The participants in these subgroups were randomized to receive ketorolac tromethamine @ % in @ eye and placebo ( ofloxacin @ % ) in the fellow eye ( Group @A ) , proparacaine hydrochloride @ % in @ eye and placebo in the fellow eye ( Group @B ) , or ketorolac tromethamine @ % in @ eye and placebo in the fellow eye , followed @ minutes later by @ drop of proparacaine hydrochloride @ % in both eyes ( Group @C ) .