[Corneal macular dystrophy: clinical, histopathologic and ultrastructural features].

OBJECTIVE To assess the main clinical, genetic, histopathological and ultrastructural features of Mexican patients with macular corneal dystrophy, and to compare the results with those previously reported. METHOD We analyzed six cases where a histopathologic diagnosis of macular corneal dystrophy had been made between 1957 and 2004. RESULTS Clinically, all corneas showed focal grayish-white stromal opacities with diffuse edges. Histopathologically, intrastromal granules stained strongly positive with Alcian blue and colloidal iron. Transmission electron microscopy showed enlargement of smooth endoplasmic reticulum and the presence of intracytoplasmic vacuoles that corresponded to glycosaminoglycans. Genetic analysis showed novel mutations in the CHST6 gene in 2 of the patients. CONCLUSIONS Females were more affected than males and the mean age at the time of diagnosis was older than that reported previously, however the clinical, histopathological and ultrastructural features were similar to those of previous reports. As described in other cases in the literature, in some instances a disorder is found in CHST6 gene as a basis for this condition.