Abstract
Purpose :
Pathologic insults like transplant rejection or trauma lead to blindness and to a so called “high-risk situation” with increased rejection rates after subsequent keratoplasty. These insults cause different immunological tissue responses. Aim of this study was to evaluate the impact of different types of corneal injury on hem- and lymphangiogenesis.
Methods :
We used 5 types of corneal injury model and naïve corneas as control (n=5 each). The suture model is the intrastromal placement of three 11.0 nylon sutures. A 2 mm filter disc soaked in 1 M NaOH was placed on the central corneal surface for 30s and the eyes were washed with PBS as the alkali burn model. Incision injury was performed in the central cornea with a linear perforating incision with 1 mm length. Corneal grafts were placed into an avascular recipient bed as the normal-risk keratoplasty model (NR-KPL). Corneal grafts were placed into the suture-induced neovascularized recipient as the high-risk keratoplasty model (HR-KPL). C57BL/6 mice were used as donor tissue in KPL and all others were Balb/c mice. 1 week after incision and 2 weeks after all other different injuries, corneas were excised and stained with CD31 and LYVE-1 for the quantification of blood vessels and lymphatic vessels.
Results :
HR-KPL and NR-KPL initiated the highest hemangiogenesis (HA), significantly higher than all other groups. Suture placement induced the second most powerful angiogenic response, significantly higher than alkali burn, incision and naïve eyes. Alkali burn evoked the third most powerful HA-response, significantly higher than naïve eyes. The incision model did not induce angiogenesis. Regarding lymphangiogenesis (LA), NR-KPL provoked the highest response, significantly higher than all other groups except HR-KPL. LA in HR-KPL was significantly higher than all other groups except NR-KPL and suture placement. Suture placement and alkali burn had a significantly higher LA compared to incision and naïve eyes. Incision provoked no significant LA compared to naïve corneas. Regarding LYVE-1+ macrophages, only NR-KPL and suture placement showed significantly more infiltration.
Conclusions :
Different types of corneal injury cause different types and degrees of neovascularization. In conclusion, different high-risk situations might result in different corneal graft survival rates. Therefore, also the potential clinical treatment of different injuries in the future might need to be customized.
This is a 2021 ARVO Annual Meeting abstract.