Nonarteritic anterior ischemic optic neuropathy associated with coexisting factor V Leiden and methylenetetrahydrofolate reductase mutations

We present a case of bilateral, not simultaneous, nonarteritic anterior ischemic optic neuropathy in a 53-year-old man with thrombophilic tendency. The investigation included determination of protein C, free protein S, antithrombin III, activated protein C resistance, and antiphospholipid syndrome study. Polymerase chain reaction and hybridization to allele-specific oligonucleotide probes were performed to determine the presence of thrombophilic polymorphisms. The patient was found to be heterozygous for factor V G1691A (Leiden) mutation and homozygous for methylenetetrahydrofolate reductase (MTHFR) C677T mutation.This case serves to demonstrate that the additive effect of two mild thrombophilic mutations may contribute to the occurrence of nonarteritic anterior ischemic optic neuropathy.