Optical coherence tomography angiography (OCTA) is a new and non-invasive imaging technique that is able to detect blood flow signal in the retina and the choroid within seconds. OCTA is different from the traditional angiography methods. The major advantages of OCTA are that it can observe blood flow signal in different layers of the retina and the choroid without injecting any dye, provide blood flow information that traditional angiography cannot provide, and enrich pathophysiological knowledge of the retinal and choroidal vascular diseases., which help us to make an accurate diagnosis and efficient evaluation of these diseases. However there is a large upgrade potential either on OCTA technique itself or on clinical application of OCTA. We need to fully understand the advantage and disadvantage, and differences of OCTA and traditional angiography. We also need to know how to interpret the result of OCTA. With that we could make a fast diagnosis in a non-invasive way and improve our knowledge of the retinal and choroidal vascular diseases.
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.
OBJECTIVE: To review the role of thyroid hormone in the peripheral nerve regeneration. METHODS: The recent literatures of experimental study and clinical application on the role of thyroid hormone in nerve regeneration were reviewed. The researches on expression, isoform and changes of thyroid hormones in rat sciatic nerve in normal or injury were summarized. The effect of thyroid hormone on local rat sciatic nerve was studied, too. RESULTS: Nuclear thyroid hormone receptors expressed in numerous nuclei of sciatic nerve during a limited period of development extending from the third week of embryonic life to the end of the second postnatal week and after injury of adult sciatic nerve. A single and local administration of thyroid hormone at the level of the transected sciatic nerve produced a lasting effect on peripheral nerve regeneration. CONCLUSION: The beneficial effects of thyroid hormones upon injured peripheral nerve may have considerable therapeutic potential.
ObjectiveTo observe and analyze the image characteristics of eyes with choroidal osteoma using swept-source OCT (SS-OCT).MethodsSeventy-three eyes of 61 patients with choroidal osteoma were enrolled in the study, including 17 males (20 eyes) and 44 females (53 eyes) with an average age of 33.5±12.7 years. Single tumor was found in 71 eyes and multiple tumors were found in 2 eyes. All patients received examinations of slit lamp ophthalmoscope, color fundus photography, fundus autofluorescence, fluorescein angiography and/or indocyanine green angiography, B-scan ultrasonography and/or computerized tomography. Tumor features were characterized using SS-OCT.ResultsAmong 75 tumors of 73 eyes, the osteoma was completely calcified in 7 tumors, completely decalcified in 5 tumors and all the other tumors were composed of calcified and decalcified portions. SS-OCT revealed normal inner retina in all the calcified areas of tumors and abnormal outer retina including external limiting membrane, ellipsoid zone, interdigitation zone and RPE in some cases. Whereas the outer retina and RPE showed abnormality in the decalcified areas of all cases. The choriocapillaris was invisible in all cases and most of the medium and large caliber vessels showed thinning or nonvisibility. Choroidal osteoma revealed a sponge-like appearance (n=39), loofah sponge appearance (n=11), lamellar pattern (n=10), mixed (n=12) and irregular patterns (n=5). Other unique features included horizontal lamellar lines (n=71), hyperreflective horizontal lines (n=47) and hyporeflective tubules (horizontal:n=39, vertical:n=42, circular:n=41) within choroidal osteoma. Hyperreflective tumor-like tissues were also detected above the disrupted Bruch’s membrane. The sclero-choroidal junction was detectable in all tumors and a posterior ciliary vessel penetrating the sclera was also seen.ConclusionsSS-OCT clearly reveals characteristic appearances of choroidal osteoma as sponge-like, loofah sponge, lamellar pattern, mixed and irregular patterns, with unique features of horizontal lamellar lines, hyperreflective horizontal lines and hyporeflective tubules within osteoma. Hyperreflective tumor-like tissues were detected to grow above the disrupted Bruch’s membrane.