Ocular histoplasmosis.(VITREOUS AND RETINA)(Disease/Disorder overview)

Signs and symptoms

Ocular histoplasmosis is a significant cause of vision loss in adults between 20 and 50 years old. (1-12) The classic hallmark signs include the triad of: (1) round, white-yellow, punched-out, circumpigmented chorioretinal lesions, classically referred to as "histo spots"; (2) peripapillary atrophy; and (3) evidence of macular chorioretinal involvement. (1-6) All lesions possess the potential to provoke subretinal cytokine formation to form choroidal neovascularization. (1-6) Other soft signs include linear streak lesions in the periphery, which may occur in up to 5% of cases. (5,6) Bilateral involvement is the norm. (1) Another distinguishing characteristic of ocular histoplasmosis is that the retinal inflammation occurs in the discrete absence of iritis or vitritis. (1) As such, until the disease produces maculopathy (with associated metamorphopsia or a drop in visual acuity), individuals remain unaware that they have it unless the disorder is discovered during a routine fundus examination. (5) The diagnosis may be confirmed with a skin test that assays for the histoplasmosis antigen; however, whether this increases the risk of reactivation in cases of quiet disease is controversial.

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Systemically, life-threatening complications are usually associated with an immunocompromised state; however, 20% of severe histoplasmosis illnesses result from a heavy inoculum in healthy persons who present at …