Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 14 de 14
Filter
1.
Orphanet J Rare Dis ; 18(1): 385, 2023 Dec 08.
Article in English | MEDLINE | ID: mdl-38066637

ABSTRACT

BACKGROUND: Microcirculatory dysfunction is associated with increased morbidity and mortality in cardiac surgery patients. This study aimed to investigate the association between preoperative retinal microcirculation evaluated using optical coherence tomography angiography (OCTA) and perioperative outcomes in patients with congenital heart disease (CHD). METHODS: This prospective, observational study was performed from May 2017 to January 2021. OCTA was used to automatically quantify the vessel density (VD) of the superficial capillary plexus, deep capillary plexus (DCP), and radial peripapillary capillary (RPC) preoperatively. The primary outcome was excessive postoperative bleeding, defined as bleeding volume > 75th percentile for 24-hour postoperative chest tube output. The secondary outcome was composite adverse outcomes, including one or more operative mortalities, early postoperative complications, and prolonged length of stay. The association between retinal VD and outcomes was assessed using Poisson regression. RESULTS: In total, 173 CHD patients who underwent cardiac surgery were included (mean age, 26 years). Among them, 43 (24.9%) and 46 (26.6%) developed excessive postoperative bleeding and composite adverse outcomes, respectively. A lower VD of DCP (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.08-1.43; P = 0.003) was independently associated with excessive postoperative bleeding, and a lower VD of RPC (OR, 1.97; 95% CI, 1.08-3.57; P = 0.027), and DCP (OR, 2.17; 95% CI, 1.08-4.37; P = 0.029) were independently associated with the postoperative composite adverse outcomes. CONCLUSION: Preoperative retinal hypoperfusion was independently associated with an increased risk of perioperative adverse outcomes in patients with CHD, suggesting that retinal microcirculation evaluation could provide valuable information about the outcomes of cardiac surgery, thereby aiding physicians in tailoring individualized treatment.


Subject(s)
Cardiac Surgical Procedures , Retina , Humans , Adult , Fluorescein Angiography/methods , Microcirculation , Prospective Studies , Tomography, Optical Coherence/methods
2.
J Atheroscler Thromb ; 29(5): 579-596, 2022 May 01.
Article in English | MEDLINE | ID: mdl-33746138

ABSTRACT

AIMS: To develop and validate a nomogram using retinal vasculature features and clinical variables to predict coronary artery disease (CAD) in patients with suspected angina. METHODS: The prediction model consisting of 795 participants was developed in a training set of 508 participants with suspected angina due to CAD, and data were collected from January 2018 to June 2019. The held-out validation was conducted with 287 consecutive patients from July 2019 to November 2019. All patients with suspected CAD received optical coherence tomography angiography (OCTA) examination before undergoing coronary CT angiography. LASSO regression model was used for data reduction and feature selection. Multivariable logistic regression analysis was used to develop the retinal vasculature model for predicting the probability of the presence of CAD. RESULTS: Three potential OCTA parameters including vessel density of the nasal and temporal perifovea in the superficial capillary plexus and vessel density of the inferior parafovea in the deep capillary plexus were further selected as independent retinal vasculature predictors. Model clinical electrocardiogram (ECG) OCTA (clinical variables+ECG+OCTA) was presented as the individual prediction nomogram, with good discrimination (AUC of 0.942 [95% CI, 0.923-0.961] and 0.897 [95% CI, 0.861-0.933] in the training and held-out validation sets, respectively) and good calibration. Decision curve analysis indicated the clinical applicability of this retinal vasculature nomogram. CONCLUSIONS: The presented retinal vasculature nomogram based on individual probability can accurately identify the presence of CAD, which could improve patient selection and diagnostic yield of aggressive testing before determining a diagnosis.


Subject(s)
Coronary Artery Disease , Angina Pectoris , Coronary Angiography , Coronary Artery Disease/complications , Coronary Artery Disease/diagnosis , Humans , Nomograms , Retinal Vessels/diagnostic imaging , Tomography, Optical Coherence/methods
3.
Acta Ophthalmol ; 100(2): 225-233, 2022 Mar.
Article in English | MEDLINE | ID: mdl-33629471

ABSTRACT

PURPOSE: To investigate the association between retinal microvasculature and the presence and severity of coronary artery disease (CAD) using optical coherence tomography angiography (OCTA). METHODS: The cross-sectional study was conducted in Guangdong Provincial People's Hospital, China. Retinal microvasculature parameters were measured by OCTA of the optic disc, including the vessel density (VD) and retinal nerve fibre thickness of the radial peripapillary capillary. In terms of the entire macula, VD of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and foveal density (FD-300) were included. The Gensini score was used to evaluate the severity of coronary artery obstructive lesions in CAD patients. RESULTS: A total of 410 participants (270 CAD patients and 140 controls) were included. Overall, participants showed significantly greater odds of having CAD in the lower versus higher VD for mean SCP, OR = 2.33 (95% CI 1.49-3.65); in the parafoveal SCP, OR = 2.68 (95% CI 1.70-4.23); and in the perifoveal SCP, OR = 2.36 (95% CI 1.49-3.72). Additionally, participants showed significantly greater odds of having CAD in the lower versus higher VD for mean DCP, OR = 4.04 (95% CI 2.53-6.45); in the parafoveal DCP, OR = 4.08 (95% CI 2.54-6.55); and in the perifoveal DCP, OR = 3.88 (95% CI 2.43-6.19). Among CAD patients, lower VD of DCP was associated with significantly greater adjusted Gensini scores (p = 0.004 for mean DCP; p = 0.035 for parafoveal DCP; p = 0.006 for perifoveal DCP). CONCLUSIONS: SCP and DCP were found to be associated with the presence of CAD among the whole population, while DCP was found to be associated with Gensini scores in CAD patients. Retinal microvasculature was associated with the presence and severity of coronary artery stenosis in CAD patients.


Subject(s)
Coronary Artery Disease/complications , Retinal Diseases/etiology , Retinal Vessels/pathology , Aged , Case-Control Studies , Computed Tomography Angiography , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Retinal Diseases/diagnostic imaging , Retinal Vessels/diagnostic imaging
4.
Front Cardiovasc Med ; 8: 712308, 2021.
Article in English | MEDLINE | ID: mdl-34532349

ABSTRACT

Background: Microcirculatory changes in congenital heart disease (CHD) patients undergoing cardiac surgery are not fully understood. We aimed to investigate the changes of retinal microcirculation in CHD patients after cardiac surgery by optical coherence tomography angiography (OCTA) and explore the association between retinal microcirculation and surgical outcome. Methods: This prospective observational study consisted of 71 CHD patients aged ≥6 years undergoing cardiac surgery including 19 cyanotic CHD (CCHD) and 52 acyanotic CHD (ACHD). Optical coherence tomography angiography (OCTA) was used to measure vessel density (VD) and capillary density (CD) of radial peripapillary capillary (RPC) and peripapillary, VD of superficial capillary plexus (SCP) and deep capillary plexus (DCP), thickness of retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) preoperatively and 1 month postoperatively. Transthoracic echocardiography was conducted to measure macrocirculation. Results: In CCHD patients, VD and CD of RPC and peripapillary increased postoperatively (all P < 0.05). In ACHD patients, VD of peripapillary, CD of RPC and peripapillary, and RNFL thickness increased postoperatively (all P < 0.05). VD of SCP and DCP, and GCC thickness did not change significantly in CHD patients after surgery. Lower preoperative retinal microvascular density was associated with longer cardiopulmonary bypass (CPB) time and postoperative length of stay (PLOS). No correlation was found between microcirculatory and macrohemodynamic parameters (all P > 0.05). Conclusions: Improved retinal microcirculation was observed after congenital cardiac surgery and impaired preoperative retinal microvasculature was associated with prolonged CPB time and PLOS, which might provide potential information about the outcome of congenital cardiac surgery.

5.
Front Aging Neurosci ; 13: 628336, 2021.
Article in English | MEDLINE | ID: mdl-33927607

ABSTRACT

Currently there is a shortage of biomarkers for stroke, one of the leading causes of death and disability in aging populations. Retinal vessels offer a unique and accessible "window" to study the microvasculature in vivo. However, the relationship between the retinal microvasculature and stroke is not entirely clear. To investigate the retinal microvascular characteristics in stroke, we recruited patients with stroke and age-matched control subjects from a tertiary hospital in China. The macular vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), foveal avascular zone (FAZ) metrics, and optical coherence tomography angiography (OCTA) measured optic disc VD were recorded for analysis. A total of 189 patients with stroke and 195 control subjects were included. After adjusting for sex, visual acuity, systolic and diastolic blood pressure, a history of smoking, levels of hemoglobulin (HbA1c), cholesterol, and high-density lipoprotein (HDL), the macular VD of SCP and DCP in all sectors was decreased in patients with stroke. In the stroke group, the VD around the FAZ and the VD of the optic disk were lower. Logistic regression found the parafovea-superior-hemi VD of DCP > 54.53% [odds ratio (OR): 0.169] as a protective factor of stroke. Using the integration of all OCTA parameters and traditional risk factors, the area under the receiver operating characteristic (AUC) curve of distinguishing patients with stroke was 0.962, with a sensitivity of 0.944 and a specificity of 0.871. Our study demonstrates that the retinal VD is decreased in patients with stroke independently of the traditional risk factors of stroke, which may shed light on the monitoring of stroke using the retinal microvascular parameters.

6.
Ann Transl Med ; 9(1): 43, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33553336

ABSTRACT

BACKGROUND: This study aimed to predict the treatment outcomes in patients with diabetic macular edema (DME) after 3 monthly anti-vascular endothelial growth factor (VEGF) injections using machine learning (ML) based on pretreatment optical coherence tomography (OCT) images and clinical variables. METHODS: An ensemble ML system consisting of four deep learning (DL) models and five classical machine learning (CML) models was developed to predict the posttreatment central foveal thickness (CFT) and the best-corrected visual acuity (BCVA). A total of 363 OCT images and 7,587 clinical data records from 363 eyes were included in the training set (304 eyes) and external validation set (59 eyes). The DL models were trained using the OCT images, and the CML models were trained using the OCT images features and clinical variables. The predictive posttreatment CFT and BCVA values were compared with true outcomes obtained from the medical records. RESULTS: For CFT prediction, the mean absolute error (MAE), root mean square error (RMSE), and R2 of the best-performing model in the training set was 66.59, 93.73, and 0.71, respectively, with an area under receiver operating characteristic curve (AUC) of 0.90 for distinguishing the eyes with good anatomical response. The MAE, RMSE, and R2 was 68.08, 97.63, and 0.74, respectively, with an AUC of 0.94 in the external validation set. For BCVA prediction, the MAE, RMSE, and R2 of the best-performing model in the training set was 0.19, 0.29, and 0.60, respectively, with an AUC of 0.80 for distinguishing eyes with a good functional response. The external validation achieved a MAE, RMSE, and R2 of 0.13, 0.20, and 0.68, respectively, with an AUC of 0.81. CONCLUSIONS: Our ensemble ML system accurately predicted posttreatment CFT and BCVA after anti-VEGF injections in DME patients, and can be used to prospectively assess the efficacy of anti-VEGF therapy in DME patients.

7.
Front Med (Lausanne) ; 8: 708491, 2021.
Article in English | MEDLINE | ID: mdl-34977052

ABSTRACT

Background: Retinal microvasculature has been associated with coronary artery disease (CAD), but the exact contributory role in coronary total occlusion (CTO) is unclear. We aimed to investigate whether retinal vasculature is associated with CTO and could provide incremental value in the assessment of CTO. Methods: A total of 218 CAD patients including 102 CTO and 116 non-CTO were enrolled. Retinal vasculature was measured by optical coherence tomography angiography (OCTA) for all patients. Receiver operating characteristic (ROC) curve was used to assess the performance of retinal vasculature in differentiating CTO from non-CTO patients. Results: In non-CTO CAD patients, vessel density (VD) of mean superficial capillary plexus (SCP) and parafovea SCP were 49.85 and 52.56%, respectively; in CTO patients, VD of mean SCP and parafovea SCP were 47.77, and 49.58%, respectively. After multiple adjustment, VD in the SCP was significantly lower in CTO patients compared to non-CTO patients. VD of superior hemi in the parafovea SCP combined with the clinical variates showed the best ability to predict CTO from CAD with an area under the curve (AUC) of 0.812 (specificity of 89.0% and sensitivity of 65.9%). Conclusions: In CTO patients, retinal VD was significantly decreased, and microvascular damage might specifically target to arterioles than capillaries. Retinal vasculature could thus be a surrogate for detecting the microvascular damage and assist in the assessment of CTO patients. OCTA examination could be suggested to monitor the process of coronary arteries lesions.

8.
Retina ; 41(5): 1110-1117, 2021 May 01.
Article in English | MEDLINE | ID: mdl-33031250

ABSTRACT

PURPOSE: To develop a deep learning (DL) model to detect morphologic patterns of diabetic macular edema (DME) based on optical coherence tomography (OCT) images. METHODS: In the training set, 12,365 OCT images were extracted from a public data set and an ophthalmic center. A total of 656 OCT images were extracted from another ophthalmic center for external validation. The presence or absence of three OCT patterns of DME, including diffused retinal thickening, cystoid macular edema, and serous retinal detachment, was labeled with 1 or 0, respectively. A DL model was trained to detect three OCT patterns of DME. The occlusion test was applied for the visualization of the DL model. RESULTS: Applying 5-fold cross-validation method in internal validation, the area under the receiver operating characteristic curve for the detection of three OCT patterns (i.e., diffused retinal thickening, cystoid macular edema, and serous retinal detachment) was 0.971, 0.974, and 0.994, respectively, with an accuracy of 93.0%, 95.1%, and 98.8%, respectively, a sensitivity of 93.5%, 94.5%, and 96.7%, respectively, and a specificity of 92.3%, 95.6%, and 99.3%, respectively. In external validation, the area under the receiver operating characteristic curve was 0.970, 0.997, and 0.997, respectively, with an accuracy of 90.2%, 95.4%, and 95.9%, respectively, a sensitivity of 80.1%, 93.4%, and 94.9%, respectively, and a specificity of 97.6%, 97.2%, and 96.5%, respectively. The occlusion test showed that the DL model could successfully identify the pathologic regions most critical for detection. CONCLUSION: Our DL model demonstrated high accuracy and transparency in the detection of OCT patterns of DME. These results emphasized the potential of artificial intelligence in assisting clinical decision-making processes in patients with DME.


Subject(s)
Artificial Intelligence , Deep Learning , Diabetic Retinopathy/diagnosis , Macular Edema/diagnosis , Tomography, Optical Coherence/methods , Visual Acuity , Diabetic Retinopathy/complications , Diabetic Retinopathy/physiopathology , Follow-Up Studies , Humans , Macular Edema/etiology , Macular Edema/physiopathology , ROC Curve , Retrospective Studies
9.
Clin Exp Ophthalmol ; 48(9): 1219-1228, 2020 12.
Article in English | MEDLINE | ID: mdl-32860305

ABSTRACT

IMPORTANCE: A high prevalence of retinal abnormalities have been reported in congenital heart disease (CHD), but quantitative analysis of retinal vasculature is scarce. Optical coherence tomography angiography (OCTA) is a noninvasive method to quantitatively assess the retinal microvasculature. BACKGROUND: To investigate the retinal microvasculature changes in CHD patients by using OCTA. DESIGN: Cross-sectional study. PARTICIPANTS: A total of 158 participants including 57 cyanotic CHD (CCHD) patients, 60 acyanotic CHD (ACHD) patients and 41 control subjects were included. METHODS: All participants underwent a comprehensive ophthalmologic examination, including refraction measurement, intraocular pressure measurement and OCTA. MAIN OUTCOME MEASURES: Vessel density (VD) was measured within the radial peripapillary capillary (RPC), superficial capillary plexus (SCP) and deep capillary plexus (DCP) of the macula. RESULTS: CCHD patients had significantly lower VD in the RPC, SCP and DCP (all P < .01) compared to control subjects, and significantly lower VD in the RPC and DCP (both P < .05) compared to ACHD patients. Besides, among the CHD group, VD in the RPC was positively correlated with oxygen saturation (whole image, ρ = 0.45; peripapillary, ρ = 0.48) and negatively correlated with haematocrit (whole image, ρ = 0.55; peripapillary, ρ = 0.55) (all P < .001). CONCLUSIONS AND RELEVANCE: Retinal VD might be a surrogate to reflect the effect of chronic systemic hypoxemia in CHD patients. OCTA could be a convenient and noninvasive tool to evaluate the retinal structure and function in CHD patients.


Subject(s)
Heart Defects, Congenital , Tomography, Optical Coherence , Cross-Sectional Studies , Fluorescein Angiography , Heart Defects, Congenital/complications , Heart Defects, Congenital/diagnosis , Humans , Microvessels
10.
Invest Ophthalmol Vis Sci ; 61(8): 42, 2020 07 01.
Article in English | MEDLINE | ID: mdl-32725211

ABSTRACT

Purpose: To investigate retinal neurovascular structural changes in patients with essential hypertension. Methods: This observational cross-sectional study consisted of 199 right eyes from 169 nondiabetic essential hypertensive patients, divided into groups as follows: group A, 113 patients with hypertensive retinopathy (HTNR); group B, 56 patients without HTNR; and a control group of 30 healthy subjects. Peripapillary retinal nerve fiber layer (RNFL), radial peripapillary segmented (RPC), ganglion cell-inner plexiform layer (GC-IPL), and superficial (SVP) and deep (DVP) vascular plexus density at the macula (6 × 6 mm2) were measured by optical coherence tomography angiography (OCTA). Results: DVP density was significantly reduced in groups A and B compared to the control group (group A DVP, P = 0.001; group B DVP P = 0.002). GC-IPL, RNFL thickness, and RPC and SVP density in group A were significantly decreased compared to the control group or group B (all P < 0.05). In hypertensive patients, GC-IPL and RNFL thickness were negatively correlated with severity of HTNR (GC-IPL, r = -0.331, P < 0.001; RNFL, r = -0.583, P < 0.001) and level of home blood pressure monitoring (HBPM) (GC-IPL, r = -0.160, P = 0.050; RNFL, r = -0.282, P = 0.001) and were positively correlated with SVP (GC-IPL, r = 0.267, P = 0.002; RNFL, r = 0.361, P < 0.001) and RPC density (GC-IPL, r = 0.298, P < 0.001; RNFL, r = 0.663, P < 0.001). Among subjects with grade 2 or 3 retinopathy, the superior RNFL was significantly thinner in patients with high HBPM level than in those with normal HBPM level (grade 2, P = 0.016; grade 3, P = 0.006). Conclusions: Reduction of retinal vessel density and RNFL thickness is observed in patients with HTNR and is inversely associated with level of HBPM.


Subject(s)
Essential Hypertension , Hypertensive Retinopathy , Retinal Ganglion Cells/pathology , Retinal Vessels , Angiography/methods , Blood Pressure Monitoring, Ambulatory/methods , Cross-Sectional Studies , Essential Hypertension/complications , Essential Hypertension/diagnosis , Essential Hypertension/physiopathology , Female , Humans , Hypertensive Retinopathy/diagnosis , Hypertensive Retinopathy/physiopathology , Male , Microvessels/diagnostic imaging , Middle Aged , Retina/diagnostic imaging , Retinal Vessels/diagnostic imaging , Retinal Vessels/pathology , Severity of Illness Index , Tomography, Optical Coherence/methods
11.
J Diabetes Res ; 2020: 9705786, 2020.
Article in English | MEDLINE | ID: mdl-32626784

ABSTRACT

PURPOSE: To evaluate the impact of restoration of foveal bulge (FB) in optical coherence tomography (OCT) images on visual acuity after resolution of diabetic macular edema with coexisting serous retinal detachment (SRD-DME). METHODS: A total of 52 eyes with resolved SRD-DME and an intact ellipsoid zone at the central fovea were included. All eyes underwent best-corrected visual acuity (BCVA) examination and OCT scanning at baseline and follow-up visits (1, 3, and 6 months). The eyes were divided into two groups according to the presence of FB at 6 months. BCVA, central foveal thickness (CFT), height of SRD (SRDH), outer nuclear layer (ONL) thickness, photoreceptor inner segment (PIS), and outer segment (POS) length were compared between the two groups. RESULTS: A FB was found in 25 of 52 (48%) eyes at 6 months. The FB (+) group had lower SRDH at baseline, and better BCVA, longer POS length at 6 months (all P < 0.05). There was no significant difference in the CFT, ONL thickness, and PIS length at 6 months between the two groups (all P > 0.05). More eyes in the FB (+) group had complete SRD resolution at 1 month (P = 0.009) and 3 months (P = 0.012). Eyes with complete SRD resolution at 1 month (P = 0.009) or 3 months (P = 0.012) were more likely to have a FB at 6 months. CONCLUSIONS: The Presence of the FB is associated with better BCVA after resolution of SRD-DME. Eyes with lower baseline SRDH or faster SRD resolution are more likely to have a FB at 6 months.


Subject(s)
Diabetic Retinopathy/physiopathology , Fovea Centralis/physiopathology , Macular Edema/physiopathology , Recovery of Function , Retinal Detachment/physiopathology , Visual Acuity , Aged , Diabetic Retinopathy/diagnostic imaging , Diabetic Retinopathy/surgery , Female , Fovea Centralis/diagnostic imaging , Humans , Light Coagulation , Macular Edema/diagnostic imaging , Macular Edema/surgery , Male , Middle Aged , Retinal Detachment/diagnostic imaging , Retinal Detachment/surgery , Tomography, Optical Coherence
12.
Curr Eye Res ; 45(5): 615-622, 2020 05.
Article in English | MEDLINE | ID: mdl-31670978

ABSTRACT

Purpose: Retinal vein occlusion is associated with an increased risk of cardiovascular diseases. Anti-vascular endothelial growth factor has been widely used as a treatment option. However, the systemic safety of intravitreal anti-vascular endothelial growth factor for retinal vein occlusion patients is still unclear.Materials and Methods: A meta-analysis was conducted to investigate all randomized controlled trials published up to February 2019 of retinal vein occlusion patients who received intravitreal anti-vascular endothelial growth factor vs. control treatments. Fixed effect models were used and results were reported as odds ratios and 95% confidence intervals.Results: Eight trials that evaluated 2320 patients were retrieved. Anti-vascular endothelial growth factor did not significantly increase the risks of cardiovascular events (odds ratio,1.54; 95% confidence interval, 0.66-3.57), hypertension (odds ratio, 0.92; 95% confidence interval, 0.63-1.33), or heart rate disorders (odds ratio,1.53; 95% confidence interval, 0.37-6.28) when compared with control treatment. Subgroup analyses did not show a significant increase of cardiovascular events in aflibercept (odds ratio,1.96; 95% confidence interval, 0.44-8.81) vs. ranibizumab trials (odds ratio, 1.47; 95% confidence interval, 0.54-4.02); 0.5 mg ranibizumab trials (odds ratio, 1.73; 95% confidence interval, 0.61-4.96) vs. 0.3 mg ranibizumab trials (odds ratio, 0.70; 95% confidence interval, 0.14-3.59); nor branch retinal vein occlusion (odds ratio, 1.32; 95% confidence interval, 0.40-4.33) vs. central retinal vein occlusion trials (odds ratio, 1.93; 95% confidence interval, 0.59-6.29).Conclusions: Intravitreal administration of anti-vascular endothelial growth factor did not significantly increase the risks of cardiovascular events, hypertension or heart rate disorders in retinal vein occlusion patients.


Subject(s)
Angiogenesis Inhibitors/adverse effects , Cardiovascular Diseases/chemically induced , Retinal Vein Occlusion/drug therapy , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Cardiovascular Diseases/diagnosis , Confidence Intervals , Female , Humans , Intravitreal Injections , Male , Middle Aged , Odds Ratio , Randomized Controlled Trials as Topic , Ranibizumab/adverse effects , Receptors, Vascular Endothelial Growth Factor , Recombinant Fusion Proteins/adverse effects
13.
Cyberpsychol Behav Soc Netw ; 22(2): 127-131, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30779616

ABSTRACT

We examined and analyzed binocular imbalance in a group of randomly selected normal subjects with corrected visual acuity of 0.8 or more in both eyes without ocular diseases, by using augmented virtual reality system. This study will quantify the correlation between binocular imbalance in these normal subjects and various spatial frequencies and temporal frequencies in the integrated binocular stimulation mode. A retrospective study was carried out and data from 97 patients (51 males and 46 females) who were diagnosed with no eye diseases, and with corrected binocular visual acuity of 0.8 or more, were collected. Their binocular visual function, Hirschberg test refraction status, and binocular imbalance were assessed using the quantified visual perception stimulation mode in an augmented virtual reality platform. When normal subjects (with corrected binocular vision of 0.8 or more without ocular diseases) were assessed using the integrated binocular stimulation mode with different temporal and spatial frequencies, a gradual reduction of binocular imbalance could be observed when spatial frequencies were increased. When contrast balance was adjusted, binocular imbalance was more prevalent in the horizontal state compared with the vertical state. This was seen when patients were stimulated by different temporal frequencies in the virtual reality testing mode. 17.53% and 29.90% of participants reached complete binocular fusion under low temporal frequency stimulation and high temporal frequency stimulation, respectively, while binocular imbalance was found in 65.9% and 62.89% of participants who were stimulated, respectively, by low temporal frequency and high temporal frequency. In addition, 16.5% and 7.21% experienced severe binocular imbalance under low temporal and high temporal frequency stimulation, respectively. The integrated binocular stimulation mode under low temporal frequency was more sensitive in detecting binocular imbalance. The status of binocular balance in normal subjects was not the same when stimulated by the augmented virtual reality platform, as many showed varying degrees of binocular imbalance. The results from our clinical study demonstrate that integrated binocular stimulation with different spatial and temporal frequencies enables a more sensitive detection of binocular imbalance, making it a powerful new tool for the diagnosis and analysis of clinical binocular abnormalities. In addition, since more than half of the normal subjects (without eye diseases who has corrected vision of 0.8 or more) exhibited binocular imbalance in our study, we believe that this brief binocular imbalance is likely a transient physiological phenomenon, which is not pathological to visual acuity and function, and should only be seen as pathological when binocular imbalance is prolonged, causing functional deficits such as reading impairment.


Subject(s)
Virtual Reality , Vision, Binocular/physiology , Visual Perception/physiology , Adult , Female , Humans , Male , Middle Aged , Photic Stimulation/methods , Retrospective Studies , Young Adult
14.
Se Pu ; 31(3): 270-4, 2013 Mar.
Article in Chinese | MEDLINE | ID: mdl-23786001

ABSTRACT

A method of high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed for the determination of thyroid hormones in milk including 3,3',5,5 '-tetraiodothyronine (T4), 3,3', 5-triiodothyronine (T3) and 3,3',5 '-triiodothyronine (rT3). The sample was extracted with acetonitrile and centrifuged, then the up layer was alkalized with concentrated ammonia water and cleaned up with a Cleanert PAX cartridge. The chromatographic separation was carried out on a Zorbax Eclipse XDB-C18 column (150 mm x 2.1 mm, 3.5 micro m) with the mobile phase of 37% water containing 0.1% (v/v) acetic acid and 63% of methanol with an isocratic elution mode at a flow rate of 0. 3 mL/min. The mass spectrometry detection was performed in positive electrospray ionization and monitored using multiple reaction monitoring (MRM) mode (m/z 652. 0/605. 5 and 652. 0/478. 6 for T3 and rT3; m/z 777. 7/731.7 and 777. 7/604.9 for T4; m/z 784. 0/737.9 and 784. 0/639.4 for T4-13C6). The analytes were identified by their retention times and relative abundance ratios of the characteristic product ions, and quantified by internal standard method. The method was linear with the correlation coefficients ( r2 ) greater than 0. 998 in the concentration ranges investigated. The limits of detection (LODs) were not more than 0.03 ng/g, and the limits of quantification (LOQ) were not more than 0.1 ng/g for the analytes. The recoveries were 80. 61% - 101.7% with the relative standard deviations (RSDs) of 1.48% - 9.70%. The results of five real milk samples showed that the contents of T3 were 0.59 - 1. 30 ng/g with the RSDs of 2.06% -7.70%, and T4 and rT3 weren't found. The method presents many merits including simple sample pretreatment, high sensitivity, good reproducibility and unequivocal confirmation and quantification for the analytes. It could be used to monitor the levels of thyroid hormones in the milk for safety quality evaluation.


Subject(s)
Chromatography, High Pressure Liquid/methods , Milk/chemistry , Tandem Mass Spectrometry/methods , Thyroid Hormones/analysis , Animals , Cattle , Food Safety/methods , Thyroxine/analysis , Triiodothyronine/analysis
SELECTION OF CITATIONS
SEARCH DETAIL
...