New method to analyze sagittal images of upper eyelid obtained by anterior segment optical coherence tomography

Purpose: To report a new method to analyze sagittal images of the upper eyelid by anterior segment optical coherence tomography (AS-OCT). Methods: Ninety subjects equally divided into young (20-39 years), middle age (40-59 years), and elderly (60-79 years) group were studied. A sagittal image of the upper eyelid was obtained by AS-OCT (CASIA2, Tomey, Japan) and the following parameters were determined: upper eyelid thickness (UET), the distance between two parallel lines tangential to the apexes of the cornea and the upper eyelid; the upper eyelid angle (UEA) was the angle formed by a line running tangential to the apex of the cornea and a line passing from the apex of the cornea to the apex of the upper eyelid; and the cross-sectional area (CSA), the area from the edge of the eyelid to a point 6 mm above the corneal apex. All parameters were compared among groups and correlation analyses were studied between age and eyelid parameters. Results: The UET was 2.09 ± 0.58 mm, 2.63 ± 1.04 mm and 2.83 ± 0.83 mm in the young, middle age and elderly group, respectively. The difference between the young and the elderly group was significant (P = 0.014). The elderly group had a significantly larger UEA than that of young group (P = 0.022). The elderly group also had significantly larger CSA than the other two groups (all P < 0.01). The age was significantly correlated with all eyelid parameters. Conclusions: AS-OCT can be used as a non-invasive and quantitative method of evaluating sagittal images of the upper eyelid.