H30-H36: Disorders of choroid and retina

H34: Retinal vascular occlusions

Retinal vascular occlusions are a group of eye conditions that occur when the blood vessels feeding the retina, the layer at the back of the eye that senses light and sends images to the brain, become blocked or clogged. This blockage can be due to blood clots, narrowing of the vessels due to high blood pressure, or hardening of the arteries. This can result in sudden painless vision loss or blurring, which can be partial or complete, depending on the area of the retina affected. The vision loss is typically sudden if the central retinal artery or one of its branches is blocked. However, if it is the central retinal vein or one of its branches that is occluded, the vision loss may be gradual. Despite the suddenness of symptoms, these conditions are typically the result of underlying health problems, most commonly cardiovascular diseases.