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        find Keyword "ptical coherence tomography" 95 results
        • Research progress on microcystic macular edema in glaucoma: current status

          Microcystic macular edema (MME) represents a pathological change that can be observed in the inner layer of the retina in patients diagnosed with glaucoma. This phenomenon is particularly prevalent in individuals with moderate to advanced glaucoma. The majority of research in this field has focused on primary open-angle glaucoma. The occurrence of MME in glaucoma has been demonstrated to be associated with younger age, advanced stage and disease progression. MME occurs in the parafoveal region, most frequently located in the inferior perimacular region, which corresponded with the most vulnerable area of ganglion cells in glaucoma. The presence of MME may affect the automatic layering of optical coherence tomography images, suggesting that clinicians should be mindful of the occurrence of MME to avoid misdiagnosis of the disease. It is hypothesised that the occurrence of MME in glaucoma may be related to macular vitreous traction, mechanical stress of the stent, and Müller cell dysfunction. A comprehensive investigation of the precise pathophysiological mechanism of MME in glaucoma will facilitate the development of a novel perspective and a scientific foundation for the diagnosis, disease monitoring and evaluation of treatment efficacy in glaucoma.

          Release date:2025-04-18 10:14 Export PDF Favorites Scan
        • Relationship between retinal thickness at the macular area and axial length in myopia

          Objective To evaluate the correlation between retinal thickness (RT) at the macular area and the axial length (AL) in myopia. Mehtods Optical coherence tomography (OCT) was used to detect the RT at the macular fovea, and at the superior, nasal, inferior, and temporal side of the fovea and parafovea area. The AL of the examined eye was measured by IOL master measuring machine, and the correlation between RT at the macular area and the Al was evaluated. Results The minimum RT in the macular area in the eyes with myopia was (150.90plusmn;22.10)mu;m.The retina at the temporal side of parafovea was the thinnest. The average RT in the areas around the fovea was negatively correlated with the AL, and there was no correlation among the minimum RT, the mean RT at the fovea, and the AL of eye. Conclusions As the AL of eye increases, the RT at the parafovea decreases, while the minimum and the average RT at the fovea remain unchanged.  (Chin J Ocul Fundus Dis, 2006, 22: 397-399)

          Release date:2016-09-02 05:51 Export PDF Favorites Scan
        • An optical coherent imaging system for measuring the strain of blood vessels

          We aimed to establish an optical coherence tomography (OCT) system to measure the strain of blood vessels. A general OCT system was constructed firstly and its reliability was confirmed by comparing the OCT imaging of the porcine coronary and the corresponding histological slices. The strain of the porcine coronary was induced by static flow pressure and correlation algorithm was used to calculate the strain field of blood vessels within OCT images. The results suggest that bright-dark stratification of blood vessels displayed in OCT images is consistent with the intima and media layers of histological image. Furthermore, the strain of media layer is greater than that of the intima layer under the same static pressure. The optical coherence imaging system could not only measure the histological structure of the blood vessels, but also qualify the vessel strain under flow pressure.

          Release date:2017-10-23 02:15 Export PDF Favorites Scan
        • Optical coherence tomography of idiopathic macular epiretinal membranes

          Objective To study the characteristics of optic al coherence tomography (OCT) in idiopathic macular epiretinal membranes (IMEM) and the relationship between the thickness of fovea and the vision of affected eyes. Methods Total of 67 cases (73 eyes) with clinica l diagnosis of IMEM by direct, indirect ophthalmoscopy, three mirror contact len s, fundus color photography or fundus fluorescein angiography(FFA)were examined with OCT. Results Epiretinal membranes(ERMs) with macular edema were found in 32 eyes, proliferative ERMs in 20 eyes, ERMs with macular pseudoholes in 14 eyes and ERMs with laminar macular holes in 7 eyes. Based on OCT, the ERMs were clearly and partially seperated from the retina (27 eyes, 38.36%), the retinal thickness of the fovea was the thickest in proliferative ERMs and the thinnest in ERMs with laminar macular holes. The statistical an alysis showed there was a negative correlation between the thickness of fovea an d visual acuity (r=-0.454, P= 0.000 ). Conclusion There were four types of image of OCT in IMEM: ERMs with macularedema, proliferative ERMs, ERMs with macular pseudohole and ERMs with laminar macular hole;and the thicker the fovea under the OCT, the poorer th e visual acnity in the affected eyes with ERMs. (Chin J Ocul Fundus Dis, 2001,17:115-118)

          Release date:2016-09-02 06:03 Export PDF Favorites Scan
        • Efficacy of optical coherence tomography angiography guided half-dose photodynamic therapy in the treatment of acute central serous chorioretinopathy

          ObjectiveTo observe the efficacy of optical coherence tomography angiography (OCTA) guided half-dose photodynamic therapy (PDT) in the treatment of acute central serous chorioretinopathy (CSC). MethodsA prospective randomized controlled trial. A total of 72 patients (72 eyes) with acute CSC in Peking University People's Hospital from April 2019 to April 2020 were included in the study. They were randomly divided into OCTA group (OCTA-guided PDT, 31 eyes of 31 patients) and indocyanine green angiography (ICGA) group (ICGA-guided PDT, 33 eyes of 33 patients). All patients underwent best corrected visual acuity (BCVA), fundus color photography, OCTA and ICGA examinations. International standard visual acuity chart was used for BCVA examination, which was converted into logarithm of the minimum angle of resolution (logMAR) visual acuity. In OCTA group, the hyper-reflective area on en face OCTA image at choriocapillaris level was identified as treating area. In ICGA group, the area of choroidal vascular hyperpermeability on ICGA which was related to the leakage on fundus fluorescein angiography (FFA) was identified as treating area. The area corresponding to the treating area on FFA or ICGA was outlined on the color fundus photograph to guide PDT laser spot. The complete subretinal fluid (SRF) resolution, BCVA, central retinal thickness (CRT) at 1, 3, 6 months and SRF recurrent rate at 3, 6 months were observed. Continuous variables between the two groups were compared by t-test or Wilcoxon rank sum test. The χ2 test was used to compare the categorical variables. ResultsAt 1, 3 and 6 months after treatment, the SRF absorption rate in OCTA group and ICGA group was 74.2% (23/31), 63.6% (21/33), 87.1% (27/31) and 84.8% (28/33), 96.8% (30/31), 91.9% (31/33), respectively. OCTA-guided PDT was demonstrated noninferior to ICGA-guided PDT for complete SRF resolution at 1, 3, 6 months [95% confidence interval (CI) -11.9%-33.1%, P=0.402; 95%CI -14.7%-19.3%, P=0.107; 95%CI -6.3%-16.1%, P=0.226]. There was no significant difference in the recurrence rate of SRF between the two groups at 3 and 6 months after treatment (χ2=0.009, 0.047; P=0.925, 0.828). The difference of CRT was statistically significant at 6 months (t=2.017, P=0.047). There was no significant difference in logMAR BCVA at 1, 3 and 6 months after treatment (t=0.529, 0.762, 1.017; P=0.581, 0.403, 0.243). ConclusionsDuring 6 months follow-up, OCTA-guided PDT was demonstrated noninferior to ICGA-guided PDT for the SRF absorption rate in patients with acute CSC.

          Release date:2023-05-18 10:05 Export PDF Favorites Scan
        • Distribution of choroidal thickness and its influencing factors in undergraduate students of Tianjin Medical University

          ObjectiveTo explore the distribution of choroidal thickness and its influence factors in university students.MethodsA cross-sectional study. A total of 896 eyes of 896 college students were included in the study. Among them, there were 350 males (350 eyes) and 546 females (546 eyes). All the eyes were right eyes. The average age was 19.18 ± 1.36 years old. According to the spherical equivalent refraction (SER), the eyes were divided into non-myopia group, low myopia group, moderate myopia group and high myopia group, which were 59, 251, 356 and 230 eyes, respectively. The subfoveal ChT (SFCT) was measured using a swept-frequency source optical coherence tomography scanner. According to the ETDRS, the choroid within 6 mm of the fovea was divided into three concentric circles centered on the fovea of the macula, which were the central area with a diameter of 1 mm, the inner ring area of 1-3 mm and the outer ring area of 3-6 mm. The outer ring area of 3-6 mm has a total of 9 zones. The inner ring and outer ring 4 regions were superior, inferior, nasal and temporal, respectively. The distribution characteristics of ChT in different regions, genders and diopter groups were observed. Bivariate correlation analysis were used to analyze the correlation of ChT and SER, axial length (AL).ResultsThe average SFCT of 896 eyes was 221.28±67.35 μm. The mean SFCT of males and females were 227.20±69.38 and 217.50±65.80 μm, respectively. The difference of SFCT between different genders was statistically significant (t=2.075, P=0.038). Compared with the central region ChT, there was no significant difference in ChT between the outer ring and the outer region (t=0.086, P=0.932). The difference of ChT in other regions was statistically significant (t=-21.973, -5.818, 36.328, -3.065, -18.017, -10.595, 57.007; P<0.001, <0.001, <0.001, <0.002, <0.001, <0.001, <0.001). In the horizontal direction, ChT gradually thickens from nasal to temporal (F=2 251.558, P<0.001); in the vertical direction, ChT gradually decreases from superior to the central, but have a little increased from central to inner inferior, then decreased to outer inferior again (F=45.425, P<0.05). Correlation analysis showed that SFCT was negatively correlated with AL (r=0.478, P<0.01) and a negative correlation with axial length (r=?0.395, P<0.01), and positively correlated with SER (r=0.478, P<0.01). SFCT decreased by 12.29 μm for every in myopic refractive error of 1 D, or by 20.14 μm for every increase in AL of 1 mm.ConclusionsChT is changed by different location. The horizontal direction is gradually thickened from nasal to temporal. The vertical direction is thicker than the center. The inferior inner ring area is thicker than the outer ring area. Gender, SER and AL are the influencing factors of SFCT.

          Release date:2018-07-23 04:02 Export PDF Favorites Scan
        • The objective evaluation of the postoperative changes of anatomical structures in macular diseases

          Objective To evaluate different methods in determ ining the postoperative changes of anatomical structures in macular diseases. Methods Thirty-one eyes of 31 cases of macular diseases, were studied among them there were 15 eyes with idiopathic macular hole (IMH),and the others included 8 eyes with macular epiretinal membranes(ERMs), 4 eyes with age relate d macular degeneration(AMD) and 4 eyes with idiopathic submacular neovasculariza tions(SRNV). All cases were examined with retinoscope or retinogra phy, fundus fluorescein angiography (FFA) and optical coherence tomography (OCT ) pre-and postoperatively. Results Funduscopy showed that all of the 15 IMHs were closed after operation, but OCT showed th at among them 2 affected eyes still had partial retinal detachment at the macular hole edge in one quadrant and the sensory layer in macular area became thinner in 1 affected eye. FFA revealed damage of retinal pigment epithelium (RPE) in 5 cases. As for the ERMs and SRNV, funduscopy could n ot identify wether they were completely removed or not after operation. FFA ind icated that SRNV and SRNV were completely removed and the damage of RPE.OCT discovere d that the ERMs and SRNV were completely removed and the sensory layer became th inner in 3 eyes. Conclusion The combination of funduscopy , FFA and OCT can get the whole view of macular diseases and their postopera tive anatomical evaluation. (Chin J Ocul Fundus Dis, 2001,17:33-36)

          Release date:2016-09-02 06:03 Export PDF Favorites Scan
        • Observation on the blood flow changes around the optic disc before and after the combined treatment of anti-vascular endothelial growth factor and Dexamethasone intravitreal implant for central retinal vein occlusion

          ObjectiveTo observe changes in peripapillary blood flow before and after combined treatment with anti-vascular endothelial growth factor (VEGF) drugs and Dexamethasone intravitreal implant (DEX) in patients with central retinal vein occlusion (CRVO). MethodsA prospective clinical study. Thirty-three eyes of 33 patients with newly diagnosed non-ischemic CRVO and macular edema (ME) were enrolled from Shanxi Eye Hospital between April 2023 and April 2024. All patients underwent best-corrected visual acuity (BCVA) and swept-source optical coherence tomography angiography (SS-OCTA) examinations. The treatment regimen consisted of three intravitreal injections of ranibizumab and one DEX implant. SS-OCTA was used to scan a 3 mm×3 mm area centered on the optic disc to measure peripapillary retinal nerve fiber layer (RNFL) thickness and blood flow density in the superficial vascular complex (SVC), deep vascular complex (DVC), and radial peripapillary capillaries (RPC). Changes in SVC, DVC, and RPC blood flow density and RNFL thickness were evaluated at 3 and 6 months post-treatment. Shapiro-Wilk test was used to assess normality, and Spearman's rank correlation coefficient was applied for correlation analysis. ResultsCompared with before treatment, the blood flow density changes of SVC and RPC showed a downward trend at 3 and 6 months after treatment. Among them, the difference was statistically significant at 6 months after treatment (Z=?2.592, ?2.070, P=0.012, 0.042), while there was no statistically significant difference at 3 months after treatment (P>0.05). The blood flow density of DVC showed an upward trend at 3 and 6 months after treatment, but the differences were not statistically significant (P>0.05). The results of the correlation analysis showed that the thickness of RNFL was negatively correlated with the blood flow density of DVC (r=?0.768, P<0.001). It was positively correlated with the blood flow densities of SVC and RPC (r=0.288, 0.398; P=0.040, 0.004). ConclusionAnti-VEGF drugs combined with DEX treatment can significantly improve the perioptic disc blood flow distribution in eyes with CRVO, manifested as a decrease in blood flow density of SVC and RPC, while a compensatory increase in blood flow of DVC. The thickness variation of RNFL is closely related to the blood flow density of different vascular layers.

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        • Correlation analysis of macular microvascular structure and intraocular fluidin patients with diabetic macular edema

          ObjectiveTo observe and analyze the correlation between the changes of macular microvascular structure and the level of intracocular fluid cytokines in patients with diabetic macular edema (DME). MethodsA prospective clinical study. From December 2022 to June 2024, 20 patients with 25 eyes of DME diagnosed by Department of Ophthalmology of Linyi People's Hospital were included in the study. Among them, 14 males had 17 eyes and 6 females had 8 eyes. Age was (55.08±10.34) years. Optical coherence tomography (OCT) and OCT angiography (OCTA) were used to scan the macular region at a range of 6 mm×6 mm. Central retinal thickness (CRT), blood flow density of superficial retinal capillary plexus (SCP) and area of fovea avascular zone (FAZ) were measured. The anterior aqueous humor was extracted before the first intravitreal injection of anti-vascular endothelial growth factor (VEGF), the concentrations of interleukin (IL-6), IL-8, VEGF, vascular cell adhesion molecule (VCAM), placental growth factor (PLGF) and monocyte chemotactic protein-1 (MCP-1) were detected. The correlation between macular microvascular structure and aqueous humor cytokines was analyzed by Spearman correlation analysis. ResultsThe CRT of the affected eyes was (617.40±167.64) μm, the SCP flow density was (39.56±1.55)%, and the FAZ area was (0.46±0.13) mm2. The concentrations of IL-6, IL-8, VEGF, VCAM, PLGF and MCP-1 in aqueous humor were (301.36±690.52), (29.15±20.56), (71.37±29.32) and (5 621.22±7 241.06), (72.40±13.43), (464.07±163.26) pg/ml, respectively. Correlation analysis showed that there was a significant positive correlation between CRT and the concentrations of aqueous cytokines VEGF and PLGF (r=0.460, 0.462, P<0.05). FAZ area was positively correlated with VEGF and MCP-1 concentrations (r=0.414, 0.465; P<0.05). There was a significant negative correlation between SCP blood flow density and IL-6 (r=0.401, P<0.05). ConclusionThere was a significant correlation between the morphological structure of macular area and the damage degree of microvessels around macular area in DME patients and the concentration of aqueous cytokines.

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        • Evaluation of the efficacy of a customized surgical approach for congenital optic disc pit with maculopathy

          Objective To observe the curative effect of a personalized surgical scheme based on scanning source optical coherence tomography (SS-OCT) image features in the treatment of congenital optic disc pit (ODP) with maculopathy (ODP-M). MethodsA prospective interventional cohort study. From September 2019 to May 2024, 15 patients with 15 eyes who were diagnosed with ODP-M by ophthalmology examination in Department of Ophthalmonogy of The First Affiliated Hospital of Zhengzhou University were included in the study. Best corrected visual acuity (BCVA) and SS-OCT were performed in all affected eyes. Standard E word visual acuity chart was used for BCVA examination, which was converted into logarithm of the minimum angle of resolution (logMAR) BCVA for record. The center retinal thickness (CRT) was measured by SS-OCT examination of macular area using VG200D of Henan SVision Imaging Technology Co., LTD. According to the morphological characteristics of ODP and the splitting, edema and detachment of macular region, combined with the degree of pulling of the boundary membrane between the posterior vitreous cortex and macular region, a personalized surgical method was designed. Class I: pars plana vitrectomy combined with macular boundary film stripping, ODP boundary film packing and vitreous cavity gas filling. Class Ⅱ: pars plana vitrectomy combined with non-retained macular boundary film stripping or ODP inner boundary film packing, vitreous cavity gas filling. Class Ⅰ and Class Ⅱ operations were performed in 10 and 5 eyes of 15 eyes, respectively. The postoperative follow-up time was >6 months. Follow-up time was performed with the same equipment before surgery. BCVA changes, CRT reduction rate and complications were observed. BCVA and CRT were compared before and after operation by paired sample t test. ResultsThere were 15 eyes in 15 cases, 4 eyes in 4 males and 11 eyes in 11 females. The age was (28.87±16.5) years. logMAR BCVA of the affected eye was 0.94±0.51. CRT was (697.80±301.80) μm. At the last follow-up, the logMAR BCVA was 0.53±0.49. CRT was (392.53±167.55) μm. Compared with before operation, BCVA and CRT were significantly improved, and the difference was statistically significant (t=3.23, 3.25; P=0.006, 0.006). After surgery, transient intraocular hypertension occurred in 2 eyes, and the intraocular pressure returned to normal level after 3 to 7 days without special treatment. Two eyes underwent an unexpected second operation. Among them, one eye underwent Class Ⅰ surgery, the tunnel at ODP was closed after surgery, and there was a small amount of subretinal fluid in the macular area. Class Ⅱ surgery was performed in 1 eye with retinal reattachment. ConclusionPersonalized surgical treatment of ODP-M based on SS-OCT image features can reduce CRT and improve visual acuity.

          Release date:2025-05-14 02:04 Export PDF Favorites Scan
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