Increase of central foveal and temporal choroidal thickness in patients with inactive thyroid eye disease

Background: In this study, we aimed to compare the choroidal thickness between a group of Korean patients with inactive thyroid eye disease (TED) and a control group of Korean patients and to analyze the variables affecting choroidal thickness. Methods: Patients diagnosed with inactive TED and without TED who underwent optical coherence tomography and axial length measurements were included and classified into the TED group and control group. Choroidal thickness was measured using images acquired in enhanced depth imaging (EDI) mode by cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA, UAS) at the central fovea and points 1.5 mm nasal and 1.5 mm temporal from the central fovea using a caliper tool provided by OCT software. Results: The mean central foveal choroidal thickness was 294.2 ± 71.4 µm and 261.1 ± 47.4 µm in the TED and control groups, respectively, while the mean temporal choroidal thickness was 267.6 ± 67.5 µm and 235.7 ± 41.3 µm in the TED and control groups, respectively, showing significant differences between the two groups (P = 0.011, P = 0.008). The mean nasal choroidal thickness was 232.1 ± 71.7 µm and 221.1 ± 59.9 µm in the TED and control groups, respectively, showing no significant difference between the two groups (P = 0.421). Multivariate regression analysis showed the factors affecting central foveal choroidal thickness were age, axial length, and degree of exophthalmos, and factors affecting temporal choroidal thickness were age and degree of exophthalmos. Conclusions: Central foveal and temporal choroidal thickness were significantly thicker in patients with inactive TED than in control subjects, while age, axial length, and degree of exophthalmos were identified as major factors affecting choroidal thickness.