Diabetic macular edema is one of the most feared consequences of diabetes mellitus.
Diabetic macular edema occupies the sad primacy of the first cause of blindness in people of working age.
And this for two reasons: it is associated with one of the most common chronic diseases in the world, diabetes mellitus, and its symptoms may initially be blurred, so the problem is too often overlooked.
According to the World Health Organization, the number of people suffering from diabetes is constantly increasing: in 2012 there were an estimated 350 million diabetics in the world.
And in the forecasts this number is destined to increase. This suggests that, sooner or later, diabetic macular edema will become a social problem of global concern.
Blood sugar and retina: a dangerous relationship
Diabetic macular edema is considered the most serious complication of diabetic retinopathy, a condition that frequently develops in people with diabetes mellitus.
To cause it is the accumulation of fluid inside the macula, which is the most central and important part of the retina. This accumulation alters the structure and functionality of the macula itself and causes visual damage.
To pay the price is above all the central vision, the one in essence that allows us to drive the car, to read, to watch TV.
There are still many uncertainties about the causes. Certainly we know that at the origin there is an alteration of capillary permeability: the very small blood vessels that supply the eye let a quantity of liquids pass outside the vessel causing the formation of edema. And this has been found in many diabetics, especially among those who for years have not kept blood sugar under control.
An excess of glucose in the blood for many years can trigger a series of biochemical reactions that lead directly to ischemia phenomena, accompanied by an excessive production of molecules known as growth factors.
Among these, the most important (and the most feared) is the vascular endothelial growth factor (VEGF): it acts on the cells of the inner wall of blood vessels, the endothelial cells precisely, promoting their growth and increasing permeability.
Increased permeability, increased passage of fluids from the inside of the vessels to the outside, formation of ocular edema. This is, in a nutshell, the sequence that leads many diabetics to suffer from this disease.
Treating diabetic macular edema
For many years, laser treatment has been the only option available for the treatment of diabetic macular edema.
Panretinal laser photocoagulation (PRP) is used to eliminate ischemic areas of the peripheral retina where VEGF production occurs.
The focal or grid macular laser is used in the most central area. These procedures help preserve the remaining vision, but do not allow the recovery of lost functionality.
Today there are new therapeutic approaches that allow to control edema thanks to the repeated intravitreal administration over time of anti-VEGF drugs or the intravitreal implantation of slow-release corticosteroids.
There are two anti-VEGF drugs indicated and reimbursed by the National Health Service: aflibercept and ranibizumab.
Aflibercept is the most recently marketed Aflibercept. It is broad-spectrum anti-angiogenic, meaning it blocks and captures all VEGF isoforms, and is also able to modulate placental growth factor (PIGF) which contributes to the inflammatory pathological mechanisms of increased permeability implicated in the formation of macular edema. Treatment with aflibercept begins with one injection per month for five consecutive doses, followed by one injection every two months.
No monitoring is necessary between injections. After the first 12 months of treatment, the dosing interval may be extended based on visual and anatomical outcomes.
Joycelyn Elders is the author and creator of EmpowerEssence, a health and wellness blog. Elders is a respected public health advocate and pediatrician dedicated to promoting general health and well-being.
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