Lacrimal hypofunction as a new mechanism of dry eye in visual display terminal users.
BACKGROUND
Dry eye has shown a marked increase due to visual display terminal (VDT) use. It remains unclear whether reduced blinking while focusing can have a direct deleterious impact on the lacrimal gland function. To address this issue that potentially affects the life quality, we conducted a large-scale epidemiological study of VDT users and an animal study.


RESULTS
Cross sectional survey carried out in Japan. A total of 1025 office workers who use VDT were enrolled. The association between VDT work duration and changes in tear film status, precorneal tear stability, lipid layer status and tear secretion were analyzed. For the animal model study, the rat VDT user model, placing rats onto a balance swing in combination with exposure to an evaporative environment was used to analyze lacrimal gland function. There was no positive relationship between VDT working duration and change in tear film stability and lipid layer status. The odds ratio for decrease in Schirmer score, index of tear secretion, were significantly increased with VDT working year (P = 0.012) and time (P = 0.005). The rat VDT user model, showed chronic reduction of tear secretion and was accompanied by an impairment of the lacrimal gland function and morphology. This dysfunction was recovered when rats were moved to resting conditions without the swing.


CONCLUSIONS
These data suggest that lacrimal gland hypofunction is associated with VDT use and may be a critical mechanism for VDT-associated dry eye. We believe this to be the first mechanistic link to the pathogenesis of dry eye in office workers.
Nakamura
Shigeru
S
Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.
Kinoshita
Shigeru
S
Yokoi
Norihiko
N
Ogawa
Yoko
Y
Shibuya
Michiko
M
Nakashima
Hideo
H
Hisamura
Ryuji
R
Imada
Toshihiro
T
Imagawa
Tomohiro
T
Uehara
Masato
M
Shibuya
Izumi
I
Dogru
Murat
M
Ward
Samantha
S
Tsubota
Kazuo
K
D000818:Animals; D016288:Computer Terminals; D003430:Cross-Sectional Studies; D004195:Disease Models, Animal; D006801:Humans; D007765:Lacrimal Apparatus / Q000378:metabolism / Q000503:physiopathology*; D009784:Occupational Diseases; D051381:Rats; D013666:Tears / Q000378:metabolism; D014985:Xerophthalmia / Q000209:etiology*