In comparing toxoplasmosis and histoplasmosis, which statement about vitritis is true?

In comparing toxoplasmosis and histoplasmosis, which statement about vitritis is true?

• A. Toxoplasmosis is more likely to have vitritis
• B. Histoplasmosis is more likely to have vitritis
• C. Both are equally likely to cause vitritis
• D. Neither causes vitritis

Answer: (A)

Vitritis is the presence of inflammatory cells in the vitreous. In ocular toxoplasmosis, the active retinochoroiditis elicits a brisk inflammatory response, so dense vitreous haze is common and often helps identify the condition (the retina is seen through a cloudy vitreous, giving a “headlight in the fog” appearance). In contrast, the typical histoplasmosis presentation—presumed ocular histoplasmosis syndrome—features peripheral chorioretinal scars with little to no vitreous inflammation; vitritis is not a prominent or defining finding. Because toxoplasmosis more reliably produces noticeable vitritis, the statement that it is more likely to have vitritis is true.

Vitritis is the presence of inflammatory cells in the vitreous. In ocular toxoplasmosis, the active retinochoroiditis elicits a brisk inflammatory response, so dense vitreous haze is common and often helps identify the condition (the retina is seen through a cloudy vitreous, giving a “headlight in the fog” appearance). In contrast, the typical histoplasmosis presentation—presumed ocular histoplasmosis syndrome—features peripheral chorioretinal scars with little to no vitreous inflammation; vitritis is not a prominent or defining finding. Because toxoplasmosis more reliably produces noticeable vitritis, the statement that it is more likely to have vitritis is true.