Fluorophotometric measurement of pH of human tears in vivo.

  title={Fluorophotometric measurement of pH of human tears in vivo.},
  author={Michiharu Yamada and Hiroshi Mochizuki and Masataka Kawai and Mami Yoshino and Yukihiko Mashima},
  journal={Current eye research},
  volume={16 5},
PURPOSE To measure the pH in the precorneal tear film of humans in vivo using a pH-sensitive fluorescent dye, bis-carboxyethyl-carboxyfluorescein (BCECF). METHODS The measurement was initiated by instilling 1 microliter of 2 mM BCECF solution into the subject's eye. The pH was calculated by measuring the ratio of fluorescent intensities at two excitation wavelengths (490/430 ratio), which was dependent on pH, but independent of the dye concentration and other variables. The tears of the same… CONTINUE READING