Latest in the treatment of Diabetic Eye Disease

[30/06/2015]

Latest in the treatment of Diabetic Eye Disease

diabetes


Diabetes is a worldwide epidemic which is literally "spreading like wild-fire". Many reasons can be attributed to the rapid rise in the number of diabetic individuals in the world and the 'affluent' lifestyle we are leading now (at least in the urban environment) is the primary reason!


We are now eating more and more (unhealthy foods), exercising less and less and the overall outlook is even more morbid when you look at the lifestyle our children lead! The technology boom over the past few decades has gone to such an extent that our children now are probably more likely to learn how to use an iPad before they learn how to speak!! As a result, more and more time is spent indoors staring at the computer screen (or mobile device) and less time outdoors playing or exercising or just enjoying the fresh air or the sun!!


Diabetes is but one of a cluster of conditions which is now referred to as the Metabolic Syndrome (the others being Obesity, Hypertension and Hypercholesterolemia). It is a systemic disorder whereby the fundamental problem is due to the inability of the body to utilize the "sugar" which is released from the foods we eat. This is due to the lack of insulin (Type 1 diabetes) or insulin resistance (Type 2 diabetes). Consequently, this 'sugar' is not absorbed and stays in the bloodstream causing all sorts of problems to all sorts of organs in our body.


Diabetes


The eyes are one of the organs affected in Diabetes and little is known that it can actually lead to blindness! Diabetics are at risk of many eye-related problems and the main ones are cataracts, glaucoma and diabetic retinopathy. Diabetes is the leading cause of blindness in the working age group and this is a little known fact! The impact of blindness in this age group is astronomical! When they are unable to work, their families suffer as the main breadwinner is affected, they become a burden to the family (emotionally and financially) and also a burden to society.


Diabetic maculopathy is a subset of diabetic retinopathy where the disease process is at the macula (which is the most important part of our retina responsible for central vision). There can be rapid vision loss with diabetic maculopathy and as many as 20% of individuals with diabetes will have visual loss with diabetic maculopathy. The majority of people with maculopathy suffer with swelling (oedema) at the macula due to leakage of fluid and blood from the fine blood vessels and a smaller proportion suffer with ischaemia (shut down of the fine blood vessels).


wpid-Photo-22-Mar-2013-1502.jpg


Fortunately now, there is treatment for Diabetic Macular Oedema. Since the advent of anti-VEGF agents in 2005, ophthalmologists have been using anti-VEGF injections to treat diabetic macular oedema. In 2012, there was approval of the first anti-VEGF (Lucentis) for the treatment of diabetic macular oedema and 3 years later, we have more options and more data to guide our treatment regimes to improve outcomes for our patients.


Latest results from research studies


In February this year, a paper was published in the New England Journal of Medicine which reported the results of a study conducted in USA whereby 3 anti-VEGF agents were used in a large cohort of patients to treat Diabetic Macular Oedema. These 3 agents (Avastin, Lucentis and Eylea) were compared head-to-head in the treatment of patients over a 1 year period. The results reported has significant impact on the way ophthalmologists will treat their patients. This study, known as Protocol T, has created ripples in the ophthalmology community as the results have far-reaching impact on how patients with Diabetic Macular Oedema. In summary:-


1) Patients with visual acuity 6/12 or better, can be treated with any of the 3 anti-VEGF agents with no significant difference in visual outcomes.


2) Patients with visual acuity worse than 6/12 will benefit more with treatment with Eylea compared to the other 2 agents.


3) The average number of injections required over the first one year period is 8 and this is regardless of whichever agent is used.


What are the immediate implications of this study on the patients?1) Patients should expect very frequent visits to the eye clinic for injections and follow-up over the first year period2) There is significant financial burden associated with treatment as per injection, Eylea and Lucentis costs approximately US$2000 whereas Avastin is a fraction of the cost (~ US$100).3) With this treatment, we are able to prevent significant visual impairment due to diabetic macular oedema when before we only had laser which was nowhere nearly as effective!


LucentisAvastineylea


In the US now, there is a big push by the US ophthalmologists to reverse a ruling passed by the FDA (Food & Drug Administration) which will practically prevent the use of Avastin for intravitreal injections. This decision by the FDA had come about following safety issues with the preparation of Avastin for injections as this drug was never made for eye treatment but for cancer treatment instead. Consequently, small amounts of Avastin have to be drawn out from the sterile bottle and issues with the correct dosage and mainly with sterility had been highlighted. There was a spate of severe eye infections from Avastin injections reported a while ago which was very 'bad publicity' for the drug!


Nevertheless, I believe each anti-VEGF agent still has its role. In my current practice in Malaysia, my patients are very price sensitive and it is only ethical that all my patients are aware of what available treatment options there are and the risks and benefits associated with each one.


So remember to always have a thorough discussion with your ophthalmologist to better understand what is required to treat your eye condition and never be afraid to seek a second (or third) opinion. I have often sent my patients away to get another opinion and they are always grateful that they are not under pressure to take my word as the 'gospel truth'! Ultimately, as physicians, we owe it to our patients to be updated with the latest treatment modalities and provide the best care we can.