The morphologically distinct diabetic or 'metabolic' cataract is rare
in newly diagnosed insulin dependent diabetes. The cases described are
of five adolescents (three girls, two boys) with newly diagnosed insu
lin dependent diabetes who developed metabolic cataracts close to the
time of diagnosis (0-16 months). They all had a prolonged duration of
symptoms before diagnosis (4-24 months) and high glycated haemoglobin
levels at diagnosis (15-21%). The pathogenesis of diabetic cataract is
not well understood in humans. An attempt is made to link clinical ob
servations with evidence from experimental animal models to understand
the mechanism of cataract formation, with particular reference to the
aldose reductase pathway. It is recommended that the lens and retina
are examined at the onset of diabetes in all children, especially thos
e who have a prolonged duration of symptoms before diagnosis and who r
eport persistent blurred vision.