Risk Determinants of Nonarteritic Ischemic Optic Neuropathy (NAION)

Background: The aim of our present study was to examine the risk factors for atherosclerosis as well as thrombophilic risk factors for their role in patients with NAION in comparison to healthy controls.

Methods: Prospective case-control-design with 109 Patients and 109 age-and sex-matched healthy controls.

Results: Elevated levels of fibrinogen, FVIII:C, FIX:C, FXI:C, plasminogen activity, von Willebrand antigen (vWF:Ag) and activity, triglycerides, elevated erythrocyte sedimentation rate and decreased levels of high density lipoprotein (HDL) proved to be significant risk factors associated with NAION (OR 1.9 to 5.4; p<0.05). The combination of these risk determinants further increased the risk in a multiplicative or supra-multiplicative way (up to OR 16.5; p<0.0001). None of the examined genetic risk factors (factor V Leiden mutation, Prothrombin mutation, platelet polymorphisms KOZAK and VNTR of glycoprotein 1bα, Hpa-1 polymorphism of GPIIb-IIIa, C807T polymorphism of GPIa/IIa, 4G/5G polymorphism of PAI-1 and C667T mutation of MTHFR gene) was significantly associated with the disease. However, when the HPA-1b allele, GPIa807T allele or the PAI-1 polymorphism were combined with increased levels of fibrinogen or vWF:Ag, a significant interaction with a supra-multiplicative increase in risk could be demonstrated.

Conclusions: In this first comprehensive analysis of a wide range of risk determinants of atherosclerosis and thrombophilia in NAION patients, several risk factors could be identified and quantified. Risk factors of arterial thrombosis appear to interact with risk factors of inflammatory atherosclerosis triggering NAION.