More than 1 million Australians have diabetes, a condition which carries an increased risk of developing eye complications. Diabetic eye disease includes complications such as diabetic retinopathy, diabetic macular oedema, cataracts and glaucoma.
Diabetes is the leading cause of blindness in working-age adults. People with all types of diabetes (type 1, type 2 and gestational, which is related to pregnancy) are at risk. It’s possible to be unaware that you have severe diabetic eye disease and suddenly go blind. Fortunately most cases of blindness can be prevented with regular eye examinations and proper care.
The persistently high blood sugar levels that occur with diabetes can damage the retina’s small blood vessels (capillaries), which deliver oxygen and nutrients. Diabetic retinopathy affects around 15% of people with diabetes and there are three main types:
A cataract is a clouding of the lens in the eye. Left untreated, cataracts can eventually lead to blindness. People with diabetes are more likely to develop cataracts at an earlier age, and suffer visual impairment faster than those without the condition. Learn more
This is a group of conditions that can damage the optic nerve. The optic nerve transmits signals from the retina to the brain for processing. Glaucoma is often (but not always) a result of increased pressure inside the eye. The risk of glaucoma in people with diabetes is nearly twice that of the general population. The two main types are open-angle glaucoma (also called ‘the sneak thief of sight’) and angle-closure glaucoma (this comes on suddenly and is a medical emergency).
Diabetic eye conditions often have no signs or symptoms, particularly in the early stages. By the time someone with diabetes notices changes in their vision, the condition is quite advanced.
Signs and symptoms may include:
(including diabetic macular oedema)
Your ophthalmologist will examine both retinas after using eye drops to widen your pupils and allow a clear view of the back of each eye.
Other tests that may be performed include:
(including diabetic macular oedema)
Various treatments are available and vision can often be at least partially recovered. The earlier these conditions are diagnosed and treated the better, as this provides the best chance of preventing severe vision loss and/or recovering vision.
Your ophthalmologist will explain your options and recommend an appropriate course of treatment. As with all medical and surgical procedures, these treatments carry risks (although they are rare). It’s important to weigh these risks up against the potential benefits. Your ophthalmologist will help you make an informed decision.
These are also referred to as intravitreal injections and involve injecting medication into the vitreous (the gel-like substance that occupies most of the space inside the eye and gives it its round shape). The medication reduces fluid and swelling in the retina by shrinking abnormal blood vessels and inhibiting growth of new blood vessels.
There are two types of injections:
Patients are given anaesthetic eye drops prior to the injection – you may feel some pressure but no pain and you won’t see the needle coming towards your eye because it is given from the side.
These injections are initially administered monthly, usually for about six months or until the condition has resolved sufficiently. Sometimes, ongoing injections are required, but the interval between injections can be extended.
Complications from eye injections are rare, but may include:
Laser treatment (photocoagulation) uses heat from a laser to seal or destroy leaking blood vessels. It is also used to destroy sick retinal tissue that is no longer functioning properly and is instead encouraging the growth of the abnormal blood vessels. Sometimes, laser treatment is used to reduce swelling at the macula. A special microscope known as a slit lamp is used together with the laser to perform the procedure.
Anaesthetic eye drops are given to numb the eye. A special lens is placed in contact with the surface of the eye to help focus the laser beam. You may feel a slight stinging sensation and see brief flashes of light when the laser is applied to your eye.
Someone will need to drive you home from the clinic after the procedure. Your eyes will remain dilated for a few hours afterwards, therefore it is important to wear sunglasses to keep bright light out of your eyes. Your vision may be blurry and your eye may be uncomfortable for a day or two following the treatment.
Complications of retinal laser treatment include:
Rarely, there may be bleeding, retinal detachment or an accidental laser burn that causes severe central vision loss.
Surgery may be required for severe cases of diabetic retinopathy. This involves removing some of the vitreous (the gel-like substance that fills the eye and gives it its shape) and any blood so that light rays can focus on the retina again. Scar tissue from the retina can also be removed and retinal detachments repaired.
Patients are given a local anaesthetic to stop pain and a sedative to reduce anxiety. Following surgery, a pad and shield will be placed over the eye to protect it until you see your ophthalmologist the next day.
Complications of vitrectomy surgery are rare, but include:
While cataracts and glaucoma are more common in people with diabetes than those without, the treatment options remain the same.
Cataracts can be fixed surgically when causing significant visual reduction and sight restored. Learn more
Glaucoma cannot be cured, but the disease can be stabilised. Options include medication (eye drops, tablets), laser treatment and surgery. Learn more