COCCIDOIDMYCOSIS
Coccidioides immitis is a dimorphic fungus that is endemic in the soil of the San Joaquin Valley (California), Arizona, New Mexico, and Texas. Intraocular coccidioidomycosis usually results as either anterior uveitis (irritis and iridocyclitis) or posterior uveitis.[
31][
32][
33] Infections of the choroids and retina appear to be a result of hematogenous seeding.[
34] In some cases of anterior uveal involvement, the diagnosis may be confirmed by anterior chamber paracentesis. [
35][
36]Smears show granulomatous inflammation and spherules containing endospores that are visible in hematoxylin and eosin stained material, but are greatly enhanced by silver preparations (Figure 8-12).
CRYPTOCOCCUS
Ocular
Cryptococcus may be associated with meningitis in otherwise healthy individuals or may be a manifestation of a disseminated infection in immunocompromised hosts. [
37][
38]It presents as a multifocal chorioretinitis with vitreous involvement.[
39][
40] The vitreous may be involved by direct extension from the uvea. Intraocular washings show budding yeast with a thick mucicarmine and periodic acid-Schiff staining capsule (Figure 8-13). The yeast forms vary in size. Associated inflammation is usually mild in immunocompromised hosts or may be intensely suppurative and granulomatous in immunocompetent individuals.
REFERENCES
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Zakka KA, Foos RY, Brown WJ. Surv Ophthalmol.1978;22:313-21.
32.
Rodenbiker HT, Ganley JP. Surv Ophthalmol. 1980;24:263-90.33.
Brown WC, Kellenberge RE, Hudson KE. Am J Ophthalmol 1958;45:102.34.
Glasgow BJ, Brown HH, Foos RY. Arch Ophthalmal 1987;104:24-27.
35.
Petti TH, Learn RN, Foos RY. Arch Ophthalmol 1967;77:655-661.36.
Mandell DB, Levy JJ, Rosenthal DL. Acta Cytol 1987;31:150-158.37.
Shields JA, Wright DM, Augsburger JJ, Wolkowicz MI. Am J Ophthalmal 1980;89:210-218.38.
Avendano J, Tanishima T, Kuwabara T. Am J Ophthalmol 1978;86:110-113.39.
Hiles DA, Font RL. Am J Ophthalmal 1968;65:98-108.40.
Henderly DE, Liggett PE, Rao NA. Retina 1987;7:75-79.
