• Eye conditions can be a sign of high homocysteine levelseye image by Pali A from Fotolia.com
  
  Homocysteine is an amino acid that exists in the blood. Too much homocysteine can lead to coronary heart disease, stroke and blood clots. Signs of high homocysteine levels include changes in cholesterol, blood clots, hardening of the arteries and eye conditions.
  
  

Change in Cholesterol Levels

• Homocysteine levels are closely related to cholesterol levels. If your cholesterol level is suddenly rising, it could be a sign of high levels of homocysteine.
  
  

Blood Clotting

• Homocysteine activates the genes that are responsible for coagulating blood. If too much homocysteine is present, the blood can start to clot.
  
  

Hardening of Arteries

• Nitric oxide is a substance that relaxes blood vessels. High levels of homocysteine interfere with nitric oxide, so the blood vessels can't relax. Arteries that can't relax become hardened--a process known as atherosclerosis. When arteries and veins harden, that can result in a stroke or heart attack.
  
  

Eye Problems

• High levels of homocysteine negatively affect veins, including those that lead to the eye. Central retinal vein occlusion, central retinal artery occlusion, and nonarteritic anterior ischemic optic neuropathy are all eye conditions that signal too much homocysteine. These eye conditions can cause glaucoma and macular degeneration.