The Effect of Supine Versus Upright Positioning on Eyelid Height in the Nonsurgical Patient

To directly compare margin-reflex distance 1, margin-reflex distance 2, and palpebral fissure in the upright versus supine positions in nonsurgical patients.

A total of 43 patients (31 female, 12 male, and age range 26-96) were enrolled. Photos were taken in the clinic in the upright and supine position with a ruler placed vertically in the same plane as the eyelid, and the above computer-analyzed measurements were obtained.

Among the 86 eyes observed, the average upright margin-reflex distance 1 was 2.97 mm (95% confidence interval [CI], 2.70-3.24), while the average supine margin-reflex distance 1 was 2.38 mm (95% CI, 2.13-2.63). These differences were statistically significant ( p < 0.001). Similarly, statistically significant differences were seen with margin-reflex distance 2 ( p < 0.001), where upright measurements averaged 5.57 mm (95% CI, 5.33-5.81), and supine measurements averaged 5.01 mm (95% CI, 4.73-5.28). Finally, palpebral fissure showed similar significance ( p < 0.001). Upright measurements averaged 8.54 mm (95% CI, 8.19-8.90), while supine measurements averaged 7.38 mm (95% CI, 7.00-7.76).

Supine positioning provides a decrease in margin-reflex distance 1, margin-reflex distance 2, and palpebral fissure when compared with upright positioning in nonsurgical patients. This contradicts a previous study on intraoperative patients when lidocaine with epinephrine was used. This study helps us better understand the normal physiologic response to position changes with regard to eyelid height in the nonsurgical patient. As such, this study may function as a control for future studies comparing anesthetic/surgical parameter effects on intra- and post-operative eyelid heights.