Choroidal Round Hyporeflectivities in Geographic Atrophy

Abstract

PurposeIn geographic atrophy (GA), choroidal vessels typically appear on structural optical coherence tomography (OCT) as hyperreflective round areas with highly reflective borders. We observed that some GA eyes show choroidal round hyporeflectivities with highly reflective borders beneath the atrophy, and futher investigated the charcteristcs by comparing structural OCT, indocyanine green angiography (ICGA) and OCT angiography (OCT-A).MethodsRound hyporeflectivities were individuated from a pool of patients with GA secondary to non-neovascular age-related macular degeneration consecutively presenting between October 2015 and March 2016 at the Medical Retina & Imaging Unit of the University Vita-Salute San Raffaele. Patients underwent a complete ophthalmologic examination including ICGA, structural OCT and OCT-A. The correspondence between choroidal round hyporeflectivities beneath GA on structural OCT and ICGA and OCT-A imaging were analyzed.ResultsFifty eyes of 26 consecutive patients (17 females and 9 males; mean age 76.8±6.2 years) with GA were included. Twenty-nine round hyporeflectivities have been found by OCT in choroidal layers in 21 eyes of 21 patients (42.0%; estimated prevalence of 57.7%). All 29 round hyporeflectivities showed constantly a hyperreflective border and a backscattering on structural OCT, and appeared as hypofluorescent in late phase ICGA and as dark foci with non detectable flow in the choroidal segmentation of OCT-A. Interestingly, the GA area was greater in eyes with compared to eyes without round hyporeflectivities (9.30±5.74 and 5.57±4.48mm2, respectively; p = 0.01).ConclusionsOur results suggest that most round hyporeflectivities beneath GA may represent non-perfused or hypo-perfused choroidal vessels with non-detectable flow.

Choroidal and Sub-Retinal Pigment Epithelium Caverns

“…Focal internal reflective feature s may represent crystallizations (Figure 2G). An especially intriguing cavern characteristic is a prominent and consistent posterior tail of hypertransmission, which differentiates caverns from choroidal vessels, “round hyporeflectivities” considered cavern precursors, 8 and fluid-filled cysts or cavitations. Tails may relate to lower absorption of incoming light by lipid than by surrounding tissue (Supplementary Information, Table 2).…”

“…To explain the appearance of caverns, the authors suggested that similar changes occur in the larger vessels of the Sattler and Haller layers, with the internal punctate hyperreflectivity corresponding to cells. These investigators subsequently described choroidal round hyporeflectivities, 8 which were similar in size to choroidal caverns, yet distinct due to hyperreflective borders and a consistent round shape, and suggested these as non-or hypo-perfused vessels, single large cells, or cavern precursors. Among the explanations for choroidal round hyporeflectivities of SD-OCT, the authors also included Friedman lipid globules, citing a preliminarily presented survey of these features.…”

Optical coherence tomography angiography (OCTA) findings in Serpiginous Choroiditis

“…Additionally, analogies could be seen between the changes of the choriocapillaris and choroid caused by SC and geographic atrophy. These included a focal flow impairment and rarefaction in the choriocapillaris beneath the area of the atrophic lesions, which is argued to represent non-perfused or hypo-perfused choroidal vessels with non-detectable flow in the literature [33][34][35].…”

Optical Coherence Tomography Angiography (OCTA) findings in Serpiginous Choroiditis

“…Additionally, analogies could be seen between the changes of the choriocapillaris and choroid caused by SC and geographic atrophy. These included a focal flow impairment and rarefaction in the choriocapillaris beneath the area of the atrophic lesions, which is argued to represent non-perfused or hypo-perfused choroidal vessels with non-detectable flow in the literature [27,28,29].…”