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Elk3 Deficiency Causes Transient Impairment in Post-Natal Retinal Vascular Development and Formation of Tortuous Arteries in Adult Murine Retinae  

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Serum Response Factor (SRF) fulfills essential roles in post-natal retinal angiogenesis and adult neovascularization. These functions have been attributed to the recruitment by SRF of the cofactors Myocardin-Related Transcription Factors MRTF-A and -B, but not the Ternary Complex Factors (TCFs) Elk1 and Elk4. The role of the third TCF, Elk3, remained unknown. We generated a new Elk3 knockout mouse line and showed that Elk3 had specific, non-redundant functions in the retinal vasculature. In Elk3(?/?) mice, post-natal retinal angiogenesis was transiently delayed until P8, after which it proceeded normally. Interestingly, tortuous arteries developed in Elk3(?/?) mice from the age of four weeks, and persisted into late adulthood. Tortuous vessels have been observed in human pathologies, e.g. in ROP and FEVR. These human disorders were linked to altered activities of vascular endothelial growth factor (VEGF) in the affected eyes. However, in Elk3(?/?) mice, we did not observe any changes in VEGF or several other potential confounding factors, including mural cell coverage and blood pressure. Instead, concurrent with the post-natal transient delay of radial outgrowth and the formation of adult tortuous arteries, Elk3-dependent effects on the expression of Angiopoietin/Tie-signalling components were observed. Moreover, in vitro microvessel sprouting and microtube formation from P10 and adult aortic ring explants were reduced. Collectively, these results indicate that Elk3 has distinct roles in maintaining retinal artery integrity. The Elk3 knockout mouse is presented as a new animal model to study retinal artery tortuousity in mice and human patients. PMID:25203538

Weinl, Christine; Wasylyk, Christine; Garcia Garrido, Marina; Sothilingam, Vithiyanjali; Beck, Susanne C.; Riehle, Heidemarie; Stritt, Christine; Roux, Michel J.; Seeliger, Mathias W.; Wasylyk, Bohdan; Nordheim, Alfred

2014-01-01

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Tortuosidad retiniana vascular en neurofibromatosis tipo 1 Tortuous retinal vessels in neurofibromatosis type 1  

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Full Text Available Caso clínico: Se describe un paciente de 4 años con neurofibromatosis tipo 1 (NF-1 y vasos retinianos tortuosos de primer, segundo y tercer orden que terminaban en forma de sacacorcho. Discusión: Los pacientes con NF-1 pueden tener anomalías retinianas vasculares.Case report: We report a 4-year-old patient with neurofibromatosis type 1 (NF-1 who had tortuous retinal vessels of first, second and third order which ended in a corkscrew appearance. Discussion: Vascular retinal abnormalities can be present in patients with NF-1.

VM Asensio-Sánchez

2005-10-01

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Tortuosidad retiniana vascular en neurofibromatosis tipo 1 / Tortuous retinal vessels in neurofibromatosis type 1  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Caso clínico: Se describe un paciente de 4 años con neurofibromatosis tipo 1 (NF-1) y vasos retinianos tortuosos de primer, segundo y tercer orden que terminaban en forma de sacacorcho. Discusión: Los pacientes con NF-1 pueden tener anomalías retinianas vasculares. [...] Abstract in english Case report: We report a 4-year-old patient with neurofibromatosis type 1 (NF-1) who had tortuous retinal vessels of first, second and third order which ended in a corkscrew appearance. Discussion: Vascular retinal abnormalities can be present in patients with NF-1. [...

VM, Asensio-Sánchez; B, Torreblanca-Agüera; MA, Miñambres-Villar.

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

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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

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New techniques for intracranial stent navigation in patients with tortuous arteries  

International Nuclear Information System (INIS)

ult 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

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Retinal artery occlusions in children.  

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The purpose of this study is to present a case of RAO in a 13 year old girl with a preceding history of hyperextension of the neck at her hairdressers for a long duration and use of her mobile phone handset resting it against the side of her neck presumably exerting some pressure on carotids during the same time. Materials and methods of this study was reported as case report and review of literature. A 13 year-old girl presented with the left supero-nasal scotoma due to an inferior temporal branch retinal artery occlusion (BRAO). She underwent extensive investigations and no underlying cause was discovered. She gave a history of cervical extension over a long period of time while having the hair coloured twice in the preceding week. She also mentioned that she was using her mobile phone more or less continuously during both these occasions keeping it against her neck. Given the above history it is possible that the pressure on the ipsilateral carotid arteries or the prolong neck extension may have been responsible for the formation of a platelet embolus resulting in the BRAO. In conclusion, although cerebro-vascular accidents due to 'beauty parlor stroke syndrome' (JAMA 269:2085-2086, 1993) have been reported previously it has not been reported in children to our knowledge. On the other hand, 'beauty parlor stroke syndrome' occurs due to a dissection of the vertebral arteries or due to mechanical compression of the vertebral arteries during the prolonged hyperextension of the neck. The central retinal artery originates from the internal carotid circulation and it is highly unlikely for an embolus to enter the retinal circulation from the vertebral arteries. Therefore, the authors favour the possibility that the compulsive use of a mobile phone exerting pressure on the carotid arteries for a long time may have led to the formation of an embolus and subsequent RAO in this case. PMID:23440575

Dharmasena, Aruna; Wallis, Simon

2014-01-01

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Metabolic syndrome and central retinal artery occlusion  

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Full Text Available Background. The accumulation of risk factors for central retinal artery occlusion can be seen in a single person and might be explained by the metabolic syndrome. Case report. We presented the case of a 52-year-old man with no light perception in his right eye. The visual loss was monocular and painless, fundoscopy showed central retinal artery occlusion and the laboratory investigation showed the raised erythrocyte sedimentation rate of 105 mm/h and the raised C-reactive protein of 22 mg/l. Specific laboratory investigations and fluorescein angiography excluded the presence of vasculitis, collagen vascular diseases, hypercoagulable state and antiphospholipid syndrome. Conclusion. The patient met all the five of the National Cholesterol Education Program (NCEP criteria for the metabolic syndrome: hypertension, abnormal lipid profile, abnormal glucose metabolism, obesity and hyperuricemia. Measurement of C-reactive protein is useful for the assessment of therapeutic systemic effect on any abnormality in the metabolic syndrome. Individual therapy for all risk factors in the metabolic syndrome is necessary to prevent complications such as cardiovascular, retinal vascular diseases and stroke.

Kosanovi?-Jakovi? Natalija

2005-01-01

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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.  

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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. PMID:22359528

Kim, Do-Hyun; Choi, Jang Hwan; Lee, Jung Ha; Kim, Hee Sup

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  

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

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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. PMID:24790408

Arai, Haruka; Sakai, Tsutomu; Okano, Kiichiro; Aoyagi, Ranko; Imai, Ayano; Takase, Hiroshi; Mochizuki, Manabu; Tsuneoka, Hiroshi

2014-01-01

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Thrombophilic screening in retinal artery occlusion patients  

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Full Text Available Valeria Nagy1, Lili Takacs1, Zita Steiber1, György Pfliegler2, Andras Berta11Department of Ophthalmology, 2Division of Rare Diseases, University of Debrecen Medical and Health Science Center, Debrecen, HungaryBackground: Retinal artery occlusion (RAO is an ischemic vascular damage of the retina, which frequently leads to sudden, mostly irreversible loss of vision. In this study, blood thrombophilic factors as well as cardiovascular risk factors were investigated for their relevance to this pathology. Thrombophilic risk factors so far not evaluated were included in the study.Patients and methods: 28 RAO patients and 81 matched control subjects were examined. From blood samples, protein C, protein S, antithrombinopathy, and factor V (Leiden mutation (FV, factor II gene polymorphism, factor VIII C level, plasminogen activity, lipoprotein(a and fibrinogen levels, hyperhomocysteinemia and presence of anticardiolipin – antiphospholipid antibodies were investigated. Possibly relevant pathologies such as diabetes mellitus, hypertension, and ischemic heart disease were also registered. Statistical analysis by logistic regression was performed with 95% confidence intervals.Results: In the group of patients with RAO only the incidence of hypertension (OR: 3.33, 95% CI: 1.30–9.70, p = 0.014 as an average risk factor showed significant difference, but thrombophilic factors such as hyperfibrinogenemia (OR: 2.9, 95% CI: 1.29–6.57, p = 0.010 and the presence of FV (Leiden mutation (OR: 3.9, 95% CI: 1.43–10.96, p = 0.008 increased the chances of developing this disease.Conclusions: Our results support the assumption that thrombophilia may contribute to the development of RAO besides vascular damage due to the presence of cardiovascular risk factors. Further studies are needed, however, to justify the possible use of secondary prophylaxis in form of anticoagulant/antiplatelet therapy.Keywords: retinal arterial occlusion, risk factors, thrombophilia

Valeria Nagy

2008-10-01

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Branch retinal artery occlusion secondary to a Hollenhorst plaque.  

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Retinal arterial circulation obstruction has serious implications. It may result in acute visual loss, but more significantly, it implies that the patient's systemic health needs further review and investigations in order to prevent severe and life-threatening consequences such as myocardial infarction and cerebrovascular accidents. We report a case of a patient with branch retinal artery occlusion with the presence of a Hollenhorst plaque. PMID:11256349

Lee, S Y; Lee, J J; Koh, A C; Chee, S P

2000-08-01

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

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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

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Orbital cellulitis complicated by central retinal artery occlusion.  

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The authors present a case of a 16-year-old boy who sought treatment in Storm Eye Institute for orbital cellulitis complicated by central retinal artery occlusion. He was examined for severe signs of orbital cellulitis, including decreased vision and an afferent pupillary defect. Intravenous antibiotics failed to provide timely improvement, and the patient was surgically managed with endoscopic orbital decompression. An ocular examination under anesthesia revealed retinal ischemia in the affected eye, and fluorescein angiography confirmed the diagnosis of central retinal artery occlusion. The patient's vision improved slightly following resolution of the infection. Central retinal artery occlusion is a rare complication of orbital cellulitis in adults and has yet to be reported in the pediatric population. PMID:23128536

Proctor, Charles M; Magrath, George N; de Castro, Luis E Fernández; Johnson, John H; Teed, Ronald G

2013-01-01

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Tortuous path chemical preconcentrator  

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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

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Unilateral central retinal artery occlusion following intravenous streptokinase.  

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Full Text Available A 38-year-old male with acute myocardial infraction who had received streptokinase presented with acute painless diminution of vision in the left eye. Examination revealed features of central retinal artery occlusion on the left side with vision of perception of light. Treatment in the form of systemic and local intraocular pressure lowering agents, retrobulbar xanthinol nicotinate and systemic injection of B-complex resulted in improvement of vision to counting fingers up to one meter. In this case thrombolytic therapy itself led to embolism into the left central retinal artery resulting in its occlusion and eventually optic atrophy and blindness.

Potdar N

2001-10-01

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Application and significance of OCT in central retinal artery occlusion  

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Full Text Available AIM: To investigate the applicationof the optical coherence tomography(OCTin the central retinal artery occlusion(CRAOdisease, and explore whether is a correlation between inner retinal thickness and visual acuity pre and post treatment.METHODS: A retrospective analysis of patients with central retinal artery occlusion in 11 cases. Patients' onsets to admission time, initial visual acuity, after-treatment visual acuity were collected. Retinal thickness in the macular area was measured with OCT. Retinal mean thickness of fovea, including macular fovea, the 1mm and 3mm up, down of the fovea, nasal and temporal side to the foveal pit, was measured and analyzed. The thickness of inner retinal layer was measured manually. In the inner retinal layer, 1mm nasal and temporal side to the foveal pit, nasal and temporal side was N1, T1 respectively; 3mm nasal and temporal to the foveal pit, nasal and temporal side was N3, T3 respectively.RESULTS: The visual acuity of 8/11 patients was improved in different degree. The unhealthy eyes macular area and nasal 3mm retinal mean thickness were thicker than the healthy eye(P0.05. Compared with the healthy eyes, the unhealthy eyes which retinal thickness under others macular area have no statistical difference(P>0.05. The unhealthy eyes were thicker than the healthy at N1, N3 and T3(P0.05. The different values that thickness in the fovea of healthy and unhealthy eyes had a negative correlation with visual acuity of after treatment, r=-0.740(P0.05. The different values of N1, T1 and T3 in healthy and unhealthy eyes also had a negative correlation with visual acuity of after treatment, rN1=-0.692, rT1=-0.754, rT3=-0.657(PCONCLUSION: OCT examination has suggestive function for the recovery of patients with central retinal artery occlusion of visual acuity after-treatment.

Jing Hao

2014-03-01

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Atherosclerotic carotid artery disease in patients with retinal ischemic syndromes.  

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The extracranial carotid systems of 105 patients with retinal ischemia were examined using B-mode ultrasonography with integrated pulsed Doppler. Sixty-four patients had amaurosis fugax (AF), 17 central retinal artery occlusions (CRAO), and 21 branch retinal artery occlusions (BRAO). The prevalence of carotid stenosis (greater than or equal to 60%) ipsilateral to the symptomatic eye was low (16%). Eighty-six percent of AF patients had either no plaque causing less than a 60% stenosis. A significant proportion of subjects with normal duplex scans had alternative explanations for their retinal ischemia (eg, migraine, cardiac embolus). Patients with Hollenhorst plaques were more likely to have stenotic or ulcerated plaque (p = 0.04). The degree of carotid stenosis correlated significantly with the number of vascular risk factors identified in individual patients (p = 0.02). The presence of risk factors was more common in CRAO and BRAO patients compared with the AF group. Combined ultrasound-Doppler investigations of the carotid bifurcation are valuable noninvasive tools for the screening of patients with retinal ischemia. PMID:3285240

Chawluk, J B; Kushner, M J; Bank, W J; Silver, F L; Jamieson, D G; Bosley, T M; Conway, D J; Cohen, D; Savino, P J

1988-06-01

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Retinal Arterial Obstruction-still Remains an Enigma.  

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Retinal artery obstruction is an ocular emergency which usually carries a poor visual prognosis. Restoration of fruitful vision depends on the underlying cause and the immediate start of treatment. However, none of the known treatment modalities, have so far, assured positive results consistently. Retinal artery obstructions are forewarners of possible systemic emboli/infarcts. Thus, it is imperative for ophthalmologists to identify the disease and get a thorough systemic examination done, preferably by a cardiologist, so as to prevent serious systemic morbidity. It is to be noted that in our case report, in spite of having delayed presentations, both the patients were subjected to thorough cardiovascular examinations. In clinical practice, patients are not further investigated, once the chances of visual recovery are bleak. Our case report highlights the importance of subjecting these patients to complete cardiovascular work ups, even though a poor visual recovery is expected, which can lead to detection of various cerebrovascular infarcts. PMID:24959499

Kakhandaki, Anupama; Gejapati, Charushila; Patil, Preetam B; S G, Vivekanand

2014-04-01

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Branch retinal artery occlusion secondary to dengue fever  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Dengue is known to affect the posterior segment of the eye, with a range of hemorrhagic and inflammatory sequelae. A 28-year-old lady convalescing from dengue fever complained of unilateral blurring of inferior visual field. She was evaluated clinically and with fluorescein angiography. Her best-corrected visual acuity was 20/20 bilaterally. Fundus examination revealed a branch retinal artery occlusion in the right eye. Fluorescein angiogram confirmed the clinical diagnos...

Kanungo Sanghamitra; Shukla Dhananjay; Kim Ramasamy

2008-01-01

 
 
 
 
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A case of incomplete central retinal artery occlusion associated with short posterior ciliary artery occlusion.  

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To our knowledge, incomplete central retinal artery occlusion associated with short posterior ciliary artery occlusion is extremely rare. Herein, we describe a case of a 62-year-old man who was referred to our hospital with of transient blindness in his right eye. At initial examination, the patient's best-corrected visual acuity was 18/20 in the right eye. Fundus examination showed multiple soft exudates around the optic disc and mild macular retinal edema in his right eye; however, a cherry red spot on the macula was not detected. Fluorescein angiography revealed delayed dye inflow into the nasal choroidal hemisphere that is supplied by the short posterior ciliary artery. The following day, the patient's visual acuity improved to 20/20. Soft exudates around the optic disc increased during observation and gradually disappeared. His hemodynamic parameters revealed subclavian steal syndrome as examined by cervical ultrasonography and digital subtraction angiography. We speculate that his transient blindness was due to ophthalmic artery spasms. In this particular case, spasms of the ophthalmic artery and occlusion of the short posterior ciliary artery occurred simultaneously. As the short posterior ciliary artery branches from the ophthalmic artery, the anatomical location of the lesion might be near the branching of both arteries. PMID:23365775

Makino, Shinji; Takezawa, Mikiko; Sato, Yukihiro

2013-01-01

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Central retinal artery occlusion resembling Purtscher-like retinopathy  

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Full Text Available 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 of the retina surrounding the fovea with a cherry red spot. Fluorescein angiography showed a delay of arm-to-retina circulation time and a partial defect of choroid circulation. Although the three cases were treated by different regimens of steroid pulse therapy and antiplatelet therapy, visual function recovered well and all disturbances of the retinal and choroid circulations resolved. Although eyes with a CRAO normally have a poor visual prognosis, our three cases responded well to the treatments and recovered good visual function. Thus, cases showing fundus changes similar to our three cases may have a pathogenesis different from that of a complete CRAO.Keywords: central retinal artery occlusion, cotton wool patches, Purtscher retinopathy, steroid therapy

Etomi T

2011-08-01

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Unilateral electronegative ERG in a presumed central retinal artery occlusion  

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: 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

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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 | Language: 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.

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Central retinal artery occlusion resembling Purtscher-like retinopathy  

Science.gov (United States)

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 of the retina surrounding the fovea with a cherry red spot. Fluorescein angiography showed a delay of arm-to-retina circulation time and a partial defect of choroid circulation. Although the three cases were treated by different regimens of steroid pulse therapy and antiplatelet therapy, visual function recovered well and all disturbances of the retinal and choroid circulations resolved. Although eyes with a CRAO normally have a poor visual prognosis, our three cases responded well to the treatments and recovered good visual function. Thus, cases showing fundus changes similar to our three cases may have a pathogenesis different from that of a complete CRAO. PMID:21847341

Kurimoto, Takuji; Okamoto, Norio; Oku, Hidehiro; Kanbara, Yuko; Etomi, Tomohiko; Tonari, Masahiro; Ikeda, Tsunehiko

2011-01-01

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A framework for retinal layer intensity analysis for retinal artery occlusion patient based on 3D OCT  

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Occlusion of retinal artery leads to severe ischemia and dysfunction of retina. Quantitative analysis of the reflectivity in the retina is very needed to quantitative assessment of the severity of retinal ischemia. In this paper, we proposed a framework for retinal layer intensity analysis for retinal artery occlusion patient based on 3D OCT images. The proposed framework consists of five main steps. First, a pre-processing step is applied to the input OCT images. Second, the graph search method was applied to segment multiple surfaces in OCT images. Third, the RAO region was detected based on texture classification method. Fourth, the layer segmentation was refined using the detected RAO regions. Finally, the retinal layer intensity analysis was performed. The proposed method was tested on tested on 27 clinical Spectral domain OCT images. The preliminary results show the feasibility and efficacy of the proposed method.

Liao, Jianping; Chen, Haoyu; Zhou, Chunlei; Chen, Xinjian

2014-03-01

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Recurrent transient monocular blindness from stenotic central retinal artery.  

Science.gov (United States)

Transient monocular blindness (TMB) is caused by a temporary reduction of blood flow to the retina or optic nerve. Even though embolism from the ipsilateral carotid artery has been considered the main mechanism of TMB, the vascular pathology remains unknown in many patients. A 42-year-old man presented with recurrent transient visual loss in the left eye for 2 months. The attacks tended to develop more frequently when his head was bent down. Fluorescence angiography during an attack revealed hypoperfusion of the left central retinal artery (CRA) and cerebral angiography documented a focal isolated stenosis of the CRA at the origin. Aspirin and nimodipine reduced the attacks markedly. Stenosis of the CRA may be a cause of TMB. Intermittent vasospasm in addition to static hypoperfusion may have caused TMB in our patient with isolated CRA stenosis. PMID:23830588

Choi, Seo Young; Moon, Hye-Jin; Huh, Young-Eun; Yang, Hee Kyung; Woo, Se Joon; Jung, Cheolkyu; Kwon, O-Ki; Kim, Ji-Soo

2013-11-01

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Nettleship collaterals: circumpapillary cilioretinal anastomoses after occlusion of the central retinal artery.  

Science.gov (United States)

In extremely rare cases, after occlusion of the central retinal artery, a complete ring of peripapillary anastomotic channels develops. One such case is described and a proposed term given to these channels--'Nettleship collaterals'--after the man who first described them. These collaterals are dilated pathways within the terminal capillary networks of the posterior ciliary arteries and the branches of the central retinal artery. Formation of the channels is believed to be promoted by prelaminar obstruction of the central retinal artery. PMID:1540571

Ragge, N K; Hoyt, W F

1992-03-01

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

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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 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

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Branch retinal artery occlusion after coil embolization of a paraclinoid aneurysm.  

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The authors report a case of a 48-year-old woman with a branch retinal artery occlusion after the neurosurgical coiling of a paraclinoid aneurysm. Clinical examination revealed a Hollenhorst plaque at the bifurcation of the inferior arcade and at a branch of the superior arcade with associated retinal whitening in the right eye. Follow-up examination at 8 months demonstrated improved visual acuity with near complete resolution of the retinal infarction but a persistent inferior Hollenhorst plaque. This case illustrates a retinal artery occlusion as a possible complication of paraclinoid aneurysmal coiling procedure. PMID:24702760

Choudhry, Netan; Brucker, Alexander J

2014-01-01

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The Feasibility of Central Retinal Artery Doppler Ultrasonography in Patients with Sudden Visual Disturbance that's Caused by Retinal Vascular Occlusion  

International Nuclear Information System (INIS)

We evaluated the usefulness of central retinal artery Doppler ultrasonography for assessing the patients with sudden visual disturbance that's caused by retinal vascular occlusion. The blood flow velocity and the resistive and pulsatile indexes were measured at the central retinal arteries of 65 patients with sudden visual disturbance. For all the subjects, the patient's affected eye was compared with the non-affected eye. We investigated the efficacy of the Doppler ultrasonography parameters to predict a significant visual loss on the Snellen test (<20/400). A significantly lower central retinal arterial flow velocity was measured in the affected eye as compared with the unaffected normal eye for all the subjects (p < 0.05). The ROC curves showed that the mean velocity was the best parameter to predict significant visual loss (p < 0.05). If a mean velocity of 4.3 cm/sec was chosen as the cutoff value to predict significant visual loss, then the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 89%, 95%, 95%, 88% and 92%, respectively (estimated area = 0.958, p-value <0.01). Central retinal artery Doppler ultrasonography was helpful for predicting significant visual loss in patients who complain of sudden visual disturbance. In addition to the other ophthalmologic diagnostic modalities, Doppler ultrasonography may be a feasible modality to depict impending further visual loss of an ischemic originn ischemic origin

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Adaptive optics assisted visualization of thickened retinal arterial wall in a patient with controlled malignant hypertension  

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Purpose We aimed to visualize the retinal arterial wall thickness, assisted by noninvasive adaptive optics scanning laser ophthalmoscopy (AO-SLO). Methods The arterial wall thickness was measured and compared between one normal subject and one patient suffering from malignant hypertensive retinopathy. Results Increased arterial wall thickness was revealed with a newly developed AO-SLO system, in a retinal artery of 1-papilla diameter temporal inferior to the optic disc. The average wall thickness, with hypertension, was 18.7 ?m, and the wall-to-lumen ratio was 0.44, both bigger than normal. Conclusion AO-SLO enabled us to evaluate the retinal wall thickness in the hypertensive patient. The arterial walls were thickened compared with normal. AO-SLO may facilitate future noninvasive study of arterial walls in human medicine. PMID:25336903

Arichika, Shigeta; Uji, Akihito; Yoshimura, Nagahisa

2014-01-01

34

3D Reconstruction of the Retinal Arterial Tree Using Subject-Specific Fundus Images  

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Systemic diseases, such as hypertension and diabetes, are associated with changes in the retinal microvasculature. Although a number of studies have been performed on the quantitative assessment of the geometrical patterns of the retinal vasculature, previous work has been confined to 2 dimensional (2D) analyses. In this paper, we present an approach to obtain a 3D reconstruction of the retinal arteries from a pair of 2D retinal images acquired in vivo. A simple essential matrix based self-calibration approach was employed for the "fundus camera-eye" system. Vessel segmentation was performed using a semi-automatic approach and correspondence between points from different images was calculated. The results of 3D reconstruction show the centreline of retinal vessels and their 3D curvature clearly. Three-dimensional reconstruction of the retinal vessels is feasible and may be useful in future studies of the retinal vasculature in disease.

Liu, D.; Wood, N. B.; Xu, X. Y.; Witt, N.; Hughes, A. D.; Samcg, Thom

35

Evaluation of body mass index and lipid fractions levels in patients with retinal artery occlusion  

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Full Text Available Background/Aim. There are studies stressing out that atherosclerosis is most common associated systemic condition in patients with retinal artery occlusion. The aim of this study was to analyze values of body mass index and lipid fractions in healthy individuals and patients with retinal artery occlusion. Methods. This study included 90 participants during a 6-year period. The population was divided into 2 groups: the group with the diagnosed retinal artery occlusion and the group without retinal artery occlusion. The observed parameters were as follows: body mass index, low and high density lipoproteins and triglycerides. Results. The study revealed no significant difference regarding body mass index and triglycerides values between the two evaluated groups, while low and high density lipoproteins values were significantly higher in the group of patients with retinal artery occlusion. Conclusions. The study demonstrated that body mass index and triglycerides have less important role in atherogenic pathogenesis of retinal artery occlusion, while low density lipoprotein is the fraction that is shown to be most potent in such etiological processes.

Risimi? Dijana

2011-01-01

36

A traveling "spot sign" in recurrent amaurosis fugax and central retinal artery occlusion.  

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Sudden monocular blindness is frequently caused by central retinal artery occlusion (CRAO) from embolic sources. Treatment options are insufficient, and spontaneous prognosis toward visual recovery is poor. In addition to ophthalmologic evaluation, transorbital sonographic assessment of the central retinal artery may help establish early diagnosis by Doppler sonographic proof of occlusion and, in some cases, by B-mode detection of an intra-arterial "spot sign". We report the case of a patient with recurrent amaurosis fugax and subsequent CRAO. Ultrasound examination after 2 incidences of amaurosis fugax demonstrated a patent but stenotic central retinal artery, with stenosis caused by an embolus visualized as a "spot sign". The following day, persisting amaurosis suddenly developed. Sonographic re-evaluation revealed downstream dislodgment of the "spot sign" and complete arterial occlusion. Thrombolytic treatment did not result in clinical improvement. In conclusion, this case report describes a single case of repeated amaurosis fugax and deterioration to CRAO via embolization into the central retinal artery and consecutive downstream dislodgment. It emphasizes that ultrasound may render valuable diagnostic information in patients with acute central retinal artery embolization toward its embolic etiology and its risk of subsequent deterioration. PMID:24957310

Nedelmann, Max; Tanislav, Christian; Kaps, Manfred

2014-10-01

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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  

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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 art...

Do-Hyun Kim; Jang Hwan Choi; Jung Ha Lee; Hee Sup Kim

2012-01-01

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Correlation between penile cavernosal artery blood flow and retinal vascular findings in arteriogenic erectile dysfunction  

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Full Text Available Ahmed M Emarah1, Shawky M El-Haggar2, Ihab A Osman2, Abdel Wahab S Khafagy21Departments of Ophthalmology, 2Andrology and Sexology, Cairo University Hospital, EgyptObjectives: Arteriogenic erectile dysfunction (ED is a target organ disease of atherosclerosis, and therefore might be a predictor of systemic atherosclerosis. Being systemic, it might be possible to evaluate the extent of atherosclerosis from retinal vascular findings. We investigated the possible correlation between penile cavernosal artery blood flow and retinal vascular findings in patients with arteriogenic ED.Patients and methods: Sixty patients with ED were divided according to the peak systolic velocity (PSV in their penile cavernosal arteries into two groups; Group A included 30 patients with PSV less than 25 cm/sec, and Group B included 30 patients with PSV more than 35 cm/sec. Blood flow in the penile cavernosal artery was measured with color Doppler ultrasonography. All patients were assessed by ocular fundus examination under amydriatic conditions to evaluate retinal vascular atherosclerotic changes using Hyman’s classification.Results: Evidence of retinal vascular atherosclerotic changes was found in 19 patients (63.3% in Group A and in 10 patients (33.3% in Group B.Conclusions: Our study confirms the possibility of predicting penile arterial vascular status in patients with ED from their retinal vascular findings by using amydriatic simple, practical funduscopy.Keywords: erectile dysfunction, atherosclerosis, retinal vascular atherosclerosis

Ahmed M Emarah

2010-09-01

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

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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

40

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

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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...

Shamshad M; Amitava A; Ahmad I.; Wahab S

2010-01-01

 
 
 
 
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Adaptive optics assisted visualization of thickened retinal arterial wall in a patient with controlled malignant hypertension  

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Full Text Available Shigeta Arichika, Akihito Uji, Nagahisa Yoshimura Department of Ophthalmology and Visual Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan Purpose: We aimed to visualize the retinal arterial wall thickness, assisted by noninvasive adaptive optics scanning laser ophthalmoscopy (AO-SLO.Methods: The arterial wall thickness was measured and compared between one normal subject and one patient suffering from malignant hypertensive retinopathy.Results: Increased arterial wall thickness was revealed with a newly developed AO-SLO system, in a retinal artery of 1-papilla diameter temporal inferior to the optic disc. The average wall thickness, with hypertension, was 18.7 µm, and the wall-to-lumen ratio was 0.44, both bigger than normal.Conclusion: AO-SLO enabled us to evaluate the retinal wall thickness in the hypertensive patient. The arterial walls were thickened compared with normal. AO-SLO may facilitate future noninvasive study of arterial walls in human medicine. Keywords: wall thickness, AO-SLO, hypertensive retinopathy

Arichika S

2014-10-01

42

Comparison of optical coherence tomography findings in a patient with central retinal artery occlusion in one eye and end-stage glaucoma in the fellow eye.  

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This case describes a patient with chronic central retinal artery occlusion in one eye and end-stage traumatic glaucoma in the fellow eye. Optical coherence tomography (OCT) of the macula of the chronic phase of central retinal artery occlusion of the right eye indicated loss of the normal foveal depression, extensive inner retinal atrophy, and marked retinal thinning. In contrast, scans of the left eye with end-stage glaucoma demonstrated an intact foveal depression and limited retinal thinning. The pattern of macular OCT findings in this patient illustrates distinguishing features between chronic central retinal artery occlusion and chronic optic neuropathy due to end-stage glaucoma. PMID:22623869

Greene, Daniel P; Richards, Charles P; Ghazi, Nicola G

2012-01-01

43

The Feasibility of Central Retinal Artery Doppler Ultrasonography in Patients with Sudden Visual Disturbance that's Caused by Retinal Vascular Occlusion  

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We evaluated the usefulness of central retinal artery Doppler ultrasonography for assessing the patients with sudden visual disturbance that's caused by retinal vascular occlusion. The blood flow velocity and the resistive and pulsatile indexes were measured at the central retinal arteries of 65 patients with sudden visual disturbance. For all the subjects, the patient's affected eye was compared with the non-affected eye. We investigated the efficacy of the Doppler ultrasonography parameters to predict a significant visual loss on the Snellen test (<20/400). A significantly lower central retinal arterial flow velocity was measured in the affected eye as compared with the unaffected normal eye for all the subjects (p < 0.05). The ROC curves showed that the mean velocity was the best parameter to predict significant visual loss (p < 0.05). If a mean velocity of 4.3 cm/sec was chosen as the cutoff value to predict significant visual loss, then the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 89%, 95%, 95%, 88% and 92%, respectively (estimated area = 0.958, p-value <0.01). Central retinal artery Doppler ultrasonography was helpful for predicting significant visual loss in patients who complain of sudden visual disturbance. In addition to the other ophthalmologic diagnostic modalities, Doppler ultrasonography may be a feasible modality to depict impending further visual loss of an ischemic origin.

Park, Ji Won; Lee, Hui Joong; Lee, Jong Min [Kyungpook National University Hospital, Daegu (Korea, Republic of)

2009-03-15

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Retrospective study of threshold time for the conventional treatment of branch retinal artery occlusion  

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Full Text Available Daisuke Muramatsu,* Teruumi Minezaki,* Kinya Tsubota,* Yoshihiro Wakabayashi, Hiroshi GotoDepartment of Ophthalmology, Tokyo Medical University, Tokyo, Japan *These authors contributed equally to this work Purpose: To investigate the medical backgrounds of patients and the treatment periods from the onset of branch retinal artery occlusion to obtaining improved final visual acuity.Methods: This was a retrospective case series study. A total of 68 consecutive patients (69 eyes with branch retinal artery occlusion who visited Tokyo Medical University Hospital from 2007 to 2012 were included in this study. All patients underwent ophthalmic examinations and visual acuity tests. We reviewed their medical records for systemic conditions, as well as the periods from onset of symptoms to treatment. Participants were categorized into 2 groups: group A (n=36, which received any treatment within 24 hours from onset, and group B (n=33, which visited our hospital after 24 hours from onset. Best corrected visual acuity (BCVA changes from the first to final visit and the relationships between systemic condition and visiting time to BCVA were assessed.Results: At the first visit, 59% of the patients had BCVA over 20/40; the ratio was increased to 74% at the final visit. BCVA improved more than 2 lines for 35% of the patients and was unchanged for 57% of those receiving conventional treatment. BCVA over 20/40 was significantly lower in hyperlipidemia patients. Hypertension, diabetes mellitus, and significant carotid stenosis were not correlated. The mean BCVA at baseline (0.91±1.03 significantly recovered to 0.35±0.91 after treatment in group A (P<0.001, Student’s t-test. The mean BCVA at baseline (0.30±0.64 was 0.25±0.61 at the final visit in group B (no significant change.Conclusion: Conventional treatment within 24 hours from onset was acceptable for branch retinal artery occlusion.Keywords: branch retinal artery occlusion, BRAO, golden period, treatment time

Muramatsu D

2014-09-01

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Diagnóstico de patología sistémica tras macroaneurisma arterial retiniano bilateral / Diagnosis of systemic disease after bilateral retinal arterial macroaneurysm  

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Full Text Available SciELO Spain | Language: Spanish Abstract in spanish Caso clínico: Un varón de 85 años sufrió pérdida de visión en ambos ojos debido a la rotura de macroaneurismas arteriales retinianos bilaterales. Discusión: Se comenta este caso inusual y hablamos de la importancia de estudiar a estos pacientes para detectar enfermedades sistémicas asociadas. [...] Abstract in english Case report: An 85 year old male suffered vision loss in both eyes due to ruptured bilateral retinal arterial macroaneurysms. Discussion: We report this unusual case and show the importance of studying these types of patients in order to detect associated systemic diseases. [...

J., Mateo; L., Lavilla; A.J., Mateo; J.A., Cristóbal; C., Recio.

2011-03-01

46

Diagnóstico de patología sistémica tras macroaneurisma arterial retiniano bilateral Diagnosis of systemic disease after bilateral retinal arterial macroaneurysm  

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Full Text Available Caso clínico: Un varón de 85 años sufrió pérdida de visión en ambos ojos debido a la rotura de macroaneurismas arteriales retinianos bilaterales. Discusión: Se comenta este caso inusual y hablamos de la importancia de estudiar a estos pacientes para detectar enfermedades sistémicas asociadas.Case report: An 85 year old male suffered vision loss in both eyes due to ruptured bilateral retinal arterial macroaneurysms. Discussion: We report this unusual case and show the importance of studying these types of patients in order to detect associated systemic diseases.

J. Mateo

2011-03-01

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Central Retinal Artery Occlusion in a Patient with Metabolic Syndrome X  

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Purpose To report a case of central retinal artery occlusion (CRAO) in a patient with metabolic syndrome X. Case Report A 64 year-old-man presented with abrupt, painless, and severe loss of vision in his left eye. Indirect ophthalmoscopy disclosed signs compatible with CRAO and laboratory investigations revealed erythrocyte sedimentation rate of 74 mm/h, C-reactive protein (CRP) level of 21 mg/l, hyperglycemia, hyperuricemia, hypertriglyceridemia and hypercholesterolemia. Fluorescein angiography and immunological studies excluded other systemic disorders. The patient met the full criteria of the National Cholesterol Education Program for metabolic syndrome X. Conclusion In addition to different vascular complications such as stroke, and cardiovascular disease, metabolic syndrome X may be associated with retinal vascular occlusions. PMID:22737328

Ceki?, Sonja Predrag; Petkovi?, Tatjana; Stankovi?-Babi?, Gordana Ljubomir; Mrši?, Jovica Mile

2010-01-01

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Cerebro-retinal ischemia after bilateral occlusion of internal carotid artery  

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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

49

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.)

50

Central retinal artery occlusion following severe blow-out fracture in young adult  

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Full Text Available Noriko Himori, Hiroshi Kunikata, Takaaki Otomo, Nobuo Fuse, Kohji NishidaDepartment of Ophthalmology and Visual Science, Tohoku University Graduate School of Medicine, Sendai, JapanAbstract: A 20-year-old woman was involved in a traffic accident while riding a motorcycle. The vision in her right eye was severely reduced. At the first examination, the eyelids of her right eye were severely swollen, and the eye could barely be seen. The fundus was not visible. She had no light perception in her vision. Computed tomography revealed a severe blow-out fracture in her right eye. Surgery was immediately performed to correct the fracture and the eye globe was replaced in the orbit. On the fourth postoperative day, the right fundus was visible and a cherry-red spot and milky-white edema were seen. Fluorescein angiography showed an arterial filling defect. Four months later, her visual acuity was light perception. Our case shows that a central retinal artery occlusion can be a complication of a blow-out fracture of the lower orbital wall and can lead to severe visual loss even with early surgical repair.Keywords: central retinal artery occlusion, blow out fracture, trauma, young adult

Noriko Himori

2009-04-01

51

Retinal artery embolization complicating Libman-Sacks endocarditis in a systemic lupus erythematosus patient.  

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Libman-Sacks endocarditis (LSE) is the most characteristic cardiac manifestation of systemic lupus erythematosus (SLE). It is usually clinically silent but heart failure due to valvular dysfunction, secondary infective endocarditis and embolic phenomena can complicate valvular abnormalities. We present a patient with SLE and blindness due to right central retinal artery occlusion. Echocardiographic examination revealed a verrucous vegetation on the posterior mitral valve leaflet consistent with LSE. Anticoagulation therapy was started. Echocardiographic regression of the vegetation was observed and there has been no recurrence of thromboembolic events to date. PMID:23523393

Marta, Liliana; Pitta, Maria Luz; Peres, Marisa; Ferreira, Vítor; Puga, Maria Clotilde; Severino, Davide; Silva, Graça Ferreira da

2013-04-01

52

[Central retinal artery occlusion in a 21-year-old male amateur bodybuilder].  

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The etiology of central retinal artery occlusion (CRAO) is usually associated with atherosclerotic risk factors and the presence of intravascular (carotid artery, aortic arch) or intracardiac embolic material. At young age, CRAO may be a manifestation of inherited or acquired thrombophilia. The authors present a case of CRAO in a 21-year-old, previously healthy, non-smoking male, with neither metabolic nor hemostatic abnormalities and with normal echocardiography. However, he had a positive family history of premature coronary heart disease and a history of anabolic-androgenic steroids (AAS) use during amateur bodybuilding. We have not found an example of CRAO in the literature on various, systemic thromboembolic complications following AAS use. PMID:20642105

Elikowski, Waldemar; Grzybowski, Andrzej; Ma?ek, Ma?gorzata; Swidurski, Wojciech; Kurosz, Jolanta; Zawilska, Krystyna

2010-06-01

53

[Therapy of arterial vascular occlusions of retinal and optic nerve (author's transl)].  

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The authors report on 136 cases of arterial occlusion (80 patients suffering from occlusion of the retinal vessels and 56 patients with vascular occlusion in the optic nerve) who were treated with the vasoactive xanthic substance Pentoxifylline (Trental). A part from its positive effect on the vascular circulation, Trental also helps to improve microcirculation in the retinal and optic nerve tissue damaged by hypoxia. After a 2-week infusion therapy with additional digitalisation, treatment was continued for another 3-6 months with oral administration of Trental 400. In 50 cases therapy was combined with the systemic administration of corticosteroids. Under the mentioned therapy a definitely improved visual acuity (at least 3 lines on the eye charts) was achieved in 56% of the cases with occlusion of the retinal vessels and in 51% of the cases with vascular occlusion in the optic nerve, i.e., in 54% of the total number of patients. Whether or not the additional administration of corticosteroids helped to this effect was not proved. PMID:545196

Küchle, H J; Richard, G

1979-01-01

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

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Full Text Available SciELO Brazil | Language: English Abstract in english 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

55

Combined central retinal artery and vein occlusion secondary to systemic non-Hodgkin?s lymphoma  

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Full Text Available We report a rare case of low-grade systemic B-cell non-Hodgkin?s lymphoma (NHL causing central retinal artery and vein occlusion, which was the only manifestation of disease recurrence. A young man with resolved systemic NHL underwent fluorescein angiography, magnetic resonance imaging and computed tomography to investigate a severe unilateral visual loss. A combined vascular occlusion was observed in the right eye. Neuroimaging detected optic nerve infiltration; but no systemic/ central nervous system involvement was observed. The patient was treated with high-doses of corticosteroids and optic nerve irradiation. The optic neuropathy and vascular occlusion were resistant to treatment. The subsequent neovascular glaucoma was treated by panretinal photocoagulation, which relieved the pain, but vision was not recovered. No further recurrence was observed over the following year.

Shukla Dhananjay

2006-01-01

56

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

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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

57

Central retinal artery occlusion following severe blow-out fracture in young adult.  

Science.gov (United States)

A 20-year-old woman was involved in a traffic accident while riding a motorcycle. The vision in her right eye was severely reduced. At the first examination, the eyelids of her right eye were severely swollen, and the eye could barely be seen. The fundus was not visible. She had no light perception in her vision. Computed tomography revealed a severe blow-out fracture in her right eye. Surgery was immediately performed to correct the fracture and the eye globe was replaced in the orbit. On the fourth postoperative day, the right fundus was visible and a cherry-red spot and milky-white edema were seen. Fluorescein angiography showed an arterial filling defect. Four months later, her visual acuity was light perception. Our case shows that a central retinal artery occlusion can be a complication of a blow-out fracture of the lower orbital wall and can lead to severe visual loss even with early surgical repair. PMID:19668585

Himori, Noriko; Kunikata, Hiroshi; Otomo, Takaaki; Fuse, Nobuo; Nishida, Kohji

2009-01-01

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Subretinal neovascularization following ruptured retinal arterial macroaneurysm: case report Neovascularização sub-retiniana secundária ao macroaneurisma arterial da retina rôto: relato de caso  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A 51-year-old black woman was referred to our Retina Clinic for evaluation of loss of vision in her left eye. She was previously diagnosed with a ruptured retinal arterial macroaneurism (RAM) in the same eye. The ophthalmoscopic examination of the affected eye disclosed a subretinal lesion with some hemorrhage and exudation in the same area previously diagnosed with ruptured RAM. Fluorescein angiography revealed a gradually hyperfluorescent net of vessels located in the subfoveal region, cons...

Vianna, Raul N. G.; Augusto Kassuga; Gabriela Onofre; Virginia Ecard; Burnier Jr, Miguel N.

2007-01-01

59

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

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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 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

60

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

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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 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

 
 
 
 
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Transcorneal electrical stimulation improves visual function in eyes with branch retinal artery occlusion  

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Purpose: To investigate the effects of transcorneal electrical stimulation (TES) on eyes that have a branch retinal artery occlusion (BRAO). Subjects and method: We studied two eyes having a BRAO, with an interval between the onset of symptoms and the beginning of treatment of >16 weeks (longstanding cases), and in three eyes with an interval of <16 weeks (fresh cases). The visual functions of the eyes were assessed by the best-corrected visual acuity (BCVA), multifocal electroretinograms (mfERGs), and automated static perimetry with the Humphrey field analyzer (HFA). The mfERGs were recorded before and 1 month after the TES, and perimetry with the HFA was done before and at 1 and 3 months after the TES. The amplitudes and implicit times of the N1, P1, and N2 components of the mfERGs were analyzed. Results: TES did not alter the BCVA significantly in all eyes, but it led to a significant increase in the amplitude of the N2 wave of the mfERGs (P < 0.01). The amplitude of the N1–P1 was also increased but not significantly. The implicit times of N1 (P < 0.01) and P1 (P < 0.05) were significantly shorter than that before the TES. The mean deviation of the HFA was increased after the TES but only in the longstanding cases. Conclusion: Our results indicate that TES improves the visual function in eyes with BRAO, mainly in longstanding cases. PMID:21499563

Oono, Shinichirou; Kurimoto, Takuji; Kashimoto, Ryosuke; Tagami, Yuichi; Okamoto, Norio; Mimura, Osamu

2011-01-01

62

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.

63

Central retinal artery occlusion and non-arteritic anterior ischemic optic neuropathy associated with an overlap syndrome: a case report  

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Full Text Available Abstract Introduction An "overlap syndrome" is defined as the sequential appearance over time of two or more risk factors for glaucomatous damage. The appearance of a new risk factor can alter the course and prognosis of previously stable disease. Exfoliation syndrome is a leading cause of glaucoma and is associated with vascular disease. We report a case of central retinal artery occlusion and non-arteritic anterior ischemic optic neuropathy in a patient with overlap syndrome. Case presentation An 87-year-old woman with longstanding stable primary open-angle glaucoma developed bilateral exfoliation syndrome, after which her intraocular pressure became uncontrolled and her glaucomatous damage progressed rapidly. She also developed ischemic arterial events in both eyes. Conclusion The case presented here shows that overlap syndromes can lead to rapid, irreversible vision impairment. To the best of our knowledge, this is the first reported case of central retinal artery occlusion and non-arteritic anterior ischemic optic neuropathy in a patient with overlap syndrome.

Lima Verônica C

2008-12-01

64

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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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

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Prevalência de hipertensão arterial em pacientes com oclusão do ramo da veia central da retina Prevalence of arterial hypertension in branch retinal vein occlusion patients  

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Full Text Available OBJETIVOS: Identificar em pacientes com oclusão do ramo da veia central da retina utilizando a monitorização ambulatorial da pressão arterial e medidas clínicas da pressão arterial: prevalência de hipertensão e o perfil noturno da pressão arterial. MÉTODOS: Prospectivamente, 93 olhos de 83 pacientes com oclusão do ramo da veia central da retina foram submetidos à avaliação oftalmológica. Após, os pacientes foram encaminhados para avaliação clínica e monitorização da pressão arterial. Pacientes sem descenso da pressão durante o sono ("non-dipper" foram definidos como um declínio na pressão arterial sistólica PURPOSE: To identify in patients with branch retinal vein occlusion using ambulatory blood pressure monitoring and clinical blood pressure measures: hypertension prevalence, and nocturnal profile of blood pressure. METHODS: Prospectively, 93 eyes of 83 patients with branch retinal vein occlusion were submitted to ophthalmological examination. Afterwards the patients were submitted to clinical evaluation and blood pressure monitoring. Non-dipper was defined as a fall in systolic blood pressure < 10%, and dipper when this value was higher. RESULTS: Disease affected one eye in 73 (88% patients. The temporal superior branch was the site of occlusion in 61 (65.6% eyes, while in the others the infero-temporal branch was affected. Seventy six (92% patients were diagnosed as hypertensive after clinical evaluation. Ambulatory blood pressure monitoring identified 76 hipertensives, 5 normotensives, 1 white-coat hypertensive and one masked hypertensive subjects. The two latter were excluded from the analysis. Of the 81 analyzed patients, forty (49% were dippers and 41 (51% were non-dippers. Among the HT (n=76, 36 (47% were dippers and 40 (53% were non-dippers. CONCLUSION: Prevalence of hypertension in our series was extremely high (92% which suggests that physiopathology of the disease has a close relationship with changes promoted by hypertension. A little more than half of the hypertensives were non-dippers (n=40; 52,6%. These evidences suggest that a 24-hour sustained level of blood pressure may be an additional risk factor for branch retinal vein occlusion.

Alexandre Antonio Marques Rosa

2008-04-01

66

Automated selection of major arteries and veins for measurement of arteriolar-to-venular diameter ratio on retinal fundus images.  

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An automated method for measurement of arteriolar-to-venular diameter ratio (AVR) is presented. The method includes optic disc segmentation for the determination of the AVR measurement zone, retinal vessel segmentation, vessel classification into arteries and veins, selection of major vessel pairs, and measurement of AVRs. The sensitivity for the major vessels in the measurement zone was 87%, while 93% of them were classified correctly into arteries or veins. In 36 out of 40 vessel pairs, at least parts of the paired vessels were correctly identified. Although the average error in the AVRs with respect to those based on the manual vessel segmentation results was 0.11, the average error in vessel diameter was less than 1 pixel. The proposed method may be useful for objective evaluation of AVRs and has a potential for detecting focal arteriolar narrowing on macula-centered screening fundus images. PMID:21489750

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

2011-09-01

67

The Dolichoarteriopathia of Common Carotid Artery Narrowing the Airway  

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Full Text Available Tortuousity of the common carotid artery is rarely seen in otorinolaryngologic  practice. In this report, a case of tortuous common carotid artery narrowing the airway and indenting the epiglottis is presented. In endoscopic examination, pulsating bulge at the level of right lateral farengeal wall, pyriform sinus and larynx was found in a 73 year-old female. Computerized tomographic scan showed tortuous  right common carotid artery bulging the submucosal area of the oropharynx and pyriform sinus. Awareness of the tortuous common carotid artery before any  laryngologic surgical intervention is very important to prevent serious complications.

Erkan Eski

2013-01-01

68

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

69

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

70

Use of ‘Guideliner’ catheter to overcome failure of delivery of Absorb™ Bioresorbable Vascular Scaffold in calcified tortuous coronary lesions: Technical considerations in ‘Real World Patients’  

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In our series of 177 real world patients (223 lesions) who underwent Absorb Bioresorbable Vascular Scaffold (BVS) implantation, 78 lesions were calcified and tortuous lesions. In four of these, despite adequate lesion bed preparation, appropriate guiding catheter support and use of buddy wires, the BVS failed to track through the proximal calcified and tortuous coronary anatomy (CTCA). “Guide Liner” catheter (GLC) had to be finally used to resuccessfully deliver and implant BVS to the lesion site. We report for the first time four cases of use of guideliner catheter to successfully overcome failed delivery of BVS to the lesion site through proximal CTCA, calcified and tortuous coronary artery (CTCA) lesions treated with Absorb™ BVS. Because the BVS is a large profile device, certain difficulties were encountered in delivering it through the GLC, which were finally overcome. We have therefore discussed the ‘lessons and learnt’ and “salient practice points” to enable successful delivery of BVS through the GLC. PMID:25173205

Seth, Ashok; Ravisekar, Vinayak; Kaul, U.

2014-01-01

71

Use of 'Guideliner' catheter to overcome failure of delivery of Absorb™ Bioresorbable Vascular Scaffold in calcified tortuous coronary lesions: technical considerations in 'Real World Patients'.  

Science.gov (United States)

In our series of 177 real world patients (223 lesions) who underwent Absorb Bioresorbable Vascular Scaffold (BVS) implantation, 78 lesions were calcified and tortuous lesions. In four of these, despite adequate lesion bed preparation, appropriate guiding catheter support and use of buddy wires, the BVS failed to track through the proximal calcified and tortuous coronary anatomy (CTCA). "Guide Liner" catheter (GLC) had to be finally used to resuccessfully deliver and implant BVS to the lesion site. We report for the first time four cases of use of guideliner catheter to successfully overcome failed delivery of BVS to the lesion site through proximal CTCA, calcified and tortuous coronary artery (CTCA) lesions treated with Absorb™ BVS. Because the BVS is a large profile device, certain difficulties were encountered in delivering it through the GLC, which were finally overcome. We have therefore discussed the 'lessons and learnt' and "salient practice points" to enable successful delivery of BVS through the GLC. PMID:25173205

Seth, Ashok; Ravisekar, Vinayak; Kaul, U

2014-01-01

72

Subretinal neovascularization following ruptured retinal arterial macroaneurysm: case report / Neovascularização sub-retiniana secundária ao macroaneurisma arterial da retina rôto: relato de caso  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Paciente de 51 anos foi encaminhada ao Setor de Retina para avaliação de perda visual no olho esquerdo. A paciente apresentava o diagnóstico prévio de macroaneurisma arterial retiniano (MAR) rôto no referido olho. O exame oftalmológico revelou lesão sub-retiniana hemorrágica associada à exsudação na [...] área previamente diagnosticada com MAR. A angiofluoresceinografia revelou hiperfluorescência gradual localizada na região subfoveal, consistente com o diagnóstico de membrana neovascular sub-retiniana (MNSR). Nosso artigo aponta para a possibilidade, embora rara, da formação de uma MNSR após MAR rôto. Abstract in english A 51-year-old black woman was referred to our Retina Clinic for evaluation of loss of vision in her left eye. She was previously diagnosed with a ruptured retinal arterial macroaneurism (RAM) in the same eye. The ophthalmoscopic examination of the affected eye disclosed a subretinal lesion with some [...] hemorrhage and exudation in the same area previously diagnosed with ruptured RAM. Fluorescein angiography revealed a gradually hyperfluorescent net of vessels located in the subfoveal region, consistent with the diagnosis of subretinal neovascular membrane. In this paper we stress the possibility of subretinal neovascularization following a ruptured RAM, even as a rare event.

Raul N. G., Vianna; Augusto, Kassuga; Gabriela, Onofre; Virginia, Ecard; Miguel N., Burnier Jr..

2007-08-01

73

Subretinal neovascularization following ruptured retinal arterial macroaneurysm: case report Neovascularização sub-retiniana secundária ao macroaneurisma arterial da retina rôto: relato de caso  

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Full Text Available A 51-year-old black woman was referred to our Retina Clinic for evaluation of loss of vision in her left eye. She was previously diagnosed with a ruptured retinal arterial macroaneurism (RAM in the same eye. The ophthalmoscopic examination of the affected eye disclosed a subretinal lesion with some hemorrhage and exudation in the same area previously diagnosed with ruptured RAM. Fluorescein angiography revealed a gradually hyperfluorescent net of vessels located in the subfoveal region, consistent with the diagnosis of subretinal neovascular membrane. In this paper we stress the possibility of subretinal neovascularization following a ruptured RAM, even as a rare event.Paciente de 51 anos foi encaminhada ao Setor de Retina para avaliação de perda visual no olho esquerdo. A paciente apresentava o diagnóstico prévio de macroaneurisma arterial retiniano (MAR rôto no referido olho. O exame oftalmológico revelou lesão sub-retiniana hemorrágica associada à exsudação na área previamente diagnosticada com MAR. A angiofluoresceinografia revelou hiperfluorescência gradual localizada na região subfoveal, consistente com o diagnóstico de membrana neovascular sub-retiniana (MNSR. Nosso artigo aponta para a possibilidade, embora rara, da formação de uma MNSR após MAR rôto.

Raul N. G. Vianna

2007-08-01

74

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

75

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

76

Obstrução arterial retiniana periférica associada com hiper-homocisteinemia: relato de caso / Peripheral retinal arterial obstruction associated with hyperhomocysteinemia: case report  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A hiperhomocisteinemia é fator de risco para fenômenos trombo-embólicos retinianos associados a quadro de oclusão vascular venosa e arterial. Descrevemos um paciente com obstrução arterial retiniana periférica, sem sinais de vasculite ativa, associada a proliferação de neovasos com tração vítreo-ret [...] iniana e hemorragia vítrea recidivante. O alto nível sérico de homocisteína decorrente de deficiência de vitamina B12 e ácido fólico, sem outras alterações na cascata da coagulação, inclusive com a pesquisa do fator V de Leiden, sugere que a hiper-homocisteinemia esteja diretamente ligada como fator causal deste quadro clínico. Embora apresentasse PPD elevado, o diagnóstico diferencial mais importante de doença de Eales foi menos considerado por ser diagnóstico de exclusão. O controle do quadro clínico foi feito com suplemento de vitaminas (B12 e ácido fólico) e fotocoagulação retiniana periférica. A homocisteína plasmática total deve ser dosada em pacientes com obstrução vascular retiniana, já que a hiper-homocisteinemia é fator de risco modificável e de fácil tratamento por meio de dieta ou suplementação vitamínica. Abstract in english Hyperhomocysteinemia is a risk factor for thromboembolic events of the retina associated with vascular venous or arterial occlusion. We describe a patient with occlusion of the peripheral arteriolar network without active vasculitis, associated with neovascular proliferation, peripheral vitreous-ret [...] inal traction and relapsing vitreous hemorrhage. The high serum homocysteine level resulting from vitamin B12 and folic acid deficiency, without further changes in the coagulation cascade including the test for Leiden's Factor V, indicates hyperhomocysteinemia as a direct causal factor in this clinical condition. Despite a high PPD, Eales Disease, a major differential diagnosis, was not fully considered, since it is established by exclusion. The patient was treated with photocoagulation and vitamin supplements and the condition was successfully controlled. Patients with retinal vascular obstruction should have their total plasma homocysteine levels measured, since this modifiable risk factor can be easily treated with dietary approaches including vitamin supplementation.

Alexandre Kazuo, Misawa; Hisashi, Suzuki; Otacílio de Oliveira, Maia Júnior; Maria Teresa Brizzi Chizzotti, Bonanomi; Carlos Sérgio Nascimento de, Melo.

2008-10-01

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Obstrução arterial retiniana periférica associada com hiper-homocisteinemia: relato de caso / Peripheral retinal arterial obstruction associated with hyperhomocysteinemia: case report  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A hiperhomocisteinemia é fator de risco para fenômenos trombo-embólicos retinianos associados a quadro de oclusão vascular venosa e arterial. Descrevemos um paciente com obstrução arterial retiniana periférica, sem sinais de vasculite ativa, associada a proliferação de neovasos com tração vítreo-ret [...] iniana e hemorragia vítrea recidivante. O alto nível sérico de homocisteína decorrente de deficiência de vitamina B12 e ácido fólico, sem outras alterações na cascata da coagulação, inclusive com a pesquisa do fator V de Leiden, sugere que a hiper-homocisteinemia esteja diretamente ligada como fator causal deste quadro clínico. Embora apresentasse PPD elevado, o diagnóstico diferencial mais importante de doença de Eales foi menos considerado por ser diagnóstico de exclusão. O controle do quadro clínico foi feito com suplemento de vitaminas (B12 e ácido fólico) e fotocoagulação retiniana periférica. A homocisteína plasmática total deve ser dosada em pacientes com obstrução vascular retiniana, já que a hiper-homocisteinemia é fator de risco modificável e de fácil tratamento por meio de dieta ou suplementação vitamínica. Abstract in english Hyperhomocysteinemia is a risk factor for thromboembolic events of the retina associated with vascular venous or arterial occlusion. We describe a patient with occlusion of the peripheral arteriolar network without active vasculitis, associated with neovascular proliferation, peripheral vitreous-ret [...] inal traction and relapsing vitreous hemorrhage. The high serum homocysteine level resulting from vitamin B12 and folic acid deficiency, without further changes in the coagulation cascade including the test for Leiden's Factor V, indicates hyperhomocysteinemia as a direct causal factor in this clinical condition. Despite a high PPD, Eales Disease, a major differential diagnosis, was not fully considered, since it is established by exclusion. The patient was treated with photocoagulation and vitamin supplements and the condition was successfully controlled. Patients with retinal vascular obstruction should have their total plasma homocysteine levels measured, since this modifiable risk factor can be easily treated with dietary approaches including vitamin supplementation.

Alexandre Kazuo, Misawa; Hisashi, Suzuki; Otacílio de Oliveira, Maia Júnior; Maria Teresa Brizzi Chizzotti, Bonanomi; Carlos Sérgio Nascimento de, Melo.

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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

79

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

80

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.

 
 
 
 
81

Síndrome do anticorpo antifosfolípide causando oclusão bilateral de artérias e veias centrais da retina: relato de caso / Antiphospholipid syndrome and bilateral retinal artery and vein occlusion: case report  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A síndrome do anticorpo antifosfolípide (SAF) tem sido associada a trombose de vasos arteriais e periféricos e de grande ou pequeno calibre. Também os vasos oculares estão sujeitos à ação destes auto-anticorpos que podem promover o aparecimento de perda visual transitória, diplopia, neuropatia óptic [...] a isquêmica e oclusão de artéria ou veia da retina. É descrito aqui, um caso de síndrome do anticorpo antifosfolípide com oclusão de vasos centrais arteriais e venosos da retina no intuito de chamar a atenção para este tipo de diagnóstico. Abstract in english The antiphospholipid syndrome (APS) has been related to venous and arterial thrombosis of large and small vessels. Ocular vessels can also be involved causing transient visual loss, diplopia, ischemic optic neuropathy and central artery and venous occlusion. We describe here a case of antiphospholip [...] id syndrome with occlusion of central retinal artery and vein to call the attention to this diagnosis.

Ana Paula, Beckhauser; Luís Augusto, Arana; Thelma Larocca, Skare.

2008-04-01

82

Síndrome do anticorpo antifosfolípide causando oclusão bilateral de artérias e veias centrais da retina: relato de caso Antiphospholipid syndrome and bilateral retinal artery and vein occlusion: case report  

Directory of Open Access Journals (Sweden)

Full Text Available A síndrome do anticorpo antifosfolípide (SAF tem sido associada a trombose de vasos arteriais e periféricos e de grande ou pequeno calibre. Também os vasos oculares estão sujeitos à ação destes auto-anticorpos que podem promover o aparecimento de perda visual transitória, diplopia, neuropatia óptica isquêmica e oclusão de artéria ou veia da retina. É descrito aqui, um caso de síndrome do anticorpo antifosfolípide com oclusão de vasos centrais arteriais e venosos da retina no intuito de chamar a atenção para este tipo de diagnóstico.The antiphospholipid syndrome (APS has been related to venous and arterial thrombosis of large and small vessels. Ocular vessels can also be involved causing transient visual loss, diplopia, ischemic optic neuropathy and central artery and venous occlusion. We describe here a case of antiphospholipid syndrome with occlusion of central retinal artery and vein to call the attention to this diagnosis.

Ana Paula Beckhauser

2008-04-01

83

Usefulness of Grasping a Guiding Catheter with a Loop-Snare Wire for Stent Placement into the Vertebrobasilar Artery  

International Nuclear Information System (INIS)

In cases in which the subclavian artery is severely tortuous or branches with an extremely angulated origin, stent placement in the vertebrobasilar artery on the approach from the femoral artery is often technically difficult. We report two cases in which a stent placement procedure for the vertebrobasilar artery was successfully performed by grasping a guiding catheter with a loop-snare wire. This technique is useful for tortuous arteries or arteries branching with an extremely angulated origin

84

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

85

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese 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 d [...] oplervelocimétricos 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. Abstract in english 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 D [...] oppler 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; Antonio Fernandes, Moron; Maria Célia dos, Santos; Nelson, Sass; Claudio Rodrigues, Pires.

2005-04-01

86

Retinal blood flow evaluation.  

Science.gov (United States)

Much of our basic knowledge of retinal blood flow regulation is based on data obtained from animal experiments through the use of invasive techniques. However, during the last decades, major developments in the field of optics and lasers have led to a variety of noninvasive techniques, which have been applied to the human eye for the investigation of retinal hemodynamics, and more specifically the regulation of retinal blood flow in response to a number of physiological and pharmacological stimuli. The Retinal Vessel Analyzer has markedly simplified the measurement of the diameter of retinal vessels, as well as the change in this diameter evoked by various physiological stimuli (dynamic measurements). Bidirectional laser Doppler velocimetry allows the measurement of absolute red blood cell centerline velocity, which, when combined with the diameter allows the calculation of retinal blood flow in the main retinal vessels. Laser Doppler flowmetry and laser speckle flowgraphy are techniques that measure the velocities of blood in discrete areas of the retinal tissue microcirculation. Adding a scanning capability, a spatial map of velocities across the retinal tissue is obtained. The blue-field simulation technique allows the quantification of the velocity, number and velocity pulsatility of leukocytes moving in the retinal capillaries of the macular region. With color Doppler imaging, the peak systolic and end-diastolic values of blood velocity in the ophthalmic and central retinal artery are measured, from which a resistivity index is obtained. These techniques may help better understand the role of altered retinal blood flow and its regulation in the pathogenesis of retinal diseases of vascular origin. PMID:23257770

Pournaras, Constantin J; Riva, Charles E

2013-01-01

87

Effect of red blood cells on platelet activation and thrombus formation in tortuous arterioles  

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Full Text Available Thrombosis is a major contributor to cardiovascular disease, which can lead to myocardial infarction and stroke. Thrombosis may form in tortuous microvessels, which are often seen throughout the human body, but the microscale mechanisms and processes are not well understood. In straight vessels, the presence of red blood cells (RBCs is known to push platelets toward walls, which may affect platelet aggregation and thrombus formation. However in tortuous vessels, the effects of RBC interactions with platelets in thrombosis are largely unknown. Accordingly, the objective of this work was to determine the physical effects of RBCs, platelet size, and vessel tortuosity on platelet activation and thrombus formation in tortuous arterioles. A discrete element computational model was used to simulate the transport, collision, adhesion, aggregation, and shear-induced platelet activation of hundreds of individual platelets and RBCs in thrombus formation in tortuous arterioles. Results showed that high shear stress near the inner sides of curved arteriole walls activated platelets to initiate thrombosis. RBCs initially promoted platelet activation, but then collisions of RBCs with mural thrombi reduced the amount of mural thrombus and the size of emboli. In the absence of RBCs, mural thrombus mass was smaller in a highly tortuous arteriole compared to a less tortuous arteriole. In the presence of RBCs however, mural thrombus mass was larger in the highly tortuous arteriole compared to the less tortuous arteriole. As well, smaller platelet size yielded less mural thrombus mass and smaller emboli, either with or without RBCs. This study shed light on microscopic interactions of RBCs and platelets in tortuous microvessels, which have implications in various pathologies associated with thrombosis and bleeding.

Hai-ChaoHan

2013-12-01

88

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

89

Nanopores and Tortuous Pathways in the Barnett Shale  

Science.gov (United States)

The Barnett Shale in north Texas is a profitable gas field, but at current recovery rates only 10-15% of the estimated gas-in-place will be extracted. Gas recovery in this tight formation is limited by tortuous pathways in shale matrix characterized by nano-sized pore spaces. In this work, we used mercury intrusion porosimetry (MIP) to measure pore-size distribution and derive permeability and tortuosity for Barnett shale samples from five different depths. MIP can intrude connected pores with pore-throat diameters down to 3 nm, and the pores in Barnett Shale are predominantly in the nm size range (with a measured median pore diameter of 6.5 nm), and tortuosity is approximately 10,000. We also directly measured chemical diffusion in the saturated Barnett shale using a suite of tracers, followed by chemical mapping using laser ablation-ICP-MS. Tortuosity obtained from tracer diffusion profiles is consistent with those from mercury intrusion porosimetry.

Gao, Z.; Hu, Q.; Ewing, R. P.

2012-12-01

90

Transcorneal Electrical Stimulation Therapy for Retinal Disease  

Science.gov (United States)

Retinitis Pigmentosa; Macula Off; Primary Open Angle Glaucoma; Hereditary Macular Degeneration; Treated Retina Detachment; Retinal Artery Occlusion; Retinal Vein Occlusion; Non-Arthritic-Anterior-Ischemic Optic-Neuropathy; Hereditary Autosomal Dominant Optic Atrophy; Dry Age Related Macular Degeneration; Ischemic Macula Edema

2012-05-03

91

Oclusão artério-venosa da retina após bloqueio retrobulbar: relato de dois casos Combined central retinal vein and artery occlusion after retrobulbar anesthesia: report of two cases  

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Full Text Available São descritos dois casos de oclusão artério-venosa da retina após cirurgia intra-ocular. As duas pacientes foram submetidas à anestesia peribulbar. Devido à sensação dolorosa e à mobilidade ocular foi necessário a realização de bloqueio retrobulbar. Ao final da cirurgia, ambas receberam injeção subconjuntival de gentamicina associada à dexametasona. No primeiro dia pós-cirúrgico as pacientes apresentaram arreflexia pupilar e acuidade visual de percepção luminosa, sendo referidas para nosso serviço. A confirmação do diagnóstico de oclusão vascular retiniana mista foi feito por meio do exame de retinografia fluorescente. As pacientes não manifestaram, em nenhum momento, alterações neurológicas, porém a perda visual foi grave e permanente. Por meio da descrição cirúrgica, da história clínica e dos achados oftalmoscópicos e angiográficos discutem-se as possíveis causas desta grave lesão vascular retiniana, dando ênfase à presumida injeção de anestésico na bainha do nervo óptico durante o bloqueio retrobulbar. Ao mesmo tempo, abordam-se medidas preventivas para evitar tal complicação.Two cases of combined central retinal artery and vein occlusion after intraocular surgery are described. Both patients were submitted to peribulbar anesthesia. Due to the painful sensation and ocular mobility retrobulbar anesthesia was necessary. At the end of the surgery both patients received a subconjunctival injection of gentamicin associated with dexamethasone. On the very first day after the surgery the two patients showed pupillary areflexia and visual acuity of luminous perception when they were referred to our service. The confirmation of the diagnosis of combined vascular occlusion of the retina was obtained by fluorescein angiography test. The two patients never showed, any neurological alteration. However visual loss was severe and permanent. By means of surgical description, clinical history, fundus photography and fluorescein angiography we are able to discuss the possible causes of this severe retinal vascular injury emphasizing the presumed anesthesic injection that was given into the optical nerve during retrobulbar anesthesia. At the same time we discuss preventive measures to avoid such problem.

Rogil José de Almeida Torres

2005-04-01

92

Retinal Vascular Geometry in Asian Persons with Diabetes and Retinopathy  

Science.gov (United States)

Purpose Our purpose was to examine the relationship of retinal vascular parameters with diabetes and retinopathy in an older Asian population. Methods Retinal photographs from participants of a population-based survey of Asian Malay persons aged 40–80 years were analyzed. Specific retinal vascular parameters (tortuosity, branching angle, fractal dimension, and caliber) were measured using a semiautomated computer-based program. Diabetes was defined as random plasma glucose ? 11.1 mmol/liter, the use of diabetes medication, or physician-diagnosed diabetes. Retinopathy signs were graded from photographs using the modified Airlie House classification system. Results A total of 2735 persons were included in the study. Persons with diabetes (n = 594) were more likely to have straighter (less tortuous) arterioles and wider arteriolar and venular caliber than those without diabetes (n = 2141). Among subjects with diabetes, those with retinopathy had wider venular caliber than those without retinopathy (211.3 versus 204.9 mm, p = .001). Among nondiabetic subjects, however, those with retinopathy had more tortuous venules than those without retinopathy [5.19(×104) versus 4.27(×104), p < .001]. Conclusions Retinal vascular parameters varied by diabetes and retinopathy status in this older Asian cohort. Our findings suggest that subtle alterations in retinal vascular architecture are influenced by diabetes. PMID:22768891

Cheung, Carol Yim-lui; Lamoureux, Ecosse; Ikram, M Kamran; Sasongko, M Bayu; Ding, Jie; Zheng, Yingfeng; Mitchell, Paul; Wang, Jie Jin; Wong, Tien Yin

2012-01-01

93

Oclusão artério-venosa da retina após bloqueio retrobulbar: relato de dois casos / Combined central retinal vein and artery occlusion after retrobulbar anesthesia: report of two cases  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese São descritos dois casos de oclusão artério-venosa da retina após cirurgia intra-ocular. As duas pacientes foram submetidas à anestesia peribulbar. Devido à sensação dolorosa e à mobilidade ocular foi necessário a realização de bloqueio retrobulbar. Ao final da cirurgia, ambas receberam injeção subc [...] onjuntival de gentamicina associada à dexametasona. No primeiro dia pós-cirúrgico as pacientes apresentaram arreflexia pupilar e acuidade visual de percepção luminosa, sendo referidas para nosso serviço. A confirmação do diagnóstico de oclusão vascular retiniana mista foi feito por meio do exame de retinografia fluorescente. As pacientes não manifestaram, em nenhum momento, alterações neurológicas, porém a perda visual foi grave e permanente. Por meio da descrição cirúrgica, da história clínica e dos achados oftalmoscópicos e angiográficos discutem-se as possíveis causas desta grave lesão vascular retiniana, dando ênfase à presumida injeção de anestésico na bainha do nervo óptico durante o bloqueio retrobulbar. Ao mesmo tempo, abordam-se medidas preventivas para evitar tal complicação. Abstract in english Two cases of combined central retinal artery and vein occlusion after intraocular surgery are described. Both patients were submitted to peribulbar anesthesia. Due to the painful sensation and ocular mobility retrobulbar anesthesia was necessary. At the end of the surgery both patients received a su [...] bconjunctival injection of gentamicin associated with dexamethasone. On the very first day after the surgery the two patients showed pupillary areflexia and visual acuity of luminous perception when they were referred to our service. The confirmation of the diagnosis of combined vascular occlusion of the retina was obtained by fluorescein angiography test. The two patients never showed, any neurological alteration. However visual loss was severe and permanent. By means of surgical description, clinical history, fundus photography and fluorescein angiography we are able to discuss the possible causes of this severe retinal vascular injury emphasizing the presumed anesthesic injection that was given into the optical nerve during retrobulbar anesthesia. At the same time we discuss preventive measures to avoid such problem.

Rogil José de Almeida, Torres; Andréa, Luchini; Wilma, Weis; Paulo Roberto, Frecceiro; Marcelo, Casella.

94

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

95

Studies on transport phenomena in polymer solutions and suspensions flowing through tubes of tortuous wall geometry  

Science.gov (United States)

Attempts have been made to analyse the momentum and heat transfer characteristics in tortuous flow of non-Newtonian fluids such as suspensions and polymer solutions through tubes of diverging-converging geometry. The results of the study indicate that the transfer coefficients are significantly higher in such systems as compared to the conventional couette flow (through uniform cylindrical tubes). Moreover, the simultaneous increase in pressure drop due to the tortuous wall geometry has been observed to be relatively insignificant. Fluids with different rheological characteristics such as Bingham plastic fluids, pseudoplastic fluids, Ellis model fluids and fluids obeying Reiner-Philippoff rheology have been studied. The specific advantages of these geometries in providing enhanced performance efficiency have been effectively highlighted.

Narayanan, C. M.

2014-02-01

96

Effects of elastic and inelastic scattering in giving electrons tortuous paths in matter.  

Science.gov (United States)

Heavy charged particles travel in essentially straight lines in matter, while electrons travel in tortuous paths. Frequent multiple elastic Coulomb scattering by atomic nuclei is often cited as the reason for this electron behavior. Heavy charged particles also undergo multiple Coulomb scattering. However, because they are massive, significant deflections occur only in rare, close encounters with nuclei. In contrast to heavy particles, the inelastic interaction of an electron with an atomic electron represents a collision with a particle of equal mass. In principle, therefore, repeated inelastic scattering of an electron can also produce large-angle deflections and thus contribute to the tortuous nature of an electron's track. To investigate the relative importance of elastic and inelastic scattering on determining the appearance of electron tracks, detailed Monte Carlo transport computations have been carried out for monoenergetic pencil beams of electrons normally incident on a water slab with initial energies from 1 keV to 1 MeV. The calculations have been performed with deflections due to (1) inelastic scattering only, (2) elastic scattering only, and (3) both types of scattering. Results are presented to show the spreading of the pencil beams with depth in the slab, the transmission through slabs of different thicknesses, and back-scattering from the slab. The results show that elastic nuclear scattering is indeed the principal physical process that causes electron paths to be tortuous; however, the smaller effect of inelastic electronic scattering is far from negligible. PMID:7635734

Turner, J E; Hamm, R N

1995-09-01

97

Platelet size and density affect shear-induced thrombus formation in tortuous arterioles  

International Nuclear Information System (INIS)

Thrombosis accounts for 80% of deaths in patients with diabetes mellitus. Diabetic patients demonstrate tortuous microvessels and larger than normal platelets. Large platelets are associated with increased platelet activation and thrombosis, but the physical effects of large platelets in the microscale processes of thrombus formation are not clear. Therefore, the objective of this study was to determine the physical effects of mean platelet volume (MPV), mean platelet density (MPD) and vessel tortuosity on platelet activation and thrombus formation in tortuous arterioles. A computational model of the transport, shear-induced activation, collision, adhesion and aggregation of individual platelets was used to simulate platelet interactions and thrombus formation in tortuous arterioles. Our results showed that an increase in MPV resulted in a larger number of activated platelets, though MPD and level of tortuosity made little difference on platelet activation. Platelets with normal MPD yielded the lowest amount of mural thrombus. With platelets of normal MPD, the amount of mural thrombus decreased with increasing level of tortuosity but did not have a simple monotonic relationship with MPV. The physical mechanisms associated with MPV, MPD and arteriole tortuosity play important roles in platelet activation and thrombus formation. (paper)

98

An anatomical study of double brachial arteries – a case report  

Directory of Open Access Journals (Sweden)

Full Text Available Superficial brachial artery is one of the major variations of the arterial pattern in the upper limb. During routine anatomical dissection in our department, we observed a case of unilateral double brachial artery in a formalin-fixed female cadaver.Left axillary artery entered into the anterior region of the arm, where it branched into two brachial arteries – the superficial brachial artery (SBA, which was longer, tortuous and with a smaller caliber, and the brachial artery (BA, which was placed deep and medially. In the cubital fossa, covered with an aponeurosis of the biceps brachii muscle, both brachial arteries were connected with an anastomotic vessel. Under this anastomotic branch, in the forearm, SBA continued as the radial artery, whereas BA continued as the ulnar artery.Variations of the arterial pattern in the upper limb are undoubtedly of interest to the anatomists as well as to the clinicians.

Krstonosic B

2010-02-01

99

Unilateral central retinal artery occlusion as the sole presenting sign of Susac syndrome in a young man: case report / Oclusão unilateral da artéria central da retina como único sinal de apresentação da síndrome de Susac em jovem do sexo masculino: relato de caso  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Descrevemos um paciente de 24 anos, sexo masculino, que se apresentou com perda súbita da visão do olho esquerdo causado por oclusão da artéria central da retina. Ele foi submetido à investigação clínica detalhada sem encontrar uma causa. Três semanas depois, no entanto, desenvolveu surdez, encefalo [...] patia e múltiplas oclusões de ramo arterial da retina no olho direito. Angiofluoresceinografia confirmou as oclusões de ramo arterial no OD e oclusão da artéria central da retina no OE, sem qualquer sinal de vascutile. O exame neurológico revelou encefalopatia difusa, enquanto que o estudo efetuado por ressonância nuclear magnética mostrou várias áreas de enfarte do cérebro e a audiometria demonstrou perda auditiva neurosensorial bilateral. A síndrome de Susac foi diagnosticada e tratamento com metilprednisolona e ciclofosfamida instituido com melhora discreta, seguida de estabilização clínica. Este caso é importante para chamar a atenção de que nem todos os três critérios diagnósticos (encefalopatia, oclusão de ramo arterial retiniano e surdez) para a síndrome de Susac precisam estar presentes de início, o que pode causar confusão diagnóstica. O diagnóstico deve portanto ser incluído no diferencial de oclusão da artéria central da retina mesmo quando ocorre em homem sem outros sintomas associados. Abstract in english We report the case of a 24-year-old man presenting with sudden visual loss in the left eye from a central retinal artery occlusion. An extensive clinical investigation revealed no etiology. Three weeks later, however, the patient developed hearing loss followed by encephalopathy and multiple branch [...] retinal artery occlusions in the right eye. Fluorescein angiography confirmed retinal vascular occlusions with no sign of vasculitis. The neurological examination revealed a diffuse encephalopathy while the MRI scan disclosed several small areas of infarcts in the brain. Bilateral sensorineural hearing loss was confirmed on audiometry. The patient was diagnosed with Susac syndrome and treated with methylprednisolone and cyclophosphamide, resulting in slight improvement and stabilization. This case shows that Susac syndrome may be diagnosed late due to the absence at onset of one or more of the symptoms of the classic triad (encephalopathy, multiple branch retinal artery occlusions and hearing loss). This case also serves to emphasize that Susac syndrome should be considered in the differential diagnosis of central retinal artery occlusion, even in apparently healthy young men.

Samira Luiza dos, Apóstolos-Pereira; Lúcia B. Passos, Kara-José; Paulo Euripedes, Marchiori; Mário Luiz Ribeiro, Monteiro.

2013-06-01

100

Unilateral central retinal artery occlusion as the sole presenting sign of Susac syndrome in a young man: case report / Oclusão unilateral da artéria central da retina como único sinal de apresentação da síndrome de Susac em jovem do sexo masculino: relato de caso  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Descrevemos um paciente de 24 anos, sexo masculino, que se apresentou com perda súbita da visão do olho esquerdo causado por oclusão da artéria central da retina. Ele foi submetido à investigação clínica detalhada sem encontrar uma causa. Três semanas depois, no entanto, desenvolveu surdez, encefalo [...] patia e múltiplas oclusões de ramo arterial da retina no olho direito. Angiofluoresceinografia confirmou as oclusões de ramo arterial no OD e oclusão da artéria central da retina no OE, sem qualquer sinal de vascutile. O exame neurológico revelou encefalopatia difusa, enquanto que o estudo efetuado por ressonância nuclear magnética mostrou várias áreas de enfarte do cérebro e a audiometria demonstrou perda auditiva neurosensorial bilateral. A síndrome de Susac foi diagnosticada e tratamento com metilprednisolona e ciclofosfamida instituido com melhora discreta, seguida de estabilização clínica. Este caso é importante para chamar a atenção de que nem todos os três critérios diagnósticos (encefalopatia, oclusão de ramo arterial retiniano e surdez) para a síndrome de Susac precisam estar presentes de início, o que pode causar confusão diagnóstica. O diagnóstico deve portanto ser incluído no diferencial de oclusão da artéria central da retina mesmo quando ocorre em homem sem outros sintomas associados. Abstract in english We report the case of a 24-year-old man presenting with sudden visual loss in the left eye from a central retinal artery occlusion. An extensive clinical investigation revealed no etiology. Three weeks later, however, the patient developed hearing loss followed by encephalopathy and multiple branch [...] retinal artery occlusions in the right eye. Fluorescein angiography confirmed retinal vascular occlusions with no sign of vasculitis. The neurological examination revealed a diffuse encephalopathy while the MRI scan disclosed several small areas of infarcts in the brain. Bilateral sensorineural hearing loss was confirmed on audiometry. The patient was diagnosed with Susac syndrome and treated with methylprednisolone and cyclophosphamide, resulting in slight improvement and stabilization. This case shows that Susac syndrome may be diagnosed late due to the absence at onset of one or more of the symptoms of the classic triad (encephalopathy, multiple branch retinal artery occlusions and hearing loss). This case also serves to emphasize that Susac syndrome should be considered in the differential diagnosis of central retinal artery occlusion, even in apparently healthy young men.

Samira Luiza dos, Apóstolos-Pereira; Lúcia B. Passos, Kara-José; Paulo Euripedes, Marchiori; Mário Luiz Ribeiro, Monteiro.

 
 
 
 
101

Presumed vascular traction-associated recurrence of retinal detachment in patients with myopic macular hole.  

Science.gov (United States)

Optical coherence tomography (OCT) and OCT-ophthalmoscopic examinations were consecutively performed in two patients with focal retinal redetachment despite previously successful repair of the myopic macular hole-related retinal detachment by vitrectomy with removal of the internal limiting membrane. A microfold developed on the redetached retinal surface in both eyes soon after surgery. C-scan analysis by OCT-ophthalmoscope showed that the retinal microfolds coincided with a retinal artery adjacent to the preexisting macular hole. OCT revealed the focal retinal detachment was most prominent beneath the retinal microfold in both study eyes and did not reach the macular hole in one eye. The retinal microfold was most marked at the initiation of the recurrence and then attenuated with the elevation of the detached retina. Inward vascular tractional force appearing as a retinal microfold can be a critical trigger of recurrent retinal detachment in patients with myopic macular hole. PMID:19205500

Sayanagi, Kaori; Oshima, Yusuke; Ikuno, Yasushi; Tano, Yasuo

2009-01-01

102

Congenital absence of the internal carotid artery diagnosed during investigation of trigeminal neuralgia  

International Nuclear Information System (INIS)

Congenital absence of the unilateral internal carotid artery (ICA) was found in a patient during MR imaging examination for right trigeminal neuralgia. Magnetic resonance angiography showed complete absence of the right ICA and a large tortuous basilar artery (BA). The source images revealed a deformed right trigeminal nerve resulting from compression by the BA. Computed tomography of the skull base showed absence of the right carotid canal, suggesting agenesis of the right ICA. Longstanding hemodynamic stress may have caused the BA to become extremely tortuous, resulting in the trigeminal neuralgia. (orig.)

103

Congenital absence of the internal carotid artery diagnosed during investigation of trigeminal neuralgia  

Energy Technology Data Exchange (ETDEWEB)

Congenital absence of the unilateral internal carotid artery (ICA) was found in a patient during MR imaging examination for right trigeminal neuralgia. Magnetic resonance angiography showed complete absence of the right ICA and a large tortuous basilar artery (BA). The source images revealed a deformed right trigeminal nerve resulting from compression by the BA. Computed tomography of the skull base showed absence of the right carotid canal, suggesting agenesis of the right ICA. Longstanding hemodynamic stress may have caused the BA to become extremely tortuous, resulting in the trigeminal neuralgia. (orig.)

Uchino, A.; Sawada, A.; Kudo, S. [Department of Radiology, Saga Medical School, 5-1-1, Nabeshima, Saga (Japan); Hirakawa, N.; Totoki, T. [Department of Anesthesiology, Saga Medical School, 5-1-1, Nabeshima, Saga (Japan)

2002-09-01

104

Retinal Tear and Detachment  

Medline Plus

Full Text Available ... a retinal tear develops. Retinal detachment is a serious eye condition. If it is not treated, it ... flashes begin suddenly, it may indicate a more serious eye problem, such as a retinal tear or ...

105

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

106

RX-08-HD, a low-viscosity, injection-moldable explosive for filling tortuous paths  

Energy Technology Data Exchange (ETDEWEB)

Cast cure, extrusion cast, and paste extrudable explosives have not been designed for transferring through long tortuous paths or into fine three dimensional shapes. To allow the crystalline explosive to flow a lubricating fluid is required. The energetic liquid ethane trinitrate (TMETN) was used as the lubricant to maximize the explosive energy. TMETN is a liquid nitrate ester which requires stabilization with conventional free radical stabilizers such as 2- nitrodiphenylamine, methyl-nitroanaline, or ethyl centrylite. Since these injection moldable explosives are expected to cure in place, a polyesterurethane binder based on polymeric isocyanate of hexamethylene diisocyanate and polycaprolactone polyols is dissolved in TMETN. The solubility of the polymer precursors in TMETN also reduces the energetic liquids sensitivity. The latent cure catalyst Dabco T-131 was used to minimize shrinkage associated with thermal expansion, reduce cost associated with oven cures, to give 4-6 hour potlife and overnight cure to handling strength. The product RX-08-HD is a new, low-viscosity, injection moldable explosive that can be extruded into complex, void-free shapes. Combined with appropriate design and other aspects of weaponization, RX-08-HD has produced outstanding results.

Hoffman, D.M.; Jessop, E.S.; Swansiger, R.W.

1997-10-01

107

Retinal ischemia in aortic arch atheromatous disease.  

Science.gov (United States)

Retinal ischemia is often caused by emboli arising from the cardiac chambers or the common carotid artery bifurcation; the latter are often composed of cholesterol. However, in many patients no lesions are identified after evaluation of these sources of emboli. Two patients were observed who had retinal ischemia and emboli originating from aortic atheromatous plaques that were visualized by transesophageal echocardiography. Cardiac, carotid, and intracranial sources of emboli were excluded. The embolic nature of retinal ischemia was further corroborated by the presence of microembolic signals during transcranial Doppler insonation of the middle cerebral artery on the side ipsilateral to the symptomatic retina. In patients with Hollenhorst plaques the aortic arch can be a potential source of emboli. Transesophageal echocardiography should be considered in these patients when the initial evaluation does not identify a cardiac or carotid lesion. PMID:9858002

Romano, J G; Babikian, V L; Wijman, C A; Hedges, T R

1998-12-01

108

Retinal Detachment  

Directory of Open Access Journals (Sweden)

Full Text Available Detachment of the retina is a serious event, which may result in complete blindness. The outer segments of the photoreceptors receive oxygen and nutrition from the choroid. If the retina is detached from the choroid, the photoreceptors will fail. The fovea has no retinal blood vessels and depends wholly on the choroid for its oxygen, so detachment of the macula leads to permanent damage to the cones and rods at the posterior pole, and loss of vision. If the macula is not detached, then good vision can be retained if the retina is re-attached promptly.

Subhadra Jalali

2003-01-01

109

Generalized Local Cubic Law for inertial fluid flow and solute transport through tortuous and rough fractures  

Science.gov (United States)

Fundamental understanding of flow and transport processes through single rough-walled fractures remains a challenge to gain insight for interpreting hydrological phenomena at continuum scale. The Generalized Local Cubic Law (GLCL) developed here is based on (1) modifying the aperture field by orienting it with the flow direction accounting for tortuosity, and (2) correcting for roughness changes associated with flow expansion/contraction and inertial effects. We compared its performance in estimating flow rate to results of direct numerical simulations with the Navier-Stokes equations (NSE) and physical flow experiments for real and synthetic three-dimensional rough-walled fractures. We also evaluated the performance of the Local Cubic Law (LCL). The LCL consistently overestimates flow rate with relative error ? ranging from 20% to 100% with arithmetic mean of |?| () equal to 45.4% depending on the degree of tortuosity and roughness. However, the GLCL performs well and improves the performance of the LCL, where ? in flow rate range from -3.1% to 11.4% with =4.7%. Furthermore, we generated breakthrough curves (BTCs) through direct numerical simulations based on the advection-diffusion equation with flow field resulting from solving the NSE (which are considered to the true or experimental BTCs). We revisited the applicability of random walk particle tracking (RWPT) to simulate solute transport dynamics through real fractures, where flow fields resulted from the GLCL and LCL, respectively. We found persistent early arrival and heavy tailing in the BTCs from both direct numerical simulations and RWPT, which are the salient characteristics of non-Fickian behavior. The LCL consistently overestimates mean flow velocity; whereas the GLCL improves estimating flow field, and markedly improves fits to the BTCs relative to those fitted with LCL solutions. Therefore, PWPT with flow field resulting from the GLCL is robust in predicting solute transport through tortuous and rough fractures.

Wang, L.; Cardenas, M.; Slottke, D. T.; Ketcham, R. A.; Sharp, J. M.

2013-12-01

110

[Characteristics of retinal vascular involvement in systemic lupus erythematosus].  

Science.gov (United States)

Retinal vascular abnormalities were studied in 194 patients with systemic lupus erythematosus (SLE). All patients fulfilled the American Rheumatism Association criteria for SLE. The mean age of patients was 31.9 +/- 9.7 years (17-63 years), women falling ill 5 times more often than men. Retinal vascular abnormalities were found in 67 (34.5%) patients and were as follows: retinal angiopathy (80.6%), cotton-wool spots (10.4%), occlusion of central vein or its branches (3%), occlusion of a retinal artery branch (4.5%), and retinal vasculitis with extensive peripheral capillary nonperfusion and neovascularization (3%). In general, retinal vascular occlusions were found in 6.7% of all SLE patients and in 19.4% of SLE patients with retinal vascular changes. Retinal vascular occlusions in SLE patients were associated with the antiphospholipid syndrome. Retinopathy did not depend on systemic hypertension or duration of SLE but correlated with disease activity. Small retinal vessels were involved more often than large vessels (p retinal vaso-occlusive disease (0.92 +/- 0.09 and 0.15 +/- 0.13, respectively, p < 0.0000). PMID:11510158

Ermakova, N A; Alekberova, Z S; Kosheleva, N M; Reshetniak, T N

2001-01-01

111

Atypical twin renal arteries with altered hilar anatomy  

Directory of Open Access Journals (Sweden)

Full Text Available Twin renal arteries (superior and inferior were encountered on the left side in a 58-year-old male Indian cadaver. Both the renal arteries took a tortuous course to the hilum. The inferior renal artery, labeled as the accessory renal artery travelled sinuously and anteriorly over the left renal vein to enter the inferior most part of the hilum. The superior artery, labeled as main renal artery bifurcated before the hilum and its two branches were placed anterior to the vein. Thus the normal anteroposterior disposition of structures viz. renal vein, renal artery and the renal pelvis was not seen. Such renal arteries having sinuous course with atypical sequence of structures at the hilum are of worth concern to the urologists performing renal angiography and to surgeons performing laparoscopies or renal transplantation.

Loh HK

2009-10-01

112

Interventional therapy of complications after liver transplantation: hepatic artery stricture  

International Nuclear Information System (INIS)

Hepatic artery stricture (HAS) after liver transplantation can lead directly to transplanted liver function exhaustion and complications of biliary system. The early diagnosis and treatment are crucial for better prognosis. Doppler ultrasound is the first method of choice, and angiography can give further clear dignosis. The balloon dilatation is still effective for hepatic arterial stenosis. With the more adaptable usage of oronary stent, if possible, would reveal more promising result especially for tortuous stenotic hepatic artery. The vascular reconstruction or repeated liver transplantation is still the effective therapeutic methods. (authors)

113

Retinal Tear and Detachment  

Medline Plus

Full Text Available ... layer of tissue in the back of the eye that is responsible for vision. It is attached ... retinal tear develops. Retinal detachment is a serious eye condition. If it is not treated, it can ...

114

Retinal Tear and Detachment  

Medline Plus

Full Text Available ... tear or break is usually treated with a laser. Some retinal tears do not need treatment. However, ... history of eye trauma and prior cataract surgery. Laser and cryoprobe treatments for retinal tears are very ...

115

Retinal Dysplasia Mimicking Retinoblastoma  

Directory of Open Access Journals (Sweden)

Full Text Available Retinal dysplasia represents a congenital disorder characterized by abnormal proliferation of retinal tissue causing leukocoria. We present a case of an infant with bilateral leukocoria, clinically diagnosed as retinoblastoma, followed by enucleation of the left eye. Microscopy however, demonstrated retinal dysplasia consisting of a disorderly proliferation of retinal tissue with formation of rosettes, mimicking retinoblastoma. Microscopic features that aid in differentiating this lesion from retinoblastoma are discussed.

Ravikumar HN

2012-10-01

116

Retinal Tear and Detachment  

Medline Plus

Full Text Available ... choroid tissue, which supplies the retina with some blood. Retinal detachment is a disease where the retina separates from the choroid. Retinal detachment is a serious eye condition. If left untreated, it can lead to blindness. Most retinal tears result from the ...

117

Diagnosis of Incidental Coronary-to-Bronchial Artery Fistula with CT Angiography: A Case Report  

Energy Technology Data Exchange (ETDEWEB)

We report the case of a 64-year-old man with coronary-to-bronchial artery fistula (CBF) that was detected incidentally; the patient presented with the clinical manifestations of aortic dissection. Coronary CT angiography demonstrated tortuous vessels originating from the left circumflex coronary artery that were in communication with the bronchial arteries. CBF is a rare coronary artery anomaly and CBFs are asymptomatic in most cases. Familiarity with CT findings of CBF may help diagnose the incidental finding of CBF through the use of CT angiography undertaken for a different diagnostic purpose.

Kang, Eun Ju; Lee, Ki Nam; Kim, Woo Jeong; Le, Jin Hwa; Oh, Jong Young [Dept. of Radiology, Dong A University Hospital, Dong A University College of Medicine, Pusan (Korea, Republic of)

2012-04-15

118

Unique variation in the course of maxillary artery in infratemporal fossa: a case report.  

Science.gov (United States)

Maxillary artery is one of the key contents of the infratemporal fossa. Mandibular nerve and its branches form a clinically important relation of maxillary artery in this region. A comprehensive knowledge of variations of maxillary artery in the fossa is of special relevance in oral maxillofacial surgeries, management of epistaxis, intractable neuralgias or headaches. We found a unique variation of maxillary artery, presenting bilaterally, in relation to branches of mandibular nerve. During routine dissection in a 55-year-old male cadaver, maxillary artery was seen passing deep to lateral pterygoid muscle and crossed through the nerve loop formed between two roots of auriculotemporal nerve and posterior division of mandibular nerve. Further course of maxillary artery was medial to the posterior division of mandibular nerve. Maxillary artery gave its middle meningeal artery branch as it traversed through the nerve loop. A tortuous course taken by maxillary artery can lead to its entrapment causing headaches or nerve irritation presenting with neuralgia. PMID:23900508

Verma, Suman; Fasil, Mohamed; Murugan, Magi; Sakkarai, Jayagandhi

2014-07-01

119

[Retinal manifestations of AIDS].  

Science.gov (United States)

Cytomegalovirus (CMV) retinitis is the most common retinal opportunistic infection in AIDS patients and is the main cause of blindness. It is generally associated with a CD4+ lymphocyte count below 50/microL. CMV retinitis is often asymptomatic (54% of the cases), frequent ophtalmoscopic screening is very important. Two virostatic drugs (Cymevan and Foscavir) have been approved for the treatment of CMV retinitis. Both are effective in preventing the progression of the lesion within 3 weeks of induction therapy. Long-term use of virostatic maintenance therapy delays the onset of relapses. The differential diagnosis of CMV retinitis are: human immunodeficiency virus retinopathy, varicella-zoster virus retinitis, ocular toxoplasmosis, syphilis, candida endophthalmitis in intravenous drug users, and unfrequently, tuberculosis, choroidal pneumocystosis, intraocular lymphoma. PMID:8949282

Cassoux, N; Reux, I; Guex-Crosier, Y; LeHoang, P

1996-09-15

120

Retinal oximetry using ultrahigh-resolution optical coherence tomography  

Directory of Open Access Journals (Sweden)

Full Text Available Yufeng Ye,1,2 Hong Jiang,2,3 Meixiao Shen,4 Byron L Lam,2 Delia Cabrera DeBuc,2 Lili Ge,2,4 Mitra Sehi,2 Jianhua Wang21Hangzhou First People’s Hospital, Hangzhou, China; 2Bascom Palmer Eye Institute, 3Neurology, University of Miami, Miami, FL, USA; 4School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang, ChinaBackground: The purpose of this study was to investigate the repeatability of retinal oximetry using slit-lamp adapted ultrahigh-resolution optical coherence tomography (SL-UHR-OCT.Methods: SL-UHR-OCT was developed and fringe patterns were obtained for a major retinal artery and a major retinal vein. A-scans at the central wavelengths of 805 nm and 855 nm were analyzed for calculating optical density ratios (ODRs, from which the percentage oxygen saturation was calculated. Measurements were made on two occasions for each person. Repeatability and coefficients of repeatability were calculated.Results: The mean ODRs of the artery were 0.79 ± 0.86 and 0.88 ± 0.97 in sessions 1 and 2, respectively. The mean ODRs of the vein were ?0.08 ± 0.69 and 0.14 ± 0.77 between the two sessions, and were significantly lower than that of the artery (P < 0.05. The coefficients of repeatability were 1.44 and 1.81 for the artery and vein, respectively. The mean oxygen saturation of the major retinal artery was 94% ± 45% and 98% ± 51% in sessions 1 and 2, respectively, and the mean oxygen saturation of the major retinal vein was 48% ± 36% and 60% ± 40% between sessions.Conclusion: Optical coherence tomographic oximetry for evaluating retinal oxygen saturation was subject to variation, although the averaged measurements in repeated sessions were matched. Further work on reducing variation will be needed.Keywords: ultrahigh-resolution optical coherence tomography, oximetry

Ye Y

2012-12-01

 
 
 
 
121

Retinal and choroidal vascular occlusion secondary to corticosteroid embolisation.  

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We report a case of visual loss following intranasal injection of triamcinolone acetonide and phenylephrine hydrochloride in a 22-year-old female with chronic sinusitis. Clinical examination and fluorescein angiography revealed vascular occlusions which involved multiple small branches of both the choroidal and retinal circulations. The mechanism of such a complication probably involves inadvertent intra-arterial injection into the anterior or the posterior ethmoidal artery, with retrograde f...

Wilkinson, W. S.; Morgan, C. M.; Baruh, E.; Gitter, K. A.

1989-01-01

122

Retinal Tear and Detachment  

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Full Text Available Retinal Tear and Detachment Introduction The retina is the layer of tissue in the back of the eye that is responsible for vision. It is attached ... retina to detach. This is known as retinal detachment. If the retina detaches from the back of the eye, partial ...

123

Retinal Tears and Detachments  

Science.gov (United States)

... All rights reserved. What are retinal tears and detachments? The retina is a thin layer of light-sensitive nerve ... prevent permanent vision loss. How is a retinal detachment diagnosed? A detached retina cannot be seen from the outside of the ...

124

Cytomegalovirus retinitis in AIDS.  

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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

125

Retinal Tear and Detachment  

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Full Text Available Retinal Tear and Detachment Introduction The retina is the layer of tissue in the back of the eye that is responsible ... much. This reference summary explains what retinal tears and detachments are. It discusses their symptoms, causes, diagnosis ...

126

Transient tractional retinal detachment in an eye with retinitis pigmentosa  

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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

127

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

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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

128

Suboccipital segment of the vertebral artery: A cadaveric study  

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Full Text Available Objective: To study the course, relationships, branches and possible anomalies of the vertebral artery in the suboccipital region in adult Indian cadavers. Materials and Methods: Twenty-one suboccipital segment vertebral artery specimens from embalmed, Indian adult cadavers were dissected and studied. Dissection was performed using microsurgical instruments and was carried out from the skin up to the vertebral artery in layers. The course, relationships and the branches of the vertebral artery were studied and measurements were taken using Vernier calipers. The readings obtained were corroborated with the measurements derived from the digital images using a computer. Observations: All the vertebral arteries had a tortuous course and were covered with rich venous plexuses. None of the specimens had an anomalous course. The artery was divided into a vertical segment (Vv between C2 and C1 vertebra and a horizontal segment (Vh from the C1 transverse foramina to its dural entry. The mean diameter of the artery was 4.8mm. The shortest distance of Vv segment from the dural tube was 16.1mm, and the distance from the C2 ganglion was 7.2mm. The average length of the Vv segment was 15mm and the average length of the Vh segment was 35.6mm. The average of the shortest distance between the vertebral artery and the midline was 13.4mm. Conclusion: The vertebral artery has a tortuous course and is prone to accidental iatrogenic injury, which can result in devastating neurological sequelae depending on contralateral vertebral artery flow. A thorough anatomical knowledge of this segment is essential for the surgeon who intends to operate in this area.

Muralimohan S

2009-01-01

129

Quantitative analysis of retinal changes in hypertension  

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Arterial hypertension is a high prevalence disease in Western countries and it is associated with increased risk for cardiovascular accidents. Retinal vessel changes are common findings in patients suffering from long-standing hypertensive disease. Morphological evaluations of the fundus oculi represent a fundamental tool for the clinical approach to the patient with hypertension. A qualitative analysis of the retinal lesions is usually performed and this implies severe limitations both in the classification of the different degrees of the pathology and in the follow-up of the disease. A diagnostic system based on a quantitative analysis of the retinal changes could overcome these problems. Our computerized approach was intended for this scope. The paper concentrates on the results and the implications of a computerized approach to the automatic extraction of numerical indexes describing morphological details of the fundus oculi. A previously developed image processing and recognition system, documented elsewhere and briefly described here, was successfully tested in pre-clinical experiments and applied in the evaluation of normal as well as of pathological fundus. The software system was developed to extract indexes such as caliber and path of vessels, local tortuosity of arteries and arterioles, positions and angles of crossings between two vessels. The reliability of the results, justified by their low variability, makes feasible the standardization of quantitative parameters to be used both in the diagnosis and in the prognosis of hypertension, and also allows prospective studies based upon them.

Giansanti, Roberto; Boemi, Massimo; Fumelli, Paolo; Passerini, Giorgio; Zingaretti, Primo

1995-05-01

130

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

131

Determinación de factores trombofílicos en pacientes con trombosis venosas retinianas Markers of thrombophilia in patients with retinal vein thrombosis  

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Background: Thrombophilia is an alteration of hemostasis that increases the risk to venous or arterial thrombosis. This condition may be the underlying cause of retinal vein thrombosis. Aim: To study the presence of thrombophilia in patients with retinal vein thrombosis. Patients and methods: Prospective study of 55 patients aged 22 to 86 years, with retinal vein thrombosis (central or branch). Antithrombin III, coagulant protein C, functional protein S, resistance to...

Leonidas Traipe C; Guillermo Conte L; Francisco J Conte S; Santiago Ibáñez L; Patricio Meza R; Basilio Rojas U; Marianela Cuneo V; Juan Verdaguer T

2005-01-01

132

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

133

Novel Neuroprotective Strategies in Ischemic Retinal Lesions  

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Full Text Available Retinal ischemia can be effectively modeled by permanent bilateral common carotid artery occlusion, which leads to chronic hypoperfusion-induced degeneration in the entire rat retina. The complex pathways leading to retinal cell death offer a complex approach of neuroprotective strategies. In the present review we summarize recent findings with different neuroprotective candidate molecules. We describe the protective effects of intravitreal treatment with: (i urocortin 2; (ii a mitochondrial ATP-sensitive K+ channel opener, diazoxide; (iii a neurotrophic factor, pituitary adenylate cyclase activating polypeptide; and (iv a novel poly(ADP-ribose polymerase inhibitor (HO3089. The retinoprotective effects are demonstrated with morphological description and effects on apoptotic pathways using molecular biological techniques.

Robert Gabriel

2010-02-01

134

Learning about Retinitis Pigmentosa  

Science.gov (United States)

... normally sighted individuals encounter when entering a dark movie theatre on a bright, sunny day. However, patients ... serious vision loss. Top of page NHGRI Clinical Research on Retinitis Pigmentosa Currently, NHGRI is not conducting ...

135

Retinal Tear and Detachment  

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Full Text Available ... a vision test, eye pressure test or eye ultrasound to diagnose the cause of your symptoms. If ... that almost always requires some sort of surgery. Treatment If a retinal tear is discovered before a ...

136

Retinal Tear and Detachment  

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Full Text Available ... months or years. However, if floaters and flashes begin suddenly, it may indicate a more serious eye ... support. As retinal detachment gets worse, the retina begins to detach from the macula, or the center ...

137

Retinal Tear and Detachment  

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Full Text Available ... tissue underneath that nourishes and supports it. Retinal cells become weak and start to die if they ... or the center of vision. This causes macular cells to not work correctly. When macular cells do ...

138

Retinal Tear and Detachment  

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Full Text Available ... light that enters the eye by changing the size of the pupil. As light passes through the ... 1 of these 3 procedures. Depending on the size, location, and complexity of the retinal detachment, the ...

139

Retinal Tear and Detachment  

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Full Text Available ... to recognize the parts of the eye before learning about retinal tears and detachments. This section reviews ... see things on either side of us. This type of vision is called peripheral vision or side ...

140

Retinal Tear and Detachment  

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Full Text Available ... condition. If it is not treated, it can lead to blindness. Each year, thousands of people are ... during that time. Unfortunately, a retinal tear sometimes leads to detachment immediately. However, there may not be ...

 
 
 
 
141

Retinal Tear and Detachment  

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Full Text Available ... may be recommended. High risk factors include family history, very near-sightedness, retinal detachment in the other eye, history of eye trauma and prior cataract surgery. Laser ...

142

Retinal Tear and Detachment  

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Full Text Available ... other eye, history of eye trauma and prior cataract surgery. Laser and cryoprobe treatments for retinal tears are ... after the procedure • A slightly lower initial success rate as compared to a scleral buckle Fortunately, more ...

143

Retinal Tear and Detachment  

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Full Text Available ... still important to repair the detachment. This helps prevent total blindness and restore some lost vision. You ... is discovered before a detachment occurs, treatment can prevent the retina from detaching. A retinal tear or ...

144

Retinal Tear and Detachment  

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Full Text Available ... retinal tears and detachment. About 7 out of 10 people experience floaters at some point during their ... not harmful and things should look normal after 10 minutes or less. If the sensation lasts longer, ...

145

Retinal Tear and Detachment  

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Full Text Available ... the macula becomes detached. Once it detaches, permanent damage is done. Macula Even if the macula is ... then examine your eyes to check for retinal damage. The doctor will not be able to see ...

146

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

147

Retinal Detachment: Torn or Detached Retina Treatment  

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... News Consumer Alerts Retinal Detachment: Torn or Detached Retina Treatment Tweet A retinal tear or a detached ... Detached Retina Treatment Retinal Detachment Vision Simulator Torn retina surgery Most retinal tears need to be treated ...

148

[Acute retinal necrosis].  

Science.gov (United States)

Acute retinal necrosis syndrome (ARN) is a rare retinitis caused by the herpes virus family, including herpes simplex virus and varicella zoster virus. ARN most commonly occurs in otherwise healthy patients of either sex at any age. It is characterized by an initial onset of episcleritis or scleritis, periorbital pain, and a frequently granulomatous anterior uveitis. The key criterion is a necrotizing retinitis starting in the periphery and spreading towards the posterior pole, associated with vitreous opacification. Optic neuropathy may also occur. A total of 75% of untreated eyes develop retinal detachment within the first two months after onset of the disease. Two out of three ARN cases show involvement of the fellow eye. Early intravenous antiviral therapy is mandatory to stop ARN progression. Peripheral retinal breaks can be treated by laser photocoagulation, thereby reducing the risk of retinal detachment. Vitreoretinal surgery is often required, and silicon oil is the tamponade of choice in ARN, resulting in good reattachment rates (90%). Visual prognosis, however, is guarded. PMID:19693512

Gandorfer, A; Thurau, S

2009-08-01

149

Retropharyngeal internal carotid artery: case report  

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Full Text Available Introduction: Variations to the course of carotid arteries may lead to abnormal pharyngeal protrusions, to which the otorhinolaryngologist should always attentive. Objective: To report a case of abnormal pharyngeal protrusion due to vascular anomaly in the course of the internal carotid artery, with literature review. Case Report: A 73- year-old woman complained of globus pharyngeus and intermittent dysphonia. A pulsating convexity was observed at the right part of the oropharynx, associated to laryngoscopic signals of pharyngo-laryngeal reflux. The pharyngeal computed tomography scan showed an abnormal tortuous internal carotid in the retropharyngeal space. The patient was sent to the vascular surgeon, who, after a normal blood flow finding at the Doppler, opted for an expectation conduct. The pharyngeal symptoms improved with the antireflux treatment. Final Comments: Internal carotid vascular anomalies must always be recalled in the pharyngeal wall convexity differential diagnosis.

Figueiredo, Ricardo Rodrigues

2009-03-01

150

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

151

If I Had - Retinitis Pigmentosa  

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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 ...

152

Amino acids in retinitis pigmentosa  

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Full Text Available Retinitis pigmentosa may be associated with amino acid? disorders; whether the association is incidental or consequential is not known. The present investigation on amino acids in retinitis pigmentosa indicates that the level of plasma amino acids does not differ significantly in pa-tients with retinitis pigmentosa compared to that of normal subjects, hence it has no etiological bearing.

Singh M

1988-01-01

153

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

154

Probabilistic retinal vessel segmentation  

Science.gov (United States)

Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

Wu, Chang-Hua; Agam, Gady

2007-03-01

155

Primary peripheral retinal nonperfusion in a family with Loeys-Dietz syndrome.  

Science.gov (United States)

Loeys-Dietz syndrome (LDS) is a connective tissue disorder associated with aggressive arterial aneurysms; rarely, it can have clinical features similar to those of Marfan syndrome, with retinal detachment, myopia, and ectopia lentis. A 19-month-old boy with history of LDS was found to have peripheral retinal nonperfusion in both eyes and a combined traction and exudative retinal detachment of the left eye. Ocular findings in the father, who also had LDS, were normal, but the patient's 34-month-old sister with LDS was also found to have less extensive peripheral retinal nonperfusion. To our knowledge, this is the first report of LDS associated with peripheral retinal nonperfusion in siblings with the same LDS mutation. PMID:24792536

Longmuir, Susannah Q; Winter, Timothy W; Gross, Jordan R; Boldt, H Culver

2014-06-01

156

Dynamic focal retinal arteriolar vasospasm in migraine  

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Full Text Available A 48-year-old man presented following an episode of sudden onset simultaneous inferior altitudinal visual loss in his left eye and visual obscuration with shimmering in the inferonasal quadrant of the right eye. Clinical examination demonstrated left superior hemiretinal artery occlusion and an area of focal dynamic spasm along the right superior temporal branch retinal artery, the arteriolar spastic cycle was about 2 sec in duration. Hematological (including complete blood count, thrombophilia screen, vasculitic screen and serum magnesium, carotid, and cardiac investigations were normal. He was given acetazolamide 500 mg orally, timolol maleate 0.5% eye drops once daily and sublingual amyl-nitrate 0.8 mg, and maintained on felodipine 10 mg/day and aspirin 100 mg/day. The area of focal arteriolar spasm in the right eye resolved over two months. To our knowledge there are no prior reports of photographically documented dynamic focal retinal vascular spasm on a MEDLINE and PUBMED search.

Abdul-Rahman Anmar

2011-01-01

157

Automated measurement of retinal blood vessel tortuosity  

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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

158

Association of retinal vessel attenuation with visual function in eyes with retinitis pigmentosa  

Science.gov (United States)

Purpose To investigate the association between visual changes and retinal vessel attenuation in patients with retinitis pigmentosa (RP). Design A retrospective, longitudinal, observational cohort study. Methods We analyzed 45 eyes from 45 subjects who were followed-up for ?3 years at our clinic. Using the computer-based Interactive Vessel Analysis program, central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) were determined. Age- and sex-matched controls from normal subjects were selected from our archived fundus photograph library. Visual acuity, visual field area (Goldmann perimetry, V4e white test light), mean deviation (Humphrey perimetry, central 10-2 program), and central macular thickness (optical coherence tomography) were analyzed for correlations with CRAE and CRVE. Results Both CRAE and CRVE were significantly decreased in RP eyes (94.9±13.5 ?m and 155.6±20.0 ?m, respectively) compared with control eyes (138.1±14.7 ?m and 215.0±20.4 ?m, respectively, both P<0.001). After 3 years of follow-up, visual field area was associated with both CRAE (r=0.584, P<0.01) and CRVE (r=0.500, P=0.008). A significant association was also observed between mean deviation and CRAE (r=0.298, P=0.047). In eyes with RP, a narrower vessel caliber at baseline was associated with a larger decline in visual acuity over the 3-year follow-up interval (CRAE: r=?0.344, P=0.021; CRVE: r=?0.314, P=0.035). Conclusion Retinal vessel caliber is associated with some visual functions in patients with RP. PMID:25143709

Nakagawa, Satoko; Oishi, Akio; Ogino, Ken; Makiyama, Yukiko; Kurimoto, Masafumi; Yoshimura, Nagahisa

2014-01-01

159

Ischemic Retinal Vasculitis and Its Management.  

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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...

Talat, L.; Lightman, S.; Tomkins-netzer, O.

2014-01-01

160

Endovascular treatment of basilar artery stenosis due to cerebral vasculopathy related to neurofibromatosis (NF1)  

Science.gov (United States)

Background Cerebrovascular lesions are uncommon in neurofibromatosis type 1 (NF1). Case Description We report a case of 34-year-old man with NF1 who developed posterior circulation stroke. Diffusion-weighted imaging showed acute infarcts in the right vertebra basilar artery territory. Digital subtraction angiography demonstrated significant stenosis of the basilar artery in the mid segment that was identified as the etiology of the symptoms. The vertebral arteries were tortuous and the basilar artery was ectatic. Subsequently endeavour resolute stent was placed across the lesion and post-procedure angiogram showed resolution of stenosis. Conclusion Selective stenotic involvement of the basilar artery with ectatic vertebrobasilar circulation associated with NF1, which was successfully treated with endovascular method, was not been reported previously to our knowledge. PMID:24920981

Alurkar, Anand; Prasanna Karanam, Lakshmi Sudha; Oak, Sagar

2014-01-01

 
 
 
 
161

An experimental study on hepatic artery embolization with absolute ethanol  

International Nuclear Information System (INIS)

The hepatic artery was embolized with absolute ethanol in 13 mongrel dogs to evaluate the embolic effect and safety of this material. Follow up angiography and liver function test were performed at 15 minutes, 1 week and 4 weeks after embolization. Retrograde cholangiography, microangiography and pathologic examination were done at 4 weeks after embolization. The result was as follows: 1. Sequential angiography showed successful and persistent occlusion of intrahepatic arteries at different levels, and reconstitution of the intrahepatic arterial circulation via collaterals. 2. Microangiography revealed avascular area in 5 cases. But in incompletely infarcted area there showed tortuous hepatic arteries, decreased perfusion of sinusoid and microcollaterals through the interlobular arteries, capsular arteries and peribiliary vascular plexus. In one sparse peribiliary plexus was observed. 3. Retrograde cholangiography revealed findings of cholangitis on involved segment. 4. The absolute ethanol was effective for achieving a permanent occlusion of intrahepatic arteries but caused damage on sinusoid and hepatic parenchyma, and on peribiliary vascular plexus resulting in sclerosing cholangitis. So in further clinical application, caution would be necessary to superselect the tumor supplying artery to avoid unnecessary parenchymal damage.

162

Differences in retinal vessels support a distinct vasculopathy causing lacunar stroke  

Science.gov (United States)

Background: Lacunar stroke is common, but the etiology of the small vessel abnormality is unknown. Retinal vessels share ontogeny, size, and physiologic characteristics with cerebral small vessels, and retinopathy is associated with stroke. We compared retinal microvessel appearance as a surrogate for cerebral small vessels in patients with lacunar and large artery cortical ischemic stroke. Methods: We prospectively recruited patients with lacunar ischemic stroke and cortical stroke controls. We took digital retinal photographs of each eye. We assessed central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) diameters and arteriovenous ratios (AVRs) using semiautomated computer software methods and quantified arteriovenous nicking and focal arteriolar narrowing. Results: Among 212 patients (105 lacunar, 107 cortical strokes) of mean age 68 years (SD 12 years), AVR was decreased (0.76 vs 0.78, p = 0.03) and CRVE was increased (44.9 pixels/218 ?m vs 42.8 pixels/208 ?m, p = 0.01) in lacunar patients compared with cortical patients, but CRAE did not differ (33.2 pixels/161 ?m vs 33.7 pixels/163 ?m, p = 0.4). On multivariable analysis, increased CRVE was associated with lacunar stroke subtype (p = 0.03) and younger age (p ischemic stroke subtypes. Conclusions: Retinal venules are wider and arteriovenous ratios are smaller in patients with lacunar strokes compared with those in patients with cortical strokes. GLOSSARY AVN = arteriovenous nicking; AVR = arteriovenous ratio; CI = confidence interval; CRAE = central retinal artery equivalent; CRVE = central retinal vein equivalent; FAN = focal arteriolar narrowing; FLAIR = fluid-attenuated inversion recovery; MR = magnetic resonance; NA = not applicable; NASCET = North American Symptomatic Carotid Endarterectomy Trial; NIHSS = NIH Stroke Scale; OR = odds ratio. PMID:19451533

Doubal, F N.; MacGillivray, T J.; Hokke, P E.; Dhillon, B; Dennis, M S.; Wardlaw, J M.

2009-01-01

163

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

164

Retinal imaging in uveitis  

Science.gov (United States)

Ancillary investigations are the backbone of uveitis workup for posterior segment inflammations. They help in establishing the differential diagnosis and making certain diagnosis by ruling out certain pathologies and are a useful aid in monitoring response to therapy during follow-up. These investigations include fundus photography including ultra wide field angiography, fundus autofluorescence imaging, fluorescein angiography, optical coherence tomography and multimodal imaging. This review aims to be an overview describing the role of these retinal investigations for posterior uveitis. PMID:24843301

Gupta, Vishali; Al-Dhibi, Hassan A.; Arevalo, J. Fernando

2014-01-01

165

Retinal Diseases and VISION 2020  

Directory of Open Access Journals (Sweden)

Full Text Available Historically, retinal disease has had a low priority in prevention of blindness programmes in developing countries. There are several reasons for this. Firstly, it was thought that retinal disease was an uncommon cause of blindness in the developing world; secondly, that the results of treating retinal disease did not justify the effort and expense involved; and, thirdly, that the equipment required was too costly and unreliable for use in a developing country environment. Finally, there is a lack of skilled personnel with sub-speciality training in retinal disease.

David Yorston

2003-01-01

166

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

167

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

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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

168

Intra-arterial chemotherapy for bilateral retinoblastoma via left ophthalmic artery and right anterior deep temporal artery.  

Science.gov (United States)

A 12-month-old boy with a history of bilateral retinoblastoma refractory to systemic chemotherapy, laser therapy and cryotherapy, with excellent response to previous intra-arterial melphalan infusion, presents with active tumour deposits in the right eye. Repeat intra-arterial chemotherapy was recommended. Previous bilateral melphalan infusion was uneventful using flow-guided catheterisation technique. Direct catheterisation of the right ophthalmic artery was unsuccessful despite employment of several flow-guided and over-the-wire catheters. Superselective catheterisation of the ipsilateral middle meningeal artery was unable to identify an anastomotic connection to the ophthalmic artery; however, angiography of the anterior deep temporal artery identified an alternate route for chemotherapy infusion. The anterior deep temporal artery was successfully and safely catheterised to infuse chemotherapy into the ophthalmic artery. The anterior deep temporal artery is an important potential anastomotic connection to the ophthalmic artery that can be used safely and effectively for central retinal artery chemotherapy infusion for retinoblastoma treatment. PMID:25240013

Amans, Matthew R; Narvid, Jared; Halbach, Van V

2014-01-01

169

Refractile superficial retinal crystals and chronic retinal detachment: Case report  

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Full Text Available Abstract Background Few previous reports have described the presence of retinal refractile opacities at the macular area in patients presenting with longstanding peripheral retinal detachment. The exact nature of these opacities is unknown. Case presentation Two patients were referred with an abnormal appearance of refractile opacities in the macular area noted during routine examination. Both were found to have longstanding peripheral retinal detachments. Subretinal fluid analysis of one patient revealed the presence of multiple birefringent crystals. We hypothesise that these crystals are the origin of the refractile macular opacities noted. Conclusion This report describes the rare presentation of asymptomatic peripheral retinal detachment by the detection of refractile macular opacities on routine examination. It highlights the importance of meticulous peripheral retinal examination in these cases. The article also describes the findings of the subretinal fluid analysis and discusses the possible hypothesis behind their appearance.

McCarthy John H

2006-01-01

170

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

171

Light paths in retinal vessel oxymetry.  

Science.gov (United States)

The oxygen utilization and, therefore, the metabolic state, of a distinctive area of the retina may be calculated from the diameter of the supplying artery and vein, the haemoglobin oxygenation, and the velocity of the blood. The first two parameters can be determined by imaging spectrometry at the patients ocular fundus. However, the reflected light emerging from a vessel followed different pathways through the ocular fundus layers and the vessel embedded in the retina. The contribution of the single pathways to the vessel reflection profile is investigated by a Monte Carlo simulation. Considering retinal vessels with diameters of 25-200 microm we found the reflection from a thin vessel to be determined by the single and double transmission of light at 560 nm. The backscattering from the blood column determines the reflectance in the case of a thick vessel. However, both components are in the same order of magnitude. This has to be considered in the calculation of the oxygen saturation of blood in retinal vessels from their reflection spectra. PMID:11341533

Hammer, M; Leistritz, S; Leistritz, L; Schweitzer, D

2001-05-01

172

If I Had - Retinitis Pigmentosa  

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173

If I Had - Retinitis Pigmentosa  

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Full Text Available ... Watch Dr. Gerry Chader, MD, Ph.D., whose research focuses on the cause, prevention, treatment, and cure of retinal disease, discuss retinitis pigmentosa. Dr. Chader is a Chief Scientist at the Doheny Retina Institute at University of Southern California Medical School. On ...

174

Pharmacotherapy of Retinal Diseases with Ranibizumab  

Directory of Open Access Journals (Sweden)

Full Text Available The development of new, abnormal and leaky blood vessels, termed choroidal neovascularization, causes loss of vision and quality of life as a result of many ocular diseases. A current therapy for a leading cause of irreversible blindness in older people in the United States, age-related macular degeneration, is intravitreal injection of ranibizumab. However, ranibizumab has also been used off-label to successfully treat a number of other ocular diseases causing significant ocular morbidity, including retinal vascular occlusion and diabetic macular edema. Despite its efficacy, the association of detectable serum levels of ranibizumab and arterial thromboembolic events in major follow-up studies since its approval by the United States Food and Drug Administration as well as its high cost relative to the possible existence of cheaper, equally efficacious alternatives has underscored the importance of understanding the mode of action and clinical utility of this novel pharmacotherapy.

Daniel F. Kiernan

2009-01-01

175

Blood pressure and retinal microvascular characteristics during pregnancy: Growing Up in Singapore Towards Healthy Outcomes (GUSTO) Study.  

Science.gov (United States)

Changes in maternal blood pressure during pregnancy are associated with poor maternal and neonatal outcomes. We investigated whether maternal blood pressure during midpregnancy has an impact on the retinal microcirculation among pregnant Asian women. A total of 665 pregnant women aged 18 to 46 years were recruited from the Growing Up in Singapore Towards Healthy Outcomes Study. Blood pressure and retinal vascular parameters were both measured at 26 weeks' gestation following a standardized protocol. Blood pressure was measured by a digital automatic blood pressure monitor (Omron HEM 705 LP). Quantitative retinal vascular parameters were assessed by a semiautomated computer-based program (Singapore I Vessel Assessment, version 3.0). In multiple linear regression models, every 10-mm Hg increase in mean arterial blood pressure was associated with a 1.9-?m (P<0.001) reduction in retinal arteriolar caliber, a 0.9° (P=0.05) reduction in retinal arteriolar branching angle, and a 0.07 (P<0.01) reduction in retinal arteriolar fractal dimension, respectively. Patients classified into a high-risk group in developing preeclampsia (mean arterial blood pressure ? 90 mm Hg) were twice as likely (odds ratio 2.1 [95% CI, 1.0-4.4]) to have generalized retinal arteriolar narrowing compared with those classified into a low-risk group (mean arterial blood pressure <90 mm Hg). Retinal venular caliber and vascular tortuosity were not associated with blood pressure measures. Elevated blood pressure is associated with a range of retinal arteriolar changes in pregnant women, providing evidence for an impact of blood pressure on the microcirculation during pregnancy. PMID:22615113

Li, Ling-Jun; Cheung, Carol Yim-Lui; Ikram, M Kamran; Gluckman, Peter; Meaney, Michael J; Chong, Yap-Seng; Kwek, Kenneth; Wong, Tien-Yin; Saw, Seang-Mei

2012-07-01

176

Predetection of diseases by retinal diagnosis using Digital image processing.  

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Full Text Available This paper presents linguistic process for detecting the risk of future heart strokes and various diseases using the retinal image. For patients, it can be reduced the need for travel and provide the access to a doctor. Ophthalmology lends itself easily to telemedicine as it’s a largely image based diagnosis to know the disease of a person earlier. The main goal of the proposed system is to diagnose the type of disease by the retinal image and to automatically detect and segment retinal diseases/various diseases in human beings without human supervision or interaction. The eyes are one place in the body through which we can actually see veins and arteries without surgery and without X-rays. The eyes also reveal the disease present in the human body like high blood pressure, diabetes and future risk of heart strokes. Hence a retina scan can provide sufficient results to predict risk of heart attack and other diseases. So we can use retinal image analysis to analyze whether a person is having high blood pressure,diabetes,crop disease by detecting crossovers and diameter of blood vessels in retina and this can be processed by the digital image processing

Vamsi Krishna Reddy Munnangi#1 , Hemanth yadav Aradhyula#2 , Riyan Mohammed

2013-08-01

177

Retinal detachment in AIDS-related cytomegalovirus retinitis.  

Science.gov (United States)

Patients with acquired immune deficiency syndrome (AIDS) and cytomegalovirus retinitis (CMVR) are surviving longer due to the use of virostatic medicines and improved treatment of opportunistic infections. As a result, retinal detachment is likely to become an increasingly common cause of visual morbidity in these patients. The incidence and outcome of retinal detachment complicating CMVR was studied at two London AIDS centres. Patients with CMVR were identified prospectively and underwent standard treatment. Retinal detachments were diagnosed during regular follow-up. If retinal reattachment surgery was performed, a standard procedure of vitrectomy and silicone oil internal tamponade was employed. Of 147 patients with CMVR, 41 (28%) developed retinal detachments (47 eyes). Forty-three detachments were rhegmatogenous and 4 were exudative. Fifteen eyes of 9 patients with rhegmatogenous detachments underwent retinal reattachment surgery. Of these, visual acuity remained stable or improved in 12 eyes (80%) in the immediate post-operative period. At the last clinic visit, 8 eyes (53%) maintained a visual acuity of 6/60 or better. The visual results of surgery are good in selected patients, bearing in mind the progressive nature of the underlying disease and poor life expectancy. PMID:7556732

Sandy, C J; Bloom, P A; Graham, E M; Ferris, J D; Shah, S M; Schulenburg, W E; Migdal, C S

1995-01-01

178

Persistent trigeminal artery variants detected by MR angiography  

Energy Technology Data Exchange (ETDEWEB)

Persistent trigeminal artery (PTA) variants are cerebellar arteries that originate directly from the precavernous portion of the internal carotid artery (ICA). The goal of our study was to determine the incidence and MR angiographic features of PTA variants. Between April 1996 and September 1999, 523 cranial MR angiographies were performed at our institution. Most of the patients examined had or were suspected of having cerebrovascular disease. We retrospectively reviewed these 523 MR angiograms. A 1.5-T scanner was used in all studies, and maximum intensity projection (MIP) images obtained using the three-dimensional time-of-flight (3D TOF) technique were displayed stereoscopically. Four PTA variants were detected on MR angiograms, at a rate of 0.76 %. At least three of the four PTA variants were anterior inferior cerebellar arteries (AICAs), small tortuous arteries arising from the precavernous portions of the ICAs and taking a posterior course. Although the clinical significance is not great, we found a relatively high incidence of PTA variants on MR angiograms. We stress that knowledge and recognition of these anomalous cerebellar arteries are useful and important in the interpretation of cranial MR angiograms. (orig.)

Uchino, A.; Kato, A.; Takase, Y.; Kudo, S. [Dept. of Radiology, Saga Medical School (Japan)

2000-11-01

179

Gelatine and hydroxyl ethyl starch hypervolemic hemodilution – Effect on hemorheology and retinal circulation in a pig model  

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Full Text Available The present study was designed to determine the effects of hemodilution with gelatine (GEL and hydroxyethyl starch (HES on hematocrit, blood viscosity, systemic hemodynamics, and central retinal arterial blood flow in anaesthetized pigs. 20 pigs were studied. Hypervolemic hemodilution was induced by 30 ml kg-1h-1 GEL (n=10 or HES (n=10 infused over 30 min. The hematocrit decreased comparably in both groups. Plasma viscosity was higher after HES than after GEL. Systolic central retinal blood flow and resistance index increased and were higher after HES than after GEL. Despite a greater plasma viscosity HES increases retinal microcirculation during hypervolemic hemodilution.

M. Grossherr

2008-04-01

180

Tubercular retinal vasculitis.  

Science.gov (United States)

Intraocular tuberculosis (TB) infection can have different clinical manifestations including retinal vasculitis. It more frequently involves the veins and is associated with retina haemorrhages and neovascularisation. The diagnosis may be difficult and presumptive being based on clinical findings and evidence of systemic TB infection. The authors present a case of a 61-year-old woman with blurred vision and floaters in her left eye for 6 years, associated with recurrent vitreous haemorrahages. A temporal branch retinal vein occlusion was presumed. Four years later her right eye was also involved. Her best-corrected visual acuity (BCVA) was 20/50 in both eyes. Fundoscopic examination showed bilateral venous occlusion with vascular staining on fluorescein angiography suggestive of vasculitis secondary to Eales Disease (ED). The interferon gamma release assay (IGRA-QuantiFERON-TB Gold) was positive and antituberculosis treatment (ATT) was started. Her final BCVA was 20/20 bilaterally, without recurrences over a follow-up of 15 months. The use of ATT is likely to reduce recurrent vitreous haemorrhages and eliminate future recurrences. PMID:23737572

Patricio, Maria Sara; Portelinha, Joana; Passarinho, Maria Picoto; Guedes, Marta Esteves

2013-01-01

 
 
 
 
181

Retinal Doppler Ultrasound and Homocystein Levels in Children with Type I Diabetes Mellitus  

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Full Text Available Aim: We aimed to measure plasma homocysteine levels and retinal arterial blood flow of type 1 diabetic children by Doppler ultrasound, which were known to be related with diabetic retinopathy and to compare them with healthy children. Materials and Methods: We selected 42 diabetic children (22 females, 20 males, between the ages of 8 to18 years (mean 13,2±4,3. Mean duration of type 1 diabetes was 5,02±2,99 years. For the control group, 30 children (15 females, 15 males between the ages of 9 to 18 years (mean 14,01±3,5 were selected. In central retinal arteries and ophthalmic arteries, peak systolic velocity, diastolic velocity, pulsatility and resistivity indexes were measured. Results: Except for the higher central retinal artery diastolic velocity in the control group, retinal blood flow velocities were similiar in diabetic children and the control group (p0,05. Mean ophthalmic artery peak systolic velocity (37,33±12,79 cm/sec for well controlled diabetic children was higher than the poorly controlled group (31,1±17,17 cm/sec; mean ophthalmic artery resistivity index (0,76±0,08 for well controlled group was lower than the mean resistivity index (0,82±0,04 of poorly controlled group. Plasma homocysteine levels were higher in diabetic children (10,3±2,18 mmol/L than the control group (9,12±1,9 mmol/L (p<0,05. Plasma homocysteine levels of the poorly controlled diabetics (9,42±2,12 mmol/L were higher than the well controlled diabetics (11,33±2,05 mmol/L.Conclusion: In the poorly controlled group total plasma homocysteine levels and ophthalmic artery resistivity indexes were increased compared to the well controlled diabetics and healthy children which might be risk factors for diabetic retinopathy. (Journal of Current Pediatrics 2008; 6: 19-25

Tolga Altu? ?en

2008-06-01

182

Advances in Retinal Tissue Engineering  

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Full Text Available Retinal degenerations cause permanent visual loss and affect millions world-wide. Current treatment strategies, such as gene therapy and anti-angiogenic drugs, merely delay disease progression. Research is underway which aims to regenerate the diseased retina by transplanting a variety of cell types, including embryonic stem cells, fetal cells, progenitor cells and induced pluripotent stem cells. Initial retinal transplantation studies injected stem and progenitor cells into the vitreous or subretinal space with the hope that these donor cells would migrate to the site of retinal degeneration, integrate within the host retina and restore functional vision. Despite promising outcomes, these studies showed that the bolus injection technique gave rise to poorly localized tissue grafts. Subsequently, retinal tissue engineers have drawn upon the success of bone, cartilage and vasculature tissue engineering by employing a polymeric tissue engineering approach. This review will describe the evolution of retinal tissue engineering to date, with particular emphasis on the types of polymers that have routinely been used in recent investigations. Further, this review will show that the field of retinal tissue engineering will require new types of materials and fabrication techniques that optimize the survival, differentiation and delivery of retinal transplant cells.

Matthew Trese

2012-01-01

183

Flexible retinal electrode array  

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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

184

Is quality of diet associated with the microvasculature? An analysis of diet quality and retinal vascular calibre in older adults.  

Science.gov (United States)

It is unknown whether diet quality is associated with microvascular structure. The present study aimed to investigate the relationship between diet quality, reflecting adherence to dietary guidelines, with retinal microvascular calibre in older adults. The dietary data of 2720 Blue Mountains Eye Study participants, aged 50+ years, were collected using a semi-quantitative FFQ. A modified version of the Healthy Eating Index for Australians was developed to determine total diet scores (TDS). Fundus photographs were taken and retinal vascular calibre measured using computer-assisted techniques and summarised. After adjusting for age, sex, BMI, mean arterial blood pressure, smoking, serum glucose, leucocyte count and history of diagnosed stroke or CHD, persons with higher TDS had healthier retinal vessels cross-sectionally, with wider retinal arteriolar calibre (by approximately 3 ?m, comparing the highest with the lowest quartile of TDS, Ptrend = 0·0001) and narrower retinal venular calibre (by approximately 2·5 ?m; Ptrend = 0·02). In younger subjects aged ?65 years, increasing TDS (lowest to the highest quartile) was associated with healthier retinal vessels: approximately 4·4 ?m wider retinal arteriolar (Ptrend < 0·0001) and approximately 2·3 ?m narrower venular calibre (Ptrend = 0·03). After multivariable adjustment, however, baseline TDS were not associated with retinal arteriolar (Ptrend = 0·89) or venular calibre (Ptrend = 0·25), 5 years later. Also, baseline TDS were not associated with the 5-year change in retinal arteriolar (? = 0·14; P=0·29) or venular calibre (? = - 0·26; P=0·07). Greater compliance with published dietary guidelines (higher diet quality) was cross-sectionally associated with wider retinal arterioles and narrower venules, indicating better retinal microvascular health. PMID:23531363

Gopinath, Bamini; Flood, Victoria M; Wang, Jie Jin; Rochtchina, Elena; Wong, Tien Y; Mitchell, Paul

2013-08-01

185

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

186

If I Had - Retinitis Pigmentosa  

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Full Text Available ... VIDEO: Autologous Stem Cell Transplantation Shows Potential as Alternative MS Treatment VIDEO: If I Had - Retinitis Pigmentosa - ... Contact Us | Disclaimer | Sitemap | Privacy | Request A Custom Feed © 2013, CEH Inc. All rights reserved. Insidermedicine does ...

187

If I Had - Retinitis Pigmentosa  

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Full Text Available Breaking Medical News and In Depth Medical Stories Search News: PROGRAMS Insidermedicine In 60 In Depth In ... pigmentosa? Dr. Chader: Retinitis pigmentosa is really a family of diseases, it’s a catch-phrase for a ...

188

If I Had - Retinitis Pigmentosa  

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189

Diplopia after retinal detachment surgery.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Diplopia following retinal detachment usually responds to simple measures. Fifteen out of 311 cases developed diplopia lasting more than three months after conventional retinal detachment surgery. Binocular single vision was restored in 12 of the 15 cases (80%). The mean follow-up was four years. Diplopia was eliminated stepwise. If prisms were ineffective, our first surgical procedure was removal of the scleral buckle. If the retina was flat, we were prepared to remove the buckle early. When...

Fison, P. N.; Chignell, A. H.

1987-01-01

190

Copper metabolism in retinitis pigmentosa.  

Science.gov (United States)

Clinically and electrophysiologically confirmed cases of primary retinitis pigmentosa have been investigated regarding their copper metabolic state. It is observed that these patients show a normal or near normal serum copper concentration, very low plasma caeruloplasmin concentration, and a very high copper urinary excretion. A similarity between this condition and hepatolenticular degeneration is drawn and it is suggested that retinitis pigmentosa may also be a condition caused by an inborn error of copper metabolism. PMID:1009056

Gahlot, D K; Khosla, P K; Makashir, P D; Vasuki, K; Basu, N

1976-11-01

191

Adult retinal stem cells revisited.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Recent advances in retinal stem cell research have raised the possibility that these cells have the potential to be used to repair or regenerate diseased retina. Various cell sources for replacement of retinal neurons have been identified, including embryonic stem cells, the adult ciliary epithelium, adult Müller stem cells and induced pluripotent stem cells (iPS). However, the true stem cell nature of the ciliary epithelium and its possible application in cell therapies has now been questio...

Bhatia, B.; Singhal, S.; Jayaram, H.; Khaw, P. T.; Limb, G. A.

2010-01-01

192

Concentric retinitis pigmentosa: clinicopathologic correlations.  

Science.gov (United States)

Progressive concentric (centripetal) loss of vision is one pattern of visual field loss in retinitis pigmentosa. This study provides the first clinicopathologic correlations for this form of retinitis pigmentosa. A family with autosomal dominant concentric retinitis pigmentosa was examined clinically and with visual function tests. A post-mortem eye of an affected 94 year old family member was processed for histopathology and immunocytochemistry with retinal cell specific antibodies. Unrelated simplex/multiplex patients with concentric retinitis pigmentosa were also examined. Affected family members of the eye donor and patients from the other families had prominent peripheral pigmentary retinopathy with more normal appearing central retina, good visual acuity, concentric field loss, normal or near normal rod and cone sensitivity within the preserved visual field, and reduced rod and cone electroretinograms. The eye donor, at age 90, had good acuity and function in a central island. Grossly, the central region of the donor retina appeared thinned but otherwise normal, while the far periphery contained heavy bone spicule pigment. Microscopically the central retina showed photoreceptor outer segment shortening and some photoreceptor cell loss. The mid periphery had a sharp line of demarcation where more central photoreceptors were near normal except for very short outer segments and peripheral photoreceptors were absent. Rods and cones showed abrupt loss of outer segments and cell death at this interface. It is concluded that concentric retinitis pigmentosa is a rare but recognizable phenotype with slowly progressive photoreceptor death from the far periphery toward the central retina. The disease is retina-wide but shows regional variation in severity of degeneration; photoreceptor death is severe in the peripheral retina with an abrupt edge between viable and degenerate photoreceptors. Peripheral to central gradients of unknown retinal molecule(s) may be defective or modify photoreceptor degeneration in concentric retinitis pigmentosa. PMID:11825021

Milam, A H; De Castro, E B; Smith, J E; Tang, W X; John, S K; Gorin, M B; Stone, E M; Aguirre, G D; Jacobson, S G

2001-10-01

193

The diagnostic value of three-dimensional contrast-enhanced MR angiography in the arterial disease of the neck region  

International Nuclear Information System (INIS)

Objectives: To analyze the diseases of arteries on three-dimensional contrast-enhanced MR angiography (3D CE-MRA) and to demonstrate the diagnostic value for diseases of arteries in neck region by comparing with digital subtraction angiography (DSA). Methods: 3D CE-MRA was performed in 741 patients with suspected disease of arteries by Doppler ultrasound (DUS) in neck region. The diseases of arteries were classified according to findings on CE-MRA. DSA was simultaneously performed in 206 patients. All of arteries in neck region were artificially divided into five groups: common carotid arteries, internal carotid arteries, external carotid arteries, subclavian arteries, and vertebral arteries. DSA and 3D CE-MRA findings were independently evaluated by two experienced radiologists. Sensitivity, specificity, and accuracy of CE-MRA detection on plaques, stenosis, and occlusion of arteries in five groups were calculated and compared with those of DSA. Results: 36.7% (272/741) cases did not show any abnormalities on 3D CE-MRA. 63.29% (469/741) cases totally showed 827 segments of abnormal arteries. Of them, plaques of atherosclerosis accounted for 34.22% (n=283), stenosis of arteries 34.46% (n=285), occlusion of arteries 3.38% (n=28), tenuous arteries 14.87% (n=123), aberrant arteries 3.87% (n=32), tortuous arteries 3.63% (n=30), aneurysms 0.72% (n=6), arterial dissections 1.21% (n=10), arteries surrounded by tumor 1.45% (n=12), and follow-up of vascular grafts 2.18% (n=18) follow-up of vascular grafts 2.18% (n=18). The rate of positive detection had significant statistic difference between DSA and 3D CE-MRA in 206 cases of common carotid arteries, internal carotid arteries, and vertebral arteries, mainly due to overestimation for evaluating the plaques (256 vs 283 segments) and stenosis (258 vs 285 segments). For the whole samples of 412 segments, there was no significant statistic difference between DSA and 3D CE-MRA in evaluating various artery diseases at the same sites. The accuracy of 3D CE-MRA was 96.60% in common carotid arteries, 96.36% in internal carotid arteries, 98.54% in external carotid arteries, 99.51% in subclavian arteries, and 93.93% in vertebral arteries, respectively. The accuracy of detecting plaques, stenosis, and occlusion of arteries was 97.71%, 97.62%, and 100%, respectively. Conclusion:3D CE-MRA is a reliable noninvasive method for evaluating arteries in neck region and it can replace DSA for the purpose of diagnosis. (authors)

194

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

195

Retinal implants: a systematic review.  

Science.gov (United States)

Retinal implants present an innovative way of restoring sight in degenerative retinal diseases. Previous reviews of research progress were written by groups developing their own devices. This systematic review objectively compares selected models by examining publications describing five representative retinal prostheses: Argus II, Boston Retinal Implant Project, Epi-Ret 3, Intelligent Medical Implants (IMI) and Alpha-IMS (Retina Implant AG). Publications were analysed using three criteria for interim success: clinical availability, vision restoration potential and long-term biocompatibility. Clinical availability: Argus II is the only device with FDA approval. Argus II and Alpha-IMS have both received the European CE Marking. All others are in clinical trials, except the Boston Retinal Implant, which is in animal studies. Vision restoration: resolution theoretically correlates with electrode number. Among devices with external cameras, the Boston Retinal Implant leads with 100 electrodes, followed by Argus II with 60 electrodes and visual acuity of 20/1262. Instead of an external camera, Alpha-IMS uses a photodiode system dependent on natural eye movements and can deliver visual acuity up to 20/546. Long-term compatibility: IMI offers iterative learning; Epi-Ret 3 is a fully intraocular device; Alpha-IMS uses intraocular photosensitive elements. Merging the results of these three criteria, Alpha-IMS is the most likely to achieve long-term success decades later, beyond current clinical availability. PMID:24403565

Chuang, Alice T; Margo, Curtis E; Greenberg, Paul B

2014-07-01

196

Neural retinal regeneration with pluripotent stem cells.  

Science.gov (United States)

Retinal degeneration represents a huge burden of blinding disease, and currently there are no effective treatments that reverse the most common causes of neural retinal degeneration. Stem cell biology has the potential to significantly ease this burden, not only through the development of disease models of retinal degeneration but also in the manufacture of a replacement for the neural retinal tissue. This review summarizes the major advancements in the last decade in the field of neural retinal regeneration with an emphasis on the differentiation of embryonic and induced pluripotent stem cells into cells with retinal and specifically photoreceptor characteristics. PMID:24732764

Ramsden, Conor M; Powner, Michael B; Carr, Amanda-Jayne F; Smart, Matthew J K; da Cruz, Lyndon; Coffey, Peter J

2014-01-01

197

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

2013-04-01

198

Missing correlation of retinal vessel diameter with high-altitude headache  

Science.gov (United States)

The most common altitude-related symptom, high-altitude headache (HAH), has recently been suggested to originate from restricted cerebral venous drainage in the presence of increased inflow caused by hypoxia. In support of this novel hypothesis, retinal venous distension was shown to correlate with the degree of HAH. We quantified for the first time retinal vessel diameter changes at 4559 m using infrared fundus images obtained from a state of the art Spectralis™ HRA+OCT with a semiautomatic VesselMap 1® software. High-altitude exposure resulted in altered arterial and venous diameter changes at high altitude, however, independent of headache burden.

Willmann, Gabriel; Fischer, M Dominik; Schommer, Kai; Bartsch, Peter; Gekeler, Florian; Schatz, Andreas

2014-01-01

199

Seasonal variability in spontaneous cervical artery dissection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

200

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)

 
 
 
 
201

The blood pressure-induced diameter response of retinal arterioles decreases with increasing diabetic maculopathy  

DEFF Research Database (Denmark)

BACKGROUND: The aim of the study was to compare the diameter response of retinal arterioles and retinal thickness in patients with different stages of diabetic maculopathy during an increase in the arterial blood pressure. METHODS: Four groups each consisting of 19 individuals were studied. Group A consisted of normal individuals and groups B-D consisted of type 2 diabetic patients matched for diabetes duration, age, and gender, and characterized by: Group B no retinopathy, Group C mild retinopathy, Group D maculopathy not requiring laser treatment. The diameter changes of a large retinal arteriole were measured using the Retinal Vessel Analyzer (RVA, Imedos, Germany) before, during, and after an increase in the blood pressure induced by isometric exercise. Additionally, the retinal thickness was measured using optical coherence tomography scanning. RESULTS: The arterioles contracted during isometric exercise in normal persons (diameter response: -0.70+/-0.48%) and in patients with no retinopathy (-1.15+/-0.44%), but dilated in patients with mild retinopathy (0.41+/-0.49%) and diabetic maculopathy (0.54+/-0.44%), p=0.01. Retinal thickness was normal in Group A (260+/-5.0 microm), Group B (257+/-4.5 microm), and Group C (253+/-4.4 microm), but was significantly (p=0.006) increased in Group D (279+/-5.3 microm). CONCLUSIONS: The diameter response was reduced in type 2 diabetic patients with retinopathy, whereas retinal thickness was increased in patients with diabetic maculopathy. This suggests that impairment of diameter response in retinal arterioles precedes the development of diabetic macular edema.

Frederiksen, Christian Alcaraz; Jeppesen, Peter

2006-01-01

202

Retinal Detachment: Torn or Detached Retina Diagnosis  

Science.gov (United States)

... News Consumer Alerts Retinal Detachment: Torn or Detached Retina Diagnosis Tweet Your ophthalmologist can diagnose retinal tear ... be performed to get additional detail of the retina. What Is A Torn Or Detached Retina? Torn ...

203

Retinal Detachment: Torn or Detached Retina Symptoms  

Science.gov (United States)

... News Consumer Alerts Retinal Detachment: Torn or Detached Retina Symptoms Tweet Symptoms of a retinal tear and ... your vision. What Is A Torn Or Detached Retina? Torn Or Detached Retina Causes Torn Or Detached ...

204

Reading Visual Braille with a Retinal Prosthesis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Lauritzen, Thomas Z.; Harris, Jordan; Mohand-said, Saddek; Sahel, Jose A.; Dorn, Jessy D.; Mcclure, Kelly; Greenberg, Robert J.

2012-01-01

205

Alternative splicing and retinal degeneration.  

Science.gov (United States)

Alternative splicing is highly regulated in tissue-specific and development-specific patterns, and it has been estimated that 15% of disease-causing point mutations affect pre-mRNA splicing. In this review, we consider the cis-acting splice site and trans-acting splicing factor mutations that affect pre-mRNA splicing and contribute to retinal degeneration. Numerous splice site mutations have been identified in retinitis pigmentosa (RP) and various cone-rod dystrophies. Mutations in alternatively spliced retina-specific exons of the widely expressed RPGR and COL2A1 genes lead primarily to X-linked RP and ocular variants of Stickler syndrome, respectively. Furthermore, mutations in general pre-mRNA splicing factors, such as PRPF31, PRPF8, and PRPF3, predominantly cause autosomal dominant RP. These findings suggest an important role for pre-mRNA splicing in retinal homeostasis and the pathogenesis of retinal degenerative diseases. The development of novel therapeutic strategies to modulate aberrant splicing, including small molecule-based therapies, has the potential to lead to new treatments for retinal degenerative diseases. PMID:23647439

Liu, M M; Zack, D J

2013-08-01

206

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

207

Choroidal melanoma clinically simulating a retinal angioma  

International Nuclear Information System (INIS)

An amelanotic fundus lesion in a 35-year-old man was associated with a dilated retinal vessel, thus suggesting the diagnosis of retinal angioma. Fluorescein angiography and B-scan ultrasonography were not diagnostic, but a radioactive phosphorus uptake test suggested the lesion was malignant. The enucleated globe showed a malignant choroidal melanoma drained by a large retinal vein

208

Choroidal melanoma clinically simulating a retinal angioma  

Energy Technology Data Exchange (ETDEWEB)

An amelanotic fundus lesion in a 35-year-old man was associated with a dilated retinal vessel, thus suggesting the diagnosis of retinal angioma. Fluorescein angiography and B-scan ultrasonography were not diagnostic, but a radioactive phosphorus uptake test suggested the lesion was malignant. The enucleated globe showed a malignant choroidal melanoma drained by a large retinal vein.

Shields, J.A.; Joffe, L.; Guibor, P.

1978-01-01

209

Arterial embolism.  

Science.gov (United States)

Surgical and intensive care patients are at a heightened risk for arterial embolization due to pre-existing conditions such as age, hypercoagulability, cardiac abnormalities and atherosclerotic disease. Most arterial emboli are clots that originate in the heart and travel to distant vascular beds where they cause arterial occlusion, ischemia, and potentially infarction. Other emboli form on the surface of eroded arterial plaque or within its lipid core. Thromboemboli are large clots that dislodge from the surface of athesclerotic lesions and occlude distal arteries causing immediate ischemia. Atheroemboli, which originate from fracturing the lipid core tend to cause a process of organ dysfunction and systemic inflammation, termed cholesterol embolization syndrome. The presentation of arterial emboli depends on the arterial bed that is affected. The most common manifestations are strokes and acute lower limb ischemia. Less frequently, emboli target the upper extremities, mesenteric or renal arteries. Treatment involves rapid diagnosis, which may be aided by precise imaging studies and restoration of blood flow. The type of emboli, duration of presentation, and organ system affected determines the treatment course. Long-term therapy includes supportive medical care, identification of the source of embolism and prevention of additional emboli. Patients who experienced arterial embolism as a result of clots formed in the heart should be anticoagulated. Arterial emboli from atherosclerotic disease of the aorta or other large arteries should prompt treatment to reduce the risk for atherosclerotic progression, such as anti-platelet therapy and the use of statin drugs. The use of anticoagulation and surgical intervention to reduce the risk of arterial embolization from atherosclerotic lesions is still being studied. PMID:23724391

Lyaker, Michael R; Tulman, David B; Dimitrova, Galina T; Pin, Richard H; Papadimos, Thomas J

2013-01-01

210

[Peripheral arteries].  

Science.gov (United States)

Peripheral arterial disease is a main cause of morbidity in industrialised countries. It chiefly affects older people. The most common causes are atherosclerosis and vasodilatatory abnormalities. In the presence of unexplained leg symptoms, peripheral arterial disease can be diagnosed or ruled out by non-invasive diagnostic methods such as history, clinical examination and the measurement of ankle and brachial artery pressure by Doppler ultrasound, as well as by calculating the ankle brachial index. Colour coded duplex sonography, computer tomography angiography, magnetic resonance angiography and arteriography are the imaging modalities used. Current diagnostic strategies are analysed for the different peripheral artery diseases. PMID:17479237

Vosshenrich, R; Reimer, P; Landwehr, P

2007-06-01

211

Human retinal circuitry and physiology  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

212

Human retinal circuitry and physiology  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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

213

Human retinal circuitry and physiology  

Directory of Open Access Journals (Sweden)

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

2008-01-01

214

Direct cervical arterial access for intracranial endovascular treatment  

International Nuclear Information System (INIS)

Tortuous vasculature is a cause of failure of endovascular treatment of intracranial vascular lesions. We report our experience of direct cervical accesses in patients in whom the arterial femoral route was not attainable. In this retrospective study, 42 direct punctures of the carotid or the vertebral arteries at the neck were performed in 38 patients. The vessel harboring the intracranial lesion was punctured at the neck above the main tortuosity, a sheath was then positioned under fluoroscopic control to allow a stable access to the intracranial circulation. After the procedure, the sheath was removed and hemostasis was gained either by manual compression or by an arterial closure device (4 of 42, 9%). The cervical route allowed access to all intracranial lesions in all 42 procedures. A complication was encountered in six procedures (14%) related to the direct puncture. In 2 of the 42 procedures (4%), a transient vasospasm was encountered. A cervical hematoma formed in 3 of the 42 procedures (7%) after sheath withdrawal (one patient in whom an 8F sheath had been used, required surgical evacuation of a hematoma compressing the upper airways; the other patients did well without surgical evacuation). In the remaining patient (1 of 42 procedures, 2%), a small asymptomatic aneurysm at the puncture site was seen on the follow-up angiogram. Direct cervical arterial approaches to accessing the intracranial circulation is effective in patients in whom the femoral route doesin patients in whom the femoral route does not allow the navigation and stabilization of guiding catheters. (orig.)

215

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

216

Direct cervical arterial access for intracranial endovascular treatment  

Energy Technology Data Exchange (ETDEWEB)

Tortuous vasculature is a cause of failure of endovascular treatment of intracranial vascular lesions. We report our experience of direct cervical accesses in patients in whom the arterial femoral route was not attainable. In this retrospective study, 42 direct punctures of the carotid or the vertebral arteries at the neck were performed in 38 patients. The vessel harboring the intracranial lesion was punctured at the neck above the main tortuosity, a sheath was then positioned under fluoroscopic control to allow a stable access to the intracranial circulation. After the procedure, the sheath was removed and hemostasis was gained either by manual compression or by an arterial closure device (4 of 42, 9%). The cervical route allowed access to all intracranial lesions in all 42 procedures. A complication was encountered in six procedures (14%) related to the direct puncture. In 2 of the 42 procedures (4%), a transient vasospasm was encountered. A cervical hematoma formed in 3 of the 42 procedures (7%) after sheath withdrawal (one patient in whom an 8F sheath had been used, required surgical evacuation of a hematoma compressing the upper airways; the other patients did well without surgical evacuation). In the remaining patient (1 of 42 procedures, 2%), a small asymptomatic aneurysm at the puncture site was seen on the follow-up angiogram. Direct cervical arterial approaches to accessing the intracranial circulation is effective in patients in whom the femoral route does not allow the navigation and stabilization of guiding catheters. (orig.)

Blanc, R. [Fondation Rothschild, Department of Interventional Neuroradiology, Paris (France); APHP, Hopital Henri Mondor, Service de Neuroradiologie Diagnostique et Therapeutique, Creteil Cedex (France); Piotin, M.; Mounayer, C.; Spelle, L. [Fondation Rothschild, Department of Interventional Neuroradiology, Paris (France); Moret, J. [Fondation Rothschild, Department of Interventional Neuroradiology, Paris (France); Hopital de la Fondation Ophtalmologique Adolphe de Rothschild, Service de Neuroradiologie Interventionnelle, Paris Cedex 19 (France)

2006-12-15

217

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

218

Arterial Catheterization  

Science.gov (United States)

... arterial lines are maintained with some fluid, like normal saline. Sometimes a blood thinner is also given to prevent clotting of the line. Other medications are not generally given in an arterial ... to normal after the catheter is removed. Source: Manthous, C., ...

219

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

220

Risk factor profile in retinal detachment  

Directory of Open Access Journals (Sweden)

Full Text Available 150 cases of retinal detachment comprising 50 patients each of bilateral retinal detachment, unilateral retinal detachment without any retinal lesions in the fellow eve and unilateral retinal detachment with retinal lesions in the fellow eye were studied and the various associated risk factors were statistically analysed. The findings are discussed in relation to their aetiological and prognostic significance in the different types of retinal detachment. Based on these observations certain guidelines are offered which may be of value in decision making, in prophylactic detachment surgery. Tractional breaks in the superior temporal quadrant especially when symptomatic. mandate prophylactic treatment. Urgency is enhanced it? the patient is aphakic. Associated myopia adds to the urgency. The higher incidence of initial right e? e involvement in all groups suggests a vascular original possibly ischaemic.

Azad Raj

1988-01-01

 
 
 
 
221

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

222

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

223

If I Had - Retinitis Pigmentosa  

Medline Plus

Full Text Available ... In Depth In the Spotlight If I Had... Universities and Hospitals By Disease or Symptom View QuickTime ... Had - Retinitis Pigmentosa - Dr. Gerry Chader, MD, PhD, University of Southern California Medical School Back to Home ...

224

HTLV-I associated uveitis revisited: characteristic grey-white, granular deposits on retinal vessels.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

AIMS: To elucidate whether there exists any clinical sign characteristic of HTLV-I associated uveitis. METHODS: Fifty five patients with HTLV-I associated uveitis were reviewed. These cases had serum antibodies to HTLV-I, and any other uveitis entities were carefully excluded by means of clinical and laboratory studies. RESULTS: Eight cases (14.5%) developed vascular lesions in the retina, characterised by grey-white, granular deposits scattered on the retinal veins and/or arteries in the pos...

Nakao, K.; Ohba, N.

1996-01-01

225

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)

226

Retinal degeneration mutants in the mouse.  

Science.gov (United States)

The Jackson Laboratory, having the world's largest collection of mouse mutant stocks and genetically diverse inbred strains, is an ideal place to look for genetically determined eye variations and disorders. Through ophthalmoscopy, electroretinography and histology, we have discovered disorders affecting all aspects of the eye including the lid, cornea, iris, lens and retina, resulting in corneal disorders, cataracts, glaucoma and retinal degenerations. Mouse models of retinal degeneration have been investigated for many years in the hope of understanding the causes of photoreceptor cell death. Sixteen naturally occurring mouse mutants that manifest degeneration of photoreceptors in the retina with preservation of all other retinal cell types have been found: retinal degeneration (formerly rd, identical with rodless retina, r, now Pde6b(rd1)); Purkinje cell degeneration (pcd); nervous (nr); retinal degeneration slow (rds, now Prph(Rd2)); retinal degeneration 3 (rd3); motor neuron degeneration (mnd); retinal degeneration 4 (Rd4); retinal degeneration 5 (rd5, now tub); vitiligo (vit, now Mitf(mi-vit)); retinal degeneration 6 (rd6); retinal degeneration 7 (rd7, now Nr2e3(rd7)); neuronal ceroid lipofuscinosis (nclf); retinal degeneration 8 (rd8); retinal degeneration 9 (Rd9); retinal degeneration 10 (rd10, now Pde6b(rd10)); and cone photoreceptor function loss (cpfl1). In this report, we first review the genotypes and phenotypes of these mutants and second, list the mouse strains that carry each mutation. We will also provide detailed information about the cpfl1 mutation. The phenotypic characteristics of cpfl1 mice are similar to those observed in patients with complete achromatopsia (ACHM2, OMIM 216900) and the cpfl1 mutation is the first naturally-arising mutation in mice to cause cone-specific photoreceptor function loss. cpfl1 mice may provide a model for congenital achromatopsia in humans. PMID:11853768

Chang, B; Hawes, N L; Hurd, R E; Davisson, M T; Nusinowitz, S; Heckenlively, J R

2002-02-01

227

Left atrial myxoma causing ophthalmic artery occlusion.  

Science.gov (United States)

A 45-year-old Caucasian woman presented with sudden onset right-sided hemiparesis, aphasia and a painful left eye. Examination revealed a bone-white fundus with no perfusion of either the retinal or choroidal circulations. Magnetic resonance imaging showed increased signal density of the left optic nerve sheath, orbital fat and extraocular muscles consistent with infarction of the ophthalmic artery distribution. An echocardiogram disclosed a mobile, multilobulated mass attached to the septal wall of the left atrium. Pathological examination of the resected tumour confirmed the diagnosis of endocardial myxoma. A colour Doppler study performed 1 month after surgery demonstrated absence of flow in the left ophthalmic artery. At 2 months, the left eye had no light perception and an intraocular pressure of 2 mmHg. This clinicopathological report describes the rare presentation of an acute ophthalmic artery obstruction secondary to atrial myxoma. PMID:9246271

Rafuse, P E; Nicolle, D A; Hutnik, C M; Pringle, C E

1997-01-01

228

Prostatic artery embolization for enlarged prostates due to benign prostatic hyperplasia. How I do it.  

Science.gov (United States)

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. PMID:23903785

Carnevale, Francisco C; Antunes, Alberto A

2013-12-01

229

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

230

Role of retinal metabolism in methanol-induced retinal toxicity  

Energy Technology Data Exchange (ETDEWEB)

Methanol is a toxicant that causes systemic and ocular toxicity after acute exposure. The folate-reduced (FR) rat is an excellent animal model that mimics characteristic human methanol toxic responses. The present study examines the role of the methanol metabolites formaldehyde and formate in the initiation of methanol-induced retinal toxicity. After a single oral dose of 3.0 g/kg methanol, blood methanol concentrations were not significantly different in FR rats compared with folate-sufficient (FS) (control) rats. However, FR rats treated with 3.0 g/kg methanol displayed elevated blood (14.6 mM) and vitreous humor (19.5 mM) formate levels and abnormal electroretinograms (loss of b-wave) 48 h postdose. FR rats pretreated with disulfiram (DSF) prior to 3.0 g/kg methanol treatment failed to display these symptoms. Formaldehyde was not detected in blood or vitreous humor with or without DSF treatment, suggesting that formate is the toxic metabolite in methanol-induced retinal toxicity. Additionally, creating a blood formate profile (14.2 mM at 48 h) similar to that observed in methanol-treated rats by iv infusion of pH-buffered formate does not alter the electroretinogram as is observed with methanol treatment. These data suggest that intraretinal metabolism of methanol is necessary for the formate-mediated initiation of methanol-induced retinal toxicity. 31 refs., 5 figs., 2 tabs.

Garner, C.D. [General Motors Corp., Warren, MI (United States)]|[Wayne State Univ., Detroit, MI (United States); Lee, E.W.; Terzo, T.S. [General Motors Corp., Warren, MI (United States); Louis-Ferdinand, R.T. [Wayne State Univ., Detroit, MI (United States)

1995-08-01

231

Retinal Image Preprocessing: Background and Noise Segmentation  

Directory of Open Access Journals (Sweden)

Full Text Available Retinal images are used for the automated screening and diagnosis of diabetic retinopathy. The retinal image quality must be improved for the detection of features and abnormalities and for this purpose preprocessing of retinal images is vital. In this paper, we present a novel automated approach for preprocessing of colored retinal images. The proposed technique improves the quality of input retinal image by separating the background and noisy area from the overall image. It contains coarse segmentation and fine segmentation. Standard retinal images databases Diaretdb0, Diaretdb1, DRIVE and STARE are used to test the validation of our preprocessing technique. The experimental results show the validity of proposed preprocessing technique.

Usman Akram

2012-07-01

232

Retinal Image Preprocessing: Background and Noise Segmentation  

Directory of Open Access Journals (Sweden)

Full Text Available Retinal images are used for the automated screening and diagnosis of diabetic retinopathy. The retinal image quality must be improved for the detection of features and abnormalities and for this purpose preprocessing of retinal images is vital. In this paper, we present a novel automated approach for preprocessing of colored retinal images. The proposed technique improves the quality of input retinal image by separating the background and noisy area from the overall image. It contains coarse segmentation and fine segmentation. Standard retinal images databases Diaretdb0, Diaretdb1, DRIVE and STARE are used to test the validation of our preprocessing technique. The experimental results show the validity of proposed preprocessing technique.

Usman Akram

2012-09-01

233

Angiographic studies of the totally arterialized rat liver.  

Science.gov (United States)

Twenty-three angiographies were performed in 20 rats with a totally arterialized liver. The arterialization was obtained by the construction of an end-to-side portacaval shunt (PCS) and an arteriovenous (AV) fistula between the left gastric artery and the portal stump. Microsurgical technique was necessary because of the small diameter of the AV fistula (0.5 mm). The angiographic examinations showed an AV fistula patency rate of 70% and a PCS rate of 100%. A successively increasing diameter of the fistula with dilation of the intrahepatic portal vessels was demonstrated in the rats with a patent arterioportal fistula. Tortuous and irregular vessels were also observed. All these signs suggest an overarterialization which developed despite the use of a very small AV fistula. None of the three rats examined histologically had cirrhosis of the liver. Further research is needed to attempt to avoid or minimize the deleterious effects of overarterialization of the portal tree, while utilizing the advantages of a dual liver blood supply in patients with decompressive PCS. PMID:6642939

Ivancev, K; Teuscher, J; Flati, G; Buchholtz, B; Holmin, T

1983-01-01

234

Embolization of internal carotid artery for carotid-cavernous fistula with laminaria  

International Nuclear Information System (INIS)

The advanced method for treatment of carotid-cavernous fistula, is selective occlusion of fistula by detachable balloon catheter, with maintaining blood flow in ipsilateral internal carotid artery. But some disadvantages are in this method, such as high cost for balloon catheter, and difficulty in the technique. Laminaria, root of sea plant, has a character, which is expanded in humidity, about 3-4 times than in dry condition. Lim et al suggested that laminaria made thrombus in a artery without adversed reaction in animal study. Laminaria, as embolus, has some advantages, which are low cost, easy modelling, and it's specific character. So authors made it small club shape for occlusion of internal carotid artery at fistula level, just likely trapping method in surgery. Tail portion of the club was inserted into the tip of guiding catheter (7F multipurpose, Cordis), and advanced to cavernous portion of internal carotid artery via catheter introducing sheath from femoral artery or from common carotid artery. And then at the portion of fistula, embolus was detached with guide wire. For 10 months, we have tried the embolization at 4 cases of traumatic CCF. 3 cases were succeeded, and one was failed and in death. He had very tortuous vessels, so that laminaria could not be reached at the fistula level, only petrous portion. And now we suggested a new method and a embolic material for treatment of carotid-cavernous fistula, which has low cost and simple technique

235

Manifestaciones oftalmológicas de la hipertensión arterial / Ophthalmological manifestations of arterial hypertension  

Scientific Electronic Library Online (English)

Full Text Available SciELO Spain | Language: Spanish Abstract in spanish La hipertensión arterial sistémica (HTA) es una de las enfermedades más frecuentes en los países industrializados, llegando su incidencia hasta un 30%, cifra que va en aumento por la mayor esperanza de vida de la población. Esta elevación de la presión arterial ocasiona o acelera los cambios en la p [...] ared vascular de los órganos diana como el riñón, cerebro, corazón y ojo. A nivel ocular, la HTA produce lesiones en la retina, la coroides y cabeza del nervio óptico, pudiendo abarcar un amplio rango de lesiones, desde un estrechamiento vascular leve hasta una pérdida visual severa por neuropatía óptica isquémica. La respuesta primaria de las arterias retinianas a la hipertensión arterial sistémica es un estrechamiento vascular y los signos que aparecen en el fondo de ojo en la retinopatía hipertensiva son la vasoconstricción difusa o focal, la extravasación por permeabilidad vascular aumentada y la arteriolosclerosis con engrosamiento de la pared de los vasos. Estas tres entidades son las responsables de la aparición de diferentes lesiones que van a caracterizar los estadíos de la enfermedad retiniana como son: los cruces arteriovenosos, exudados duros y algodonosos, trombosis, embolias, hemorragias en el parénquima retiniano, desprendimiento seroso de retina, edema de papila y neuropatía óptica isquémica en los casos más severos como el caso de la hipertensión arterial maligna. Abstract in english Systemic Arterial hypertension (AHT) is one of the most frequent diseases in the industrialised countries, with an incidence reaching 30%, a figure that is rising due to the greater life expectancy of the population. This rise in arterial tension causes, or accelerates, changes in the vascular wall [...] of the target organs such as the kidney, brain, heart and eye. At the ocular level, AHT produces lesions in the retina, the choroids and optic nerve head; this can include a wide range of lesions, from slight vascular narrowing to severe visual loss due to ischaemic optical neuropathy. The primary response of the retinal arteries to systemic arterial hypertension is vascular narrowing and the manifestations that appear at the back of the eye in hypertensive retinopathy are diffuse or focal vasoconstriction, extravasation due to increased vascular permeability and arteriosclerosis with swelling of the wall of the vessels. These three entities are responsible for the appearance of different lesions that characterise the stages of the retinal disease, which are: arteriovenous crossings, hard and cotton-like exudates, thrombosis, embolisms, haemorrhages in the retinal parenchyma, vitreous detachment from the retina, papilla edema and ischaemic optical neuropathy in the more severe cases, such as in case malign arterial hypertension.

N. A., Rodríguez; A., Zurutuza.

236

Fractal Modeling of Retinal Blood Vessel System  

Directory of Open Access Journals (Sweden)

Full Text Available  This paper proposes a novel approach to extract the main features of retinal blood vessel system. The purpose of the study is to evaluate the blood flow in the retinal blood vessel system using Darcy’s law, Reynold’s number, Poiseuille’s law and Forchheimer equation. A new algorithm has been established to traverse through the retinal blood vessel system in a robust manner. 

V. Shanthoshini Deviha

2014-02-01

237

Distribution, markers and functions of retinal microglia  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Retinal microglia originate from hemopoietic cells and invade the retina from the retinal margin and the optic disc, most likely via the blood vessels of the ciliary body and iris, and the retinal vasculature, respectively. The microglial precursors that appear in the retina prior to vascularization are major histocompatibility complex (MHC) class I- and II-positive and express the CD45 marker, but lack specific macrophage markers. They differentiate into ramified parenchymal microglia in the...

2002-01-01

238

Neuroprotection gene therapy in retinal degeneration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Retinal degenerative disease, which includes age-related macular degeneration and retinitis pigmentosa, is the main cause of blindness in developed countries. Degeneration of the retinal pigment epithelium (RPE) and photoreceptor cells through apoptosis is believed to be the main mechanism of cell death. X-linked inhibitor of apoptosis (XIAP) is an endogenous anti-apoptotic protein that mediates its effects through the inhibition of caspases - the proteins regulating the final stages of ap...

Shan, Haidong; Maclaren, Robert

2013-01-01

239

Retinal complications after bungee jumping.  

Science.gov (United States)

Bungee jumping is becoming a popular sport in the Western world with some cases of ophthalmic complications being reported in recent literature. The authors reported a case of a 23-year-old healthy female who presented retinal complications following a bungee jumping. Her fundi showed superficial retinal hemorrhages in the right eye and a sub-internal limiting membrane hemorrhage affecting the left eye. A general examination, including a full neurological examination, was normal and laboratorial investigations were all within normal values. More studies are necessary to identify risk factors and the true incidence of related ocular lesions, but until then, we think this sport activity should be desencouraged, especially to those that are not psychological and physically fit. PMID:7642337

Filipe, J A; Pinto, A M; Rosas, V; Castro-Correia, J

240

Retinal vasculopathy in Fanconi anemia.  

Science.gov (United States)

The authors present a case of Fanconi anemia with bilateral rapid onset retinal neovascularization and vitreous hemorrhage. The patient developed branch retinal vein occlusion in the left eye complicated by vitreous hemorrhage and was treated conservatively with intravitreal hyaluronidase injection. He declined vitrectomy and his visual acuity deteriorated to no perception of light. On follow-up, the right eye was noted to have clinical and angiographic evidence of sheathed vessels, an isolated large frond of neovascularization associated with areas of capillary nonperfusion. Panretinal photocoagulation and vitrectomy were performed with stabilization of vasculopathy and visual acuity. This case illustrates rapid onset peripheral occlusive vasculopathy with an atypical large isolated frond of neovascularization in a patient with Fanconi anemia resulting in blindness in one eye. Patients with Fanconi anemia would benefit from close and regular ophthalmological review. PMID:19772276

Chai, Shu-Ming; Mathur, Ranjana; Ong, Sze-Guan

2009-01-01

 
 
 
 
241

Differential diameter responses in macular and peripheral retinal arterioles may contribute to the regional distribution of diabetic retinopathy lesions  

DEFF Research Database (Denmark)

BACKGROUND: Diabetic retinopathy is assumed to be due to impaired retinal autoregulation, involving both pressure autoregulation and metabolic autoregulation. The disease displays regional differences, with signs of hyperperfusion in the macular area and capillary occlusion with retinal ischemia in the peripheral retinal areas. It can be hypothesized that these regional differences in the occurrence of retinopathy lesions may reflect differences in the capacity of retinal arterioles to autoregulate the diameter of retinal arterioles. METHODS: Seventeen normal persons and two matched groups of patients with respectively diabetic maculopathy and proliferative diabetic retinopathy were examined. The diameter change of a macular and a peripheral retinal arteriole during an increase in the arterial blood pressure induced by isometric exercise, during an increase in retinal metabolism induced by flicker stimulation, and during both stimulus paradigms simultaneously were studied using the dynamic vessel analyzer (DVA). RESULTS: During isometric exercise, the diameter response was reduced in both macular and peripheral retinal arterioles in the two groups of patients with diabetes mellitus. During flicker stimulation, the diameter response was significantly reduced in patients with proliferative diabetic retinopathy, but there was no significant difference between the responses of macular and peripheral arterioles. During simultaneous isometric exercise and flicker stimulation, there was no difference between the diameter response of macular arterioles in the three groups, whereas the diameter response of macular arterioles was significantly lower in normal persons and significantly higher in persons with proliferative diabetic retinopathy as compared to peripheral arterioles. CONCLUSIONS: Regional differences in the disturbances of the diameter response to increased blood pressure may contribute to the regional differences in the distribution of diabetic retinopathy lesions. In the central retinal areas, the diameter response to increased blood pressure and retinal metabolism interacted in a way that may potentially protect this area from ischaemia, whereas this protective mechanism was absent in the peripheral retinal arterioles. An elucidation of the mechanisms underlying diameter regulation to increased blood pressure and retinal metabolism, and the interaction between these two mechanisms, may help in understanding the pathophysiology of diabetic retinopathy.

Skov Jensen, Peter; Jeppesen, Peter

2011-01-01

242

A Retinal Image Processing System  

Science.gov (United States)

An image processing system that incorporated some retinal properties was investigated for the processing of two dimensional images. The system was required to carry out basic image processing tasks such as edge detection. A new filtering technique was deduced from the physiological findings on the distribution of the receptive fields of the retinal ganglion cells. This filtering technique was then incorporated in the design of an image processing system in, which the spatial resolution increased linearly towards the centre of, the image. The design, was based on a discrete polar distribution of processing areas on an inhomogeneous triangular sampling grid. This resulted in a highly localized processing system which simplified the development of the higher image processing tasks such asboundary following. The retinal image processing system was simulated on a VAX 11/750. The computational cost of conducting operations such as edge detection, boundary detection and boundary following, using the designed system, was evaluated and compared with that of the conventional image processing system.

Riahi, Nader; Lawrence, Peter D.

1989-03-01

243

Retinal deimination in aging and disease.  

Science.gov (United States)

Deimination is a posttranslational modification and refers to the conversion of protein bound arginine into citrulline. In the retina, deimination is predominantly catalyzed by Peptidylarginine deiminase type 2 (PAD2). PAD2 expression and deimination are found in many different retinal layers: choroid, retinal pigment epithelium (RPE), photoreceptors, inner plexiform layer, inner nuclear layer, and retinal ganglion cell (RGC) layer. Although decreased retinal deimination and PAD2 expression have been found during normal aging, elevated PAD2 expression and deimination have been observed in age-related neurodegenerative diseases. The role of deimination in normal physiology and in late-onset and progressive ocular or retinal degenerative diseases, such as glaucoma and experimental autoimmune encephalomyelitis remains to be elucidated. PMID:19391158

Bhattacharya, Sanjoy K

2009-05-01

244

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.

245

Retinal Implants for Blind Patients  

Science.gov (United States)

Recently, very promising results have been obtained in clinical trials with eye-prostheses for the blind. There is a chance that advances in surgical techniques, microelectronics design, and material science may lead to the first really useful applications of retinal implants in the near future. This chapter will focus on the actual status of subretinal surgery and implant technologies. Opportunities and limitations of the different technologies will be discussed in terms of patients benefit and technological challenges. Finally, a vision on how the devices may work and look like in the future will be given.

Rothermel, Albrecht

246

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

247

Cone pathway function in relation to asymmetric carotid artery stenosis : correlation to blood pressure  

DEFF Research Database (Denmark)

Purpose:  To examine retinal function in relation to retinal perfusion pressure in patients with carotid artery stenosis. Methods:  Thirteen patients with carotid artery stenosis without clinical eye disease underwent assessment of ophthalmic artery systolic blood pressure (OSP) by ocular pneumoplethysmography, carotid artery obstructive disease by ultrasonography, intraocular pressure by applanation tonometry, retinal perfusion by fluorescein angiography and retinal function by multifocal electroretinography (mfERG). Data analysis compared the eye on the most stenotic side with the fellow eye in the same patient. Results:  Ophthalmic systolic pressure was 95.8?±?13.1?mmHg on the side with the highest degree of carotid artery stenosis (mean 94.0%) and 111.7?±?10.3?mmHg in the fellow eyes on the side with the lesser degree of stenosis (mean 33.9%). Summed mfERG implicit times (N1 and P1) were 3.4% and 2.0% longer (p?=?0.013 and 0.021), and N1 and P1 amplitudes were 18.0% and 16.0% (p?=?0.0041 and 0.020) lower in eyes on the side with the higher stenosis compared with the contralateral eyes. Shorter implicit times and higher amplitudes were correlated with higher brachial systolic arterial blood pressure (p?=?0.0028, 0.011, 0.041 for N1, P1, N2 implicit times, respectively, and p?=?0.0086, 0.016, 0.040 for N1, P1, N2 for amplitudes, respectively, corrected for OSP). Conclusion:  Cone function deviation was observed in clinically healthy eyes on the side with highest degree of carotid artery stenosis and was found correlated to arterial blood pressure.

Kofoed, Peter Kristian; Munch, Inger Christine

2013-01-01

248

Neural remodeling in retinal degeneration.  

Science.gov (United States)

Mammalian retinal degenerations initiated by gene defects in rods, cones or the retinal pigmented epithelium (RPE) often trigger loss of the sensory retina, effectively leaving the neural retina deafferented. The neural retina responds to this challenge by remodeling, first by subtle changes in neuronal structure and later by large-scale reorganization. Retinal degenerations in the mammalian retina generally progress through three phases. Phase 1 initiates with expression of a primary insult, followed by phase 2 photoreceptor death that ablates the sensory retina via initial photoreceptor stress, phenotype deconstruction, irreversible stress and cell death, including bystander effects or loss of trophic support. The loss of cones heralds phase 3: a protracted period of global remodeling of the remnant neural retina. Remodeling resembles the responses of many CNS assemblies to deafferentation or trauma, and includes neuronal cell death, neuronal and glial migration, elaboration of new neurites and synapses, rewiring of retinal circuits, glial hypertrophy and the evolution of a fibrotic glial seal that isolates the remnant neural retina from the surviving RPE and choroid. In early phase 2, stressed photoreceptors sprout anomalous neurites that often reach the inner plexiform and ganglion cell layers. As death of rods and cones progresses, bipolar and horizontal cells are deafferented and retract most of their dendrites. Horizontal cells develop anomalous axonal processes and dendritic stalks that enter the inner plexiform layer. Dendrite truncation in rod bipolar cells is accompanied by revision of their macromolecular phenotype, including the loss of functioning mGluR6 transduction. After ablation of the sensory retina, Müller cells increase intermediate filament synthesis, forming a dense fibrotic layer in the remnant subretinal space. This layer invests the remnant retina and seals it from access via the choroidal route. Evidence of bipolar cell death begins in phase 1 or 2 in some animal models, but depletion of all neuronal classes is evident in phase 3. As remodeling progresses over months and years, more neurons are lost and patches of the ganglion cell layer can become depleted. Some survivor neurons of all classes elaborate new neurites, many of which form fascicles that travel hundreds of microns through the retina, often beneath the distal glial seal. These and other processes form new synaptic microneuromas in the remnant inner nuclear layer as well as cryptic connections throughout the retina. Remodeling activity peaks at mid-phase 3, where neuronal somas actively migrate on glial surfaces. Some amacrine and bipolar cells move into the former ganglion cell layer while other amacrine cells are everted through the inner nuclear layer to the glial seal. Remodeled retinas engage in anomalous self-signaling via rewired circuits that might not support vision even if they could be driven anew by cellular or bionic agents. We propose that survivor neurons actively seek excitation as sources of homeostatic Ca(2+) fluxes. In late phase 3, neuron loss continues and the retina becomes increasingly glial in composition. Retinal remodeling is not plasticity, but represents the invocation of mechanisms resembling developmental and CNS plasticities. Together, neuronal remodeling and the formation of the glial seal may abrogate many cellular and bionic rescue strategies. However, survivor neurons appear to be stable, healthy, active cells and given the evidence of their reactivity to deafferentation, it may be possible to influence their emergent rewiring and migration habits. PMID:12892644

Marc, Robert E; Jones, Bryan W; Watt, Carl B; Strettoi, Enrica

2003-09-01

249

Gene therapy for retinal and choroidal diseases.  

Science.gov (United States)

The eye is a small compartment separated from the systemic circulation by the blood-ocular barriers, providing advantages for intraocular gene transfer - an approach which is being investigated for several types of retinal and choroidal diseases. A compelling application is gene replacement for homozygous loss-of-function mutations in genes differentially expressed in photoreceptors or retinal pigmented epithelial (RPE) cells that result in retinal degeneration. Considerable progress has been made in this area, including demonstration of return of visual function in RPE65 (-/-) dogs after subretinal injection of adeno-associated viral vectors encoding RPE65, providing groundwork for a clinical trial in patients with Leber's Congenital Amaurosis. Proof of principle has been provided for intraocular gene transfer of ribozymes for dominantly inherited retinal degenerations. Survival factor gene therapy shows promise for treatments that may be used in multiple retinal degenerations. Transduction of intraocular and/or periocular cells with constructs that encode antiangiogenic proteins provides a new approach for sustained local delivery treatment of retinal and choroidal neovascularisation. While considerable investigation remains to work out critical details, there is substantial evidence suggesting that in the near future, gene therapy-based treatments will be an important addition to what is currently offered to patients with retinal and/or choroidal diseases. PMID:12079489

Campochiaro, Peter A

2002-06-01

250

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

251

Retinal repair with induced pluripotent stem cells.  

Science.gov (United States)

Retinal degeneration such as age-related macular degeneration and other inherited forms, such as Stargardt's disease and retinitis pigmentosa, and optic neuropathies including glaucoma and ischemic optic neuropathy are major causes of vision loss and blindness worldwide. Damage to retinal pigment epithelial cells and photoreceptors in the former, and to retinal ganglion cell axons in the optic nerve and their cell bodies in the retina in the latter diseases lead to the eventual death of these retinal cells, and in humans there is no endogenous replacement or repair. Cell replacement therapies provide 1 avenue to restore function in these diseases, particularly in the case of retinal repair, although there are considerable issues to overcome, including the differentiation and integration of the transplanted cells. What stem cell sources could be used for such therapies? One promising source is induced pluripotent stem cells (iPSCs), which could be drawn from an individual patient needing therapy, or generated and banked from select donors. We review developing research in the use of iPSCs for retinal cell replacement therapy. PMID:24291154

Al-Shamekh, Shomoukh; Goldberg, Jeffrey L

2014-04-01

252

Bilateral acute retinal necrosis after herpetic meningitis  

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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

253

Studies on retinal and retinal pigment epithelial gene expression.  

Science.gov (United States)

The 'completion' of the murine and human genomes and creation of high-density expressed sequence tag (EST) databases from multiple tissues and multiple species, coupled with the development of high-throughput expression profiling approaches such as microarrays and Serial Analysis of Gene Expression (SAGE), is making possible the in-depth analysis of gene expression patterns in health and disease to an extent that was not previously possible. Such new information is providing insight into normal function, and into how normal function is altered in disease. Efforts have begun, and are accelerating, in the application of expression profiling to the study of the retina and retinal pigment epithelium (RPE). In this chapter we will review progress in this area. We will also discuss technical issues that make expression studies of the RPE particularly challenging, and share our experience in methodological approaches to overcome these challenges. PMID:14750601

Chowers, Itay; Esumi, Noriko; Campochiaro, Peter; Zack, Donald J

2004-01-01

254

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

255

Electrical properties of retinal electrode interface  

Science.gov (United States)

A critical element of a retinal prosthesis is the stimulating electrode array, which is placed in close proximity to the retina. It is via this retinal-electrode interface that a retinal prosthesis electrically stimulates nerve cells to produce the perception of light. The impedance load seen by the current driver consists of the tissue resistance and the complex electrode impedance. The results in this paper show that the tissue resistance of the retina is significantly greater than that of the vitreous humor in the eye. Circuit models of the electrode-retina interface are used to parameterize the different contributors to the overall impedance.

Shah, Samip; Hines, Amy; Zhou, David; Greenberg, Robert J.; Humayun, Mark S.; Weiland, James D.

2007-03-01

256

Photostress Testing Device for Diagnosing Retinal Disease  

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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

257

Retinal neovascularization after intravitreal fibroblast injection.  

Science.gov (United States)

We have developed a new model of retinal neovascularization in the rabbit. After intravitreal autotransplantation of 250,000 tissue-cultured skin fibroblasts, we observed strand formation in the midvitreous cavity. These strands grew toward the vascularized part of the retina and attached to it. Once the attachment was established, retinal neovascularization began with growth of vessels along the fibrous strand. After three months, this retinal neovascularization regressed. The presence of immature capillaries was confirmed by electron microscopic examination. Of 43 eyes, 31 (72%) developed neovascularization. PMID:6167170

Tano, Y; Chandler, D B; Machemer, R

1981-07-01

258

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 are an appropriate and feasible model for UAE with TAGM.

259

PACAP Application Improves Functional Outcome of Chronic Retinal Ischemic Injury in Rats-Evidence From Electroretinographic Measurements.  

Science.gov (United States)

Retinoprotective effects of pituitary adenylate cyclase activating polypeptide (PACAP) are well-known and have been demonstrated in various pathological conditions, such as diabetic retinopathy, excitotoxic retinal injury, UV light-induced degeneration, and ischemic retinal lesion. The neuronal degeneration observed in the different retinal layers under the above pathological conditions can be successfully decreased by PACAP; however, whether this morphological improvement is also reflected in functional amelioration remains unknown. Therefore, our purpose was to investigate the protective effect of PACAP on the rat retina after bilateral common carotid artery occlusion (BCCAO) with electroretinography (ERG) to parallel the functional data with the previous morphological and neurochemical observations. Control eyes received saline treatment while PACAP was injected into the vitreous space of the other eye immediately after the induction of ischemia. Retinal damage and protective effects of PACAP were quantified by the changes in the wave forms and amplitudes. On postoperative days 2 and 14, several parameters were assessed with special attention to the changes of b wave. The results confirm that the previously described morphological protection induced by PACAP treatment is reflected in functional improvement in ischemic retinal lesions. PMID:24723665

Danyadi, Bese; Szabadfi, Krisztina; Reglodi, Dora; Mihalik, Agoston; Danyadi, Tibor; Kovacs, Zsolt; Batai, Istvan; Tamas, Andrea; Kiss, Peter; Toth, Gabor; Gabriel, Robert

2014-11-01

260

High quality optical microangiography of ocular microcirculation and measurement of total retinal blood flow in mouse eye  

Science.gov (United States)

Visualization and measurement of retinal blood flow (RBF) is important to the diagnosis and management of different eye diseases, including diabetic retinopathy. Optical microangiography (OMAG) is developed for generating 3D dynamic microcirculation image and later refined into ultra-high sensitive OMAG (UHS-OMAG) for true capillary vessels imaging. Here, we present the application of OMAG imaging technique for visualization of depth-resolved vascular network within retina and choroid as well as measurement of total retinal blood flow in mice. A fast speed spectral domain OCT imaging system at 820nm with a line scan rate of 140 kHz was developed to image mouse posterior eye. By applying UHS-OMAG scanning protocol and processing algorithm, we achieved true capillary level imaging of retina and choroid vasculature in mouse eye. The vascular pattern within different retinal layers and choroid was presented. An en face Doppler OCT approach [1] without knowing Doppler angle was adopted for the measurement of total retinal blood flow. The axial blood flow velocity is measured in an en face plane by raster scanning and the flow is calculated by integrating over the vessel area of the central retinal artery.

Zhi, Zhongwei; Yin, Xin; Dziennis, Suzan; Alpers, Charles E.; Wang, Ruikang K.

2013-03-01

 
 
 
 
261

Cleavage of ?-Carotene to Retinal  

Science.gov (United States)

Elucidating the physiological roles played by vitamins has always been a major goal of nutritionists and biochemists. In humans, vitamin A deficiency disorder (VADD) in milder forms leads to night blindness, whilst more severe progression can lead to corneal malformations, e.g. xerophthalmia (See Volume 5, Chapters 8 and 9). This deficiency also affects the immune system, leads to infertility and causes malformations during embryogenesis. The molecular basis for these diverse effects lies in the dual role of vitamin A (retinol, 1) derivatives. In all visual systems, retinal (2), or a closely related compound such as 3-hydroxyretinal (3), is the chromophore of the visual pigments (e.g. rhodopsin) [1,2]. In vertebrates, the derivative retinoic acid (RA, 4) is a major signalling molecule that controls a wide range of processes. Retinoic acid is the ligand of the nuclear retinoic acid receptors (RARs) and retinoid X receptors (RXRs) [3-6] (see Chapter 15).

Wyss, Adrian; von Lintig, Johannes

262

BLOOD VESSEL DIAMETER MEASUREMENT ON RETINAL IMAGE  

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Full Text Available Accurate measurement of vessel diameters on retinal images plays an important part in diagnosing cardiovascular diseases and early signs of certain systemic diseases, such as diabetes and hypertension. In this study we develop new method based on computer aided to determine the width of retinal blood vessels by analysing the color fundus image. Retinal vessel diameter was measured based on blood vessel wall estimating on the digital fundus image. We suggested a dependable and accurate technique to determine the diameter (width of retinal blood vessel based on suggested mask created to use specifically on measuring the blood vessel diameter. The suggested system starts by removing the bifurcations and determine the width for each blood vessel segment. Suggested algorithm tested and gives accurate and promised results.

Nidhal El Abbadi

2014-01-01

263

Screening Diabetic Retinopathy Through Color Retinal Images  

Science.gov (United States)

Diabetic Retinopathy (DR) is a common complication of diabetes that damages the eye's retina. Recognition DR as early as possible is very important to protect patients' vision. We propose a method for screening DR and distin-guishing Prolifetive Diabetic Retinopathy (PDR) from Non-Prolifetive Retino-pathy (NPDR) automatatically through color retinal images. This method evaluates the severity of DR by analyzing the appearnce of bright lesions and retinal vessel patterns. The bright lesions are extracted through morphlogical re-consturction. After that, the retinal vessels are automatically extracted using multiscale matched filters. Then the vessel patterns are analyzed by extracting the vessel net density. The experimental results domonstrate that it is a effective solution to screen DR and distinguish PDR from NPDR by only using color retinal images.

Li, Qin; Jin, Xue-Min; Gao, Quan-Xue; You, Jane; Bhattacharya, Prabir

264

Retinal breaks due to intravitreal ocriplasmin  

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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

Tretinoin (Retin-A) and Pregnancy  

Science.gov (United States)

... or visit us online at: www.OTISpregnancy.org . Tretinoin (Retin-A ® ) and Pregnancy In every pregnancy, a ... advice from your health care professional. What is tretinoin? Tretinoin is a medicine that is applied to ...

266

[Paediatric retinal detachment and hereditary vitreoretinal disorders].  

Science.gov (United States)

The number of retinal detachments in children is very low in comparison to the number in adults. One predisposing factor for development of paediatric retinal detachment is suffering from hereditary vitreoretinal degeneration (e.g., Stickler syndrome, Wagner syndrome, Kniest dysplasia, familial exudative vitreoretinopathy, congenital X-linked retinoschisis, Knobloch syndrome, incontinentia pigmenti, Norrie disease). Hereditary vitreoretinopathies are characterised by an abnormal-appearing vitreous gel with associated retinal changes. In most of these eyes further ocular abnormalities can be diagnosed. A group of hereditary disorders is associated with characteristic systemic abnormalities. Allied conditions should be considered in the clinical diagnosis. Vitreoretinopathies are the most common cause of inherited retinal detachment. In most eyes primary vitrectomy is necessary, and disease-specific surgical treatment is discussed. PMID:23986190

Meier, P

2013-09-01

267

Solitary retinal astrocytoma in a dog.  

Science.gov (United States)

An intraocular mass from a 13-year old Husky-mix dog was diagnosed as retinal astrocytoma. The mass arose from the ganglion layer of the retina and occupied 50% of the vitreous space. The mass was immunoreactive for neuron-specific enolase, S-100, vimentin, and glial fibrillary acidic protein. The neoplasm had characteristics similar to solitary retinal astrocytomas of humans but lacked the marked vascularity. PMID:15017032

Meyerholz, D K; Haynes, J S

2004-03-01

268

Photochemistry of retinal chromophore in mouse melanopsin  

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In mammals, melanopsin is exclusively expressed in intrinsically photosensitive retinal ganglion cells (ipRGCs), which play an important role in circadian photoentrainment and other nonimage-forming functions. These ipRGCs reside in the inner retina, far removed from the pigment epithelium, which synthesizes the 11-cis retinal chromophore used by rod and cone photoreceptors to regenerate opsin for light detection. There has been considerable interest in the identification of the melanopsin ch...

Walker, Marquis T.; Brown, R. Lane; Cronin, Thomas W.; Robinson, Phyllis R.

2008-01-01

269

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

270

Dolicomegarterias ilíacas.: Presentación de un caso. Iliac mega-dolicho arteries: Presentation of a case  

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Full Text Available Las anomalías del árbol vascular son comunes. Los aneurismas aislados de las arterias ilíacas son de observación bastante rara. Representan un porcentaje escaso de las distintas estadísticas y a menudo se resalta su aislamiento, precisamente para recordar su rareza. Reportamos un caso masculino, de 74 años de edad, que asistió a consulta por presentar síntomas urinarios. Se le realizó un ultrasonido de abdomen, observándose hidronefrosis renal bilateral moderada, además masas complejas una en cada fosa ilíaca. Se le indicó Tomografía Axial Computarizada de abdomen, donde se confirmó la hidronefrosis renal bilateral y aneurismas de ambas arterias ilíacas. Se completó el estudio con un Angiotac, y se demostró que ambas ilíacas estaban tortuosas y dilatadas (DOLICOMEGARTERIAS.Vascular tree anomalies are common. Iliac arteries isolated aneurisms are very unusual. They represent an scarce percent of the different statistics and their isolation is frequently highlighted, precisely to recollect their rareness.We report the case of a male, 74-years-old patient, assisting the consultation with urinary symptoms. An abdominal ultrasound was made, showing moderated bilateral renal hydronephrosis and also complex masses in each iliac fosse. An abdomen computed axial tomography was indicated, confirming the bilateral renal hydronephrosis and aneurisms in both iliac arteries. The study was completed with an Angiotac and it was demonstrated that both iliac arteries were tortuous and dilated ( Mega-dolicho arteries .

Yariana Martínez Sánchez

2010-02-01

271

Dolicomegarterias ilíacas.: Presentación de un caso. / Iliac mega-dolicho arteries: Presentation of a case  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Las anomalías del árbol vascular son comunes. Los aneurismas aislados de las arterias ilíacas son de observación bastante rara. Representan un porcentaje escaso de las distintas estadísticas y a menudo se resalta su aislamiento, precisamente para recordar su rareza. Reportamos un caso masculino, de [...] 74 años de edad, que asistió a consulta por presentar síntomas urinarios. Se le realizó un ultrasonido de abdomen, observándose hidronefrosis renal bilateral moderada, además masas complejas una en cada fosa ilíaca. Se le indicó Tomografía Axial Computarizada de abdomen, donde se confirmó la hidronefrosis renal bilateral y aneurismas de ambas arterias ilíacas. Se completó el estudio con un Angiotac, y se demostró que ambas ilíacas estaban tortuosas y dilatadas (DOLICOMEGARTERIAS). Abstract in english Vascular tree anomalies are common. Iliac arteries isolated aneurisms are very unusual. They represent an scarce percent of the different statistics and their isolation is frequently highlighted, precisely to recollect their rareness.We report the case of a male, 74-years-old patient, assisting the [...] consultation with urinary symptoms. An abdominal ultrasound was made, showing moderated bilateral renal hydronephrosis and also complex masses in each iliac fosse. An abdomen computed axial tomography was indicated, confirming the bilateral renal hydronephrosis and aneurisms in both iliac arteries. The study was completed with an Angiotac and it was demonstrated that both iliac arteries were tortuous and dilated ( Mega-dolicho arteries ).

Yariana, Martínez Sánchez; Enélida, Matos Abrahantes; Juliana M, Tarajano Márquez; Jacqueline, Ramos Serpa; José Antonio, Rodríguez González.

272

Coronary Artery Bypass Graft  

Medline Plus

Full Text Available ... known as coronary arteries. Symptoms and Their Causes Cholesterol deposits accumulate in the coronary arteries, forming “plaques” ... Healthy diet and medications that lower your blood cholesterol can help slow the process that clogs arteries. ...

273

Carotid Artery Disease  

Science.gov (United States)

... brain with blood. If you have carotid artery disease, the arteries become narrow, usually because of atherosclerosis. ... one of the causes of stroke. Carotid artery disease often does not cause symptoms, but there are ...

274

Coronary Artery Bypass Graft  

Medline Plus

Full Text Available ... the chest wall or arteries from the arm (radial artery) are then used to bypass the clogged ... final location using the same chest incision. The radial artery may also be used as a graft. ...

275

Coronary Artery Bypass Graft  

Medline Plus

Full Text Available ... lower your blood cholesterol can help slow the process that clogs arteries. Exercise and losing weight, under ... the clogged arteries. Coronary Artery Bypass Graft This process of taking blood vessels from one part of ...

276

Pulmonary Arterial Hypertension  

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... other causes. What Happens to the Body with Pulmonary Arterial Hypertension? With PAH, the arteries become too narrow to ... to your brain. What are the Symptoms of Pulmonary Arterial Hypertension? There may be no signs or symptoms of ...

277

Coronary Artery Bypass Graft  

Medline Plus

Full Text Available ... the legs, or arteries going to the chest wall or arteries from the arm (radial artery) are ... usually rerouted from the inside of the chest wall to its final location using the same chest ...

278

Retinal iron homeostasis in health and disease  

Directory of Open Access Journals (Sweden)

Full Text Available 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 aceruloplasminemia, Friedreich’s ataxia, and pantothenate kinase-associated neurodegeneration. Similarly, mice with targeted mutation of the iron exporter ceruloplasmin and its homolog hephaestin showed age-related retinal iron accumulation and retinal degeneration with features resembling human age-related macular degeneration (AMD. Post mortem AMD eyes have increased levels of iron in retina compared to age-matched healthy donors. Iron accumulation in AMD is likely to result, in part, from inflammation, hypoxia, and oxidative stress, all of which can cause iron dysregulation. Fortunately, it has been demonstrated by in vitro and in vivo studies that iron in the retinal pigment epithelium and retina is chelatable. Iron chelation protects photoreceptors and retinal pigment epithelial cells (RPE in a variety of mouse models. This has therapeutic potential for diminishing iron-induced oxidative damage to prevent or treat AMD.

DeluSong

2013-06-01

279

Timing of retinal vein occlusion laser photocoagulation  

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Full Text Available AIM:To observe the clinical curative effect of different duration of retinal vein occlusion(RVOby laser photocoagulation treatment, discuss the timing of the RVO laser photocoagulation treatment, provide the basis for clinical choice of RVO photocoagulation treatment time. METHODS: Retrospective analysis. Line selection retinal laser photocoagulation treatment for 103 cases(103 eyeswith RVO, patients were divided into three groups according to the onset time. In group A(46 eyes, course ?1mo, 28 eyes with branch retinal vein occlusion(BRVO, 18 eyes with central retinal vein occlusion(CRVO; 30 eyes were ischemic RVO, 16 eyes were non-ischemic RVO. In group B(38 eyes, 1moRESULTS: The best corrected visual acuity improved rate, retinal hemorrhage, macular edema, absorption, macular center concave thickness decreased of patients with different course after RVO photocoagulation treatment, the early group was better than that of the late, non-ischemic RVO was better than that of ischemic RVO, laser photocoagulation treatment effect BRVO was better than that of CRVO and the difference was statistically significant(PCONCLUSION: RVO laser photocoagulation in the early intervention treatment can accelerate the retinal hemorrhage, macular edema, absorption, effectively protect the patient's existing vision, improve the long-term vision, and has a certain clinical practical significance.

Wei Zhang

2014-08-01

280

Retinal Vascular Fractals and Cognitive Impairment  

Science.gov (United States)

Background Retinal microvascular network changes have been found in patients with age-related brain diseases such as stroke and dementia including Alzheimer's disease. We examine whether retinal microvascular network changes are also present in preclinical stages of dementia. Methods This is a cross-sectional study of 300 Chinese participants (age: ?60 years) from the ongoing Epidemiology of Dementia in Singapore study who underwent detailed clinical examinations including retinal photography, brain imaging and neuropsychological testing. Retinal vascular parameters were assessed from optic disc-centered photographs using a semiautomated program. A comprehensive neuropsychological battery was administered, and cognitive function was summarized as composite and domain-specific Z-scores. Cognitive impairment no dementia (CIND) and dementia were diagnosed according to standard diagnostic criteria. Results Among 268 eligible nondemented participants, 78 subjects were categorized as CIND-mild and 69 as CIND-moderate. In multivariable adjusted models, reduced retinal arteriolar and venular fractal dimensions were associated with an increased risk of CIND-mild and CIND-moderate. Reduced fractal dimensions were associated with poorer cognitive performance globally and in the specific domains of verbal memory, visuoconstruction and visuomotor speed. Conclusion A sparser retinal microvascular network, represented by reduced arteriolar and venular fractal dimensions, was associated with cognitive impairment, suggesting that early microvascular damage may be present in preclinical stages of dementia.

Ong, Yi-Ting; Hilal, Saima; Cheung, Carol Yim-lui; Xu, Xin; Chen, Christopher; Venketasubramanian, Narayanaswamy; Wong, Tien Yin; Ikram, Mohammad Kamran

2014-01-01

 
 
 
 
281

Hyperautofluorescence in Outer Retinal Layers Thinning  

Science.gov (United States)

Purpose. To evaluate if paracentral hyperautofluorescence (HAF) retinal regions, which can be occasionally found and analyzed by optical coherence tomography (OCT), were related to retinal layer changes and to detect which layer was involved. Methods. This is a cross-sectional and retrospective study. 648 OCT files were revised. OCTs that showed a paracentral HAF area by using the fundus autofluorescence imaging in Heidelberg Spectralis (Heidelberg Engineering, Germany) were selected. Then retinal layer morphology was analyzed observing OCT scans and a retinal thickness was measured. Results. 31 patients were selected: 20 patients had chronic serous epitheliopathy (CSE), 8 patients had resolved central serous chorioretinopathy (CSC), and 3 patients wet age related macular degeneration (ARMD). The HAF zones corresponded to areas of thickness reduction of the external hyporeflective band. In all these areas the retinal pigment epithelium was not atrophic and the neuroepithelium was more or less dystrophic. In particular the retinal thickness was 264?um, 232?um, and 243?um in wet ARMD, CSE, and CSC, respectively; the reduction was significant (P < 0.01) compared to the same area of the other eye. Discussion. The presence of HAF imaging might be mostly due to a “window effect” rather than an accumulation of lipofuscin. PMID:25276816

2014-01-01

282

Coronary arteries  

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Coronary angiography (CA) is presently considered the gold standard for the assessment of the coronary arteries. However, the presence of ionizing radiation, its invasiveness and the small associated risk of morbidity prompted long ago the development of more patient-friendly imaging modalities. A promising technique, magnetic resonance imaging (MRI), has been regarded as the major modality in the coming decade. Although still in its infancy qualitatively, its flexibility and non-invasiveness opens the door for a comprehensive evaluation of the heart and the coronary arteries in one single sitting with high anatomical definition and excellent soft tissue contrast capabilities, double-oblique tomographic sections and the possibility to quantify an innumerable number of cardiovascular physiological parameters. Numerous ideas have been assessed, comprising breath-hold and free-breathing two-dimensional and three-dimensional measurements. New ongoing trials with intravascular contrast agents may provide for all these techniques the long-awaited essential boost for reliable magnetic resonance coronary angiography (MRCA). Introduction of parallel MRI acquisition techniques, such as simultaneous acquisition of spatial harmonics (SMASH) and sensitivity encoding (SENSE) may provide the speed enhancement required to shorten imaging time for all techniques explored to date. (orig.)

Wielopolski, P.A.; Oudkerk, M. [Dept. of Radiology, Daniel den Hoed Cancer Center, University Hospital Rotterdam (Netherlands); Geuns, R.J.M. van; Feyter, P.J. de [Thoraxcentre, University Hospital Rotterdam (Netherlands)

2000-01-01

283

Peripheral artery disease - legs  

Science.gov (United States)

Peripheral vascular disease; PVD; PAD; Arteriosclerosis obliterans; Blockage of leg arteries; Claudication; Intermittent claudication; Vaso-occlusive disease of the legs; Arterial insufficiency of ...

284

Resolution of exudative retinal detachment and regression of retinal macrocyst post-laser in Coats disease  

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Full Text Available Yusoff Munira,1 Embong Zunaina,1,2 Yaakub Azhany1,2 1Department of Ophthalmology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia; 2Hospital Universiti Sains Malaysia, Jalan Raja Perempuan Zainab II, Kubang Kerian, Kelantan, Malaysia Abstract: A 15-year-old boy presented with painless progressive blurring of vision in the right eye for 1 year in duration. His visual acuity in the right eye was hand movement. The right fundus showed presence of extensive subretinal exudates at the posterior pole and a retinal macrocyst at the temporal periphery. It was associated with exudative retinal detachment at the inferior periphery of the retina. Fundus angiography revealed telangiectatic retinal vessels at the superotemporal retina. Based on clinical and angiographic findings, a diagnosis of Coats disease was made. He was treated with retinal laser photocoagulation. There was resolution of the exudative retinal detachment, reduction of subretinal exudates, and regression of the retinal macrocyst with improvement of visual acuity to 1/60 post-laser therapy. Keywords: exudative retinal detachment, retinal macrocyst, Coats disease, laser

Munira Y

2013-08-01

285

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

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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

286

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

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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)

287

Toward high-resolution optoelectronic retinal prosthesis  

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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

288

Multiple sclerosis and optic nerve: an analysis of retinal nerve fiber layer thickness and color Doppler imaging parameters.  

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PurposeTo compare both retinal nerve fiber layer thickness and orbital color Doppler ultrasonography parameters in patients with multiple sclerosis (MS) versus healthy controls.MethodsThis is an observational case-control study. Forty eyes from MS patients and twenty eyes from healthy volunteers were examined. Eyes were classified into three groups as group 1, eyes from MS patients with previous optic neuritis (n=20); group 2, eyes from MS patients without previous optic neuritis (n=20); and group 3, eyes from healthy controls (n=20). Following complete ophthalmologic examination and retinal nerve fiber layer thickness measurement for each group, blood flow velocities of posterior ciliary arteries, central retinal artery, ophthalmic artery, and superior ophthalmic vein were measured. Pourcelot index (resistive index), an indicator of peripheral vascular resistance, was also calculated. The statistical assessment was performed with the assistance of Pearson's Chi-square test, Mann-Whitney U-test, Kruskal-Wallis test, and Spearman's correlation test.ResultsThe studied eyes exposed similar values in terms of intraocular pressure and central corneal thickness, implying no evidence in favor of glaucoma. All nerve fiber layer thickness values, except superior nasal quadrants, in group 1 were found to be significantly thinner than groups 2 and 3. Blood flow velocity and mean resistivity index parameters were similar in all the groups.ConclusionsIn MS patients, especially with previous optic neuritis, diminished retinal nerve fiber layer thickness was observed. Contrary to several studies in the current literature, no evidence supporting potential vascular origin of ocular involvement in MS was found. PMID:25081285

Akçam, H T; Capraz, I Y; Aktas, Z; Batur Caglayan, H Z; Ozhan Oktar, S; Hasanreisoglu, M; Irkec, C

2014-10-01

289

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

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Full Text Available Introduction. An altered perfusion of the optic nerve head has been proposed as a pathogenic factor in glaucoma. Objective. To evaluate changes of haemodynamic parameters in the retrobulbar arterial circulation after a decrease of elevated intraocular pressure (IOP in patients with primary open angle glaucoma (POAG. Methods. Twenty-six patients were examined, 14 men and 12 women, 21 up to 50 years old and 5 below, all with previously diagnosed and treated POAG, and all examined at the Eye Clinic, Clinical Centre of Serbia. IOP was measured both with a Goldmann aplanation tonometer and dynamic contour tonometer. Central corneal thickness was measured with ultrasound pachymeter. Imaging of the retrobulbar arterial circulation by colour Doppler was performed at the Neurology Clinic, Clinical Centre of Serbia. It involved measuring of haemodynamic parameters of the ophthalmic artery, central retinal artery, and posterior ciliary arteries. Peak systolic velocity (PSV and end-diastolic velocity (EDV were measured, and resistive index (RI and pulsatility index (PI were calculated. Results. Haemodynamic arterial parameters PSV and EDV in the ophthalmic and central retinal artery after decrease of IOP were lower, while RI and PI were higher. In the posterior ciliary arteries PSV, EDV and PI were lower, and RI was higher. Conclusion. Changes of the retrobulbar arterial circulation after elevated IOP in POAG patients are important for approach and treatment, while the role of vascular factors in the supplement of the optic disc neuroretinal rim could be a key for progression backlash of glaucoma and the radix of neuroprotection.

Kneževi? Miroslav

2011-01-01

290

Encoding Visual Information in Retinal Ganglion Cells with Prosthetic Stimulation  

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Retinal prostheses aim to restore functional vision to those blinded by outer retinal diseases using electric stimulation of surviving retinal neurons. The ability to replicate the spatiotemporal pattern of ganglion cell spike trains present under normal viewing conditions is presumably an important factor for restoring high-quality vision. In order to replicate such activity with a retinal prosthesis, it is important to consider both how visual information is encoded in ganglion cell spike t...

Freeman, Daniel K.; Rizzo, Joseph F.; Fried, Shelley I.

2011-01-01

291

Bilateral intraocular calcification in necrotizing cytomegalovirus retinitis.  

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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

292

Jules gonin. Pioneer of retinal detachment surgery  

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Full Text Available Before the turn of the 20th century, eyes with a retinal detachment were considered doomed. Contrary to other branches of ophthalmology, such as cataract extraction, the surgical treatment of retinal detachment was still in its infancy, and the surgical success rates were less than five percent. From 1902 to 1921 Jules Gonin almost single handedly changed the landscape of retinal detachment surgery forever. He recognised that the retinal break was the cause - and not the consequence as it was largely believed at the time - of the retinal detachment, and that the treatment had at all costs to comprise the closure of the break by cauterisation. He named the procedure ignipuncture , as he cauterised the retina through the sclera with a very hot pointed instrument. Despite rigorously detailed clinical observations and increasing success rates, his discovery was not readily accepted and sometimes openly opposed by a large part of the ophthalmic establishment. It was not until 1929 that he received worldwide acclaim at the International Ophthalmological Congress in Amsterdam for his surgical technique. His legacy lives on in the eye hospital in Lausanne that bears his name, in the Gonin Medal awarded by the International Council of Ophthalmology every four years for the highest achievement in ophthalmology, and in a street named after him, the very street that he used to walk from his home to the hospital every day.

Wolfensberger Thomas

2003-01-01

293

Retinal coenzyme Q in the bovine eye.  

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Coenzyme Q plays an integral role in oxygen metabolism and management, and there is a positive correlation between low tissue coenzyme Q concentrations and the progression of many degenerative diseases. Retinal oxidative damage plays a role in the pathogenesis of many degenerative eye diseases; nevertheless, despite the retina's high rate of oxygen metabolism, there is little data relating to retinal coenzyme Q concentrations. In this study, we quantified coenzyme Q in the model bovine eye and determined whether it could function as a retinal lipid antioxidant. We found that the neural retina's ubiquinone concentration exceeded those of the vitreous humor, lens, choroid, and extraocular muscle, but it was lower than those measured in heart, kidney, liver, and brain tissues. Ubiquinol was found to be as effective as vitamin E as a retinal lipid antioxidant. The overall relatively low levels of ubiquinone found in the retina, coupled with the retina's need for lipid antioxidants and oxidative metabolism, suggests that retinal function might be sensitive to changes in ubiquinone concentrations. PMID:21989945

Qu, Jinfeng; Ma, Li; Washington, Ilyas

2011-01-01

294

Management of pseudoaneurysms in the intracranial segment of the internal carotid artery with covered stents specially designed for use in the intracranial vasculature: technical notes  

International Nuclear Information System (INIS)

Vascular diseases like aneurysms, pseudoaneurysms and direct high-flow carotid-cavernous fistulas on the intracranial segment of the internal carotid artery are usually managed through transarterial embolization with detachable coils or balloons. Utility of covered stents has been reported with good results in the treatment of selective cases. But the current generation of covered stents for coronary use is rather stiff and difficult to navigate in tortuous vessels particularly in the intracranial vasculature. Herein, we report on the use and technical respects of balloon-expanded covered stents specially designed for intracranial vasculature in the treatment of two pseudoaneurysms secondary to the successful obliteration of direct CCFs on the intracranial segment of the internal carotid artery. This is the first report of covered stents specially developed for use in intracranial vasculature. (orig.)

295

Zinc-desferrioxamine attenuates retinal degeneration in the rd10 mouse model of retinitis pigmentosa.  

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Iron-associated oxidative injury plays a role in retinal degeneration such as age-related macular degeneration and retinitis pigmentosa. The metallo-complex zinc-desferrioxamine (Zn/DFO) may ameliorate such injury by chelation of labile iron in combination with release of zinc. We explored whether Zn/DFO can affect the course of retinal degeneration in the rd10 mouse model of retinitis pigmentosa. Zn/DFO-treated animals showed significantly higher electroretinographic responses at 3 and 4.5 weeks of age compared with saline-injected controls. Corresponding retinal (photoreceptor) structural rescue was observed by quantitative histological and immunohistochemical techniques. When administered alone, the components of the complex, Zn and DFO, showed a lesser, partial effect. TBARS, a marker of lipid peroxidation, and levels of oxidative DNA damage as quantified by 8-OHdG immunostaining were significantly lower in Zn/DFO-treated retinas compared with saline-injected controls. Reduced levels of retinal ferritin as well as reduced iron content within ferritin molecules were measured in Zn/DFO-treated retinas. The data, taken together, suggest that the protective effects of the Zn/DFO complex are mediated through modulation of iron bioavailability, leading to attenuation of oxidative injury. Reducing iron-associated oxidative stress using complexes such as Zn/DFO may serve as a "common pathway" therapeutic approach to attenuate injury in retinal degeneration. PMID:21824515

Obolensky, Alexey; Berenshtein, Eduard; Lederman, Michal; Bulvik, Baruch; Alper-Pinus, Ruslana; Yaul, Ruth; Deleon, Efrat; Chowers, Itay; Chevion, Mordechai; Banin, Eyal

2011-10-15

296

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

297

[Retinal and corneal dysplasias in the Yorkshire terrier and other dog breeds in Austria].  

Science.gov (United States)

Mother and son of a Yorkshire Terrier family showed excessive multifocal retinal dysplasia (RD1) and geographical retinal dysplasia (RD2), intra- and preretinal hemorrhages partial and total retinal detachment (total RD/RD3), residues of the pupillary membrane and as a newness in this combination a geographical, subepithelial corneal opacity, composed of small dots. One, not examined son of the same litter was congenitally blind. Similar corneal opacities were also found in two Rough Collies affected with CEA, RD, and microphthalmia, a young German Wirehair Pointer with primary absolute glaucoma in conjunction with goniodysplasia and RD in the healthy seeming fellow eye as well as in a poodle puppy affected with bilateral posterior suture-line cataract in connection with persistent primary hyperplastic vitreous (PHPV) in one and a globe-shaped deformed retina in connection with a persistent, blood conducting hyaloid artery in the other eye. The latter finally resulted in intraocular hemorrhage and secondary glaucoma. A pathogenetic connection between ocular malformations and subepithelial corneal opacity seems to be likely. PMID:9157632

Walde, I

1997-01-01

298

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

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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

299

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

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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

300

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 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)

 
 
 
 
301

Retinal detachment associated with traumatic chorioretinal rupture.  

Science.gov (United States)

Traumatic chorioretinal rupture, also known as sclopetaria, is a full-thickness break of the choroid and retina caused by a high-velocity projectile striking or passing adjacent to, but not penetrating, the globe. Previous reports have emphasized that retinal detachment seldom occurs, and observation alone has been the recommended management strategy. However, the authors present herein a series of consecutive patients with retinal detachment associated with sclopetaria and provide a literature review of the topic. They recommend that patients with traumatic chorioretinal rupture be monitored closely for the development of retinal detachment during the first few weeks after the injury. [Ophthalmic Surg Lasers Imaging Retina. 2014;45:451-455.]. PMID:25153657

Papakostas, Thanos D; Yonekawa, Yoshihiro; Wu, David; Miller, John B; Veldman, Peter B; Chee, Yewlin E; Husain, Deeba; Eliott, Dean

2014-09-01

302

Retinal Fiber Tracing by In Ovo Electroporation  

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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

303

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)

304

Marfan Syndrome Presenting with Bilateral Retinal Detachment  

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Full Text Available Marfan syndrome is an autosomal dominant systemic disorder of the connective tissue. Marfan syndrome affects most organs and tissues, especially the skeleton, lungs, eyes, heart, and the large blood vessels. Eye involvement may be in the form of retinal detachment which is a potentially dangerous manifestation for its sight threatening nature .We report a case where a 17 year old male developed sudden blindness due to spontaneous bilateral retinal detachment. Examination revealed features of Marfan syndrome and was stamped as a case of Marfan syndrome by Ghent criteria . The point to stress upon is that a young male developing spontaneous retinal detachment, a diagnosis of underlying Marfan syndrome should be kept in mind if appropriate clinical stigmata are present. [Natl J Med Res 2014; 4(1.000: 104-105

Subrata Chakrabarti

2014-02-01

305

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

306

Reading visual braille with a retinal prosthesis.  

Science.gov (United States)

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 visual braille as a sensory substitution for reading written letters and words. The Argus II retinal prosthesis system, used in this study, includes a 10?×?6 electrode array implanted epiretinally, a tiny video camera mounted on a pair of glasses, and a wearable computer that processes the video and determines the stimulation current of each electrode in real time. In the braille reading system, individual letters are created by a subset of dots from a 3 by 2 array of six dots. For the visual braille experiment, a grid of six electrodes was chosen out of the 10?×?6 Argus II array. Groups of these electrodes were then directly stimulated (bypassing the camera) to create visual percepts of individual braille letters. Experiments were performed in a single subject. Single letters were stimulated in an alternative forced choice (AFC) paradigm, and short 2-4-letter words were stimulated (one letter at a time) in an open-choice reading paradigm. The subject correctly identified 89% of single letters, 80% of 2-letter, 60% of 3-letter, and 70% of 4-letter words. This work suggests that text can successfully be stimulated and read as visual braille in retinal prosthesis patients. PMID:23189036

Lauritzen, Thomas Z; Harris, Jordan; Mohand-Said, Saddek; Sahel, Jose A; Dorn, Jessy D; McClure, Kelly; Greenberg, Robert J

2012-01-01

307

Aggressive retinal astrocytoma associated with tuberous sclerosis  

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Full Text Available Machiko Tomida,1 Yoshinori Mitamura,1 Takashi Katome,1 Hiroshi Eguchi,1 Takeshi Naito,1 Takayuki Harada21Department of Ophthalmology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, 2Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, JapanAbstract: We report the case of a patient with an aggressive retinal astrocytoma accompanied with macular edema and neovascular vessels, who was initially treated with intravitreal bevacizumab injections. A 24-year-old male presented to our clinic complaining of visual disturbance in his right eye. At 8 years of age, he had been diagnosed as having tuberous sclerosis complex. Fundus examination demonstrated a retinal tumor accompanied with marked neovascular vessels on the surface, retinal hemorrhage, and macular edema. After six monthly intravitreal bevacizumab injections, fundus examination demonstrated marked regression of the macular edema and neovascular vessels. Two months later, a vitreous hemorrhage developed which necessitated pars plana vitrectomy. After additional intravitreal bevacizumab injection for preventing intraoperative bleeding, vitrectomy with endophotocoagulation for the tumor was performed. The vitreous sample was obtained during vitrectomy, and we measured the vascular endothelial growth factor concentration by enzyme-linked immunosorbent assay. The surgically removed epiretinal neovascular membrane and biopsied retinal tumor expressed vascular endothelial growth factor, although several intravitreal bevacizumab injections led to a vitreous vascular endothelial growth factor concentration of undetectable levels. The clinical course and immunohistochemical analyses indicate that intravitreal bevacizumab monotherapy may have been insufficient to treat the aggressive retinal astrocytoma with macular edema and that laser photocoagulation or photodynamic therapy for the tumor should be considered following intravitreal bevacizumab injection in such cases.Keywords: aggressive retinal astrocytoma, bevacizumab, macular edema, tuberous sclerosis, vitrectomy, vitreous hemorrhage 

Tomida M

2012-05-01

308

Reading visual Braille with a retinal prosthesis  

Directory of Open Access Journals (Sweden)

Full Text Available 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 visual Braille as a sensory substitution for reading written letters and words. The Argus II retinal prosthesis system, used in this study, includes a 10 x 6 electrode array implanted epiretinally, a tiny video camera mounted on a pair of glasses, and a wearable computer that processes the video and determines the stimulation current of each electrode in real time. In the Braille reading system, individual letters are created by a subset of dots from a 3 by 2 array of six dots. For the visual Braille experiment, a grid of six electrodes was chosen out of the 10 x 6 Argus II array. Groups of these electrodes were then directly stimulated (bypassing the camera to create visual percepts of individual Braille letters. Experiments were performed in a single subject. Single letters were stimulated in an alternative forced choice (AFC paradigm, and short 2-4-letter words were stimulated (one letter at a time in an open-choice reading paradigm. The subject correctly identified 89% of single letters, 80% of 2-letter, 60% of 3-letter, and 70% of 4-letter words. This work suggests that text can successfully be stimulated and read as visual Braille in retinal prosthesis patients.

ThomasZaccarinLauritzen

2012-11-01

309

MEMS conformal electrode array for retinal implant.  

Energy Technology Data Exchange (ETDEWEB)

Retinal prosthesis projects around the world have been pursuing a functional replacement system for patients with retinal degeneration. In this paper, the concept for a micromachined conformal electrode array is outlined. Individual electrodes are designed to float on micromachined springs on a substrate that will enable the adjustment of spring constants-and therefore contact force-by adjusting the dimensions of the springs at each electrode. This also allows the accommodation of the varying curvature/topography of the retina. We believe that this approach provides several advantages by improving the electrode/tissue interface as well as generating some new options for in-situ measurements and overall system design.

Wessendorf, Kurt O.; Christenson, Todd R.; Myers, Ramona Lynn; Lemp, Thomas; Okandan, Murat; James, Conrad D.; Shul, Randy John; Stein, David J.; Baker, Michael Sean

2003-03-01

310

Retinal image analysis: preprocessing and feature extraction  

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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

311

Risk Factors for Central and Branch Retinal Vein Occlusion: A Meta-Analysis of Published Clinical Data  

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Retinal vein occlusion (RVO) is a major cause of vision loss. Of the two main types of RVO, branch retinal vein occlusion (BRVO) is 4 to 6 times more prevalent than central retinal vein occlusion (CRVO). A basic risk factor for RVO is advancing age. Further risk factors include systemic conditions like hypertension, arteriosclerosis, diabetes mellitus, hyperlipidemia, vascular cerebral stroke, blood hyperviscosity, and thrombophilia. A strong risk factor for RVO is the metabolic syndrome (hypertension, diabetes mellitus, and hyperlipidemia). Individuals with end-organ damage caused by diabetes mellitus and hypertension have greatly increased risk for RVO. Socioeconomic status seems to be a risk factor too. American blacks are more often diagnosed with RVO than non-Hispanic whites. Females are, according to some studies, at lower risk than men. The role of thrombophilic risk factors in RVO is still controversial. Congenital thrombophilic diseases like factor V Leiden mutation, hyperhomocysteinemia and anticardiolipin antibodies increase the risk of RVO. Cigarette smoking also increases the risk of RVO as do systemic inflammatory conditions like vasculitis and Behcet disease. Ophthalmic risk factors for RVO are ocular hypertension and glaucoma, higher ocular perfusion pressure, and changes in the retinal arteries. PMID:25009743

2014-01-01

312

Determinación de factores trombofílicos en pacientes con trombosis venosas retinianas Markers of thrombophilia in patients with retinal vein thrombosis  

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Full Text Available Background: Thrombophilia is an alteration of hemostasis that increases the risk to venous or arterial thrombosis. This condition may be the underlying cause of retinal vein thrombosis. Aim: To study the presence of thrombophilia in patients with retinal vein thrombosis. Patients and methods: Prospective study of 55 patients aged 22 to 86 years, with retinal vein thrombosis (central or branch. Antithrombin III, coagulant protein C, functional protein S, resistance to activated C protein, homocysteine, prothrombin G20210A gene, lupus anticoagulant and anticardiolipin antibodies were measured in all. Results: Seventeen patients had thrombophilic markers (antiphospholipid syndrome in seven, hyperhomocysteinemia in six and resistance to protein C in three. Of these 17 patients, 53% had high blood pressure, 35% an abnormal serum lipid profile and 23% a personal history of thrombosis. The thrombosis was central in 12 (ischemic in four and of a branch in five (ischemic in two. Conclusions: Thrombophilic markers must be assessed in patients with retinal vein thrombosis (Rev Méd Chile 2005; 133: 167-74

Leonidas Traipe C

2005-02-01

313

Dual stent migration to the heart and pulmonary artery.  

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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

314

Retinitis pigmentosa and congenital toxoplasmosis: A rare coexistence  

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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

315

The Relationship of Retinal Vessel Diameters and Fractal Dimensions with Blood Pressure and Cardiovascular Risk Factors  

Science.gov (United States)

Background This study aimed to investigate the correlation between quantitative retinal vascular parameters such as central retinal arteriolar equivalent (CRAE) and retinal vascular fractal dimension (D(f)), and cardiovascular risk factors in the Chinese Han population residing in the in islands of southeast China. Methodology/Principle Findings In this cross-sectional study, fundus photographs were collected and semi-automated analysis software was used to analyze retinal vessel diameters and fractal dimensions. Cardiovascular risk factors such as relevant medical history, blood pressure (BP), lipids, and blood glucose data were collected. Subjects had a mean age of 51.9±12.0 years and included 812 (37.4%) males and 1,357 (62.6%) females. Of the subjects, 726 (33.5%) were overweight, 226 (10.4%) were obese, 272 (12.5%) had diabetes, 738 (34.0%) had hypertension, and 1,156 (53.3%) had metabolic syndrome. After controlling for the effects of potential confounders, multivariate analyses found that age (??=?0.06, P?=?0.008), sex (??=?1.33, P?=?0.015), mean arterial blood pressure (??=??0.12, P<0.001), high-sensitivity C-reactive protein (??=??0.22, P?=?0.008), and CRVE (??=?0.23, P<0.001) were significantly associated with CRAE. Age (??=??0.0012, P<0.001), BP classification (prehypertension: ??=??0.0075, P?=?0.014; hypertension: ??=??0.0131, P?=?0.002), and hypertension history (??=??0.0007, P?=?0.009) were significantly associated with D(f). Conclusions/Significance D(f) exhibits a stronger association with BP than CRAE. Thus, D(f) may become a useful indicator of cardiovascular risk. PMID:25188273

Li, Qiaowei; Yuan, Yin; Gao, Zhonghai; Chen, Falin

2014-01-01

316

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

317

Probing how initial retinal configuration controls photochemical dynamics in retinal proteins  

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Full Text Available 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.

Sheves M.

2013-03-01

318

Laser-induced retinal nerve fiber layer (NFL) damage  

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Retinal nerve fiber layer (NFL) damage can be induced by retinal laser photocoagulation. This type of thermal injury involves degeneration in both descending and ascending directions from the photic injury site. We have repeated early studies in evaluation of the acute phases of the injury process. Our findings indicate that the ascending or Wallerian portion of the NFL degeneration requires less time than the descending portion; an early neural debris channel occurs in close proximity to retinal vessels and appears to enter the optic disc in close proximity to the retinal vasculature. Angiography of the ascending debris sheath suggests possible capillary pattern modulation associated with this neural debris sheath. Retinal traction evident in with other acute injuries appears at 2 weeks and disappears after 8 weeks suggesting secondary control factors other than retinal hemorrhage in the development of retinal traction bands.

Zwick, Harry; Gagliano, Donald A.; Zuclich, Joseph A.; Stuck, Bruce E.; Belkin, Michael

1995-05-01

319

Gene Therapy in the Retinal Degeneration Slow Model of Retinitis Pigmentosa  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Human blinding disorders are often initiated by hereditary mutations that insult rod and/or cone photoreceptors and cause subsequent cellular death. Generally, the disease phenotype can be predicted from the specific mutation as many photoreceptor genes are specific to rods or cones; however certain genes, such as Retinal Degeneration Slow (RDS), are expressed in both cell types and cause different forms of retinal disease affecting rods, cones, or both photoreceptors. RDS is a transmembrane ...

Cai, Xue; Conley, Shannon M.; Naash, Muna I.

2010-01-01

320

Laser-induced retinal damage thresholds for annular retinal beam profiles  

Science.gov (United States)

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

 
 
 
 
321

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

322

Murine Cytomegalovirus Infection and Apoptosis in Organotypic Retinal Cultures Short title: MCMV Infection in Retinal Culture  

Science.gov (United States)

Purpose An organotypic retinal culture model was used to determine the pattern of murine cytomegalovirus (MCMV) infection and if apoptosis was induced in MCMV infected cultured retinas. Methods Retinas harvested from C57BL/6 mice were individually cultured at 37°C on 3 ?m filter inserts placed in 24 well plates. Some retinas were infected with MCMV (5 × 105 PFU/well). At day 4, 7, and 11 post infection (p.i.), the culture medium and cultured retinas were collected for examination. Results Replicating virus was recovered and viral early antigen (EA) and late antigen (LA) positive cells were observed n the MCMV infected retinal cultures. The majority of MCMV infected cells were glia and horizontal cells. Infection resulted in atrophy of the photoreceptor cells and cytomegaly. Apoptosis of uninfected bystander cells, including photoreceptor cells and horizontal cells, was observed. TNF-? was produced by activated microglia during MCMV infection of the retina. Mouse apoptosis microarray studies, caspase activity studies, and RTPCR studies showed that the genes involved in both the death receptor mediated apoptotic pathway as well as the mitochondrial pathway were upregulated. Conclusions Many aspects of MCMV infection of retinal cultures parallel those observed during MCMV retinitis in mice. Thus, this in vitro system might be used to explore the role of apoptosis of uninfected retinal cells as well as the contribution of cytokines and other modulators to the pathogenesis of cytomegalovirus retinitis. PMID:18172106

Zhang, Ming; Marshall, Brendan; Atherton, Sally S.

2014-01-01

323

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

324

Quantification of rat retinal growth and vascular population changes after single and split doses of proton irradiation: translational study using stereology methods  

Science.gov (United States)

This study quantified architectural and population changes in the rat retinal vasculature after proton irradiation using stereology. A 100 MeV conformal proton beam delivered 8, 14, 20 and 28 Gy as single and split doses to the whole eye. The vascular networks were prepared from retinal digests. Stereological methods were used to obtain the area of the retina and unbiased estimates of microvessel/artery/vein endothelial, pericyte and smooth muscle population, and vessel length. The retinal area increased progressively in the unirradiated, age-matched controls and in the retinas irradiated with 8 and 14 Gy, indicating uniform progressive retinal growth. No growth occurred after 20 and 28 Gy. Regression analysis of total endothelial cell number in all vessels (arteries, veins and capillaries) after irradiation documented a progressive time- and dose-dependent cell loss occurring over 15 to 24 months. The difference from controls was significant (P<0.01) after 28 Gy given in single and split doses and after 20 Gy given as a split dose (P<0.05). Total vessel length in microvessel was significantly shortened at 20 and 28 Gy compared to that of controls (P<0.05). No evident dose recovery was observed in the endothelial populations after split doses. At 10 Gy, the rate of endothelial cell loss, a dose parameter used to characterize the time- and dose-dependent loss of the endothelial population, was doubled.

Mao, Xiao W.; Archambeau, John O.; Kubinova, Lucie; Boyle, Soames; Petersen, Georgia; Grove, Roger; Nelson, G. A. (Principal Investigator)

2003-01-01

325

Photodynamic therapy for juxtapapillary retinal capillary hemangioma.  

Science.gov (United States)

Various treatment modalities have been described for retinal capillary hemangioma. Our purpose is to present a case of juxtapapillary retinal capillary hemangioma treated with photodynamic therapy. A 69-year-old woman with no previous ocular history presented with blurred vision and photopsias in the right eye three months ago. At presentation, her best corrected visual acuity was 6/9 in the right eye and 6/6 in the left eye. The anterior segment was totally normal and IOP was normal in both eyes as well. Dilated fundoscopy revealed a yellowish, well-circumscribed, elevated area with blood vessels, on the inferior margin of the right optic disc, as optic disc edema. Fluorescein angiography and angiogram with indocyanine green confirmed the diagnosis of juxtapapillary retinal capillary hemangioma. The patient was treated with photodynamic therapy with verteporfin and three months later her visual acuity was 6/7.5 in the right eye, while the lesion was slightly smaller. These findings remained stable at the one-year follow-up. In conclusion, photodynamic therapy offers promising anatomical and functional results for juxtapapillary retinal capillary hemangioma, providing visual acuity improvement or even stabilization and restriction of enlargement of the lesion. PMID:24716060

Mitropoulos, Panagiotis G; Chatziralli, Irini P; Peponis, Vasileios G; Tsiotra, Vasileia A; Parikakis, Efstratios A

2014-01-01

326

Retinal oscillations carry visual information to cortex  

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Full Text Available Thalamic relay cells fire action potentials that transmit information from retina to cortex. The amount of information that spike trains encode is usually estimated from the precision of spike timing with respect to the stimulus. Sensory input, however, is only one factor that influences neural activity. For example, intrinsic dynamics, such as oscillations of networks of neurons, also modulate firing pattern. Here, we asked if retinal oscillations might help to convey information to neurons downstream. Specifically, we made whole-cell recordings from relay cells to reveal retinal inputs (EPSPs and thalamic outputs (spikes and then analyzed these events with information theory. Our results show that thalamic spike trains operate as two multiplexed channels. One channel, which occupies a low frequency band (<30 Hz, is encoded by average firing rate with respect to the stimulus and carries information about local changes in the visual field over time. The other operates in the gamma frequency band (40-80 Hz and is encoded by spike timing relative to retinal oscillations. At times, the second channel conveyed even more information than the first. Because retinal oscillations involve extensive networks of ganglion cells, it is likely that the second channel transmits information about global features of the visual scene.

KilianKoepsell

2009-04-01

327

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

328

Cytomegalovirus retinitis in HIV/AIDS patients  

Science.gov (United States)

Abstract Human immunodeficiency virus (HIV) has the ability to affect any organ in the body. In 70% of HIV-infected patients ocular manifestations were observed, which in the vast majority reflect the systemic disease and may be the first sign of a disseminated infection. Aim: The purpose of this paper is to determine the prevalence and the clinical aspects of cytomegalovirus retinitis in HIV/AIDS (Acquired Immunodeficiency Syndrome) patients. Method: The study is retrospective, conducted in the Ophthalmology Office of "Matei Bals" Infectious Diseases Hospital in Bucharest during the period August 1, 2007 - August 1, 2013. Each patient was examined thoroughly at the slit lamp biomicroscope by using a lens of 90D and a 20D lens using the indirect microscope after administration of topical mydriatics. Results: 131 patients were followed for HIV / AIDS with posterior segment ocular involvement. 36.64% of the 131 patients having affected the posterior segment have been diagnosed with CMV retinitis. Conclusions: Doctors should be aware of the existence of ocular damage in HIV/AIDS and to emphasize the importance of regular ophthalmologic examination of patients with HIV/AIDS. Abbreviations: HIV- human immunodeficiency virus, AIDS- acquired immunodeficiency syndrome, CMV retinitis- cytomegalovirus retinitis

Chiotan, C; Radu, L; Serban, R; Corn?cel, C; Cioboata, M; Anghel, A

2014-01-01

329

Photodynamic Therapy for Juxtapapillary Retinal Capillary Hemangioma  

Science.gov (United States)

Various treatment modalities have been described for retinal capillary hemangioma. Our purpose is to present a case of juxtapapillary retinal capillary hemangioma treated with photodynamic therapy. A 69-year-old woman with no previous ocular history presented with blurred vision and photopsias in the right eye three months ago. At presentation, her best corrected visual acuity was 6/9 in the right eye and 6/6 in the left eye. The anterior segment was totally normal and IOP was normal in both eyes as well. Dilated fundoscopy revealed a yellowish, well-circumscribed, elevated area with blood vessels, on the inferior margin of the right optic disc, as optic disc edema. Fluorescein angiography and angiogram with indocyanine green confirmed the diagnosis of juxtapapillary retinal capillary hemangioma. The patient was treated with photodynamic therapy with verteporfin and three months later her visual acuity was 6/7.5 in the right eye, while the lesion was slightly smaller. These findings remained stable at the one-year follow-up. In conclusion, photodynamic therapy offers promising anatomical and functional results for juxtapapillary retinal capillary hemangioma, providing visual acuity improvement or even stabilization and restriction of enlargement of the lesion. PMID:24716060

Mitropoulos, Panagiotis G.; Chatziralli, Irini P.; Peponis, Vasileios G.; Tsiotra, Vasileia A.; Parikakis, Efstratios A.

2014-01-01

330

Prophylactic vitrectomy for acute retinal necrosis syndrome  

Directory of Open Access Journals (Sweden)

Full Text Available AIM: To evaluate the efficacy of prophylactic vitrectomy for acute retinal necrosis syndrome(ARNS.METHODS: Twenty-six patients(33 eyeswere retrospectively included in this study. The eyes were divided into 2 groups by treatment, including routine treatment, which consisted of antiviral medication and vitrectomy after retinal detachment(RD(n=20, and prophylactic vitrectomy, which consisted of antiviral medication and vitrectomy for the prevention of RD performed during the active inflammatory phase(n=13. The follow-up period ranged from 6 to 48 months. RESULTS: In the routine treatment group, retinal detachment occurred in 11 eyes(55%, 4 eyes(20%developed ocular atrophy, 3 eyes(15%achieved increased visual acuity. In the prophylactic vitrectomy group, RD occurred in 1 eyes(8%, 5 eyes(38%achieved increased visual acuity. There was lower incident of retinal detachment in the prophylactic vitrectomy group than that in the routine treatment group(PCONCLUSION: Prophylactic vitrectomy can prevent RD and improve the prognosis of ARNS.

Sheng-Guo Li

2013-10-01

331

Vitreous Mediators in Retinal Hypoxic Diseases  

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The causes of retinal hypoxia are many and varied. Under hypoxic conditions, a variety of soluble factors are secreted into the vitreous cavity including growth factors, cytokines, and chemokines. Cytokines, which usually serve as signals between neighboring cells, are involved in essentially every important biological process, including cell proliferation, inflammation, immunity, migration, fibrosis, tissue repair, and angiogenesis. Cytokines and chemokines are multifunctional mediators that...

Roberto dell'Omo; Francesco Semeraro; Giulio Bamonte; Francesco Cifariello; Romano, Mario R.; Ciro Costagliola

2013-01-01

332

Coronary Artery Bypass Graft  

Medline Plus

Full Text Available ... by the bypass machine. Veins taken from the legs, or arteries going to the chest wall or ... are used, they are usually taken from your legs through multiple small incisions. If an artery is ...

333

Coronary Artery Bypass Graft  

Medline Plus

Full Text Available ... Introduction Sometimes people have serious problems with their heart and the arteries that go into it. Coronary ... surgery, or CABG, bypasses clogged arteries in the heart to improve blood flow to the heart and ...

334

Coronary Artery Bypass Graft  

Medline Plus

Full Text Available ... the clogged arteries in the heart. Once the new blood vessels are connected, blood can flow through ... usual daily activities. To decrease the chances of new blockages in your arteries: • You should avoid smoking. • ...

335

Mesenteric artery ischemia  

Science.gov (United States)

... important to make lifestyle changes (such as a healthy diet and exercise) to prevent hardening of the arteries from getting ... risk for narrowing of the arteries: Getting regular exercise ... Treating heart rhythm problems Keeping your blood cholesterol ...

336

Coronary Artery Bypass Graft  

Medline Plus

Full Text Available ... are known as coronary arteries. Symptoms and Their Causes Cholesterol deposits accumulate in the coronary arteries, forming “ ... do not let enough blood go through. This causes blood flow to decrease, which can cause heart ...

337

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.

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

338

Combination of Rare Right Arterial Variation with Anomalous Origins of the Vertebral Artery, Aberrant Subclavian Artery and Persistent Trigeminal Artery  

Science.gov (United States)

Summary A 32-year-old woman hospitalized for subarachnoid hemorrhage showed rare arterial variation on the right side with anomalous origins of the vertebral artery, aberrant subclavian artery and persistent trigeminal artery. Angiography showed the right vertebral artery to originate from the right common carotid artery, the right subclavian artery to arise separately from the descending aorta, and persistent trigeminal artery on the right side. The possible embryonic mechanism of this previously unreported variant combination is discussed. PMID:22005696

Ishihara, H.; San Millan Ruiz, D.; Abdo, G.; Asakura, F.; Yilmaz, H.; Lovblad, K.O.; Rufenacht, D.A.

2011-01-01

339

Correlation of ophthalmic findings with carotid artery stenosis.  

Science.gov (United States)

Patients presenting with symptoms suggestive of amaurosis fugax, or with findings of Hollenhorst plaques on fundoscopy are frequently referred for duplex evaluation to detect possible carotid artery disease. To better determine the reliability of monocular visual loss and the presence of Hollenhorst plaques for predicting the presence or significance of carotid artery stenosis, we prospectively studied 66 patients with these ocular signs and symptoms. After evaluation, the patients were categorized as follows: 34 of 66 (52%) patients had amaurosis fugax, 23 (35%) had asymptomatic Hollenhorst plaques, 7 (11%) had retinal artery occlusion, and 2 (3%) had venous stasis retinopathy. All patients were evaluated ophthalmologically, with carotid duplex scanning and spectral analysis. A stenosis of greater than 60% was regarded as significant. The presence of risk factors including hypertension, diabetes, a history of CVA or TIA's, tobacco use and hyperlipidemia was recorded. There were no statistically significant differences (p greater than 0.05) in the incidence of atherosclerotic risk factors between the four groups. Patients with amaurosis fugax were more likely to have a significant carotid artery stenosis than those with asymptomatic Hollenhorst plaques or retinal artery occlusion (53% vs 9% vs 0% respectively) (p less than 0.006). We conclude that routine carotid duplex scanning is indicated in all patients with amaurosis fugax in view of the frequent association with significant carotid stenosis (53%). However, the presence of Hollenhorst plaques in the absence of visual symptoms appears not to have a significant association with carotid disease and may not necessarily require routine screening unless other risk factors for carotid stenosis are present.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1527143

Bull, D A; Fante, R G; Hunter, G C; VanDalen, J; Lee, D; Bernhard, V M; McIntyre, K E

1992-01-01

340

Automatic detection of significant and subtle arterial lesions from coronary CT angiography  

Science.gov (United States)

Visual analysis of three-dimensional (3D) Coronary Computed Tomography Angiography (CCTA) remains challenging due to large number of image slices and tortuous character of the vessels. We aimed to develop an accurate, automated algorithm for detection of significant and subtle coronary artery lesions compared to expert interpretation. Our knowledge-based automated algorithm consists of centerline extraction which also classifies 3 main coronary arteries and small branches in each main coronary artery, vessel linearization, lumen segmentation with scan-specific lumen attenuation ranges, and lesion location detection. Presence and location of lesions are identified using a multi-pass algorithm which considers expected or "normal" vessel tapering and luminal stenosis from the segmented vessel. Expected luminal diameter is derived from the scan by automated piecewise least squares line fitting over proximal and mid segments (67%) of the coronary artery, considering small branch locations. We applied this algorithm to 21 CCTA patient datasets, acquired with dual-source CT, where 7 datasets had 17 lesions with stenosis greater than or equal to 25%. The reference standard was provided by visual and quantitative identification of lesions with any >=25% stenosis by an experienced expert reader. Our algorithm identified 16 out of the 17 lesions confirmed by the expert. There were 16 additional lesions detected (average 0.13/segment); 6 out of 16 of these were actual lesions with <25% stenosis. On persegment basis, sensitivity was 94%, specificity was 86% and accuracy was 87%. Our algorithm shows promising results in the high sensitivity detection and localization of significant and subtle CCTA arterial lesions.

Kang, Dongwoo; Slomka, Piotr; Nakazato, Ryo; Cheng, Victor Y.; Min, James K.; Li, Debiao; Berman, Daniel S.; Kuo, C.-C. Jay; Dey, Damini

2012-02-01

 
 
 
 
341

Carotid Artery Disease  

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... the NHLBI on Twitter. What Is Carotid Artery Disease? Carotid (ka-ROT-id) artery disease is a disease in which a waxy substance ... the United States. Other conditions, such as certain heart problems and ... or treat carotid artery disease and may reduce the risk of stroke. If ...

342

Occult iliac artery stenosis  

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Assurance of adequate aortoiliac inflow is of paramount importance prior to femoropopliteal reconstruction. Even with the use of arteriography, significant iliac artery stenosis may remain unrecognized. Intraoperative measurement of common femoral artery pressures and exploration of the appropriate iliac system as described here, permits the correction of occult inflow artery lesions and promotes the success of femoropopliteal bypass grafting.

Criado, Francisco J.; Wilson, Theodore H.

1981-01-01

343

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

2014-01-01

344

Retinal Ganglion Cell Dendritic Atrophy in DBA/2J Glaucoma  

Science.gov (United States)

Glaucoma is a complex disease affecting an estimated 70 million people worldwide, characterised by the progressive degeneration of retinal ganglion cells and accompanying visual field loss. The common site of damage to retinal ganglion cells is thought to be at the optic nerve head, however evidence from other optic neuropathies and neurodegenerative disorders suggests that dendritic structures undergo a prolonged period of atrophy that may accompany or even precede soma loss and neuronal cell death. Using the DBA/2J mouse model of glaucoma this investigation aims to elucidate the impact of increasing intraocular pressure on retinal ganglion cell dendrites using DBA/2J mice that express YFP throughout the retinal ganglion cells driven by Thy1 (DBA/2J.Thy1(YFP)) and DiOlistically labelled retinal ganglion cells in DBA/2J mice. Here we show retinal ganglion cell dendritic degeneration in DiOlistically labelled DBA/2J retinal ganglion cells but not in the DBA/2J.Thy1(YFP) retinal ganglion cells suggesting that a potential downregulation of Thy1 allows only ‘healthy’ retinal ganglion cells to express YFP. These data may highlight alternative pathways to retinal ganglion cell loss in DBA/2J glaucoma. PMID:23977271

Williams, Pete A.; Howell, Gareth R.; Barbay, Jessica M.; Braine, Catherine E.; Sousa, Gregory L.; John, Simon W. M.; Morgan, James E.

2013-01-01

345

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

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

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

349

Renal Artery Stenosis.  

Science.gov (United States)

Among the indications for renal artery revascularization, either surgical or endovascular, in patients with renal artery stenosis are poorly controlled hypertension, ischemic nephropathy (preservation of renal function), or recurrent episodes of "flash" pulmonary edema and congestive heart failure. Pharmacologic treatment is the first-line therapy to control blood pressure. If the disease is unilateral, the blood pressure regimen should include an angiotensin-converting enzyme inhibitor. Guidelines published in the Sixth Report of the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of high blood pressure should be followed. Revascularization is recommended if patients have at least 75% stenosis of one or both renal arteries, combined with resistant or poorly controlled hypertension; recurrent flash pulmonary edema; dialysis-dependent renal failure resulting from renal artery stenosis; chronic renal insufficiency and bilateral renal artery stenosis; or renal artery stenosis to a solitary functioning kidney. To treat fibromuscular disease of the renal arteries, percutaneous transluminal angioplasty is the revascularization procedure of choice. Ex vivo surgical repair of the renal artery may be required if there is significant branch renal artery stenosis. To treat atherosclerotic renal artery stenosis, the revascularization procedure of choice is percutaneous transluminal angioplasty and stent implantation, especially if there is concomitant ostial or proximal renal artery disease. Surgical revascularization is performed if concomitant aortic surgery is required, such as for abdominal aortic aneurysm. PMID:11096469

Begelman; Olin

1999-06-01

350

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

351

Surgical Treatment of Retinal Detachment Following Acute Retinal Necrosis Syndrome: Surgical Results in Four Patients.  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Acute retinal necrosis (ARN syndrome is an uncommon but severe oculardisease that typically affects otherwise healthy individuals. It is frequentlycomplicated with retinal detachment and the visual prognosis in such patientsis usually poor.Methods: We operated on four eyes in four patients from 1999 through 2001. Threeophthalmologists in our hospital did these operations, respectively. The surgicalmethods included pars plana vitrectomy, lensectomy, encircling scleralbuckling combined with membrane dissection, air-fluid exchange, endolaserphotocoagulation, and retinal tamponade with silicone oil or perfluoropropanegas.Results: Three patients received one operation and the other one needed a secondoperation to release the retinal traction. One patient needed a lensectomy atthe time of vitrectomy. Macular attachment was achieved in all four eyes(100%. Vision improved in two patients but none achieved visual acuity betterthan 20/200. The complications were cataract in three patients, macularpucker in three, and silicone keratopathy in one.Conclusion: Our results suggest that modern vitrectomy techniques provide a very highretinal attachment rate in patients with retinal detachment following ARNsyndrome.

Chiun-Ho Hou

2003-11-01

352

Transscleral diode laser retinopexy in retinal reattachment surgery  

Directory of Open Access Journals (Sweden)

Full Text Available PURPOSE: Transscleral diode retinal photocoagulation (diopexy is becoming an accepted technique in the treatment of selected retinal diseases. The objective of this study is to evaluate diopexy technique in the production of adhesive chorioretinal lesions during the surgical treatment of the rhegmatogenous retinal detachment. METHODS: 25 patients with rhegmatogenous retinal detachment were enrolled in a prospective clinical-surgical study to evaluate the technique of transscleral diode laser photocoagulation to obtain adhesive chorioretinal lesions during retinal reattachment surgery. The surgery consisted of the placement of an exoplant silicon to produce a buckle effect combined with a drainage of subretinal fluid in most cases. RESULTS: By a mean follow-up of 10 months, 21 of 25 eyes had their retinas reattached after only one surgery with diopexy used in all cases. CONCLUSION: Transscleral diode laser photocoagulation was a technically easy, controlled, effective, reproducible and safe means of obtaining chorioretinal adhesion in retinal reattachment surgery.

Gonçalves João Carlos de Miranda

2004-01-01

353

Coupling of Retinal, Protein, and Water Dynamics in Squid Rhodopsin  

Science.gov (United States)

The light-induced isomerization of the retinal from 11-cis to all-trans triggers changes in the conformation of visual rhodopsins that lead to the formation of the activated state, which is ready to interact with the G protein. To begin to understand how changes in the structure and dynamics of the retinal are transmitted to the protein, we performed molecular dynamics simulations of squid rhodopsin with 11-cis and all-trans retinal, and with two different force fields for describing the retinal molecule. The results indicate that structural rearrangements in the binding pocket, albeit small, propagate toward the cytoplasmic side of the protein, and affect the dynamics of internal water molecules. The sensitivity of the active-site interactions on the retinal force-field parameters highlights the coupling between the retinal molecule and its immediate protein environment. PMID:20923654

Jardon-Valadez, Eduardo; Bondar, Ana-Nicoleta; Tobias, Douglas J.

2010-01-01

354

Unexplained postoperative retinal hemorrhage after 23-gauge sutureless vitrectomy  

Directory of Open Access Journals (Sweden)

Full Text Available Hisato Ohno, Kenji InoueInouye Eye Hospital, Tokyo, JapanAbstract: We report five cases of unexplained retinal hemorrhage after 23-gauge sutureless vitrectomy. A 23-gauge sutureless vitrectomy was performed for four cases of macular holes (MH and one case of macular hole retinal detachment (MHRD. Retinal hemorrhages were observed on the first day after surgery and disappeared within several months without leaving any recognizable damage. We speculate that the retinal hemorrhages might have resulted from repeated collapse of the globe through a cannula under air perfusion, but other causes such as retinal vein congestion by face-down positioning are also possible.Keywords: retinal hemorrhage, vitrectomy, postoperative, macular hole, sutureless surgery

Ohno H

2011-07-01

355

The effect of dendritic cells on the retinal cell transplantation  

International Nuclear Information System (INIS)

The potential of bone marrow cell-derived immature dendritic cells (myeloid iDCs) in modulating the efficacy of retinal cell transplantation therapy was investigated. (1) In vitro, myeloid iDCs but not BMCs enhanced the survival and proliferation of embryonic retinal cells, and the expression of various neurotrophic factors by myeloid iDCs was confirmed with RT-PCR. (2) In subretinal transplantation, neonatal retinal cells co-transplanted with myeloid iDCs showed higher survival rate compared to those transplanted without myeloid iDCs. (3) CD8 T-cells reactive against donor retinal cells were significantly increased in the mice with transplantation of retinal cells alone. These results suggested the beneficial effects of the use of myeloid iDCs in retinal cell transplantation therapy

356

Efficient Estimation of Retinal Ganglion Cell Number: a Stereological Approach  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Retinal ganglion cells (RGCs) are the only output neurons of the retina, and their degeneration after damage to the optic nerve or in glaucoma is a well established system for studying apoptosis in the central nervous system. Frequently used procedures for assessing RGC number in retinal flat mounts suffer from two problems: RGC densities are not uniform across retinal flat mounts, and density measures may therefore not reflect total number, and flat mounts do not allow efficient use of tissu...

Fileta, John B.; Huang, Wei; Kwon, Gina P.; Filippopoulos, Theodoros; Ben, Yixin; Dobberfuhl, Adam; Grosskreutz, Cynthia L.

2008-01-01

357

Management of varicella zoster virus retinitis in AIDS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

358

Bilateral Serous Retinal Detachments Associated with Accelerated Hypertensive Choroidopathy  

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Purpose. We report a case of hypertensive choroidopathy with bilateral serous retinal detachments. Patient. A 50-year-old man underwent bilateral serous retinal detachments. Retinal arteriolar narrowing, vascular tortuosity, and arteriovenous nicking were identified in both eyes. The blood pressure was 206/125?mmHg. The patient was diagnosed with bilateral hypertensive choroidopathy and treated with oral antihypertensive treatment. Results and discussion. One month after antihyperte...

Yoshio Hirano; Tsutomu Yasukawa; Yuichiro Ogura

2010-01-01

359

Functional annotation of the human retinal pigment epithelium transcriptome  

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Abstract Background To determine level, variability and functional annotation of gene expression of the human retinal pigment epithelium (RPE), the key tissue involved in retinal diseases like age-related macular degeneration and retinitis pigmentosa. Macular RPE cells from six selected healthy human donor eyes (aged 63–78 years) were laser dissected and used for 22k microarray studies (Agilent technologies). Data were analyzed with Rosetta Resolver, the web tool DAVID and ...

Gmf, Gorgels Theo; van der Spek Peter J; Jmh, Verkerk Annemieke; Hw, Essing Anke; Ma, Swagemakers Sigrid; van Soest Simone; Booij Judith C; Ab, Bergen Arthur

2009-01-01

360

Scleral buckling for retinal detachment in patients with retinoblastoma  

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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

 
 
 
 
361

Electroretinographic assessment of retinal function at high altitude.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

362

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

363

Identification of diabetic retinopathy stages in human retinal image  

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A novel method to identify the Diabetic retinopathy stages in human retinal image is proposed. Diabetic retinopathy is the dangerous eye disease cause the blindness in worldwide. The first manifestation of diabetic retinopathy is microaneurysms. They are appearing as small reddish dot in human retinal image. The number of microaneurysms is the important parameter used to identify the severity of the diabetic retinopathy. Hence the detection of microaneurysms in human retinal image is the majo...

A Alaimahal, Dr S. Vasuki

2013-01-01

364

Progressive Outer Retinal Necrosis and Immunosuppressive Therapy in Myasthenia Gravis  

Science.gov (United States)

Introduction Progressive outer retinal necrosis (PORN) is a rare but devastating infectious retinitis associated with varicella zoster virus (VZV) and responsible for severe visual loss. Case Report A 59-year-old man treated for generalized myasthenia with oral azathioprine and prednisone presented with severe unilateral necrotizing retinitis. Polymerase chain reaction of the aqueous and vitreous humors was diagnostic for VZV PORN. Conclusion VZV PORN is a severe potential ocular complication of immunosuppression, prompting urgent diagnosis and appropriate treatment. PMID:24926266

Coisy, Solene; Ebran, Jean-Marc; Milea, Dan

2014-01-01

365

Retinal vascular fractal dimension is associated with cognitive dysfunction.  

Science.gov (United States)

Fractal analysis is a method used to quantify the geometric branching complexity and density of retinal vessels. This study examined the relationship of retinal vascular fractal dimension and other retinal vascular parameters with cognitive dysfunction in an older Asian population. Subjects aged 60 years and older from the Singapore Malay Eye Study were selected for analysis. Retinal vascular fractal dimension (Df) and other quantitative retinal vascular parameters (branching angle, tortuosity, and caliber) were measured based on a standardized grading protocol from photographs of the retinal fundus using a computer-assisted program. Qualitative retinal signs were also assessed from photographs. Cognitive dysfunction was defined as a locally validated Abbreviated Mental Test (AMT) score ?6/10 in participants with 0-6 years of formal education and an AMT score ?8/10 in those with more than 6 years of formal education. Cognitive dysfunction was identified in 262 of the 1202 participants (21.8%). Decreased retinal vascular Df was significantly associated with lower AMT score (P = .019). In multivariate logistic regression analysis, participants with lower retinal vascular Df values were more likely to have cognitive dysfunction (odds ratio, 1.71; 95% confidence interval, 1.03-2.82, comparing the lowest and highest Df quintiles). In subgroup analysis stratified for cardiovascular risk factors, this association was present in participants with hypertension and current smokers. Other retinal vascular signs were not associated with cognitive dysfunction. Decreased retinal vascular Df is associated with cognitive dysfunction in older persons. Rarefaction of the retinal vasculature may reflect similar changes in the cerebral microvasculature that may contribute to cognitive deterioration. PMID:23099042

Cheung, Carol Yim-lui; Ong, ShinYeu; Ikram, M Kamran; Ong, Yi Ting; Chen, Christopher P; Venketasubramanian, N; Wong, Tien Yin

2014-01-01

366

Calcium preconditioning triggers neuroprotection in retinal ganglion cells  

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In the mammalian retina, excitotoxicity has been shown to be involved in apoptotic retinal ganglion cell (RGC) death and is associated with certain retinal disease states including glaucoma, diabetic retinopathy and retinal ischemia. Previous studies from this lab (Wehrwein et al., 2004) have demonstrated that acetylcholine (ACh) and nicotine protects against glutamate-induced excitotoxicity in isolated adult pig RGCs through nicotinic acetylcholine receptors (nAChRs). Activation of nAChRs in...

Brandt, Sean K.; Weatherly, Monique E.; Ware, Lillian; Linn, David M.; Linn, Cindy L.

2011-01-01

367

Case of Bilateral Retinal Neovascularization Associated with Chronic Idiopathic Myelofibrosis  

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We report a case of bilateral peripheral retinal neovascularization and chronic idiopathic myelofibrosis in a 69-year-old man. Ophthalmic examination revealed peripheral retinal nonperfusion with retinal neovascularization in both eyes and vitreous hemorrhage in the right eye. Fluorescein angiography of both eyes showed a marked midperipheral and peripheral avascular retina temporally with arteriovenous anastomosis and sea-fan neovascularizations. Blood tests showed pancytopenia and teardrop-...

Kim, Moon Jung; Yu, Hyeong Gon

2010-01-01

368

Hemorrhagic retinal macrocysts, simulating choroidal melanoma: a case report  

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Ahmad M Mansour,1 Mahmoud O Jaroudi21Department of Ophthalmology, American University of Beirut, Beirut, Lebanon; 2Department of Ophthalmology, Rafic Hariri University Hospital, Beirut, LebanonIntroduction: Hemorrhagic retinal macrocysts are extremely rare retinal lesions that can be mistaken for malignancy with subsequent enucleation. Such a case was diagnosed, by a retina specialist based on ultrasonography, as a choroidal melanoma with exudative retinal detachment and the patient was advis...

Am, Mansour; Mo, Jaroudi

2013-01-01

369

Taurine Provides Neuroprotection against Retinal Ganglion Cell Degeneration  

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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

370

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

371

Fluoroquinolone-induced retinal degeneration in cats.  

Science.gov (United States)

Although the exact mechanism of fluoroquinolone-induced retinal degeneration in cats remains to be elucidated, it appears from the literature that a similar retinal degeneration can be reproduced from either direct intravitreal injection of high concentrations of drug or exposure to UVA light and drug in laboratory animals. (19,25) The fluoroquinolone molecular structure is also similar structurally to other drugs that are known to directly induce retinal degeneration, including the cinchona alkaloids and halogenated hydroquinolones. Experimental evidence suggests that both the parent compound and its breakdown products via metabolism and photodegradation are active inducers of retinal degeneration. (18,25) Development of toxicoses also appears to be dependent on the maximum concentration of active drug, metabolite, or both reaching the retina over time. (18) Evaluation of the literature suggests that risk factors predisposing cats to fluoroquinolone-induced retinal degeneration may include the following: 1) large doses or plasma concentrations of drug, 2) rapid IV infusion of the antibiotic, 3) prolonged courses of treatment, and 4) age. Theoretically, other risk factors may also be involved including the following: 1) prolonged exposure to UVA light while the antibiotic is being administered, 2) drug interactions, and 3) drug or metabolite accumulation from altered metabolism or reduced elimination. To date, there are no published reports suggesting that the dose of fluoroquinolones should be reduced in geriatric cats or those with renal or hepatic failure. However, accumulation of fluoroquinolone metabolites in dogs and of the parent compound in humans with decreased renal function has been reported. (8-10) In humans with decreased renal function has been reported. (8-10) humans, fluoroquinolone doses are typically decreased in response to the degree of renal impairment. (28) In general, all fluoroquinolone antibiotics should be reserved for severe or recurrent infections, and whenever possible their use should be based on results whenever possible their use should be based on results of culture and susceptibility tests. When indicated, the fluoroquinolones, including enrofloxacin, can be used with limited risk of developing retinal degeneration in cats, provided the manufacturer's guidelines are adhered to and dose reduction is considered in geriatric cats or those with renal impairment. Dosing on renal impairment. Dosing on exact body weight using split dosing (2.5 mg/kg, PO, q 12 h) and avoidance of rapid IV infusions, and drug interactions may help to reduce the risk of retinal degeneration in some cases. Furthermore, monitoring cats for mydriasis and avoidance of UVA light while undergoing treatment may also be of benefit. Further evaluation of the pharmacokinetics of enrofloxacin and the other fluoroquinolones is required in geriatric cats or those with mild to moderate renal or liver impairment to determine whether drug accumulation, elevated peak concentrations of drug, or both may be occurring in this subset of cats. Therapeutic monitoring of drug concentrations may not always be feasible because of time and cost, but renal panels with dose or frequency reduction in response to the degree of renal impairment and the site and severity of infection may help to reduce retinal toxicosis. PMID:12479325

Wiebe, Valerie; Hamilton, Patti

2002-12-01

372

Action spectrum for retinal thermal injury  

Science.gov (United States)

The action spectrum for light-induced damage to the retina results from the wavelength dependence transmission of the preretinal ocular media, wavelength dependent absorption in retinal chromophores and chromatic aberration of the eye optics. While various light/tissue interaction mechanisms have been implicated, thermal mechanisms dominate in the red and near-infrared for all exposure durations and in the visible for exposures shorter than a few seconds. A number of investigators have measured the transmission of the eye and the spectra of retinal absorbers, and thermal models based on these data predict the broad features of the action spectrum. Dose/response studies with lasers and incoherent light sources, conducted over the past 10 years mainly validate the thermal models.

Lund, David J.; Edsall, Peter R.

1999-06-01

373

Retinal breaks due to intravitreal ocriplasmin  

Science.gov (United States)

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.

Silva, Ruwan A; Moshfeghi, Darius M; Leng, Theodore

2014-01-01

374

Retinal breaks due to intravitreal ocriplasmin.  

Science.gov (United States)

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. PMID:25210426

Silva, Ruwan A; Moshfeghi, Darius M; Leng, Theodore

2014-01-01

375

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

376

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

377

Aggressive retinal astrocytoma associated with tuberous sclerosis  

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Machiko Tomida,1 Yoshinori Mitamura,1 Takashi Katome,1 Hiroshi Eguchi,1 Takeshi Naito,1 Takayuki Harada21Department of Ophthalmology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, 2Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, JapanAbstract: We report the case of a patient with an aggressive retinal astrocytoma accompanied with macular edema and neovascular vessels, who was initially treated with intravitreal bevaci...

Tomida M; Mitamura Y; Katome T; Eguchi H; Naito T.; Harada T

2012-01-01

378

Avulsão vascular retiniana Avulsed retinal vessels  

Directory of Open Access Journals (Sweden)

Full Text Available OBJETIVO: Descrever a evolução de uma série de casos com avulsão vascular retiniana sem descolamento tratados pelo fotocoagulação ou introflexão escleral. MÉTODOS: Análise observacional retrospectiva. No período entre 2001-2003 foram tratados 13 olhos com avulsão sem descolamento utilizando-se o laser ou a introflexão escleral. O seguimento mínimo foi de 6 meses. Média etária de 53,6 anos. RESULTADOS: Oito olhos foram somente fotocoagulados e 5, submetidos a introflexão. O sintoma mais comum foi a baixa na acuidade visual. Em 7 olhos (53,8% a hemorragia vítrea em quantidade variável estava presente ao diagnóstico. Destes, 3 tiveram novo episódio após os procedimentos (42,8%. A acuidade visual final em todos os olhos foi igual ou melhor do que a inicial. Nenhuma complicação foi observada. CONCLUSÃO: Nesta série de casos com avulsão vascular sem descolamento houve evolução favorável, independente das técnicas utilizadas. A hemorragia vítrea tardia é a principal intercorrência tardia observada, mas não comprometeu os resultados.PURPOSE: To describe the clinical evolution of cases with avulsed retinal vessels without retinal detachment treated with laser or scleral buckle. METHODS: Retrospective analysis of cases with avulsed retinal vessels treated between 2001-2003. Laser photocoagulation or scleral buckle was used. The minimum follow-up was 6 months. Average age was 53.6 years. RESULTS: Of 13 patients, 8 were photoagulated with argon laser and 5 were submitted to a scleral buckle. The most common symptom was reduction in visual acuity. Vitreous hemorrhage was present in 7 eyes (53.8% at diagnosis, and was the most frequent complication after treatment (30.7%. Final visual acuity was unchanged. CONCLUSION: Avulsed retinal vessels have a good prognosis using laser or buckle. Late vitreous hemorrhage was the main complication.

Leonardo Pérez Zeni

2006-02-01

379

Avulsão vascular retiniana / Avulsed retinal vessels  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: Descrever a evolução de uma série de casos com avulsão vascular retiniana sem descolamento tratados pelo fotocoagulação ou introflexão escleral. MÉTODOS: Análise observacional retrospectiva. No período entre 2001-2003 foram tratados 13 olhos com avulsão sem descolamento utilizando-se o las [...] er ou a introflexão escleral. O seguimento mínimo foi de 6 meses. Média etária de 53,6 anos. RESULTADOS: Oito olhos foram somente fotocoagulados e 5, submetidos a introflexão. O sintoma mais comum foi a baixa na acuidade visual. Em 7 olhos (53,8%) a hemorragia vítrea em quantidade variável estava presente ao diagnóstico. Destes, 3 tiveram novo episódio após os procedimentos (42,8%). A acuidade visual final em todos os olhos foi igual ou melhor do que a inicial. Nenhuma complicação foi observada. CONCLUSÃO: Nesta série de casos com avulsão vascular sem descolamento houve evolução favorável, independente das técnicas utilizadas. A hemorragia vítrea tardia é a principal intercorrência tardia observada, mas não comprometeu os resultados. Abstract in english PURPOSE: To describe the clinical evolution of cases with avulsed retinal vessels without retinal detachment treated with laser or scleral buckle. METHODS: Retrospective analysis of cases with avulsed retinal vessels treated between 2001-2003. Laser photocoagulation or scleral buckle was used. The m [...] inimum follow-up was 6 months. Average age was 53.6 years. RESULTS: Of 13 patients, 8 were photoagulated with argon laser and 5 were submitted to a scleral buckle. The most common symptom was reduction in visual acuity. Vitreous hemorrhage was present in 7 eyes (53.8%) at diagnosis, and was the most frequent complication after treatment (30.7%). Final visual acuity was unchanged. CONCLUSION: Avulsed retinal vessels have a good prognosis using laser or buckle. Late vitreous hemorrhage was the main complication.

Leonardo Pérez, Zeni; Manuel Augusto Pereira, Vilela.

2006-02-01

380

Non-Coding RNAs in Retinal Development  

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Retinal development is dependent on an accurately functioning network of transcriptional and translational regulators. Among the diverse classes of molecules involved, non-coding RNAs (ncRNAs) play a significant role. Members of this family are present in the cell as transcripts, but are not translated into proteins. MicroRNAs (miRNAs) are small ncRNAs that act as post-transcriptional regulators. During the last decade, they have been implicated in a variety of biological processes, including...

Robert Hindges; Maiorano, Nicola A.

2012-01-01

 
 
 
 
381

Hemorrhagic retinal macrocysts, simulating choroidal melanoma: a case report  

Directory of Open Access Journals (Sweden)

Full Text Available Ahmad M Mansour,1 Mahmoud O Jaroudi21Department of Ophthalmology, American University of Beirut, Beirut, Lebanon; 2Department of Ophthalmology, Rafic Hariri University Hospital, Beirut, LebanonIntroduction: Hemorrhagic retinal macrocysts are extremely rare retinal lesions that can be mistaken for malignancy with subsequent enucleation. Such a case was diagnosed, by a retina specialist based on ultrasonography, as a choroidal melanoma with exudative retinal detachment and the patient was advised to have brachytherapy.Case presentation: A 15-year-old Caucasian boy suffered sudden visual loss in the left eye and exam revealed vitreous hemorrhage. Magnetic resonance imaging revealed the mass as hyperintense on T1-weighted images and isointense on T2-weighted images with no enhancement after gadolinium dye. Following scleral buckle, the hemorrhagic retinal macrocyst collapsed gradually over a period of 5 weeks. The patient recovered visual acuity of 6/7.5 at the 1-year follow up.Conclusion: A hemorrhagic retinal macrocyst can be erroneously diagnosed as choroidal melanoma. Hints for the presence of retinal macrocysts include: egg shape; cyst wall configuration; no attachment to the choroid; and presence of retinal detachment.Keywords: choroidal melanoma, retinal macrocyst, retinal detachment

Mansour AM

2013-05-01

382

Chromophore interaction in xanthorhodopsin--retinal dependence of salinixanthin binding.  

Science.gov (United States)

Xanthorhodopsin is a light-driven proton pump in the extremely halophilic bacterium Salinibacter ruber. Its unique feature is that besides retinal it has a carotenoid, salinixanthin, with a light harvesting function. Tight and specific binding of the carotenoid antenna is controlled by binding of the retinal. Addition of all-trans retinal to xanthorhodopsin bleached with hydroxylamine restores not only the retinal chromophore absorption band, but causes sharpening of the salinixanthin bands reflecting its rigid binding by the protein. In this report we examine the correlation of the changes in the two chromophores during bleaching and reconstitution with native all-trans retinal, artificial retinal analogs and retinol. Bleaching and reconstitution both appear to be multistage processes. The carotenoid absorption changes during bleaching occurred not only upon hydrolysis of the Schiff base but continued while the retinal was leaving its binding site. In the case of reconstitution, the 13-desmethyl analog formed the protonated Schiff base slower than retinal, and provided the opportunity to observe changes in carotenoid binding at various stages. The characteristic sharpening of the carotenoid bands, indicative of its reduced conformational heterogeneity in the binding site, occurs when the retinal occupies the binding site but the covalent bond to Lys-240 via a Schiff base is not yet formed. This is confirmed by the results for retinol reconstitution, where the Schiff base does not form but the carotenoid exhibits its characteristic spectral change from the binding. PMID:18399915

Imasheva, Eleonora S; Balashov, Sergei P; Wang, Jennifer M; Smolensky, Elena; Sheves, Mordechai; Lanyi, Janos K

2008-01-01

383

Retinal detachment secondary to ocular perforation during retrobulbar Anaesthesia  

Directory of Open Access Journals (Sweden)

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

384

Talc emboli and retinal neovascularization in a drug abuser.  

Science.gov (United States)

A 38-year-old male drug abuser had multiple emboli in the retinal circulation of the posterior pole of both eyes. He showed widespread peripheral retinal capillary nonperfusion and neovascular proliferation at the junction of perfused and nonperfused retina. The emboli were considered to be talc particles from the intravenous administration of suspensions of oral medications. The presumed mechanism of development of neovascularization in this case was the filtering out of the particles by the retinal vasculature with vaso-occlusion, ischemia and subsequent retinal neovascularization. PMID:434093

Kresca, L J; Goldberg, M F; Jampol, L M

1979-03-01

385

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

386

Gene therapy for inherited retinal degenerations.  

Science.gov (United States)

Gene therapy is quickly becoming a reality applicable in the clinic for inherited retinal diseases. Progress over the past decade has moved proof-of-concept gene therapies from bench to bedside. The remarkable success in safety and efficacy, in the phase I/II clinical trials for the form of the severe childhood-onset blindness, Leber's Congenital Amaurosis (LCA) type II (due to mutations in the RPE65 gene) generated significant interest and opened up possibilities for a new era of retinal gene therapies. Success in these clinical trials was due to combining the favorable features of both the retina as a target organ and adeno-associated virus (AAV) as a vector. The retina offers several advantages for gene therapy approaches. It is an anatomically defined structure that is readily accessible for therapy and has some degree of immune privilege, making it suitable for application of viral vectors. AAV, on the other hand, is a non-pathogenic helper dependent virus that has little immunogenicity. This viral vector transduces quiescent cells efficiently and thanks to its small size diffuses well in the interneural matrix, making it suitable for applications in neural tissue. Building on this initial clinical success with LCA II, we have now many opportunities to extend this proof-of-concept to other retinal diseases. This article will discuss what are some of the most imminent targets for such therapies and what are the challenges that we face in moving these therapies to the clinic. PMID:24702845

Dalkara, Deniz; Sahel, José-Alain

2014-03-01

387

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

388

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

389

Modeling of light propagation in retinal tissue  

Science.gov (United States)

Techniques used in retinal imaging provide a unique method for gaining information about biological structures and processes without being invasive. Applications within the fields of medicine and clinical diagnosis provide great scope for such research. Being able to measure haemoglobin oxygenation from retinal images provides useful information in the diagnosis of conditions such as diabetic retinopathy, age-related macular degeneration and galucoma. We describe how existing methods have been used to gain information from retinal images. Problems of calibration and difficulties encountered in validating the various models are also discussed. Existing techniques to model multi-layered tissue, such as Monte Carlo methods and radiative transfer approaches, are explained and their respective advantages and disadvantages are highlighted. A proposal to employ a standard fundus camera, adapted to accommodate a liquid crystal tunable filter, is presented and the characteristics required of the images are outlined. We finish with a discussion of the techniques deemed to be the most promising and how the captured images can be used to validate them.

Ramachandran, Sonny; Taylor, Nick K.; McNaught, Andrew I.; Harvey, Andrew R.

2004-07-01

390