Objective To observe the performance of hyperspectral non-mydriatic fundus camera prototype and its application on ocular fundus diseases. Methods The narrow band filters was inserted into the optical path of the Canon non-mydriatic retinal camera (CR-DGi). The image was converted to digital data by charge-coupled device (CCD), and then analyzed by hyperspectral data software. Twelve volunteers were examined by hyperspectral nonmydriatic fundus camera prototype to confirm the characteristic wavelength spectrums of ocular fundus diseases and the repeatability of prototype. Fifty-nine patients with ocular fundus diseases who underwent fluorescein angiography were also examined by hyperspectral non-mydriatic fundus camera prototype, to compared the images of prototype and fluorescein angiography. Results Each of the highest power of the light at the focus point and the power per unit were safe. 536, 547, 579 nm were selected as the specific retinal imaging spectrums and 608 nm as the specific choroidal imaging spectrum. The intra-observer and inter-observer reproducibility was equal or greater than 0.85. The correlation between hyperspectral non-mydriatic fundus camera prototype and fluorescein angiography in choroidal neovascularization patients were 0.782 and 0.833. Conclusions The hyperspectral nonmydriatic fundus camera prototype is safe and reliable. It shows pathological retinal and choroidal structures with specific spectrums. There are good prospects for the application in clinical diagnosis, especially for macular diseases.
Objective lt;brgt;To investigate the morphological features of choroidal neovascularization (CNV) in central exudative chorioretinopathy (CEC) using optical coherence tomography（OCT）. lt;brgt; lt;brgt;Methods lt;brgt;OCT and fundus fluorescein angiography (FFA) were performed in 41 cases (43 eyes) of CEC,and the course of CEC disease was from 1 week to 10 months. Twenty-seven of 43 eyes were also examined by indocyanine green angiography (ICGA). lt;brgt; lt;brgt;Results lt;brgt;OCT images revealed 5 kinds of morphological features of CEC: well-defined CNV（41.86 %）,poorly-defined CNV(30.23 %),hemorrhagic pigment epithelium detachment （PED）(16.28 %), CNV companied with serous (6.98 %) or hemorrhagic neurosensory retina detachment (4.65 %). CNV mainly showed well-defined and poorly-defined CNV (72.09 %).In those eyes that could clear define the CNV boundary,there were 12 eyes on FFA examination and 20 eyes on ICGA examination which defined the boundary from retinal horizontal plane, while there were 23 eyes on OCT examination which defined the boundary from retinal vertical section. Classic CNV on FFA consistently presented with well-defined boundaries on OCT, whereas non-classic CNV had a variable cross-sectional appearance. lt;brgt; lt;brgt;Conclusions lt;brgt;The OCT morphological features of CNV in CEC is mainly well-defined CNV and poorly-defined CNV; OCT examination can precisely observe the retinal and choriocapillaries pathological anatomy of CEC from retinal vertical section, in making the CEC diagnosis as an important complementary examination of FFA and ICGA which observe the focus from retinal horizontal plane. lt;brgt; lt;brgt;(Chin J Ocul Fundus Dis, 2002, 18: 121-124)
Objective To investigate the characteristics and analyze the differences of choroidal neovascularization (CNV) image between exudative age-related macular degeneration (AMD) and central exudative chorioretinopathy (CEC) using optical coherence tomography (OCT). Methods Twenty-three eyes of 22 patients with exudative AMD and 20 eyes of 19 patients with CEC, which were diagnosed as CNV using fundus fluorescein angiograph (FFA) or indocyanine green angiograph ( ICGA), were examined by OCT.The size of CNV and the thickness of retinal neurosen sory layer in foveola were measured by OCT software. Results On OCT image, CNV had three main types of morphological features including simple CNV, CNV with serous retinal neurosensory layer detachment and CNV with choroidoretinal exudation. Exudative AMD mainly showed CNV with choroidoretinal exudation (56.52%) and CEC showed simple CNV (90.0%). The thickness of retinal neurosensory layer in foveola of patients with exudative AMD was thicker than that of patients with CEC and the size of CNV of patients with exudative AMD was larger than that of patients with CEC. Negative correlation was found between retinal neurosensory layer thickness in foveola and vision in both groups (gamma;=-0.521, P=0.001). Conclusions There were certain discrepancy in morphology and area in volved of CNV between exudative AMD and CEC on OCT images. (Chin J Ocul Fundus Dis, 2001,17:299-302)
Pathological myopia can induce choroidal neovascularization (PM-CNV). The potential risk factors include ageing, long axial length of the eyeball, thinning of subfoveal choroidal thickness, fundus atrophy spot and lacquer crack. These factors may induce atrophy of retinal pigment epithelial cells (RPE) and hypoxia, resulting in vascular endothelial growth factors (VEGF) secretion by outer retina. The lesion type, location and activity of PM-CNV can be determined by fundus fluorescein angiography. The features of PM-CNV on optical coherence tomography include strong reflective area close to RPE with very small amount of subretinal fluid (active stage), surface strong reflection with signal attenuation area (scar stage) and flat lesion and chorioretinal atrophy (atrophy stage). Photodynamic therapy and intravitreal injection of anti-VEGF drugs are major treatments for PM-CNV, the latter is more commonly used now. However, more large randomized controlled studies are required to explore the treatment regimen (such as frequency, indications for repeated or termination of treatment) and the efficacy factors further.
Pachychoroid spectrum diseases includes central serous chorioretinopathy (CSC), pachychoroid pigment epitheliopathy, pachychoroid neovasculopathy, and polypoidal choroidal vasculopathy, which share common characteristics, including focal or diffused increased choroidal thickness, choroidal hyper-permeability, and dilated choroidal vessels. These diseases are likely to represent a continuum of the same pathogenic process. Similar features and association among them suggest that they may have similar etiology. It is of great clinical significance to understand the composition and typical morphological changes of pachychoroid-related diseases and to explore its possible pathogenesis.
As a new and non-invasive imaging technology, optical coherence tomography angiography (OCTA) has been using in ocular fundus diseases, glaucoma and neuro-ophthalmic disorders for more than 4 years. The most valuable and efficient application of OCTA is in detecting neovascular diseases in the macula. The big advantage of OCTA is for diagnosing all kinds of choroidal neovascularization. OCTA can observe blood flow information in different layers of the retina. To a large extent, it changes our diagnostic thinking and pathway in macular diseases. Before acquiring OCTA image, the operator should be well trained to ensure to get high quality images with good signal strength and less artifact. OCTA report should show the segmentation slab that the ophthalmologist wants to see. So far, OCTA has difficulty to reach peripheral retina with default setting. Even so, OCTA has provided much information of blood flow within retinal vascular arcade for evaluating structural and functional changes. We are expecting that the swept source OCTA could give us better observation of the choroidal blood flow. That should be the breakthrough of the new generation of OCTA.