Effects of thrombocyte rich plasma, autologous serum and umbilical cord serum on corneal healing after penetrating keratoplasty in New Zealand rabbit (oryctolagus cuniculus)

In this study, it was aimed to investigate of the possible effect of autologous blood serum (ABS), platelet rich plasma (PRP) and umbilical cord serum (UCS) on cornea healing, graft re-epithelization and intact epithelium protection. The animal material of the study consisted of 120 New Zealand Rabbits (Oryctolagus Cuniculus). Rabbits were divided into groups as PRP, ABS, UCS, Penetrating Keratoplasty (PK), control and donor cornea group after penetrating keratoplasty and these groups were also divided into five subgroups which are followed for 7, 14, 21 and 84 days postoperatively. In the clinical evaluation of the corneal healing process after penetrating keratoplasty; while there was no statistically significant difference between the groups in terms of corneal vascularization (p> 0.05), the averages of the groups of 3 and 12 weeks were higher and statistically significant compared to the 1-week group (p <0.05). In the histopathological examination, the OBS and PRP groups reached a value in 3 weeks while the parallel lamella formation reached in the same value in 12 weeks in PK group, and the mean of the findings obtained from the 1, 2 and 3 week groups was higher and statistically significant compared to the 12 weeks' group (p<0.05). The stromal overgrowth development in 30% of rabbits after PK according to the application groups was seen in 50% of PK, 35% in PRP, 20% in UCS and 15% in ABS. It was noted that the mean number of wound area vessels increased continuously compared to weeks, and that both ABS, PRP and UCS were not statistically significant but observationally low compared to PK both in application groups and 12-week sub-application groups. The number of corneal inflammatory cells increased over time in parallel with the weeks, but it was found statistically significantly higher in the 12-week group compared to previous weeks and a positive correlation was found between the number of inflammatory cells and the number of vessels. In the immunohistochemical evaluation; in terms of CD4, CD8 and MHC-II, no statistically significant relationship was found between the application groups, while the 12-week group was found to be higher and significant compared to the other xxx weeks in the evaluation made by weeks (p<0.05). In the first three weeks post-PK, it was found that ABS, PRP and UCS did not increase MHC-II and CD4+ cell activation compared to PK, but these blood substances increased the number of MHC-II and CD4+ cells statistically at 12 weeks (p<0.05). It was observed that ABS, PRP did not cause an increase in CD8+ T cell activation in the first three weeks postoperatively compared to PK, but a statistically significant increase occurred in 12 weeks. These reactions were found to include both CD4+ and CD8+ T lymphocyte response mediated by ABS and PRP. It was noted that mostly CD4+ T cell mediated response was occurred by UCS. As a result, we suggest that ABS, PRP and UCS have positive effects on corneal healing, graft re-epithelization, parallel lamella formation and vascularization, but they increased CD4+, CD8+ and MHC-II positive cells at the 12th week.