Toxoplasmosis of the eye can induce visual changes, retinochoroiditis, and in some cases, blindness. Infection with T. gondii stimulates T helper 1 cells to produce IL-10, a cytokine implicated in toxoplasmosis resistance. The association between OT and the GG genotype at the IL-10 promoter SNPs suggests that abnormalities in the genetic regulation of cytokine levels may have an impact on the human immune response in OT