Not all blood in the eye is bad. Most bleeding, coincidentally, that is visible, doesn’t cause any problems. It is the blood that you don’t see that can cause problems.
A subconjunctival hemorrhage is a broken blood vessel in the front of the eye. It presents as a red spot on the white part, or conjunctiva. Typically, the red spot increases in size before decreasing. It can take up to a few weeks to dissipate and the color of the hemorrhage changes from a deep red to a grayish-yellow as it resolves. A subconjunctival hemorrhage is caused by an increase in vasovagal pressure within the body. A sneeze or cough can cause this to happen. Many weight lifters have frequent episodes of hemorrhages. They are similar to a bruise and do not cause long-term damage.
A Hyphema is blood between the iris and the cornea inside what is called the anterior chamber of the eye. Most hyphemas are caused by trauma to the eye but there are tumors that could cause this as well. A hyphema frequently dissipates on its own but it should be treated with eye drops to decrease the incidence of scarring and glaucoma. If the hyphema is significant, there is a greater risk of causing glaucoma. In rare circumstances, the blood needs to be removed with surgery.
Blood in the retina can be caused by trauma as well but the most common etiologies are Diabetes and Hypertension. If uncontrolled, Diabetes and High Blood Pressure cause hypoxia within the eye. This can cause new blood vessels to form which are frequently leaky and can bleed. Mild forms of these diseases cause more localized bleeding. Hypertension can also cause occlusion of the vessels in the eye, which can result in long-term visual loss.
Blood in the vitreous can cause temporary visual loss. This can result from Diabetes and Hypertension but can also result from more benign entities, such as Posterior Vitreous Detachment. When the vitreous pulls from the eye, it can sever a blood vessel, causing bleeding. Usually the blood dissipates on its own but patients sometimes need to have the blood surgically removed.
Happy Halloween from the North Shore Eye Care team!!