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HomemifeatureThe Unspoken Truths of Diabetes Mellitus

The Unspoken Truths of Diabetes Mellitus

Cardiovascular disease, diabetes and obesity are by far the largest health challenges Australians will face as our population grows older. As an optometrist, and having lived with diabetes since I was nine years old, I know there are some things your patients probably won’t voluntarily disclose about their health, that you really need to know.

Diabetes mellitus is a chronic systemic disease characterised by elevated blood glucose levels. This can be due to a primary deficiency or a resistance of the body to the effects of insulin. Approximately one in 10 diabetics have Juvenile Diabetes (Type 1). As the name suggests this usually develops during childhood or in early adulthood and is treated with insulin injections for life as it is not reversible and currently there is no cure. Then there is Type 2 diabetes, which is more often diagnosed during adulthood and treated with dietary and physical exercise change. Depending on the severity, treatment can also include oral medication and/or insulin.

Due to the chronic nature of diabetes, it is well established that many complications can develop. The risks of these complications increases with the duration of diabetes, poor history of blood glucose control and poor blood pressure. Complications include peripheral vascular disease, nephropathy, cardiovascular disease, and neuropathy including peripheral neuropathy that can ultimately lead to limb amputations. Diabetic retinopathy is one of the most common complications of diabetes.

Primary Eye Care Involvement

Did you know that diabetic retinopathy is the leading cause of blindness among working adults in the world?1

Your proactive role can ultimately change their life outcomes, simply through early detection and the right intervention…

There are two phases of this disease: non- proliferative (early stage) and proliferative diabetic retinopathy (late stage). Affected diabetics are usually unaware that they have diabetic eye disease, which can inadvertently lead to advanced stages including clinically significant macula oedema, (CSME) – the single leading cause of vision loss from diabetes.2

It’s quite likely that on any given day, you will have undiagnosed, unaware diabetic patients sitting in your consultation chair. Your proactive role can ultimately change their life outcomes, simply through early detection and the right intervention, but where do you start?

While it can be tempting to rely on a patient’s medical history for the random dot haemorrhage, cluster of exudates, etc, we need to proactively screen all patients to identify subtle changes.

We all know it is essential for diabetics to establish and maintain good blood glucose control, have a well-balanced diet, engage in regular physical activity, be compliant and diligent with doctor and eye appointments and take their medications as prescribed.

We also know early detection of any diabetic eye disease is vital to ensure the best possible management options and outcomes.

However, as primary eye care practitioners, is there more that we can be doing?

Are we asking the right questions on history taking… and are we being appropriately active and involved our diabetic patients’ care?

Unfortunately, asking patients whether they are diabetic, if they are on medications and if their diabetes is well-controlled, is not enough. The answers to these three questions will only ever offer a hint about their diabetic health status.

As primary eye care practitioners, we really need to ask our diabetic patients deeper questions: when were they diagnosed, what was their last HbA1C result… and what have their blood glucose readings been in most recent times. What are the blood sugars first thing in the morning? Do they spike in the afternoon? What are they like in the evening? How many times would they experience hypoglycaemia or hyperglycaemia in a week?

Type 1 diabetics are often required to test their blood glucose levels at least three times a day (usually before meals) and some even after meals. More often than not, they feel reluctant or guilty about sharing these daily readings, especially if it means confessing that their blood glucose has been poorly controlled.

For some, this can be because they feel embarrassed, are in denial, don’t want to feel as if they have failed, or they don’t want to be reported to their specialist. However, by getting into the specifics, we can get a true understanding of how well controlled a patient’s blood glucose readings have been. This in turn will allow us to provide better patient education, and more effectively co-manage the patient’s overall care with their general practitioner, dietitian and ophthalmologist.

I find the key to getting this information out of my patients is in the way I ask these questions. It is important to make sure they do not feel as if they’re under interrogation. Diabetics know they have a lifestyle condition. If they do have a history of poor control, and all they hear from their health care practitioners is doom and gloom, they are likely to give up trying and lose all hope.

It is also important to be honest and up front about the facts, and it’s crucial to educate them about the steps they can take to preserve their current level of vision and eye health – just as recent television advertisements have encouraged smokers to quit by outlining the benefits of each cigarette they eliminate.

One of the most effective ways I work with my patients is to clearly define their current situation and to present all the options going forward. I discuss the management and treatment for each stage of diabetic eye disease and the benefits. I also outline the consequences of not proceeding with any treatment. In doing so, patients feel they are in control and that they have the support and guidance needed to turn the ship around if that’s what they want to do.

Treatment Options

Treatment for diabetic eye disease takes place once it has advanced to the proliferative stage or maculae oedema develops. Some of the current treatment options include laser therapy and intravitreal injections which in some cases are used in combination, depending on the severity and location of retinopathy. In more severe cases, retinal surgeons may also need to resort to surgery including a vitrectomy. Either way, when it comes to diabetic eye disease treatment, the goal is simply to reduce the risk of further vision loss.3

Traditionally, surgeons resorted using panretinal laser therapy where typically 1,500 and 2,000 laser burns are made to a significant portion of the retina sparing the macula, or macular laser therapy whereby surgeons use either focal or grid treatment with a low energy laser. Although treatment can reduce further risks by 50 per cent,2 it is important to take into consideration the possible associated risks with this form of treatment. Such risks include stress on the macula and/or increase in macula oedema, loss of peripheral vision and altered colour vision. This is where patient education, and risk versus benefit is crucial.

More recently, vascular endothelial growth factor (anti-VEGF) injections and steroid injections have been used to manage growth of new vessels and macula oedema. The side effects of intravitreal injections are extremely rare, however due to the nature of administration, some side effects can be severe, including devastating ocular infections and systemic adverse reactions.4 Studies continue to analyse the long-term effects of intravitreal injections.3

My two cents worth? Put yourself in your patient’s shoes. For me this is quite easy. I cannot talk on behalf of ophthalmologists but I can share my knowledge and experience as a living and breathing diabetic. I urge you to communicate closely with the ophthalmologists in your patient’s treatment care about the options.

There are many ways to manage macular oedema. While laser methods have been long used and can often seem to be the best way to ‘manage’ a non-compliant patient, it is important to look at the big picture; can I educate my patient to be compliant and see the benefits of intravitreal injections? Will an alternate treatment option potentially save them from losing their peripheral vision due to laser burns? This is not an easy question to answer, because unfortunately an ophthalmologist will tell you it’s just not that simple. Ophthalmologists are not typically trigger happy but rather they can sense when a patient will not comply with turning up to eight-weekly injections over several months, so the question becomes, do I risk my patient losing all their vision due to non-compliance or do I gamble with their peripheral vision to preserve what potentially can be the only vision they can keep a hold of.

The main take home message here is stay actively involved and communicate constantly with your patient’s ophthalmologist. They respect your input and value that you probably know more about the patient, their personality and their level of compliance than they do as you see the patient more frequently.

What Now?

First and foremost, if you haven’t already, it’s time to become more involved in understanding your diabetic patients’ history and day to day control of their disease. Always keep an eye out for that undiagnosed, unaware patient sitting in your chair. There is no question that in order to substantially reduce the number of Australians unnecessarily going blind from diabetic eye disease, we must develop and implement an effective and efficient diabetic eye screening program that is accessible to all Australians with diabetes. But when this will happen, is anyone’s guess.

Diabetic Eye Disease: Prevalence and Costs

Almost everyone with Type 1 diabetes and more than 60 per cent with Type 2 diabetes will develop some form of diabetic retinopathy within 20 years of diabetes diagnosis.3

According to projections by the International Diabetes Federation, the number of diabetics in the world will increase to 552 million by 2030. In Australia, faced with a growing population, it is predicted that there will be four million people living with diabetes by 2030.5 Worryingly, without large scale, publicly funded diabetic screening programs, half of these cases are unlikely to be undiagnosed.4

One measure of the impact of diabetes is the cost to the Australian economy. By 2033, according to The Australian Diabetes, Obesity and Lifestyle Study (AusDiab), that cost is forecast to be AU$20 billion.6 That’s a lot of money!

In numbers, one in three diabetics will develop a form of diabetic eye disease. AusDiab reported 19.3 per cent of diabetics had non-proliferative diabetic retinopathy, 2.1 per cent had proliferative retinopathy and 3.3 per cent had diabetic macular oedema.7 Focusing on Australia, The Melbourne Vision Impairment Project reported that 29.1 per cent of diabetics over the age of 40 years develop diabetic eye disease, the majority being non-proliferative, 4.2 per cent proliferative and 5.6 per cent CSME. The Blue Mountains Eye Study also showed 32.4 per cent of diabetics 49 years of age and over had diabetic eye disease with 4.3 per cent having CSME.8

Indigenous Australians are four times more likely than non-Indigenous Australians to develop diabetes.9 Consequently, Indigenous Australians are at an even higher risk of developing diabetic eye disease, due to limitations on eye care and health care access. The National Indigenous Eye Health Survey10 found one in three Indigenous Australian diabetics had diabetic eye disease. It also reported that CSME presented in the earlier stages of diabetes, when compared to non-Indigenous Australians.

It is not surprise that when managing diabetics and diabetic eye disease complication, prevention is key. I cannot stress this enough.

The Incredible Power of Treatment

A 34-year-old Type 1 diabetic female presented with clinically significant macula oedema and associated diabetic retinopathy. The patient had long standing poor control with HbA1C readings ranging between 11–13 over the past 24 months and has been a diabetic for 20 years.

Prior to treatment, her vision had dropped from BCVA OD 6/6- to 6/15 OS 6/6– to 6/15+. Having initially been advised that she would require extensive laser treatment by an ophthalmologist, she received a second opinion suggesting intravitreal injections may provide a preferred outcome.

The patient followed the advice of the second opinion and a month following her first treatment, Ocular Coherence Tomography revealed complete resolution of the macula oedema and BCVA returned to 6/6- OU.

The patient was educated on the importance of blood glucose control and the risks of diabetic retinopathy progression. Since this episode, she has been treated with intervals of intravitreal injections, which have slowly been stretched out over the course of 12 months. At this stage the patient does not require long term intravitreal injections, largely due to stabilising blood glucose levels and no progression in retinopathy or re-occurrence of macula oedema.

Dr. Amira Howari B.Optom (Hons), MOptom (UNSW) GradCertOcTher, CCLSA, OAA is a clinical optometrist and industry speaker. She has worked as Professional Affairs Manager at Alcon, as a clinical optometrist at Luxottica and HCF, a professional optometric manager at PersonalEyes, where she founded the PersonalEyes annual conference event (PEACE), and a clinical supervisor at University of New South Wales School of Optometry and Vision Science. Dr Howari is also on the member services committee for Optometry Australia NSW/ACT and specialises in Industry Engagement.

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2. Shaw, J.E., R.A. Sicree, and P.Z. Zimmet, Global estimates of the prevalence of diabetes for 2010 and 2030. Diabetes Res Clin Pract, 2010. 87(1): p. 4–14.
3. Lee, C.M., et al., The cost of diabetes in adults in Australia. Diabetes Res Clin Pract, 2013. 99(3): p. 385–90.
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5. Mohamed Q, Gillies MC, and Wong TY, Management of diabetic retinopathy: a systematic review. JAMA., 2007. 298: p. 902–916.
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7. Mitchell, P., et al., Prevalence of diabetic retinopathy in an older community. The Blue Mountains Eye Study. Ophthalmology, 1998. 105(3): p. 406–11.
8. Gracey, M., et al., An Aboriginal-driven program to prevent, control and manage nutrition-related “lifestyle” diseases including diabetes. Asia Pac J Clin Nutr, 2006. 15(2): p. 178–88.
9. Xie, J., et al., Prevalence of self-reported diabetes and diabetic retinopathy in indigenous Australians: the National Indigenous Eye Health Survey. Clin Experiment Ophthalmol, 2011. 39(6): p. 487–93.
10. Falavarjani KG, Nguyen QD. Adverse events and complications associated with intravitreal injection of anti-VEGF agents: a review of literature. Eye (Lond) 2013;27(7):787–94.