RELIEVING DRY EYE SYMPTOMS FOR COMPUTER USERS
((Vo Van Toi and B. Dumery)) Tufts University, Electrical Engineering and Computer Science Departmen t, Biomedical Engineering Laboratory, Medford, MA 02155.
Purpose. It has been reported that people who use computers
extensively may experience dry eye symptoms which eventually disappear
with rest. We wanted to determine whether keeping the eye moist, either
by increasing the eye’s blink rate or by periodically supplying the eyes
with saline, would help to relieve recurring dry eye symptoms.
Methods. Six subjects (2 females and 4 males, age:26 ± 10) who use computers frequently participated
in the experiment. They were not diagnosed with chronic dry eye syndromes
or other eye diseases but have often experienced dry eye symptoms while
working with computers. All but one were first-time subjects to our
experiment. To trigger blinking or to periodically supply drops to the
subject’s eyes, the Automatically Medicated Instrument for Eyedrops
(AMIE)1 was used. It was set to automatically eject either a
minuscule jet of air every 10 seconds (6 ejections/minute) or a 5m l droplet of 0.9% saline every minute.
Subject’s blink rate was monitored. Each subject performed three tests
conducted on different days: (1) the subject worked on the computer on a
specific task for two consecutive hours, (2) the subject repeated test 1
while wearing the AMIE which ejected a jet of air to trigger supplementary
blinking, and (3) the subject repeated test 1 while wearing the AMIE which
delivered saline droplets. To prevent the air jet from causing the eyes
to dry, only one eye received the jet which was aimed toward the nasal
corner of the upper eye lid. In contrast, saline droplets were delivered
to the caruncles of both eyes. Before and after each session, the subjects
had their visual acuity tested and completed a questionnaire designed to
reveal typical dry eye symptoms. Each question was rated from 1 to 5
(1:not at all; 5:extreme).
Results. (1) Performing test 1 caused temporary dry eye
symptoms for all subjects; (2) The average blink rates of the subjects in
tests 2 and 3 were similar (about 15 bpm) and higher than in test 1 (about
8 bpm); (3) Increasing the blinking rate alone reduced the severity rating
of the dry eye symptoms by a factor of 1.5; (4) Periodically supplying
saline droplets eliminated all dry eye symptoms; and (5) Comparing the
visual acuity before and after each test we found that it decreased in
test 1, remained constant in test 2, and increased in test 3.
Conclusions. Increasing the blink rate partially relieved
the dry eye symptoms experienced by frequent computer users. Supplying
saline drops periodically was effective in preventing dry eye symptoms
from recurring. 1