频域相干光断层深度增强成像技术的研究进展

频域相干光断层深度增强成像(EDI SD-OCT)是在传统频域OCT的基础上改进的能反映脉络膜组织结构的技术.通过将设备进一步靠近受检眼,使更多的光线集中照射在脉络膜内部甚至更深层的巩膜水平从而得到较清晰的脉络膜影像,为观察脉络膜血管结构以及定量测量脉络膜厚度提供依据.目前关于EDI SD-OCT的研究主要集中在脉络膜厚度方面.通过测量脉络膜厚度,不仅可对高度近视、年龄相关性黄斑变性、息肉样脉络膜血管病变等疾病的发病机制进行探讨,还能用于年龄相关性黄斑变性、息肉样脉络膜血管病变、各种脉络膜肿瘤等的鉴别诊断,以及对脉络膜新生血管、Vogt-小柳原田病等治疗后疗效观察,具有较大的应用价值.     

局限性脉络膜凹陷患者的EDI-OCT特征及并发症观察

目的 观察局限性脉络膜凹陷(FCE)患者的增强深部成像光学相干断层扫描(EDI-OCT)的影像学特征及并发症发生情况.方法 将2014年12月至2020年12月在佛山市第二人民医院眼科中心首诊并经EDI-OCT检查确诊的47例47眼FCE患者纳入研究.记录患者的性别、年龄、屈光度、logMAR最佳矫正视力及凹陷的数量、...     

Enhanced depth imaging spectral-domain optical coherence tomography of subfoveal choroidal thickness in normal Japanese eyes

Purpose  

To investigate the subfoveal choroidal thickness of healthy Japanese subjects using enhanced depth imaging optical coherence tomography and to evaluate the association between subfoveal choroidal thickness and age in a group of subjects with a wide age range.     

Enhanced optical coherence tomography imaging by multiple scan averaging

AIMS: To describe a method for computerised alignment and averaging of sequences in optical coherence tomography (OCT) B-scans and to present selected clinical observations based on the resulting improvement in retinal imaging. METHODS: A methodological study and retrospective investigation of selected cases. Five human subjects were included, one healthy subject, two patients with central serous chorioretinopathy, one patient with branch retinal vein occlusion, and one patient with cilioretinal artery pseudo-occlusion. Based on computerised alignment of sets of B-scans obtained at identical retinal locations, average OCT images were produced and displayed in false colour or grayscale. These enhanced tomograms were compared with other morphological and functional characteristics. RESULTS: Improved retinal imaging enabled assignment of the OCT image to retinal anatomy particularly at the outer layer of the photoreceptors and the retinal pigment epithelium, both in the healthy eye and in pathology. Identification of both post-oedematous structural disorganisation as well as post-ischaemic attenuation of the inner retina was superior to standard OCT images. CONCLUSIONS: Averaging of multiple OCT B-scans enhances the quality of retinal imaging sufficiently to reveal new details of retinal pathophysiology. Using the technique on OCT3 scans enables visualisation of details comparable with the results obtained using ultra high resolution OCT.     

Enhanced vitreous imaging optical coherence tomography in primary macular holes

The aim of the current pilot study is to investigate the efficacy of a novel enhanced vitreous imaging (EVI) in primary macular holes (MHs) using a spectral-domain optical coherence tomography (SD-OCT). Thirty-four eyes of 32 consecutive patients with a MH were examined in one time cross-sectional study. The vitreomacular interface was assessed using SD-OCT with conventional and EVI technique. Twenty-three of the 34 eyes did not show a Weiss ring, and in 22 of those, we observed a MH with an open roof or operculum and a detached posterior vitreous cortex with conventional vitreous imaging. Using EVI-OCT, we visualized the reflection of the posterior vitreous with a vitreopapillary attachment. One of the 23 eyes without a Weiss ring had a central round retinal defect without an operculum, and the conventional SD-OCT showed an empty vitreous, suggesting a complete posterior vitreous detachment. However, the EVI-OCT revealed the reflection of the posterior vitreous, and the cortex appeared to still be completely attached. In all the 23 eyes without a Weiss ring, EVI-OCT detected the reflection of the posterior vitreous and vitreopapillary attachment. In all 11 eyes with a Weiss ring (stage 4 hole), EVI-OCT showed an optically empty space in the posterior vitreous cavity without a vitreopapillary attachment. EVI-OCT may be a new reliable method for preoperative evaluations to determine the presence or absence of a complete posterior vitreous detachment in macular diseases with an indistinct Weiss ring.     

In vivo quantification of human aqueous veins by enhanced depth imaging optical coherence tomography and optical coherence tomography angiography images

AIM: To investigate the aqueous vein in vivo by using enhanced depth imaging optical coherence tomography (EDI-OCT) and optical coherence tomography angiography (OCTA). METHODS: In this cross-sectional comparative study, 30 healthy participants were enrolled. Images of the aqueous and conjunctival veins were captured by EDI-OCT and OCTA before and after water loading. The area, height, width, location depth and blood flow of the aqueous vein and conjunctival vein were measured by Image J software. RESULTS: In the static state, the area of the aqueous vein was 8166.7±3272.7 μm2, which was smaller than that of the conjunctival vein (13 690±7457 μm2, P<0.001). The mean blood flow density of the aqueous vein was 35.3%±12.6%, which was significantly less than that of the conjunctival vein (51.5%±10.6%, P<0.001). After water loading, the area of the aqueous vein decreased significantly from 8725.8±779.4 μm2 (baseline) to 7005.2±566.2 μm2 at 45min but rose to 7863.0±703.2 μm2 at 60min (P=0.032). The blood flow density of the aqueous vein decreased significantly from 41.2%±4.5% (baseline) to 35.4%±3.2% at 30min but returned to 45.6%±3.6% at 60min (P=0.021). CONCLUSION: The structure and blood flow density of the aqueous vein can be effectively evaluated by OCT and OCTA. These may become biological indicators to evaluate aqueous vein changes and aqueous outflow resistance under different interventions in glaucoma patients.     

Standardization of choroidal thickness measurements using enhanced depth imaging optical coherence tomography

AIM:To describe and evaluate a standardized protocol for measuring the choroidal thickness (ChT) using enhanced depth imaging optical coherence tomography (EDI OCT).METHODS:Single 9 mm EDI OCT line scans across the fovea were used for this study. The protocol used in this study classified the EDI OCT images into four groups based on the appearance of the choroidal-scleral interface and suprachoroidal space. Two evaluation iterations of experiments were performed:first, the protocol was validated in a pilot study of 12 healthy eyes. Afterwards, the applicability of the protocol was tested in 82 eyes of patients with diabetes. Inter-observer and intra-observer agreements on image classifications were performed using Cohen’s kappa coefficient (k). Intraclass correlation coefficient (ICC) and Bland-Altman’s methodology were used for the measurement of the ChT.RESULTS:There was a moderate (k=0.42) and perfect (k=1) inter- and intra-observer agreements on image classifications from healthy eyes images and substantial (k=0.66) and almost perfect (k=0.86) agreements from diabetic eyes images. The proposed protocol showed excellent inter- and intra-observer agreements for the ChT measurements on both, healthy eyes and diabetic eyes (ICC>0.90 in all image categories). The Bland-Altman plot showed a relatively large ChT measurement agreement in the scans that contained less visible choroidal outer boundary.CONCLUSIONS:A protocol to standardize ChT measurements in EDI OCT images has been developed; the results obtained using this protocol show that the technique is accurate and reliable for routine clinical practice and research.