Diabetes Care, Vol 16, Issue 4 630-633, Copyright © 1993 by American Diabetes Association
Pupillary abnormalities in type I diabetes occurring during adolescence. Comparisons with cardiovascular reflexes
J Schwingshandl, JM Simpson, K Donaghue, MA Bonney, NJ Howard and M Silink
Ray Williams Institute of Pediatric Endocrinology, Children's Hospital, Camperdown, Australia.
OBJECTIVE--To evaluate computerized infrared pupillometry for the
assessment of autonomic neuropathy in adolescents with type I diabetes.
RESEARCH DESIGN AND METHODS--We measured resting pupil diameters and
pupillary light reflexes in 142 adolescents with type I diabetes (72 boys
and 70 girls, 10.4-19.8 yr of age, duration of diabetes 0.7-18.3 yr) and in
75 nondiabetic control subjects (29 boys, 46 girls, 11.3-19.8 yr of age).
All study participants were assessed using four standard cardiovascular
tests: maximum-minimum heart rate during deep breathing (mean of three
cycles); heart-rate change during a Valsalva maneuver (Valsalva ratio, mean
of three maneuvers); lying-to-standing heart-rate change (30:15 ratio); and
lying-to-standing BP change. RESULTS--Mean resting pupil diameters were
significantly smaller in the diabetic group: 6.28 +/- 0.06 vs. 6.77 +/-
0.11 mm, P < 0.0001); and significantly smaller with greater duration of
diabetes (r = -0.29, P = 0.0006) and higher levels of GHb (r = -0.24, P =
0.004). Patients with retinopathy grade 30 or more (Wisconsin 191 grading)
had significantly smaller resting pupil diameters: 5.9 +/- 0.16 vs. 6.4 +/-
0.12 mm, P = 0.008). The phasic light reflex as determined by reflex
amplitude and maximum constriction velocity was significantly reduced in
the diabetic group: 2.27 +/- 0.03 vs. 2.44 +/- 0.04 mm, P = 0.0009; and
6.68 +/- 0.12 vs. 7.24 +/- 0.16 mm/s, P = 0.007). Reduced reflex amplitude
was related to a longer postpubertal duration of diabetes (r = -0.18, P =
0.04). We found no association between pupillary and cardiovascular tests.
CONCLUSIONS--Infrared computerized pupillometry demonstrates subclinical
diabetic autonomic neuropathy as early as adolescence. Its presence seems
to be related to longer duration of diabetes and unfavorable metabolic
control.