MEASUREMENT OF THE PRECORNEAL TEAR FILM THICKNESS WITH A NONCONTACT OPTICAL INTERFEROMETRY FILM THICKNESS MEASUREMENT SYSTEM

In this study, the authors measured precorneal tear film thickness in one mouse, one rabbit, and two humans in vivo using a non-contact opti cal interferometry film thickness measurement system. The precorneal t ear film thickness was 21.1 mum in the mouse, 18.4 mum in the rabbit, and 12.0 mum and 10.3 mum in the two humans. Our measurements probably did not include the corneal epithelium, at least in the rabbit and th e humans. In addition, taking into consideration the three-layer struc ture of the tear film, it was concluded that the thickness measured wi th this system was that of the entire precorneal tear film layer. The system described can be used to measure tear film thickness noninvasiv ely in a short period of time and with accuracy, and is considered use ful for the study of tear film physiology.