Diabetes and Eye Health
By Carolien Koreneff, CDE-RN, FADEA
The human eye is an extraordinary sensory organ. Our vision is one of the most precious gifts we have, it is a part of who we are. We often have an underappreciation of the importance of our eyes until we experience a problem with them. Unfortunately, people with diabetes have an increased risk of developing eye problems, which, if left untreated, can lead to reduced vision or even blindness. Credentialled diabetes educator Carolien Koreneff explains short-term and long-term problems that can affect the health of the eye.
Diabetes can cause both short- and long-term eye problems.
Diabetes and short-term eye problems
Short-term eye problems include:
- Blurred vision – high blood glucose levels can cause a short-term blurring of vision due to temporary changes in the shape of the lens of the eye. Blurry vision can occur at different times in the diabetes journey – before diagnosis, when starting a new treatment or when blood glucose levels fluctuate.
- Conjunctivitis is quite common, particularly in children, it can occur due to bacterial, viral, allergic, or chemical causes, that lead to inflammation and redness of the conjunctiva, the lining of the whites of the eyes and the membranes surrounding the inner eyelids.
- Uveitis, is an inflammation of the middle portion of the eye, the uvea. A viral, fungal, bacterial, or parasitic infection can cause this.
- Sty can occur when oil glands on the eyelid become blocked, which can cause a painful eye infection along the lash line.
The risk of serious, more permanent eye problems increases with high blood glucose levels over a long period of time, or if the blood pressure or cholesterol levels are high.
Diabetes and long-term eye problems
Long-term eye problems include:
Occur when protein from the lens clumps together and makes the lens cloudy. Cataracts are very common in people over the age of 80. Although sun damage and ageing are the main risk factors, people with diabetes tend to develop cataracts faster and at a younger age than others. Without surgical treatment cataracts will continue to develop until eventually vision loss is complete.
Glaucoma occurs when there is damage to the optic nerve, causing a build-up of pressure inside the eye. It can affect anyone, but again, it’s more common in people with diabetes. There are two kinds of glaucoma: open-angle glaucoma, caused by conditions that are chronic or long-term and acute or closed angle glaucoma (sometimes also referred to as angle closure), which is the kind that occurs suddenly. Prescription eye drops is the usual treatment for glaucoma. Although, occasionally the use of laser and surgical procedures may occur.
Diabetic retinopathy occurs when, over time, high blood glucose levels damage the small blood vessels in the retina of the eye, causing them to leak fluid. New blood vessels grow to compensate for the ones that are damaged. However, these new vessels are weak and rupture easily, which will cause them to bleed or haemorrhage.
Diabetic macular oedema
Diabetic macular oedema is an additional and important complication of diabetes that can be found with any stage of diabetic retinopathy and that can run an independent course. The new blood vessels can leak protein or fluid into the macula and this can lead to macular oedema, which can affect the person’s central vision.
Retinal detachment occurs when the retina separates from the tissue that it normally attaches to, like wallpaper peeling off a damp wall. For the eye to survive and work properly, the retina must be attached to the back of the eye. Retinal detachment can result in the loss of some or all the vision permanently, if not treated urgently. It can occur at any age, but it most commonly occurs in Caucasian males over the age of 40. However, retinal detachment is quite rare, occurring in just 1 in 10,000 people each year.
There are five stages of diabetic retinopathy. These include:
|Stage 1: |
|There are no abnormalities at this time, it is recommended to get eyes checked every 1-2 years.|
|Stage 2: |
Mild Non-Proliferative Diabetic Retinopathy or mild NPDR
|Microaneurysms, small areas of balloon-like swelling in the retina’s tiny blood vessels, are forming. It is recommended to get eyes checked again in 6-12 months. Avoiding large fluctuations in blood glucose levels and aiming for glucose levels as close to the target range as possible will help slow any progression and in many cases the retinopathy can still improve at this stage.|
|Stage 3: |
Moderate Non-Proliferative Diabetic Retinopathy
|Microaneurysms and other signs are present (including dot and blot haemorrhages, hard exudates, or cotton wool spots). Visual changes are unlikely at this stage, but the damage is there and keeping glucose levels as close to target as possible and avoiding large glucose excursions will slow the progression to the next stage. It is important to get eye checks every 3-6 months.|
|Stage 4: |
Severe Non-Proliferative Diabetic Retinopathy
|Many more blood vessels are blocked, causing several areas of the retina to be without their required blood supply. Review needed every 3 months. A referral to an ophthalmologist is definitely required by this stage.|
|At this advanced stage, the signals sent by the retina for nourishment trigger the growth of new blood vessels. These new blood vessels grow along the retina and along the surface of the clear, vitreous gel and are very fragile. By themselves, these blood vessels do not cause symptoms or vision loss. However, if they leak blood severe vision loss and even blindness can result. A referral to ophthalmologist should have already occurred and monthly check ups are needed.|
Eye health recommendations for people with diabetes
People with diabetes should have their eyes checked on a regular basis – generally at least every two years – by an optometrist or an ophthalmologist (eye specialist).If the person already has eye problems or are planning a pregnancy, eye checks should be more regular.
Medicare provides a full rebate on most optometry appointments. However it does not reimburse glasses. Most private health funds will at least partially reimburse for prescription glasses, depending on the level of cover.
To get a Medicare rebate for an ophthalmology consultation, a patient must receive a referral from a GP, optometrist or other medical specialist. Prioritisation of appointments id done according to medical need, with red eyes commonly seen immediately upon referral.
KeepSight is a program designed to make it easier for people with diabetes to get their eyes checked. The KeepSight program, which is run by Diabetes Australia in partnership with Vision 2020 Australia, Centre for Eye Research Australia and Oculo, is co-funded by the Australian Government, Specsavers, Bayer, Novartis and Mylan. The program has widespread support from leading diabetes and eye health groups including the Royal Australian and New Zealand College of Ophthalmologists, Orthoptics Australia, Optometry Australia, the Australian Diabetes Society and the Australian Diabetes Educators Association. KeepSight provides electronic alerts and reminders to help people remember their diabetes eye checks. KeepSight can also help you find optometrists. Visit the website here
Vision Australia is a leading national provider of blindness and low vision services in Australia. They work in partnership with Australians who are blind or have low vision to help them achieve the possibilities they choose in life. Vision Australia are a not-for-profit organisation, they support more than 25,500 people of all ages and life stages, and circumstances. They do this through 35 Vision Australia centres and a number of outreach programs across the country.