Abstract
Purpose :
Pathological corneal (lymph)angiogenesis is a known risk factor for immune-mediated allograft rejection after keratoplasty. However, there is no efficient treatment to regress pre-existing pathological corneal blood and lymphatic vessels in vascularized high-risk eyes prior to corneal transplantation. This study assessed the possibility to regress corneal blood and lymphatic vessels by photodynamic therapy (PDT) after systemic intravenous Verteporfin injection and the influence of timing of PDT after injection of the photosensitizer.
Methods :
Female BALB/c mice were used for suture-induced inflammatory corneal neovascularization to induce combined hem- and lymphangiogenesis. Thereafter, the treatment group received PDT treatment 3 minutes, 1 hour and 24 hours after an intravenous injection of Verteporfin (control group: phosphate buffered saline (PBS)). Corneas were excised 3 days after corneal photodynamic therapy and corneal flatmounts were stained with FITC-conjugated CD31 and LYVE-1 to quantify hem- and lymphangiogenesis.
Results :
Corneal blood vessels showed a significant reduction when PDT was performed 3 minutes after Verteporfin injection (p<0.05) while lymphatic vessels showed no significant difference. Both blood vessels (BV) and lymphatic vessels (LV) were significantly regressed when performing PDT 1 hour (BV: p<0.01; LV: p<0.001) or 24 hours (BV: p<0.05; LV: p<0.01) after intravenous application of Verteporfin.
Conclusions :
This study shows that PDT after intravenous injection of Verteporfin can selectively regress pre-existing corneal blood vessels or both blood and lymphatic vessels depending on the timing of PDT after injection. PDT 1 hour and more after a systemic photosensitizer injection destroys both vessel types.
Therefore, this PDT strategy might be a promising anti(lymph)angiogenic method to reduce pre-existing blood and lymphatic vessels prior to keratoplasty in high-risk eyes to promote corneal graft survival.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.