Objective:

To evaluate a contact lens delivering PDRN and DMPC for corneal epithelial repair and tear-film outcomes in rabbit models.

Approach:

• Intervention: Rabbits wore either a control lens or a lens co-delivering polydeoxyribonucleotide (PDRN) and the tear-film lipid mimic DMPC for six hours daily.
• Models and outcomes: The study used corneal epithelial wound and meibomian gland dysfunction-induced dry eye models. Outcomes included epithelial defect area, tear break-up time, tear osmolarity, histology, and gene expression.

Key Findings:

• In the wound model, mean residual epithelial defect area on the afternoon of day two was 0.37% with the combination lens and 4.46% with the control lens; both groups were nearly re-epithelialized by the following morning.
• On day three, regenerated epithelium was thicker with the combination lens than with the control lens (28.33 μm vs 14.82 μm).
• In the dry eye model, tear break-up time increased from about 3.5 seconds at baseline to 15.1 seconds by day seven with the combination lens, compared with 8.0 seconds with the control lens. Tear osmolarity was also lower at several time points.
• Treated eyes showed fewer desquamated epithelial cells and preserved MUC5AC expression and conjunctival goblet cells. MUC1 and MUC16 expression decreased.

Interpretation:

The study authors proposed that PDRN-related regeneration and anti-inflammatory effects, together with DMPC's tear-film lipid-mimicking properties, may support corneal repair and tear-film stability. They interpreted the mucin findings as possible normalization of inflammation-associated signaling.

Limitations:

• The study was short-term and conducted in rabbits.
• The individual contributions of PDRN, DMPC, and the contact lens were not separated.
• Eye allocation was nonrandomized.

Conclusion:

The findings provide preclinical proof of concept for a combination drug-eluting contact lens; effects in humans were not established.

Sources:

• Scientific Reports study (as described in the provided context)