The Impact of the Position of the Upper Eyelid on the Profile of Epithelial Thickness and the Topography of the Cornea.

Aim: To evaluate the impact of the position of the upper eyelid on the corneal epithelial thickness, anterior elevation map, and corneal aberrations in patients with unimpaired function of the eyelids. Methods: Sixty-one right eyes were included in this prospective, non-randomized study. The low-positioned eyelid group (LP group) consisted of 30 patients with a mean upper eyelid margin position at 3.45 ± 0.45 mm above the corneal apex at primary gaze. The high-positioned eyelid group (HP group) comprised 31 eyes for which the respective value was 4.56 ± 0.36 mm. The anterior elevation map, corneal aberrations, and epithelial thickness profile were obtained with eyes wide open, using a MS-39 corneal tomograph (CSO, Florence, Italy). The analysis was also performed at measurement points 0.3 mm above and 0.3 mm below the eyelid margin. Results: Significantly thinner epitheliums at 4.5 mm above the center of the cornea on the vertical meridian in the LP group were observed (p < 0.05). Higher anterior elevations and thicker epitheliums of the cornea were observed at the measurement location of 0.3 mm above the upper eyelid's margin in the HP group (p < 0.05). A negative correlation between the height of the upper eyelid and spherical aberration was noted. Conclusions: The findings provide evidence that the positioning of the upper eyelid in individuals with normal eyelid function influences the epithelial thickness map, the anterior elevation map, and corneal spherical aberrations.