Effect of Subconjunctival Injection of Canine Adipose-Derived Mesenchymal Stem Cells on Canine Spontaneous Corneal Epithelial Defects

Spontaneous chronic corneal epithelial defects (SCCEDs) are characterized by nonadherent corneal epithelium leading to poor attachment to the corneal stroma. The objective of this study was to characterize corneal outcomes concurrently with the quantification of tumor necrosis factor-alpha (TNF-alpha) and vascular endothelial growth factor-A (VEGF-A) in tear fluid after the subconjunctival injection of canine adipose-derived mesenchymal stem cells (cAD-MSCs) in canine SCCEDs. Ten eyes with SCCEDs, which were nonresponsive to two rounds of diamond burr debridement, were included in this study. All eyes received a single subconjunctival injection of 1 x 106 cAD-MSCs. Ophthalmic examinations were performed before treatment and on day 7, 14, and 21 after treatment. Tear samples were collected for the quantification of TNF-alpha and VEGF-A concentrations by a canine multiplex immunoassay. Nine out of ten eyes revealed complete healing by day 21. The mean healing time was 10.89 +/- 1.7 days. All eyes showed a decreased degree of ocular discomfort, in accordance with the degree of corneal characteristics. The concentrations of VEGF-A significantly reduced from pre-treatment (4334.91 +/- 1275.92 pg/mL) to day 21 post-treatment (3064.61 +/- 1028.66 pg/mL). No significant difference in TNF-alpha concentration was observed before/after treatment. In conclusion, the single use of a subconjunctival injection of cAD-MSCs could be used as an alternative treatment for canine SCCEDs.