Comparison of the recovery characteristics for canine corneal ulcer treated with corneoconjunctival transposition or conjunctival autografts

Corneal ulceration induced by Staphylococcus pseudintermedius (S. pseudintermedius) is a common clinical eye disease. Antibiotics combined with corneoconjunctival transposition (CCT) or conjunctival autografts (CA) are often used, but the recovery characteristics are still unknown. In this experiment, canine corneal ulcer models induced by S. pseudintermedius and treated with levofloxacin eye drops (LED) were created. The models were used to compare the recovery characteristics of CCT and CA, combined with LED, by clinical observation, histopathology, and cytokine expression detected by qRT-PCR analysis. The results showed that the ulcerative cornea with only LED treatment perforated after 48 h. The mRNA expression of TLR2, IL-1β, IL-6, IL-8, and TNF-α genes was significantly elevated on 14, 28, and 35 days after the surgery compared to normal (p < 0.01). On day 42, the inflammatory damage had resolved, but the corneal transparency and arrangement of collagen fibrils in the CCT group were higher than those in the CA group. The mRNA expression of EGF, FGF, TGF-β1 and VEGF genes increased significantly (p < 0.01), mostly until day 42, proving that CCT and CA surgery contributed to the corneal recovery, and relieved the inflammatory reaction, with the elimination of corneal cicatrices needing a period of reconstruction. Therefore, this study has provided, for the first time, the method for establishing a canine corneal ulcer model induced by S. pseudintermedius. More importantly, the recovery of canine ulcerative corneas with CCT or CA surgery is reported for the first time.