Endophthalmitis is uncommon. It is caused by organisms that have entered the eye through a surgical incision or an injury to the eyeball or, less often, have traveled through the bloodstream into the eye. Infection in the bloodstream has many possible causes, such as dental procedures, intravenous drug abuse, an abscess (a pocket of pus), skin ulcers, infections such as pneumonia or sepsis, or surgery anywhere in the body. Infection is usually due to bacteria (such as Staphylococcus aureus), but fungi or protozoa may also be responsible. Viruses can also cause extensive eye infections, but these are not usually classified as endophthalmitis.
The diagnosis of endophthalmitis is based on the symptoms, an examination of the eye, and cultures to identify the organism causing the infection. Cultures may be taken from the aqueous humor (fluid inside the front of the eye, also called the aqueous) and the vitreous humor (the jellylike substance that fills the back of the eyeball, also called the vitreous) to determine which organisms are causing the infection and which drugs are most active against them. People may also need blood and urine cultures.
Endophthalmitis is a medical emergency.
Immediate treatment with antibiotics is usually needed to preserve vision and to protect the health of the eye. A delay of even a few hours can result in irreversible vision loss in extreme cases. The choice of antibiotic may be adjusted depending on which organism is found to be causing the endophthalmitis. Antibiotics may be injected into the eye, given by vein (intravenously), or both.
People who have very poor vision when they are seen by a doctor may be given corticosteroids or have surgery. Corticosteroids can be given by mouth for a few days after the antibiotic injection, or, less commonly, they can be injected into the eye. Surgery may be needed to remove infected tissue from inside the eye, which may improve the chances of stopping the infection.