Tear cytokine profiles between children with allergic conjunctivitis at varying eye rubbing frequencies and keratoconus: A cross-sectional study.

PURPOSE: To investigate the effects of different eye rubbing frequencies on tear cytokines in children with allergic conjunctivitis and their association with keratoconus.

METHODS

A total of 44 patients with keratoconus, allergic conjunctivitis, and healthy controls were enrolled from January 2023 to May 2025. Patients with allergic conjunctivitis were divided into two groups: a high-frequency eye rubbing group (AC-eye rubbing) and a comparison group (AC), resulting in four groups of 11 patients each. Tear samples were collected using Schirmer strips, and the levels of 30 cytokines were measured using the RayBioTech Quantibody® Custom Array QAH-CUST kit. Differences in tear cytokines among the four groups were analyzed.

RESULTS

Allergic conjunctivitis patients with higher eye rubbing frequencies exhibited differential upregulation of IFN-γ, PDGF-BB, MIG, MIP-1α, EOT, and EOT2 in tear samples. Enrichment analysis revealed that the differentially expressed proteins were primarily associated with leukocyte migration and chemotaxis, cytokine and chemokine activity, JAK-STAT signaling pathway, and chemokine signaling pathway. Keratoconus patients showed downregulation of MIG, IL-2, IL-6, MIP-1d, I-309, and EOT2 in tear samples. Enrichment analysis indicated that these differentially expressed proteins were mainly involved in chemokine activity, cytokine-cytokine receptor interaction, chemokine signaling pathway, and JAK-STAT signaling pathway.

CONCLUSIONS

Eye rubbing frequency influences the tear cytokine profile in children with allergic conjunctivitis. The levels of MIG and EOT2 were associated with both frequent eye rubbing and the presence of keratoconus, suggesting their potential involvement in the disease link between allergic conjunctivitis and keratoconus. CLINICAL TRIAL REGISTRATION NUMBER: ChiCTR2200064660.