Effects of obesity on retrobulbar flow hemodynamics: color Doppler ultrasound evaluation.

PURPOSE: To evaluate intraocular pressure (IOP) and extraocular orbital vessels with color Doppler ultrasound (CDU) and investigate the effects of obesity on retrobulbar blood flow. METHODS: Fifty-nine patients were included in this prospective study. Patients were divided into two groups according to body mass index: Group 1 (31 obese patients) and Group 2 (28 non-obese patients). IOP was measured with a Goldmann applanation tonometer, and CDU was used to evaluate the retrobulbar vessels. RESULTS: The mean IOP was 18 ± 6.68 mmHg in the obese group and 13.71 ± 1.60 mmHg in the control group (p<0.001). When the CDU values for the central retinal artery were compared between the groups, the pulsatility index was found to be significantly lower in the obese group than in the control group (p<0.001). When the CDU values for the ophthalmic artery (OA) were compared between the groups, the peak systolic velocity (p<0.001) and end-diastolic velocity (p=0.002) values were found to be significantly lower in the obese group than in the control group. CONCLUSIONS: Obese patients have a higher mean IOP and lower flow velocity than non-obese patients. Increased IOP together with decreased retrobulbar blood flow, particularly in obese individuals, may increase the risk of glaucoma development.

Effects of obesity on retrobulbar flow hemodynamics: color Doppler ultrasound evaluation / Efeitos da obesidade na hemodinâmica do fluxo retrobulbar: avaliação por ultrassom doppler colorido

ABSTRACT Purpose: To evaluate intraocular pressure (IOP) and extraocular orbital vessels with color Doppler ultrasound (CDU) and investigate the effects of obesity on retrobulbar blood flow. Methods: Fifty-nine patients were included in this prospective study. Patients were divided into two groups according to body mass index: Group 1 (31 obese patients) and Group 2 (28 non-obese patients). IOP was measured with a Goldmann applanation tonometer, and CDU was used to evaluate the retrobulbar vessels. Results: The mean IOP was 18 ± 6.68 mmHg in the obese group and 13.71 ± 1.60 mmHg in the control group (p<0.001). When the CDU values for the central retinal artery were compared between the groups, the pulsatility index was found to be significantly lower in the obese group than in the control group (p<0.001). When the CDU values for the ophthalmic artery (OA) were compared between the groups, the peak systolic velocity (p<0.001) and end-diastolic velocity (p=0.002) values were found to be significantly lower in the obese group than in the control group. Conclusions: Obese patients have a higher mean IOP and lower flow velocity than non-obese patients. Increased IOP together with decreased retrobulbar blood flow, particularly in obese individuals, may increase the risk of glaucoma development.

RESUMO Objetivo: Avaliar a pressão intraocular (PIO) e vasos orbitários extraoculares com ultrassom Doppler colorido (UDC) e investigar os efeitos da obesidade sobre o fluxo sanguíneo retrobulbar. Métodos: Cinquenta e nove pacientes foram incluídos neste estudo prospectivo. Os pacientes foram divididos em dois grupos de acordo com o índice de massa corpo ral (IMC): Grupo 1 (31 pacientes obesos) e Grupo 2 (28 não obesos). As pressões intraoculares (PIOs) foram medidas com tonômetro de aplanação de Goldmann e o UDC foi utilizada para a avaliação de vasos retrobulbar. Resultados: As PIOs foram 18 ± 6,68 mmHg nos pacientes obesos e 13,71 ± 1,60 mmHg nos grupos controle (p<00,001). Quando os valores da artéria central da retina (ACR) foram comparados entre os grupos controle e obeso. O índice pulsátil (PI) foi marcadamente menor no grupo obeso (p<00,001). Quando os valores da artéria oftálmica (AO) dos grupos obesos e de controle foram comparados. Os valores de Velocidade do pico sistólico (PSV) (p<00,001) e velocidade diastólica final (EDV) (p=00,002) foram significativamente mais baixos no grupo obeso. Conclusão: Pacientes obesos têm maior PIO do que os pacientes não obesos. Os pacientes obesos têm diminuição nas velocidades de fluxo da AO. O aumento da PIO. Juntamente com a diminuição do fluxo sanguíneo retrobulbar, especialmente em indivíduos obesos, pode aumentar o risco de desenvolvimento de glaucoma.

Ocular toxicity assessment of chronic sildenafil therapy for pulmonary arterial hypertension.

PURPOSE: The aim of this study was to investigate possible functional and structural ocular changes caused by chronic sildenafil therapy to treat pulmonary arterial hypertension (PAH). METHODS: Case-control study included patients with pulmonary arterial hypertension: chronically using sildenafil and without sildenafil treatment. A comprehensive ophthalmologic exam including ectoscopy, extrinsic ocular motility, logMAR visual acuity measurement, contrast sensitivity test, color test, anterior segment biomicroscopy, Schirmer test 1, intraocular pressure, fundus exam under pupil dilation, fundus pictures, time domain and spectral domain optical coherence tomography, ocular Doppler ultrasound were performed. Full-field electroretinography (ERG) was tested for each eye in a subgroup of sildenafil-treated patients. RESULTS: Twenty patients from each group were tested. Bilateral severe keratitis was found in seven (35 %) patients under sildenafil therapy. Lacrimal film break-up time (BUT) was significantly reduced (p = 0.006 respectively) and Doppler ultrasound showed a reduced resistance index of the central retinal artery in the group of sildenafil users (p = 0.019). No diffuse retinal functional abnormalities were found in ERG in treated patients. Visual acuity, contrast sensitivity and color discrimination were normal in both groups. No abnormalities were found in both time-domain and spectral-domain OCT for retinal parameters. CONCLUSIONS: One-third of the treated PAH group showed severe bilateral keratitis. This finding could be related to connective tissue abnormalities usually present in patients with this condition that might be exacerbated with the sildenafil usage. The resistance index of the central retinal artery was diminished in the chronic users group and it could be associated to the vasodilation caused by the medication in the choroidal vessels. An ophthalmic assessment for these patients is recommended to diagnose and treat possible ocular surface and choroidal blood flow abnormalities caused by sildenafil.

Blood flow velocity in monocular retinoblastoma assessed by color doppler

OBJECTIVE: To analyze the flow of retrobulbar vessels in retinoblastoma by color Doppler imaging. METHODS: A prospective study of monocular retinoblastoma treated by enucleation between 2010 and 2014. The examination comprised fundoscopy, magnetic resonance imaging, ultrasonography and color Doppler imaging. The peak blood velocities in the central retinal artery and central retinal vein of tumor-containing eyes (tuCRAv and tuCRVv, respectively) were assessed. The velocities were compared with those for normal eyes (nlCRAv and nlCRVv) and correlated with clinical and pathological findings. Tumor dimensions in the pathological sections were compared with those in magnetic resonance imaging and ultrasonography and were correlated with tuCRAv and tuCRVv. In tumor-containing eyes, the resistivity index in the central retinal artery and the pulse index in the central retinal vein were studied in relation to all variables. RESULTS: Eighteen patients were included. Comparisons between tuCRAv and nlCRAv and between tuCRVv and nlCRVv revealed higher velocities in tumor-containing eyes (p <0.001 for both), with a greater effect in the central retinal artery than in the central retinal vein (p =0.024). Magnetic resonance imaging and ultrasonography measurements were as reliable as pathology assessments (p =0.675 and p =0.375, respectively). A positive relationship was found between tuCRAv and the tumor volume (p =0.027). The pulse index in the central retinal vein was lower in male patients (p =0.017) and in eyes with optic nerve invasion (p =0.0088). CONCLUSIONS: TuCRAv and tuCRVv are higher in tumor-containing eyes than in normal eyes. Magnetic resonance imaging and ultrasonography measurements are reliable. The tumor volume is correlated with a higher tuCRAv and a reduced pulse in the central retinal vein is correlated with male sex and optic nerve invasion.

Blood flow velocity in monocular retinoblastoma assessed by color Doppler.

OBJECTIVE: To analyze the flow of retrobulbar vessels in retinoblastoma by color Doppler imaging. METHODS: A prospective study of monocular retinoblastoma treated by enucleation between 2010 and 2014. The examination comprised fundoscopy, magnetic resonance imaging, ultrasonography and color Doppler imaging. The peak blood velocities in the central retinal artery and central retinal vein of tumor-containing eyes (tuCRAv and tuCRVv, respectively) were assessed. The velocities were compared with those for normal eyes (nlCRAv and nlCRVv) and correlated with clinical and pathological findings. Tumor dimensions in the pathological sections were compared with those in magnetic resonance imaging and ultrasonography and were correlated with tuCRAv and tuCRVv. In tumor-containing eyes, the resistivity index in the central retinal artery and the pulse index in the central retinal vein were studied in relation to all variables. RESULTS: Eighteen patients were included. Comparisons between tuCRAv and nlCRAv and between tuCRVv and nlCRVv revealed higher velocities in tumor-containing eyes (p < 0.001 for both), with a greater effect in the central retinal artery than in the central retinal vein (p = 0.024). Magnetic resonance imaging and ultrasonography measurements were as reliable as pathology assessments (p = 0.675 and p = 0.375, respectively). A positive relationship was found between tuCRAv and the tumor volume (p = 0.027). The pulse index in the central retinal vein was lower in male patients (p = 0.017) and in eyes with optic nerve invasion (p = 0.0088). CONCLUSIONS: TuCRAv and tuCRVv are higher in tumor-containing eyes than in normal eyes. Magnetic resonance imaging and ultrasonography measurements are reliable. The tumor volume is correlated with a higher tuCRAv and a reduced pulse in the central retinal vein is correlated with male sex and optic nerve invasion.

Temporary morphological changes in plus disease induced during contact digital imaging.

OBJECTIVE: To compare and quantify the retinal vascular changes induced by non-intentional pressure contact by digital handheld camera during retinopathy of prematurity (ROP) imaging by means of a computer-based image analysis system, Retinal Image multiScale Analysis. METHODS: A set of 10 wide-angle retinal pairs of photographs per patient, who underwent routine ROP examinations, was measured. Vascular trees were matched between 'compression artifact' (absence of the vascular column at the optic nerve) and 'not compression artifact' conditions. Parameters were analyzed using a two-level linear model for each individual parameter for arterioles and venules separately: integrated curvature (IC), diameter (d), and tortuosity index (TI). RESULTS: Images affected with compression artifact showed significant vascular d (P<0.01) changes in both arteries and veins, as well as in artery IC (P<0.05). Vascular TI remained unchanged in both groups. CONCLUSIONS: Non-adverted corneal pressure with the RetCam lens could compress and decrease intra-arterial diameter or even collapse retinal vessels. Careful attention to technique is essential to avoid absence of the arterial blood column at the optic nerve head that is indicative of increased pressure during imaging.

The effects of carotid endarterectomy on the retrobulbar circulation of patients with severe occlusive carotid artery disease. An investigation by color Doppler imaging.

OBJECTIVE: To analyze the effects of carotid endarterectomy on the retrobulbar circulation of patients with severe occlusive carotid artery disease (OCAD) by means of color Doppler imaging (CDI). DESIGN: Prospective. PARTICIPANTS: A total of 17 consecutive patients with severe OCAD and neurologic symptoms (with a history of transitory ischemic attack or cerebral vascular accident) participated. INTERVENTION: All 17 patients underwent carotid endarterectomy. The CDI of both orbits was performed by one masked investigator before surgery and at 1 week and 1 month after surgery. MAIN OUTCOME MEASURES: Peak systolic velocity, end diastolic velocity, and resistive index of the ophthalmic, central retinal, and temporal short posterior ciliary arteries were measured. The authors compared the hemodynamic parameters at all intervals. RESULTS: Peak systolic and end diastolic velocities in the ophthalmic, central retinal, and temporal short posterior ciliary arteries increased significantly 1 week and 1 month after carotid endarterectomy (P < 0.05). After surgery, the resistive indices in the central retinal and temporal short posterior ciliary arteries decreased significantly at both intervals (P < 0.05). The six patients who had reversed ophthalmic artery flow before surgery showed forward ophthalmic artery flow after carotid endarterectomy. The contralateral orbits showed no significant hemodynamic change after endarterectomy (P < 0.05). CONCLUSIONS: Hemodynamic changes in patients with severe OCAD undergoing carotid endarterectomy suggest improvement in the ipsilateral retrobulbar blood flow.

Collateral blood supply through the ophthalmic artery: a steal phenomenon analyzed by color Doppler imaging.

OBJECTIVE: This study aimed to evaluate the retrobulbar circulatory effects of reversed ophthalmic artery flow (ROAF) on the ophthalmic artery branches by means of color Doppler imaging. DESIGN: The design was a case-controlled study. PARTICIPANTS: Among 56 consecutive patients with severe (>70% stenosis) occlusive carotid artery disease, 15 patients (26.8%) with ROAF were identified. The control group consisted of 15 patients with similar degrees of carotid artery stenosis and forward ophthalmic artery flow. INTERVENTION: Arteriography and measurement of the retrobulbar hemodynamic parameters with color Doppler imaging were performed. MAIN OUTCOME MEASURES: Blood flow velocities and resistive index in the ophthalmic, central retinal, and temporal short posterior ciliary arteries were measured. RESULTS: Arteriography confirmed the diagnosis of ROAF in all 15 patients. There was no patient with ROAF diagnosed by arteriography and not diagnosed by color Doppler imaging. The frequency of bilateral severe occlusive carotid artery disease was significantly higher in the ROAF group (40%) compared to the control group (6.6%) (P = 0.04). Patients with ROAF showed significantly reduced vascular resistance in the ophthalmic artery (P = 0.03), higher vascular resistance, and lower blood flow velocities in the central retinal and temporal short posterior ciliary arteries (P < 0.05). CONCLUSION: This study suggests that patients with ROAF show a steal phenomenon, characterized by a shunt to the low-resistance intracranial circuit and reduction of retrobulbar blood flow.

Experimental studies with perfluoro-octane for hemostasis during vitreoretinal surgery.

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.

Significado del pulso venoso espontaneo en la retina / Heaning of the spontaneous venous pulsation in the retina

El hallazgo del pulso venoso espontáneo en una o varias venas retinianas en un porcentaje apreciable de la población mundial, ha sido un fenómeno que se viene estudiando desde finales del siglo pasado. Su etiología ha sido explicada mediante diversas teorías. Con el estudio de la incidencia del pulso venoso espontáneo en pacientes y en la población general, se llegó a comprender su mecanismo de producción, y ha llegado a ser un instrumento clínico de despistaje en el campo de la neuroftalmología. Antes de entrar es su importancia clínica se deben considerar algunos aspectos

Color Doppler hemodynamics of giant cell arteritis.

OBJECTIVES: To determine quantitative and qualitative hemodynamic alterations within the ophthalmic, central retinal, and short posterior ciliary arteries in patients with giant cell arteritis (GCA) proved by biopsy specimen. DESIGN, PATIENTS, AND SETTING: A consecutive case series of patients with GCA referred to an urban eye hospital who were evaluated with color Doppler imaging that was used to analyze orbital blood flow velocities and vascular resistance in 22 consecutive patients with GCA compared with age and sex-matched controls. RESULTS: Patients with GCA all demonstrated significantly reduced central retinal and short posterior ciliary arterial mean flow velocities as well as significantly increased vascular resistance compared with matched controls. Ophthalmic artery mean flow velocity demonstrated marked variation depending on the anatomic location studied. Other color Doppler imaging characteristics of GCA included the following: ophthalmic artery aliasing (high velocity and turbulent flow at presumed focal vasculitic stenoses), reversal of flow within the ophthalmic artery, reduced and truncated time-velocity waveforms of the central retinal and short posterior ciliary arteries, and absolute deficits of flow within the central retinal and short posterior ciliary arteries. Aliasing of flow velocity within the ophthalmic artery (two patients) was associated with clinical progression of GCA. CONCLUSIONS: These data support the concept that quantitative and qualitative alterations in blood flow or pathophysiologic mechanisms of visual loss in GCA. This technique may be useful in the diagnosis and management of GCA since some of the color Doppler waveforms observed in GCA have not been seen in non-arteritic optic neuropathy. Treatment with corticosteroids often appears to stop the progression of these hemodynamic abnormalities but generally does not improve preexisting vascular abnormalities.

[Imaging of intraocular and orbital vessels using angiodynography]. / Darstellung von intraokularen und orbitalen Gefssen mittels Angiodynographie.

Color Doppler imaging (CDI) is a recent advance in ultrasonography. It allows simultaneous two-dimensional structural imaging and evaluation of blood-flow characteristics. The velocity information of the scan is extracted and added to the images as color information. A total of 20 normal eyes and 30 patients with intraocular tumors were examined with this technique. The central retinal artery, the posterior cliliary arteries, the opthalmic artery and the central retinal vein could be located in all patients. In the intraocular tumors blood flow was detected reliably. Spectrum analysis of the displayed vessels allows semiquantitative assessment of blood flow in these vessels. This new technique of color Doppler imaging offers a new modality to study ocular and orbital blood flow.

Central retinal artery occlusion without retrobulbar hemorrhage after retrobulbar anaesthesia

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)