Tear exchange under hydrogel contact lenses: methodological considerations.

Abstract

Estimates of postlens tear exchange using a slit lamp fluorophotometer are similar to previously reported rates using similar fluorophotometric techniques. Fluorescent decay behind a hydrogel lens is most precisely described using a double-exponential curve equation and tear exchange may be described using ER, TRR and T(95), although the T(95) may be the least reliable of these measures. The technique appears capable of discriminating between lens types.