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Ocular Histoplasmosis Syndrome |
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Histoplasmosis is caused when airborne spores of Histoplasma capsulatum (a microscopic fungus) are inhaled into the lungs. Histoplasmosis often produces no apparent systemic symptoms, but can later cause a serious eye disease called ocular histoplasmosis syndrome (OHS). In the USA, the highest incidence of OHS occurs in the Mississippi river valley. Since most cases of histoplasmosis are undiagnosed, anyone who has lived in this area is considered at risk. How does histoplasma cause ocular histoplasmosis syndrome?Histoplasma capsulatum (histo) spores spread from the lungs to the eye, lodging in the choroid, a layer of blood vessels beneath the retina. There, the organism predisposes your eye to develop fragile, abnormal blood vessels that can leak, bleed, and cause scaring. If the lesion is close to the center of the retina (the macula), then vision loss ensues.
What are the symptoms of OHS?In the early stages OHS usually has no symptoms. An eye doctor may notice “histo spots” in your retina on a routine exam. However, in more advanced disease, part of your vision may become blurred or blank.
How is OHS diagnosed?An ophthalmologist can diagnose OHS with a dilated eye exam. Sometimes fluorescein angiography, optical coherence tomography, or a blood test is useful.
How is OHS treated?When the disease is active or threatening vision, your doctor may recommend laser, photodynamic therapy, or anti-VEGF therapy.
More information? The National Institute of Health http://www.nlm.nih.gov/medlineplus/ency/article/001082.htm
The National Eye Institute http://www.nei.nih.gov/health/histoplasmosis/index.asp |
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Retina Center Minnesota
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Contact Us Tel: (612) 871-2292 (800) 233-8504 Fax: (612) 871-0195 staff@retinadocs.com |