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1.
Microvasc Res ; 148: 104535, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37024073

RESUMO

Impairments of blood flow and autoregulation have been implicated in diabetic retinopathy and glaucoma. Thus, identifying biomarkers of retinal vascular compliance and regulatory capacity is of potential value for understanding the pathophysiology and evaluating onset or progression of disease. Pulse wave velocity (PWV) represents the speed of the pulse-propagated pressure wave within blood vessels and has shown promise as a marker of vascular compliance. The purpose of the current study was to report a method for comprehensive assessment of retinal PWV based on spectral analysis of pulsatile intravascular intensity waveforms and determine alterations due to experimental ocular hypertension. Retinal PWV was linearly related to vessel diameter. Increased retinal PWV was associated with elevated intraocular pressure. Retinal PWV has the potential to serve as a vasoregulation biomarker for investigating vascular factors that contribute to the development of retinal diseases in animal models.


Assuntos
Glaucoma , Hipertensão , Hipertensão Ocular , Humanos , Análise de Onda de Pulso , Velocidade do Fluxo Sanguíneo , Resistência Vascular/fisiologia , Hipertensão Ocular/diagnóstico , Biomarcadores , Pressão Sanguínea/fisiologia
2.
Exp Eye Res ; 230: 109439, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36931487

RESUMO

We here attempt to improve quantification of the ischemic retinal insult, that is, what is imposed on the retinal tissue by ischemia, especially in experimental models of ischemia. The ischemic retinal insult initiates the ischemic retinal injury (or outcome). Accordingly, it is reasonable to assume that the better the quantification of the insult, the better the correlation with, and thereby estimation of, the injury. The insult seldom has been quantified in terms of the relevant physiological factors, especially in connection with the rate of oxygen delivery (DO2). We here propose the accumulated oxygen deficit (AO2D) as an indicator of the ischemic retinal insult. We hypothesized that AO2D is correlated with the rate of oxygen metabolism measured 1 h after reperfusion following an episode of ischemia (MO2_1_Hr). Previously, we showed that MO2_1_Hr is related to the electroretinogram amplitude and the retinal thickness when they are measured seven days after reperfusion. We studied 27 rats, as well as 26 rats from our published data on retinal ischemia in which we had measurements of DO2 and duration of ischemia (T) of various levels and durations. We also measured DO2 in 29 rats treated with sham surgery. Ischemia was induced by either ipsilateral or bilateral common carotid artery occlusion or by ophthalmic artery occlusion, which gave a wide range of DO2. DO2 and MO2_1_Hr were evaluated based on three types of images: 1) red-free images to measure vessel diameters, 2) fluorescence images to estimate blood velocities by the displacement of intravascular fluorescent microspheres over time, and 3) phosphorescence images to quantify vascular oxygen tension from the phosphorescence lifetime of an intravascular oxygen sensitive phosphor. Loss of oxygen delivery (DO2L) was calculated as the difference between DO2 under normal/sham condition and DO2 during ischemia. AO2D, a volume of oxygen, was calculated as the product DO2L and T. Including all data, the linear relationship between AO2D and MO2_1_Hr was significant (R2 = 0.261, P = 0.0003). Limiting data to that in which T or DO2L was maximal also yielded significant relationships, and revealed that DO2L at a long duration of ischemia contributed disproportionately more than T to MO2_1_Hr. We discuss the potential of AO2D for quantifying the ischemic retinal insult, predicting the ischemic retinal injury and evaluating the likelihood of infarction.


Assuntos
Oxigênio , Doenças Retinianas , Ratos , Animais , Oxigênio/metabolismo , Retina/metabolismo , Doenças Retinianas/metabolismo , Vasos Retinianos/metabolismo , Isquemia/metabolismo
3.
Exp Eye Res ; 225: 109278, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36252653

RESUMO

Ischemia-reperfusion (I/R) is an established model for retinal neurodegeneration. However, there is limited knowledge of retinal physiological metrics and their relationships to retinal function and morphology in the I/R model. The purpose of the study was to test the hypotheses that retinal hemodynamic and oxygen metrics are impaired and associated with visual dysfunction, retinal thinning, and retinal ganglion cell (RGC) loss due to I/R injury. Intraocular pressure (IOP) was increased in one eye of 10 rats for 90 min followed by reperfusion. Fellow eyes served as controls. After one week of reperfusion, multimodal imaging was performed to quantify total retinal blood flow (TRBF) and retinal vascular oxygen contents. Retinal oxygen delivery (DO2) and metabolism (MO2) were calculated. Pattern-evoked electroretinography (PERG) and optical coherence tomography were performed to measure RGC function and retinal thicknesses, respectively. RGCs were counted from retina whole mounts. After one week of reperfusion, TRBF was lower in study eyes than in control eyes (p < 0.0003). Similarly, DO2 and MO2 were reduced in study eyes compared to control eyes (p < 0.003). PERG amplitude, TRT, IRT, ORT, and RGCs were also lower in study eyes (p ≤ 0.01). DO2 and MO2 were correlated with PERG amplitude, TRT, IRT, and ORT (r ≥ 0.6, p ≤ 0.005). The findings improve knowledge of physiological metrics affected by I/R injury and have the potential for identifying biomarkers of injury and outcomes for evaluating experimental treatments.


Assuntos
Glaucoma , Hipertensão Ocular , Traumatismo por Reperfusão , Ratos , Animais , Oxigênio/metabolismo , Benchmarking , Retina/metabolismo , Hipertensão Ocular/metabolismo , Traumatismo por Reperfusão/metabolismo , Reperfusão , Isquemia/metabolismo , Hemodinâmica , Eletrorretinografia , Modelos Animais de Doenças
4.
Exp Eye Res ; 205: 108480, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33539865

RESUMO

The retinal degeneration 1 (rd1) mouse is a well-established model of inherited retinal degeneration, displaying photoreceptor degeneration and retinal vasculature damage. The purpose of the current study was to determine alterations in the rate of oxygen delivery from retinal circulation (DO2), the rate of oxygen extraction from the retinal circulation for metabolism (MO2), and oxygen extraction fraction (OEF) in rd1 mice. The study was performed in a total of 18 wild type (WT) and 10 rd1 mice at both 3-weeks and 12-weeks of age. Retinal arterial and venous oxygen contents (O2A and O2V) were measured using phosphorescence lifetime imaging. Total retinal blood flow (TRBF) was determined by fluorescence and red-free imaging. DO2 and MO2 were determined as TRBF × O2A and TRBF × (O2A-O2V), respectively. OEF was calculated as MO2/DO2. The thickness of individual retinal layers was measured from histology sections and inner retina (IR) and total retina (TR) thickness were calculated. TRBF, DO2 and MO2 were lower in rd1 mice compared to WT mice (P ≤ 0.001), whereas OEF was not significantly different between rd1 and WT mice (P = 0.4). TRBF and DO2 were lower at 3-weeks of age compared to 12-weeks of age (P ≤ 0.01), while MO2 was not significantly different between age groups (P = 0.4) and OEF was higher at 3-weeks of age compared to 12-weeks of age (P = 0.003). Additionally, the outer and inner retinal cell layer thicknesses were decreased in rd1 mice at 12-weeks of age compared to both age-matched WT mice and rd1 mice at 3-weeks of age (P ≤ 0.02). MO2 was directly correlated with both IR and TR thickness (R ≥ 0.50; P ≤ 0.03, N = 20). The findings indicate that the rate oxygen is supplied by the retinal circulation is decreased and the reduction in oxygen extracted for metabolism is related to retinal cell layer thinning in rd1 mice.


Assuntos
Modelos Animais de Doenças , Oxigênio/sangue , Retina/patologia , Degeneração Retiniana/fisiopatologia , Vasos Retinianos/fisiologia , Animais , Feminino , Masculino , Camundongos , Camundongos Mutantes , Tamanho do Órgão , Consumo de Oxigênio/fisiologia , Fluxo Sanguíneo Regional/fisiologia
5.
Retina ; 38(9): 1652-1667, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29135799

RESUMO

PURPOSE: To describe the features of peripapillary pachychoroid syndrome (PPS), a novel pachychoroid disease spectrum (PDS) entity. METHODS: Medical records of 31 eyes (16 patients) with choroidal thickening associated with intraretinal and/or subretinal fluid in the nasal macula extending from the disk were reviewed (patients with PPS). Choroidal thickness was compared with 2 age-matched cohorts: typical PDS (17 eyes with central serous chorioretinopathy or pachychoroid neovasculopathy) and 19 normal eyes. RESULTS: The patients with PPS were 81% men aged 71 ± 7 years. Peripapillary pachychoroid syndrome eyes displayed thicker nasal versus temporal macular choroids, unlike PDS eyes with thicker temporal macular choroids (P < 0.0001). Peripapillary intraretinal and/or subretinal fluid was often overlying dilated Haller layer vessels (pachyvessels). Fundus autofluorescence and fluorescein angiography illustrated peripapillary pigmentary mottling without focal leakage. Most PPS eyes (70%) exhibited other PDS findings including serous pigment epithelial detachment or gravitational tracks. Indocyanine green angiography illustrated dilated peripapillary pachyvessels and choroidal hyperpermeability. The disk was usually crowded, with edema noted in 4/31 (13%) eyes and mild late fluorescein disk leakage identified in half of the cases. Choroidal folds (77%), short axial lengths (39% less than 23 mm), and hyperopia (86%) were common. CONCLUSION: Peripapillary pachychoroid syndrome is a distinct PDS variant, in which peripapillary choroidal thickening is associated with nasal macular intraretinal and/or subretinal fluid and occasional disk edema. Recognition of PPS is important to distinguish it from disorders with overlapping features such as posterior uveitis and neuro-ophthalmologic conditions.


Assuntos
Doenças da Coroide/diagnóstico , Corioide/patologia , Angiofluoresceinografia/métodos , Macula Lutea/patologia , Disco Óptico/patologia , Tomografia de Coerência Óptica/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Fundo de Olho , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Síndrome
6.
Hum Factors ; 58(1): 43-57, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26857436

RESUMO

OBJECTIVE: The aim of this study is to identify the interdependencies of human and organizational subsystems of multiple complex, safety-sensitive technological systems and their interoperability in the context of sustainability and resilience of an ecosystem. BACKGROUND: Recent technological disasters with severe environmental impact are attributed to human factors and safety culture causes. One of the most populous and environmentally sensitive regions in the world, the (Persian) Gulf, is on the confluence of an exponentially growing number of two industries--nuclear power and seawater desalination plants--that is changing its land- and seascape. METHOD: Building upon Rasmussen's model, a macrosystem integrative framework, based on the broader context of human factors, is developed, which can be considered in this context as a "meta-ergonomics" paradigm, for the analysis of interactions, design of interoperability, and integration of decisions of major actors whose actions can affect safety and sustainability of the focused industries during routine and nonroutine (emergency) operations. CONCLUSION: Based on the emerging realities in the Gulf region, it is concluded that without such systematic approach toward addressing the interdependencies of water and energy sources, sustainability will be only a short-lived dream and prosperity will be a disappearing mirage for millions of people in the region. APPLICATION: This multilayered framework for the integration of people, technology, and ecosystem--which has been applied to the (Persian) Gulf--offers a viable and vital approach to the design and operation of large-scale complex systems wherever the nexus of water, energy, and food sources are concerned, such as the Black Sea.


Assuntos
Meio Ambiente , Ergonomia , Energia Nuclear , Animais , Humanos , Oceano Índico , Energia Renovável , Alimentos Marinhos , Água do Mar
7.
Retina ; 35(6): 1247-55, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25763464

RESUMO

PURPOSE: To evaluate anatomical and functional outcomes of pneumatic retinopexy (PR) for primary repair of rhegmatogenous retinal detachments and to determine demographic and ocular risk factors for failure of the procedure. DESIGN: Retrospective interventional case series. METHODS: A chart review on 97 eyes of 97 consecutive patients who had undergone PR as the initial procedure for unilateral recent primary retinal detachments with causative break(s) in the superior two-third of the retina. After injection of 0.35 mL to 0.60 mL of sulfur hexafluoride, 6 hours face-down positioning, and the steamroller maneuver, the patient's head position was changed so that the gas could efficiently tamponade the retinal break(s). Pre- and post-gas injection laser photocoagulation of break(s) and 360° peripheral retina was applied. RESULTS: Seventy-two male and 25 female patients were included in this study. The single-operation success rate was 82.5%. The pars plana vitrectomy procedure as the second intervention was not adversely affected by the preceding PR. Presence of proliferative vitreoretinopathy (odds ratio: 58.7, 95% confidence interval: 7.8-443.5) and delay between initial symptoms and PR (odds ratio: 1.21 per each additional day, 95% confidence interval: 1.07-1.37) were the only independent predictors for the failure. CONCLUSION: With proper selection of cases, PR is a good surgical option for primary rhegmatogenous retinal detachments with acceptable success rate, minimal discomfort to the patient, and minimal surgical risks.


Assuntos
Tamponamento Interno , Procedimentos Cirúrgicos Oftalmológicos , Descolamento Retiniano/cirurgia , Hexafluoreto de Enxofre/administração & dosagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos , Decúbito Ventral , Descolamento Retiniano/fisiopatologia , Estudos Retrospectivos , Fatores de Risco , Falha de Tratamento , Acuidade Visual/fisiologia
8.
Sci Rep ; 14(1): 4414, 2024 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-38388657

RESUMO

Previous studies have reported increased retinal venous oxygen saturation and decreased retinal blood flow and oxygen metabolism in non-proliferative diabetic retinopathy (NPDR). The current study aimed to determine alterations in both inner retinal oxygen delivery (DO2) and metabolism (MO2) in proliferative DR (PDR) as well as at stages of NPDR. A total of 123 subjects participated in the study and were categorized into five groups: non-diabetic control (N = 32), diabetic with no diabetic retinopathy (NDR, N = 34), mild NPDR (N = 31), moderate to severe NPDR (N = 17), or PDR (N = 9). Multi-modal imaging was performed to measure oxygen saturation and blood flow, which were used for derivation of DO2 and MO2. There were significant associations of groups with DO2 and MO2. DO2 was lower in PDR and not significantly different in NDR and NPDR stages as compared to the non-diabetic control group. MO2 was decreased in PDR and moderate to severe NPDR as compared to the control group, and not significantly reduced in NDR and mild NPDR. The findings demonstrate reductions in both DO2 and MO2 in PDR and MO2 in moderate to severe NPDR, suggesting their potential as biomarkers for monitoring progression and treatment of DR.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Humanos , Retinopatia Diabética/metabolismo , Retina/metabolismo , Oximetria , Biomarcadores , Oxigênio/metabolismo
9.
Int J Fertil Steril ; 18(3): 201-206, 2024 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-38973271

RESUMO

BACKGROUND: Following COVID-19 vaccination, some women suffered from menstrual cycle disturbances. This study aimed to investigate menstrual cycle disturbances after COVID-19 vaccination in women of reproductive age. MATERIALS AND METHODS: This cross-sectional study was performed on 407 vaccinated women in the vaccination center of Imam Hossein Hospital (Tehran, Iran) between October 2021 and October 2022. They were interviewed based on a research-made checklist which consisted of two areas of questions about the baseline characteristics of participants and menstrual cycle characteristics to explore menstrual characteristics following COVID-19 vaccination. RESULTS: The prevalence of menstrual disturbances was higher after the third dose (38.3%) compared with the second (27.9%) and first (17.7%) doses (P<0.001). After the first dose, a history of polycystic ovarian syndrome [PCOS, odds ratio (OR)=7.35, 95% confidential interval (CI)= (3.64-14.82), P<0.001] and menstrual disturbances with unknown etiology [OR=15.23, 95% CI=(6.30-36.80), P<0.001] could predict menstrual disturbances. After the second dose, a history of menstrual disturbances with unknown etiology [OR=3.83, 95% CI=(1.47-9.94), P=0.006] and menstrual disturbances after the first dose [OR=201.96, 95% CI= (40.99-994.90), P<0.001] were predictors of menstrual disturbances. After the third dose, a history of menstrual disturbances with unknown etiology [OR=3.09, 95% CI= (1.00-9.52), P=0.048], menstrual disturbances after the first [OR=9.82, 95% CI=(1.38-69.69), P=0.022] and second [OR=7.83, 95% CI=(1.46-41.92), P=0.016] doses could predict menstrual disturbances. CONCLUSION: We detected that many women experienced various menstrual disturbances after vaccination against SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Furthermore, a history of menstrual abnormalities (before COVID-19 vaccination and following the previous doses of these vaccines) was associated with developing menstrual disturbances.

10.
Sci Rep ; 13(1): 17149, 2023 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-37816947

RESUMO

Vascular pulsation at the optic nerve head (ONH) reflects vessel properties. Reduction in the stimulated retinal vasodilatory capacity has been reported in diabetes, but its relation with vascular pulsation is unknown. Here we report a new retinal imaging system for correlative assessment of ONH vascular pulsation and stimulated retinal vasodilation. Retinal reflectance images were acquired before and during light flicker stimulation to quantify arterial and venous vasodilation (DAR, DVR) in subjects with and without diabetic retinopathy (N = 25). ONH vascular pulsation amplitude and frequency (PA, PF), were quantified by curve fitting of periodic intensity waveforms acquired in retinal vasculature (RV) and ONH tissue (ONHT) regions. The relationships between pulsation metrics, heart rate (HR), intraocular pressure (IOP), and vasodilatory responses were evaluated. Pulsation metrics were not significantly different between regions (p ≥ 0.70). In RV, inter-image variabilities of PA and PF were 10% and 6%, whereas inter-observer variabilities were 7% and 2% respectively. In both regions, PF was correlated with HR (p ≤ 0.001). PA was associated with DAR in both regions (p ≤ 0.03), but only with DVR in RV (p ≤ 0.05). Overall, ONH vascular pulsation was associated with stimulated retinal vasodilation, suggesting diabetes may have concomitant effects on retinal vasculature compliance and neurovascular coupling.


Assuntos
Diabetes Mellitus , Disco Óptico , Humanos , Disco Óptico/irrigação sanguínea , Vasodilatação , Retina/diagnóstico por imagem , Vasos Retinianos , Pressão Intraocular
11.
Int J Fertil Steril ; 18(1): 60-66, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-38041461

RESUMO

BACKGROUND: Women with uterine fibroids (UFs) experience many clinical manifestations that affect their quality of life (QOL). The Uterine Fibroid Symptom and Health-related Quality of Life (UFS-QOL) questionnaire is an English instrument specifically designed to assess fibroid-related symptoms and their impact on QOL. This study aims to investigate the reliability and validity of the Persian version of the UFS-QOL questionnaire in Iranian women with UF. MATERIALS AND METHODS: In this psychometric study, women with UFs who presented to Imam Hossein Hospital (Tehran, Iran) between August 2022 and January 2023 were enrolled in this study. A forward-backward approach was applied to translate the UFS-QOL questionnaire into Persian. The reliability of the UFS-QOL questionnaire was assessed by internal consistency and test-retest correlation. Confirmatory factor analysis (CFA) was used to assess convergent validity between items and subscales of the UFS-QOL questionnaire. Pearson's correlation coefficient was used to assess convergence validity between subscales of the UFS-QOL and the World Health Organization Quality of Life Brief Version 26 questionnaire (WHOQOL-BREF-26). RESULTS: Overall, we assessed 226 women with UFs. All subscales of the UFS-QOL questionnaire had acceptable internal consistency (Cronbach's alpha>0.7). Test-retest analysis indicated significant positive correlations between two measurements of all subscales of the UFS-QOL questionnaire: symptom severity (P<0.001), concern (P<0.001), activities (P<0.001), energy/mood (P<0.001), control (P<0.001), self-consciousness (P=0.002), and sexual function (P<0.001). The Kaiser-Meyer-Olkin (KMO) measure value was 0.920, and the result of Bartlett's test of sphericity was significant (P<0.001). CFA identified six factors for the health-related QOL (HRQL) questionnaire, which explained 73.827% of the total variation. Most subscales of the UFS-QOL questionnaire correlated with domains of the WHOQOL-BREF-26 questionnaire (P<0.05). CONCLUSION: The Persian version of the UFS-QOL questionnaire is a valid and reliable instrument to evaluate UFrelated symptoms and QOL among Iranian women.

12.
J Reprod Immunol ; 158: 103952, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37201456

RESUMO

Menstruation is a monthly shedding of the uterine wall, presented by menstrual bleeding in women of reproductive age. Menstruation is regulated by fluctuation of estrogen and progesterone, as well as other endocrine and immune pathways. Many women experienced menstrual disturbances after vaccination against the novel coronavirus in the last two years. Vaccine-induced menstrual disturbances have led to discomfort and concern among reproductive-age women, such that some decided not to receive the subsequent doses of the vaccine. Although many vaccinated women report these menstrual disturbances, the mechanism is still poorly understood. This review article discusses the endocrine and immune changes following COVID-19 vaccination and the possible mechanisms of vaccine-related menstrual disturbances.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Feminino , Humanos , Vacinas contra COVID-19/efeitos adversos , COVID-19/prevenção & controle , Distúrbios Menstruais/induzido quimicamente , Menstruação , Vacinação/efeitos adversos
13.
Case Rep Ophthalmol ; 13(3): 686-691, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36845454

RESUMO

Proliferative diabetic retinopathy (PDR) is a vision-threatening complication of diabetes. Panretinal photocoagulation (PRP) and anti-vascular endothelial growth factor (anti-VEGF) are approved treatment modalities aimed at regressing neovascularization. Data are lacking about abnormalities in retinal vascular and oxygen metrics before and after combination treatments. A 32-year-old Caucasian male diagnosed with PDR in the right eye was treated by a combination of PRP and multiple anti-VEGF treatments over a 12-month period. The subject underwent optical coherence tomography (OCT) angiography, Doppler OCT, and retinal oximetry before treatment and at 12 months, which was 6 months following the last treatment. Measurements of vascular metrics (vessel density [VD] and mean arterial and venous diameters [DA, DV]) and oxygen metrics (total retinal blood flow [TRBF], inner retinal oxygen delivery [DO2], metabolism [MO2], and extraction fraction [OEF]) were obtained. Both before and after treatments, VD, TRBF, MO2, and DO2 were below the normal lower confidence limits. Additionally, DV and OEF were decreased after treatments. Alterations in retinal vascular and oxygen metrics were reported for the first time in untreated and treated PDR. Future studies are warranted to evaluate the clinical value of these metrics in PDR.

14.
Cells ; 11(15)2022 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-35954257

RESUMO

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder that affects the brain and retina and lacks reliable biomarkers for early diagnosis. As amyloid beta (Aß) manifestations emerge prior to clinical symptoms and plaques of amyloid may cause vascular damage, identification of retinal vascular biomarkers may improve knowledge of AD pathophysiology and potentially serve as therapeutic targets. The purpose of the current study was to test the hypothesis that retinal hemodynamic and oxygen metrics are altered in 5XFAD mice. METHODS: Thirty-two male mice were evaluated at 3 months of age: sixteen 5XFAD transgenic and sixteen wild-type mice. Spectral-domain optical coherence tomography, vascular oxygen tension, and blood flow imaging were performed in one eye of each mouse. After imaging, the imaged and fellow retinal tissues were submitted for histological sectioning and amyloid protein analysis, respectively. Protein analysis was also performed on the brain tissues. RESULTS: Retinal physiological changes in venous diameter and blood velocity, arterial and venous oxygen contents, coupled with anatomical alterations in the thickness of retinal cell layers were detected in 5XFAD mice. Moreover, an increase in Aß42 levels in both the retina and brain tissues was observed in 5XFAD mice. Significant changes in retinal oxygen delivery, metabolism, or extraction fraction were not detected. Based on compiled data from both groups, arterial oxygen content was inversely related to venous blood velocity and nerve fiber/ganglion cell layer thickness. CONCLUSIONS: Concurrent alterations in retinal hemodynamic and oxygen metrics, thickness, and tissue Aß42 protein levels in 5XFAD mice at 3 months of age corresponded to previously reported findings in human AD. Overall, these results suggest that this mouse model can be utilized for studying pathophysiology of AD and evaluating potential therapies.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Doença de Alzheimer/metabolismo , Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Biomarcadores/metabolismo , Modelos Animais de Doenças , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Oxigênio/metabolismo , Retina/metabolismo
15.
Transl Vis Sci Technol ; 10(12): 20, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34661625

RESUMO

Purpose: Previous studies have reported alterations in total retinal blood flow (TRBF), oxygen delivery (DO2), oxygen metabolism (MO2), and oxygen extraction fraction (OEF) due to retinal diseases. The purposes of the current study were to determine variabilities and establish normal confidence intervals (CIs) for these metrics. Methods: A total of 22 healthy and 14 diabetic subjects participated in the study. Retinal vascular oxygen saturation (SO2) and TRBF were measured by oximetry and Doppler optical coherence tomography, respectively. DO2, MO2, and OEF were calculated from SO2 and TRBF measurements. Means, standard deviations (SDs), and CIs of metrics were determined in healthy subjects. Intra-visit variability was determined by the mean SDs of repeated measurements. Inter-visit variability was determined by the difference of measurements between two visits. Results: TRBF was 44 ± 15 µL/min (95% CI, 37-51) in healthy subjects. Intra-visit variabilities of TRBF were 5 µL/min and 6 µL/min in healthy and diabetic subjects, respectively. Inter-visit variability of TRBF was 3 µL/min in diabetic subjects. DO2, MO2, and OEF were 8.3 ± 2.9 µLO2/min (95% CI, 7.0-9.6), 3.2 ± 0.9 µLO2/min (95% CI, 2.8-3.6), and 0.40 ± 0.08 (95% CI, 0.36-0.43), respectively, in healthy subjects. Inter-visit variabilities of DO2, MO2, and OEF were 0.6 µLO2/min, 0.1 µLO2/min, and 0.03, respectively, in diabetic subjects. Conclusions: The findings established variabilities and normal baselines for TRBF, DO2, MO2, and OEF measurements in a small cohort of subjects. Translational Relevance: The variability and normal baselines of retinal oxygen metrics may be useful for diagnosing and monitoring patients with retinal diseases.


Assuntos
Diabetes Mellitus , Oxigênio , Benchmarking , Humanos , Consumo de Oxigênio , Fluxo Sanguíneo Regional , Vasos Retinianos/diagnóstico por imagem
16.
J Glaucoma ; 30(8): 666-671, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33979111

RESUMO

PRECIS: An association between macular vessel density (VD) and total retinal blood flow (TRBF) was demonstrated in subjects with primary open-angle glaucoma (POAG) and visual field (VF) loss. PURPOSE: The purpose of this study was to report relationships of macular VD metrics and TRBF in POAG. MATERIALS AND METHODS: A total of 24 POAG and 19 healthy control subjects participated in the study. Subjects underwent optical coherence tomography and angiography for measurements of inner retinal thickness (IRT), VD, and spacing between large vessels (SLV) and small vessels (SSV). Doppler optical coherence tomography imaging was performed for TRBF measurement. In POAG subjects, automated perimetry was performed and VF loss expressed as mean deviation was measured. RESULTS: Compared with the control group, POAG group had decreased VD, TRBF, IRT, and increased SLV (P<0.0001). Decreased VD (Pearson correlation, r=0.51; P<0.0001; N=43) and increased SLV (Spearman correlation, rs=-0.47; P=0.001) were correlated with decreased TRBF. Decreased VD and SSV (r≥0.39; P≤0.001; N=43) and increased SLV (rs=-0.71; P<0.0001) were associated with decreased IRT. Decreased VF mean deviation was correlated with decreased VD, SSV, IRT (r≥0.53; P≤0.001; N=24), and with increased SLV (rs=-0.84; P<0.0001). CONCLUSIONS: The finding of an association between macular VD and TRBF supports the role of vascular factors in the pathophysiology of POAG and potential conduct of future studies aimed at identifying multiple image-based vascular metrics for disease diagnosis.


Assuntos
Glaucoma de Ângulo Aberto , Estudos Transversais , Glaucoma de Ângulo Aberto/diagnóstico , Humanos , Pressão Intraocular , Fibras Nervosas , Vasos Retinianos/diagnóstico por imagem , Tomografia de Coerência Óptica , Campos Visuais
18.
Retin Cases Brief Rep ; 12 Suppl 1: S102-S104, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29176532

RESUMO

PURPOSE: To report a case of paraneoplastic vitelliform maculopathy in a patient with metastatic melanoma of unknown primary site. METHODS: Case report. Main outcome measures include funduscopic examination, fluorescein angiography, fundus autofluorescence, and spectral domain optical coherence tomography. RESULTS: A 44-year-old man with a known history of metastatic melanoma was referred for ophthalmic evaluation because of bilateral vision loss. Funduscopic examination was remarkable for vitelliform maculopathy that was confirmed with fundus autofluorescence and spectral domain optical coherence tomography. CONCLUSION: We describe a rare case of paraneoplastic vitelliform maculopathy. There are many etiologies of acquired vitelliform retinal lesions in the retina. Multimodal retinal imaging, including fundus autofluorescence and spectral domain optical coherence tomography, can be best used to identify these lesions. A history of systemic metastatic melanoma should be ruled out in patients with vitelliform maculopathy.


Assuntos
Melanoma/secundário , Síndromes Paraneoplásicas Oculares/diagnóstico por imagem , Distrofia Macular Viteliforme/diagnóstico por imagem , Adulto , Humanos , Masculino
19.
J Ophthalmic Vis Res ; 13(2): 195-199, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29719650

RESUMO

PURPOSE: We report the clinicopathological features and surgical outcomes of two cases of intraocular lens (IOL) calcification along with a review of the current literature. CASE REPORT: The first patient was a 53-year-old woman with diabetes mellitus (type 2) who underwent phacoemulsification with posterior chamber IOL insertion (PCIOL), and pars plana vitrectomy. Significant clouding of the IOL was first noted after 1.5 years, and the IOL was replaced with an Artisan lens. The second patient was a 22-year-old woman with Vogt-Koyanagi-Harada syndrome; she underwent a lensectomy, PCIOL, and pars plana vitrectomy. IOL opacification was first noted 4.5 years after the initial surgery and the IOL was extracted. CONCLUSION: The calcification of each IOL was confirmed by a pathologist. Further studies are required to determine the primary causes and mechanisms of the calcification of biomaterials including IOLs.

20.
Am J Ophthalmol ; 187: 10-20, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29269100

RESUMO

PURPOSE: To analyze the long-term growth patterns of type 1 neovascularization (NV) in eyes with age-related macular degeneration (AMD) receiving anti-vascular endothelial growth factor (VEGF) therapy. DESIGN: Retrospective cohort study. METHODS: Patients were enrolled from 2 eye centers and underwent optical coherence tomography angiography (OCTA) imaging with follow-up greater than 1 year. Choroidal neovascularization (CNV) was manually segmented on OCTA images and compared between time points. CNV growth was subdivided into 3 categories based on OCTA area measurement: CNV doubling, modest growth of less than 50%, and shrinkage. These growth rates were correlated with OCTA morphologic features. RESULTS: Forty-one eyes were analyzed. Mean CNV area was 1.60 ± 1.84 mm2 at baseline and 1.80 ± 1.84 mm2 at 1 year. Thirty-three eyes (80%) displayed an increase in CNV area at 1 year with a mean increase of 0.20 ± 0.38 mm2 (P = .001). Eleven eyes (27%) underwent CNV doubling, 19 eyes (46%) illustrated modest growth, and 6 (15%) showed shrinkage. Anatomic features including a capillary fringe (odds ratio [OR] = 5.3, P = .036) and immature lesion morphology (OR = 4.2, P = .015) were significantly associated with CNV doubling. CNV growth occurred in 3 predominant patterns: "symmetric" growth, "asymmetric" growth, and "finger-like projections," which reflected the orientation of expansion of CNV. "Symmetric" and "asymmetric" growth together correlated with greater frequency of CNV doubling (OR = 15, P = .0048). CONCLUSION: OCTA provides noninvasive measurement of the area of neovascular lesions in AMD. Sustained growth of type 1 NV can be identified in the majority of lesions (80%) that display characteristic patterns of progression despite ongoing anti-VEGF therapy.


Assuntos
Neovascularização de Coroide/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Degeneração Macular Exsudativa/complicações , Idoso , Idoso de 80 Anos ou mais , Inibidores da Angiogênese/uso terapêutico , Neovascularização de Coroide/classificação , Progressão da Doença , Feminino , Angiofluoresceinografia/métodos , Seguimentos , Humanos , Injeções Intravítreas , Masculino , Estudos Retrospectivos , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Acuidade Visual , Degeneração Macular Exsudativa/tratamento farmacológico
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