4 Although they evaluated OCT of only the posterior pole, these findings suggest that UWF-OCT in these patients would provide additional information about retinal healing after retinal detachment repair in the mid-far periphery where retinal breaks typically occur.įigure 2. 4 They found that these ORF were associated with poorer visual outcomes at one year, and that those treated with vitrectomy were at greater risk of postoperative ORF. A post-hoc analysis of the PIVOT trial comparing vitrectomy and pneumatic retinopexy for the treatment of retinal detachment examined postoperative outer retinal folds on OCT. 3 Other OCT findings confirmed what’s been described in past histological analyses, including coagulative necrosis and retinal splitting after laser retinopexy, as well as retinal layer destruction and RPE separation post-cryopexy. 3 OCT findings post-cryopexy revealed separation of the choroid and sclera in the first week, a previously undescribed finding. Toronto’s Wei Wei Lee, MD, and colleagues presented longitudinal findings captured by the Optos Silverstone that provided insight into the response of the retina to treatments including laser retinopexy and cryopexy. UWF-OCT, however, acquires crucial information both before and after retinal detachment treatment. Microstructural retinal details such as photoreceptor integrity and resolution of subretinal fluid are difficult to ascertain on clinical exam or UWF fundus photography. There’s potential for the use of UWF-OCT in the diagnosis, monitoring, and management of retinal detachments. 2Īs mentioned, in the following sections we’ll look at the utility of WF and UWF in various conditions. A company called Toward Pi has also developed a swept-source OCT machine with an 81 x 68 degree field of view and an A-scan speed of 400 kHz. However, the Heidelberg Spectralis HRA-OCT (Heidelberg Engineering USA) (using a steering technique), the Silverstone (Optos PLC Edinburgh), the Plex Elite 9000 (Zeiss, Oberkochen, Germany) and the Xephilio OCT-S1 (Canon Medical Systems, Japan) have introduced UWF capabilities. Until recently, capturing the far periphery of the retina with OCT was nearly impossible. A depiction of these definitions appears in Figure 1. 1 This represents a 110 to 220-degree field of view. 1 It defined ultra-widefield imaging as an image of the far periphery of the retina, including the anterior edge of the vortex vein ampulla and beyond. In 2019, the International Widefield Imaging Study Group defined widefield imaging as a field of view of approximately 60 to 100 degrees, capturing the mid-periphery of the retina up to the posterior edge of the vortex vein ampulla. Demonstrated here are the demarcation boundaries described for the posterior pole, the mid-periphery and the far periphery. A single image from the International Widefield Imaging Study Group demonstrating the definition of widefield and ultra-widefield with reference to the vortex vein ampullae. In this literature review, we’ll outline four disease entities in which UWF-OCT has shown promise: retinal detachments pathological myopia peripheral retinal degenerations and choroidal pathologies, as well as highlight the uses of this modality in pediatrics and UWF-OCT angiography.įigure 1. With the advent of these UWF imaging modalities, many researchers have initiated studies investigating the utility of UWF-OCT imaging. In the course of its use and development, OCT technology has spawned widefield and ultra-widefield imaging methods that allow fields of view of up to 220 degrees. The ability of this technology to capture the peripheral retina has allowed for new and expanded clinical applications. Since its inception in the 1990s, optical coherence tomography has become a crucial tool in the practice of ophthalmology by informing diagnosis, disease monitoring and long-term prognosis.
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