Metabolic cataracts in newly diagnosed diabetes

Abstract

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 insulin 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 observations 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 those who have a prolonged duration of symptoms before diagnosis and who report persistent blurred vision. <h3>Key messages</h3> Metabolic cataracts may occur in newly diagnosed insulin dependent diabetes, but are rare Metabolic cataracts are more likely to occur in children who have prolonged poor control or who present with prolonged duration of symptoms before diagnosis The lens of the eye should be examined in all newly diagnosed cases of insulin dependent diabetes, especially those with blurred vision, to diagnose cataracts early If lens opacities are suspected, specialist ophthalmological opinion should be sought and, if required, surgery offered to improve the quality of life