[Anisocoria in the chronic phase of Chagas' disease].

To compare the frequency of anisocoria in patients with chronic Chagas' disease a prospective double-blind study was done in 131 patients with positive serology for Chagas' disease and 138 negative, at Mambaí (GO-Brazil), which is an endemic area for Chagas' disease. To detect anisocoria, pupillometry was done with a millimetric ruler. Anisocoria was seen in 10(7.6%) patients with Chagas' disease and in 3(2.1%) normal subjects. The chi-square test showed statistical significance at level of 5%. Chagas' disease must be included among the causes of anisocoria.