[A model to measure the volume of choroidal melanomas (author's transl)].

A formula to calculate the volume of biconvex-shaped malignant melanomata of the choroid is presented. The axial length of the eye, whatever the refractive error, has nearly no influence on the results. A computer printout of the range of results is added for clinical use. The reliability of contact B-Scan ultrasonography to obtain those parameters is examined using various tumor models of defined sizes.