Chitosan–Hyaluronate Lubricant Eye Drops for Corneal Staining in Children Wearing Orthokeratology Lenses: A Randomized Controlled Trial

OBJECTIVE: This study compared chitosan-hyaluronate lubricant eye drops with conventional rewetting drops for orthokeratology (Ortho-K)-associated corneal staining in children. METHODS: In this prospective, multicenter, randomized, controlled trial, children (8-15 years) with Ortho-K-associated corneal staining were randomized 1:1 to chitosan-hyaluronate drops or conventional rewetting drops for 14 days. The primary outcome was corneal fluorescein staining (CFS) graded by masked examiners using the National Eye Institute scale. The secondary outcome was tear break-up time (TBUT). Generalized estimating equations accounted for intereye correlation. RESULTS: Fifty-nine participants were randomized; 54 (107 eyes) completed follow-up. In the chitosan-hyaluronate group, CFS decreased from 3.9±2.96 to 2.4±3.09 at day 14; the control group showed no significant change (4.7±3.47-3.8±3.20). The between-group difference at day 14 was significant (P=0.006). TBUT remained stable in both groups (all P>0.05). CONCLUSION: Chitosan-hyaluronate eye drops were more effective than a conventional rewetting solution in reducing Ortho-K-associated corneal staining in children over 14 days, supporting their potential as an adjunctive formulation for managing corneal staining in children wearing orthokeratology lenses.