Blood glucose levels and retinal health

The importance of monitoring and the use of innovative devices

Pubblicato il

Monday, 15 May 2017

Argomento

Retina

The results of an Italian study just published in the journal Acta Diabetologica demonstrate a Correlation between glycaemic variability (GV) and early retinal neurodegeneration in subjects with type 1 diabetes mellitus (DM).

I glycaemic levelsin particular a tendency to hyperglycaemia, is one of the main risk factors contributing to the onset of diabetic retinopathy (RD), one of the most serious diabetic complications that can partially or totally impair vision. However, the role of daily glycaemic variability, which the diabetic subject constantly experiences, on the development of certain diabetic vascular complications has not yet been fully clarified.

The authors of this research analysed the role of glucose fluctuations on neuroretina, expressed as glycated haemoglobin (HbA1c) and VG values, observing a direct association between retinal structural damage and VG. In particular, the results of the study revealed a decrease in layer thickness of nerve fibres of the eye (RNFL, Retinal Nerve Fiber Layer), due to the progressive loss of astrocytes and ganglion cells, and an increase in thickness of the inner nuclear layer of the retinaconsisting of neurons that act as a bridge between photoreceptors and Muller cells, the main cells of the glia. In particular, these cells are significantly sensitive to fluctuating glucose levels and, therefore, involved in the first step by retinal neurodegeneration. Indeed, in the presence of high blood glucose levels, these cells are first hyper-activated, performing an initial neuroprotective function, and later lose their proper function, leading to neuronal cell degeneration.

In addition, experiments in vitro on retinal cells demonstrated a reduced survival of neuronal cells in the retina following a decrease in glycaemic levelsresulting in the appearance of soft exudates, typical signs of ischaemic retinopathy.

Thus, it is clear from the results of the study that the retinal neurodegenerationcaused by fluctuations in glucose levels, is an event that can occur early in diabetic patients and represents the preclinical phase of diabetic retinopathy.

How important is it, therefore, to monitor blood glucose levels on time? And, how to do it?

As recommended by the guidelines of the Italian Society of Diabetology (SID)the glycaemic control is indispensable for patients with diabetes and must be considered an integral part of therapy in order to prevent the onset and/or progression of diabetic complications. However, various statistics indicate that self-monitoring of blood glucosealthough it can be done through the use of simple deviceis, however, only carried out by 20% of the diabetic subjects, while the remaining 80% do not adequately monitor their daily blood glucose levels, contributing to aggravating their condition.

Innovative tools that increasingly meet the needs of any diabetic include device from wristwearable like a normal watch and capable of taking a blood glucose measurement without the need to draw the patient's blood. The technology of this device is based on a system of 0.5 mm-thick micro-needles that take and analyse the interstitial fluid present just below the skin, causing only slight pressure.

In addition, these devices can be connected to a smartphone which keeps all glycaemic records within a specific application, thus making self-monitoring of blood glucose easier and faster and contributing to the prevention of important ocular complications of diabetes.