What effect does sorbitol have on the lens of a diabetic dog?

Sorbitol plays a significant role in the pathophysiology of diabetic cataracts in dogs. In diabetic patients, elevated blood glucose levels lead to increased sorbitol accumulation in the lens of the eye. This accumulation occurs because glucose is converted to sorbitol via the polyol pathway, primarily through the action of the enzyme aldose reductase.

As sorbitol accumulates, it draws water into the lens through osmosis, leading to an increase in lens thickness. This process induces swelling and changes in the biochemical composition of the lens fibers, ultimately resulting in lens opacification and cataract formation. As a result, the presence of elevated sorbitol levels in the lens is a key factor contributing to the development of cataracts in diabetic dogs, making the association between sorbitol and cataract formation a critical aspect of understanding diabetes-related ocular complications.