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find Author "Chen Youxin" 13 results
  • Classification of polypoidal choroidal vasculopathy and its influencing factors

    Polypoidal choroidal vasculopathy (PCV) is a fundus disease characterized by choroidal anomalous branch vascular network and terminal polypoidal dilatation. According to its fundus feature, lesion location, imaging feature and disease progression, PCV can be divided into different types or stages. It can be divided into hemorrhage and exudation PCV according to the fundus features, into macular, peripapillary, periphery and mixed types according to the lesion locations. It can also be divided into type 1 and 2 according to the ICGA (indocyanine green angiography) manifestations, and can be classified as early stage and late stage according to disease progression. There were different correlations between different types of PCV and some risk genetic loci, such as ARMS2 (age-related macular degeneration factor 2)/ HTRA1 (high temperature essential protein A1) , C2, complement factor B, complement factor H, and elastin genes. The response to therapy and prognosis are also different between different types. It is important to further study the clinical classification of PCV, to explore the genetic characteristics, influencing factors and treatment or prognosis features of different types of PCV. The results will improve the differential diagnosis of PCV, and the effectiveness of individualized treatment.

    Release date:2017-05-15 12:38 Export PDF Favorites Scan
  • Research progress of optical coherence tomography angiography in retinal vein occlusion

    Retinal vein occlusion (RVO) is a vascular disease characterized by intraretinal hemorrhage, edema and hard exudation, which is caused by increased retinal vein pressure. OCT angiography (OCTA) has been widely used in the diagnosis of retinal vascular diseases including RVO by virtue of non-invasive, high resolution and stratified display of superficial, deep retinal vessels and quantification of retinal vessel density and non-perfusion area size. OCTA can provide information of retinal microvascular structure and blood perfusion under the condition of disease, it also can be used to evaluate the effect of treatment and changes of retinal circulation during the course of disease follow-up. Although OCTA cannot replace fundus angiography completely, it has brought us more information about the pathogenesis, disease progression and prognostic factors of RVO. It is believed that with the progress of technology, OCTA will bring us a new chapter in the study of retinal vascular diseases including RVO.

    Release date:2019-07-16 05:35 Export PDF Favorites Scan
  • The imaging characteristics of pachychoroidopathy and the research status and progress of pathogenesis and treatment based on the imaging characteristics

    Pachychoroidopathy is a type of retinal choroidal disease with similar clinical features, which is characterized by attenuation of the choriocapillaris overlying dilated choroidal veins, and associated with progressive retinal pigment epithelium dysfunction and neovascularization. At present, pachychoroidopathy includes pachychoroid pigment epitheliopathy, central serous chorioretinopathy pachychoroid neovasculopathy, polypoidal choroidal vasculopathy, focal choroidal excavationm, and peripapillary pachychoroid syndrom. These diseases not only have common imaging features, but also individual imaging features. This not only provides us with important clues about the pathogenesis of pachychoroidopathy, but also provides guidance for their treatment decisions. Although the exact pathogenesis of pachychoroidopathy is still unclear, and the treatment method is still controversial; but it is believed that with the development of imaging technology and the development of high-quality clinical and basic research, patients with pachychoroidopathy can be provided with more reasonable treatment in the future.

    Release date:2020-10-19 05:11 Export PDF Favorites Scan
  • Clinical observation and fundus angiography with fluorescein and indocyanine green in stargardt′s disease

    Purpose To investigate the clinical characteristics of the Stargardt is disease and to evaluate the value of the fundus fluorescein angiography (ICGA) in Stargardt is disease. Methods Routine eye examination,VEP,ERG,EOG,and perimetry were performed in 25 cases(30 eyes) of Stargardtprime;s disease (15 men and 10 women) aged 12-41,on an average of 23.FFA was done in 15 cases (30eyes),and ICGA was done in 10 cases (20 eyes). Results Visual acuity was below 0.1 for 90.0% of the cases.Every eye showed macular lesions that wrere horizontal ellipse in shape,1.3-3.2PD in horizontal diameter and tinged with metal or beated copper color.Fundus flavimaculatus was found in 84.0% of the cases.On fluorescein angiography,window defect hyperfluorescence was found in the macular lesion of ocular fundus,with typical quot;bullprime;s eyequot; pattern.A quot; dark choroidquot; was revealed in 91.70% of the whole cases.On indocyanine green angigraphy,hypofluorescent area appeared at the macula in the early phase,even in very early stage of the Stargardtprime;s disease.Areas of fundus flavimaculatus were also hypoflurescent that became more apparent in the later phase. Conclusion Fluorescein angiography combined with indocyanine green angiography was useful for studying the clinical features and the pathological mechnism of the Stargardtprime;s disease. (Chin J Ocul Fundus Dis,1998,14:72-75)

    Release date:2016-09-02 06:11 Export PDF Favorites Scan
  • FLUORESCEIN ANGIOGRAPHIC CHARACTERISTICS OF IDIOPATHIC SENILE MACULAR HOLE

    OBJECTIVE:To inwestigate the value of fundus fluorescein angiography in evaluation of idiopathic senile macular hole(ISMH). METHODS:fundus fluorescein angiography(FFA)and other clinical examination were performed in 26 cases (31eyes)of ISMH patients. RESULTS:Full-thickness macular holes were in 17 and lamellar holes were in 14 of the 31 eyes. Hyperfluorescencequot;window defectquot;was found at the base of all the eyes with full-thickness maeular holes and 2 eyes with lamellar holes. The size of hyperfluorescence zone was smaller than that of those seen in redfree film, hyperfluorescence in 6 eyes (19.4%) showed homogenous ancl 10 eyes (32.5%) granular in pattern. The small yellowish dots in macular hole showed blocked fluorescence,while the halo of macular hole showed hyperfluorescence. CONCLUSION:Fundus fluorescein angiography was useful in differentiating lamellar from full-thickness macular hole and understanding the degree of retinal pigment epithelium damages in macular holes. (Chin J Ocul Fundus Dis,1996,12: 208-210 )

    Release date:2016-09-02 06:21 Export PDF Favorites Scan
  • Insights and prospectives of ophthalmologic artificial intelligence technology

    For the past few years, artificial intelligence (AI) technology has developed rapidly and has become frontier and hot topics in medical research. While the deep learning algorithm based on artificial neural networks is one of the most representative tool in this field. The advancement of ophthalmology is inseparable from a variety of imaging methods, and the pronounced convenience and high efficiency endow AI technology with promising applications in screening, diagnosis and follow-up of ophthalmic diseases. At present, related research on ophthalmologic AI technology has been carried out in terms of multiple diseases and multimodality. Many valuable results have been reported aiming at several common diseases of ophthalmology. It should be emphasized that ophthalmic AI products are still faced with some problems towards practical application. The regulatory mechanism and evaluation criteria have not yet integrated as a standardized system. There are still a number of aspects to be optimized before large-scale distribution in clinical utility. Briefly, the innovation of ophthalmologic AI technology is attributed to multidisciplinary cooperation, which is of great significance to China's public health undertakings, and will be bound to benefit patients in future clinical practice.

    Release date:2019-03-18 02:49 Export PDF Favorites Scan
  • Microvascular changes of macular edema secondary to branch retinal vein occlusion treated with intravitreal conbercept injection

    ObjectiveTo observe the changes of macular microvascular structure in eyes with macular edema secondary to branch retinal vein occlusion (BRVO-ME) after intravitreal injection of conbercept and analyze its relationship with visual function and central retinal thickness (CRT).MethodsA prospective clinical study. From July 2018 to June 2019, 21 eyes of 21 patients with unilateral temporal BRVO-ME diagnosed in the Department of Ophthalmology of Peking Union Medical College Hospital were included in the study. Among them, there were 14 eyes of 14 males and 7 eyes of 7 females; the average age was 58.0±8.3 years. There were 13 eyes and 8 eyes with occlusion of the superior temporal and inferior temporal branches of the retinal vein, respectively. The affected area was defined as the side of the venous obstruction. All the affected eyes underwent best-corrected visual acuity (BCVA) and optical coherence tomography angiography (OCTA) examination. The BCVA was tested using the international standard logarithmic visual acuity chart, which was converted into the logarithmic minimum angle of resolution (logMAR) visual acuity during statistical analysis. All the eyes were treated with intravitreal injection of conbercept once a month for 3 months, and then treated as needed. A 3 mm × 3 mm scan centered on fovea was obtained and the vascular density of superficial capillary plexus (SCP) and deep capillary plexus (DCP), fovea avascular zone (FAZ) area, perimeter of FAZ (PERIM), acircularity index (AI), foveal vascular density in a 300 μm wide region around FAZ (FD-300) and central retinal thickness (CRT) were measured. The follow-up time after treatment was 6 months. The vascular density and FAZ parameters were compared before and after treatment by paired t test. The correlations of BCVA, CRT and vascular density, FAZ area and the other parameters at 6 months after treatment were analyzed by linear regression analysis. ResultsBefore treatment, the logMAR BCVA of the eyes was 0.506±0.159, and the CRT was 375.4±81.3 μm; 6 months after treatment, the logMAR BCVA of the eyes was 0.294±0.097, and the CRT was 266.3±46.7 μm. There was a statistically significant difference of logMAR BCVA and CRT between the eyes before and after treatment (t=8.503, 9.843; P<0.05). There was no statistically significant difference in the overall vascular density of SCP and DCP before and 6 months after treatment (t=-0.091, -0.320; P>0.05). The foveal vascular density decreased, and the difference was statistically significant (t=8.801, 3.936; P<0.05). The vascular density of DCP of the affected area increased, and the difference was statistically significant (t=-2.198, P<0.05). Compared with those before treatment, the FAZ area and PERIM of the affected eyes had an increasing trend, while AI and FD-300 had a decreasing trend, and the differences were statistically significant (t=-18.071, -12.835, 2.555, 8.610; P<0.05). The linear regression analysis showed that BCVA and FAZ area 6 months after treatment have significant correlation (t=2.532, P=0.024). ConclusionCRT decreased and BCVA increased after intravitreal injection of conbercept in BRVO-ME eyes. After treatment, the foveal vascular density of SCP and DCP decreased while the vascular density of DCP of the affected area increased. The FAZ increased and the PERIM and AI decreased during follow-up. The BCVA was significantly correlated with the FAZ area 6 months after treatment.

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  • Issues related to artificial intelligence research in ophthalmology

    At present, artificial intelligence (AI) has been widely used in the diagnosis and treatment of various ophthalmological diseases, but there are still many problems. Due to the lack of standardized test sets, gold standards, and recognized evaluation systems for the accuracy of AI products, it is difficult to compare the results of multiple studies. When it comes to the field of image generation, we hardly have an efficient approach to evaluating research results. In clinical practice, ophthalmological AI research is often out of touch with actual clinical needs. The requirements for the quality and quantity of clinical data put more burden on AI research, limiting the transformation of AI studies. The prediction of systemic diseases based on fundus images is making progressive advancement. However, the lack of interpretability of the research lower the acceptance. Ophthalmology AI research also suffer from ethical controversy due to unconstructed regulations and regulatory mechanisms, concerns on patients’ privacy and data security, and the risk of aggravating the unfairness of medical resources.

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  • Clinical features and long-term follow-ups of juxtapapillary retinal capillary hemangioma

    ObjectiveTo evaluate the clinical features and follow-up effect of treatment for retinal capillary hemangioma (RCH) of myopic disc.MethodsRetrospective case series studies. A total of 14 patients (15 eyes) diagnosed with juxtapapillary RCH (JRCH) at Peking Union Medical College Hospital and followed up for more than 12 months from January 2007 to December 2019 were included. Among these patients, there were 7 males (7 eyes) and 7 females (8 eyes) with the average age of 29.8 ±12.7 years. There were 6 isolated JRCH cases, all of which were monocular patients, including 1 case with a single peripheral RCH; 8 cases with von Hippel-Lindau disease, including 5 cases of binocular RCH. Out of 15 eyes, 6 eyes were merged with peripheral RCH. Three eyes were simply observed, and 12 eyes were treated with photodynamic therapy (PDT) alone or PDT combined with other treatments. The average follow-up time was 55.2 months. Its clinical characteristics and long-term treatment effects were analyzed.ResultsAt the first visit, among the 15 eyes, 3 eyes had visual acuity<0.1, 5 eyes were 0.1-0.4, and 7 eyes were>0.5. The endogenous and fixed exogenous JRCH were 12 (80%, 12/15) and 3 (20%, 3/15) eyes, respectively. The size of the tumor was 1/4 to 4 optic disc diameters (DD); the combined macular edema, epiretinal membrane, and macular hole were 11, 5, and 1 eyes, respectively. There were 3 eyes with tumor diameter less than 1 DD. The visual acuity at the first diagnosis was 0.6-1.0, and no treatment was given. The follow-up time was 12 months in 2 eyes and 120 months in 1 eye. At the last follow-up, his vision remained stable and the tumor did not enlarge. Six eyes with tumor diameter ranging from 1.0 to 2.5 DD, visual acuity was 0.06 to 0.6 at first diagnosis, accompanied by retinal exudation. 5 eyes were treated with PDT alone, and 1 eye was treated with PDT combined with anti-vascular endothelial growth factor drugs. The follow-up time was 12 to 84 months. At the last follow-up, the visual acuity improved or stabilized in 5 eyes and decreased in 1 eye. There were 6 eyes with peripheral RCH, including 4 eyes with retinal detachment, 2 eyes with epiretinal membrane, and 1 eye with vitreous hemorrhage. The visual acuity at the first visit was 0.02-0.6. All patients were treated with PDT combined with transpupillary thermotherapy, extrascleral drainage, and vitrectomy. The follow-up time was 12 to 132 months. At the last follow-up, all eyesight decreased.ConclusionsVisual decrease cause by JRCH often occurs at young adults. Bilateral JRCH are more common in patients with von Hippel-Lindau's disease. The tumor can cause retinal exudation, macular edema, epiretinal membrane and macular hole, resulting in gradual vision loss. PDT and/or combined anti-vascular endothelial growth factor drugs for medium sized JRCH with retinal exudation can maintain long-term vision stability. Patients with large JRCH or severe complications such as retinal detachment tend to have poor prognosis.

    Release date:2021-06-18 01:57 Export PDF Favorites Scan
  • The fast blood flow density of intermediate choroid in endogenous Cushing syndrome: analysis of optical coherence tomography angiography

    ObjectiveTo compare the fast blood flow density (FBFD) of intermediate choroid between endogenous Cushing syndrome (ECS) patients and healthy control subjects.MethodsThirteen eyes of 7 eligible ECS patients (ECS group) and 13 eyes of 7 gender, age, axial length matched healthy volunteers (control group) were enrolled in this study. For each subject, macular radial scan with swept source optical coherence tomography (SS-OCT) was performed and subfoveal choroidal thickness (SCT) was measured. Then 3.0 mm×3.0 mm macular scan with SS-OCT angiography was performed, and selected blood flow image at intermediate choroid level or 1/2 SCT beneath Bruch membrane. The grayscale images were then binarized for the analysis of FBFD.ResultsThe SCT in ECS group was (394.7±77.7) μm, which was significantly thicker than (332.1±68.1) μm in control group (t=2.923, P=0.008). The FBFD of intermediate choroid in ECS group were (76.35±14.46)%, which were significantly greater than (63.57±13.42)% in control group (t=2.775, P=0.01).ConclusionECS patients had increased FBFD at intermediate choroid level compared with healthy controls.

    Release date:2017-07-17 02:38 Export PDF Favorites Scan
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