Written by:  Dr Norman Nieder-Heitmann, Ophthalmologist from Paarl Eye Centre MBChB (Stell), Dip Ophth (SA),FC Ophth (SA), MMED Ophth(UCT) Diabetes mellitus (DM) refers to a condition where the body is unable to produce or respond to the hormone insulin.  This in turn, leads to impaired metabolism of carbohydrates and ultimately raised blood sugar. Raised blood