Levator palpebrae superioris function and corneal astigmatism in university students with normal eyelid morphology

Background: Eyelids have been shown to influence corneal shape. The effects of eyelid pathologies on corneal astigmatism have been widely investigated. This study aimed to determine the correlation between levator palpebrae superioris (LPS) muscle function and with-the-rule (WTR) corneal astigmatism in university students with normal eyelid morphology.Methods: This was a cross-sectional study with a sample of 58 university students of Chinese origin selected by simple random sampling at the University College Sedaya International (UCSI) University Optometry Clinic, Kuala Lumpur, Malaysia. We included participants aged 18 to 30 years, regardless of sex, with normal eyelid morphology, normal LPS function, and WTR corneal astigmatism. For LPS muscle function, the distance of the upper eyelid margin from the maximal downgaze to the upgaze was measured, while the frontalis function was negated by the thumb of the examiner. Corneal astigmatism was measured using a manual Keratometry (Topcon OM-4; Topcon Corporation, Tokyo, Japan). Results: Of the 58 participants, 23 (39.7%) were men and 35 (60.3%) were women. The mean ± standard deviation (SD) age was 23.22 ± 1.77 years. For all participants, the means ± SDs for LPS muscle function and corneal astigmatism were 14.72 ± 1.74 mm and - 1.16 ± 0.47 D, respectively. Of the 58 participants, 25 and 33 had low and moderate WTR corneal astigmatism, respectively. The mean LPS muscle functions were not significantly different between the low and moderate WTR corneal astigmatism groups (P > 0.05). A positive but statistically insignificant correlation (r = + 0.14; P > 0.05) was found between LPS muscle function and WTR corneal astigmatism. Conclusions: We found no significant difference in the mean LPS muscle function between low and moderate WTR corneal astigmatism groups in young university students of Chinese origin with normal eyelid morphology. Furthermore, no significant correlation was found between LPS muscle function and low-to-moderate WTR corneal astigmatism.