Stability of back-toric prism-ballast hydrogel contact lenses

We fitted each of 20 eyes with 3 different Hydrocurve contact lenses: (1) spherical with prism ballast, (2) back-toric without prism ballast, and (3) back-toric with prism ballast. We monitored the stability of the lenses. The prism-ballast lenses were generally stable on corneas with zero to 3.5 DK of with-the-rule toricity; the back-toric nonprism lenses were not stable.