Levator excursion as a predictor of both eyelid lag and lagophthalmos in thyroid eye disease

To evaluate the relationship between levator excursion and both eyelid lag and lagophthalmos in thyroid eye disease.

We retrospectively reviewed 104 eyelids of 52 thyroid eye disease patients over a 9-month interval by measuring levator function (mm), eyelid lag (0-4+) and lagophthalmos (mm).

Lower levator excursion is associated with higher eyelid lag scores (p < 0.001) and with greater degrees of lagophthalmos (p < 0.001). Both associations were upheld after adjustment for upper eyelid margin reflex distance and Hertel exophthalmometry (p < 0.0001). For every 1-mm decrease in levator function, eyelid lag score increases on average by 0.29 and lagophthalmos increases on average by 0.23 mm.

Diminished levator excursion is associated with increasing levels of eyelid lag and lagophthalmos. Levator excursion is an important clinical measurement in thyroid eye disease patients and may replace eyelid lag grading and lagophthalmos as a more accurate indicator of eyelid retraction in thyroid eye disease.