Vascular changes of the peripapillary choroidal area in the thyroid orbitopathy.

Purpose: The aim of this study was to investigate the peripapillary choroidal vascular changes in thyroid orbitopathy (TO).

Methods: The study included 20 eyes of 10 patients with active TO (aTO), 30 eyes of 15 patients with inactive TO (inaTO) and 30 eyes of 30 healthy subjects. The peripapillary choroidal vascular change was assessed with peripapillary choroidal vascular index (pCVI), peripapillary choroidal luminal area (pLA), peripapillary choroidal stromal area (pSA), peripapillary total choroidal area (pTCA).

Results: Compared to the control group, there was a reduction in the nasal and temporal areas of pCVI in both the aTO and inaTO groups (aTO vs control: nasal p = 0.001 and temporal p = 0.004; inaTO vs control: nasal p = 0.007 and temporal p < 0.001), while the inferior area was lower only in the inaTO group (p = 0.001). Compared to the other groups, the inaTO group exhibited a decrease pSA (vs aTO: total p = 0.004, inferior p = 0.02 and vs control: total p = 0.01, inferior p = 0.03), pLA (vs aTO: total p = 0.02, inferior p = 0.02, temporal p < 0.001 and vs control: total p = 0.002, inferior p < 0.001, temporal p < 0.001) and pTCA (vs aTO: total p = 0.009, inferior p = 0.01, temporal p < 0.001 and vs control: total p = 0.003, inferior p = 0.001, temporal p < 0.001).

Conclusion: The horizontal area (nasal and temporal area) of the peripapillary choroidal vascular structure may be more sensitive than the vertical area in TO patients. The first affected quadrant of RPC-VD in the active TO may be the inferior quadrant. Structural or vascular choroidal changes may occur during the chronic or post-active phase of the disease.