Case study: Diabetes insipidus and Cushing’s disease

We optometrists hear the word ‘diabetes’ on a daily basis but how many times do we get to see patients with diabetes insipidus? Diabetes mellitus is fairly common condition with three million UK sufferers of type 2 diabetes.

Diabetes insipidus is rare, occurring in just 1 in 25,000 patients per year, so 3,000 UK insipidus sufferers as opposed to three million diabetes mellitus sufferers. Diabetes is derived from the Greek word ‘diabainain’ meaning standing with legs apart like a drawing compass, relating to the adopted stance associated with excessive urination.

Diabetes insipidus relates to the production of urine that is insipid, with no smell or taste. Diabetes mellitus, on the other hand, describes excessive sugar in the urine. Both conditions lead to drinking excessive fluid (polydipsia) and passing of excessive urine (polyuria), but the volume of urine produced in diabetes insipidus is much more excessive than in diabetes mellitus.