Multiple radial midpupil lid distances: a simple method for lid contour analysis.

PURPOSE To describe a new computerized method for the analysis of lid contour based on the measurement of multiple radial midpupil lid distances. DESIGN Evaluation of diagnostic technology. PARTICIPANTS AND CONTROLS Monocular palpebral fissure images of 35 patients with Graves' upper eyelid retraction and of 30 normal subjects. METHODS Custom software was used to measure the conventional midpupil upper lid distance (MPLD) and 12 oblique MPLDs on each 15° across the temporal (105°, 120°, 135°, 150°, 165°, and 180°) and nasal (75°, 60°, 45°, 30°, 15°, and 0°) sectors of the lid fissure. MAIN OUTCOME MEASURES Mean, standard deviation, 5th and 95th percentiles of the oblique MPLDs obtained for patients and controls. Temporal/nasal MPLD ratios of the same angles with respect to the midline. RESULTS The MPLDs increased from the vertical midline in both nasal and temporal sectors of the fissure. In the control group the differences between the mean central MPLD (90°) and those up to 30° in the nasal (75° and 60°) and temporal sectors (105° and 120°) were not significant. For greater eccentricities, all temporal and nasal mean MPLDs increased significantly. When the MPLDs of the same angles were compared between groups, the mean values of the Graves' patients differed from control at all angles (F = 4192; P<0.0001). The greatest temporal/nasal asymmetry occurred 60° from the vertical midline. CONCLUSIONS The measurement of radial MPLD is a simple and effective way to characterize lid contour abnormalities. In patients with Graves' upper eyelid retraction, the method demonstrated that the maximum amplitude of the lateral lid flare sign occurred at 60° from the vertical midline.