• Neuro-Ophthalmology/Orbit, Oculoplastics/Orbit

    This study evaluated the optic nerve sheath diameter in eyes with dysthyroid optic neuropathy.

    Study design

    This prospective case-control study enrolled 47 healthy eyes, 36 thyroid-associated ophthalmopathy eyes without dysthyroid optic neuropathy and 33 eyes with dysthyroid optic neuropathy. B-scan ultrasonography was used to measure vertical and horizontal optic nerve sheath diameters at 3 mm and 6 mm behind the eyeball.

    Outcomes

    The AUC for distinguishing dysthyroid optic neuropathy eyes from those without was 0.77 and 0.75 at 3 mm and 6 mm, respectively.

    Limitations

    B-scan ultrasonography readings are dependent on technician skill. As such, these results may be difficult to disseminate widely.

    Clinical significance

    A significant increase in optic nerve sheath diameter was evident in dysthyroid optic neuropathy eyes, independent of clinical activity. This may be used as another clinical marker to distinguish patients with optic nerve compromise from thyroid-associated ophthalmopathy from those without.