Background: Non-arteritic anterior ischemic optic neuropathy (NAION) is a multifactorial disease that is caused by an infarction of the vessels that supply the optic nerve head. This study aims at evaluating the role of traditional and emerging cardiovascular risk factors on the development of NAION.
Methods: A total of 85 newly diagnosed NAION patients and 107 age- and gender-matched healthy controls were studied. All participants underwent blood testing for homocysteine and lipoprotein(a). Plasma levels of vitamin B6 and B12, and folic acid were also determined. Plasma values of all these parameters were evaluated as continuous variables, by a logarithmic transformation. In addition, traditional cardiovascular risk factors were considered.
Results: With univariate analysis, higher values of homocysteine and Lp(a) (OR 4.24, 95% CI 2.01-8.94, p < 0.0001; OR 1.32, 95% CI 1.04-1.67, p = 0.03, respectively) and lower values of vitamin B6 (OR 0.44, 95% CI 0.25-0.76, p = 0.003) were significantly associated with NAION. At multivariate analysis, adjusted for age, gender, smoking habit, hypertension, dyslipidemia, diabetes, sleep apnea, and thrombophilic risk factors, the higher homocysteine and Lp(a) values (OR 5.74, 95% CI 2.41-13.67, p = 0.0001; OR 1.27, 95% CI 1.01-1.63, p = 0.04) and lower vitamin B6 values (OR 0.42, 95% CI 0.23-0.77, p = 0.005) maintained their significant relationship with NAION.
Conclusions: This study demonstrated that elevated plasma homocysteine and lipoprotein(a) levels, as well as low vitamin B6 levels, may increase the risk of developing NAION. A screening for these thrombophilic markers could be useful in subjects experiencing NAION.