Ocular Histoplasmosis

While much rarer than toxoplasmosis, it does have a similarity, in that it is a long-delayed eye reaction of an illness many years — sometimes decades — earlier. In all likelihood, you would not even recall it, as it usually takes the form of a cough, fever or muscle aches, similar to flu. Although the recovery seemed to have been complete, the body was left with a form of allergy, which later leads to the ocular histoplasmosis type of eye problems.

During the many years between the original "flu-type" infection and the identification of vision problems, small scars will have developed under the retina. Although the scars, themselves, are usually harmless, they sometimes lead to the formation of tiny abnormal, and very fragile, blood vessels. Their fragility often leads to them leaking fluid and blood.

If that leaking gets under the macula, it can lift it from its normal position and dramatically affect vision.

If you visit Dr. Uniat with problems like this, she will carry out a detailed eye examination with an ophthalmoscope to study the retina and the blood supply. She might also use a slit lamp microscope to view the retina. Based on the results of these examinations a more detailed study will be carried out, using the OCT unit or fluorescein angiogram to identify the locations of any abnormal blood vessels or leakages.

Quite often, little can be done to stop the development of ocular histoplasmosis, but laser treatment can often help seal leaks or destroy abnormal blood vessels. This kind of treatment, however, needs to be carried out early in the treatment program.

It is important, once this disease has been identified, to have routine follow-up examinations to check for the worsening of the problem, which would call for laser treatment.

When a diagnosis of ocular histoplasmosis has been made, it is strongly recommended that patients test their vision daily with the Amsler grid. Such a home testing will readily show any deterioration or distortion. If such a change is noticed, it is vital to make an appointment to see the doctor as quickly as possible.

Run your mouse over the photo at right to see how your vision can be affected.

Scarring of the macula
is the result of histoplasmosis


To see central vision distortion due to histoplasmosis,
run your mouse over
the image above