Thyroid Eye Disease Affects Optic Nerve Head Vessel Densities

Graves’ ophthalmopathy (also known as thyroid eye disease (TED), dysthyroid/thyroid-associated orbitopathy (TAO), Graves’ orbitopathy) is an autoimmune inflammatory disorder affecting the orbit around the eye, characterized by upper eyelid retraction, lid lag, swelling, redness (erythema), conjunctivitis, and bulging eyes (exopthalmos). It is part of a systemic process with variable expression in the eyes, thyroid, and skin, caused by autoantibodies that bind to tissues in those organs, and, in general, occurs with hyperthyroidism. The most common form of hyperthyroidism is Graves’ disease. About 10% of cases do not have Graves’ disease, but do have autoantibodies.
The changes were significant for patients with moderate-severe disease and those with dysthyroid optic neuropathy.

Vessel densities (VD) of the optic nerve head gradually decline in the course of thyroid eye disease (TED), significantly so for patients with moderate-severe disease and those with dysthyroid optic neuropathy (DON), according to research published in Ophthalmic Plastic and Reconstructive Surgery.

Researchers conducted a prospective comparative study evaluating the retinal peripapillary capillary (RPC) vessel density (VD) in 4 groups of patients on the spectrum of thyroid eye disease (TED) and healthy volunteers between January 2018 to March 2021. 

The 5 participant groups were patients with Graves’ disease without TED (26 eyes of 13 patients), those with mild TED (28 eyes of 14 patients), those with moderate-severe TED (30 eyes of 17 patients), those with TED with dysthyroid optic neuropathy (DON; 21 eyes of 12 patients), and healthy volunteers (39 eyes and 20 patients). All participants underwent ocular and periocular examination, and visual field indices, RPC-VD (with optical coherence tomography angiography), and retinal nerve fiber layer, and macular ganglion cell complex thickness were recorded.

The researchers characterized an insignificant increase in the peripapillary-VD (pp-VD) and whole image-VD (wi-VD) between healthy volunteers and patients with Graves’ disease without TED followed by a significant decrease in RPC-VD in different severity grades of the TED (P =.001). Using paired comparisons, the team found that the significant decrease within the Graves’ disease group occurred in the moderate-severe and DON groups (.001≤ P ≤.04). 

In a multivariate analysis, the researchers did not observe any significant associations between patient-/disease-related variables (sex, age, smoking, intraocular pressure, clinical activity score, duration of TED, and duration of dysthyroid disease) and the VD. 

They found that a lower wi-VD and pp-VD were significantly correlated with the impaired optic nerve functional and structural tests (.001≤ P ≤.009) and that the sensitivity and specificity of wi-VD (81% and 76%) and pp-VD (69% and 71%) for detecting the DON were statistically significant (P <.001).

“Despite an insignificant rise in the wi- and pp-VD from the healthy volunteers to the patients with Graves’ disease without TED, VD showed a declining trend in the course of patients with TED, which was statistically significant in the moderate-severe TED and DON groups,” according to the researchers.

Reference

Abdolalizadeh P, Kashkouli MB, Moradpasandi F, Falavarjani KG, Mirshahi R, Akbarian S. Optic nerve head vessel density changes from graves’ disease without ted to ted dysthyroid optic neuropathy: does optic nerve head ischemia play a role? Ophthalmic Plast Reconstr Surg. 2022;38(3):250-257. doi:10.1097/IOP.0000000000002046