Bat Eye Disease

Bat Eye disease is a fungal infection better known as Ocular Histoplasmosis Syndrome (OHS). Because initial infection, which occurs in the lungs, is often overlooked, it is the leading cause of blindness in people between the ages of 20 and 40.

Definition

• Histoplasmosis is an airborne fungus common in bats and birds. It is released into the air when soil containing infected bat guano or bird droppings is disturbed.

In the Eye

• According to the National Eye Institute, infection of the eye occurs when histoplasmosis spores move from the lungs and lodge in the choroid, the layer of the eye between the retina and sclera, which contains blood vessels responsible for nourishing the back of the eye.

Symptoms

• Saint Luke's Eye Cataract and Laser Institute and the National Eye Institute agree that there are normally no symptoms experienced during the diseases earliest stages. As the Bat Eye disease progresses, those infected often experience distorted vision, blind spots and retinal scaring. If left untreated, the infection can and will result in total blindness.

Diagnosis

• To diagnose Ocular Histoplasmosis Syndrome in the eye, an ocular specialist will first look for spores residing in the inner eye, known as histo-spots, to verify exposure. If histo-spots are present, he then looks for retinal swelling. As a final measure to confirm OHS, the eye must be dilated and the retina carefully examined for specific markers of the infection.

Diagnosis

• According to the National Eye Institute, the most common treatment is to surgically remove abnormal blood vessels from the eye. This is typically accomplished through a laser surgical procedure called photocoagulation.