Eye Signs of Systemic Disease: Case 3 Presumed Ocular Histoplasmosis Syndrome
Long-standing chorioretinal scarring in both eyes did not affect a 67-year-old woman’s vision. The scars were roundish, irregular, and yellowish white with interior pigmentation (A and B). This patient had presumed ocular histoplasmosis syndrome (POHS), a common disorder in regions such as the Mississippi, Ohio, and Missouri river valleys, where the fungus Histoplasma capsulatum is endemic. Inhaled spores of the culprit organism cause granulomas in the lungs, liver, spleen, and the choroid of the eye. Unless the macula is involved, the patient’s vision is unaffected. Typical findings in infected patients include:
- Punched-out “histo” spots that can be seen throughout the retina (A and B).
- Peripapillary—diffuse, circumferential choroidal—atrophy that extends beyond the disc margin (C, in a different patient).
- Linear streaks of chorioretinal atrophy seen in the periphery.
- Choroidal neovascularization, which may be characterized by serous detachment of the retina, subretinal hemorrhage, and hard lipid exudate. In most patients, the choroidal neovascularization occurs at the edge of an old healed chorioretinal scar.
- Absence of vitritis or iritis.
- Positive skin tests for Histoplasma. This is a common finding in most patients with POHS. Refer those with active lesions to an infectious disease specialist.
- HLA markers B7, DR2, and DQ1, which may genetically predispose persons to POHS.
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