Serum homocysteine levels may be associated with changes in retinal architecture

Am J Ophthalmol. 2009;148(6):902-909.

Elevated levels of circulating homocysteine may confer a greater risk for narrower retinal vasculature in men, according to a study.

In a subset of 1,772 patients originally followed in the Blue Mountains Eye Study, investigators noted an inverse relationship between serum homocysteine level above 17 µmol/L and arterial caliber in men, with a 0.86 µm reduction in arterial caliber per 1.0 µmol/L increase in homocysteine. However, no such relationship was found in women in the study.

Overall in the study, hyperhomocysteinemia (> 20 µmol/L of serum homocysteine) increased with age while mean arterial diameter, measured using fundus photography and reported as central retinal artery equivalents, decreased with age. As well, hyperhomocysteinemia was associated with narrower mean central retinal artery equivalents compared with normal homocysteine levels (≤ 15 µmol/L), 189.29 µm vs. 193.60 µm, respectively. Hyperhomocysteinemia was also associated with a lower arteriole-to-venule ratio, 0.85 vs. 0.87, compared to patients with homocysteine levels below 20 µmol/L.

"Our findings provide evidence that hyperhomocysteinemia, a potentially modifiable [cardiovascular disease] risk factor, may possibly influence the microcirculation, which could represent a potential pathway linking homocysteine to [cardiovascular disease]," the study authors wrote.