People with all types of diabetes (type 1, type 2 and gestational) are at risk of a number of eye conditions, which together are known as diabetic eye disease.
“It is possible to unknowingly have severe diabetic eye disease before ‘suddenly’ going blind,” says Dr David Ng from Vision Eye Institute. “About 15% of people with diabetes will develop diabetic retinopathy, where persistently high sugar levels can damage the small blood vessels that deliver oxygen and nutrients to the retina at the back of the eye.”
Cataract and glaucoma risks
“People with diabetes are also much more likely to develop cataracts at an earlier age, with faster progression to visual impairment. Left untreated, cataracts can eventually lead to blindness.
“The risk of glaucoma in people with diabetes is also high – nearly twice that of the general population. Glaucoma actually refers to a group of conditions that damage the optic nerve, which is responsible for transmitting signals from the retina to the brain. Glaucoma is often (but not always) a result of increased pressure inside the eye.”
Dr Ng says the earlier these conditions are diagnosed and treatment initiated, the better.
“Cataracts can be fixed surgically and sight restored. In fact, with the latest technology your vision may actually end up better than it was before the cataracts developed. With new treatments for diabetic retinopathy, vision can often be at least partially recovered. Treatment options include injections into the eye, laser treatment and surgery.”
“Unfortunately, vision loss due to glaucoma is not reversible,” says Dr Ng. “Instead, treatment is aimed at stabilising the course of the disease. Options include medication, such as topical drops or tablets, laser treatment and surgery.”
“Achieving optimal control of your blood sugar, blood pressure and blood cholesterol is critical, although this will not reverse any damage that has already occurred. If you smoke, please stop – smokers who have diabetes are at a much higher risk of losing their sight, having a heart attack or stroke and developing kidney failure.”
“People diagnosed with diabetes should always have an initial screening eye test to check for signs of eye disease. Your eyes should be checked on a regular basis afterwards, usually at least every 1–2 years. It is important to see an ophthalmologist who specialises in diabetic retinopathy or an optometrist, who will refer you for specialist care if required.”
For more expert advice on diabetic eye disease and eye health, visit Vision Eye Institute.
Diabetic eye disease includes:
This affects around 15% of people with diabetes. Persistently high blood sugar levels can damage the small blood vessels (capillaries) that deliver oxygen and nutrients to the retina at the back of the eye. The retina is responsible for receiving light rays entering through the cornea and lens. This information is then transmitted via the optic nerve to the brain for processing (i.e. to produce the image).
There are three main types:
1.Non-proliferative diabetic retinopathy – the early stage where capillary damage results in leakage of blood or fluid, causing the retina to swell. Usually minimal or no effect on vision, depending on the number of vessels affected.
2.Diabetic macular oedema – occurs if swelling extends to the macula, which is the part of the retina responsible for central vision. Vision can become blurred and colours appear faded, resulting in trouble reading, recognising faces and driving. Macular oedema is the usual cause of vision loss related to diabetes and the level of impairment can be significant.
3.Proliferative diabetic retinopathy – advanced stage of the disease, with growth of new but fragile blood vessels that bleed and can form scar tissue. Symptoms include headache or blurred vision. If these new vessels bleed, the person may see ‘floaters’ or lose all vision – this is an ocular emergency.
People with diabetes are much more likely to develop cataracts at an earlier age, with faster progression to visual impairment. A cataract is a clouding of the lens in the eye. Symptoms include blurred/clouded/dim vision, faded colours, reduced night vision, sensitivity to light and glare, seeing halos around lights, and a frequently changing spectacle or contact lens prescription. Left untreated, cataracts can eventually lead to blindness.
This is a group of conditions that damage the optic nerve, which transmits signals from the retina to the brain. 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.
There are two main types:
1.Open-angle glaucoma – this is the most common form and usually progresses slowly, with a gradual deterioration in vision (it is often called ‘the sneak thief of sight’). The disease is quite advanced by the time vision loss is noticed.
2.Angle-closure glaucoma – symptoms are often more noticeable with this form, particularly with acute (sudden-onset) cases since there is a sharp increase in eye pressure. Acute symptoms include eye pain, severe headache, nausea and vomiting, blurred vision and seeing halos/rainbows around lights. Acute angle-closure glaucoma is an ocular emergency.
Although rare, double vision is another potential complication of diabetes – this usually resolves over a few months.