Cutting Edge: Novel Treatment Options Targeting Corneal Neovascularization to Improve High-Risk Corneal Graft Survival.

Abstract

Corneal neovascularization is an important risk factor for graft rejection after keratoplasty, although its role in posterior lamellar keratoplasty is not yet well defined. The aim of this work was to describe clinically available approaches that target corneal neovascularization preoperatively to improve graft survival after subsequent penetrating keratoplasty (PK) and to present findings on Descemet membrane endothelial keratoplasty (DMEK) in eyes with neovascularization. Recent work on the use of anti-vascular endothelial growth factor agents, fine needle diathermy (FND), and corneal collagen crosslinking (CXL) to regress corneal neovascularization before PK is summarized. Furthermore, studies that have investigated the outcome of DMEK in vascularized eyes are presented. Pretreatment of recipient corneas with FND combined with anti-vascular endothelial growth factor agents is an effective method to reduce long-standing corneal neovascularization and results in relatively low rejection rates after subsequent high-risk PK. Peripheral CXL also seems to be a potent method to regress corneal neovascularization, although data on the impact of pretransplant CXL on long-term graft survival are not yet available. There are only limited data on graft rejection rates after DMEK in vascularized eyes, but initial studies indicate that DMEK seems to be a viable therapeutic option when no stromal scars are present. Furthermore, preexisting stromal neovascularization seems to regress after high-risk DMEK. Several angioregressive strategies to treat corneal neovascularization before PK have entered the clinic with promising initial results, which warrants larger trials with longer follow-up. Studies will also have to define the precise role of preexisting corneal neovascularization in high-risk DMEK.