We tested this possibility by treating streptozotocin diabetic rats with insulin implants. These implants release insulin to bring average blood glucose almost down to control levels. These data underscore that it is important to maintain tight control of blood glucose to help slow the vision loss in diabetes. Summary Our findings therefore demonstrate that in an animal model retinal neurons begin to die within months of diabetes onset. A similar degeneration also appears to occur in humans.
Retinas contain millions of neurons, and even during diabetes only a few die at any given time.
It is possible that a constant loss of small numbers of neurons begins soon after onset and continues over years of diabetes. The cumulative neurodegeneration then likely results eventually in vision loss and may also cause alterations in the blood supply evident in ophthalmic observation during later stages of diabetic retinopathy.