Ultra-wide field fundus autofluorescence (FAF) imaging is a new noninvasive technique with an imaging range of about 200 °. It can detect peripheral retinal lesions that cannot be found in previous FAFs and more objectively reflect intracellular content and distribution of lipofuscin in the retinal pigment epithelium (RPE) and RPE cell metabolic status. The ultra-wide field FAF can find the abnormal autofluorescence (AF) in the peripheral retina of the eyes of age-related macular degeneration (AMD), and different AF manifestations may have an impact on the diagnosis and treatment of the different AMD subtypes. It is helpful to evaluate subretinal fluid in the eyes of central serous choroidal retinopathy and can accurately detect the changes in the outer retina of the eyes without subretinal fluid. It can help to determine the type of uveitis and fully display the evolution of the disease. It can also assess the peripheral photoreceptor cell layer and RPE in patients with retinal dystrophy and retinitis pigmentosa, and comprehensively evaluate their retinal function and monitor the progress of disease. It can also assist in the evaluation of the short-term efficacy and RPE cell function after the scleral buckling surgery for patients with rhegmatogenous retinal detachment. In the future, ultra-wide field FAF may change the knowledge and intervention strategy of ocular fundus diseases and promote the clinical and scientific research in this field.
Optical imaging technology of ocular fundus, including fundus fluorescein angiography (FFA), optical coherence tomography (OCT) and fundus autofluorescence (FAF), is growing at an unprecedented speed and scale and is integrating into the routine clinical management of ocular fundus diseases, such as diagnosis, treatment, and mechanism study. While FFA allow us to observe the retinal and choroidal blood circulation, OCT and FAF are non-invasive, fast and quantifiable measurement; such techniques show even more unique advantages and are favored tools. All these retinal imaging technologies, together with a variety of retinal function assessments, bring us into the era of big data of ocular fundus diseases. All of these developments are the challenges and opportunities for the operator and user of these fundus optics imaging technologies. In order to improve its clinical applications and allocate resources rationally, we need to understand the optical properties of these retinal imaging technologies, and standardize diagnosis behavior. This is a continuous learning process needs to continue to explore.
The hallmark of the recent latest advances in diagnostic fundus imaging technology is combination of complex hierarchical levels and depths, as well as wide-angle imaging, ultra-wide imaging. The clinical application of wide-angle and ultra-wide imaging, not only can reevaluate the role of the peripheral retina, the classification types and treatment modalities of central retinal vein occlusion, and enhance the reliability of diabetic retinopathy screening, improve the classification and therapeutic decision of diabetic retinopathy, and but also can help guide and improve laser photocoagulation. However we must clearly recognize that the dominant role of ophthalmologists in the diagnosis of ocular fundus diseases cannot be replaced by any advanced fundus imaging technology including wide-angle imaging. We emphasize to use the three factors of cognitive performance (technology, knowledge and thinking) to improve the diagnosis of ocular fundus diseases in China.
Using optical imaging equipment with different wavelength and computer technology, fundus optical imaging diagnostic techniques can record fundus reflected light, auto fluorescence and emitted light after excitation by external light source in order to observe and analyze the structure and pathological process of retina and choroid. Advances in fundus optical image capture technology (including laser, confocal laser, spontaneous auto-fluorescence, multispectral imaging) and storage and analysis technology, promote this field into a high-definition digital imaging era, with features of rapid, non-invasive, wide-angle three-dimensional multi-level integration, dynamic automatic navigation location tracking and combined application of a variety of optical imaging diagnostic techniques. In order to promote clinical and scientific research of ocular fundus diseases, we need to understand the development trend of optical imaging diagnostic technique, interpret the fundus imaging features appropriately, reasonably chose different inspection techniques, establish standardized diagnosis criteria and continue to expand clinical applications.
ObjectiveTo summarize the diagnosis and measurement methods of bone defect in anterior shoulder instability (glenoid bone defect and Hill-Sachs lesion).MethodsThe related literature on the diagnosis and measurement of the bone defect in anterior shoulder instability was reviewed and summarized.ResultsThe commonly used techniques for the diagnosis of anterior glenoid bone defect and Hill-Sachs lesion of humeral head include X-ray, CT, MRI, arthroscopy, arthrography. The methods for measuring the degree of anterior glenoid bone defect include Griffith method, glenoid index method, Pico method, and best-fit circle method. The indexes for measuring the Hill-Sachs lesion include the length, width, depth, and volume. X-ray is mainly used for primary screening. Best-fit circle method on three-dimensional (3D) CT reconstruction is commonly used to measure the glenoid bone defect currently. Glenoid track theory on 3D CT reconstruction is popular in recent years. Reliability of measuring the glenoid bone defect and Hill-Sachs lesion with MRI and arthroscopy is still debatable. Arthrography is more and more used in the diagnosis of shoulder joint instability of bone defect and concomitant soft tissue injury.ConclusionHow to improve the accuracy of evaluating glenoid bone defect and Hill-Sachs lesion before surgery still need further study.
Objective To investigate the characteristics of ultrasonogram of eyes with silicon oil tamponade. Methods Forty-seven patients (47 eyes) who had undergone the operation of silicon-oil removing were examined by A-(to determine the length of ocular axis) and B-scan before and after the operation respectively. The length of ocular axis and cubage of vitreous chamber were detected and the characteristics of the ultrasonograms were observed according to the default parameters of ultrasonograph. Results The results of A-scan showed that the preoperative axial length was 1.465 times of the postoperative one in the eyes without lens, and 1.284 times in eyes with lens; after modified the parameter according to the acoustic velocity, the preoperative axial length was (0.78±0.34) mm longer than the postoperative one in the eyes without lens, and (0.56±0.32) mm in eyes with lens. The results of A-scan showed that the cubage of vitreous chamber enlarged obviously in eyes with silicon oil tamponade, and the acoustic features included complete filling and partial filling according to the amount of silicon oil. Several arc echoes at the posterior segment of eye were detected in the silicon-oil-filling eyes with retinal detachment. Conclusion In the silicon-oil-filling eyes with lengthened ocular axis, the characteristics of B-scan images are affected by acoustic velocity through silicon oil, the amount of silicon oil capacity and the emulsification of silicon oil. (Chin J Ocul Fundus Dis，2004，20：349-351)
The improvement of diagnostic levels for fundus diseases depend on the advancements of fundus imaging technology. Different fundus imaging technologies allow doctors to inspect ocular fundus from different aspects such as morphological or functional changes of retina. As a basic fundus examination method, optical coherence tomography provides highresolution and crosssectional retinal images coupled with noninvasive advantages. Fully understanding of the advantages and disadvantages of each fundus imaging technique, appropriate choosing one or combining several imaging techniques, and optimizing diagnostic procedures for each fundus disease are crucial steps to improve our diagnostic levels of ocular fundus diseases.