Flow Changes in Orbital Vessels Detected with Color Doppler Ultrasound in Patients with Early Dysthyroid Optic Neuropathy

Alterations in retrobulbar haemodynamics in thyroid eye disease

PURPOSE

To study the orbital perfusion parameters of ophthalmic artery (OA) and central retinal artery (CRA) in inactive TED and the changes following surgical decompression.

METHODS

Non-randomised clinical trial. 24 inactive moderate-to-severe TED orbits of 24 euthyroid cases underwent surgical decompression and examined again at 3 months. The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) of OA and CRA were evaluated using colour doppler imaging and normative database was established using 18 healthy controls.

RESULTS

The mean age was 39.38 ± 12.56 years and male: female ratio was 1: 1.18. Intraocular pressure was higher, and CRA-PSV, CRA-RI, OA-PSV, and OA-EDV were lower in TED in comparison to heathy orbits. The CRA-PSV, CRA-EDV, OA-PSV, and OA-EDV negatively correlated with proptosis and duration of thyroid disease. The area under curve of OA-PSV (95% CI:0.964-1.000, p < 0.001) and OA-EDV (95% CI:0.699-0.905, p < 0.001) helped in differentiating TED orbits from HC, and in predicting the severity of disease. Post decompression, CRA-PSV, CRA-EDV, OA-PSV, and OA-EDV improved, with decrease in CRA-RI and OA-RI in both lipogenic and MO.

CONCLUSIONS

The orbital perfusion is reduced in inactive TED. The changes in OA flow velocities can help in differentiating inactive TED from healthy orbits and progression of TED. Sequential orbital CDI of OA and CRA can serve as an objective tool for case selection and monitoring response to surgical decompression.

Evaluation of Microcirculation in Optic Nerve Head Using Laser Speckle Flowgraphy in Active Thyroid Eye Disease

Background

Laser speckle flowgraphy (LSFG) can be used to estimate optic nerve blood flow. This study used LSFG to evaluate optic nerve microcirculation in patients with thyroid eye disease (TED).

Methods

This was a retrospective review of patients with active TED who underwent LSFG between October 2020 and June 2021. The mean blur rate (MBR) for different severities of active TED was analyzed by one-way analysis of variance (ANOVA).

Results

A total of 30 patients (60 eyes) with a diagnosis of active TED who underwent LSFG were included. The mean age was 49 (range, 33–74) years. Mean best-corrected visual acuity was the worst in the group with sight-threatening active TED (0.29 ± 0.33 logarithm of the minimum angle of resolution, p = 0.01). The MBR-overall was the highest in the group with mild active TED (28.5 ± 2.7), followed by that in the moderate to severe (23.6 ± 3.2), and in the sight-threatening (20.2 ± 4.3) active TED groups (p < 0.001). The MBR-vessel was 57.1, 47.0, and 39.3 in the mild, moderate to severe, and sight-threatening active TED groups, respectively (p < 0.001). The MBR-tissue was 16.9, 14.4, and 12.0 in the mild, moderate to severe, and sight-threatening active TED groups, respectively (p < 0.001).

Conclusions

This study demonstrates that optic nerve blood flow is lower with more severe active TED. In addition, LSFG is an effective, objective, and noninvasive method for evaluating the severity of TED.

[The importance of OCT angiography and Doppler ultrasound methods in diagnosis of optic neuropathies]

This review of literature presents an assessment of circulatory disorders of the optic nerve and the retina in patients with optic neuropathy of different origin by ultrasound and OCTA methods, outlines basic principles of analyzing the state of blood flow in the ocular vessels, and analyzes the results of Russian and foreign research on this topic.