RESUMEN
A major hurdle to therapeutic development in cerebral small vessel diseases is the lack of in-vivo method that can be used repeatedly for evaluating directly cerebral microvessels. We hypothesised that Adaptive Optics (AO), which allows resolution images up to 1-2 µm/pixel at retinal level, could provide a biomarker for monitoring vascular changes in CADASIL, a genetic form of such condition. In 98 patients and 35 healthy individuals, the wall to lumen ratio (WLR), outer and inner diameter, wall thickness and wall cross-sectional area were measured in a parapapillary and/or paramacular retinal artery. The ratio of vessel diameters before and after light flicker stimulations was also calculated to measure vasoreactivity (VR). Multivariate mixed-model analysis showed that WLR was increased and associated with a larger wall thickness and smaller internal diameter of retinal arteries in patients. The difference was maximal at the youngest age and gradually reduced with aging. Average VR in patients was less than half of that of controls since the youngest age. Any robust association was found with clinical or imaging manifestations of the disease. Thus, AO enables the detection of early functional or structural vascular alterations in CADASIL but with no obvious link to the clinical or imaging severity.
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CADASIL , Arteria Retiniana , Humanos , CADASIL/fisiopatología , CADASIL/diagnóstico por imagen , CADASIL/patología , Persona de Mediana Edad , Masculino , Femenino , Adulto , Arteria Retiniana/diagnóstico por imagen , Arteria Retiniana/fisiopatología , Arteria Retiniana/patología , Anciano , Luz , Vasodilatación/fisiología , Remodelación Vascular/fisiologíaRESUMEN
Background The associations of time-averaged cumulative blood pressure (BP) from midlife to late life with microvasculature expressed as retinal vessel diameters is not well studied. The aim of this study was to evaluate the association of cumulative systolic BP and diastolic BP (DBP) with retinal vessel calibers, focusing on race differences. Methods and Results The analysis included 1818 adults from the ARIC (Atherosclerosis Risk in Communities) study attending the fifth visit (2011-2013; age 77±5 years, 17.1% Black participants). Time-averaged cumulative BPs were calculated as the sum of averaged BPs from adjacent consecutive visits (visits 1-5) indexed to total observation time (24±1 years). Summarized estimates for central retinal arteriolar equivalent and central retinal venular equivalent at the fifth visit represent average retinal vessel diameters. The arteriole:venule ratio was calculated. We tested for effect modification by race. Results from multiple linear regression models suggested that higher time-averaged cumulative DBP (ß [95% CI] per 1-SD increase: -1.78 [-2.53, -1.02], P<0.001 and -0.005 [-0.009, -0.002], P=0.004, respectively) but not systolic BP (-0.52 [-1.30, 0.26], P=0.189 and 0.001 [-0.002, 0.005], P=0.485, respectively) was associated with smaller central retinal arteriolar equivalent and arteriole:venule ratio. The association between time-averaged cumulative DBP and arteriole:venule ratio was strongest in White participants (interaction P=0.007). The association of cumulative systolic BP and DBP with central retinal venular equivalent was strongest in Black participants (interaction P=0.015 and 0.011, respectively). Conclusions Exposure to higher BP levels, particularly DBP, from midlife to late life is associated with narrower retinal vessel diameters in late life. Furthermore, race moderated the association of cumulative BP exposure with retinal microvasculature.
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Presión Sanguínea , Hipertensión , Microvasos , Vasos Retinianos , Factores de Edad , Anciano , Anciano de 80 o más Años , Arteriolas/fisiopatología , Población Negra , Presión Sanguínea/fisiología , Diástole , Humanos , Hipertensión/complicaciones , Hipertensión/diagnóstico , Hipertensión/etnología , Hipertensión/fisiopatología , Microvasos/fisiopatología , Arteria Retiniana/fisiopatología , Vena Retiniana/fisiopatología , Vasos Retinianos/fisiopatología , Sístole , Factores de Tiempo , Vénulas/fisiopatología , Población BlancaRESUMEN
The aim of this retrospective, observational study was to examine the intraretinal locations of ruptured retinal arterial macroaneurysms (RMAs) and investigate the associations with the visual prognosis. Fifty patients (50 eyes) with untreated RMA rupture who visited the Department of Ophthalmology at Kyoto University Hospital (April 2014-July 2019) were included. The intraretinal position of the ruptured RMAs relative to the affected retinal artery was examined using optical coherence tomography (OCT) and color fundus photography (CFP). The relative RMA positions were anterior to (anterior type, 44%), at the same level as (lateral type, 20%), or posterior to (posterior type, 34%) the affected artery. At the initial visit, the posterior type showed greater subretinal hemorrhage thickness than did the lateral and anterior types (P = 0.016 and 0.006, respectively), and poorer visual acuity (VA) than did the anterior type (P = 0.005). At the final visit, the length of the foveal ellipsoid zone band defect was longer (P = 0.005) and VA was poorer (P < 0.001) for the posterior type than for the anterior type. The intraretinal positions of ruptured RMAs vary, affect the thickness of foveal subretinal hemorrhage and predict future damage to the foveal photoreceptors. The visual prognosis may be poor for posteriorly ruptured RMAs.
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Macroaneurisma Arterial de Retina/diagnóstico por imagen , Macroaneurisma Arterial de Retina/fisiopatología , Agudeza Visual , Anciano , Anciano de 80 o más Años , Femenino , Fóvea Central/diagnóstico por imagen , Fóvea Central/fisiopatología , Humanos , Arteria Retiniana/diagnóstico por imagen , Arteria Retiniana/fisiopatología , Estudios Retrospectivos , Tomografía de Coherencia ÓpticaRESUMEN
PURPOSE: The roles of vascular dysfunction and chronic stress have been extensively discussed in the pathophysiology of glaucoma. Our aim was to test whether chronic stress causes retinal vascular dysfunction and therewith induces retinal ganglion cells (RGCs) loss. METHODS: Twelve mice underwent chronic social defeat (CSD) stress, while 12 mice received control treatment only. Intraocular pressure (IOP) was measured with a rebound tonometer. Blood plasma corticosterone concentration and adrenal gland weight were used to assess stress levels. Brn-3a staining in retinas and PPD staining in optic nerve cross sections were conducted to assess the survival of RGCs and axons respectively. The ET-1 and α-SMA levels were determined in retina. Retinal vascular autoregulation, functional response to various vasoactive agents and vascular mechanics were measured using video microscopy. RESULTS: No significant difference in IOP levels was observed during and after CSD between CSD mice and controls. CSD stress caused hypercortisolemia 2 days post-CSD. However, increased corticosterone levels went back to normal 8 months after CSD. CSD-exposed mice developed adrenal hyperplasia 3 days post-CSD, which was normalized by 8 months. RGC and axon survival were similar between CSD mice and controls. However, CSD stress caused irreversible, impaired autoregulation and vascular dysfunction of retinal arterioles in CSD mice. In addition, impaired maximal dilator capacity of retinal arterioles was observed 8 months post-CSD rather than 3 days post-CSD. Remarkably, ET-1 levels were increased 3 days post-CSD while α-SMA levels were decreased 8 months post-CSD. CONCLUSIONS: We found that CSD stress does not cause IOP elevation, nor loss of RGCs and their axons. However, it strikingly causes irreversible impaired autoregulation and endothelial function in murine retinal arterioles. In addition, CSD changed vascular mechanics on a long-term basis. Increased ET-1 levels and loss of pericytes in retina vessels may involve in this process.
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Arteria Retiniana/fisiopatología , Enfermedades de la Retina/fisiopatología , Células Ganglionares de la Retina/patología , Derrota Social , Estrés Psicológico/fisiopatología , Actinas/metabolismo , Hiperplasia Suprarrenal Congénita/fisiopatología , Animales , Supervivencia Celular , Enfermedad Crónica , Corticosterona/sangre , Modelos Animales de Enfermedad , Trastorno del Desarrollo Sexual 46,XY/fisiopatología , Endotelina-1/metabolismo , Presión Intraocular/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Hipertensión Ocular/fisiopatología , Nervio Óptico/fisiopatología , Arteria Retiniana/metabolismo , Enfermedades de la Retina/metabolismo , Células Ganglionares de la Retina/metabolismo , Estrés Psicológico/metabolismo , Tonometría Ocular , Factor de Transcripción Brn-3A/metabolismo , Grabación en VideoRESUMEN
Retinal arterial macroaneurysms are characterized by the acquired fusiform or saccular dilatations of the retinal artery. Angiotensin II (Ang II) is a major signal molecule of the renin-angiotensin system, which exerts a range of pathogenic actions that are relevant to retinal vascular abnormalities. We aimed to study the effect of Ang II on retinal vessels and explore its relationship with retinal aneurysmal disease. C57BL/6J male mice were administered Ang II at 1000 ng/kg/min for 28 days, and the mice given saline served as controls. The mice in the treatment group were treated once daily by gastric gavage of candesartan cilexetil (an antagonist of Ang II type 1 (AT1) receptor) at 100 mg/kg/day. The in vivo imaging of murine retinas was performed using fundus photography, optical coherence tomography, fluorescein angiography, and indocyanine green angiography at 7th, 14th, and 28th days of infusion. At the end of the infusion and treatment, the morphological changes were evaluated by histopathological examination and electron microscopy; the levels of related proteins in murine retinas were examined by antibody array and Western blot analyses. We found that Ang II infusion induced aneurysm formation in mice retina, which presented as either solitary aneurysms or retinal arterial beading. The aneurysm formation was often accompanied with vessel leakage. Moreover, Ang II infusion itself may result in increased vascular permeability and ganglion cell and inner plexiform layer thickening. The blockade of AT1 receptors by systemic administration of candesartan cilexetil alleviated the Ang II-induced retinal vasculopathy. The protein level analysis further showed that Ang II upregulated IL-1ß, PDGFR-ß, and MMP-9 expression, and the expression of IL-1ß could be inhibited by AT1 receptor antagonist. Our study provides evidence that Ang II is a crucial factor in retinal aneurysm formation and vessel leakage. It is probably the combined effect of Ang II on vessel inflammatory response, pericyte function, and extracellular matrix remodeling that predisposes the retinal arterial wall to aneurysm formation and blood-retinal barrier breakdown.
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Angiotensina II/fisiología , Macroaneurisma Arterial de Retina/metabolismo , Arteria Retiniana/fisiopatología , Vasoconstrictores/metabolismo , Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Animales , Bencimidazoles/farmacología , Compuestos de Bifenilo/farmacología , Presión Sanguínea/fisiología , Barrera Hematorretinal , Western Blotting , Colorantes/administración & dosificación , Modelos Animales de Enfermedad , Angiografía con Fluoresceína , Verde de Indocianina/administración & dosificación , Interleucina-1beta/metabolismo , Masculino , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones , Ratones Endogámicos C57BL , Receptor de Angiotensina Tipo 1/metabolismo , Receptor de Angiotensina Tipo 2/metabolismo , Receptor beta de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Macroaneurisma Arterial de Retina/diagnóstico , Macroaneurisma Arterial de Retina/tratamiento farmacológico , Tetrazoles/farmacología , Tomografía de Coherencia ÓpticaRESUMEN
Central retinal artery occlusion (CRAO) is a form of acute ischemic stroke which affects the retina. Intravenous thrombolysis is emerging as a compelling therapeutic approach. However, it is not known which patients may benefit from this therapy because there are no imaging modalities that adequately distinguish viable retina from irreversibly infarcted retina. The inner retina receives arterial supply from the central retinal artery and there is robust collateralization between this circulation and the outer retinal circulation, provided by the posterior ciliary circulation. Fundus photography can show canonical changes associated with CRAO including a cherry-red spot, arteriolar boxcarring and retinal pallor. Fluorescein angiography provides 2-dimensional imaging of the retinal circulation and can distinguish a complete from a partial CRAO as well as central versus peripheral retinal non-perfusion. Transorbital ultrasonography may assay flow through the central retinal artery and is useful in the exclusion of other orbital pathology that can mimic CRAO. Optical coherence tomography provides structural information on the different layers of the retina and exploratory work has described its utility in determining the time since onset of ischemia. Two experimental techniques are discussed. 1) Retinal functional imaging permits generation of capillary perfusion maps and can assay retinal oxygenation and blood flow velocity. 2) Photoacoustic imaging combines the principles of optical excitation and ultrasonic detection and - in animal studies - has been used to determine the retinal oxygen metabolic rate. Future techniques to determine retinal viability in clinical practice will require rapid, easily used, and reproducible methods that can be deployed in the emergency setting.
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Angiografía con Fluoresceína , Imagen de Perfusión , Fotograbar , Oclusión de la Arteria Retiniana/diagnóstico por imagen , Arteria Retiniana/diagnóstico por imagen , Tomografía de Coherencia Óptica , Ultrasonografía , Animales , Velocidad del Flujo Sanguíneo , Toma de Decisiones Clínicas , Circulación Colateral , Humanos , Técnicas Fotoacústicas , Valor Predictivo de las Pruebas , Pronóstico , Flujo Sanguíneo Regional , Arteria Retiniana/fisiopatología , Oclusión de la Arteria Retiniana/fisiopatología , Oclusión de la Arteria Retiniana/terapiaAsunto(s)
Drusas del Disco Óptico/complicaciones , Disco Óptico/irrigación sanguínea , Arteria Retiniana/fisiopatología , Enfermedades de la Retina/complicaciones , Oclusión de la Vena Retiniana/etiología , Adulto , Inhibidores de la Angiogénesis/uso terapéutico , Colorantes/administración & dosificación , Femenino , Angiografía con Fluoresceína , Humanos , Verde de Indocianina/administración & dosificación , Inyecciones Intravítreas , Edema Macular/diagnóstico , Edema Macular/tratamiento farmacológico , Edema Macular/etiología , Drusas del Disco Óptico/diagnóstico por imagen , Receptores de Factores de Crecimiento Endotelial Vascular/uso terapéutico , Proteínas Recombinantes de Fusión/uso terapéutico , Arteria Retiniana/diagnóstico por imagen , Enfermedades de la Retina/diagnóstico por imagen , Enfermedades de la Retina/fisiopatología , Oclusión de la Vena Retiniana/diagnóstico , Oclusión de la Vena Retiniana/tratamiento farmacológico , Tomografía de Coherencia Óptica , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidoresRESUMEN
PURPOSE: To evaluate association between ocular blood flow biomarkers and lamina cribrosa parameters in normotensive glaucoma suspects compared to glaucoma patients and healthy controls. METHODS: A total of 211 subjects (72 normotensive glaucoma suspects, 70 with primary open-angle glaucoma and 69 controls) were included. Ocular blood flow biomarkers in ophthalmic artery, central retinal artery, as well as in nasal and temporal short posterior ciliary arteries were measured using colour Doppler imaging. Lamina cribrosa position was assessed by measuring its depth, deflection depth, lamina cribrosa shape index and its horizontal equivalent (LCSIH) on B-scan images obtained using optical coherence tomography. RESULTS: Ocular blood flow biomarkers in glaucoma patients were statistically significantly reduced when compared to healthy controls in peak systolic velocity (PSV) (P = 0.001 in ophthalmic artery and P<0.001 in central retinal artery) and mean flow velocity (Vm) (P = 0.008 in ophthalmic artery and P = 0.008 in central retinal artery), but not statistically significantly different to that of glaucoma suspects except for PSV in central retinal artery (P = 0.011). Statistically significant correlations corrected for age, central corneal thickness and intraocular pressure were found in glaucoma patients between LCSIH and end diastolic velocity of central retinal artery (P = 0.011), and of nasal short posterior ciliary artery (P = 0.028), and between LCSIH and Vm of central retinal artery (P = 0.011) and of nasal short posterior ciliary artery (P = 0.007). No significant correlations were observed between these parameters in glaucoma suspects and healthy controls. CONCLUSIONS: Impaired ocular blood flow associated with the deformation of lamina cribrosa was found in glaucoma patients, whereas glaucoma suspects had similar lamina cribrosa shape to glaucoma patients but that deformation was not associated with ocular blood flow biomarkers.
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Biomarcadores/metabolismo , Ojo/irrigación sanguínea , Glaucoma/sangre , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Ojo/fisiopatología , Femenino , Glaucoma/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Hipertensión Ocular/fisiopatología , Flujo Sanguíneo Regional , Arteria Retiniana/diagnóstico por imagen , Arteria Retiniana/patología , Arteria Retiniana/fisiopatología , Ultrasonografía Doppler en ColorAsunto(s)
Angiografía con Fluoresceína/métodos , Flujo Sanguíneo Regional/fisiología , Oclusión de la Arteria Retiniana/fisiopatología , Arteria Retiniana/fisiopatología , Tomografía de Coherencia Óptica/métodos , Adulto , Femenino , Fondo de Ojo , Humanos , Arteria Retiniana/diagnóstico por imagen , Oclusión de la Arteria Retiniana/diagnósticoAsunto(s)
Arterias Ciliares/diagnóstico por imagen , Angiografía con Fluoresceína , Presión Intraocular , Hipertensión Ocular/complicaciones , Fotograbar , Flujo Pulsátil , Oclusión de la Arteria Retiniana/diagnóstico por imagen , Arteria Retiniana/diagnóstico por imagen , Adulto , Arterias Ciliares/fisiopatología , Humanos , Masculino , Hipertensión Ocular/diagnóstico por imagen , Hipertensión Ocular/fisiopatología , Valor Predictivo de las Pruebas , Arteria Retiniana/fisiopatología , Oclusión de la Arteria Retiniana/etiología , Oclusión de la Vena Retiniana/etiologíaRESUMEN
Background: We evaluated ocular hemodynamic changes, malondialdehyde(MDA) and vascular endothelial growth factor (VEGF) levels in patients with IBD.Methods: We used ocular color Doppler ultrasonography to analyze 56 eyes with Crohn's disease (CD), 62 eyes with ulcerative colitis (UC), 68 eyes of healthy volunteers. We measured peak systolic velocity (PSV),end-diastolic velocity (EDV),and the resistivity index (RI) of ophthalmic artery (OA) and central retinal artery (CRA). MDA and VEGF levels were measured in the plasma samples.Results: MDA levels were significantly higher in both UC and CD patients, whereas VEGF levels were only higher in the CD group (p = .003,p < .001,p = .01).The PSV and EDV of the OA were significantly lower in CD patients (p = .017,p = .001). The EDV of the CRA was significantly lower in CD patients than UC patients and controls (p = .014,p < .001).Conclusions: CD patients exhibited decreased blood flow in both the OA and CRA. Ocular vascular flow was only affected in CD patients. We found that ocular ischemia may occur in CD patients even in the absence of any clinical finding.
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Colitis Ulcerosa/fisiopatología , Enfermedad de Crohn/fisiopatología , Malondialdehído/sangre , Arteria Oftálmica/fisiopatología , Arteria Retiniana/fisiopatología , Factor A de Crecimiento Endotelial Vascular/sangre , Adolescente , Adulto , Colitis Ulcerosa/sangre , Enfermedad de Crohn/sangre , Femenino , Hemodinámica , Humanos , Presión Intraocular , Masculino , Persona de Mediana Edad , Flujo Sanguíneo Regional/fisiología , Ultrasonografía Doppler en Color , Adulto JovenRESUMEN
Purpose: Although it is known that the retinal arteriolar vasculature is constricted in hypertension, the details of retinal hemodynamics and perfusion of the retinal circulation have yet to be adequately characterized. Methods: Male and female spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) controls were anesthetized before measurements of mean arterial blood pressure and preparation for intravital microscopy of the retinal microcirculation. Retinal vascular velocities were measured with the use of fluorescent microspheres, and diameters and mean circulation times were measured after the infusion of fluorescent dextran. Arteriolar and venular shear rates were calculated from the ratio of velocity to diameter. Results: In the retinas of SHR, velocities were elevated (compared with control WKY) in arterioles, but not in venules. Both arteriolar and venular diameters were significantly smaller in SHR versus WKY, with substantial increases in shear rates. Despite a tendency toward lower retinal blood flow rates, the mean circulation time through the SHR retina was much faster than can be explained by the measured arteriolar and venular velocities. Conclusions: The pattern of hypertension-induced increases in blood velocity, dissipating from the arteriolar to venular side of the retinal circulation, indicates a potential transfer of the extra kinetic energy through the vasculature. The combination of elevated velocities through narrower retinal arterioles resulted in a markedly higher level of wall shear rate that may induce changes in the vessel wall. Finally, significantly more rapid transits through the hypertensive retina could be a result of altered blood flow distribution.
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Hipertensión/fisiopatología , Arteria Retiniana/fisiopatología , Animales , Arteriolas/fisiopatología , Tiempo de Circulación Sanguínea , Velocidad del Flujo Sanguíneo/fisiología , Presión Sanguínea/fisiología , Femenino , Colorantes Fluorescentes , Hemodinámica/fisiología , Masculino , Microcirculación , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKYRESUMEN
To evaluate retrobulbar hemodynamics in patients with optic disc drusen (ODD) by color Doppler imaging. A prospective study included 52 patients with bilateral ODD and 50 age-matched controls. Blood flow in the central retinal artery (CRA) in both eyes was evaluated. Peak-systolic velocity (PSV), end-diastolic velocity (EDV), and the resistivity index (RI) were measured. Mean values of the blood flow Doppler parameters were compared between the patients with ODD and the controls. Both PSV and EDV in the CRA were significantly lower in patients with ODD than in the controls (p < 0.001). The RI in the CRA of ODD patients was significantly higher than in the controls (p < 0.001). Women with ODD presented with significantly lower values of PSV and EDV than men (p = 0.05 and p = 0.03, respectively). Arterial hypertension, cigarette smoking and location of ODD in the left or right eye did not exert a significant effect on the blood flow in the CRA. Blood flow in the CRA is considerably disturbed in patients with ODD. This disturbance might result from mechanical stenosis of the vascular wall caused by the drusen. Color Doppler ultrasound is a useful method in the assessment of retrobulbar hemodynamics in ODD.
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Velocidad del Flujo Sanguíneo , Hemodinámica , Drusas del Disco Óptico/patología , Flujo Sanguíneo Regional , Arteria Retiniana/fisiopatología , Adulto , Estudios de Casos y Controles , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Drusas del Disco Óptico/sangre , Pronóstico , Estudios Prospectivos , Ultrasonografía Doppler en ColorRESUMEN
The effect of various combinations of cervical arterial ligations (Combinations) on retinal blood flow (RBF) levels is not known in rats. We hypothesized: 1) No artery exists between the Circle of Willis and the eye, 2) Selective Combinations enable varying RBF levels between normal and zero, 3) In certain Combinations, the capillary bed of the head participates in supplying the eye. Twenty-six Combinations were studied in one eye of 20 Long-Evans rats under general anesthesia. RBF was quantitatively evaluated with our published imaging methods based on direct measurements of venous diameter and blood velocity from the displacement of fluorescent microspheres over time. For each Combination, one or more RBF values (runs) were measured. Data were obtained from 59 runs (2.9 ± 2.7 runs/rat). Levels of RBF ranged from normal to zero. An artery between the Circle of Willis and the eye was excluded. With some Combinations, flow traversed the capillary bed. Combinations were consolidated into five Groups based on the blood flow paths remaining after the ligations. A mixed linear model accounting for multiple measurements in the same eye demonstrated an effect of Group on RBF (P < 0.0005). By major source of ocular blood supply, the trend of RBF levels was: ipsilateral carotid artery > contralateral carotid artery > ipsilateral distal internal carotid artery retrograde from Circle of Willis. The findings advanced knowledge of the sources of blood supply to the rat eye and demonstrated a method of selective cervical arterial ligations for varying RBF levels with potential to impact future retinal ischemia research.
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Velocidad del Flujo Sanguíneo/fisiología , Flujo Sanguíneo Regional/fisiología , Retina/fisiopatología , Arteria Retiniana/cirugía , Enfermedades de la Retina/fisiopatología , Animales , Modelos Animales de Enfermedad , Ligadura , Masculino , Ratas , Ratas Long-Evans , Arteria Retiniana/fisiopatologíaAsunto(s)
Angiografía con Fluoresceína/métodos , Degeneración Macular/diagnóstico , Arteria Retiniana/fisiopatología , Tomografía de Coherencia Óptica/métodos , Vasodilatación/fisiología , Enfermedad Aguda , Anciano , Fondo de Ojo , Humanos , Degeneración Macular/fisiopatología , Masculino , Arteria Retiniana/diagnóstico por imagenRESUMEN
The aim of the current study is to identify possible new Ocular Response Analyzer (ORA) waveform parameters related to changes of retinal structure/deformation, as measured by the peripapillary retinal arteries angle (PRAA), using a generative deep learning method of variational autoencoder (VAE). Fifty-four eyes of 52 subjects were enrolled. The PRAA was calculated from fundus photographs and was used to train a VAE model. By analyzing the ORA waveform reconstructed (noise filtered) using VAE, a novel ORA waveform parameter (Monot1-2), was introduced, representing the change in monotonicity between the first and second applanation peak of the waveform. The variables mostly related to the PRAA were identified from a set of 41 variables including age, axial length (AL), keratometry, ORA corneal hysteresis, ORA corneal resistant factor, 35 well established ORA waveform parameters, and Monot1-2, using a model selection method based on the second-order bias-corrected Akaike information criterion. The optimal model for PRAA was the AL and six ORA waveform parameters, including Monot1-2. This optimal model was significantly better than the model without Monot1-2 (p = 0.0031, ANOVA). The current study suggested the value of a generative deep learning approach in discovering new useful parameters that may have clinical relevance.
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Córnea/diagnóstico por imagen , Glaucoma de Ángulo Abierto/diagnóstico , Retina/diagnóstico por imagen , Arteria Retiniana/diagnóstico por imagen , Tonometría Ocular/métodos , Adulto , Anciano , Anciano de 80 o más Años , Córnea/irrigación sanguínea , Córnea/fisiopatología , Técnicas de Diagnóstico Oftalmológico/tendencias , Femenino , Glaucoma de Ángulo Abierto/diagnóstico por imagen , Glaucoma de Ángulo Abierto/fisiopatología , Humanos , Presión Intraocular/fisiología , Masculino , Persona de Mediana Edad , Retina/fisiopatología , Arteria Retiniana/fisiopatologíaRESUMEN
BACKGROUND: Diabetic retinopathy is characterised by morphological lesions in the retina secondary to disturbances in retinal blood flow. Previous studies have shown that the carbonic anhydrase inhibitor (CAI) dorzolamide can induce immediate dilatation of retinal arterioles and a sustained increase in retinal blood flow in primary open-angle glaucoma. However, the effect of sustained treatment with CAI on retinal arterioles in normal persons and in patients with diabetic retinopathy is unknown. METHODS: The Dynamic Vessel Analyzer was used to assess the baseline diameter and the diameter response of retinal arterioles during an increase in arterial blood pressure induced by isometric exercise and during flicker stimulation before and 2 h, 24 h and 1 week after onset of topical treatment with dorzolamide. At each examination the diameter responses were studied before and during breathing in of a hypercapnic gas mixture. RESULTS: Treatment with dorzolamide for 1 week significantly increased the diameter of retinal arterioles in normal persons, and breathing in of a hypercapnic gas mixture reduced this response. The pathological vasodilatation and reduced retinal autoregulation in patients with diabetic retinopathy were unaffected by dorzolamide and hypercapnia. CONCLUSIONS: The study suggests a lack of relevance of CAI for the treatment of pathological vasodilatation in early diabetic retinopathy.
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Inhibidores de Anhidrasa Carbónica/administración & dosificación , Diabetes Mellitus Tipo 1/fisiopatología , Retinopatía Diabética/fisiopatología , Arteria Retiniana/fisiopatología , Sulfonamidas/administración & dosificación , Tiofenos/administración & dosificación , Vasodilatación/efectos de los fármacos , Administración Oftálmica , Adulto , Arteriolas/fisiopatología , Presión Sanguínea/fisiología , Femenino , Homeostasis/fisiología , Humanos , Presión Intraocular/efectos de los fármacos , Masculino , Soluciones Oftálmicas , Estudios Prospectivos , Flujo Sanguíneo Regional/fisiologíaRESUMEN
INTRODUCTION: To identify novel velocity waveform parameters of the ophthalmic artery and central retinal artery by computer-aided image processing of Doppler ultrasonography measurements, and to evaluate correlations between the waveform parameters and different demographics and disease severity of open-angle glaucoma patients. METHODS: Thirty-six images of 36 open-angle glaucoma patients were considered. A semiautomated image processing code was used to detect the digitalized ophthalmic artery and central retinal artery velocity waveforms and to extract the waveform parameters. Concordance correlation coefficient, two-sample t-test, and Pearson's correlation coefficient were used to test for similarities, differences, and associations among variables. RESULTS: Female glaucoma patients showed a statistically higher ophthalmic artery normalized distance between ascending and descending limb (p = 0.004), hypertensive glaucoma patients a statistically higher ophthalmic artery peak systolic velocity time (p = 0.025), glaucoma patients with hyperlipidemia a statistically higher ophthalmic artery resistivity index (p = 0.023) and a statistically higher ophthalmic artery peak systolic velocity acceleration (p = 0.025), glaucoma patients with cardiovascular diseases a statistically lower central retinal artery normalized distance between ascending and descending limb of the wave (p = 0.033) and a statistically higher central retinal artery period (p = 0.028), and patients with different body mass index a statistically different central retinal artery normalized distance between ascending and descending limb of the wave (p = 0.016). Groups with different disease severity, classified following the Brusini glaucoma staging system 2, showed statistically different central retinal artery normalized distance between ascending and descending limb of the wave (p < 0.001) and central retinal artery period (p = 0.016). No statistical differences were found in regard to race, diabetes status, glaucoma family history, and smoking. DISCUSSION: Ophthalmic artery and central retinal artery computer-aided analysis of velocity waveforms could identify novel waveform parameters capable of differentiating among different demographics and disease severity of open-angle glaucoma patients.
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Glaucoma de Ángulo Abierto/fisiopatología , Arteria Oftálmica/fisiopatología , Arteria Retiniana/fisiopatología , Anciano , Anciano de 80 o más Años , Velocidad del Flujo Sanguíneo/fisiología , Femenino , Glaucoma de Ángulo Abierto/diagnóstico por imagen , Humanos , Procesamiento de Imagen Asistido por Computador , Presión Intraocular/fisiología , Masculino , Persona de Mediana Edad , Arteria Oftálmica/diagnóstico por imagen , Disco Óptico/irrigación sanguínea , Arteria Retiniana/diagnóstico por imagen , Ultrasonografía Doppler en ColorRESUMEN
PURPOSE: Transorbital sonography easily detects papilledema and enlarged optic nerve sheath diameters (ONSD) in IIH (idiopathic intracranial hypertension) patients. As the central retinal artery is located within the optic nerve, its hemodynamic properties might be affected by the increased pressure. In this study we assessed the diagnostic usefulness of transorbital sonography in IIH with a special focus on color Doppler imaging of the central retinal artery. IIH patients presented papilledema and enlarged ONSD. ONSD accurately predicted an increased intracranial pressure in IIH (cut-off: 5.8â¯mm, 81% sensitivity, 80% specificity). 24â¯h following therapeutic lumbar puncture ONSD diminished significantly, whereas papilledema was not changed. PSV (peak systolic velocity) and Vmean (mean flow velocity) of the central retinal artery were increased in IIH patients compared to controls. PSV accurately predicted an increase of intracranial pressure (cut-off: 11.0â¯cm/s, 70% sensitivity, 69% specificity). PI (pulsatility index), PSV and Vmean decreased following lumbar puncture. PSV and Vmean decreases were statistically significant for right eyes only in which the values changed to normal. In summary, besides ONSD enlargement and papilledema transbulbar sonography demonstrated an alteration of central retinal artery blood flow in IIH patients. Especially PSV might serve as valuable surrogate marker for intracranial pressure in IIH. Furthermore, the change of intra-individual central retinal arteries PI might be a valuable parameter to demonstrate response to lumbar puncture in IIH patients.
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Nervio Óptico/diagnóstico por imagen , Seudotumor Cerebral/diagnóstico por imagen , Arteria Retiniana/diagnóstico por imagen , Ultrasonografía/métodos , Adulto , Femenino , Hemodinámica , Humanos , Presión Intracraneal , Masculino , Persona de Mediana Edad , Arteria Retiniana/fisiopatologíaRESUMEN
PURPOSE: To report a case of inducible transient central retinal artery vasospasm with associated imaging. METHODS: Observational case report. RESULTS: A 51-year-old man presented for outpatient follow-up for recurrent inducible transient vision loss in his right eye. He experienced an episode during examination and was found to have central retinal artery vasospasm. Fundus photography and fluorescein angiography obtained during his vasospastic attack confirmed retinal arterial vasospasm. Treatment with a calcium-channel blocker (nifedipine) has been effective in preventing recurrent attacks. CONCLUSION: Idiopathic primary vasospasm is a rare cause of transient vision loss that is difficult to confirm because of the transient nature. We obtained imaging showing the initiation and resolution of the vasospastic event. The patient was then successfully treated with a calcium-channel blocker.