Prospective screening for thimerosal hypersensitivity: a pilot study.

This pilot study was conducted to determine if prospective patch-test screening could predict ocular tolerance to a thimerosal-preserved chemical disinfection system. Thirty patients were patch tested for thimerosal hypersensitivity before beginning soft contact lens wear. Only one patient exhibited a positive prospective patch test and subsequently developed an ocular thimerosal hypersensitivity. Two other patients with negative patch tests developed thimerosal hypersensitivity reactions over the 1-year study duration. Prospective patch testing for thimerosal hypersensitivity was neither clinically valuable nor sensitive in this particular sample.