Relationship between the axis and degree of high astigmatism and obliquity of palpebral fissure.

Purpose: To investigate a possible relationship between the slanting of palpebral fissures and the magnitude and axis of astigmatism in children with astigmatism.

Methods: Cross-sectional study at a referral center of 53 children with astigmatism of more than +1.50 D in at least 1 eye. Visual acuity testing, cycloplegic refraction, slit-lamp biomicroscopy, and ophthalmoscopy were done on every patient. Corneal topography was obtained in 40 cooperative patients. External photographs of the midface were taken in 45 children. The degree of slanting of the palpebral fissures was evaluated based on the photographs. The statistical analysis tool used was repeated measures analysis of variance. Patients in whom photographic analysis was not available were excluded from the part of the statistical analysis dealing with eyelid slant.

Results: Palpebral fissure slant (P =.013) and gender (P =.0005) were highly correlated with the obliquity of cylinder axis. There was a possible correlation between gender and eyelid slant (P =.0594), with females having slightly larger degrees of upward palpebral fissure slanting and male more downward slanting of their fissures compared to published angles in an age-matched population. We found a statistically significant correlation between the degree of total astigmatism and a larger abnormal slant (P =.0192) and between the axis and magnitude of corneal astigmatism and abnormal slant (P =.0092). Higher degrees of eyelid slant (> 8 degrees or < -4 degrees ) increased the risk of high cylinder magnitude (> 3.00 D) by an odds ratio of 4.17 (95% CI: 1.03, 19.95).

Conclusions: Children with astigmatism with large degrees of slanting of their palpebral fissures are at higher risk for high astigmatism (> 3.00 D). The axis of the astigmatism is highly correlated with the slanting of the palpebral fissure.