Diabetic eye disease includes cataracts, glaucoma and diabetic retinopathy, a leading cause of irriversible blindness in developed countries including Malta.

Diabetic retinopathy

Diabetic retinopathy is divided into four stages. The initial phases include a change in vision, but as it advances, blindness can occur:

• Mild non-proliferative retinopathy: the retina’s tiny blood vessels swell up (microaneurysms).

• Moderate non-proliferative retino-pathy: some blood vessels that supply the retina are blocked.

• Severe non-proliferative retinopathy: many blood vessels are blocked, depriving the retina of nutrients, signalling the body to produce more blood vessels.

• Proliferative retinopathy: new growth of abnormal, fragile, small blood vessels along the retina and along the surface of the gel that fills the inside of the eye.

Blood vessels can cause change in vision or even blindness in two ways. The first is that blood leaking from abnormal blood vessels into the centre of the eye causes blurring of vision. This only occurs in proliferative retinopathy.

Blood can also leak in the centre of the macula, the part where sharp vision occurs, resulting in swelling of the macula (macular oedema) and blurred vision.

This can occur in any of the four stages of diabetic retinopathy, but more commonly in the last two. The longer you have diabetes, the greater the risk of developing diabetic retinopathy.

People with type 1 diabetes rarely develop retinopathy before five years of being diagnosed with diabetes, but unfortunately, those with type 2 diabetes usually have early signs when diabetes is first diagnosed.

During the first three stages of diabetic retinopathy, no treatment is needed, unless you have macular oedema. Proliferative retinopathy is treated with a procedure called scatter laser treatment, where a laser is used to burn the areas of the retina away from the macula, causing the abnormal vessels to shrink.

Two or more sessions are usually required and it works best before the new vessels start to leak blood. Unfortunately, this treatment may decrease your peripheral vision, colour and night vision.

Macular oedema is also treated with laser surgery, but this procedure is called focal laser treatment. Laser is used on the areas of retinal leakage surrounding the macula to slow the leakage of fluid.

Laser surgery and appropriate follow-up care can reduce the risk of blindness; however, laser surgery often cannot restore the vision that has already been lost. The only way to prevent vision loss is to find diabetic retinopathy early.

Cataracts and glaucoma

Cataracts are a disease that involves the clouding of the eye’s lens, which allows us to focus on an image; thus, if you develop cataracts, you will develop blurred vision. Although anyone can get cataracts, patients with diabetes develop them earlier. Cataract surgery is available in Malta and is done regularly.

Glaucoma occurs when fluid in the eye does not drain properly. Excessive pressure then builds up, leading to nerve and blood vessel damage. This results in changes in vision. There may be no symptoms until the disease is very advanced.

It is very uncommon for patients to also have headaches, eye aches, blurred vision and to see halos around lights.

Treatment for this include eye drops, laser procedures, medicine or surgery.

Preventing eye problems

It is important that those who have been diagnosed with diabetes have their eyes checked annually. The earlier the problem is identified, the better the chance of preventing vision loss.

Women with diabetes, who later become pregnant, should have an eye examination during the first trimester and should be followed up regularly for the duration of the whole pregnancy.

You should control your blood sugar and blood pressure as much as possible, so regular monitoring of these is essential.

It is important to address other risk factors, such as smoking and high cholesterol intake, and you should contact your doctor if you experience one of the following: blurred vision; flashes of light; ‘holes’ in your vision; or black spots in your vision.