Can Diabetes lead to Glaucoma?

By Thabang Malambe - B.Optom (UJ)

What is diabetes?

This is a disease that occurs when our blood sugar level is too high, so blood sugar is our main source of energy and it comes from the food that we eat. Insulin is a hormone made from the pancreas that helps get the sugar/glucose from the food we eat to the cells in our body for use as energy. Diabetes comes in when the pancreas does not produce enough or any insulin, resulting in excessive sugar in the blood. There are different types of the condition and all can affect the eye. Specific parts of the eye that can be damaged by this and they include; Lens, vitreous, retina and the optic Nerve.

What is Glaucoma?

This is a condition that causes damage to your eye’s optic nerve and gets worse over time, this is often associated with a build-up of pressure inside your eyes. It may be inherited and not show up until later in one’s life.

This increased pressure called intraocular pressure can damage the eye nerve that sends images to our brain. If this damage continues, it can lead to permanent loss of vision. If no treatment is given it can cause permanent blindness within a few years.

How does diabetes lead to Glaucoma?

Individuals with Diabetes are twice as likely to develop glaucoma in comparison to non-diabetics. A rare type of glaucoma called neovascular glaucoma is commonly associated with diabetes, in certain cases of diabetes (Diabetic Retinopathy), blood vessels on the retina are damaged, and as a result the retina manufactures new abnormal blood vessels. If this new abnormal blood vessels grow on the Iris (the coloured part of the eye), this closes the fluid flow in the eye and can cause raised intraocular pressure.

Neovascular glaucoma is a very difficult condition to treat and one of the available options is laser to reduce these abnormal blood vessels.This makes it of utmost importance for regular check-ups, as with the many eye complications seen with diabetes, the recommendation from the National Eye Institute is to have regular eye exams at least once a year to rule out any of these abnormalities.