Serum Eye Drops for Canine Corneal Disease: A Systematic Review of Epithelial Repair and Clinical Outcomes

To systematically evaluate the clinical efficacy, safety, and evidence quality of serum eye drops in veterinary ophthalmology and identify key knowledge gaps requiring future investigation.

Six canine clinical studies, three noncanine clinical reports (cat, elephant, horse), and six experimental investigations involving mice, rats, and rabbits.

Electronic databases (PubMed and Scopus) were searched for peer-reviewed in vivo and clinical studies using serum-based ophthalmic formulations. Eligible studies were categorized into three evidence tiers and graded according to the OCEBM 2011 Levels of Evidence.

Six canine clinical studies, three noncanine clinical reports, and six experimental models met the inclusion criteria. Autologous, homologous, and xenogeneic serum formulations were consistently well tolerated and supported corneal epithelial healing. However, controlled clinical trials in dogs did not demonstrate superiority over conventional medical therapy. Evidence quality ranged from Level 2 to Level 5, reflecting small sample sizes and methodological heterogeneity. Experimental findings in rabbits and rodents supported antiapoptotic and antiprotease activities attributable to serum components such as albumin, fibronectin, and growth factors.

Serum eye drops appear to be a safe, biocompatible adjunct for managing corneal surface disease in animals, although they are not a proven superior substitute for standard therapy. Their benefit likely varies according to disease type and severity. Rigorous randomized, independently assessed, and standardized studies are needed to determine optimal preparation protocols, dosing concentrations, and clinical indications within the context of antimicrobial stewardship.