Diabetes & blindness. due to DME BLINDNESS IN EUROPE

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1 Diabetes & blindness due to DME BLINDNESS IN EUROPE Blindness is a life-changing disability which puts a heavy strain on the daily lives of sufferers, their families, and society at large. Today, 284 million people, approximately the equivalent of half of the EU population are severely visually impaired worldwide, 39 million of which are totally blind. 1 Hence, together with major chronic diseases such as cancer and respiratory infections, blindness is among the leading disease burdens worldwide. In addition to the tremendous human aspect it also carries a significant social and economic impact. In an effort to tackle the burden of blindness, countries are being forced to develop initiatives and infrastructures that go beyond medical expenditure. For instance, in 2007, the UK spent 18 billion, the same amount it spends on public safety 2, for the development of nursing home care, guide dogs, urban infrastructure and specific government programmes relating to the treatment of blindness. Knowing that one European in every 30 will experience sight loss and that the large majority of the visually impaired will be unemployed, it becomes clear that blindness constitutes a major burden to society. It is therefore all the more frustrating to hear that 85% of global visual impairment could be avoided. 3 As far as diabetes induced vision-loss is concerned, this can be controlled or even avoided thanks to existing and emerging diagnostic and treatment options. However, in practice, this is rarely the case. 1

2 DIABETES AND BLINDNESS: WHAT IS THE LINK? Diabetic retinopathy is a complication of diabetes that results from damage to the blood vessels of the retina in the back of the eye. The risk of related visual loss in people with diabetes is up to 25 times higher than the population not affected by diabetes. Visual impairment is therefore the most feared complication of diabetes. There are two major stages of diabetic retinopathy: an early stage non-proliferative diabetic retinopathy and a later stage proliferative diabetic retinopathy. The fluid leakage into the area of the retina which is responsible for clear central vision is called Diabetic Macular Edema (DME). It can occur in both of these stages and in any patients with type 1 or type 2 diabetes. Diabetic Macular Edema is therefore a specific type of diabetic retinopathy. More precisely, it is a specific type of DME called Clinically Significant Macular Edema (CSME) which is sightthreatening and which causes moderate to severe visual loss. Today, about 11% of diabetes patients have DME 4, and 1-3% actually suffer from loss of vision because of DME 5. From a health economics perspective, the annual cost per patient with DME is approximately twice as high as those of patients with diabetes alone 6. An additional 11,500 is required from DME patients every year for non-medical costs. This is mainly due to the fact that DME calls for outpatient visits, nursing and inpatient care, and non-medicinal therapies. Whilst DME only affects a certain percentage of diabetic patients, its burden is likely to grow. With the number of people suffering from diabetes in Europe expected to rise from 55.2 million in 2010 to 66.2 million in , DME cases would increase proportionately. 2

3 DIAGNOSIS OPTIONS: PREVENTION IS POSSIBLE Although the disease can permanently damage the retina and hence lead to visual impairment and even blindness, the sight can be restored if the two possible sightthreatening complications, DME or proliferative diabetic retinopathy, are caught at early stages. Systematic eye screening offers today the possibility of identifying the early signs of maculopathy, thus preventing visual loss due to DME. These periodic eye examinations, which consist of fundus examination through dilated pupil or sometimes taking a photograph of the retina, can detect the specific sightthreatening changes of the retina 8. Iceland and the Swedish community of Laxa have demonstrated, through the success of their eye screening programmes, that it is possible to prevent blindness due to DME or any other form of diabetic retinopathy. Both countries have recorded an extremely low rate (nearly inexistent) of DME or any other form of diabetic retinopathy patients becoming legally blind. In Iceland, a national screening programme was founded in 1980, since then patients with Type 2 diabetes have been receiving regular eye screening. This means that patients can rely on a timely diagnosis and treatment, and address the disease before its status is irreversible. Unfortunately, such examples of good screening practice are rare. Although running regular eye examinations allows for early diagnosis and timely treatment, the vast majority of patients with diabetes, as well as many doctors, are still not aware of the critical need to undergo regular eye checks. This is because of a lack of both comprehensive screening and sufficient cooperation between the different disciplines. 3

4 TREATMENT OPTIONS AGAINST DME Various treatments exist for people with diabetic retinopathy or DME, involving both surgical and medical therapies. The control of blood glucose, blood pressure and dyslipidemia are the mainstay in the fight against visual loss due to DME or any form of diabetic retinopathy. Laser photocoagulation is the current standard treatment for DME. If applied timely, laser photocoagulation can at best maintain the current visual acuity and thus reduce the risk of vision loss, but rarely improve vision. New therapeutic compounds are emerging, as the biochemical processes underlying diabetic retinopathy are being increasingly understood. Researchers have today developed drugs used as eye injections that block a chemical signal that stimulates blood vessel growth, known as vascular endothelial growth factor (VEGF). Studies using these anti-vegf compounds show that they may prevent blood vessels from leaking fluid and causing macular edema. Some of these compounds have been licensed for several years to treat wet AMD, another disabling retinal disease. These drugs are now going through necessary clinical trials or have already obtained authorisation to treat also DME patients in indicated cases. Promising studies show that combinations of anti-vegf compounds with the laser treatment may offer a higher chance of improving vision-related function and quality of life. It has also been proven that the combination approach reduces the risk of ocular adverse effects, such as endophthalmitis due to eye injection, a harmful eye inflammation. Current research efforts focus on preventing the development of diabetic retinopathy, slowing its progression, or finding a cure. 4

5 POTENTIAL PATIENT SAFETY CONCERNS WITH REGARD TO UNLICENSED TREATMENT As with any medication, new compounds used for DME should be licensed for their use in DME. There are several anti VEGF compounds which are in the process of being or are already authorized after going through the necessary clinical trials as required by the drug agencies in order to ensure their clinical safety and efficacy. Nonetheless, unlicensed treatment of DME has become an issue. Unlicensed meaning that the drug used has been authorized for an altogether different illness, in a different dosage and form and route of administration 9. The experience of many AMD patients shows that national health officials, doctors and regulators have frequently been ignoring this rising issue of unlicensed usage. It is therefore imperative that patients both suffers of AMD or DME demand to be adequately informed of the choice they have between licensed and unlicensed medicines to treat their disease, and of the consequences that this choice entails. References 1 Visual impairment and blindness - Factsheet, World Health Organization Public Spending Details for 2010, UK Public Spending Visual impairment and blindness - Factsheet, World Health Organization This is an estimation, as the rate differs according to the studied populations, the duration of diabetes, and several other factors. For instance, the prevalence can rise up to 24% in people with duration of diabetes of 25 years or more. 5 Precision Health Economics Williams et al International Diabetes Federation «Vision for the future», Parliament magazine, Issue 320, 14 January 2011, p.22 7 IDF Diabetes Atlas, International Diabetes Federation Eye Screening for People with Diabetes - the Facts, NHS 9 Off-label use and promotion in the EU: risks and potential liability, Liesbeth Weynants and Carla Schoonderbeek, Regulatory Affairs Pharma, November