James Rushton, PhD, MRCVS
Dr. Simone Gabner, PhD
Cordula Bartel, PhD
Dr. Alexander Tichy 
Univ. Prof. Dr. Monika Egerbacher
Ao. Univ Prof. Dr. Barbara Nell, Dipl. ECVO

ABSTRACT

Corneal ulcerative disease is a major concern to both veterinarians and the equine industry. Despite advances in medical therapy of ulcerative diseases, a plethora of cases still exists, which do not respond to treatment and require subsequent surgical therapy.

Regenerative medicine has evolved dramatically in equine medicine in recent years, foremost in equine orthopaedics. Equine platelet-rich-plasma has become a widely used treatment modality for equine joint and tendon diseases. It has also been applied in human ophthalmology. However to the authors´ knowledge the use of platelet rich plasma has not been introduced in equine ophthalmology to date. It is therefore the aim of this study to evaluate the in-vitro effects of equine platelet rich plasma in comparison to equine serum on corneal wound healing. 

Equine corneal epithelial cells, keratocytes and limbal stem cells, harvested from eyes of horses, euthanized for reasons unrelated to the present study will be cultured. Equine serum will be generated by centrifugation of freshly drawn blood from horses, owned by the University of Veterinary Medicine Vienna. Equine platelet rich plasma will be produced using a commercially available system (E-PET) using blood obtained from the same university owned horses. Upon confluence of corneal tissue cultures a lesion will be artificially induced and time to close the defect will be measured, with addition of equine platelet rich plasma, serum, and saline as control. Both, cell morphology and time to recover total confluence of each cell type under the respective treatment modalities will be statistically analysed using linear mixed models. 

Based on the results of previous studies various commercially available platelet rich plasma systems produce different amounts of growth factors (PDGF-BB; TGF-β1). A study from 2003 determined that growth factors PDGF-BB and EGF stimulate corneal epithelial and keratocyte proliferation, whereas TGF-β1 inhibits proliferation of the respective corneal cells. We therefore expect the commercially available E-PET system to result in the most rapid cell confluence in all cell cultures, due to the presence of high levels of PDGF-BB and minimum amounts of TGF-β1.