Analysis of lid contour in thyroid eye disease with upper and lower eyelid retraction using multiple radial midpupil lid distances

Purpose: The aim of this study was to analyze upper and lower eyelid contours in adult patients with thyroid eye disease (TED) and normal adults using a software program that measures multiple radial midpupil lid distance (MPLD). Methods: Analysis targeted 61 eyes from 61 normal adults who had never undergone eyelid surgery or ophthalmic surgery and 63 eyes from 63 patients with TED. Digital pictures of primary gaze were analyzed using custom software. Conventional MPLD (90°, 270°) and 12 oblique MPLDs were collected every 15° across the temporal (105°, 120°, 135°, 150°, 165°, 180°) and nasal (75°, 60°, 45°, 30°, 15°, 0°) sectors of the upper eyelid. For lower eyelid contours, 9 oblique MLPDs in the temporal sector (255°, 240°, 225°, 210°, 195°) and nasal sector (285°, 300°, 315°, 330°) of the lower eyelid were analyzed. Results: From all angles, theMPLD of patients with TED was larger than that of the control group. The mean difference between the 2 groups was larger for the upper eyelid (0° ∼ 180°) than the lower eyelid (195° ∼ 330°). When comparing symmetry by dividing into each angle, the ratio of 90°/270° (MRD1/MRD2) demonstrated greater in patients with TED (P=0.000). Temporal/nasal eyelid contour symmetry in the upper eyelid, investigated using the distance ratio of the nasal sector/temporal sector (15°/165°, 30°/ 150°, 45°/135°, 60°/120°, 75°/105°), was significantly smaller in patients with TED (P<0.05). However, there was no significant difference between the 2 groups regarding temporal/nasal eyelid contour symmetry of the lower eyelid (330°/210°, 315°/225°, 300°/240°, 285°/255°). Conclusions: Radial MPLD is effective for analyzing eyelid contour. In our study, lateral flare of upper lid retraction and flat appearance of lower lid retraction were distinct characteristics in patients with TED. Consideration of eyelid contour in patients with TED may improve corrective surgery for eyelid retraction.