Abnormal Functional Connectivity Density in Patients with Dysthyroid Optic Neuropathy

Area of Science:

• Neuroscience
• Ophthalmology
• Radiology

Background:

• Dysthyroid optic neuropathy (DON) is a vision-threatening complication of thyroid-associated ophthalmopathy (TAO).
• Understanding the underlying pathophysiology of DON is crucial for effective management.

Purpose of the Study:

• To investigate brain functional connectivity density (FCD) abnormalities in patients with DON using fMRI.
• To identify cortical regions associated with DON and explore potential pathogenetic mechanisms.

Main Methods:

• Functional connectivity density (FCD) mapping was employed on MRI data from 30 TAO patients.
• Patients were categorized into DON (visual field mean deviation [MD] < -5 dB) and non-DON (nDON) groups (MD ≥ -2 dB).
• Comprehensive ophthalmological examinations, including visual field testing, were performed.

Main Results:

• DON patients showed significant FCD abnormalities in the right inferior frontal gyrus/orbital part and left precuneus compared to nDON patients.
• Decreased FCD was observed in several frontal, temporal, and parietal regions, while increased FCD was noted in other temporal, occipital, and parietal areas.
• A significant correlation was found between binocular visual field MD and brain FCD.

Conclusions:

• Abnormal FCD in cortical regions of DON patients indicates a potential central nervous system involvement in the disease's pathogenesis.
• These findings highlight the utility of FCD mapping in understanding the complex mechanisms of DON.