Hyperreflectivity on Optical Coherence Tomography in Macular Telangiectasia Type 2

Abstract

Purpose: To define, characterize, and classify hyperreflectivity on optical coherence tomography and report its prevalence in macular telangiectasia Type 2.Methods: In a primary cross-sectional analysis, multimodal imaging data were retrospectively analyzed. The definition of hyperreflectivity and neovascularization on optical coherence tomography followed optical coherence tomography angiographybased criteria. Eyes were graded for the presence of hyperreflectivity and neovascularization and further categorized into three classes based on position and extent of hyperreflectivity. In a secondary analysis, eyes were reviewed for $24 months using optical coherence tomography imaging.Results: Three hundred and twenty-two eyes from 161 patients were analyzed in the cross-sectional analysis. Hyperreflectivity was found in 177 (55%) and neovascular membranes in 49 (15%) eyes. Hyperreflectivity correlated significantly with parameters indicative of disease progression. In the longitudinal analysis, 206 eyes from 103 patients were reviewed over a mean of 35.6 months. 17/86 eyes (20%) showed a de novo development of hyperreflectivity. 8/29 eyes (28%) with preexistent intraretinal hyperreflectivity developed outer retinal hyperreflectivity. A high proportion of eyes with outer retinal hyperreflectivity (17/52 [33%]) developed neovascular membranes.Conclusion: Hyperreflectivity represents a common finding in macular telangiectasia Type 2 but lacks a uniform definition. We propose a hyperreflectivity grading scale that may help to estimate disease progression and identify eyes at risk for developing neovascular membranes.

Characterizing right-angled vessel in macular telangiectasia type 2 with structural optical coherence tomography

“…Hyporeflective cavities on OCT revealed no internal structures on histology, suggesting these cavities are filled with fluid 3 . Müller cells are responsible for the maintenance of the ion and water homeostasis of the retinal tissue and are also involved in the control of angiogenesis and neuronal signaling 13 . In a healthy retina, Müller cells dehydrate the retinal tissue via K + channels and aquaporin-4 water channels on their plasma membrane and Kir4.1 channels on the perivascular processes of Müller cells 13 .…”

“…Müller cells are responsible for the maintenance of the ion and water homeostasis of the retinal tissue and are also involved in the control of angiogenesis and neuronal signaling 13 . In a healthy retina, Müller cells dehydrate the retinal tissue via K + channels and aquaporin-4 water channels on their plasma membrane and Kir4.1 channels on the perivascular processes of Müller cells 13 . However, in an ischemic or inflamed retina, the expression of the above-mentioned channels is dysregulated, resulting in Müller cell dysfunction 13 .…”

“…In a healthy retina, Müller cells dehydrate the retinal tissue via K + channels and aquaporin-4 water channels on their plasma membrane and Kir4.1 channels on the perivascular processes of Müller cells 13 . However, in an ischemic or inflamed retina, the expression of the above-mentioned channels is dysregulated, resulting in Müller cell dysfunction 13 . Therefore, dysfunction of Müller cells may lead to surrounding cavities with fluid in MacTel type 2.…”

“…Longstanding outer retinal cavities with atrophy of Müller cells, not by Müller cone cells, might cause the collapse of the retina and loss of photoreceptor cells, which would present as inner retinal disorganization and EZ disruption on SD-OCT. Moreover, Müller cells produce factors, such as pigment epithelium-derived growth factor (PEDF), tumor necrosis factor, and vascular endothelial growth factor (VEGF), that regulate the tightness of the endothelial barrier 13 . In diseased retinae, such as those in diabetic retinopathy, the production of VEGF is increased, while that of PEDF is reduced 13 .…”

“…Moreover, Müller cells produce factors, such as pigment epithelium-derived growth factor (PEDF), tumor necrosis factor, and vascular endothelial growth factor (VEGF), that regulate the tightness of the endothelial barrier 13 . In diseased retinae, such as those in diabetic retinopathy, the production of VEGF is increased, while that of PEDF is reduced 13 . Hence, decreased release of anti-angiogenic factors, such as PEDF, may be associated with RAV (and RCA) in MacTel type 2.…”