RESUMO
OBJECTIVE: To evaluate the effect of a synthetic progestin on the vascular resistance of the ophthalmic and central retinal arteries in climacteric women, compared to placebo, using transorbital ultrasound with Doppler velocimetry. METHODS: We performed a prospective, randomized, double-blinded, placebo-controlled study with 216 climacteric women. Subjects were randomly allocated to one of two groups: either the group receiving placebo (one pill/day for 30 days) (n = 108) or the group receiving progestin (5 mg medroxyprogesterone acetate/day for 30 days) (n = 108). Transorbital Doppler velocimetric ultrasound was performed, before and after treatment; we measured the pulsatility index, resistance index and systole/diastole ratio. RESULTS: The mean ages of the participants in the study group and the control group were 54 ± 6.2 years (range 48-59 years) and 55 ± 6.8 years (range 46-60 years), respectively. When we compared the effect of the progestin on the central retinal artery before and after treatment, we observed a significant increase after the treatment in all Doppler indices. The same was observed when we compared the effect of the progestin on the ophthalmic artery. In the group of women receiving placebo, the Doppler indices were similar before and after treatment. CONCLUSIONS: Our results demonstrate the existence of a progestogenic vasoconstrictive effect in the ophthalmic and central retinal arteries. As this study provides new data, the observed effect needs further investigations to better elucidate its extent. Moreover, our findings may be particularly useful to others interested in understanding the vascular dynamics of the cerebral vessels and to researchers running clinical trials related to hormone replacement therapy.
Assuntos
Acetato de Medroxiprogesterona/administração & dosagem , Acetato de Medroxiprogesterona/efeitos adversos , Menopausa , Artéria Oftálmica/efeitos dos fármacos , Artéria Retiniana/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacos , Método Duplo-Cego , Terapia de Reposição de Estrogênios/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade , Placebos , Estudos Prospectivos , Reologia , Ultrassonografia Doppler , VasoconstritoresRESUMO
OBJECTIVE: The aim of this study was to evaluate the effect of tibolone on vascular resistance of the central retinal and ophthalmic artery in postmenopausal women and to compare this effect with that of placebo using transorbital ultrasound with Doppler velocimetry. METHODS: We performed a prospective randomized, double-blinded, placebo-controlled study. A total of 100 healthy postmenopausal women (follicle-stimulating hormone, >40 IU/L) younger than 65 years were studied. The participants were randomly allocated to two groups: placebo (n = 50) and tibolone (2.5 mg; n = 50). Transorbital Doppler velocimetric ultrasound was performed before treatment and 80 days after. RESULTS: The mean age was similar in both groups. Participants who received tibolone did not show any difference in pulsatility index, resistance index, and systole/diastole ratio of the central retinal and ophthalmic arteries after treatment. The same was observed in participants who received placebo. CONCLUSIONS: Our study demonstrates that tibolone administration to healthy postmenopausal women does not affect the resistance of small-caliber cerebral arteries.
Assuntos
Moduladores de Receptor Estrogênico/uso terapêutico , Norpregnenos/uso terapêutico , Artéria Oftálmica/efeitos dos fármacos , Pós-Menopausa/efeitos dos fármacos , Artéria Retiniana/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacos , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Pessoa de Meia-Idade , Artéria Oftálmica/diagnóstico por imagem , Artéria Retiniana/diagnóstico por imagem , Ultrassonografia DopplerRESUMO
OBJECTIVE: The aim of this study was to evaluate the effect of estrogen on the vascular resistance of the central retinal artery in postmenopausal women, compared with placebo, using transorbital ultrasound with Doppler velocimetry. METHODS: We performed a prospective, randomized, triple-blinded placebo-controlled study. A total of 51 healthy postmenopausal women (follicle-stimulating hormone, >40 IU/L) with a mean (SD) age of 53.6 (4.8) years were studied. Participants were randomly allocated into two groups: placebo (n = 23) and estrogen (0.625 mg conjugated estrogens; n = 28). Transorbital Doppler velocimetric ultrasound was performed before and after treatment in sitting and supine positions. RESULTS: The mean age was similar in both groups. The pulsatility index of the central retinal arteries had a significant decrease after the use of estrogen, when women were evaluated in the sitting position. Women who received placebo did not show any difference in pulsatility index of the central retinal arteries after treatment. When the same comparison was done with participants in the supine position, no difference was observed in either group. CONCLUSIONS: Our study demonstrates that estrogen reduces the vascular resistance of the central retinal artery in postmenopausal women because of a vasodilatory effect.
Assuntos
Estrogênios/administração & dosagem , Pós-Menopausa , Artéria Retiniana/efeitos dos fármacos , Artéria Retiniana/fisiologia , Resistência Vascular/efeitos dos fármacos , Resistência Vascular/fisiologia , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Pressão Sanguínea , Circulação Cerebrovascular , Terapia de Reposição de Estrogênios , Olho/irrigação sanguínea , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Fluxo Pulsátil/efeitos dos fármacos , Valores de Referência , Artéria Retiniana/diagnóstico por imagem , Ultrassonografia Doppler em CoresRESUMO
PURPOSE: The actual effect of steroid hormones on cerebral microcirculation is still controversial. Therefore, the aim of our study was to investigate vascular flow variations in the central retinal artery that may exist during the ovulatory menstrual cycle. METHODS: A total of 34 healthy women were included in this observational, longitudinal, and prospective study. All participants were submitted to dopplerfluxometric evaluation of the eyes in order to study the pulsatility index (PI) of the central retinal arteries, during four phases of the menstrual cycle: early follicular, mid follicular, periovulatory, and mid luteal phases. RESULTS: Subjects' ages ranged from 14 to 47 years old (mean: 29.7 ± 10.1) and PI did not differ among age groups. The PI of the central retinal artery was different among the four phases of the menstrual cycle. PI showed a significant decrease from early follicular phase (1.72) to mid follicular phase (1.57) (p = 0.037), and was similar during periovulatory phase (1.56) and significantly increased in mid luteal phase (1.70). After that it returned to the values observed in the early follicular phase. CONCLUSION: Our results suggest the existence of an oestrogen vasodilatation effect on the central retinal artery that is menstrual phase-related and antagonized by progesterone.
Assuntos
Estrogênios/farmacologia , Ciclo Menstrual/fisiologia , Progesterona/farmacologia , Fluxo Pulsátil/efeitos dos fármacos , Artéria Retiniana/efeitos dos fármacos , Vasodilatadores/farmacologia , Adolescente , Adulto , Feminino , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Estudos Prospectivos , Artéria Retiniana/fisiologia , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia , Adulto JovemRESUMO
PURPOSE: to evaluate the effect of tibolone use on doppler-velocimetric 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(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.
Assuntos
Moduladores de Receptor Estrogênico/farmacologia , Fluxometria por Laser-Doppler , Norpregnenos/farmacologia , Artéria Oftálmica/efeitos dos fármacos , Artéria Oftálmica/fisiologia , Artéria Retiniana/efeitos dos fármacos , Artéria Retiniana/fisiologia , Método Duplo-Cego , Feminino , Humanos , Pessoa de Meia-Idade , Estudos ProspectivosAssuntos
Humanos , Catarata/tratamento farmacológico , Degeneração Macular/tratamento farmacológico , Retinopatia Diabética/tratamento farmacológico , Nefropatias Diabéticas/tratamento farmacológico , Catarata/prevenção & controle , Catarata/fisiopatologia , Degeneração Macular/prevenção & controle , Degeneração Macular/fisiopatologia , Ácido Ascórbico/uso terapêutico , beta Caroteno/uso terapêutico , Antioxidantes/uso terapêutico , Zinco/uso terapêutico , Vitamina E/uso terapêutico , Retinopatia Diabética/fisiopatologia , Retinopatia Diabética/prevenção & controle , Vasos Retinianos/efeitos dos fármacos , Artéria Retiniana/efeitos dos fármacos , Nefropatias Diabéticas/prevenção & controle , Estudos Multicêntricos como Assunto , Circulação Renal/efeitos dos fármacos , Ensaios Clínicos como Assunto , Resultado do Tratamento , Cristalino/efeitos dos fármacos , Retina/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacosRESUMO
Objetivo: Estudar os efeitos na circulaçäo retrobulbar e no campo visual de uma dose oral única de 100 mg de citrato de sildenafil (Viagra). Métodos: Um estudo duplo-mascarado e controlado por placebo foi realizado em 10 voluntários do sexo masculino, com idade média de 27,7 ñ 5,68 anos. O olho direito de cada voluntário foi submetido aos exames de Doppler colorido de órbita e análise de campo visual por meio de perimetria computadorizada (Humphrey, programa 30-2, estratégia "Full Threshold") em 3 ocasiöes: "baseline",1 hora após placebo e 1 hora após 100 mg de sildenafil via oral. No campo visual, analisaram-se o limiar foveal e o "mean deviation" (MD) nas 3 ocasiöes. No Doppler colorido, medimos a velocidade sistólica máxima (VSM), a velocidade diastólica final (VDF) e o índice de resistência (IR) da artéria central da retina (ACR) e da artéria oftálmica (AO) nas 3 ocasiöes. Resultados: A administraçäo do sildenafil näo alterou significativamente o limiar foveal e o "mean deviation" em relaçäo ao "baseline" e ao placebo. Houve um aumento significativo da velocidade sistólica máxima e velocidade diastólica final na artéria oftálmica após a administraçäo do citrato de sildenafil (p<0,001). Näo houve alteraçäo significativa dos parâmetros hemodinâmicos na artéria central da retina e no índice de resistência da artéria oftálmica. Conclusöes: A administraçäo de 100 mg de citrato de sildenafil promoveu um aumento da velocidade de fluxo sanguíneo na artéria oftálmica de indivíduos normais e näo promoveu alteraçäo significativa no limiar foveal e "mean deviation" da campimetria computadorizada.
Assuntos
Humanos , Masculino , Adulto , Piperazinas/administração & dosagem , Artéria Retiniana/efeitos dos fármacos , Campos Visuais/efeitos dos fármacos , Administração Oral , Método Duplo-Cego , Fóvea Central , Dose Única , Ultrassonografia Doppler em Cores , Velocidade do Fluxo Sanguíneo/fisiologia , Testes de Campo VisualRESUMO
Objetivos: Analisar os resultados, anatômicos e funcionais, do tratamento das obstruções venosas retinianas pelo fator tecidual ativador de plasminogênio recombinante (rt-PA) intravítreo. Pacientes e Métodos: Cinco pacientes com obstrução da veia central da retina (OVCR) e um paciente com obstrução venosa hemi-retiniana foram submetidos a uma injeção intravítrea de 75mg de rt-PA e reavaliados através de exame oftalmológico completo, retinografia e retinografia flourescente. Resultados: Observou-se melhora anatômica em dois dos seis pacientes estudados, dentre os quais o paciente que apresentava obstrução venosa hemi-retiniana que evoluiu com rápida e acentuada resolução do quadro obstrutivo. Nenhum dos pacientes apresentou melhora funcional. Um dos pacientes apresentou hemorragia vítrea de pequena magnitude e rápida resolução, um mês após a terapêutica, e outro paciente apresentou hemorragia vítrea quanze meses após, tendo esta ocorrido após cirurgia cardíaca.
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Ativadores de Plasminogênio/administração & dosagem , Ativadores de Plasminogênio , Ativadores de Plasminogênio/uso terapêutico , Plasminogênio/análise , Retina , Artéria Retiniana/efeitos dos fármacosRESUMO
PURPOSE: To investigate the effect of perfluoro-octane on coagulation studies and on intraoperative hemostasis during vitreoretinal surgery in an animal model. METHODS: In vitro study--comparison of coagulation profiles (bleeding time, whole blood clotting time, partial thromboplastin time, and one-stage prothrombin time) of blood taken from healthy volunteers with and without the addition of perfluoro-octane. In vivo study--comparison of times taken to achieve hemostasis in a rabbit model with large retinal arterial bleeding in vitrectomized and aphakic eyes with and without intraocular injection of perfluoro-octane. RESULTS: In vitro study--perfluoro-octane had no significant effect on coagulation profiles. In vivo study--intraocular perfluoro-octane significantly reduced the time to achieve hemostasis (P < 0.01) at all infusion bottle heights in vitrectomized and aphakic rabbit eyes. CONCLUSIONS: Perfluoro-octane may be used to control bleeding during vitreoretinal surgery. A direct effect on the clotting cascade could not be demonstrated.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Embolização Terapêutica/métodos , Fluorocarbonos/administração & dosagem , Complicações Intraoperatórias/terapia , Hemorragia Retiniana/terapia , Vitrectomia/efeitos adversos , Adulto , Animais , Coagulação Sanguínea/fisiologia , Modelos Animais de Doenças , Olho , Fluorocarbonos/farmacologia , Humanos , Injeções , Complicações Intraoperatórias/etiologia , Complicações Intraoperatórias/fisiopatologia , Coelhos , Valores de Referência , Artéria Retiniana/efeitos dos fármacos , Artéria Retiniana/fisiopatologia , Hemorragia Retiniana/etiologia , Hemorragia Retiniana/fisiopatologia , Resultado do TratamentoRESUMO
Four patients had central retinal artery occlusions after retrobulbar anaesthesia with lidocaine HCl was administered before photocoagulation. One of these four had two separate episodes of closure. Only one had permanent visual loss and none had evidence of retrobulbar hemorrhage. Each patient had a severe hematologic or vascular disorder. We think that direct trauma to the central retinal artery behind the globe, the pharmacologic or compressive effects of the injected solution,or both caused the occlusions in these patients. (AU)