (p = 0.003, p = 0.008 & p = 0.003 respectively. The increase in posterior corneal elevation was highly significant in all the three groups after surgery (p = 0.0000, p = 0.0001 & p = 0.0001 respectively. The increase in the posterior corneal elevation was more than the increase in the anterior elevation and was significant statistically in all the three groups (group I: p = 0.02; group II: p = 0.01; group III: p = 0.008. Conclusions Retinal/ vitreoretinal surgeries cause a significant increase in the corneal elevations and have a greater effect on the posterior corneal surface.

Pandey RM

2004-08-01

402

Retinitis pigmentosa and ocular blood flow  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Is the concept of integrative, preventive and personalised medicine applicable to the relationship between retinitis pigmentosa (RP and ocular blood flow (OBF? RP encompasses a group of hereditary diseases of the posterior segment of the eye characterised by degeneration, atrophy and finally loss of photoreceptors and retinal pigment epithelium, leading to progressive visual loss. Many different mutations affecting different genes can lead to the clinical picture of RP. Even though the disease has a clear genetic background, there are obviously other factors influencing the manifestation and progression of RP. In this review, we focus on the role of OBF. There is evidence that, in PR patients, OBF is more reduced than one would expect secondary to the retinal atrophy. The main cause of this additional component seems to be primary vascular dysregulation (PVD syndrome. As PVD syndrome is partly treatable, a vascular evaluation of RP patients is meaningful. Based on the outcome, a targeted individualised, preventive or supportive treatment might be introduced in selected RP patients.

Konieczka Katarzyna

2012-12-01

403

Extraction and reconstruction of retinal vasculature.  

Science.gov (United States)

Information about retinal vasculature morphology is used in grading the severity and progression of diabetic retinopathy. An image analysis system can help ophthalmologists make accurate and efficient diagnoses. This paper presents the development of an image processing algorithm for detecting and reconstructing retinal vasculature. The detection of the vascular structure is achieved by image enhancement using contrast limited adaptive histogram equalization followed by the extraction of the vessels using bottom-hat morphological transformation. For reconstruction of the complete retinal vasculature, a region growing technique based on first-order Gaussian derivative is developed. The technique incorporates both gradient magnitude change and average intensity as the homogeneity criteria that enable the process to adapt to intensity changes and intensity spread over the vasculature region. The reconstruction technique reduces the required number of seeds to near optimal for the region growing process. It also overcomes poor performance of current seed-based methods, especially with low and inconsistent contrast images as normally seen in vasculature regions of fundus images. Simulations of the algorithm on 20 test images from the DRIVE database show that it outperforms many other published methods and achieved an accuracy range (ability to detect both vessel and non-vessel pixels) of 0.91 - 0.95, a sensitivity range (ability to detect vessel pixels) of 0.91 - 0.95 and a specificity range (ability to detect non-vessel pixels) of 0.88 - 0.94. PMID:17994417

Ahmad Fadzil, M H; Izhar, Lila Iznita; Venkatachalam, P A; Karunakar, T V N

2007-01-01

404

The all-trans-retinal dimer series of lipofuscin pigments in retinal pigment epithelial cells in a recessive Stargardt disease model  

OpenAIRE

The bis-retinoid pigments that accumulate in retinal pigment epithelial cells as lipofuscin are associated with inherited and age-related retinal disease. In addition to A2E and related cis isomers, we previously showed that condensation of two molecules of all-trans-retinal leads to the formation of a protonated Schiff base conjugate, all-trans-retinal dimer-phosphatidylethanolamine. Here we report the characterization of the related pigments, all-trans-retinal dimer-ethanolamine and unconju...

Kim, So R.; Jang, Young P.; Jockusch, Steffen; Fishkin, Nathan E.; Turro, Nicholas J.; Sparrow, Janet R.

2007-01-01

405

PARP1 gene knock-out increases resistance to retinal degeneration without affecting retinal function.  

Science.gov (United States)

Retinitis pigmentosa (RP) is a group of inherited neurodegenerative diseases affecting photoreceptors and causing blindness in humans. Previously, excessive activation of enzymes belonging to the poly-ADP-ribose polymerase (PARP) group was shown to be involved in photoreceptor degeneration in the human homologous rd1 mouse model for RP. Since there are at least 16 different PARP isoforms, we investigated the exact relevance of the predominant isoform - PARP1 - for photoreceptor cell death using PARP1 knock-out (KO) mice. In vivo and ex vivo morphological analysis using optic coherence tomography (OCT) and conventional histology revealed no major alterations of retinal phenotype when compared to wild-type (wt). Likewise, retinal function as assessed by electroretinography (ERG) was normal in PARP1 KO animals. We then used retinal explant cultures derived from wt, rd1, and PARP1 KO animals to test their susceptibility to chemically induced photoreceptor degeneration. Since photoreceptor degeneration in the rd1 retina is triggered by a loss-of-function in phosphodiesterase-6 (PDE6), we used selective PDE6 inhibition to emulate the rd1 situation on non-rd1 genotypes. While wt retina subjected to PDE6 inhibition showed massive photoreceptor degeneration comparable to rd1 retina, in the PARP1 KO situation, cell death was robustly reduced. Together, these findings demonstrate that PARP1 activity is in principle dispensable for normal retinal function, but is of major importance for photoreceptor degeneration under pathological conditions. Moreover, our results suggest that PARP dependent cell death or PARthanatos may play a major role in retinal degeneration and highlight the possibility to use specific PARP inhibitors for the treatment of RP. PMID:21124852

Sahaboglu, Ayse; Tanimoto, Naoyuki; Kaur, Jasvir; Sancho-Pelluz, Javier; Huber, Gesine; Fahl, Edda; Arango-Gonzalez, Blanca; Zrenner, Eberhart; Ekström, Per; Löwenheim, Hubert; Seeliger, Mathias; Paquet-Durand, François

2010-01-01

406

Superdominant right coronary artery with absent left circumflex artery  

OpenAIRE

Noninvasive imaging of coronary artery disease is rapidly replacing angiography as the first line of investigation. Multislice CT is the non-invasive modality of choice for imaging coronary artery disease and provides high speed with good spatial resolution. CT coronary angiography in addition to detecting and characterising atherosclerotic coronary artery disease is also a good imaging tool for evaluating anomalies of coronary arteries. Superdominant right coronary artery with absent left ci...

Warade, M.; Sinha, J.; Kalyanpur, A.; Gupta, T.; Majid, Y.

2011-01-01

407

A novel transgenic zebrafish model for blood-brain and blood-retinal barrier development  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Development and maintenance of the blood-brain and blood-retinal barrier is critical for the homeostasis of brain and retinal tissue. Despite decades of research our knowledge of the formation and maintenance of the blood-brain (BBB and blood-retinal (BRB barrier is very limited. We have established an in vivo model to study the development and maintenance of these barriers by generating a transgenic zebrafish line that expresses a vitamin D-binding protein fused with enhanced green fluorescent protein (DBP-EGFP in blood plasma, as an endogenous tracer. Results The temporal establishment of the BBB and BRB was examined using this transgenic line and the results were compared with that obtained by injection of fluorescent dyes into the sinus venosus of embryos at various stages of development. We also examined the expression of claudin-5, a component of tight junctions during the first 4 days of development. We observed that the BBB of zebrafish starts to develop by 3 dpf, with expression of claudin-5 in the central arteries preceding it at 2 dpf. The hyaloid vasculature in the zebrafish retina develops a barrier function at 3 dpf, which endows the zebrafish with unique advantages for studying the BRB. Conclusion Zebrafish embryos develop BBB and BRB function simultaneously by 3 dpf, which is regulated by tight junction proteins. The Tg(l-fabp:DBP-EGFP zebrafish will have great advantages in studying development and maintenance of the blood-neural barrier, which is a new application for the widely used vertebrate model.

Sugimoto Masahiko

2010-07-01

408

Types of avulsed retinal vessels associated with rhegmatogenous retinal detachment: treatment and results.  

Science.gov (United States)

We performed a prospective study of 87 cases with avulsed retinal vessels in conjunction with tears and rhegmatogenous retinal detachment. The postoperative follow-up period ranged from 6 months to 5 years. The avulsed vessels were classified according to their location (peripheral or central) as well as with respect to their form (5 types). The surgical procedure comprised the fixation of an episcleral sponge implant (high indentation), cryoapplication, and, if necessary, laser coagulation or endodiathermy at a later stage. The postoperative condition of the avulsed vessel mainly depended on its location, the type of avulsion, and the buckle height. PMID:3609759

Theodossiadis, G P; Koutsandrea, C N

1987-01-01

409

Retinal fluorescein contrast arrival time of young patients with the hepatosplenic form of the Schistosomiasis mansoni  

Directory of Open Access Journals (Sweden)

Full Text Available Schistosoma mansoni is responsible for lesions that can alter the hemodinamic of the portal venous circulation, lung arterial and venous sistemic systems. Therefore, hemodinamic changes in the ocular circulation of mansonic schistosomotic patients with portal hypertension and hepatofugal venous blood flow is also probable. The purpose of this study was to determine the fluorescein contrast arrival time at the retina of young patients with the hepatosplenic form of schistosomiasis, clinically and surgically treated. The control group included 36 non schistosomotic patients, mean age of 17.3 years, and the case group was represented by 25 schistosomotic patients, mean age of 18.2 years, who were cared for at The University Hospital (Federal University of Pernambuco, Brazil, from 1990 to 2001. They underwent digital angiofluoresceinography and were evaluated for the contrast arrival time at the early retinal venous phase of the exam. Both groups were ophthalmologically examined at the same hospital (Altino Ventura Foundation, Recife, Brazil, using the same technique. There was retardation of the retinal contrast arrival time equal or more than 70 sec in the eyes of three schistosomotic patients (12% and in none of the control group, however, the mean contrast arrival time between the two groups were not statistically different. These findings lend support to the hypothesis that there could be a delay of the eye venous blood flow drainage.

Ana Catarina Delgado de Souza

2002-10-01

410

Object size, spatial-frequency content and retinal contrast  

Science.gov (United States)

Recent interest in HDR scene capture and display has stimulated measurements of the usable range of contrast information for human vision. These experiments have led to a model that calculates the retinal contrast image. A fraction of the light from each scene pixel is scattered to all retinal pixels. The amount of scattered light decreases with distance from the other pixels. By summing the light falling on each retinal pixel from all the scene pixels we can calculate the retinal image contrast. As objects, such as text letters, get smaller, their retinal contrast gets lower, even though the scene contrast is constant. This paper studies the Landolt C data, a commonly used test targets for measuring visual acuity, using three frameworks. First, it compares the visual acuity measurements with the receptor mosaic dimension. Second, discusses the Campbell and Robson's experiments and the limits of the Contrast Sensitivity Function (CSF). Third, the paper reports the calculated retinal stimulus after intraocular scatter of both Landolt C and Campbell and Robson's stimuli. These three different frameworks are useful in understanding limits of human vision. Each approach gives only one piece of the puzzle. Retinal contrast, CSF, and retinal cone spacing all influence our understanding of human vision limits. We have analyzed Landolt C and CSF using retinal contrast. Glare effect on Landolt C shows that retinal images are significantly different from target images. Veiling glare of the sine-wave stimuli used by Campbell and Robson to measure CSF, results in a retinal contrast decrease. This, above 3-4 cpd, correlates well with the data reported by them.

Rizzi, Alessandro

2010-02-01

411

Carotid Artery Disease  

Science.gov (United States)

... you may soon have a stroke. Sometimes called "mini-strokes," TIAs are temporary episodes of headache, dizziness, ... Arteriography and digital subtraction angiography (DSA), which takes X-ray pictures of the carotid artery after a special ...

412

Peripheral Artery Disease  

Science.gov (United States)

... an angioplasty procedure, an interventional radiologist threads a catheter through a blood vessel to the affected artery and inflates a small balloon to reopen it. In some cases, the insertion of a stent is required to ...

413

Peripheral artery disease - legs  

Science.gov (United States)

... high cholesterol or diabetes. Tests for PAD include: Angiography of the arteries in the legs ( arteriography ) Blood pressure measured in the arms and legs for comparison (ankle/brachial index, or ...

414

Uterine artery embolization - discharge  

Science.gov (United States)

Uterine fibroid embolization - discharge; UFE - discharge; UAE - discharge ... You had uterine artery embolization (UAE). UAE is a procedure to treat ... the blood supply of the fibroids was blocked. This caused ...

415

Radial Artery Catheterization  

Science.gov (United States)

... the leg and prolonged immobility. Previous Section Next Section The Radial Artery Catheterization Procedure Before beginning the procedure, the ... placement of a compression band. Previous Section Next Section Risks of Radial Catheterization Any invasive procedure carries some risk of ...

416

CT of the chest in the evaluation of idiopathic pulmonary arterial hypertension in children  

Energy Technology Data Exchange (ETDEWEB)

Idiopathic pulmonary arterial hypertension (IPAH) is a rare disease in children. By definition it is a diagnosis of exclusion, and CT of the chest is primarily performed to exclude other causes. Previous studies have defined CT features suggestive of the diagnosis of IPAH, but these have all been limited to the adult population. Contrast-enhanced chest CT and high-resolution CT findings in IPAH were evaluated in an attempt to define features consistently seen in children with this condition. The chest CT scans performed at initial presentation were reviewed in 17 children with echocardiographic or angiographic evidence of IPAH. There were nine boys and eight girls, ranging in age from 1 month to 17 years. The extrapulmonary findings included cardiomegaly with right-sided cardiac enlargement, which was seen in 13 children. The central pulmonary arteries were enlarged in 15 children, with peripheral enlargement in two. In six children this resulted in bronchial compression. In addition, mediastinal and hilar lymphadenopathy was noted in three children. Prominent intrapulmonary features included a peripheral vasculopathy, with enlarged tortuous vessels, seen in eight children. Ill-defined ground-glass centrilobular opacities were also noted in eight children, representing the most common parenchymal abnormality. Other findings included septal lines in five, diffuse ground-glass opacification in four and focal hyperlucent zones in three. Mosaic attenuation was seen in one child. A variety of imaging findings are identified in IPAH. Features particularly consistent with the diagnosis include peripheral vasculopathy and centrilobular opacities in the setting of cardiomegaly and central pulmonary arterial enlargement. (orig.)

Chaudry, Gulraiz [University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada); Children' s Hospital Boston, Department of Radiology, Boston, MA (United States); MacDonald, Cathy; Gundogan, Munire; Manson, David [University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada); Adatia, Ian [UCSF Children' s Hospital, Department of Pediatric Cardiology, San Francisco, CA (United States)

2007-04-15

417

Agujero retiniano en polo posterior secundario a un foco de retinitis por cándida / Posterior retinal hole secondary to a candida retinitis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Caso Clínico: Varón de 36 años, heroinómano y HIV negativo, que presenta en su ojo izquierdo una lesión focal de retinitis candidiásica en polo posterior acompañada de iritis moderada y vitritis leve. El tratamiento con fluconazol provocó una buena cicatrización del foco retiniano y desaparición de [...] la vitritis pero dejó una tracción vítrea sobre el foco retiniano con una contracción de la membrana limitante interna macular. A los 2 años la tracción vítrea acabó produciendo un agujero retiniano que precisó fotocoagulación con láser de argón. Discusión: Los focos de retinitis por cándida pueden producir en su evolución agujeros retinianos por la fibrosis y tracción vítrea sobre la propia lesión retiniana. Abstract in english Case report: We describe the case of a 36-year-old man with a history of intravenous heroin use, who was HIV negative. Left ocular examination disclosed a focal candida retinitis in the posterior pole associated with vitritis and moderate iritis. Treatment with fluconazole inactived the chorio-retin [...] al lesion and resolved the vitritis, but developed an inner limiting membrane contraction over the macula. Two years later, vitreous traction produced a retinal hole that needed argon laser photocoagulation. Discussion: Candida retinitis which penetrates into the vitreous cavity can produce retinal holes by vitreous traction over the lesion.

ML, Álvarez-Suárez; L, Sánchez-Tabar; MJ, Viescas-Fernández; MA, Fernández-Álavarez.

2005-07-01

418

Agujero retiniano en polo posterior secundario a un foco de retinitis por cándida Posterior retinal hole secondary to a candida retinitis  

Directory of Open Access Journals (Sweden)

Full Text Available Caso Clínico: Varón de 36 años, heroinómano y HIV negativo, que presenta en su ojo izquierdo una lesión focal de retinitis candidiásica en polo posterior acompañada de iritis moderada y vitritis leve. El tratamiento con fluconazol provocó una buena cicatrización del foco retiniano y desaparición de la vitritis pero dejó una tracción vítrea sobre el foco retiniano con una contracción de la membrana limitante interna macular. A los 2 años la tracción vítrea acabó produciendo un agujero retiniano que precisó fotocoagulación con láser de argón. Discusión: Los focos de retinitis por cándida pueden producir en su evolución agujeros retinianos por la fibrosis y tracción vítrea sobre la propia lesión retiniana.Case report: We describe the case of a 36-year-old man with a history of intravenous heroin use, who was HIV negative. Left ocular examination disclosed a focal candida retinitis in the posterior pole associated with vitritis and moderate iritis. Treatment with fluconazole inactived the chorio-retinal lesion and resolved the vitritis, but developed an inner limiting membrane contraction over the macula. Two years later, vitreous traction produced a retinal hole that needed argon laser photocoagulation. Discussion: Candida retinitis which penetrates into the vitreous cavity can produce retinal holes by vitreous traction over the lesion.

ML Álvarez-Suárez

2005-07-01

419

Popliteal Artery Injuries  

OpenAIRE

Popliteal artery injuries are an important cause of amputation and morbidity. Existence of concomittant bone or other different pathologies and prolonged time of transport to the hospital leads to increased mortality. On the other hand, early surgical intervention, prevention of hypovolemic shock, systemic anticoagulation and fasciotomy in proper cases decrease morbidity and mortality. In both artery and vein injuries, vein ligation must be a non desirable choice, and when it is inevitable fa...

Mehmet ?ahin; Adem Güler; Murat Kadan

2011-01-01

420

Acute carotid artery injury  

OpenAIRE

A case of acute carotid artery injury with unusual presentation is described. Although the clinical and radiographic examinations were in favor of a large cerebral infarction, the initial angiogram in this patient failed to demonstrate any intracranial or extracranial vascular injury. A subsequent angiogram, however, demonstrated a pseudoaneurysm of the left common carotid artery which was treated surgically. He made an excellent recovery in his neurological functions postoperatively.

Sankhla Suresh

2006-01-01

421

Acute carotid artery injury  

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Full Text Available A case of acute carotid artery injury with unusual presentation is described. Although the clinical and radiographic examinations were in favor of a large cerebral infarction, the initial angiogram in this patient failed to demonstrate any intracranial or extracranial vascular injury. A subsequent angiogram, however, demonstrated a pseudoaneurysm of the left common carotid artery which was treated surgically. He made an excellent recovery in his neurological functions postoperatively.

Sankhla Suresh

2006-01-01

422

Retinal Vessel Calibers Predict Long-term Microvascular Complications in Type 1 Diabetes Mellitus : The Danish Cohort of Pediatric Diabetes 1987 (DCPD1987)  

DEFF Research Database (Denmark)

Diabetic neuropathy, nephropathy and retinopathy cause significant morbidity in patients with type 1 diabetes, even though improvements in treatment modalities delay the appearance and reduce the severity of these complications. To prevent or further delay the onset, it is necessary to better understand common underlying pathogenesis and to discover pre-clinical biomarkers of these complications.Retinal vessel calibers have been associated with the presence of microvascular complications but their long-term predictive value has only been sparsely investigated.We examined retinal vessel calibers as 16-year predictors of diabetic nephropathy, neuropathy and proliferative retinopathy in a young population-based Danish cohort with type 1 diabetes. We used semi-automated computer software to analyze vessel diameters on baseline retinal photos. Calibers of all vessels coursing through a zone 0.5-1 disc diameter from the disc margin were measured and summarized as the central artery and vein equivalents.In multiple regression analyzes we found both wider venular diameters and smaller arteriolar diameters to be predictive of the 16-year development of nephropathy, neuropathy and proliferative retinopathy. Early retinal vessel caliber changes are seemingly early markers of microvascular processes, precede the development of microvascular complications and a potential non-invasive predictive test on future risk of diabetic retinopathy, neuropathy and nephropathy.

Broe, Rebecca; Rasmussen, Malin L

2014-01-01

423

Foscarnet as treatment for cytomegalovirus retinitis following bone marrow transplantation.  

OpenAIRE

This report describes a patient with chronic granulocytic leukaemia who developed cataracts on busulphan treatment. Following allogeneic bone marrow transplantation, he developed cytomegalovirus retinitis, which was treated successfully with trisodium phosphonoformate (foscarnet). Cytomegalovirus retinitis and its therapy, and busulphan-induced cataract are discussed.

Ganly, P. S.; Arthur, C.; Goldman, J. M.; Schulenburg, W. E.

1988-01-01

424

Retinal glia promote dorsal root ganglion axon regeneration.  

Science.gov (United States)

Axon regeneration in the adult central nervous system (CNS) is limited by several factors including a lack of neurotrophic support. Recent studies have shown that glia from the adult rat CNS, specifically retinal astrocytes and Müller glia, can promote regeneration of retinal ganglion cell axons. In the present study we investigated whether retinal glia also exert a growth promoting effect outside the visual system. We found that retinal glial conditioned medium significantly enhanced neurite growth and branching of adult rat dorsal root ganglion neurons (DRG) in culture. Furthermore, transplantation of retinal glia significantly enhanced regeneration of DRG axons past the dorsal root entry zone after root crush in adult rats. To identify the factors that mediate the growth promoting effects of retinal glia, mass spectrometric analysis of retinal glial conditioned medium was performed. Apolipoprotein E and secreted protein acidic and rich in cysteine (SPARC) were found to be present in high abundance, a finding further confirmed by western blotting. Inhibition of Apolipoprotein E and SPARC significantly reduced the neuritogenic effects of retinal glial conditioned medium on DRG in culture, suggesting that Apolipoprotein E and SPARC are the major mediators of this regenerative response. PMID:25816134

Lorber, Barbara; Chew, Daniel J; Hauck, Stefanie M; Chong, Rachel S; Fawcett, James W; Martin, Keith R

2015-01-01

425

Alström syndrome – an uncommon cause of early childhood retinal dystrophy  

Science.gov (United States)

Alström syndrome (AS) is a ciliopathy and an uncommon cause of syndromic retinal dystrophy. This case reports findings in a 5-year-old boy with severe early onset retinal dystrophy, and how the recognition of extraocular features with genetic analysis led to the correct diagnosis of AS after 4 years of investigation. PMID:22688943

Sheck, Leo; Al-Taie, Rasha; Sharp, Dianne; Vincent, Andrea

2011-01-01

426