Relationships between eyelid position and levator-superior rectus complex and inferior rectus muscle in patients with Graves' orbitopathy with unilateral upper eyelid retraction

Abstract

To assess the relationships between eyelid position and levator palpebrae superioris (LPS)-superior rectus (SR) complex and inferior rectus (IR) muscle volume in patients with Graves' orbitopathy (GO) with unilateral upper eyelid retraction. This was a cross-sectional observational study of 48 patients with GO with unilateral upper eyelid retraction. To measure muscle volume, computerized tomography scans were performed, and 3D images were analyzed. Digital photographs were taken, and vertical eyelid height was measured using computed eyelid analysis software. The measured muscle volumes and eyelid heights were assessed, and correlation analysis was performed. To verify the parameters that are predictive for the presence of upper eyelid retraction, receiver operating characteristic curves were analyzed, and logistic regression was performed. The volume of the LPS/SR muscle complex in the eyes with upper eyelid retraction was increased in 41 eyes (85.4%). The mean volume of the LPS/SR complex was 0.92 +/- 0.40 cm(3) in the eyes with upper eyelid retraction and 0.72 +/- 0.27 cm(3) in the contralateral eyes (p < 0.0001). While there was no correlation between LPS/SR complex volume and margin reflex distance1 (MRD1, the vertical distance between the center of the pupil to the center of the upper eyelid margin) (R = 0.024, p = 0.869), MRD1 and MRD2 (the vertical distance between the center of the pupil and the center of the lower eyelid margin) in the retracted eyes were negatively correlated (R = - 0.441, p = 0.002). In patients with upper eyelid retraction without increased LPS/SR complex volume, IR volume and MRD2 of the contralateral eye were 0.48 +/- 0.10 cm(3) and 5.92 +/- 0.45 mm, respectively. In the retracted eye, they were 0.37 +/- 0.17 cm(3) and 5.32 +/- 0.59 mm, respectively (p = 0.018, and 0.028). Regression models incorporating LPS/SR complex volume, MRD1, and lid lag could predict the presence of upper eyelid retraction with an accuracy of 92.5%. In patients with GO, increased LPS/SR complex volume in the retracted eye and increased IR volume of the contralateral eye were both associated with unilateral upper eyelid retraction. The combination of LPS/SR complex volume, MRD1, and lid lag can be used as a reliable index of upper eyelid retraction in patients with GO.