Dynamic changes in tear meniscus curvature at the rigid contact lens edge.
OBJECTIVE
To investigate dynamic changes in tear meniscus curvature at the edge of a rigid contact lens.


METHODS
Four eyes of four men and seven eyes of seven women who were daily wearers of rigid contact lenses were enrolled in the study. A digital video-meniscometer was used to observe real-time changes in tear meniscus curvature. Quantitative measurements have not previously been made at these locations.


RESULTS
The meniscus at the lens edge showed stereotypical changes with each blink. The meniscus radius is lowest at the end of the up-phase of the blink and then increases to a steady value 0.213 +/- 0.024 mm (mean +/- SD, n = 6) after about 1 second.


CONCLUSIONS
The video-meniscometer permitted observation of real-time changes in meniscus curvature at the contact lens edge during the blink. The short radius at the end of the up-phase suggests that tears are drawn away from the lens during the upward movement of the lid and lens. The restoration of a longer radius of curvature in the period that follows is thought to be due to a flow of fluid into the meniscus from the neighboring tear film.
Yokoi
Norihiko
N
Department of Ophthalmology, Kyoto Prefectural University of Medicine, Japan. nyokoi@ophth.kpu-m.ac.jp
Maruyama
Kunio
K
Kinoshita
Shigeru
S
Bron
Anthony J
AJ
Tiffany
John M
JM
D000328:Adult; D001767:Blinking / Q000502:physiology; D003261:Contact Lenses; D003315:Cornea / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010781:Photography; D013666:Tears / Q000502:physiology*; D014741:Video Recording