The von Gräfe sign measurement

To measure the amplitude of upper eyelid saccadic movements in patients with Graves' retraction.

The amplitude and velocity of lid saccades were quantified using customized software in 36 patients with Graves' upper eyelid retraction (GO) and in 32 subjects of a control group (CG). All patients were in the chronic phase of the disease and had a controlled thyroid status. Eyelid retraction was measured using the software ImageJ. Levator palpebrae superioris muscle (LPSM) dimensions were measured through orbital computed tomography (CT).

The mean MRD1 was 6.5 mm and 3.9 mm in the GO and CG groups, respectively. The LPSM was radiologically enlarged in patients. The absolute values of both amplitude and velocity of lid movement did not differ between the two groups. However, considering the final position of the lid margin in relation to the pupil in downgaze, the margin-reflex distance of the patients was significantly higher than that of the controls.

In patients with upper eyelid retraction in inactive GO the relaxation of the LPSM are not affected, despite the muscle enlargement. However, the amplitude of the downward lid movement of the patients does not compensate for the lid retraction. The final position of the lid margin of the patients in downgaze is significantly higher than in controls, indicating the inability of the LPMS relaxation to overcome lid retraction. The von Gräfe sign is thus a relative phenomenon and not an absolute indication of loss of the lid elastic properties.