Hydroxypropyl-Methylcellulose and GlicoPro® Eyedrops in the Treatment of Dry Eye Disease: In Vitro and Clinical Study

Introduction: Artificial tear substitutes are key elements in the first-line treatment of dry eye disease (DED). We hypothesized that GlicoPro®, a new multimolecular complex based on proteins, sulfured and unsulfured glycosaminoglycans and opiorphin, was able to significantly improve the effect of hydroxypropyl-methylcellulose (HPMC) eyedrops in treating DED. Methods: We performed an in vitro experiment and a clinical study, comparing an HPMC + GlicoPro®-based to an HPMC-based ophthalmic formulation (similar kinematic viscosity and comparable HPMC concentration). An in vitro dry eye model was established by inducing hyperosmolarity in the base medium of human corneal epithelial cells HCE-2. After treatment with ophthalmic formulations, the expression levels of inflammatory cytokines and enzymes (IL-20, IL-1β, TNF-α, IL-6, IL-8, MMP-9, and MCP-1) was measured by real-time polymerase chain reaction. Moreover, we performed a single-blind randomized 1:1 clinical trial, aimed to compare the efficacy of the two formulations instilled four times per day (QID), in treating mild-to-moderate DED. Symptoms (Ocular Surface Disease Index and Symptom Assessment iN Dry Eye), clinical signs, and ocular surface imaging data were assessed at baseline and after 1 and 3 months of treatment. Results: In vitro experiment: under hyperosmotic conditions, corneal epithelial cells upregulated the expression of inflammatory cytokines IL-20, IL-1β, TNF-α, IL-6, and IL-8. Treatment with HPMC + GlicoPro® significantly decreased the expression of all inflammatory markers tested, including cytokines, MMP-9, and MCP-1 (P < 0.05). Clinical study: the HPMC + GlicoPro® formulation showed a significantly higher effect in improving symptoms (overall treatment effect: P < 0.001), tear film stability, and markers of inflammation on corneal confocal microscopy (P < 0.01). Conclusions: Both in vitro and clinical data provided evidence supporting the role of GlicoPro® in improving the effect of HPMC in DED treatment. Clinical Trial Registration: NCT06726525.