Lateral Globe Exposure Associated With Graves Upper Eyelid Retraction: The Influence of the Superior Complex Enlargement and Proptosis.

Purpose: To investigate the association of the lateral exposure of the globe with proptosis and the enlargement of the superior complex (SC) (levator palpebrae superioris muscle + superior rectus muscle) in patients with Graves upper eyelid retraction.

Methods: Twenty-eight patients with upper lid retraction secondary to Graves orbitopathy and 28 controls matched by age and gender participated in the study. The variables exophthalmometry, margin-reflex distance 1, and upper lid fissure temporal and nasal areas were assessed. Coronal CT scans were evaluated for the measurement of the SC area. A 5% level of significance was assumed for analysis.

Results: Abnormal temporal nasal area differences (T-N), defined as values above the superior limit of the control distribution (15.58mm2) were detected in 18 patients. Multiple regression analysis showed a significant correlation of abnormal temporo-nasal asymmetries with the SC area and the proptosis (T-N = -6.7 + 0.62* proptosis + 12.3 SC area, R2 = 0.37; p = 0.003).

Conclusion: The etiology of the enhanced lateral globe exposure is not unifactorial. SC enlargement and, to a lesser extent, proptosis are important factors correlated to lateral globe exposure.