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 To evaluate the diagnostic value of Heidelberg retinal angiography(HRA) combined with optical coherence tomography (OCT) to detect neovascularization (CNV) in exudative agerelated macular degeneration (AMD) patients. Methods This is a cross-sectional study of a series of clinical cases. AMD diagnosis was established by international standard vision chart, Slit lamp microscope, direct or indirect ophthalmoscope examination. A total of 50 eyes (42 cases) of exudative AMD received HRA and frequency domain OCT scan. All 50 eyes received fundus fluorescein angiography (FFA) and frequency domain OCT simultaneously, and among them 15 eyes also received indocyanine green angiography (ICGA) at the same time. FFA and ICGA were carried out by conventional methods, CNV was localized by real-time localization technology of frequency domain OCT. In the radial and grid-like section from the areas with b fluorescence, image acquisition settings are 7 mu;m fault for each frame, 30 deg; intervals for radial section, 10 vertical and 10 horizontal scan lines for gridlike section. CNV can be divided into 4 types (typical CNV, partial typical CNV, occult CNV, CNV scarring) according to their boundaries demonstrated in FFA. Based on the features of the OCT images, there were 3 types of integrated image (sub-RPE type, sub-retinal type and mixed type). Results CNV was detected in all 50 eyes. There were 4 eyes (8%) of typical CNV, 11 eyes (22%) of partial typical CNV, 32 eyes (64%, including 27 eyes of RPE detachment and 5 eyes of passive late leakage) of occult CNV and 3 eyes (6%) of CNV scarring. There were 4 eyes (8%) of subRPE type (CNV under the RPE light band) , 16 eyes (32%) of subretinal type(interrupted light band of RPE and choroid capillary layer) and 30 eyes (60%) of mixed type of integrated image. Conclusion The image integration technology of the HRA and frequency domain OCT system provide a valuable tool to classify and measure CNV, which will benefit the clinical treatment of AMD patients.
Objective To compare the characteristics of the results of fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) in patients with classic choroidal neovasculazation (CNV). Methods The data of FFA and ICGA of 34 patients (36 eyes) with classic CNV were analyzed retrospectively and the results of the two examinations were analyzed contrastively. Results The results of FFA revealed the clew or cartheel-tike configuration of classic CNV at the early phase in 3 out of 15 eyes (20%) with age-related macular degeneration (AMD); in 5 out of 7 eyes with pathological myopia(71.4%); and in 9 out of 14 eyes with central exudative chorioretinopathy (CEC),(64.3%),In 36 eyes with classic CNV, the images of ICGA indicated CNV distinctly in 20 (55.6%) and indistinctly in 15 (41.6%); CNV was not detected by ICGA in 1 eye (2.8%); feeding blood vessels in 6 eyes (16.7%) were detected by ICGA but none by FFA. Conclusions At the early phase of FFA, the configuration of classic CNV is clew-like in eyes with pathological myopia and CEC, and erose in eyes with AMD. The image of ICGA which indicated the outline of classic CNV is not as clear as the one of FFA, but it can reveal the feeding vessels which FFA can not. (Chin J Ocul Fundus Dis, 2006, 22: 217-209)
Objective To investigate the manifestations of indocyanine green an giography (ICGA) of the choroidal neovascular membrane (CNV) and the relationship with histopathological changes in patients with age-related macular degeneration (AMD). Methods Twenty-one eyes of 21 patients with AMD diagnosed by ICGA were classified into three types based on ICGA findings: developing type in 9 eyes , degenerating type in 9, and stabilizing type in 3. CNV was extracted by vitrectomy and the histopathological characteristics of CNV was observed under the light and electron microscope. Results The histopathological characteristics of the specimens of developing type revealed abundant CNV partly enwrapped with non-pigmental cells and fibrous tissue or a few pigmental cells; degenerating type revealed reduced activation duration of CNV, many pigmental cells and a little fibrous tissue; stabilizing type revealed a mass of fibrous tissue，few CNV and nonexistence of pigmental cells. Conclusion The histopathological characteristics of exudative AMD may be related to the manifestations of ICGA. (Chin J Ocul Fundus Dis，2004，20：71-74)
Objective To investigate the possible relationship between choroidal neovascularization (CNV) and macular choroidal watershed zones (CWZ) in patients with age-related macular degeneration (AMD). Methods Fifty-seven selected indocyanine green video angiograms (ICGA) of 57 patients (57 eyes) with AMD were evaluated, and 35 ones of the healthy fellow eyes of 35 patients with unilateral non-AMD fundus diseases were selected as age-matched control. The video angiograms were evaluated for investigating the relationship between CNV and macular CWZ. Results In 57 eyes with AMD, 35 (61.4%) had macular CWZ, while in 35 control patients only 3 (8.57% ) had. The difference was significant (Plt;0.05). In 43 eyes with exudative AMD and CNV, 32 (74.4%) had macular CWZ, including 29 eyes (90.6%) with CNV caused by macular CWZ. Conclusion Macular CWZ could be a predilection site of CNV in exudative AMD. (Chin J Ocul Fundus Dis，2003，19：76-78)
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.