Diabetes is a condition in which the body does not properly regulate and use sugar (glucose) for its energy needs, usually because of a failure to produce enough insulin. Diabetes may affect many organs in the body, including blood vessels, nerves, the kidneys, the heart and the eyes.(1)

How does diabetes affect the eyes?

Poorly regulated and high levels of sugar in the blood can cause changes in the optics of the eye, resulting in blurred vision and changes in eyeglass prescriptions. The condition may also interfere with focusing of the eye. Control of the blood sugar levels usually corrects these problems.

Diabetes can cause cataracts, a clouding of the lens inside the eye that blurs vision.

Diabetes can cause double vision when it affects the nerves that control the alignment and movement of the eyes. It can also cause the optic nerve to be more easily damaged by glaucoma.

The most important cause of visual impairment in people with diabetes is diabetic retinopathy, a condition in which changes occur in the tiny blood vessels that nourish the retina.

The chances of having some form of diabetic retinopathy increase the longer a person has had diabetes.

What is the detection and treatment of Diabetes?

Research has shown that severe visual loss from diabetic retinopathy can be prevented or delayed by laser treatment, but only if the retinopathy is diagnosed early enough. This is why it is important for most people with diabetes, particularly those who have had the disease for 5 years or more, to have an annual eye exam performed by a medical doctor trained to recognize the early signs of diabetic retinopathy.

Diabetic retinopathy is precisely located and documented with special photographs of the retina called fluorescein angiogram. Treatment with laser photocoagulation is aimed a sealing leaky vessels and preventing the growth of new, abnormal vessels. Laser treatment has risks and side effects, which must be weighed against the benefits for each individual patient. In more advanced retinopathy, the benefits usually out weigh the risks.

Despite treatment, or for lack of it, some people with diabetes bleed massively into the eye and require a delicate, operation called vitrectomy to remove blood and scan tissue from the eye. Others also need surgery for retinal detachment.

Research into diabetes and diabetic retinopathy is continuing and encourages the hope for prevention and better treatment.

sources: (1) Canadian Ophthalmological Society