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find Keyword "体层摄影术,光学相干" 203 results
  • Research progress in the pathogenesis and imaging of peripapillary intrachoroidal cavitation

    Peripapillary intrachoroidal cavitation (PICC) is a common pathological change observed in high myopia. The exact pathogenesis of PICC is still unclear. Expansion and mechanical stretching of the peripapillary sclera, breakage and defect in the retina near the border of the myopic conus and communication between intrachoroidal cavity and the vitreous space may be important segments during the development of PICC. Color fundus photography shows a localized and well-circumscribed peripapillary lesion with yellow-orange colour, often accompanied by fundus changes, such as myopic conus excavation, optic disc tilting and inferotemporal retinal vein bending at the transition from the PICC to the myopic conus. However, the PICC lesion is not easy to be recognized in the fundus photography. Fluorescein angiography shows early hypofluorescence and later progressively staining in the lesion. Indocyanine green angiography shows hypofluorescence throughout the examination. Optical coherence tomography (OCT) is vital in diagnosing PICC. Hyporeflective cavities inside the choroid, sometimes communicating with the vitreous chamber, can be observed in OCT images. OCT angiography indicates lower vessel density or even absence of choriocapillary network inside or around PICC lesions.

    Release date:2017-09-19 03:09 Export PDF Favorites Scan
  • Changes in the vessel densities of macular and optic nerve head and their relationships with axial length in pathological myopia

    ObjectiveTo observe the changes of vessel densities (VD) in the macula and optic disc and its correlation with axial length (AL) in pathological myopia (PM). MethodsA retrospective clinical study. A total of 171 eyes from 171 patients admitted to Department of Ophthalmology of Jinshan Hospital of Fudan University from June 2019 to December 2019 were included in this study. Among them, there were 72 males and 99 females; age was 35.0±10.8 years old. The patients were divided into PM group, high myopia (HM) group and non-HM group, 51 cases with 51 eyes, 70 cases with 70 eyes, and 50 cases with 50 eyes, respectively. Optical coherence tomography angiography was used to scan the macular and optic disc areas of all the examined eyes in the range of 6 mm×6 mm. According to the early treatment of diabetic retinopathy study, the 6 mm macular and optic disc scan range was centered on the macular fovea and optic disc, respectively, then divided into two concentric circles with diameters of 1 mm of central area, an annulus between 1-3 mm circles of paracentral area. The paracentral area was divided into superior, inferior, nasal, temporal four quadrants by 2 radiation lines. The VD of superficial capillary plexus (SCP), deep capillary plexus (DCP), outer retina, and choriocapillaris layer were calculated in the central, superior, inferior, nasal, and temporal areas, respectively. The VD of PM, HM and non-HM groups were compared. The variance analysis was used to compare the VD among the three groups; Pearson’s correlation was used to assess the correlation between VD and AL. ResultsThe perifoveal VD of the SCP, outer retina and choriocapillaris layers were all lower in the PM than those of HM and non-HM group, and the differences were statistically significant (P<0.05). The VD of DCP macular central was higher in the PM than in the HM group, and the difference was statistically significant (P=0.020). In the optic disc, the VD were lower in the PM group than in the non-HM group except for the area of DCP superior, inferior, temporal, outer retinal center, and the differences were statistically significant (P<0.05). The results of correlation analysis showed that the VD in the DCP macular central, ONH superior and the choriocapillaris ONH central were not correlated with AL (P=0.647, 0.688, 0.146), and the other VDs were negatively correlated with AL (P<0.05). ConclusionCompared with HM and non-HM groups, the majority of VDs in macular and ONH are lower in participants with PM.

    Release date:2022-07-18 03:05 Export PDF Favorites Scan
  • One year clinical results of different surgical methods in the treatment of idiopathic macular hole

    ObjectiveTo observe the effect of 25G pars plana vitrectomy (PPV) combined with or without internal limiting membrane (ILM) flap and sterile air or perfluoropropane (C3F8) tamponade in the treatment of idiopathic macular hole (IMH).MethodsA retrospective case analysis. From December 2015 to December 2016 in Tianjin Eye Hospital, 101 eyes of 98 consecutive IMH patients who underwent 25G PPV combined with or without ILM flap and sterile air or C3F8 tamponade, were included in this study. All patients underwent BCVA and OCT examination. The BCVA examination was performed using the international standard visual acuity chart, which was converted into logMAR visual acuity. The patients were divided into three groups according to preoperative minimum liner diameter of Hole (MLD) and surgical methods: MLD<400 μm for the group A, 41 eyes of 39 patients, MLD more than 400 μm without ILM flap surgery as the group B, 39 eyes of 38 patients, including 16 eyes tamponaded with air and 23 eyes tamponaded with C3F8, MLD more than 400 μm with ILM flap as the group C, a total of 21 patients of 21 eyes, including 7 eyes tamponaded with air and 14 eyes tamponaded with C3F8. The logMAR BCVA of group A, B and C were 0.82±0.39, 1.11±0.42, 1.25±0.50, respectively. The follow-up times were 1 week, 1 month, 3 month, 6 month and 1 year post operation, BCVA and OCT were performed at each follow-up time. The hole closure rate and BCVA improvement were observed.ResultsThe postoperative BCVA of group A, B and C was improved obviously, the differences were statistically significant (t=−11.66, −7.52, −4.99; P<0.01). There was no significant difference in improvement of visual acuity between the three groups (A and B, A and C, B and C group: t=0.77, −0.41, 0.28; P=0.44, 0.72, 0.76). 96.94% macular hole closure occurred in 7 days post operation. The postoperative visual acuity improved significantly in 3 mouth after operation,ConclusionsThe macular hole closure occurred mainly in 1 week after operation, postoperative visual acuity increased mostly in the 3rd month post operation. There is no advantage of ILM flap in improve postoperative visual acuity of IMH patients with MLD more than 400 μm.

    Release date:2020-01-11 10:26 Export PDF Favorites Scan
  • Clinical application and new progress of optical coherence tomography in detecting lamina cribrosa structure

    The lamina cribrosa (LC) is a complicated collagenous meshwork of trabeculae and laminar pores contain capillaries, nerves and neurogliocytes, which provides structural and nutrient support to the retinal ganglion cell axons as they exit the eye. The intraocular pressure causes direct damage or deformation and remodeling of LC, leads to axoplaxmic transport and blood supply disturbance. The preponderance of evidence suggests that LC is the principal site of glaucomatous damage. The development of optic coherence tomography (OCT) technology has improved the imaging quality of deep structures of the optic nerve head and makes it possible to detect LC. The quantitative research indexes of LC structure include LC depth, laminar curvature, laminar thickness, prelaminar tissue, laminar pore, laminar defect and hemodynamics. To improve the understanding of LC structure, explore the characteristics of LC and understand the biomechanical and hemodynamic pathogenesis of glaucoma, which would be contribute to the application of big data research in the diagnosis and treatment of glaucoma.

    Release date:2021-03-19 07:10 Export PDF Favorites Scan
  • 光相干断层扫描血管成像对息肉样脉络膜血管病变异常分支血管网及息肉样病灶的检出率分析

    Release date:2018-01-17 03:16 Export PDF Favorites Scan
  • Retinal thickness changes of diabetes patients after short-term insulin intensive treatment

    Objective To observe retinal thickness changes of diabetes patients after shortterm insulin intensive treatment. Methods Thirty-two eyes of 32 diabetes patients with non-proliferative diabetic retinopathy who underwent short-term insulin intensive treatment were enrolled in this study. There were 12 males and 20 females. The patients aged from 35 to 72 years with a mean age of (56plusmn;9) years. The macular edema index (MED) and morphosis parameter of the optic disc including cup area (CA), rim area (RA), cup volume (CV), rim volume (RV), mean retinal nerve fiber layer thickness (mRNFLT), height variation contour (HVC), the ratio of cup/rim area (C/DAR) in all the patients were measured by Heidelberg retinal tomography Ⅱ (HRTⅡ) before treatment and at the 1st, 3rd and 6th month after treatment. The repeated measurement and leastsignificant difference (LSD) pairwise comparison statistical methods were used to analyze the data. Results At the 1st, 3rd and 6th month after treatment, the 1string and the 2nd-ring MED both decreased after treatment, which were significantly different compared with before treatment (1st-ring: t=2.169, 2.261, 2.306; P<0.05. 2nd-ring: t=2.293, 2.147, 2.038; P<0.05).There was no significant difference on the 3rd-ring MED between before and after treatment (t=1.719, 1.145, 1.280; P>0.05). There was no significant difference in CA, RA, CV, RV, mRNFLT and C/DAR between before and after treatment. There was significant difference in HVC between before treatment and at the 1st month after treatment (t=-2.242, P=0.037), but no significant differences at the 3rd and 6th month after treatment (t=-1.485, -0.527; P>0.05). Conclusions The MED of diabetes patients decreases within six months after short-term insulin intensive treatment, but there is no obvious change in morphosis parameters of the optic disc.

    Release date:2016-09-02 05:25 Export PDF Favorites Scan
  • 频域光相干断层扫描分层分析及其在眼科疾病中的应用

    光相干断层扫描(OCT)作为一种快速非侵入性和非接触性的检查技术,能对视网膜的解剖结构进行高分辨率的重建。OCT分层分析是随着高分辨率第四代频域(SD)OCT(SD-OCT)广泛应用衍生出来的研究疾病的新方法,能够确定内界膜到Bruch膜之间不同视网膜结构层面的边界并测量相应层面的视网膜结构厚度或面积。有助于对视网膜病变结构和功能研究深入到更细微层面;对了解相关疾病的发生机制,监测评估及早期诊断将会产生深远的影响。但目前分层分析方法尚不十分成熟,在临床或实验过程中,测量时仍存在一定的误差和局限性。还需要以科学审慎的态度解读SD-OCT分层分析的结果,以便客观正确应用这一技术,推动我们对疾病发生发展过程中不同视网膜层面改变的认识不断深入。

    Release date:2016-09-02 05:22 Export PDF Favorites Scan
  • Expanding the analysis of optical coherence tomography images

    Optical coherence tomography (OCT), as a high-resolution, non-invasive, in-vivo image method has been widely used in retinal field, especially in the examination of fundus diseases. Nowadays, the modality has been gradually popularized in most of the national basic-level hospitals. However, OCT is only employed as a diagnostic tool in most cases, ophthalmologists lack of awareness of further exploring the information behind the raw data. In the era of fast-developing artificial intelligence, on the basis of standardized information management, a more comprehensive OCT database should be established. Further original image processing, lesion analysis, and artificial intelligence development of OCT images will help improve the understanding level of vitreoretinal diseases among clinicians and assist ophthalmologists to make more appropriate clinical decisions.

    Release date:2022-12-16 10:13 Export PDF Favorites Scan
  • Changes of choroidal thickness in patients with superior temporal branch retinal vein occlusion complicated with macular edema

    ObjectiveTo observe the characteristics of choroidal thickness in patients with macular edema secondary to superior temporal branch retinal vein occlusion (BRVO-ME). MethodsA retrospective control study. From November 2020 to September 2021, 30 patients (30 eyes) with BRVO-ME (BRVO-ME group) were diagnosed by ophthalmology examination in Department of Ophthalmology, The Affiliated Hospital of Chengde Medical College and 14 healthy volunteers (28 eyes) were enrolled in the study. The choroidal thickness of macular area was measured by enhanced deep imaging technique of frequency domain optical coherence tomography. According to the subdivision of the diabetic retinopathy treatment group, the choroid within the 6 mm of the macular fovea was divided into three concentric circles with the macular fovea as the center, namely, the central area with the diameter of 1 mm, the inner ring of 1-3 mm and the outer ring of 3-6 mm. The inner ring area and the outer ring area are divided into upper, lower, nasal and temporal sides, respectively, which are denoted as S3, I3, N3, T3 and S6, I6, N6, T6, totaling 9 areas. To observe the distribution characteristics of choroidal thickness in different regions of two groups of eyes. The choroidal thickness of different macular regions was compared by independent sample t-test. ResultsThe choroidal thicknesses in the central area, S3, T3, I3, N3, S6, T6, I6, and N6 of the eyes in the control group and BRVO-ME group were 214.11±56.04, 207.89±57.92, 214.07±54.82, 207.14±61.54, 180.18±53.53, 204.25±59.60, 193.93±51.50, 190.54±51.21, 139.82±39.84 μm and 258.00±71.14, 256.43±68.70, 252.07±72.97, 244.37±68.49, 243.10±70.93, 247.20±68.36, 221.00±61.28, 223.77±58.64, 183.20±60.15 μm. In both groups, the choroidal thickness was the thickest in the central area, gradually thinning to the nasal side and temporal side, and the nasal choroidal thickness was thinner than other regions, and N6 area was the thinnest. Compared with the control group, the choroidal thickness of central area, S3, T3, I3, N3, S6, I6 and N6 in BRVO-ME group were significantly thicker (t=-2.899, -2.229, -2.172,-3.250, -2.543, -2.292, -3.214; P<0.05), there was no significant difference in T6 area (t=-1.814, P=0.075). ConclusionThe choroidal thickness of macular area in patients with BRVO-ME is thicker than that in normal subjects.

    Release date:2022-10-14 04:28 Export PDF Favorites Scan
  • The image characteristics of spectral-domain optical coherence tomography on retinal tuft

    Objective To describe the spectral-domain optical coherence tomography (SD-OCT) features of retinal tuft. MethodsA retrospective clinical study. From May 2019 to April 2020, 22 patients (22 eyes) diagnosed as retinal tuft by clinical fundus examination in Eye Hospital of Wenzhou Medical University at Hangzhou were included in the study. There were 9 eyes in 9 males and 13 eyes in 13 females. All patients underwent ultra-widefield laser scanning fundus photography and SD-OCT examination. SD-OCT was performed with a 55° wide-angle lens to observe the morphology, color, size and location of the lesions. ResultsTwenty-six retinal tuft lesions were found in 22 eyes, all of which were solitary, gray, thylakoid and protrusion. SD-OCT images showed that all the lesions of retinal tuft showed a local protuberant appearance with moderate and hyperreflectivity, which was higher than the surrounding retina plane. In 22 lesions (84.62%, 22/26), there were one or more irregular hyporeflective cavities between the retinal neuroepithelial layers, and the other 4 lesions (15.38%,4/26) contained no hyporeflective cavities. In addition, 23 cases (88.46%, 23/26) with hyperreflective condensed cortical vitreous attached to the retina at the top of lesions, 8 cases (30.77%, 8/26) with retinal tear, and 6 cases (23.08%, 6/26) with shallow retinal detachment. ConclusionsIn SD-OCT, the retinal tufts show moderate and strong local protrusion, which are higher than the surrounding retinal plane. In most of the lesions, there are multiple or single irregular weak reflex cavities, and there are hyperreflective condensed cortical vitreous attached to the retina at the top of lesions. Local retinal tears or shallow retinal detachment are present in some lesions.

    Release date:2022-12-16 10:13 Export PDF Favorites Scan
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