Diabetes: a serious threat to the retina

Dr Manel Puig, head of the Endocrinology Department at Germans Trias i Pujol Hospital: “strict control of glycemia is the best prevention against retinal pathology”

Dr Manel Puig, head of the Endocrinology Department at Germans Trias i Pujol Hospital, confirmed yesterday at an event organised by IMO Foundation and the ADC (Catalunya Diabetics Association) to mark World Diabetes Day, that "strict control of glycemia is the best prevention against retinal pathology".

"There are still many barriers to fighting diabetes and its consequences, "barriers that depend 50% on the doctor, 30% on the patient and 20% on the health system”. Dr. Puig, head of the Endocrinology Department at Germans Trias i Pujol Hospital.

According to Puig, it is important to promote active detection of diabetes, since early diagnosis and treatment prevent diabetic retinopathy and other diabetes-related pathologies. According to the specialist, the HbA1c indicator (glycated haemoglobin) used to determine the evolution of blood glucose is "the key indicator to ensure that insulin is properly controlled".

During the conference “Diabetes: where are we and where are we heading”, Puig insisted on the importance of acting when the diabetes is first diagnosed (particularly for type 2) since, according to the endocrinologist, after 10 years of elevated glycemia at more than 150-160 mg/dl, we can no longer avoid consequences, due to "the body's diagnostic memory”. Therefore, Puig discredited expressions such as "I have a little glucose" and warned of the high risk this entails, comparing its action to "putting salt on a car engine".

Despite significant advances in research and technology, Dr Manel Puig confirmed that there are still many barriers to fighting diabetes and its consequences, "barriers that depend 50% on the doctor, 30% on the patient and 20% on the health system". The specialist encouraged working towards improving doctor-patient interaction and denounced the existence of too many cases of "physician inertia", which occurs "when the doctor knows they should do something because their patient isn't well but buries their head in the sand or makes excuses such as not having time to perform retinograms" (retina tests that can be performed during a consultation).

Similarly, the head of Can Ruti Endocrinology highlighted the importance of the patient assuming a more active role in managing the disease and urged diabetics to "work harder and stick to the treatment more closely". In this regard, Puig referred to a study carried out several years ago at Hospital Clínic Barcelona, which showed that only 18% of patients continued with the treatment 6-12 months after discharge.

Puig explained that high levels of glycemia cause diseases in both the large and small vessels, as occurs with the retina or kidney. In this sense, he explained that “the treatment for retinopathies and nephrology should aim for haemoglobin levels to be below 7% because at this level the risk of a microvascular pathology shoots up”.

Although the glycemia level is key to preventing retinopathies, the endocrinologist referred to the triple gauge -stress, glycemia and cholesterol- to prevent other "large vessel" diseases such as cardiovascular pathologies.

Puig placed special emphasis on risk factors such as cholesterol. smoking and obesity, "a growing problem we need to fight against". He recalled that in 2004, 13% of children in Spain were obese, who, he says, "will become adults with serious diseases and many of them will have diabetes". To combat this, the endocrinologist recommends monitoring "the quantity and quality of what we eat: “the fewer legs the animal has the better, and if they don't have any, like fish, better still”. Similarly, he called for people to reduce "alarming" levels of sedentary lifestyles in today's society and confirmed that “it is essential to do 30 minutes of physical activity every day, moderate alcohol consumption -maximum 200 cm3 of wine with meals-, stop smoking and undergo regular medical checks”.

To conclude, Puig confirmed that the future of diabetes prevention and treatment must move towards "clinical research focused on greater efficiency but, above all, on effectiveness, efficiency and reduced dependence on the drug industry, as well as less medicalised assistance based on shared decision-making and professional training focused on the patient and not the disease, led by competent professors and flexible and intelligent management of the health service”.

Diabetic eye

Doctors Borja Corcóstegui, José García-Arumí, Anniken Burés, Carlos Mateo y Rafael Navarro significant risk factor for sight and that high levels of blood sugar for lengthy periods can mean that the “diabetic eye" of people with diabetes can become particularly sensitive, and they can develop different ocular complications with diabetic retinopathy and diabetic ocular lesions being the most common.

During the event, the specialists explained that diabetic retinopathy occurs because the walls of the retinal vessels change and become more permeable as a result of the increased levels of glycemia (blood glucose). These vessels are no longer competent and allow the passage of fluids into the extracellular space, which causes ponding in the retina and, if this extends to the macula, it may cause a macular oedema (the main cause of reduced visual acuity in diabetic patients).
In more advanced cases, “proliferative diabetic retinopathy”, "the most serious diabetes-related disease, can occur, which affects 20% of diabetics and can lead to severe loss of vision", as explained by IMO ophthalmologists.

According to retina specialists, the main preventative measures diabetic patients can adopt to avoid or delay the appearance of diabetic retinopathy are the strict control of blood glucose and rigorous ophthalmological monitoring with a basic eye test at least once a year. They pointed out that “if this test reveals any problems with the retina, checks should be stepped up”. The ophthalmologists explained that some of the symptoms of diabetic retinopathy are gradual loss of visual acuity, distortion of images or the appearance of “floaters” in the visual field, although they pointed out that generally, at the start, the disease does not affect vision, “and this is exactly when we need to start to act”.

Treatments being studied

As regards current treatments -laser photocoagulation, intravitreal injections orvitrectomy-, the specialists confirmed that they are able to delay the disease's evolution and can improve the patient's visual prognosis. As regards intravitreal injections, Dr Rafael Navarro announced that IMO is currently taking part in an international and multicentre clinical trial on the treatment of diabetic macular oedema, the complication of diabetic retinopathy that most damages vision, due to ponding of the macula or central retina area, which is where the detailed vision that enables us to read, drive or recognise faces is concentrated.

Main cause of blindness in people of working age

It is estimated that over half of people suffering from diabetes for more than 15 years present some sign of diabetic retinopathy, the main cause of severe vision loss in people of working age in developed countries. Although diabetic patients are 25 times more likely to suffer total blindness than those without the disease, visual damage due to diabetes does not have to be serious. This will depend on the time passed since the onset of the disease and the level of control of the same by the patient.