Investigative Ophthalmology and Visual Science (supp), vol 37, No. 3, p. 3300
| ' | |
| BLUE FIELD ENTOPTIC STUDY: DIURNAL AND LONG TERM FLUCTUATION OF LEUKOCYTE CHARACTERISTICS | |
| Tạp chí Investigative Ophthalmology and Visual Science 1996 ; 3 (37):3300 | |
| Tác giả | J. Bottari, B. Laidlaw, K. Pandey and Vo Van Toi |
| Nơi thực hiện | Department of Biomedical Engineering and Comp. Sci. Depart., Biomedical Eng, Bioengineering Center,Tufts University, 4 Colby Street, Medford, MA 02155 |
| Từ khóa | ARTIFICIAL TEARS, |
| DOI URL [ PDF] | |
English[sửa]
Purpose. To determine if this psychophysical technique is reliable enough for clinical studies.
Methods.
The
entoptoscope,
equipped
with
a
LCD
Spatial
Light
Modulator,
was
used
to
stimulate
the
perception
of
leukocytes
whose
velocity
and
number
were
determined
by
three
paradigms:
Superimposing
(Su),
Alternating
(Al)
and
Side-by-side
(Si)
(ref
1
and
2).
The
wavelength
of
the
stimulated
light
was
430
nm,
luminance
15
cd/m2
and
field
size
120.
The
measurements
were
triplicated,
and
the
results
were
averaged
and
analyzed
using
standard
statistical
methods.
All
observers
were
healthy
with
normal
vision.
The
diurnal
fluctuation
study
was
performed
with
three
experienced
male
subjects;
the
measurement
was
established
every
two
hours
for
8
hours
a
day.
The
long
term
fluctuation
study
was
performed
with
10
naive
subjects
(6
males,
4
females,
age:
20-50);
each
subject
attended
10
measurement
sessions
for
6
consecutive
weeks,
the
subjects
were
instructed
not
to
change
their
living
habits.
Results. Overall, neither the difference between subjects nor the variation of velocity were statistically significant. The coefficients of variance (CV) obtained with the Si paradigm were higher than those obtained with the other two paradigms and close to those obtained by Yap et al. (ref 3). Further, in the diurnal fluctuation study, the three paradigms yielded: (a) similar average velocity with different CV (Su=0.77mm/s± 10%, Al=0.77± 12%, Si=0.73± 22%) and (b) different average number with different CV (Su=80± 19%, Al=63± 22% and Si=72± 29%). In the long term fluctuation study, we found that: (a) the average values and the CV were compatible with those obtained in the diurnal fluctuation study, (b) the learning curve showed a strong effect in most subjects, (c) some subject performed be tter with one paradigm than another, however no single paradigm consistently yielded better results in all subjects and the preferable paradigm to the subject might not yield the lowest CV, (d) the average velocity did not change for the whole testing per iod while the average number of leukocytes tended to increase, (e) the testing time was shortest with the Su paradigm and longest with the Al.
Conclusions. (a) the velocity is a reliable parameter for clinical studies, (b) having experience is necessary to obtain repeatable results, (c) although the Si paradigm yielded larger average CV, some subjects performed b etter with it, therefore all three paradigms should be used.
