Predictive Role of C677T MTHFR Polymorphism in Variable Efficacy of Photodynamic Therapy for Neovascular Age-Related Macular Degeneration

Age-related macular degeneration (AMD) complicated by subfoveal choroidal neovascularization (CNV) is the leading cause of severe central blindness in developed countries. AMD-related CNVs are distinguishable in classic and occult subtypes, characterized by variable natural history and different responsiveness to therapeutic procedures. Combined and repeated use of photodynamic therapy with verteporfin (PDT-V) and antiangiogenic drugs represents the most promising strategy against neovascular AMD, but it is unavoidably associated with mounting health-resource utilization. Predictive correlations between peculiar coagulation-balance gene variants and different levels of post-PDT-V benefit have recently been documented in Caucasians with AMD-related CNVs. In particular, methylenetetrahydrofolate reductase C677T substitution, a common thrombophilic folate pathway genotypic polymorphism, influences a better CNV responsiveness to PDT-V in classic- but not in occult-CNV cases. These pharmacogenetic findings indicate the opportunities to optimize the eligibility criteria of PDT-V and/or to perform this intriguing therapy in a customized manner, for finally minimizing the socio-economic burden of neovascular AMD.