Serum Eye Drops for Ocular Surface Disease in Veterinary Ophthalmology: A Translational Review of Human and Veterinary Evidence.

BACKGROUND

Serum closely resembles natural tears in composition and contains higher growth factor levels than plasma in humans. Beyond its well-established anticollagenase properties, evidence from human ophthalmology suggests a broader therapeutic potential that may extend to the management of ocular surface diseases in animals.

OBJECTIVES

This review examines the composition, mechanisms, and clinical applications of serum eye drops (SEDs) in human and veterinary ophthalmology, compares serum with plasma, and proposes a protocol for their formulation.

RESULTS

SEDs provide a physiological blend of epitheliotropic factors, including EGF, TGF-β, vitamin A, fibronectin, and protease inhibitors (α2-macroglobulin). Key human indications include dry eye disease and persistent epithelial defects. In veterinary patients, SEDs are primarily used for keratomalacia, with additional potential applications-such as non-healing ulcers, neurotrophic and herpetic keratitis, chemical injuries, toxic keratopathy, and keratoconjunctivitis sicca-though evidence remains limited and largely extrapolated from human studies. Optimal preparation involves 120-min clotting, centrifugation at 3000×g, and optional dilution with saline, BSS, or sodium hyaluronate. Refrigerated storage (4°C) for up to 7 days is supported for canine serum, and at -20°C for 6 months, though stability of some components may vary. Aseptic handling, single-patient use, and refrigeration minimize contamination. SEDs are well tolerated, with few adverse effects reported in humans and none yet in veterinary patients.

CONCLUSIONS

SEDs offer physiologically rational adjunctive therapy for OSD in animals. Although serum and plasma have similar antiprotease activity, serum may promote better epithelial healing. Further veterinary studies are warranted.