in partial fulfil]ment of the - MSpace - University of Manitoba

70
TÀBIE 1 9
Comparison of
scores of dark adaptation test parameters and serum
Vitamin À Ievel.
Dark Àdaptation
Test Parameters
Subj ec t s
Controls
Vitamin A
sufficient
patients
Vitamin A
deficient
patients
Rapid Dark Ädaptation
Test Time (in minutes)
4.4110.83
4 . 59r0. 97
7 .63!1 .79
Rod-cone Break
Time (in minutes)
8.0r0.7
5.711.1
9.611.8
Final Dark Adapted
Threshold (1og/ca/mz )
-4 "9!0 .2
-4.9!0.2
-4.4!0 .4
Serum Vitamin À
( in ug/dI )
45r'11
44r1 3
26!8
(Vi. nton and Russell , 1 981 )
1980). Subjects for this study were adult patients with liver disease,
gastro-ínLestinal disease and chronic alcoholism. Each subject had a
normal ophthalmoscopic exam. Blood samples were collected and serum
Vitamin A levels were determined. Dark adaptation abiliLy was measured
using the Classical Dark Adaptation Test. Comparison of serum Vitamin A
levels and the final dark adapted threshold revealed that a serum
Vitamin A level of >40 ug/dl predicted normal dark adaplation 95% of the
time. À serum Vitamin a level of >30 ug/d1 predicted normal dark adaptation
68% of. the time and a level of. >20 ug/dl predicted normal dark
adaptation 27% of the time (Carney and Russell, 1980)"