The Effects of Eye Rubbing on Corneal Topography and Biomechanics in Children With Allergic Conjunctivitis.

Purpose: To characterize corneal topographic and biomechanical alterations in children with allergic conjunctivitis and evaluate their association with eye rubbing frequency. Methods: This cross-sectional study enrolled children aged eight to fourteen years with diagnosed perennial/seasonal allergic conjunctivitis treated at our institution (January 2023-March 2025). All participants underwent routine ophthalmologic examinations, corneal topography, and visualized corneal biomechanics assessments. The results were compared with age- and sex-matched healthy controls. Eye rubbing frequency was documented, and correlation analyses and mediation effect analysis were conducted between eye rubbing frequency and altered corneal topographic and biomechanical parameters. Results: No significant differences were found between the allergic conjunctivitis group and the control group regarding age, sex, or spherical equivalent. Among corneal topographic parameters, front elevation at the thinnest point (Fe) and front difference deviation (Df) were significantly higher in the allergic group compared to controls. In terms of corneal biomechanical parameters, the first applanation length (A1L) and stiffness parameter at first applanation (SP-A1) were significantly lower in the allergic group. Fe and Df were positively correlated with eye rubbing frequency and fully mediated the effect of eye rubbing on the Tomographic and Biomechanical Index (TBI). A1L and SP-A1 were not correlated with eye rubbing frequency and did not mediate its effect of eye rubbing on TBI. Conclusions: Children with allergic conjunctivitis exhibit increased anterior corneal surface height and front difference deviation. These abnormalities are associated with the frequency of eye rubbing, which influences the TBI via changes in Fe and Df. Translational Relevance: Eye rubbing in children with allergic conjunctivitis causes specific corneal topographic changes. Detecting these changes early allows for timely intervention to reduce rubbing and may help prevent the risk of progressive corneal deformation.