RESUMO
Ecstasy, a psychoactive amphetamine derivative, is a popular party drug. We report the cases of 2 young adults who developed cerebral edema due to hyponatremia. One patient was released from the hospital without any sequelae, whereas the second patient died due to cerebral edema. Severe cases of symptomatic hyponatremia after ecstasy consumption are described in the literature with partially fatal clinical outcomes. Thus, physicians should be aware of early and consequent control of the sodium and choose an interdisciplinary treatment decision.
Assuntos
Edema Encefálico/etiologia , Alucinógenos/efeitos adversos , Hiponatremia/complicações , N-Metil-3,4-Metilenodioxianfetamina/efeitos adversos , Humanos , Hiponatremia/etiologia , Sódio , Adulto JovemRESUMO
We report the case of a 49-year-old woman who was admitted with community-acquired pneumonia. The medical state worsened despite administration of antibiotics. She was intubated and ventilated because of respiratory distress. Several hours after intubation, she developed massive subcutaneous emphysema. The bronchoscopy showed tracheal transmural rupture 3 cm long on the posterior wall of the trachea. The high-risk surgery and massive doses of catecholamine favoured conservative treatment with bilateral endobronchial intubation and veno-venous extracorporeal membrane oxygenation. The patient made a full recovery.
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Infecções Comunitárias Adquiridas/terapia , Oxigenação por Membrana Extracorpórea/métodos , Intubação Intratraqueal/métodos , Enfisema Pulmonar/terapia , Síndrome do Desconforto Respiratório/terapia , Enfisema Subcutâneo/terapia , Terapia Combinada/métodos , Infecções Comunitárias Adquiridas/diagnóstico , Feminino , Humanos , Pessoa de Meia-Idade , Enfisema Pulmonar/diagnóstico , Síndrome do Desconforto Respiratório/diagnóstico , Enfisema Subcutâneo/diagnóstico , Resultado do TratamentoRESUMO
The case presents a wall adherent structure in the right atrium in a young patient with peripheral t-cell lymphoma followed by successful prolonged lysis therapy resulting in the resolution of the thrombus is presented. This case highlights the utility of multimodality imaging in an accurate assessment of the right atrium thrombus and the effectiveness of prolonged lysis therapy.
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OBJECTIVE: The document describes macular hole surgery and examines the available evidence to address questions about the efficacy of the procedure for different stages of macular hole, complications during and after surgery, and modifications to the technique. METHODS: A literature search conducted for the years 1968 to 2000 retrieved over 400 citations that matched the search criteria. This information was reviewed by panel members and a methodologist, and it was evaluated for the quality of the evidence presented. RESULTS: There are three multicenter, controlled, randomized trials that constitute Level I evidence and compare the value of surgery versus observation for macular hole. There are three multicenter, controlled, randomized trials studying the use of adjuvant therapy in macular hole repair. Postoperative vision of 20/40 or better has been reported in 22% to 49% of patients in randomized trials. The risks of surgical complications include retinal detachment (3%), endophthalmitis (<1%), cataract (>75%), and late reopening the hole (2% to 10%). CONCLUSIONS: The evidence does not support surgery for patients with stage 1 holes. Level I evidence supports surgery for stage 2 holes to prevent progression to later stages of the disease and further visual loss. Level I evidence shows that surgery improves the vision in a majority of patients with stage 3 and stage 4 holes. There is no strong evidence that adjuvant therapy used at the time of surgery results in improved surgical outcomes. Patient inconvenience, patient preference, and quality of life issues have not been studied.
Assuntos
Procedimentos Cirúrgicos Oftalmológicos , Oftalmologia , Perfurações Retinianas/cirurgia , Avaliação da Tecnologia Biomédica , Ensaios Clínicos como Assunto , Humanos , Complicações Intraoperatórias , Procedimentos Cirúrgicos Oftalmológicos/normas , Complicações Pós-Operatórias , Perfurações Retinianas/classificação , Sociedades Médicas , Estados Unidos , Acuidade VisualRESUMO
A tool was developed that assists surgeons in manipulating surgical instruments more precisely than is possible manually. The tool is a telemanipulator that scales down the surgeon's hand motion and filters tremor in the motion. The signals measured from the surgeon's hand are transformed and used to drive a six-degrees-of-freedom robot to position the surgical instrument mounted on its tip. A pilot study comparing the performance of the telemanipulator system against manual instrument positioning was conducted at the University of Southern California School of Medicine. The results show that a telerobotic tool can improve the performance of a microsurgeon by increasing the precision with which he can position surgical instruments, but this is achieved at the cost of increased time in performing the task. We believe that this technology will extend the capabilities of microsurgeons and allow more surgeons to perform highly skilled procedures currently performed only by the best surgeons. It will also enable performance of new surgical procedures that are beyond the capabilities of even the most skilled surgeons.
Assuntos
Microcirurgia/instrumentação , Robótica/instrumentação , Estudos de Avaliação como Assunto , Humanos , Microcirurgia/métodos , Projetos Piloto , Instrumentos CirúrgicosRESUMO
PURPOSE: This report evaluates the clinical characteristics of surfing-related ocular trauma to learn the nature of such injuries and propose possible preventive measures. METHODS: The authors reviewed 11 cases of surfing-related eye injuries caused by direct trauma from the surfboard, studying their mechanism of injury, the associated ocular complications, and the anatomic and visual outcomes of surgical repair. RESULTS: Surfing-related ocular injuries occurred exclusively in young males (mean age, 24.8 years; range, 14-37 years). The mechanism of injury most frequently responsible was impact with the sharp nose of the surfboard following a fall. Serious posterior segment complications were observed in all 11 patients, with nine patients suffering ruptured globes. Despite immediate medical attention, five patients did not recover ambulatory levels of visual acuity (>5/200). CONCLUSIONS: Surfing-related ocular trauma presenting to the retinal specialist typically leaves the patient with a permanent visual disability. Important factors contributing to these high-velocity injuries include the sharply pointed nose of the surfboard and the leash keeping the surfer in close proximity to the board following a fall. A simple modification in surfboard design such as blunting the sharp nose of the surfboard, or appropriate protective guards fitted over the surfboard nose, should lessen the severity of such injuries.
Assuntos
Traumatismos em Atletas/etiologia , Lesões da Córnea , Ferimentos Oculares Penetrantes/etiologia , Esclera/lesões , Equipamentos Esportivos/efeitos adversos , Adolescente , Adulto , Traumatismos em Atletas/patologia , Traumatismos em Atletas/cirurgia , Córnea/patologia , Córnea/cirurgia , Ferimentos Oculares Penetrantes/patologia , Ferimentos Oculares Penetrantes/cirurgia , Dispositivos de Proteção dos Olhos , Seguimentos , Humanos , Masculino , Procedimentos Cirúrgicos Oftalmológicos , Estudos Retrospectivos , Ruptura , Esclera/patologia , Esclera/cirurgia , Acuidade VisualRESUMO
OBJECTIVES: The purpose of this study was to determine what risk factors play a role in the development of retinopathy of prematurity (ROP). STUDY DESIGN: Data were collected on 157 infants born and cared for in one institution between January 1991 and July 1994. Initially we evaluated all children enrolled in the study to determine potential risk factors for the development of ROP. We subsequently compared multiple variables for ROP positive singletons with ROP positive twins to determine ROP risk factors for each group and to determine if one group was more susceptible to a given risk factor. RESULTS: Of the 157 infants examined, 72 infants (46%) developed ROP. Infants who developed ROP had a lower gestational age, a lower birth weight, a higher number of days on oxygen/ventilator, more days in the intensive care unit (ICU), a greater need for steroids and a higher incidence of sepsis when compared to infants who did not develop ROP. There was no significant difference noted between singleton and twin gestation infants that developed ROP when comparing gestational age, weight, ventilator time or length of ICU stay. Total number of days on oxygen therapy was higher in the singleton group and this difference did reach statistical significance. CONCLUSIONS: Several risk factors are associated with a higher incidence of ROP. These variables may not be independent risk factors but may be a sign of the increased severity of illness associated with those infants who are born earlier with a lower birth weight. Multiple gestational births do not appear to increase the risk of developing ROP when compared to a similar group of singleton birth infants.
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Retinopatia da Prematuridade/etiologia , Feminino , Humanos , Recém-Nascido , Masculino , Oxigênio/efeitos adversos , Oxigênio/uso terapêutico , Respiração Artificial/efeitos adversos , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , GêmeosRESUMO
This study identifies bumetanide-sensitive chloride transport in cultured fetal human retinal pigment epithelium (RPE). Ion flux and electrophysiologic studies were performed on fetal human RPE grown to confluence on microporous culture wells mounted in modified Ussing chambers. Unidirectional transepithelial Cl- fluxes were measured along with the transepithelial potential (TEP), resistance (Rt), and short circuit current (Isc). In separate experiments the apical and basal membrane voltages (Vap and Vba) and membrane resistance ratio (Rap/Rba) were measured using standard electrophysiological techniques. The average electrical parameters under control conditions were TEP = 3.6 +/- 2.1 mV, Rt = 385 +/- 98 ohm cm2, and Isc = 8.8 +/- 3.6 microA cm-2. Apical bumetanide (10(-5) M) reduced the TEP and Isc an average of 0.6 +/- 0.4 mV and 1.6 +/- 0.8 microA cm-2, respectively. Under open-circuit conditions, we measured a net apical to basal 36Cl flux of 0.30 microEq cm-2 hr-1. Bumetanide reduced this net Cl- flux by 83% by reducing the unidirectional apical-to-basal Cl- flux. Apical bumetanide hyperpolarized Vba from -58 +/- 14 to -66 +/- 17 mV and reduced Rap/Rba from 1.17 +/- 0.50 to 0.85 +/- 0.38, consistent with blockade of Cl- uptake and reduction of the Cl- equilibrium potential at a basal membrane Cl- channel. Basal bumetanide had no effect on electrical parameters. We identified a bumetanide sensitive Cl- uptake mechanism at the apical membrane which may represent the Na-K-2Cl cotransporter reported in explant and other cultured preparations of mammalian RPE.
Assuntos
Cloretos/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Oxirredutases/genética , Epitélio Pigmentado Ocular/metabolismo , Receptores de Hidrocarboneto Arílico/genética , Transporte Biológico Ativo/efeitos dos fármacos , Bumetanida/farmacologia , Células Cultivadas , Citocromo P-450 CYP1A2 , Impedância Elétrica , Feto , Humanos , Transporte de Íons , Potenciais da MembranaRESUMO
PURPOSE: To study the choroidal circulation after surgical excision of subfoveal choroidal neovascular membranes (SFCNVM) in age-related macular degeneration (ARMD). METHODS: Twelve eyes of eleven patients with ARMD that underwent surgical excision of SFCNVMs were evaluated with stereoscopic color fundus photography, stereoscopic fluorescein angiography (FA) and scanning laser ophthalmoscope-indocyanine green videoangiography (SLO-ICGv). The patients were followed for a mean of 7.9 months (range 2 to 14 months). RESULTS: Preoperatively, all eyes had angiographic evidence of a SFCNVM, with SLO-ICGv showing the presence of a choriocapillary blush. Postoperatively, stereoscopic color fundus photographs documented that the bed of the surgical excision was characterized by an absence of visible retinal pigment epithelial (RPE) pigmentation in all eyes. Stereoscopic FA of the excision bed revealed choriocapillary hypofluorescence with visible dye perfusion in the underlying medium and large choroidal vessels in all eyes. SLO-ICGv of the excision bed disclosed the presence of perfused medium and large choroidal vessels, but a marked choroidal hypofluorescence with loss of the choriocapillary and small choroidal vascular filling within the excision bed in eleven of the twelve eyes. CONCLUSION: Our results indicate that both choriocapillary and small choroidal vascular filling is frequently abnormal or absent in the bed of surgically excised subfoveal neovascular membranes in ARMD. This finding, which may represent either pathologic or iatrogenic choriocapillary and small choroidal vascular atrophy or occlusion with preservation of perfusion in the underlying medium and large choroidal vessels, may influence structural and visual recovery after submacular surgery for ARMD, despite RPE transplantation or regeneration.
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Corioide/irrigação sanguínea , Fóvea Central , Degeneração Macular/complicações , Microcirculação/fisiologia , Neovascularização Patológica/cirurgia , Idoso , Idoso de 80 Anos ou mais , Membrana Basal/cirurgia , Corioide/patologia , Feminino , Angiofluoresceinografia , Seguimentos , Fundo de Olho , Humanos , Degeneração Macular/diagnóstico , Masculino , Neovascularização Patológica/diagnóstico , Neovascularização Patológica/etiologia , Estudos Retrospectivos , Acuidade VisualRESUMO
PURPOSE: To study the clinical course of accidental, single-focus Nd:YAG laser injuries to the macula. METHODS: We reviewed the clinical course of five eyes (four patients) that sustained macular injuries from a Nd:YAG laser. All patients were examined within 24 hours of injury and were observed without surgical intervention for a mean of 20 months (range, 12 to 32 months). RESULTS: A single full-thickness foveal or parafoveal retinal hole was apparent in all eyes either on initial examination or within two weeks of injury. All macular holes were within 650 microns of the foveal center. The mean final visual acuity was 20/60 (range, 20/25 to 20/400) and was related to the distance between the macular hole and the foveal center. None of the eyes developed either subretinal neovascularization or clinically significant epiretinal membrane formation during the study period. CONCLUSIONS: Despite initial poor visual acuity in patients who had a full-thickness foveal or parafoveal retinal hole, visual acuity improved without treatment when the site of the laser injury was located outside the foveal center.
Assuntos
Lasers/efeitos adversos , Macula Lutea/lesões , Perfurações Retinianas/etiologia , Adulto , Feminino , Seguimentos , Fóvea Central/lesões , Fóvea Central/patologia , Fóvea Central/efeitos da radiação , Fundo de Olho , Humanos , Macula Lutea/patologia , Macula Lutea/efeitos da radiação , Masculino , Perfurações Retinianas/patologia , Acuidade VisualRESUMO
AIMS: This study was carried out to investigate the precise pattern of visual loss associated with subfoveal choroidal neovascular membranes and the mechanism by which vision is stabilised or improved after submacular surgery. METHODS: Preoperative and postoperative quantitative microperimetry using the scanning laser ophthalmoscope was performed on six eyes of five patients with age-related macular degeneration who underwent subfoveal choroidal neovascular membrane excision. The relation of the microperimetry findings to the preoperative and postoperative fluorescein angiographic features was also assessed. RESULTS: Four of the six eyes had visual improvement by the 6 month postoperative visit; the other two had stabilisation of vision at the preoperative level. Despite these beneficial visual effects, none of the patients fixated within the bed of the excised choroidal neovascular membrane. Subfoveal choroidal membrane excision was associated with a 36% average increase in the absolute scotoma at the 1 month postoperative visit, compared with the preoperative size. The postoperative scotoma appeared to remain stable or decreased slightly in size between the 6 month and 1 year postoperative visits. Recovery of vision was associated with the development of a more stable preferred eccentric fixation locus, of which the distance from the centre of the foveal avascular zone was related to final postoperative vision. Most of the eccentric fixation loci were inferotemporal to the bed of the excised choroidal neovascular membrane. The surgical retinotomy site was associated with persistent postoperative relative scotoma in five of the six cases, but resolved in one patient after 1 year. CONCLUSION: These findings indicate that quantitative scanning laser ophthalmoscope microperimetry may aid in the surgical planning of subfoveal choroidal neovascular membrane excision.
Assuntos
Fundo de Olho , Degeneração Macular/patologia , Microscopia Confocal , Oftalmoscopia , Idoso , Idoso de 80 Anos ou mais , Feminino , Fixação Ocular , Angiofluoresceinografia , Seguimentos , Humanos , Degeneração Macular/diagnóstico , Degeneração Macular/cirurgia , Masculino , Testes VisuaisAssuntos
Doença de Alzheimer/diagnóstico , Pupila/efeitos dos fármacos , Tropicamida , Adulto , Idoso , Feminino , Humanos , MasculinoRESUMO
PURPOSE: To identify K+ conductances on the apical and basolateral membranes in cultured monolayers of fetal bovine and human retinal pigment epithelium (RPE). METHODS: Bovine and human RPE cells were grown on a permeable substrate for an average of 4 and 25 months, respectively, mounted in a modified Ussing chamber that allowed rapid solution changes at both membranes, and perfused with modified Ringer's solutions. Conventional microelectrode recording techniques were used to record intracellularly from RPE cells. RESULTS: Electrical parameters under control conditions for bovine (n = 11) and human (n = 7) cultures respectively, were: transepithelial potential, 0.6 +/- 0.2 and 3.2 +/- 0.5 mV; Rt, 70 +/- 12 and 227 +/- 30 ohm.cm2; and Vap, -61 +/- 3 and -51 +/- 2 mV (mean +/- SEM). The relative K+ conductance (TK) was estimated from responses to 10-fold increases in [K+]o. For the apical and basal membranes, the values for TK were 0.65 and 0.37, respectively, in bovine and 0.33 and 0.45, respectively, in human RPE. Barium applied to either surface of the cultures produced membrane depolarizations and suppressed the responses significantly to K+. In bovine, a 10-fold decrease in basal [K+]o hyperpolarized Vba by 2 +/- 1 mV; a similar decrease in apical [K+]o hyperpolarized Vap by 14 +/- 1 mV. At both membranes, perfusion with Ba2+ unmasked a significant membrane depolarization induced by lowering [K+]o; this phenomenon, observed previously at the apical membrane in fresh explant bovine, frog, and toad RPE, appears to be an unmasking of Na+/K+ pump modulation by K+. CONCLUSIONS: These results indicate the presence of Ba2+ sensitive K+ conductances at the apical and basal membranes of confluent monolayers of cultured fetal human and bovine RPE and the presence of Na+/K+ pump sites at both membranes of cultured bovine cells.
Assuntos
Epitélio Pigmentado Ocular/fisiologia , Canais de Potássio/fisiologia , Potássio/fisiologia , Animais , Transporte Biológico Ativo , Bovinos , Células Cultivadas , Feto , Humanos , Transporte de Íons , Potenciais da Membrana/efeitos dos fármacos , Microeletrodos , Epitélio Pigmentado Ocular/citologia , Epitélio Pigmentado Ocular/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
BACKGROUND: Macular edema is relatively rare in the Vogt-Koyanagi-Harada (VKH) syndrome, in contrast to many other syndromes of chronic intraocular inflammation, in which macular edema is relatively common. Five eyes of three patients with chronic VKH syndrome and macular edema are described. METHODS: The authors retrospectively reviewed the clinical and fluorescein angiographic records of 27 patients with chronic VKH syndrome (duration of disease more than 3 months) and identified three patients (five eyes) who had macular edema. Fluorescein angiography was performed using a scanning laser ophthalmoscope. RESULTS: These patients had either unusually severe and protracted inflammation (3 eyes) of the presence of an epiretinal membrane (2 eyes). Fluorescein angiography demonstrated prominent perifoveal fluorescein leakage with pooling of fluorescein within perifoveal cystoid spaces. Treatment with sub-Tenon's triamcinolone injections resulted in improvement of visual acuity by two or more Snellen lines in four of the five eyes. CONCLUSION: Macular edema is an uncommon but treatable cause of late loss of vision in patients with the VKH syndrome, and may be the result of leakage from perifoveal retinal capillaries or leakage of fluid at the level of the retinal pigment epithelium.
Assuntos
Edema Macular/complicações , Síndrome Uveomeningoencefálica/complicações , Adolescente , Anti-Inflamatórios/uso terapêutico , Doença Crônica , Fáscia , Feminino , Angiofluoresceinografia , Fundo de Olho , Humanos , Injeções , Edema Macular/tratamento farmacológico , Edema Macular/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Triancinolona/uso terapêutico , Síndrome Uveomeningoencefálica/tratamento farmacológico , Síndrome Uveomeningoencefálica/patologia , Acuidade VisualRESUMO
PURPOSE: To investigate the macular choriocapillary circulation (MCC) in eyes with age-related macular degeneration (ARMD) and to correlate these findings with the associated clinical and angiographic drusen characteristics. METHODS: Scanning laser ophthalmoscope fluorescein videoangiography was performed on 34 eyes with age-related macular degeneration and eight age-matched normal volunteers. Drusen characteristics were assessed using the Wisconsin age-related maculopathy grading scale. RESULTS: A delayed macular choriocapillary circulation (DMCC) was defined as a macular choriocapillary filling time greater than 3 standard deviations from the normal mean (greater than 5 seconds). Nine (26%) of the 34 eyes with ARMD were found to have a DMCC. After age adjustment, eyes with DMCC were more likely to have geographic atrophy of the retinal pigment epithelium (p = 0.003) or choroidal neovascularization p = 0.07) than were eyes with a normal MCC. Regional differences in choriocapillary filling times were present in the eyes with a DMCC, including nasal-to-temporal, central-to-peripheral, and inferior-to-superior gradients of progressively less choriocapillary filling delay. The DMCC correlated with the location, number, size, confluence, and fluorescein staining characteristics of the associated drusen. CONCLUSION: DMCC occurs in some eyes with ARMD. This finding may not only assist in defining eyes at risk for progressive disease but may also help to elucidate the pathogenesis of age-related macular degeneration.
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Corioide/irrigação sanguínea , Macula Lutea/irrigação sanguínea , Degeneração Macular/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Capilares , Corioide/fisiopatologia , Estudos Transversais , Feminino , Angiofluoresceinografia , Fundo de Olho , Humanos , Macula Lutea/fisiopatologia , Degeneração Macular/etiologia , Masculino , Microcirculação/fisiologia , Drusas Retinianas/patologia , Drusas Retinianas/fisiopatologiaRESUMO
PURPOSE: To localize NaK ATPase sites on cultured human retinal pigment epithelium (RPE). METHODS: Cultured human RPE from fetal, 2-year-old, and 21-year-old donors was grown to confluence in microporous culture wells for 4 months to 2 years, mounted in a small-volume Ussing chamber, and perfused with growth medium. Ouabain (10(-5)-M) was applied to the basal and apical sides of the RPE. Changes in transepithelial resistance (Rt), transepithelial potential (TEP), and apical and basal membrane potentials were measured. RESULTS: Application of ouabain to the basal side of RPE produced a small sustained increase in TEP after 6 minutes and, simultaneously, small depolarizations of both apical and basal membranes. During the continued presence of ouabain on the basal side, application of ouabain to the apical side produced a significantly larger TEP decrease and greater depolarization of both membranes. Significant changes in Rt were not observed. CONCLUSIONS: These results indicate that NaK ATPase sites are present on both the apical and basolateral membranes of cultured human RPE. The greater effect of ouabain when applied to the apical side suggests that functional NaK ATPase sites are more abundant on the apical membrane.
Assuntos
Epitélio Pigmentado Ocular/química , ATPase Trocadora de Sódio-Potássio/análise , Adulto , Membrana Basal/química , Membrana Celular/química , Células Cultivadas , Pré-Escolar , Eletrofisiologia , Feto/fisiologia , Humanos , Potenciais da Membrana/efeitos dos fármacos , Ouabaína/farmacologia , Epitélio Pigmentado Ocular/citologia , Epitélio Pigmentado Ocular/fisiologiaRESUMO
Macular detachment due to peripheral retinal tears that occur after pars plana vitrectomy for proliferative diabetic retinopathy can result in severe visual loss despite successful retinal reattachment. The authors reviewed the records of three patients who developed peripheral sclerotomy-related rhegmatogenous retinal detachments one to six months after vitrectomy for proliferative diabetic retinopathy, despite the absence of detectable sclerotomy-related retinal tears by indirect ophthalmoscopy and scleral depression at the conclusion of surgery. All three patients had received standard panretinal laser photocoagulation in a complete encircling pattern either prior to or during the initial vitrectomy. Clinically or echographically, each patient was seen to have a partial or complete annual peripheral sclerotomy-related rhegmatogenous retinal detachment delimited to the equator. In each of these three cases, posterior extension of the peripheral retinal detachment into the macular area was prevented by the most anterior row of the photocoagulation scars. Standard panretinal laser photocoagulation applied in a complete encircling pattern may be useful in the prophylaxis of macular detachment from sclerotomy-related retinal tears that occur after vitrectomy for proliferative diabetic retinopathy.
Assuntos
Retinopatia Diabética/cirurgia , Fotocoagulação a Laser , Retina/cirurgia , Descolamento Retiniano/etiologia , Descolamento Retiniano/prevenção & controle , Vitrectomia/efeitos adversos , Idoso , Retinopatia Diabética/diagnóstico por imagem , Feminino , Humanos , Macula Lutea , Masculino , Pessoa de Meia-Idade , Descolamento Retiniano/cirurgia , UltrassonografiaRESUMO
Digital fundus angiography has advantages over conventional photography. However, digital angiography as it is normally performed, provides no stereoscopic information. Because stereoscopic data can be crucial in the evaluation of conditions such as age-related macular degeneration, we developed methods to record stereoscopic information during video angiography with a scanning laser ophthalmoscope and to produce high-quality static stereoscopic images. Stereoscopic information was collected by moving the scanning laser ophthalmoscope side-to-side and with a modified Allen separator. Stereoscopic images were displayed as stereoscopic pairs on 35-mm film, stereoscopic pairs from a digital printer, and as stereoscopic images directly on a conventional video monitor. This system to capture and display stereoscopic information is convenient, uses readily available technology, and can be adapted to any digital angiography system.
Assuntos
Angiofluoresceinografia , Oftalmoscopia , Fotografação , Fundo de Olho , Humanos , Lasers , Oftalmoscopia/métodos , Doenças Retinianas/diagnóstico , Gravação em VídeoRESUMO
Cultured fetal human retinal pigment epithelium (RPE) was grown on a permeable substrate and sealed in an Ussing chamber. The average electrical resistance (R) was 330 ohm-cm2, the average transepithelial voltage (Ve) was 3.0 mV (apical side positive), and the average short circuit current (Isc) was 9.1 microA/cm2. When these RPE preparations were exposed to isoproterenol (a beta-adrenergic agonist), the Isc increased by 88%, R was reduced by 6%, and Ve increased by 85%. The effect of isoproterenol was blocked by propranolol (a beta-adrenergic antagonist). When cultured human RPE was exposed to isoproterenol, intracellular cyclic adenosine monophosphate (AMP) levels rose more than threefold. The effect of isoproterenol on cyclic AMP levels was blocked by propranolol. When the cultured RPE was exposed to dibutyryl cyclic AMP, both Ve and Isc rose by 47% with a time course similar to that which occurred when the cells were exposed to isoproterenol. Preparations treated with dibutyryl cyclic AMP did not respond to subsequently applied isoproterenol. These results indicate that cultured human RPE possesses a beta-adrenergic receptor and that stimulation of this receptor produces a change in cyclic AMP concentration which affects RPE electrical activity.