Swept Source Optical Coherence Tomography Angiography of Neovascular Macular Telangiectasia Type 2

Abstract

Objective To image subretinal neovascularization in proliferative macular telangiectasia type 2 (MacTel2) using swept source optical coherence tomography based microangiography (OMAG). Study Design Patients with MacTel2 were enrolled in a prospective, observational study known as the MacTel Project and evaluated using a high-speed 1050nm swept-source OCT (SS-OCT) prototype system. The OMAG algorithm generated en face flow images from three retinal layers, as well as the region bounded by the outer retina and Bruch’s membrane, the choriocapillaris, and the remaining choroidal vasculature. The en face OMAG images were compared to images from fluorescein angiography (FA) and indocyanine green angiography (ICGA). Results Three eyes with neovascular MacTel2 were imaged. The neovascularization was best identified from the en face OMAG images that included a layer between the outer retinal boundary and Bruch’s membrane. OMAG images identified these abnormal vessels better than FA and were comparable to the images obtained using ICGA. In all three cases, OMAG identified choroidal vessels communicating with the neovascularization, and these choroidal vessels were evident in the two cases with ICGA imaging. In one case, monthly injections of bevacizumab reduced the microvascular complexity of the neovascularization, as well as the telangiectatic changes within the retinal microvasculature. In another case, less frequent bevacizumab therapy was associated with growth of the subretinal neovascular complex. Conclusions OMAG imaging provided detailed, depth-resolved information about subretinal neovascularization in MacTel2 eyes demonstrating superiority to FA imaging and similarities to ICGA imaging for documenting the retinal microvascular changes, the size and extent of the neovascular complex, the communications between the neovascular complex and the choroidal circulation, and the response to monthly bevacizumab therapy.

Quantitative assessment of the retinal microvasculature using optical coherence tomography angiography

“…5,6 In addition, OCTA has documented microvascular abnormalities in other macular diseases such as branch retinal vein occlusion (BRVO), central retinal vein occlusion, 7 and macular telangiectasia type 2 (MacTel2). 8 Compared with conventional dye-based angiography, OCTA offers a safer, faster, and more cost effective alternative for ocular imaging of the macular vasculature. Overall, the combination of OCT and OCTA can present integrated structural and flow information of the human eye in vivo, opening new opportunities for both qualitative and quantitative analysis of ocular diseases.…”

Natural history and effect of therapeutic interventions on subretinal fluid causing foveal detachment in macular telangiectasia type 2

“…However, the current generation of en face OCT angiography devices have limited depth resolution and are susceptible to projection artefacts; therefore, the possibility of chorioretinal anastomoses as has been described in other MacTel phenotypes cannot be excluded 12 13. High-resolution three-dimensional reconstructions of OCT angiography images could provide further insights into the pathogenesis of MacTel 14 15…”

Novel perspectives on swept-source optical coherence tomography

“…In some patients, the anastomoses progress to form sub-retinal neovascularization. OCTA reveals these changes at every stage of disease progression [89–91] (Fig. 6).…”