Eye Disease A Linked To Common Soil Fungus

7 Sep 2011, 12:04
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Eye Disease

Histoplasmosis is a fungal infection that enters the body through the lungs, and individuals living in Ohio River Valley have probably heard about it. Usually connected with pulmonary disease, if left untreated histoplasmosis can also lead to loss of vision and blindness. 


The southeastern, mid-Atlantic and Midwestern portions of the U.S. are the most common areas for the soil born histoplasma capsulatum fungus. In soil contaminated with bird or bat droppings the fungus is more concentrated. 


The eye, like other areas of the body that can be infected from histoplasmosis, can remain asymptomatic for several years. 


Ryan Prall, M.D., assistant professor of ophthalmology at the Eugene and Marilyn Glick Eye Institute said: "The fungus can lodge in the layer of the eye behind the retina causing histoplasmosis spots or scars. These scars are usually not significant".


"Ocular histoplasmosis is generally uncommon but here in Indiana a significant number of people have the spots caused by the scar tissue," explained Dr. Prall, a member of the Indiana University School of Medicine faculty.


He said: "If the scars are on the macula, which is the center of the retina, they can cause new blood vessels to grow through and around those scars, which causes swelling and loss of vision, this is known as choroidal neovascularization". 


With advancements in treatments fewer than 1 percent of patients with the condition lose significant vision. Within the past decade, a drug that inhibits the growth of blood vessels, anti-VEGF, has been effective in treatment of histoplasmosis in the macula. If diagnosed and treated early, there typically is minimal vision loss. 


Although most people with ocular histoplasmosis were probably exposed as children, the condition usually doesn't present as a problem until people are in their 40s and 50s.


Ocular histoplasmosis research has been a long interest for the Indiana University School of Medicine faculty, including Theodore Schlaegel Jr., M.D., an IU Department of Ophthalmology professor and a graduate of the IU School of Medicine class of 1942, one of the first pioneers in the field.


Dr. Schlaegel worked together with investigators across the U.S. and England in epidemiological studies, and was also one of the initial researchers who believed the scars where due to the exposure of the fungus.


The founding president of the American Uveitis Society, which focuses on inflammatory disease of the eye, Dr. Schlaegel is also credited with discovering the connection between histoplasmosis and a blinding retinal disease which causes inflammation and scarring in the retina. 

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  • Frank Whiteman

    There were like dozens of these eye problems  and now these soil fungus. Ther only good thing - it is rare. 

    16 Sep 2011 in 17:31
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